FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Viola, VE Kwiatkowski, K Natowitz, JB Yennello, SJ AF Viola, VE Kwiatkowski, K Natowitz, JB Yennello, SJ TI Breakup densities of hot nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPLEX FRAGMENT EMISSION; LEVEL-DENSITY; AU-197 REACTIONS; MASS; PARAMETER; MULTIFRAGMENTATION; TEMPERATURE; TRANSITION; PROTONS; HE-3 AB Breakup densities of hot Au-197-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy E-*/Aless than or similar to2 MeV, followed by a gradual decrease to a near-constant value of rho/rho(0)similar to0.3 for E-*/Agreater than or similar to5 MeV. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, IUCF, Bloomington, IN 47405 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. RP Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RI Natowitz, Joseph/D-4160-2015; Yennello, Sherry/B-5803-2015 OI Yennello, Sherry/0000-0003-3963-5217 NR 35 TC 31 Z9 31 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 24 PY 2004 VL 93 IS 13 AR 132701 DI 10.1103/PhysRevLett.93.132701 PG 4 WC Physics, Multidisciplinary SC Physics GA 857PS UT WOS:000224131400032 ER PT J AU LaViolette, RA Glass, RJ AF LaViolette, RA Glass, RJ TI Self organized spatio-temporal structure within the fractured Vadose Zone: The influence of dynamic overloading at fracture intersections SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID UNSATURATED FLOW-THROUGH AB Under low flow conditions ( where gravity and capillary forces dominate) within an unsaturated fracture network, fracture intersections act as capillary barriers to integrate flow from above and then release it as a pulse below. Water exiting a fracture intersection is often thought to enter the single connected fracture with the lowest invasion pressure. When the accumulated volume varies between intersections, the smaller volume intersections can be overloaded to cause all of the available fractures exiting an intersection to flow. We included the dynamic overloading process at fracture intersections within our previously discussed model where intersections were modeled as tipping buckets connected within a two-dimensional diamond lattice. With dynamic overloading, the flow behavior transitioned smoothly from diverging to converging flow with increasing overload parameter, as a consequence of a heterogeneous field, and they impose a dynamic structure where additional pathways activate or deactivate in time. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP LaViolette, RA (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. EM yaq@inel.gov NR 11 TC 2 Z9 2 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 23 PY 2004 VL 31 IS 18 AR L18501 DI 10.1029/2004GL020659 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 857OB UT WOS:000224126000003 ER PT J AU Gibbs, GV Cox, DF Rosso, KM AF Gibbs, GV Cox, DF Rosso, KM TI A connection between empirical bond strength and the localization of the electron density at the bond critical points of the SiO bonds in silicates SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID POPULATION ANALYSIS; POLYMORPH COESITE; DIFFRACTION DATA; MODEL STRUCTURES; DISTRIBUTIONS; STISHOVITE; PRESSURE; EXPLORATION; CRYSTALS; QUARTZ AB The empirical bond strength of the SiO bond correlates with the value of the electron density at the bond critical point calculated for a large number of silicates and observed for the silica polymorphs stishovite and coesite. The greater the bond strength, the greater the localization of the electron density at the critical point, the shorter the bond, and the greater the covalent character of the bonded interaction. Bond strength and resonance bond number are considered to represent similar properties of the electronic structure of the bond. C1 Virginia Polytech Inst & State Univ, Dept Geosci, Blacksburg, VA 24061 USA. Virginia Polytech Inst & State Univ, Dept Mat Sci & Engn, Blacksburg, VA 24061 USA. Virginia Polytech Inst & State Univ, Dept Math, Blacksburg, VA 24061 USA. Virginia Polytech Inst & State Univ, Dept Chem Engn, Blacksburg, VA 24061 USA. Pacific NW Natl Lab, WW Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Gibbs, GV (reprint author), Virginia Polytech Inst & State Univ, Dept Geosci, Blacksburg, VA 24061 USA. EM gvgibbs@vt.edu NR 22 TC 25 Z9 25 U1 0 U2 5 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 23 PY 2004 VL 108 IS 38 BP 7643 EP 7645 DI 10.1021/jp047202s PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 854RX UT WOS:000223922100003 ER PT J AU Van Hove, MA AF Van Hove, MA TI Enhanced vibrations at surfaces with back-bonds nearly parallel to the surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY-ELECTRON-DIFFRACTION; MOLECULAR-DYNAMICS AB It has been discovered that several very different surfaces exhibit a common property: unusually large vibration amplitudes of the outermost atoms, well beyond the enhancement normally expected at typical clean surfaces. These special surfaces are ice H2O(0001), alpha-Al2O3(0001), alpha-Ga(010), and Si(111)-(2 x 1). The root-mean-square vibration amplitudes in these surfaces are at least double the bulk values. The common cause that may explain these vibration amplitudes is that the surface atoms (or molecules in the case of ice) only have back-bonds that are nearly parallel to the surface. In this geometry, vibrations, especially perpendicular to the surface, involve primarily bond bending rather than bond stretching/compression: since bond bending is relatively soft, the corresponding vibration modes can have larger amplitudes. It is suggested that theory examine and confirm this cause of enhanced surface vibration amplitudes and explore its implications for other phenomena such as adsorption and catalysis. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Livermore, CA 95616 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. EM MAVanHove@lbl.gov RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 22 TC 8 Z9 9 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 2004 VL 108 IS 38 BP 14265 EP 14269 DI 10.1021/jp040047x PG 5 WC Chemistry, Physical SC Chemistry GA 854SB UT WOS:000223922500007 ER PT J AU Bluhm, H Havecker, M Knop-Gericke, A Kleimenov, E Schlogl, R Teschner, D Bukhtiyarov, VI Ogletree, DF Salmeron, M AF Bluhm, H Havecker, M Knop-Gericke, A Kleimenov, E Schlogl, R Teschner, D Bukhtiyarov, VI Ogletree, DF Salmeron, M TI Methanol oxidation on a copper catalyst investigated using in situ X-ray photoelectron spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID UNTERSUCHUNG VON OBERFLACHENREAKTIONEN; ABSORPTION-SPECTROSCOPY; SURFACE SCIENCE; METAL-SURFACES; PRESSURE GAP; OXYGEN; RANGE; LEED; PHOTOEMISSION; HYDROGENATION AB The surface and near-surface regions of an active catalyst and the adjacent gas-phase reactants were investigated simultaneously under reaction conditions using in situ X-ray photoelectron spectroscopy (XPS). This investigation of methanol oxidation on a copper catalyst showed that there was a linear correlation between the catalytic activity of the sample and the presence of a subsurface oxygen species that can only be observed in situ. The concentration profile of the subsurface oxygen species within the first few nanometers below the surface was determined using photon-energy-dependent depth-profiling. The chemical composition of the surface and the near-surface regions varied strongly with the oxygen-to-methanol ratio in the reactant stream. The experiments show that the pure metal is not an active catalyst for the methanol oxidation reaction, but that a certain amount of oxygen has to be present in the subsurface region to activate the catalytic reaction. Oxide formation was found to be detrimental to formaldehyde production. Our results demonstrate also that for an understanding of heterogeneous catalysts a characterization of the surface alone may not be sufficient, and that subsurface characterization is essential. C1 Max Planck Gesell, Fritz Haber Inst, Abt Anorgan Chem, D-14195 Berlin, Germany. Hungarian Acad Sci, Inst Isotope & Surface Chem, CRC, H-1525 Budapest, Hungary. Boreskov Inst Catalysis, Novosibirsk 6300090, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Bluhm, H (reprint author), Max Planck Gesell, Fritz Haber Inst, Abt Anorgan Chem, Faradayweg 4-6, D-14195 Berlin, Germany. EM hbluhm@lbl.gov RI Bukhtiyarov, Valerii/E-9487-2012 OI Bukhtiyarov, Valerii/0000-0003-4382-1207 NR 55 TC 118 Z9 121 U1 6 U2 60 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 2004 VL 108 IS 38 BP 14340 EP 14347 DI 10.1021/jp040080j PG 8 WC Chemistry, Physical SC Chemistry GA 854SB UT WOS:000223922500018 ER PT J AU Feibelman, PJ Alavi, A AF Feibelman, PJ Alavi, A TI Entropy of H2O wetting layers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PARTIAL DISSOCIATION; RESIDUAL ENTROPY; ICE; WATER; CRYSTALS; HYDROGEN; SURFACES; RU(0001); SYSTEMS; D2O AB Proton order is less constrained in a fully H-bonded, adsorbed H2O monolayer than in bulk ice. Thus, though weakly, configurational entropy favors wetting by deposited H2O over formation of 3-D crystalline mounds. A Pauling-type estimate yields a 0 K adlayer entropy of similar to(1)/(2)k(B) In(9/2), almost twice that of ice Ih. Thus, at 150 K, where periodic adlayers on metals are observed, residual entropy reduces their free energies relative to a 3-D ice crystal by 4.5 meV/molecule, or similar to3% of the cost of the adlayers' broken H-bonds. A Debye model implies that vibrational entropy contributes no more than another 4.4 meV/molecule to the free energy preference for wetting, at 150 K. This information, though only a bound because of substantial uncertainty in measured adlayer Debye temperatures, is nonetheless sufficient to conclude that T = 0 K energies dominate the free energy balance between wetting and mound formation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England. RP Feibelman, PJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 22 Z9 22 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 2004 VL 108 IS 38 BP 14362 EP 14367 DI 10.1021/jp049934q PG 6 WC Chemistry, Physical SC Chemistry GA 854SB UT WOS:000223922500021 ER PT J AU Thiel, PA Evans, JW AF Thiel, PA Evans, JW TI Energetic parameters for atomic-scale processes on Ag(100) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENHANCED RAMAN-SCATTERING; FROM-EQUILIBRIUM NANOSTRUCTURES; MONTE-CARLO SIMULATIONS; METAL-SURFACES; EPITAXIAL-GROWTH; SELF-DIFFUSION; AG/AG(100) HOMOEPITAXY; ISLAND FORMATION; STEP FORMATION; NUCLEATION AB Key energetic parameters that control growth and mass transport in clean Ag films and nanostructures on Ag(100) are compiled. These parameters have been derived from a number of different types of experiments, and from increasingly refined lattice-gas modeling, over several years. The modeling based upon these parameters appears to have good predictive capability in the temperature range 120-300 K. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Thiel, PA (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. EM pthiel@iastate.edu NR 62 TC 11 Z9 11 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 2004 VL 108 IS 38 BP 14428 EP 14433 DI 10.1021/jp049884p PG 6 WC Chemistry, Physical SC Chemistry GA 854SB UT WOS:000223922500029 ER PT J AU Yang, MC Chou, KC Somorjai, GA AF Yang, MC Chou, KC Somorjai, GA TI The structures and reactions of linear and cyclic C-6 hydrocarbons adsorbed on the Pt(111) crystal surface by sum frequency generation vibrational spectroscopy pressure, temperature, and H-2 coadsorption effects SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CATALYTIC TRANSFER HYDROGENATION; BISMUTH-COVERED PT(111); N-ALKANES; IN-SITU; METAL-SURFACES; DEHYDROGENATION; CYCLOHEXANE; ADSORPTION; 1,4-CYCLOHEXADIENE; MONOLAYERS AB We studied the adsorption structures and reactions of C-6 hydrocarbon molecules (cyclohexene, cyclohexane, 1-methylcyclohexene, n-hexane, 2- and 3-methylpentanes, and 1-hexene) on Pt(111) using sum frequency generation (SFG) vibrational spectroscopy. The experiments were performed in the presence and absence of excess hydrogen and as a function of temperature. Upon cyclohexene adsorption on Pt(111) at 1.5 Torr, 1,3- and 1,4-cyclohexadienes and pi-allyl C6H9 were observed in the presence of excess hydrogen. Cyclohexane adsorption at 1.5 Torr resulted in the formation of cyclohexyl on the surface in the presence of excess hydrogen but pi-allyl C6H9 in absence of excess hydrogen. 1-Methylcyclohexene formed methylcyclohexenyl on the surface only in the presence of excess hydrogen. n-Hexane and 3-methylpentane adsorbed molecularly on Pt(111) at 296 K in the presence of excess hydrogen. 2-Methylpentane and 1-hexene were readily dehydrogenated to form metallacyclobutane and hexylidyne even at 296 K, regardless of the presence of excess hydrogen. n-Hexane was dehydrogenated to form hexylidyne or metallacyclic species at high temperature in the presence of excess hydrogen. Hexylidyne and metallacyclic species were also main surface intermediates in dehydrogenation of 2- and 3-methylpentane. The absence of excess hydrogen induced dehydrocyclization of n-hexane to form pi-allyl c-C6H9. On the basis of the SFG results, the mechanism of the n-hexane conversion to benzene is discussed. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM somorjai@socrates.berkeley.edu RI Chou, Kuo-Chen/A-8340-2009 NR 58 TC 29 Z9 29 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 23 PY 2004 VL 108 IS 38 BP 14766 EP 14779 DI 10.1021/jp048238n PG 14 WC Chemistry, Physical SC Chemistry GA 854SB UT WOS:000223922500074 ER PT J AU Weber, T Czasch, AO Jagutzki, O Muller, AK Mergel, V Kheifets, A Rotenberg, E Meigs, G Prior, MH Daveau, S Landers, A Cocke, CL Osipov, T Muino, RD Schmidt-Bocking, H Dorner, R AF Weber, T Czasch, AO Jagutzki, O Muller, AK Mergel, V Kheifets, A Rotenberg, E Meigs, G Prior, MH Daveau, S Landers, A Cocke, CL Osipov, T Muino, RD Schmidt-Bocking, H Dorner, R TI Complete photo-fragmentation of the deuterium molecule SO NATURE LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; DOUBLE-PHOTOIONIZATION; DOUBLE-IONIZATION; HYDROGEN MOLECULE; D-2; H-2; HE; GAMMA,2E AB All properties of molecules - from binding and excitation energies to their geometry - are determined by the highly correlated initial-state wavefunction of the electrons and nuclei. Details of these correlations can be revealed by studying the break-up of these systems into their constituents. The fragmentation might be initiated by the absorption of a single photon(1-6), by collision with a charged particle(7,8) or by exposure to a strong laser pulse(9,10): if the interaction causing the excitation is sufficiently understood, the fragmentation process can then be used as a tool to investigate the bound initial state(11,12). The interaction and resulting fragment motions therefore pose formidable challenges to quantum theory(13-15). Here we report the coincident measurement of the momenta of both nuclei and both electrons from the single-photon-induced fragmentation of the deuterium molecule. The results reveal that the correlated motion of the electrons is strongly dependent on the inter-nuclear separation in the molecular ground state at the instant of photon absorption. C1 Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Canberra, ACT 0200, Australia. Auburn Univ, Allison Lab 206, Auburn, AL 36849 USA. Donostia Int Phys Ctr, Donostia San Sebastian 20018, Spain. Unidad Fis Mat, Donostia San Sebastian 20018, Spain. RP Dorner, R (reprint author), Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. EM doerner@hsb.uni-frankfurt.de RI Kheifets, Anatoli/C-9131-2009; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014; Rotenberg, Eli/B-3700-2009; Diez Muino, Ricardo/C-9203-2009; Doerner, Reinhard/A-5340-2008; CSIC-UPV/EHU, CFM/F-4867-2012; Landers, Allen/C-1213-2013; Weber, Thorsten/K-2586-2013 OI Kheifets, Anatoli/0000-0001-8318-9408; Rotenberg, Eli/0000-0002-3979-8844; Diez Muino, Ricardo/0000-0001-8593-0327; Doerner, Reinhard/0000-0002-3728-4268; Weber, Thorsten/0000-0003-3756-2704 NR 30 TC 109 Z9 110 U1 0 U2 11 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 23 PY 2004 VL 431 IS 7007 BP 437 EP 440 DI 10.1038/nature02839 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 855UN UT WOS:000224000500036 PM 15386008 ER PT J AU Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C Machado, AA Magnin, J Massafferri, A de Miranda, JM Pepe, IM Polycarpo, E dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Segoni, I Stenson, K Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Wang, M Benussi, L Bertani, L Bianco, S Fabbri, FL Zallo, A Reyes, M Cawlfield, C Kim, DY Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Boschini, M Cerutti, A D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Pegna, DL Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Mendez, H Paris, A Quinones, J Ramirez, JE Zhang, Y Wilson, JR Handler, T Mitchell, R Bryant, AD Engh, D Hosack, M Johns, WE Luiggi, E Nehring, M Sheldon, PD Vaandering, EW Webster, M Sheaff, M AF Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C Machado, AA Magnin, J Massafferri, A de Miranda, JM Pepe, IM Polycarpo, E dos Reis, AC Carrillo, S Casimiro, E Cuautle, E Sanchez-Hernandez, A Uribe, C Vazquez, F Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Segoni, I Stenson, K Butler, JN Cheung, HWK Chiodini, G Gaines, I Garbincius, PH Garren, LA Gottschalk, E Kasper, PH Kreymer, AE Kutschke, R Wang, M Benussi, L Bertani, L Bianco, S Fabbri, FL Zallo, A Reyes, M Cawlfield, C Kim, DY Rahimi, A Wiss, J Gardner, R Kryemadhi, A Chung, YS Kang, JS Ko, BR Kwak, JW Lee, KB Cho, K Park, H Alimonti, G Barberis, S Boschini, M Cerutti, A D'Angelo, P DiCorato, M Dini, P Edera, L Erba, S Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Mezzadri, M Moroni, L Pedrini, D Pontoglio, C Prelz, F Rovere, M Sala, S Davenport, TF Arena, V Boca, G Bonomi, G Gianini, G Liguori, G Merlo, MM Pantea, D Pegna, DL Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Mendez, H Paris, A Quinones, J Ramirez, JE Zhang, Y Wilson, JR Handler, T Mitchell, R Bryant, AD Engh, D Hosack, M Johns, WE Luiggi, E Nehring, M Sheldon, PD Vaandering, EW Webster, M Sheaff, M TI Measurement of the ratio of the vector to pseudoscalar charm semileptonic decay rate Gamma(D+ ->(K)over-bar(*0)mu+v(mu))/Gamma(D+->(K)over-bar(0) (+)(mu)v(mu)) SO PHYSICS LETTERS B LA English DT Article ID HEAVY MESONS; QUARK-MODEL; LIGHT MESONS; FORM-FACTORS; B-MESONS; QCD; SPECTROMETER; FLAVORS; LATTICE; FOCUS AB Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report on the measurement of the ratio of semileptonic rates Gamma(D+ --> Kpimu(+)nu(mu))/Gamma(D+ --> K(0)mu(+)nu(mu)) = 0.625 +/- 0.045 +/- 0.034. Allowing for the Kpi S-wave interference measured in [J.M. Link, et al., FOCUS Collaboration, Phys. Lett. B 544 (2002) 89], we extract the vector to pseudoscalar ratio Gamma(D+ --> (K) over bar*(0)mu(+)nu(mu))/Gamma(D+ --> (K) over bar (0)mu(+)nu(mu)) = 0.594 +/- 0.043 +/- 0.033 and the ratio Gamma(D+ --> (K) over bar (0)mu(+)numu)/Gamma(D+ --> (K) over bar (-)pi(+)pi(+)) = 1.019 +/- 0.076 +/- 0.065. Our results show a lower ratio for F(D --> K* lv)/Gamma(D --> Klv) than has been reported recently and indicate the current world average branching fractions for the decays D+ --> (K) over bar (0)(mu(+), e(+))nu(mu,e) are low. Using the world average B(D+ --> K(-)pi(+)pi(+)) [K. Hagiwara, et al., Particle Data Group Collaboration, Phys. Rev. D 66 (2002) 010001, and 2003 partial update for edition 2004 (http://pdg.lbl.gov)] we extract B(D+ --> (K) over bar (0)mu(+)nu) = (9.27 +/- 0.69 +/- 0.59 +/- 0.61)%. (C) 2004 Elsevier B.V. All rights reserved. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Univ Calif Davis, Davis, CA 95616 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 07000, DF, Mexico. Univ Colorado, Boulder, CO 80309 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Guanajuato, Guanajuato 37150, Mexico. Univ Illinois, Urbana, IL 61801 USA. Indiana Univ, Bloomington, IN 47405 USA. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, I-20133 Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. Dipartimento Fis Teorica & Nucl, Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Puerto Rico, Mayaguez, PR 00681 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Vanderbilt Univ, Dept Phys & Astron, 6301 Stevenson Ctr, Nashville, TN 37235 USA. EM will.johns@vanderbilt.edu RI Gobel Burlamaqui de Mello, Carla /H-4721-2016; Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889 NR 36 TC 15 Z9 15 U1 0 U2 2 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 23 PY 2004 VL 598 IS 1-2 BP 33 EP 41 DI 10.1016/j.physleth.2004.07.060 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 853ZR UT WOS:000223870100004 ER PT J AU Kantardjieff, KA Rupp, B AF Kantardjieff, KA Rupp, B TI Protein isoelectric point as a predictor for increased crystallization screening efficiency SO BIOINFORMATICS LA English DT Article ID 2ND VIRIAL-COEFFICIENT; CRYSTAL-GROWTH; STRUCTURAL GENOMICS; GLOBULAR-PROTEINS; SOLUBILITY; DNA; CRYSTALLOGRAPHY; NUCLEATION; INTERFACE AB Motivation: Increased efficiency in initial crystallization screening reduces cost and material requirements in structural genomics. Because pH is one of the few consistently reported parameters in the Protein Data Bank (PDB), the isoelectric point (pI) of a protein has been explored as a useful indirect predictor for the optimal choice of range and distribution of the pH sampling in crystallization trials. Results: We have analyzed 9596 unique protein crystal forms from the August 2003 PDB and have found a significant relationship between the calculated pI of successfully crystallized proteins and the difference between pI and reported pH at which they were crystallized. These preferences provide strong prior information for the design of crystallization screening experiments with significantly increased efficiency and corresponding reduction in material requirements, leading to potential cost savings of millions of US$ for structural genomics projects involving high-throughput crystallographic structure determination. C1 Calif State Univ Fullerton, Dept Chem & Biochem, Fullerton, CA 92834 USA. Calif State Univ Fullerton, WM Keck Fdn Ctr Mol Struct, Fullerton, CA 92834 USA. Texas A&M Univ, Dept Biochem & Biophys, College Stn, TX 77843 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Kantardjieff, KA (reprint author), Calif State Univ Fullerton, Dept Chem & Biochem, Fullerton, CA 92834 USA. EM kkantardjieff@fullerton.edu; br@llnl.gov FU NIGMS NIH HHS [P50 GM62410] NR 34 TC 68 Z9 70 U1 1 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP 22 PY 2004 VL 20 IS 14 BP 2162 EP 2168 DI 10.1093/bioinformatics/bth066 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 856YX UT WOS:000224083100002 PM 14871873 ER PT J AU Kantardjieff, KA Jamshidian, M Rupp, B AF Kantardjieff, KA Jamshidian, M Rupp, B TI Distributions of pI versus pH provide prior information for the design of crystallization screening experiments: Response to comment on 'Protein isoelectric point as a predictor for increased crystallization screening efficiency' SO BIOINFORMATICS LA English DT Letter ID MACROMOLECULES; DATABASE; DNA C1 Calif State Univ Fullerton, Dept Chem & Biochem, Fullerton, CA 92834 USA. Calif State Univ Fullerton, WM Keck Fdn Ctr Mol Struct, Fullerton, CA 92834 USA. Calif State Univ Fullerton, Dept Math, Fullerton, CA 92834 USA. Texas A&M Univ, Dept Biochem & Biophys, College Stn, TX 77843 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Kantardjieff, KA (reprint author), Calif State Univ Fullerton, Dept Chem & Biochem, Fullerton, CA 92834 USA. EM kkantardjieff@fullerton.edu NR 22 TC 14 Z9 14 U1 1 U2 9 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP 22 PY 2004 VL 20 IS 14 BP 2171 EP 2174 DI 10.1093/bioinformatics/bth453 PG 4 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 856YX UT WOS:000224083100004 ER PT J AU Mao, LY Resat, H AF Mao, LY Resat, H TI Probabilistic representation of gene regulatory networks SO BIOINFORMATICS LA English DT Article ID QUALITATIVE SIMULATION; SINGLE-GENE; EXPRESSION; NOISE; MODEL; REPRESSOR; LAMBDA; AUTOREGULATION; STOCHASTICITY; INDUCTION AB Motivation: Recent experiments have established unambiguously that biological systems can have significant cell-to-cell variations in gene expression levels even in isogenic populations. Computational approaches to studying gene expression in cellular systems should capture such biological variations for a more realistic representation. Results: In this paper, we present a new fully probabilistic approach to the modeling of gene regulatory networks that allows for fluctuations in the gene expression levels. The new algorithm uses a very simple representation for the genes, and accounts for the repression or induction of the genes and for the biological variations among isogenic populations simultaneously. Because of its simplicity, introduced algorithm is a very promising approach to model large-scale gene regulatory networks. We have tested the new algorithm on the synthetic gene network library bioengineered recently. The good agreement between the computed and the experimental results for this library of networks, and additional tests, demonstrate that the new algorithm is robust and very successful in explaining the experimental data. C1 Pacific NW Natl Lab, Computat Biosci Grp, Richland, WA 99352 USA. RP Resat, H (reprint author), Pacific NW Natl Lab, Computat Biosci Grp, POB 999,Mail Stop K1-92, Richland, WA 99352 USA. EM haluk.resat@pnl.gov RI Mao, Linyong/A-2873-2011 NR 48 TC 12 Z9 14 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP 22 PY 2004 VL 20 IS 14 BP 2258 EP 2269 DI 10.1093/bioinformatics/bth236 PG 12 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 856YX UT WOS:000224083100016 PM 15073019 ER PT J AU Heredia-Langner, A Cannon, WR Jarman, KD Jarman, KH AF Heredia-Langner, A Cannon, WR Jarman, KD Jarman, KH TI Sequence optimization as an alternative to de novo analysis of tandem mass spectrometry data SO BIOINFORMATICS LA English DT Article ID PROTEIN IDENTIFICATION; COMPLEXES; ALGORITHM; PEPTIDES; SPECTRA; SEARCH AB Motivation: Peptide identification following tandem mass spectrometry (MS/MS) is usually achieved by searching for the best match between the mass spectrum of an unidentified peptide and model spectra generated from peptides in a sequence database. This methodology will be successful only if the peptide under investigation belongs to an available database. Our objective is to develop and test the performance of a heuristic optimization algorithm capable of dealing with some features commonly found in actual MS/MS spectra that tend to stop simpler deterministic solution approaches. Results: We present the implementation of a Genetic Algorithm (GA) in the reconstruction of amino acid sequences using only spectral features, discuss some of the problems associated with this approach and compare its performance to a de novo sequencing method. The GA can potentially overcome some of the most problematic aspects associated with de novo analysis of real MS/MS data such as missing or unclearly defined peaks and may prove to be a valuable tool in the proteomics field. We assess the performance of our algorithm under conditions of perfect spectral information, in situations where key spectral features are missing, and using real MS/MS spectral data. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Heredia-Langner, A (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM Alejandro.Heredia-Langner@pnl.gov RI Jarman, Kenneth/B-6157-2011; Cannon, William/K-8411-2014 OI Jarman, Kenneth/0000-0002-4396-9212; Cannon, William/0000-0003-3789-7889 NR 24 TC 19 Z9 20 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP 22 PY 2004 VL 20 IS 14 BP 2296 EP 2304 DI 10.1093/bioinformatics/bth242 PG 9 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 856YX UT WOS:000224083100020 PM 15087321 ER PT J AU Kaufman, J Modzeleki, W Feucht, T Simon, TR Anderson, M Shaw, K Arias, I Barrios, L AF Kaufman, J Modzeleki, W Feucht, T Simon, TR Anderson, M Shaw, K Arias, I Barrios, L TI School-associated suicides - United States, 1994-1999 (Reprinted from MMWR, vol 53, pg 476-478, 2004) SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Reprint C1 Univ Miami, Dept Sociol, Coral Gables, FL 33124 USA. US DOE, Off Safe & Drug Free Sch Program, Washington, DC 20585 USA. US Dept Justice, Natl Inst Justice, Washington, DC 20530 USA. CDC, Div Violence Prevent, Natl Ctr Injury Prevent & Control, Atlanta, GA 30333 USA. CDC, Div Adolescent & Sch Hlth, Natl Ctr Chron Dis Prevent & Hlth Promot, Atlanta, GA 30333 USA. RP Kaufman, J (reprint author), Univ Miami, Dept Sociol, Coral Gables, FL 33124 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0098-7484 J9 JAMA-J AM MED ASSOC JI JAMA-J. Am. Med. Assoc. PD SEP 22 PY 2004 VL 292 IS 12 BP 1423 EP 1424 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA 856FT UT WOS:000224031800008 ER PT J AU Chuvil'deev, V Nieh, TG Gryaznov, MY Kopylov, VI Sysoev, AN AF Chuvil'deev, V Nieh, TG Gryaznov, MY Kopylov, VI Sysoev, AN TI Superplasticity and internal friction in microcrystalline AZ91 and ZK60 magnesium alloys processed by equal-channel angular pressing SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT 9th International Symposium on Physics of Materials CY SEP 01-04, 2003 CL Charles Univ, Fac Math & Phys, Prague, CZECH REPUBLIC SP Charles Univ, Dept Met Phys HO Charles Univ, Fac Math & Phys DE metals; grain boundaries; acoustic properties; strain ID LOW-TEMPERATURE SUPERPLASTICITY; NONEQUILIBRIUM GRAIN-BOUNDARIES AB Low-temperature superplasticity (LTSP) and internal friction in microcrystalline ZK60 and AZ91 magnesium alloys processed by equal-channel angular pressing (ECAP) are reported. Excellent low-temperature superplasticity (<300degreesC) was observed in ECAP-processed materials: elongations to failure are 810 and 570% in ZK60 and AZ91 alloys, respectively, at a strain rate of 3 x 10(-3) S-1. Internal friction can be practically used to determine the optimum temperature for superplasticity. (C) 2004 Elsevier B.V. All rights reserved. C1 Nizhny Novgorod State Univ, Res Phys & Tech Inst, Nizhnii Novgorod 603950, Russia. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Natl Acad Sci, Phys Tech Inst, Minsk 220141, Byelarus. RP Chuvil'deev, V (reprint author), Nizhny Novgorod State Univ, Res Phys & Tech Inst, 23-3 Gagarin Ave, Nizhnii Novgorod 603950, Russia. EM chuvildeev@nifti.unn.ru RI Nieh, Tai-Gang/G-5912-2011; Kopylov, Vladimir/J-5253-2013; Chuvil'deev, Vladimir/A-6710-2014; OI Nieh, Tai-Gang/0000-0002-2814-3746; Kopylov, Vladimir/0000-0002-0725-9918; Chuvil'deev, Vladimir/0000-0002-0328-1923; Vladimir, Chuvil'deev/0000-0002-5411-6557 NR 16 TC 40 Z9 45 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 22 PY 2004 VL 378 IS 1-2 BP 253 EP 257 DI 10.1016/j.jallcom.2003.10.062 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 853BL UT WOS:000223801100049 ER PT J AU Tilson, JL Naleway, C Seth, M Shepard, R Wagner, AF Ermler, WC AF Tilson, JL Naleway, C Seth, M Shepard, R Wagner, AF Ermler, WC TI Ab initio study of AmCl+: f-f spectroscopy and chemical binding SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; CONCENTRATED ELECTROLYTE-SOLUTIONS; IONIZATION-POTENTIALS; CRYSTAL-STRUCTURES; INFRARED-SPECTRA; LANTHANIDE; COMPLEXES; HALIDES; EUCL2; IONS AB A valence full configuration interaction study with a polarized double-zeta quality basis set has been carried out for the lowest 49 electronic states of AmCl+. The calculations use a pseudopotential treatment for the core electrons and incorporate a one-electron spin-orbit interaction operator. Electrons in the valence s, p, d, and f subshells were included in the active space. The resulting electronic potential energy curves are largely repulsive. The chemical bonding is ionic in character with negligible participation of 5f electrons. The molecular f-f spectroscopy of AmCl+ arises essentially from an in situ Am2+ core with states slightly redshifted by the presence of chloride ion. Am++Cl asymptotes which give rise to the few attractive potential energy curves can be predicted by analysis of the f-f spectroscopy of isolated Am+ and Am2+. The attractive curves have substantial binding energies, on the order of 75-80 kcal/mol, and are noticeably lower than recent indirect measurements on the isovalent EuCl+. An independent empirical correlation supports the predicted reduction in AmCl+ binding energy. The energies of the repulsive curves are strongly dependent on the selection of the underlying atomic orbitals while the energies of the attractive curves do not display this sensitivity. The calculations were carried out using our recently developed parallel spin-orbit configuration interaction software. (C) 2004 American Institute of Physics. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Memphis, Dept Chem, Computat Res Mat Inst, Memphis, TN 38152 USA. RP Tilson, JL (reprint author), Univ Buffalo, Ctr Computat Res, Buffalo, NY 14260 USA. RI Ermler, Walter/B-6876-2011 NR 39 TC 4 Z9 4 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 22 PY 2004 VL 121 IS 12 BP 5661 EP 5675 DI 10.1063/1.1665420 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 854AJ UT WOS:000223872000013 PM 15366990 ER PT J AU Alexandrova, AN Boldyrev, AI Fu, YJ Yang, X Wang, XB Wang, LS AF Alexandrova, AN Boldyrev, AI Fu, YJ Yang, X Wang, XB Wang, LS TI Structure of the NaxClx+1- (x=1-4) clusters via ab initio genetic algorithm and photoelectron spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GLOBAL GEOMETRY OPTIMIZATION; SODIUM-CHLORIDE CLUSTERS; ALKALI-HALIDE CLUSTERS; ELECTROSPRAY MASS-SPECTROMETRY; GAUSSIAN-BASIS SETS; BINDING-ENERGIES; SILICON CLUSTERS; IONIZATION-POTENTIALS; LASER VAPORIZATION; EXCESS ELECTRON AB The application of the ab initio genetic algorithm with an embedded gradient has been carried out for the elucidation of global minimum structures of a series of anionic sodium chloride clusters, NaxClx+1- (x=1-4), produced in the gas phase using electrospray ionization and studied by photoelectron spectroscopy. These are all superhalogen species with extremely high electron binding energies. The vertical electron detachment energies for NaxClx+1- were measured to be 5.6, 6.46, 6.3, and 7.0 eV, for x=1-4, respectively. Our ab initio gradient embedded genetic algorithm program detected the linear global minima for NaCl2- and Na2Cl3- and three-dimensional structures for the larger species. Na3Cl4- was found to have C-3v symmetry, which can be viewed as a Na4Cl4 cube missing a corner Na+ cation, whereas Na4Cl5- was found to have C-4v symmetry, close to a 3x3 planar structure. Excellent agreement between the theoretically calculated and the experimental spectra was observed, confirming the obtained structures and demonstrating the power of the developed genetic algorithm technique. (C) 2004 American Institute of Physics. 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 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. EM boldyrev@cc.usu.edu; ls.wang@pnl.gov RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 81 TC 180 Z9 181 U1 7 U2 40 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 22 PY 2004 VL 121 IS 12 BP 5709 EP 5719 DI 10.1063/1.1783276 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 854AJ UT WOS:000223872000017 PM 15366994 ER PT J AU Feldman, WC Prettyman, TH Maurice, S Plaut, JJ Bish, DL Vaniman, DT Mellon, MT Metzger, AE Squyres, SW Karunatillake, S Boynton, WV Elphic, RC Funsten, HO Lawrence, DJ Tokar, RL AF Feldman, WC Prettyman, TH Maurice, S Plaut, JJ Bish, DL Vaniman, DT Mellon, MT Metzger, AE Squyres, SW Karunatillake, S Boynton, WV Elphic, RC Funsten, HO Lawrence, DJ Tokar, RL TI Global distribution of near-surface hydrogen on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE composition; glaciation; Mars ID GROUND ICE; WATER-ICE; SUMMER TEMPERATURES; EPITHERMAL NEUTRONS; MARTIAN ATMOSPHERE; RAY SPECTROMETER; CO2 FROST; ODYSSEY; STABILITY; EVOLUTION AB Neutron data observed using the Neutron Spectrometer aboard 2001 Mars Odyssey provide a lower limit to the global inventory of Martian water-equivalent hydrogen. Hydrogen-rich deposits ranging between about 20% and 100% water-equivalent by mass are found poleward of +/-50degrees latitude, and less rich, but significant, deposits are found at near-equatorial latitudes. The equatorial deposits between +/-45degrees latitude range between 2% and 10% water-equivalent hydrogen by mass and reach their maximum in two regions that straddle the 0-km elevation contour. Higher water abundances, up to similar to11%, are required in subsurface regolith of some equatorial regions if the upper 10 g/cm(2) of regolith is desiccated, as suggested on average by comparison of epithermal and fast neutron data. The hydrogen contents of surface soils in the latitude range between 50degrees and 80degrees north and south are equal within data uncertainties. A lower-limit estimate of the global inventory of near surface hydrogen amounts to a global water layer about 14 cm thick if the reservoir sampled from orbit is assumed to be 1 m thick. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. RP Los Alamos Natl Lab, Mail Stop D466, Los Alamos, NM 87545 USA. EM wfeldman@lanl.gov; thp@lanl.gov RI Karunatillake, Suniti/A-5934-2009; Funsten, Herbert/A-5702-2015; Mellon, Michael/C-3456-2016; Lawrence, David/E-7463-2015 OI Karunatillake, Suniti/0000-0001-9891-1432; Funsten, Herbert/0000-0002-6817-1039; Lawrence, David/0000-0002-7696-6667 NR 46 TC 199 Z9 199 U1 3 U2 28 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 22 PY 2004 VL 109 IS E9 AR E09006 DI 10.1029/2003JE002160 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 857OL UT WOS:000224127100001 ER PT J AU Kling, MF Cahoon, JF Glascoe, EA Shanoski, JE Harris, CB AF Kling, MF Cahoon, JF Glascoe, EA Shanoski, JE Harris, CB TI The role of odd-electron intermediates and in-cage electron transfer in ultrafast photochemical disproportionation reactions in Lewis bases SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLYBDENUM; MECHANISMS; COMPLEXES; RADICALS; TUNGSTEN; DIMERS C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Harris, CB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM harris@socrates.berkeley.edu RI Kling, Matthias/D-3742-2014 NR 16 TC 14 Z9 14 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 22 PY 2004 VL 126 IS 37 BP 11414 EP 11415 DI 10.1021/ja046223x PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 854RU UT WOS:000223921800007 PM 15366868 ER PT J AU Bartholomew, GP Rumi, M Pond, SJK Perry, JW Tretiak, S Bazan, GC AF Bartholomew, GP Rumi, M Pond, SJK Perry, JW Tretiak, S Bazan, GC TI Two-photon absorption in three-dimensional chromophores based on [2.2]-paracyclophane SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DENSITY-FUNCTIONAL THEORY; ABSORBING FLUORENE DERIVATIVES; NONLINEAR-OPTICAL PROPERTIES; SPACE CHARGE-TRANSFER; CROSS-SECTIONS; ORGANIC CHROMOPHORES; EXCITED-STATES; BIS(STYRYL)BENZENE DERIVATIVES; ORGANOMETALLIC COMPLEXES; OCTUPOLAR MOLECULES AB A series of alpha,omega-bis donor substituted oligophenylenevinylene dimers held together by the [2.2]-paracyclophane core were synthesized to probe how the number of repeat units and through-space delocalization influence two-photon absorption cross sections. Specifically, the paracyclophane molecules are tetra(4,7,12,15)-(4'-dihexylaminostyryl)[2.2]paracyclophane (3R(D)), tetra(4,7,12,15)-(4"-(4'-dihexylaminostyryl)-styryl)[2.2]paracyclophane (5R(D)), and tetra(4,7,12,15)-(4"'-(4"-(4'-dihexylaminostyryl)styryl)styryl)[2.2]-paracyclophane (7R(D)). The compounds bis(1,4)-(4'-dihexylaminostyryl)benzene (3R) and bis(1,4)-(4"-(4'dihexylaminostyryl)styryl) benzene (5R) were also synthesized to reveal the properties of the "monomeric" counterparts. The two-photon absorption cross sections were determined by the two-photon induced fluorescence method using both femtosecond and nanosecond pulsed lasers as excitation sources. While there is a red shift in the linear absorption spectra when going from the "monomer" chromophore to the paracyclophane "dimer"(i.e., 3R --> 3R(D), 5R --> 5R(D)), there is no shift in the two-photon absorption maxima. A theoretical treatment of these trends and the dependence of transition dipole moments on molecular structure rely on calculations that interfaced time-dependent density functional theory (TDDFT) techniques with the collective electronic oscillator (CEO) program. These theoretical and experimental results indicate that intermolecular interactions can strongly affect B-u states but weakly perturb A(g) states, due to the small dipole-dipole coupling between A(g) states on the chromophores in the dimer. C1 Univ Calif Santa Barbara, Dept Chem & Biochem, Ctr Polymers & Organ Solids, Santa Barbara, CA 93106 USA. Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. RP Perry, JW (reprint author), Univ Calif Santa Barbara, Dept Chem & Biochem, Ctr Polymers & Organ Solids, Santa Barbara, CA 93106 USA. EM joe.perry@chemistry.gatech.edu; serg@lanl.gov; bazan@chem.ucsb.edu RI Tretiak, Sergei/B-5556-2009; Rumi, Mariacristina/C-9474-2009; Perry, Joseph/B-7191-2011; Bazan, Guillermo/B-7625-2014 OI Tretiak, Sergei/0000-0001-5547-3647; Rumi, Mariacristina/0000-0002-4597-9617; Perry, Joseph/0000-0003-1101-7337; NR 77 TC 137 Z9 141 U1 3 U2 34 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 22 PY 2004 VL 126 IS 37 BP 11529 EP 11542 DI 10.1021/ja038743i PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 854RU UT WOS:000223921800038 PM 15366899 ER PT J AU Cho, HM de Jong, WA McNamara, BK Rapko, BM Burgeson, IE AF Cho, HM de Jong, WA McNamara, BK Rapko, BM Burgeson, IE TI Temperature and isotope substitution effects on the structure and NMR properties of the pertechnetate ion in water SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SPIN COUPLING-CONSTANTS; DENSITY-FUNCTIONAL THEORY; AB-INITIO METHODS; MOLECULAR-PROPERTIES; SHIELDING TENSORS; METHANE MOLECULE; SCREENING MODEL; CHEMICAL-SHIFTS; FORCE-FIELD; TC-99 NMR AB The uniquely well-resolved Tc-99 NMR spectrum of the pertechnetate ion in liquid water poses a stringent test of the accuracy of ab initio calculations. The displacement of the Tc-99 chemical shift as a function of temperature has been measured over the range 10-45 degreesC for the three isotopomers Tc(O-16)(4)(-), Tc(O-16)(3)(O-18)(-), and Tc(O-16)(3)(O-17)(-) at natural oxygen isotope abundance levels, and in addition the temperature dependence of the Tc-O scalar coupling was determined for the Tc(O-16)(3)(O-17)(-) isotopomer. Values for these parameters were computed using relativistic spin-orbit density functional theory with an unsolvated ion approximation and with treatments of the solvated ion based on the COnductor-like Screening MOdel (COSMO) approach. The temperature and isotope dependence of Tc-99 NMR parameters inferred by these methods were in good quantitative agreement with experimental observations. The change in the Tc-O bond length associated with the changes in temperatures considered here was determined to be of the order of 10(-4) Angstrom. Vibrational energies and Tc-O bond lengths derived from these models also compare favorably with previous experimental studies. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Cho, HM (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM hm.cho@pnl.gov RI DE JONG, WIBE/A-5443-2008 OI DE JONG, WIBE/0000-0002-7114-8315 NR 58 TC 14 Z9 14 U1 0 U2 5 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 22 PY 2004 VL 126 IS 37 BP 11583 EP 11588 DI 10.1021/ja047447i PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 854RU UT WOS:000223921800044 PM 15366905 ER PT J AU Bryan, JD Heald, SM Chambers, SA Gamelin, DR AF Bryan, JD Heald, SM Chambers, SA Gamelin, DR TI Strong room-temperature ferromagnetism in Co2+-doped TiO2 made from colloidal nanocrystals SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRICAL SPIN INJECTION; DOPED TITANIUM-DIOXIDE; MAGNETIC QUANTUM DOTS; THIN-FILMS; SEMICONDUCTOR HETEROSTRUCTURE; CO; ANATASE; SPECTROSCOPY; NANOPARTICLES; TRANSITION AB Colloidal cobalt-doped TiO2 (anatase) nanocrystals were synthesized and studied by electronic absorption, magnetic circular dichroism, transmission electron microscopy, magnetic susceptibility, cobalt K-shell X-ray absorption spectroscopy, and extended X-ray absorption fine structure measurements. The nanocrystals were paramagnetic when isolated by surface-passivating ligands, weakly ferromagnetic (M-s approximate to 1.5 x 10(-3) mu(B)/Co2+ at 300 K) when aggregated, and strongly ferromagnetic (up to M-s = 1.9 mu(B)/Co2+ at 300 K) when spin-coated into nanocrystalline films. X-ray absorption data reveal that cobalt is in the Co2+ oxidation state in all samples. In addition to providing strong experimental support for the existence of intrinsic ferromagnetism in cobalt-doped TiO2, these results demonstrate the possibility of using colloidal TiO2 diluted magnetic semiconductor nanocrystals as building blocks for assembly of ferromagnetic semiconductor nanostructures with potential spintronics applications. C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Pacific NW Natl Lab, Fundamental Sci Directorate, Richland, WA 99352 USA. RP Univ Washington, Dept Chem, Seattle, WA 98195 USA. EM Gamelin@chem.washington.edu NR 55 TC 172 Z9 174 U1 6 U2 58 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 22 PY 2004 VL 126 IS 37 BP 11640 EP 11647 DI 10.1021/ja047381r PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 854RU UT WOS:000223921800050 PM 15366911 ER PT J AU Minofar, B Mucha, M Jungwirth, P Yang, X Fu, YJ Wang, XB Wang, LS AF Minofar, B Mucha, M Jungwirth, P Yang, X Fu, YJ Wang, XB Wang, LS TI Bulk versus interfacial aqueous solvation of dicarboxylate dianions SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MULTIPLY-CHARGED ANIONS; PHOTODETACHMENT PHOTOELECTRON-SPECTROSCOPY; GAS-PHASE; AIR/WATER INTERFACE; IONIC SOLVATION; WATER CLUSTERS; CHLORIDE-ION; CHEMISTRY; POLARIZABILITY; STABILIZATION AB Solvation of dicarboxylate dianions of varying length of the aliphatic chain in water clusters and in extended aqueous slabs was investigated using photoelectron spectroscopy and molecular dynamics simulations. Photoelectron spectra of hydrated succinate, adipate, and tetradecandioic dianions with up to 20 water molecules were obtained. Even-odd effects were observed as a result of the alternate solvation mode of the two negative charges with increasing solvent numbers. The competition between hydrophilic interactions of the charged carboxylate groups and hydrophobic interactions of the aliphatic chain leads to conformation changes in large water clusters containing dicarboxylates bigger than adipate. It also leads to a transition from bulk aqueous solvation of small dicarboxylates to solvation at the water/vapor interface of the larger ones. Whereas oxalate and adipate solvate in the inner parts of the aqueous slab, suberate and longer dicarboxylate dianions have a strong propensity to the surface. This transition also has consequences for the folding of the flexible aliphatic chain and for the structure of aqueous solvation shells around the dianions. C1 Acad Sci Czech Republ, Inst Organ Chem & Biochem, Prague 16610 6, Czech Republic. Ctr Complex Mol Syst & Biomol, Prague 16610 6, Czech Republic. Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Jungwirth, P (reprint author), Acad Sci Czech Republ, Inst Organ Chem & Biochem, Flemingovo Nam 2, Prague 16610 6, Czech Republic. EM pavel.jungwirth@uochb.cas.cz; ls.wang@pnl.gov RI Jungwirth, Pavel/D-9290-2011; Minofar, Babak/D-7361-2016 OI Jungwirth, Pavel/0000-0002-6892-3288; NR 46 TC 37 Z9 38 U1 3 U2 13 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 22 PY 2004 VL 126 IS 37 BP 11691 EP 11698 DI 10.1021/ja047493i PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 854RU UT WOS:000223921800056 PM 15366917 ER PT J AU Medvedev, DG Tripathi, A Clearfield, A Celestian, AJ Parise, JB Hanson, J AF Medvedev, DG Tripathi, A Clearfield, A Celestian, AJ Parise, JB Hanson, J TI Crystallization of sodium titanium silicate with sitinakite topology: Evolution from the sodium nonatitanate phase SO CHEMISTRY OF MATERIALS LA English DT Article ID ION-EXCHANGE PROPERTIES; POROUS TITANOSILICATE; NA4TI9O20.XH2O; STRONTIUM; ZEOLITES; DETECTOR; DIOXIDE AB Titanium silicate (TS) with sitinakite topology and composition Na(2)Ti(2)O(3)SiO(4)(.)2H(2)O has received considerable attention because of its high ion-exchange selectivity toward cesium and strontium. In this paper we report the results of the studies of the crystallization process of TS with a combination of ex and in situ experiments. The effects of various parameters, such as gel composition, time, and temperature of the synthesis, on crystallinity and composition of the final product have been investigated. In situ X-ray powder diffraction studies carried out during the synthesis of TS revealed that the process begins with the formation of layered sodium nonatitanate (SNT) with chemical composition Na(4)Ti(9)O(20)(.)xH(2)O, which is also an excellent ion exchanger, selective for strontium and actinides. The pathway of transformation of SNT to the final product is sensitive to alkalinity of the starting gels. At high hydroxide concentration the reaction resulted in the formation of sodium titanium oxide silicate, Na2TiSiO5, which has the mineral natisite topology. This study has revealed a pathway for the synthesis of a combined SNT-TS exchanger for removal of Cs, Sr, and actinides by a single-step in-tank process. C1 Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA. SUNY Stony Brook, Dept Geosci, Ctr Environm Mol Sci, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11793 USA. RP Clearfield, A (reprint author), Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. EM Clearfleld@mail.chem.tamu.edu RI Hanson, jonathan/E-3517-2010; Clearfield, Abraham/D-4184-2015 OI Clearfield, Abraham/0000-0001-8318-8122 NR 38 TC 13 Z9 13 U1 1 U2 22 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 21 PY 2004 VL 16 IS 19 BP 3659 EP 3666 DI 10.1021/cm049479a PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 855LI UT WOS:000223974300013 ER PT J AU Reynolds, BJ Ruegg, ML Balsara, NP Radke, CJ Shaffer, TD Lin, MY Shull, KR Lohse, DJ AF Reynolds, BJ Ruegg, ML Balsara, NP Radke, CJ Shaffer, TD Lin, MY Shull, KR Lohse, DJ TI Thermodynamics of polymer blends organized by balanced block copolymer surfactants studied by mean-field theories and scattering SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; TERNARY HOMOPOLYMER/DIBLOCK BLENDS; MULTICOMPONENT POLYOLEFIN BLENDS; PHASE-BEHAVIOR; DIBLOCK COPOLYMERS; COPOLYMER/HOMOPOLYMER BLENDS; BICONTINUOUS MICROEMULSIONS; MODEL; MIXTURES; SYSTEMS AB Parameters determined from binary experiments were used to predict the behavior of multicomponent A/B/A-C polymer blends, where A is saturated polybutadiene with 90% 1,2-addition (sPB90), B is polyisobutylene (PIB), and C is also saturated polybutadiene but with 63% 1,2-addition (sPB63). The polymers were chosen such that the binary interactions (A/B, A/C, and B/C) are analogous to those in oil (A)/water (B)/nonionic surfactant (A-C) systems, where A/B and A/C are unfavorable interactions (chi > 0) and B/C is a favorable interaction (chi < 0). The Flory-Huggins interaction parameters (chi(AB), chi(AG), and chi(BC)) and the statistical segment lengths (l(A), l(B), and l(C)) were all determined experimentally by fitting the random phase approximation (RPA) to small-angle neutron scattering (SANS) data from the three binary homopolymer blends. These parameters were successfully used to predict the scattering from concentration fluctuations in a homogeneous A/B/A-C blend using multicomponent RPA. These same binary parameters were also used as the only inputs to self-consistent field theory (SCFT) calculations of ordered multicomponent polymer blends. The SCFT calculations enabled quantitative interpretation of the SANS profiles from microphase separated A/B/A-C blends. The phase separation temperatures predicted by theory for the blends were within the experimental error, and the theoretical domain spacings were within 10% of the experimental values. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. ExxonMobil Res & Engn, Annandale, NJ 08801 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RP Balsara, NP (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Shull, Kenneth/B-7536-2009 NR 74 TC 20 Z9 21 U1 3 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 21 PY 2004 VL 37 IS 19 BP 7401 EP 7417 DI 10.1021/ma049779d PG 17 WC Polymer Science SC Polymer Science GA 855RA UT WOS:000223990200047 ER PT J AU Spieler, H AF Spieler, H TI Imaging detectors and electronics - a view of the future SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 5th International Workshop on Radiation Imaging Detectors CY SEP 07-11, 2003 CL Riga, LATVIA DE radiation detectors; imaging; electronics; noise; bolometers ID HIGH-RESISTIVITY SILICON; TIME-PROJECTION CHAMBER; HIGH-ENERGY-PHYSICS; STRIP DETECTORS; PIXEL DETECTOR; LOW-NOISE; READOUT; ARRAYS; BOLOMETER; SENSORS AB Imaging sensors and readout electronics have made tremendous strides in the past two decades. The application of modern semiconductor fabrication techniques and the introduction of customized monolithic integrated circuits have made large-scale imaging systems routine in high-energy physics. This technology is now finding its way into other areas, such as space missions, synchrotron light sources, and medical imaging. I review current developments and discuss the promise and limits of new technologies. Several detector systems are described as examples of future trends. The discussion emphasizes semiconductor detector systems, but I also include recent developments for large-scale superconducting detector arrays. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Spieler, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, MS 50B-6222,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM hgspieler@LBL.gov NR 29 TC 8 Z9 8 U1 2 U2 4 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 2004 VL 531 IS 1-2 BP 1 EP 17 DI 10.1016/j.nima.2004.05.070 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 859AE UT WOS:000224233400002 ER PT J AU Wang, ZW Zhao, YS Tait, K Liao, XZ Schiferl, D Zha, CS Downs, RT Qian, J Zhu, YT Shen, TD AF Wang, ZW Zhao, YS Tait, K Liao, XZ Schiferl, D Zha, CS Downs, RT Qian, J Zhu, YT Shen, TD TI A quenchable superhard carbon phase synthesized by cold compression of carbon nanotubes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID X-RAY-DIFFRACTION; HEXAGONAL DIAMOND; HIGH-PRESSURE; GRAPHITE; TRANSFORMATION; TEMPERATURE AB A quenchable superhard high-pressure carbon phase was synthesized by cold compression of carbon nanotubes. Carbon nanotubes were placed in a diamond anvil cell, and x-ray diffraction measurements were conducted to pressures of approximate to100 GPa. A hexagonal carbon phase was formed at approximate to75 GPa and preserved at room conditions. X-ray and transmission electron microscopy electron diffraction, as well as Raman spectroscopy at ambient conditions, explicitly indicate that this phase is a sp(3)-rich hexagonal carbon polymorph, rather than hexagonal diamond. The cell parameters were refined to a(0) = 2.496(4) Angstrom, c(0) = 4.123(8) Angstrom, and V-0 = 22.24(7) Angstrom(3). There is a significant ratio of defects in this nonhomogeneous sample that contains regions with different stacking faults. In addition to the possibly existing amorphous carbon, an average density was estimated to be 3.6 +/- 0.2 g/cm(3), which is at least compatible to that of diamond (3.52 g/cm(3)). The bulk modulus was determined to be 447 GPa at fixed K'equivalent to4, slightly greater than the reported value for diamond of approximate to440-442 GPa. An indented mark, along with radial cracks on the diamond anvils, demonstrates that this hexagonal carbon is a superhard material, at least comparable in hardness to cubic diamond. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. Cornell Univ, Cornell High Energy Synchrotron Source, Wilson Lab, Ithaca, NY 14853 USA. RP Wang, ZW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM z_wang@lanl.gov RI Zhu, Yuntian/B-3021-2008; Liao, Xiaozhou/B-3168-2009; Lujan Center, LANL/G-4896-2012 OI Zhu, Yuntian/0000-0002-5961-7422; Liao, Xiaozhou/0000-0001-8565-1758; FU PHS HHS [DMR 9713424] NR 19 TC 85 Z9 88 U1 0 U2 17 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 21 PY 2004 VL 101 IS 38 BP 13699 EP 13702 DI 10.1073/pnas0405877101 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856UF UT WOS:000224069800003 PM 15361581 ER PT J AU Mueller, RL Macey, JR Jaekel, M Wake, DB Boore, JL AF Mueller, RL Macey, JR Jaekel, M Wake, DB Boore, JL TI Morphological homoplasy, life history evolution, and historical biogeography of plethodontid salamanders inferred from complete mitochondrial genomes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE partitioned Bayesian analysis; larvae; tongues; tail autotomy; digits ID FAMILY PLETHODONTIDAE; LUNGLESS SALAMANDERS; TONGUE EVOLUTION; SPECIES TREES; BAYES FACTORS; GENE TREES; AMPHIBIA; PHYLOGENETICS; SEQUENCE; CAUDATA AB The evolutionary history of the largest salamander family (Plethodontidae) is characterized by extreme morphological homoplasy. Analysis of the mechanisms generating such homoplasy requires an independent molecular phylogeny. To this end, we sequenced 24 complete mitochondrial genomes (22 plethodontids and two outgroup taxa), added data for three species from GenBank, and performed partitioned and unpartitioned Bayesian, maximum likelihood, and maximum parsimony phylogenetic analyses. We explored four dataset partitioning strategies to account for evolutionary process heterogeneity among genes and codon positions, all of which yielded increased model likelihoods and decreased numbers of supported nodes in the topologies (Bayesian posterior probability >0.95) relative to the unpartitioned analysis. Our phylogenetic analyses yielded congruent trees that contrast with the traditional morphology-based taxonomy; the monophyly of three of four major groups is rejected. Reanalysis of current hypotheses in light of these evolutionary relationships suggests that (i) a larval life history stage reevolved from a direct-developing ancestor multiple times; (it) there is no phylogenetic support for the "Out of Appalachia" hypothesis of plethodontid origins; and (iii) novel scenarios must be reconstructed for the convergent evolution of projectile tongues, reduction in toe number, and specialization for defensive tail loss. Some of these scenarios imply morphological transformation series that proceed in the opposite direction than was previously thought. In addition, they suggest surprising evolutionary lability in traits previously interpreted to be conservative. C1 Univ Calif Berkeley, Museum Vertebrate Zool, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Joint Genome Inst, Dept Energy, Evolut Genom Dept, Walnut Creek, CA 94598 USA. Lawrence Berkeley Lab, Walnut Creek, CA 94598 USA. RP Mueller, RL (reprint author), Univ Calif Berkeley, Museum Vertebrate Zool, 3101 Valley Life Sci Bldg, Berkeley, CA 94720 USA. EM rachel@socrates.berkeley.edu NR 54 TC 161 Z9 171 U1 6 U2 27 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 21 PY 2004 VL 101 IS 38 BP 13820 EP 13825 DI 10.1073/pnas.0405785101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856UF UT WOS:000224069800024 PM 15365171 ER PT J AU Chain, PSG Carniel, E Larimer, FW Lamerdin, J Stoutland, PO Regala, WM Georgescu, AM Vergez, LM Land, ML Motin, VL Brubaker, RR Fowler, J Hinnebusch, J Marceau, M Medigue, C Simonet, M Chenal-Francisque, V Souza, B Dacheux, D Elliott, JM Derbise, A Hauser, LJ Garcia, E AF Chain, PSG Carniel, E Larimer, FW Lamerdin, J Stoutland, PO Regala, WM Georgescu, AM Vergez, LM Land, ML Motin, VL Brubaker, RR Fowler, J Hinnebusch, J Marceau, M Medigue, C Simonet, M Chenal-Francisque, V Souza, B Dacheux, D Elliott, JM Derbise, A Hauser, LJ Garcia, E TI Insights into the evolution of Yersinia pestis through whole-genome comparison with Yersinia pseudotuberculosis SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HIGH-PATHOGENICITY ISLAND; PASTEURELLA PESTIS; ESCHERICHIA-COLI; GLYOXYLATE CYCLE; FLEA VECTOR; VIRULENCE; PLASMID; PLAGUE; ENTEROCOLITICA; SEQUENCE AB Yersinia pestis, the causative agent of plague, is a highly uniform clone that diverged recently from the enteric pathogen Yersinia pseudotuberculosis. Despite their close genetic relationship, they differ radically in their pathogenicity and transmission. Here, we report the complete genomic sequence of Y. pseudotuberculosis IP32953 and its use for detailed genome comparisons with available Y. pestis sequences. Analyses of identified differences across a panel of Yersinia isolates from around the world reveal 32 Y. pestis chromosomal genes that, together with the two Y. pestis-specific plasmids, to our knowledge, represent the only new genetic material in Y. pestis acquired since the the divergence from Y. pseudotuberculosis. In contrast, 149 other pseudogenes (doubling the previous estimate) and 317 genes absent from Y. pestis were detected, indicating that as many as 13% of Y. pseudotuberculosis genes no longer function in Y. pestis. Extensive insertion sequence-mediated genome rearrangements and reductive evolution through massive gene loss, resulting in elimination and modification of preexisting gene expression pathways, appear to be more important than acquisition of genes in the evolution of Y. pestis. These results provide a sobering example of how a highly virulent epidemic clone can suddenly emerge from a less virulent, closely related progenitor. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Inst Pasteur, Yersinia Res Unit, F-75724 Paris 15, France. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Michigan State Univ, Dept Microbiol & Mol Genet, E Lansing, MI 48824 USA. NIAID, Rocky Mt Labs, Hamilton, MT 59840 USA. Univ Lille 2, Inst Natl Sante & Rech Med, Inst Pasteur, F-59021 Lille, France. CNRS, UMR 8030, F-91006 Evry, France. RP Garcia, E (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, 7000 E Ave,L-452, Livermore, CA 94550 USA. EM garcia12@llnl.gov RI Land, Miriam/A-6200-2011; Hauser, Loren/H-3881-2012; chain, patrick/B-9777-2013; Motin, Vladimir/O-1535-2013; MARCEAU, Michael/O-6497-2016 OI Land, Miriam/0000-0001-7102-0031; MARCEAU, Michael/0000-0002-4403-8081 NR 46 TC 387 Z9 1273 U1 5 U2 42 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 21 PY 2004 VL 101 IS 38 BP 13826 EP 13831 DI 10.1073/pnas.0401412101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856UF UT WOS:000224069800025 PM 15358858 ER PT J AU Rothfork, JM Timmins, GS Harris, MN Chen, X Lusis, AJ Otto, M Cheung, AL Gresham, HD AF Rothfork, JM Timmins, GS Harris, MN Chen, X Lusis, AJ Otto, M Cheung, AL Gresham, HD TI Inactivation of a bacterial virulence pheromone by phagocyte-derived oxidants: New role for the NADPH oxidase in host defense SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID CHRONIC GRANULOMATOUS-DISEASE; RESISTANT STAPHYLOCOCCUS-AUREUS; QUORUM-SENSING SYSTEM; AUTOINDUCING PEPTIDES; IN-VITRO; INFECTION; COMMUNICATION; MODEL; MYELOPEROXIDASE; DETERMINANTS AB Quorum sensing triggers virulence factor expression in medically important bacterial pathogens in response to a density-dependent increase in one or more autoinducing pheromones. Here, we show that phagocyte-derived oxidants target these autoinducers for inactivation as an innate defense mechanism of the host. In a skin infection model, expression of phagocyte NADPH oxidase, myelo-peroxidase, or inducible nitric oxide synthase was critical for defense against a quorum-sensing pathogen, Staphylococcus aureus, but not for defense against a quorum sensing-deficient mutant. A virulence-inducing peptide of S. aureus was inactivated in vitro and in vivo by reactive oxygen and nitrogen intermediates, including HOCl and ONOO-. Inactivation of the autoinducer prevented both the up-regulation of virulence gene expression and the downstream sequelae. MS analysis of the inactivated peptide demonstrated that oxidation of the C-terminal methionine was primarily responsible for loss of activity. Treatment of WT but not NADPH oxidase-deficient mice with N-acetyl methionine to scavenge the inhibitory oxidants increased in vivo quorum sensing independently of the bacterial burden at the site of infection. Thus, oxidant-mediated inactivation of an autoinducing peptide from S. aureus is a critical innate defense mechanism against infection with this pathogen. C1 Vet Affairs Med Ctr, Res Serv, Albuquerque, NM 87108 USA. Univ New Mexico, Dept Mol Genet & Microbiol, Albuquerque, NM 87131 USA. Univ New Mexico, Coll Pharm, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Microbiol Immunol & Mol Genet, Los Angeles, CA 90095 USA. NIAID, Rocky Mt Labs, NIH, Hamilton, MT 59840 USA. Dartmouth Coll Sch Med, Dept Microbiol, Hanover, NH 03755 USA. RP Gresham, HD (reprint author), Univ New Mexico 1, MSCO8 4660, Albuquerque, NM 87131 USA. EM hgresham@salud.unm.edu OI timmins, graham/0000-0002-4971-718X; Otto, Michael/0000-0002-2222-4115 FU NHLBI NIH HHS [HL30568, P01 HL030568]; NIAID NIH HHS [AI46615, AI47441, R01 AI046615, R01 AI047441] NR 38 TC 69 Z9 72 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 21 PY 2004 VL 101 IS 38 BP 13867 EP 13872 DI 10.1073/pnas.0402996101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856UF UT WOS:000224069800032 PM 15353593 ER PT J AU Gopalan, G He, Z Balmer, Y Romano, P Gupta, R Heroux, A Buchanan, BB Swaminathan, K Luan, S AF Gopalan, G He, Z Balmer, Y Romano, P Gupta, R Heroux, A Buchanan, BB Swaminathan, K Luan, S TI Structural analysis uncovers a role for redox in regulating FKBP13, an immunophilin of the chloroplast thylakoid lumen SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID CIS-TRANS ISOMERASE; CYTOCHROME B(6)F COMPLEX; BINDING-PROTEIN; MOLECULAR REPLACEMENT; ARABIDOPSIS-THALIANA; THIOREDOXIN; CYCLOPHILIN; FK506; LIGHT; NMR AB Change in redox status has long been known to link light to the posttranslational regulation of chloroplast enzymes. So far, studies have been conducted primarily with thioredoxin-linked members of the stroma that function in a broad array of biosynthetic and degradatory processes. Consequently, little is known about the role of redox in regulating the growing number of enzymes found to occur in the lumen, the site of oxygen evolution in thylakoid membranes. To help fill this gap, we have studied AtFKBP13, an FKBP-type immunophilin earlier shown to interact with a redoxactive protein of the lumen, and found the enzyme to contain a pair of disulfide bonds in x-ray structural studies. These disulfides, which in protein mutagenesis experiments were shown to be essential for the associated peptidyl-prolyl isomerase activity, are unique to chloroplast FKBPs and are absent in animal and yeast counterparts. Both disulfide bonds were redox-active and were reduced by thioredoxin from either chloroplast or bacterial sources in a reaction that led to loss of enzyme activity. The results suggest a previously unrecognized paradigm for redox regulation in chloroplasts in which activation by light is achieved in concert with oxygen evolution by the oxidation of sulfhydryl groups (conversion of SH to S-S). Such a mechanism, occurring in the thylakoid lumen, is in direct contrast to regulation of enzymes in the stroma, where reduction of disulfides targeted by thioredoxin (S-S converted to SH) leads to an increase in activity in the light. C1 Natl Univ Singapore, Dept Biol Sci, Singapore 119260, Singapore. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Inst Mol & Cell Biol, Singapore 138673, Singapore. RP Swaminathan, K (reprint author), Natl Univ Singapore, Dept Biol Sci, Singapore 119260, Singapore. EM dbsks@nus.edu.sg; sluan@nature.berkeley.edu RI ASTAR, IMCB/E-2320-2012 NR 40 TC 82 Z9 86 U1 0 U2 9 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 21 PY 2004 VL 101 IS 38 BP 13945 EP 13950 DI 10.1073/pnas.0405240101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856UF UT WOS:000224069800045 PM 15356344 ER PT J AU Morris, JR Ye, YY Lee, YB Harmon, BN Gschneidner, KA Russell, AM AF Morris, JR Ye, YY Lee, YB Harmon, BN Gschneidner, KA Russell, AM TI Ab initio calculation of bulk and defect properties of ductile rare-earth intermetallic compounds SO ACTA MATERIALIA LA English DT Article DE intermetallic phases; dislocation; plastic deformation; ab initio electron theory; slip systems ID NIAL SINGLE-CRYSTALS; MECHANICAL-PROPERTIES; DEFORMATION; ALLOYS; TEMPERATURE; SHEAR; SLIP; FRACTURE; STRENGTH; ALUMINUM AB We have used ab initio calculations to examine various properties of YAg and YCu, two members of a class of fully ordered stoichiometric intermetallics with the CsCl-type 132 lattice. These two alloys, and numerous similar compounds, have been found to have significant polycrystalline ductility, in some cases exceeding 20% ductility in tension. Calculated bulk properties are consistent with experimental data, where available, including lattice parameters, elastic constants, and stability with respect to the B27 FeB structure. Anti-phase boundary energies are large, consistent with the high degree of orders in these systems, and with the absence of b = <1 1 1> slip in single crystal experiments. However, unstable stacking faults associated with b = <1 0 0> slip are quite low, in contrast with NiAl where these energies exceed those of the anti-phase boundaries. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Oak Ridge Natl Lab, Dept Met, Ceram Div, Oak Ridge, TN 37831 USA. Wuhan Univ, Ctr Anal & Testing, Hubei, Peoples R China. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Morris, JR (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. EM morrisj@ornl.gov RI Morris, J/I-4452-2012; OI Morris, J/0000-0002-8464-9047; Russell, Alan/0000-0001-5264-0104 NR 31 TC 75 Z9 77 U1 1 U2 10 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 2004 VL 52 IS 16 BP 4849 EP 4857 DI 10.1016/j.actamat.2004.06.050 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 852YX UT WOS:000223794000013 ER PT J AU Li, SY Beyerlein, IJ Necker, CT Alexander, DJ Bourke, M AF Li, SY Beyerlein, IJ Necker, CT Alexander, DJ Bourke, M TI Heterogeneity of deformation texture in equal channel angular extrusion of copper SO ACTA MATERIALIA LA English DT Article DE ECAE; texture; heterogeneity; finite element; polycrystal plasticity ID SEVERE PLASTIC-DEFORMATION; MODELING TEXTURE; SIMPLE SHEAR; EVOLUTION; ALUMINUM; STRAIN AB Texture evolution and heterogeneity during equal channel angular extrusion (ECAE) of an annealed pure copper billet are investigated using a combined finite element-polycrystal modeling approach. For the first ECAE pass, texture predictions at several locations across the billet using either the visco-plastic self consistent (VPSC) or Taylor model are compared against orientation imaging microscopy (OIM) texture measurements. The results show significant spatial variation in texture, in good agreement with the OIM measurements, and indicate a better performance of the VPSC model than the Taylor model. The study was extended for routes A and C up to 16 passes. For route A the textures at the top and middle regions are similar, remain much stronger than that in the bottom region, and strengthen with the number of passes. In route C, the textures at the top and bottom positions become similar after the second pass, but are quite different from the textures in the middle; the texture heterogeneity is smaller for odd-numbered passes than for even-numbered passes. Published by Elsevier Ltd on behalf of Acta Materialia Inc. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA. RP Li, SY (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. EM saiyi@lanl.gov RI Li, Saiyi/J-3968-2012; Beyerlein, Irene/A-4676-2011 NR 34 TC 102 Z9 104 U1 0 U2 10 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 2004 VL 52 IS 16 BP 4859 EP 4875 DI 10.1016/j.actamat.2004.06.042 PG 17 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 852YX UT WOS:000223794000014 ER PT J AU Scaffidi, J Pearman, W Lawrence, M Carter, JC Colston, BW Angel, SM AF Scaffidi, J Pearman, W Lawrence, M Carter, JC Colston, BW Angel, SM TI Spatial and temporal dependence of interspark interactions in femtosecond-nanosecond dual-pulse laser-induced breakdown spectroscopy SO APPLIED OPTICS LA English DT Article ID INDUCED PLASMA SPECTROSCOPY; PRE-ABLATION SPARK; SHOCK-WAVES; LIBS PLASMA; EMISSION; EXCITATION; EXCIMER; SPECTROMETRY; WAVELENGTH; ATMOSPHERE AB A femtosecond air spark has recently been combined with a nanosecond ablative pulse in order to map the spatial and temporal interactions of the two plasmas in femtosecond-nanosecond orthogonal preablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS). Good spatial and temporal correlation was found for reduced atomic emission from atmospheric species (nitrogen and oxygen) and increased atomic emission from ablated species (copper and aluminum) in the femtosecond-nanosecond plasma, suggesting a potential role for atmospheric pressure or nitrogen/oxygen concentration reduction following air spark formation in generating atomic emission enhancements in dual-pulse LIBS. (C) 2004 Optical Society of America. C1 Univ S Carolina, Dept Chem & Biochem, Columbia, SC 29208 USA. US Mil Acad, Dept Chem, West Point, NY 10996 USA. Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94550 USA. RP Scaffidi, J (reprint author), Univ S Carolina, Dept Chem & Biochem, Columbia, SC 29208 USA. EM angel@mail.chem.sc.edu OI Angel, Stanley/0000-0002-0328-0568 NR 42 TC 24 Z9 24 U1 2 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 20 PY 2004 VL 43 IS 27 BP 5243 EP 5250 DI 10.1364/AO.43.005243 PG 8 WC Optics SC Optics GA 854SF UT WOS:000223922900015 PM 15473246 ER PT J AU Tan, X Hu, DH Squier, TC Lu, HP AF Tan, X Hu, DH Squier, TC Lu, HP TI Probing nanosecond protein motions of calmodulin by single-molecule fluorescence anisotropy SO APPLIED PHYSICS LETTERS LA English DT Article ID TARGET RECOGNITION; PEPTIDE COMPLEX; ENERGY-TRANSFER; MODULATION; ACTIVATION; DYNAMICS; DOMAINS; BINDING; NMR AB We report a single-molecule fluorescence anisotropy study of calmodulin, a regulatory protein for calcium-dependent cell signaling. Calmodulin in this study contains a site-specifically inserted tetra-cysteine motif that reacted with FlAsH, a biarsenic fluorescein derivative that can be rotationally locked to the host protein. A photon time-stamping technique was employed that combined the capability for both subnanosecond time resolution of time-correlated single photon counting and single-molecule time trajectory recording. The study provided direct characterization of the nanosecond motions of calmodulin tethered to a biologically compatible surface under physiological buffer solution. The unique technical approaches are applicable to single-molecule study of protein conformational dynamics and protein-protein interactions at a wide range of time scales and without the signal convolution of probe-dye molecular motions. (C) 2004 American Institute of Physics. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Lu, HP (reprint author), Pacific NW Natl Lab, Fundamental Sci Div, POB 999, Richland, WA 99352 USA. EM peter.lu@pnl.gov RI Hu, Dehong/B-4650-2010 OI Hu, Dehong/0000-0002-3974-2963 NR 25 TC 21 Z9 21 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 20 PY 2004 VL 85 IS 12 BP 2420 EP 2422 DI 10.1063/1.1791329 PG 3 WC Physics, Applied SC Physics GA 857UW UT WOS:000224145300089 ER PT J AU Lloyd-Ronning, NM Zhang, B AF Lloyd-Ronning, NM Zhang, B TI On the kinetic energy and radiative efficiency of gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; radiation mechanisms : nonthermal ID AFTERGLOW LIGHT CURVES; INTERNAL SHOCKS; ENERGETICS; RESERVOIR; MODEL; JET; FLASHES; SPECTRA AB Using measured X-ray luminosities of 17 gamma-ray bursts (GRBs) during the afterglow phase and accounting for radiative losses, we calculate the kinetic energy of these bursts and investigate its relation to other GRB properties. We then use the observed radiated energy during the prompt phase to determine the radiative efficiency of these bursts and explore how the efficiency relates to other GRB observables. We find that the kinetic energy in the afterglow phase is directly correlated with the radiated energy, total energy, and possibly the jet opening angle and spectral peak energy. More importantly, we find the intriguing fact that the efficiency is correlated with the radiated energy and mildly with the total energy, jet opening angle, and spectral peak energy. XRF 020903 also seems to follow the trends we find for our GRB sample. We discuss the implications of these results for the GRB radiation and jet models. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16803 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Lloyd-Ronning, NM (reprint author), Los Alamos Natl Lab, MS D436, Los Alamos, NM 87544 USA. EM ronning@lanl.gov; bzhang@astro.psu.edu NR 29 TC 62 Z9 62 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 20 PY 2004 VL 613 IS 1 BP 477 EP 483 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 856VW UT WOS:000224074400039 ER PT J AU Herwig, F Austin, SM AF Herwig, F Austin, SM TI Nuclear reaction rates and carbon star formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE nuclear reactions, nucleosynthesis, abundances; stars : abundances; stars : AGB and post-AGB; stars : carbon ID 3RD DREDGE-UP; INTERMEDIATE-MASS STARS; GIANT BRANCH EVOLUTION; STELLAR EVOLUTION; AGB STARS; S-FACTOR; N-14(P,GAMMA)O-15; CONVECTION; OVERSHOOT AB We have studied how the third dredge-up and the carbon star formation in low-mass asymptotic giant branch stars depend on certain key nuclear reaction rates. From a set of complete stellar evolution calculations of a 2 M-circle dot, model with Z=0.01 including mass loss, we find that varying either the N-14(p,gamma)O-15 or the triple-alpha reaction rate within their uncertainties as given in the NACRE compilation results in dredge-up and yields that differ by a factor of 2. Model tracks with a higher rate for the triple-alpha rate and a lower rate for the N-14(p,gamma)O-15 reaction both show more efficient third dredge-up. New experimental results for the N-14(p,gamma)O-15 reaction rates are surveyed, yielding a rate that is about 40% lower than the tabulated NACRE rate and smaller than NACRE's lower limit. We discuss the possible implications of the revised nuclear reaction rate for stellar evolution calculations that aim to reproduce the observed carbon star formation at low mass, which requires efficient third dredge-up. C1 Los Alamos Natl Lab, Theoret Astrophys Grp, Los Alamos, NM 87545 USA. Michigan State Univ, Natl Supercond Cyclotron Lab, E Lansing, MI 48824 USA. Michigan State Univ, Joint Inst Nucl Astrophys, E Lansing, MI 48824 USA. RP Herwig, F (reprint author), Los Alamos Natl Lab, Theoret Astrophys Grp, T-6,MS B227, Los Alamos, NM 87545 USA. EM fherwig@lanl.gov; austin@nscl.msu.edu NR 24 TC 46 Z9 48 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 20 PY 2004 VL 613 IS 1 BP L73 EP L76 DI 10.1086/424872 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 856VZ UT WOS:000224074700019 ER PT J AU Pines, E Pines, D Ma, YZ Fleming, GR AF Pines, E Pines, D Ma, YZ Fleming, GR TI Femtosecond pump-probe measurements of solvation by hydrogen-bonding interactions SO CHEMPHYSCHEM LA English DT Article DE femtochemistry; hydrogen-bonding interactions; photoacids; pump-probe spectroscopy; solvation dynamics ID ULTRAFAST INFRARED-SPECTROSCOPY; RESONANCE LIGHT-SCATTERING; DOUBLE-PROTON-TRANSFER; VIBRATIONAL SPECTROSCOPY; CONDENSED-PHASE; PHOTON-ECHO; ELECTRONIC EXCITATION; 7-AZAINDOLE DIMERS; BONDED COMPLEXES; SOLVENT RESPONSE AB An additional ultrafast blue shift in the transient absorption spectra of hydrogen-bonding complexes of a strong photoacid, 8 hydroxypyrene 1,3,6-trisdimethylsulfonamide (HPTA), over the solvation response of the uncomplexed HPTA and also over that of the methoxy derivative of the photoacid (MPTA) in the presence of the hydrogen-bonding base was observed on optical excitation of the photoacid. The additional 55+/-1 fs solvation response was found to be about 35% and 19% of the total C(t) of HPTA in dichloromethane (DCM) when it was hydrogen bonded to dimethylsulfoxide (DMSO) and dioxane, respectively, and about 29% of the total C(t) of HPTA in dichloroethane (DCE) when it was hydrogen-bonded to DMSO. We have assigned this additional dynamic spectral shift to a transient change in the hydrogen bond (O-H...O) that links HPTA to the complexing base, after the electronic excitation of the photoacid. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. RP Pines, E (reprint author), Ben Gurion Univ Negev, Dept Chem, POB 653, IL-84105 Beer Sheva, Israel. EM epines@bgumail.bgu.ac.il RI Ma, Yingzhong/L-6261-2016 OI Ma, Yingzhong/0000-0002-8154-1006 NR 80 TC 61 Z9 61 U1 1 U2 20 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1439-4235 J9 CHEMPHYSCHEM JI ChemPhysChem PD SEP 20 PY 2004 VL 5 IS 9 BP 1315 EP 1327 DI 10.1002/cphc.200301004 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 857VQ UT WOS:000224147700005 PM 15499848 ER PT J AU Banerjee, S Hemraj-Benny, T Balasubramanian, M Fischer, DA Misewich, JA Wong, SS AF Banerjee, S Hemraj-Benny, T Balasubramanian, M Fischer, DA Misewich, JA Wong, SS TI Surface chemistry and structure of purified, ozonized, multiwalled carbon nanotubes probed by NEXAFS and vibrational spectroscopies SO CHEMPHYSCHEM LA English DT Article DE nanotechnology; nanotubes; surface chemistry; vibrational spectroscopy; X-ray absorption spectroscopy ID X-RAY-ABSORPTION; SIDEWALL FUNCTIONALIZATION; CHEMICAL FUNCTIONALIZATION; FINE-STRUCTURE; PURIFICATION; OXIDATION; COMPOSITES; GROWTH; FILMS AB Understanding of oxidative processes such as solution-phase ozonolysis in multiwalled carbon nanotubes (MWNTs) is of funda mental importance in devising applications of these tubes as components in composite materials, as well as for development of cutting and filling protocols. We present here an evaluation of various spectroscopic tools to study the structure and composition of functionalized nanotubes. We demonstrate near-edge X-ray absorption fine structure (NEXAFS) spectroscopy as a particularly useful and effective technique for studying the surface chemistry of carbon nanotubes. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. RP SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. EM sswong@notes.cc.sunysb.edu NR 58 TC 56 Z9 56 U1 3 U2 10 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 1439-4235 EI 1439-7641 J9 CHEMPHYSCHEM JI ChemPhysChem PD SEP 20 PY 2004 VL 5 IS 9 BP 1416 EP 1422 DI 10.1002/cphc.200400122 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 857VQ UT WOS:000224147700017 PM 15499859 ER PT J AU Boukhalfa, H Reilly, SD Smith, WH Neu, MP AF Boukhalfa, H Reilly, SD Smith, WH Neu, MP TI EDTA and mixed-ligand complexes of tetravalent and trivalent plutonium SO INORGANIC CHEMISTRY LA English DT Article ID ETHYLENEDIAMINETETRAACETIC ACID; QUADRI-VALENT; TER-VALENT; IONS; HYDROLYSIS; STABILITY; OLATION; AGENTS AB EDTA forms stable complexes with plutonium that are integral to nuclear material processing, radionuclide decontamination, and the potentially enhanced transport of environmental contamination. To characterize the aqueous Pu(4+/3+)EDTA species formed under the wide range of conditions of these processes, potentiometry, spectrophotometry, and cyclic voltammetry were used to measure solution equilibria. The results reveal new EDTA and mixed-ligand complexes and provide more accurate stability constants for previously identified species. In acidic solution (pH < 4) and at 1:1 ligand to metal ratio, PuY (where Y4- is the tetra-anion of EDTA) is the predominant species, with an overall formation constant of log beta(110) = 26.44. At higher pH, the hydrolysis species, PuY(OH)(-) and PuY(OH)(2)(2-), form with the corresponding overall stability constants log beta(11-1) = 21.95 and 109 beta(11-2) = 15.29, The redox potential of the complex PuY at pH = 2.3 was determined to be E-1/2 = 342 mV. The correlation between redox potential, pH, and the protonation state of PuY- was derived to estimate the redox potential of the pU(4+/3+)y complex as a function of pH. Under conditions of neutral pH and excess EDTA relative to Pu4+, PuY24- forms with an overall formation constant of log beta(120) = 35.39. In the presence of ancillary ligands, mixed-ligand complexes form, as exemplified by the citrate and carbonate complexes PuY(citrate)(3-) (log beta(1101) = 33.45) and PuY(carbonate)(2)(log beta(1101) = 35.51). Cyclic voltarnmetry shows irreversible electrochemical behavior for these coordinatively saturated Pu4+ complexes: The reduction wave is shifted approximately -400 mV from the reduction wave of the complex PuY, while the oxidation wave is invariant. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87544 USA. RP Neu, MP (reprint author), Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87544 USA. EM mneu@lanl.gov NR 37 TC 35 Z9 35 U1 1 U2 30 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 20 PY 2004 VL 43 IS 19 BP 5816 EP 5823 DI 10.1021/ic035484p PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 854VG UT WOS:000223931000008 PM 15360230 ER PT J AU Bunge, SD Boyle, TJ Pratt, HD Alam, TM Rodriguez, MA AF Bunge, SD Boyle, TJ Pratt, HD Alam, TM Rodriguez, MA TI Synthesis and characterization of a series of rubidium alkoxides and rubidium-titanium double alkoxides SO INORGANIC CHEMISTRY LA English DT Article ID X-RAY STRUCTURES; CRYSTAL-STRUCTURES; THIN-FILMS; MOLECULAR PRECURSORS; LITHIUM; COMPLEXES; ARYLOXIDES; NEOPENTOXIDES; AGGREGATION; REACTIVITY AB This report investigates the structural aspects of the products isolated from the reactions of a series of titanium alkoxides {[Ti(OR)(4)](n) n = 2, OR OCH2C(CH3)(3) (ONep) (1); n = 1, OC6H3(CH3)(2)-2,6 (DMP) (2)} with rubidium alkoxides {[Rb(OR)](infinity) where OR (ONep) (3), (DMP) (4), and OC6H3(CH(CH3)(2))(2)-2,6 (DIP) (5)}. The resultant double alkoxides were determined by single crystal X-ray diffraction to be [Rb(mu-ONeP)(4)(py)Ti(ONep)](2) (6), [Rb(mu-DMP)Ti(DMP)(4)](infinity) (7), and [Rb(mu-DMP)(2)(mu-ONeP)(2)Ti(ONep)](infinity) (8). Compound 1 is the previously reported dinculear species with trigonal bipyramidal Ti metal centers whereas compound 2 is a monomer with a tetrahedral Ti center. Suitable X-ray quality crystals of 3 were not isolated. Compounds 4 and 5 demonstrate extended polymeric networks with Rb coordination ranging from two to five utilizing terminal mu- and mu(3)-OR ligands and pi-interactions of neighboring OAr ligands. The double alkoxide 6 revealed a simple tetranuclear structure with mu-ONep acting as the bridge, terminal ONep ligands on the Ti, and one terminal py on the Rb. For 7 and 8, the pi-interaction facilitated the formation of extended polymeric systems. All complexes were further characterized by FT-IR and multinuclear NMR spectroscopy. C1 Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Boyle, TJ (reprint author), Sandia Natl Labs, Adv Mat Lab, 1001 Univ Blvd SE, Albuquerque, NM 87106 USA. EM tjboyle@Sandia.gov NR 41 TC 19 Z9 19 U1 0 U2 4 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 20 PY 2004 VL 43 IS 19 BP 6035 EP 6041 DI 10.1021/ic049325x PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 854VG UT WOS:000223931000031 PM 15360253 ER PT J AU Dohrmann, CR Bochev, PB AF Dohrmann, CR Bochev, PB TI A stabilized finite element method for the Stokes problem based on polynomial pressure projections SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE Stokes equations; stabilized mixed methods; equal-order interpolation; inf-sup condition ID ORDER; APPROXIMATION; FORMULATION; FLOWS AB A new stabilized finite element method for the Stokes problem is presented. The method is obtained by modification of the mixed variational equation by using local L 2 polynomial pressure projections. Our stabilization approach is motivated by the inherent inconsistency of equal-order approximations for the Stokes equations, which leads to an unstable mixed finite element method. Application of pressure projections in conjunction with minimization of the pressure-velocity mismatch eliminates this inconsistency and leads to a stable variational formulation. Unlike other stabilization methods, the present approach does not require specification of a stabilization parameter or calculation of higher-order derivatives, and always leads to a symmetric linear system. The new method can be implemented at the element level and for affine families of finite elements on simplicial grids it reduces to a simple modification of the weak continuity equation. Numerical results are presented for a variety of equal-order continuous velocity and pressure elements in two and three dimensions. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Sandia Natl Labs, Struct Dynam Res Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Struct Dynam Res Dept, Mail Stop 0847, Albuquerque, NM 87185 USA. EM crdohrm@sandia.gov; pbboche@sandia.gov NR 23 TC 127 Z9 134 U1 0 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0271-2091 EI 1097-0363 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD SEP 20 PY 2004 VL 46 IS 2 BP 183 EP 201 DI 10.1002/fld.752 PG 19 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 849ZW UT WOS:000223581500004 ER PT J AU Vetter, PA AF Vetter, PA TI Experimental tests of fundamental symmetries in positronium annihilation SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 1st International Workshop on Positronium Physics CY MAY 30-31, 2003 CL Inst Particle Phys, ETH Zurich, Zurich, SWITZERLAND HO Inst Particle Phys, ETH Zurich DE positronium; annihilation; CPT tests ID STANDARD MODEL; NEUTRINO EXPERIMENT; DECAY; ORTHOPOSITRONIUM; SEARCH; GAMMASPHERE; CPT; INVARIANCE; VIOLATION; ELECTRON AB Using the Gammasphere array of high-purity germanium detectors at the 88" Cyclotron at Lawrence Berkeley National Laboratory, we have made several measurements to test discrete fundamental symmetries in positronium annihilation. We tested charge conjugation symmetry (C) by searching for decays of ortho- and para-positronium to the "wrong" number of photons. We measured the five-photon annihilation mode of ortho-positronium, finding agreement with tree-level QED calculations at order alpha(8). In a second experiment, we searched for decays of polarized ortho-positronium which violate the combined symmetry operation CPT. We improved existing limits on this CPT test by roughly a factor of ten. We are studying the feasibility of an experiment to search for "invisible" decays of ortho-positronium. Invisible decays could be caused by extra dimensions (invoked in string theories). General requirements for an experiment sensitive to decay branching ratios of order 10(-9) are discussed. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Vetter, PA (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 31 TC 6 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD SEP 20 PY 2004 VL 19 IS 23 BP 3865 EP 3878 DI 10.1142/S0217751X04020130 PG 14 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 860CN UT WOS:000224316300008 ER PT J AU Malli, GL Siegert, M Turner, DP AF Malli, GL Siegert, M Turner, DP TI Relativistic and electron correlation effects for molecules of heavy elements: Ab initio fully relativistic coupled-cluster calculations for PbH4 SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT 7th European Workshop on Quantum Systems in Chemistry and Physics (QSCP 7)* CY SEP 10-15, 2002 CL Bratislava, SLOVAKIA DE relativistic and electron correlation effects; molecules of heavy elements; fully relativistic coupled-cluster calculations; PbH4 ID GAUSSIAN-BASIS SET; EFFECTIVE CORE POTENTIALS; INCOMPLETE MODEL SPACES; SPIN-ORBIT OPERATORS; LINKED-DIAGRAM; FOCK CALCULATIONS; BOUND-STATES; HYDROGEN; SPECTRA; ATOMS AB Ab initio fully relativistic all-electron Dirac-Fock (DF) and nonrelativistic (NR) Hartree-Fock (HF) limit self-consistent field (SCF) benchmark molecular calculations are reported for the tetrahedral (T-d) PbH4 at various Pb-H bond distances. Our fully relativistic Dirac-Fock and nonrelativistic HF calculations predict for a PbH4 bond distance of 1.75 and 1.82 Angstrom, respectively. Both our DF and NR HF limit SCF calculations predict the ground state of PbH4 (T-d) to be bound, with the predicted atomization energy (A(e)) of 7.20 and 8.63 eV, respectively. There are antibinding effects due to relativity of similar to1.4 eV to the predicted atornization energy (A(e)) of PbH4. Our relativistic four-component coupled-cluster singles and doubles (RCCSD) calculations, which correlate 50 electrons and include 302 active molecular spinors with energies up to similar to46 a.u. in the active space predict the relativistic second-order Moller-Plesset (RMP2), RCCSD and RCCSD (T) (RCCSD plus the triple excitation correction included perturbationally) correlation energies as -1.271, -1.161, and -1.186 hartree, respectively. The contribution of the RMP2, RCCSD, and RCCSD (T) electron correlation energies toward the atornization energy of PbH4 as predicted by our above-mentioned CC calculation is 3.78, 4.22, and 4.30 eV, respectively. We predict the NR and relativistic MP2, CCSD, and CCSD (T) atornization energies (A(e)) for PbH4 at the optimized Pb-H bond distances as 12.72, 12.90, 1.77 and 10.98, 11.42, and 11.50 eV, respectively. With the inclusion of both the electron correlation and effects of relativity, we predict the atornization energy for PbH4 to be -10-11 eV. This should encourage experimentalists to devise new synthetic methods to prepare plumbane, so that its chemical and physical properties can be investigated as in the case of its lighter congeners. (C) 2004 Wiley Periodicals, Inc. C1 Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. Simon Fraser Univ, Acad Comp Serv, Burnaby, BC V5A 1S6, Canada. Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr NERSC, Berkeley, CA USA. RP Malli, GL (reprint author), Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. EM malli@sfu.ca NR 50 TC 7 Z9 7 U1 3 U2 9 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD SEP 20 PY 2004 VL 99 IS 6 SI SI BP 940 EP 949 DI 10.1002/qua.20142 PG 10 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 846ZC UT WOS:000223357300009 ER PT J AU Lipnikov, K Morel, J Shashkov, M AF Lipnikov, K Morel, J Shashkov, M TI Mimetic finite difference methods for diffusion equations on non-orthogonal non-conformal meshes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE mimetic finite differences; quadrilateral meshes; diffusion equation ID DISCRETIZATION SCHEME; REFINEMENT TECHNIQUES AB Mimetic discretizations based on the support-operators methodology are derived for non-orthogonal locally refined quadrilateral meshes. The second-order convergence rate on non-smooth meshes is verified with numerical examples. (C) 2004 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Comp & Computat Sci Div, CCS 2, Los Alamos, NM 87545 USA. RP Lipnikov, K (reprint author), Los Alamos Natl Lab, Div Theoret, T-7,Mail Stop B284, Los Alamos, NM 87545 USA. EM lipnikov@lanl.gov; jim@lanl.gov; shashkov@lanl.gov NR 12 TC 58 Z9 61 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 2004 VL 199 IS 2 BP 589 EP 597 DI 10.1016/j.jcp.2004.02.016 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 857TV UT WOS:000224142100007 ER PT J AU Anderson, RW Elliott, NS Pember, RB AF Anderson, RW Elliott, NS Pember, RB TI An arbitrary Lagrangian-Eulerian method with adaptive mesh refinement for the solution of the Euler equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID HYPERBOLIC CONSERVATION-LAWS; HYDRODYNAMICS; FLOW AB A new algorithm that combines staggered grid arbitrary Lagrangian-Eulerian (ALE) techniques with structured local adaptive mesh refinement (AMR) has been developed for the solution of the Euler equations. The novel components of the method are driven by the need to reconcile traditional AMR techniques with the staggered variables and moving, deforming meshes associated with Lagrange based ALE schemes. Interlevel coupling is achieved with refinement and coarsening operators, as well as mesh motion boundary conditions. Elliptic mesh relaxation schemes are extended for use within the context of an adaptive mesh hierarchy. Numerical examples are used to highlight the utility of the method over single level ALE solution methods, facilitating substantial efficiency improvements and enabling the efficient solution of a highly resolved three-dimensional Richtmyer-Meshkov instability problem. (C) 2004 Published by Elsevier Inc. C1 Ctr Appl Sci Comp, Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Anderson, RW (reprint author), Ctr Appl Sci Comp, Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM anderson110@llnl.gov NR 25 TC 46 Z9 48 U1 1 U2 6 PU ACADEMIC PRESS INC ELSEVIER SCIENCE 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 2004 VL 199 IS 2 BP 598 EP 617 DI 10.1016/j.jcp.2004.02.021 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 857TV UT WOS:000224142100008 ER PT J AU Salle, B Lacour, JL Vors, E Fichet, P Maurice, S Cremers, DA Wiens, RC AF Salle, B Lacour, JL Vors, E Fichet, P Maurice, S Cremers, DA Wiens, RC TI Laser-induced breakdown spectroscopy for Mars surface analysis: capabilities at stand-off distances and detection of chlorine and sulfur elements SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE laser-induced breakdown spectroscopy; Mars elemental analysis; metals; rocks; chlorine; sulfur ID INDIVIDUAL FLUID INCLUSIONS; EMISSION-SPECTROSCOPY; PLASMA EMISSION; SOIL; SPECTROMETRY; METALS; WATER; GASES; IONS AB An international consortium is studying the feasibility of performing in situ geochemical analysis of Mars soils and rocks at stand-off distances up to several meters using the laser-induced breakdown spectroscopy (LIBS) technique. Stand-off analysis for Martian exploration imposes particular requirements on instrumentation, and it is necessary to first test the performance of such a system in the laboratory. In this paper, we test the capabilities of two different experimental setups. The first one is dedicated to the qualitative analysis of metals and rocks at distances between 3 and 12 in. With the second one, we have obtained quantitative results for aluminum alloys and developed a spectral database under Martian conditions for sulfur and chlorine, two elements that are geologically. interesting but generally difficult to detect by LIBS under standard conditions (atmospheric pressure, close distance). These studies were carried out to determine an optimal instrumental design for in situ Mars analysis. The quality of analytical results affected by the optical elements and spectrometer has been particularly highlighted. (C) 2004 Elsevier B.V. All rights reserved. C1 CEA Saclay, DEN, DPC, SCP,LRSI, F-91191 Gif Sur Yvette, France. Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. Los Alamos Natl Lab, Grp C ADI, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Grp ISR 1, Los Alamos, NM 87545 USA. RP Fichet, P (reprint author), CEA Saclay, DEN, DPC, SCP,LRSI, Batiment 391, F-91191 Gif Sur Yvette, France. EM fichet@camac.cea.fr NR 38 TC 98 Z9 104 U1 1 U2 36 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD SEP 20 PY 2004 VL 59 IS 9 BP 1413 EP 1422 DI 10.1016/j.sab.2004.06.006 PG 10 WC Spectroscopy SC Spectroscopy GA 863UW UT WOS:000224589900009 ER PT J AU Ozcelik, S Guvenc, ZB Durmus, P Jellinek, J AF Ozcelik, S Guvenc, ZB Durmus, P Jellinek, J TI Reactivity of the Ni(n)(T) (n=54,55,56) clusters with D(2)(v,j) molecule: molecular dynamics simulations SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 22nd European Conference on Surface Science (ECOSS 22) CY SEP 07-12, 2003 CL Prague, CZECH REPUBLIC SP Inst Phys Acad Sci Czecg Republic, European Phys Soc, Surface Interface Div, Surf Div Int Union Vacuum Sci, Tech & Applicat DE nickel; clusters; molecule-solid reactions; deuterium; molecular dynamics ID NI CLUSTERS; DISSOCIATION DYNAMICS; NICKEL CLUSTERS; METAL-CLUSTERS; H-2; D2; CHEMISORPTION; DEPENDENCE; DEUTERIUM; HYDROGEN AB The reactive channel of the D(2) (v, j) + Ni(n) (T) (n = 54, 55, 56) collision system is studied via quasiclassical molecular dynamics simulations. The cluster is described using an embedded-atom potential, and the interaction between the molecule and the cluster is modeled by a LEPS (London-Eyring-Polanyi-Sato) potential energy function. Dissociative chemisorption probabilities are computed as functions of the impact parameter and the collision energy, and are used to evaluate the reaction cross-sections. Effects of the initial rovibrational states of the molecule and the temperatures of the clusters on the reactive channel are analyzed. Reaction rate constants are also computed and compared with those measured experimentally. (C) 2004 Elsevier B.V. All rights reserved. C1 Gazi Univ, Dept Phys, TR-06500 Ankara, Turkey. Cankaya Univ, Dept Elect & Commun Engn, TR-06530 Ankara, Turkey. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Ozcelik, S (reprint author), Gazi Univ, Dept Phys, TR-06500 Ankara, Turkey. EM sozcelik@gazi.edu.tr; guvenc@cankaya.edu.tr RI Ozcelik, Suleyman/J-6494-2014 OI Ozcelik, Suleyman/0000-0002-3761-3711 NR 22 TC 3 Z9 5 U1 1 U2 3 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 2004 VL 566 BP 377 EP 382 DI 10.1016/j.susc.2004.05.074 PN 1 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 859BX UT WOS:000224238200067 ER PT J AU Vanossi, A Bishop, AR Franchini, A Bortolani, V AF Vanossi, A Bishop, AR Franchini, A Bortolani, V TI Modelling study of microscopic sliding on irregular substrates SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 22nd European Conference on Surface Science (ECOSS 22) CY SEP 07-12, 2003 CL Prague, CZECH REPUBLIC SP Inst Phys Acad Sci Czecg Republic, European Phys Soc, Surface Interface Div, Surf Div Int Union Vacuum Sci, Tech & Applicat DE atomistic dynamics; models of non-linear phenomena; friction; tribology ID FRENKEL-KONTOROVA MODEL AB In connection with microscopic solid friction phenomena, we study the underdamped dynamics of a driven Frenkel-Kontorova chain subject to a substrate potential defined by the sum of two sinusoidal function with different periodicity. We simulate microscopic sliding over quasiperiodic and multiple-well (periodic) substrates. We comment on the nature of the particle dynamics in the vicinity of the pinning-depinning transition point and consider the role played by the coverage variable on the depinning mechanism. We also investigate on the different nonlinear excitations forming during sliding and characterizing the dynamical states observed at different strengths of the imposed driving. The dependence of the static friction on the ratio of the model interaction strengths is analyzed. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Modena, Dipartimento Fis, I-41100 Modena, Italy. INFM S3, I-41100 Modena, Italy. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Univ Modena, Dipartimento Fis, Via Campi 213-A, I-41100 Modena, Italy. EM franchini.anna@unimore.it RI FRANCHINI, Anna/H-2464-2013 OI FRANCHINI, Anna/0000-0002-2701-1848 NR 11 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD SEP 20 PY 2004 VL 566 BP 816 EP 820 DI 10.1016/j.susc.2004.06.015 PN 2 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 859BY UT WOS:000224238300028 ER PT J AU Cox, EJ Ledieu, J Dhanak, VR Barrett, SD Jenks, CJ Fisher, I McGrath, R AF Cox, EJ Ledieu, J Dhanak, VR Barrett, SD Jenks, CJ Fisher, I McGrath, R TI An STM and SXPS study of the interaction of C-60 with the ten-fold surface of the Al72Ni11Co17 quasicrystal SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 22nd European Conference on Surface Science (ECOSS 22) CY SEP 07-12, 2003 CL Prague, CZECH REPUBLIC SP Inst Phys Acad Sci Czecg Republic, European Phys Soc, Surface Interface Div, Surf Div Int Union Vacuum Sci, Tech & Applicat DE soft X-ray photoelectron spectroscopy; scanning tunneling microscopy; surface structure, morphology, roughness, and; topography; alloys; fullerenes AB The adsorption of C-60 on the ten-fold surface of the decagonal Al-Ni-Co quasicrystal at room temperature has been investigated using scanning tunnelling microscopy (STM) and soft X-ray photoemission spectroscopy (SXPS). STM indicates disordered adsorption of intact C-60 molecules on the surface up to a coverage of 1 ML, followed by the formation of a C-60 multilayer. No step decoration is observed indicating that the molecules are immobile at room temperature. SXPS data of the Al 2p core level indicate a strong interaction of the C-60 molecules with the Al atoms of the substrate in the sub-monolayer regime. Valence band data indicate that the C-60 multilayer desorbs after annealing to 700 K leaving only the strongly bonded layer on the surface. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Surface Sci Res Ctr, Liverpool L69 3BX, Merseyside, England. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP McGrath, R (reprint author), Univ Liverpool, Dept Phys, Surface Sci Res Ctr, Liverpool L69 3BX, Merseyside, England. EM mcgrath@liv.ac.uk RI McGrath, Ronan/A-1568-2009; Barrett, Stephen/C-4512-2013; Ledieu, Julian/F-1430-2010 OI McGrath, Ronan/0000-0002-9880-5741; NR 14 TC 7 Z9 7 U1 1 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 2004 VL 566 BP 1200 EP 1205 DI 10.1016/j.susc.2004.06.089 PN 2 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 859BY UT WOS:000224238300098 ER PT J AU Suntharalingam, P Jacob, DJ Palmer, PI Logan, JA Yantosca, RM Xiao, YP Evans, MJ Streets, DG Vay, SL Sachse, GW AF Suntharalingam, P Jacob, DJ Palmer, PI Logan, JA Yantosca, RM Xiao, YP Evans, MJ Streets, DG Vay, SL Sachse, GW TI Improved quantification of Chinese carbon fluxes using CO2/CO correlations in Asian outflow SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE regional carbon fluxes; multiple-species correlations; atmospheric; CO2 modeling ID TRACE-P EXPERIMENT; WESTERN NORTH PACIFIC; ATMOSPHERIC CO2; CHEMICAL EVOLUTION; CONTINENTAL OUTFLOW; TRANSPORT PATHWAYS; EMISSIONS; SINKS; MONOXIDE; DIOXIDE AB [1] We use observed CO2: CO correlations in Asian outflow from the TRACE-P aircraft campaign ( February - April 2001), together with a three-dimensional global chemical transport model (GEOS-CHEM), to constrain specific components of the east Asian CO2 budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the source of CO2 ( different combustion types versus the terrestrial biosphere) and provides a characteristic signature of source regions and source type. Observed CO2/CO correlation slopes in east Asian boundary layer outflow display distinct regional signatures ranging from 10 - 20 mol/mol ( outflow from northeast China) to 80 mol/mol ( over Japan). Model simulations using best a priori estimates of regional CO2 and CO sources from Streets et al. [ 2003] ( anthropogenic), the CASA model (biospheric), and Duncan et al. [ 2003] (biomass burning) overestimate CO2 concentrations and CO2/CO slopes in the boundary layer outflow. Constraints from the CO2/CO slopes indicate that this must arise from an overestimate of the modeled regional net biospheric CO2 flux. Our corrected best estimate of the net biospheric source of CO2 from China for March - April 2001 is 3200 Gg C/d, which represents a 45% reduction of the net flux from the CASA model. Previous analyses of the TRACE-P data had found that anthropogenic Chinese CO emissions must be similar to 50% higher than in Streets et al.' s [ 2003] inventory. We find that such an adjustment improves the simulation of the CO2/CO slopes and that it likely represents both an underreporting of sector activity ( domestic and industrial combustion) and an underestimate of CO emission factors. Increases in sector activity would imply increases in Chinese anthropogenic CO2 emissions and would also imply a further reduction of the Chinese biospheric CO2 source to reconcile simulated and observed CO2 concentrations. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Argonne Natl Lab, Argonne, IL 60439 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Harvard Univ, Div Engn & Appl Sci, Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA. EM pns@io.harvard.edu; djj@io.harvard.edu; pip@io.harvard.edu; jal@io.harvard.edu; bmy@io.harvard.edu; xyp@io.harvard.edu; mje@io.harvard.edu; dstreets@anl.gov; s.a.vay@larc.nasa.gov; g.w.sachse@larc.nasa.gov RI Palmer, Paul/F-7008-2010; Evans, Mathew/A-3886-2012; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014 OI Evans, Mathew/0000-0003-4775-032X; Yantosca, Robert/0000-0003-3781-1870; NR 57 TC 65 Z9 66 U1 1 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 18 PY 2004 VL 109 IS D18 AR D18S18 DI 10.1029/2003JD004362 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 857NH UT WOS:000224123700001 ER PT J AU Wei, YN Li, HL Fu, D AF Wei, YN Li, HL Fu, D TI Oligomeric state of the Escherichia coli metal transporter YiiP SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ZINC TRANSPORTER; LIGHT-SCATTERING; MULTIDRUG-RESISTANCE; ELECTRON-MICROSCOPY; DETERGENT BINDING; MEMBRANE-PROTEINS; ABC TRANSPORTERS; MECHANISM; ZITB; SELECTIVITY AB YiiP is a 32.9-kDa metal transporter found in the plasma membrane of Escherichia coli (Chao, Y., and Fu, D. (2004) J. Biol. Chem. 279, 17173 - 17180). Here we report the determination of the YiiP oligomeric state in detergent-lipid micelles and in membranes. Molecular masses of YiiP solubilized with dodecyl-, undecyl-, decyl-, or nonyl-beta-D-maltoside were measured directly using size-exclusion chromatography coupled with laser light-scattering photometry, yielding a mass distribution of YiiP homo-oligomers within a narrow range (68.0 - 68.8 kDa) that equals the predicted mass of a YiiP dimer within experimental error. The detergent-lipid masses associated with YiiP in the mixed micelles were found to increase from 135.5 to 232.6 kDa, with an apparent correlation with the alkyl chain length of the maltoside detergents. Cross-linking the detergent-solubilized YiiP with 1-ethyl-3- [3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) resulted in a dimeric cross-linked product in an EDC concentration-dependent manner. The oligomeric state of the purified YiiP in reconstituted membranes was determined by electron microscopic analysis of two-dimensional YiiP crystals in negative stain. A projection structure calculated from measurable optical diffractions to 25 Angstrom revealed a pseudo-2-fold symmetry within a molecular boundary of similar to 75 x 40 Angstrom, indicative of the presence of YiiP dimers in membranes. These data provide direct structural evidence for a dimeric association of YiiP both in detergent-lipid micelles and in the reconstituted lipid bilayer. The functional relevance of the dimeric association in YiiP is discussed. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Fu, D (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463, Upton, NY 11973 USA. EM dax@bnl.gov FU NIGMS NIH HHS [R01 GM65137] NR 30 TC 37 Z9 38 U1 0 U2 13 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 EI 1083-351X J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 17 PY 2004 VL 279 IS 38 BP 39251 EP 39259 DI 10.1074/jbc.M407044200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 852YA UT WOS:000223791500009 PM 15258151 ER PT J AU Manchekar, M Richardson, PE Forte, TM Datta, G Segrest, JP Dashti, N AF Manchekar, M Richardson, PE Forte, TM Datta, G Segrest, JP Dashti, N TI Apolipoprotein b-containing lipoprotein particle assembly - Lipid capacity of the nascent lipoprotein particle SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID TRIGLYCERIDE TRANSFER PROTEIN; LOW-DENSITY LIPOPROTEINS; CARBOXYL-TERMINAL TRUNCATION; APO-B; ENDOPLASMIC-RETICULUM; AMPHIPATHIC HELIX; HEPG2 CELLS; RAT-LIVER; SECRETION; VITELLOGENIN AB We previously proposed that the N-terminal 1000-residue betaalpha(1) domain of apolipoprotein B ( apoB) forms a bulk lipid pocket homologous to that of lamprey lipovitellin. In support of this "lipid pocket" hypothesis, we demonstrated that apoB: 1000 ( residues 1 - 1000) is secreted by a stable transformant of McA-RH7777 cells as a monodisperse particle with high density lipoprotein 3 (HDL3) density. In contrast, apoB: 931 ( residues 1 - 931), missing only 69 residues of the sequence homologous to lipovitellin, was secreted as a particle considerably more dense than HDL3. In the present study we have determined the stoichiometry of the lipid component of the apoB: 931 and apoB: 1000 particles. The secreted [H-3]glycerol- labeled apoB: 1000 particles, isolated by nondenaturing gradient gel electrophoresis, contained 50 phospholipid (PL) and 11 triacylglycerol ( TAG) molecules/ particle. In contrast, apoB: 931 particles contained only a few molecules of PL and were devoid of TAG. The unlabeled apoB: 1000 particles, isolated by immunoaffinity chromatography, contained 56 PL, 8 TAG, and 7 cholesteryl ester molecules/ particle. The surface to core lipid ratio of apoB: 1000-containing particles was similar to4: 1 and was not affected by oleate supplementation. Although very small amounts of microsomal triglyceride transfer protein (MTP) were associated with apoB: 1000 particles, it never approached a 1: 1 molar ratio of MTP to apoB. These results support a model in which (i) the first 1000 amino acid residues of apoB are competent to complete the lipid pocket without a structural requirement for MTP; (ii) a portion, or perhaps all, of the amino acid residues between 931 and 1000 of apoB-100 are critical for the formation of a stable, bulk lipid-containing nascent lipoprotein particle, and (iii) the lipid pocket created by the first 1000 residues of apoB-100 is PL-rich, suggesting a small bilayer type organization and has a maximum capacity on the order of 50 molecules of phospholipid. C1 Univ Alabama, Med Ctr, Dept Med, Atherosclerosis Res Unit, Birmingham, AL 35294 USA. Univ Alabama, Med Ctr, Dept Biochem & Mol Genet, Birmingham, AL 35294 USA. Georgia Inst Technol, Dept Biol, Atlanta, GA 30332 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dashti, N (reprint author), Univ Alabama, Med Ctr, Dept Med, Atherosclerosis Res Unit, Birmingham, AL 35294 USA. EM ndashti@uab.edu FU NHLBI NIH HHS [P01 HL34343, HL18574] NR 48 TC 43 Z9 44 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 17 PY 2004 VL 279 IS 38 BP 39757 EP 39766 DI 10.1074/jbc.M406302200 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 852YA UT WOS:000223791500069 PM 15254032 ER PT J AU Kim, HJ Gritti, F Guiochon, G AF Kim, HJ Gritti, F Guiochon, G TI Effect of the temperature on the isotherm parameters of phenol in reversed-phase liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption isotherms; affinity energy distribution; inverse method; band profiles; phenol; silica-based stationary phase ID ADSORPTION ENERGY-DISTRIBUTIONS; EXPECTATION-MAXIMIZATION METHOD; STATIONARY PHASES; SURFACE HETEROGENEITY; RAMAN-SPECTROSCOPY; COLUMN TEMPERATURE; RETENTION; SILICA; DEPENDENCE AB Adsorption isotherm data of phenol from an aqueous solution of methanol onto a C-18-bonded silica (Symmetry-C-18) were acquired by frontal analysis (FA) at six different temperatures, in a wide concentration range. The non-linear fitting of these data provided the bi-Langmuir model as best isotherm model, a conclusion further supported by the results of the calculation of the affinity energy distribution (AED). The isotherm parameters were obtained using several methods, the fitting of FA isotherm data, the calculation of the AED, and the inverse method, that uses overloaded elution band profiles. The different values obtained are in close agreement. They allow a quantitative investigation of the separate properties of the low- and the high-energy sites on the adsorbent surface. Increasing the temperature decreases the saturation capacity of the low-energy adsorption sites and the adsorption constant of the high-energy sites. In contrast, increasing the temperature does not cause any significant changes in either the saturation capacity of the high-energy sites or the adsorption constant of the low-energy sites. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 30 TC 22 Z9 22 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD SEP 17 PY 2004 VL 1049 IS 1-2 BP 25 EP 36 DI 10.1016/j.chroma.2004.08.025 PG 12 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 858BO UT WOS:000224165300004 PM 15499914 ER PT J AU Han, J Singh, AK AF Han, J Singh, AK TI Rapid protein separations in ultra-short microchannels: microchip sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE SDS-PAGE; microchip; photopolymerization; protein separation; isoelectric focusing ID INDUCED FLUORESCENCE DETECTION; COLUMN IMAGING DETECTION; CAPILLARY-ELECTROPHORESIS; POLY(DIMETHYLSILOXANE); COMPLEXES; CHANNELS; PEPTIDES; SYSTEM AB We have developed novel protein gel electrophoresis techniques, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF) in short microchannels (similar tomillimeters) that take less than a minute. A photopatterning technique was used to cast in situ crosslinked polyacrylamide gel in a microchannel to perform SDS-PAGE. A fluorescent protein marker sample (M, range of 20 000-200 000) was separated in less than 30 s in less than 2 mm of channel length. Crosslinked polyacrylamide gel, patterned in channels using UV light, provides higher sieving power and sample stacking effect, therefore yielding faster and higher-resolution separation in a chip. IEF of proteins was also achieved in a microchannel, and several proteins were focussed within tens of seconds in mm-length channels. As resolution in IEF is independent of separation distance, focusing in ultra-short channels results in not only faster separation but also more concentrated bands potentially allowing detection of low-concentration species. (C) 2004 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA USA. RP Han, J (reprint author), MIT, Dept Elect Engn & Comp Sci, Elect Res Lab, Room 36-841,77 Massachusetts Ave, Cambridge, MA 02139 USA. EM jyhan@mit.edu NR 26 TC 46 Z9 46 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD SEP 17 PY 2004 VL 1049 IS 1-2 BP 205 EP 209 DI 10.1016/j.chroma.2004.08.018 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 858BO UT WOS:000224165300024 PM 15499934 ER PT J AU Beacom, JF Bell, NF Dodelson, S AF Beacom, JF Bell, NF Dodelson, S TI Neutrinoless universe SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRITIUM BETA-SPECTRUM; LONG-RANGE FORCES; FLAVOR OSCILLATIONS; DARK-MATTER; MAJORON MODEL; DECAY; MASS; ASYMMETRY; LIGHT; WMAP AB We consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of neutrinos to a light (compared to m(nu)) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Beacom, JF (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. OI Beacom, John/0000-0002-0005-2631 NR 62 TC 71 Z9 71 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 121302 DI 10.1103/PhysRevLett.93.121302 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800018 PM 15447250 ER PT J AU Bei, H Lu, ZP George, EP AF Bei, H Lu, ZP George, EP TI Theoretical strength and the onset of plasticity in bulk metallic glasses investigated by nanoindentation with a spherical indenter SO PHYSICAL REVIEW LETTERS LA English DT Article ID INSTRUMENTED INDENTATION; MECHANICAL-PROPERTIES; DEFORMATION; ALLOYS AB The mechanical behavior of bulk metallic glasses (BMGs) was investigated by nanoindentation with a spherical indenter. The transition from perfectly elastic behavior to plastic deformation was clearly observed as a pop-in event (sudden displacement excursion) on the load-displacement curves. Hertzian stress analysis was used to describe fully the load-displacement behavior during elastic deformation and to determine the theoretical shear strengths of the BMGs. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Bei, H (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RI Lu, Zhao-Ping/A-2718-2009; George, Easo/L-5434-2014; OI Bei, Hongbin/0000-0003-0283-7990 NR 19 TC 118 Z9 122 U1 8 U2 56 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 125504 DI 10.1103/PhysRevLett.93.125504 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800045 PM 15447277 ER PT J AU Brouet, V Yang, WL Zhou, XJ Hussain, Z Ru, N Shin, KY Fisher, IR Shen, ZX AF Brouet, V Yang, WL Zhou, XJ Hussain, Z Ru, N Shin, KY Fisher, IR Shen, ZX TI Fermi surface reconstruction in the CDW state of CeTe3 observed by photoemission SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; ORGANIC CONDUCTOR; OSCILLATIONS; SMTE3; CHAIN AB CeTe3 is a layered compound where an incommensurate charge density wave (CDW) opens a large gap (similar or equal to400 meV) in optimally nested regions of the Fermi surface (FS), whereas other sections with poorer nesting remain ungapped. Through angle-resolved photoemission, we identify bands backfolded according to the CDW periodicity. They define FS pockets formed by the intersection of the original FS and its CDW replica. Such pockets illustrate very directly the role of nesting in the CDW formation but they could not be detected so far in a CDW system. We address the reasons for the weak intensity of the folded bands, by comparing different foldings coexisting in CeTe3. C1 Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Paris 11, Phys Solides Lab, UMR 8502, F-91405 Orsay, France. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Geballe Lab Adv Mat, Stanford, CA 94305 USA. RP Brouet, V (reprint author), Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA. RI Yang, Wanli/D-7183-2011 OI Yang, Wanli/0000-0003-0666-8063 NR 18 TC 74 Z9 74 U1 2 U2 25 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 126405 DI 10.1103/PhysRevLett.93.126405 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800059 PM 15447291 ER PT J AU Chen, YC Afanasev, A Brodsky, SJ Carlson, CE Vanderhaeghen, M AF Chen, YC Afanasev, A Brodsky, SJ Carlson, CE Vanderhaeghen, M TI Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPTON-SCATTERING; FORM-FACTORS; DISTRIBUTIONS; ASYMMETRY AB We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the two-photon exchange amplitude to the generalized parton distributions which appear in hard exclusive processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2-photon correction does reproduce the Rosenbluth cross sections. C1 Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RP Chen, YC (reprint author), Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan. NR 20 TC 169 Z9 170 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 122301 DI 10.1103/PhysRevLett.93.122301 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800022 PM 15447254 ER PT J AU Faleev, SV van Schilfgaarde, M Kotani, T AF Faleev, SV van Schilfgaarde, M Kotani, T TI All-electron self-consistent GW approximation: Application to Si, MnO, and NiO SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY; SPECTRA; OXIDE; GAS AB We present a new kind of self-consistent GW approximation based on the all-electron, full-potential linear muffin-tin orbital method. By iterating the eigenfunctions of the GW Hamiltonian, self-consistency in both the charge density and the quasiparticle spectrum is achieved. We explain why this form of self-consistency should be preferred to the conventional one. Some results for Si (a representative semiconductor) are presented. Finally we consider many details in the electronic structure of the antiferromagnetic insulators MnO and NiO. Excellent agreement with experiment is shown for many properties, suggesting that a Landau quasiparticle (energy band) picture provides a reasonable description of electronic structure even in these correlated materials. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Arizona State Univ, Tempe, AZ 85284 USA. Osaka Univ, Dept Phys, Toyonaka, Osaka 560, Japan. RP Faleev, SV (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. RI kotani, takao/G-4355-2011 OI kotani, takao/0000-0003-1693-7052 NR 21 TC 284 Z9 286 U1 4 U2 37 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 126406 DI 10.1103/PhysRevLett.93.126406 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800060 PM 15447292 ER PT J AU Gonzalez, C Snijders, PC Ortega, J Perez, R Flores, F Rogge, S Weitering, HH AF Gonzalez, C Snijders, PC Ortega, J Perez, R Flores, F Rogge, S Weitering, HH TI Formation of atom wires on vicinal silicon SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; SI(112); GA; ENERGETICS; GROWTH; CHAINS; MODEL; AL AB The feasibility of creating atomic wires on vicinal silicon surfaces via pseudomorphic step-edge decoration has been analyzed for the case of Ga on Si(112). Scanning tunneling microscopy and density functional theory calculations indicate the formation of Ga zigzag chains intersected by quasiperiodic vacancy lines or "misfit dislocations." This structure strikes a balance between the system's drive towards chemical passivation and its need for strain relaxation in the atom chains. Spatially fluctuating disorder, intrinsic to the reconstruction, originates from the two symmetry-degenerate orientations of the zigzag chains on vicinal Si. C1 Univ Autonoma Madrid, Fac Ciencias, Dept Fis Teor Mat Condensada, Madrid 28049, Spain. Delft Univ Technol, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Univ Autonoma Madrid, Fac Ciencias, Dept Fis Teor Mat Condensada, Madrid 28049, Spain. RI Perez, Ruben/F-1849-2010; Gonzalez, Cesar/C-4834-2011; Flores, fernando/K-2362-2014; Ortega Mateo, Jose/I-4358-2014; Rogge, Sven/G-3709-2010 OI Perez, Ruben/0000-0001-5896-541X; Gonzalez, Cesar/0000-0001-5118-3597; Ortega Mateo, Jose/0000-0001-9156-1038; NR 17 TC 25 Z9 25 U1 1 U2 7 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 17 PY 2004 VL 93 IS 12 AR 126106 DI 10.1103/PhysRevLett.93.126106 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800054 PM 15447286 ER PT J AU Hastings, MB AF Hastings, MB TI Decay of correlations in Fermi systems at nonzero temperature SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; MATRIX AB The locality of correlation functions is considered for Fermi systems at nonzero temperature. We show that for all short-range, lattice Hamiltonians, the correlation function of any two fermionic operators decays exponentially with a correlation length which is of order the inverse temperature for small temperature. We discuss applications to numerical simulation of quantum systems at nonzero temperature. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Hastings, MB (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, POB 1663, Los Alamos, NM 87545 USA. EM hastings@lanl.gov NR 11 TC 20 Z9 20 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 17 PY 2004 VL 93 IS 12 AR 126402 DI 10.1103/PhysRevLett.93.126402 PG 3 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800056 PM 15447288 ER PT J AU Koslowski, M LeSar, R Thomson, R AF Koslowski, M LeSar, R Thomson, R TI Avalanches and scaling in plastic deformation SO PHYSICAL REVIEW LETTERS LA English DT Article ID SELF-ORGANIZED CRITICALITY; ACOUSTIC-EMISSION; SINGLE-CRYSTALS; LINES; NOISE AB Plastic deformation of crystalline materials is a complex nonhomogeneous process characterized by avalanches in the motion of dislocations. We study the evolution of dislocation loops using an analytically solvable phase-field model of dislocations for ductile single crystals during monotonic loading. The distribution of dislocation loop sizes is given by P(A)similar toA(-sigma), with sigma=1.8+/-0.1. The exponent is in agreement with those found in acoustic emission experiments. This model also predicts a range of macroscopic behaviors in agreement with observation, including hardening with monotonic loading, and a maximum in the acoustic emission signal at the onset of yielding. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Koslowski, M (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM marisol@lanl.gov RI Koslowski, Marisol/B-3123-2008; LeSar, Richard/G-1609-2012 NR 24 TC 65 Z9 66 U1 0 U2 23 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 125502 DI 10.1103/PhysRevLett.93.125502 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800043 PM 15447275 ER PT J AU Laveissiere, G Todor, L Degrande, N Jaminion, S Jutier, C Di Salvo, R Van Hoorebeke, L Alexa, LC Anderson, BD Aniol, KA Arundell, K Audit, G Auerbach, L Baker, FT Baylac, M Berthot, J Bertin, PY Bertozzi, W Bimbot, L Boeglin, WU Brash, EJ Breton, V Breuer, H Burtin, E Calarco, JR Cardman, LS Cavata, C Chang, CC Chen, JP Chudakov, E Cisbani, E Dale, DS de Jager, CW De Leo, R Deur, A d'Hose, N Dodge, GE Domingo, JJ Elouadrhiri, L Epstein, MB Ewell, LA Finn, JM Fissum, KG Fonvieille, H Fournier, G Frois, B Frullani, S Furget, C Gao, H Gao, J Garibaldi, F Gasparian, A Gilad, S Gilman, R Glamazdin, A Glashausser, C Gomez, J Gorbenko, V Grenier, P Guichon, PAM Hansen, JO Holmes, R Holtrop, M Howell, C Huber, GM Hyde-Wright, CE Incerti, S Iodice, M Jardillier, J Jones, MK Kahl, W Kato, S Katramatou, AT Kelly, JJ Kerhoas, S Ketikyan, A Khayat, M Kino, K Kox, S Kramer, LH Kumar, KS Kumbartzki, G Kuss, M Leone, A LeRose, JJ Liang, M Lindgren, RA Liyanage, N Lolos, GJ Lourie, RW Madey, R Maeda, K Malov, S Manley, DM Marchand, C Marchand, D Margaziotis, DJ Markowitz, P Marroncle, J Martino, J McCormick, K McIntyre, J Mehrabyan, S Merchez, F Meziani, ZE Michaels, R Miller, GW Mougey, JY Nanda, SK Neyret, D Offermann, EAJM Papandreou, Z Pasquini, B Perdrisat, CF Perrino, R Petratos, GG Platchkov, S Pomatsalyuk, R Prout, DL Punjabi, VA Pussieux, T Quemener, G Ransome, RD Ravel, O Real, JS Renard, F Roblin, Y Rowntree, D Rutledge, G Rutt, PM Saha, A Saito, T Sarty, AJ Serdarevic, A Smith, T Smirnov, G Soldi, K Sorokin, P Souder, PA Suleiman, R Templon, JA Terasawa, T Tieulent, R Tomasi-Gustaffson, E Tsubota, H Ueno, H Ulmer, PE Urciuoli, GM Vanderhaeghen, M Van De Vyver, R Van der Meer, RLJ Vernin, P Vlahovic, B Voskanyan, H Voutier, E Watson, JW Weinstein, LB Wijesooriya, K Wilson, R Wojtsekhowski, BB Zainea, DG Zhang, WM Zhao, J Zhou, ZL AF Laveissiere, G Todor, L Degrande, N Jaminion, S Jutier, C Di Salvo, R Van Hoorebeke, L Alexa, LC Anderson, BD Aniol, KA Arundell, K Audit, G Auerbach, L Baker, FT Baylac, M Berthot, J Bertin, PY Bertozzi, W Bimbot, L Boeglin, WU Brash, EJ Breton, V Breuer, H Burtin, E Calarco, JR Cardman, LS Cavata, C Chang, CC Chen, JP Chudakov, E Cisbani, E Dale, DS de Jager, CW De Leo, R Deur, A d'Hose, N Dodge, GE Domingo, JJ Elouadrhiri, L Epstein, MB Ewell, LA Finn, JM Fissum, KG Fonvieille, H Fournier, G Frois, B Frullani, S Furget, C Gao, H Gao, J Garibaldi, F Gasparian, A Gilad, S Gilman, R Glamazdin, A Glashausser, C Gomez, J Gorbenko, V Grenier, P Guichon, PAM Hansen, JO Holmes, R Holtrop, M Howell, C Huber, GM Hyde-Wright, CE Incerti, S Iodice, M Jardillier, J Jones, MK Kahl, W Kato, S Katramatou, AT Kelly, JJ Kerhoas, S Ketikyan, A Khayat, M Kino, K Kox, S Kramer, LH Kumar, KS Kumbartzki, G Kuss, M Leone, A LeRose, JJ Liang, M Lindgren, RA Liyanage, N Lolos, GJ Lourie, RW Madey, R Maeda, K Malov, S Manley, DM Marchand, C Marchand, D Margaziotis, DJ Markowitz, P Marroncle, J Martino, J McCormick, K McIntyre, J Mehrabyan, S Merchez, F Meziani, ZE Michaels, R Miller, GW Mougey, JY Nanda, SK Neyret, D Offermann, EAJM Papandreou, Z Pasquini, B Perdrisat, CF Perrino, R Petratos, GG Platchkov, S Pomatsalyuk, R Prout, DL Punjabi, VA Pussieux, T Quemener, G Ransome, RD Ravel, O Real, JS Renard, F Roblin, Y Rowntree, D Rutledge, G Rutt, PM Saha, A Saito, T Sarty, AJ Serdarevic, A Smith, T Smirnov, G Soldi, K Sorokin, P Souder, PA Suleiman, R Templon, JA Terasawa, T Tieulent, R Tomasi-Gustaffson, E Tsubota, H Ueno, H Ulmer, PE Urciuoli, GM Vanderhaeghen, M Van De Vyver, R Van der Meer, RLJ Vernin, P Vlahovic, B Voskanyan, H Voutier, E Watson, JW Weinstein, LB Wijesooriya, K Wilson, R Wojtsekhowski, BB Zainea, DG Zhang, WM Zhao, J Zhou, ZL CA Jefferson Lab Hall A Collaboration TI Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q(2)=0.92 and 1.76 GeV2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID AMPLITUDE; NUCLEON; MODEL AB We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P-LL-P-TT/epsilon and P-LT, and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q(2)) and beta(M)(Q(2)) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q(2), and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q(2), compensated at higher Q(2) by a paramagnetic contribution from piN intermediate states. C1 Univ Clermont Ferrand, IN2P3, F-63177 Aubiere, France. Old Dominion Univ, Norfolk, VA 23529 USA. State Univ Ghent, B-9000 Ghent, Belgium. Univ Regina, Regina, SK S4S 0A2, Canada. Kent State Univ, Kent, OH 44242 USA. Calif State Univ Los Angeles, Los Angeles, CA 90032 USA. Coll William & Mary, Williamsburg, VA 23187 USA. CEA Saclay, F-91191 Gif Sur Yvette, France. Temple Univ, Philadelphia, PA 19122 USA. Univ Georgia, Athens, GA 30602 USA. MIT, Cambridge, MA 02139 USA. Inst Phys Nucl, F-91406 Orsay, France. Florida Int Univ, Miami, FL 33199 USA. Univ Maryland, College Pk, MD 20742 USA. Univ New Hampshire, Durham, NH 03824 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy. Ist Super Sanita, I-00161 Rome, Italy. Univ Kentucky, Lexington, KY 40506 USA. Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy. Univ Bari, I-70126 Bari, Italy. Lab Phys Subatom Cosmol, F-38026 Grenoble, France. Duke Univ, Durham, NC 27706 USA. Hampton Univ, Hampton, VA 23668 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Kharkov Phys & Technol Inst, UA-61108 Kharkov, Ukraine. Syracuse Univ, Syracuse, NY 13244 USA. Yamagata Univ, Yamagata 990, Japan. Yerevan Phys Inst, Yerevan 375036, Armenia. Tohoku Univ, Sendai, Miyagi 980, Japan. Princeton Univ, Princeton, NJ 08544 USA. Ist Nazl Fis Nucl, Sez Lecce, I-73100 Lecce, Italy. Univ Virginia, Charlottesville, VA 22901 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Ist Nazl Fis Nucl, Sez Pavia, ECT, I-38050 Trent, Italy. Univ Pavia, DFNT, Trent, Italy. Norfolk State Univ, Norfolk, VA 23504 USA. Florida State Univ, Tallahassee, FL 32306 USA. N Carolina Cent Univ, Durham, NC 27707 USA. Univ Mainz, Inst Kernphys, D-55099 Mainz, Germany. Harvard Univ, Cambridge, MA 02138 USA. RP Laveissiere, G (reprint author), Univ Clermont Ferrand, IN2P3, F-63177 Aubiere, France. RI Perrino, Roberto/B-4633-2010; Gao, Haiyan/G-2589-2011; Kuss, Michael/H-8959-2012; Sarty, Adam/G-2948-2014; McIntyre, Justin/P-1346-2014; CAVATA, Christian/P-6496-2015; Cisbani, Evaristo/C-9249-2011; OI Perrino, Roberto/0000-0002-5764-7337; McIntyre, Justin/0000-0002-3706-4310; Cisbani, Evaristo/0000-0002-6774-8473; Incerti, Sebastien/0000-0002-0619-2053 NR 29 TC 24 Z9 24 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 2004 VL 93 IS 12 AR 122001 DI 10.1103/PhysRevLett.93.122001 PG 5 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800020 PM 15447252 ER PT J AU Lee, KC Borukhov, I Gelbart, WM Liu, AJ Stevens, MJ AF Lee, KC Borukhov, I Gelbart, WM Liu, AJ Stevens, MJ TI Effect of mono- and multivalent salts on angle-dependent attractions between charged rods SO PHYSICAL REVIEW LETTERS LA English DT Article ID MONTE-CARLO-SIMULATION; POLYELECTROLYTE SOLUTIONS; SIMPLE-MODEL; DNA; CONDENSATION; BINDING; COUNTERIONS; ACTIN AB Using molecular dynamics simulations we examine the effective interactions between two like-charged rods as a function of angle and separation. In particular, we determine how the competing electrostatic repulsions and multivalent-ion-induced attractions depend upon concentrations of simple and multivalent salts. We find that with increasing multivalent salt, the stable configuration of two rods evolves from isolated rods to aggregated perpendicular rods to aggregated parallel rods; at sufficiently high concentration, additional multivalent salt reduces the attraction. Monovalent salt enhances the attraction near the onset of aggregation and reduces it at a higher concentration of multivalent salt. C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lee, KC (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. NR 25 TC 60 Z9 62 U1 2 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 2004 VL 93 IS 12 AR 128101 DI 10.1103/PhysRevLett.93.128101 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800076 PM 15447308 ER PT J AU Lokshin, KA Zhao, YS He, DW Mao, WL Mao, HK Hemley, RJ Lobanov, MV Greenblatt, M AF Lokshin, KA Zhao, YS He, DW Mao, WL Mao, HK Hemley, RJ Lobanov, MV Greenblatt, M TI Structure and dynamics of hydrogen molecules in the novel clathrate hydrate by high pressure neutron diffraction SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPRESSIBILITY; N-2-CLATHRATE; DISORDER; STORAGE; METHANE; ICE AB The D-2 clathrate hydrate crystal structure was determined as a function of temperature and pressure by neutron diffraction for the first time. The hydrogen occupancy in the (32+X)H-2.136H(2)O, x=0-16 clathrate can be reversibly varied by changing the large (hexakaidecahedral) cage occupancy between two and four molecules, while remaining single occupancy of the small (dodecahedral) cage. Above 130-160 K, the guest D-2 molecules were found in the delocalized state, rotating around the centers of the cages. Decrease of temperature results in rotation freezing followed by a complete localization below 50 K. C1 Los Alamos Natl Lab, LANSCE 12, Los Alamos, NM 87544 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Rutgers State Univ, Dept Chem & Biol Chem, Piscataway, NJ 08854 USA. RP Lokshin, KA (reprint author), Los Alamos Natl Lab, LANSCE 12, POB 1663, Los Alamos, NM 87544 USA. EM lokshin@lanl.gov RI Mao, Wendy/D-1885-2009; Lobanov, Maxim/C-2963-2012; Lujan Center, LANL/G-4896-2012 NR 23 TC 179 Z9 185 U1 4 U2 41 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2004 VL 93 IS 12 AR 125503 DI 10.1103/PhysRevLett.93.125503 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800044 PM 15447276 ER PT J AU Pezze, L Pitaevskii, L Smerzi, A Stringari, S Modugno, G de Mirandes, E Ferlaino, F Ott, H Roati, G Inguscio, M AF Pezze, L Pitaevskii, L Smerzi, A Stringari, S Modugno, G de Mirandes, E Ferlaino, F Ott, H Roati, G Inguscio, M TI Insulating behavior of a trapped ideal Fermi gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION; MOLECULES AB We investigate theoretically and experimentally the center-of-mass motion of an ideal Fermi gas in a combined periodic and harmonic potential. We find a crossover from a conducting to an insulating regime as the Fermi energy moves from the first Bloch band into the band gap of the lattice. The conducting regime is characterized by an oscillation of the cloud about the potential minimum, while in the insulating case the center of mass remains on one side of the potential. C1 Univ Trent, Ist Nazl Fis Mat BEC CRS, I-38050 Povo, Italy. Univ Trent, Dipartimento Fis, I-38050 Povo, Italy. PL Kapitza Phys Problems Inst, Moscow 117334, Russia. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Florence, LENS, I-50019 Sesto Fiorentino, Italy. Univ Florence, Dipartimento Fis, I-50019 Sesto Fiorentino, Italy. INFM, I-50019 Sesto Fiorentino, Italy. RP Pezze, L (reprint author), Univ Trent, Ist Nazl Fis Mat BEC CRS, I-38050 Povo, Italy. RI Modugno, Giovanni/C-3179-2009; roati, giacomo/C-5459-2009; Ferlaino, francesca/E-6726-2012; PEZZE, LUCA/D-5967-2014; Ott, Herwig/F-9449-2015 OI Modugno, Giovanni/0000-0002-4394-8593; PEZZE, LUCA/0000-0003-0325-9555; NR 23 TC 72 Z9 72 U1 0 U2 1 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 17 PY 2004 VL 93 IS 12 AR 120401 DI 10.1103/PhysRevLett.93.120401 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800002 PM 15447234 ER PT J AU Zhu, WG Weitering, HH Wang, EG Kaxiras, E Zhang, ZY AF Zhu, WG Weitering, HH Wang, EG Kaxiras, E Zhang, ZY TI Contrasting growth modes of Mn on Ge(100) and Ge(111) surfaces: Subsurface segregation versus intermixing SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC SEMICONDUCTORS; SI(111); ENERGY; PSEUDOPOTENTIALS; FERROMAGNETISM; (GA,MN)AS; POINTS; BORON; GE AB Based on first-principles total energy calculations within density functional theory, we show that a low dose of Mn on Ge(100) initiates in a novel subsurface growth mode, characterized by easy access to, and strong preference for, interstitial sites located between the two topmost Ge layers. Strikingly, such a "subsurfactant action" is preserved even during epitaxial growth of additional Ge layers, analogous to the well-known phenomenon of surfactant action. In contrast, along the [111] orientation, Mn can easily diffuse into the bulk via interstitial sites. These results are discussed within the context of dopant control in dilute magnetic semiconductors. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Chinese Acad Sci, Int Ctr Quantum Struct, Beijing 100080, Peoples R China. Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Zhu, WG (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Zhu, Wenguang/F-4224-2011 OI Zhu, Wenguang/0000-0003-0819-595X NR 27 TC 52 Z9 52 U1 1 U2 13 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 17 PY 2004 VL 93 IS 12 AR 126102 DI 10.1103/PhysRevLett.93.126102 PG 4 WC Physics, Multidisciplinary SC Physics GA 854SO UT WOS:000223923800050 PM 15447282 ER PT J AU Nellist, PD Chisholm, MF Dellby, N Krivanek, OL Murfitt, MF Szilagyi, ZS Lupini, AR Borisevich, A Sides, WH Pennycook, SJ AF Nellist, PD Chisholm, MF Dellby, N Krivanek, OL Murfitt, MF Szilagyi, ZS Lupini, AR Borisevich, A Sides, WH Pennycook, SJ TI Direct sub-angstrom imaging of a crystal lattice SO SCIENCE LA English DT Article ID TRANSMISSION ELECTRON-MICROSCOPY; RESOLUTION C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Nion Co, Kirkland, WA 98033 USA. RP Pennycook, SJ (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. EM pennycooksj@ornl.gov RI Borisevich, Albina/B-1624-2009 OI Borisevich, Albina/0000-0002-3953-8460 NR 5 TC 299 Z9 304 U1 8 U2 120 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 17 PY 2004 VL 305 IS 5691 BP 1741 EP 1741 DI 10.1126/science.1100965 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 856IS UT WOS:000224039500031 PM 15375260 ER PT J AU Borrok, D Fein, JB Tischler, M O'Loughlin, E Meyer, H Liss, M Kemner, KM AF Borrok, D Fein, JB Tischler, M O'Loughlin, E Meyer, H Liss, M Kemner, KM TI The effect of acidic solutions and growth conditions on the adsorptive properties of bacterial surfaces SO CHEMICAL GEOLOGY LA English DT Article DE metals; sorption; acid; bacteria; anaerobic; surface complexation modeling ID POSITIVE SOIL BACTERIUM; ISOLATED CELL-WALLS; METAL ADSORPTION; BACILLUS-SUBTILIS; HEAVY-METALS; BINDING; SORPTION; THERMODYNAMICS; SYSTEMS; CADMIUM AB Data must be collected over a wide pH range to accurately model the adsorption of protons and metal onto bacterial surfaces; however, alterations in the structural and chemical properties of bacterial surfaces resulting from exposure to acidic solutions may affect the mechanisms of cation binding. Binding properties of bacteria may also be affected by nutrient and oxygen levels present during their growth. We measured Cd, Co, and Pb adsorption onto bacteria by using (1) bacteria washed with acidic solutions (pH approximate to 1.5), (2) non-acid-washed bacteria exposed to acidic parent solutions, and (3) non-acid-washed bacteria exposed to neutral parent solutions. The purpose was to determine the effect of acidic conditions on the adsorptive properties of Pseudomonas mendocina, Pseudomonas aeruginosa, Bacillus subtilis, and Bacillus cereus. We also measured Co adsorption onto bacteria (Pseudomonas fluorescens) gown under nutrient-rich and nutrient-limited conditions and onto the facultative bacterium Shewanella oneidensis MR-1 grown under aerobic and anaerobic conditions. Bacteria exposed to acidic solutions adsorbed more metals than bacteria not exposed to such solutions. We attribute the increase in adsorption to the irreversible displacement of structurally bound Mg and Ca by protons. After displacement, the protonated sites can participate in reversible metal adsorption reactions. Thermodynamic modeling suggests that concentrations of functional group sites on bacterial surfaces increase by as much as five times in response to acid washing, assuming that stability constants for the bacterial surface complexes remain the same. Although the sizes of the bacteria changed markedly in response to nutrient limits and oxygen content during growth, the mass-normalized extent of Co adsorption onto both P. fluorescens and S. oneidensis MR-1 was independent of growth conditions. We conclude that adsorption constants derived from experiments in which the bacteria are never exposed to acidic conditions probably provide the most accurate estimates of the extent of bacteria-metal adsorption in natural settings. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. Benedictine Univ, Dept Biol Sci, Lisle, IL 60532 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Borrok, D (reprint author), Univ Notre Dame, Dept Civil Engn & Geol Sci, 156 Fitzpatrick Hall, Notre Dame, IN 46556 USA. EM dborrok@nd.edu; fein.l@nd.edu; Mtischler@ben.edu; oloughlin@anl.gov; kemner@anl.gov RI O'Loughlin, Edward/C-9565-2013 OI O'Loughlin, Edward/0000-0003-1607-9529 NR 29 TC 69 Z9 70 U1 4 U2 25 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 16 PY 2004 VL 209 IS 1-2 BP 107 EP 119 DI 10.1016/j.chemgeo.2004.04.025 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 848SX UT WOS:000223488500006 ER PT J AU Karimabadi, H Daughton, W Quest, KB AF Karimabadi, H Daughton, W Quest, KB TI Role of electron temperature anisotropy in the onset of magnetic reconnection SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Predictions of tearing saturation in a neutral sheet range from minute amplitude to explosive growth. It is shown that in 2D, single island tearing saturates at very small amplitudes due to preferential electron heating in the parallel direction. However, the presence of multiple unstable modes allows the system to get past the stabilization and grow to ion scales. In 3D there are two current aligned instabilities that can affect the tearing mode. One is the Weibel instability driven by electron anisotropy T-perpendicular toe/T-parallel toe < 1 and the other is the lower hybrid drift instability (LHDI). The Weibel instability is shown to at most increase the single island tearing saturation amplitude up to the singular layer thickness. On the other hand, recent studies suggest that LHDI can affect tearing through the generation of T-&BOTTOM;e/T-&PAR;e > 1 within the current layer. In this limit, the parallel Weibel instability merges with tearing to give rise to anisotropic tearing, which becomes the dominant electron anisotropy driven mode with a broad angular spectrum. The level of electron anisotropy generated by the LHDI can significantly enhance the tearing growth rate and extend the spectrum to very short wavelength which expedites the transition to large scale reconnection. Thus LHDI's main contribution to reconnection onset is not through anomalous resistivity but through its effect on tearing mode. C1 Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Karimabadi, H (reprint author), Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. EM homa@ece.ucsd.edu RI Daughton, William/L-9661-2013 NR 10 TC 43 Z9 43 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 16 PY 2004 VL 31 IS 18 AR L18801 DI 10.1029/2004GL020791 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 857NA UT WOS:000224122900005 ER PT J AU Fleming, GR Scholes, GD AF Fleming, GR Scholes, GD TI Physical chemistry - Quantum mechanics for plants SO NATURE LA English DT Editorial Material ID ENERGY-TRANSFER; DYNAMICS C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Toronto, Dept Chem, Lash Miller Chem Labs, Toronto, ON M5S 3H6, Canada. RP Fleming, GR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. EM grfleming@lbl.gov; gscholes@chem.utoronto.ca NR 11 TC 100 Z9 103 U1 1 U2 30 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 16 PY 2004 VL 431 IS 7006 BP 256 EP 257 DI 10.1038/431256a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 853XJ UT WOS:000223864000025 PM 15372016 ER PT J AU Schmutz, J Martin, J Terry, A Couronne, O Grimwood, J Lowry, S Gordon, LA Scott, D Xie, G Huang, W Hellsten, U Tran-Gyamfi, M She, XW Prabhakar, S Aerts, A Altherr, M Bajorek, E Black, S Branscomb, E Caoile, C Challacombe, JF Chan, YM Denys, M Detter, JC Escobar, J Flowers, D Fotopulos, D Glavina, T Gomez, M Gonzales, E Goodstein, D Grigoriev, I Groza, M Hammon, N Hawkins, T Haydu, L Israni, S Jett, J Kadner, K Kimball, H Kobayashi, A Lopez, F Lou, YN Martinez, D Medina, C Morgan, J Nandkeshwar, R Noonan, JP Pitluck, S Pollard, M Predki, P Priest, J Ramirez, L Retterer, J Rodriguez, A Rogers, S Salamov, A Salazar, A Thayer, N Tice, H Tsai, M Ustaszewska, A Vo, N Wheeler, J Wu, K Yang, J Dickson, M Cheng, JF Eichler, EE Olsen, A Pennacchio, LA Rokhsar, DS Richardson, P Lucas, SM Myers, RM Rubin, EM AF Schmutz, J Martin, J Terry, A Couronne, O Grimwood, J Lowry, S Gordon, LA Scott, D Xie, G Huang, W Hellsten, U Tran-Gyamfi, M She, XW Prabhakar, S Aerts, A Altherr, M Bajorek, E Black, S Branscomb, E Caoile, C Challacombe, JF Chan, YM Denys, M Detter, JC Escobar, J Flowers, D Fotopulos, D Glavina, T Gomez, M Gonzales, E Goodstein, D Grigoriev, I Groza, M Hammon, N Hawkins, T Haydu, L Israni, S Jett, J Kadner, K Kimball, H Kobayashi, A Lopez, F Lou, YN Martinez, D Medina, C Morgan, J Nandkeshwar, R Noonan, JP Pitluck, S Pollard, M Predki, P Priest, J Ramirez, L Retterer, J Rodriguez, A Rogers, S Salamov, A Salazar, A Thayer, N Tice, H Tsai, M Ustaszewska, A Vo, N Wheeler, J Wu, K Yang, J Dickson, M Cheng, JF Eichler, EE Olsen, A Pennacchio, LA Rokhsar, DS Richardson, P Lucas, SM Myers, RM Rubin, EM TI The DNA sequence and comparative analysis of human chromosome 5 SO NATURE LA English DT Article ID HUMAN-GENOME; GENE; REGION; MOUSE; MAP; RECOMBINATION; EVOLUTION; ELEMENTS; CLUSTER; DOMAIN AB Chromosome 5 is one of the largest human chromosomes and contains numerous intrachromosomal duplications, yet it has one of the lowest gene densities. This is partially explained by numerous gene-poor regions that display a remarkable degree of noncoding conservation with non-mammalian vertebrates, suggesting that they are functionally constrained. In total, we compiled 177.7 million base pairs of highly accurate finished sequence containing 923 manually curated protein-coding genes including the protocadherin and interleukin gene families. We also completely sequenced versions of the large chromosome-5-specific internal duplications. These duplications are very recent evolutionary events and probably have a mechanistic role in human physiological variation, as deletions in these regions are the cause of debilitating disorders including spinal muscular atrophy. C1 Stanford Univ, Sch Med, Stanford Human Genome Ctr, Dept Genet, Palo Alto, CA 94304 USA. DOEs Joint Genome Inst, Walnut Creek, CA 94598 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Case Western Reserve Univ, Sch Med, Ctr Computat Genom, Dept Genet, Cleveland, OH 44106 USA. Case Western Reserve Univ, Sch Med, Ctr Human Genet, Cleveland, OH 44106 USA. Univ Hosp Cleveland, Cleveland, OH 44106 USA. Stanford Univ, Sch Med, Dept Genet, Stanford, CA 94305 USA. RP Schmutz, J (reprint author), Stanford Univ, Sch Med, Stanford Human Genome Ctr, Dept Genet, 975 Calif Ave, Palo Alto, CA 94304 USA. EM jeremy@shgc.stanford.edu; EMRubin@lbl.gov RI Couronne, Olivier Couronne/G-1244-2012; OI Terry, Astrid/0000-0002-5234-1224 NR 44 TC 52 Z9 505 U1 1 U2 9 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 16 PY 2004 VL 431 IS 7006 BP 268 EP 274 DI 10.1038/nature02919 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 853XJ UT WOS:000223864000030 PM 15372022 ER PT J AU Gandon, V Leca, D Aechtner, T Vollhardt, KPC Malacria, M Aubert, C AF Gandon, V Leca, D Aechtner, T Vollhardt, KPC Malacria, M Aubert, C TI Synthesis of fused arylboronic esters via cobalt(0)-mediated cycloaddition of alkynylboronates with alpha,omega-diynes SO ORGANIC LETTERS LA English DT Article ID CROSS-COUPLING REACTIONS; ORGANOBORON COMPOUNDS; COBALT; ACIDS; CYCLOTRIMERIZATION; CYCLIZATIONS; DERIVATIVES; ALKYNES; CYCLOISOMERIZATION; CONSTRUCTION AB Co-2(CO)(6)-complexed alkynyl pinacolborane derivatives are readily transformed with functional group tolerance into fused arylboronates via the [2 + 2 + 2]cycloaddition to alpha,omega-diynes. C1 Univ Paris 06, Chim Organ Lab, CNRS, F-75252 Paris 05, France. 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 Gandon, V (reprint author), Univ Paris 06, Chim Organ Lab, CNRS, 4 Pl Jussieu,Tour 44-54,2eme Etage,Case 229, F-75252 Paris 05, France. EM aubert@ccr.jussieu.fr RI Gandon, Vincent/C-1942-2014 OI Gandon, Vincent/0000-0003-1108-9410 NR 38 TC 69 Z9 71 U1 0 U2 7 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 16 PY 2004 VL 6 IS 19 BP 3405 EP 3407 DI 10.1021/ol0485823 PG 3 WC Chemistry, Organic SC Chemistry GA 852ZD UT WOS:000223794600048 PM 15355063 ER PT J AU Karliner, M Lipkin, HJ AF Karliner, M Lipkin, HJ TI Why the Theta(+) is seen in some experiments and not in others - a possible explanation SO PHYSICS LETTERS B LA English DT Article ID BARYON; STRANGENESS; COLLISIONS; SEARCH; MASS AB The contradiction between evidence for and against the existence of the Theta(+) pentaquark might be resolved if it only appears as a result of a particular production mechanism which is present in some experiments and absent in others. We examine the implications of Theta(+) production via decay of a cryptoexotic N* resonance with a mass of about 2.4 GeV corresponding to a peak in the experimental data for the invariant mass of the (Theta(+), K-) system. Further experimental checks are suggested. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Cambridge, Cavendish Lab, Cambridge, England. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, Tel Aviv, Israel. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Argonne Natl Lab, High Energy Phys Div, Argonne, IL 60439 USA. RP Karliner, M (reprint author), Univ Cambridge, Cavendish Lab, Cambridge, England. EM marek@proton.tau.ac.il; ftlipkin@clever.weizmann.ac.il NR 65 TC 33 Z9 35 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 16 PY 2004 VL 597 IS 3-4 BP 309 EP 313 DI 10.1016/j.physletb.2004.07.027 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 851FJ UT WOS:000223670700010 ER PT J AU Dong, X Esumi, S Sorensen, P Xu, N Xu, Z AF Dong, X Esumi, S Sorensen, P Xu, N Xu, Z TI Resonance decay effects on anisotropy parameters SO PHYSICS LETTERS B LA English DT Article DE elliptic flow; resonance decays; coalescence ID FLOW AB We present the elliptic flow nu(2) of pions produced from resonance decays. The transverse momentum PT spectra of the parent particles are taken from thermal model fits and their nu(2) are fit under the assumption that they follow a number-of-constituent-quark (NCQ) scaling law expected from quark-coalescence models. The nu(2) of pions from resonance particle decays is found to be similar to the measured pion nu(2). We also propose the measurement of electron nu(2) as a means to extract open-charm nu(2) and investigate whether a thermalized system of quasi-free quarks and gluons (a quark-gluon plasma) is created in collisions of An nuclei at RHIC. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Sci & Technol China, Dept Modern Phys, Anhua 230026, Peoples R China. Lawrence Berkeley Lab, Nucl Sci Div, Berkeley, CA 94720 USA. Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, Phys Div, Upton, NY 11973 USA. RP Dong, X (reprint author), Univ Sci & Technol China, Dept Modern Phys, Anhua 230026, Peoples R China. EM xdong@lbl.gov RI Dong, Xin/G-1799-2014; OI Dong, Xin/0000-0001-9083-5906; Sorensen, Paul/0000-0001-5056-9391 NR 23 TC 90 Z9 91 U1 0 U2 2 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 16 PY 2004 VL 597 IS 3-4 BP 328 EP 332 DI 10.1016/j.physletb.2004.06.110 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 851FJ UT WOS:000223670700013 ER PT J AU Zhou, XC Zhou, JZ AF Zhou, XC Zhou, JZ TI Improving the signal sensitivity and photostability of DNA hybridizations on microarrays by using dye-doped core-shell silica nanoparticles SO ANALYTICAL CHEMISTRY LA English DT Article ID OLIGONUCLEOTIDE ARRAYS; FLUORESCENT NANOCRYSTALS; CDNA MICROARRAYS; QUANTUM DOTS; PROBES; SCATTERING; OPTIMIZATION; BIOMOLECULES; CONJUGATION; RECOGNITION AB The development of new highly sensitive and selective methods for microarray-based analysis is a great challenge because, for many bioassays, the amount of genetic material available for analysis is extremely limited. Currently, imaging and detection of DNA microarrays are based primarily on the use of organic dyes. To overcome the problems of photobleaching and low signal intensities of organic dyes, we developed a new class of silica core-shell nanoparticles that encapsulated with cyanine dyes and applied the dye-doped nanoparticles as labeling in the DNA microarray-based bioanalysis. The developed nanoparticles have core-shell structure containing 15-nm Au colloidal cores with 95 dye-alkanethiol (dT)(20) oligomers chemisorbed on the each Au particle surface and 10-15-nm silica coatings bearing thiol functional groups. To be utilized for microarray detection, the dye-doped nanoparticles were conjugated with DNA signaling probes by using heterobifunctional cross-linker. The prepared nanoparticle conjugates are stable in both aqueous electrolytes and organic solvents. Two-color DNA microarray-based detection was demonstrated in this work by using Cy3- and Cy5-doped nanoparticles in sandwich hybridization. The use of the fluorophore-doped nanoparticles in high-throughput microarray detection reveals higher sensitivity with a detection limit of 1 pM for target DNA in sandwich hybridization and greater photostable signals than the direct use of organic fluorophore as labeling. A wide dynamic range of similar to4 orders of magnitude was also found when the dye-doped nanoparticles were applied in microarray-based DNA bioanalysis. In addition, the use of these dye-doped nanoparticles as the labeling in hybridization also improved the differentiation of single-nucleotide polymorphisms. This work offers promising prospects for applying dye-doped nanoparticles as labeling for gene profiling based on DNA microarray technology. C1 Oak Ridge Natl Lab, Div Environm Sci, Microbial Genom & Ecol Grp, Oak Ridge, TN 37831 USA. RP Zhou, JZ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Microbial Genom & Ecol Grp, POB 2008, Oak Ridge, TN 37831 USA. EM zhouj@ornl.gov NR 51 TC 146 Z9 149 U1 4 U2 60 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 2004 VL 76 IS 18 BP 5302 EP 5312 DI 10.1021/ac049472c PG 11 WC Chemistry, Analytical SC Chemistry GA 854UL UT WOS:000223928800008 PM 15362886 ER PT J AU Liu, T Qian, WJ Strittmatter, EF Camp, DG Anderson, GA Thrall, BD Smith, RD AF Liu, T Qian, WJ Strittmatter, EF Camp, DG Anderson, GA Thrall, BD Smith, RD TI High-throughput comparative proteome analysis using a quantitative cysteinyl-peptide enrichment technology SO ANALYTICAL CHEMISTRY LA English DT Article ID CATALYZED O-16-TO-O-18 EXCHANGE; MAMMARY EPITHELIAL-CELLS; CODED AFFINITY TAGS; MASS-SPECTROMETRY; LIQUID-CHROMATOGRAPHY; ACCURATE MASS; IDENTIFICATION TECHNOLOGY; AMINO-ACIDS; PROTEINS; STRATEGY AB A new quantitative cysteinyl-peptide enrichment technology (QCET) was developed to achieve higher efficiency, greater dynamic range, and higher throughput in quantitative proteomics that use stable-isotope labeling techniques combined with high-resolution liquid chromatography (LC)-mass spectrometry (MS). This approach involves 180 labeling of tryptic peptides, high-efficiency enrichment of cysteine-containing peptides, and confident protein identification and quantification using the accurate mass and time tag strategy. Proteome profiling of naive and in vitro-differentiated human mammary epithelial cells using QCET resulted in the identification and quantification of 603 proteins in a single LC-Fourier transform ion cyclotron resonance MS analysis. Advantages of this technology include the following: (1) a simple, highly efficient method for enriching cysteinyl-peptides; (2) a high-throughput strategy suitable for extensive proteome analysis; and (3) improved labeling efficiency for better quantitative measurements. This technology enhances both the functional analysis of biological systems and the detection of potential clinical biomarkers. C1 Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Div Biol Sci, POB 999, Richland, WA 99352 USA. RI Qian, Weijun/C-6167-2011; Smith, Richard/J-3664-2012; Liu, Tao/A-9020-2013 OI Smith, Richard/0000-0002-2381-2349; Liu, Tao/0000-0001-9529-6550 FU NCRR NIH HHS [RR018522] NR 33 TC 110 Z9 118 U1 0 U2 15 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 2004 VL 76 IS 18 BP 5345 EP 5353 DI 10.1021/ac049485q PG 9 WC Chemistry, Analytical SC Chemistry GA 854UL UT WOS:000223928800013 PM 15362891 ER PT J AU Zhu, ZM Kelley, MJ AF Zhu, ZM Kelley, MJ TI Poly(ethylene terephthalate) surface modification by deep UV (172 nm) irradiation SO APPLIED SURFACE SCIENCE LA English DT Article DE surface modification; surface characterization; excimer lamp; polymer photochemistry ID ION MASS-SPECTROMETRY; TOF-SIMS; LASER; REACTIVITY; RADIATION; INTENSITY; POLYMERS; FILMS AB The prospects of obtaining desired surface-mediated characteristics while retaining bulk-mediated physical properties and avoiding potential environmental issues with wet chemical technology lends considerable appeal to photochemical approaches. We investigated the response of poly(ethylene terephthalate) to 172 nm UV from a xenon excimer lamp in the absence of oxygen, using XPS, ToF/SIMS, and AFM. The main effects are increasing loss of a C=O moiety and carboxylic acid production without effect on topography upto a total fluence of 16 J/cm(2). Above this level no further change in surface chemistry was evident, but surfaces became rougher, suggesting the onset of etching. (C) 2004 Elsevier B.V. All rights reserved. C1 Coll William & Mary, Dept Appl Sci, Appl Res Ctr, Newport News, VA 23606 USA. Jefferson Lab, Free Electron Laser Dept, Newport News, VA 23606 USA. RP Kelley, MJ (reprint author), Coll William & Mary, Dept Appl Sci, Appl Res Ctr, 12050 Jefferson Ave,Suite 601, Newport News, VA 23606 USA. EM mkelley@jlab.org NR 13 TC 19 Z9 19 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD SEP 15 PY 2004 VL 236 IS 1-4 BP 416 EP 425 DI 10.1016/j.apsusc.2004.05.012 PG 10 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 856HE UT WOS:000224035500049 ER PT J AU Boore, JL AF Boore, JL TI Complete mitochondrial genome sequence of Urechis caupo, a representative of the phylum Echiura SO BMC GENOMICS LA English DT Article ID DNA; ORGANIZATION; PLATYNEREIS; ANNELIDA AB Background: Mitochondria contain small genomes that are physically separate from those of nuclei. Their comparison serves as a model system for understanding the processes of genome evolution. Although hundreds of these genome sequences have been reported, the taxonomic sampling is highly biased toward vertebrates and arthropods, with many whole phyla remaining unstudied. This is the first description of a complete mitochondrial genome sequence of a representative of the phylum Echiura, that of the fat innkeeper worm, Urechis caupo. Results: This mtDNA is 15,113 nts in length and 62% A+ T. It contains the 37 genes that are typical for animal mtDNAs in an arrangement somewhat similar to that of annelid worms. All genes are encoded by the same DNA strand which is rich in A and C relative to the opposite strand. Codons ending with the dinucleotide GG are more frequent than would be expected from apparent mutational biases. The largest non-coding region is only 282 nts long, is 71% A+ T, and has potential for secondary structures. Conclusions: Urechis caupo mtDNA shares many features with those of the few studied annelids, including the common usage of ATG start codons, unusual among animal mtDNAs, as well as gene arrangements, tRNA structures, and codon usage biases. C1 DOE Joint Genome Inst, Evolutionary Genom Dept, Walnut Creek, CA 94598 USA. Lawrence Berkeley Lab, Walnut Creek, CA USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. RP Boore, JL (reprint author), DOE Joint Genome Inst, Evolutionary Genom Dept, 2800 Mitchell Dr, Walnut Creek, CA 94598 USA. EM jlboore@lbl.gov NR 13 TC 32 Z9 38 U1 1 U2 2 PU BIOMED CENTRAL LTD PI LONDON PA MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T 4LB, ENGLAND SN 1471-2164 J9 BMC GENOMICS JI BMC Genomics PD SEP 15 PY 2004 VL 5 AR 67 DI 10.1186/1471-2164-5-67 PG 8 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 859NU UT WOS:000224276000002 PM 15369601 ER PT J AU Mertens, AC Mitby, PA Radloff, G Jones, IM Perentesis, J Kiffmeyer, WR Neglia, JP Meadows, A Potter, JD Friedman, D Yasui, Y Robison, LL Davies, SM AF Mertens, AC Mitby, PA Radloff, G Jones, IM Perentesis, J Kiffmeyer, WR Neglia, JP Meadows, A Potter, JD Friedman, D Yasui, Y Robison, LL Davies, SM TI XRCC1 and glutathione-S-transferase gene polymorphisms and susceptibility to radiotherapy-related malignancies in survivors of Hodgkin disease - A report from the childhood cancer survivor study SO CANCER LA English DT Article DE survivor; Hodgkin disease; polymorphism; radiotherapy; subsequent malignancy ID DNA-REPAIR GENES; ACID SUBSTITUTION VARIANTS; BREAST-CANCER; 2ND CANCERS; IONIZING-RADIATION; YOUNG-WOMEN; RISK; NEOPLASMS; ADOLESCENCE; FREQUENCY AB BACKGROUND. One of the most serious late effects of treatment for childhood cancer is the occurrence of subsequent malignancy. Survivors of Hodgkin disease (HD), in particular, have been shown to be at high risk of subsequent malignancy, the occurrence of which has been associated strongly with exposure to radiotherapy. METHODS. In the current study, the authors investigated the association between polymorphisms in 3 genes-glutathione-S-transferase M1 (GSTM1), glutathione-S-transferase T1 (GSTT1), and XRCC1, with roles in protection from a variety of DNA-damaging agents-and the risk of subsequent malignancy in 650 survivors of HD enrolled in the Childhood Cancer Survivor Study who had received radiotherapy. RESULTS. individuals lacking GSTM1 but not GSTT1 were at increased risk of any subsequent malignancy (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.0-2.3), and for subsequent cancer within the radiation field (OR, 1.4; 95% CI, 0.9-2.1). A nonsignificant increased risk of thyroid carcinoma was observed in individuals lacking either GSTM1 (OR, 2.9; 95% CI, 0.8-10.9) or GSTT1 (OR, 3.7; 95% CI, 0.6-23.5). Individuals having the genotype of the arginine/glutamine polymorphism at codon 399 in the XRCC1 gene (11399) showed a nonsignificant increased risk of breast carcinoma compared with those without (OR, 1.4; 95% CI, 0.7-2.7), and a nonsignificant decreased risk against a subsequent thyroid carcinoma (OR, 0.6; 95% CI, 0.2-1.6). No differences in genotype frequencies were observed between survivors with basal cell carcinoma when compared with survivors without a subsequent cancer. CONCLUSIONS. These data illustrated the potential value of incorporating the collection of genomic DNA in longitudinal cohort studies of populations with well defined, potentially carcinogenic exposures. Evaluation of additional genetic polymorphisms in this cohort may help define genes that influence individual sensitivity to radiotherapy. (C) 2004 American Cancer Society. C1 Univ Minnesota, Div Pediat Epidemiol & Clin Res, Dept Pediat, Minneapolis, MN USA. Univ Minnesota, Dept Pediat, Div Hematol & Oncol, Minneapolis, MN USA. Univ Minnesota, Ctr Canc, Minneapolis, MN USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. Cincinnati Childrens Hosp, Div Pediat Hematol Oncol, Med Ctr, Cincinnati, OH USA. Childrens Hosp Philadelphia, Div Pediat Hematol Oncol, Philadelphia, PA USA. Fred Hutchinson Canc Res Ctr, Div Publ Hlth Sci, Seattle, WA 98104 USA. Childrens Hosp & Reg Med Ctr, Div Pediat Hematol & Oncol, Seattle, WA USA. RP Mertens, AC (reprint author), Univ Minnesota, Div Pediat Epidemiol & Clin Res, Dept Pediat, Minneapolis, MN USA. EM mertens@epi.umn.edu RI Yasui, Yutaka/E-2564-2015; OI Yasui, Yutaka/0000-0002-7717-8638; Potter, John/0000-0001-5439-1500 FU NCI NIH HHS [CA 55727] NR 43 TC 36 Z9 36 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0008-543X J9 CANCER JI Cancer PD SEP 15 PY 2004 VL 101 IS 6 BP 1463 EP 1472 DI 10.1002/cncr.20520 PG 10 WC Oncology SC Oncology GA 851VV UT WOS:000223715100024 PM 15368334 ER PT J AU Zuccaro, G Lapenta, G Maizza, G AF Zuccaro, G Lapenta, G Maizza, G TI Particle in cell simulation of combustion synthesis of TiC nanoparticles SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE self propagating high temperature synthesis (SHS); mesoscopic modeling; particle-in-cell method (PIC); molecular dynamics (MD) ID SYSTEMS AB A coupled continuum-discrete numerical model is presented to study the synthesis of TiC nanosized aggregates during a self-propagating combustion synthesis (SHS) process. The overall model describes the transient of the basic mechanisms governing the SHS process in a two-dimensional micrometer size system. At each time step, the continuum (micrometer scale) model computes the current temperature field according to the prescribed boundary conditions. The continuum system is discretized with a desired number of uniform computational cells. Each cell contains a convenient number of computational particles which represent the actual particles mixture. The particle-in-cell (discrete) model maps the temperature field from the (continuum) cells to the particles. Depending on the temperature reached by the cell, the titanium particles may undergo a solid-liquid transformation. If the distance between the carbon particle and the liquid titanium particles is within a certain tolerance they react and a TiC particle is formed in the cell. Accordingly, the molecular dynamic method updates the location of all particles in the cell and the amount of transformation heat accounted by the cell is entered into the source term of the (continuum) heat conduction equation. The new temperature distribution progresses depending on the cells which undergo the chemical reaction. As a demonstration of the effectiveness of the overall model some examples are shown. (C) 2004 Elsevier B.V. All rights reserved. C1 INFM, Sez Torino, Turin, Italy. Politecn Torino, Dipartimento Sci Mat & Ingn Chim, Turin, Italy. Los Alamos Natl Lab, Div Theoret, Plasma Theory Grp, Los Alamos, NM 87545 USA. RP Lapenta, G (reprint author), INFM, Sez Torino, Turin, Italy. EM gianluca.zuccaro@epfl.ch; lapenta@lanl.gov; giovanni.maizza@polito.it OI Lapenta, Giovanni/0000-0002-3123-4024 NR 21 TC 2 Z9 3 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP 15 PY 2004 VL 162 IS 2 BP 89 EP 101 DI 10.1016/j.cpc.2004.05.004 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 852KL UT WOS:000223754100002 ER PT J AU Zawisza, I Burgess, I Szymanski, G Lipkowski, J Majewski, J Satija, S AF Zawisza, I Burgess, I Szymanski, G Lipkowski, J Majewski, J Satija, S TI Electrochemical, neutron reflectivity and in situ PM-FT-IRRAS studies of a monolayer of n-octadecanol at a Au(111) electrode surface SO ELECTROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 54th Annual ISE Meeting CY SEP 01-05, 2003 CL Sao Pedro, BRAZIL DE Langmuir-Blodgett method; chronocoulomerty; photon polarization modulation Fourier transform infrared reflection absorption spectroscopy; Neutron reflectometry ID X-RAY-DIFFRACTION; AIR-WATER-INTERFACE; ANGLE AUTOCORRELATION SPECTROSCOPY; LANGMUIR-BLODGETT MONOLAYERS; TIME SAMPLING ELECTRONICS; NORMAL-ALKYL CHAINS; H STRETCHING MODES; AIR/WATER INTERFACE; PHASE-DIAGRAM; TILT ANGLES AB The horizontal touch and Langmuir-Blodgett techniques have been used to transfer a monolayer of n-octadecanol from the gas-solution interface of a Langmuir trough onto the metal-solution interface of a Au(111) electrode. Chronocoulometry has been used to determine the charge density at the electrode surface covered by the film of n-octadecanol. The surface pressure of this film was calculated from the charge density data and was found to be controlled by the electrode potential. We have demonstrated that by dialing the potential applied to the electrode via a potentiostat the monolayer adsorbed on the surface can be compressed or decompressed. Two states of the monolayer were observed. The transition between these states took place at a film pressure similar to12 mN m(-1). Neutron reflectometry and polarization modulation Fourier transform infrared reflection absorption spectroscopy have been employed to determine the nature of the two states. The results show that octadecanol molecules form a two-dimensional solid film at all film pressures. At film pressures larger than 12 mN m(-1), the film has low compressibility and n-octadecanol molecules assume a small tilt angle with respect to the surface normal. At film pressures lower than 12 mN m(-1) a compressive film is formed in which the tilt angle progressively increases with decreasing surface pressure. We have demonstrated that the properties of a monolayer of n-octadecanol at the metal-solution interface display many similarities to the properties of that film at the air-solution interface. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. Los Alamos Natl Lab, MLNSCE, LANSCE 12, Los Alamos, NM 87545 USA. NIST, Ctr Neutron Res, Gaithersburg, MD USA. RP Lipkowski, J (reprint author), Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. EM lipkowski@chembio.uoguelph.ca RI Lujan Center, LANL/G-4896-2012 NR 53 TC 12 Z9 12 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD SEP 15 PY 2004 VL 49 IS 22-23 BP 3651 EP 3664 DI 10.1016/j.electacta.2004.02.051 PG 14 WC Electrochemistry SC Electrochemistry GA 839XL UT WOS:000222818100004 ER PT J AU Sasaki, K Wang, JX Balasubramanian, M McBreen, J Uribe, F Adzic, RR AF Sasaki, K Wang, JX Balasubramanian, M McBreen, J Uribe, F Adzic, RR TI Ultra-low platinum content fuel cell anode electrocatalyst with a long-term performance stability SO ELECTROCHIMICA ACTA LA English DT Article; Proceedings Paper CT 54th Annual ISE Meeting CY SEP 01-05, 2003 CL Sao Pedro, BRAZIL DE Pt monolayer; Ru nanoparticles; H-2 oxidation; CO tolerance; fuel cells ID RU(0001) SURFACE; CO; RU; REACTIVITY; ADSORPTION; OXIDATION; CATALYST; ALLOY AB An active anode electrocatalyst, consisting of 1/8 of a monolayer of Pt on a surface of carbon-supported Ru nanoparticles, has been shown to exhibit excellent long-term performance stability in an operating fuel cell. The electrocatalyst has the reduced susceptibility to poisoning by CO, which, in addition to the strong segregation of the Pt atoms on the Ru substrate, determines this characteristic. Kinetic parameters were determined by electrochemical techniques using thin-film rotating disk electrodes. X-ray absorption spectroscopy near edge structure was used to determine the d-band vacancies of a Pt submonolayer on a surface of carbon-supported Ru nanoparticles, and to relate it to the bonding strength of CO. The data point the way to ultimately reduce Pt content in anode electrocatalysts while maintaining their high activity and thereby alleviating the problem of high Pt loading in existing fuel cell technology. (C) 2004 Elsevier Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Adzic, RR (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. EM adzic@bnl.gov RI Wang, Jia/B-6346-2011 NR 20 TC 91 Z9 94 U1 2 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD SEP 15 PY 2004 VL 49 IS 22-23 BP 3873 EP 3877 DI 10.1016/j.electacta.2004.01.086 PG 5 WC Electrochemistry SC Electrochemistry GA 839XL UT WOS:000222818100028 ER PT J AU Moore, JR Glaser, SD Morrison, HF Hoversten, GM AF Moore, JR Glaser, SD Morrison, HF Hoversten, GM TI The streaming potential of liquid carbon dioxide in Berea sandstone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POROUS-MEDIA; PERMEABILITY; ANOMALIES; SYSTEMS AB We report here, for the first time, evolution of the streaming potential coupling coefficient as liquid carbon dioxide infiltrates Berea sandstone. Using 125 Omega-m tap water, the coupling coefficient determined before and after each CO2 flood of five samples averaged approximately -30 mV/0.1 MPa. After liquid CO2 passed through the specimens displacing all mobile pore water, trapped water remained and the coupling coefficient was approximately -3 mV/0.1 MPa. A bound water limit of the coupling coefficient for liquid CO2 flow was found using an air-dried sample to be - 0.02 mV/0.1 MPa. For initially water-saturated samples, bulk resistivity varied during CO2 invasion from 330 Omega-m, to 150 Omega-m during CO2/water mixing, to a final value of 380 Omega-m. Results suggest that trapped and bound water control electrical conduction and the electrokinetic response. Applications include monitoring CO2 injectate in subsurface reservoirs using the self potential method. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Moore, JR (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, 440 Davis Hall, Berkeley, CA 94720 USA. EM moore@decf.berkeley.edu NR 18 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 2004 VL 31 IS 17 AR L17610 DI 10.1029/2004GL020774 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 857MZ UT WOS:000224122800005 ER PT J AU Doney, SC Lindsay, K Caldeira, K Campin, JM Drange, H Dutay, JC Follows, M Gao, Y Gnanadesikan, A Gruber, N Ishida, A Joos, F Madec, G Maier-Reimer, E Marshall, JC Matear, RJ Monfray, P Mouchet, A Najjar, R Orr, JC Plattner, GK Sarmiento, J Schlitzer, R Slater, R Totterdell, IJ Weirig, MF Yamanaka, Y Yool, A AF Doney, SC Lindsay, K Caldeira, K Campin, JM Drange, H Dutay, JC Follows, M Gao, Y Gnanadesikan, A Gruber, N Ishida, A Joos, F Madec, G Maier-Reimer, E Marshall, JC Matear, RJ Monfray, P Mouchet, A Najjar, R Orr, JC Plattner, GK Sarmiento, J Schlitzer, R Slater, R Totterdell, IJ Weirig, MF Yamanaka, Y Yool, A TI Evaluating global ocean carbon models: The importance of realistic physics SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE global carbon models; ocean carbon systems; OCMIP-2 ID GENERAL-CIRCULATION MODEL; PARTICULATE ORGANIC-MATTER; ANTARCTIC BOTTOM WATER; NORTH-ATLANTIC; TRACER TRANSPORTS; ATMOSPHERIC CO2; HEAT-TRANSPORT; WORLD OCEAN; FLUXES; DRIVEN AB A suite of standard ocean hydrographic and circulation metrics are applied to the equilibrium physical solutions from 13 global carbon models participating in phase 2 of the Ocean Carbon-cycle Model Intercomparison Project (OCMIP-2). Model-data comparisons are presented for sea surface temperature and salinity, seasonal mixed layer depth, meridional heat and freshwater transport, 3-D hydrographic fields, and meridional overturning. Considerable variation exists among the OCMIP-2 simulations, with some of the solutions falling noticeably outside available observational constraints. For some cases, model-model and model-data differences can be related to variations in surface forcing, subgrid-scale parameterizations, and model architecture. These errors in the physical metrics point to significant problems in the underlying model representations of ocean transport and dynamics, problems that directly affect the OCMIP predicted ocean tracer and carbon cycle variables (e.g., air-sea CO2 flux, chlorofluorocarbon and anthropogenic CO2 uptake, and export production). A substantial fraction of the large model-model ranges in OCMIP-2 biogeochemical fields (+/-25-40%) represents the propagation of known errors in model physics. Therefore the model-model spread likely overstates the uncertainty in our current understanding of the ocean carbon system, particularly for transport-dominated fields such as the historical uptake of anthropogenic CO2. A full error assessment, however, would need to account for additional sources of uncertainty such as more complex biological-chemical-physical interactions, biases arising from poorly resolved or neglected physical processes, and climate change. C1 Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. Natl Ctr Atmospher Res, Climate & Global Dynam Div, Boulder, CO 80307 USA. Lawrence Livermore Natl Lab, Climate Syst Modeling Grp, Livermore, CA 94550 USA. Univ Liege, Liege, Belgium. Nansen Environm & Remote Sensing Ctr, Bergen, Norway. CEA Saclay, Lab Sci Climat & Environm, F-91191 Gif Sur Yvette, France. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08542 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Inst Global Change Res, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Univ Paris 06, Lab Oceanog Dynam & Climatol, F-75252 Paris, France. Max Planck Inst Meteorol, D-20146 Hamburg, Germany. CSIRO, Div Marine Res, Hobart, Tas 7001, Australia. UPS, IRD, CNRS, CNES,Lab Etud Geophys & Ocanog Spatiales, F-31401 Toulouse, France. Penn State Univ, Dept Meteorol, State Coll, PA 16802 USA. Alfred Wegener Inst Polar & Marine Res, D-27515 Bremerhaven, Germany. Univ Southampton, George Deacon Div, Southampton SO14 3ZH, Hants, England. Univ Southampton, Southampton Oceanog Ctr, Dept Oceanog, Southampton SO14 3ZH, Hants, England. RP Doney, SC (reprint author), Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. EM kenc@llnl.gov; campin@astro.ulg.ac.be; mick@plume.mit.edu; marshall@gulf.mit.edu RI Gnanadesikan, Anand/A-2397-2008; Orr, James/C-5221-2009; madec, gurvan/E-7825-2010; Gruber, Nicolas/B-7013-2009; Caldeira, Ken/E-7914-2011; Follows, Michael/G-9824-2011; Yool, Andrew/B-4799-2012; matear, richard/C-5133-2011; Doney, Scott/F-9247-2010; Mouchet, Anne/K-1911-2014; gao, yongqi/N-9347-2014; Yamanaka, Yasuhiro/H-7393-2012; Plattner, Gian-Kasper/A-5245-2016 OI Gnanadesikan, Anand/0000-0001-5784-1116; madec, gurvan/0000-0002-6447-4198; Gruber, Nicolas/0000-0002-2085-2310; Yool, Andrew/0000-0002-9879-2776; Doney, Scott/0000-0002-3683-2437; Mouchet, Anne/0000-0002-8846-3063; Yamanaka, Yasuhiro/0000-0003-3369-3248; Plattner, Gian-Kasper/0000-0002-3765-0045 NR 75 TC 135 Z9 137 U1 2 U2 26 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP 15 PY 2004 VL 18 IS 3 AR GB3017 DI 10.1029/2003GB002150 PG 22 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 857ND UT WOS:000224123200001 ER PT J AU Nersessian, N Or, SW Carman, GP Choe, W Radousky, HB AF Nersessian, N Or, SW Carman, GP Choe, W Radousky, HB TI Hollow and solid spherical magnetostrictive particulate composites SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PARTICLES; SPHERES; NANOPARTICLES AB Nickel microspheres were produced by the spark erosion technique under both liquid nitrogen and water conditions. Density measurements and Scanning electron microscope analysis revealed that a significant portion of the Ni particles produced under the liquid nitrogen conditions are hollow spheres with a density of 6.67(4)g/cm(3) while the particles produced in water are primarily solid spheres with a density of 8.40(1)g/cm(3), close to the bulk nickel value of 8.90 g/cm(3). Nickel/polymer composites incorporating the hollow and solid nickel microspheres were manufactured with volume fractions of 25% and 36%, respectively. The hollow and solid nickel composites exhibited saturation magnetostrictions of -24 and -28 ppm, respectively. In addition, small quantities of Terfenol-D (Tb0.3Dy0.7Fe2) were spark eroded under liquid argon conditions with similar to10% by volume of the spark eroded particles being solid microspheres. Calculations indicate that aligned composites that incorporate these Terfenol-D microspheres could reach a strain value of 2000 ppm. (C) 2004 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Angeles, Mech & Aerosp Dept, Los Angeles, CA 90095 USA. RP Radousky, HB (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. EM radousky1@llnl.gov RI Or, Siu Wing/A-3608-2010; Choe, Wonyoung/H-8495-2012 OI Choe, Wonyoung/0000-0003-0957-1187 NR 24 TC 11 Z9 14 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2004 VL 96 IS 6 BP 3362 EP 3365 DI 10.1063/1.1775303 PG 4 WC Physics, Applied SC Physics GA 851XO UT WOS:000223720000049 ER PT J AU Heo, YW Abernathy, C Pruessner, K Sigmund, W Norton, DP Overberg, M Ren, F Chisholm, MF AF Heo, YW Abernathy, C Pruessner, K Sigmund, W Norton, DP Overberg, M Ren, F Chisholm, MF TI Structure and optical properties of cored wurtzite (Zn,Mg)O heteroepitaxial nanowires SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; ZINC-OXIDE NANOWIRES; VAPOR TRANSPORT; CATALYTIC GROWTH; TEMPERATURE; DEPOSITION; NANOBELTS; NANORODS; DEVICES AB The synthesis, structure, and optical properties of one-dimensional heteroepitaxial cored (Zn,Mg)O semiconductor nanowires grown by a catalyst-driven molecular beam epitaxy technique are discussed. The structures form spontaneously in a Zn, Mg and O-2/O-3 flux, consisting of a single crystal, Zn-rich Zn1-xMgxO(x<0.02) core encased by an epitaxial Zn1-yMgyO(y>0.02) sheath. High resolution Z-contrast scanning transmission electron microscopy shows core diameters as small as 4 nm. The cored structure forms spontaneously under constant flux due to a bimodal growth mechanism in which the core forms via bulk like vapor-liquid-solid growth, while the outer sheath grows as a heteroepitaxial layer. Temperature-dependent photoluminescence shows a slight blueshift in the near band edge peak, which is attributed to a few percent Mg doping in the nanoscale ZnO core. The catalyst-driven molecular beam epitaxy technique provides for site-specific nanorod growth on arbitrary substrates. (C) 2004 American Institute of Physics. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32606 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32606 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Norton, DP (reprint author), Univ Florida, Dept Mat Sci & Engn, POB 116400,Rhines Hall, Gainesville, FL 32606 USA. EM dnort@mse.ufl.edu RI Sigmund, Wolfgang/B-2856-2008; Pruessner, Karin/A-4949-2009 NR 31 TC 21 Z9 21 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2004 VL 96 IS 6 BP 3424 EP 3428 DI 10.1063/1.1774257 PG 5 WC Physics, Applied SC Physics GA 851XO UT WOS:000223720000060 ER PT J AU Hsueh, CH Wereszczak, AA AF Hsueh, CH Wereszczak, AA TI Multiple cracking of brittle coatings on strained substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID IN-SITU OBSERVATION; RESIDUAL-STRESSES; THIN-FILM; FRACTURE; SYSTEMS; BEHAVIOR; ADHESION; LAYERS AB Multiple cracking of well-adhered brittle coatings on strained substrates has been commonly observed in many coating applications. Here we found two significant uses for this cracking phenomenon. First, if crack density as a function of applied strain is measured at one coating thickness, it can be used to predict those for other coating thicknesses. Second, if the residual stress in the coating is unknown, the crack density versus applied strain relation can be used to deduce this residual stress. The key to our method is to obtain a master curve by normalizing the crack density and the applied strain, respectively, by the coating thickness and the critical applied strain in initiating cracking. (C) 2004 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hsueh, CH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM hsuehc@ornl.gov RI Hsueh, Chun-Hway/G-1345-2011; Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 21 TC 20 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2004 VL 96 IS 6 BP 3501 EP 3506 DI 10.1063/1.1783613 PG 6 WC Physics, Applied SC Physics GA 851XO UT WOS:000223720000076 ER PT J AU Rajamani, A Sheldon, BW Nijhawan, S Schwartzman, A Rankin, J Walden, BL Riester, L AF Rajamani, A Sheldon, BW Nijhawan, S Schwartzman, A Rankin, J Walden, BL Riester, L TI Chemistry-induced intrinsic stress variations during the chemical vapor deposition of polycrystalline diamond SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; CVD DIAMOND; GRAIN-BOUNDARIES; GROWTH; SURFACE; COALESCENCE; RELAXATION; MORPHOLOGY; COPPER; SILVER AB Intrinsic tensile stresses in polycrystalline films are often attributed to the coalescence of neighboring grains during the early stages of film growth, where the energy decrease associated with converting two free surfaces into a grain boundary provides the driving force for creating tensile stress. Several recent models have analyzed this energy trade off to establish relationships between the stress and the surface/interfacial energy driving force, the elastic properties of the film, and the grain size. To investigate these predictions, experiments were conducted with diamond films produced by chemical vapor deposition. A multistep processing procedure was used to produce films with significant variations in the tensile stress, but with essentially identical grain sizes. The experimental results demonstrate that modest changes in the deposition chemistry can lead to significant changes in the resultant tensile stresses. Two general approaches were considered to reconcile this data with existing models of stress evolution. Geometric effects associated with the shape of the growing crystal were evaluated with a finite element model of stress evolution, and variations in the surface/interfacial energy driving force were assessed in terms of both chemical changes in the deposition atmosphere and differences in the crystal growth morphology. These attempts to explain the experimental results were only partially successful, which suggests that other factors probably affect intrinsic tensile stress evolution due to grain boundary formation. (C) 2004 American Institute of Physics. C1 Brown Univ, Div Engn, Providence, RI 02912 USA. Trinity Coll, Dept Phys, Hartford, CT 06106 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Rajamani, A (reprint author), Brown Univ, Div Engn, Providence, RI 02912 USA. NR 38 TC 10 Z9 10 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2004 VL 96 IS 6 BP 3531 EP 3539 DI 10.1063/1.1777811 PG 9 WC Physics, Applied SC Physics GA 851XO UT WOS:000223720000081 ER PT J AU Guo, Y Kawano, A Thompson, DL Wagner, AF Minkoff, M AF Guo, Y Kawano, A Thompson, DL Wagner, AF Minkoff, M TI Interpolating moving least-squares methods for fitting potential energy surfaces: Applications to classical dynamics calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NO DERIVATIVES; STATE; SYSTEM AB As a continuation of our efforts to develop efficient and accurate interpolating moving least-squares (IMLS) methods for generating potential energy surfaces, we carry out classical trajectories and compute kinetics properties on higher degree IMLS surfaces. In this study, we have investigated the choice of coordinate system, the range of points (i.e., the cutoff radius) used in fitting, and strategies for selections of data points and basis elements. We illustrate and test the method by applying it to hydrogen peroxide (HOOH). In particular, reaction rates for the O-O bond breaking in HOOH are calculated on fitted surfaces using the classical trajectory approach to test the accuracy of the IMLS method for providing potentials for dynamics calculations. (C) 2004 American Institute of Physics. C1 Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Guo, Y (reprint author), Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. NR 20 TC 50 Z9 55 U1 1 U2 10 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 15 PY 2004 VL 121 IS 11 BP 5091 EP 5097 DI 10.1063/1.1777572 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600010 PM 15352800 ER PT J AU Kalos, MH de Saavedra, FA AF Kalos, MH de Saavedra, FA TI Calculating expectations with time-dependent perturbations in quantum Monte Carlo SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ALGORITHMS; ESTIMATORS; ENERGIES; STATES; ATOMS AB We show that a small perturbation periodic in imaginary time can be used to compute expectation values of nondifferential operators that do not commute with the Hamiltonian within the framework of quantum diffusion Monte Carlo. Some results for the harmonic oscillator and the helium atom are presented showing the validity of the proposed method. (C) 2004 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Granada, Fac Ciencias, Dept Fis Moderna, E-18071 Granada, Spain. RP Kalos, MH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Arias de Saavedra, Fernando/H-1634-2015 OI Arias de Saavedra, Fernando/0000-0001-9895-8740 NR 24 TC 2 Z9 2 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 2004 VL 121 IS 11 BP 5143 EP 5147 DI 10.1063/1.1783151 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600016 PM 15352806 ER PT J AU Knickelbein, MB AF Knickelbein, MB TI Spin relaxation in isolated molecules and clusters: The interpretation of Stern-Gerlach experiments SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MAGNETIC-MOMENTS; DEFLECTION SPECTRUM AB Intramolecular spin relaxation may occur in isolated molecules or clusters provided that the density of rovibrational eigenstates is sufficiently high to serve as an energy bath and angular momentum is conserved. In the coupled, zero-field limit, total angular momentum (J) is the sum of spin (S) and rotational (N) momenta such that J and M-J are good angular momentum quantum numbers. In the coupled limit, transitions between Zeeman levels (DeltaM(J)not equal0) cannot occur in the absence of an external torque. However, in the high-field limit, J and M-J are no longer good quantum numbers, as N and S are decoupled and only their projections on the z axis defined by the external field are invariant. In this case M-N and M-S remain as good quantum numbers so that angular momentum conserving transitions can occur subject to the selection rule DeltaM(N)=-DeltaM(S). Determination of the magnetic moments of isolated molecules and clusters via a thermodynamics-based analysis requires that their magnetizations are measured at sufficiently large fields that spin-rotation effects become negligible and the Zeeman level structure approaches the free-spin case. (C) 2004 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Knickelbein, MB (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 21 Z9 21 U1 0 U2 14 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 15 PY 2004 VL 121 IS 11 BP 5281 EP 5283 DI 10.1063/1.1781156 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600031 PM 15352821 ER PT J AU Schwegler, E Grossman, JC Gygi, F Galli, G AF Schwegler, E Grossman, JC Gygi, F Galli, G TI Towards an assessment of the accuracy of density functional theory for first principles simulations of water. II SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RADIAL-DISTRIBUTION FUNCTIONS; MOLECULAR-DYNAMICS; LIQUID WATER; SELF-DIFFUSION; MODEL; QUANTUM; ENERGY; H2O; EXCHANGE; DIMER AB A series of 20 ps ab initio molecular dynamics simulations of water at ambient density and temperatures ranging from 300 to 450 K are presented. Car-Parrinello (CP) and Born-Oppenheimer (BO) molecular dynamics techniques are compared for systems containing 54 and 64 water molecules. At 300 K, an excellent agreement is found between radial distribution functions (RDFs) obtained with BO and CP dynamics, provided an appropriately small value of the fictitious mass parameter is used in the CP simulation. However, we find that the diffusion coefficients computed from CP dynamics are approximately two times larger than those obtained with BO simulations for T>400 K, where statistically meaningful comparisons can be made. Overall, both BO and CP dynamics at 300 K yield overstructured RDFs and slow diffusion as compared to experiment. In order to understand these discrepancies, the effect of proton quantum motion is investigated with the use of empirical interaction potentials. We find that proton quantum effects may have a larger impact than previously thought on structure and diffusion of the liquid. (C) 2004 American Institute of Physics. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Schwegler, Eric/F-7294-2010; Schwegler, Eric/A-2436-2016 OI Schwegler, Eric/0000-0003-3635-7418 NR 49 TC 243 Z9 244 U1 6 U2 49 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 15 PY 2004 VL 121 IS 11 BP 5400 EP 5409 DI 10.1063/1.1782074 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600044 PM 15352834 ER PT J AU Wang, GF Van Hove, MA Ross, PN Baskes, MI AF Wang, GF Van Hove, MA Ross, PN Baskes, MI TI Monte Carlo simulations of segregation in Pt-Re catalyst nanoparticles SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EMBEDDED-ATOM METHOD; ELECTRONIC-STRUCTURE CALCULATIONS; SINGLE-CRYSTAL SURFACES; OXYGEN REDUCTION; METALS; ALLOYS; POTENTIALS; CLUSTERS; PLATINUM; NI AB We have investigated the segregation of Pt atoms to the surfaces of Pt-Re nanoparticles using the Monte Carlo method and modified embedded-atom method potentials that we have developed for Pt-Re alloys. The Pt75Re25 nanoparticles (containing from 586 to 4033 atoms) are assumed to have disordered fcc configurations and cubo-octahedral shapes (terminated by {111} and {100} facets), while the Pt50Re50 and Pt25Re75 nanoparticles (containing from 587 to 4061 atoms) are assumed to have disordered hcp configurations and truncated hexagonal bipyramidal shapes (terminated by {0001} and {10 (1) over bar1} facets). We predict that due to the segregation process the equilibrium Pt-Re nanoparticles would achieve a core-shell structure, with a Pt-enriched shell surrounding a Pt-deficient core. For fcc cubo-octahedral Pt75Re25 nanoparticles, the shells consist of almost 100 at. % of Pt atoms. Even in the shells of hcp truncated hexagonal bipyramidal Pt50Re50 nanoparticles, the concentrations of Pt atoms exceed 85 at. % (35 at. % higher than the overall concentration of Pt atoms in these nanoparticles). Most prominently, all Pt atoms will segregate to the surfaces in the hcp truncated hexagonal bipyramidal Pt25Re75 nanoparticles containing less than 1000 atoms. We also find that the Pt atoms segregate preferentially to the vertex sites, less to edge sites, and least to facet sites on the shell of Pt-Re nanoparticles. (C) 2004 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Los Alamos Natl Lab, MST 8 Struct & Property Relat Grp, Los Alamos, NM 87545 USA. RP Wang, GF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM gfwang@lbl.gov RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 48 TC 43 Z9 43 U1 1 U2 17 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 2004 VL 121 IS 11 BP 5410 EP 5422 DI 10.1063/1.1781151 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600045 PM 15352835 ER PT J AU Wang, XQ Hanson, JC Liu, G Rodriguez, JA Iglesias-Juez, A Fernandez-Garcia, M AF Wang, XQ Hanson, JC Liu, G Rodriguez, JA Iglesias-Juez, A Fernandez-Garcia, M TI The behavior of mixed-metal oxides: Physical and chemical properties of bulk Ce1-xTbxO2 and nanoparticles of Ce1-xTbxOy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-ABSORPTION; ELECTRONIC-STRUCTURE CALCULATIONS; OXYGEN BUFFERING CAPACITY; CERIUM OXIDE; POWDER DIFFRACTION; 3-WAY CATALYSTS; PLANE-WAVE; POPULATION ANALYSIS; REDOX BEHAVIOR; TWC COMPONENT AB The physical and chemical properties of bulk Ce1-xTbxO2 and Ce1-xTbxOy nanoparticles (xless than or equal to0.5) were investigated using synchrotron-based x-ray diffraction (XRD), x-ray adsorption near edge spectroscopy (XANES), Raman spectroscopy (RS), and first-principles density-functional (DF) calculations. DF results and Raman spectra point to a small tetragonal distortion after introducing terbium in ceria. The results of XRD show a small contraction (less than or equal to 0.08 A) in the cell dimensions. The presence of Tb generates strain in the lattice through the variation of the ionic radii and creation of crystal imperfections and O vacancies. The strain increases with the content of Tb and affects the chemical reactivity of the Ce1-xTbxOy nanoparticles towards hydrogen, SO2, and NO2. DF calculations for bulk Ce1-xTbxO2 and Ce8-nTbnO16 (n=0, 1, 2, or 4) clusters show oxide systems that are not fully ionic. The theoretical results and XANES spectra indicate that neither a Ce<---->Tb exchange nor the introduction of oxygen vacancies in Ce1-xTbxOy significantly affect the charge on the Ce cations. In contrast, the O K-edge and Tb L-III-edge XANES spectra for Ce1-xTbxOy nanoparticles show substantial changes with respect to the corresponding spectra of Ce and Tb single oxide references. The Ce0.5Tb0.5Oy compounds exhibit a much larger Tb3+/Tb4+ ratio than TbO1.7. A comparison with the properties of Ce1-xZrxOy and Ce1-xCaxOy shows important differences in the charge distribution, the magnitude of the dopant induced strain in the oxide lattice, and a superior behavior in the case of the Ce1-xTbxOy systems. The Tb-containing oxides combine stability at high temperature against phase segregation and a reasonable concentration of O vacancies, making them attractive for chemical and catalytic applications. (C) 2004 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. CSIC, Inst Catalisis & Petroleoquim, E-28049 Madrid, Spain. RP Fernandez-Garcia, M (reprint author), Brookhaven Natl Lab, Dept Chem, Bldg 555, Upton, NY 11973 USA. RI Hanson, jonathan/E-3517-2010; Fernandez-Garcia, Marcos/A-8122-2014; Iglesias-Juez, Ana/K-6048-2014 OI Iglesias-Juez, Ana/0000-0002-1218-5490 NR 86 TC 79 Z9 80 U1 1 U2 54 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 15 PY 2004 VL 121 IS 11 BP 5434 EP 5444 DI 10.1063/1.1781116 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600048 PM 15352838 ER PT J AU Smilowitz, L Henson, BF Greenfield, M Sas, A Asay, BW Dickson, PM AF Smilowitz, L Henson, BF Greenfield, M Sas, A Asay, BW Dickson, PM TI On the nucleation mechanism of the beta-delta phase transition in the energetic nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID KINETICS C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smilowitz, L (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 6 TC 27 Z9 29 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 15 PY 2004 VL 121 IS 11 BP 5550 EP 5552 DI 10.1063/1.1782491 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851XU UT WOS:000223720600060 PM 15352850 ER PT J AU Chisholm-Brause, CJ Berg, JM Little, KM Matzner, RA Morris, DE AF Chisholm-Brause, CJ Berg, JM Little, KM Matzner, RA Morris, DE TI Uranyl sorption by smectites: spectroscopic assessment of thermodynamic modeling SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE uranium; sorption; smectite; clay; emission spectroscopy; speciation; surface complexation ID SURFACE COMPLEXATION MODEL; LASER-INDUCED FLUORESCENCE; ENERGY-GAP LAW; RAY-ABSORPTION SPECTROSCOPY; TRANSFER EXCITED-STATES; ELECTRONIC-STRUCTURE; AQUEOUS-SOLUTION; BINDING-SITES; LUMINESCENCE DECAY; CRYSTAL-STRUCTURES AB Batch sorption experiments and thermodynamic modeling of the interaction of UO22+ and its hydrolysis products with two smectitic clay minerals, the reference material SWy-1 [McKinley et al., Clays Clay Miner. 43 (1995) 586] and the soil isolate LK-1 [Turner et al., Geochim. Cosmochim. Acta 30 (1996) 3399], have established a conceptual framework for uranyl/smectite surface complexation based on general reactions between aqueous uranyl species and the reactive sites on the mineral surfaces. In this report, we have formulated and spectroscopically tested a set of hypotheses based on this conceptual framework using samples prepared under similar or identical conditions to evaluate the agreement between surface complexation/speciation as enumerated by spectroscopic characterization and that elaborated by the surface complexation model. Both steady-state and time-resolved optical emission spectral data are presented for uranyl on both smectite minerals as well as on the analogue phases SiO2 and Al(OH)(3) spanning the pH range from similar to4 to 8 and the background electrolyte concentrations from similar to0.00 1 to 0. 1 M. The spectral data enable the explicit identification of an outer-sphere exchange-site population of the hydrated cation [UO2 (OH2) (2+)(5)] in SWy-1. Spectral data also clearly establish the existence of inner-sphere surface complexes on the analogue phases and on the amphoteric clay crystallite edge sites [aluminol (>Al-OH) and silanol (>Si-OH)]. Based on the spectral characteristics of these uranyl edge-site populations, it is possible to readily infer for the SiO2, Al(OH)(3), and SWy-1 samples the evolution in surface speciation with increasing pH to more hydrolyzed uranyl-surface complexes consistent with the conceptual model. The spectral domain characteristics of the edge-site populations on LK-1 with increasing pH suggest that there is no change in the hydrolysis of the uranyl-surface species. However, emission lifetime data are interpreted as indicating a shift in the surface speciation of the same uranyl-surface species from aluminol sites to silanol sites with pH increase. This observation is also consistent with the conceptual framework of the model. Data are also reported for Eu3+/smectite samples to provide additional insight into the exchange site populations. The emission spectra for Eu3+ in the basal-plane exchange sites differs significantly between SWy-1 and LK-1 samples reflecting a difference in the basal plane spacing between these two minerals, but the emission lifetime data suggest that the Eu3+ cation remains fully hydrated in both systems. The overall general description of surface speciation of uranyl on these mineral phases as enumerated by spectroscopy is in good accord with that derived from the conceptual thermodynamic model, lending added confidence to our understanding and descriptions of surface complexation behavior in this complex geochemical system. (C) 2004 Elsevier Inc. All rights reserved. C1 Coll William & Mary, Dept Appl Sci, Appl Res Ctr, Newport News, VA 23606 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. RP Chisholm-Brause, CJ (reprint author), Coll William & Mary, Dept Appl Sci, Appl Res Ctr, 12050 Jefferson Ave, Newport News, VA 23606 USA. EM cbrause@jlab.org; demorris@lanl.gov RI Morris, David/A-8577-2012 NR 76 TC 36 Z9 36 U1 2 U2 17 PU ACADEMIC PRESS INC ELSEVIER SCIENCE 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 2004 VL 277 IS 2 BP 366 EP 382 DI 10.1016/j.jcis.2004.04.047 PG 17 WC Chemistry, Physical SC Chemistry GA 847FU UT WOS:000223378900016 PM 15341848 ER PT J AU Skoug, RM Gosling, JT Steinberg, JT McComas, DJ Smith, CW Ness, NF Hu, Q Burlaga, LF AF Skoug, RM Gosling, JT Steinberg, JT McComas, DJ Smith, CW Ness, NF Hu, Q Burlaga, LF TI Extremely high speed solar wind: 29-30 October 2003 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE high-speed solar wind; extreme solar wind; coronal mass ejections; interplanetary shocks; solar wind plasma; interplanetary magnetic field ID ADVANCED COMPOSITION EXPLORER; CORONAL MASS EJECTION; ALPHA MONITOR SWEPAM; PROTON; ELECTRON; ORBIT AB [1] On 29 - 30 October 2003 the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on the Advanced Composition Explorer ( ACE) spacecraft measured solar wind speeds in excess of 1850 km/s, some of the highest speeds ever directly measured in the solar wind. These speeds were observed following two large coronal mass ejection (CME) driven shocks. Surprisingly, despite the unusually high speeds, many of the other solar wind parameters were not particularly unusual in comparison with other large transient events. The magnetic field reached - 68 nT, a large but not unprecedented value. The proton temperatures were significantly higher than typical for a CME in the solar wind at 1 AU (> 10(7) K), but the proton densities were moderate, leading to low to moderate proton beta. The solar wind dynamic pressure was not unusual for large events but, when coupled with the large negative B-z, was sufficient to cause intense geomagnetic disturbances. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. SW Res Inst, Instrumentat & Space Res Div, San Antonio, TX 78238 USA. Univ New Hampshire, Inst Earth Oceans & Space, Durham, NH 03824 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19711 USA. Univ Calif Riverside, Inst Geophys & Planetary Phys, Riverside, CA 92521 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Skoug, RM (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM rskoug@lanl.gov NR 20 TC 152 Z9 154 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 15 PY 2004 VL 109 IS A9 AR A09102 DI 10.1029/2004JA010494 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 857NT UT WOS:000224125100005 ER PT J AU Gaspar, AM Marques, MA Cabaco, MI Marques, MID Kolesnikov, AI Tomkinson, J Li, JC AF Gaspar, AM Marques, MA Cabaco, MI Marques, MID Kolesnikov, AI Tomkinson, J Li, JC TI Structure and dynamics of concentrated aqueous solutions of aluminium chloride, beryllium chloride and aluminium bromide: Raman, inelastic neutron scattering and x-ray diffraction results SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID INITIO MOLECULAR-DYNAMICS; PROTON MAGNETIC RESONANCE; INTERMEDIATE-RANGE ORDER; LES SOLUTIONS DELECTROLYTES; RECHERCHES SUR LEXISTENCE; SOLVENT-WATER MOLECULES; IONIC-SOLUTIONS; ELECTROLYTE-SOLUTIONS; SALT-SOLUTIONS; CATIONS COMPLEXES AB Structural and dynamical investigations on concentrated aqueous solutions of aluminium chloride and bromide in liquid and glassy states have been performed by means of Raman and inelastic neutron scattering spectroscopy and by x-ray diffraction. Inelastic neutron scattering results for solutions of beryllium chloride in a glassy state are compared with the results for the aluminium cation solutions. Isotopic changes on going from H2O to D2O of the Raman spectra assigned to vibrations of water molecules in the cation hydration shells are discussed. Inelastic neutron scattering data complement and corroborate the Raman spectral study. Further structural information is obtained from x-ray diffraction experiments, and its interpretation is supported by calculations based on ad hoc molecular models. The existence of a liquid-type quasi-close packing is suggested for concentrated aqueous solutions of aluminium halides, in agreement with previous studies. C1 Ctr Fis Atom, P-1649003 Lisbon, Portugal. Univ Tecn Lisboa, Dept Fis, Inst Super Tecn, P-1049001 Lisbon, Portugal. Argonne Natl Lab, Argonne, IL 60439 USA. Rutherford Appleton Lab, CCLRC, Didcot OX11 0QX, Oxon, England. Univ Manchester, Dept Phys, Manchester M60 1QD, Lancs, England. RP Gaspar, AM (reprint author), Ctr Fis Atom, Avenida Prof Gama Pinto 2, P-1649003 Lisbon, Portugal. EM agaspar@cii.fc.ul.pt RI Cabaco, Maria Isabel/M-4767-2013; Kolesnikov, Alexander/I-9015-2012 OI Cabaco, Maria Isabel/0000-0001-8444-5135; Kolesnikov, Alexander/0000-0003-1940-4649 NR 96 TC 11 Z9 11 U1 0 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 15 PY 2004 VL 16 IS 36 BP 6343 EP 6364 AR PII S0953-8984(04)81476-0 DI 10.1088/0953-8984/16/36/002 PG 22 WC Physics, Condensed Matter SC Physics GA 876OQ UT WOS:000225507000004 ER PT J AU Lorenz, CD Stevens, MJ Wool, RP AF Lorenz, CD Stevens, MJ Wool, RP TI Fracture behavior of triglyceride-based adhesives SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE adhesives; computer modelling; crosslinking; fracture; molecular dynamics; Monte Carlo; networks; simulations ID DIVINYLBENZENE THERMOSETTING COPOLYMERS; POLYMER ADHESIVES; SIMULATIONS; DYNAMICS; SURFACE; RESINS; BONDS AB The use of natural plant oils in the production of adhesives has been the focus of much research because natural oils are a renewable resource which have environmental and economic advantages over the petroleum-derived chemicals used in traditional adhesives. The network formation and the stress-strain behavior of these plant oil-based adhesives is studied using a combination of simulation techniques. An off-lattice Monte Carlo simulation has been developed to model the formation of these networks via the free-radical copolymerization of the triglycerides present in natural oils. Networks of systems representing the triglycerides found in soybean oil, linseed oil, and olive oil are generated, as are networks made from other "theoretical" natural oils. The structure of the networks is characterized by percolation analysis. The stress-strain behavior of these networks is studied using large-scale molecular dynamics simulations. Tensile strains are applied to the networks and it is observed that with increasing n the failure stress increases but the failure strain decreases. Also, for systems with low values of n, large voids form while the system is strained and then the system fails cohesively. However, for large n, no significant voiding is observed and the system fails close to the interface. The simulation results are shown to be consistent with the vector percolation theoretical prediction for how the failure stress relates to n. (C) 2004 Wiley Periodicals, Inc. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Delaware, Dept Chem Engn, Newark, DE 19716 USA. RP Lorenz, CD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM cdloren@sandia.gov RI Lorenz, Christian/A-6996-2017 OI Lorenz, Christian/0000-0003-1028-4804 NR 27 TC 15 Z9 15 U1 0 U2 9 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 2004 VL 42 IS 18 BP 3333 EP 3343 DI 10.1002/polb.20198 PG 11 WC Polymer Science SC Polymer Science GA 851NM UT WOS:000223691800003 ER PT J AU Silvestre, C Cimmino, S Lin, JS AF Silvestre, C Cimmino, S Lin, JS TI Structure, morphology, and crystallization process of isotactic polypropylene/hydrogenated hydrocarbon resin blends SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE structure; morphology; crystallization; isotactic polypropylene; hydrocarbon resin ID HYDROGENATED OLIGO(CYCLOPENTADIENE) BLENDS; EXTRUDED ISOTROPIC FILMS; NATURAL TERPENE RESINS; ANGLE X-RAY; MECHANICAL-PROPERTIES; THERMAL-BEHAVIOR; PHASE-STRUCTURE; SCATTERING; MICROSTRUCTURE; DIAGRAM AB The structure, morphology, and isothermal and nonisothermal crystallization of isotactic polypropylene/low-molecular-mass hydrocarbon resin blends (iPP/HR) (up to 20% in weight of HR) have been studied, using optical and electron microscopy, wide- and small-angle X-ray and differential scanning calorimetry. New structures and morphologies can be activated, using appropriate preparation and crystallization conditions and blend composition. For every composition and crystallization condition, iPP crystallizes in a-form, with a spherulitic morphology. The size of iPP spherulites increases with resin content, whereas the long period decreases. In the range of crystallization temperatures investigated, HR modifies the birefringence of iPP spherulites, favoring the formation of radial lamellae and changing the ratio between tangential and radial lamellae. Spherulitic radial growth rates, overall crystallization rates, and melting temperatures are strongly affected by resin, monotonically decreasing with resin content. This confirms miscibility in the melt between the two components of the blends. (C) 2004 Wiley Periodicals, Inc. C1 CNR, Ist Chim & Tecnol Polimeri, I-80078 Pozzuoli, NA, Italy. Oak Ridge Natl Lab, Condensed Matters Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RP Silvestre, C (reprint author), CNR, Ist Chim & Tecnol Polimeri, Via Campi Flegrei,34, I-80078 Pozzuoli, NA, Italy. EM silv@irtemp.na.cnr.it OI SILVESTRE, CLARA/0000-0001-7886-4990; Cimmino, Sossio/0000-0002-8414-7186 NR 29 TC 5 Z9 5 U1 1 U2 11 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 2004 VL 42 IS 18 BP 3368 EP 3379 DI 10.1002/polb.20199 PG 12 WC Polymer Science SC Polymer Science GA 851NM UT WOS:000223691800007 ER PT J AU Gedik, N Orenstein, J AF Gedik, N Orenstein, J TI Absolute phase measurement in heterodyne detection of transient gratings SO OPTICS LETTERS LA English DT Article ID STIMULATED RAMAN-SCATTERING; LIQUIDS AB We present a method of measuring the absolute phase in heterodyne-detected transient grating experiments. The method permits direct and sensitive characterization of the amplitude and phase of the grating parameters. We also present a convenient implementation of this technique and demonstrate its efficacy in a cuprate superconductor. (C) 2004 Optical Society of America. C1 Univ Calif Berkeley, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Gedik, N (reprint author), Univ Calif Berkeley, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Orenstein, Joseph/I-3451-2015 NR 7 TC 23 Z9 23 U1 0 U2 13 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 2004 VL 29 IS 18 BP 2109 EP 2111 DI 10.1364/OL.29.002109 PG 3 WC Optics SC Optics GA 851MN UT WOS:000223689300001 PM 15460872 ER PT J AU Creutz, M AF Creutz, M TI Playing with sandpiles SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE self-organized criticality ID MODEL AB The Bak-Tang-Wiesenfeld sandpile model provides a simple and elegant system with which to demonstrate self-organized criticality. This model has rather remarkable mathematical properties first elucidated by Dhar. I demonstrate some of these properties graphically with a simple computer simulation. Published by Elsevier B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Creutz, M (reprint author), Brookhaven Natl Lab, Dept Phys, 510A,POB 5000, Upton, NY 11973 USA. EM creutz@bnl.gov NR 8 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 EI 1873-2119 J9 PHYSICA A JI Physica A PD SEP 15 PY 2004 VL 340 IS 4 BP 521 EP 526 DI 10.1016/j.physa.2004.05.063 PG 6 WC Physics, Multidisciplinary SC Physics GA 847LF UT WOS:000223393300002 ER PT J AU Mo, SK Denlinger, JD Kim, HD Allen, JW Sekiyama, A Yamasaki, A Suga, S Saitoh, Y Muro, T Metcalf, P AF Mo, SK Denlinger, JD Kim, HD Allen, JW Sekiyama, A Yamasaki, A Suga, S Saitoh, Y Muro, T Metcalf, P TI Distortion of V 3d line shape due to Auger emission in resonant photoemission spectra of (V1-xCrx)(2)O-3 at the V 2p -> 3d absorption edge SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Symposium on Synchrotron Radiation Research for Spin and Electronic States in d and f Electron Systems CY NOV 19-21, 2003 CL Higashihiroshima, JAPAN SP Minist Educ, Culture, Sport, Sci & Technol, Council HSRC Res Promot, Assoc Supporters Hiroshima Univ, Satake Fdn, Inoue Fdn Sci, Elect Technol Res Fdn Chugoku, Sumitomo Heavy Ind Ltd DE V2O3; metal insulator transition; resonant photoemission ID METAL-INSULATOR-TRANSITION; VANADIUM-OXIDES; V2O3; SPECTROSCOPY AB We report high-resolution resonant photoemission spectra of (V1-xCrx)(2)O-3 at the V 2p --> 3d edge. Distortion of the V 3d line shape due to Auger emission is observed in all phases, metal and insulating. Therefore, spectra that is not in the resonance photon energy range were used in making a recent comparison of experiment to the theoretical spectrum calculated by combining the local density approximation with the dynamical mean field theory. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Pohang Accelerator Lab, Pohang 790784, South Korea. Osaka Univ, Grad Sch Engn Sci, Dept Mat Phys, Toyonaka, Osaka 5608531, Japan. Japan Atom Energy Res Inst, Dept Synchrotron Radiat Res, SPring8, Sayo, Hyogo 6795143, Japan. Japan Synchrotron Radiat Res Inst, SPring8, Sayo, Hyogo 6795143, Japan. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RP Mo, SK (reprint author), Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. EM sungkwan@umich.edu RI Mo, Sung-Kwan/F-3489-2013; Sekiyama, Akira/G-1851-2016 OI Mo, Sung-Kwan/0000-0003-0711-8514; NR 18 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD SEP 15 PY 2004 VL 351 IS 3-4 BP 235 EP 239 DI 10.1016/j.physb.2004.06.014 PG 5 WC Physics, Condensed Matter SC Physics GA 855VK UT WOS:000224002800003 ER PT J AU Yoshida, T Zhou, XJ Yagi, H Lu, DH Tanaka, K Fujimori, A Hussain, Z Shen, ZX Kakeshita, T Eisaki, H Uchida, S Segawa, K Lavrov, AN Ando, Y AF Yoshida, T Zhou, XJ Yagi, H Lu, DH Tanaka, K Fujimori, A Hussain, Z Shen, ZX Kakeshita, T Eisaki, H Uchida, S Segawa, K Lavrov, AN Ando, Y TI Thermodynamic and transport properties of underdoped cuprates from ARPES data SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Symposium on Synchrotron Radiation Research for Spin and Electronic States in d and f Electron Systems CY NOV 19-21, 2003 CL Higashi Hiroshima, JAPAN SP Minist Educ, Culture, Sport, Sci & Technol, Council HSRC Res Promot, Assoc Supporters Hiroshima Univ, Satake Fdn, Inoue Fdn Sci, Elect Technol Res Fdn Chugoku, Sumitomo Heavy Ind Ltd DE angle-resolved photoemission; high-T-c cuprates; specific heat; electrical resisitivity ID HIGH-TEMPERATURE SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; LA2-XSRXCUO4 AB The relationship between photoemission spectra of high-T-c cuprates and their thermodynamic and transport properties are discussed. The doping dependence of the expected quasi-particle density at the Fermi level (E-F) are compared with the electronic specific heat coefficient gamma and that of the spectral weight at E-F with the in-plane and out-of-plane superfluid density. We have estimated the electrical resistivity of underdoped cuprates from the momentum distribution curve (MDC) at E-F in the nodal direction. The temperature dependence of the MDC width is also consistent with that of the electrical resistivity. (C) 2004 Elsevier B.V. All rights reserved. C1 Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Complex Sci & Engn, Bunkyo Ku, Tokyo 1130033, Japan. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. ISTEC, Superconduct Res Lab, Koto Ku, Tokyo 1350062, Japan. Univ Tokyo, Dept Phys, Tokyo 1138656, Japan. Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan. Cent Res Inst Elect Power Ind, Komae, Tokyo 2018511, Japan. RP Yoshida, T (reprint author), Stanford Univ, Dept Appl Phys, MC Cullough Bldg,Room 220,476 Lomita Hall, Stanford, CA 94305 USA. EM teppei@stanford.edu RI Ando, Yoichi/B-8163-2013; SEGAWA, Kouji/D-4204-2014 OI Ando, Yoichi/0000-0002-3553-3355; SEGAWA, Kouji/0000-0002-3633-4809 NR 14 TC 11 Z9 11 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD SEP 15 PY 2004 VL 351 IS 3-4 BP 250 EP 255 DI 10.1016/j.physb.2004.06.017 PG 6 WC Physics, Condensed Matter SC Physics GA 855VK UT WOS:000224002800006 ER PT J AU Ino, A Higashiguchi, M Yamazaki, K Yamasaki, T Narimura, T Kobayashi, K Shimada, K Namatame, H Taniguchi, M Yoshida, T Fujimori, A Shen, ZX Kakeshita, T Uchida, S Adachi, S Tajima, S AF Ino, A Higashiguchi, M Yamazaki, K Yamasaki, T Narimura, T Kobayashi, K Shimada, K Namatame, H Taniguchi, M Yoshida, T Fujimori, A Shen, ZX Kakeshita, T Uchida, S Adachi, S Tajima, S TI ARPES study of T*-phase cuprate superconductor SmLa0.85Sr0.15CuO4-delta SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Symposium on Synchrotron Radiation Research for Spin and Electronic States in d and f Electron Systems CY NOV 19-21, 2003 CL Higashihiroshima, JAPAN SP Minist Educ, Culture, Sport, Sci & Technol, Council HSRC Res Promot, Assoc Supporters Hiroshima Univ, Satake Fdn, Inoue Fdn Sci, Elect Technol Res Fdn Chugoku, Sumitomo Heavy Ind Ltd DE angle-resolved photoemission; T*-phase cuprate superconductor; electronic evolution; kink structure ID INSULATOR AB The electronic structure of the T*-phase cuprate superconductor SmLa0.85Sr0.15CuO4-delta has been studied by angle-resolved photoemission spectroscopy (ARPES). While a clear Fermi surface has been observed near (pi/2, pi/2), the electronic band is lowered to similar to -180 meV around (pi, 0) due to the pseudogap formation. These features are quite similar to the ARPES result of Ca1.9Na0.1CuO2Cl2 rather than La2-xSrxCuO4. We have also observed a distinct "kink" in the nodal band dispersion as in all the other hole-doped cuprates. (C) 2004 Elsevier B.V. All rights reserved. C1 Hiroshima Univ, Grad Sch Sci, Higashihiroshima 7398526, Japan. Hiroshima Univ, Hiroshima Synchrotron Radiat Ctr, Higashihiroshima 7398526, Japan. Stanford Univ, Dept Appl Phys, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tokyo, Dept Complex Sci & Engn, Tokyo 1130033, Japan. Univ Tokyo, Dept Adv Mat Sci, Kashiwa, Chiba 2778651, Japan. SRL, Int Superconduct Technol Ctr, Tokyo 1350062, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. RP Ino, A (reprint author), Hiroshima Univ, Grad Sch Sci, Higashihiroshima 7398526, Japan. EM ino@hiroshima-u.ac.jp RI Shimada, Kenya/G-5080-2016 OI Shimada, Kenya/0000-0002-1945-2352 NR 8 TC 1 Z9 1 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD SEP 15 PY 2004 VL 351 IS 3-4 BP 274 EP 276 DI 10.1016/j.physb.2004.06.024 PG 3 WC Physics, Condensed Matter SC Physics GA 855VK UT WOS:000224002800013 ER PT J AU Tanaka, K Yoshida, T Fujimori, A Lu, DH Zhou, XJ Shen, ZX Hussain, Z Eisaki, H Uchida, S Sugaya, T Mizuno, T Terasaki, I AF Tanaka, K Yoshida, T Fujimori, A Lu, DH Zhou, XJ Shen, ZX Hussain, Z Eisaki, H Uchida, S Sugaya, T Mizuno, T Terasaki, I TI Angle-resolved photoemission study of the lightly doped cuprates Bi2212 SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Symposium on Synchrotron Radiation Research for Spin and Electronic States in d and f Electron Systems CY NOV 19-21, 2003 CL Higashi Hiroshima, JAPAN SP Minist Educ, Culture, Sport, Sci & Technol, Council HSRC Res Promot, Assoc Supporters Hiroshima Univ, Satake Fdn, Inoue Fdn Sci, Elect Technol Res Fdn Chugoku, Sumitomo Heavy Ind Ltd DE angle-resolved photoemission; high-T-c; cuprates; t-J model ID FERMI-SURFACE; SUPERCONDUCTORS; OXYGEN AB Insulating and underdoped Bi2-zPbzSr2Ca1-xRxCuO8+y. (R = Pr, Er) (Bi2212) has been studied by photoemission spectroscopy and compared with La2-xSrxCuO4 (LSCO). The lower-Hubbard band of the insulating Bi2212 shows a stronger dispersion along the underlying Fermi surface than that of undoped LaCuO4. The flat band at k similar to (pi, 0) is found to be deeper in Bi2212 than in LSCO. These observations suggest that the magnitude of the next-nearest-neighbor hopping \t'\ of the single-band model is larger in Bi2212 than in LSCO. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tokyo, Fac Sci, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Complex Sci & Engn, Tokyo 1130033, Japan. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Waseda Univ, Dept Appl Phys, Tokyo 1698555, Japan. RP Tanaka, K (reprint author), Univ Tokyo, Fac Sci, Dept Phys, Bunkyo Ku, Bld 1 Room 502,Hongo 7-3-1, Tokyo 1130033, Japan. EM tanaka@wyvern.phys.s.u-tokyo.ac.jp RI TERASAKI, Ichiro/I-7083-2014 OI TERASAKI, Ichiro/0000-0002-6073-2639 NR 11 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD SEP 15 PY 2004 VL 351 IS 3-4 BP 277 EP 279 DI 10.1016/j.physb.2004.06.025 PG 3 WC Physics, Condensed Matter SC Physics GA 855VK UT WOS:000224002800014 ER PT J AU Linder, EV AF Linder, EV TI Reconstructing and deconstructing dark energy SO PHYSICAL REVIEW D LA English DT Article AB The acceleration of the expansion of the Universe, ascribed to a dark energy, is one of the most intriguing discoveries in science. In addition to precise, systematics controlled data, clear, robust interpretation of the observations is required to reveal the nature of dark energy. Even for the simplest question: is the data consistent with the cosmological constant? there are important subtleties in the reconstruction of the dark energy properties. We discuss the roles of analysis both in terms of the Hubble expansion rate or dark energy density rho(DE)(z) and in terms of the dark energy equation of state w(z), arguing that each has its carefully defined place. Fitting the density is best for learning about the density, but using it to probe the equation of state can lead to instability and bias. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. Michigan Ctr Theoret Phys, Ann Arbor, MI USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. NR 21 TC 17 Z9 17 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 2004 VL 70 IS 6 AR 061302 DI 10.1103/PhysRevD.70.061302 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 862AS UT WOS:000224462000002 ER PT J AU Pasqua, A Zumino, B AF Pasqua, A Zumino, B TI Constraints and superspin for super Poincare algebras in diverse dimensions SO PHYSICAL REVIEW D LA English DT Article ID SUPERFIELDS AB We generalize to arbitrary dimension the construction of a covariant and supersymmetric constraint for the massless super Poincare algebra, which was given for the 11-dimensional case in a previous work. We also contrast it with a similar construction appropriate to the massive case. Finally we show that the constraint uniquely fixes the representation of the algebra. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Pasqua, A (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 6 TC 3 Z9 3 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 2004 VL 70 IS 6 AR 066010 DI 10.1103/PhysRevD.70.066010 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 862AS UT WOS:000224462000114 ER PT J AU Wang, SY AF Wang, SY TI Gauge dependence of the fermion quasiparticle poles in hot gauge theories SO PHYSICAL REVIEW D LA English DT Article ID QUARK-GLUON PLASMA; THERMAL FIELD-THEORY; 3-LOOP FREE-ENERGY; HIGH-TEMPERATURE; FINITE-TEMPERATURE; QCD; SCATTERING; AMPLITUDES; IDENTITIES; PROPAGATOR AB .The gauge dependence of the complex fermion quasiparticle poles corresponding to soft collective excitations is studied in hot gauge theories at one-loop order and next-to-leading order in the high-temperature expansion, with a view towards going beyond the leading order hard thermal loops and resummations thereof. We find that for collective excitations of momenta ksimilar toeT the dispersion relations are gauge independent, but the corresponding damping rates are gauge dependent. For kmuch less thaneT and in the k-->0 limit, both the dispersion relations and the damping rates are found to be gauge dependent. The gauge dependence of the position of the complex quasiparticle poles signals the need for resummation. Possible cancellation of the leading gauge dependence at two-loop order in the case of QED is briefly discussed. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. EM sywang@physics.udel.edu NR 37 TC 5 Z9 5 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 2004 VL 70 IS 6 AR 065011 DI 10.1103/PhysRevD.70.065011 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 862AS UT WOS:000224462000093 ER PT J AU Zangar, RC Davydov, DR Verma, S AF Zangar, RC Davydov, DR Verma, S TI Mechanisms that regulate production of reactive oxygen species by cytochrome P450 SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Review DE cytochrome P450; oxidative stress; hydrogen peroxide; superoxide anion radical; lipid peroxidation; reactive oxygen species; uncoupling; review ID RAT-LIVER MICROSOMES; ETHANOL-INDUCIBLE CYTOCHROME-P450; ELECTRON-PARAMAGNETIC RESONANCE; MANGANESE SUPEROXIDE-DISMUTASE; HIGH-PRESSURE SPECTROSCOPY; DEPENDENT PROTEIN-KINASE; LIPID-PEROXIDATION; OXIDATIVE STRESS; P450 REDUCTASE; ROTATIONAL DIFFUSION AB Mammalian cytochromes P450 (P450) are a family of heme-thiolate enzymes involved in the oxidative metabolism of a variety of endogenous and exogenous lipophilic compounds. Poor coupling of the P450 catalytic cycle results in continuous production of reactive oxygen species (ROS), which affects signaling pathways and other cellular functions. P450 generation of ROS is tightly controlled by regulation of gene transcription as well as by modulation of interactions between protein constituents of the monooxygenase that affects its activity, coupling, and stability. Malfunction of these mechanisms may result in a burst of ROS production, which can cause lipid peroxidation and oxidative stress. In turn, oxidative stress downregulates P450 levels by a variety of feedback mechanisms. This review provides an overview of recent advances in our understanding of these feedback mechanisms that serve to limit P450 production of ROS. Some of the more likely physiological and cellular effects of P450 generation of ROS are also discussed. (C) 2004 Elsevier Inc. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Texas, Dept Pharmacol & Toxicol, Galveston, TX 77555 USA. RP Zangar, RC (reprint author), Pacific NW Natl Lab, 902 Batelle Blvd,MS P7-56, Richland, WA 99352 USA. EM richard.zangar@pnl.gov RI Davydov, Dmitri/H-2736-2013 FU NIDDK NIH HHS [R01 DK54812] NR 147 TC 194 Z9 201 U1 9 U2 37 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD SEP 15 PY 2004 VL 199 IS 3 BP 316 EP 331 DI 10.1016/j.taap.2004.01.018 PG 16 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 856ZL UT WOS:000224084700012 PM 15364547 ER PT J AU Dyer, RB Maness, SJ Peterson, ES Franzen, S Fesinmeyer, RM Andersen, NH AF Dyer, RB Maness, SJ Peterson, ES Franzen, S Fesinmeyer, RM Andersen, NH TI The mechanism of beta-hairpin formation SO BIOCHEMISTRY LA English DT Article ID FOLDING TRANSITION-STATE; FAST EVENTS; SECONDARY STRUCTURE; HYDROGEN-BONDS; PROTEIN-G; RELAXATION DYNAMICS; HYDROPHOBIC CLUSTER; TEMPERATURE-JUMP; SH3 DOMAIN; PEPTIDE AB beta-Hairpins constitute an important class of connecting protein secondary structures. Several groups have postulated that such structures form early in the folding process and serve to nucleate the formation of extended beta-sheet structures. Despite the importance of beta-hairpins in protein folding, little is known about the mechanism of formation of these structures. While it is well established that there is a complex interplay between the stability of a beta-hairpin and loop conformational propensity, loop length, and the formation of stabilizing cross-strand interactions (H-bonds and hydrophobic interactions), the influence of these factors on the folding rate is poorly understood. Peptide models provide a simple framework for exploring the molecular details of the formation of beta-hairpin structures. We have explored the fundamental processes of folding in two linear peptides that form beta-hairpin structures, having a stabilizing hydrophobic cluster connected by loops of differing lengths. This approach allows us to evaluate existing models of the mechanism of beta-hairpin formation. We find a substantial acceleration of the folding rate when the connecting loop is made shorter (i.e., the hydrophobic cluster is moved closer to the turn). Analysis of the folding kinetics of these two peptides reveals that this acceleration is a direct consequence of the reduced entropic cost of the smaller loop search. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. N Carolina State Univ, Dept Chem, Raleigh, NC 27695 USA. Bowdoin Coll, Dept Chem, Brunswick, ME 04011 USA. Univ Washington, Dept Chem, Seattle, WA 98195 USA. RP Dyer, RB (reprint author), Los Alamos Natl Lab, Biosci Div, Mail Stop J586, Los Alamos, NM 87545 USA. EM bdyer@lanl.gov FU NIGMS NIH HHS [GM53640, GM59658] NR 48 TC 65 Z9 66 U1 2 U2 15 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 14 PY 2004 VL 43 IS 36 BP 11560 EP 11566 DI 10.1021/bi049177m PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 851TP UT WOS:000223708700020 PM 15350142 ER PT J AU Daum, PH Kleinman, LI Springston, SR Nunnermacker, LJ Lee, YN Weinstein-Lloyd, J Zheng, J Berkowitz, CM AF Daum, PH Kleinman, LI Springston, SR Nunnermacker, LJ Lee, YN Weinstein-Lloyd, J Zheng, J Berkowitz, CM TI Origin and properties of plumes of high ozone observed during the Texas 2000 Air Quality Study (TexAQS 2000) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE urban pollution; ozone formation; industrial hydrocarbons ID MIDDLE TENNESSEE OZONE; URBAN PLUME; JULY 18; NASHVILLE; HYDROCARBONS; SENSITIVITY; EMISSIONS; CHEMISTRY; HOUSTON; FORMALDEHYDE AB [1] The Department of Energy (DOE) G-1 research aircraft made flights on 13 days during the month long Texas 2000 Air Quality Study (TexAQS 2000) to understand the sources and formation mechanism of the very high concentration O-3 plumes that are frequently observed in the Houston metropolitan area during the late summer. On six of those days the aircraft sampled plumes exhibiting O-3 concentrations in excess of 150 ppbv at a number of different locations in and around the greater Houston area. The composition of these plumes differed significantly from those typically observed in other urban areas, exhibiting unusually high concentrations of hydrocarbon oxidation products such as HCHO and photochemical product species such as peroxides. Estimates of the integrated formation efficiency of O-3 with respect to NOx, OPEx, indicate that O-3 had been formed in these high concentration plumes with efficiencies ranging between 6.4 and 11 ppbv O-3 per ppbv of NOx consumed. Without exception, back trajectories from the locations where these high O-3 plumes were observed passed over, or in close proximity to, sources of NOx and hydrocarbons surrounding the Houston Ship Channel. Calculations of instantaneous ozone formation rates and efficiencies using a box model constrained by measurements of stable species showed that ozone formation over and around the Houston Ship Channel could be very rapid ( instantaneous rates up to 140 ppbv/h) and very efficient ( OPEx up to 28) and, in some instances, limited by the availability of NOx. High concentrations of reactive hydrocarbons and NOx emitted by industries in this area appeared to be the cause of these high rates and efficiencies. Examination of the distribution of photochemical product distributions in the high O-3 plumes arising from Ship Channel emissions suggests that O-3 formation in these plumes was much more NOx limited than in typical urban plumes at equivalent times in their evolution. However, chemical/transport model simulations with realistic emissions inventories are needed to resolve the question of whether a NOx- or hydrocarbon-based control strategy would be most effective at controlling greater Houston O-3 concentrations. C1 Brookhaven Natl Lab, Div Atmospher Sci, Dept Environm Sci, Upton, NY 11973 USA. SUNY Coll Old Westbury, Dept Chem & Phys, Old Westbury, NY 11568 USA. SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. Pacific NW Natl Lab, Atmospher Sci & Global Change Div, Richland, WA 99352 USA. RP Daum, PH (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, Dept Environm Sci, Upton, NY 11973 USA. EM phdaum@bnl.gov RI Zheng, Jun/E-6772-2010 NR 27 TC 46 Z9 46 U1 3 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 14 PY 2004 VL 109 IS D17 AR D17306 DI 10.1029/2003JD004311 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 857NE UT WOS:000224123300001 ER PT J AU McNaughton, CS Clarke, AD Howell, SG Moore, KG Brekhovskikh, V Weber, RJ Orsini, DA Covert, DS Buzorius, G Brechtel, FJ Carmichael, GR Tang, YH Eisele, FL Mauldin, RL Bandy, AR Thornton, DC Blomquist, B AF McNaughton, CS Clarke, AD Howell, SG Moore, KG Brekhovskikh, V Weber, RJ Orsini, DA Covert, DS Buzorius, G Brechtel, FJ Carmichael, GR Tang, YH Eisele, FL Mauldin, RL Bandy, AR Thornton, DC Blomquist, B TI Spatial distribution and size evolution of particles in Asian outflow: Significance of primary and secondary aerosols during ACE-Asia and TRACE-P SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ACE-Asia; TRACE-P; aerosol size distribution; nucleation; primary and secondary aerosols; condensation and coagulation ID CONDENSATION NUCLEUS COUNTER; CONTINENTAL BOUNDARY-LAYER; PULSE-HEIGHT ANALYSIS; TERNARY NUCLEATION; SULFURIC-ACID; GROWTH-RATES; RELATIVE-HUMIDITY; BINARY NUCLEATION; SOUTH-KOREA; TRANSPORT AB Quasi-Lagrangian aircraft measurements above the Yellow Sea, East China Sea, and Sea of Japan revealed synoptic-scale secondary aerosol formation and condensational growth during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) and Transport and Chemical Evolution over the Pacific (TRACE-P) experiment. This occurred in the presence of pollution and mineral dust aerosol surface areas as high as 1200 mum(2) cm(-3). Concentrations of sulfuric acid generally appeared insufficient for binary nucleation, but observations, models, and theory are consistent with a ternary nucleation mechanism involving H2SO4-H2O-NH3. Growth rates of similar to2 nm h(-1) can be explained by the condensation of sulfuric acid at a rate of 2+/-1 x 10(6) molecules cm(-3) s(-1). Aerosol volatility suggested increasing neutralization of the aerosol during growth. Size distribution measurements suggest that weak (mean condensation nuclei (CN) 3-13 nm approximate to 500 cm(-3)) new particle production was a common occurrence in the region. However, new particle production was enhanced by similar to1 order of magnitude (mean CN 3-13 nm approximate to 5000 cm(-3)) in postfrontal air masses associated with offshore flow during cloud-free conditions. Fog and clouds appear to be regionally important in modulating nucleation events through scavenging of secondary aerosol and through depletion of gas-phase precursors through enhanced heterogeneous chemistry. Our results indicate that only 10-30% of the total aerosol population consists of aged secondary aerosols after similar to2 days of transport from source regions. In spite of their high production during nucleation events, secondary aerosols advected out over the Pacific Ocean will have a small impact upon indirect forcing and a negligible impact upon direct forcing compared to primary aerosol emissions and the species that condense upon them. C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. Univ Iowa, Dept Chem & Biochem Engn, Iowa City, IA 52242 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. RP Univ Hawaii, Sch Ocean & Earth Sci & Technol, 1000 Pope Rd, Honolulu, HI 96822 USA. EM cameronm@soest.hawaii.edu; tclarke@soest.hawaii.edu; showell@soest.hawaii.edu; kmoore@soest.hawaii.edu; verab@soest.hawaii.edu; rweber@eas.gatech.edu; douglas.orsini@eas.gatech.edu; dcovert@u.washington.edu; gintas@nps.edu; fredb@bnl.gov; gcarmich@icaen.uiowa.edu; ytang@cgrer.uiowa.edu; eisele@ucar.edu; mauldin@ucar.edu; bandyar@drexel.edu; thorntdc@drexel.edu; blomquis@hawaii.edu RI Tang, Youhua/D-5205-2016 OI Tang, Youhua/0000-0001-7089-7915 NR 72 TC 25 Z9 26 U1 4 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 14 PY 2004 VL 109 IS D19 AR D19S06 DI 10.1029/2003JD003528 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 857NI UT WOS:000224123800001 ER PT J AU Rose, SJ van Hoof, PAM Jonauskas, V Keenan, FP Kisielius, R Ramsbottom, C Foord, ME Heeter, RF Springer, PT AF Rose, SJ van Hoof, PAM Jonauskas, V Keenan, FP Kisielius, R Ramsbottom, C Foord, ME Heeter, RF Springer, PT TI Calculation of photoionized plasmas with an average-atom model SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID INCLUDING 2-ELECTRON TRANSITIONS; CHARGE-STATE DISTRIBUTION; LASER-PRODUCED PLASMA; ENERGY-BALANCE; IONIZATION AB We use a simple average-atom model (NIMP) to calculate the distribution of ionization in a photoionization-dominated plasma, for comparison with recent experimental measurements undertaken on the Z-machine at the Sandia National Laboratory. The agreement between theory and experiment is found to be as good for calculations with an average-atom model as for those generated by more detailed models. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Rose, SJ (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Pk Rd, Oxford OX1 3PU, England. EM s.rose1@physics.ox.ac.uk NR 12 TC 22 Z9 24 U1 0 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 2004 VL 37 IS 17 BP L337 EP L342 AR PII s0953-4075(04)82536-7 DI 10.1088/0953-4075/37/17/L05 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 861LR UT WOS:000224418500005 ER PT J AU McCurdy, CW Baertschy, M Rescigno, TN AF McCurdy, CW Baertschy, M Rescigno, TN TI Solving the three-body Coulomb breakup problem using exterior complex scaling SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Review ID ELECTRON-IMPACT IONIZATION; DIFFERENTIAL CROSS-SECTIONS; 3 CHARGED-PARTICLES; CLOSE-COUPLING FORMALISM; PHOTO-DOUBLE-IONIZATION; S-WAVE MODEL; ATOMIC-HYDROGEN; NEAR-THRESHOLD; DOUBLE PHOTOIONIZATION; ANGULAR-DISTRIBUTIONS AB Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a 'reduction to computation' of all aspects of the physics is given by the application of exterior complex scaling, a modem variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic. properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wavefunction can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Colorado, Dept Phys, Denver, CO 80217 USA. RP McCurdy, CW (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM cwmccurdy@lbl.gov; mark@physics.cudenver.edu; tnrescigno@lbl.gov NR 105 TC 185 Z9 186 U1 6 U2 25 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 2004 VL 37 IS 17 BP R137 EP R187 DI 10.1088/0953-4075/37/17/R01 PG 51 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 861LR UT WOS:000224418500006 ER PT J AU Libera, JA Gurney, RW Nguyen, ST Hupp, JT Liu, C Conley, R Bedzyk, MJ AF Libera, JA Gurney, RW Nguyen, ST Hupp, JT Liu, C Conley, R Bedzyk, MJ TI X-ray nanoscale profiling of layer-by-layer assembled metal/organophosphonate films SO LANGMUIR LA English DT Article ID PHOSPHONATE MULTILAYER FILMS; STANDING WAVES; THIN-FILMS; SURFACE-LAYERS; TRANSPORT; MEMBRANES; FLUORESCENCE; ADSORPTION; GENERATION; MICROSCOPY AB The nanoscale structure of multilayer metal/phosphonate thin films prepared via a layer-by-layer assembly process was studied using specular X-ray reflectivity (XRR), X-ray fluorescence (XRF), and long-period X-ray standing wave (XSW) analysis. After the SiO2 X-ray mirror surfaces were functionalized with a monolayer film terminated with phosphonate groups, the organic multilayer films were assembled by alternating immersions in (a) aqueous solutions containing Zr4+, Hf4+, or Y3+ cations and then (b) organic solvent solutions of PO3-R-PO3, where R was a porphyrin or porphyrin-square spacer molecule. The different heavy metal cations provided X-ray fluorescence marker layers at different heights within the different multilayer assemblies. The XSW measurements used a 22 nm period Si/Mo multilayer mirror. The long-period XSW generated by the zeroth-order (total external reflection) through fourth-order Bragg diffraction conditions made it possible to examine the Fourier transforms of the fluorescent atom distributions over a much larger q(z) range in reciprocal space than previously achieved. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Nanoscale Sci & Engn Ctr, Evanston, IL 60208 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Bedzyk, MJ (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. EM bedzyk@northwestern.edu RI Bedzyk, Michael/B-7503-2009; Hupp, Joseph/K-8844-2012; Conley, Ray/C-2622-2013; Bedzyk, Michael/K-6903-2013; Nguyen, SonBinh/C-1682-2014 OI Hupp, Joseph/0000-0003-3982-9812; Nguyen, SonBinh/0000-0002-6977-3445 FU NIGMS NIH HHS [GM62109-02] NR 37 TC 20 Z9 20 U1 0 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 14 PY 2004 VL 20 IS 19 BP 8022 EP 8029 DI 10.1021/la048904b PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 853SF UT WOS:000223847300021 PM 15350067 ER PT J AU Yan, BJ Yue, GZ Yang, J Guha, S Williamson, DL Han, D Jiang, CS AF Yan, BJ Yue, GZ Yang, J Guha, S Williamson, DL Han, D Jiang, CS TI Hydrogen dilution profiling for hydrogenated microcrystalline silicon solar cells SO APPLIED PHYSICS LETTERS LA English DT Article AB The structural properties of hydrogenated microcrystalline silicon solar cells are investigated using Raman, x-ray diffraction, and atomic force microscopy. The experimental results showed a significant increase of microcrystalline volume fraction and grain size with increasing film thickness. The correlation between the cell performance and the microstructure suggests that the increase of grain size and microcrystalline volume fraction with thickness is the main reason for the deterioration of cell performance as the intrinsic layer thickness increases. By varying the hydrogen dilution in the gas mixture during deposition, microstructure evolution has been controlled and cell performance significantly improved. (C) 2004 American Institute of Physics. C1 United Solar Ovon Corp, Troy, MI 48084 USA. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Yan, BJ (reprint author), United Solar Ovon Corp, 1100 W Maple Rd, Troy, MI 48084 USA. EM byan@uni-solar.com RI jiang, chun-sheng/F-7839-2012 NR 8 TC 93 Z9 99 U1 1 U2 10 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 2004 VL 85 IS 11 BP 1955 EP 1957 DI 10.1063/1.1788877 PG 3 WC Physics, Applied SC Physics GA 854SJ UT WOS:000223923300029 ER PT J AU Liu, HZ Hu, JZ Shu, JF Hausermann, D Mao, HK AF Liu, HZ Hu, JZ Shu, JF Hausermann, D Mao, HK TI Lack of the critical pressure for weakening of size-induced stiffness in 3C-SiC nanocrystals under hydrostatic compression SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY-DIFFRACTION; INDUCED STRUCTURAL TRANSITIONS; CDSE NANOCRYSTALS; PHASE-TRANSITION; LATTICE STRAINS; TRANSFORMATION; DEPENDENCE; WURTZITE; GPA AB Using in situ high-pressure x-ray diffraction methods, the compressibility of 30 nm 3C-SiC nanocrystals was studied under hydrostatic conditions while helium was used as pressure transmitting medium, as well as under nonhydrostatic conditions without pressure medium. No threshold pressure phenomenon was observed for the compressibility of the nanocrystals during compression in hydrostatic conditions, while the critical pressure around 10.5 GPa was observed during nonhydrostatic compression. These indicate that the threshold pressure phenomena, recently reported that the nanocrystals initially exhibited much higher bulk modulus below the threshold pressure during compression [Appl. Phys. Lett. 83, 3174 (2003); J. Phys. Chem. 107, 14151 (2003)], were mainly caused by the nonhydrostatic effect instead of a specific feature of nanocrystals upon compression. The bulk modulus of 3C-SiC nanocrystals is estimated as 220.6+/-0.6 GPa based on the hydrostatic compression data. (C) 2004 American Institute of Physics. C1 Argonne Natl Lab, HPCAT, Adv Photon Source, Argonne, IL 60439 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RP Liu, HZ (reprint author), Argonne Natl Lab, HPCAT, Adv Photon Source, Bldg 434E,9700 S Cass Ave, Argonne, IL 60439 USA. EM hliu@hpcat.aps.anl.gov RI Liu, Haozhe/E-6169-2011 NR 37 TC 27 Z9 28 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 2004 VL 85 IS 11 BP 1973 EP 1975 DI 10.1063/1.1789240 PG 3 WC Physics, Applied SC Physics GA 854SJ UT WOS:000223923300035 ER PT J AU Wang, RM Liu, CM Zhang, HZ Chen, CP Guo, L Xu, HB Yang, SH AF Wang, RM Liu, CM Zhang, HZ Chen, CP Guo, L Xu, HB Yang, SH TI Porous nanotubes of Co3O4: Synthesis, characterization, and magnetic properties SO APPLIED PHYSICS LETTERS LA English DT Article ID COBALT AB Stoichiometric Co3O4 porous nanotubes have been synthesized through a simple modified microemulsion method. The structural and the chemical information of the as-grown nanotubes have been investigated by means of x-ray diffraction, electron microscopy, electron energy loss spectroscopy, and dynamic force microscopy. The results reveal that the as-grown materials are formed by concentric stacking of Co3O4 (111) planes or weaved porous nanotubes with diameters ranging from tens to similar to200 nm and sidewall thickness ranging from 2 to similar to20 nm. Magnetic property of the sample demonstrates a magnetic transition temperature at 8.4 K, indicating macroscopic quantum confinement effects from the sidewall thickness of the porous nanotube. (C) 2004 American Institute of Physics. C1 Peking Univ, Dept Phys, Electron Microscopy Lab, Beijing 100871, Peoples R China. Peking Univ, Dept Phys, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Beijing Univ Aeronaut & Astronaut, Dept Mat & Engn, Beijing 100083, Peoples R China. Hong Kong Univ Sci & Technol, Dept Chem, Kowloon, Hong Kong, Peoples R China. RP Wang, RM (reprint author), Peking Univ, Dept Phys, Electron Microscopy Lab, Beijing 100871, Peoples R China. EM rmwang@pku.edu.cn; guolin@buaa.edu.cn RI Guo, Lin/A-3564-2011; Chen, Chinping/A-9169-2012; Zhang, Hongzhou/B-6883-2009; Wang, Rongming/B-2163-2010; OI Zhang, Hongzhou/0000-0002-1188-7810; Wang, Rongming/0000-0003-4075-6956; Yang, Shihe/0000-0002-6469-8415 NR 10 TC 92 Z9 95 U1 2 U2 31 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 2004 VL 85 IS 11 BP 2080 EP 2082 DI 10.1063/1.1789577 PG 3 WC Physics, Applied SC Physics GA 854SJ UT WOS:000223923300071 ER PT J AU Wang, Q Ward, S Duda, A Hu, J Stradins, P Crandall, RS Branz, HM Perlov, C Jackson, W Mei, P Taussig, C AF Wang, Q Ward, S Duda, A Hu, J Stradins, P Crandall, RS Branz, HM Perlov, C Jackson, W Mei, P Taussig, C TI High-current-density thin-film silicon diodes grown at low temperature SO APPLIED PHYSICS LETTERS LA English DT Article ID CURRENT-VOLTAGE CHARACTERISTICS; P-I-N; MICROCRYSTALLINE SILICON; MEMORY; CELLS AB High-performance thin-film silicon n-i-p diodes are fabricated at temperatures below 160 degreesC using hot-wire chemical vapor deposition. The 0.01 mm(2) diodes have a forward current-density of near 1000 A/cm(2) and a rectification ratio over 10(7) at +/-2 V. Use of microcrystalline silicon i and n layers results in higher current-density diodes than with amorphous silicon, primarily by lowering a barrier to carrier injection. A 30 nm intrinsic Si buffer layer between the i and p layers is needed to reduce the reverse leakage current. Minimizing diode area increases forward current density by reducing the voltage drop across the external series resistances. (C) 2004 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Hewlett Packard Lab, Palo Alto, CA 94304 USA. RP Wang, Q (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM qi_wang@nrel.gov NR 18 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 13 PY 2004 VL 85 IS 11 BP 2122 EP 2124 DI 10.1063/1.1789580 PG 3 WC Physics, Applied SC Physics GA 854SJ UT WOS:000223923300085 ER PT J AU Rapti, Z Trombettoni, A Kevrekidis, PG Frantzeskakis, DJ Malomed, BA Bishop, AR AF Rapti, Z Trombettoni, A Kevrekidis, PG Frantzeskakis, DJ Malomed, BA Bishop, AR TI Modulational instabilities and domain walls in coupled discrete nonlinear Schrodinger equations SO PHYSICS LETTERS A LA English DT Article ID BOSE-EINSTEIN CONDENSATE; WAVES; LATTICES; DYNAMICS; ATOMS AB We consider a system of two discrete nonlinear Schrodinger equations, coupled by nonlinear and linear terms. For various physically relevant cases, we derive a modulational instability criterion for plane-wave solutions. We also find and examine domain-wall solutions in the model with the linear coupling. (C) 2004 Published by Elsevier B.V. C1 Univ Athens, Dept Phys, Athens, Greece. Tel Aviv Univ, Fac Engn, Dept Interdisciplinary Studies, IL-69978 Tel Aviv, Israel. Ist Nazl Fis Mat, I-43100 Parma, Italy. Univ Parma, Dipartimento Fis, I-43100 Parma, Italy. Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA. RP Frantzeskakis, DJ (reprint author), Univ Athens, Dept Phys, Athens, Greece. EM dfrantz@cc.uoa.gr OI Trombettoni, Andrea/0000-0002-1108-4727 NR 39 TC 11 Z9 11 U1 0 U2 0 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 13 PY 2004 VL 330 IS 1-2 BP 95 EP 106 DI 10.1016/j.physleta.2004.07.052 PG 12 WC Physics, Multidisciplinary SC Physics GA 853CL UT WOS:000223803800014 ER PT J AU Valeev, EF AF Valeev, EF TI Improving on the resolution of the identity in linear R12 ab initio theories SO CHEMICAL PHYSICS LETTERS LA English DT Article ID BASIS-SETS; WAVE-FUNCTIONS; TERMS; ENERGIES; BENCHMARK AB Here we analyze the use of the resolution of the identity (RI) in approximating many-electron matrix elements in linear R12 theories. A modified standard approximation is proposed that involves expansion in the orthogonal complement to the span of orbital basis set (OBS). The new formulation is labeled complementary auxiliary basis set (CABS) approach. CABS MP2-R12 method has a smaller RI error vis-A-vis the standard ABS approach. Both ABS and CABS approaches are most accurate if the auxiliary basis includes OBS explicitly. The CABS approach found to be more numerically robust than the ABS counterpart. (C) 2004 Elsevier B.V. All rights reserved. C1 Georgia Inst Technol, Ctr Computat Mol Sci & Technol, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Valeev, EF (reprint author), Georgia Inst Technol, Ctr Computat Mol Sci & Technol, Atlanta, GA 30332 USA. EM edward.valeev@chemistry.gatech.edu RI Valeyev, Eduard/A-5313-2009 OI Valeyev, Eduard/0000-0001-9923-6256 NR 21 TC 251 Z9 251 U1 1 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 11 PY 2004 VL 395 IS 4-6 BP 190 EP 195 DI 10.1016/j.cplett.2004.07.061 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 852PX UT WOS:000223770000004 ER PT J AU Shkrob, IA AF Shkrob, IA TI Geminate recombination dynamics studied via electron reexcitation: kinetic analysis for anion CTTS photosystems SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PAIR SEPARATION TECHNIQUE; LIQUID WATER; SOLVATED ELECTRONS; HYDRATED ELECTRON; MULTIPHOTON IONIZATION; ULTRAFAST DYNAMICS; AQUEOUS-SOLUTION; PHOTODETACHMENT; FEMTOSECOND; SOLVENT AB Recently, it became practicable to study geminate recombination dynamics of solvated electrons in polar liquids by using short-pulses of light to reexcite these electrons back into the conduction band of the liquid and observe a change in the fraction of electrons that escape geminate recombination. In this Letter, the potential of this technique to provide additional insight into the recombination dynamics of electrons generated by charge-transfer-to-solvent (CTTS) photodetachment from monovalent anions in polar liquids is studied theoretically. The resulting expression accounts for the recent results for electron photodetachment from Na- in tetrahydrofuran. Published by Elsevier B.V. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shkrob@anl.gov NR 36 TC 6 Z9 6 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 11 PY 2004 VL 395 IS 4-6 BP 264 EP 268 DI 10.1016/j.cplett.2004.07.094 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 852PX UT WOS:000223770000017 ER PT J AU Ajo-Franklin, JB Geller, JT Harris, JM AF Ajo-Franklin, JB Geller, JT Harris, JM TI The dielectric properties of granular media saturated with DNAPL/water mixtures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TIME-DOMAIN REFLECTOMETRY; GROUND-PENETRATING RADAR; ULTRASONIC VELOCITIES; REFRACTIVE-INDEXES; WATER-CONTENT; SOIL AB We present the results of five experiments investigating the dielectric properties of granular materials partially saturated with trichloroethylene (TCE), a common dense non-aqueous contaminant. Previous research has investigated the radar signatures of similar solvents in controlled field experiments but no core-scale measurements have verified the appropriate petrophysical model. Broadband dielectric measurements were performed using a time domain reflectometry (TDR) system coupled to a solvent-compatible coaxial transmission line. Two synthetic samples and three natural aquifer samples were fully saturated with water and then subjected to an axial TCE injection until breakthrough was observed. The resulting dielectric measurements show good agreement with the empirical complex refractive index model (CRIM) allowing a reasonable prediction of the radar reflectivities and transmission velocities expected in field surveys targeting pools of similar non-aqueous contaminants. C1 Stanford Univ, Dept Geophys, Stanford, CA 94305 USA. Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA USA. RP Ajo-Franklin, JB (reprint author), Stanford Univ, Dept Geophys, Mitchell Bldg,Rm 360, Stanford, CA 94305 USA. EM jfrank@pangea.stanford.edu RI Ajo-Franklin, Jonathan/G-7169-2015; OI Ajo-Franklin, Jonathan/0000-0002-6666-4702 NR 23 TC 15 Z9 17 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 11 PY 2004 VL 31 IS 17 AR L17501 DI 10.1029/2004GL020672 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 854HB UT WOS:000223891900004 ER PT J AU Reuland, M Rottgering, H van Breugel, W De Breuck, C AF Reuland, M Rottgering, H van Breugel, W De Breuck, C TI Dust and star formation in distant radio galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Review DE galaxies : active; galaxies : formation; galaxies : high-redshift; radio continuum : galaxies; submillimetre ID DEEP SUBMILLIMETER SURVEY; LYMAN-BREAK GALAXIES; BRIGHT QUASAR SURVEY; HYPERLUMINOUS INFRARED GALAXIES; CLERK-MAXWELL-TELESCOPE; HIGH-REDSHIFT QUASARS; DIGITAL SKY SURVEY; MM MAMBO/IRAM-30 M; 4C 41.17; STATISTICAL-METHODS AB We present the results of an observing programme with the Submillimetre Common User Bolometer Array (SCUBA) to measure the submillimetre (submm) dust continuum emission of 24 distant (z > 1) radio galaxies. We detected submm emission in 12 galaxies with signal-to-noise > 3, including nine detections at z > 3. When added to previous published results these data almost triple the number of radio galaxies with z > 3 detected. in the submm and yield a sample of 69 observed radio galaxies over the redshift range z = 1-5. We find that the range in rest-frame far-infrared luminosities is about a factor of 10. We have investigated the origin of this dispersion, correlating the luminosities with radio source power, size, spectral index, K-band magnitude and Lyalpha luminosity. No strong correlations are apparent in the combined data set. We confirm and strengthen the result from previous submm observations of radio galaxies that the detection rate is a strong function of redshift. We compare the redshift dependence of the submm properties of radio galaxies with those of quasars and find that for both classes of objects the observed submm flux density increases with redshift to z approximate to 4, beyond which, for the galaxies, we find tentative evidence for a decline. We find evidence for an anticorrelation between submm luminosity and ultraviolet polarization fraction, for a subsample of 13 radio galaxies, indicating that starbursts are the dominant source of heating for dust in radio galaxies. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. CNRS, Inst Astrophys Paris, F-75014 Paris, France. RP Reuland, M (reprint author), Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands. EM reuland@strw.leidenuniv.nl OI De Breuck, Carlos/0000-0002-6637-3315 NR 118 TC 65 Z9 65 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2004 VL 353 IS 2 BP 377 EP 390 DI 10.1111/j.1365-2966.2004.08063.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 856OI UT WOS:000224054100004 ER PT J AU Dohlus, M Flottmann, K Kozlov, OS Limberg, T Piot, P Saldin, EL Schneidmiller, EA Yurkov, MV AF Dohlus, M Flottmann, K Kozlov, OS Limberg, T Piot, P Saldin, EL Schneidmiller, EA Yurkov, MV TI Start-to-end simulations of SASE FEL at the TESLA Test Facility, phase 1 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE free electron lasers; femtosecond pulses; coherent synchrotron radiation; space charge ID FREE-ELECTRON LASER; STATISTICAL PROPERTIES; RADIATION; BUNCH; DESY; VUV; REGIME; NM AB Phase 1 of the vacuum ultra-violet free-electron laser (FEL) at the TESLA Test Facility recently concluded operation. It successfully demonstrated the saturation of a SASE FEL in the wavelength range of 80-120 nm. We present a posteriori start-to-end numerical simulations of this FEL. These simulations are based on the programs Astra and elegant for the generation and transport of the electron distribution. An independent simulation of the intricate beam dynamics in the magnetic bunch compressor is performed with the program CSRtrack. The SASE FEL process is simulated with the code FAST. From our detailed simulations and the resulting phase space distribution at the undulator entrance, we found that the FEL was driven only by a small fraction (slice) of the electron bunch. This "lasing slice" is located in the head of the bunch, and has a peak current of approximately 3 kA. A strong energy chirp (due to the space charge field after compression) within this slice had a significant influence on the FEL operation. Our study shows that the radiation pulse duration is about 40 fs (FWHM) with a corresponding peak power of 1.5 GW. The simulated FEL properties are compared with various experimental data and found to be in excellent agreement. (C) 2004 Elsevier B.V. All rights reserved. C1 DESY, D-22607 Hamburg, Germany. Joint Inst Nucl Res, Moscow 141980, Russia. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Schneidmiller, EA (reprint author), DESY, Notkestr 85, D-22607 Hamburg, Germany. EM schneidm@mail.desy.de NR 29 TC 18 Z9 20 U1 0 U2 6 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 11 PY 2004 VL 530 IS 3 BP 217 EP 233 DI 10.1016/j.nima.2004.04.221 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 858EM UT WOS:000224173100004 ER PT J AU Batarin, VA Butler, J Chen, TY Davidenko, AM Derevschikov, AA Goncharenko, YM Grishin, VN Kachanov, VA Khodyrev, VY Konstantinov, AS Kravtsov, VI Kubota, Y Lukanin, VS Matulenko, YA Melnick, YM Meschanin, AP Mikhalin, NE Minaev, NG Mochalov, VV Morozov, DA Nogach, LV Ryazantsev, AV Semenov, PA Semenov, VK Shestermanov, KE Soloviev, LF Stone, S Uzunian, AV Vasiliev, AN Yakutin, AE Yarba, J AF Batarin, VA Butler, J Chen, TY Davidenko, AM Derevschikov, AA Goncharenko, YM Grishin, VN Kachanov, VA Khodyrev, VY Konstantinov, AS Kravtsov, VI Kubota, Y Lukanin, VS Matulenko, YA Melnick, YM Meschanin, AP Mikhalin, NE Minaev, NG Mochalov, VV Morozov, DA Nogach, LV Ryazantsev, AV Semenov, PA Semenov, VK Shestermanov, KE Soloviev, LF Stone, S Uzunian, AV Vasiliev, AN Yakutin, AE Yarba, J TI Comparison of radiation damage in lead tungstate crystals under pion and gamma irradiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE lead tungstate crystal; radiation damage; pion/gamma irradiation ID ENERGY AB Studies of the radiation hardness of lead tungstate crystals produced by the Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of Ceramics in China have been carried out at IHEP, Protvino. The crystals were irradiated by a 40 GeV pion beam. After full recovery, the same crystals were irradiated using a Cs-137 gamma-ray source. The dose rate profiles along the crystal length were observed to be quite similar. We compare the effects of the two types of radiation on the crystal's light output. (C) 2004 Elsevier B.V. All rights reserved. C1 Inst High Energy Phys, Protvino, Russia. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Nanjing Univ, Nanjing 210008, Peoples R China. Univ Minnesota, Minneapolis, MN 55455 USA. Syracuse Univ, Syracuse, NY 13244 USA. RP Uzunian, AV (reprint author), Inst High Energy Phys, Protvino, Russia. EM uzunian@sirius.ihep.su RI Semenov, Vitaliy/E-9584-2017 NR 11 TC 11 Z9 11 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 11 PY 2004 VL 530 IS 3 BP 286 EP 292 DI 10.1016/j.nima.2004.04.231 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 858EM UT WOS:000224173100009 ER PT J AU Sarantites, DG Reviol, W Chiara, CJ Charity, RJ Sobotka, LG Devlin, M Furlotti, M Pechenaya, OL Elson, J Hausladen, P Fischer, S Balamuth, D Clark, RM AF Sarantites, DG Reviol, W Chiara, CJ Charity, RJ Sobotka, LG Devlin, M Furlotti, M Pechenaya, OL Elson, J Hausladen, P Fischer, S Balamuth, D Clark, RM TI "Neutron Shell": a high efficiency array of neutron detectors for gamma-ray spectroscopic studies with Gammasphere SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID DESIGN AB A shell of neutron detectors was designed, constructed, and employed in gamma-ray spectroscopy with Gammasphere. It consists of up to 35 tapered regular hexagons that replace the same number of forward Ge-detector modules in Gammasphere. The shell was designed for high detection efficiency and very good neutron-gamma discrimination. The simultaneous use of time-of-flight, and two methods of pulse shape discrimination between neutrons and gamma rays is described. Techniques for spectroscopy with efficient detection of two neutrons are discussed. (C) 2004 Elsevier B.V. All rights reserved. C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Sarantites, DG (reprint author), Washington Univ, Dept Chem, 1 Brookings Dr,POB 1134, St Louis, MO 63130 USA. EM dgs@wuchem.wustl.edu RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 7 TC 32 Z9 32 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 11 PY 2004 VL 530 IS 3 BP 473 EP 492 DI 10.1016/j.nima.2004.04.243 PG 20 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 858EM UT WOS:000224173100026 ER PT J AU Spinka, C Holan, S Spinka, H AF Spinka, C Holan, S Spinka, H TI Estimating relative luminosity for RHIC spin physics SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE luminosity monitoring; rate induced biases AB Relative luminosities for different beam spin states must be determined to better than 10(-4)-10(-3) in order to measure spin asymmetries to the desired accuracy at RHIC. It is demonstrated that biases due to high rates in luminosity monitors can be kept acceptably small for anticipated RHIC operating conditions. Additionally, the distribution of the estimates is shown to be approximately Gaussian (normal) with known mean and standard error, permitting the construction of confidence intervals for the true spin asymmetry. (C) 2004 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, High Energy Phys Div, Argonne, IL 60439 USA. Texas A&M Univ, Dept Stat, College Stn, TX 77843 USA. RP Spinka, H (reprint author), Argonne Natl Lab, High Energy Phys Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hms@anl.gov NR 5 TC 0 Z9 0 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 2004 VL 530 IS 3 BP 536 EP 540 DI 10.1016/j.nima.2004.04.213 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 858EM UT WOS:000224173100031 ER PT J AU Stern, D van Dokkum, PG Nugent, P Sand, DJ Ellis, RS Sullivan, M Bloom, JS Frail, DA Kneib, JP Koopmans, LVE Treu, T AF Stern, D van Dokkum, PG Nugent, P Sand, DJ Ellis, RS Sullivan, M Bloom, JS Frail, DA Kneib, JP Koopmans, LVE Treu, T TI Discovery of a transient U-band dropout in a Lyman break survey: A tidally disrupted star at z=3.3? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (A267); galaxies : high-redshift; stars : flare; supernovae : general ID ULTRAVIOLET LUMINOSITY DENSITY; HIGH-REDSHIFT SUPERNOVAE; SUPERMASSIVE BLACK-HOLE; DIGITAL SKY SURVEY; IA SUPERNOVAE; SPECTROSCOPIC CONFIRMATION; INFRARED-EMISSION; FORMING GALAXIES; ALPHA EMITTERS; MS 1512-CB58 AB We report the discovery of a transient source in the central regions of galaxy cluster A267. The object, which we call "PALS-1,'' was found in a survey aimed at identifying highly magnified Lyman break galaxies in the fields of intervening rich clusters. At discovery, the source had U(n)>24.7 (2 sigma; AB), g=21.96+/-0.12, and very blue g-r and r-i colors; i.e., PALS-1 was a "U-band dropout,'' characteristic of star-forming galaxies and quasars at zsimilar to3. However, 3 months later the source had faded by more than 3 mag. Further observations showed a continued decline in luminosity, to R>26.4 at 7 months after discovery. Although the apparent brightness suggests a supernova at roughly the cluster redshift, we show that the photometry and light curve argue against any known type of supernova at any redshift. The spectral energy distribution and location near the center of a galaxy cluster are consistent with the hypothesis that PALS-1 is a gravitationally lensed transient at zapproximate to3.3. If this interpretation is correct, the source is magnified by a factor of 4-7, and two counterimages are predicted. Our lens model predicts that there are time delays between the three images of 1-10 yr and that we have witnessed the final occurrence of the transient. The intense luminosity (M(AB)similar to-23.5 after correcting for lensing) and blue UV continuum (implying Tgreater than or similar to50,000 K) argue that the source may have been a flare resulting from the tidal disruption of a star by a 10(6)-10(8) M(circle dot) black hole. Regardless of its physical nature, PALS-1 highlights the importance of monitoring regions of high magnification in galaxy clusters for distant time-varying phenomena. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Durham, Dept Phys, Durham DH1 3LE, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Stern, D (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA. RI Kneib, Jean-Paul/A-7919-2015; OI Kneib, Jean-Paul/0000-0002-4616-4989; Sullivan, Mark/0000-0001-9053-4820 NR 78 TC 19 Z9 19 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2004 VL 612 IS 2 BP 690 EP 697 DI 10.1086/422744 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 852XW UT WOS:000223791100011 ER PT J AU Podsiadlowski, P Langer, N Poelarends, AJT Rappaport, S Heger, A Pfahl, E AF Podsiadlowski, P Langer, N Poelarends, AJT Rappaport, S Heger, A Pfahl, E TI The effects of binary evolution on the dynamics of core collapse and neutron star kicks SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; globular clusters : general; stars : evolution; stars : neutron; supernovae : general; X-rays : stars ID BLACK-HOLE FORMATION; CIRCLE-DOT MODEL; X-RAY BINARIES; ELECTRON-CAPTURE SUPERNOVAE; ACCRETION-INDUCED COLLAPSE; MASSIVE CLOSE BINARIES; VELOCITY DISTRIBUTION; GLOBULAR-CLUSTERS; RADIO PULSARS; PRESUPERNOVA EVOLUTION AB We systematically examine how the presence in a binary affects the final core structure of a massive star and its consequences for the subsequent supernova explosion. Interactions with a companion star may change the final rate of rotation, the size of the helium core, the strength of carbon burning, and the final iron core mass. Stars with initial masses larger than similar to11 M-. that experience core collapse will generally have smaller iron cores at the point of explosion if they lost their envelopes through a binary interaction during or soon after core hydrogen burning. Stars below similar to11 M-., on the other hand, can end up with larger helium and metal cores if they have a close companion, since the second dredge-up phase that reduces the helium core mass dramatically in single stars does not occur once the hydrogen envelope is lost. We find that the initially more massive stars in binary systems with masses in the range 8 - 11 M-. are likely to undergo an electron-capture supernova, while single stars in the same mass range would end as ONeMg white dwarfs. We suggest that the core collapse in an electron-capture supernova ( and possibly in the case of relatively small iron cores) leads to a prompt or fast explosion rather than a very slow, delayed neutrino-driven explosion and that this naturally produces neutron stars with low-velocity kicks. This leads to a dichotomous distribution of neutron star kicks, as inferred previously, where neutron stars in relatively close binaries attain low kick velocities. We illustrate the consequences of such a dichotomous kick scenario using binary population synthesis simulations and discuss its implications. This scenario has also important consequences for the minimum initial mass of a massive star that becomes a neutron star. For single stars the critical mass may be as high as 10 - 12 M-., while for close binaries it may be as low as 6 - 8 M-.. These critical masses depend on the treatment of convection, the amount of convective overshooting, and the metallicity of the star, and will generally be lower for larger amounts of convective overshooting and lower metallicity. C1 Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. Astron Inst, NL-3508 TA Utrecht, Netherlands. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Podsiadlowski, P (reprint author), Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. EM podsi@astro.ox.ac.uk; n.langer@astro.uu.nl; sar@mit.edu; alex@6.lanl.gov; epfahl@cfa.harvard.edu NR 72 TC 193 Z9 195 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2004 VL 612 IS 2 BP 1044 EP 1051 DI 10.1086/421713 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 852XW UT WOS:000223791100043 ER PT J AU Denissenkov, PA Herwig, F AF Denissenkov, PA Herwig, F TI Enhanced extra mixing in low-mass red giants: Lithium production and thermal stability SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : chemically peculiar; stars : evolution; stars : interiors; stars : late-type; stars : rotation ID CARBON-ISOTOPE RATIOS; GLOBULAR-CLUSTER STARS; RICH K-GIANTS; AGB STARS; MERIDIONAL CIRCULATION; STELLAR EVOLUTION; EVOLVED STARS; MU-GRADIENTS; BRANCH STARS; BINARY STARS AB We show that canonical extra mixing with a diffusion coefficient D-mix approximate to 10(9) cm(2) s(-1), which is thought to start working in the majority of low-mass stars when they reach the bump luminosities on the red giant branch (RGB), cannot lead to an Li flash or a thermal instability, as has been proposed. The abundance levels of Li-7 measured in the most extreme Li-rich giants can be reproduced with models including enhanced extra mixing with a diffusion coefficient D-mix approximate to 10(11) cm(2) s(-1). We propose that if extra mixing in RGB stars is driven by rotation, then enhanced extra mixing and Li enrichment in some of these stars can be triggered by their spinning up by an external source of angular momentum. As plausible mechanisms of the spinning up, we consider tidal synchronization of a red giant's spin and orbital rotation in a close binary system and engulfment of a massive planet. The most convincing theoretical argument in favor of our hypothesis is a finding that a 10-fold increase of the spin angular velocity of a solar metallicity upper RGB star results in appropriate changes of both extra-mixing depth and rate, exactly as required for efficient Li production. We regard the existence of binary and single RGB stars with rotational velocities approaching similar to 10% of their equatorial Keplerian velocities, as well as the much larger proportion of Li-rich giants ( similar to 50%) among rapidly rotating objects, as the observational support for our hypothesis. C1 Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada. Los Alamos Natl Lab, T 6 Theoret Astrophys Grp, Los Alamos, NM 87545 USA. RP Denissenkov, PA (reprint author), Univ Victoria, Dept Phys & Astron, POB 3055, Victoria, BC V8W 3P6, Canada. EM dpa@uvastro.phys.uvic.ca; fherwig@lanl.gov NR 48 TC 44 Z9 44 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2004 VL 612 IS 2 BP 1081 EP 1091 DI 10.1086/422575 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 852XW UT WOS:000223791100047 ER PT J AU Gates, E Gyuk, G Harris, HC Subbarao, M Anderson, S Kleinman, SJ Liebert, J Brewington, H Brinkmann, J Harvanek, M Krzesinski, J Lamb, DQ Long, D Neilsen, EH Newman, PR Nitta, A Snedden, SA AF Gates, E Gyuk, G Harris, HC Subbarao, M Anderson, S Kleinman, SJ Liebert, J Brewington, H Brinkmann, J Harvanek, M Krzesinski, J Lamb, DQ Long, D Neilsen, EH Newman, PR Nitta, A Snedden, SA TI Discovery of new ultracool white dwarfs in the Sloan Digital Sky Survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (SDSS j0854-35, SDSS J0947-44, SDSS J1001-39, SDSS J1220-09, SDSS J1403-45); white dwarfs ID VERY-LOW LUMINOSITY; 1ST DATA RELEASE; GALACTIC DISK; COOL; ATMOSPHERES; SYSTEM; STARS; AGE AB We report the discovery of five new white dwarfs in the Sloan Digital Sky Survey. Four are ultracool, exhibiting strong collision-induced absorption (CIA) from molecular hydrogen and are similar in color to the three previously known coolest white dwarfs, SDSS J1337 + 00, LHS 3250, and LHS 1402. The fifth star shows milder CIA flux suppression and has a color and spectral shape similar to WD 0346 + 246. All five new white dwarfs are faint (g > 18.9) and have significant proper motions. One of the new ultracool white dwarfs, SDSS J0947, appears to be in a binary system with a slightly warmer (T-eff similar to 5000 K) white dwarf companion. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Adler Planetarium & Astron Museum, Chicago, IL 60605 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Apache Point Observ, Sunspot, NM 88349 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Cracow Pedag Univ, Mt Suhora Observ, PL-30084 Krakow, Poland. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Gates, E (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM gates@oddjob.uchicago.edu NR 35 TC 42 Z9 42 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2004 VL 612 IS 2 BP L129 EP L132 DI 10.1086/424568 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 852XX UT WOS:000223791200011 ER PT J AU Zucker, DB Kniazev, AY Bell, EF Martinez-Delgado, D Grebel, EK Rix, HW Rockosi, CM Holtzman, JA Walterbos, RAM Annis, J York, DG Ivezic, Z Brinkmann, J Brewington, H Harvanek, M Hennessy, G Kleinman, SJ Krzesinski, J Long, D Newman, PR Nitta, A Snedden, SA AF Zucker, DB Kniazev, AY Bell, EF Martinez-Delgado, D Grebel, EK Rix, HW Rockosi, CM Holtzman, JA Walterbos, RAM Annis, J York, DG Ivezic, Z Brinkmann, J Brewington, H Harvanek, M Hennessy, G Kleinman, SJ Krzesinski, J Long, D Newman, PR Nitta, A Snedden, SA TI Andromeda IX: A new dwarf spheroidal satellite of M31 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : dwarf; galaxies : evolution; galaxies : individual (Andromeda V, andromeda IX); Local Group ID DIGITAL SKY SURVEY; SURFACE BRIGHTNESS GALAXIES; DATA RELEASE; LOCAL GROUP; PHOTOIONIZATION; COMPANIONS; SYSTEM; SEARCH; HALO AB We report the discovery of a new dwarf spheroidal satellite of M31, Andromeda IX, based on resolved stellar photometry from the Sloan Digital Sky Survey (SDSS). Using both SDSS and public archival data, we have estimated its distance and other physical properties, and compared these to the properties of a previously known dwarf spheroidal companion, Andromeda V, also observed by SDSS. Andromeda IX is the lowest surface brightness galaxy found to date (mu(V,0) similar to 26.8 mag arcsec(-2)), and at the distance we estimate from the position of the tip of Andromeda IX's red giant branch, (m - M)(0) similar to 24.5 (805 kpc), Andromeda IX would also be the faintest galaxy known (M-V similar to - 8.3). C1 Max Planck Inst Astron, D-69117 Heidelberg, Germany. Univ Basel, Astron Inst, CH-4102 Binningen, Switzerland. Univ Washington, Dept Astron, Seattle, WA 98195 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Apache Point Observ, Sunspot, NM 88349 USA. USN Observ, Washington, DC 20392 USA. RP Zucker, DB (reprint author), Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany. EM zucker@mpia.de OI /0000-0002-1891-3794; Bell, Eric/0000-0002-5564-9873 NR 32 TC 73 Z9 73 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 2004 VL 612 IS 2 BP L121 EP L124 DI 10.1086/424691 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 852XX UT WOS:000223791200009 ER PT J AU Chun, HH Cary, RB Lansigan, F Whitelegge, J Rawlings, DJ Gatti, RA AF Chun, HH Cary, RB Lansigan, F Whitelegge, J Rawlings, DJ Gatti, RA TI ATM protein purified from vaccinia virus expression system: DNA binding requirements for kinase activation SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article DE ataxia-telangiectasia; ATM; vaccinia virus; purification; expression; protein kinase; atomic force microscopy; DNA; recombinant protein ID ATAXIA-TELANGIECTASIA GENE; DOUBLE-STRANDED DNA; IONIZING-RADIATION; HUMAN PLACENTA; PURIFICATION; PRODUCT; CLONING; DAMAGE; AUTOPHOSPHORYLATION; PHOSPHORYLATION AB The ataxia-telangiectasia, mutated (ATM) gene product plays a role in responding to double stand DNA breaks. Some biochemical studies of ATM function have been hampered by lack of an efficient expression system and abundant purified ATM protein. We report the construction of a vaccinia virus expressing ATM, vWR-ATM, which was used to produce large amounts of functional FLAG-tagged ATM protein (FLAG-ATM) in HeLa cells. Kinase activity of the purified FLAG-ATM was dependent on manganese and inhibited with wortmannin. Using the FLAG-ATM recombinant protein, GST-p53 serine 15 phosphorylation increased in the presence of damaged DNA. PHAS-1 phosphorylation was found to be DNA independent. Purified FLAG-ATM was recovered in the autophosphorylated form, as demonstrated by phosphorylation of ATM serine 1981. As shown by atomic force microscopy, FLAG-ATM bound to linear DNA both at broken ends and in mid-strands. Vaccinia virus is the most efficient ATM expression system described to date. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Calif Los Angeles, David Geffen Sch Med, Dept Pathol, Los Angeles, CA 90095 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, David Geffen Sch med, Dept Pediat, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Neuropsychiat, Dept Psychiat & Biobehav Sci, Pasarow Mass Spectrometry Lab, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Neuropsychiat, Dept Chem & Biochem, Pasarow Mass Spectrometry Lab, Los Angeles, CA 90095 USA. Univ Washington, Sch Med, Dept Pediat, Seattle, WA 98195 USA. RP Gatti, RA (reprint author), Univ Calif Los Angeles, David Geffen Sch Med, Dept Pathol, Los Angeles, CA 90095 USA. EM rgatti@mednet.ucla.edu FU NINDS NIH HHS [NS35322] NR 31 TC 6 Z9 6 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD SEP 10 PY 2004 VL 322 IS 1 BP 74 EP 81 DI 10.1016/j.bbrc.2004.07.085 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 849ZS UT WOS:000223581000011 PM 15313175 ER PT J AU Waltz, J AF Waltz, J TI Parallel adaptive refinement for unsteady flow calculations on 3D unstructured grids SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE adaptive refinement; unstructured grids; computational fluid dynamics; parallel computing ID MESHES AB A parallel adaptive refinement algorithm for three-dimensional unstructured grids is presented. The algorithm is based on an hierarchical h-refinement/derefinement scheme for tetrahedral elements. The algorithm has been fully parallelized for shared-memory platforms via a domain decomposition of the mesh at the algebraic level. The effectiveness of the procedure is demonstrated with applications which involve unsteady compressible fluid flow. A parallel speedup study of the algorithm also is included. Published in 2004 by John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Waltz, J (reprint author), Los Alamos Natl Lab, Div Appl Phys, MST086,POB 1663, Los Alamos, NM 87545 USA. EM jwaltz@lanl.gov NR 16 TC 17 Z9 18 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD SEP 10 PY 2004 VL 46 IS 1 BP 37 EP 57 DI 10.1002/fld.674 PG 21 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 848FR UT WOS:000223453500003 ER PT J AU Phillips, JD Whitby, FG Warby, CA Labbe, P Yang, C Pflugrath, JW Ferrara, JD Robinson, H Kushner, JP Hill, CP AF Phillips, JD Whitby, FG Warby, CA Labbe, P Yang, C Pflugrath, JW Ferrara, JD Robinson, H Kushner, JP Hill, CP TI Crystal structure of the oxygen-dependant coproporphyrinogen oxidase (Hem13p) of Saccharomyces cerevisiae SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HEREDITARY COPROPORPHYRIA; III OXIDASE; ESCHERICHIA-COLI; DIFFRACTION DATA; ACTIVE-SITE; RAT-LIVER; IN-HOUSE; CHOLESTEROL OXIDASE; HEME-BIOSYNTHESIS; RADICAL SAM AB Coproporphyrinogen oxidase (CPO) is an essential enzyme that catalyzes the sixth step of the heme biosynthetic pathway. Unusually for heme biosynthetic enzymes, CPO exists in two evolutionarily and mechanistically distinct families, with eukaryotes and some prokaryotes employing members of the highly conserved oxygen-dependent CPO family. Here, we report the crystal structure of the oxygen-dependent CPO from Saccharomyces cerevisiae (Hem13p), which was determined by optimized sulfur anomalous scattering and refined to a resolution of 2.0 Angstrom. The protein adopts a novel structure that is quite different from predicted models and features a central flat seven-stranded antiparallel sheet that is flanked by helices. The dimeric assembly, which is seen in different crystal forms, is formed by packing of helices and a short isolated strand that forms a beta-ladder with its counterpart in the partner subunit. The deep active-site cleft is lined by conserved residues and has been captured in open and closed conformations in two different crystal forms. A substratesized cavity is completely buried in the closed conformation by the similar to8-Angstrom movement of a helix that forms a lid over the active site. The structure therefore suggests residues that likely play critical roles in catalysis and explains the deleterious effect of many of the mutations associated with the disease hereditary coproporphyria. C1 Univ Utah, Sch Med, Dept Med, Div Hematol, Salt Lake City, UT 84132 USA. Univ Utah, Sch Med, Dept Biochem, Salt Lake City, UT 84132 USA. Univ Paris 07, CNRS, Inst Jacques Monod, Lab Biochim Porphyrines, F-75251 Paris, France. Rigaku Mol Struct Corp, The Woodlands, TX 77381 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Hill, CP (reprint author), Univ Utah, Sch Med, Dept Med, Div Hematol, 4C416 SOM,50 N 1900 E, Salt Lake City, UT 84132 USA. EM chris@biochem.utah.edu FU NIDDK NIH HHS [R01 DK020503, DK20503]; NIGMS NIH HHS [R01 GM056775, GM56775] NR 55 TC 51 Z9 56 U1 1 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 10 PY 2004 VL 279 IS 37 BP 38960 EP 38968 DI 10.1074/jbc.M406050200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 851KN UT WOS:000223684100110 PM 15194705 ER PT J AU Evans, OR Bell, AT Tilley, TD AF Evans, OR Bell, AT Tilley, TD TI Oxidative dehydrogenation of propane over vanadia-based catalysts supported on high-surface-area mesoporous MgAl2O4 SO JOURNAL OF CATALYSIS LA English DT Article DE propane; oxidative dehydrogenation; vanadia ID METAL-OXIDE CATALYSTS; ISOPROPANOL DECOMPOSITION; RAMAN-SPECTROSCOPY; ZIRCONIA CATALYSTS; AL2O3/MGO OXIDES; V2O5 CATALYSTS; LASER RAMAN; V2O5/TIO2; GAMMA-AL2O3; REACTIVITY AB The oxidative dehydrogenation of propane to propene was investigated over a series of novel vanadia-based catalysts supported on high-surface-area magnesium spinel. A mesoporous MgAl2O4 support was synthesized via a low-temperature sol-gel process involving the heterobimetallic alkoxide precursor, Mg[Al(O Pr-i)(4)](2). A high-purity catalyst support was obtained after calcination at 1173 K under O-2 atmosphere and active vanadia catalysts were prepared from the thermolysis of OV(O Bu-t)3 after grafting onto the spinel support. MgAl2O4-supported catalysts prepared in this manner have BET surface areas of 234-245 m(2)/g. All of the catalysts were characterized by X-ray powder diffraction, and Raman, solid-state NMR, and diffuse-reflectance UV-vis spectroscopy. At all vanadium loadings the vanadia supported on MgAl2O4 exist as a combination of isolated monovanadate and tetrahedral polyvanadate species. As the vanadium surface density increases for these catalysts the ratio of polyvanadate species to isolated monovandate species increases. In addition, as the vanadium surface density increases for these catalysts, the initial rate of propane ODH per V atom increases and reaches a maximum value at 6 VOx/nm(2). Increasing the vanadium surface density past this point results in a decrease in the rate of propane ODH owing to the formation of multilayer species in which subsurface vanadium atoms are essentially rendered catalytically inactive. The initial propene selectivity increases with increasing vanadium surface density and reaches a plateau of similar to 95% for the V/MgAl catalysts. Rate coefficients for propane ODH (k(1)), propane combustion (k(2)), and propene combustion (k(3)) were calculated for these catalysts. The value of k(1) increases with increasing VOx surface density, reaching a maximum at about 5.5 VOx/nm(2). On the other hand, the ratio (k(2)/k(1)) for V/MgAl decreases with increasing VOx surface density. The ratio (k(3)/k(1)) for both sets of catalysts shows no dependence on the vanadia surface density. The observed trends in k(1), (k(2)/k(1)), and (k(3)/k(1)) are discussed in terms of the surface structure of the catalyst. (C) 2004 Published by Elsevier Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem & Chem Engn, Berkeley, CA 94720 USA. RP Bell, AT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. EM bell@cchem.berkeley.edu NR 36 TC 65 Z9 66 U1 5 U2 45 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD SEP 10 PY 2004 VL 226 IS 2 BP 292 EP 300 DI 10.1016/j.jcat.2004.06.002 PG 9 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 845XG UT WOS:000223278100005 ER PT J AU Buttner, H Gaididei, YB Saxena, A Lookman, T Bishop, AR AF Buttner, H Gaididei, YB Saxena, A Lookman, T Bishop, AR TI Domain wall junctions as vortices: static structure SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID TOPOLOGICAL DEFECTS; SUPERSYMMETRIC QCD; QUARK CONFINEMENT; PHASE-TRANSITION; DARK-MATTER; DYNAMICS; EQUATION; STRINGS; SYSTEMS; MODELS AB For a model system with a complex scalar field static topological solutions are found analytically. Various domain wall structures are discussed and especially the junction of three different domains (called Y-type junctions) is studied in detail. It is shown that these junction structures are equivalent to a vortex with winding number k = 1. C1 Univ Bayreuth, Inst Phys, D-95440 Bayreuth, Germany. Bogolyubov Inst Theoret Phys, UA-01413 Kiev, Ukraine. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Buttner, H (reprint author), Univ Bayreuth, Inst Phys, POB 101251, D-95440 Bayreuth, Germany. NR 45 TC 2 Z9 2 U1 0 U2 2 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 10 PY 2004 VL 37 IS 36 BP 8595 EP 8608 AR PII S0305-4470(04)77838-5 DI 10.1088/0305-4470/37/36/002 PG 14 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 859UB UT WOS:000224292300003 ER PT J AU Cerda, J Michaelides, A Bocquet, ML Feibelman, PJ Mitsui, T Rose, M Fomin, E Salmeron, M AF Cerda, J Michaelides, A Bocquet, ML Feibelman, PJ Mitsui, T Rose, M Fomin, E Salmeron, M TI Novel water overlayer growth on Pd(111) characterized with scanning tunneling microscopy and density functional theory SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; ADSORPTION; FORMALISM; SURFACES; RU(0001) AB Scanning tunneling microscopy (STM) images of water submonolayers on Pd(111) reveal quasiperiodic and isolated adclusters with internal structure that would ordinarily be ascribed to icelike puckered hexagonal units. However, density functional theory and STM simulations contradict this conventional picture, showing instead that the water adlayers are composed mainly of flat-lying molecules arranged in planar water hexagons. A new rule for two dimensional (2D) water growth is offered that generates the structures observed experimentally from planar hexamer units. C1 CSIC, Inst Ciencia Mat Madrid, E-28049 Madrid, Spain. Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England. Ecole Normale Super, Chim Lab, UMR 5182, Lyon, France. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Cerda, J (reprint author), CSIC, Inst Ciencia Mat Madrid, Cantoblanco, E-28049 Madrid, Spain. EM mbocquet@ens-lyon.fr RI BOCQUET, MARIE-LAURE/A-7810-2011; Cerda, Jorge/F-4043-2010; Michaelides, Angelos/K-8727-2012 OI Cerda, Jorge/0000-0001-6176-0191; NR 21 TC 124 Z9 126 U1 3 U2 41 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 2004 VL 93 IS 11 AR 116101 DI 10.1103/PhysRevLett.93.116101 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400035 PM 15447355 ER PT J AU Cuk, T Baumberger, F Lu, DH Ingle, N Zhou, XJ Eisaki, H Kaneko, N Hussain, Z Devereaux, TP Nagaosa, N Shen, ZX AF Cuk, T Baumberger, F Lu, DH Ingle, N Zhou, XJ Eisaki, H Kaneko, N Hussain, Z Devereaux, TP Nagaosa, N Shen, ZX TI Coupling of the B-1g phonon to the antinodal electronic states of Bi2Sr2Ca0.92Y0.08Cu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; TIGHT-BINDING MODEL; NEUTRON-SCATTERING; SELF-ENERGY; T-C; DISPERSION; YBA2CU3O7; SPECTRA; WAVE AB Angle-resolved photoemission spectroscopy on optimally doped Bi2Sr2Ca0.92Y0.08Cu2O8+delta uncovers a coupling of the electronic bands to a 40 meV mode in an extended k-space region away from the nodal direction, leading to a new interpretation of the strong renormalization of the electronic structure seen in Bi2212. Phenomenological agreements with neutron and Raman experiments suggest that this mode is the B-1g oxygen bond-buckling phonon. A theoretical calculation based on this assignment reproduces the electronic renormalization seen in the data. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Natl Inst Adv Ind Sci & Technol, Nanoelect Res Inst, Tsukuba, Ibaraki 3058568, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Univ Tokyo, Dept Appl Phys, CREST, Bunkyo Ku, Tokyo 113, Japan. Univ Zurich, Inst Phys, CH-8057 Zurich, Switzerland. RP Cuk, T (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI Baumberger, Felix/A-5170-2008; Nagaosa, Naoto/G-7057-2012 OI Baumberger, Felix/0000-0001-7104-7541; NR 29 TC 150 Z9 151 U1 5 U2 27 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 2004 VL 93 IS 11 AR 117003 DI 10.1103/PhysRevLett.93.117003 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400050 PM 15447370 ER PT J AU Devereaux, TP Cuk, T Shen, ZX Nagaosa, N AF Devereaux, TP Cuk, T Shen, ZX Nagaosa, N TI Anisotropic electron-phonon interaction in the cuprates SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; SUPERCONDUCTIVITY; FLUCTUATION; YBA2CU3O7 AB We explore manifestations of electron-phonon coupling on the electron spectral function for two phonon modes in the cuprates exhibiting strong renormalizations with temperature and doping. Applying simple symmetry considerations and kinematic constraints, we find that the out-of-plane, out-of-phase O buckling mode (B-1g) involves small momentum transfers and couples strongly to electronic states near the antinode while the in-plane Cu-O breathing modes involve large momentum transfers and couples strongly to nodal electronic states. Band renormalization effects are found to be strongest in the superconducting state near the antinode, in full agreement with angle-resolved photoemission spectroscopy data. C1 Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ Tokyo, Dept Appl Phys, CREST, Bunkyo Ku, Tokyo 1138656, Japan. RP Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. RI Nagaosa, Naoto/G-7057-2012 NR 32 TC 155 Z9 155 U1 4 U2 28 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 10 PY 2004 VL 93 IS 11 AR 117004 DI 10.1103/PhysRevLett.93.117004 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400051 PM 15447371 ER PT J AU Ewald, G Nortershauser, W Dax, A Gotte, S Kirchner, R Kluge, HJ Kuhl, T Sanchez, R Wojtaszek, A Bushaw, BA Drake, GWF Yan, ZC Zimmermann, C AF Ewald, G Nortershauser, W Dax, A Gotte, S Kirchner, R Kluge, HJ Kuhl, T Sanchez, R Wojtaszek, A Bushaw, BA Drake, GWF Yan, ZC Zimmermann, C TI Nuclear charge radii of Li-8,Li-9 determined by laser spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID VARIATIONAL CALCULATIONS; HYPERFINE-STRUCTURE; MODEL-CALCULATIONS; LITHIUM ISOTOPES; LIGHT; STATE; IONS; SPIN; LI AB The 2s-->3s transition of Li-6,Li-7,Li-8,Li-9 was studied by high-resolution laser spectroscopy using two-photon Doppler-free excitation and resonance-ionization detection. Hyperfine structure splittings and isotope shifts were determined with precision at the 100 kHz level. Combined with recent theoretical work, the changes in the nuclear-charge radii of Li-8,Li-9 were determined. These are now the lightest short-lived isotopes for which the charge radii have been measured. It is found that the charge radii monotonically decrease with increasing neutron number from Li-6 to Li-9. C1 Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. Univ Tubingen, Dept Phys, D-72076 Tubingen, Germany. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada. Univ New Brunswick, Dept Phys, Fredericton, NB E3B 5A3, Canada. RP Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. RI Kuhl, Thomas/C-2243-2012; Zimmermann, Claus/E-9598-2014; Yan, Zong-Chao/F-6668-2014; Nortershauser, Wilfried/A-6671-2013 OI Kuhl, Thomas/0000-0001-6306-4579; Nortershauser, Wilfried/0000-0001-7432-3687 NR 20 TC 73 Z9 74 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2004 VL 93 IS 11 AR 113002 DI 10.1103/PhysRevLett.93.113002 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400015 PM 15447335 ER PT J AU Fincke, JR Lanier, NE Batha, SH Hueckstaedt, RM Magelssen, GR Rothman, SD Parker, KW Horsfield, CJ AF Fincke, JR Lanier, NE Batha, SH Hueckstaedt, RM Magelssen, GR Rothman, SD Parker, KW Horsfield, CJ TI Postponement of saturation of the Richtmyer-Meshkov instability in a convergent geometry SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN FLUID LAYER; RAYLEIGH-TAYLOR; SYSTEM; GROWTH; DRIVEN; LASER AB Strongly shocked cylindrically convergent implosions were conducted on the OMEGA laser. The directly driven targets consist of a low-density foam core and an embedded aluminum shell covered by an epoxy ablator. The outer surface of the aluminum shell has imposed single-mode perturbations with wave numbers k=0.08, 0.25, and 0.7 (rad/mum) and initial amplitudes eta(0)/lambda=0.013, 0.04 and 0.11. The perturbation growth rate is found to scale with k and, in our convergent geometry, no evidence of saturation for eta/lambda as large as 5 is observed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. AWE Aldermaston, Aldermaston, England. RP Fincke, JR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 19 TC 11 Z9 11 U1 3 U2 12 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 2004 VL 93 IS 11 AR 115003 DI 10.1103/PhysRevLett.93.115003 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400029 PM 15447349 ER PT J AU Guthrie, M Tulk, CA Benmore, CJ Xu, J Yarger, JL Klug, DD Tse, JS Mao, HK Hemley, RJ AF Guthrie, M Tulk, CA Benmore, CJ Xu, J Yarger, JL Klug, DD Tse, JS Mao, HK Hemley, RJ TI Formation and structure of a dense octahedral glass SO PHYSICAL REVIEW LETTERS LA English DT Article ID INDUCED COORDINATION CHANGES; HIGH-PRESSURE; GEO2 GLASS; MOLECULAR-DYNAMICS; VITREOUS GERMANIA; RANGE ORDER; DIFFRACTION; SIO2; SILICATE AB We have performed in situ x-ray and neutron-diffraction measurements, and molecular dynamics simulations, of GeO2, an archetypal network-forming glass under pressure. Below 5 GPa, additional atoms encroaching on the first tetrahedral shell are seen to be a precursor of local coordination change. Between 6 and 10 GPa, we observe structures with a constant average coordination of similar to5, indicating a new metastable, intermediate form of the glass. At 15 GPa, the structure of a fully octahedral glass has been measured. This structure is not retained upon decompression and, therefore, must be studied in situ. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Carnegie Inst Washington, Washington, DC 20015 USA. Univ Wyoming, Laramie, WY 82071 USA. Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. RP Guthrie, M (reprint author), Univ Edinburgh, Sch Phys, CSEC, Edinburgh EH9 3JZ, Midlothian, Scotland. RI Guthrie, Malcolm/K-3099-2012; Yarger, Jeff/L-8748-2014; Tulk, Chris/R-6088-2016; OI Yarger, Jeff/0000-0002-7385-5400; Tulk, Chris/0000-0003-3400-3878; Benmore, Chris/0000-0001-7007-7749 NR 29 TC 111 Z9 111 U1 2 U2 30 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 2004 VL 93 IS 11 AR 115502 DI 10.1103/PhysRevLett.93.115502 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400031 PM 15447351 ER PT J AU Hemmers, O Guillemin, R Rolles, D Wolska, A Lindle, DW Cheng, KT Johnson, WR Zhou, HL Manson, ST AF Hemmers, O Guillemin, R Rolles, D Wolska, A Lindle, DW Cheng, KT Johnson, WR Zhou, HL Manson, ST TI Nondipole effects in the photoionization of Xe 4d(5/2) and 4d(3/2): Evidence for quadrupole satellites SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; RANDOM-PHASE APPROXIMATION; DISTRIBUTION PARAMETERS; MULTIPOLE CORRECTIONS; DIPOLE APPROXIMATION; RAY PHOTOEMISSION; LOW ENERGIES; ATOMS; RETARDATION AB Measurements of nondipole parameters in spin-orbit-resolved Xe 4d photoionization demonstrate dynamical differences arising from relativistic effects. The experimental data do not agree with relativistic random-phase approximation calculations of single ionization dipole and quadrupole channels. It is suggested that the discrepancy is due to the omission of multiple-excitation quadrupole channels, i.e., quadrupole satellite transitions. C1 Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. RP Hemmers, O (reprint author), Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. RI Rolles, Daniel/C-2384-2008; Wolska, Anna/A-5818-2012 NR 31 TC 9 Z9 9 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 2004 VL 93 IS 11 AR 113001 DI 10.1103/PhysRevLett.93.113001 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400014 PM 15447334 ER PT J AU Li, SC Jia, JF Dou, RF Xue, QK Batyrev, IG Zhang, SB AF Li, SC Jia, JF Dou, RF Xue, QK Batyrev, IG Zhang, SB TI Borderline magic clustering: The fabrication of tetravalent Pb cluster arrays on Si(111)-(7x7) surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; PHASES; PB/SI(111); DIFFUSION; COVERAGE AB Well-ordered arrays of identical Pb clusters have been fabricated on a Si(111)-(7x7) substrate by the temperature-mediated surface clustering method. Interestingly, these clusters can easily transform into other forms when the growth temperature deviates slightly from the optimal values. In accord with experiments, first-principle total-energy calculations reveal several cluster structures centered on a mixed cluster model involving surface Pb and Si exchange. This borderline Pb/Si(111) system provides a unique, controlled way to study surface magic cluster formation and breakup dynamics. C1 Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, Beijing 100080, Peoples R China. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Li, SC (reprint author), Chinese Acad Sci, Inst Phys, State Key Lab Surface Phys, POB 603, Beijing 100080, Peoples R China. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 25 TC 68 Z9 72 U1 2 U2 24 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 10 PY 2004 VL 93 IS 11 AR 116103 DI 10.1103/PhysRevLett.93.116103 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400037 PM 15447357 ER PT J AU Shalizi, CR Shalizi, KL Haslinger, R AF Shalizi, CR Shalizi, KL Haslinger, R TI Quantifying self-organization with optimal predictors SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPLEXITY; MECHANICS AB Despite broad interest in self-organizing systems, there are few quantitative, experimentally applicable criteria for self-organization. The existing criteria all give counter-intuitive results for important cases. In this Letter, we propose a new criterion, namely, an internally generated increase in the statistical complexity, the amount of information required for optimal prediction of the system's dynamics. We precisely define this complexity for spatially extended dynamical systems, using the probabilistic ideas of mutual information and minimal sufficient statistics. This leads to a general method for predicting such systems and a simple algorithm for estimating statistical complexity. The results of applying this algorithm to a class of models of excitable media (cyclic cellular automata) strongly support our proposal. C1 Univ Michigan, Ctr Study Complex Syst, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Stat, Ann Arbor, MI 48109 USA. Massachusetts Gen Hosp, Dept Radiol, MGH NMR Ctr, Charlestown, MA 02129 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Shalizi, CR (reprint author), Univ Michigan, Ctr Study Complex Syst, Ann Arbor, MI 48109 USA. EM cshalizi@umich.edu; kshalizi@umich.edu; robhh@nmr.mgh.harvard.edu NR 29 TC 60 Z9 60 U1 2 U2 10 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 2004 VL 93 IS 11 AR 118701 DI 10.1103/PhysRevLett.93.118701 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400065 PM 15447385 ER PT J AU Wu, YZ Won, C Scholl, A Doran, A Zhao, HW Jin, XF Qiu, ZQ AF Wu, YZ Won, C Scholl, A Doran, A Zhao, HW Jin, XF Qiu, ZQ TI Magnetic stripe domains in coupled magnetic sandwiches SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-REORIENTATION TRANSITION; ULTRATHIN FILMS; 2-DIMENSIONAL FERROMAGNETS; ANISOTROPY; TEMPERATURE; MULTILAYERS; FE/CU(100) AB Magnetic stripe domains in the spin reorientation transition region are investigated in (Fe/Ni)/Cu(001) and Co/Cu/(Fe/Ni)/Cu(001) using photoemission electron microscopy. For (Fe/Ni)/Cu(001), the stripe domain width decreases exponentially as the Fe/Ni film approaches the spin reorientation transition point. For Co/Cu/(Fe/Ni)/Cu(001), the Fe/Ni stripe orientation is aligned with the Co in-plane magnetization, and the stripe domain width decreases exponentially with increasing the interlayer coupling between the Fe/Ni and Co films. By considering magnetic stripes within an in-plane magnetic field, we reveal a universal dependence of the stripe domain width on the magnetic anisotropy and on the interlayer coupling. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. IOP CAS, Int Ctr Quantum Struct, Beijing 100080, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China. RP Wu, YZ (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI wu, YiZheng/O-1547-2013; Wu, yizheng/P-2395-2014; Scholl, Andreas/K-4876-2012; Qiu, Zi Qiang/O-4421-2016 OI Wu, yizheng/0000-0002-9289-1271; Qiu, Zi Qiang/0000-0003-0680-0714 NR 36 TC 59 Z9 60 U1 2 U2 17 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 10 PY 2004 VL 93 IS 11 AR 117205 DI 10.1103/PhysRevLett.93.117205 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400057 PM 15447377 ER PT J AU Yusof, ZM Conde, ME Gai, W AF Yusof, ZM Conde, ME Gai, W TI Schottky-enabled photoemission in a rf accelerator photoinjector: Possible generation of ultralow transverse thermal-emittance electron beam SO PHYSICAL REVIEW LETTERS LA English DT Article ID AL SURFACES; EMISSION; MG; OXIDE; XPS AB We present a clear signature of the Schottky effect in a rf photoinjector using photons with energy lower than the Mg cathode work function. This signature is manifested by the shift in the rf phase angle for the onset of the detection of photoelectrons via single-photon absorption and allows for a reasonable estimate of the field enhancement factor. This is a viable method to generate an electron beam with very low thermal emittance and thus, a high brightness beam. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Yusof, ZM (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 18 TC 16 Z9 16 U1 1 U2 2 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 10 PY 2004 VL 93 IS 11 AR 114801 DI 10.1103/PhysRevLett.93.114801 PG 4 WC Physics, Multidisciplinary SC Physics GA 852ZB UT WOS:000223794400025 PM 15447345 ER PT J AU Ostrom, H Nordlund, D Ogasawara, H Weiss, K Triguero, L Pettersson, LGM Nilsson, A AF Ostrom, H Nordlund, D Ogasawara, H Weiss, K Triguero, L Pettersson, LGM Nilsson, A TI Geometric structure and chemical bonding of acetylene adsorbed on Cu(110) SO SURFACE SCIENCE LA English DT Article DE alkynes; copper; carbon; chemisorption; X-ray photoelectron spectroscopy; X-ray absorption spectroscopy ID RAY-EMISSION-SPECTROSCOPY; LOCAL ADSORPTION STRUCTURE; SHAPE RESONANCES; SURFACE ADSORBATES; FINE-STRUCTURE; ETHYLENE; C2H2; HYDROCARBONS; ABSORPTION; CU(100) AB The chemical bonding and geometric structure of acetylene adsorbed on Cu(I 10) is analyzed using X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) in combination with density functional theory (DFT) total energy geometry optimizations and spectral calculations. XPS reveals two different adsorbed species at liquid nitrogen temperature. The molecular alignment is deduced from angle-resolved XAS, revealing that in one site the molecules are aligned with the C-C axis along the [0 0 1] direction and in the other site with an average angle of 35degrees to the Cu rows. The position of the shape resonance is used to deduce a C-C bond length of 1.35 Angstrom, which is close to the values obtained from the DFT geometry optimizations. XES reveals strong sigma-pi mixing and new occupied states close to the Fermi level, originating from the out-of-plane pi* orbital, which becomes occupied upon adsorption in agreement with the Dewar-Chatt-Duncanson model of the bonding. (C) 2004 Elsevier B.V. All rights reserved. C1 Stockholm Univ, Dept Phys, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Uppsala Univ, Dept Phys, SE-75121 Uppsala, Sweden. KTH Syd, SE-13640 Haninge, Sweden. RP Ostrom, H (reprint author), Stockholm Univ, Dept Phys, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden. EM Lars.Petterson@physto.se RI Nordlund, Dennis/A-8902-2008; Nilsson, Anders/E-1943-2011; Pettersson, Lars/F-8428-2011; Pettersson, Lars/J-4925-2013; Ogasawara, Hirohito/D-2105-2009 OI Nordlund, Dennis/0000-0001-9524-6908; Nilsson, Anders/0000-0003-1968-8696; Pettersson, Lars/0000-0003-1133-9934; Ogasawara, Hirohito/0000-0001-5338-1079 NR 52 TC 19 Z9 19 U1 2 U2 14 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 2004 VL 565 IS 2-3 BP 206 EP 222 DI 10.1016/j.susc.2004.07.012 PG 17 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 854CO UT WOS:000223878100014 ER PT J AU Wang, XQ Hanson, JC Frenkel, AI Kim, JY Rodriguez, JA AF Wang, XQ Hanson, JC Frenkel, AI Kim, JY Rodriguez, JA TI Time-resolved studies for the mechanism of reduction of copper oxides with carbon monoxide: Complex behavior of lattice oxygen and the formation of suboxides SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SAMARIA-DOPED CERIA; GAS SHIFT REACTION; CO OXIDATION; CATALYTIC-ACTIVITY; SUPPORT; CU2O; CUO; DIFFRACTION; KINETICS; SURFACE AB Temperature-programmed reduction (TPR), synchrotron-based time-resolved X-ray diffraction (TR-XRD), extended X-ray absorption fine-structure (EXAFS), and X-ray absorption near-edge structure (XANES) were b employed in this work to systematically study the reaction of CuO and CU2O With CO gas molecules. Both TPR and isothermal reduction results showed that CuO was easier to reduce than CU2O under the same reaction conditions. In situ measurements of XRD and XANES showed a direct transformation pathway for CuO reduction (CuO --> Cu) when there was a large supply of CO, while they showed a sequential step pathway involving one intermediate (CuO --> Cu2O --> CU) with a limited supply of CO. An induction period for CuO reduction was seen and increased with decreasing temperature. 0 vacancies in CuO were observed during the induction period that could foster formation of a nonstoichiometric metastable copper-oxide species. The metastable species can either react rapidly with CO to form metallic copper during high CO flow rates or can relax into a CuO lattice when the supply of CO is limited. The CU2O-like intermediate showed extra disordered oxygen in the empty tetrahedral sites Of CU2O. Based on these observations, a possible mechanism for CuO reduction is proposed. This study demonstrates that the mechanism for the reduction of an oxide by CO can vary considerably with the experimental conditions (gas flow rate, temperature, sample size, etc.), and its complex kinetics cannot be described by a single n(th)-order expression over the entire range of reaction. The behavior of CuO-based catalysts is discussed in the light of these results. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Yeshiva Univ, Dept Phys, New York, NY 10016 USA. Pohang Accelerator Lab, Beamline Div, Pohang 790784, South Korea. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov RI Hanson, jonathan/E-3517-2010; Frenkel, Anatoly/D-3311-2011 OI Frenkel, Anatoly/0000-0002-5451-1207 NR 39 TC 114 Z9 114 U1 0 U2 48 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 9 PY 2004 VL 108 IS 36 BP 13667 EP 13673 DI 10.1021/jp040366o PG 7 WC Chemistry, Physical SC Chemistry GA 851RW UT WOS:000223703900017 ER PT J AU Uetsuka, H Henderson, MA Sasahara, A Onishi, H AF Uetsuka, H Henderson, MA Sasahara, A Onishi, H TI Formate adsorption on the (111) surface of rutile TiO2 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; FORMIC-ACID; TIO2(110) SURFACE; DISSOCIATIVE ADSORPTION; OXIDE SURFACES; DECOMPOSITION; SPECTROSCOPY; ENERGY; ORIENTATION; REACTIVITY AB The (111) surface of rutile TiO2 was prepared with argon ion sputtering and vacuum annealing at 970 K. Scanning tunneling microscope observation revealed nanometer-scale domains of (1 x 1) and (1 x 2) phases on the surface. Formic acid was dissociatively adsorbed on the surface at room temperature. The recombination and decomposition temperatures of the adsorbed formate were similar to those reported on the (110) surface. The CH-related and COO-related stretching modes probed by high-resolution electron energy loss showed two or more types of formate. The wavenumber of the vibrational modes can be interpreted with a mixture of monodentate, bidentate, and bridge form of adsorption. The number density of the formates counted in microscope images supported monodentate and bidentate forms. Sequential imaging revealed limited mobility of the formates, reflecting the wide separation of surface Ti atoms. C1 Kanagawa Acad Sci & Technol, Surface Chem Lab, KSP, Kawasaki, Kanagawa 2130012, Japan. Pacific NW Natl Lab, Interfacial Chem & Engn Grp, Richland, WA 99352 USA. RP Onishi, H (reprint author), Kanagawa Acad Sci & Technol, Surface Chem Lab, KSP, Kawasaki, Kanagawa 2130012, Japan. EM oni@kobe-u.ac.jp NR 33 TC 29 Z9 29 U1 0 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 9 PY 2004 VL 108 IS 36 BP 13706 EP 13710 DI 10.1021/jp049126z PG 5 WC Chemistry, Physical SC Chemistry GA 851RW UT WOS:000223703900023 ER PT J AU Jackson, DD Fisk, Z AF Jackson, DD Fisk, Z TI Anisotropy in magnetic and transport properties of GdCrSb3 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE magnetism; antimonides; resistivity; RCrSb3 ID LN=LA-ND; ANTIMONIDES; FERROMAGNET; LACRSB3; CR; SM AB We report the first measurements of anisotropy in magnetic susceptibility, magnetization, and electrical resistivity using single crystals of GdTSb3 (T = Cr, V). GdTSb3 is a quasi-two dimensional system with orthorhombic crystal structure (space group: Pbcm). Unlike the other light rare earth chromium antimonides (R = Ce-Nd, Sm), in which two magnetic transitions are observed, GdCrSb3 undergoes a single ferrimagnetic transition at T-C = 86 K, which is evident in both the magnetic susceptibility and electrical resistivity. Within the b-c plane, GdCrSb3 is found to have metallic behavior from 5 to 300 K, but it is found to have insulating behavior (drho(a)/dT<0) along the stacking axis. GdVSb3 is found to have a Neel transition at 5 K due to the localized Gd ions, but no ferromagnetic transition. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. RP Jackson, DD (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM djackson@mailaps.org NR 15 TC 12 Z9 12 U1 3 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 8 PY 2004 VL 377 IS 1-2 BP 243 EP 247 DI 10.1016/j.jallcom.2004.01.062 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 853BK UT WOS:000223801000045 ER PT J AU Peters, B Bell, AT Chakraborty, A AF Peters, B Bell, AT Chakraborty, A TI Rate constants from the reaction path Hamiltonian. I. Reactive flux simulations for dynamically correct rates SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; MOLECULAR-DYNAMICS; CHEMICAL-REACTIONS; POTENTIAL BARRIERS; CYCLOHEXANE; ISOMERIZATION; INVERSION; CHEMISTRY; PROGRAM; LIQUIDS AB As ab initio electronic structure calculations become more accurate, inherent sources of error in classical transition state theory such as barrier recrossing and tunneling may become major sources of error in calculating rate constants. This paper introduces a general method for diabatically constructing the transverse eigensystem of a reaction path Hamiltonian in systems with many degenerate transverse frequencies. The diabatically constructed reaction path Hamiltonian yields smoothly varying coupling constants that, in turn, facilitate reactive flux calculations. As an example we compute the dynamically corrected rate constant for the chair to boat interconversion of cyclohexane, a system with 48 degrees of freedom and a number of degenerate frequencies. The transmission coefficients obtained from the reactive flux simulations agree with previous results that have been calculated using an empirical potential. Furthermore, the calculated rate constants agree with experimental values. Comparison to variational transition state theory shows that, despite finding the true bottleneck along the reaction pathway, variational transition state theory only accounts for half of the rate constant reduction due to recrossing trajectories. (C) 2004 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem Engn, 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 Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Chakraborty, A (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM arup@uclink.berkeley.edu OI Bell, Alexis/0000-0002-5738-4645 NR 44 TC 17 Z9 17 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2004 VL 121 IS 10 BP 4453 EP 4460 DI 10.1063/1.1778161 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 848UV UT WOS:000223494500002 PM 15332874 ER PT J AU Peters, B Bell, AT Chakraborty, A AF Peters, B Bell, AT Chakraborty, A TI Rate constants from the reaction path Hamiltonian. II. Nonseparable semiclassical transition state theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMAL RATE CONSTANTS; INITIAL-VALUE REPRESENTATION; COMPLEX MOLECULAR-SYSTEMS; POTENTIAL-ENERGY SURFACES; CHEMICAL-REACTIONS; AB-INITIO; GAS-PHASE; HYDROGEN ABSTRACTION; PRACTICAL METHODS; DYNAMICS AB For proton transfer reactions, the tunneling contributions to the rates are often much larger than thermally activated rates at temperatures of interest. A number of separable tunneling corrections have been proposed that capture the dependence of tunneling rates on barrier height and imaginary frequency size. However, the effects of reaction pathway curvature and barrier anharmonicity are more difficult to quantify. The nonseparable semiclassical transition state theory (TST) of Hernandez and Miller [Chem. Phys. Lett. 214, 129 (1993)] accounts for curvature and barrier anharmonicity, but it requires prohibitively expensive cubic and quartic derivatives of the potential energy surface at the transition state. This paper shows how the reaction path Hamiltonian can be used to approximate the cubic and quartic derivatives used in nonseparable semiclassical transition state theory. This enables tunneling corrections that include curvature and barrier anharmonicity effects with just three frequency calculations as required by a conventional harmonic transition state theory calculation. The tunneling correction developed here is nonseparable, but can be expressed as a thermal average to enable efficient Monte Carlo calculations. For the proton exchange reaction NH2+CH(4)double left right arrowNH(3)+CH3, the nonseparable rates are very accurate at temperatures from 300 K up to about 1000 K where the TST rate itself begins to diverge from the experimental results. (C) 2004 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. 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. RP Chakraborty, A (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM arup@uclink.berkeley.edu OI Bell, Alexis/0000-0002-5738-4645 NR 31 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2004 VL 121 IS 10 BP 4461 EP 4466 DI 10.1063/1.1778162 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 848UV UT WOS:000223494500003 PM 15332875 ER PT J AU Fohlisch, A Wurth, W Stichler, M Keller, C Nilsson, A AF Fohlisch, A Wurth, W Stichler, M Keller, C Nilsson, A TI X-ray emission spectroscopy of (2 root 3x2 root 3)R30 degrees CO/Ru(0001): Comparison to c(2x2) CO/Ni(100) and c(2x2)CO/Cu(100) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID METAL-SURFACES; CARBON-MONOXIDE; VIBRATIONAL SPECTROSCOPY; ADSORBATE INTERACTIONS; SYNCHROTRON-RADIATION; STRUCTURAL INFLUENCES; ADSORPTION ENERGY; CO CHEMISORPTION; RU(001); CU(100) AB The atom specific electronic structure of (2root3x2root3)R30degreesCO on hcp Ru(0001) has been determined with resonantly excited x-ray emission spectroscopy. We find that the general features of the local adsorbate electronic structure are similar to the situation of CO adsorbed on the fcc metals Ni(100) and Cu(100). The interpretation of the surface chemical bond of (2root3x2root3)R30degreesCO/Ru(0001) based on the direct application of the local, allylic model from on-top adsorption on the fcc(100) surfaces Ni(100) and Cu(100) explains many aspects of the surface chemical bond. However, also nonlocal contributions like adsorbate-adsorbate interaction and the deviation from upright on-top adsorption on the Ru(0001) surface influence observables like the heat of adsorption and the Me-CO bond strength. (C) 2004 American Institute of Physics. C1 Univ Hamburg, Inst Expt Phys, D-22761 Hamburg, Germany. Fachhsch Rosenheim, D-83024 Rosenheim, Germany. Tech Univ Munich, Phys Dept E20, D-85747 Garching, Germany. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Stockholm Univ, Albanova Univ Ctr, Fysikum, SE-10691 Stockholm, Sweden. RP Fohlisch, A (reprint author), Univ Hamburg, Inst Expt Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany. EM alexander.foehlisch@desy.de RI Nilsson, Anders/E-1943-2011 OI Nilsson, Anders/0000-0003-1968-8696 NR 44 TC 14 Z9 14 U1 0 U2 15 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 2004 VL 121 IS 10 BP 4848 EP 4852 DI 10.1063/1.1778380 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 848UV UT WOS:000223494500048 PM 15332920 ER PT J AU Boeck, WL Suszcynsky, DM Light, TE Jacobson, AR Christian, HJ Goodman, SJ Buechler, DE Guillen, JLL AF Boeck, WL Suszcynsky, DM Light, TE Jacobson, AR Christian, HJ Goodman, SJ Buechler, DE Guillen, JLL TI A demonstration of the capabilities of multisatellite observations of oceanic lightning SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE atmospheric electricity; lightning; remote sensing ID OPTICAL TRANSIENT DETECTOR; TRANSIONOSPHERIC PULSE PAIRS; MEASURING MISSION TRMM; FORTE SATELLITE; PHOTODIODE DETECTOR; RADIO-FREQUENCY; CLOUDS; SENSOR; PHENOMENOLOGY; MICROWAVE AB [ 1] We have examined lightning flashes in five nighttime, oceanic thunderstorms, which were jointly observed by Tropical Rainfall Measuring Mission (TRMM) and Fast On-Orbit Recording of Transient Events ( FORTE). The multiplicity of instruments on board these satellites presents a multiphenomenological snapshot view of oceanic nighttime convection. Data are available for five oceanic storms with a total of 40 flashes. The independent optical imagers on each satellite establish the flash locations. The relative fraction of Lightning Imaging Sensor ( LIS)-detected optical pulses that were also observed by the FORTE/photodiode detector varied from 0% for LIS range less than 10(4) J sr(-1) m(-2) mum(-1) to 100% for LIS range greater than 10(6) muJ(-1) sr(-1) m(-2) mum(-1). The FORTE/VHF data sometimes allow estimation of the VHF source emissions heights and identification of individual discharge processes as positive or negative, in-cloud or cloud-to-ground. These observations reinforce the concepts that the VHF pulses are produced by a breakdown process, while the optical pulses are the result of current flow. C1 Niagara Univ, Dept Comp & Informat Sci, Niagara, NY 14109 USA. Univ Alabama, Ctr Earth Syst Sci, Huntsville, AL 35816 USA. Natl Space Sci Technol Ctr, Global Hydrol & Climate Ctr, Huntsville, AL 35816 USA. Sandia Natl Labs, Sensors & Elect Dept, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Boeck, WL (reprint author), Niagara Univ, Dept Comp & Informat Sci, Niagara, NY 14109 USA. EM boeck@niagara.edu NR 26 TC 5 Z9 5 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 8 PY 2004 VL 109 IS D17 AR D17204 DI 10.1029/2003JD004491 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 854HD UT WOS:000223892200002 ER PT J AU Littlewood, PB Eastham, PR Keeling, JMJ Marchetti, FM Szymanska, MH AF Littlewood, PB Eastham, PR Keeling, JMJ Marchetti, FM Szymanska, MH TI Models of coherent exciton condensation SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 1st Workshop of the EU RT Network CY MAR 28-31, 2003 CL Gregynog, WALES ID COUPLED QUANTUM-WELLS; ELECTRON-HOLE GAS; BOSE-EINSTEIN CONDENSATION; SEMICONDUCTOR MICROCAVITY; GROUND-STATE; PHASE-TRANSITIONS; POTENTIAL TRAPS; SYSTEM; SUPERCONDUCTIVITY; IMPURITIES AB That excitons in solids might condense into a phase-coherent ground state was proposed about 40 years ago, and has been attracting experimental and theoretical attention ever since. Although experimental confirmation has been hard to come by, the concepts released by this phenomenon have been widely influential. This tutorial review discusses general aspects of the theory of exciton and polariton condensates, focusing on the reasons for coherence in the ground state wavefunction, the BCS to Bose crossover(s) for excitons and for polaritons, and the relationship of the coherent condensates to standard lasers. C1 Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. Los Alamos Natl Lab, Pulsed Field Facil, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Littlewood, PB (reprint author), Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. RI Keeling, Jonathan/B-7827-2008; Cavendish, TCM/C-9489-2009; Littlewood, Peter/B-7746-2008; Marchetti, Francesca Maria/F-7695-2012 OI Keeling, Jonathan/0000-0002-4283-552X; Simons, Benjamin/0000-0002-3875-7071; Eastham, Paul/0000-0002-7054-1457; Marchetti, Francesca Maria/0000-0003-1394-7394 NR 89 TC 59 Z9 61 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 8 PY 2004 VL 16 IS 35 BP S3597 EP S3620 AR PII S0953-8984(04)83322-8 DI 10.1088/0953-8984/16/35/003 PG 24 WC Physics, Condensed Matter SC Physics GA 858MP UT WOS:000224196200004 ER PT J AU Fu, AH Micheel, CM Cha, J Chang, H Yang, H Alivisatos, AP AF Fu, AH Micheel, CM Cha, J Chang, H Yang, H Alivisatos, AP TI Discrete nanostructures of quantum dots/Au with DNA SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS; HYBRIDIZATION 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. RP Alivisatos, AP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM alivis@uclink4.berkeley.edu RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 27 TC 197 Z9 198 U1 2 U2 45 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 8 PY 2004 VL 126 IS 35 BP 10832 EP 10833 DI 10.1021/ja04647x PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 851NH UT WOS:000223691300018 PM 15339154 ER PT J AU Jaeger, TD van Heijnsbergen, D Klippenstein, SJ von Helden, G Meijer, G Duncan, MA AF Jaeger, TD van Heijnsbergen, D Klippenstein, SJ von Helden, G Meijer, G Duncan, MA TI Vibrational spectroscopy and density functional theory of transition-metal ion-benzene and dibenzene complexes in the gas phase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CATION-PI INTERACTIONS; RADIATIVE ASSOCIATION KINETICS; COLLISION-INDUCED DISSOCIATION; FREE-ELECTRON-LASER; INFRARED-SPECTROSCOPY; CHARGE-TRANSFER; CLUSTER IONS; PHOTOELECTRON-SPECTROSCOPY; SANDWICH CLUSTERS; BINDING-ENERGIES AB Metal-benzene complexes of the form M(benzene)(n) (M = Ti, V, Fe, Co, Ni) are produced in the gas-phase environment of a molecular beam by laser vaporization in a pulsed nozzle cluster source. These complexes are photoionized with an ArF excimer laser, producing the corresponding cations. The respective mono- and dibenzene complex ions are isolated in an ion-trap mass spectrometer and studied with infrared resonance enhanced multiple-photon dissociation (IR-REMPD) spectroscopy using a tunable free electron laser. Photodissociation of all complexes occurs by the elimination of intact neutral benzene molecules, and this process is enhanced on resonances in the vibrational spectrum, making it possible to measure vibrational spectroscopy for size-selected complexes. Vibrational bands in the 600-1700 cm(-1) region are characteristic of the benzene molecular moiety with systematic shifts caused by the metal bonding. The spectra in this solvent-free environment exhibit periodic trends in band shifts and intensities relative to the free benzene molecule that varies with the metal. Density functional theory calculations are employed to investigate the structures, energetics, and vibrational frequencies of these complexes. The comparison between experiment and theory provides fascinating new insight into the bonding in these prototypical organometallic complexes. C1 Univ Georgia, Dept Chem, Athens, GA 30602 USA. FOM, Inst Plasmaphys Rijnhuizen, NL-3439 MN Nieuwegein, Netherlands. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. RP Univ Georgia, Dept Chem, Athens, GA 30602 USA. RI Meijer, Gerard/D-2141-2009; von Helden, Gert/H-9357-2012; OI von Helden, Gert/0000-0001-7611-8740; Klippenstein, Stephen/0000-0001-6297-9187 NR 65 TC 120 Z9 120 U1 4 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 8 PY 2004 VL 126 IS 35 BP 10981 EP 10991 DI 10.1021/ja0477165 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 851NH UT WOS:000223691300048 PM 15339184 ER PT J AU Posner, RG Paar, JM Licht, A Pecht I Conrad, DH Hlavacek, WS AF Posner, RG Paar, JM Licht, A Pecht, I Conrad, DH Hlavacek, WS TI Interaction of a monoclonal IgE-specific antibody with cell-surface IgE-Fc epsilon RI: Characterization of equilibrium binding and secretory response SO BIOCHEMISTRY LA English DT Article ID BASOPHILIC LEUKEMIA-CELLS; HISTAMINE-RELEASE; CROSS-LINKING; MAST-CELLS; IMMUNOGLOBULIN-E; DIVALENT HAPTENS; BIVALENT LIGANDS; DIMERIZATION KINETICS; SIGNAL-TRANSDUCTION; RECEPTOR COMPLEXES AB Aggregation of FcepsilonR1, the high-affinity cell-surface receptor for IgE antibody, is required for degranulation of basophils and mast cells, but not all receptor aggregates elicit this cellular response. The stereochemical constraints on clusters of FcepsilonRI that are able to signal cellular responses, such as degranulation, have yet to be fully defined. To improve our understanding of the properties of FcepsilonRI aggregates that influence receptor signaling, we have studied the interaction of 23G3, a rat IgG(1kappa), IgE-specific monoclonal antibody, with IgE-FcERI complexes on rat mucosal-type mast cells (RBL-2H3 line). We find that 23G3 is a potent secretagogue. This property and the structural features of 23G3 (two symmetrically arrayed IgE-specific binding sites) make 23G3 a potentially valuable reagent for investigating the relationship between FcepsilonRI clustering and FcepsilonRI-mediated signaling events. To develop a mathematical model of 23G3-induced aggregation of FcepsilonRI, we used fluorimetry and flow cytometry to quantitatively monitor equilibrium binding of FITC-labeled 23G3 intact Ab and its Fab' fragment to cell-surface IgE. The results indicate that IgE bound to FcepsilonRI expresses two epitopes for 23G3 binding; that 23G3 binds IgE resident on the cell surface with negative cooperativity; and that 23G3 appears to induce mostly but not exclusively noncyclic dimeric aggregates of FcepsilonRI. There is no simple relationship between receptor aggregation at equilibrium and the degranulation response. Further studies are needed to establish how 23G3-induced aggregation of IgE-FcepsilonRI correlates with cellular responses. C1 No Arizona Univ, Dept Biol, Flagstaff, AZ 86011 USA. Pacific Univ, Dept Chem, Forest Grove, OR 97116 USA. Weizmann Inst Sci, Dept Immunol, IL-76100 Rehovot, Israel. Virginia Commonwealth Univ, Dept Microbiol & Immunol, Richmond, VA 23298 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Posner, RG (reprint author), No Arizona Univ, Dept Biol, Flagstaff, AZ 86011 USA. EM richard.posner@nau.edu FU FIC NIH HHS [F06TW002308]; NIAID NIH HHS [AI35977, AI28433] NR 56 TC 6 Z9 6 U1 0 U2 2 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 7 PY 2004 VL 43 IS 35 BP 11352 EP 11360 DI 10.1021/bi049686o PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 851TM UT WOS:000223708400022 PM 15366945 ER PT J AU Nieto, MM Turyshev, SG AF Nieto, MM Turyshev, SG TI Finding the origin of the Pioneer anomaly SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID SOLAR SAIL; MISSION; EXPLANATION AB Analysis of radio-metric tracking data from the Pioneer 10/11 spacecraft at distances between 20 and 70 astronomical units (AU) from the Sun has consistently indicated the presence of an anomalous, small, constant Doppler frequency drift. The drift can be interpreted as being due to a constant acceleration of a(P) = (8.74 +/- 1.33) x 10(-8) cm s(-2) directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. As a result, the nature of this anomaly has become of growing interest. Here we present a concept for a deep-space experiment that will reveal the origin of the discovered anomaly and will also characterize its properties to an accuracy of at least two orders of magnitude below the anomaly's size. The proposed mission will not only provide a significant accuracy improvement in the search for small anomalous accelerations, it will also determine if the anomaly is due to some internal systematic or has an external origin. A number of critical requirements and design considerations for the mission are outlined and addressed. If only already existing technologies were used, the mission could be flown as early as 2010. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Los Alamos Natl Lab, Div Theoret, MS-B285, Los Alamos, NM 87545 USA. EM mmn@lanl.gov; turyshev@jpl.nasa.gov NR 25 TC 37 Z9 37 U1 2 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 EI 1361-6382 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD SEP 7 PY 2004 VL 21 IS 17 BP 4005 EP 4023 AR PII S0264-9381(04)72106-1 DI 10.1088/026409381/21/17/001 PG 19 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 859TH UT WOS:000224290300003 ER PT J AU Xu, T Zvelindovsky, AV Sevink, GJA Gang, O Ocko, B Zhu, YQ Gido, SP Russell, TP AF Xu, T Zvelindovsky, AV Sevink, GJA Gang, O Ocko, B Zhu, YQ Gido, SP Russell, TP TI Electric field induced sphere-to-cylinder transition in diblock copolymer thin films SO MACROMOLECULES LA English DT Article ID ORDER-ORDER TRANSITION; BLOCK-COPOLYMER; GYROID TRANSITION; INDUCED ALIGNMENT; PHASE-TRANSITION; DOMAIN ALIGNMENT; MICROSTRUCTURE; MECHANISMS; MELTS; KINETICS AB An electric field induced sphere-to-cylinder transition in thin films of asymmetric polystyrene-b-poly(methyl methacrylate) diblock copolymers was observed. In the absence of an applied electric field, thin films of the asymmetric diblock copolymer consisted of layers of spherical microdomains with poor in-plane long-range ordering. Under a similar to40V/mum applied electric field, hexagonally packed cylindrical microdomains normal to the surface were found. Cross-sectional transmission electron microscopy images of the intermediate stages of the alignment indicated that, under an electric field, the asymmetric diblock copolymer formed spherical microdomains that were deformed into ellipsoids and, with time, interconnected into cylindrical microdomains oriented in the direction of the applied electric field. Simulations suggest that improved long-range order of the cylindrical microdomains could be achieved by cycling the electrical field. C1 Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. Leiden Univ, Leiden Inst Chem, NL-2300 RA Leiden, Netherlands. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Russell, TP (reprint author), Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. RI Zvelindovsky, Andrei/B-2662-2009 OI Zvelindovsky, Andrei/0000-0003-4464-3254 NR 37 TC 72 Z9 73 U1 1 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 7 PY 2004 VL 37 IS 18 BP 6980 EP 6984 DI 10.1021/ma049235b PG 5 WC Polymer Science SC Polymer Science GA 851IA UT WOS:000223677600047 ER PT J AU Huynh, MHV Meyer, TJ AF Huynh, MHV Meyer, TJ TI Colossal kinetic isotope effects in proton-coupled electron transfer SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ATOM TRANSFER-REACTIONS; HYDROGEN; MECHANISMS; MODEL; OXIDATION; DYNAMICS; OXIDASE AB The kinetics of reduction of benzoquinone (Q) to hydroquinone (H(2)Q) by the Os(IV) hydraziclo (trans-[Os-IV(tpy)(Cl)(2)(N(H)N(CH2)(4)O)]-PF6 = [1]PF6, tpy = 2,2':6',2"-terpyridine), sulfilimido (trans-[Os-IV(tpy)(CO2(NS(H)-4-C6H4Me)]PF6 = [2]PF6), and phosphoraniminato (trans-[Os-IV(Tp)(Cl)(2)(NP(H)(Et)(2))] = [3], Tp- = tris(pyrazolyl)-borate) complexes have been studied in 1:1 (vol/vol) CH3CN/H2O and CH3CN/D2O (1-0 M in NH4PF6/KNO3 at 25.0 +/- 0.1degreesC). The reactions are first order in both IQ] and Os([V) complex and occur by parallel pH-independent (k(1)) and pH-dependent (k(2)) pathways that can be separated by pH-dependent measurements. Saturation kinetics are observed for the acid-independent pathway, consistent with formation of a H-bonded intermediate (K-A) followed by a redox step (k(red)). For the pH-independent pathway, k(1)(H2O)/k(1)(D2O) kinetic isotope effects are 455 +/- 8 for [1(+)], 198 +/- 6 for [2(+)], and 178 +/- 5 for [3]. These results provide an example of colossal kinetic isotope effects for proton-coupled electron transfer reactions involving nitrogen, sulfur, and phosphorus as proton-donor atoms. C1 Mat Dynam Grp, Dynam Experimentat Div, MS C920, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Meyer, TJ (reprint author), Mat Dynam Grp, Dynam Experimentat Div, MS C920, Los Alamos, NM 87545 USA. EM tjmeyer@lanl.gov NR 29 TC 38 Z9 38 U1 0 U2 11 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 7 PY 2004 VL 101 IS 36 BP 13138 EP 13141 DI 10.1073/pnas.0405086101 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 853AT UT WOS:000223799100009 PM 15331783 ER PT J AU Shin, DH Lou, Y Jancarik, J Yokota, H Kim, R Kim, SH AF Shin, DH Lou, Y Jancarik, J Yokota, H Kim, R Kim, SH TI Crystal structure of YjeQ from Thermotoga maritima contains a circularly permuted GTPase domain SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE ribosome binding oligonucleotide/oligosaccharide-binding fold; zinc-finger motif ID PROTEIN-STRUCTURE; ESCHERICHIA-COLI; CLASSIFICATION; PHOSPHATASE; INSIGHTS; ANATOMY; MAD AB We have determined the crystal structure of the GDP complex of the YjeQ protein from Thermotoga maritima (TmYjeQ), a member of the YjeQ GTPase subfamaily. TmYjeQ, a homologue of Escherichia coli YjeQ, which is known to bind to the ribosome, is composed of three domains: an N-terminal oligonucleotide/oligosaccharide-binding fold domain, a central GTPase domain, and a C-terminal zinc-finger domain. The crystal structure of TmYjeQ reveals two interesting domains: a circularly permutated GTPase domain and an unusual zinc-finger domain. The binding mode of GDP in the GTPase domain of TmYjeQ is similar to those of GDP or GTP analogs in ras proteins, a prototype GTPase. The N-terminal oligonucleotide/oligosaccharide-binding fold domain, together with the GTPase domain, forms the extended RNA-binding site. The C-terminal domain has an unusual zinc-finger motif composed of Cys-250, Cys-255, Cys-263, and His-257, with a remote structural similarity to a portion of a DNA-repair protein, rad51 fragment. The overall structural features of TmYjeQ make it a good candidate for an RNA-binding protein, which is consistent with the biochemical data of the YjeQ subfamily in binding to the ribosome. C1 Lawrence Berkeley Lab, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Lawrence Berkeley Lab, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. EM shkim@lbl.gov FU NIGMS NIH HHS [P50 GM062412, GM62412] NR 32 TC 31 Z9 33 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 7 PY 2004 VL 101 IS 36 BP 13198 EP 13203 DI 10.1073/pnas.0405202101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 853AT UT WOS:000223799100020 PM 15331784 ER PT J AU Lienert, U Han, TS Almer, J Dawson, PR Leffers, T Margulies, L Nielsen, SF Poulsen, HF Schmidt, S AF Lienert, U Han, TS Almer, J Dawson, PR Leffers, T Margulies, L Nielsen, SF Poulsen, HF Schmidt, S TI Investigating the effect of grain interaction during plastic deformation of copper SO ACTA MATERIALIA LA English DT Article DE plastic deformation; metal; internal stresses; finite-element modelling; X-ray diffraction ID POLYCRYSTALS; METALS AB By diffraction of high-energy synchrotron X-rays, the variance of the axial lattice strains of individual grains is measured during tensile loading of a weakly textured copper polycrystal. Peak profiles are measured for 14401 reflections arising from 20 bulk grains, all of which are at least one average grain diameter below the surfaces within a 0.2-mm thick specimen. The reflecting lattice planes are all perpendicular to the tensile axis. The variance in lattice strain between grains can therefore be attributed to differences in the boundary conditions imposed by the different sets of neighboring grains. The results are compared to finite-element modelling (FEM). Up to the highest applied strain of 2%, the experimental and FEM values are in fair agreement and the standard deviations may be roughly approximated as 6% of the average axial lattice strains. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Cornell Univ, Ithaca, NY 14853 USA. Riso Natl Lab, Dept Mat Res, Ctr Fundamental Res, Met Struct Dimens 4, DK-4000 Roskilde, Denmark. RP Lienert, U (reprint author), Argonne Natl Lab, Adv Photon Source, Bldg 431,9700 S Cass Ave, Argonne, IL 60439 USA. EM lienert@aps.anl.gov RI Schmidt, Soren/B-1483-2010; Poulsen, Henning/A-4131-2012; Han, Tong-Seok/G-7998-2012 OI Schmidt, Soren/0000-0002-8694-2044; NR 23 TC 33 Z9 33 U1 2 U2 22 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 6 PY 2004 VL 52 IS 15 BP 4461 EP 4467 DI 10.1016/j.actamat.2004.05.051 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 852YW UT WOS:000223793900006 ER PT J AU Zhao, YH Liao, XZ Jin, Z Valiev, RZ Zhu, YT AF Zhao, YH Liao, XZ Jin, Z Valiev, RZ Zhu, YT TI Microstructures and mechanical properties of ultrafine grained 7075 Al alloy processed by ECAP and their evolutions during annealing SO ACTA MATERIALIA LA English DT Article DE severe plastic deformation; aluminum alloy; aging hardening; microstructures; mechanical properties ID SEVERE PLASTIC-DEFORMATION; SERIES ALUMINUM-ALLOYS; REFINEMENT; METALS; MG; STABILITY; MAGNESIUM; DUCTILITY; KINETICS; SYSTEM AB Microstructures and mechanical properties of equal-channel angular pressing (ECAP) processed and naturally aged ultrafine grained (UFG) and coarse grained (CG) 7075 Al alloys as well as their evolutions during annealing were investigated. After the same natural aging, the tensile yield strength, ultimate strength, and microhardness of the UFG samples were 103%, 35%, and 48% higher, respectively, than those of the CG samples, because of higher densities of Guinier-Preston (G-P) zones and dislocations in the UFG sample. Upon annealing, the microhardness of the UFG sample decreased gradually, while a hardening peak appeared for the CG sample. The peak was caused by the precipitation hardening of the metastable eta' phase. For the UFG sample, the precipitation hardening was overcompensated by the significant decrease of microstrain (dislocation density) upon annealing, resulting in a lack of precipitation hardening peak. Differential scanning calorimetry indicates that the ECAP process only accelerated the phase precipitations, but did not change the sequence of phase precipitation. This study shows that severe plastic deformation has the potential to significantly improve the mechanical properties of age-hardening Al alloys. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. Alcoa Tech Ctr, Alcoa Ctr, PA 15069 USA. Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, MS G755,MST-STC, Los Alamos, NM 87545 USA. EM zhao@lanl.gov; yzhu@lanl.gov RI Zhu, Yuntian/B-3021-2008; Zhao, Yonghao/A-8521-2009; Liao, Xiaozhou/B-3168-2009; Lujan Center, LANL/G-4896-2012 OI Zhu, Yuntian/0000-0002-5961-7422; Liao, Xiaozhou/0000-0001-8565-1758; NR 40 TC 342 Z9 368 U1 20 U2 165 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 6 PY 2004 VL 52 IS 15 BP 4589 EP 4599 DI 10.1016/j.actamat.2004.06.017 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 852YW UT WOS:000223793900018 ER PT J AU Williams, OA Curat, S Gerbi, JE Gruen, DM Jackman, RB AF Williams, OA Curat, S Gerbi, JE Gruen, DM Jackman, RB TI n-type conductivity in ultrananocrystalline diamond films SO APPLIED PHYSICS LETTERS LA English DT Article ID DRIFT MOBILITY; CARBON AB Hall effect measurements have been carried out to determine the carrier density and mobilities in ultrananocrystalline diamond films grown with added nitrogen. The results show clear n-type conductivity with very low thermal activation energy. Mobility values of 1.5 cm(2) V(-1) s(-1) are found for a sheet carrier concentration of 2x10(17) cm(-2). These measurements indicate that ultrananocrystalline films grown with high nitrogen levels in the growth gas mixture can have bulk carrier concentrations of up to 10(21), which is very high for diamond films. The n-type nature of this material was also confirmed by Seebeck effect measurements. (C) 2004 American Institute of Physics. C1 Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. UCL, Dept Elect & Elect Engn, London WC1E 7JE, England. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Williams, OA (reprint author), Argonne Natl Lab, Ctr Nanoscale Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. EM o.williams@anl.gov RI Williams, Oliver/B-2776-2009; OI Williams, Oliver/0000-0002-7210-3004 NR 19 TC 110 Z9 110 U1 1 U2 12 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 2004 VL 85 IS 10 BP 1680 EP 1682 DI 10.1063/1.1785288 PG 3 WC Physics, Applied SC Physics GA 853WL UT WOS:000223859800008 ER PT J AU Mitlin, D Misra, A Mitchell, TE Hoagland, RG Hirth, JP AF Mitlin, D Misra, A Mitchell, TE Hoagland, RG Hirth, JP TI Influence of overlayer thickness on the density of Lomer dislocations in nanoscale Ni-Cu bilayer thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID SINGLE-CRYSTAL FILMS; MISFIT DISLOCATIONS; EPITAXIAL MULTILAYERS; REBOUND MECHANISM; 001 PLANES; ACCOMMODATION; DEFECTS; COPPER; NICKEL; METALS AB We report on the evolution of the spacing and the character of misfit dislocations with increasing Ni overlayer thickness at an (001) Ni-Cu interface. At low Ni overlayer thicknesses (3 and 5 nm), most of the interface dislocations are 60degrees 1/2<110> glide dislocations, while Lomer edge dislocations constitute only about 5% of the total interface dislocation content. At a 13 nm Ni overlayer thickness, the fraction of Lomer dislocations increases to approximately 40% of the total content. This dramatic increase in the fraction of Lomer dislocations is likely related to a "rebound mechanism" which initiates at some critical thickness between 5 and 13 nm. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Mitlin, D (reprint author), Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2G6, Canada. EM dmitlin@valberta.ca RI Hoagland, Richard/G-9821-2012; Misra, Amit/H-1087-2012; Mitlin , David /M-5328-2016 OI Mitlin , David /0000-0002-7556-3575 NR 18 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 2004 VL 85 IS 10 BP 1686 EP 1688 DI 10.1063/1.1779343 PG 3 WC Physics, Applied SC Physics GA 853WL UT WOS:000223859800010 ER PT J AU Ahrenkiel, RK Metzger, W Friedman, DF AF Ahrenkiel, RK Metzger, W Friedman, DF TI Transport properties of ordered-GalnP/GaAs heterostructures SO APPLIED PHYSICS LETTERS LA English DT Article ID GAINP AB We have studied the transport and recombination properties of Ga0.52In0.48P/GaAs heterostructures by two transient techniques; Time-resolved photoluminescence and resonant coupled photoconductive decay. When the Ga0.52In0.48P is ordered, the two techniques produce radically different excess-carrier decay characteristics. These data can be explained by invoking a charge-separation mechanism at a type-II heterointerface. At higher excess-carrier injection levels, the charge-separation mechanism vanishes, and the type-I interface properties develop. These data are compatible with the polarization field model of ordered Ga0.52In0.48P. (C) 2004 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahrenkiel, RK (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM richard_ahrenkiel@nrel.gov NR 6 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 6 PY 2004 VL 85 IS 10 BP 1733 EP 1735 DI 10.1063/1.1784876 PG 3 WC Physics, Applied SC Physics GA 853WL UT WOS:000223859800026 ER PT J AU Waters, JF Riester, L Jouzi, M Guduru, PR Xu, JM AF Waters, JF Riester, L Jouzi, M Guduru, PR Xu, JM TI Buckling instabilities in multiwalled carbon nanotubes under uniaxial compression SO APPLIED PHYSICS LETTERS LA English DT Article ID STRENGTH; STRAIN AB We report experimental observations of shell buckling instabilities in freestanding, vertically aligned multiwalled carbon nanotubes subjected to uniaxial compression. Highly ordered and uniform arrays of carbon nanotubes embedded in an alumina matrix were fabricated and subjected to uniaxial compression using a nanoindenter. The buckling load was found to be on the order of 2 muN for nanotubes with 25 nm outer radius, 13 nm inner radius, and heights of 50 and 100 nm. Good agreement was found between the experimental observations and the predictions of linear elastic shell buckling theory. (C) 2004 American Institute of Physics. C1 Brown Univ, Div Engn, Providence, RI 02912 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Guduru, PR (reprint author), Brown Univ, Div Engn, Providence, RI 02912 USA. EM pradeep_guduru@brown.edu NR 14 TC 64 Z9 64 U1 2 U2 13 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 6 PY 2004 VL 85 IS 10 BP 1787 EP 1789 DI 10.1063/1.1790602 PG 3 WC Physics, Applied SC Physics GA 853WL UT WOS:000223859800044 ER PT J AU Klem, MT Corbett, JD AF Klem, MT Corbett, JD TI Synthesis, structure, and bonding of the nonclassical zintl phase K5As3Pb3 SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; PB-9(4-) CLUSTERS; ANIONS; LA3IN5; ATOMS AB The title phase was synthesized by direct fusion of a stoichiometric amount of the elements followed by annealing at 650 degreesC for 3 weeks. The compound crystallizes in the orthorhombic space group Pnma (No. 62), Z = 4, with a = 19.451(6) Angstrom, b = 12.164(3) Angstrom, c = 6.581(1) Angstrom. The compound is made up of As3Pb35- crown clusters that can be likened geometrically and electronically to 6-atom hypho-clusters derived from a tricapped trigonal prismatic closo parent. These crowns are interconnected via intercluster Pb-Pb bonds to form infinite chains along the b axis, which means the compound contains an extra two cations and two electrons per formula unit. Extended Huckel calculations indicate that the two additional electrons per cluster are accommodated in pi* states on the cluster and predict that the phase should be semiconducting. The latter is confirmed by microwave resistivity measurements, rho(298) = 1.0 X 10(2) muOmega.cm; (deltarho/deltaT)/rho = -0.14(3) K-1. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, DOE, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. EM jcorbett@iastate.edu NR 30 TC 0 Z9 0 U1 1 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 6 PY 2004 VL 43 IS 18 BP 5501 EP 5504 DI 10.1021/ic040045r PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 851JA UT WOS:000223680200008 PM 15332800 ER PT J AU Madland, DG Burvenich, TJ Maruhn, JA Reinhard, PG AF Madland, DG Burvenich, TJ Maruhn, JA Reinhard, PG TI On the isovector channels in relativistic point coupling models within the Hartree and Hartree-Fock approximations SO NUCLEAR PHYSICS A LA English DT Article DE relativistic mean-field model; Hartree; Hartree-Fock; Fierz transformation ID SKYRME TYPE INTERACTIONS; SYMMETRY ENERGY; NUCLEI; LAGRANGIANS; DENSITY AB We investigate the consequences of Fierz transformations acting upon the contact interactions for nucleon fields occurring in relativistic point coupling models in Hartree approximation, which yield the same models but in Hartree-Fock approximation instead. Identical nuclear ground state observables are calculated in the two approximations, but the magnitudes of the coupling constants are different. We find for model studies of four-fermion interactions occurring in two existing relativistic point coupling phenomenologies that whereas in Hartree the isovector-scalar strength alpha(TS), corresponding to delta-meson exchange, is unnaturally small, indicating a possible new symmetry, in Hartree-Fock it is instead comparable to the isovector-vector strength alpha(TV) corresponding to delta-meson exchange, but the sum of the two isovector coupling constants appears to be preserved in both approaches. Furthermore, in Hartree-Fock approximation, both QCD-scaled isovector coupling constants are natural (dimensionless and of order 1) whereas in Hartree approximation only that of the isovector-vector channel is natural. This indicates that it is not necessary to search for a new symmetry and, moreover, that the role of the delta-meson should be reexamined. This work presents the first comparisons of naturalized coupling constants coming from relativistic Hartree and relativistic Hartree-Fock solutions to the same Lagrangian. (C) 2004 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Goethe Univ Frankfurt, Inst Theoret Phys, D-60325 Frankfurt, Germany. Univ Erlangen Nurnberg, Inst Theoret Phys 2, D-91058 Erlangen, Germany. RP Madland, DG (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM dgm@lanl.gov NR 24 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 6 PY 2004 VL 741 BP 52 EP 59 DI 10.1016/j.nuclphys.2004.06.003 PG 8 WC Physics, Nuclear SC Physics GA 847EV UT WOS:000223376400004 ER PT J AU Gorchtein, M Guichon, PAM Vanderhaeghen, M AF Gorchtein, M Guichon, PAM Vanderhaeghen, M TI Beam normal spin asymmetry in elastic lepton-nucleon scattering SO NUCLEAR PHYSICS A LA English DT Article DE elastic electron-nucleon scattering; perturbative calculations; generalized parton distributions ID MAGNETIC FORM-FACTORS; PARTON DISTRIBUTIONS; COMPTON-SCATTERING; PROTON AB We discuss the two-photon exchange contribution to observables which involve lepton helicity flip in elastic lepton-nucleon scattering. This contribution is accessed through the single spin asymmetry for a lepton beam polarized normal to the scattering plane. We estimate this beam normal single spin asymmetry at large momentum transfer using a parton model and we express the corresponding amplitude in terms of generalized parton distributions. (C) 2004 Elsevier B.V. All rights reserved. C1 Jefferson Lab, Newport News, VA 23606 USA. Univ Genoa, Ist Nazl Fis Nucl, Sez Genoa, Dipartimento Fis, I-16146 Genoa, Italy. CEA Saclay, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RP Vanderhaeghen, M (reprint author), Jefferson Lab, Newport News, VA 23606 USA. EM marcvdh@jlab.org NR 29 TC 26 Z9 26 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 6 PY 2004 VL 741 BP 234 EP 248 DI 10.1016/j.nuclphysa.2004.06.008 PG 15 WC Physics, Nuclear SC Physics GA 847EV UT WOS:000223376400012 ER PT J AU Boyanovsky, D de Vega, HJ Wang, SY AF Boyanovsky, D de Vega, HJ Wang, SY TI Nonequilibrium pion dynamics near the critical point in a constituent quark model SO NUCLEAR PHYSICS A LA English DT Article ID HOT GAUGE-THEORIES; CHIRAL PHASE-TRANSITION; QUANTUM-FIELD THEORY; LINEAR SIGMA-MODEL; FINITE-TEMPERATURE; TRANSPORT-COEFFICIENTS; RENORMALIZATION-GROUP; QCD; CHROMODYNAMICS; SUPERCONDUCTIVITY AB We study static and dynamical critical phenomena of chiral symmetry breaking in a two-flavor Nambu-Jona-Lasinio constituent quark model. We obtain the low-energy effective action for scalar and pseudoscalar degrees of freedom to lowest order in quark loops and to quadratic order in the meson fluctuations around the mean field. The static limit of critical phenomena is shown to be described by a Ginzburg-Landau effective action including spatial gradients. Hence static critical phenomena is described by the universality class of the O(4) Heisenberg ferromagnet. Dynamical critical phenomena is studied by obtaining the equations of motion for pion fluctuations. We find that for T < T-c the are stable long-wavelength pion excitations with dispersion relation omega(pi) (k) = k described by isolated pion poles. The residue of the pion pole vanishes near T-c as Z proportional to 1/\ln(1- T/T-c)\ and long-wavelength fluctuations are damped out by Landau damping on a time scale t(rel)(k) proportional to 1/k, reflecting critical slowing down of pion fluctuations near the critical point. At the critical point, the pion propagator features mass shell logarithmic divergences which we conjecture to be the harbinger of a (large) dynamical anomalous dimension. We find that while the classical spinodal line coincides with that of the Ginzburg-Landau theory, the growth rate of long-wavelength spinodal fluctuations has a richer wavelength dependence as a consequence of Landau damping. We argue that Landau damping prevents a local low-energy effective action in terms of a derivative expansion in real time at least at the order studied. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Paris 06, LPTHE, F-75252 Paris 05, France. Univ Paris 07, LPTHE, F-75252 Paris 05, France. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Boyanovsky, D (reprint author), Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. EM boyan@pitt.edu; devega@lpthe.jussieu.fr; swang@lanl.gov NR 89 TC 4 Z9 4 U1 0 U2 1 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 6 PY 2004 VL 741 BP 323 EP 357 DI 10.1016/j.nuclphysa.2004.06.007 PG 35 WC Physics, Nuclear SC Physics GA 847EV UT WOS:000223376400017 ER PT J AU Chekanov, S Derrick, A Loizides, JH Magill, S Miglioranzi, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Pavel, N Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Clindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Montanari, A Nania, R Palmonari, F Pesci, A Rinaldi, L Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kind, O Meyer, U Paul, E Rautenberg, J Renner, R Stifutkin, A Tandler, J Voss, KC Wang, M Bailey, DS Brook, NH Cole, JE Heath, GP Namsoo, T Robins, S Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Kim, JY Lim, IT Ma, KJ Pac, MY Helbich, M Ning, Y Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Galas, A Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Lukasik, J Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Adler, V Behrens, U Bloch, I Borras, K Chiochia, V Dannheim, D Drews, G Fourletova, J Fricke, U Geiser, A Gottlicher, P Gutsche, O Haas, T Hain, W Hillert, S Horn, C Kahle, B Kotz, U Kowalski, H Kramberger, G Labes, H Lelas, D Lim, H Lohr, B Mankel, R Melzer-Pellmann, IA Nguyen, CN Notz, D Nuncio-Quiroz, AE Polini, A Raval, A Rurua, L Schneekloth, U Stosslein, U Wolf, G Youngman, C Zeuner, W Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Karstens, F Dobur, D Vlasov, NN Bell, M Bussey, PJ Doyle, AT Ferrando, J Hamilton, J Hanlon, S Saxon, DH Skillicorn, IO Gialas, I Carli, T Gosau, T Holm, U Krumnack, N Lohrmann, E Milite, M Salehi, H Schleper, P Schorner-Sadenius, T Stonjek, S Wichmann, K Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Tapper, AD Cloth, R Filges, D Kataoka, P Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, A Boos, EG Pokrovskiy, NS Zhautykov, BO Son, D Piotrzkowski, K Barreiro, F Glasman, C Gonzalez, O Labarga, L del Peso, J Tassi, E Terron, J Zambrana, M Barbi, M Corriveau, F Gliga, S Lainesse, J Padhi, S Stairs, DG Walsh, R Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, R Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Zotkin, SA Abt, I Buttner, C Caldwell, A Liu, X Sutiak, J Coppola, N Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Vazquez, M Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Cooper-Sarkar, AM Cottrell, A Devenish, RCE Foster, B Grzelak, G Gwenlan, C Kohno, T Patel, S Straub, PB Walczak, R Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Metlica, F Oh, BY Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Kuze, M Fusayasu, T Kagawa, S Tawara, T Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kaji, H Kitamura, S Matsuzawa, K Costa, M Ferrero, MI Monaco, V Sacchi, R Solano, A Arneodo, M Ruspa, M Koop, T Martin, JF Mirea, A Butterworth, JM Hall-Wilton, R Jones, TW Lightwood, MS Sutton, MR Targett-Adams, C Ciborowski, J Ciesielski, R Luzniak, P Nowak, RJ Pawlak, JM Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Hochman, D Karshon, U Riveline, M Everett, A Gladilin, LK Kcira, D Lammers, S Li, L Reeder, DD Rosin, M Ryan, P Savin, AA Smith, WH Dhawan, S Bhadra, S Catterall, CD Fourletov, S Hartner, G Menary, S Soares, M Standage, J AF Chekanov, S Derrick, A Loizides, JH Magill, S Miglioranzi, S Musgrave, B Repond, J Yoshida, R Mattingly, MCK Pavel, N Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Clindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Margotti, A Montanari, A Nania, R Palmonari, F Pesci, A Rinaldi, L Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kind, O Meyer, U Paul, E Rautenberg, J Renner, R Stifutkin, A Tandler, J Voss, KC Wang, M Bailey, DS Brook, NH Cole, JE Heath, GP Namsoo, T Robins, S Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Kim, JY Lim, IT Ma, KJ Pac, MY Helbich, M Ning, Y Ren, Z Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Galas, A Olkiewicz, K Stopa, P Zawiejski, L Adamczyk, L Bold, T Grabowska-Bold, I Kisielewska, D Kowal, AM Kowal, M Lukasik, J Przybycien, M Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Adler, V Behrens, U Bloch, I Borras, K Chiochia, V Dannheim, D Drews, G Fourletova, J Fricke, U Geiser, A Gottlicher, P Gutsche, O Haas, T Hain, W Hillert, S Horn, C Kahle, B Kotz, U Kowalski, H Kramberger, G Labes, H Lelas, D Lim, H Lohr, B Mankel, R Melzer-Pellmann, IA Nguyen, CN Notz, D Nuncio-Quiroz, AE Polini, A Raval, A Rurua, L Schneekloth, U Stosslein, U Wolf, G Youngman, C Zeuner, W Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Karstens, F Dobur, D Vlasov, NN Bell, M Bussey, PJ Doyle, AT Ferrando, J Hamilton, J Hanlon, S Saxon, DH Skillicorn, IO Gialas, I Carli, T Gosau, T Holm, U Krumnack, N Lohrmann, E Milite, M Salehi, H Schleper, P Schorner-Sadenius, T Stonjek, S Wichmann, K Wick, K Ziegler, A Ziegler, A Collins-Tooth, C Foudas, C Goncalo, R Long, KR Tapper, AD Cloth, R Filges, D Kataoka, P Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, A Boos, EG Pokrovskiy, NS Zhautykov, BO Son, D Piotrzkowski, K Barreiro, F Glasman, C Gonzalez, O Labarga, L del Peso, J Tassi, E Terron, J Zambrana, M Barbi, M Corriveau, F Gliga, S Lainesse, J Padhi, S Stairs, DG Walsh, R Tsurugai, T Antonov, A Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, R Katkov, II Khein, LA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Zotkin, SA Abt, I Buttner, C Caldwell, A Liu, X Sutiak, J Coppola, N Grijpink, S Koffeman, E Kooijman, P Maddox, E Pellegrino, A Schagen, S Tiecke, H Vazquez, M Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Ling, TY Cooper-Sarkar, AM Cottrell, A Devenish, RCE Foster, B Grzelak, G Gwenlan, C Kohno, T Patel, S Straub, PB Walczak, R Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Heaphy, EA Metlica, F Oh, BY Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Abramowicz, H Gabareen, A Kananov, S Kreisel, A Levy, A Kuze, M Fusayasu, T Kagawa, S Tawara, T Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kaji, H Kitamura, S Matsuzawa, K Costa, M Ferrero, MI Monaco, V Sacchi, R Solano, A Arneodo, M Ruspa, M Koop, T Martin, JF Mirea, A Butterworth, JM Hall-Wilton, R Jones, TW Lightwood, MS Sutton, MR Targett-Adams, C Ciborowski, J Ciesielski, R Luzniak, P Nowak, RJ Pawlak, JM Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Hochman, D Karshon, U Riveline, M Everett, A Gladilin, LK Kcira, D Lammers, S Li, L Reeder, DD Rosin, M Ryan, P Savin, AA Smith, WH Dhawan, S Bhadra, S Catterall, CD Fourletov, S Hartner, G Menary, S Soares, M Standage, J CA ZEUS Collaboration TI Exclusive electroproduction of J/psi mesons at HERA SO NUCLEAR PHYSICS B LA English DT Article ID DEEP-INELASTIC SCATTERING; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; PARTON DISTRIBUTIONS; VECTOR-MESONS; JET DATA; QCD; PHOTOPRODUCTION; CONSTRUCTION; DESIGN AB The exclusive electroproduction of J/psi mesons, ep --> epJ/psi, has been studied with the ZEUS detector at HERA for virtualities of the exchanged photon in the ranges 0.15 < Q(2) < 0.8 GeV2 and 2 < Q(2) < 100 GeV2 using integrated luminosities of 69 and 83 pb(-1), respectively. The photonproton centre-of-mass energy was in the range 30 < W < 220 GeV and the squared four-momentum transfer at the proton vertex \t\ < 1 GeV2. The cross sections and decay angular distributions are presented as functions of Q(2), W and t. The effective parameters of the pomeron trajectory are in agreement with those found in J/psi photoproduction. The spin-density matrix elements, calculated from the decay angular distributions, are consistent with the hypothesis of s-channel helicity conservation. The ratio of the longitudinal to transverse cross sections, sigma(L)/sigma(T), grows with Q(2), whilst no dependence on W or t is observed. The results are in agreement with perturbative QCD calculations and exhibit a strong sensitivity to the gluon distribution in the proton. (C) 2004 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Humboldt Univ, Inst Phys, Berlin, Germany. Univ Bologna, Bologna, Italy. INFN Bologna, 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 500757, South Korea. Columbia Univ, Nevis Labs, Irvington, NY USA. Inst Nucl Phys, Krakow, Poland. AGH Univ Sci & Technol, Fac Phys & Nucl Tech, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY Zeuthen, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fak Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Aegean, Dept Engn Management & Finance, Aegean, Greece. Univ Hamburg, Inst Phys Expt, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu, South Korea. Catholic Univ Louvain, Inst Nucl Phys, B-3000 Louvain, Belgium. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Engn Phys Inst, Moscow 115409, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. 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. Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea. Tel Aviv Univ, Sch Phys, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 158, Japan. Univ Turin, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Piemonte Orientale, Novara, Italy. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, 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 06520 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Li, Liang/O-1107-2015; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Doyle, Anthony/C-5889-2009; collins-tooth, christopher/A-9201-2012; Ferrando, James/A-9192-2012; Levchenko, B./D-9752-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Wiggers, Leo/B-5218-2015; Gliga, Sebastian/K-4019-2015 OI dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Li, Liang/0000-0001-6411-6107; Arneodo, Michele/0000-0002-7790-7132; Chwastowski, Janusz/0000-0002-6190-8376; Gutsche, Oliver/0000-0002-8015-9622; Gladilin, Leonid/0000-0001-9422-8636; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Ferrando, James/0000-0002-1007-7816; Wiggers, Leo/0000-0003-1060-0520; Gliga, Sebastian/0000-0003-1729-1070 NR 67 TC 123 Z9 123 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 6 PY 2004 VL 695 IS 1-2 BP 3 EP 37 DI 10.1016/j.nuclphysb.2004.06.034 PG 35 WC Physics, Particles & Fields SC Physics GA 848VE UT WOS:000223495400001 ER PT J AU Beane, SR AF Beane, SR TI In search of the chiral regime SO NUCLEAR PHYSICS B LA English DT Article ID PERTURBATION-THEORY; ONE-LOOP AB A critical appraisal is given of a recent analysis of the quark-mass and finite-size dependence of unquenched lattice QCD data for the nucleon mass. We use this forum to estimate the boundary of the chiral regime for nucleon properties. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. EM silas@physics.unh.edu NR 18 TC 41 Z9 41 U1 0 U2 0 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 6 PY 2004 VL 695 IS 1-2 BP 192 EP 198 DI 10.1016/j.nuclphysb.2004.06.002 PG 7 WC Physics, Particles & Fields SC Physics GA 848VE UT WOS:000223495400008 ER PT J AU Chang, JH Kim, KJ Shin, YK Liu, J AF Chang, JH Kim, KJ Shin, YK Liu, J TI Biomimetic hydrolysis of p-nitrophenyl alkanoates with functionalized mesoporous silicas SO CHEMISTRY LETTERS LA English DT Article ID MODEL AB A biomimetic catalysis of p-nitrophenyl alkanoate esters as a function of their alkyl chain lengths through multifunctionalization of molecular self-assembly onto ordered silica nanopores has been investigated in Tris-HCl buffer, and their kinetic parameters were calculated including a Michaelis-Menten kinetics. C1 Korea Inst Ceram Engn & Technol, Seoul 153801, South Korea. Chungbuk Natl Univ, Dept Chem, Chungbuk 361703, South Korea. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chang, JH (reprint author), Korea Inst Ceram Engn & Technol, Seoul 153801, South Korea. NR 8 TC 3 Z9 3 U1 0 U2 3 PU CHEMICAL SOC JAPAN PI TOKYO PA 1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPAN SN 0366-7022 EI 1348-0715 J9 CHEM LETT JI Chem. Lett. PD SEP 5 PY 2004 VL 33 IS 9 BP 1204 EP 1205 DI 10.1246/cl2004.1204 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 855CZ UT WOS:000223951900065 ER PT J AU Gritti, F Guiochon, G AF Gritti, F Guiochon, G TI Comparison between the adsorption behaviors of an organic cation and an organic anion on several reversed-phase liquid chromatography adsorbents SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption equilibria; adsorption isotherms; moreau isotherm model; overloaded band profiles; inverse method; ion-pair complexes; propranolol; sodium 1-naphthalene sulfonate ID OVERLOADED BAND PROFILES; ESTABLISHED COLUMN EQUILIBRIA; ION-PAIR RPLC; IONIZABLE COMPOUNDS; ZONE FORMATION; MOBILE-PHASE; RETENTION; MECHANISM; ISOTHERM; STRENGTH AB Adsorption data of an organic cation (propranololium chloride) and an organic anion (sodium I-naphthalene sulfonate) were measured by frontal analysis on two RPLC adsorbents, Symmetry-C-18 and XTerra-C-18, with aqueous solutions of methanol as the mobile phases. The influence of supporting neutral salts on the adsorption behavior of these two ions are compared. The Henry constants are close (H similar or equal to 5). The four sets of isotherm data are all well accounted for using the bi-Moreau model. However, the isotherms of the two ions behave differently at high concentrations. The initial behaviors of all the isotherms are antilangmuirian but remain so in a much wider concentration range for the cation than for the anion, due to its stronger adsorbate-adsorbate interactions on the low-energy adsorption sites. The retention times of both ions increase with increasing concentration of neutral salt in the mobile phase, suggesting the formation of ion-pair complexes, with Cl- for the cation and with Na+ for the anion. The adsorbate-adsorbate interactions vanish in the presence of salt and the bi-Moreau isotherm model tends toward a bi-Langmuir model. Differences in adsorption behavior are also observed between the cation and the anion when bivalent inorganic anions and cations, respectively, are dissolved in the mobile phase. High concentration band profiles of 1-naphthalene sulfonic acid are langmuirian, except in the presence of a trivalent cation, while those of propranolol are antilangmuirian under certain conditions even with uni- or divalent cations. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 32 TC 15 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD SEP 3 PY 2004 VL 1048 IS 1 BP 1 EP 15 DI 10.1016/j.chroma.2004.06.134 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 855FR UT WOS:000223959100001 PM 15453413 ER PT J AU Gallagher, DT Monbouquette, HG Schroder, I Robinson, H Holden, MJ Smith, NN AF Gallagher, DT Monbouquette, HG Schroder, I Robinson, H Holden, MJ Smith, NN TI Structure of alanine dehydrogenase from Archaeoglobus: Active site analysis and relation to bacterial cyclodeaminases and mammalian mu crystallin SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE hyperthermophile; nicotinamide adenine dinucleotide; Rossmann-fold ID GLUTAMATE-DEHYDROGENASE; ORNITHINE CYCLODEAMINASE; PROTEIN STRUCTURES; LENS CRYSTALLINS; COMPLETE GENOME; PURIFICATION; FULGIDUS; RESOLUTION; MECHANISM; STABILITY AB The hyperthermophilic archaeon Archaeoglobus fulgidus contains an L-Ala dehydrogenase (AlaDH, EC 1.4.1.1) that is not homologous to known bacterial dehydrogenases and appears to represent a previously unrecognized archaeal group of NAD-dependent dehydrogenases. The gene (Genbank AAB89583; TIGR AF1665) was annotated initially as an ornithine cyclodeaminase (OCD) on the basis of strong homology with the mu crystallin/OCD protein family. We report the structure of the NAD-bound AF1665 AlaDH (AF-AlaDH) at 2.3 Angstrom in a C2 crystal form with the 70 kDa. dimer in the asymmetric unit, as the first structural representative of this family Consistent with its lack of homology to bacterial AlaDH proteins, which are mostly hexameric, the archaeal dimer has a novel structure. Although both types of AlaDH enzyme include a Rossmann-type NAD-binding domain, the arrangement of strands in the C-terminal half of this domain is novel, and the other (catalytic) domain in the archaeal protein has a new fold. The active site presents a cluster of conserved Arg and Lys side-chains over the pro-R face of the cofactor. In addition, the best ordered of the 338 water molecules in the structure is positioned well for mechanistic interaction. The overall structure and active site are compared with other dehydrogenases, including the AlaDH from Phormidium lapideum. Implications for the catalytic mechanism and for the structures of homologs are considered. The archaeal AlaDH represents an ancient and previously undescribed subclass of Rossmann-fold proteins that includes bacterial ornithine and lysine cyclodeaminases, marsupial lens proteins and, in man, a thyroid hormone-binding protein that exhibits 30% sequence identity with AF1665. (C) 2004 Elsevier Ltd. All rights reserved. C1 Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Microbiol Mol Genet & Immunol, Los Angeles, CA 90095 USA. Brookhaven Natl Labs, Dept Biol, Upton, NY 11973 USA. RP Gallagher, DT (reprint author), Natl Inst Stand & Technol, Div Biotechnol, Gaithersburg, MD 20899 USA. EM travis.gallagher@nist.gov NR 40 TC 22 Z9 24 U1 1 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD SEP 3 PY 2004 VL 342 IS 1 BP 119 EP 130 DI 10.1016/j.jmb.2004.06.090 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 849YY UT WOS:000223578800010 PM 15313611 ER PT J AU Chaudhry, C Horwich, AL Brunger, AT Adams, PD AF Chaudhry, C Horwich, AL Brunger, AT Adams, PD TI Exploring the structural dynamics of the E-coli chaperonin GroEL using translation-libration-screw crystallographic refinement of intermediate states SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE chaperonin; translation-libration-screw; crystallographic refinement; structural dynamics; protein folding ID SEGMENTED ANISOTROPIC REFINEMENT; ANGSTROM CRYSTAL-STRUCTURE; MACROMOLECULAR STRUCTURES; ALLOSTERIC MECHANISM; SUBSTRATE-BINDING; TRYPSIN-INHIBITOR; ATPASE CYCLE; PROTEIN; COMPLEX; POLYPEPTIDE AB Large rigid-body domain movements are critical to GroEL-mediated protein folding, especially apical domain elevation and twist associated with the formation of a folding chamber upon binding ATP and chaperonin GroES. Here, we have modeled the anisotropic displacements of GroEL domains from various crystallized states, unliganded GroEL, ATPgammaS-bound, ADP-AlFx/GroES-bound, and ADP/GroES bound, using translation-libration-screw (TLS) analysis. Remarkably, the TLS results show that the inherent motions of unliganded GroEL, a polypeptide-accepting state, are biased along the transition pathway that leads to the folding-active state. In the ADP-AlFx/GroES-bound folding-active state the dynamic modes of the apical domains become reoriented and coupled to the motions of bound GroES. The ADP/GroES complex exhibits these same motions, but they are increased in magnitude, potentially reflecting the decreased stability of the complex after nucleotide hydrolysis. Our results have allowed the visualization of the anisotropic molecular motions that link the static conformations previously observed by X-ray crystallography. Application of the same analyses to other macromolecules where rigid body motions occur may give insight into the large scale dynamics critical for function and thus has the potential to extend our fundamental understanding of molecular machines. Published by Elsevier Ltd. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. Yale Univ, Dept Genet, New Haven, CT 06510 USA. Yale Univ, Howard Hughes Med Inst, New Haven, CT 06510 USA. Stanford Univ, Dept Mol & Cellular Physiol Neurol & Neurol Sci, Stanford, CA 94305 USA. Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Adams, PD (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,Bldg 4R0230, Berkeley, CA 94720 USA. EM pdadams@lbl.gov RI Adams, Paul/A-1977-2013; OI Adams, Paul/0000-0001-9333-8219; Brunger, Axel/0000-0001-5121-2036 NR 55 TC 67 Z9 67 U1 0 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD SEP 3 PY 2004 VL 342 IS 1 BP 229 EP 245 DI 10.1016/j.jmb.2004.07.015 PG 17 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 849YY UT WOS:000223578800019 PM 15313620 ER PT J AU Chou, YS Stevenson, JW AF Chou, YS Stevenson, JW TI Novel infiltrated phlogopite mica compressive seals for solid oxide fuel cells SO JOURNAL OF POWER SOURCES LA English DT Article DE thermal cycling; compressive seal; phlogopite rnica; leak rate; open circuit voltage ID SEALANTS; SOFC AB A novel compressive Phlogopite mica seal was developed that showed superior thermal cycle stability with very low leak rates at 800degreesC. A commercially available Phlogopite mica paper was infiltrated with a wetting or melt-forming agent, and tested in a hybrid form during thermal cycling. The results of H3BO3-infiltrated mica showed a continued decrease in leak rates over thermal cycling, and very low rates (<5 x 10(-4) sccm/cm) were obtained after similar to15 thermal cycles. The results of Bi-nitrate infiltrated mica exhibited a constant leak rate of (1-4) x 10(-3) sccnVcm over 36 thermal cycles. The leak rates of the infiltrated mica were one to two orders of magnitude lower than leak rates for the as-received micas. Open circuit voltage tests were also conducted using dense 8YSZ plates to assess the effectiveness of the mica seals. Open circuit voltages equivalent to, or close to, the theoretical (Nernst) values were obtained. (C) 2004 Published by Elsevier B.V. C1 Pacific NW Natl Lab, Div Mat Sci, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Natl Lab, Div Mat Sci, POB 999, Richland, WA 99352 USA. EM yeong-shyung.chou@pnl.gov NR 12 TC 31 Z9 33 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD SEP 3 PY 2004 VL 135 IS 1-2 BP 72 EP 78 DI 10.1016/j.jpowsour.2004.02.037 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 855HQ UT WOS:000223964400011 ER PT J AU Doeff, MM Richardson, TJ Hwang, KT AF Doeff, MM Richardson, TJ Hwang, KT TI Electrochemical and structural characterization of titanium-substituted manganese oxides based on Na0.44MnO2 SO JOURNAL OF POWER SOURCES LA English DT Article DE manganese oxides; cathodes; Na0.44MnO2; lithium rechargeable batteries ID ORTHORHOMBIC NAXMNO2; POLYMER BATTERIES; ELECTRODE AB A series of titanium-substituted manganese oxides, LixTiyMn1-yO2 (y = 0.11, 0,22, 0.33, 0.44, and 0.55) with the Na0.44MnO2, struclure were prepared from NaxTiyMn1-yO2 (x approximate to 0.44) precursors. The electrochemical characteristics of these compounds, which retain the unique double-tunnel structure during ion exchange, were examined in lithium/polymer electrolyte cells operating at 85 degreesC. All of the substituted cathode materials intercalated lithium reversibly, with LixTi0.22Mn0.78O2 exhibiting the highest capacity in polymer cells, about 10-20% greater than that of unsubstituted LixMnO2 made from Na0.44MnO2. In common with LixMnO2, the Ti-substituted materials exhibited good capacity retention over one hundred or more cycles, with some compositions exhibiting a fade rate of less than 0.03% per cycle. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Doeff, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM mmdoeff@lbl.gov RI Doeff, Marca/G-6722-2013 OI Doeff, Marca/0000-0002-2148-8047 NR 15 TC 32 Z9 32 U1 4 U2 43 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD SEP 3 PY 2004 VL 135 IS 1-2 BP 240 EP 248 DI 10.1016/j.jpowsour.2004.03.073 PG 9 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 855HQ UT WOS:000223964400028 ER PT J AU Liska, R Shashkov, M Ganzha, V AF Liska, R Shashkov, M Ganzha, V TI Analysis and optimization of inner products for mimetic finite difference methods on a triangular grid SO MATHEMATICS AND COMPUTERS IN SIMULATION LA English DT Article; Proceedings Paper CT 1st International Conference on Applications of Computer Algebra (ACA 2001) CY 2001 CL Univ New Mexico, Albuquerque, NM SP Int Assoc Math & Comp Simulat HO Univ New Mexico DE support operator; mimetic finite difference method; triangular grid ID LOGICALLY RECTANGULAR GRIDS; NATURAL DISCRETIZATIONS; DIVERGENCE; GRADIENT; CURL AB The support operator method designs mimetic finite difference schemes by first constructing a discrete divergence operator based on the divergence theorem, and then defining the discrete gradient operator as the adjoint operator of the divergence based on the Gauss theorem connecting the divergence and gradient operators, which remains valid also in the discrete case. When evaluating the discrete gradient operator, one needs to define discrete inner products of two discrete vector fields. The local discrete inner product on a given triangle is defined by a 3 x 3 symmetric positive definite matrix M defined by its six independent elements-parameters. Using the Gauss theorem over our triangle, we evaluate the discrete gradient in the triangle. We require the discrete gradient to be exact for linear functions, which gives us a system of linear equations for elements of the matrix M. This system, together with inequalities which guarantee positive definiteness of the matrix M, results in a one parameter family of inner products which give exact gradients for linear functions. The traditional inner product is a member of this family. The positive free parameter can be used to improve another property of the discrete method. We show that accuracy of the method for quadratic functions improves with decreasing this parameter, however, at the same time, the condition number of the matrix M, which is the local matrix of the linear system for computing the discrete gradient, increases to infinity when the parameter goes to zero, so one needs to choose a compromise between accuracy and solvability of the local system. Our analysis has been performed by computer algebra tools which proved to be essential. (C) 2004 Published by Elsevier B.V. on behalf of IMACS. C1 Czech Tech Univ, Fac Nucl Sci & Phys Engn, Prague 11519 1, Czech Republic. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Tech Univ Munich, Dept Informat, D-80333 Munich, Germany. RP Liska, R (reprint author), Czech Tech Univ, Fac Nucl Sci & Phys Engn, Brehova 7, Prague 11519 1, Czech Republic. EM liska@siduri.fjfi.cvut.cz RI Liska, Richard/C-3142-2009 OI Liska, Richard/0000-0002-6149-0440 NR 11 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4754 J9 MATH COMPUT SIMULAT JI Math. Comput. Simul. PD SEP 3 PY 2004 VL 67 IS 1-2 BP 55 EP 66 DI 10.1016/j.matcom.2004.05.008 PG 12 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 858QD UT WOS:000224205900006 ER PT J AU Ahn, JR Byun, JH Koh, H Rotenberg, E Kevan, SD Yeom, HW AF Ahn, JR Byun, JH Koh, H Rotenberg, E Kevan, SD Yeom, HW TI Mechanism of gap opening in a triple-band peierls system: In atomic wires on Si SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM CHAINS; SURFACE; SILICON AB One dimensional (1D) metals are unstable at low temperature undergoing a metal-insulator transition coupled with a periodic lattice distortion, a Peierls transition. Angle-resolved photoemission study for the 1D metallic chains of In on Si(111), featuring a metal-insulator transition and triple metallic bands, clarifies in detail how the multiple band gaps are formed at low temperature. In addition to the gap opening for a half-filled ideal 1D band with a proper Fermi surface nesting, two other quasi-1D metallic bands are found to merge into a single band, opening a unique but k-dependent energy gap through an interband charge transfer. This result introduces a novel gap-opening mechanism for a multiband Peierls system where the interband interaction is important. C1 Yonsei Univ, Ctr Atom Wires & Layers, Seoul 120749, South Korea. Yonsei Univ, Inst Phys & Appl Phys, Seoul 120749, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. RP Yeom, HW (reprint author), Yonsei Univ, Ctr Atom Wires & Layers, Seoul 120749, South Korea. EM yeom@phya.yonsei.ac.kr RI Rotenberg, Eli/B-3700-2009; Kevan, Stephen/F-6415-2010 OI Rotenberg, Eli/0000-0002-3979-8844; Kevan, Stephen/0000-0002-4621-9142 NR 16 TC 95 Z9 95 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2004 VL 93 IS 10 AR 106401 DI 10.1103/PhysRevLett.93.106401 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600039 PM 15447426 ER PT J AU Ashie, Y Hosaka, J Ishihara, K Itow, Y Kameda, J Koshio, Y Minamino, A Mitsuda, C Miura, M Moriyama, S Nakahata, M Namba, T Nambu, R Obayashi, Y Shiozawa, M Suzuki, Y Takeuchi, Y Taki, K Yamada, S Ishitsuka, M Kajita, T Kaneyuki, K Nakayama, S Okada, A Okumura, K Ooyabu, T Saji, C Takenaga, Y Desai, S Kearns, E Likhoded, S Stone, JL Sulak, LR Walter, CW Wang, W Goldhaber, M Casper, D Cravens, JP Gajewski, W Kropp, WR Liu, DW Mine, S Smy, MB Sobel, HW Sterner, CW Vagins, MR Ganezer, KS Hill, J Keig, WE Jang, JS Kim, JY Lim, IT Ellsworth, RW Tasaka, S Guillian, G Kibayashi, A Learned, JG Matsuno, S Takemori, D Messier, MD Hayato, Y Ichikawa, AK Ishida, T Ishii, T Iwashita, T Kobayashi, T Maruyama, T Nakamura, K Nitta, K Oyama, Y Sakuda, M Totsuka, Y Suzuki, AT Hasegawa, M Hayashi, K Inagaki, T Kato, I Maesaka, H Morita, T Nakaya, T Nishikawa, K Sasaki, T Ueda, S Yamamoto, S Haines, TJ Dazeley, S Hatakeyama, S Svoboda, R Blaufuss, E Goodman, JA Sullivan, GW Turcan, D Scholberg, K Habig, A Fukuda, Y Jung, CK Kato, T Kobayashi, K Malek, M Mauger, C McGrew, C Sarrat, A Sharkey, E Yanagisawa, C Toshito, T Miyano, K Tamura, N Ishii, J Kuno, Y Nagashima, Y Takita, M Yoshida, M Kim, SB Yoo, J Okazawa, H Ishizuka, T Choi, Y Seo, HK Gando, Y Hasegawa, T Inoue, K Shirai, J Suzuki, A Koshiba, M Nakajima, Y Nishijima, K Harada, T Ishino, H Nishimura, R Watanabe, Y Kielczewska, D Zalipska, J Berns, HG Gran, R Shiraishi, KK Stachyra, A Washburn, K Wilkes, RJ AF Ashie, Y Hosaka, J Ishihara, K Itow, Y Kameda, J Koshio, Y Minamino, A Mitsuda, C Miura, M Moriyama, S Nakahata, M Namba, T Nambu, R Obayashi, Y Shiozawa, M Suzuki, Y Takeuchi, Y Taki, K Yamada, S Ishitsuka, M Kajita, T Kaneyuki, K Nakayama, S Okada, A Okumura, K Ooyabu, T Saji, C Takenaga, Y Desai, S Kearns, E Likhoded, S Stone, JL Sulak, LR Walter, CW Wang, W Goldhaber, M Casper, D Cravens, JP Gajewski, W Kropp, WR Liu, DW Mine, S Smy, MB Sobel, HW Sterner, CW Vagins, MR Ganezer, KS Hill, J Keig, WE Jang, JS Kim, JY Lim, IT Ellsworth, RW Tasaka, S Guillian, G Kibayashi, A Learned, JG Matsuno, S Takemori, D Messier, MD Hayato, Y Ichikawa, AK Ishida, T Ishii, T Iwashita, T Kobayashi, T Maruyama, T Nakamura, K Nitta, K Oyama, Y Sakuda, M Totsuka, Y Suzuki, AT Hasegawa, M Hayashi, K Inagaki, T Kato, I Maesaka, H Morita, T Nakaya, T Nishikawa, K Sasaki, T Ueda, S Yamamoto, S Haines, TJ Dazeley, S Hatakeyama, S Svoboda, R Blaufuss, E Goodman, JA Sullivan, GW Turcan, D Scholberg, K Habig, A Fukuda, Y Jung, CK Kato, T Kobayashi, K Malek, M Mauger, C McGrew, C Sarrat, A Sharkey, E Yanagisawa, C Toshito, T Miyano, K Tamura, N Ishii, J Kuno, Y Nagashima, Y Takita, M Yoshida, M Kim, SB Yoo, J Okazawa, H Ishizuka, T Choi, Y Seo, HK Gando, Y Hasegawa, T Inoue, K Shirai, J Suzuki, A Koshiba, M Nakajima, Y Nishijima, K Harada, T Ishino, H Nishimura, R Watanabe, Y Kielczewska, D Zalipska, J Berns, HG Gran, R Shiraishi, KK Stachyra, A Washburn, K Wilkes, RJ CA Super-Kamiokande Collaboration TI Evidence for an oscillatory signature in atmospheric neutrino oscillations SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-NEUTRINO; FLUX AB Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu(mu)<---->nu(tau) neutrino oscillation parameters; 1.9x10(-3)0.90 at 90% confidence level. C1 Univ Tokyo, Inst Cosm Ray Res, Kamioka Observ, Gifu 5061205, Japan. Univ Tokyo, Inst Cosm Ray Res, Res Ctr Cosm Neutrinos, Chiba 2778582, Japan. Boston Univ, Dept Phys, Boston, MA 02215 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Calif State Univ Dominguez Hills, Dept Phys, Carson, CA 90747 USA. Chonnam Natl Univ, Dept Phys, Kwangju 500757, South Korea. George Mason Univ, Dept Phys, Fairfax, VA 22030 USA. Gifu Univ, Dept Phys, Gifu 5011193, Japan. Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan. Kobe Univ, Dept Phys, Kobe, Hyogo 6578501, Japan. Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87544 USA. Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Univ Minnesota, Dept Phys, Duluth, MN 55812 USA. Miyagi Univ Educ, Dept Phys, Sendai, Miyagi 9800845, Japan. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Nagoya Univ, Dept Phys, Aichi 4648602, Japan. Niigata Univ, Dept Phys, Niigata 9502181, Japan. Osaka Univ, Dept Phys, Osaka 5600043, Japan. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Shizuoka Seika Coll, Shizuoka 4258611, Japan. Shizuoka Univ, Dept Syst Engn, Shizuoka 4328561, Japan. Sungkyunkwan Univ, Dept Phys, Suwon 440746, South Korea. Tohoku Univ, Res Ctr Neutrino Sci, Sendai, Miyagi 9808578, Japan. Univ Tokyo, Tokyo 1130033, Japan. Tokai Univ, Dept Phys, Kanagawa 2591292, Japan. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP Ashie, Y (reprint author), Univ Tokyo, Inst Cosm Ray Res, Kamioka Observ, Gifu 5061205, Japan. RI Takeuchi, Yasuo/A-4310-2011; Nakamura, Kenzo/F-7174-2010; Sobel, Henry/A-4369-2011; Suzuki, Yoichiro/F-7542-2010; Wilkes, R.Jeffrey/E-6011-2013; Kim, Soo-Bong/B-7061-2014; Ishino, Hirokazu/C-1994-2015; Koshio, Yusuke/C-2847-2015; Kibayashi, Atsuko/K-7327-2015; Obayashi, Yoshihisa/A-4472-2011; Yoo, Jonghee/K-8394-2016 OI Ishino, Hirokazu/0000-0002-8623-4080; Koshio, Yusuke/0000-0003-0437-8505; NR 16 TC 500 Z9 503 U1 2 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2004 VL 93 IS 10 AR 101801 DI 10.1103/PhysRevLett.93.101801 PG 6 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600008 PM 15447395 ER PT J AU Bearden, IG Beavis, D Besliu, C Budick, B Boggild, H Chasman, C Christensen, CH Christiansen, P Cibor, J Debbe, R Enger, E Gaardhoje, JJ Germinario, M Hagel, K Hansen, O Holm, A Holme, AK Ito, H Jipa, A Jundt, F Jordre, JI Jorgensen, CE Karabowicz, R Kim, EJ Kozik, T Larsen, TM Lee, JH Lee, YK Lovhoiden, G Majka, Z Makeev, A Mikelsen, M Murray, M Natowitz, J Nielsen, BS Norris, J Olchanski, K Ouerdane, D Planeta, R Rami, F Ristea, C Rohrich, D Samset, BH Sandberg, D Sanders, SJ Scheetz, RA Staszel, P Tveter, TS Videbaek, F Wada, R Yin, Z Zgura, IS AF Bearden, IG Beavis, D Besliu, C Budick, B Boggild, H Chasman, C Christensen, CH Christiansen, P Cibor, J Debbe, R Enger, E Gaardhoje, JJ Germinario, M Hagel, K Hansen, O Holm, A Holme, AK Ito, H Jipa, A Jundt, F Jordre, JI Jorgensen, CE Karabowicz, R Kim, EJ Kozik, T Larsen, TM Lee, JH Lee, YK Lovhoiden, G Majka, Z Makeev, A Mikelsen, M Murray, M Natowitz, J Nielsen, BS Norris, J Olchanski, K Ouerdane, D Planeta, R Rami, F Ristea, C Rohrich, D Samset, BH Sandberg, D Sanders, SJ Scheetz, RA Staszel, P Tveter, TS Videbaek, F Wada, R Yin, Z Zgura, IS CA BRAHMS Collaboration TI Nuclear stopping in Au+Au collisions at root s(NN) = 200 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID BARYON RAPIDITY LOSS; MODEL AB Transverse momentum spectra and rapidity densities, dN/dy, of protons, antiprotons, and net protons (p-(p) over bar) from central (0%-5%) Au+Au collisions at roots(NN)=200 GeV were measured with the BRAHMS experiment within the rapidity range 0less than or equal toyless than or equal to3. The proton and antiproton dN/dy decrease from midrapidity to y=3. The net-proton yield is roughly constant for y<1 at dN/dysimilar to7, and increases to dN/dysimilar to12 at ysimilar to3. The data show that collisions at this energy exhibit a high degree of transparency and that the linear scaling of rapidity loss with rapidity observed at lower energies is broken. The energy loss per participant nucleon is estimated to be 73+/-6 GeV. 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, Smoluchkowski Inst Phys, Krakow, Poland. Johns Hopkins Univ, Baltimore, MD 21218 USA. NYU, New York, NY 10003 USA. Texas A&M Univ, College Stn, TX USA. Univ Bergen, Dept Phys, Bergen, Norway. Univ Kansas, Lawrence, KS 66045 USA. Univ Oslo, Dept Phys, Oslo, Norway. Univ Bucharest, Bucharest, Romania. 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; Samset, Bjorn H./B-9248-2012 OI Christensen, Christian Holm/0000-0002-1850-0121; Christensen, Christian/0000-0002-1850-0121; Bearden, Ian/0000-0003-2784-3094; Samset, Bjorn H./0000-0001-8013-1833 NR 22 TC 155 Z9 160 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 2004 VL 93 IS 10 AR 102301 DI 10.1103/PhysRevLett.93.102301 PG 5 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600010 PM 15447397 ER PT J AU Daughton, W Lapenta, G Ricci, P AF Daughton, W Lapenta, G Ricci, P TI Nonlinear evolution of the lower-hybrid drift instability in a current sheet SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN CURRENT SHEETS; NEUTRAL SHEET; MAGNETIC RECONNECTION; FIELD; SIMULATIONS; DYNAMICS; SUBSTORM; CLUSTER; REGIONS; ONSET AB The lower-hybrid drift instability is simulated in an ion-scale current sheet using a fully kinetic approach with values of the ion to electron mass ratio up to m(i)/m(e)=1836. Although the instability is localized on the edge of the layer, the nonlinear development increases the electron flow velocity in the central region resulting in a strong bifurcation of the current density and significant anisotropic heating of the electrons. This dramatically enhances the collisionless tearing mode and may lead to the rapid onset of magnetic reconnection for current sheets near the critical scale. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ist Nazl Fis Mat, Sez Torino, Turin, Italy. RP Daughton, W (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Daughton, William/L-9661-2013; OI Lapenta, Giovanni/0000-0002-3123-4024 NR 29 TC 85 Z9 86 U1 0 U2 17 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2004 VL 93 IS 10 AR 105004 DI 10.1103/PhysRevLett.93.105004 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600024 PM 15447411 ER PT J AU Davidson, BA Ramazashvili, R Kos, S Eckstein, JN AF Davidson, BA Ramazashvili, R Kos, S Eckstein, JN TI Broken particle-hole symmetry at atomically flat a-axis YBa2Cu3O7-delta interfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID VACUUM TUNNELING SPECTROSCOPY; CUPRATE SUPERCONDUCTORS; SURFACE-STATES; IMPURITY ATOMS; VORTEX CORES; THIN-FILMS; BI2SR2CACU2O8+DELTA; JUNCTIONS; GAP; CONDUCTANCE AB We have studied quasiparticle tunneling into atomically flat a-axis films of YBa2Cu3O7-delta and DyBa2Cu3O7-delta through epitaxial CaTiO3 barriers. The junction heterostructures were grown by oxide molecular beam epitaxy and were carefully optimized using in situ monitoring techniques, resulting in unprecedented crystalline perfection of the superconductor-insulator interface. Below T-c, the tunneling conductance shows the evolution of a large unexpected asymmetrical feature near zero-bias. This is evidence that superconducting YBCO crystals, atomically truncated along the lobe direction with a titanate layer, have intrinsically broken particle-hole symmetry over macroscopically large areas. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. INFM, TASC Natl Lab, I-34012 Basovizza, TS, Italy. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. EM davidson@tasc.infm.it RI Ramazashvili, Revaz/J-5090-2013; Davidson, Bruce/C-6010-2009; Kos, Simon/G-3289-2016 OI Ramazashvili, Revaz/0000-0001-5133-8253; Davidson, Bruce/0000-0003-1616-9380; Kos, Simon/0000-0003-1657-9793 NR 42 TC 3 Z9 3 U1 0 U2 3 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 2004 VL 93 IS 10 AR 107004 DI 10.1103/PhysRevLett.93.107004 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600054 PM 15447441 ER PT J AU Hayden, ME Archibald, G Barnes, PD Buttler, WT Clark, DJ Cooper, MD Espy, M Golub, R Greene, GL Lamoreaux, SK Lei, C Marek, LJ Peng, JC Penttila, SI AF Hayden, ME Archibald, G Barnes, PD Buttler, WT Clark, DJ Cooper, MD Espy, M Golub, R Greene, GL Lamoreaux, SK Lei, C Marek, LJ Peng, JC Penttila, SI TI Neutron-detected tomography of impurity-seeded superfluid helium SO PHYSICAL REVIEW LETTERS LA English DT Article ID MASS DIFFUSION-COEFFICIENT; LIQUID-HELIUM; HE-4; TURBULENCE; MIXTURES; FLOW AB We describe a neutron radiography technique that can be used to map the distribution of He-3 impurities in liquid He-4, providing direct and quantitative access to underlying transport processes. Images reflecting finite normal- and superfluid-component He-4 velocity fields are presented. C1 Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. Univ Tennessee, Dept Phys, Knoxville, TN 37966 USA. Univ Illinois, Urbana, IL 61801 USA. RP Hayden, ME (reprint author), Simon Fraser Univ, Dept Phys, 8888 Univ Dr, Burnaby, BC V5A 1S6, Canada. NR 29 TC 11 Z9 11 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 2004 VL 93 IS 10 AR 105302 DI 10.1103/PhysRevLett.93.105302 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600026 PM 15447413 ER PT J AU Levitas, VI Idesman, AV Preston, DL AF Levitas, VI Idesman, AV Preston, DL TI Microscale simulation of martensitic microstructure evolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHAPE-MEMORY ALLOY; THERMOMECHANICAL BEHAVIOR; PSEUDOELASTIC BEHAVIOR; MICROMECHANICAL MODEL; TENSION AB A new model for the evolution of multivariant martensitic microstructure in single crystals and polycrystals is developed. In contrast with Landau-Ginzburg models, which are limited in practice to nanoscale specimens, this new scale-free model is valid for length scales greater than 100 nm and without an upper bound. It is based on a thermodynamic potential in the volume fractions of the martensitic variants that exhibits an instability resulting in microstructure formation. Simulated microstructures in elastic single crystals and polycrystals under uniaxial loading are in qualitative agreement with those observed experimentally. C1 Texas Tech Univ, Dept Mech Engn, Ctr Mechanochem & Synth New Mat, Lubbock, TX 79409 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Levitas, VI (reprint author), Texas Tech Univ, Dept Mech Engn, Ctr Mechanochem & Synth New Mat, Lubbock, TX 79409 USA. NR 17 TC 50 Z9 50 U1 3 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 3 PY 2004 VL 93 IS 10 AR 105701 DI 10.1103/PhysRevLett.93.105701 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600032 PM 15447419 ER PT J AU Marts, B Hagberg, A Meron, E Lin, AL AF Marts, B Hagberg, A Meron, E Lin, AL TI Bloch-front turbulence in a periodically forced Belousov-Zhabotinsky reaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID REACTION-DIFFUSION SYSTEM; DEFECT-MEDIATED TURBULENCE; CURVED FRONTS; BIFURCATIONS; TRANSITION; PATTERNS; WALLS; SPOTS AB Experiments on a periodically forced Belousov-Zhabotinsky chemical reaction show front breakup into a state of spatiotemporal disorder involving continual events of spiral-vortex nucleation and destruction. Using the amplitude equation for forced oscillatory systems and the normal form equations for a curved front line, we identify the mechanism of front breakup and explain the experimental observations. C1 Duke Univ, Dept Phys, Durham, NC 27708 USA. Los Alamos Natl Lab, Math Modeling & Anal Theoret Div, Los Alamos, NM 87545 USA. Ben Gurion Univ Negev, Dept Solar Energy & Environm Phys, BIDR, IL-84990 Sede Boqer, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. RP Marts, B (reprint author), Duke Univ, Dept Phys, Durham, NC 27708 USA. RI MERON, EHUD/F-1810-2012 NR 24 TC 26 Z9 26 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 3 PY 2004 VL 93 IS 10 AR 108305 DI 10.1103/PhysRevLett.93.108305 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600078 PM 15447465 ER PT J AU Scielzo, ND Freedman, SJ Fujikawa, BK Vetter, PA AF Scielzo, ND Freedman, SJ Fujikawa, BK Vetter, PA TI Measurement of the beta-nu correlation using magneto-optically trapped Na-21 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY; NUCLEI; EFFICIENCIES; ABSOLUTE; DETECTOR AB The beta-neutrino correlation coefficient, a(betanu), in Na-21 is inferred from detecting the beta(+) and low-energy recoil daughter nucleus. Na-21 is produced at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory and 800 000 atoms are maintained in a magneto-optical trap. From the measured time of flight of recoil ions in the presence of a drift electric field, we find a(betanu)=0.5243+/-0.0091. There may be a dependence on the trapped atom population. This and other systematic uncertainties are discussed. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Scielzo, ND (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 27 TC 55 Z9 55 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 2004 VL 93 IS 10 AR 102501 DI 10.1103/PhysRevLett.93.102501 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600011 PM 15447398 ER PT J AU Stewart, DA Leonard, F AF Stewart, DA Leonard, F TI Photocurrents in nanotube junctions SO PHYSICAL REVIEW LETTERS LA English DT Article ID INDIUM-PHOSPHIDE NANOWIRES; CARBON NANOTUBES; DEVICES; SINGLE; TRANSPORT AB Photocurrents in nanotube p-n junctions are calculated using a nonequilibrium Green function quantum transport formalism. The short-circuit photocurrent displays band-to-band transitions and photon-assisted tunneling, and has multiple sharp peaks in the infrared, visible, and ultraviolet. The operation of such devices in the nanoscale regime leads to unusual size effects, where the photocurrent scales linearly and oscillates with device length. The oscillations can be related to the density of states in the valence band, a factor that also determines the relative magnitude of the photoresponse for different bands. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Stewart, DA (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. RI Stewart, Derek/B-6115-2008; OI Stewart, Derek/0000-0001-7355-2605 NR 18 TC 58 Z9 58 U1 0 U2 12 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 2004 VL 93 IS 10 AR 107401 DI 10.1103/PhysRevLett.93.107401 PG 4 WC Physics, Multidisciplinary SC Physics GA 851WQ UT WOS:000223717600062 PM 15447449 ER PT J AU Hallam, SJ Putnam, N Preston, CM Detter, JC Rokhsar, D Richardson, PM DeLong, EF AF Hallam, SJ Putnam, N Preston, CM Detter, JC Rokhsar, D Richardson, PM DeLong, EF TI Reverse methanogenesis: Testing the hypothesis with environmental genomics SO SCIENCE LA English DT Article ID METHANE-OXIDIZING ARCHAEA; MARINE-SEDIMENTS; ANAEROBIC OXIDATION; CARBONATES; PATHWAYS; BACTERIA; GENES AB Microbial methane consumption in anoxic sediments significantly impacts the global environment by reducing the flux of greenhouse gases from ocean to atmosphere. Despite its significance, the biological mechanisms controlling anaerobic methane oxidation are not well characterized. One current model suggests that relatives of methane-producing Archaea, developed the capacity to reverse methanogenesis and thereby to consume methane to produce cellular carbon and energy. We report here a test of the "reverse-methanogenesis" hypothesis by genomic analyses of methane-oxidizing Archaea, from deep-sea sediments. Our results show that nearly all genes typically associated with methane production are present in one specific group of archaeal methanotrophs. These genome-based observations support previous hypotheses and provide an informed foundation for metabolic modeling of anaerobic methane oxidation. C1 Monterey Bay Aquarium Res Inst, Moss Landing, CA 95064 USA. Joint Genome Inst, Walnut Creek, CA 94598 USA. RP DeLong, EF (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM delong@mit.edu RI Putnam, Nicholas/B-9968-2008 OI Putnam, Nicholas/0000-0002-1315-782X NR 24 TC 329 Z9 358 U1 12 U2 90 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 3 PY 2004 VL 305 IS 5689 BP 1457 EP 1462 DI 10.1126/science.1100025 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 852NK UT WOS:000223761900047 PM 15353801 ER PT J AU Paul, R Paddison, SJ AF Paul, R Paddison, SJ TI Structure and dielectric saturation of water in hydrated polymer electrolyte membranes: Inclusion of the internal field energy SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; STATISTICAL-MECHANICAL MODEL; REVERSE MICELLES; EXCHANGE MEMBRANE; FUEL-CELLS; PROTON; POLARIZATION; NAFION(R); PORES; TRANSPORT AB The nature of the water in hydrated polymer electrolyte membranes (PEMs) is distinct from that of bulk water and affects the rate of diffusion of protons in the material. Traditional methods used in the study of the phenomenon of dielectric saturation involve the assumption of the presence of a homogeneous or slowly varying external field, conditions that are hardly appropriate for PEMs. If the condition of field homogeneity is relaxed, a nonphysical divergence in the permittivity results. In this paper we show that through proper inclusion of the internal field energy the difficulty is rectified. Our recently derived equilibrium statistical mechanical model for the calculation of the spatial variation in the permittivity of water within PEMs has been extended to include the field energy. Using simple model calculations, we demonstrate that the interaction of the water molecules with the anionic sites constitute a more important contribution to the energy than the intermolecular forces. We have recalculated pore-radial profiles of the dielectric constant of the water in Nafion and 65% sulfonated PEEKK (poly arylene ether ketone) polymer electrolyte membranes over a range of hydration levels obtaining qualitative agreement with experiments. These profiles quantitatively show the increased ordering of the water in the neighborhood of the anionic sites, and although only the affect due to these sites is specifically computed, confinement effects on the water is implicitly included. In separate investigations, it was determined that both the uniformity in the distribution of the sulfonate groups, and the intrusion of these groups into the pore volume, will dramatically affect the permittivity of the water. Together our results help to elucidate the impact of structure and ordering of the water due to the effect of the fixed anionic groups on the underlying mechanisms of proton conduction in PEMs. C1 Los Alamos Natl Lab, Mol Phys & Theoret Chem Grp, Los Alamos, NM 87545 USA. Univ Calgary, Dept Chem, Calgary, AB T2N 1N4, Canada. RP Paul, R (reprint author), Los Alamos Natl Lab, Mol Phys & Theoret Chem Grp, Los Alamos, NM 87545 USA. EM rpaul@ucalgary.ca; paddison@t12.lan1.gov RI Paddison, Stephen/B-2935-2014 NR 42 TC 40 Z9 40 U1 0 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 2 PY 2004 VL 108 IS 35 BP 13231 EP 13241 DI 10.1021/jp048501k PG 11 WC Chemistry, Physical SC Chemistry GA 850HC UT WOS:000223600800024 ER PT J AU Tang, DC Hwang, KS Salmeron, M Somorjai, GA AF Tang, DC Hwang, KS Salmeron, M Somorjai, GA TI High pressure scanning tunneling microscopy study of CO poisoning of ethylene hydrogenation on Pt(111) and Rh(111) single crystals SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SUM-FREQUENCY GENERATION; INDUCED THERMAL-DESORPTION; DI-SIGMA; VIBRATIONAL-SPECTRA; SURFACE-REACTIONS; BONDED ETHYLENE; ADSORPTION SITE; IN-SITU; ETHYLIDYNE; PLATINUM AB Using a high-pressure scanning tunneling microscope we monitored the coadsorption of hydrogen, ethylene, and carbon dioxide on platinum(111) and rhodium(111) crystal faces in the mtorr pressure range at 300 K in equilibrium with the gas phase. During the catalytic hydrogenation of ethylene to ethane in the absence of CO the metal surfaces are covered by an adsorbate layer that is very mobile on the time scale of STM imaging. We found that the addition of CO poisons the hydrogenation reaction and induces ordered structures on the single-crystal surfaces. Several ordered structures were observed upon CO addition to the surfaces precovered with hydrogen and ethylene: a rotated (root19 x root19)R23.4degrees on Pt(111), and domains of c(4 x 2)-CO + C2H3, previously unobserved (4 x 2)-CO + 3C(2)H(3), and (2 x 2)-3CO on Rh(111). A mechanism for CO poisoning of ethylene hydrogenation on the metal single crystals was proposed, in which CO blocks surface metal sites and reduces adsorbate mobility to limit adsorption and reaction rate of ethylene and hydrogen. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM somorjai@socrates.berkeley.edu NR 52 TC 53 Z9 53 U1 2 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 2 PY 2004 VL 108 IS 35 BP 13300 EP 13306 DI 10.1021/jp036580e PG 7 WC Chemistry, Physical SC Chemistry GA 850HC UT WOS:000223600800034 ER PT J AU Crooker, SA Rickel, DG Balatsky, AV Smith, DL AF Crooker, SA Rickel, DG Balatsky, AV Smith, DL TI Spectroscopy of spontaneous spin noise as a probe of spin dynamics and magnetic resonance SO NATURE LA English DT Article ID ATOMIC SPIN; DIODE-LASER; FLUCTUATIONS AB Not all noise in experimental measurements is unwelcome. Certain fundamental noise sources contain valuable information about the system itself - a notable example being the inherent voltage fluctuations ( Johnson noise) that exist across any resistor, which allow the temperature to be determined(1,2). In magnetic systems, fundamental noise can exist in the form of random spin fluctuations(3,4). For example, statistical fluctuations of N paramagnetic spins should generate measurable noise of order rootN spins, even in zero magnetic field(5,6). Here we exploit this effect to perform perturbation-free magnetic resonance. We use off-resonant Faraday rotation to passively(7,8) detect the magnetization noise in an equilibrium ensemble of paramagnetic alkali atoms; the random fluctuations generate spontaneous spin coherences that precess and decay with the same characteristic energy and timescales as the macroscopic magnetization of an intentionally polarized or driven ensemble. Correlation spectra of the measured spin noise reveal g-factors, nuclear spin, isotope abundance ratios, hyperfine splittings, nuclear moments and spin coherence lifetimes - without having to excite, optically pump or otherwise drive the system away from thermal equilibrium. These noise signatures scale inversely with interaction volume, suggesting a possible route towards non-perturbative, sourceless magnetic resonance of small systems. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. RP Crooker, SA (reprint author), Los Alamos Natl Lab, Natl High Magnet Field Lab, POB 1663, Los Alamos, NM 87545 USA. EM crooker@lanl.gov NR 30 TC 126 Z9 126 U1 6 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 2 PY 2004 VL 431 IS 7004 BP 49 EP 52 DI 10.1038/nature02804 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 850VC UT WOS:000223641500037 PM 15343328 ER PT J AU Campuzano, JC Kaminski, A Rosenkranz, S Fretwell, HM AF Campuzano, JC Kaminski, A Rosenkranz, S Fretwell, HM TI Time-reversal symmetry breaking? Reply SO NATURE LA English DT Editorial Material ID RESOLVED PHOTOEMISSION SPECTROSCOPY; FERMI-SURFACE; BI2SR2CACU2O8 C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Campuzano, JC (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM campuzano5@comcast.net RI Rosenkranz, Stephan/E-4672-2011 OI Rosenkranz, Stephan/0000-0002-5659-0383 NR 9 TC 1 Z9 1 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 2 PY 2004 VL 431 IS 7004 DI 10.1038/nature02932 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 850VC UT WOS:000223641500034 ER PT J AU Murayama, H AF Murayama, H TI CPT tests: kaon vs. neutrinos SO PHYSICS LETTERS B LA English DT Article ID STERILE NEUTRINOS; OSCILLATIONS; VIOLATION; LSND; REACTOR; SEARCH AB CPT violation has an impressive limit in the neutral kaon system \m(K-0) - m((K) over bar (0))\ < 10(-18)m(K) = 0.50 x 10(-18) GeV. However, if viewed as a constraint on the mass-squared, the bound appears weak, \m(2)(K-0) - m(2)((K) over bar (0))\ < 0.25 eV(2). We point out that neutrino oscillation offers better limits on CPT violation in this caste. The comparison of solar and rector neutrino results puts the best limit on CPT violation by far, \Deltam(v)(2) - Deltam(v)(2)\ < 1.3 x 10(-3) eV(2) (90% CL). (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM murayama@lbl.gov RI Murayama, Hitoshi/A-4286-2011 NR 36 TC 16 Z9 17 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 2 PY 2004 VL 597 IS 1 BP 73 EP 77 DI 10.1016/j.physletb.2004.06.106 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 848CY UT WOS:000223446000008 ER PT J AU Davis, TA Gilbert, JR Larimore, SI Ng, EG AF Davis, TA Gilbert, JR Larimore, SI Ng, EG TI A column approximate minimum degree ordering algorithm SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE algorithms; experimentation; performance; sparse nonsymmetric matrices; linear equations; ordering methods ID SPARSE CHOLESKY FACTORIZATION; SYMBOLIC FACTORIZATION; GAUSSIAN-ELIMINATION; MULTIFRONTAL METHOD; MATRICES; IMPLEMENTATION; SYSTEMS; FILL AB Sparse Gaussian elimination with partial pivoting computes the factorization PAQ = LU of a sparse matrix A, where the row ordering P is selected during factorization using standard partial pivoting with row interchanges. The goal is to select a column preordering, Q, based solely on the nonzero pattern of A, that limits the worst-case number of nonzeros in the factorization. The fill-in also depends on P, but Q is selected to reduce an upper bound on the fill-in for any subsequent choice of P. The choice of Q can have a dramatic impact on the number of nonzeros in L and U. One scheme for determining a good column ordering for A is to compute a symmetric ordering that reduces fill-in in the Cholesky factorization of A(T)A. A conventional minimum degree ordering algorithm would require the sparsity structure of A(T)A to be computed, which can be expensive both in terms of space and time since A(T)A may be much denser than A. An alternative is to compute Q directly from the sparsity structure of A; this strategy is used by MATLAB's COLMMD preordering algorithm. A new ordering algorithm, COLAMD, is presented. It is based on the same strategy but uses a better ordering heuristic. COLAMD is faster and computes better orderings, with fewer nonzeros in the factors of the matrix. C1 Univ Florida, Comp & Informat Sci & Engn Dept, Gainesville, FL 32611 USA. Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. Microsoft Corp, Redmond, WA 98052 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Davis, TA (reprint author), Univ Florida, Comp & Informat Sci & Engn Dept, Gainesville, FL 32611 USA. EM davis@cise.ufl.edu; gilbert@cs.ucsb.edu; slarimore@Exchange.Microsoft.com; EGNg@lbl.gov RI Davis, Timothy/I-7248-2012 NR 46 TC 81 Z9 86 U1 1 U2 2 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 2004 VL 30 IS 3 BP 353 EP 376 DI 10.1145/1024074.1024079 PG 24 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 860EP UT WOS:000224325600005 ER PT J AU Davis, TA Gilbert, JR Larimore, SI Ng, EG AF Davis, TA Gilbert, JR Larimore, SI Ng, EG TI Algorithm 836: COLAMD, a column approximate minimum degree ordering algorithm SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE algorithms; experimentation; performance; linear equations; ordering methods; sparse nonsymmetric matrices AB Two codes are discussed, COLAMD and SYMAMD, that compute approximate minimum degree orderings for sparse matrices in two contexts: (1) sparse partial pivoting, which requires a sparsity preserving column pre-ordering prior to numerical factorization, and (2) sparse Cholesky factorization, which requires a symmetric permutation of both the rows and columns of the matrix being factorized. These orderings are computed by COLAMD and SYMAMD, respectively. The ordering from COLAMD is also suitable for sparse QR factorization, and the factorization of matrices of the form A(T)A and AA(T), such as those that arise in least-squares problems and interior point methods for linear programming problems. The two routines are available both in MATLAB and C-callable forms. They appear as built-in routines in MATLAB Version 6.0. C1 Univ Florida, Comp & Informat Sci & Engn Dept, Gainesville, FL 32611 USA. Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. Microsoft Corp, Redmond, WA 98052 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Davis, TA (reprint author), Univ Florida, Comp & Informat Sci & Engn Dept, Gainesville, FL 32611 USA. EM davis@eise.ufl.edu; gilbert@cs.ucsb.edu; slari-more@Exchange.Microsoft.com; EGNg@lbl.gov RI Davis, Timothy/I-7248-2012 NR 7 TC 37 Z9 37 U1 0 U2 0 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 2004 VL 30 IS 3 BP 377 EP 380 DI 10.1145/1024074.1024080 PG 4 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 860EP UT WOS:000224325600006 ER PT J AU Qiao, ZJ AF Qiao, ZJ TI Integrable hierarchy, 3x3 constrained systems, and parametric solutions SO ACTA APPLICANDAE MATHEMATICAE LA English DT Article DE Hamiltonian system; matrix equation; zero curvature representation; integrable equation; parametric solution ID NONLINEAR-EVOLUTION-EQUATIONS; ALGEBRO-GEOMETRIC SOLUTION; SHALLOW-WATER EQUATION; HEREDITARY SYMMETRIES; EIGENVALUE PROBLEMS; BILLIARD SOLUTIONS; PEAKED SOLITONS; PDES AB This paper provides a new integrable hierarchy. The DP equation: m(t) + um(x) + 3mu(x) = 0, m = u - u(xx), proposed recently by Degasperis and Procesi, is the first member in the negative order hierarchy while the first equation in the positive order hierarchy is: m(t) = 4(m(-2/3))(x) - 5( m(-2/3))(xxx) + (m(-2/3))(xxxxx). The whole hierarchy is shown Lax-integrable through solving a key matrix equation. To obtain the parametric solutions for the whole hierarchy, we separately discuss the negative order and the positive order hierarchies. For the negative order hierarchy, its 3 x 3 Lax pairs and corresponding adjoint representations are cast in Liouville-integrable Hamiltonian canonical systems under the Dirac-Poisson bracket defined on a symplectic submanifold of R-6N. Based on the integrability of those finite-dimensional canonical Hamiltonian systems we give the parametric solutions of all equations in the negative order hierarchy. In particular, we obtain the parametric solution of the DP equation. Moreover, for the positive order hierarchy, we consider a different constraint and process a procedure similar to the negative case to obtain the parametric solutions of the positive order hierarchy. In a special case, we give the parametric solution of the 5th-order PDE m(t) = 4(m(-2/3))(x) - 5(m(-2/3))(xxx) + (m(-) (2/3))(xxxxx). Finally, we discuss the stationary solutions of the 5th-order PDE, which may be included in the parametric solution. C1 Univ Texas Pan Amer, Dept Math, Edinburg, TX 78539 USA. Los Alamos Natl Lab, T CNLS, Los Alamos, NM 87545 USA. Fudan Univ, Inst Math, Shanghai 200433, Peoples R China. RP Qiao, ZJ (reprint author), Univ Texas Pan Amer, Dept Math, Edinburg, TX 78539 USA. NR 31 TC 29 Z9 30 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-8019 J9 ACTA APPL MATH JI Acta Appl. Math. PD SEP PY 2004 VL 83 IS 3 BP 199 EP 220 DI 10.1023/B:ACAP.0000038872.88367.dd PG 22 WC Mathematics, Applied SC Mathematics GA 848QV UT WOS:000223483100001 ER PT J AU Sofield, CD Walter, MD Andersen, RA AF Sofield, CD Walter, MD Andersen, RA TI Amidobis[eta(5)-1,3-bis(trimethylsilyl)cyclopentadienyl]titanium(III) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID NITROGEN AB The title compound, [Ti(C11H21Si2)(2)(NH2)], crystallizes as a bent metallocene, with the NH2 group oriented to maximize the pi interaction between the N atom and the Ti-III center. The increased pi bonding is reflected in a short Ti-N bond length of 1.933 (3) Angstrom. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Walter, MD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. EM mwalter@rhrk.uni-kl.de RI Walter, Marc/E-4479-2012 NR 9 TC 3 Z9 3 U1 0 U2 0 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD SEP PY 2004 VL 60 BP M465 EP M466 DI 10.1107/S0108270104018840 PN 9 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 858XT UT WOS:000224226700022 PM 15345836 ER PT J AU Sekar, K Rajakannan, V Velmurugan, D Yamane, T Thirumurugan, R Dauter, M Dauter, Z AF Sekar, K Rajakannan, V Velmurugan, D Yamane, T Thirumurugan, R Dauter, M Dauter, Z TI A redetermination of the structure of the triple mutant (K53,56,120M) of phospholipase A(2) at 1.6 angstrom resolution using sulfur-SAS at 1.54 angstrom wavelength SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID PROTEIN CRYSTAL-STRUCTURES; ANOMALOUS SCATTERING; DIFFRACTION DATA; S-ATOMS; MACROMOLECULAR CRYSTALLOGRAPHY; REFINEMENT; SIGNAL; SUBSTRUCTURE; COMBINATION; RADIATION AB The crystal structure of the triple mutant K53,56,120M of bovine pancreatic phospholipase A(2) has been redetermined using sulfur single-wavelength anomalous scattering. The synchrotron data-were collected at lambda = 1.54 Angstrom and the crystal diffracted to 1.6 Angstrom resolution. The program SOLVE was used to locate the heavy atoms and to estimate the initial phases and the resulting map was then subjected to RESOLVE. The output of 455 non-H atoms, including 12 S atoms, one calcium ion and one chloride ion, were then subjected to ARP/wARP followed by REFMAC With the improved phases, the automatic model building successfully built more than 85%, of the 123 residues, excluding the N- and C-terminal residues. The final crystallographic R factor is 17.7% (R-free = 21.7%). The refined model consists of 954 non-H protein atoms, 165 water 0 atoms, three 2-methyl-2,4-pentanediol (MPD) molecules, one calcium ion and one chloride ion. The present work is yet another example that shows the utility of single-wavelength anomalous scattering data for solving a protein structure. C1 Indian Inst Sci, Bioinformat Ctr, Bangalore 560012, Karnataka, India. Indian Inst Sci, Supercomp Educ & Res Ctr, Bangalore 560012, Karnataka, India. Univ Madras, Dept Crystallog & Biophys, Madras 600025, Tamil Nadu, India. Nagoya Univ, Grad Sch Engn, Dept Biotechnol & Biomat Sci, Chikusa Ku, Nagoya, Aichi 4648603, Japan. Albert Einstein Coll Med, Dept Physiol & Biophys, Bronx, NY 10461 USA. SAIC Frederick Inc, Basic Res Program, Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sekar, K (reprint author), Indian Inst Sci, Bioinformat Ctr, Bangalore 560012, Karnataka, India. EM sekar@physics.iisc.ernet.in NR 44 TC 15 Z9 15 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0907-4449 EI 1399-0047 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP PY 2004 VL 60 BP 1586 EP 1590 DI 10.1107/S090744490401697X PN 9 PG 5 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 849GD UT WOS:000223525800011 PM 15333929 ER PT J AU Jancarik, J Pufan, R Hong, C Kim, SH Kim, R AF Jancarik, J Pufan, R Hong, C Kim, SH Kim, R TI Optimum solubility (OS) screening: an efficient method to optimize buffer conditions for homogeneity and crystallization of proteins SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID DYNAMIC LIGHT-SCATTERING AB One of the most critical steps in the preparation of protein samples for structural studies by X-ray crystallography is to obtain biochemically pure and conformationally homogenous protein samples. Very often, the purified sample does not meet these qualifications and therefore does not crystallize. A screening method, Optimum Solubility Screen, has been developed that consists of two steps. The first step selects a better buffer than that used during purification. 24 different buffers ranging from pH 3 to pH 10 are screened using a vapor-diffusion method and very small amounts of protein. The solubility of the protein is first determined by visual examination using a light microscope and those drops that remain clear after 24 h are further evaluated using dynamic light scattering. If the results from the first step are still not satisfactory, a second step explores a variety of chemical additives in order to improve the monodispersity of the protein sample. In 64% of the cases, crystallization was successful from proteins that had initially shown high levels of aggregation. This screen can be configured to perform in an automated high-throughput mode and can be expanded for additional buffers and additives. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Kim, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Struct Genom Ctr, Berkeley, CA 94720 USA. EM r_kim@lbl.gov FU NIGMS NIH HHS [GM 62412] NR 7 TC 69 Z9 74 U1 1 U2 9 PU BLACKWELL MUNKSGAARD 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 2004 VL 60 BP 1670 EP 1673 DI 10.1107/S0907444904010972 PN 9 PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 849GD UT WOS:000223525800033 PM 15333951 ER PT J AU Sofield, CD Walter, MD Andersen, RA AF Sofield, CD Walter, MD Andersen, RA TI Bis[eta(5)-1,3-bis(trimethylsilyl)cyclopentadienyl]vanadium(II) SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article ID CRYSTAL-STRUCTURE; VANADOCENE; VANADIUM; COMPLEXES AB The title compound, [V(C11H21Si2)(2)], crystallizes in space group C2/c with the V atom located on a twofold symmetry axis. The vanadium(II) center is coordinated by two 1,3-bis(trimethylsilyl) cyclopentadienyl rings (Cp") to form a slightly bent metallocene [Cp(centroid)-V-Cp(centroid)=173.0 (1)degrees]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Walter, MD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. EM mwalter@rhrk.uni-kl.de RI Walter, Marc/E-4479-2012 NR 13 TC 1 Z9 1 U1 0 U2 3 PU BLACKWELL MUNKSGAARD 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 2004 VL 60 BP M1296 EP M1297 DI 10.1107/S1600536804020276 PN 9 PG 2 WC Crystallography SC Crystallography GA 850PI UT WOS:000223624500041 ER PT J AU Mortveit, HS Reidys, CM AF Mortveit, HS Reidys, CM TI Neutral evolution and mutation rates of sequential dynamical systems SO ADVANCES IN COMPLEX SYSTEMS LA English DT Article DE sequential dynamical systems; neutral evolution; error thresholds; acyclic orientations ID RNA SECONDARY STRUCTURES; NETWORKS; LANDSCAPES AB In this paper we study the evolution of sequential dynamical systems (SDS) as a result of the erroneous replication of the SDS words. An SDS consists of (a) a finite, labeled graph Y in which each vertex has a state, (b) a vertex labeled sequence of functions (F-vi,F-Y), and (c) a word omega, i.e. a sequence (omega(1),...,omega(k)), where each omega(i) is a Y-vertex. The function Fomega(i),(Y) updates the state of vertex omega(i) as a function of the states of omega(i) and its Y-neighbors and leaves the states of all other vertices fixed. The SDS over the word omega and Y is the composed map: [Fy, omega] = Pi(i)(k)=(1) F-omegai. The word omega represents the genotype of the SDS in a natural way. We will randomly flip consecutive letters of w with independent probability q and study the resulting evolution of the SDS. We introduce combinatorial. properties of SDS which allow us to construct a new distance measure D for words. We show that D captures the similarity of corresponding SDS. We will use the distance measure D to study neutrality and mutation rates in the evolution of words. We analyze the structure of neutral networks of words and the transition of word populations between them. Furthermore, we prove the existence of a critical mutation rate beyond which a population of words becomes essentially randomly distributed, and the existence of an optimal mutation rate at which a population maximizes its mutant offspring. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mortveit, HS (reprint author), Los Alamos Natl Lab, CCS-5, Los Alamos, NM 87545 USA. EM duck@santafe.edu NR 16 TC 1 Z9 1 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-5259 EI 1793-6802 J9 ADV COMPLEX SYST JI Adv. Complex Syst. PD SEP-DEC PY 2004 VL 7 IS 3-4 BP 395 EP 418 DI 10.1142/S0219525904000275 PG 24 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 902FY UT WOS:000227341100008 ER PT J AU Lu, ZM Zhang, DX AF Lu, ZM Zhang, DX TI Conditional simulations of flow in randomly heterogeneous porous media using a KL-based moment-equation approach SO ADVANCES IN WATER RESOURCES LA English DT Article DE Karhunen Loeve decomposition; conditional simulation; moment equations; uncertainty; higher-order correction; heterogeneity ID STEADY-STATE FLOW; LOCALIZED ANALYSES; TRANSPORT; PROBABILITIES AB In this study, we extend the KLME approach, a moment-equation approach based on the Karhunen-Loeve decomposition (KL), developed by Zhang and Lu [An efficient, higher-order perturbation approach for flow in randomly heterogeneous porous media via Karhunen-Loeve decomposition. J Comput Phys 2004;194(2):773-94] to efficiently incorporate existing direct measurements of the log hydraulic conductivity. We first decompose the conditional log hydraulic conductivity Y = lnK, as an infinite series on the basis of a set of orthogonal Gaussian standard random variables {xi(i)}. The coefficients of this series are related to eigenvalues and eigenfunctions of the conditional covariance function of the log hydraulic conductivity. We then write head as an infinite series whose terms It" represent the head contribution at the nth order in terms of ay, the standard deviation of Y, and derive a set of recursive equations for h((n)) We assume that h((n)) can be expressed as infinite series in terms of the products of n Gaussian random variables. The coefficients in these series are determined by substituting decompositions of Y and h((m)), m < n, into those recursive equations. We solve the conditional mean head up to fourth-order in ay and the conditional head covariances up to third-order in sigma(y)(2). The Y higher-order corrections for the conditional mean flux and flux covariance can be determined directly from the higher-order moments of the head, using Darcy's law. We compare the results from the KLME approach against those from Monte Carlo (MC) simulations and the conventional first-order moment method. It is evident that the KLME approach with higher-order corrections is superior to the conventional first-order approximations and is computationally more efficient than both the Monte Carlo simulations and the conventional first-order moment method. (C) 2004 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, Los Alamos, NM 87545 USA. Univ Oklahoma, Mewbourne Sch Petr & Geol Engn, Norman, OK 73019 USA. RP Lu, ZM (reprint author), Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, EES-6,MS T003, Los Alamos, NM 87545 USA. EM zhiming@lanl.gov RI Zhang, Dongxiao/D-5289-2009; OI Zhang, Dongxiao/0000-0001-6930-5994; Lu, Zhiming/0000-0001-5800-3368 NR 26 TC 20 Z9 24 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD SEP PY 2004 VL 27 IS 9 BP 859 EP 874 DI 10.1016/j.advwatres.2004.08.001 PG 16 WC Water Resources SC Water Resources GA 862MC UT WOS:000224494000001 ER PT J AU Wu, YS Pan, LH Pruess, K AF Wu, YS Pan, LH Pruess, K TI A physically based approach for modeling multiphase fracture-matrix interaction in fractured porous media SO ADVANCES IN WATER RESOURCES LA English DT Article DE naturally fractured reservoir; double-porosity model; dual-continuum model; fracture-matrix interaction; relative permeability ID HEAT-FLOW; TRANSPORT; FLUID AB A physically based numerical approach is presented for modeling fracture-matrix interaction, which is a key issue for fractured reservoir simulation. Commonly used mathematical models for dealing with such interactions employ a dual- or multiple-continuum concept, in which fractures and matrix are represented as overlapping, different, but interconnected continua, described by parallel sets of conservation equations. The conventional single-point upstream weighting scheme, in which the fracture relative permeability is used to represent the counterpart at the fracture matrix interface, is the most common scheme by which to estimate flow mobility for fracture-matrix flow terms. However, such a scheme has a serious flaw, which may lead to unphysical solutions or significant numerical errors. To overcome the limitation of the conventional upstream weighting scheme, this paper presents a physically based modeling approach for estimating physically correct relative permeability in calculating multiphase flow between fractures and the matrix, using continuity of capillary pressure at the fracture-matrix interface. The proposed approach has been implemented into two multiphase reservoir simulators and verified using analytical solutions and laboratory experimental data. The new method is demonstrated to be accurate, numerically efficient, and easy to implement in dual- or multiple-continuum models. Published by Elsevier Ltd. C1 Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Lawrence Berkeley Natl Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. EM yswu@lbl.gov RI Wu, Yu-Shu/A-5800-2011; Pan, Lehua/G-2439-2015 NR 28 TC 24 Z9 26 U1 3 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD SEP PY 2004 VL 27 IS 9 BP 875 EP 887 DI 10.1016/j.advwatres.2004.07.002 PG 13 WC Water Resources SC Water Resources GA 862MC UT WOS:000224494000002 ER PT J AU Vanamu, G Lester, K Datye, AK Weigle, JC Chen, CK Kelly, D Phillips, J AF Vanamu, G Lester, K Datye, AK Weigle, JC Chen, CK Kelly, D Phillips, J TI Modifying irregular titania powders in a low power microwave plasma torch SO AICHE JOURNAL LA English DT Article DE titania; plasma processing; phase transformation; purification; photocatalysis ID LOW-PRESSURE PLASMAS; CHARGE FLUCTUATIONS; PARTICLE GROWTH; REACTOR; TIO2; PHASE; COAGULATION; DEGRADATION; DEPOSITION; DEGUSSA AB Rapid passage of titania powder as an aerosol through a plasma generated with a low power microwave torch, resulted in many changes to the powder. Some or all of the titania became spherical, its phase changed, the level of carbon impurity changed, and its surface area declined. The final state of the titania depended on plasma operating conditions. For example, all of the titania became spherical and converted to the rutile phase, only if the processing rate remained low. Complete spherodization occurred only if the energy absorbed by the particles was <2.5% of the total power applied. Excess solid loading reduced the fraction spherodized or otherwise modified, as well as the net rate of conversion. Passing titania through an oxygen plasma removed virtually all the carbon impurity. This process is similar to alumina studies in the same apparatus and suggests that many refractory oxides can be modified by low-power plasmas. (C) 2004 American Institute of Chemical Engineers. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Chem & Nucl Engn, Farris Engn Ctr, Albuquerque, NM 87131 USA. RP Phillips, J (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM phillips@lanl.gov RI Phillips, Jonathan/D-3760-2011; OI Datye, Abhaya/0000-0002-7126-8659 NR 40 TC 6 Z9 6 U1 0 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD SEP PY 2004 VL 50 IS 9 BP 2090 EP 2100 DI 10.1002/aic.10244 PG 11 WC Engineering, Chemical SC Engineering GA 849EH UT WOS:000223521000008 ER PT J AU Shi, BS Philpott, SM Weiser, B Kuiken, C Brunner, C Fang, GW Fowke, KR Plummer, FA Rowland-Jones, S Bwayo, J Anzala, AO Kimani, J Kaul, R Burger, H AF Shi, BS Philpott, SM Weiser, B Kuiken, C Brunner, C Fang, GW Fowke, KR Plummer, FA Rowland-Jones, S Bwayo, J Anzala, AO Kimani, J Kaul, R Burger, H TI Construction of an infectious HIV type 1 molecular clone from an African patient with a subtype D/C recombinant virus SO AIDS RESEARCH AND HUMAN RETROVIRUSES LA English DT Article ID SEQUENCES AB The majority of HIV-1 infections worldwide occur in Africa, where subtype B viruses are rare and intersubtype recombinants are common. Pathogenesis and vaccine studies need to focus on viruses derived from African patients, and infectious HIV-1 molecular clones can be useful tools. To clone non-B subtypes and recombinant viruses from patients, we cultivated HIV-1 from the plasma of a Kenyan long-term survivor. Viral DNA was cloned into a plasmid, which was transfected into COS cells; progeny virus was propagated in PBMCs. Sequence analyses revealed that both the patient's plasma HIV-1 RNA and the cloned DNA genomes were recombinants between subtypes D and C; subtype C sequences comprised the nef and LTR regions. The cloned virus used the CCR5 coreceptor and did not form syncytia in vitro. This infectious HIV-1 subtype D/C recombinant molecular clone obtained from a Kenyan long-term survivor promises to be useful to study pathogenesis and vaccine design. C1 New York State Dept Hlth, Wadsworth Ctr, Albany, NY 12208 USA. Albany Med Coll, Albany, NY 12208 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Manitoba, Winnipeg, MB R3E 0W3, Canada. Univ Oxford, Oxford OX3 9DS, England. Univ Nairobi, Nairobi, Kenya. RP Burger, H (reprint author), New York State Dept Hlth, Wadsworth Ctr, 120 New Scotland Ave, Albany, NY 12208 USA. EM burger@Wadsworth.org OI Shi, binshan/0000-0003-1169-6237; Fowke, Keith/0000-0001-8227-6649 FU NIAID NIH HHS [R01-AI-42555] NR 15 TC 5 Z9 5 U1 0 U2 1 PU MARY ANN LIEBERT INC PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 0889-2229 J9 AIDS RES HUM RETROV JI Aids Res. Hum. Retrovir. PD SEP PY 2004 VL 20 IS 9 BP 1015 EP 1018 DI 10.1089/aid.2004.20.1015 PG 4 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 863FO UT WOS:000224546600013 PM 15585089 ER PT J AU Lin, YM Dueker, SR Follett, JR Fadel, JG Arjomand, A Schneider, PD Miller, JW Green, R Buchholz, BA Vogel, JS Phair, RD Clifford, AJ AF Lin, YM Dueker, SR Follett, JR Fadel, JG Arjomand, A Schneider, PD Miller, JW Green, R Buchholz, BA Vogel, JS Phair, RD Clifford, AJ TI Quantitation of in vivo human folate metabolism SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE folate; metabolism; C-14; accelerator mass spectrometry; kinetic model ID FOLIC-ACID; PHARMACOKINETIC PARAMETERS; INTESTINAL-ABSORPTION; URINARY-EXCRETION; BLOOD FOLATE; LONG-TERM; SAAM II; DISEASE; MODEL; CHOLESTYRAMINE AB Background: A quantitative understanding of human folate metabolism is needed. Objective: The objective was to quantify and interpret human folate metabolism as it might occur in vivo. Design: Adults (n = 13) received 0.5 nmol [C-14]pteroylmonoglutamate (100 nCi radioactivity) plus 79.5 nmol pteroylmonoglutamate in water orally. C-14 was measured in plasma, erythrocytes, urine, and feces for greater than or equal to40 d. Kinetic modeling was used to analyze and interpret the data. Results: According to the data, the population was healthy and had a mean dietary folate intake of 1046 nmol/d, and the apparent dose absorption of C-14 was 79%. The model predictions showed that only 0.25% of plasma folate was destined for marrow, mean bile folate flux was 5351 nmol/d, and the digestibility of the mix (1046 + 5351 nmol/d) was 92%. About 33% of visceral pteroylmonoglutamate was converted to the polyglutamate form, most of the body folate was visceral (>99%), most of the visceral folate was pteroylpolyglutamate (>98%), total body folate was 225 mumol, and pteroylpolyglutamate synthesis, recycling, and catabolism were 1985, 1429, and 556 nmol/d, respectively. Mean residence times were 0.525 d as visceral pteroylmonoglutamate, 119 d as visceral pteroylpolyglutamate, 0.0086 d as plasma folate, and 0.1 d as gastrointestinal folate. Conclusions: Across subjects, folate absorption, bile folate flux, and body folate stores were larger than prior estimates. Marrow folate uptake and pteroylpolyglutamate synthesis, recycling, and catabolism are saturable processes. Visceral pteroylpolyglutamate was an immediate precursor of plasma p-aminobenzoylglutamate. The model is a working hypothesis with derived features that are explicitly model-dependent. It successfully quantitated folate metabolism, encouraging further rigorous testing. C1 Univ Calif Davis, Dept Nutr, Davis, CA 95616 USA. Univ Calif Davis, Dept Anim Sci, Davis, CA 95616 USA. Univ Calif Davis, Med Ctr, Ctr Canc, Sacramento, CA 95817 USA. Univ Calif Davis, Med Ctr, Dept Pathol, Sacramento, CA 95817 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Integrat BioInformat Inc, Rockville, MD USA. RP Clifford, AJ (reprint author), Univ Calif Davis, Dept Nutr, 1 Shields Ave, Davis, CA 95616 USA. EM ajclifford@ucdavis.edu RI Buchholz, Bruce/G-1356-2011 FU NCRR NIH HHS [RR 13461, P41 RR013461]; NIDDK NIH HHS [DK 45939] NR 60 TC 52 Z9 53 U1 0 U2 3 PU AMER SOC CLINICAL NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, SUBSCRIPTIONS, RM L-3300, BETHESDA, MD 20814-3998 USA SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD SEP PY 2004 VL 80 IS 3 BP 680 EP 691 PG 12 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 849SR UT WOS:000223561500021 PM 15321809 ER PT J AU Kim, JJ Smorodinsky, S Lipsett, M Singer, BC Hodgson, AT Ostro, B AF Kim, JJ Smorodinsky, S Lipsett, M Singer, BC Hodgson, AT Ostro, B TI Traffic-related air pollution near busy roads - The East Bay children's respiratory health study SO AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE LA English DT Article DE air pollution; asthma; bronchitis; epidemiology; vehicle emissions ID SOUTHERN CALIFORNIA COMMUNITIES; CHILDHOOD ASTHMA; ALLERGIC SENSITIZATION; CARBON CONCENTRATION; DIFFERING LEVELS; LUNG-FUNCTION; SYMPTOMS; EXPOSURE; PARTICLES; AMBIENT AB Recent studies, primarily in Europe, have reported associations between respiratory symptoms and residential proximity to traffic; however, few have measured traffic pollutants or provided information about local air quality. We conducted a school-based, cross-sectional study in the San Francisco Bay Area in 2001. Information on current bronchitis symptoms and asthma, home environment, and demographics was obtained by parental questionnaire (n = 1,109). Concentrations of traffic pollutants (particulate matter, black carbon, total nitrogen oxides [NOX], and nitrogen dioxide [NO2]) were measured at 10 school sites during several seasons. Although pollutant concentrations were relatively low, we observed differences in concentrations between schools nearby versus those more distant (or upwind) from major roads. Using a two-stage multiple-logistic regression model, we found associations between respiratory symptoms and traffic-related pollutants. Among,those living at their current residence for at least 1 year, the adjusted odds ratio for asthma in relationship to an interquartile difference in NOX was 1.07 (95% confidence interval, 1.00-1.14). Thus, we found spatial variability in traffic pollutants and associated differences in respiratory symptoms in a region with good air quality. Our findings support the hypothesis that traffic-related pollution is associated with respiratory symptoms in children. C1 Calif Environm Protect Agcy, Off Environm Hlth Hazard Assessment, Oakland, CA 94612 USA. Lawrence Berkeley Lab, Dept Atmospher Sci, Berkeley, CA USA. Lawrence Berkeley Lab, Indoor Environm Dept, Environm Energy Technol Div, Berkeley, CA USA. RP Ostro, B (reprint author), Calif Environm Protect Agcy, Off Environm Hlth Hazard Assessment, 1515 Clay St,16th Floor, Oakland, CA 94612 USA. EM bostro@oehha.ca.gov RI Osborne, Nicholas/N-4915-2015 OI Osborne, Nicholas/0000-0002-6700-2284 NR 38 TC 217 Z9 220 U1 7 U2 62 PU AMER THORACIC SOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019-4374 USA SN 1073-449X J9 AM J RESP CRIT CARE JI Am. J. Respir. Crit. Care Med. PD SEP 1 PY 2004 VL 170 IS 5 BP 520 EP 526 DI 10.1164/rccm.200403-2810C PG 7 WC Critical Care Medicine; Respiratory System SC General & Internal Medicine; Respiratory System GA 850IR UT WOS:000223605000011 PM 15184208 ER PT J AU Barnes, JH Schilling, GD Stone, SF Sperline, RP Denton, MB Young, ET Barinaga, CJ Koppenaal, DW Hieftje, GM AF Barnes, JH Schilling, GD Stone, SF Sperline, RP Denton, MB Young, ET Barinaga, CJ Koppenaal, DW Hieftje, GM TI Simultaneous multichannel mass-specific detection for high-performance liquid chromatography using an array detector sector-field mass spectrometer SO ANALYTICAL AND BIOANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT Winter Conference on Plasma Spectrochemistry CY JAN 05-10, 2004 CL Ft Lauderdale, FL DE array detector; inductively coupled plasma mass spectrometry; sector field mass; spectrometry; liquid chromatography; simultaneous detection; focal plane camera ID RB-SR GEOCHRONOLOGY; ICP-MS; SPECIATION ANALYSIS; ELEMENT SPECIATION; PLASMA; ISOTOPE; SEPARATION; TRACE; SPECTROGRAPH; TEMPERATURE AB The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP-MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP-MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Univ Maryland Baltimore Cty, Dept Chem, Baltimore, MD 21250 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hieftje, GM (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. EM hieftje@indiana.edu NR 43 TC 10 Z9 10 U1 1 U2 3 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1618-2642 J9 ANAL BIOANAL CHEM JI Anal. Bioanal. Chem. PD SEP PY 2004 VL 380 IS 2 BP 227 EP 234 DI 10.1007/s00216-004-2686-y PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 862ZB UT WOS:000224528900008 PM 15551077 ER PT J AU Hoyt, PR Doktycz, MJ AF Hoyt, PR Doktycz, MJ TI Optimized beadmilling of tissues for high-throughput RNA production and microarray-based analyses SO ANALYTICAL BIOCHEMISTRY LA English DT Article DE microarray; DNA array; RNA; high throughput; beadmilling; sample preparation ID GRAM-POSITIVE BACTERIA; CDNA MICROARRAY; GENE-EXPRESSION; DNA; EXTRACTION AB The preparation of RNA samples has become the rate-limiting step when performing genome-scale analyses by DNA microarrays. Methods to improve throughput of RNA isolation from tissues are needed. The effects of bead size and composition for disrupting mouse tissues have been evaluated in small centrifuge tubes and optimized for RNA production. The resulting process is inexpensive, resistant to cross-contamination, and amenable to robotic processing. After optimization, very-high-quality RNA call be produced. Comparisons between RNAs isolated by beadmilling (followed by solid-phase purification) and those by conventional isolation processes show that RNA produced by beadmilling is suitable for microarray analyses. Parallel implementation of beadmilling will enable a high-throughput tissue-to-RNA processing system for large-scale microarray analyses. (C) 2004 Elsevier Inc. All rights reserved. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Genome Sci & Technol Program, Knoxville, TN 37916 USA. RP Hoyt, PR (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. EM hoytpr@ornl.gov RI Doktycz, Mitchel/A-7499-2011 OI Doktycz, Mitchel/0000-0003-4856-8343 NR 16 TC 2 Z9 3 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD SEP 1 PY 2004 VL 332 IS 1 BP 100 EP 108 DI 10.1016/j.ab.2004.04.025 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 845YF UT WOS:000223280700012 PM 15301954 ER PT J AU Lin, YM Hillegonds, DJ Gertz, ER Van Loan, MD Vogel, JS AF Lin, YM Hillegonds, DJ Gertz, ER Van Loan, MD Vogel, JS TI Protocol for assessing bone health in humans by tracing long-lived Ca-41 isotope in urine, serum, and saliva samples SO ANALYTICAL BIOCHEMISTRY LA English DT Editorial Material ID RESORPTION C1 Univ Calif Davis, Dept Nutr, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. ARS, USDA, Western Human Nutr Res Ctr, Davis, CA 95616 USA. RP Lin, YM (reprint author), Access Business Grp, 5600 Beach Blvd,POB 5940, Buena Pk, CA 90622 USA. EM yumei.liti@accessbusinessgroup.com FU NCRR NIH HHS [RR-13461] NR 11 TC 11 Z9 12 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD SEP 1 PY 2004 VL 332 IS 1 BP 193 EP 195 DI 10.1016/j.ab.2004.05.019 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 845YF UT WOS:000223280700024 PM 15301966 ER PT J AU Reichmuth, DS Shepodd, TJ Kirby, BJ AF Reichmuth, DS Shepodd, TJ Kirby, BJ TI On-chip high-pressure picoliter injector for pressure-driven flow through porous media SO ANALYTICAL CHEMISTRY LA English DT Article ID IN-SITU POLYMERIZATION; MICROFLUIDIC DEVICES; SEPARATION MEDIA; ELECTROCHROMATOGRAPHY; MONOLITHS; VALVES; ELECTROPHORESIS; CHROMATOGRAPHY; MICROCHIP; ANALYZER AB A high-pressure (>3 MPa) on-chip injector has been developed for microchip applications including HPLC. The mechanical injector is implemented using in situ photopolymerization of fluorinated acrylates inside wet-etched silica microchips. The injector allows reproducible injections as small as 180 pL with <250 ms duration. The injector operated robustly over 60 days and over 1000 injections. The injector is unique among polymerbased valves as it functions in aqueous, acetonitrile, and mixed buffers at high pressures without detectable leakage. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Kirby, BJ (reprint author), Sandia Natl Labs, POB 969,MS 9951, Livermore, CA 94551 USA. EM bk88@cornell.edu NR 22 TC 40 Z9 41 U1 1 U2 11 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 2004 VL 76 IS 17 BP 5063 EP 5068 DI 10.1021/ac0493572 PG 6 WC Chemistry, Analytical SC Chemistry GA 852CS UT WOS:000223733400039 PM 15373443 ER PT J AU Kornreich, DE Parsons, DK AF Kornreich, DE Parsons, DK TI The Green's function method for effective multiplication benchmark calculations in multi-region slab geometry SO ANNALS OF NUCLEAR ENERGY LA English DT Article ID SPHERES; EIGENVALUES; SCATTERING AB There are relatively few benchmark-quality solutions for effective multiplication calculations in multi-region multiplying systems. The purpose of this paper is to describe and add a benchmark-quality calculation for such test problems. Green's functions are used to model a multi-region, one-group, isotropically scattering, multiplying system in Cartesian geometry to obtain boundary flux values for an eigenvalue search and subsequent eigenfunction calculation. As usual with multi-region Cartesian systems, the solution is facilitated using (1) Placzek's lemma, which allows us to consider a multi-region system one region at a time as an infinite medium, and (2) the calculation of the Green's function solution for a nonphysical infinite multiplying medium. The Green's function method is aesthetically pleasing both for its calculational efficiency and pedagogical clarity, and can, under certain circumstances, perform better than a discrete ordinates code. (C) 2004 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kornreich, DE (reprint author), Los Alamos Natl Lab, POB 1663,MS F609, Los Alamos, NM 87545 USA. EM drewek@lanl.gov; dkp@lanl.gov NR 14 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD SEP PY 2004 VL 31 IS 13 BP 1477 EP 1494 DI 10.1016/j.anucene.2004.03.012 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 840XM UT WOS:000222893500003 ER PT J AU Pearson, A Huang, Z Ingalls, AE Romanek, CS Wiegel, J Freeman, KH Smittenberg, RH Zhang, CL AF Pearson, A Huang, Z Ingalls, AE Romanek, CS Wiegel, J Freeman, KH Smittenberg, RH Zhang, CL TI Nonmarine crenarchaeol in Nevada hot springs SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID GRADIENT GEL-ELECTROPHORESIS; IN-SITU HYBRIDIZATION; ARCHAEAL DIVERSITY; MEMBRANE-LIPIDS; THERMOPLASMA-ACIDOPHILUM; PLANKTONIC ARCHAEA; MASS-SPECTROMETRY; RIBOSOMAL-RNA; ETHER LIPIDS; FOREST SOIL AB Glycerol dialkyl glycerol tetraethers (GDGTs) are core membrane lipids of the Crenarchaeota. The structurally unusual GDGT crenarchaeol has been proposed as a taxonomically specific biomarker for the marine planktonic group I archaea. It is found ubiquitously in the marine water column and in sediments. In this work, samples of microbial community biomass were obtained from several alkaline and neutral-pH hot springs in Nevada, United States. Lipid extracts of these samples were analyzed by high-performance liquid chromatography-mass spectrometry and by gas chromatography-mass spectrometry. Each sample contained GDGTs, and among these compounds was crenarchaeol. The distribution of archaeal lipids in Nevada hot springs did not appear to correlate with temperature, as has been observed in the marine environment. Instead, a significant correlation with the concentration of bicarbonate was observed. Archaeal DNA was analyzed by denaturing gradient gel electrophoresis. All samples contained 16S rRNA gene sequences which were more strongly related to thermophilic crenarchaeota than to Cenarchaeum symbiosum, a marine nonthermophilic crenarchaeon. The occurrence of crenarchaeol in environments containing sequences affiliated with thermophilic crenarchaeota suggests a wide phenotypic distribution of this compound. The results also indicate that crenarchaeol can no longer be considered an exclusive biomarker for marine species. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC USA. Univ Georgia, Dept Microbiol, Athens, GA 30602 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RP Pearson, A (reprint author), Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. EM pearson@eps.harvard.edu; zhang@srel.edu RI Smittenberg, Rienk/A-3296-2008; Pearson, Ann/A-6723-2009; Freeman, Katherine/H-5140-2011; OI Freeman, Katherine/0000-0002-3350-7671; Smittenberg, Rienk/0000-0001-5578-9916; Wiegel, Juergen/0000-0002-6343-6464 NR 53 TC 104 Z9 112 U1 3 U2 25 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 2004 VL 70 IS 9 BP 5229 EP 5237 DI 10.1128/AEM.70.9.5229-5237.2004 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 854KI UT WOS:000223901100023 PM 15345404 ER PT J AU Ye, Q Roh, Y Carroll, SL Blair, B Zhou, JZ Zhang, CL Fields, MW AF Ye, Q Roh, Y Carroll, SL Blair, B Zhou, JZ Zhang, CL Fields, MW TI Alkaline anaerobic respiration: Isolation and characterization of a novel alkaliphilic and metal-reducing bacterium SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID GEN. NOV.; MICROBIAL REDUCTION; SODA LAKES; IRON; METABOLISM; MANGANESE; DIVERSITY; OXIDATION; SELENIUM; FE(III) AB Iron-reducing enrichments were obtained from leachate ponds at the U.S. Borax Company in Boron, Calif. Based on partial small-subunit (SSU) rRNA gene sequences (approximately 500 nucleotides), six isolates shared 98.9% nucleotide identity. As a representative, the isolate QYMF was selected for further analysis. QYMF could be grown with Fe(III)-citrate, Fe(III)-EDTA, Co(III)-EDTA, or Cr(VI) as electron acceptors, and yeast extract and lactate could serve as electron donors. Growth during iron reduction occurred over the pH range of 7.5 to 11.0 (optimum, pH 9.5), a sodium chloride range of 0 to 80 g/liter (optimum, 20 g/liter), and a temperature range of 4 to 45degreesC (optimum, approximately 35degreesC), and iron precipitates were formed. QYMF was a strict anaerobe that could be grown in the presence of borax, and the cells were straight rods that produced endospores. Sodium chloride and yeast extract stimulated growth. Phylogenetic analysis of the SSU rRNA gene indicated that the bacterium was a low-G+C gram-positive microorganism and had 96 and 92% nucleotide identity with Alkaliphilus transvaalensis and Alkaliphilus crotonatoxidans, respectively. The major phospholipid fatty acids were 14:1, 16:1w7c, and 16:0, which were different from those of other alkaliphiles but similar to those of reported iron-reducing bacteria. The results demonstrated that the isolate might represent a novel metal-reducing alkaliphilic species. The name Alkaliphilus metalliredigens sp. nov. is proposed. The isolation and activity of metal-reducing bacteria from borax-contaminated leachate ponds suggest that bioremediation of metal-contaminated alkaline environments may be feasible and have implications for alkaline anaerobic respiration. C1 Miami Univ, Dept Microbiol, Oxford, OH 45056 USA. Jackson State Univ, Dept Biol, Jacksonville, AL USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN USA. Univ Missouri, Dept Geol, Columbia, MO 65211 USA. RP Fields, MW (reprint author), Miami Univ, Dept Microbiol, Pearson Hall,Rm 32, Oxford, OH 45056 USA. EM fieldsmw@muohio.edu NR 48 TC 86 Z9 91 U1 0 U2 27 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 2004 VL 70 IS 9 BP 5595 EP 5602 DI 10.1128/AEM.70.9.5595-5602.2004 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 854KI UT WOS:000223901100068 PM 15345448 ER PT J AU Beller, HR Madrid, V Hudson, GB McNab, WW Carlsen, T AF Beller, HR Madrid, V Hudson, GB McNab, WW Carlsen, T TI Biogeochemistry and natural attenuation of nitrate in groundwater at an explosives test facility SO APPLIED GEOCHEMISTRY LA English DT Article ID SANDY AQUIFER; FRESH-WATER; EXCESS AIR; DENITRIFICATION; NITROGEN; MECHANISM; SEAWATER; FRANCE; OXYGEN AB An interdisciplinary study was conducted to characterize the distribution and fate of NO3- in groundwater at Lawrence Livermore National Laboratory (LLNL) Site 300, a high-explosives test facility in the semi-arid Altamont Hills of California. Site 300 groundwater contains NO3- concentrations ranging from <0.5 to >200 mg NO3-/L. Several lines of evidence strongly suggest that denitrification is naturally attenuating NO3- in the confined, O-2-depleted region of the bedrock aquifer under study (Tnbs(2)): (a) both NO3- and dissolved O-2(DO) concentrations in groundwater decrease dramatically as groundwater flows from unconfined to confined aquifer conditions, (b) stable isotope signatures (i.e., delta(15)N and delta(18)O) of groundwater NO3- indicate a trend of isotopic enrichment that is characteristic of denitrification, and (c) dissolved N-2 gas, the product of denitrification, was highly elevated in NO3--depleted groundwater in the confined region of the Tnbs(2) aquifer. Long-term NO3- concentrations were relatively high and constant in recharge-area monitoring wells (typically 70-100 mg NO3-/L) and relatively low and constant in the downgradient confined region (typically <0.1-3 mg NO3-/L), suggesting a balance between rates of NO3- loading and removal by denitrification. Chemolithoautotrophic denitrification with pyrite as the electron donor is plausible in the Tnbs(2) aquifer, based on the low dissolved organic C concentrations (< 1.5 mg/L) that could not support heterotrophic denitrification, the common occurrence of disseminated pyrite in the aquifer, and the trend of increasing SO42- as groundwater flows from aerobic, 4 unconfined to anoxic, confined aquifer conditions. Nitrate sources were investigated by experimentally determining the delta(15)N and delta(18)O signatures of NO3- from three potential anthropogenic sources of NO3- at Site 300: Ba(NO3)(2) (mock explosive), HNO3, and photolysis of the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine). The isotopic signatures of these potential NO3- sources were markedly different than those of NO3- in Tnbs(2) groundwater samples, suggesting that other sources must contribute significantly to the NO3- loading at Site 300. In particular, NO3- and NO2- resulting from RDX photolysis reflected dramatically depleted delta(15)N (ca. -7.4parts per thousand) and delta(18)O (ca. -25.7parts per thousand) values. (C) 2004 Elsevier Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Beller, HR (reprint author), Lawrence Livermore Natl Lab, POB 808,7000 East Ave,L-542, Livermore, CA 94551 USA. EM beller2@llnl.gov RI Beller, Harry/H-6973-2014 NR 31 TC 37 Z9 39 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD SEP PY 2004 VL 19 IS 9 BP 1483 EP 1494 DI 10.1016/j.apgeochem.2003.12.010 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 845JI UT WOS:000223238200010 ER PT J AU Hettrick, MC Cuneo, ME Porter, JL Ruggles, LE Simpson, WW Vargas, MF Wenger, DF AF Hettrick, MC Cuneo, ME Porter, JL Ruggles, LE Simpson, WW Vargas, MF Wenger, DF TI Profiled bar transmission gratings: soft-x-ray calibration of new Kirchoff solutions (vol 43, pg 3772, 2004) SO APPLIED OPTICS LA English DT Correction C1 Hettrick Sci, Fuchu, Tokyo 1830002, Japan. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hettrick, MC (reprint author), Hettrick Sci, 1-39-59 Tama Cho, Fuchu, Tokyo 1830002, Japan. EM hettrickscientific@yahoo.com NR 1 TC 0 Z9 0 U1 1 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2004 VL 43 IS 25 BP 4785 EP 4785 DI 10.1364/AO.43.004785 PG 1 WC Optics SC Optics GA 851CP UT WOS:000223663300001 ER PT J AU Zhang, XR Xu, X Rubenchik, AM AF Zhang, XR Xu, X Rubenchik, AM TI Simulation of microscale densification during femtosecond laser processing of dielectric materials SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID 3-DIMENSIONAL OPTICAL MEMORY; WAVE-GUIDES; TRANSPARENT MATERIALS; FUSED-SILICA; GLASSES; PULSES AB It has been demonstrated that femtosecond laser pulses can be used to process dielectric materials such as optical glass. One of the applications of this process is to produce sub-diffraction-limit structures whose index of refraction is different from that of the host medium. Due to the small size of these 'bits', it has been proposed to use this technique for high-density optical data storage. This paper is concerned with the mechanisms of the change of the index of refraction in such a small domain. We propose that the laser-induced strain field is responsible for the localized change of the index of refraction. It is demonstrated that the compressive strain field could be smaller than the area where the laser energy is absorbed in the glass. C1 Purdue Univ, Sch Mech Engn, W Lafayette, IN 47907 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Xu, X (reprint author), Purdue Univ, Sch Mech Engn, W Lafayette, IN 47907 USA. EM xxu@ecn.purdue.edu NR 16 TC 18 Z9 18 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD SEP PY 2004 VL 79 IS 4-6 BP 945 EP 948 DI 10.1007/s00339-004-2576-3 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 839EL UT WOS:000222766100055 ER PT J AU Chinni, RC Gold, DM Brown, SB Chang, JT Angel, SM Colston, BW AF Chinni, RC Gold, DM Brown, SB Chang, JT Angel, SM Colston, BW TI A non-lensed fiber-optic resonance-enhanced multiphoton ionization probe SO APPLIED SPECTROSCOPY LA English DT Article DE resonance-enhanced multiphoton ionization; REM-PI; fiber optic; volatile organic compounds; electrode; achromatic ID MULTI-PHOTON IONIZATION; MASS-SPECTROMETRY; ATOMIC-HYDROGEN; SUBSTITUTED CYCLOHEXANONE; 3-PHOTON IONIZATION; AIR FLAME; SPECTROSCOPY; CONTAMINATION; HYDROCARBONS; FLUORESCENCE AB We have developed a miniature fiber-optic probe with no focusing optics for in situ analysis of volatile organic compounds (VOCs). The probe uses an optical fiber to transmit a laser pulse to a vapor sample causing it to ionize adjacent to the fiber tip through a resonance-enhanced multiphoton ionization (REMPI) process. The distal end of the optical fiber is contained co-axially within 2-mm-inner-diameter stainless steel tubing that serves as an electrode. The electrode is biased at a high positive potential to collect electrons. The current generated is shown to be proportional over about two orders of magnitude to the concentration of the species ionized. Visible wavelength REMPI spectroscopy is used to determine probe sensitivities of 20 ppb (benzene) and 43 ppb (toluene). Designing the probe without focusing optics specifies an achromatic ionization region constant in size and position as the laser wavelength is scanned, which simplifies data collection and reduction. Focusing achromatic systems are discussed and the potential signal improvement is estimated. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ S Carolina, Columbia, SC 29208 USA. RP Colston, BW (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. OI Angel, Stanley/0000-0002-0328-0568 NR 39 TC 1 Z9 1 U1 2 U2 12 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2004 VL 58 IS 9 BP 1038 EP 1043 DI 10.1366/0003702041959479 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 857HH UT WOS:000224106500005 PM 15479519 ER PT J AU Melgaard, DK Haaland, DM AF Melgaard, DK Haaland, DM TI Effects of nonlinearities and uncorrelated or correlated errors in realistic simulated data on the prediction abilities of augmented classical least squares and partial least squares SO APPLIED SPECTROSCOPY LA English DT Article DE partial least squares; PLS; augmented classical least squares; ACLS; prediction ability comparisons; nonlinearities; correlated errors ID PRINCIPAL COMPONENT ANALYSIS; SPECTRAL ANALYSES; HYBRID ALGORITHM AB Comparisons of prediction models from the new augmented classical least squares (ACLS) and partial least squares (PLS) multivariate spectral analysis methods were conducted using simulated data containing deviations from the idealized model. The simulated data were based on pure spectral components derived from real near-infrared spectra of multicomponent dilute aqueous solutions. Simulated uncorrelated concentration errors, uncorrelated and correlated spectral noise, and nonlinear spectral responses were included to evaluate the methods on situations representative of experimental data. The statistical significance of differences in prediction ability was evaluated using the Wilcoxon signed rank test. The prediction differences were found to be dependent on the type of noise added, the numbers of calibration samples, and the Component being predicted. For analyses applied to simulated spectra with noise-free nonlinear response, PLS was shown to be statistically superior to ACLS for most of the cases. With added uncorrelated spectral noise, both methods performed comparably. Using 50 calibration samples with simulated correlated spectral noise, PLS showed an advantage in 3 out of 9 cases, but the advantage dropped to 1 out of 9 cases with 25 calibration samples. For cases with different noise distributions between calibration and validation, ACLS predictions were statistically better than PLS for two of the four components. Also, when experimentally derived correlated spectral error was added, ACLS gave better predictions that were statistically significant in 15 out of 24 cases simulated. On data sets with nonuniform noise, neither method was statistically better, although ACLS usually had smaller standard errors of prediction (SEPs). The varying results emphasize the need to use realistic simulations when making comparisons between various multivariate calibration methods. Even when the differences between the standard error of predictions were statistically significant, in most cases the differences in SEP were small. This study demonstrated that unlike CLS, ACLS is competitive with PLS in modeling nonlinearities in spectra without knowledge of all the component concentrations. This competitiveness is important when maintaining and transferring models for system drift, spectrometer differences, and unmodeled components, since ACLS models can be rapidly updated during prediction when used in conjunction with the prediction augmented classical least squares (PACLS) method, while PLS requires full recalibration. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Melgaard, DK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 10 Z9 10 U1 0 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD SEP PY 2004 VL 58 IS 9 BP 1065 EP 1073 DI 10.1366/0003702041959334 PG 9 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 857HH UT WOS:000224106500009 PM 15479523 ER PT J AU Hamilton, SD Roth, KW Brodrick, J AF Hamilton, SD Roth, KW Brodrick, J TI Displacement ventilation SO ASHRAE JOURNAL LA English DT Editorial Material C1 Verdae, Poughkeepsie, NY USA. HVAC, Cambridge, MA USA. TIAX, Refrigerat Technol Sector, Cambridge, MA USA. US DOE, Bldg Technol Program, Washington, DC USA. RP Hamilton, SD (reprint author), Verdae, Poughkeepsie, NY USA. NR 7 TC 7 Z9 9 U1 0 U2 5 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD SEP PY 2004 VL 46 IS 9 BP 56 EP 58 PG 3 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 852DS UT WOS:000223736000026 ER PT J AU Hayter, SJ AF Hayter, SJ TI Energy and money savings without increasing time, costs SO ASHRAE JOURNAL LA English DT Article C1 Natl Renewable Energy Lab, Golden, CO USA. RP Hayter, SJ (reprint author), Natl Renewable Energy Lab, Golden, CO USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD SEP PY 2004 VL 46 IS 9 BP S48 EP S50 PG 3 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 852DS UT WOS:000223736000020 ER PT J AU Torcellini, PA Judkoff, R Crawley, DB AF Torcellini, PA Judkoff, R Crawley, DB TI High-performance buildings SO ASHRAE JOURNAL LA English DT Article C1 NREL, Ctr Bldg & Thermal Syst, Denver, CO USA. US DOE, Off Bldg Technol, Washington, DC USA. NR 18 TC 6 Z9 6 U1 0 U2 3 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 0001-2491 J9 ASHRAE J JI ASHRAE J. PD SEP PY 2004 VL 46 IS 9 BP S4 EP S11 PG 8 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 852DS UT WOS:000223736000013 ER PT J AU Hopkins, PF Strauss, MA Hall, PB Richards, GT Cooper, AS Schneider, DP Vanden Berk, DE Jester, S Brinkmann, J Szokoly, GP AF Hopkins, PF Strauss, MA Hall, PB Richards, GT Cooper, AS Schneider, DP Vanden Berk, DE Jester, S Brinkmann, J Szokoly, GP TI Dust reddening in Sloan Digital Sky Survey quasars SO ASTRONOMICAL JOURNAL LA English DT Article DE dust, extinction; quasars : general ID SURVEY PHOTOMETRIC SYSTEM; ABSORPTION-LINE QUASARS; INFRARED EXTINCTION LAW; LARGE-MAGELLANIC-CLOUD; 1ST DATA RELEASE; INTERSTELLAR DUST; RED QUASARS; MILKY-WAY; SPECTRA; SAMPLE AB We explore the form of extragalactic reddening toward quasars using a sample of 9566 quasars with redshifts 0 < z < 2.2 and accurate optical colors from the Sloan Digital Sky Survey (SDSS). We confirm that dust reddening is the primary explanation for the red "tail'' of the color distribution of SDSS quasars. Our fitting to five-band photometry normalized by the modal quasar color as a function of redshift shows that this tail is well described by SMC-like reddening but not by reddening that is LMC-like, Galactic, or as recently described by Gaskell and coworkers. Extension to longer wavelengths using a subset of 1886 SDSS - Two Micron All Sky Survey matches confirms these results at high significance. We carry out Monte Carlo simulations that match the observed distribution of quasar spectral energy distributions using a Lorentzian dust-reddening distribution; 2% of quasars selected by the main SDSS targeting algorithm (i.e., that are not extincted out of the sample) have E(B-V) > 0.1, and less than 1% have E(B-V) > 0.2, where the extinction is relative to quasars with modal colors. Reddening is uncorrelated with the presence of intervening narrow-line absorption systems, but reddened quasars are much more likely to show narrow absorption at the redshift of the quasar than are unreddened quasars. Thus the reddening toward quasars is dominated by SMC-like dust at the quasar redshift. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Apache Point Observ, Sunspot, NM 88349 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. RP Hopkins, PF (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI Brinkmann, Jonathan/H-2779-2014 OI Brinkmann, Jonathan/0000-0001-6128-659X NR 48 TC 145 Z9 147 U1 0 U2 2 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 2004 VL 128 IS 3 BP 1112 EP 1123 DI 10.1086/423291 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850SW UT WOS:000223633800010 ER PT J AU De Breuck, C Bertoldi, F Carilli, C Omont, A Venemans, B Rottgering, H Overzier, R Reuland, M Miley, G Ivison, R van Breugel, W AF De Breuck, C Bertoldi, F Carilli, C Omont, A Venemans, B Rottgering, H Overzier, R Reuland, M Miley, G Ivison, R van Breugel, W TI A multi-wavelength study of the proto-cluster surrounding the z=4.1 radio galaxy TN J1338-1942 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : individual : TN J1338-1942; galaxies : clusters : individual : TN J1338-1942; galaxies : formation; cosmology : observations ID LYMAN-BREAK GALAXIES; SUBMILLIMETER-SELECTED GALAXIES; STAR-FORMING GALAXIES; EXTREMELY RED OBJECTS; HUBBLE-DEEP-FIELD; LY-ALPHA EMITTERS; HIGH-REDSHIFT; SOURCE IDENTIFICATIONS; MILLIMETER SOURCES; SPECTRAL INDEX AB We present a 1.2 mm (250 GHz) map obtained with MAMBO on the IRAM 30 m telescope of the central 25 arcmin(2) of the proto-cluster surrounding the z=4.1 radio galaxy TN J1338-1942. The map reaches a 1sigma sensitivity of 0.6 mJy in the central area, increasing to 1.2 mJy at the edges. We detect 10 candidate mm sources, of which 8 are also detected in a deep VLA 1.4 GHz map and/or a VLT R-band image. Three sources have a flux density S-1.2 mm>4.0 mJy, representing a 7sigma overdensity compared to random field surveys, which predict only 1 such source in our map area. We obtained SCUBA/JCMT 850 mum and 450 mum photometry of six radio/optically identified MAMBO sources, confirming 5 of them with S/N>4. Radio-to-mm and mm-to-submm redshift estimators cannot put strong constraints on the redshifts of these MAMBO sources, but 9 of them are consistent within the uncertainties (mean Deltaz=+2.6) with z=4.1. One faint MAMBO source is possibly identified with an extremely red object (R-K=6.1) at a likely spectroscopic redshift z=1.18. The four brightest MAMBO sources are all located north of the radio galaxy, while the densest area of companion Lyalpha excess and Lyman break galaxies is to the southeast. None of the 14 spectroscopically confirmed Lyalpha emitters in the MAMBO field are detected at 1.2 mm; their average 1.2 mm flux density is (S-1.2 mm)=0.25+/-0.24 mJy. If the mm sources lie at z=4.1, none of them show excess Lyalpha emission in our narrow-band images. Both populations thus show no apparent overlap, possibly due to dust quenching the Lyalpha emission. If the turn sources are part of the proto-cluster, our results suggest that galaxies with star formation rates of a few 1000 M-circle dot yr(-1) could be spread throughout the proto-cluster over projected scales of at least 2 Mpc. C1 European So Observ, D-85748 Garching, Germany. CNRS, Inst Astrophys Paris, F-75014 Paris, France. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Natl Radio Astron Observ, Socorro, NM 87801 USA. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. LLNL, IGPP, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Royal Observ, Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Edinburgh, Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. RP De Breuck, C (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany. EM cdebreuc@eso.org; bertoldi@mpifr-bonn.mpg.de; ccarilli@nrao.edu; omont@iap.fr; venemans@strw.leidenuniv.nl; rottgeri@strw.leidenuniv.nl; overzier@strw.leidenuniv.nl; mreuland@igpp.ucllnl.org; miley@strw.leidenuniv.nl; rji@roe.ac.uk; wil@igpp.ucllnl.org RI Ivison, R./G-4450-2011; OI Ivison, R./0000-0001-5118-1313; De Breuck, Carlos/0000-0002-6637-3315 NR 84 TC 32 Z9 33 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2004 VL 424 IS 1 BP 1 EP 12 DI 10.1051/0004-6361:20035885 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 857DD UT WOS:000224095500001 ER PT J AU Jonauskas, V Keenan, FP Foord, ME Heeter, RF Rose, SJ Ferland, GJ Kisielius, R van Hoof, PAM Norrington, PH AF Jonauskas, V Keenan, FP Foord, ME Heeter, RF Rose, SJ Ferland, GJ Kisielius, R van Hoof, PAM Norrington, PH TI Dirac-Fock energy levels and transition probabilities for oxygen-like Fe xix SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE atomic data ID IRON PROJECT; ATOMIC DATA; OSCILLATOR-STRENGTHS; CONFIGURATION; SPECTROSCOPY; EXCITATION; PROGRAM; IONS AB Multiconfigurational Dirac-Fock calculations are reported for 656 energy levels and the 214 840 electric dipole (E I), electric quadrupole (E2) and magnetic dipole (M1) transition probabilities in oxygen-like Fe xix. The spectroscopic notations as well as the total transition probabilities from each energy level are provided. Good agreement is found with data compiled by NIST. C1 Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Univ Kentucky, Dept Phys, Lexington, KY 40506 USA. Queens Univ Belfast, Dept Appl Math & Theoret Phys, Belfast BT7 1NN, Antrim, North Ireland. RP Jonauskas, V (reprint author), Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. OI Rose, Steven/0000-0001-6808-6355; Ferland, Gary/0000-0003-4503-6333 NR 13 TC 8 Z9 8 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2004 VL 424 IS 1 BP 363 EP 369 DI 10.1051/0004-6361:20040496 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 857DD UT WOS:000224095500035 ER PT J AU Venemans, BP Rottgering, HJA Overzier, RA Miley, GK De Breuck, C Kurk, JD van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Pentericci, L AF Venemans, BP Rottgering, HJA Overzier, RA Miley, GK De Breuck, C Kurk, JD van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Pentericci, L TI Discovery of six Ly alpha emitters near a radio galaxy at z similar to 5.2 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : clusters : general; galaxies : evolution; cosmology : observations; cosmology : early Universe ID SUBARU DEEP SURVEY; CLUSTERING PROPERTIES; LUMINOSITY FUNCTION; EMITTING GALAXIES; FIELD GALAXIES; PROTO-CLUSTER; EMISSION; Z=3 AB We present the results of narrow-band and broad-band imaging with the Very Large Telescope* of the field surrounding the radio galaxy TN J0924-2201 at z = 5.2. Fourteen candidate Lyalpha emitters with a rest-frame equivalent width of >20 Angstrom were detected. Spectroscopy of 8 of these objects showed that 6 have redshifts similar to that of the radio galaxy. The density of emitters at the redshift of the radio galaxy is estimated to be a factor 1.5-6.2 higher than in the field, and comparable to the density of Lya emitters in radio galaxy protoclusters at z = 4.1, 3.1 and 2.2. The Lyalpha emitters near TN J0924-2201 Could therefore be part of a structure that will evolve into a massive cluster. These observations confirm that substantial clustering of Lyalpha emitters occurs at z > 5 and support the idea that radio galaxies pinpoint high density regions in the early Universe. C1 Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. European So Observ, D-85748 Garching, Germany. Osserv Astrofis Arcetri, INAF, I-50125 Florence, Italy. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. RP Venemans, BP (reprint author), Sterrewacht Leiden, POB 9513, NL-2300 RA Leiden, Netherlands. EM venemans@strw.leidenuniv.nl NR 28 TC 67 Z9 69 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2004 VL 424 IS 2 BP L17 EP L20 DI 10.1051/0004-6361:200400041 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 859XD UT WOS:000224300800005 ER PT J AU Blanc, G Afonso, C Alard, C Albert, JN Aldering, G Amadon, A Andersen, J Ansari, R Aubourg, E Balland, C Bareyre, P Beaulieu, JP Charlot, X Conley, A Coutures, C Dahlen, T Derue, F Fan, X Ferlet, R Folatelli, G Fouque, P Garavini, G Glicenstein, JF Goldman, B Goobar, A Gould, A Graff, D Gros, M Haissinski, J Hamadache, C Hardin, D Hook, IM de Kat, J Kent, S Kim, A Lasserre, T Le Guillou, L Lesquoy, E Loup, C Magneville, C Marquette, JB Maurice, E Maury, A Milsztajn, A Moniez, M Mouchet, M Newberg, H Nobili, S Palanque-Delabrouille, N Perdereau, O Prevot, L Rahal, YR Regnault, N Rich, J Ruiz-Lapuente, P Spiro, M Tisserand, P Vidal-Madjar, A Vigroux, L Walton, NA Zylberajch, S AF Blanc, G Afonso, C Alard, C Albert, JN Aldering, G Amadon, A Andersen, J Ansari, R Aubourg, E Balland, C Bareyre, P Beaulieu, JP Charlot, X Conley, A Coutures, C Dahlen, T Derue, F Fan, X Ferlet, R Folatelli, G Fouque, P Garavini, G Glicenstein, JF Goldman, B Goobar, A Gould, A Graff, D Gros, M Haissinski, J Hamadache, C Hardin, D Hook, IM de Kat, J Kent, S Kim, A Lasserre, T Le Guillou, L Lesquoy, E Loup, C Magneville, C Marquette, JB Maurice, E Maury, A Milsztajn, A Moniez, M Mouchet, M Newberg, H Nobili, S Palanque-Delabrouille, N Perdereau, O Prevot, L Rahal, YR Regnault, N Rich, J Ruiz-Lapuente, P Spiro, M Tisserand, P Vidal-Madjar, A Vigroux, L Walton, NA Zylberajch, S TI Type Ia supernova rate at a redshift of similar to 0.1 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : supernovae : general; galaxies : evolution; cosmology : miscellaneous; methods : observational ID BVRI LIGHT CURVES; LUMINOSITY FUNCTION; MAGELLANIC-CLOUD; STAR-FORMATION; GALAXY; EVOLUTION; DENSITY; COUNTS; MAPS AB We present the type la rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type la were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type la supernova explosion rate at a redshift similar to0.13. The result is 0.125(-0.034-0.028)(+0.044+0.028) h(70)(2) SNu where 1 SNu = 1 SN / 10(10) L-.(B) / century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type la supernova rate. C1 CEA Saclay, DSM, DAPNIA, F-91191 Gif Sur Yvette, France. Univ Paris 11, CNRS, IN2P3, Lab Accelerateur Lineaire, F-91405 Orsay, France. Observ Marseille, F-13248 Marseille, France. Coll France, CNRS, IN2P3, F-75231 Paris, France. CNRS, INSU, Inst Astrophys Paris, F-75014 Paris, France. Univ Copenhagen, Astron Observ, DK-2100 Copenhagen, Denmark. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. European So Observ, Santiago 19, Chile. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Stockholm, Dept Phys, AlbaNova Univ Ctr, S-10691 Stockholm, Sweden. Osserv Astron Padova, INAF, I-35122 Padua, Italy. Univ Paris 06, CNRS, IN2P3, Lab Phys Nucl & Hautes Energies, F-75252 Paris 05, France. Univ Paris 07, CNRS, IN2P3, Lab Phys Nucl & Hautes Energies, F-75252 Paris 05, France. Ecole Polytech, LLR, Lab Leprince Ringuet, F-91128 Palaiseau, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Observ Paris, LUTH, F-92195 Meudon, France. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Paris 07, F-75005 Paris, France. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Paris, GEPI, F-75014 Paris, France. Univ Oxford, Dept Phys, Nucl & Astrophys Lab, Oxford OX1 3RH, England. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Barcelona, Dept Astron, Barcelona, Spain. RP Blanc, G (reprint author), CEA Saclay, DSM, DAPNIA, F-91191 Gif Sur Yvette, France. EM blanc@pd.astro.it RI Folatelli, Gaston/A-4484-2011; Le Guillou, Laurent/B-7712-2009 NR 46 TC 56 Z9 56 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2004 VL 423 IS 3 BP 881 EP 894 DI 10.1051/0004-6361:20035948 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 853SY UT WOS:000223850400013 ER PT J AU Ahrens, J Ackermann, M Andres, E Bai, X Barwick, SW Bay, RC Becka, T Becker, KH Bernardini, E Bertrand, D Binon, F Biron, A Boersma, DJ Boser, S Botner, O Bouchta, A Bouhali, O Burgess, T Carius, S Castermans, T Chirkin, D Conrad, J Cooley, J Cowen, DF Davour, A De Clercq, C DeYoung, T Desiati, P Dewulf, JP Dickinson, E Ekstrom, P Engel, R Evenson, P Feser, T Gaisser, TK Ganugapati, R Gaug, M Geenen, H Gerhardt, L Goldschmidt, A Hallgren, A Halzen, F Hanson, K Hardtke, R Hauschildt, T Hellwig, M Herquet, P Hill, GC Hinton, JA Hubert, D Hughey, B Hulth, PO Hultqvist, K Hundertmark, S Jacobsen, J Karle, A Kim, J Kopke, L Kowalski, M Kuehn, K Lamoureux, JI Leich, H Leuthold, M Lindahl, P Liubarsky, I Lloyd-Evans, J Madsen, J Mandli, K Marciniewski, P Matis, HS McParland, CP Messarius, T Miller, TC Minaeva, Y Miocinovic, P Mock, PC Morse, R Nahnhauer, R Neunhoffer, T Niessen, P Nygren, DR Ogelman, H Olbrechts, P de los Heros, CP Pohl, AC Porrata, R Price, PB Przybylski, GT Rawlins, K Resconi, E Rhode, W Ribordy, M Richter, S Rochester, K Martino, JR Ross, D Sander, HG Schmidt, T Schinarakis, K Schlenstedt, S Schneider, D Schwarz, R Silvestri, A Solarz, M Spiczak, GM Spiering, C Stamatikos, M Stanev, T Steele, D Steffen, P Stokstad, RG Sulanke, KH Taboada, I Tilav, S Walck, C Wagner, W Wang, YR Watson, AA Wiebusch, CH Wiedemann, C Wischnewski, R Wissing, H Woschnagg, K Wu, W Yodh, G Young, S AF Ahrens, J Ackermann, M Andres, E Bai, X Barwick, SW Bay, RC Becka, T Becker, KH Bernardini, E Bertrand, D Binon, F Biron, A Boersma, DJ Boser, S Botner, O Bouchta, A Bouhali, O Burgess, T Carius, S Castermans, T Chirkin, D Conrad, J Cooley, J Cowen, DF Davour, A De Clercq, C DeYoung, T Desiati, P Dewulf, JP Dickinson, E Ekstrom, P Engel, R Evenson, P Feser, T Gaisser, TK Ganugapati, R Gaug, M Geenen, H Gerhardt, L Goldschmidt, A Hallgren, A Halzen, F Hanson, K Hardtke, R Hauschildt, T Hellwig, M Herquet, P Hill, GC Hinton, JA Hubert, D Hughey, B Hulth, PO Hultqvist, K Hundertmark, S Jacobsen, J Karle, A Kim, J Kopke, L Kowalski, M Kuehn, K Lamoureux, JI Leich, H Leuthold, M Lindahl, P Liubarsky, I Lloyd-Evans, J Madsen, J Mandli, K Marciniewski, P Matis, HS McParland, CP Messarius, T Miller, TC Minaeva, Y Miocinovic, P Mock, PC Morse, R Nahnhauer, R Neunhoffer, T Niessen, P Nygren, DR Ogelman, H Olbrechts, P de los Heros, CP Pohl, AC Porrata, R Price, PB Przybylski, GT Rawlins, K Resconi, E Rhode, W Ribordy, M Richter, S Rochester, K Martino, JR Ross, D Sander, HG Schmidt, T Schinarakis, K Schlenstedt, S Schneider, D Schwarz, R Silvestri, A Solarz, M Spiczak, GM Spiering, C Stamatikos, M Stanev, T Steele, D Steffen, P Stokstad, RG Sulanke, KH Taboada, I Tilav, S Walck, C Wagner, W Wang, YR Watson, AA Wiebusch, CH Wiedemann, C Wischnewski, R Wissing, H Woschnagg, K Wu, W Yodh, G Young, S CA AMANDA Collaborations SPASE Collaborations TI Measurement of the cosmic ray composition at the knee with the SPASE-2/AMANDA-B10 detectors SO ASTROPARTICLE PHYSICS LA English DT Article DE cosmic rays; neutrino astronomy; mass composition ID EXTENSIVE AIR-SHOWERS; ENERGY-SPECTRUM; SOUTH-POLE; CHERENKOV-LIGHT; GRAN SASSO; DEEP ICE; TEV; PRIMARIES; CASCADES; AMANDA AB The mass composition of high-energy cosmic rays at energies above 10(15) eV can provide crucial information for the understanding of their origin. Air showers were measured simultaneously with the SPASE-2 air shower array and the AMANDA-B10 Cherenkov telescope at the South Pole. This combination has the advantage to sample almost all high-energy shower muons and is thus a new approach to the determination of the cosmic ray composition. The change in the cosmic ray mass composition was measured versus existing data from direct measurements at low energies. Our data show an increase of the mean log atomic mass by about 0.8 between 500 TeV and 5 PeV. This trend of an increasing mass through the "knee" region is robust against a variety of systematic effects. (C) 2004 Elsevier B.V. All rights reserved. C1 Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany. DESY, D-15735 Zeuthen, Germany. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Berg Univ Wuppertal, Fachbereich Phys 8, D-42097 Wuppertal, Germany. Free Univ Brussels, Fac Sci, B-1050 Brussels, Belgium. Uppsala Univ, Div High Energy Phys, S-75121 Uppsala, Sweden. Univ Stockholm, SCFAB, Dept Phys, SE-10691 Stockholm, Sweden. Kalmar Univ, Dept Technol, S-39182 Kalmar, Sweden. Univ Mons, B-7000 Mons, Belgium. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Free Univ Brussels, ELEM, B-1050 Brussels, Belgium. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA. Univ Simon Bolivar, Dept Fis, Caracas 1080A, Venezuela. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. RP Johannes Gutenberg Univ Mainz, Inst Phys, Staudinger Weg 7, D-55099 Mainz, Germany. EM sbarwick@uci.edu RI Wiebusch, Christopher/G-6490-2012; Hundertmark, Stephan/A-6592-2010; Botner, Olga/A-9110-2013; Hallgren, Allan/A-8963-2013; GAug, Markus/L-2340-2014; OI Wiebusch, Christopher/0000-0002-6418-3008; GAug, Markus/0000-0001-8442-7877; Perez de los Heros, Carlos/0000-0002-2084-5866; Hubert, Daan/0000-0002-4365-865X NR 34 TC 25 Z9 25 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD SEP PY 2004 VL 21 IS 6 BP 565 EP 581 DI 10.1016/j.astropartphys.2004.04.007 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 855XE UT WOS:000224007400001 ER PT J AU Behar, E Leutenegger, M Doron, R Gudel, M Feldman, U Audard, M Kahn, SM AF Behar, E Leutenegger, M Doron, R Gudel, M Feldman, U Audard, M Kahn, SM TI Resolving X-ray sources from B stars spectroscopically: The example of mu Leporis SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : activity; stars : chemically peculiar; stars : coronae; stars : pre-main-sequence; X-rays : stars ID COMPANIONS; ABUNDANCE; SPECTRUM; CHANDRA AB We present high-resolution X-ray observations of the chemically peculiar late-type B star mu Lep. However, we find spectroscopic and astrometric evidence, which shows that the X-rays are not traced back to the B star itself but rather to a previously unresolved companion, mu Lep-B, whose X-ray spectrum resembles that of a coronally active source. We discuss the possibility that mu Lep-B is a pre-main-sequence companion, most likely of the nonaccreting magnetically active type. C1 Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Weizmann Inst Sci, IL-76100 Rehovot, Israel. Paul Scherrer Inst, CH-5303 Wurenlingen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Artep Inc, Ellicott City, MD 21042 USA. Stanford Linear Accelerator Ctr, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. RP Behar, E (reprint author), Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. EM behar@physics.technion.ac.il RI Doron, Ramy/I-2064-2013; Guedel, Manuel/C-8486-2015 OI Guedel, Manuel/0000-0001-9818-0588 NR 17 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2004 VL 612 IS 1 BP L65 EP L68 DI 10.1086/424485 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TE UT WOS:000223634600017 ER PT J AU Starrfield, S Timmes, FX Hix, WR Sion, EM Sparks, WM Dwyer, SJ AF Starrfield, S Timmes, FX Hix, WR Sion, EM Sparks, WM Dwyer, SJ TI Surface hydrogen-burning modeling of supersoft X-ray binaries: Are they type Ia supernova progenitors? SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; novae, cataclysmic variables; stars : individual (CAL 83, CAL 87); supernovae : general ID ACCRETING WHITE-DWARFS; NUCLEAR-REACTION RATES; SHELL FLASHES; EVOLUTIONARY SEQUENCES; SPECTRA; CAL-87; STATE; NUCLEOSYNTHESIS; CONSISTENCY; EXPLOSIONS AB Nova explosions occur on the white dwarf (WD) component of a cataclysmic variable stellar system that is accreting matter lost by a companion. A Type Ia supernova (SN Ia) explosion is thought to result when a WD, in a similar binary configuration, grows in mass to the Chandrasekhar limit. Here, we present calculations of accretion of solar matter, at a variety of mass accretion rates, onto hot (2.3x10(5) K), luminous (30 L(circle dot)), massive (1.25, 1.35 M(circle dot)) carbon-oxygen WDs. In contrast to our nova simulations, where the WD has a low initial luminosity and a thermonuclear runaway (TNR) occurs and ejects material, these simulations do not eject material ( or only a small fraction of the accreted material), and the WD grows in mass. A hydrogen TNR does not occur because hydrogen fuses to helium in the surface layers, and we call this process surface hydrogen burning (SHB). As the helium layer grows in mass, it gradually fuses either to carbon and oxygen or to more massive nuclei, depending on the WD mass and mass accretion rate. If such a WD were to explode in a SN Ia event, therefore, it would show neither hydrogen nor helium in its spectrum as is observed. Moreover, the luminosities and effective temperatures of our simulations agree with the observations of some of the supersoft X-ray binary sources, and therefore, our results strengthen previous speculation that some of them (CAL 83 and CAL 87, for example) are probably progenitors of SN Ia explosions. Finally, we have achieved SHB for values of the mass accretion rate that almost span the observed values of the cataclysmic variables. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Villanova Univ, Dept Astron, Villanova, PA 19085 USA. Sci Applicat Int Corp, San Diego, CA 92121 USA. RP Starrfield, S (reprint author), Arizona State Univ, Dept Phys & Astron, Box 871504, Tempe, AZ 85287 USA. EM sumner.starrfield@asu.edu; fxt44@mac.com; raph@phy.ornl.gov; edward.sion@villanova.edu; wms@lanl.gov; steven.dwyer@asu.edu RI Hix, William/E-7896-2011 OI Hix, William/0000-0002-9481-9126 NR 39 TC 42 Z9 42 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 1 PY 2004 VL 612 IS 1 BP L53 EP L56 DI 10.1086/424513 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TE UT WOS:000223634600014 ER PT J AU Rieke, GH Young, ET Engelbracht, CW Kelly, DM Low, FJ Haller, EE Beeman, JW Gordon, KD Stansberry, JA Misselt, KA Cadien, J Morrison, JE Rivlis, G Latter, WB Noriega-Crespo, A Padgett, DL Stapelfeldt, KR Hines, DC Egami, E Muzerolle, J Alonso-Herrero, A Blaylock, M Dole, H Hinz, JL Le Floc'h, E Papovich, C Perez-Gonzalez, PG Smith, PS Su, KYL Bennett, L Frayer, DT Henderson, D Lu, N Masci, F Pesenson, M Rebull, L Rho, J Keene, J Stolovy, S Wachter, S Wheaton, W Werner, MW Richards, PL AF Rieke, GH Young, ET Engelbracht, CW Kelly, DM Low, FJ Haller, EE Beeman, JW Gordon, KD Stansberry, JA Misselt, KA Cadien, J Morrison, JE Rivlis, G Latter, WB Noriega-Crespo, A Padgett, DL Stapelfeldt, KR Hines, DC Egami, E Muzerolle, J Alonso-Herrero, A Blaylock, M Dole, H Hinz, JL Le Floc'h, E Papovich, C Perez-Gonzalez, PG Smith, PS Su, KYL Bennett, L Frayer, DT Henderson, D Lu, N Masci, F Pesenson, M Rebull, L Rho, J Keene, J Stolovy, S Wachter, S Wheaton, W Werner, MW Richards, PL TI The Multiband Imaging Photometer for Spitzer (MIPS) SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared : general; space vehicles : instruments ID SIRTF; ARRAY AB The Multiband Imaging Photometer for Spitzer (MIPS) provides long-wavelength capability for the mission in imaging bands at 24, 70, and 160 mum and measurements of spectral energy distributions between 52 and 100 mum at a spectral resolution of about 7%. By using true detector arrays in each band, it provides both critical sampling of the Spitzer point-spread function and relatively large imaging fields of view, allowing for substantial advances in sensitivity, angular resolution, and efficiency of areal coverage compared with previous space far-infrared capabilities. The 24 mum array has excellent photometric properties, and measurements with rms relative errors of about 1% can be obtained. The two longer-wavelength arrays use detectors with poor photometric stability, but a system of onboard stimulators used for relative calibration, combined with a unique data pipeline, produce good photometry with rms relative errors of less than 10%. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Rieke, GH (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. RI Stapelfeldt, Karl/D-2721-2012; Perez-Gonzalez, Pablo/J-2871-2016; Alonso-Herrero, Almudena/H-1426-2015; OI Perez-Gonzalez, Pablo/0000-0003-4528-5639; Alonso-Herrero, Almudena/0000-0001-6794-2519; Rebull, Luisa/0000-0001-6381-515X; Su, Kate/0000-0002-3532-5580 NR 18 TC 1409 Z9 1411 U1 3 U2 23 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2004 VL 154 IS 1 BP 25 EP 29 DI 10.1086/422717 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TB UT WOS:000223634300004 ER PT J AU Hinz, JL Rieke, GH Gordon, KD Perez-Gonzalez, PG Engelbracht, CW Alonso-Herrero, A Morrison, JE Misselt, K Hines, DC Gehrz, RD Polomski, E Woodward, CE Humphreys, RM Regan, MW Rho, J Beeman, JW Haller, EE AF Hinz, JL Rieke, GH Gordon, KD Perez-Gonzalez, PG Engelbracht, CW Alonso-Herrero, A Morrison, JE Misselt, K Hines, DC Gehrz, RD Polomski, E Woodward, CE Humphreys, RM Regan, MW Rho, J Beeman, JW Haller, EE TI Energy sources of the far-infrared emission of M33 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : individual (M33); galaxies : spiral; galaxies : structure; infrared : galaxies ID SUPERMASSIVE BLACK-HOLE; SPIRAL GALAXY M33; STAR-FORMATION; H-ALPHA; DUST; LUMINOSITY; RADIATION; FIR AB We present observations of the spiral galaxy M33 with Spitzer at 24, 70, and 160 mum. The excellent resolution and mapping capabilities of Spitzer combined with the proximity of M33 result in observations that enable a detailed study of the distribution of star formation (SF) and dust in the galaxy. We compare the morphology of M33 at far-infrared wavelengths with other standard SF indicators such as Halpha and radio continuum using a Fourier filtering technique to separate the diffuse emission components from compact sources. We find that the infrared emission at 24 and 70 mum follows closely the structure of the ionized gas, indicating that it is heated largely by hot, ionizing stars. At 160 mum a diffuse cold dust component matches only approximately the structure of the old red stellar population or the distribution of blue light. It is, however, very similar to the structure of the diffuse nonthermal radio emission. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Lawrence Berkeley Natl Labs, Berkeley, CA 94720 USA. RP Hinz, JL (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. EM jhinz@as.arizona.edu; grieke@as.arizona.edu; kgordon@as.arizona.edu; pgperez@as.arizona.edu; cengelbracht@as.arizona.edu; aalonso@as.arizona.edu; jmorrison@as.arizona.edu; kmisselt@as.arizona.edu; dhines@as.arizona.edu; gehrz@astro.umn.edu; elwood@astro.umn.edu; chelsea@astro.umn.edu; roberta@astro.umn.edu; mregan@stsci.edu; rho@ipac.caltech.edu RI Perez-Gonzalez, Pablo/J-2871-2016; Alonso-Herrero, Almudena/H-1426-2015 OI Perez-Gonzalez, Pablo/0000-0003-4528-5639; Alonso-Herrero, Almudena/0000-0001-6794-2519 NR 28 TC 45 Z9 45 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2004 VL 154 IS 1 BP 259 EP 265 DI 10.1086/422558 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TB UT WOS:000223634300048 ER PT J AU Hines, DC Rieke, GH Gordon, KD Rho, J Misselt, KA Woodward, CE Werner, MW Krause, O Latter, WB Engelbracht, CW Egami, E Kelly, DM Muzerolle, J Stansberry, JA Su, KYL Morrison, JE Young, ET Noriega-Crespo, A Padgett, DL Gehrz, RD Polomski, E Beeman, JW Haller, EE AF Hines, DC Rieke, GH Gordon, KD Rho, J Misselt, KA Woodward, CE Werner, MW Krause, O Latter, WB Engelbracht, CW Egami, E Kelly, DM Muzerolle, J Stansberry, JA Su, KYL Morrison, JE Young, ET Noriega-Crespo, A Padgett, DL Gehrz, RD Polomski, E Beeman, JW Haller, EE TI Imaging of the supernova remnant Cassiopeia A with the multiband imaging photometer for Spitzer (MIPS) SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared : ISM; ISM : individual (Cassiopeia A); supernova remnants ID DUST; EJECTA AB We present new images of the supernova remnant (SNR) Cas A observed in the 24 and 70 mum bands of the Spitzer Space Telescope (Spitzer). The IR emission correlates well with the Si X-ray and optical [S II] emission but poorly with either the synchrotron-dominated radio structure or the continuum X-ray emission. The IR is therefore dominated by thermal emission from dust within the SNR and associated with emission-line gas inside the reverse shock region, confirming earlier IRAS and Infrared Space Observatory results. Supplemented by new photometric measurements from archived Midcourse Space Experiment images, we suggest stochastic heating to model the overall mid- to far-IR spectral energy distribution. The 24 and 70 mum images also reveal a counterjet to the well-known northeast jet feature imaged previously at X-ray, optical, and radio wavelengths. This IR counterjet corresponds well with (optical) fast-moving knots confirming its outflow nature. The opposing jetlike features define a symmetry axis that bisects the SNR and suggest that the supernova explosion was axisymmetric. The IR images also show a region in which the SNR forward shock appears to be propagating into a similar to650 M-circle dot molecular cloud. The new images also show other details of the surrounding ISM structure, including two groups of knots extending similar to6'-12' on either side of the SNR. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hines, DC (reprint author), Space Sci Inst, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. OI Su, Kate/0000-0002-3532-5580 NR 33 TC 71 Z9 71 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2004 VL 154 IS 1 BP 290 EP 295 DI 10.1086/422583 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TB UT WOS:000223634300054 ER PT J AU Roellig, TL Van Cleve, JE Sloan, GC Wilson, JC Saumon, D Leggett, SK Marley, MS Cushing, MC Kirkpatrick, JD Mainzer, AK Houck, JR AF Roellig, TL Van Cleve, JE Sloan, GC Wilson, JC Saumon, D Leggett, SK Marley, MS Cushing, MC Kirkpatrick, JD Mainzer, AK Houck, JR TI Spitzer Infrared Spectrograph (IRS) observations of M, L, and T dwarfs SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared : stars; stars : low-mass, brown dwarfs ID EXTRASOLAR GIANT PLANETS; BROWN DWARF; ATMOSPHERIC CHEMISTRY; SPECTROSCOPIC SURVEY; MODEL ATMOSPHERES; SPACE-TELESCOPE; SKY SURVEY; SPECTRA; STARS; CLOUDS AB We present the first mid-infrared spectra of brown dwarfs, together with observations of a low-mass star. Our targets are the M3.5 dwarf GJ 1001A, the L8 dwarf DENIS-P J0255-4700, and the T1/T6 binary system epsilon Indi Ba/Bb. As expected, the mid-infrared spectral morphology of these objects changes rapidly with spectral class because of the changes in atmospheric chemistry resulting from their differing effective temperatures and atmospheric structures. By taking advantage of the unprecedented sensitivity of the Infrared Spectrograph on the Spitzer Space Telescope, we have detected the 7.8 mum methane and 10 mum ammonia bands for the first time in brown dwarf spectra. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Ball Aerosp & Technol Corp, Boulder, CO 80301 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Virginia, Charlottesville, VA 22903 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Joint Astron Ctr, Hilo, HI 96720 USA. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Roellig, TL (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM thomas.l.roellig@nasa.gov RI Marley, Mark/I-4704-2013; OI Leggett, Sandy/0000-0002-3681-2989 NR 37 TC 50 Z9 50 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2004 VL 154 IS 1 BP 418 EP 421 DI 10.1086/421978 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 850TB UT WOS:000223634300076 ER PT J AU Galmarini, S Bianconi, R Klug, W Mikkelsen, T Addis, R Andronopoulos, S Astrup, P Baklanov, A Bartniki, J Bartzis, JC Bellasio, R Bompay, F Buckley, R Bouzom, M Champion, H D'Amours, R Davakis, E Eleveld, H Geertsema, GT Glaab, H Kollax, M Ilvonen, M Manning, A Pechinger, U Persson, C Polreich, E Potemski, S Prodanova, M Saltbones, J Slaper, H Sofiev, MA Syrakov, D Sorensen, JH Van der Auwera, L Valkama, I Zelazny, R AF Galmarini, S Bianconi, R Klug, W Mikkelsen, T Addis, R Andronopoulos, S Astrup, P Baklanov, A Bartniki, J Bartzis, JC Bellasio, R Bompay, F Buckley, R Bouzom, M Champion, H D'Amours, R Davakis, E Eleveld, H Geertsema, GT Glaab, H Kollax, M Ilvonen, M Manning, A Pechinger, U Persson, C Polreich, E Potemski, S Prodanova, M Saltbones, J Slaper, H Sofiev, MA Syrakov, D Sorensen, JH Van der Auwera, L Valkama, I Zelazny, R TI Ensemble dispersion forecasting - Part I: concept, approach and indicators SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE long-range transport and dispersion; multi-model ensemble dispersion forecast and analysis ID LONG-RANGE TRANSPORT; ATMOSPHERIC DISPERSION; MODEL; EMERGENCY; RADIONUCLIDES; VALIDATION; SYSTEM; UK AB The paper presents an approach to the treatment and analysis of long-range transport and dispersion model forecasts. Long-range is intended here as the space scale of the order of few thousands of kilometers known also as continental scale. The method is called multi-model ensemble dispersion and is based on the simultaneous analysis of several model simulations by means of ad-hoc statistical treatments and parameters. The models considered in this study are operational long-range transport and dispersion models used to support decision making in various countries in case of accidental releases of harmful volatile substances, in particular radionuclides to the atmosphere. The ensemble dispersion approach and indicators provide a way to reduce several model results to few concise representations that include an estimate of the models' agreement in predicting a specific scenario. The parameters proposed are particularly suited for long-range transport and dispersion models although they can also be applied to short-range dispersion and weather fields. (C) 2004 Elsevier Ltd. All rights reserved. C1 Commiss European Communities, Joint Res Ctr, IES REM, I-21020 Ispra, Italy. Enviroware srl, I-20041 Agrate Brianza, Italy. Riso Natl Lab, Wind Energy Dept, DK-4000 Roskilde, Denmark. Savannah River Technol Ctr, Aiken, SC 29808 USA. NCSR Demokritos, Environm Res Lab, Athens 15310, Greece. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. Norwegian Meteorol Inst, N-0313 Oslo, Norway. METEOFRANCE, F-31057 Toulouse, France. RIVM, Lab Radiat Res, Bilthoven, Netherlands. KNMI, NL-3730 AE De Bilt, Netherlands. German Weather Serv DWD, D-63004 Offenbach, Germany. Meteorol Off, Exeter EX1 3PB, Devon, England. Canadian Meteorol Ctr, Dorval, PQ H9P 1J3, Canada. SMHI, SE-60176 Norrkoping, Sweden. Cent Inst Meteorol & Geodynam, A-1191 Vienna, Austria. Res Grp B1P, Inst Atom Energy, PL-05400 Otwock, Poland. NMHI, BU-1784 Sofia, Bulgaria. KMI, B-1180 Brussels, Belgium. FMI, Air Qual Reas, FIN-00810 Helsinki, Finland. VTT Proc, FIN-02044 Espoo, Finland. RP Galmarini, S (reprint author), Commiss European Communities, Joint Res Ctr, IES REM, TP 441, I-21020 Ispra, Italy. EM stefano.galmarini@jrc.it RI Mikkelsen, Torben/E-7997-2010; Potempski, Slawomir/A-1401-2013; Mikkelsen, Torben/N-3123-2013; Sofiev, Mikhail/F-7606-2016 OI Potempski, Slawomir/0000-0002-3877-5464; Mikkelsen, Torben/0000-0002-5428-856X; Sofiev, Mikhail/0000-0001-9542-5746 NR 29 TC 90 Z9 92 U1 1 U2 8 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 2004 VL 38 IS 28 BP 4607 EP 4617 DI 10.1016/j.atmosenv.2004.05.030 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 847XX UT WOS:000223432500001 ER PT J AU Galmarini, S Bianconi, R Addis, R Andronopoulos, S Astrup, P Bartzis, JC Bellasio, R Buckley, R Champion, H Chino, M D'Amours, R Davakis, E Eleveld, H Glaab, H Manning, A Mikkelsen, T Pechinger, U Polreich, E Prodanova, M Slaper, H Syrakov, D Terada, H Van der Auwera, L AF Galmarini, S Bianconi, R Addis, R Andronopoulos, S Astrup, P Bartzis, JC Bellasio, R Buckley, R Champion, H Chino, M D'Amours, R Davakis, E Eleveld, H Glaab, H Manning, A Mikkelsen, T Pechinger, U Polreich, E Prodanova, M Slaper, H Syrakov, D Terada, H Van der Auwera, L TI Ensemble dispersion forecasting - Part II: application and evaluation SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE ensemble dispersion modeling; european tracer experiment; model evaluation ID ETEX AB The data collected during the long-range European tracer experiment (ETEX) conducted in 1994, are used to estimate quantitatively the ensemble dispersion concept presented in Part I. The modeling groups taking part to the ENSEMBLE activities (see, Part I) repeated model simulations of the dispersion of ETEX release 1 and the model ensemble is compared with the monitoring data. The scope of the comparison is to estimate to what extent the ensemble analysis is an improvement with respect to the single model results and represents a superior analysis of the process evolution. (C) 2004 Elsevier Ltd. All rights reserved. C1 Commiss European Communities, Joint Res Ctr, IES REM, I-21020 Ispra, Italy. Enviroware srl, I-20041 Agrate Brianza, Italy. Savannah River Technol Ctr, Aiken, SC 29808 USA. NCSR Demokritos, Environm Res Lab, Athens 15310, Greece. Riso Natl Lab, Wind Energy Dep, DK-4000 Roskilde, Denmark. Met Off, Exeter EX1 3PB, Devon, England. Canadian Metorol Ctr, Dorval, PQ H9P 1J3, Canada. RIVM, Lab Radiat Res, Bilthoven, Netherlands. Geman Weather Serv DWD, D-63004 Offenbach, Germany. Zentralanstalt Meteorol & Geodynam, A-1191 Vienna, Austria. NMHI, Sofia 1784, Bulgaria. JAERI, Naka, Ibaraki 3191195, Japan. KMI, Brussels, Belgium. RP Galmarini, S (reprint author), Commiss European Communities, Joint Res Ctr, IES REM, TP 441, I-21020 Ispra, Italy. EM stefano.galmarini@jrc.it RI Mikkelsen, Torben/E-7997-2010; Mikkelsen, Torben/N-3123-2013 OI Mikkelsen, Torben/0000-0002-5428-856X NR 20 TC 55 Z9 58 U1 0 U2 3 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 2004 VL 38 IS 28 BP 4619 EP 4632 DI 10.1016/j.atmosenv.2004.05.031 PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 847XX UT WOS:000223432500002 ER PT J AU Nunnermacker, LJ Weinstein-Lloyd, J Kleinman, L Daum, PH Lee, YN Springston, SR Klotz, P Newman, L Neuroth, G Hyde, P AF Nunnermacker, LJ Weinstein-Lloyd, J Kleinman, L Daum, PH Lee, YN Springston, SR Klotz, P Newman, L Neuroth, G Hyde, P TI Ground-based and aircraft measurements of trace gases in Phoenix, Arizona (1998) SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE ozone; ozone production efficiency; biogenic hydrocarbons; isoprene; carbon monoxide; nitrogen oxides ID POWER-PLANT PLUMES; OZONE PRODUCTION EFFICIENCY; MIDDLE TENNESSEE OZONE; SOUTHERN OXIDANTS; NONENZYMATIC METHOD; STAGNATION EPISODE; URBAN PLUME; JULY 18; NASHVILLE; CHEMISTRY AB In May and June of 1998, an extensive measurement campaign was fielded in the city of Phoenix and its environs. Measurements were made at ground sites and aboard the Department of Energy's G-1 research aircraft in an effort to understand the production Of O-3 in this area. Diurnal variations in O-3 differed at the upwind Palo Verde, downtown Phoenix Super Site, and downwind Usery Pass surface stations. Air masses entering the metropolitan area had O-3 concentrations greater than 40 ppbv. Maximum O-3 concentrations near 100 ppbv were observed downtown at 14:00 local standard time; similar concentrations occurred much later in the day at the downwind site. One aircraft case study on 5 June, 1998 is presented to illustrate ozone production in the region. Calculated ozone production rate and efficiency varied from 1 to 7 ppbv h(-1), and 1-3 molecules Of O-3 per molecule of NOz, respectively, for this flight. Hydrocarbon apportionment, based upon ground site and aircraft measurements, establishes that biogenic species are not significant contributors to O-3 production in the Phoenix area. Therefore, carbon monoxide becomes a major contributor to OH reactivity as the more reactive anthropogenic hydrocarbons become depleted. The relatively low ozone production observed in this study is attributed to a low rate of radical production in the dry atmosphere. (C) 2004 Elsevier Ltd. All rights reserved. C1 Div Atmospher Sci, Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Coll Old Westbury, Dept Chem Phys, Old Westbury, NY 11568 USA. Arizona Dept Environm Qual, Phoenix, AZ 85012 USA. RP Div Atmospher Sci, Brookhaven Natl Lab, Bldg 815E,Rutherford St, Upton, NY 11973 USA. EM lindan@bnl.gov NR 33 TC 9 Z9 9 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2004 VL 38 IS 29 BP 4941 EP 4956 DI 10.1016/j.atmosenv.2004.04.033 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 850WY UT WOS:000223646300014 ER PT J AU Velasco, E Siegmann, P Siegmann, HC AF Velasco, E Siegmann, P Siegmann, HC TI Exploratory study of particle-bound polycyclic aromatic hydrocarbons in different environments of Mexico City SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE particulate matter; polycyclic aromatic hydrocarbons; personal monitor; photoelectric charging; Mexican pollution ID PARTICULATE AIR-POLLUTION; AMBIENT AIR; COMBUSTION AEROSOLS; SURFACE-AREA; US CITIES; FINE; MORTALITY; ULTRAFINE; EMISSIONS; EXPOSURE AB Several studies regarding particulate matter in air pollution have been performed in Mexico City, but none have focused on environment exposure to particle-bound polycyclic aromatic hydrocarbons (PPAH), which are related to the occurrence of cardiopulmonary diseases and mortality. On this account, this study presents measurements of personal exposure to PPAH in different outdoor and indoor environments, as well as along roadways in Mexico City. The measurements were done with portable sensors based on photoelectric charging and diffusion charging to determine the PPAH concentrations and the joint active surface of all particles, respectively. The use of these two sensors in parallel is a useful tool to qualitatively identify the major sources and to describe the physical and chemical characteristics of the particles. The highest exposures were found in ambient air near traffic sources, mainly at sites with great influence of diesel vehicles, such as urban transfer bus stations. Roadway measurements showed that Mexican PPAH pollution levels are between those in large cities in Europe and USA. For indoor environments such as residences, shopping centers, restaurants and hospitality venues, it was found that secondhand smoke is the major contributor, however badly calibrated pilot stoves, inefficient ventilation and faulty air-conditioning systems can be additional sources of PPAH. (C) 2004 Elsevier Ltd. All rights reserved. C1 Washington State Univ, Dept Civil & Environm Engn, Lab Atmospher Res, Pullman, WA 99164 USA. Univ Sheffield, Dept Mech Engn, Sheffield S1 3JD, S Yorkshire, England. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Washington State Univ, Dept Civil & Environm Engn, Lab Atmospher Res, Pullman, WA 99164 USA. EM he_velasco@wsu.edu RI Siegmann, Philip/H-7528-2014 OI Siegmann, Philip/0000-0002-0231-0446 NR 39 TC 36 Z9 38 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 EI 1873-2844 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2004 VL 38 IS 29 BP 4957 EP 4968 DI 10.1016/j.atmosenv.2004.05.020 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 850WY UT WOS:000223646300015 ER PT J AU Jiang, GF Fast, JD AF Jiang, GF Fast, JD TI Modeling the effects of VOC and NOX emission sources on ozone formation in Houston during the TexAQS 2000 field campaign SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE regional photochemical modeling; emission inventories; air quality; ethene and propene; houtson; Tx ID CLOSURE-MODEL; TURBULENCE AB A meteorological and chemical modeling system is used to determine the effect of ethene and propene point source emission rates on the magnitude and distribution of ozone in the vicinity of Houston. The model performance is evaluated using surface and airborne meteorological and chemical measurements made as part of the 2000 Texas Air Quality Study. A simulation that employed the reported mobile, area, biogenic, and point source emissions produced ozone mixing ratios as high as 120 ppb and distributions of nitrogen oxides that were similar to measurements at most locations, but the model underestimated ozone mixing ratios greater than 140 ppb that were located just downwind of petrochemical facilities. When the point source emission rates of ethene and propene were increased by a factor of 10, the simulated peak ozone levels were in better agreement with surface, aircraft, and lidar observations. The magnitude of the simulated ethene and olefin concentrations were in better agreement with canister samples aloft as well; however, there was still a large amount of scatter in the results. While the highest ozone mixing ratios were produced just downwind of large point source emissions of VOCs, sensitivity simulations also showed that reductions in anthropogenic emissions of NOx would be needed to reduce ozone mixing ratios over a larger area. (C) 2004 Elsevier Ltd. All rights reserved. C1 Pacific NE Natl Lab, Richland, WA 99352 USA. RP Fast, JD (reprint author), Pacific NE Natl Lab, POB 999,K9-30, Richland, WA 99352 USA. EM jerome.fast@pnl.gov NR 26 TC 42 Z9 42 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2004 VL 38 IS 30 BP 5071 EP 5085 DI 10.1016/j.atmosenv.2004.06.012 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 853CR UT WOS:000223804400009 ER PT J AU Calvert, JG Lindberg, SE AF Calvert, JG Lindberg, SE TI Potential influence of iodine-containing compounds on the chemistry of the troposphere in the polar spring. I. Ozone depletion SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE arctic O-3 depletion; computer simulations; atmospheric chemistry; iodine-containing compounds ID MARINE BOUNDARY-LAYER; METHYL-IODIDE; HALOGENATED HYDROCARBONS; OCLO PHOTODISSOCIATION; ATMOSPHERIC CHEMISTRY; ARCTIC TROPOSPHERE; SELF-REACTION; KINETICS; MECHANISM; CHLORINE AB Iodine in the atmosphere, identified largely by the presence of 10, is a ubiquitous component of the troposphere in coastal and oceanic areas. The role, if any, that iodine chemistry plays in the polar ozone depletion episodes is not known. These events are rationalized today largely in terms of Br-2- and BrCl-initiated reactions. The potential for enhancement of ozone depletions through the presence of iodine-containing molecules (I-2, IBr, ICl, CH2I2, CH2IBr, CH2IC], and CH3I) is investigated in this study. Computer simulations of the homogeneous chemistry are made using a reasonably complete reaction mechanism for Br-, Cl- and I-containing species together with representative chemistry of trace gases in the clean troposphere. The extent of uncertain alternative pathways and efficiencies for 010 and I2O2 photolyses are varied over a range of possible values to establish the sensitivity of the depletion events to these variables. The study shows that significant enhancements of the polar ozone depletion are expected when small amounts of iodine-containing compounds such as CH2I2, IBr, or ICl are present in a polar air mass containing representative Br-2-BrCl-trace gas mixtures. The synergistic effect of the iodine compounds results from additional halogen-atom formation from IO-IO, IO-BrO, and IO-CIO reactions. Measurements of 10 and precursor iodine-containing compounds are encouraged for future polar spring studies, as well as currently acknowledged important trace species (O-3, CH2O, BrO, Br-2, and BrCl). (C) 2004 Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Calvert, JG (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. EM calvertj@ornl.gov; lindbergse@ornl.gov NR 71 TC 43 Z9 44 U1 3 U2 13 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 2004 VL 38 IS 30 BP 5087 EP 5104 DI 10.1016/j.atmosenv.2004.05.049 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 853CR UT WOS:000223804400010 ER PT J AU Calvert, JG Lindberg, SE AF Calvert, JG Lindberg, SE TI The potential influence of iodine-containing compounds on the chemistry of the troposphere in the polar spring. II. Mercury depletion SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE AMDE; RGM; computer simulations; polar Hg chemistry; halogen chemistry ID OZONE DEPLETION; GASEOUS MERCURY; ATMOSPHERIC IMPLICATIONS; MOLECULAR HALOGENS; OXIDATION; SUNRISE; CHLORINE; KINETICS; BROMINE; EVENTS AB Simulations of atomic mercury depletion episodes in the polar spring are now based largely on Br-2 and Br-atom initiated chemistry. Chlorine is believed to contribute little to the observed depletion. The role, if any, that the presence of iodine compounds play in Hg-atom depletion is unknown at present. The theoretically predicted instability of the HgI species suggests that I-atom reactions with mercury may be an unimportant loss process. However, iodine atoms react rapidly with ozone to develop 10 radicals that interact with BrO radicals to enhance Br- and I-atom concentrations, so an indirect influence of iodine compounds on Hg removal might be expected. Computer simulations are described in this study that test this hypothesis using the homogeneous portion of the chemistry of the mercury depletion in the troposphere. Conditions are chosen equivalent to the 1300-1400h on a clear day (17 March) at the location of Barrow, Alaska (Atmos. Environ. 37 (2003) 4467). Small amounts of reactive trace gases, representative of the Arctic spring, are present initially with typical background levels of Hg (0.24 ppt) and 50 ppb Of O-3. The simulations show that gaseous atomic mercury depletion in typical Br2 and BrCl mixtures can be enhanced significantly by the presence of small amounts of iodine-containing compounds (I-2, CH2I2, CH2IBr, CH2ICl, IBr, and ICl). The major initial product of the possible mercury reactions is HgBr. The subsequent coupling reactions of this species with Br, BrO, Cl, ClO, 1, 10, and OH radicals are expected to lead to a variety of reactive gaseous mercury-containing products. (C) 2004 Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Calvert, JG (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM calvertj@ornl.gov; lindbergse@ornl.gov NR 22 TC 46 Z9 47 U1 1 U2 14 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 2004 VL 38 IS 30 BP 5105 EP 5116 DI 10.1016/j.atmosenv.2004.05.050 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 853CR UT WOS:000223804400011 ER PT J AU Sandiford, M Wallace, M Coblentz, D AF Sandiford, M Wallace, M Coblentz, D TI Origin of the in situ stress field in south-eastern Australia SO BASIN RESEARCH LA English DT Article ID PLATE MOTIONS; PACIFIC BOUNDARY; NEW-ZEALAND; CONSTRAINTS; VICTORIA; TECTONICS; SCALE; SEISMICITY; PATTERNS; FORCES AB The in situ stress field of south-eastern Australia inferred from earthquake focal mechanisms and bore-hole breakouts is unusual in that it is characterised by large obliquity between the maximum horizontal compressive stress orientation (S-Hmax) and the absolute plate motion azimuth. The evolution of the neotectonic strain field deduced from historical seismicity and both onshore and offshore faulting records is used to address the origin of this unusual stress field. Strain rates derived from estimates of the seismic moment release rate (up to similar to10(-16) s(-1)) are compatible with Quaternary fault-slip rates. The record of more or less continuous tectonic activity extends back to the terminal Miocene or early Pliocene (10-5 Ma). Terminal Miocene tectonic activity was characterised by regional-scale tilting and local uplift and erosion, now best preserved by unconformities in offshore basins. Plate-scale stress modelling suggests the in situ stress field reflects increased coupling of the Australian and Pacific Plate boundary in the late Miocene, associated with the formation of the Southern Alps in New Zealand. C1 Univ Melbourne, Sch Earth Sci, Parkville, Vic 3010, Australia. Los Alamos Natl Lab, Los Alamos, NM USA. RP Univ Melbourne, Sch Earth Sci, Parkville, Vic 3010, Australia. EM mikes@unimelb.edu.au RI Sandiford, Mike/B-5020-2016 OI Sandiford, Mike/0000-0002-9757-745X NR 46 TC 82 Z9 83 U1 1 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0950-091X EI 1365-2117 J9 BASIN RES JI Basin Res. PD SEP PY 2004 VL 16 IS 3 BP 325 EP 338 DI 10.1111/j.1365-2117.2004.00235.x PG 14 WC Geosciences, Multidisciplinary SC Geology GA 848UY UT WOS:000223494800002 ER PT J AU Yan, FN Chen, LH Tang, QL Rong, W AF Yan, FN Chen, LH Tang, QL Rong, W TI Synthesis and characterization of a photocleavable cross-linker and its application on tunable surface modification and protein photodelivery SO BIOCONJUGATE CHEMISTRY LA English DT Article ID NITROBENZYL PHOTOLABILE LINKER; ATOMIC-FORCE MICROSCOPY; DIP-PEN NANOLITHOGRAPHY; ORGANIC-SYNTHESIS; IMMOBILIZATION; CHEMISTRY; REAGENTS AB A heterobifunctional photocleavable cross-linker based on an o-nitrobenzyl ester moiety was synthesized. The cross-linker has N-hydroxysuccinimidyl and disulfide groups attached at each end and thus can anchor a protein to a gold-coated substrate surface. Steady-state spectroscopic studies suggest that the cross-linker undergoes a clean C-O fragmentation upon irradiation with a quantum yield of 0.1. Consequently, immobilized proteins (such as avidin or antibodies) on a substrate surface can be released efficiently (>95%) under UV irradiation (lambda > 300 nm) without degrading the protein functionality. We also demonstrated protein delivery via bioconjugation of protein molecules to a gold-coated atomic-force microscope (AFM) tip. When the proteins are photoreleased from the AFM tip, they are delivered to the substrate surface as protein clusters of uniform size. This has been confirmed using both AFM and fluorescence microscopy. The application of bioconjugation in this study opens a new avenue for tunable surface modification and controllable protein delivery in studies of biological systems on the nanometer scale. C1 Argonne Natl Lab, Argonne, IL 60439 USA. IIT, Chicago, IL 60616 USA. RP Chen, LH (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. EM lhchen@anl.gov; wangr@iit.edu NR 28 TC 29 Z9 29 U1 2 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1043-1802 J9 BIOCONJUGATE CHEM JI Bioconjugate Chem. PD SEP-OCT PY 2004 VL 15 IS 5 BP 1030 EP 1036 DI 10.1021/bc049901d PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Multidisciplinary; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA 854WL UT WOS:000223934300011 PM 15366956 ER PT J AU Swanston, C Homann, PS Caldwell, BA Myrold, DD Ganio, L Sollins, P AF Swanston, C Homann, PS Caldwell, BA Myrold, DD Ganio, L Sollins, P TI Long-term effects of elevated nitrogen on forest soil organic matter stability SO BIOGEOCHEMISTRY LA English DT Article DE C sequestration; density fractionation; incubation; nitrogen; soil organic matter; stabilization ID COASTAL DOUGLAS-FIR; OLD-GROWTH FOREST; MICROBIAL BIOMASS; DENSITY FRACTIONS; LIGHT-FRACTION; PHANEROCHAETE-CHRYSOSPORIUM; LITTER DECOMPOSITION; NMR-SPECTROSCOPY; BRITISH-COLUMBIA; NEEDLE LITTER AB Nitrogen addition may alter the decomposition rate for different organic-matter pools in contrasting ways. Using a paired-plot design, we sought to determine the effects of long-term elevated N on the stability of five organic-matter pools: organic horizons (Oe + a), whole mineral soil (WS), mineral soil fractions including the light fraction (LF), heavy fraction (HF), and a physically recombined fraction (RF). These substrates were incubated for 300 days, and respiration, mineralized N, and active microbial biomass were measured. Samples with elevated N gave 15% lower cumulative respiration for all five substrates. Over the 300-day incubation, the Oe + a gave twice the cumulative respiration (g C kg(-1) initial C) as the LF, which gave slightly higher respiration than the HE Respiration was 35% higher for the WS than for the RE Mineralized N was similar between N treatments and between the LF and HE Net N mineralized by the LF over the course of the 300-day incubation decreased with higher C:N ratio, due presumably to N immobilization to meet metabolic demands. The pattern was opposite for HF, however, which could be explained by a release of N in excess of metabolic demands due to recalcitrance of the HF organic matter. Mineralized N increased with respiration for the HF but showed no pattern, or perhaps even decreased, for the LF WS and RF showed decreasing active microbial biomass near the end of the incubation, which corresponded with decreasing respiration and increasing nitrate. Our results show that long-term elevated N stabilized organic matter in whole soil and soil fractions. C1 Western Washington Univ, Huxley Coll Environm Studies, Dept Environm Sci, Bellingham, WA 98225 USA. Oregon State Univ, Dept Crop & Soil Sci, Corvallis, OR 97331 USA. Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. RP Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, POB 808 L-397, Livermore, CA 94550 USA. EM swanston@orst.edu RI Myrold, David/E-1813-2011 OI Myrold, David/0000-0001-6418-226X NR 66 TC 37 Z9 39 U1 1 U2 30 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0168-2563 EI 1573-515X J9 BIOGEOCHEMISTRY JI Biogeochemistry PD SEP PY 2004 VL 70 IS 2 BP 227 EP 250 DI 10.1023/B:BIOG.0000049341.37579.86 PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 890NU UT WOS:000226518900002 ER PT J AU Mulholland, PJ AF Mulholland, PJ TI The importance of in-stream uptake for regulating stream concentrations and outputs of N and P from a forested watershed: evidence from long-term chemistry records for Walker Branch Watershed SO BIOGEOCHEMISTRY LA English DT Article DE end-member mixing analysis; nitrate; nitrogen; nutrient cycling; phosphorus; stream; watershed ID N-15 TRACER ADDITION; UNITED-STATES; NITROGEN EXPORT; NEW-YORK; CATSKILL MOUNTAINS; HEADWATER STREAMS; NORTHEASTERN USA; TEMPERATE FOREST; NEW-HAMPSHIRE; NITRATE AB Long-term, weekly measurements of streamwater nitrogen and phosphorus concentrations in the West Fork of Walker Branch, a 1st order forested stream in eastern Tennessee, were used to assess the importance of in-stream processes for controlling stream concentrations and watershed exports. Over the period from 1991 to 2002, there was a slight declining trend in watershed export of dissolved inorganic N via streamflow, despite relatively high and constant wet N deposition rates (5 kg/ha/y). The watershed retains > 90% of N deposition inputs. Concentrations of NO3- and soluble reactive phosphorus (SRP) showed distinct seasonal patterns with autumn and early spring minima and summer maxima. An end-member mixing analysis indicated that these seasonal concentration patterns were largely a result of seasonal variations in in-stream uptake processes, with net uptake of NO3- and SRP having the greatest impact on streamwater concentrations in November (reductions of 29 mug N/l and 2.5 mug P/l, respectively). This was likely a result of high rates of uptake by microbes colonizing new inputs of leaf detritus. For NO3- there was a secondary peak in net uptake in March and April (about 9 mug N/l) resulting from increased uptake by stream algae and bryophytes. Summer was a period of net release of NO3- to streamwater (peaking at 9 mug N/l in July) and minimal net effects on SRP concentrations. On average, in-stream processes resulted in removal of about 20% of the NO3- and 30% of the SRP entering the stream from the catchment annually. This study, as well as other recent work, suggests that in-stream processes are important buffers on stream nutrient concentrations and exports reducing the effects of changes in inputs and retention in terrestrial portions of watersheds. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Mulholland, PJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM mulhollandpj@ornl.gov RI Mulholland, Patrick/C-3142-2012 NR 58 TC 63 Z9 66 U1 0 U2 33 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD SEP PY 2004 VL 70 IS 3 BP 403 EP 426 DI 10.1007/s10533-004-0364-y PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 890NW UT WOS:000226519100006 ER PT J AU Choi, CH Sabourin, NA Reagor, DW Redondo, A Usheva, A AF Choi, CH Sabourin, NA Reagor, DW Redondo, A Usheva, A TI Capacitance-derived dielectric constants demonstrate differential preinitiation complexes in TBP-independent and TBP-dependent transcription SO BIOPHYSICAL CHEMISTRY LA English DT Article DE capacitance measurement of protein interactions; dielectric constant; specific protein-DNA interaction; transcription initiation; TBP-independent transcription; TBP-dependent transcription ID RNA-POLYMERASE-II; BASAL TRANSCRIPTION; TATA-ELEMENT; DNA; YY1; INITIATOR; BINDING; TFIIB AB The electronic properties of proteins and DNA may change dramatically upon complex formation, yet there are not many experimental methods which can be used to measure these properties. It has been previously shown that measuring the capacitance of a solution containing interacting DNA and protein species can yield information about changing dipole moments. The measured dielectric constant relates directly to the dipole moment of the complexes in solution. Here, we apply this method to partial transcription initiation complexes in order to investigate the changing electronic properties in the transcriptional preinitiation complex. These experiments are the first reported observations relating to the overall dipole moment and its changes in preinitiation complex formation. Comparing results from TBP-independent and TBP-dependent transcriptional systems shows a divergence in the electronic properties of built-up transcription complexes, suggesting that they initiate transcription by significantly different electronic and structural pathways. (C) 2004 Elsevier B.V. All rights reserved. C1 Beth Israel Deaconess Med Ctr, Dept Med Endocrinol, Boston, MA 02215 USA. Harvard Univ, Sch Med, Boston, MA 02215 USA. Los Alamos Natl Lab, Superconductiv Technol Ctr, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Theoret Chem & Mol Phys Div, Los Alamos, NM 87545 USA. RP Usheva, A (reprint author), Beth Israel Deaconess Med Ctr, Dept Med Endocrinol, 99 Brookline Ave, Boston, MA 02215 USA. EM ausheva@bidmc.harvard.edu NR 9 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD SEP 1 PY 2004 VL 111 IS 1 BP 9 EP 14 DI 10.1016/j.bpc.2004.03.007 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA 855BM UT WOS:000223947900002 PM 15450370 ER PT J AU Bolan, NS Wong, L Adriano, DC AF Bolan, NS Wong, L Adriano, DC TI Nutrient removal from farm effluents SO BIORESOURCE TECHNOLOGY LA English DT Article DE bark; BOD; COD; farm effluent; nutrients; suspended solid; pond treatment; zeolite ID WASTE-WATER; NEW-ZEALAND; DENITRIFICATION; AMMONIUM; ZEOLITE; NITROGEN; COMPOST; NITRATE; MEDIA; BARK AB The objectives of the study were: (i) to examine the efficiency of nutrient removal during the treatment of dairy farm effluent in a two-pond system, and (ii) to produce an inexpensive but effective nutrient trap which could be recycled as a nutrient source or soil mulch. The concentration of chemical oxygen demand (COD), biological oxygen demand (BOD), nitrogen (N), phosphorus (P) and potassium (K) in a two-pond system used to treat dairy farm effluent was monitored over a period of 7 months. The retention of nutrients by two porous materials was examined both in the laboratory batch (zeolite and bark) and pilot-scale field (bark) experiments. The results indicated that biological treatment of farm effluents using the two-pond system was not effective in the removal of nutrients, which are likely to become pollutant when discharged to waterways. Both the bark and zeolite materials were effective in the removal of N, P and K from effluent. These materials can be placed in the second (i.e., aerobic) pond to treat effluents, which can then be discharged to streams with minimum impact on water quality. The nutrient-enriched porous materials can be recycled as a source of nutrients and soil conditioner. (C) 2004 Elsevier Ltd. All rights reserved. C1 Massey Univ, Soil & Earth Sci Grp, Inst Nat Resources, Palmerston North, New Zealand. New Zealand Bark Resources Ltd, Wellington, New Zealand. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Bolan, NS (reprint author), Massey Univ, Soil & Earth Sci Grp, Inst Nat Resources, Palmerston North, New Zealand. EM n.s.bolan@massey.ac.nz RI Bolan, Nanthi/E-8535-2011 OI Bolan, Nanthi/0000-0003-2056-1692 NR 37 TC 36 Z9 36 U1 1 U2 16 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0960-8524 J9 BIORESOURCE TECHNOL JI Bioresour. Technol. PD SEP PY 2004 VL 94 IS 3 BP 251 EP 260 DI 10.1016/j.biotech.2004.01.012 PG 10 WC Agricultural Engineering; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA 831LP UT WOS:000222196200004 PM 15182831 ER PT J AU Lee, BD Apel, WA Walton, MR AF Lee, BD Apel, WA Walton, MR TI Screening of cyanobacterial species for calcification SO BIOTECHNOLOGY PROGRESS LA English DT Article ID STEADY-STATE PHOTOSYNTHESIS; PCC 7942; HCO3; CO2; GREENHOUSE; CARBON; MICROALGAE; MECHANISM; TRANSPORT; INDUCTION AB Species of cyanobacteria in the genera Synechococcus and Synechocystis are known to be the catalysts of a phenomenon called "whitings", which is the formation and precipitation of fine-grained CaCO3 particles. Whitings occur when the cyanobacteria fix atmospheric CO2 through the formation of CaCO3 on their cell surfaces, which leads to precipitation to the ocean floor and subsequent entombment in mud. Whitings represent one potential mechanism for CO2 sequestration. Research was performed to determine the ability of various strains of Synechocystis and Synechococcus to calcify when grown in microcosms amended with 2.5 mM HCO3- and 3.4 mM Ca2+. Results indicated that although all strains tested have the ability to calcify, only two Synechococcus species, strains PCC 8806 and PCC 8807, were able to calcify to the extent that a CaCO3 precipitate was formed. Enumeration of the cyanobacterial cultures during testing indicated that cell density did not appear to have a direct effect on calcification. Factors that had the greatest effect on calcification were CO2 removal and subsequent generation of alkaline pH. Whereas cell density was similar for all strains tested, differences in maximum pH were demonstrated. As CO2 was removed, growth medium pH increased and soluble Ca2+ was removed from solution. The largest increases in growth medium pH occurred when CO2 levels dropped below 400 ppmv. Research presented demonstrates that, under the conditions tested, many species of cyanobacteria in the genera Synechocystis and Synechococcus are able to calcify but only two species of Synechococcus were able to calcify to an extent that led to the precipitation of calcium carbonate. C1 Idaho Natl Engn & Environm Lab, Dept Biotechnol, Idaho Falls, ID USA. RP Lee, BD (reprint author), Idaho Natl Engn & Environm Lab, Dept Biotechnol, POB 1625, Idaho Falls, ID USA. OI Walton, Michelle/0000-0003-4169-4443 NR 30 TC 17 Z9 18 U1 3 U2 17 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 2004 VL 20 IS 5 BP 1345 EP 1351 DI 10.1021/bp0343561 PG 7 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 860XP UT WOS:000224377700006 PM 15458316 ER PT J AU Gubernak, M Liu, XD Kaczmarski, K Guiochon, G AF Gubernak, M Liu, XD Kaczmarski, K Guiochon, G TI Mass transfer kinetics in the chromatography of insulin variants under nonlinear conditions SO BIOTECHNOLOGY PROGRESS LA English DT Article ID MULTICOMPONENT ADSORPTION; BAND PROFILES; PHASE; PRESSURE; COLUMNS; MODEL; SEPARATION; SIMULATION; DIFFUSION; RETENTION AB Experimental data regarding the thermodynamics and kinetics of adsorption of lispro, an insulin variant, onto a YMC ODS-A column, from an aqueous solution of acetonitrile (31%) and TFA are reinterpreted, using a more complex model of the mass transfer kinetics. The adsorption behavior follows the Toth isotherm model, suggesting either a strongly heterogeneous surface or, rather, that when insulin molecules adsorb they contact the surface along different areas of the molecule. The lumped pore diffusion (POR) model of chromatography accounts well for the band profiles. The internal mass transfer resistances are higher than expected, which suggests that intraparticle diffusion is slower. Furthermore, the pore diffusion coefficient increases with decreasing sample size. That surface diffusion accounts for the mass transfer kinetics inside particles explains these results. Assuming that the gradient of the surface concentration is the driving force of surface diffusion, it is possible to account very well for the band profiles of samples of widely different sizes, using a single value of the surface diffusivity. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Rzeszow Univ Technol, Fac Chem, PL-35959 Rzeszow, Poland. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM guiochon@utk.edu NR 28 TC 10 Z9 10 U1 0 U2 2 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 2004 VL 20 IS 5 BP 1496 EP 1506 DI 10.1021/bp0300691 PG 11 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 860XP UT WOS:000224377700025 PM 15458335 ER PT J AU Harris, MN Ozpolat, B Abdi, F Gu, S Legler, A Mawuenyega, KG Tirado-Gomez, M Lopez-Berestein, G Chen, X AF Harris, MN Ozpolat, B Abdi, F Gu, S Legler, A Mawuenyega, KG Tirado-Gomez, M Lopez-Berestein, G Chen, X TI Comparative proteomic analysis of all-trans-retinoic acid treatment reveals systematic posttranscriptional control mechanisms in acute promyelocytic leukemia SO BLOOD LA English DT Article ID PROTEIN-KINASE-C; INITIATION-FACTOR 4G; D1 MESSENGER-RNA; PML-RAR-ALPHA; CHRONIC LYMPHOCYTIC-LEUKEMIA; CELL-CYCLE ARREST; TRANSLATION INITIATION; IN-VIVO; INDUCED DIFFERENTIATION; HISTONE DEACETYLASE AB All-trans-retinoic acid (ATRA) induces growth inhibition, differentiation, and apoptosis in cancer cells, including acute promyelocytic leukemia (APL). In APL, expression of promyelocytic leukemia protein retinoic acid receptor-alpha (PML-RARalpha) fusion protein, owing to the t(15; 17) reciprocal translocation, leads to a block in the promyelocytic stage of differentiation. Here, we studied molecular mechanisms involved in ATRA-induced growth inhibition and myeloid cell differentiation in APL. By employing comprehensive high-throughput proteomic methods of 2-dimensional (2-D) gel electrophoresis and amino acid-coded' mass tagging coupled with electrospray ionization (ESI) mass spectrometry, we systematically identified a total of 59 differentially expressed proteins that were consistently modulated in response to ATRA treatment. The data revealed significant downregulation of eukaryotic initiation and elongation factors, initiation factor 2 (IF2), eukaryotic initiation factor 4Al (elF4Al), elF4G, elF5, elF6, eukaryotic elongation factor 1A-1 (eEF1A-1), EF-1-delta, eEF1gamma, 14-3-3epsilon, and 14-3-3zeta/delta (P < .05). The translational inhibitor DAP5/p97/NAT1 (death-associated protein 5) and PML isoform-1 were found to be up-regulated (P < .05). Additionally, the down-regulation of heterogeneous nuclear ribonucleoproteins (hnRNPs) C1/C2, UP2, K, and F; small nuclear RNPs (snRNPs) D3 and E; nucleoprotein tumor potentiating region (TPR); and protein phosphatase 2A (PP2A) were found (P < .05); these were found to function in pre-mRNA processing, splicing, and export events. Importantly, these proteomic findings were validated by Western blot analysis. Our data in comparison with previous cDNA microarray studies and our reverse transcription-polymerase chain reaction (RT-PCR) experiments demonstrate that broad networks of posttranscriptional suppressive pathways are activated during ATRA-induced growth inhibition processes in APL. (C) 2004 by The American Society of Hematology. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Texas, MD Anderson Canc Ctr, Dept Bioimmunotherapy, Sect Immunobiol & Drug Carriers, Houston, TX 77030 USA. Appl Biosyst Inc, Framingham, MA USA. RP Chen, X (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663,BN-2,MS M888, Los Alamos, NM 87545 USA. EM glopez@mdanderson.org; chen_xian@lanl.gov RI Ozpolat, Berkant/Q-6981-2016 NR 76 TC 79 Z9 88 U1 0 U2 5 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 2004 VL 104 IS 5 BP 1314 EP 1323 DI 10.1182/blood-2004-01-0046 PG 10 WC Hematology SC Hematology GA 849MX UT WOS:000223544000022 PM 15142884 ER PT J AU Bardayan, DW AF Bardayan, DW TI Studies in nuclear astrophysics using radioactive beams at the HRIBF SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL ID CROSS-SECTION; FACILITY AB The availability of radioactive beams has produced great opportunities for advances in our understanding of the nucleosynthesis occurring in stellar explosions such as novae, X-ray bursts, and supernovae. At the HRIBF, we have used proton-rich beams such as F-17,F-18 and neutron-rich beams such as Ge-82 to study astrophysically-important reaction rates. Large-area detector arrays and kinematically-complete measurements have been used to overcome the challenges of low beam currents and beam impurities. The experimental methods and results are discussed. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Bardayan, DW (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 745 EP 748 DI 10.1590/S0103-97332004000500010 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300010 ER PT J AU Back, BB Baker, MD Ballintijn, M Barton, DS Becker, B Betts, RR Bickley, AA Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E Gburek, T George, N Gulbrandsen, K Gushue, S Halliwell, C Hamblen, J Harrington, AS Heintzelman, GA Henderson, C Hofman, DJ Hollis, RS Holynski, R Holzman, B Iordanova, A Johnson, E Kane, JL Katzy, J Khan, N Kucewicz, W Kulinich, P Kuo, CM Lee, JW Lin, WT Manly, S McLeod, D Mignerey, AC Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sagerer, J Sarin, P Sawicki, P Sedykh, I Skulski, W Smith, CE Steinberg, P Stephans, GSF Sukhanov, A Tang, JL Tonjes, MB Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Veres, GI Wolfs, FLH Wosiek, B Wozniak, K Wuosmaa, AH Wyslouch, B Zhang, J AF Back, BB Baker, MD Ballintijn, M Barton, DS Becker, B Betts, RR Bickley, AA Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E Gburek, T George, N Gulbrandsen, K Gushue, S Halliwell, C Hamblen, J Harrington, AS Heintzelman, GA Henderson, C Hofman, DJ Hollis, RS Holynski, R Holzman, B Iordanova, A Johnson, E Kane, JL Katzy, J Khan, N Kucewicz, W Kulinich, P Kuo, CM Lee, JW Lin, WT Manly, S McLeod, D Mignerey, AC Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sagerer, J Sarin, P Sawicki, P Sedykh, I Skulski, W Smith, CE Steinberg, P Stephans, GSF Sukhanov, A Tang, JL Tonjes, MB Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Veres, GI Wolfs, FLH Wosiek, B Wozniak, K Wuosmaa, AH Wyslouch, B Zhang, J TI Recent results from PHOBOS at RHIC SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL AB PHOBOS is one of the four heavy ion experiments currently running at the Relativistic Heavy Ion Collider (RHIC). In this paper we will present some of the current results from PHOBOS: the study of charged multiplicity roots(NN) distribution as function of pseudorapidity and centrality at roots(NN) = 19.6, 130 and 200 GeV a discussion of multiplicity scaling, and a measurement of transverse momentum spectra (p(T)) of charged hadrons produced in d+Au and Au+Au interactions at roots(NN) = 200 GeV The dependence of the Au+Au yields as function of centrality is found to be independent of p(T). A strong suppression in the Au+Au hadron spectra relative to p (p) over bar at high P-T is observed. The spectral shape for d+Au collisions is significantly different from the observations in Au+Au, the yield suppression is not observed in d+Au. 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 Phys Nucl, 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, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Decowski, Patrick/A-4341-2011; Mignerey, Alice/D-6623-2011 NR 8 TC 1 Z9 1 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0103-9733 EI 1678-4448 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 829 EP 832 DI 10.1590/S0103-97332004000500032 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300032 ER PT J AU Marti, GV Pacheco, AJ Testoni, JE Abriola, D Capurro, OA DiGregorio, DE Niello, JOF Macchiavelli, AO Clark, RM Fallon, P Goergen, A Ward, D Wu, CY Hayes, A Cline, D Teng, R AF Marti, GV Pacheco, AJ Testoni, JE Abriola, D Capurro, OA DiGregorio, DE Niello, JOF Macchiavelli, AO Clark, RM Fallon, P Goergen, A Ward, D Wu, CY Hayes, A Cline, D Teng, R TI Measurement of inelastic-scattering cross sections in the O-16+(28) Si system to discriminate regular and chaotic regimes SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL ID NUCLEAR-SCATTERING; GAMMASPHERE AB A new experiment to measure differential cross sections as a function of the bombarding energy and scattering angle for the O-16 + (28) Si system in order to discriminate regular and chaotic regimes, was performed using the particle spectrometer CHICO combined with the multidetector array Gammasphere. In this contribution we summarize the characteristics of the method developed to analyze the experimental data and present the preliminary results. C1 Comis Nacl Energia Atom, Dept Fis, Lab TANDAR, RA-1429 Buenos Aires, DF, Argentina. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Rochester, Dept Phys & Astron, Nucl Struct Res Lab, Rochester, NY 14627 USA. RP Marti, GV (reprint author), Comis Nacl Energia Atom, Dept Fis, Lab TANDAR, Av Libertador 8250, RA-1429 Buenos Aires, DF, Argentina. OI Gorgen, Andreas/0000-0003-1916-9941 NR 8 TC 1 Z9 1 U1 0 U2 2 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 885 EP 888 DI 10.1590/S0103-97332004000500048 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300048 ER PT J AU Battistoni, G Cavinato, M Cerutti, F Clivio, A Fabrici, E Gadioli, E Erba, EG Garzelli, MV Mairani, A Empl, A Pinsky, LS Ballarini, F Ottolenghi, A Fasso, A Ferrari, A Ranft, J Sala, PR AF Battistoni, G Cavinato, M Cerutti, F Clivio, A Fabrici, E Gadioli, E Erba, EG Garzelli, MV Mairani, A Empl, A Pinsky, LS Ballarini, F Ottolenghi, A Fasso, A Ferrari, A Ranft, J Sala, PR TI Heavy ion interactions from coulomb barrier to few GeV/n: Boltzmann master equation theory and FLUKA code performances SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL ID MONTE-CARLO CALCULATIONS; MEV NUCLEON; COLLISIONS; EMISSION; FUSION; O-16 AB Results which have been recently obtained with the Boltzmann master equation and the FLUKA code in the analysis of heavy ion interactions at relative energies ranging from Coulomb barrier up to a few GeV/n are discussed. C1 Univ Milan, I-20122 Milan, Italy. Univ Houston, Houston, TX 77004 USA. Univ Pavia, I-27100 Pavia, Italy. SLAC, Stanford, CA USA. CERN, CH-1211 Geneva 23, Switzerland. Univ Siegen, D-5900 Siegen, Germany. ETH, Zurich, Switzerland. RP Battistoni, G (reprint author), Univ Milan, I-20122 Milan, Italy. RI Garzelli, Maria Vittoria/G-8055-2011; sala, paola/E-2868-2013; Ballarini, Francesca/J-7293-2013; Battistoni, Giuseppe/B-5264-2012 OI sala, paola/0000-0001-9859-5564; Ballarini, Francesca/0000-0002-6629-3382; Battistoni, Giuseppe/0000-0003-3484-1724 NR 16 TC 6 Z9 6 U1 1 U2 2 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 897 EP 900 DI 10.1590/S0103-97332004000500051 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300051 ER PT J AU Smith, ES AF Smith, ES TI JLab: Probing hadronic physics with electrons and photons SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL ID BARYONS AB Precision measurements of the structure of nucleons and nuclei in the regime of strong interaction QCD are now possible with the availability of high current polarized electron beams, polarized targets, and recoil polarimeters, in conjunction with modern spectrometers and detector instrumentation. The physics at JLab will be highlighted using two recent measurements of general interest. The ratio of the proton electric to magnetic form factors indicates the importance of the role of angular momentum in the structure of the nucleon. The existence of 5-quark configurations in the ground state wavefunctions of hadrons is confirmed by a narrow peak attributed to an exotic baryon with strangeness S=+1. These and other examples will be used to illustrate the capabilities and focus of the experimental program at JLab. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Smith, ES (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 910 EP 913 DI 10.1590/S0103-97332004000500055 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300055 ER PT J AU Mastinu, PF Abbondanno, U Aerts, G Alvarez, H Andriamonje, S Angelopoulos, A Assimakopoulos, P Bacri, CO Badurek, G Baumann, P Becvar, F Beer, H Benlliure, J Berthier, B Berthomieux, E Boffi, S Borcea, C Boscolo-Marchi, E Bustreo, N Calvino, P Cano-Ott, D Capote, R Carlson, P Cennini, P Chepel, V Chiaveri, E Coceva, C Colonna, N Cortes, G Cortina, D Couture, A Cox, J Dababneh, S Dahlfors, M David, S Dolfini, R Domingo-Pardo, C Duran, I Eleftheriadis, C Embid-Segura, M Ferrant, L Ferrari, A Ferreira-Lourenco, L Ferreira-Marques, R Frais-Koelbl, H Furman, WI Giomataris, Y Goncalves, IF Gonzalez-Romero, E Goverdovski, A Gramegna, F Griesmayer, E Gunsing, F Haight, R Heil, M Herrera-Martinez, A Ioannides, KG Janeva, N Jericha, E Kappeler, F Kadi, Y Karamanis, D Kelic, A Ketlerov, V Kitis, G Koehler, PE Konovalov, V Kossionides, E Lacoste, V Leeb, H Lindote, A Lopes, MI Loriggiola, M Lozano, M Lukic, S Markov, S Marigo, S Marrone, S Martinez-Val, J Mengoni, A Milazzo, PM Minguez, E Molina-Coballes, A Moreau, C Neves, F Oberhummer, H O'Brien, S Pancin, J Papaevangelou, T Paradela, C Pavlik, A Pavlopoulos, P Perez-Parra, A Perlado, JM Perrot, L Peskov, V Plag, R Plompen, A Plukis, A Poch, A Policarpo, A Pretel, C Quesada, JM Radici, M Raman, S Rapp, W Rauscher, T Reifarth, R Rejmund, F Rosetti, M Rubbia, C Rudolf, G Rullhusen, P Salgado, J Savvidis, E Soares, JC Stephan, C Tagliente, G Tain, JL Tapia, C Tassan-Goth, L Tavora, LMN Terlizzi, R Terrani, M Tsangas, N Vannini, G Vaz, P Ventura, A Villamarin-Fernandez, D Vincente-Vincente, M Vlachoudis, V Vlastou, R Voss, F Wendler, H Wiescher, M Wisshak, K Zanini, L AF Mastinu, PF Abbondanno, U Aerts, G Alvarez, H Andriamonje, S Angelopoulos, A Assimakopoulos, P Bacri, CO Badurek, G Baumann, P Becvar, F Beer, H Benlliure, J Berthier, B Berthomieux, E Boffi, S Borcea, C Boscolo-Marchi, E Bustreo, N Calvino, P Cano-Ott, D Capote, R Carlson, P Cennini, P Chepel, V Chiaveri, E Coceva, C Colonna, N Cortes, G Cortina, D Couture, A Cox, J Dababneh, S Dahlfors, M David, S Dolfini, R Domingo-Pardo, C Duran, I Eleftheriadis, C Embid-Segura, M Ferrant, L Ferrari, A Ferreira-Lourenco, L Ferreira-Marques, R Frais-Koelbl, H Furman, WI Giomataris, Y Goncalves, IF Gonzalez-Romero, E Goverdovski, A Gramegna, F Griesmayer, E Gunsing, F Haight, R Heil, M Herrera-Martinez, A Ioannides, KG Janeva, N Jericha, E Kappeler, F Kadi, Y Karamanis, D Kelic, A Ketlerov, V Kitis, G Koehler, PE Konovalov, V Kossionides, E Lacoste, V Leeb, H Lindote, A Lopes, MI Loriggiola, M Lozano, M Lukic, S Markov, S Marigo, S Marrone, S Martinez-Val, J Mengoni, A Milazzo, PM Minguez, E Molina-Coballes, A Moreau, C Neves, F Oberhummer, H O'Brien, S Pancin, J Papaevangelou, T Paradela, C Pavlik, A Pavlopoulos, P Perez-Parra, A Perlado, JM Perrot, L Peskov, V Plag, R Plompen, A Plukis, A Poch, A Policarpo, A Pretel, C Quesada, JM Radici, M Raman, S Rapp, W Rauscher, T Reifarth, R Rejmund, F Rosetti, M Rubbia, C Rudolf, G Rullhusen, P Salgado, J Savvidis, E Soares, JC Stephan, C Tagliente, G Tain, JL Tapia, C Tassan-Goth, L Tavora, LMN Terlizzi, R Terrani, M Tsangas, N Vannini, G Vaz, P Ventura, A Villamarin-Fernandez, D Vincente-Vincente, M Vlachoudis, V Vlastou, R Voss, F Wendler, H Wiescher, M Wisshak, K Zanini, L CA nTOF Collaboration TI A low-mass neutron flux monitor for the n_TOF facility at CERN SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL AB A small-mass system has been developed for monitoring the flux of neutrons with energy up to 1 MeV at the new time-of-flight facility at CERN, n_TOF. The monitor is based on a thin Mylar foil with a Li-6 deposit, placed in the neutron beam, and an array of Silicon detectors, placed outside the beam, for detecting the products of the Li-6(n, alpha)H-3 reaction. The small amount of material on the beam ensures a minimal perturbation of the flux and minimizes the background related to scattered neutrons. Moreover, a further reduction of the gamma-ray background has been obtained by constructing the scattering chamber hosting the device in carbon fibre. A detailed description of the flux monitor is here presented, together with the characteristics of the device, in terms of efficiency, resolution and induced background. The use of the monitor in the measurement of neutron capture cross-sections at n_TOF is discussed. C1 Ist Nazl Fis Nucl, Sez Trieste, Trieste, Italy. CEA Saclay, DSM, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. Univ Santiago de Compostela, Santiago De Compostela, Spain. Univ Athens, AstroParticle Consortium, GR-10679 Athens, Greece. Univ Ioannina, AstroParticle Consortium, GR-45110 Ioannina, Greece. IPN, CNRS, IN2P3, Orsay, France. Vienna Tech Univ, Atominst Osterreich Univ, A-1040 Vienna, Austria. CNRS, IN2P3, IreS, Strasbourg, France. Charles Univ, Prague, Czech Republic. Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany. Univ Pavia, I-27100 Pavia, Italy. CERN, Geneva, Switzerland. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Univ Politecn Catalunya, Barcelona, Spain. Ctr Invest Energet Medioambientales & Tecnol, Madrid, Spain. Univ Sevilla, Seville, Spain. Kungliga Tekn Hogskolan, Dept Phys, Stockholm, Sweden. Lab Instrumentacao & Phis Expt Particulas, Coimbra, Portugal. ENEA, Bologna, Italy. Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy. Univ Notre Dame, Notre Dame, IN 46556 USA. Forschungszentrum Karlsruhe GmbH, Karlsruhe, Germany. Univ Valencia, CSIC, Inst Fis Corpuscular, E-46003 Valencia, Spain. Univ Thessaloniki, AstroParticle Consortium, GR-54006 Thessaloniki, Greece. Inst Tecnol & Nucl, Lisbon, Portugal. Fachhsch Wiener Neustadt, Vienna, Austria. Dubna Joint Nucl Res Inst, Frank Lab Neutron Phys, Dubna 141980, Russia. Inst Phys & Power Engn, Obninsk, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, Sofia, Bulgaria. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NCSR Demokritos, AstroParticle Consortium, Athens, Greece. Univ Politecn Madrid, Madrid, Spain. Univ Vienna, Inst Isotopenforsch & Kernphys, A-1010 Vienna, Austria. Univ Basel, CH-4003 Basel, Switzerland. IRMM, JRC, CEC, Geel, Belgium. Democritus Univ Thrace, AstroParticle Consortium, Xanthi, Greece. Dipartimento Fis, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. RP Mastinu, PF (reprint author), Ist Nazl Fis Nucl, Sez Trieste, Trieste, Italy. RI Rauscher, Thomas/D-2086-2009; Jericha, Erwin/A-4094-2011; Martinez-Val, Jose/D-3871-2013; Lindote, Alexandre/H-4437-2013; Neves, Francisco/H-4744-2013; Vaz, Pedro/K-2464-2013; Lopes, Isabel/A-1806-2014; Tain, Jose L./K-2492-2014; Cano Ott, Daniel/K-4945-2014; Quesada Molina, Jose Manuel/K-5267-2014; Gonzalez Romero, Enrique/L-7561-2014; Pretel Sanchez, Carme/L-8287-2014; Capote Noy, Roberto/M-1245-2014; Alvarez Pol, Hector/F-1930-2011; Cortina-Gil, Dolores/H-9626-2015; Paradela, Carlos/J-1492-2012; Papaevangelou, Thomas/G-2482-2016; Calvino, Francisco/K-5743-2014; Benlliure, Jose/K-8407-2014; Mengoni, Alberto/I-1497-2012; OI Rauscher, Thomas/0000-0002-1266-0642; Jericha, Erwin/0000-0002-8663-0526; Martinez-Val, Jose/0000-0002-6325-6981; Lindote, Alexandre/0000-0002-7965-807X; Neves, Francisco/0000-0003-3635-1083; Vaz, Pedro/0000-0002-7186-2359; Lopes, Isabel/0000-0003-0419-903X; Cano Ott, Daniel/0000-0002-9568-7508; Quesada Molina, Jose Manuel/0000-0002-2038-2814; Gonzalez Romero, Enrique/0000-0003-2376-8920; Dababneh, Saed/0000-0002-7376-1084; Gramegna, Fabiana/0000-0001-6112-0602; Marques, Rui/0000-0003-3549-8198; Paradela Dobarro, Carlos/0000-0003-0175-8334; Chepel, Vitaly/0000-0003-0675-4586; Lozano Leyva, Manuel Luis/0000-0003-2853-4103; Koehler, Paul/0000-0002-6717-0771; Domingo-Pardo, Cesar/0000-0002-2915-5466; Capote Noy, Roberto/0000-0002-1799-3438; Alvarez Pol, Hector/0000-0001-9643-6252; Cortina-Gil, Dolores/0000-0001-7672-9912; Papaevangelou, Thomas/0000-0003-2829-9158; Calvino, Francisco/0000-0002-7198-4639; Benlliure, Jose/0000-0002-5114-1298; Mengoni, Alberto/0000-0002-2537-0038; Pavlik, Andreas/0000-0001-7526-3372; Goncalves, Isabel/0000-0002-1997-955X NR 7 TC 0 Z9 0 U1 1 U2 11 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 914 EP 918 DI 10.1590/S0103-97332004000500056 PG 5 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300056 ER PT J AU Psaker, A AF Psaker, A TI Inclusive photoproduction of lepton pairs in the parton model SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL AB In the framework of the QCD parton model, we study unpolarized scattering of high energy real photons from a proton target into lepton pairs and a system of hadrons. For a given parametrization of parton distributions in the proton, we calculate the cross section of this process and show the cancellation of the interference terms. C1 Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Psaker, A (reprint author), Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 944 EP 947 DI 10.1590/S0103-97332004000500064 PG 4 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300064 ER PT J AU Cole, PL Gordon, C Kellie, J Klein, F Livingston, K Mehrabyan, S Melone, J Sanabria, JC Tedeschi, D Wood, M AF Cole, PL Gordon, C Kellie, J Klein, F Livingston, K Mehrabyan, S Melone, J Sanabria, JC Tedeschi, D Wood, M CA CLAS Collaboration TI Vector meson and associated strangeness production using a linearly polarized photon beam at Jefferson Lab SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 5th Latin American Symposium on Nuclear Physics/26th Workshop on Nuclear Physics in Brazil CY SEP 01-05, 2003 CL Santos, BRAZIL AB The set of experiments forming the g8a run took place in the summer of 2001 in Hall B of Jefferson Lab. The g8a run was the commissioning experiment for the linearly-polarized photon beam at CLAS. The aim of these experiments is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. A beam of tagged and collimated linearly polarized photons (energy range 1.8-2.2 GeV) in conjunction with the large solid angle coverage of CLAS make possible the extraction of the differential cross-sections and polarization observables for the photoproduction of vector mesons and kaons. The reaction channels (γ) over right arrowp --> rho(0)p --> pi(+)pi(-)p and (γ) over right arrowp --> K(+)Lambda(0) --> K(+)pi(-)p are under investigation to search for possibly missing nucleon resonances. An overview of the experiment and preliminary results on the measurement of the photon asymmetries of the aforementioned reactions will be presented in this paper. C1 Jefferson Lab, Newport News, VA 23606 USA. RP Cole, PL (reprint author), Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD SEP PY 2004 VL 34 IS 3A BP 986 EP 990 DI 10.1590/S0103-97332004000500077 PG 5 WC Physics, Multidisciplinary SC Physics GA 856GI UT WOS:000224033300077 ER PT J AU Singh, J Itahana, Y Knight-Krajewski, S Kanagawa, M Campbell, KP Bissell, MJ Muschler, J AF Singh, J Itahana, Y Knight-Krajewski, S Kanagawa, M Campbell, KP Bissell, MJ Muschler, J TI Proteolytic enzymes and altered glycosylation modulate dystroglycan function in carcinoma cells SO CANCER RESEARCH LA English DT Article ID DYSTROPHIN-GLYCOPROTEIN COMPLEX; CONGENITAL MUSCULAR-DYSTROPHIES; ALPHA-DYSTROGLYCAN; BETA-DYSTROGLYCAN; TUMOR-CELLS; FURIN; RECEPTOR; MEMBRANE; LAMININ; BREAST AB Alterations in the basement membrane receptor dystroglycan (DG) are evident in muscular dystrophies and carcinoma cells and characterized by a selective loss or modification of the extracellular alpha-DG subunit. Defects in posttranslational modifications of DG have been identified in some muscular dystrophies, but the underlying modifications in carcinoma cells have not yet been defined. We reveal here multiple posttranslational modifications that modulate the composition and function of DG in normal epithelial cells and carcinoma cells. We show that alpha-DG is shed from the cell surface of normal and tumorigenic epithelial cells through a proteolytic mechanism that does not require direct cleavage of either alpha- or beta-DG. Shedding is dependent on metalloprotease activity and the proprotein convertase furin. Surprisingly, furin is also found to directly process alpha-DG as a proprotein substrate, changing the existing model of DG composition. We also show that the glycosylation of alpha-DG is altered in invasive carcinoma cells, and this modification causes complete loss of laminin binding properties. Together, these data elucidate several novel events regulating the functional composition of DG and reveal defects that arise during cancer progression, providing direction for efforts to restore this link with the basement membrane in carcinoma cells. C1 Calif Pacific Med Ctr, Res Inst, San Francisco, CA 94115 USA. Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA USA. Univ Iowa, Coll Med, Howard Hughes Med Inst, Dept Physiol & Biophys, Iowa City, IA USA. RP Muschler, J (reprint author), Calif Pacific Med Ctr, Res Inst, 2330 Clay St, San Francisco, CA 94115 USA. EM muschler@cooper.cpmc.org NR 37 TC 72 Z9 72 U1 1 U2 5 PU AMER ASSOC CANCER RESEARCH PI PHILADELPHIA PA 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD SEP 1 PY 2004 VL 64 IS 17 BP 6152 EP 6159 DI 10.1158/0008-5472.CAN-04-1638 PG 8 WC Oncology SC Oncology GA 850IA UT WOS:000223603200034 PM 15342399 ER PT J AU Walters, DG Young, PJ Agus, C Knize, MG Boobis, AR Gooderham, NJ Lake, BG AF Walters, DG Young, PJ Agus, C Knize, MG Boobis, AR Gooderham, NJ Lake, BG TI Cruciferous vegetable consumption alters the metabolism of the dietary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in humans SO CARCINOGENESIS LA English DT Article ID HUMAN UDP-GLUCURONOSYLTRANSFERASES; BRUSSELS-SPROUTS; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE PHIP; BRASSICA VEGETABLES; LIVER-MICROSOMES; HETEROCYCLIC AMINES; COOKED BEEF; CAFFEINE; URINE; GLUCURONIDATION AB Consumption of red meat is associated with an increased risk of colorectal cancer, whereas cruciferous vegetable consumption reduces cancer risk. While the mechanisms remain to be determined, cruciferous vegetables may act by altering the metabolism of carcinogens present in cooked food, such as the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). The aim of this study was to evaluate the effect of cruciferous vegetable consumption on the metabolism of PhIP in 20 non-smoking Caucasian male subjects. The study consisted of three 12-day phases, namely two periods of avoidance of cruciferous vegetables (phases 1 and 3) and a high cruciferous vegetable diet period (phase 2), when subjects ingested 250 g each of Brussels sprouts and broccoli per day. At the end of each study phase, the subjects consumed a cooked meat meal containing 4.90 mug PhIP and urine samples were collected for up to 48 h. Cruciferous vegetable consumption significantly increased hepatic CYP1A2, as demonstrated by changes in saliva caffeine kinetics. Samples of N-2-hydroxy-PhIP-N-2-glucuronide (the major urinary metabolite of PhIP in humans), N-2-hydroxy-PhIP-N-3-glucuronide and their trideuterated derivatives (to serve as internal standards) were synthesized and a liquid chromatography-mass spectrometry-mass spectrometry method developed for their analysis. In phases 1 and 3, the excretion of N-2-hydroxy-N-2-PhIP-glucuronide in 0-48 h urine samples was six times that of N-2-hydroxy-PhIP-N-3-glucuronide. Cruciferous vegetable consumption significantly increased the urinary excretion of N-2-hydroxy-PhIP-N-2-glucuronide in 0-48 h urine samples to 127 and 136% of levels observed in phases 1 and 3, respectively. In contrast, the urinary excretion of N-2-hydroxy-PhIP-N-3-glucuronide was unchanged. While the urinary excretion of both PhIP metabolites accounted for similar to39% of the PhIP dose in phases 1 and 3, they accounted for similar to49% of the dose in phase 2. This study demonstrates that cruciferous vegetable consumption can induce both the phase I and II metabolism of PhIP in humans. C1 BIBRA Int Ltd, Carshalton SM5 4DS, Surrey, England. Univ Surrey, Ctr Toxicol, Sch Biomed & Mol Sci, Surrey GU2 7XH, England. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Univ London Imperial Coll Sci Technol & Med, Div Med, London W12 0NN, England. RP Lake, BG (reprint author), BIBRA Int Ltd, Woodmansterne Rd, Carshalton SM5 4DS, Surrey, England. EM blake@bibra.co.uk OI Boobis, Alan/0000-0003-3371-386X NR 42 TC 56 Z9 56 U1 0 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD SEP PY 2004 VL 25 IS 9 BP 1659 EP 1669 DI 10.1093/carcin/bgh164 PG 11 WC Oncology SC Oncology GA 850CM UT WOS:000223588800013 PM 15073045 ER PT J AU Epling, WS Campbell, LE Yezerets, A Currier, NW Parks, JE AF Epling, WS Campbell, LE Yezerets, A Currier, NW Parks, JE TI Overview of the fundamental reactions and degradation mechanisms of NOx storage/reduction catalysts SO CATALYSIS REVIEWS-SCIENCE AND ENGINEERING LA English DT Review DE emissions; NOx storage/reduction catalysts; NO oxidation; NOx release; NOx storage; catalyst ID LEAN-BURN CONDITIONS; STORAGE-REDUCTION CATALYSTS; GAS-SHIFT REACTION; EMISSION CONTROL CATALYSIS; SILICA-SUPPORTED PLATINUM; GROUP METAL-CATALYSTS; NITROGEN-OXIDES; SELECTIVE REDUCTION; NO(X) STORAGE; EXCESS OXYGEN AB Over the last several years, nitrogen oxide(s) (NOx) storage/reduction (NSR) catalysts, also referred to as NOx adsorbers or lean NOx traps, have been developed as an aftertreatment technology to reduce NOx emissions from lean-burn power sources. NSR operation is cyclic: during the lean part of the cycle, NOx are trapped on the catalyst; intermittent rich excursions are used to reduce the NOx to N2 and restore the original catalyst surface; and lean operation then resumes. This review will describe the work carried out in characterizing, developing, and understanding this catalyst technology for application in mobile exhaust-gas aftertreatment. The discussion will first encompass the reaction process fundamentals, which include five general steps involved in NOx reduction to N(2) on NSR catalysts; NO oxidation, NO(2) and NO sorption leading to nitrite and nitrate species, reductant evolution, NOx release, and finally NOx reduction to N(2). Major unresolved issues and questions are listed at the end of each of the reaction process fundamental sections. Degradation mechanisms and their effects on NSR catalyst performance are also described in relation to these generalized reactions. Since at this stage it does not appear possible to arrive at a complete and consistent mechanistic model describing the broad, existing experimental phenomenology for these processes, this review is primarily focused on summarizing and evaluating literature data and reconciling the many differences presented. C1 EmeraChem, Maryville, TN USA. Adv Catalyst Syst, Maryville, TN USA. Cummins Inc, Columbus, IN USA. Oak Ridge Natl Lab, Natl Transportat Res Ctr, Knoxville, TN USA. RP Epling, WS (reprint author), EmeraChem, 2375 Cherahala Blvd, Knoxville, TN 37932 USA. EM bill.epling@cummins.com NR 184 TC 583 Z9 595 U1 22 U2 193 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0161-4940 J9 CATAL REV JI Catal. Rev.-Sci. Eng. PD SEP PY 2004 VL 46 IS 2 BP 163 EP 245 DI 10.1081/CR-200031932 PG 83 WC Chemistry, Physical SC Chemistry GA 912YM UT WOS:000228116200004 ER PT J AU Carreras, BA Lynch, VE Dobson, I Newman, DE AF Carreras, BA Lynch, VE Dobson, I Newman, DE TI Complex dynamics of blackouts in power transmission systems SO CHAOS LA English DT Article ID MODEL AB In order to study the complex global dynamics of a series of blackouts in power transmission systems a dynamical model of such a system has been developed. This model includes a simple representation of the dynamical evolution by incorporating the growth of power demand, the engineering response to system failures, and the upgrade of generator capacity. Two types of blackouts have been identified, each having different dynamical properties. One type of blackout involves the loss of load due to transmission lines reaching their load limits but no line outages. The second type of blackout is associated with multiple line outages. The dominance of one type of blackout over the other depends on operational conditions and the proximity of the system to one of its two critical points. The model displays characteristics such as a probability distribution of blackout sizes with power tails similar to that observed in real blackout data from North America. (C) 2004 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. Univ Alaska, Dept Phys, Fairbanks, AK 99775 USA. RP Carreras, BA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dobson, Ian/C-3989-2008; Lynch, Vickie/J-4647-2012 OI Dobson, Ian/0000-0001-7018-5475; Lynch, Vickie/0000-0002-5836-7636 NR 23 TC 89 Z9 100 U1 1 U2 16 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD SEP PY 2004 VL 14 IS 3 BP 643 EP 652 DI 10.1063/1.1781391 PG 10 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 854LL UT WOS:000223904400014 PM 15446974 ER PT J AU Wilder, JW Smith, DH AF Wilder, JW Smith, DH TI Simple predictive relations, fugacities, and enthalpies of dissociation for single guest clathrate hydrates in porous media SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE hydrates; equilibrium; dissociation; thermodynamics ID PORE-SIZE DISTRIBUTIONS; CARBON-DIOXIDE; SILICA-GELS; METHANE; PROPANE; PRESSURES; TEMPERATURES; EQUILIBRIA; SYSTEMS; ETHANE AB We present two sets of explicit relations for the equilibrium fugacities of single-guest gas hydrates. These relations can be applied whether the hydrate is dissociated under bulk conditions, or in porous media. The first set of presented relations explicitly shows the dependence of the equilibrium fugacity and the enthalpy of dissociation on classical statistical thermodynamic parameters. The second set of relations for the fugacity and enthalpy represent a very simple empirical form which can be used to calculate these quantities, without having to resort to the use of the full statistical thermodynamic model. it is hoped that these relations will prove useful in engineering or computational endeavors where the speed and/or ease of their use may be advantageous. (C) 2004 Elsevier Ltd. All rights reserved. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Wilder, JW (reprint author), W Virginia Univ, Dept Math, POB 6310, Morgantown, WV 26506 USA. EM wilder@math.wvu.edu; dsmith@netl.doe.gov NR 19 TC 3 Z9 3 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 EI 1873-4405 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD SEP PY 2004 VL 59 IS 18 BP 3945 EP 3954 DI 10.1016/j.ces.2004.06.002 PG 10 WC Engineering, Chemical SC Engineering GA 856CN UT WOS:000224021300015 ER PT J AU Nordlund, D Ogasawara, H Wernet, P Nyberg, M Odelius, M Pettersson, LGM Nilsson, A AF Nordlund, D Ogasawara, H Wernet, P Nyberg, M Odelius, M Pettersson, LGM Nilsson, A TI Surface structure of thin ice films SO CHEMICAL PHYSICS LETTERS LA English DT Article ID HYDROGEN-BOND; LIQUID WATER; SPECTRA; SPECTROSCOPY; H2O; SCATTERING; DESORPTION; EXCITATION; ADSORPTION; CLUSTERS AB An angular dependent X-ray absorption spectroscopy study of the surface of thin ice films grown on Pt(1 1 1) is presented. Using different probing depths together with spectral calculations based on density functional theory, the spectra are interpreted in terms of the structure of surface, subsurface and bulk regions. It is shown that the crystalline ice is terminated with a large abundance of isotropically distributed free O-H groups and a distorted subsurface. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Stockholm, FYSIKUM, Albanova Univ Ctr, SE-10691 Stockholm, Sweden. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Pettersson, LGM (reprint author), Univ Stockholm, FYSIKUM, Albanova Univ Ctr, SE-10691 Stockholm, Sweden. EM lgm@physto.se RI Nordlund, Dennis/A-8902-2008; Nilsson, Anders/E-1943-2011; Pettersson, Lars/F-8428-2011; Wernet, Philippe/A-7085-2013; Pettersson, Lars/J-4925-2013; Odelius, Michael/A-7628-2014; Ogasawara, Hirohito/D-2105-2009 OI Nordlund, Dennis/0000-0001-9524-6908; Nilsson, Anders/0000-0003-1968-8696; Wernet, Philippe/0000-0001-7011-9072; Pettersson, Lars/0000-0003-1133-9934; Odelius, Michael/0000-0002-7023-2486; Ogasawara, Hirohito/0000-0001-5338-1079 NR 25 TC 50 Z9 50 U1 2 U2 16 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 1 PY 2004 VL 395 IS 1-3 BP 161 EP 165 DI 10.1016/j.cplett.2004.06.141 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 851VT UT WOS:000223714800030 ER PT J AU Fernandez-Garcia, M Martinez-Arias, A Hanson, JC Rodriguez, JA AF Fernandez-Garcia, M Martinez-Arias, A Hanson, JC Rodriguez, JA TI Nanostructured oxides in chemistry: Characterization and properties SO CHEMICAL REVIEWS LA English DT Review ID X-RAY-ABSORPTION; SCANNING-TUNNELING-MICROSCOPY; ATOMIC-FORCE MICROSCOPY; MIXED-METAL OXIDES; RESOLUTION ELECTRON-MICROSCOPY; PAIR DISTRIBUTION FUNCTION; DENSITY-FUNCTIONAL THEORY; NEAR-EDGE STRUCTURE; OXYGEN HANDLING PROPERTIES; CLUSTER MODEL-CALCULATIONS C1 CSIC, Inst Catalisis & Petroleoquim, Madrid 28049, Spain. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP CSIC, Inst Catalisis & Petroleoquim, C Marie Curie S-N,Campus Cantoblanco, Madrid 28049, Spain. RI Hanson, jonathan/E-3517-2010; Fernandez-Garcia, Marcos/A-8122-2014 NR 566 TC 542 Z9 559 U1 19 U2 212 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 2004 VL 104 IS 9 BP 4063 EP 4104 DI 10.1021/cr030032f PG 42 WC Chemistry, Multidisciplinary SC Chemistry GA 853FQ UT WOS:000223812900010 PM 15352786 ER PT J AU Iorio, JP Duffy, PB Govindasamy, B Thompson, SL Khairoutdinov, M Randall, D AF Iorio, JP Duffy, PB Govindasamy, B Thompson, SL Khairoutdinov, M Randall, D TI Effects of model resolution and subgrid-scale physics on the simulation of precipitation in the continental United States SO CLIMATE DYNAMICS LA English DT Article ID COMMUNITY CLIMATE MODEL; GLOBAL CLIMATE; VARIABILITY; EXTREMES; CCM3 AB We analyze simulations of the global climate performed at a range of spatial resolutions to assess the effects of horizontal spatial resolution on the ability to simulate precipitation in the continental United States. The model investigated is the CCM3 general circulation model. We also preliminarily assess the effect of replacing cloud and convective parameterizations in a coarse-resolution (T42) model with an embedded cloud-system resolving model (CSRM). We examine both spatial patterns of seasonal-mean precipitation and daily time scale temporal variability of precipitation in the continental United States. For DJF and SON, high-resolution simulations produce spatial patterns of seasonal-mean precipitation that agree more closely with observed precipitation patterns than do results from the same model (CCM3) at coarse resolution. However, in JJA and MAM, there is little improvement in spatial patterns of seasonal-mean precipitation with increasing resolution, particularly in the southeast USA. This is because of the dominance of convective (i.e., parameterized) precipitation in these two seasons. We further find that higher-resolution simulations have more realistic daily precipitation statistics. In particular, the well-known tendency at coarse resolution to have too many days with weak precipitation and not enough intense precipitation is partially eliminated in higher-resolution simulations. However, even at the highest resolution examined here (T239), the simulated intensity of the mean and of high-percentile daily precipitation amounts is too low. This is especially true in the southeast USA, where the most extreme events occur. A new GCM, in which a cloud-resolving model (CSRM) is embedded in each grid cell and replaces convective and stratiform cloud parameterizations, solves this problem, and actually produces too much precipitation in the form of extreme events. However, in contrast to high-resolution versions of CCM3, this model produces little improvement in spatial patterns of seasonal-mean precipitation compared to models at the same resolution using traditional parameterizations. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Duffy, PB (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM pduffy@llnl.gov RI Randall, David/E-6113-2011 OI Randall, David/0000-0001-6935-4112 NR 27 TC 51 Z9 55 U1 2 U2 16 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD SEP PY 2004 VL 23 IS 3-4 BP 243 EP 258 DI 10.1007/s00382-004-0440-y PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 859NF UT WOS:000224274500002 ER PT J AU Sperber, KR AF Sperber, KR TI Madden-Julian variability in NCAR CAM2.0 and CCSM2.0 SO CLIMATE DYNAMICS LA English DT Article ID SEA-SURFACE TEMPERATURE; GENERAL-CIRCULATION MODEL; OUTGOING LONGWAVE RADIATION; INTRASEASONAL OSCILLATIONS; MOISTURE CONVERGENCE; WESTERN PACIFIC; OCEAN MODEL; LIFE-CYCLE; PARAMETERIZATION; SIMULATIONS AB The Madden-Julian Oscillation (MJO) dominates tropical variability on time scales of 30-70 days. During the boreal winter/spring it is manifested as an eastward propagating disturbance, with a strong convective signature over the eastern hemisphere. Here, 20-100 day bandpass filtered outgoing longwave radiation (OLR) for the months of November-March from the National Center for Atmospheric Research Community Atmospheric Model Version 2.0 (NCAR CAM2.0) and the Community Coupled System Model Version 2.0 (CCSM2.0) models is projected onto the observed patterns of MJO convection. This provides for the analysis of the models within a standard framework. Additionally, only analyzing years when the lead/lag relationship of the simulated principal components lie in the observed phase-space better isolates the simulated MJO signal. CCSM2.0 yields a better representation of the MJO than CAM2.0 due to the presence of air-sea interaction. Even so, the amplitude and spatial extent of the intraseasonal convection are underestimated relative to observed OLR, with a pronounced underestimate of the near-equatorial convection. Due to the development of a split inter-tropical convergence zone in the western Pacific, which is independent of the MJO, the models are precluded from representing the low-level moisture convergence that is central to the eastward propagation of the MJO. Once the systematic model error is remedied the underlying capability of the models to simulate the MJO will be possible. C1 Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, Livermore, CA 94550 USA. RP Sperber, KR (reprint author), Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, POB 808,L-103, Livermore, CA 94550 USA. EM sperberl@llnl.gov RI Sperber, Kenneth/H-2333-2012 NR 47 TC 50 Z9 60 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD SEP PY 2004 VL 23 IS 3-4 BP 259 EP 278 DI 10.1007/s00382-004-0447-4 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 859NF UT WOS:000224274500003 ER PT J AU Zhou, LG Hsiung, LM Huang, HC AF Zhou, LG Hsiung, LM Huang, HC TI Nucleation and propagation of deformation twin in polysynthetically twinned TiAl SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article DE TiAl; twin; dislocation; interface; molecular dynamics ID PST CRYSTALS; ALLOYS; CREEP; MICROSTRUCTURE AB Using molecular dynamics simulations, we study the deformation of polysynthetically twinned (PST) TiA1 at room temperature. The simulation cell is pre-strained and thermodynamically relaxed to zero stress, so that no dislocations pre-exist in gamma-alpha(2) interfaces. A uniaxial compression is then applied along one [1/6<112] direction. Our results show that interfacial dislocation pairs nucleate at the gamma-alpha(2) interface under the compression. The glide and agglomeration of these dislocations lead to the nucleation of deformation twins from the interface. Based on our studies, twins may nucleate without pre-existing interfacial dislocations. Further we have monitored the propagation of the deformation twin, specifically its interaction with gamma-gamma and gamma-alpha(2) interfaces. The observations show that gamma-alpha(2) interfaces are stronger obstacles to the twin propagation than gamma-gamma interfaces are. C1 Rensselaer Polytech Inst, Dept Mech Aerosp & Nucl Engn, Troy, NY 12180 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Zhou, LG (reprint author), Rensselaer Polytech Inst, Dept Mech Aerosp & Nucl Engn, Troy, NY 12180 USA. RI Huang, Hanchen/A-9323-2008 NR 21 TC 2 Z9 2 U1 0 U2 4 PU TECH SCIENCE PRESS PI NORCROSS PA 6825 JIMMY CARTER BLVD, STE 1850, NORCROSS, GA 30071 USA SN 1526-1492 EI 1526-1506 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PD SEP PY 2004 VL 6 IS 3 BP 245 EP 251 PG 7 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 853PW UT WOS:000223840500002 ER PT J AU Reagan, MT Najm, HN Debusschere, BJ Le Maitre, OP Knio, M Ghanem, RG AF Reagan, MT Najm, HN Debusschere, BJ Le Maitre, OP Knio, M Ghanem, RG TI Spectral stochastic uncertainty quantification in chemical systems SO COMBUSTION THEORY AND MODELLING LA English DT Article ID GENERALIZED POLYNOMIAL CHAOS; PROJECTION METHOD; FINITE-ELEMENTS; REACTING-FLOW; FLUID-FLOW; SIMULATION; VARIABLES; WIENER AB Uncertainty quantification (UQ) in the computational modelling of physical systems is important for scientific investigation, engineering design, and model validation. We have implemented an 'intrusive' UQ technique in which (1) model parameters and field variables are modelled as stochastic quantities, and are represented using polynomial chaos (PC) expansions in terms of Hermite polynomial functions of Gaussian random variables, and (2) the deterministic model equations are reformulated using Galerkin projection into a set of equations for the time evolution of the field variable PC mode strengths. The mode strengths relate specific parametric uncertainties to their effects on model outputs. In this work, the intrusive reformulation is applied to homogeneous ignition using a detailed chemistry model through the development of a reformulated pseudospectral chemical source term. We present results analysing the growth of uncertainty during the ignition process. We also discuss numerical issues pertaining to the accurate representation of uncertainty with truncated PC expansions, and ensuing stability of the time integration of the chemical system. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Univ Evry Val Essonne, Evry, France. Johns Hopkins Univ, Baltimore, MD 21218 USA. RP Najm, HN (reprint author), Sandia Natl Labs, 7011 East Ave,MS 9051, Livermore, CA 94550 USA. EM hnnajm@sandia.gov RI Knio, Omar/A-3318-2010; Ghanem, Roger/B-8570-2008; Le Maitre, Olivier/D-8570-2011; Reagan, Matthew/D-1129-2015 OI Ghanem, Roger/0000-0002-1890-920X; Le Maitre, Olivier/0000-0002-3811-7787; Reagan, Matthew/0000-0001-6225-4928 NR 31 TC 56 Z9 56 U1 2 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD SEP PY 2004 VL 8 IS 3 BP 607 EP 632 AR PII S1364-7830(04)71214-0 DI 10.1088/1364-7830/8/3/010 PG 26 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 863DP UT WOS:000224541200010 ER PT J AU Gardner, MK Thulasidasan, S Feng, WC AF Gardner, MK Thulasidasan, S Feng, WC TI User-space auto-tuning for TCP flow control in computational grids SO COMPUTER COMMUNICATIONS LA English DT Article DE flow-control; buffer tuning; TCP; auto-tuning; dynamic right-sizing; FTP; GridFTP AB With the advent of computational grids, networking performance over the wide-area network (WAN) has become a critical component in the grid infrastructure. Unfortunately, many high-performance grid applications only use a small fraction of their available bandwidth because operating systems and their associated protocol stacks are still tuned for yesterday's network speeds. As a result, network gurus undertake the tedious process of manually tuning system buffers to allow TCP flow control to scale to today's WAN environments. And although recent research has shown how to set the size of these system buffers automatically at connection set-up, the buffer sizes are only appropriate at the beginning of the connection's lifetime. To address these problems, we describe an automated and lightweight technique called Dynamic Right-Sizing that can improve throughput by as much as an order of magnitude while still abiding by TCP semantics. We show the performance of two user-space implementations of DRS: drsFTP and DRS-enabled GridFTP. (C) 2004 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Comp & Computat Sci Div, Los Alamos, NM 87545 USA. RP Gardner, MK (reprint author), Los Alamos Natl Lab, Comp & Computat Sci Div, POB 1663, Los Alamos, NM 87545 USA. EM mkg@lanl.gov; sunil@lanl.gov; feng@lanl.gov NR 35 TC 4 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD SEP 1 PY 2004 VL 27 IS 14 SI SI BP 1364 EP 1374 DI 10.1016/j.comcom.2004.02.013 PG 11 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 836ER UT WOS:000222538900003 ER PT J AU Foster I Fidler, M Roy, A Sander V Winkler, L AF Foster, I Fidler, M Roy, A Sander, V Winkler, L TI End-to-end quality of service for high-end applications SO COMPUTER COMMUNICATIONS LA English DT Article DE quality of service; high-end applications; application programmer interfaces; general-purpose architecture for reservation and allocation (GARA) AB High-end networked applications such as distance visualization, distributed data analysis, and advanced collaborative environments have demanding quality of service (QoS) requirements. Particular challenges include concurrent flows with different QoS specifications, highband-width flows, application-level monitoring and control, and end-to-end QoS across networks and other devices. We describe a QoS architecture and implementation that together help to address these challenges. The General-purpose Architecture for Reservation and Allocation (GARA) supports flow-specific QoS specification, immediate and advance reservation, and online monitoring and control of both individual resources and heterogeneous resource ensembles. Mechanisms provided by the Globus Toolkit are used to address resource discovery and security issues when resources span multiple administrative domains. Our prototype GARA implementation builds on differentiated services mechanisms to enable the coordinated management of two distinct flow types-foreground media flows and background bulk transfers-as well as the co-reservation of networks, CPUs, and storage systems. We present results obtained on a wide area differentiated services testbed that demonstrate our ability to deliver QoS for realistic flows. (C) 2004 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. Univ Aachen, Dept Comp Sci, D-52064 Aachen, Germany. Univ Wisconsin, Dept Comp Sci, Madison, WI 53706 USA. Forschungszentrum Julich, Cent Inst Appl Math, D-52425 Julich, Germany. RP Foster I (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM foster@mcs.anl.gov NR 55 TC 66 Z9 67 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD SEP 1 PY 2004 VL 27 IS 14 BP 1375 EP 1388 DI 10.1016/j.comcom.2004.02.014 PG 14 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 836ER UT WOS:000222538900004 ER PT J AU Fattebert, JL Gygi, F AF Fattebert, JL Gygi, F TI Linear scaling first-principles molecular dynamics with controlled accuracy SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE first-principles molecular dynamics; density functional theory; finite differences; linear scaling ID ELECTRONIC-STRUCTURE CALCULATIONS; DENSITY-FUNCTIONAL-THEORY; NONORTHOGONAL LOCALIZED ORBITALS; TOTAL-ENERGY CALCULATIONS; WANNIER FUNCTIONS; SIMULATIONS; PSEUDOPOTENTIALS; MINIMIZATION; ALGORITHM AB In our quest for accurate linear scaling first-principles molecular dynamics methods for psendopotential DFT calculations, we investigate the accuracy of real-space grid approaches, with finite differences and spherical localization regions. We examine how the positions of the localization centers affect accuracy and the convergence rate in the optimization process. In particular we investigate the accuracy of the atomic forces computation compared to the standard O(N-3) approach. We show the exponential decay of the error on the energy and forces with the size of the localization regions for a variety of realistic physical systems. We propose a new algorithm to automatically adapt the localization centers during the ground state computation which allows for molecular dynamics simulations with diffusion processes. The combination of algorithms proposed lead to a genuine linear scaling First-Principles Molecular Dynamics method with controlled accuracy. We illustrate our approach with examples of microcanonical molecular dynamics with localized orbitals. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, CASC, Livermore, CA 94551 USA. RP Fattebert, JL (reprint author), Lawrence Livermore Natl Lab, CASC, POB 808,L-561, Livermore, CA 94551 USA. EM fattebert1@llnl.gov NR 30 TC 39 Z9 39 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD SEP 1 PY 2004 VL 162 IS 1 BP 24 EP 36 DI 10.1016/j.cpc.2004.06.068 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 849FI UT WOS:000223523700003 ER PT J AU Schultz, EE AF Schultz, EE TI The case for one-time credentials SO COMPUTERS & SECURITY LA English DT Editorial Material C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, EE (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. EM eeugeneschultz2@aol.com NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 441 EP 442 DI 10.1016/j.cose.2004.08.001 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800001 ER PT J AU Schultz, E AF Schultz, E TI Malicious code update SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 443 EP 444 DI 10.1016/j.cose.2004.08.002 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800002 ER PT J AU Schultz, E AF Schultz, E TI Cybercrime war update SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 444 EP 446 PG 3 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800003 ER PT J AU Schultz, E AF Schultz, E TI Update on anti-spam legislation SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 446 EP 447 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800006 ER PT J AU Schultz, E AF Schultz, E TI SPY Act is passed in US SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 446 EP 446 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800005 ER PT J AU Schultz, E AF Schultz, E TI Man fired for planting monitoring software in his boss's computer SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 446 EP 446 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800004 ER PT J AU Schultz, E AF Schultz, E TI Efforts to achieve government agency compliance continue SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 447 EP 448 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800008 ER PT J AU Schultz, E AF Schultz, E TI Identity Theft Penalty Enhancement Act is passed SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 447 EP 447 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800007 ER PT J AU Schultz, E AF Schultz, E TI Results of studies on security incidents are released SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 448 EP 449 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800009 ER PT J AU Schultz, E AF Schultz, E TI Surveys indicate that compliance boosts security, but is costly SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 449 EP 450 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800010 ER PT J AU Schultz, E AF Schultz, E TI New e-voting developments SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 450 EP 451 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800011 ER PT J AU Schultz, E AF Schultz, E TI US DHS: network outages should be kept secret SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 451 EP 452 PG 2 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800014 ER PT J AU Schultz, E AF Schultz, E TI Mobile phone virus prompts joint effort to develop new security scheme SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 451 EP 451 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800012 ER PT J AU Schultz, E AF Schultz, E TI IEEE 802.11i ratification may boost confidence in WLAN security SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 451 EP 451 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800013 ER PT J AU Schultz, E AF Schultz, E TI Windows XP Service Pack 2 stirs gigantic controversy SO COMPUTERS & SECURITY LA English DT News Item C1 Univ Calif Berkeley Lab, Berkeley, CA 94720 USA. RP Schultz, E (reprint author), Univ Calif Berkeley Lab, Cyclotron Rd,MS 50A-3111, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-4048 J9 COMPUT SECUR JI Comput. Secur. PD SEP PY 2004 VL 23 IS 6 BP 452 EP 452 PG 1 WC Computer Science, Information Systems SC Computer Science GA 861YF UT WOS:000224453800015 ER PT J AU Trucano, T Post, D AF Trucano, T Post, D TI Verification and validation in computational science and engineering SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Editorial Material C1 Sandia Natl Labs, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Trucano, T (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM tgtruca@sandia.gov; post@lanl.gov NR 0 TC 5 Z9 5 U1 0 U2 13 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2004 VL 6 IS 5 BP 8 EP 9 DI 10.1109/MCSE.2004.38 PG 2 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 848GY UT WOS:000223456800004 ER PT J AU Calder, A Dursi, J Fryxell, B Plewa, T Weirs, G Dupont, T Robey, H Kane, J Remington, B Timmes, F Dimonte, G Hayes, J Zingale, M Drake, P Ricker, P Stone, J Olson, K AF Calder, A Dursi, J Fryxell, B Plewa, T Weirs, G Dupont, T Robey, H Kane, J Remington, B Timmes, F Dimonte, G Hayes, J Zingale, M Drake, P Ricker, P Stone, J Olson, K TI Validating astrophysical simulation codes SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID RAYLEIGH-TAYLOR; HYDRODYNAMICS; SUPERNOVA; DIFFUSION; FLAMES C1 Univ Chicago, Chicago, IL 60637 USA. Lawrence Livermore Natl Lab, ICF Program, Livermore, CA USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif San Diego, San Diego, CA 92103 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Illinois, Champaign, IL USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Calder, A (reprint author), Univ Chicago, Chicago, IL 60637 USA. EM calder@flash.uchicago.edu; ljdursi@flash.uchicago.edu; fryxell@flash.uchicago.edu; tomek@flash.uchicago.edu; weirs@flash.uchicago.edu; t-dupont@uchicago.edu; robey1@llnl.gov; jave@llnl.gov; remington2@llnl.gov; timmes@lanl.gov; dimonte@lani.gov; jchayes@ucsd.edu; zingale@ucolick.org; pmricker@uiuc.edu; zingale@ucolick.org; Kevin.Olson@gsfc.nasa.gov RI Plewa, Tomasz/C-1470-2010; Calder, Alan/E-5348-2011; OI Plewa, Tomasz/0000-0002-1762-2565; Zingale, Michael/0000-0001-8401-030X; Dursi, Jonathan/0000-0002-4697-798X NR 25 TC 2 Z9 2 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2004 VL 6 IS 5 BP 10 EP 20 DI 10.1109/MCSE.2004.44 PG 11 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 848GY UT WOS:000223456800005 ER PT J AU Benjamin, RF AF Benjamin, RF TI An experimenter's perspective on validating codes and models with experiments having shock-accelerating fluid interfaces SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID UNSTABLE GAS-CYLINDERS; RAYLEIGH-TAYLOR; INSTABILITY; LAYER; DYNAMICS; CURTAIN; GROWTH; TRANSITION; TURBULENCE; EVOLUTION C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Benjamin, RF (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 24 TC 2 Z9 3 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2004 VL 6 IS 5 BP 40 EP 49 DI 10.1109/MCSE.2004.30 PG 10 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 848GY UT WOS:000223456800008 ER PT J AU Day, SD Whalen, MT King, KJ Hust, GA Wong, LL Estill, JC Rebak, RB AF Day, SD Whalen, MT King, KJ Hust, GA Wong, LL Estill, JC Rebak, RB TI Corrosion behavior of Alloy 22 in oxalic acid and sodium chloride solutions SO CORROSION LA English DT Article DE Alloy 22; corrosion potential; crevice corrosion; cyclic polarization; general corrosion; localized corrosion; oxalic acid; sodium chloride; UNSN06022 ID ORGANIC-ACIDS; NICKEL; WASTE AB Nickel-based Alloy 22 (UNS N06022) is used extensively in aggressive industrial applications, especially due to its resistance to localized corrosion and stress corrosion cracking in high-chloride environments. The purpose of this work was to characterize the anodic behavior of Alloy 22 in oxalic acid (COOHCOOH) solution and to compare its behavior to sodium chloride (NaCl) solutions. Standard electrochemical tests such as polarization resistance and cyclic polarization were used. Results show that the corrosion rate of Alloy 22 in oxalic acid solutions increased rapidly as the temperature and the acid concentration increased. Extrapolation studies show that even at a concentration of 10(-4) M oxalic acid, the corrosion rate of Alloy 22 would be higher in oxalic acid than in I M NaCl solution. Alloy 22 was not susceptible to localized corrosion in oxalic acid solutions. Cyclic polarization tests of artificially creviced specimens in 1 M NaCl showed that Alloy 22 was susceptible to crevice corrosion at 90degreesC but was not susceptible at 60degreesC. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rebak, RB (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. OI Rebak, Raul/0000-0002-8070-4475 NR 27 TC 10 Z9 10 U1 0 U2 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD SEP PY 2004 VL 60 IS 9 BP 804 EP 814 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 856BX UT WOS:000224019700002 ER PT J AU Chew, CM Ristic, RI Dennehy, RD De Yoreo, JJ AF Chew, CM Ristic, RI Dennehy, RD De Yoreo, JJ TI Crystallization of paracetamol under oscillatory flow mixing conditions SO CRYSTAL GROWTH & DESIGN LA English DT Article; Proceedings Paper CT 6th International Conference on the Crystal Growth of Organic Materials CY SEP 18-21, 2003 CL Univ Strathclyde, Glasgow, SCOTLAND HO Univ Strathclyde ID PROFILE-REFINEMENT METHOD; RATE DISTRIBUTIONS; CRYSTAL-SURFACES; VICINAL FACE; GROWTH; STRAIN; MACROSTEPS; ENERGY; SIZE AB There has been an increasing effort in designing pharmaceutical particles with controllable properties (quality) such as chemical purity, morphology, size distribution, surface characteristics, and microstrain content. In this paper, we explore the feasibility of oscillatory flow mixing (OFM) in improving the quality of pharmaceutical precipitates, using paracetamol (4-acetamidophenol) as a model system. In-situ atomic force microscopy (AFM) and optical microscopy were applied to observe the growth of {110} faces of single paracetamol crystals. These studies showed that (a) the bunching and macrostep formation occur at all values of supersaturation; and (b) the oscillation of solution with respect to the growing interface and its relative velocity are the critical parameters for the minimization of the interfacial instabilities, and in turn, for maintaining structural quality. These findings were tested in a conventional impeller driven batch crystallizer (IDBC) and in an oscillatory baffled batch crystallizer (OBBC), in which, apart from hydrodynamics, all external conditions such as initial supersaturation and crystallization temperature were kept constant. The physical properties (the quality) of the precipitates were characterized by low angle laser light scattering (LALLS), scanning electron microscopy (SEM), and X-ray powder diffraction (XRPD), respectively. The analysis of obtained results and their comparison for these two types of mixing shows clearly that particles precipitated in OBBC are of significantly higher quality than those produced in IDBC. A computational fluid dynamics (CFD) software package, Fluent 5, was used to model dynamical fluid patterns in both crystallizers. C1 Univ Sheffield, Dept Chem & Proc Engn, Sheffield S1 3JD, S Yorkshire, England. GlaxoSmithKline, Strateg Technol, Tonbridge TN11 9AN, Kent, England. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ristic, RI (reprint author), Univ Sheffield, Dept Chem & Proc Engn, Mappin St, Sheffield S1 3JD, S Yorkshire, England. EM r.i.ristic@sheffield.ac.uk NR 33 TC 26 Z9 26 U1 3 U2 24 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1528-7483 J9 CRYST GROWTH DES JI Cryst. Growth Des. PD SEP-OCT PY 2004 VL 4 IS 5 BP 1045 EP 1052 DI 10.1021/cg0499131 PG 8 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA 851VL UT WOS:000223714000023 ER PT J AU Cole-McLaughlin, K Edelsbrunner, H Harer, J Natarajan, V Pascucci, V AF Cole-McLaughlin, K Edelsbrunner, H Harer, J Natarajan, V Pascucci, V TI Loops in Reeb graphs of 2-manifolds SO DISCRETE & COMPUTATIONAL GEOMETRY LA English DT Article; Proceedings Paper CT 19th ACM Symposium on Computational Geometry CY JUN 08-10, 2003 CL San Diego, CA SP ACM ID TOPOLOGY AB Given a Morse function f over a 2-manifold with or without boundary, the Reeb graph is obtained by contracting the connected components of the level sets to points. We prove tight upper and lower bounds on the number of loops in the Reeb graph that depend on the genus, the number of boundary components, and whether or not the 2-manifold is orientable. We also give an algorithm that constructs the Reeb graph in time O(n log n), where n is the number of edges in the triangulation used to represent the 2-manifold and the Morse function. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Duke Univ, Dept Math, Durham, NC 27708 USA. Duke Univ, Dept Comp Sci, Durham, NC 27708 USA. Raindrop Geomag, Res Triangle Pk, NC 27709 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. EM kree@mac.com; edels@cs.duke.edu; harer@math.duke.edu; vijay@cs.duke.edu; pascucci@acm.org NR 18 TC 49 Z9 49 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0179-5376 EI 1432-0444 J9 DISCRETE COMPUT GEOM JI Discret. Comput. Geom. PD SEP PY 2004 VL 32 IS 2 BP 231 EP 244 DI 10.1007/s00454-004-1122-6 PG 14 WC Computer Science, Theory & Methods; Mathematics SC Computer Science; Mathematics GA 842BW UT WOS:000222978700006 ER PT J AU Reneau, SL Drakos, PG Katzman, D Malmon, DV McDonald, EV Ryti, RT AF Reneau, SL Drakos, PG Katzman, D Malmon, DV McDonald, EV Ryti, RT TI Geomorphic controls on contaminant distribution along an ephemeral stream SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article DE sediment contamination; plutonium; aggradation-degradation cycle; sediment transport; ephemeral stream ID EFFLUENT-RECEIVING AREAS; LOS-ALAMOS; CLIMATE VARIATION; NEW-MEXICO; SEDIMENT; RIVER; TRANSPORT; PLUTONIUM; ENVIRONMENTS; DEPOSITION AB Sediment-borne contamination in a watershed can be highly variable as a result of fluvial processes operating over a range of time scales. This study presents a detailed analysis of the distribution of one contaminant along an ephemeral stream after 55 years of sediment transport, deposition, and exchange by flash floods. Wastewater containing plutonium was discharged into the Pueblo Canyon watershed from 1945 until 1964, and plutonium concentrations in fluvial deposits vary over five orders of magnitude. These variations can be attributed to three primary factors: time since contaminant releases, particle-size sorting, and mixing of sediment from different sources. The highest concentrations occur in fine-grained sediment deposits near the source that date to the period of effluent releases, and concentrations are lower in younger deposits, in coarser-grained deposits, and in deposits farther downstream. The spatial distribution of plutonium is strongly affected by longitudinal variations in the size of sediment deposits of different age. A major aggradation-degradation cycle in the lower canyon overlapped with the period of active effluent releases, and a significant portion of the total plutonium inventory is contained within large coarse-grained deposits below fill terraces that post-date 1945. The spatial pattern of contamination is thus determined by the specific geomorphic history of the watershed, in addition to processes of mixing and sorting during transport that occur in all fluvial systems. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Glorieta Geosci Inc, Santa Fe, NM 87505 USA. Swanson Hydrol & Geomorphol, Santa Cruz, CA 95060 USA. Desert Res Inst, Reno, NV 89512 USA. Neptune & Co, Los Alamos, NM 87544 USA. RP Reneau, SL (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, EES-9,MS D462, Los Alamos, NM 87545 USA. EM sreneau@lanl.gov NR 37 TC 17 Z9 17 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0197-9337 J9 EARTH SURF PROC LAND JI Earth Surf. Process. Landf. PD SEP PY 2004 VL 29 IS 10 BP 1209 EP 1223 DI 10.1002/esp.1085 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 858CW UT WOS:000224168900003 ER PT J AU Mills, E AF Mills, E TI Inter-comparison of North American residential energy analysis tools SO ENERGY AND BUILDINGS LA English DT Article AB Energy analysis software is an essential component of efforts to foster increased energy efficiency in buildings. In North America alone, there exist hundreds of web- and disk-based building energy analysis tools, serving a diversity of audiences. Some are specialized while others consider the building as a whole. We evaluated 50 web-based residential tools and 15 disk-based tools. While the state-of-the art in tool design has risen considerably over the past three decades, today's users are faced with an increasing-and often overwhelming-array of choices and, often, conflicting results. A surprising number provide little or no detailed analysis of energy savings options. A number of important building energy issues and efficiency features cannot be sufficiently well evaluated using any of the existing tools. Many factors conspire to confound performance comparisons among tools, and the sources or implications of observed differences in results are difficult to pinpoint. For the tools we tested, predicted whole-house energy bills ranged widely (by nearly a factor of three), and far more so at the end-use level. We also discovered a remarkable number of indications of errors in programming or algorithms. Tool design should be grounded in social science and engineering. Analytical results (e.g., benchmarking) and end-use-specific "what-if" functions are more helpful for many users than ratified engineering outputs. Desirable technical features include modeling of occupant effects, open-ended energy calculations as well as results normalized to actual consumption history, incorporating means for users to grasp the uncertainties embodied in the results, and ensuring quality control to remove errors from the design and programming of tools. More coordinated planning of tool development could help address the fragmentation and dilution of efforts that has historically hampered tool quality and market penetration. (C) 2004 Elsevier B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Energy Anal Dept, Berkeley, CA 94720 USA. RP Mills, E (reprint author), Lawrence Berkeley Natl Lab, Energy Anal Dept, MS 90-4000, Berkeley, CA 94720 USA. EM emills@lbl.gov NR 14 TC 16 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD SEP PY 2004 VL 36 IS 9 BP 865 EP 880 DI 10.1016/j.enbuild.2003.11.005 PG 16 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 847IG UT WOS:000223385300001 ER PT J AU Tanaka, R Sato, S Takanohashi, T Hunt, JE Winans, RE AF Tanaka, R Sato, S Takanohashi, T Hunt, JE Winans, RE TI Analysis of the molecular weight distribution of petroleum asphaltenes using laser desorption-mass spectrometry SO ENERGY & FUELS LA English DT Article AB Laser desorption mass spectrometry (LD-MS) was used to measure three asphaltenes, their sub-fractions separated using gel-permeation chromatography (GPC), and model compounds to ascertain their molecular weight distributions and averaged molecular weights. The asphaltenes were isolated from three crude oils: Maya (MY), Khafji (KF), and Iranian Light (IL). To optimize the measurement conditions for LD-MS, the effects of instrument mode, matrix, and laser energy were determined. Linear mode detection gave larger ion counts and higher signal-to-noise ratios than did reflector mode. The use of a matrix to determine the asphaltene molecular weight distribution was not useful as it enhanced the ionization of only some of the asphaltene fractions. The chosen laser energy provided significant ionization of the high-molecular-weight fractions, while minimizing polymerization and fragmentation. Various model compounds were measured to clarify the dependence of the ionization capacity on molecular structure. Pure and small alkyl-substituted aromatics ionize easily, and tend to polymerize at relatively low laser energies. Bridged aromatics are easily disrupted at the alkyl bridge and do not polymerize. Aliphatic hydrocarbons are very difficult to ionize in the absence of an appropriate matrix. The higher the molecular weight of a compound, the more difficult it is to ionize. The characterization of the asphaltenes was aided by separating each into six sub-fractions using GPC. These fractions fell into two groups: high- and low-aromaticity groups. In each group, the lower the molecular weight of a sub-fraction, the higher its aromaticity. Maya asphaltene (As-MY) had a larger molecular weight fraction than the other asphaltenes, but the distribution pattern of As-KF was similar to that of As-MY, except for this fraction. All the As-IL sub-fractions had lower molecular weights and higher aromaticity than the corresponding sub-fractions of the other asphaltenes. The averaged molecular weights of the asphaltenes were determined from the weighted average of the averaged molecular weight of each of the six sub-fractions. For As-MY, As-KF, and As-IL the values are 1657, 1628, and 1462 amu, respectively. C1 Idemitsu Kosan Co Ltd, Cent Res Labs, Sodegaura, Chiba 2990293, Japan. Natl Inst Adv Ind Sci & Technol, Inst Energy Utilizat, Tsukuba, Ibaraki 3058569, Japan. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Tanaka, R (reprint author), Idemitsu Kosan Co Ltd, Cent Res Labs, 1280 Kamiizumi, Sodegaura, Chiba 2990293, Japan. EM ryuzo.tanaka@si.idemitsu.co.jp NR 18 TC 69 Z9 69 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2004 VL 18 IS 5 BP 1405 EP 1413 DI 10.1021/ef034083r PG 9 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 855MG UT WOS:000223976800022 ER PT J AU Clark, W Isherwood, W AF Clark, W Isherwood, W TI Distributed generation: remote power systems with advanced storage technologies SO ENERGY POLICY LA English DT Article DE distributed generation energy; environmentally sound technologies; remote communities; advanced technologies; optimization and economic models AB The paper discusses derived from an earlier hypothetical study of remote villiages. It considers the policy implications for communities who have their own local power resources rather than those distributed through transmission from distant Sources such as darns. coal power plants or even renewables generation from wind farms, solar thermal or other resources. The issues today, post 911 and the energy crises in California, Northeast North America and Europe, signal the need for a new and different approach to energy supply(s), reliability and dissemination. Distributed generation (DG) as explored in the earlier paper appears to be one such approach that allows for local Communities to become energy self-sufficient. Along with energy conservation, efficiency, and on-site generation, local power Sources provide concrete definitions and understandings for heretofore ill defined concepts such as sustainability and eco-systems. The end result for any region and nation-state are "agile energy systems" which use flexible DG, on-site generation and conservation systems meeting the needs of local communities. Now the challenge is to demonstrate and provide economic and policy structures for implementing new advanced technologies for local communities. For institutionalizing economically viable and Sound environmental technologies then new finance mechanisms must be established that better reflect the true costs of clean energy distributed in local communities. For example, the aggregation of procurement contracts for on-site solar systems is far more cost effective than for each business owner, public building or household to purchase its own separate units. Thus mass purchasing contracts that are link technologies as hybrids can dramatically reduce Costs. In Short public-private partnerships can implement the once costly clean energy technologies into local DG system.,. (C) 2004 Elsevier Ltd. All rights reserved. C1 Governors Off Planning & Res, Sacramento, CA 95184 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Clark, W (reprint author), Governors Off Planning & Res, 1400 10th St, Sacramento, CA 95184 USA. EM wclark13@aol.com NR 63 TC 27 Z9 30 U1 3 U2 19 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-4215 J9 ENERG POLICY JI Energy Policy PD SEP PY 2004 VL 32 IS 14 BP 1573 EP 1589 DI 10.1016/S0301-4215(03)00017-X PG 17 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 821ZD UT WOS:000221501200002 ER PT J AU Shao, Q Wilson, MD Romanek, CS Hobson, KA AF Shao, Q Wilson, MD Romanek, CS Hobson, KA TI Time series analysis of elemental and isotopic data from biomineralized whale tissue SO ENVIRONMENTAL AND ECOLOGICAL STATISTICS LA English DT Article DE Arctic; autoregressive moving-average series; baleen; bowhead whale; likelihood ratio test; linear trend; isotope; seasonality; time series; trace elements ID BALAENA-MYSTICETUS; BALEEN; SEA AB A temporal record of environmental conditions is often contained within accretionary biological tissue. These records can provide knowledge of the environmental conditions that existed at the time the tissue was formed. In this study, we look at trace element concentrations and isotopic ratios of carbon and nitrogen as contained in baleen from bowhead whales in the eastern and western Arctic Ocean. Time series techniques, including maximum likelihood method and likelihood ratio tests, are applied to analysis of data and inference about their mean structures. C1 Univ Toledo, Dept Math, Toledo, OH 43606 USA. Univ Georgia, Savannah River Ecol Lab, Athens, GA 30602 USA. Univ Georgia, Dept Geol, Athens, GA 30602 USA. Environm Canada, Canadian Wildlife Serv, Ottawa, ON K1A 0H3, Canada. RP Shao, Q (reprint author), Univ Toledo, Dept Math, Toledo, OH 43606 USA. OI Wilson, Machelle/0000-0003-1734-2755 NR 16 TC 3 Z9 3 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1352-8505 J9 ENVIRON ECOL STAT JI Environ. Ecol. Stat. PD SEP PY 2004 VL 11 IS 3 BP 323 EP 337 DI 10.1023/B:EEST.0000038019.84117.e1 PG 15 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA 846RD UT WOS:000223332600006 ER PT J AU Efroymson, RA Nicolette, JP Suter, GW AF Efroymson, RA Nicolette, JP Suter, GW TI A framework for net environmental benefit analysis for remediation or restoration of contaminated sites SO ENVIRONMENTAL MANAGEMENT LA English DT Article ID OIL-SPILL; ECOLOGICAL RISKS; BIOREMEDIATION; EQUIVALENCE; VALUATION; TOXICITY; RECOVERY; SOILS; GAIN; USA AB Net environmental benefits are gains in value of environmental services or other ecological properties attained by remediation or ecological restoration minus the value of adverse environmental effects caused by those actions. Net environmental benefit analysis (NEBA) is a methodology for comparing and ranking net environmental benefits associated with multiple management alternatives. A NEBA for chemically contaminated sites typically involves comparison of several management alternatives: (1) leaving contamination in place; (2) physically, chemically, or biologically remediating the site through traditional means; (3) improving ecological value through onsite and offsite restoration alternatives that do not directly focus on removal of chemical contamination; or (4) a combination of those alternatives. NEBA involves activities that are common to remedial alternatives analysis for state regulations and the Comprehensive Environmental Response, Compensation, and Liability Act, post-closure and corrective action permits under the Resource Conservation and Recovery Act, evaluation of generic types of response actions pertinent to the Oil Pollution Act, and land management actions that are negotiated with regulatory agencies in flexible regulatory environments (i.e., valuing environmental services or other ecological properties, assessing adverse impacts, and evaluating remediation or restoration options). This article presents a high-level framework for NEBA at contaminated sites with subframeworks for natural attenuation (the contaminated reference state), remediation, and ecological restoration alternatives. Primary information gaps related to NEBA include nonmonetary valuation methods, exposure-response models for all stressors, the temporal dynamics of ecological recovery, and optimal strategies for ecological restoration. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. CH2M Hill Inc, Atlanta, GA 30346 USA. US EPA, Cincinnati, OH 45268 USA. RP Efroymson, RA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. EM Efroymson@ornl.gov OI Efroymson, Rebecca/0000-0002-3190-880X NR 51 TC 24 Z9 29 U1 6 U2 36 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD SEP PY 2004 VL 34 IS 3 BP 315 EP 331 DI 10.1007/s00267-004-0089-7 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA 861WA UT WOS:000224448100001 PM 15520889 ER PT J AU Said, A Stevens, DK Sehlke, G AF Said, A Stevens, DK Sehlke, G TI An innovative index for evaluating water quality in streams SO ENVIRONMENTAL MANAGEMENT LA English DT Article DE Big Lost River; Idaho; 303(d) list; total maximum daily load; National Sanitation Foundation; water quality index AB A water quality index expressed as a single number is developed to describe overall water quality conditions using multiple water quality variables. The index consists of water quality variables: dissolved oxygen, specific conductivity, turbidity, total phosphorus, and fecal coliform. The objectives of this study were to describe the preexisting indices and to define a new water quality index that has advantages over these indices. The new index was applied to the Big Lost River Watershed in Idaho, and the results gave a quantitative picture for the water quality situation. If the new water quality index for the impaired water is less than a certain number, remediation-likely in the form of total maximum daily loads or changing the management practices-may be needed. The index can be used to assess water quality for general beneficial uses. Nevertheless, the index cannot be used in making regulatory decisions, indicate water quality for specific beneficial uses, or indicate contamination from trace metals, organic contaminants, and toxic substances. C1 Univ S Florida, Dept Civil & Environm Engn, Tampa, FL 33620 USA. Utah State Univ, Civil & Environm Dept, Logan, UT 84322 USA. Idaho Natl Engn & Environm Lab, Integrated Environm Anal Dept, Idaho Falls, ID 83415 USA. RP Said, A (reprint author), Univ S Florida, Dept Civil & Environm Engn, Tampa, FL 33620 USA. EM asaid@cc.usu.edu RI STevens, David/B-3185-2013 NR 10 TC 71 Z9 74 U1 1 U2 23 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0364-152X J9 ENVIRON MANAGE JI Environ. Manage. PD SEP PY 2004 VL 34 IS 3 BP 406 EP 414 DI 10.1007/s00267-004-0210-y PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA 861WA UT WOS:000224448100009 PM 15520897 ER PT J AU Szecsody, JE Fruchter, JS Williams, MD Vermeul, VR Sklarew, D AF Szecsody, JE Fruchter, JS Williams, MD Vermeul, VR Sklarew, D TI In situ chemical reduction of aquifer sediments: Enhancement of reactive iron phases and TCE dechlorination SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ZERO-VALENT IRON; CARBON-TETRACHLORIDE; CHROMIUM(VI) REDUCTION; EXTRACTION TECHNIQUES; IRON(III) OXIDES; CR(VI) REDUCTION; TRANSPORT; KINETICS; FE(II); TRANSFORMATION AB In situ chemical reduction of aquifer sediments is currently being used for chromate and TCE remediation by forming a permeable reactive barrier. The chemical and physical processes that occur during abiotic reduction of natural sediments during flow by sodium dithionite were investigated. In different aquifer sediments, 10-22% of amorphous and crystalline Fe-III-oxides were dissolved/reduced, which produced primarily adsorbed Fe-II, and some siderite. Sediment oxidation showed predominantly one Fell phase, with a second phase being oxidized more slowly. The sediment reduction rate (3.3 h batch half-life) was chemically controlled (58 kJ mol(-1)), with some additional diffusion control during reduction in sediment columns (8.0 h half-life). It was necessary to maintain neutral to high pH to maintain reduction efficiency and prevent iron mobilization, as reduction generated H+. Sequential extractions on reduced sediment showed that adsorbed ferrous iron controlled TCE reactivity. The mass and rate of field-scale reduction of aquifer sediments were generally predicted with laboratory data using a single reduction reaction. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Szecsody, JE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM jim.szecsody@pnl.gov NR 57 TC 38 Z9 39 U1 5 U2 42 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 2004 VL 38 IS 17 BP 4656 EP 4663 DI 10.1021/es034756k PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 851IN UT WOS:000223678900035 PM 15461176 ER PT J AU Oh, JE Touati, A Gullett, BK Mulholland, JA AF Oh, JE Touati, A Gullett, BK Mulholland, JA TI PCDD/F TEQ indicators and their mechanistic implications SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MUNICIPAL WASTE INCINERATORS; CHLORINATED DIBENZODIOXINS; COMBUSTION; CHLOROPHENOLS; DIBENZOFURAN; CHLOROBENZENES; PRECURSORS; EMISSIONS; PATTERNS; DIOXINS AB Stack gas samples from two incinerator facilities with different operating conditions were investigated to understand how indicators of toxic equivalency (TEQ) from among the 210 polychlorinated dibenzo-p-dioxin/furan (PCDD/F) isomers varied. This effort was motivated by the need to find more easily monitored indicator compound(s) of TEQ and to reconcile the varying indicator compounds reported in the literature. The measured isomer patterns were compared with those expected from known formation mechanisms to identify the dominant mechanism(s) and explain why certain compounds are relevant TEQ indicators. Despite differences in the facility types and operating conditions, a common pattern was found for the highly chlorinated (4Cl and higher) PCDDs/Fs. A combination of chlorination/dechlorination reactions as the dominant formation mechanism for PCDF was consistent with the observed isomer patterns, whereas condensation reactions of phenolic precursors appeared to be responsible for PCDD formation. PCDF isomers, rather than the PCDD isomers, were more closely related to the TEQ measure, likely because the chlorination mechanism favors 2,3,7,8-Cl-substitution more than the phenol condensation mechanism. Unlike highly chlorinated PCDD/F isomer patterns, less chlorinated PCDD/F patterns (especially, mono- and di-CDF) were sensitive to operating conditions and facility type. Competing formation mechanisms were inferred from the variation of observed isomer distribution patterns; this sensitivity resulted in relatively low correlations of these isomers with PCDD/F TEQ values. This suggests that any use of the low-chlorinated compounds as TEQ indicators for online monitoring processes are likely best suited for plant-specific, rather than universal, applications. In addition to many of the highly chlorinated (penta-CDF, hexa-, and hepta-CDD/F) isomers being identified as strong TEQ indicators, 1 of 12 (8%), 5 of 17 (29%), and 5 of 28 (18%) of the separable tri-CDD, tri-CDF, and tetra-CDF isomers, respectively, were identified as strong (R-2 > 0.7) TEQ. indicators in both incinerators. C1 US EPA, Natl Risk Management Res Lab, Off Res & Dev, Res Triangle Pk, NC 27711 USA. ARCADIS G&M, Res Triangle Pk, NC 27709 USA. Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30332 USA. Oak Ridge Inst Sci & Educ, Postdoctoral Program, Oak Ridge, TN 37831 USA. RP Gullett, BK (reprint author), US EPA, Natl Risk Management Res Lab, Off Res & Dev, E305-01, Res Triangle Pk, NC 27711 USA. EM gullett.brian@epa.gov NR 19 TC 10 Z9 11 U1 1 U2 12 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 2004 VL 38 IS 17 BP 4694 EP 4700 DI 10.1021/es034997s PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 851IN UT WOS:000223678900040 PM 15461181 ER PT J AU Rugh, JP Farrington, RB Bharathan, D Vlahinos, A Burke, R Huizenga, C Zhang, H AF Rugh, JP Farrington, RB Bharathan, D Vlahinos, A Burke, R Huizenga, C Zhang, H TI Predicting human thermal comfort in a transient nonuniform thermal environment SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article; Proceedings Paper CT 5th International Manikin and Modelling Meeting CY SEP, 2003 CL Strasbourg, FRANCE DE automotive; human physiology; numerical modeling; thermal comfort; thermal manikin AB The National Renewable Energy Laboratory has developed a suite of thermal comfort tools to assist in the development of smaller and more efficient climate control systems in automobiles. These tools, which include a 126-segment sweating manikin, a finite element physiological model of the human body, and a psychological model based on human testing, are designed to predict human thermal comfort in transient, nonuniform thermal environments, such as automobiles. The manikin measures the heat loss from the human body in the vehicle environment and sends the heat flux from each segment to the physiological model. The physiological model predicts the body's response to the environment, determines 126-segment skin temperatures, sweat rate, and breathing rate, and transmits the data to the manikin. The psychological model uses temperature data from the physiological model to predict the local and global thermal comfort as a function of local skin and core temperatures and their rates of change. Results of initial integration testing show the thermal response of a manikin segment to transient environmental conditions. C1 Natl Renewable Energy Lab, Golden, CO USA. Adv Engn Solut, Castle Rock, CO 80104 USA. Measurement Technol NW, Seattle, WA 98199 USA. Univ Calif Berkeley, Ctr Environm Design Res, Berkeley, CA 94720 USA. RP Rugh, JP (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO USA. EM john_rugh@nrel.gov NR 6 TC 15 Z9 16 U1 0 U2 17 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1439-6319 J9 EUR J APPL PHYSIOL JI Eur. J. Appl. Physiol. PD SEP PY 2004 VL 92 IS 6 BP 721 EP 727 DI 10.1007/s00421-004-1125-2 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 862UZ UT WOS:000224518000026 PM 15221399 ER PT J AU Lagergren, K Cederwall, B Clark, RM Fallon, P Gorgen, A Issa, T Janssens, RVF Johnson, A Macchiavelli, AO Milechina, L Sarantites, DG Wyss, R AF Lagergren, K Cederwall, B Clark, RM Fallon, P Gorgen, A Issa, T Janssens, RVF Johnson, A Macchiavelli, AO Milechina, L Sarantites, DG Wyss, R TI Isospectral superdeformed bands in the N=46 nuclei Mo-88 and Tc-89 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID IDENTICAL BANDS; RESPONSE CHARACTERISTICS; PSEUDOSPIN SYMMETRY; CHANNEL-SELECTION; MEAN-FIELD; STATES; ALIGNMENT; GAMMASPHERE AB Superdeformed bands in Mo-88 and Tc-89 were populated Using Ca-40-induced fusion-evaporation reactions on Ni-58 at a beam energy of 185 MeV. Gamma-rays emitted in the reactions were detected using the Gammasphere spectrometer, in coincidence with charged particles detected by the Microball array. A new superdeformed band was assigned to the nucleus Mo-88, leading to a revisit of earlier configuration assignments for superdeformed structures in this nucleus. In particular, the theoretical interpretation of a pair of identical (isospectral) superdeformed bands in Mo-88/Tc-89 is discussed. The configurations that are assigned to the four SD bands belonging to Mo-88 have properties that are predicted to be significantly affected by pair correlations. C1 Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. RP Lagergren, K (reprint author), Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. EM karin@nuclear.kth.se RI Cederwall, Bo/M-3337-2014; OI Cederwall, Bo/0000-0003-1771-2656; Gorgen, Andreas/0000-0003-1916-9941 NR 24 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 2004 VL 21 IS 3 BP 375 EP 381 DI 10.1140/epja/i2003-10222-0 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 865WB UT WOS:000224733800004 ER PT J AU Thomas, JC Achouri, L Aysto, J Beraud, R Blank, B Canchel, G Czajkowski, S Dendooven, P Ensallem, A Giovinazzo, J Guillet, N Honkanen, J Jokinen, A Laird, A Lewitowicz, M Longour, C Santos, FD Perajarvi, K Stanoiu, M AF Thomas, JC Achouri, L Aysto, J Beraud, R Blank, B Canchel, G Czajkowski, S Dendooven, P Ensallem, A Giovinazzo, J Guillet, N Honkanen, J Jokinen, A Laird, A Lewitowicz, M Longour, C Santos, FD Perajarvi, K Stanoiu, M TI Beta-decay properties of Si-25 and P-26 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID SD-SHELL NUCLEI; GAMOW-TELLER STRENGTH; DELAYED-PROTON DECAY; ENERGY-LEVELS; LIGHT-NUCLEI; 2ND-CLASS CURRENTS; ASYMMETRY; MG-21; RATES; A=20 AB The beta-decay properties of the neutron-deficient nuclei Si-25 and P-26 have been investigated at the GANIL/LISE3 facility by means of charged-particle and gamma-ray spectroscopy. The decay schemes obtained and the Gamow-Teller strength distributions are compared to shell-model calculations based on the USD interaction. B(GT) values derived from the absolute measurement of the beta-decay branching ratios give rise to a quenching factor of the Gamow-Teller strength of 0.6. A precise half-life of 43.7 (6) ms was determined for (26)p, the beta-(2)p decay mode of which is described. C1 Ctr Etud Nucl Bordeaux Gradignan, F-33170 Gradignan, France. Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium. LPC Caen, F-14050 Caen, France. Univ Jyvaskyla, Dept Phys, Jyvaskyla 40014, Finland. Inst Phys Nucl, F-69622 Villeurbanne, France. Kernfys Versneller Inst, NL-9747 AA Groningen, Netherlands. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Grand Accelerateur Natl Ions Lourds, F-14076 Caen 5, France. Inst Rech Subatom, F-67037 Strasbourg, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Inst Phys Nucl, F-91406 Orsay, France. RP Thomas, JC (reprint author), Ctr Etud Nucl Bordeaux Gradignan, Allee Haut Vigneau,BP 120, F-33170 Gradignan, France. EM blank@cenbg.in2p3.fr RI Jokinen, Ari/C-2477-2017 OI Jokinen, Ari/0000-0002-0451-125X NR 41 TC 32 Z9 32 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 2004 VL 21 IS 3 BP 419 EP 435 DI 10.1140/epja/i2003-10218-8 PG 17 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 865WB UT WOS:000224733800008 ER PT J AU Shnirman, A Mozyrsky, D Martin, I AF Shnirman, A Mozyrsky, D Martin, I TI Output spectrum of a measuring device at arbitrary voltage and temperature SO EUROPHYSICS LETTERS LA English DT Article ID SINGLE-ELECTRON TRANSISTOR; RELAXATION; DETECTOR AB We calculate the noise spectrum of the electrical current in a quantum point contact which is used for continuous measurements of a two-level system (qubit). We generalize the previous results obtained for the regime of high transport voltages (when V is much larger than the qubit's energy level splitting B (we put e = (h) over bar = 1)) to the case of arbitrary voltages and temperatures. When V similar to B, the background output spectrum is essentially asymmetric in frequency, i.e., it is no longer classical. Yet, the spectrum of the amplified signal, i.e., the two coherent peaks at omega = +/-B, is still symmetric. In the emission (negative frequency) part of the spectrum the coherent peak can be 8 times higher than the background pedestal. Alternatively, this ratio can be seen in the directly measureable excess noise. For V < B and T = 0 the coherent peaks do not appear at all. We relate these results to the properties of linear amplifiers. C1 Univ Karlsruhe, Inst Theoret Festkorperphys, D-76128 Karlsruhe, Germany. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Shnirman, A (reprint author), Univ Karlsruhe, Inst Theoret Festkorperphys, Kaiserstr 12, D-76128 Karlsruhe, Germany. NR 32 TC 25 Z9 25 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP PY 2004 VL 67 IS 5 BP 840 EP 846 DI 10.1209/epl/i2003-10309-6 PG 7 WC Physics, Multidisciplinary SC Physics GA 858NU UT WOS:000224199800023 ER PT J AU Nussinov, Z Biskup, M Chayes, L van den Brink, J AF Nussinov, Z Biskup, M Chayes, L van den Brink, J TI Orbital order in classical models of transition-metal compounds SO EUROPHYSICS LETTERS LA English DT Article ID X-RAY-SCATTERING; PHASE-TRANSITIONS; REFLECTION POSITIVITY; SPIN SYSTEMS; FLUCTUATIONS; LATTICE; OXIDES; RANGE; MANGANITES; DEGENERACY AB We study the classical 120 degree and related orbital models. These are the classical limits of quantum models which describe the interactions among orbitals of transition-metal compounds. We demonstrate that at low temperatures these models exhibit a long-range order which arises via an "order by disorder" mechanism. This strongly indicates that there is orbital ordering in the quantum version of these models, notwithstanding recent rigorous results on the absence of spin order in these systems. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. Leiden Univ, Lorentz Inst Theoret Phys, NL-2300 RA Leiden, Netherlands. RP Nussinov, Z (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Biskup, Marek/A-7204-2010; van den Brink, Jeroen/E-5670-2011 OI van den Brink, Jeroen/0000-0001-6594-9610 NR 36 TC 75 Z9 77 U1 0 U2 4 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP PY 2004 VL 67 IS 6 BP 990 EP 996 DI 10.1209/epl/i2004-10134-5 PG 7 WC Physics, Multidisciplinary SC Physics GA 866WW UT WOS:000224805100019 ER PT J AU Billig, M AF Billig, M TI The Venezuelan oil crisis - How to secure America's energy SO FOREIGN AFFAIRS LA English DT Editorial Material C1 US DOE, Washington, DC USA. RP Billig, M (reprint author), US DOE, Washington, DC 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 2004 VL 83 IS 5 BP 2 EP 7 DI 10.2307/20034062 PG 6 WC International Relations SC International Relations GA 846FC UT WOS:000223299800001 ER PT J AU Jayakumar, RJ AF Jayakumar, RJ TI Transport and stability studies in negative central shear advanced tokamak plasmas SO FUSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th International Stellarator Workshop CY SEP 22-26, 2003 CL Greifswald, GERMANY DE tokamak; stability; transport ID DIII-D TOKAMAK; REVERSED MAGNETIC SHEAR; H-MODE DISCHARGES; FUSION TEST REACTOR; CURRENT DRIVE; BARRIER FORMATION; ASDEX UPGRADE; MAGNETOHYDRODYNAMIC STABILITY; ENHANCED CONFINEMENT; ELECTRON CONFINEMENT AB Achieving high performance for long duration is a key goal of advanced tokamak research around the world To this end, tokamak experiments are focusing on obtaining (a) a high fraction of well-aligned noninductive plasma current, (b) internal transport barriers (ITBs) in the ion and electron transport channels over a wide radial region with transport approaching neoclassical values, and (c) control of resistive wall modes and neoclassical tearing modes that limit the achievable beta. A current profile that yields a negative central magnetic shear (NCS) in the core is consistent with this focus; NCS is conducive for obtaining ITBs, a high degree of bootstrap current alignment, and reaching the second stability region for ideal ballooning modes, while being stable to ideal kink modes at high beta with wall stabilization and neoclassical tearing modes in the core NCS region. Much progress has been made in obtaining advanced performance in several tokamaks through an increasing understanding of the stability and transport properties of tokamak plasmas. Radio-frequency and neutral beam current drive scenarios are routinely developed and implemented in experiments to access new advanced regimes and control plasma profiles. Short-duration and sustained ITBs have been obtained in the ion and electron channels. The formation of an ITB is attributable to the stabilization of ion and electron temperature gradient and trapped electron modes by the negative shear and by the enhanced E x B flow shear rate and rarefaction of resonant surfaces near the rational q(min) values. The progress in understanding the underlying physics in such plasmas and the development of techniques and technology would be of interest in stellarator efforts. C1 Lawrence Livermore Natl Lab, Livermore, CA USA. RP Jayakumar, RJ (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. EM jayakumar@fusion.gat.com NR 62 TC 2 Z9 2 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 1536-1055 J9 FUSION SCI TECHNOL JI Fusion Sci. Technol. PD SEP PY 2004 VL 46 IS 2 BP 225 EP 233 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 859IJ UT WOS:000224256300003 ER PT J AU Baldzuhn, J Baylor, LR Lyon, JF AF Baldzuhn, J Baylor, LR Lyon, JF TI Penetration studies for deuterium pellets in Wendelstein 7-AS SO FUSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th International Stellarator Workshop CY SEP 22-26, 2003 CL Greifswald, GERMANY DE pellets; suprathermal particles; particle fueling; W7-AS ID STELLARATOR; ABLATION; CLOUD; INJECTION; DATABASE; PLASMAS; TOKAMAK AB Deep particle fueling into a fusion-relevant plasma can be performed by the injection of cryogenic hydrogen or deuterium pellets. However, the penetration depth and fueling efficiency can be greatly limited when enhanced pellet ablation by fast particles occurs. Only a limited database exists for the penetration depth of ice pellets into stellarators. The penetration depth is measured during pellet injection into purely electron cyclotron resonance heated plasmas on the Wendelstein 7-AS (W7-AS) stellarator. These data are compared with the International Pellet Ablation Database (IPADBASE). Good agreement is found, if the neutral gas shielding model is applied for the scaling law of the penetration depth. The experimental data from W7-AS are used as a basis for planning a new pellet injection system for the Wendelstein 7-X stellarator, which is now under construction. C1 EURATOM, Max Planck Inst Plasma Phys, D-17491 Greifswald, Germany. Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. RP Baldzuhn, J (reprint author), EURATOM, Max Planck Inst Plasma Phys, Wendelsteinstr 1, D-17491 Greifswald, Germany. EM baldzuhn@ipp.mpg.de NR 13 TC 3 Z9 3 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 1536-1055 J9 FUSION SCI TECHNOL JI Fusion Sci. Technol. PD SEP PY 2004 VL 46 IS 2 BP 348 EP 354 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 859IJ UT WOS:000224256300018 ER PT J AU Russell, LB AF Russell, LB TI Effects of male germ-cell stage on the frequency, nature, and spectrum of induced specific-locus mutations in the mouse SO GENETICA LA English DT Article; Proceedings Paper CT 2nd Georgia Genetics Symposium CY SEP 06-09, 2000 CL Univ Georgia, Athens, GA HO Univ Georgia DE chemical mutagenesis; germ-cell stage sensitivity; germline mutations; mutational spectrum; specific-locus test ID DOMINANT LETHAL MUTATIONS; MALE-MICE; MOLECULAR ANALYSIS; DELETION COMPLEX; INDUCTION; REGION; SPERMATOGONIA; ETOPOSIDE; CHROMOSOME-4; ACRYLAMIDE AB By means of the mouse specific-locus test (SLT) with visible markers, which is capable of detecting intragenic mutations as well as larger lesions, about 20 mutagens have been studied comparatively across arrays of male germ-cell stages. In addition, a very large historical control, accumulated over decades, provides data on spontaneous mutations in males. Each mutagen has a characteristic germ-cell-stage sensitivity pattern. Although most chemicals yield their maximum numbers of mutations following exposure of spermatozoa and late spermatids, mutagens have now been identified that peak in each of the major stages of spermatogenesis and spermiogenesis, including those in which effects on recombination can also be induced. Stem-cell spermatogonia have yielded positive results with only five of 15 mutagenic chemicals. In postspermatogonial stages, all chemicals, as well as radiations, induce primarily large lesions (LL). By contrast, in spermatogonia (either stem-cell or differentiating) all chemicals except one ( bleomycin) produce very few such lesions. The spectrum of relative mutation frequencies at the seven loci of the SLT is characteristic for treated germ-cell stage and mutagen. Treatments that induce primarily LL are characterized by a great preponderance of s (Ednrb)-locus mutations ( possibly due to a paucity of haplo-insufficient genes in the surrounding region); and those that induce very few, if any, LL by a great preponderance of p-locus mutations. Spontaneous locus-spectra differ from both types of treatment-induced spectra; moreover, there are two distinct types of spontaneous spectra, depending on whether mutations occurred in mitotic cells or during the perigametic interval. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Russell, LB (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. EM russelllb@ornl.gov FU NIEHS NIH HHS [Y1-ES-8048/0524-I119-A1] NR 45 TC 30 Z9 30 U1 2 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0016-6707 J9 GENETICA JI Genetica PD SEP PY 2004 VL 122 IS 1 BP 25 EP 36 DI 10.1007/s10709-004-1443-7 PG 12 WC Genetics & Heredity SC Genetics & Heredity GA 867QT UT WOS:000224858000004 PM 15619958 ER PT J AU Angert, A Cappa, CD DePaolo, DJ AF Angert, A Cappa, CD DePaolo, DJ TI Kinetic O-17 effects in the hydrologic cycle: Indirect evidence and implications SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID TRIPLE-ISOTOPE COMPOSITION; HYDROGEN ISOTOPES; STABLE ISOTOPES; OXYGEN; PRECIPITATION; FRACTIONATION; WATER; PRODUCTIVITY; DELTA-O-17; BIOSPHERE AB The abundances of O-18 and deuterium in the present and past hydrologic cycle have proven to be an important tool in Earth systems science. In contrast, the abundance of O-17 in precipitation has thus far been assumed to carry no additional information to that of O-18. Here, we demonstrate, using known constraints on oxygen isotope abundances from the O-2 cycle and existing data about the natural abundance of O-17 in water, that the relationship between the discrimination against O-17 and O-18 in water may vary. This relationship, presented here as theta = In ((17)alpha)/In ((18)alpha), is found to be 0.511 +/- 0.005 for kinetic transport effects and 0.526 +/- 0.001 for equilibrium effects, with very low temperature sensitivity. As a result, the (17)Delta of precipitation is controlled primarily by kinetic effects during evaporation of the initial vapor and, in contrast to the deuterium excess, is independent of the temperature at the evaporation (and condensation) site. This makes (17)Delta a unique tracer that complements O-18 and deuterium, and may allow for a decoupling of changes in the temperature of the ocean, that serves as the vapor source, from changes in the relative humidity above it. In addition, the (17)Delta of ice caps is influenced by the kinetic effects in ice formation, and therefore measurement of ice (17)Delta can be used as an additional constraint for better understanding and parameterization of these effects. Copyright (C) 2004 Elsevier Ltd C1 Univ Calif Berkeley, Berkeley Atmospher Sci Ctr, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Angert, A (reprint author), Univ Calif Berkeley, Berkeley Atmospher Sci Ctr, Berkeley, CA 94720 USA. EM angert@atmos.berkeley.edu NR 35 TC 43 Z9 47 U1 3 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2004 VL 68 IS 17 BP 3487 EP 3495 DI 10.1016/j.gca.2004.02.010 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 850EJ UT WOS:000223593700004 ER PT J AU Anovitz, LM Labotka, TC Blencoe, JG Horita, J AF Anovitz, LM Labotka, TC Blencoe, JG Horita, J TI Experimental determination of the activity-composition relations and phase equilibria of H2O-CO2-NaCl fluids at 500 degrees C, 500 bars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PALLADIUM-SILVER ALLOYS; CARBON-DIOXIDE; VOLUMETRIC PROPERTIES; HIGH-TEMPERATURES; HIGH-PRESSURES; DEGREES-C; SYSTEM H2O-CO2-NACL; NACL-H2O SOLUTIONS; SOLUBILITY; EQUATION AB An understanding of the activity-composition (a-X) relations and phase equilibria of halite-bearing, mixed-species supercritical fluids is critically important in many geological and industrial applications. We have performed experiments on H2O-CO2-NaCl fluids at 500degreesC, 500 bar, to obtain accurate and precise data on their a-X relations and phase equilibria. Two kinds of experiments were performed. First, H2O-CO2-NaCl samples were reacted at fixed activities of H2O = 0.078, 0.350, 0.425, 0.448, 0.553, 0.560, 0.606, 0.678, 0.798, 0.841, and 0.935 to define the tie lines of known H2O activity in the halite-vapor and vapor-brine fields. Results indicate that fluids with all but the last of these H2O activities lie in the vapor-halite two-phase region and that a fluid with all,1 = 0.841 has a composition close to the three-phase (vapor + brine + halite) field. A second set of experiments was performed to determine the solubility of NaCl in parts of the system in equilibrium with halite. Data from these experiments suggest that the vapor corner of the three-phase field lies at H2O contents above XH2O = 0.58 and X-NaCl = 0.06, and below X-H2O = 0.75 and X-NaCl = 0.06, which is a significantly more H2O-rich composition than indicated by existing thermodynamic models. Copyright (C) 2004 Elsevier Ltd C1 Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Anovitz, LM (reprint author), Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA. EM lanovitz@utk.edu RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 63 TC 16 Z9 16 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2004 VL 68 IS 17 BP 3557 EP 3567 DI 10.1016/j.gca.2003.12.012 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 850EJ UT WOS:000223593700010 ER PT J AU Cole, DR Horita, J Polyakov, VB Valley, JW Spicuzza, MJ Coffey, DW AF Cole, DR Horita, J Polyakov, VB Valley, JW Spicuzza, MJ Coffey, DW TI An experimental and theoretical determination of oxygen isotope fractionation in the system magnetite-H2O from 300 to 800 degrees C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CO-SUBSTITUTED MAGNETITES; HIGH-TEMPERATURE PHASE; MOSSBAUER-SPECTROSCOPY; ION MICROPROBE; THERMODYNAMIC PROPERTIES; EQUILIBRIUM OXYGEN; HYDROGEN ISOTOPES; HEAT-CAPACITY; HIGH-PRESSURE; GAMMA-RAYS AB Oxygen isotope fractionations have been determined between magnetite and water from 300 to 800degreesC and pressures between 10 and 215MPa. We selected three reaction pathways to investigate fractionation: (a) reaction of fine-grained magnetite with dilute aqueous NaCl solutions; (b) reduction of fine-grained hematite through reaction with dilute acetic acid; and (c) oxidation of fine iron power in either pure water or dilute NaCl solutions. Effective use of acetic acid was limited to temperatures up to about 400degreesC, whereas oxide-solution isotope exchange experiments were conducted at all temperatures. Equilibrium O-18/O-16 fractionation factors were calculated from the oxide-water experiments by means of the partial isotope exchange method, where generally four isotopically different waters were used at any given temperature. Each run product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and on a limited basis, high-resolution transmission electron microscopy (HRTEM) and Mossbauer spectroscopy. Results from the microscopic examinations indicate the formation of well-crystallized octahedra and dodecahedra. of magnetite where the extent of crystallization, grain size, and grain habit depend on the initial starting material, P, T, solution composition, and duration of the run. The greatest amount of oxygen isotope exchange (similar to90% or greater) was observed in experiments where magnetite either recrystallized in the presence of 0.5 m NaCl from 500 to 800degreesC or formed from hematite reacted with 0.5 m acetic acid at 300, 350 and 400degreesC. Fractionation factors (10(3) In alpha(mt-H2O)) determined from these partial exchange experiments exhibit a steep decrease (to more negative values) with decreasing temperature down to about 500degreesC, followed by shallower slope. A least-squares regression model of these partial exchange data, which accounts for analytical errors and errors generated by mass balance calculations, gives the following expression for fractionation that exhibits no minimum: 1000 In alpha(mt-w) = -8.984(+/-0.3803)x + 3.302(+/-0.377)x(2) - 0.426(+/-0.092)x(3) with an R-2 = 0.99 for 300 less than or equal to T less than or equal to 800degreesC (x = 10(6)/T-2). The Fe oxidation results also exhibit this type of temperature dependence but shifted to slightly more negative 10(3) In a values; there is the suggestion that a kinetic isotope effect may contribute to these fractionations. A theoretical assessment of oxygen isotope fractionation using beta-factors derived from heat capacity and Mossbauer temperature (second-order Doppler) shift measurements combined with known beta-factors for pure water yield fractionations that are somewhat more negative compared to those determined experimentally. This deviation may be due to the combined solute effects of dissolved magnetite plus NaCl (aq), as well as an underestimation of beta(mt) at low temperatures. The new magnetite-water experimental fractionations agree reasonably well with results reported from other experimental studies for temperatures > 500degreesC, but differ significantly with estimates based on quasi-theoretical and empirical approaches. Calcite-magnetite and quartz-magnetite fractionation factors estimated from the combination of magnetite P's calculated in this study with those for calcite and quartz reported by Clayton and Kieffer (1991) agree very closely with experimentally determined mineral-pair fractionations. Copyright (C) 2004 Elsevier Ltd C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. VI Vernadskii Inst Geochem & Analyt Chem, Moscow B-334, Russia. Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Cole, DR (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. EM coledr@ornl.gov RI Valley, John/B-3466-2011; Polyakov, Veniamin/N-9747-2015 OI Valley, John/0000-0003-3530-2722; Polyakov, Veniamin/0000-0002-6718-580X NR 72 TC 27 Z9 28 U1 0 U2 14 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 2004 VL 68 IS 17 BP 3569 EP 3585 DI 10.1016/j.gca.2004.02.017 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 850EJ UT WOS:000223593700011 ER PT J AU Dixon, ET Bogard, DD Garrison, DH Rubin, AE AF Dixon, ET Bogard, DD Garrison, DH Rubin, AE TI Ar-39-Ar-40 evidence for early impact events on the LL parent body SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID L-GROUP CHONDRITES; AR-AR AGES; THERMAL HISTORY; H-CHONDRITES; SHERGOTTY ACHONDRITE; METEORITES; METAMORPHISM; FRAGMENTATION; AR-40-AR-39; CHRONOLOGY AB We determined Ar-39-Ar-40 ages of eight LL chondrites, and one igneous inclusion from an LL chondrite, with the object of understanding the thermal history of the LL-chondrite parent body. The meteorites in this study have a range of petrographic types from LL3.3 to LL6, and shock stages from SI to S4. These meteorites reveal a range of K-Ar ages from greater than or equal to3.66 to greater than or equal to4.50 Ga, and peak ages from greater than or equal to3.74 to greater than or equal to4.55 Ga. Significantly, three of the eight chondrites (LL4, 5, 6) have K-Ar ages of similar to4.27 Ga. One of these (MIL99301) preserves an Ar-39-Ar-40 age of 4.23 +/- 0.03 Ga from low-temperature extractions, and an older age of 4.52 +/- 0.08 Ga from the highest temperature extractions. In addition, an igneous-textured impact melt DOM85505,22 has a peak Ar-39-Ar-40 age of greater than or equal to4.27 Ga. We interpret these results as evidence for impact events that occurred at about 4.27 Ga on the LL parent body that produced local impact melts, reset the Ar-39-Ar-40 ages of some meteorites, and exhumed (or interred) others, resulting in a range of cooling ages. The somewhat younger peak age of 3.74 Ga from GR095658 (LL3.3) suggests an additional impact event close to timing of impact-reset ages of some other ordinary chondrites between 3.6-3.8 Ga. The results from MIL99301 suggest that some apparently unshocked (S1) chondrites may have substantially reset Ar-39-Ar-40 ages. A previous petrographic investigation of MIL99301 suggested that reheating to temperatures less than or equal to type 4 petrographic conditions (600degreesC) caused fractures in olivine to anneal, resulting in a low apparent shock stage of S1 (unshocked). The Ar-39-Ar-40 age spectrum of MIL99301 is consistent with this interpretation. Older ages from high-T extractions may date an earlier impact event at 4.52 0.08 Ga, whereas younger ages from lower-T extractions date a later impact event at 4.23 0.03 Ga that may have caused annealing of feldspar and olivine. Copyright (C) 2004 Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, ARES, Code SR, Houston, TX 77058 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Los Alamos Natl Lab, Isotope & Nucl Chem CINC, POB 1663,MS J514, Los Alamos, NM 87545 USA. EM edixon@lanl.gov NR 52 TC 27 Z9 28 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2004 VL 68 IS 18 BP 3779 EP 3790 DI 10.1016/j.gca.2004.02.023 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 850SO UT WOS:000223632900011 ER PT J AU Ekdahl, EJ Teranes, JL Guilderson, TP Turton, CL McAndrews, JH Wittkop, CA Stoermer, EF AF Ekdahl, EJ Teranes, JL Guilderson, TP Turton, CL McAndrews, JH Wittkop, CA Stoermer, EF TI Prehistorical record of cultural eutrophication from Crawford Lake, Canada SO GEOLOGY LA English DT Article DE diatoms; eutrophication; Iroquoian; carbon; ecological disturbance; Crawford Lake ID BOREAL-FOREST LAKE; SOUTHERN ONTARIO; AGE CALIBRATION; LAND-USE AB Cultural eutrophication-the process by which human activities increase nutrient input rates to aquatic ecosystems and thereby cause undesirable changes in surface-water quality-is generally thought to have begun with the start of the industrial era. The prehistoric dimension of human impacts on aquatic ecosystems remains relatively undescribed, particularly in North America. Here we present fossil plankton data (diatoms and rotifers), organic and inorganic carbon accumulations, and carbon isotope ratios from a 1000 yr sediment core record from Crawford Lake, Ontario, Canada. The data document increased nutrient input to Crawford Lake caused by Iroquoian horticultural activity from A.D. 1268 to 1486 and show how this increased nutrient input elevated lake productivity, caused bottom-water anoxia, and irreversibly altered diatom community structure within just a few years. Iroquoian settlement in the region declined in the fifteenth century, yet diatom communities and lake circulation never recovered to the predisturbance state. A second phase of cultural eutrophication starting in A.D. 1867, initiated by Canadian agricultural disturbance, increased lake productivity but had comparatively less impact on diatom assemblages and carbon-storage pathways than the initial Iroquoian disturbance. This study deepens our understanding of the impact of cultural eutrophication on lake systems, highlights the lasting influence of initial environmental perturbation, and contributes to the debate on the ecological impacts of density and agricultural practices of native North American inhabitants. C1 Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Royal Ontario Museum, Toronto, ON M5S 2C6, Canada. Univ Toronto, Dept Bot, Toronto, ON M5S 3B2, Canada. Univ Toronto, Dept Geol, Toronto, ON M5S 3B2, Canada. Univ Minnesota, Limnol Res Ctr, Dept Geol & Geophys, Minneapolis, MN 55455 USA. Univ Michigan, Sch Nat Resources, Ann Arbor, MI 48109 USA. RP Ekdahl, EJ (reprint author), Univ Michigan, Dept Geol Sci, 2534 CC Little Bldg, Ann Arbor, MI 48109 USA. NR 27 TC 40 Z9 43 U1 4 U2 22 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD SEP PY 2004 VL 32 IS 9 BP 745 EP 748 DI 10.1130/G20496.1 PG 4 WC Geology SC Geology GA 851PG UT WOS:000223696500003 ER PT J AU Babich, LP Donskoi, EN Kutsyk, IM Roussel-Dupre, RA AF Babich, LP Donskoi, EN Kutsyk, IM Roussel-Dupre, RA TI Runaway relativistic electron avalanche Bremsstrahlung in the atmosphere SO GEOMAGNETISM AND AERONOMY LA English DT Article ID GAMMA-RAY FLASHES; AIR BREAKDOWN; NEUTRAL ATOMS; THUNDERSTORM; FIELDS AB Relativistic runaway electron avalanche bremsstrahlung in the atmosphere has been calculated in two versions using the Monte-Carlo method. In one version, the spectral-angular distribution of bremsstrahlung was calculated in accordance with the process of avalanche development. In another version, first, the spectralangular distribution of the bremsstrahlung generation rate for the steady-state angle and energy distributions of electrons and, then, the bremsstrahlung characteristics have been calculated for specified times. A universal energy distribution independent of delta exists in a wide range of overvoltages (delta). The spectral-angular distributions of the emission (more accurate than the distributions published previously) are recommended for interpreting results of the field experimental studies of the processes responsible for the generation of penetrating radiation by thunderstorm fields. C1 RFYaTs, VNIIEF, Nizhnii Novgorod, Russia. LANL, Los Alamos, NM 87545 USA. RP Babich, LP (reprint author), RFYaTs, VNIIEF, Nizhnii Novgorod, Russia. NR 21 TC 13 Z9 13 U1 0 U2 0 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 0016-7932 J9 GEOMAGN AERONOMY+ JI Geomagn. Aeron. PD SEP-OCT PY 2004 VL 44 IS 5 BP 645 EP 651 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 867YT UT WOS:000224879700018 ER PT J AU Commer, M Newman, G AF Commer, M Newman, G TI A parallel finite-difference approach for 3D transient electromagnetic modeling with galvanic sources SO GEOPHYSICS LA English DT Article ID 3-DIMENSIONAL STRUCTURES; EQUATIONS; EARTH; TIME; COEFFICIENTS; INVERSION; DIFFUSION; ALGORITHM; GERMANY; BODY AB A parallel finite-difference algorithm for the solution of diffusive, three-dimensional (313) transient electromagnetic field simulations is presented. The purpose of the scheme is the simulation of both electric fields and the time derivative of magnetic fields generated by galvanic sources (grounded wires) over arbitrarily complicated distributions of conductivity and magnetic permeability. Using a staggered grid and a modified DuFort-Frankel method, the scheme steps Maxwell's equations in time. Electric field initialization is done by a conjugate-gradient solution of a 3D Poisson problem, as is common in 3D resistivity modeling. Instead of calculating the initial magnetic field directly, its time derivative and curl are employed in order to advance the electric field in time. A divergence-free condition is enforced for both the magnetic-field time derivative and the total conduction-current density, providing accurate results at late times. In order to simulate large realistic earth models, the algorithm has been designed to run on parallel computer platforms. The upward continuation boundary condition for a stable solution in the infinitely resistive air layer involves a two-dimensional parallel fast Fourier transform. Example simulations are compared with analytical, integral-equation and spectral Lanczos decomposition solutions and demonstrate the accuracy of the scheme. C1 Univ Cologne, Inst Geophys & Meteorol, D-50923 Cologne, Germany. Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Commer, M (reprint author), Univ Cologne, Inst Geophys & Meteorol, Albertus Magnus Pl, D-50923 Cologne, Germany. EM m.commer@uni-koeln.de; ganewman@lbl.gov RI Newman, Gregory/G-2813-2015; Commer, Michael/G-3350-2015 OI Commer, Michael/0000-0003-0015-9217 NR 37 TC 54 Z9 64 U1 1 U2 20 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 2004 VL 69 IS 5 BP 1192 EP 1202 DI 10.1190/1.1801936 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 861XC UT WOS:000224450900006 ER PT J AU White, MD Oostrom, M Lenhard, RJ AF White, MD Oostrom, M Lenhard, RJ TI A practical model for mobile, residual, and entrapped NAPL in water-wet porous media SO GROUND WATER LA English DT Article ID GOVERNING MULTIPHASE FLOW; NONAQUEOUS-PHASE LIQUID; VARIABLY-SATURATED SAND; CARBON-TETRACHLORIDE; WETTABILITY; AIR; ENTRAPMENT; RETENTION; BEHAVIOR; ZONE AB Flow of nonvolatile nonaqueous phase liquid (NAPL) and aqueous phases that account for mobile, entrapped, and residual NAPL in variably saturated water-wet porous media is modeled and compared against results from detailed laboratory experiments. Residual saturation formation in the vadose zone is a process that is often ignored in multifluid flow simulators, which might cause an overestimation of the volume of NAPL that reaches the ground water. Mobile NAPL is defined as being continuous in the pore space and flows under a pressure gradient or gravitational body force. Entrapped NAPL is defined as being occluded by the aqueous phase, occurring as immobile ganglia surrounded by aqueous phase in the pore space and formed when NAPL is replaced by the aqueous phase. Residual NAPL is defined as immobile, nonwater entrapped NAPL that does not drain from the pore spaces and is conceptualized as being either continuous or discontinues. Free NAPL comprises mobile and residual NAPL. The numerical model is formulated on mass conservation equation for oil and water, transported via NAPL and aqueous phases through variably saturated porous media. To account for phase transitions, a primary variable switching scheme is implemented for the oil-mass conservation equation over three phase conditions: (1) aqueous or aqueous-gas with dissolved oil, (2) aqueous or aqueous-gas with untrapped NAPL, and (3) aqueous or aqueous gas with free NAPL. Two laboratory-scale column experiments are modeled to verify the numerical model. Comparisons between the numerical simulations and experiments demonstrate the necessity to include the residual NAPL formation process in multifluid flow simulators. C1 Pacific NW Natl Lab, Hydrol Grp, Richland, WA 99352 USA. Idaho Natl Environm & Engn Lab, Subsurface Sci Initiat, Idaho Falls, ID 83415 USA. RP Oostrom, M (reprint author), Pacific NW Natl Lab, Hydrol Grp, POB 999,MS K9-33, Richland, WA 99352 USA. NR 35 TC 20 Z9 20 U1 0 U2 13 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 2004 VL 42 IS 5 BP 734 EP 746 DI 10.1111/j.1745-6584.2004.tb02727.x PG 13 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 852BI UT WOS:000223729800013 PM 15457796 ER PT J AU Kase, KR AF Kase, KR TI Radiation protection principles of NCRP SO HEALTH PHYSICS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the National-Council-on-Radiation-Protection-and-Measurement CY APR 09-10, 2003 CL Arlington, VA SP Natl Council Radiat Protect & Measurements DE national council on radiation protection and; measurements; radiation protection; safety standards; regulatory guides AB The current recommendations of the National Council on Radiation Protection and Measurements (NCRP) relative to ionizing radiation are based on radiation protection principles that developed historically as information about radiation effects on human populations became available. Because the NCRP Charter states that the NCRP will cooperate with the International Commission on Radiological Protection (ICRP), the basic principles and recommendations for radiation protection of the NCRP are closely coupled with those of the ICRP. Thus, the fundamental principles of justification, optimization, and dose limitation as initially stated in ICRP Publication 26 have been adopted and applied by the NCRP in its recommendations. ICRP and NCRP recommendations on dose limitation for the general public and for occupationally exposed individuals are based on the same analyses of radiation risk, and, while similar, there are differences reflecting the aspects of radiation application and exposure circumstances unique to the United States. The NCRP has recently extended its guidance to address exposure to individuals engaged in space activities. Several reports have been issued or are in preparation to provide recommendations on dose limitation and the development of radiation safety programs to apply the radiation protection principles in space activities. The biological basis for these recommendations is provided in these and accompanying NCRP reports. Recommendations for the application of basic radiation protection principles have been made in many reports over the years. Those that are most current appear in approximately 50 reports published in the last 15 y. These address radiation safety practices in industrial and medical institutions, control of radionuclides in the environment, protection of the public, and assessment of radiation risk. Some of the aspects of these recommendations will be discussed. Current recommendations related to radiation safety practice are based on the principles and dose limits specified in Report No. 116. The limits are based on estimates of the risk of fatal cancer and an assessment of the risk that should be tolerated by workers who are occupationally exposed and by the general public. These levels of risk are related to other risks that individuals accept in their lives. Looking to the future, one might consider other directions that the NCRP could take in developing radiation safety recommendations that are still based upon the stated principles, such as relating dose to loss of life expectancy instead of fatal cancer risk. It may also be that the principles of justification, optimization, and dose limitation should be reconsidered. For example, the NCRP may make recommendations about the relationship of radiation dose to various biological effects or outcomes and the resulting estimates of risk, but not specify dose limits. This would relieve the NCRP of the necessity to speculate about acceptable risks. One can also imagine that the principle of justification could be applied not only to the introduction of a new source of radiation, but also to the removal of an existing source of radiation, i.e., the idea of justifying decontamination efforts. It is clear that as we move into the 21st century there will be a continuing need for the NCRP to identify the principles upon which radiation protection is to be based and to provide guidance on the application of those principles for the many beneficial uses of radiation and radioactive materials in society. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Kase, KR (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM krk@slac.stanford.edu NR 46 TC 8 Z9 8 U1 1 U2 4 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 2004 VL 87 IS 3 BP 251 EP 257 DI 10.1097/00004032-200409000-00005 PG 7 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 847GO UT WOS:000223380900005 PM 15303061 ER PT J AU Jones, CR AF Jones, CR TI Radiation protection challenges facing the federal agencies SO HEALTH PHYSICS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the National-Council-on-Radiation-Protection-and-Measurement CY APR 09-10, 2003 CL Arlington, VA SP Natl Council Radiat Protect & Measurements DE national council on radiation protection and; measurements; international commission on radiological; protection; safety standards; regulatory guides AB In the United States, federal agencies are responsible for setting national policy and performance expectations for radiation protection programs. National policy establishes a regulatory regime, under which society can realize the beneficial uses of radiation while at the same time protecting workers, the public, and environment from the potential hazards of radiation. The challenges facing federal agencies continue to revolve around finding the right balance between benefit and adverse impact. Federal agencies are petitioned to support the research community to provide a sound scientific basis for informing the decision-making process related to radiation protection policy. The federal agencies are further challenged to consider the deliberations of the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) who bring together the best technical minds in the field to consider the latest scientific information and provide recommendations for establishing comprehensive and coherent radiation protection programs. The uncertainty inherent in research and the conservatism in the models and recommendations of the ICRP and NCRP should be transparent and communicated because determining the level of uncertainty and the degree of conservatism acceptable to society is a challenge for, and the responsibility of, the federal agencies in creating performance-based policies in public health and radiation protection. It is through the federal government's open, inclusive, and democratic processes where society strikes the balance that defines adequate radiation protection policy, builds public trust, and allows the radiation protection professionals to properly implement and manage that policy. C1 US DOE, Off Worker Protect Policy & Programs, Washington, DC 20585 USA. RP Jones, CR (reprint author), US DOE, Off Worker Protect Policy & Programs, EH-52,1000 Independence Ave SW, Washington, DC 20585 USA. EM Rick.Jones@eh.doe.gov NR 30 TC 5 Z9 5 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 2004 VL 87 IS 3 BP 273 EP 281 DI 10.1097/00004032-200409000-00007 PG 9 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 847GO UT WOS:000223380900007 PM 15303063 ER PT J AU Wong, PC Thomas, J AF Wong, PC Thomas, J TI Visual analytics SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Editorial Material C1 Pacific NW Natl Lab, Richland, WA USA. RP Wong, PC (reprint author), Pacific NW Natl Lab, Richland, WA USA. EM tpak.wong@pnl.gov; jim.thomas@pnl.gov NR 0 TC 55 Z9 60 U1 1 U2 6 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP-OCT PY 2004 VL 24 IS 5 BP 20 EP 21 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 851KP UT WOS:000223684300005 PM 15628096 ER PT J AU Hetzler, E Turner, A AF Hetzler, E Turner, A TI Analysis experiences using information visualization SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Pacific NW Natl Lab, Richland, WA USA. RP Hetzler, E (reprint author), Pacific NW Natl Lab, Richland, WA USA. NR 7 TC 25 Z9 25 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD SEP-OCT PY 2004 VL 24 IS 5 BP 22 EP 26 DI 10.1109/MCG.2004.22 PG 5 WC Computer Science, Software Engineering SC Computer Science GA 851KP UT WOS:000223684300006 PM 15628097 ER PT J AU Vo-Dinh, T Stokes, DL Wabuyele, MB Martin, ME Song, JM Jagannathan, R Michaud, E Lee, RJ Pan, XG AF Vo-Dinh, T Stokes, DL Wabuyele, MB Martin, ME Song, JM Jagannathan, R Michaud, E Lee, RJ Pan, XG TI A hyperspectral imaging system for in vivo optical diagnosis SO IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE LA English DT Article ID ACOUSTOOPTIC TUNABLE FILTER; CANCER-DIAGNOSIS; FLUORESCENCE C1 Oak Ridge Natl Lab, Div Life Sci, Ctr Adv Biomed Photon, Oak Ridge, TN 37831 USA. Chungnam Natl Univ, Dept Chem, Taejon, South Korea. Ohio State Univ, Coll Pharm, Columbus, OH 43210 USA. Ohio State Univ, Ctr Comprehens Canc, Columbus, OH 43210 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Ctr Adv Biomed Photon, POB 2008, Oak Ridge, TN 37831 USA. EM vodinht@oml.gov FU NCI NIH HHS [R01 CA88787-01] NR 17 TC 66 Z9 69 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0739-5175 J9 IEEE ENG MED BIOL JI IEEE Eng. Med. Biol. Mag. PD SEP-OCT PY 2004 VL 23 IS 5 BP 40 EP 49 PG 10 WC Engineering, Biomedical; Medical Informatics SC Engineering; Medical Informatics GA 868WD UT WOS:000224942900007 PM 15565798 ER PT J AU Liu, Y Braiman, Y AF Liu, Y Braiman, Y TI Synchronization of high-power broad-area semiconductor lasers SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE broad-area laser; external cavity; grating; injection locking; laser array; lens array; nonlinear dynamics; semiconductor laser ID SINGLE-MODE OPERATION; EXTERNAL-CAVITY; DIODE-LASER; INJECTION LOCKING; PHASE-LOCKING; ARRAY; BEAM; SYSTEM; FEEDBACK; MIRROR AB Semiconductor lasers offer significant operational advantages due to their compactness and high electrical-optical conversion efficiency. The major drawback in considering semiconductor lasers for many applications is the relatively small emission power that can be obtained from a single semiconductor laser. Synchronization of laser arrays provides a unique solution to this limitation. In this paper, we describe our recent research on the synchronization of high-power broad-area semiconductor lasers and laser arrays. We demonstrate experimental results on 1) simultaneous injection locking of multiple broad-area lasers to achieve single longitudinal/transverse mode beams and 2) synchronization and coherent beam combination of an integrated 19 broad-area laser array based on a scalable external cavity. A number of issues in the synchronization of broad-area lasers have been addressed in this paper. These include the effects of laser coupling on the array synchronization performance and the gigahertz complementary intensity oscillations occurring at different transverse modes of broad-area lasers subject to the optical injection. C1 Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Comp & Computat Sci Directorate, Oak Ridge, TN 37831 USA. RP Liu, Y (reprint author), Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Comp & Computat Sci Directorate, POB 2008, Oak Ridge, TN 37831 USA. EM liuy2@ornl.gov NR 46 TC 8 Z9 11 U1 3 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD SEP-OCT PY 2004 VL 10 IS 5 BP 1013 EP 1024 DI 10.1109/JSTQE.2004.835310 PG 12 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 878RU UT WOS:000225665200022 ER PT J AU Nordquist, CD Muyshondt, A Pack, MV Finnegan, PS Dyck, CW Reines, IC Kraus, GM Plut, TA Sloan, GR Goldsmith, CL Sullivan, CT AF Nordquist, CD Muyshondt, A Pack, MV Finnegan, PS Dyck, CW Reines, IC Kraus, GM Plut, TA Sloan, GR Goldsmith, CL Sullivan, CT TI An X-band to Ku-band RF MEMS switched coplanar strip filter SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE adaptive filters; microelectromechanical devices; switched filters; tunable filters ID INTEGRATED-CIRCUITS; CAPACITORS; LINES AB Radio frequency microelectromechanical systems (RF MEMS) are key enabling technologies for miniature reconfigurable circuits such as microwave filters. We present a two-pole monolithic RF MEMS switched filter, fabricated on GaAs, that employs surface-micromachined capacitors to present a variable capacitance to a coupled coplanar strip filter, thereby switching the filter center frequency 37% between 10.7 GHz and 15.5 GHz with voltages of 20 and 0 V. respectively. This 15% bandwidth filter occupies a chip area of 2.2 x 1.5 mm and demonstrates less than 2-dB of loss, making it promising for numerous applications within these critical frequency bands. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. L&M Technol, Albuquerque, NM 87109 USA. MEMtron Corp, Plano, TX 75075 USA. RP Nordquist, CD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM cdnordq@sandia.gov NR 15 TC 15 Z9 15 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD SEP PY 2004 VL 14 IS 9 BP 425 EP 427 DI 10.1109/LMWC.2004.832071 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 848WI UT WOS:000223498400009 ER PT J AU Frincke, D Bishop, M AF Frincke, D Bishop, M TI Joining the security education community SO IEEE SECURITY & PRIVACY LA English DT Editorial Material C1 Pacific NW Natl Lab, Cybersecur Grp, Richland, WA USA. Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. Univ Calif Davis, Comp Secur Lab, Davis, CA 95616 USA. RP Frincke, D (reprint author), Pacific NW Natl Lab, Cybersecur Grp, Richland, WA USA. EM deborah.frincke@pnl.gov; bishop@cs.ucdavis.edu NR 0 TC 2 Z9 2 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 1540-7993 J9 IEEE SECUR PRIV JI IEEE Secur. Priv. PD SEP-OCT PY 2004 VL 2 IS 5 BP 61 EP 63 DI 10.1109/MSP.2004.75 PG 3 WC Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA 907LD UT WOS:000227718700014 ER PT J AU Adams, RJ Champagne, NJ AF Adams, RJ Champagne, NJ TI A numerical implementation of a modified form of the electric field integral equation SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE electric field integral equation (EFIE); preconditioner ID ELECTROMAGNETIC SCATTERING AB The details of a Galerkin discretization scheme for a modified form of the electric field integral equation are outlined for smooth, three-dimensional, perfectly conducting scatterers. Limitations of the divergence conforming finite-element bases in preserving the self-stabilizing properties of the electric field integral equation operator are indicated. A numerically efficient alternative is outlined which relies on an operator-based Helmholtz decomposition. The condition number of the resulting matrix equation is demonstrated to be frequency independent for scattering from a perfectly conducting sphere at various frequencies. C1 Univ Kentucky, Dept Elect & Comp Engn, Lexington, KY 40506 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Adams, RJ (reprint author), Univ Kentucky, Dept Elect & Comp Engn, Lexington, KY 40506 USA. EM rjadams@uky.edu; cham-pagn@latech.edu NR 10 TC 38 Z9 39 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD SEP PY 2004 VL 52 IS 9 BP 2262 EP 2266 DI 10.1109/TAP.2004.834112 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 854AB UT WOS:000223871200007 ER PT J AU James, CD Spence, AJH Dowell-Mesfin, NM Hussain, RJ Smith, KL Craighead, HG Isaacson, MS Shain, W Turner, JN AF James, CD Spence, AJH Dowell-Mesfin, NM Hussain, RJ Smith, KL Craighead, HG Isaacson, MS Shain, W Turner, JN TI Extracellular recordings from patterned neuronal networks using planar microelectrode arrays SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE hippocampal pyramidal neuron; microcontact printing; microelectrode array; neuron networks ID HIPPOCAMPAL PYRAMIDAL CELLS; CULTURED NEURONS; IONIC CONDUCTANCES; ACTION-POTENTIALS; BIOMOLECULES; SURFACES; ELECTRODES; DENDRITES; PROTEINS; ADHESION AB Neuronal cell networks have been reconstructed on planar microelectrode arrays (MEAs) from dissociated hippocampal pyramidal neurons. Microcontact printing (muCP) and a photoresist-liftoff method were used to selectively localize poly-L-lysine (PLL) on the surface of MEAs. Haptotaxis led to the organization of the neurons into networks localized adjacent to microelectrodes. Various grids of PLL with 2-25-mum-wide lines spaced by 50-200 mum with 15-25-mum nodes at intersection points were used to guide cell body attachment and neurite outgrowth. Bursting activity with spike amplitude attenuation was observed, and multichannel recordings detected instances of coincident firing activity. Finally, we present here an extracellular recording from a similar to2 mum bundle of guided neurites. C1 Cornell Univ, Ithaca, NY 14850 USA. Wadsworth Ctr, Albany, NY 12201 USA. Sch Publ Hlth, Albany, NY 12201 USA. RP James, CD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM cdjame@sandia.gov NR 42 TC 79 Z9 81 U1 1 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9294 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD SEP PY 2004 VL 51 IS 9 BP 1640 EP 1648 DI 10.1109/TBME.2004.927252 PG 9 WC Engineering, Biomedical SC Engineering GA 848BG UT WOS:000223441500015 PM 15376512 ER PT J AU Carreras, BA Newman, DE Dobson, I Poole, AB AF Carreras, BA Newman, DE Dobson, I Poole, AB TI Evidence for self-organized criticality in a time series of electric power system blackouts SO IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS LA English DT Article DE blackouts; complex systems; power system security; reliability; risk analysis; time series ID HIGHLY OPTIMIZED TOLERANCE; MODEL; SECURITY; LAWS AB We analyze a 15-year time series of North American electric power transmission system blackouts for evidence of self-organized criticality (SOC). The probability distribution functions of various measures of blackout size have a power tail and rescaled range analysis of the time series shows moderate long-time correlations. Moreover, the same analysis applied to a time series from a sandpile model known to be self-organized critical gives results of the same form. Thus, the blackout data seem consistent with SOC. A qualitative explanation of the complex dynamics observed in electric power system blackouts, is suggested. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Alaska, Dept Phys, Fairbanks, AK 99775 USA. Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. Fed Energy Reulatory Commiss, Washington, DC 20426 USA. RP Carreras, BA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM carrerasba@ornl.gov; ffden@uaf.edu; dobson@engr.wisc.edu; dobson@engr.wisc.edu RI Dobson, Ian/C-3989-2008 OI Dobson, Ian/0000-0001-7018-5475 NR 32 TC 150 Z9 195 U1 2 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1057-7122 J9 IEEE T CIRCUITS-I JI IEEE Trans. Circuits Syst. I-Regul. Pap. PD SEP PY 2004 VL 51 IS 9 BP 1733 EP 1740 DI 10.1109/TCSI.2004.834513 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 854VN UT WOS:000223931800008 ER PT J AU Mills, TD Hoskins, RS Nemier, MS AF Mills, TD Hoskins, RS Nemier, MS TI Application of material characterization techniques to electrical forensic analysis SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT IEEE/IAS Industrial and Commercial Power Systems Technical Conference CY MAY 04-07, 2003 CL ST LOUIS, MO SP IEEE, IAS DE forensics; material characterization; scanning electron microscope (SEM); seismic qualification; uninterruptible power supply (UPS) AB The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component "failure" event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion. C1 Bechtel Savannah River Inc, Aiken, SC 29808 USA. Westinghouse Savannah River Co, Aiken, SC 29808 USA. Trentec Inc, Cincinnati, OH 45245 USA. RP Mills, TD (reprint author), Bechtel Savannah River Inc, Savannah River Site, Aiken, SC 29808 USA. EM d.mills@ieee.org; richard.hoskins@srs.gov; mnemier@trentec.com NR 2 TC 0 Z9 0 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD SEP-OCT PY 2004 VL 40 IS 5 BP 1200 EP 1204 DI 10.1109/TIA.2004.834126 PG 5 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA 856SZ UT WOS:000224066500004 ER PT J AU Li, QZ Asma, E Qi, JY Bading, JR Leahy, RM AF Li, QZ Asma, E Qi, JY Bading, JR Leahy, RM TI Accurate estimation of the fisher information matrix for the PET image reconstruction problem SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE Fisher information matrix; image reconstruction; PET; uniform resolution ID SPATIAL-RESOLUTION PROPERTIES; MAP RECONSTRUCTION; LIKELIHOOD; VARIANCE; SPECT AB The Fisher information matrix (FIM) plays a key role in the analysis and applications of statistical image reconstruction methods based on Poisson data models. The elements of the FIM are a function of the reciprocal of the mean values of sinogram elements. Conventional plug-in FIM estimation methods do not work well at low counts, where the FIM estimate is highly sensitive to the reciprocal mean estimates at individual detector pairs. A generalized error look-up table (GELT) method is developed to estimate the reciprocal of the mean of the sinogram data. This approach is also extended to randoms precorrected data. Based on these techniques, an accurate FIM estimate is obtained for both Poisson and randoms precorrected data. As an application, the new GELT method is used to improve resolution uniformity and achieve near-uniform image resolution in low count situations. C1 Univ So Calif, Inst Signal & Image Proc, Los Angeles, CA 90089 USA. Univ Calif Berkeley, Ctr Funct Imaging, LBL, Berkeley, CA 94270 USA. Univ So Calif, PET Imaging Sci Ctr, Los Angeles, CA 90033 USA. RP Leahy, RM (reprint author), Univ So Calif, Inst Signal & Image Proc, Los Angeles, CA 90089 USA. EM leahy@sipi.usc.edu RI Qi, Jinyi/A-1768-2010 OI Qi, Jinyi/0000-0002-5428-0322 FU NIBIB NIH HHS [R01 EB000363] NR 18 TC 28 Z9 28 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD SEP PY 2004 VL 23 IS 9 BP 1057 EP 1064 DI 10.1109/TMI.2004.833202 PG 8 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA 849YE UT WOS:000223576800001 PM 15377114 ER PT J AU Qi, JY Huesman, RH AF Qi, JY Huesman, RH TI Propagation of errors from the sensitivity image in list mode reconstruction SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE emission tomography; error propagation; list mode reconstruction; Poisson likelihood; sensitivity image ID POSITRON EMISSION MAMMOGRAPHY; SCATTER CORRECTION; EM ALGORITHM; MAXIMUM-LIKELIHOOD; 3D PET AB List mode image reconstruction is attracting renewed attention. It eliminates the storage of empty sinogram bins. However, a single back projection of all LORs is still necessary for the pre-calculation of a sensitivity image. Since the detection sensitivity is dependent on the object attenuation and detector efficiency, it must be computed for each study. Exact computation of the sensitivity image can be a daunting task for modern scanners with huge numbers of LORs. Thus, some fast approximate calculation may be desirable. In this paper, we analyze the error propagation from the sensitivity image into the reconstructed image. The theoretical analysis is based on the fixed point condition of the list mode reconstruction. The nonnegativity constraint is modeled using the Kuhn-Tucker condition. With certain assumptions and the first-order Taylor series approximation, we derive a closed form expression for the error in the reconstructed image as a function of the error in the sensitivity image. The result shows that the error response is frequency-dependent and provides a simple expression for determining the required accuracy of the sensitivity image calculation. Computer simulations show that the theoretical results are in good agreement with the measured results. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Med & Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Biomed Engn, Davis, CA 95616 USA. RP Qi, JY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Nucl Med & Funct Imaging, Berkeley, CA 94720 USA. EM jqi@lbl.gov RI Qi, Jinyi/A-1768-2010 OI Qi, Jinyi/0000-0002-5428-0322 FU NCI NIH HHS [R01 CA67911]; NIBIB NIH HHS [R01 EB000194, R01 EB000194-02, R01 EB00194, R01 EB000194-01A1] NR 21 TC 16 Z9 16 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD SEP PY 2004 VL 23 IS 9 BP 1094 EP 1099 DI 10.1109/TMI.2004.829333 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA 849YE UT WOS:000223576800005 PM 15377118 ER PT J AU Paton, R Gregory, R Vlachos, C Saunders, J Wu, H AF Paton, R Gregory, R Vlachos, C Saunders, J Wu, H TI Evolvable social agents for bacterial systems modeling SO IEEE TRANSACTIONS ON NANOBIOSCIENCE LA English DT Article DE adaptive behavior; artificial ecologies; individual-based modeling (IbM); network-based models; rule-based models; virtual bacteria ID CELL AB We present two approaches to the individual-based modeling (IbM) of bacterial ecologies and evolution using computational tools. The IbM approach is introduced, and its important complementary role to biosystems modeling is discussed. A fine-grained model of bacterial evolution is then presented that is based on networks of interactivity between computational objects representing genes and proteins. This is followed by a coarser grained agent-based model, which is designed to explore the evolvability of adaptive behavioral strategies in artificial bacteria represented by learning classifier systems. The structure and implementation of the two proposed individual-based bacterial models are discussed, and some results from simulation experiments are presented, illustrating their adaptive properties. C1 Univ Liverpool, Dept Comp Sci, BioComp & Computat Biol Res Grp, Liverpool L69 7ZF, Merseyside, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Liverpool, Sch Biol Sci, Microbiol & Genomics Div, Liverpool L69 7ZB, Merseyside, England. Univ Liverpool, Dept Elect & Elect Engn, Fac Engn, Liverpool L69 3GJ, Merseyside, England. RP Gregory, R (reprint author), Univ Liverpool, Dept Comp Sci, BioComp & Computat Biol Res Grp, Liverpool L69 7ZF, Merseyside, England. RI Saunders, Jonathan/B-5884-2011 NR 25 TC 9 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1536-1241 J9 IEEE T NANOBIOSCI JI IEEE Trans. Nanobiosci. PD SEP PY 2004 VL 3 IS 3 BP 208 EP 216 DI 10.1109/TNB.2004.833701 PG 9 WC Biochemical Research Methods; Nanoscience & Nanotechnology SC Biochemistry & Molecular Biology; Science & Technology - Other Topics GA 853AJ UT WOS:000223797900009 PM 15473073 ER PT J AU Kenyon, GT Travis, BJ Theiler, J George, JS Stephens, GJ Marshak, DW AF Kenyon, GT Travis, BJ Theiler, J George, JS Stephens, GJ Marshak, DW TI Stimulus-specific oscillations in a retinal model SO IEEE TRANSACTIONS ON NEURAL NETWORKS LA English DT Article DE gamma oscillations; phase locking; synchrony; temporal code segmentation ID LATERAL GENICULATE-NUCLEUS; GANGLION-CELLS; CAT RETINA; PRIMATE RETINA; RESPONSES; SYNCHRONIZATION; POTENTIALS; PARASOL; ALPHA AB High-frequency oscillatory potentials (HFOPs) in the vertebrate retina are stimulus specific. The phases of HFOPs recorded at any given retinal location drift randomly over time, but regions activated by the same stimulus tend to remain phase locked with approximately zero lag, whereas regions activated by spatially separate stimuli are typically uncorrelated. Based on retinal anatomy, we previously postulated that HFOPs are mediated by feedback from a class of axon-bearing amacrine cells that receive excitation from neighboring ganglion cells-via gap junctions-and make inhibitory synapses back onto the surrounding ganglion cells. Using a computer model, we show here that such circuitry can account for the stimulus specificity of HFOPs in response to both high- and low-contrast features. Phase locking between pairs of model ganglion cells did not depend critically on their separation distance, but on whether the applied stimulus created a continuous path between them. The degree of phase locking between spatially separate stimuli was reduced by lateral inhibition, which created a buffer zone around strongly activated regions. Stimulating the inhibited region between spatially separate stimuli increased their degree of phase locking proportionately. Our results suggest several experimental strategies for testing the hypothesis that stimulus-specific HFOPs arise from axon-mediated feedback in the inner retina. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Texas, Sch Med, Dept Neurobiol & Anat, Houston, TX 77030 USA. RP Kenyon, GT (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM gkeyon@lanl.gov; bjtravis@lanl.gov; jt@lanl.gov; jsg@lanl.gov; gstephens@lanl.gov; David.W.Marshak@uth.tmc.edu FU NEI NIH HHS [EY06472]; NINDS NIH HHS [NS38310] NR 29 TC 12 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1045-9227 J9 IEEE T NEURAL NETWOR JI IEEE Trans. Neural Netw. PD SEP PY 2004 VL 15 IS 5 BP 1083 EP 1091 DI 10.1109/TNN.2004.832722 PG 9 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 853AN UT WOS:000223798400015 PM 15484885 ER PT J AU Basso, TS DeBlasio, R AF Basso, TS DeBlasio, R TI IEEE 1547 series of standards: Interconnection issues SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article DE certification; communications; dispersed storage and generation; distributed generation; distributed power; distributed resources; fuel cells; interconnection; monitoring and control; photovoltaic power systems; power distribution; power generation; power systems; regulation; standards test AB IEEE 1547 2003 Standard for Interconnecting Distributed Resources With Electric Power Systems is the first in the 1547 series of planned interconnection standards. Major issues and a wealth of constructive dialogue arose during 1547 development. There was also a perceived increased vitality in updating complementary IEEE standards and developing additional standards to accommodate modern electrical and electronics systems and improved grid communications and operations. Power engineers and other stakeholders looking to the future are poised to incorporate 1547 into their knowledge base to help transform our nation's aging distribution systems while alleviating some of the burden on existing transmission systems. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Basso, TS (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM thomas_basso@nrel.gov; deblasid@tcplink.nrel.gov NR 5 TC 52 Z9 56 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8993 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD SEP PY 2004 VL 19 IS 5 BP 1159 EP 1162 DI 10.1109/TPEL.2004.834000 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA 851ZB UT WOS:000223723900002 ER PT J AU Mazumder, SK Acharya, K Haynes, CL Williams, R von Spakovsky, MR Nelson, DJ Rancruel, DE Hartvigsen, J Gemmen, RS AF Mazumder, SK Acharya, K Haynes, CL Williams, R von Spakovsky, MR Nelson, DJ Rancruel, DE Hartvigsen, J Gemmen, RS TI Solid-oxide-fuel-cell performance and durability: Resolution of the effects of power-conditioning systems and application loads SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article DE power-conditioning system (PCS); power-electronics subsystem (PES); solid-oxide-fuel-cell (SOFC) AB We describe methodologies for comprehensive and reduced-order modeling of solid-oxide-fuel-cell (SOFC) power-conditioning system (PCS) at the subsystem/component and system levels to resolve the interactions among SOFC, balance-of-plant subsystem, and power-electronics subsystem (PES) and application loads (ALs). Using these models, we analyze the impacts of electrical-feedback effects (e.g., ripple-current dynamics and load transients) on the performance and reliability of the SOFC. Subsequently, we investigate the effects of harmonies in the current, drawn from the SOFC by a PES, on the temperature and fuel utilization of the SOFC. We explore the impacts of inverter space-vector modulation strategies on the transient response, flow parameters, and current density of the SOFC during load transients and demonstrate how these two traditionally known superior modulation/control methodologies may in fact have a negative effect on the performance and durability of the SOFC unless carefully implemented. Further, we resolve the impacts of the current drawn by the PES from the SOFC, on its microcrack density and electrode/electrolyte degradation. The comprehensive analytical models and interaction-analysis methodologies and the results provided in this paper lead to an improved understanding, and may yield realizations of cost-effective, reliable, and optimal PESs, in particular, and SOFC PCSs, in general. C1 Univ Illinois, Dept Elect & Comp Engn, LESES, Chicago, IL 60607 USA. Georgia Inst Technol, Ctr Innovat & Battery Technol, Atlanta, GA 30332 USA. Virginia Polytech Inst & State Univ, Energy Management Inst, Ctr Automot Fuel Cell Syst, Dept Mech Engn, Blacksburg, VA 24061 USA. Ceramatec Inc, Salt Lake City, UT 84119 USA. Natl Energy Technol Lab, Gas Energy Syst Div, Morgantown, WV 26507 USA. RP Mazumder, SK (reprint author), Univ Illinois, Dept Elect & Comp Engn, LESES, Chicago, IL 60607 USA. EM mazumder@ece.uic.edu; comas.haynes@gtri.gatech.edu; vonspako@vt.edu; jjh@ceramatec.com; randall.gemmen@netl.doe.gov RI von Spakovsky, Michael/F-2465-2014 OI von Spakovsky, Michael/0000-0002-3884-6904 NR 26 TC 54 Z9 54 U1 0 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8993 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD SEP PY 2004 VL 19 IS 5 BP 1263 EP 1278 DI 10.1109/TPEL.2004.833992 PG 16 WC Engineering, Electrical & Electronic SC Engineering GA 851ZB UT WOS:000223723900015 ER PT J AU Deschamps, T Malladi, R Ravve, I AF Deschamps, T Malladi, R Ravve, I TI Fast evolution of image manifolds and application to filtering and segmentation in 3D medical images SO IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS LA English DT Article DE Beltrami flow; subjective surfaces; unconditionally stable scheme; segmentation; Eikonal equation; fast-marching; volume visualization ID NONLINEAR DIFFUSION; EDGE-DETECTION; ALGORITHMS; CURVATURE; RECONSTRUCTION; FRONTS AB In many instances, numerical integration of space-scale PDEs is the most time consuming operation of image processing. This is because the scale step is limited by conditional stability of explicit schemes. In this work, we introduce the unconditionally stable semi-implicit linearized difference scheme that is fashioned after additive operator split (AOS) [ 1], [ 2] for Beltrami and the subjective surface computation. The Beltrami flow [ 3], [ 4], [ 5] is one of the most effective denoising algorithms in image processing. For gray-level images, we show that the flow equation can be arranged in an advection-diffusion form, revealing the edge-enhancing properties of this flow. This also suggests the application of AOS method for faster convergence. The subjective surface [ 6] deals with constructing a perceptually meaningful interpretation from partial image data by mimicking the human visual system. However, initialization of the surface is critical for the final result and its main drawbacks are very slow convergence and the huge number of iterations required. In this paper, we first show that the governing equation for the subjective surface flow can be rearranged in an AOS implementation, providing a near real-time solution to the shape completion problem in 2D and 3D. Then, we devise a new initialization paradigm where we first "condition" the viewpoint surface using the Fast-Marching algorithm. We compare the original method with our new algorithm on several examples of real 3D medical images, thus revealing the improvement achieved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, Berkeley, CA 94720 USA. RP Deschamps, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, Berkeley, CA 94720 USA. EM TDeschamps@lbl.gov; R.Malladi@lbl.gov NR 33 TC 11 Z9 11 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1077-2626 J9 IEEE T VIS COMPUT GR JI IEEE Trans. Vis. Comput. Graph. PD SEP-OCT PY 2004 VL 10 IS 5 BP 525 EP 535 DI 10.1109/TVCG.2004.26 PG 11 WC Computer Science, Software Engineering SC Computer Science GA 833TA UT WOS:000222360600005 PM 15794135 ER PT J AU Crooks, WJ Christian, JD AF Crooks, WJ Christian, JD TI Densities and partial molal volumes of sodium tetrafluoroborate aqueous solutions at 20 degrees C SO INDIAN JOURNAL OF CHEMISTRY SECTION A-INORGANIC BIO-INORGANIC PHYSICAL THEORETICAL & ANALYTICAL CHEMISTRY LA English DT Article AB Densities of solutions of NaBF4 in H2O have been determined at 20.00 degreesC over the concentration range 0.05 to 9.0 molal (0 to 50 wt%) NaBF4. The results are represented by d (g/mL, 20degreesC) = 9.726x10(-5) m(3) - 3.2157x10(-3) m(2) + 6.7447x10(-2) m + 0.99843, where d is density and in is molality. This equation has been used to derive concentrative properties for NaBF4 solutions. The raw density data have been used to derive partial molal volumes. The partial molal volume at infinite dilution is 37.6 +/- 2.7 mL/mol at 20degreesC. The partial molal volume at 20degreesC is represented by (ν) over bar (2) = 37.5 + 9.22m(1/2) - 2.92m from 0 to 2.5 in NaBF4 and (ν) over bar (2) = 44.6 + 0.081m from 2.5 to 9 in NaBF4. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Crooks, WJ (reprint author), Los Alamos Natl Lab, MS G-730, Los Alamos, NM 87545 USA. EM crooks@lanl.gov; jerryc@srv.net NR 8 TC 9 Z9 9 U1 1 U2 2 PU NATL INST SCIENCE COMMUNICATION PI NEW DELHI PA DR K S KRISHNAN MARG, NEW DELHI 110 012, INDIA SN 0376-4710 J9 INDIAN J CHEM A JI Indian J. Chem. Sect A-Inorg. Bio-Inorg. Phys. Theor. Anal. Chem. PD SEP PY 2004 VL 43 IS 9 BP 1872 EP 1875 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 855XF UT WOS:000224007500009 ER PT J AU Bennett, JP Kwong, KS AF Bennett, JP Kwong, KS TI An overview of recycling refractory materials SO INDUSTRIAL CERAMICS LA English DT Article AB Refractory materials must be disposed of or recycled when removed from service. Off-specification or reject material has been reused by the refractory industry for a number of years, with small percentages of these materials added as a part of refractory formulations. Historically, limited reuse of spent refractory materials in other applications has occurred. Environmental legislation, stewardship programs, and other forces have encouraged some businesses to recycle spent refractory material varies considerably among different industries and with the location of the industrial user. Efforts to recycle the driving forces for recycling, and issues and steps to be taken into account when initiating a recycling program will be discussed. C1 US DOE, Albany Res Ctr, Albany, OR USA. RP Bennett, JP (reprint author), US DOE, Albany Res Ctr, Albany, OR USA. NR 16 TC 3 Z9 4 U1 0 U2 4 PU TECHNA SRL PI FAENZA PA PO BOX 174, 48018 FAENZA, ITALY SN 1121-7588 J9 IND CERAM JI Ind. Ceram. PD SEP-DEC PY 2004 VL 24 IS 3 BP 165 EP 171 PG 7 WC Materials Science, Ceramics SC Materials Science GA 896QB UT WOS:000226947500001 ER PT J AU Dahl, JK Weimer, AW Lewandowski, A Bingham, C Bruetsch, F Steinfeld, A AF Dahl, JK Weimer, AW Lewandowski, A Bingham, C Bruetsch, F Steinfeld, A TI Dry reforming of methane using a solar-thermal aerosol flow reactor SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID GREENHOUSE GASES; STEAM; HYDROGEN; SYNGAS; DRIVEN AB Research has focused on dry reforming because it offers a sink for CO2 and relative to steam methane reforming produces a more desirable ratio of H-2 to CO for feed to a Fischer-Tropsch synthesis process. To form synthesis gas by dry reforming in a rapid, environmentally benign manner, a fluid-wall aerosol flow reactor powered by concentrated sunlight has been designed. Operating with residence times on the order of 10 ms and temperatures of approximately 2000 K, CH4 and CO2 conversions of 70% and 65%, respectively, have been achieved in the absence of any added catalysts. Methane to carbon dioxide feed ratios greater than unity were fed in order to prevent reaction of CO2 with the graphite tube. The carbon black particles formed by reaction were amorphous carbon black with a primary particle size of approximately 20-40 nm. C1 Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. ETH, Swiss Fed Inst Technol, Inst Energy Technol, Dept Mech & Proc Engn, CH-8092 Zurich, Switzerland. RP Weimer, AW (reprint author), Univ Colorado, Dept Chem Engn, ECCH 111,Campus Box 424, Boulder, CO 80309 USA. EM Alan.Weimer@Colorado.edu RI Steinfeld, Aldo/B-8869-2008 OI Steinfeld, Aldo/0000-0001-7797-686X NR 20 TC 56 Z9 58 U1 3 U2 21 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 1 PY 2004 VL 43 IS 18 BP 5489 EP 5495 DI 10.1021/ie030307h PG 7 WC Engineering, Chemical SC Engineering GA 850XT UT WOS:000223648400010 ER PT J AU Pandey, P Turton, R Yue, P Shadle, L AF Pandey, P Turton, R Yue, P Shadle, L TI Nonintrusive particle motion studies in the near-wall region of a pilot-scale circulating fluidized bed SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID GAS-SOLID FLOW; VOIDAGE PROFILES; SUSPENSION FLOW; 2-PHASE FLOW; VELOCITY; RISER; CLUSTERS; TRACER; MODEL; PROBE AB A backscatter LDV system was used to record velocities of solid particles in the near-wall region of the riser section of a pilot-scale cold-flow CFB. The riser was 30.5 cm in diameter and 15.2 m in height. The bed material comprised cork particles with a Sauter mean diameter of 812 mum and a particle density of 189 kg/m(3). The superficial gas velocity was varied from 3.75 to 5.4 m/s with a solids circulation rate ranging from 3.4 to 17.1 kg/m(2.)s. A bimodal velocity distribution was observed near the wall region. The mean velocity of solids was found to increase with increasing superficial gas velocity and decreasing solids circulation rate. The mean velocity of particles moving in the downward direction was relatively insensitive to changes in operating conditions. A criterion for defining clusters was proposed and justified, and the effects of operating conditions on the mean velocity and size of clusters were examined. The mean cluster velocity for most of the operating conditions was in the range of 0.8-1.4 m/s in the downward direction. The mean cluster size was found to increase with increasing solids-to-gas load ratio. C1 W Virginia Univ, Dept Chem Engn, Morgantown, WV 26506 USA. US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Turton, R (reprint author), W Virginia Univ, Dept Chem Engn, Morgantown, WV 26506 USA. EM riturton@mail.wvu.edu OI Shadle, Lawrence/0000-0002-6283-3628 NR 65 TC 12 Z9 12 U1 2 U2 5 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 1 PY 2004 VL 43 IS 18 BP 5582 EP 5592 DI 10.1021/ie0307737 PG 11 WC Engineering, Chemical SC Engineering GA 850XT UT WOS:000223648400019 ER PT J AU Gray, GA Kolda, TG Sale, K Young, MM AF Gray, GA Kolda, TG Sale, K Young, MM TI Optimizing an empirical scoring function for transmembrane protein structure determination SO INFORMS JOURNAL ON COMPUTING LA English DT Article DE optimization; computational biology; nonlinear programming; parallel algorithm; protein structure; Bundler scoring function ID PARALLEL PATTERN SEARCH; MEMBRANE-PROTEINS; COUPLED RECEPTOR; OPTIMIZATION; PREDICTION; PACKING; DISTRIBUTIONS; INFORMATION; CONVERGENCE; RHODOPSIN AB We examine the problem of transmembrane protein structure determination. Like many questions that arise in biological research, this problem cannot be addressed generally by traditional laboratory experimentation alone. Instead, an approach that integrates experiment and computation is required. We formulate the transmembrane protein structure determination problem as a bound-constrained optimization problem using a special empirical scoring function, called Bundler, as the objective function. In this paper, we describe the optimization problem and its mathematical properties, and we examine results obtained using two different derivative-free optimization algorithms. C1 Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. Sandia Natl Labs, Biosyst Res Dept, Livermore, CA 94551 USA. RP Gray, GA (reprint author), Sandia Natl Labs, Computat Sci & Math Res Dept, POB 969 MS 9159, Livermore, CA 94551 USA. EM gagray@sandia.gov; tgkolda@sandia.gov; klsale@sandia.gov; mmyoung@sandia.gov RI Kolda, Tamara/B-1628-2009 OI Kolda, Tamara/0000-0003-4176-2493 NR 72 TC 10 Z9 10 U1 0 U2 2 PU INFORMS PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, AIPORT SQUARE, LINTHICUM HTS, MD 21090-2908 USA SN 1091-9856 J9 INFORMS J COMPUT JI INFORMS J. Comput. PD FAL PY 2004 VL 16 IS 4 BP 406 EP 418 DI 10.1287/ijoc.1040.0102 PG 13 WC Computer Science, Interdisciplinary Applications; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA 871ET UT WOS:000225113100009 ER PT J AU Obot, CJ Lee, KM Fuciarelli, AF Renne, RA McKinney, WJ AF Obot, CJ Lee, KM Fuciarelli, AF Renne, RA McKinney, WJ TI Characterization of mainstream cigarette smoke-induced biomarker responses in ICR and C57Bl/6 mice SO INHALATION TOXICOLOGY LA English DT Article ID OBSTRUCTIVE PULMONARY-DISEASE; CONNECTIVE-TISSUE BREAKDOWN; NECROSIS-FACTOR-ALPHA; GLUTATHIONE DISULFIDE; EMPHYSEMATOUS CHANGES; SCAVENGER RECEPTORS; PERIPHERAL AIRWAYS; LUNG DESTRUCTION; HEALTHY SMOKERS; LAVAGE FLUID AB Pulmonary emphysema is a major component of the morbidity and mortality of chronic obstructive pulmonary disease (COPD). Currently there are no predictive biomarkers for COPD. Initial steps toward identifying potentially predictive biomarkers involve utilizing well-characterized mainstream smoke (MS) exposure conditions (dose-response) to identify changes in biomarkers of effect (inflammation, tissue injury, oxidative stress) in emphysema-susceptible and -resistant mouse strains. C57Bl/6 mice have been reported to develop emphysema when exposed chronically to cigarette smoke, while similarly exposed ICR mice do not. Male C57Bl/6 and ICR mice were exposed 2 h/day for 7 consecutive days to MS from a standard reference cigarette (2R4F) at 75, 250, and 600 mug total particulate matter (TPM)/L or filtered air. To confirm exposure, blood samples were collected toward the end of the last exposure and analyzed for carboxyhemoglobin, nicotine, and cotinine. Bronchoalveolar lavage (BAL) fluid samples were collected 2 or 12 h postexposure and analyzed for biomarkers of effect. MS dose differed slightly between strains. More necrosis was observed in nasal epithelium of exposed C57Bl/6 mice. Exposure concentration-dependent increases in apoptosis, chemokines, and neutrophil counts were greater in ICR mice. Similar increases in thymus and activated-regulated chemokine were only observed in C57Bl/6 mice. BAL fluid cells of C57Bl/6 mice appear to undergo necrosis, while the BAL fluid cells of ICR mice appear to undergo apoptosis following MS exposure. Utilizing two strains of mice we identified MS-responsive biomarkers of effect that may be predictive of COPD pathology. Chronic MS exposures are needed to link these biomarkers with emphysema. C1 Philip Morris Inc, Res Ctr, Postgrad Res Program, Richmond, VA 23261 USA. Battelle Toxicol NW, Richland, WA USA. RP McKinney, WJ (reprint author), Philip Morris Inc, Res Ctr, Postgrad Res Program, POB 26583, Richmond, VA 23261 USA. EM Willie.J.Mckinney@pmusa.com NR 64 TC 18 Z9 20 U1 0 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0895-8378 J9 INHAL TOXICOL JI Inhal. Toxicol. PD SEP PY 2004 VL 16 IS 10 BP 701 EP 719 DI 10.1080/08958370490476604 PG 19 WC Toxicology SC Toxicology GA 850CT UT WOS:000223589500004 PM 15371058 ER PT J AU Xu, XF Lee, JS Pletcher, RH Shehata, AM McEligot, DM AF Xu, XF Lee, JS Pletcher, RH Shehata, AM McEligot, DM TI Large eddy simulation of turbulent forced gas flows in vertical pipes with high heat transfer rates SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID DIRECT NUMERICAL-SIMULATION; CHANNEL FLOW; CIRCULAR TUBES; LAMINARIZATION; LAYER AB Large eddy simulation (LES) of vertical turbulent pipe flows with significant property variations has been performed to investigate the effects of high heat fluxes on the turbulent structures and transport. The Cartesian-based, compressible filtered Navier-Stokes equations were solved using a second-order accurate finite volume method. Low Mach number preconditioning was used to enable the compressible code to perform efficiently at low Mach numbers. A dynamic subgrid-scale stress model accounted for the subgrid-scale turbulence. In this study, the simulations were designed to simulate the experiments of Shehata and McEligot with three different near-constant heat fluxes. Step-periodic boundary conditions based on a quasi-developed assumption were used. The predicted integral parameters and mean velocity and temperature profiles agreed well with the experimental data. The fluid structures have been distorted due to high heat fluxes leading to significant property variations in the near wall region. The results showed that strong heating resulted in remarkable reductions of turbulent intensities, shear stresses, and turbulent heat flux. Apparent "laminarization" of the flow has been observed. (C) 2004 Published by Elsevier Ltd. C1 Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. Xerox Corp, Webster, NY 14580 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Univ Arizona, Tucson, AZ 85721 USA. RP Pletcher, RH (reprint author), Iowa State Univ, Dept Mech Engn, 2025 Black Engn Bldg, Ames, IA 50011 USA. EM pletcher@iastate.edu RI LEE, JOON SANG/A-8560-2009 NR 25 TC 13 Z9 13 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 2004 VL 47 IS 19-20 BP 4113 EP 4123 DI 10.1016/j.ijheatmasstransfer.2004.05.011 PG 11 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 847SC UT WOS:000223414200009 ER PT J AU Beck, JV Haji-Sheikh, A Amos, DE Yen, D AF Beck, JV Haji-Sheikh, A Amos, DE Yen, D TI Verification solution for partial heating of rectangular solids SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID EXPONENTIAL INTEGRALS; CONDUCTION AB One method for verification of numerical solutions in heat transfer uses exact solutions for multi-dimensional parallelepipeds. The usual solution of these problems utilizes the method of separation of variables for both the steady and transient parts of the solution; however, this method for the steady-state part often produces solutions that converge slowly at the boundaries of greatest interest. Steady-state solutions having low convergence are illustrated for a rectangle with zero prescribed temperatures except one surface having a step change of temperature. Two forms of the steady-state solution are available and even then difficulties may be encountered. Another method called time-partitioning is used and is shown to have several superior features in the solution of this problem. (C) 2004 Elsevier Ltd. All rights reserved. C1 Michigan State Univ, Dept Mech Engn, E Lansing, MI 48824 USA. Univ Texas, Dept Mech & Aerosp Engn, Arlington, TX 76019 USA. Sandia Natl Labs, Albuquerque, NM 87110 USA. Michigan State Univ, Dept Math, E Lansing, MI 48824 USA. RP Beck, JV (reprint author), Michigan State Univ, Dept Mech Engn, E Lansing, MI 48824 USA. EM beck@egr.msu.edu NR 14 TC 23 Z9 23 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 2004 VL 47 IS 19-20 BP 4243 EP 4255 DI 10.1016/j.ijheatmasstransfer.2004.04.021 PG 13 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 847SC UT WOS:000223414200019 ER PT J AU Xue, L Keblinski, P Phillpot, SR Choi, SUS Eastman, JA AF Xue, L Keblinski, P Phillpot, SR Choi, SUS Eastman, JA TI Effect of liquid layering at the liquid-solid interface on thermal transport SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE interfacial thermal resistance; liquid-solid interface; molecular dynamics simulations; nanofluids ID MOLECULAR-DYNAMICS SIMULATION; PHASE-TRANSITIONS; HEAT-TRANSFER; CONDUCTIVITY; CONFINEMENT; NANOFLUIDS; FLUID; RESISTANCE; FILMS; SHEAR AB Using non-equilibrium molecular dynamics simulations in which a temperature gradient is imposed, we study how the ordering of the liquid at the liquid-solid interface affects the interfacial thermal resistance. Our simulations of a simple monoatomic liquid show no effect on the thermal transport either normal to the surface or parallel to the surface. Even for of a liquid that is highly confined between two solids, we find no effect on thermal conductivity. This contrasts with well-known significant effect of confinement on the viscoelastic response. Our findings suggest that the experimentally observed large enhancement of thermal conductivity in suspensions of solid nanosized particles (nanofluids) can not be explained by altered thermal transport properties of the layered liquid. (C) 2004 Elsevier Ltd. All rights reserved. C1 Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Keblinski, P (reprint author), Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. EM keblip@rpi.edu RI Eastman, Jeffrey/E-4380-2011; Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535; Eastman, Jeff/0000-0002-0847-4265 NR 29 TC 250 Z9 257 U1 10 U2 70 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD SEP PY 2004 VL 47 IS 19-20 BP 4277 EP 4284 DI 10.1016/ijheatmasstransfer.2004.05.016 PG 8 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 847SC UT WOS:000223414200022 ER PT J AU Gropp, W Lusk, E AF Gropp, W Lusk, E TI Fault tolerance in Message Passing Interface programs 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 10-13, 2002 CL Chateau Faverges, FRANCE SP Sun Microsyst Inc, Myricom Inc, Hewlett Packard DE MPI; fault tolerance; process management; parallel computing AB In this paper we examine the topic of writing fault-tolerant Message Passing Interface (MPI) applications. We discuss the meaning of fault tolerance in general and what the MPI Standard has to say about it. We survey several approaches to this problem, namely checkpointing, restructuring a class of standard MPI programs, modifying MPI semantics, and extending the MPI specification. We conclude that, within certain constraints, MPI can provide a useful context for writing application programs that exhibit significant degrees of fault tolerance. C1 Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. RP Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. OI Gropp, William/0000-0003-2905-3029 NR 18 TC 41 Z9 43 U1 0 U2 1 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 2004 VL 18 IS 3 BP 363 EP 372 DI 10.1177/1094342004046045 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 846PP UT WOS:000223328200009 ER PT J AU Kottenstette, R Cotrell, J AF Kottenstette, R Cotrell, J TI Hydrogen storage in wind turbine towers SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE wind turbine; tower; hydrogen; storage; pressure vessel AB Modem utility-scale wind turbine towers are typically conical steel structures that could also be used to store gaseous hydrogen in what we have termed a hydrogen tower. This paper examines potential technical barriers to this technology and identifies a minimum cost design. We discovered that hydrogen towers have a "crossover pressure" at which the critical mode of failure crosses over from fatigue to bursting. The crossover pressure for many turbine towers is between 1.0 and 1.5 MPa (approximately 10-15 atm). The hydrogen tower design resulting in the least expensive hydrogen storage uses all of the available volume for storage and is designed at its crossover pressure. An 84-m tall hydrogen tower for a 1.5-MW turbine would cost an additional $83,000 (beyond the cost of the conventional tower) and would store 940 kg of hydrogen at 1.1 MPa of pressure. The resulting incremental storage cost of $88/kg is approximately 30% of that for conventional pressure vessels. Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy. C1 Natl Renewable Energy Lab, Natl Wind Technol Ctr, Golden, CO 80401 USA. Santa Clara Univ, Santa Clara, CA 95050 USA. RP Cotrell, J (reprint author), Natl Renewable Energy Lab, Natl Wind Technol Ctr, 1614 Cole Blvd, Golden, CO 80401 USA. EM jason_cotrell@nrel.gov NR 24 TC 7 Z9 7 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD SEP PY 2004 VL 29 IS 12 BP 1277 EP 1288 DI 10.1016/j.ijhydene.2003.12.003 PG 12 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 831AE UT WOS:000222164500010 ER PT J AU Belykh, SF Veryovkin, IV Palitsin, VV Samartsev, AV Adriaens, A Adams, F AF Belykh, SF Veryovkin, IV Palitsin, VV Samartsev, AV Adriaens, A Adams, F TI Temperature dependence of secondary ion emission from tantalum produced by atomic and polyatomic gold projectiles SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE secondary atomic and cluster ion emission; atomic and polyatomic ion bombardment; temperature dependence; non-additive sputtering ID CLUSTER EMISSION; CHARGED CLUSTERS; BOMBARDMENT; METALS; NIOBIUM; YIELDS AB Temperature dependencies have been measured within a wide range of target temperatures of 300 K less than or equal to T less than or equal to 2400 K for secondary ion yields of Ta-n(+), TanO(m)(+), TanNb+ and TanAu+(n = 1-14, m = 1-3) under the bombardment of tantalum target with 12 keV atomic Au- and 18 keV polyatomic Au-3(-) projectiles. It is demonstrated that yields of Ta-n(+) (n = 2-14) and TanNb+ ions increase with temperature for T less than or equal to 1700K and then tend to become temperature independent. On the contrary, the yields of TanOm+ and TanAu+ ions slightly increase with temperature reaching their maxima in the range of 1000K less than or equal to T less than or equal to 1500 K and then sharply decrease to zero at T approximate to 1700 and 2100K, respectively. These trends are interpreted to indicate the redistribution of the sputtered flux between these different emission channels while sputtering conditions change with the target temperature. Oxygen presence on the surface at lower temperatures limits the yield of Ta-n(+) clusters and stimulates that of TanOm+. Removing oxygen from the surface enhances the yield of Ta-n(+) clusters and the disappearance of TanOm+. After clean surfaces are established in the range of 1700 K less than or equal to T less than or equal to 2400 K, the yield of the Ta-n(+) and TanNb+ cluster ions becomes constant thus indicating that their ionization probability does not depend on the target temperature in this range. Some differences in the temperature dependencies obtained under the atomic and polyatomic ion bombardment are observed and interpreted as the indication of different efficiencies of the sputtering process since polyatomic projectiles sputter more material than atomic ones. This, in addition to better surface cleaning, enhances yields of cluster ions. For atomic ions Ta+, an additional emission channel, thermal evaporation/surface ionization, is identified at target temperatures T > 2300 K. No evaporated cluster ions are observed. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Instelling Antwerp, Dept Chem, B-2610 Antwerp, Belgium. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Univ Duisburg Gesamthsch, Inst Expt Phys, D-45117 Essen, Germany. State Univ Ghent, Dept Analyt Chem, B-9000 Ghent, Belgium. RP Belykh, SF (reprint author), Univ Instelling Antwerp, Dept Chem, Univ Splein 1, B-2610 Antwerp, Belgium. EM belikh@uia.ua.ac.be RI Adriaens, Annemie/F-2520-2013 OI Adriaens, Annemie/0000-0003-4034-1881 NR 23 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD SEP PY 2004 VL 237 IS 1 BP 55 EP 63 DI 10.1016/j.ijms.2004.06.010 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 850LE UT WOS:000223612000007 ER PT J AU Melnikov, K Weinstein, M AF Melnikov, K Weinstein, M TI On the evolution of a massless scalar field in a Schwarzschild background: A new look at Hawking radiation and the information paradox SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article DE black holes; Hawking radiation; information paradox; Hamiltonian approach ID BLACK-HOLES AB We exhibit an explicit foliation of Schwarzschild space-time by spacelike hypersurfaces which extend from Schwarzschild r = 0 to r = infinity. This allows us to compute the values of a massless scalar field for all space-time points which lie in the future of the surface on which we initially quantize the theory. This is to be contrasted with approaches which start at past null infinity and propagate to future null infinity. One of its virtues is that this method allows us to discuss both asymptotic Hawking radiation and what is happening at finite distances from the black hole. In order to explain the techniques we use, we begin by discussing variants of the flat-space moving mirrors problem. Then we discuss the canonical quantization of the massless scalar field theory and the geometric optics approximation which we use to solve the Heisenberg equations of motion in the black hole background. Using the example of an infalling mirror, an analogue of the moving mirror problem, we show that, although our spacelike slices extend to r = 0, we can avoid discussing an initial state which extends through the horizon. Furthermore, we show that in the same way we avoid having to deal with the singularity at r = 0 when we first quantize the system. This discussion naturally leads to a suggestion of how to handle the question of what is happening when the mirror hits the singularity. In the last section of the paper we discuss a discretization of the computation which behaves in the manner we suggest and yet exhibits Hawking radiation.(5) This formulation of the problem allows us to discuss all the issues in an explicitly unitary setting. The resulting picture raises some interesting questions about the information paradox. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Melnikov, K (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM melnikov@slac.stanford.edu; niv@slac.stanford.edu NR 11 TC 8 Z9 8 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2004 VL 13 IS 8 BP 1595 EP 1635 DI 10.1142/S0218271804005249 PG 41 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 867DT UT WOS:000224823100003 ER PT J AU Chapline, G AF Chapline, G TI Quantum mechanics and pattern recognition SO INTERNATIONAL JOURNAL OF QUANTUM INFORMATION LA English DT Article DE Bayesian network; Helmholtz machine; pattern recognition AB It has long been known that the Schrodinger equation provides a description of a certain kind of statistical Markov process. We show here that as a consequence, one can view quantum mechanics as an extension of the Helmholtz machine approach to pattern recognition. Not only does this observation throw new light on the relationship between quantum mechanics and computing theory, but it suggests that mathematical techniques developed for inverse scattering problems might provide an alternative to conventional pattern recognition algorithms. C1 Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94550 USA. RP Chapline, G (reprint author), Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94550 USA. NR 22 TC 2 Z9 2 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-7499 J9 INT J QUANTUM INF JI Int. J. Quantum Inf. PD SEP PY 2004 VL 2 IS 3 BP 295 EP 303 DI 10.1142/S0219749904000328 PG 9 WC Computer Science, Theory & Methods; Physics, Particles & Fields; Physics, Mathematical SC Computer Science; Physics GA 907LN UT WOS:000227719700002 ER PT J AU Kamenev, DI Berman, GP Kassman, RB Tsifrinovich, VI AF Kamenev, DI Berman, GP Kassman, RB Tsifrinovich, VI TI Modeling full adder in ising spin quantum computer with 1000 qubits using quantum maps SO INTERNATIONAL JOURNAL OF QUANTUM INFORMATION LA English DT Article DE universal quantum gates; solid state; scalable AB The quantum adder is an essential attribute of a quantum computer, just as classical adder is needed for operation of a digital computer. We model the quantum full adder as a realistic complex algorithm on a large number of qubits in an Ising spin quantum computer. Our results axe an important step toward effective modeling of the quantum modular adder which is needed for Shor's and other quantum algorithms. Our full adder has the following features. (i) The neax-resonant transitions with small detunings are completely suppressed, which allows us to decrease errors by several orders of magnitude and to model a 1000-qubit full adder. (We add a 1000-bit number using 2001 spins.) (ii) We construct the full adder gates directly as sequences of radio-frequency pulses, rather than breaking them down into generalized logical gates, such as Control-Not and one qubit gates. This substantially reduces the number of pulses needed to implement the full adder. (The maximum number of pulses required to add one bit (F-gate) is 15.) (iii) Full adder is realized in a homogeneous spin chain. (iv) The phase error is minimized: the F-gates generate approximately the same phase for different states of the superposition. (v) Modeling of the full adder is performed using quantum maps instead of differential equations. This allows us to reduce the calculation time to a reasonable value. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Polytech Univ, IDS Dept, New York, NY 11201 USA. RP Kamenev, DI (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-7499 J9 INT J QUANTUM INF JI Int. J. Quantum Inf. PD SEP PY 2004 VL 2 IS 3 BP 323 EP 340 DI 10.1142/S0219749904000304 PG 18 WC Computer Science, Theory & Methods; Physics, Particles & Fields; Physics, Mathematical SC Computer Science; Physics GA 907LN UT WOS:000227719700004 ER PT J AU Berman, GP Kamenev, DI Tsifrinovich, VI AF Berman, GP Kamenev, DI Tsifrinovich, VI TI Minimization of nonresonant effects in a scalable ising spin quantum computer SO INTERNATIONAL JOURNAL OF QUANTUM INFORMATION LA English DT Article DE solid state; errors; perturbation theory AB The errors caused by the transitions with large frequency offsets (nonresonant transitions) are calculated analytically for a scalable solid-state quantum computer based on a one-dimensional spin chain with lsing interactions between neighboring spins. Selective excitations of the spins are enabled by a uniform gradient of the external magnetic field. We calculate the probabilities of all unwanted nonresonant transitions associated with the flip of each spin with nonresonant frequency and with flips of two spins: one with resonant and one with nonresonant frequencies. It is shown that these errors oscillate with changing gradient of the external magnetic field. Choosing the optimal values of this gradient allows us to decrease these errors by 50%. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Polytech Univ, IDS Dept, New York, NY 11201 USA. RP Berman, GP (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0219-7499 J9 INT J QUANTUM INF JI Int. J. Quantum Inf. PD SEP PY 2004 VL 2 IS 3 BP 379 EP 392 DI 10.1142/S0219749904000286 PG 14 WC Computer Science, Theory & Methods; Physics, Particles & Fields; Physics, Mathematical SC Computer Science; Physics GA 907LN UT WOS:000227719700007 ER PT J AU Chen, J Parilla, PA Bhattacharya, RN Ren, ZF AF Chen, J Parilla, PA Bhattacharya, RN Ren, ZF TI Growth of biaxially textured CeO2/YSZ/CeO2 and SrTiO3 buffer layers on textured Ni substrates by pulsed laser deposition SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE superconductor; coated conductor; buffer layer ID CRITICAL-CURRENT DENSITY; SUPERCONDUCTING TAPES; CONDUCTORS AB Biaxially textured CeO2/YSZ/CeO2 and SrTiO3 buffer layers have been grown by pulsed laser deposition (PLD) on rolling assisted biaxially textured substrates (RABiTS) made of Ni. Full width at half maximum (FWHM) of the omega scan, phi scan of these buffer layers were comparable to the Ni substrates indicating good epitaxial growth on RABiTS. Atomic force microscopy (AFM) and scanning electron microscope (SEM) measurements showed that these buffer layers were smooth and crack-free. CeO2/YSZ/CeO2/Ni and SrTiO3/Ni buffer layers prepared by this technique can be used as templates for the growth of high-T-c superconductors coated conductors. Unlike CeO2 seed layers, which could be easily epitaxially grown on RABiTS Ni substrates in forming gas, cube-on-cube epitaxial growth of SrTiO3 on RABiTS Ni substrates can be achieved only in a narrow window of deposition temperatures and forming gas pressure. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. RP Chen, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM flcj1999@yahoo.com RI Ren, Zhifeng/B-4275-2014 NR 7 TC 13 Z9 13 U1 0 U2 4 PU INST PURE APPLIED PHYSICS PI TOKYO PA TOYOKAIJI BLDG NO. 12, 6-9-6 SHINBASHI, MINATO-KU, TOKYO, 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD SEP PY 2004 VL 43 IS 9A BP 6040 EP 6043 DI 10.1143/JJAP.43.6040 PG 4 WC Physics, Applied SC Physics GA 863RI UT WOS:000224579000020 ER PT J AU Gatti-Bono, C Perkins, NC AF Gatti-Bono, C Perkins, NC TI Effect of loop shape on the drag-induced lift of fly line SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article ID FLYLINE AB This note explains why casting a loop with a positive angle of attack is advantageous in distance fly casting. Several loop shapes, one with a positive angle of attack, one with a negative angle of attack, and two symmetrical loops with zero angle of attack are studied. For each loop, we compute the vertical drag component, i.e., the "lift." It is found that a loop with a positive angle of attack generates lift about four times larger than a symmetrical loop. Thus, loops with positive angles of attack stay "aerialized longer" which is consistent with observations made by (competition) distance fly casters. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Gatti-Bono, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. EM gattic@umich.edu; ncp@umich.edu NR 14 TC 0 Z9 0 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD SEP PY 2004 VL 71 IS 5 BP 745 EP 747 DI 10.1115/1.1778414 PG 3 WC Mechanics SC Mechanics GA 870II UT WOS:000225050400021 ER PT J AU Axness, CL Kerr, B Wunsch, TF AF Axness, CL Kerr, B Wunsch, TF TI Analytic light-or radiation-induced pn junction photocurrent solutions to the multidimensional ambipolar diffusion equation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TRANSIENT-RESPONSE; TRANSISTORS; DIODES AB We transform the n-dimensional ambipolar transport equation to the n-dimensional nonhomogeneous heat equation, which has been solved for most common initial and boundary conditions. Thus, general solutions to the nonhomogeneous heat equation, obtained in a robust form through finite Fourier transforms, provide an easy approach to solving the ambipolar transport equation, which previously had been solved with more difficulty through Laplace transform techniques. We then obtain a general analytic one-dimensional time-dependent solution to the excess carrier and current densities in a pn junction diode in response to a transient radiation or light pulse under low-injection conditions. We derive most of the known analytic solutions to this problem and we examine the limiting behavior of these solutions to show that they are consistent. The model includes the effects of a constant electric field in the quasineutral region, a finite diode length, and an arbitrary generation function in terms of space and time. In the area of light communication, we use the model to examine the impact of doping parameters on the buildup of diffusive photocurrent that limits the signal bandwidth. Solutions to the ambipolar diffusion equation assuming more general initial and boundary conditions are easily obtained via the given transformation. The model may be applied to problems involving photodiodes, light-emitting diode or laser communication, transient radiation effects in microelectronics, dosimetry, or the response of solar cells to light. (C) 2004 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. New Mexico Inst Min & Technol, Dept Math, Socorro, NM 87801 USA. RP Axness, CL (reprint author), Sandia Natl Labs, MS 0776,POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 1 Z9 1 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2004 VL 96 IS 5 BP 2646 EP 2655 DI 10.1063/1.1769100 PG 10 WC Physics, Applied SC Physics GA 851XH UT WOS:000223719300034 ER PT J AU Hauser, H AF Hauser, H TI Energetic model of ferromagnetic hysteresis: Isotropic magnetization SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DOMAIN BEHAVIOR; STABILITY; SHEETS; CURVES; MEDIA; FILMS; FIELD AB The model is based on considerations of energy balance and statistical domain behavior. The parameters are related to macroscopic hysteresis features such as coercivity, initial susceptibility, saturation, and remanence and identification strategies are presented for static and dynamic magnetization processes. Furthermore, the model parameters are related to spontaneous magnetization, magnetocrystalline anisotropy, magnetostriction, and microstructure geometry which assist in the interpretation of the hysteresis dependence on stress, temperature, and direction of magnetization. Examples and predictions are the magnetization reversal in low dimensional structures, stress demagnetization, temporary decay of magnetization, Barkhausen noise, and the behavior of materials with multiple phases. Finally, the fictitious statistical domains (or unit magnetization reversals) are related to the magnetic spin moments, which enables a quantum-mechanical interpretation of the model. (C) 2004 American Institute of Physics. C1 Vienna Univ Technol, Fac Elect Engn & Informat Technol, Inst Sensor & Actuator Syst, A-1040 Vienna, Austria. RP Hauser, H (reprint author), Iowa State Univ, Ames Lab, 105 Met Dev, Ames, IA 50011 USA. EM Hans.Hauser@TUwien.ac.at NR 43 TC 61 Z9 61 U1 3 U2 14 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2004 VL 96 IS 5 BP 2753 EP 2767 DI 10.1063/1.1771479 PG 15 WC Physics, Applied SC Physics GA 851XH UT WOS:000223719300049 ER PT J AU Choudhury, B Shinar, R Shinar, J AF Choudhury, B Shinar, R Shinar, J TI Glucose biosensors based on organic light-emitting devices structurally integrated with a luminescent sensing element SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SOL-GEL MATRIX; OXYGEN SENSORS; COMPLEXES; ELECTROLUMINESCENCE; RUTHENIUM(II); EFFICIENCY; POLYMERS; EMISSION AB A platform for photoluminescence (PL) based biosensing is demonstrated for glucose. The sensor is structurally integrated, i.e., individually addressable organic light-emitting device (OLED) pixels (serving as the light source) and the sensing element are fabricated on glass or plastic substrates attached back-to-back. This results in a very compact, potentially miniaturizable sensor, which should strongly impact PL-based biosensor technology. The sensing element is an oxygen-sensitive dye coembedded with glucose oxidase in a thin film or dissolved in solution. The glucose biosensor is demonstrated for two OLED/dye pairs: [blue OLED]/[Ru dye] and [green OLED]/[Pt dye]. Both PL-intensity and PL-lifetime modes are demonstrated for each pair; the lifetime mode eliminates the need for frequent sensor calibration. The sensor performance is evaluated in terms of design, dynamic range, limit of detection, and stability. The use of the glucose biosensor in conjunction with an oxygen sensor is also discussed. (C) 2004 American Institute of Physics. C1 Iowa State Univ, Microelect Res Ctr, Ames, IA 50011 USA. Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Shinar, R (reprint author), Iowa State Univ, Microelect Res Ctr, Ames, IA 50011 USA. EM rshinar@iastate.edu; shinar@ameslab.gov NR 33 TC 67 Z9 68 U1 0 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2004 VL 96 IS 5 BP 2949 EP 2954 DI 10.1063/1.1778477 PG 6 WC Physics, Applied SC Physics GA 851XH UT WOS:000223719300077 ER PT J AU Liu, FZ Ward, S Gedvilas, L Keyes, B To, B Wang, Q Sanchez, E Wang, SL AF Liu, FZ Ward, S Gedvilas, L Keyes, B To, B Wang, Q Sanchez, E Wang, SL TI Amorphous silicon nitride deposited by hot-wire chemical vapor deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILM TRANSISTORS; A-SI-H; HYDROGEN CONTENT; ATOMIC-HYDROGEN; CVD; PLASMA; QUALITY; AMMONIA; SYSTEM; GROWTH AB High-quality amorphous silicon nitrides were deposited by hot-wire chemical vapor deposition using SiH4, NH3, and H-2 gases. These films show a high deposition rate of 5 Angstrom/s, a low processing temperature of 300 degreesC, an excellent conformal coverage, a low etching rate of 7 Angstrom/min, an index of refraction of 2.1, an optical band gap of 4.0 eV, and a high breakdown field of 3 MV/cm. The effects of hydrogen dilution, substrate temperature, chamber pressure, and filament temperature on silicon nitride film property were studied to optimize the process. We found that adding H-2 to the processing significantly enhances the silicon nitride films' properties. The N content in the film increased significantly based on the infrared measurement. Hydrogen dilution is believed to play a key role for the conformal silicon nitride film. Hydrogen dilution also improves the process in that the gas ratio of NH3/SiH4 has been greatly reduced with the assistance of the H-2 gas. With substrate temperatures varying from 23degrees to 400 degreesC, this study showed a best film at near 300 degreesC. However, a good-quality silicon nitride can be grown even if starting with a substrate at room temperature. Furthermore, we found that increasing chamber pressure and a high filament temperature result in higher deposition rate and better quality in the films. The optimized films were grown with hydrogen dilution at about 300 degreesC substrate temperature, 83 mTorr pressure, and 2100 degreesC filament temperature. (C) 2004 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Appl Mat Inc, Sunnyvale, CA 94086 USA. RP Wang, Q (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM qi_wang@nrel.gov NR 28 TC 16 Z9 17 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2004 VL 96 IS 5 BP 2973 EP 2979 DI 10.1063/1.1775046 PG 7 WC Physics, Applied SC Physics GA 851XH UT WOS:000223719300081 ER PT J AU McCarter, JD Stephens, D Shoemaker, K Rosenberg, S Kirsch, JF Georgiou, G AF McCarter, JD Stephens, D Shoemaker, K Rosenberg, S Kirsch, JF Georgiou, G TI Substrate specificity of the Escherichia coli outer membrane protease OmpT SO JOURNAL OF BACTERIOLOGY LA English DT Article ID PHAGE DISPLAY; IDENTIFICATION; PURIFICATION; PLASMINOGEN; LIBRARIES; RESIDUES; SURFACE; PROTEOLYSIS; ACTIVATION; PROTEINS AB OmpT is a surface protease of gram-negative bacteria that has been shown to cleave antimicrobial peptides, activate human plasminogen, and degrade some recombinant heterologous proteins. We have analyzed the substrate specificity of OmpT by two complementary substrate filamentous phage display methods: (i) in situ cleavage of phage that display protease-susceptible peptides by Escherichia coli expressing OmpT and (ii) in vitro cleavage of phage-displayed peptides using purified enzyme. Consistent with previous reports, OmpT was found to exhibit a virtual requirement for Arg in the P1 position and a slightly less stringent preference for this residue in the P1' position (P1 and P1' are the residues immediately prior to and following the scissile bond). Lys, Gly, and Val were also found in the P1' position. The most common residues in the P2' position were Val or Ala, and the P3 and P4 positions exhibited a preference for Trp or Arg. Synthetic peptides based upon sequences selected by bacteriophage display were cleaved very efficiently, with k(cat)/K-m values up to 7.3 x 10(6) M-1 s(-1). In contrast, a peptide corresponding to the cleavage site of human plasminogen was hydrolyzed with a k(cat)/K-m almost 10(6)-fold lower. Overall, the results presented in this work indicate that in addition to the P1 and P1' positions, additional amino acids within a six-residue window (between P4 and P2') contribute to the binding of substrate polypeptides to the OmpT binding site. C1 Univ Texas, Dept Chem Engn, Austin, TX 78705 USA. Univ Texas, Inst Cell & Mol Biol, Austin, TX 78705 USA. Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA USA. RP Georgiou, G (reprint author), Univ Texas, Dept Chem Engn, Austin, TX 78705 USA. EM gg@che.utexas.edu RI Tang, Amy/L-3226-2016 OI Tang, Amy/0000-0002-5772-2878 NR 34 TC 48 Z9 54 U1 0 U2 5 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD SEP PY 2004 VL 186 IS 17 BP 5919 EP 5925 DI 10.1128/JB.186.17.5919-5925.2004 PG 7 WC Microbiology SC Microbiology GA 848HX UT WOS:000223459300039 PM 15317797 ER PT J AU Motin, VL Georgescu, AM Fitch, JP Gu, PP Nelson, DO Mabery, SL Garnham, JB Sokhansanj, BA Ott, LL Coleman, MA Elliott, JM Kegelmeyer, LM Wyrobek, AJ Slezak, TR Brubaker, RR Garcia, E AF Motin, VL Georgescu, AM Fitch, JP Gu, PP Nelson, DO Mabery, SL Garnham, JB Sokhansanj, BA Ott, LL Coleman, MA Elliott, JM Kegelmeyer, LM Wyrobek, AJ Slezak, TR Brubaker, RR Garcia, E TI Temporal global changes in gene expression during temperature transition in Yersinia pestis SO JOURNAL OF BACTERIOLOGY LA English DT Article ID PASTEURELLA-PESTIS; ESCHERICHIA-COLI; GENOME SEQUENCE; ENTEROCOLITICA; VIRULENCE; PSEUDOTUBERCULOSIS; PROTEIN; GROWTH; PLAGUE; ANTIGEN AB DNA microarrays encompassing the entire genome of Yersinia pestis were used to characterize global regulatory changes during steady-state vegetative growth occurring after shift from 26 to 37degreesC in the presence and absence of Ca2+. Transcriptional profiles revealed that 51, 4, and 13 respective genes and open reading frames (ORFs) on pCD, pPCP, and pMT were thermoinduced and that the majority of these genes carried by pCD were downregulated by Ca2+. In contrast, Ca2+ had little effect on chromosomal genes and ORFs, of which 235 were thermally upregulated and 274 were thermally downregulated. The primary consequence of these regulatory events is profligate catabolism of numerous metabolites available in the mammalian host. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Mississippi State Univ, Dept Microbiol & Mol Genet, E Lansing, MI USA. RP Garcia, E (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-452,7000 E Ave, Livermore, CA 94550 USA. EM garcia12@llnl.gov RI Motin, Vladimir/O-1535-2013; OI Coleman, Matthew/0000-0003-1389-4018 FU NIAID NIH HHS [1-U54-AI-057153, R21 AI053508, R21 AI53508, U54 AI057153] NR 37 TC 108 Z9 111 U1 0 U2 5 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD SEP PY 2004 VL 186 IS 18 BP 6298 EP 6305 DI 10.1128/JB.186.18.6298-6305.2004 PG 8 WC Microbiology SC Microbiology GA 851QM UT WOS:000223699900036 PM 15342600 ER PT J AU Powers, R Acton, TB Chiang, YW Rajan, PK Cort, JR Kennedy, MA Liu, JF Ma, LC Rost, B Montelione, GT AF Powers, R Acton, TB Chiang, YW Rajan, PK Cort, JR Kennedy, MA Liu, JF Ma, LC Rost, B Montelione, GT TI Letter to the Editor: H-1, C-13 and N-15 assignments for the Archaeglobus fulgidis protein AF2095 SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE Archaeglobus fulgidis; NMR; protein AF2095; resonance assignments; secondary structure ID NMR C1 Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. Rutgers State Univ, Dept Mol Biol & Biochem, Ctr Adv Biotechnol & Med, Piscataway, NJ 08854 USA. Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. Columbia Univ, Dept Biochem & Mol Biophys, New York, NY 10032 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Biochem, Piscataway, NJ 08854 USA. RP Powers, R (reprint author), Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. EM rpowers3@unl.edu FU NIGMS NIH HHS [P50 GM62413] NR 10 TC 2 Z9 2 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD SEP PY 2004 VL 30 IS 1 BP 107 EP 108 DI 10.1023/B:JNMR.0000042947.19593.80 PG 2 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 857EU UT WOS:000224099800013 PM 15452442 ER PT J AU Hillegonds, DJ Vogel, JS AF Hillegonds, DJ Vogel, JS TI A new technique for measurement of small changes in bone turnover rates in individual human subjects SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 4th International Conference on Cancer-Induced Bone Diseases CY DEC 08, 2003 CL San Antonio, TX C1 Lawrence Livermore Natl Lab, Livermore, CA USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2004 VL 19 IS 9 BP 1585 EP 1586 PG 2 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 850JP UT WOS:000223607500101 ER PT J AU Rard, JA Wijesinghe, AM Wolery, TJ AF Rard, JA Wijesinghe, AM Wolery, TJ TI Review of the thermodynamic properties of Mg(No-3)(2)(aq) and their representation with the standard and extended ion-interaction (Pitzer) models at 298.15 K SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Review ID EARTH ELECTROLYTE-SOLUTIONS; SATURATED AQUEOUS-SOLUTIONS; HIGHER-ORDER TERMS; ACTIVITY-COEFFICIENTS; ISOPIESTIC DETERMINATION; MAGNESIUM-NITRATE; OSMOTIC COEFFICIENTS; WATER ACTIVITIES; HEAT-CAPACITIES; CALCIUM NITRATE AB Published thermodynamic data yielding the osmotic coefficients, relative apparent molar enthalpies, and apparent molar heat capacities of Mg(NO3)(2)(aq) have been collected, recalculated consistently, and critically assessed. The more reliable of these data have been used to evaluate the parameters of the standard three-parameter form of Pitzer's ion-interaction model to higher molalities than previously available, along with the parameters of Archer's four-parameter, extended ion-interaction model at 298.15 K. Published experimental thermodynamic data were essentially represented equally well by these two models, provided that the exponential coefficient a, of the standard Pitzer model is fixed at the optimum value of alpha(1) = 1.55 kg(1/2.)mol(-1/2) rather than the traditional value of alpha(1) = 2.0 kg(1/2.)mol(-1/2). The use of the standard Pitzer model with this modified alpha(1) value is recommended for Mg(NO3)(2)(aq). In addition, an empirical equation is given for the variation of the water activity of a saturated solution with temperature, from 273.54 to 328.20 K, with Mg(NO3)(2).6H(2)O(s) as the solid phase. C1 Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Rard, JA (reprint author), Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. EM rard1@llnl.gov NR 67 TC 11 Z9 12 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD SEP-OCT PY 2004 VL 49 IS 5 BP 1127 EP 1140 DI 10.1021/je049865l PG 14 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 853NA UT WOS:000223833100001 ER PT J AU Venkatapathy, R Moudgal, CJ Bruce, RM AF Venkatapathy, R Moudgal, CJ Bruce, RM TI Assessment of the oral rat chronic lowest observed adverse effect level model in TOPKAT, a QSAR software package for toxicity prediction SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article ID MOLECULAR GRAPHS; CARCINOGENICITY; MUTAGENICITY; INFORMATION; VALIDATION; CHEMICALS AB The performance of the rat chronic lowest observed adverse effect level (LOAEL, the lowest exposure level at which there are biologically significant increases in the severity of adverse effects) model in Toxicity Prediction by Komputer Assisted Technology (TOPKAT), a commercial quantitative structure-activity relationship software package, was tested on a database of chemicals that are of interest to the U.S. EPA's Office of Pesticide Programs. The testing was repeated on a database of chemicals from three U.S. EPA sources that report peer-reviewed LOAELs. The results of this study were also contrasted with the results of the testing performed during TOPKAT's model-building process. C1 US EPA, NCEA, Oak Ridge Inst Sci & Educ, Cincinnati, OH 45268 USA. US EPA, Natl Ctr Environm Assesment, Off Res & Dev, Cincinnati, OH 45268 USA. RP Venkatapathy, R (reprint author), US EPA, NCEA, Oak Ridge Inst Sci & Educ, 26 W Martin Luther King Dr, Cincinnati, OH 45268 USA. EM venkatapathy.raghuraman@epa.gov NR 26 TC 31 Z9 33 U1 0 U2 7 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 2004 VL 44 IS 5 BP 1623 EP 1629 DI 10.1021/ci049903s PG 7 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 858IQ UT WOS:000224185900012 PM 15446819 ER PT J AU Majumdar, D Balasubramanian, K AF Majumdar, D Balasubramanian, K TI Theoretical study of the electronic states of Nb-4, Nb-5 clusters and their anions (Nb-4(-),Nb-5(-)) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COLLISION-INDUCED DISSOCIATION; TRANSITION-METAL CLUSTERS; NIOBIUM CLUSTERS; DENSITY; REACTIVITY; CO; PHOTOIONIZATION; CHEMISORPTION; POTENTIALS; PATHWAYS AB Geometries and energy separations of the various low-lying electronic states of Nb-n and Nb-n(-) (n=4,5) clusters with various structural arrangements have been investigated. The complete active space multiconfiguration self-consistent field method followed by multireference singles and doubles configuration interaction (MRSDCI) calculations that included up to 52x10(6) configuration spin functions have been used to compute several electronic states of these clusters. The ground states of both Nb-4 ((1)A', pyramidal) and Nb-4(-) (B-2(3g), rhombus) are low-spin states at the MRSDCI level. The ground state of Nb-5 cluster is a doublet with a distorted trigonal bipyramid (DTB) structure. The anionic cluster of Nb-5 has two competitive ground states with singlet and triplet multiplicities (DTB). The low-lying electronic states of these clusters have been found to be distorted due to Jahn-Teller effect. On the basis of the energy separations of our computed electronic states of Nb-4 and Nb-5, we have assigned the observed photoelectron spectrum of Nb-n(-) (n=4,5) clusters. We have also compared our MRSDC1 results with density functional calculations. The electron affinity, ionization potential, dissociation and atomization energies of Nb-4 and Nb-5 have been calculated and the results have been found to be in excellent agreement with the experiment. (C) 2004 American Institute of Physics. C1 Univ Calif Davis, Ctr Image Proc & Integrated Computing, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Glenn T Seaborg Ctr, Berkeley, CA 94720 USA. RP Balasubramanian, K (reprint author), Univ Calif Davis, Ctr Image Proc & Integrated Computing, Livermore, CA 94550 USA. EM kbala@ucdavis.edu NR 43 TC 15 Z9 15 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2004 VL 121 IS 9 BP 4014 EP 4032 DI 10.1063/1.1769358 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 850PB UT WOS:000223623800008 PM 15332947 ER PT J AU Brixner, T Mancal, T Stiopkin, IV Fleming, GR AF Brixner, T Mancal, T Stiopkin, IV Fleming, GR TI Phase-stabilized two-dimensional electronic spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSFORM SPECTRAL INTERFEROMETRY; TRANSIENT-GRATING SPECTROSCOPY; DOMAIN RESONANT SPECTROSCOPIES; STIMULATED PHOTON-ECHO; DIFFRACTIVE OPTICS; FEMTOSECOND SPECTROSCOPY; INFRARED-SPECTROSCOPY; INTRAMOLECULAR VIBRATIONS; HETERODYNE-DETECTION; TIME AB Two-dimensional (2D) spectroscopy is a. powerful technique to study nuclear and electronic correlations between different transitions or initial and final states. Here we describe in detail our development of inherently phase-stabilized 2D Fourier-transform spectroscopy for electronic transitions. A diffractive-optic setup is used to realize heterodyne-detected femtosecond four-wave mixing in a phase-matched box geometry. Wavelength tunability in the visible range is accomplished by means of a 3 kHz repetition-rate laser system and optical parametric amplification. Nonlinear signals are fully characterized by spectral interferometry. Starting from fundamental principles, we discuss the origin of phase stability and the precise calibration of excitation-pulse time delays using movable glass wedges. Automated subtraction of undesired scattering terms removes experimental artifacts. On the theoretical side, the response-function formalism is extended to describe molecules with three electronic levels, and the shape of 2D spectral features is discussed. As an example for this technique, experimental 2D spectra are shown for the dye molecule Nile Blue in acetonitrile at 595 nm, recorded for a series of population times. Simulations explore the influence of different model parameters and qualitatively reproduce the experimental results. We show that correlations between different electronically excited states can be determined from the spectra. The technique described here can be used to measure the third-order response function of complex systems covering several electronic transitions. (C) 2004 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM grfleming@lbl.gov RI Mancal, Tomas/B-9688-2014; Brixner, Tobias/S-1451-2016 OI Mancal, Tomas/0000-0003-1736-3054; Brixner, Tobias/0000-0002-6529-704X NR 47 TC 297 Z9 300 U1 9 U2 131 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 2004 VL 121 IS 9 BP 4221 EP 4236 DI 10.1063/1.1776112 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 850PB UT WOS:000223623800031 PM 15332970 ER PT J AU Barnard, AS Zapol, P AF Barnard, AS Zapol, P TI A model for the phase stability of arbitrary nanoparticles as a function of size and shape SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EQUILIBRIUM SHAPE; SEMICONDUCTOR NANOCRYSTALS; SILICON SURFACES; DIAMOND; STRESS; NANODIAMOND; ENERGETICS; ENERGIES; CARBON; STEPS AB A thermodynamic model describing relative stability of different shapes for nanoparticles as a function of their size was developed for arbitrary crystalline solids and applied to group IV semiconductors. The model makes use of various surface, edge and corner energies, and takes into account surface tension. Approximations and importance of each term of the model were analyzed. The predictions for clean and hydrogenated diamond nanoparticles are compared to explicitly calculated density functional results. It is shown that diamond nanocrystal morphology is markedly different from silicon and germanium. (C) 2004 American Institute of Physics. C1 Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Zapol, P (reprint author), Argonne Natl Lab, Ctr Nanoscale Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. EM amanda.barnard@anl.gov; zapol@anl.gov RI Barnard, Amanda/A-7340-2011; Zapol, Peter/G-1810-2012 OI Barnard, Amanda/0000-0002-4784-2382; Zapol, Peter/0000-0003-0570-9169 NR 33 TC 180 Z9 181 U1 8 U2 64 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 1 PY 2004 VL 121 IS 9 BP 4276 EP 4283 DI 10.1063/1.1775770 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 850PB UT WOS:000223623800036 PM 15332975 ER PT J AU Liu, DJ AF Liu, DJ TI Lattice-gas modeling of CO adlayers on Pd(100) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARD-SQUARE LATTICE; PHASE-TRANSITIONS; CARBON-MONOXIDE; ADSORPTION; PALLADIUM; BEHAVIOR; COVERAGE; PD(111); ENERGY AB Using a lattice-gas model with pairwise interactions, we study the ordered structures, coverage dependence of the heat of adsorption, and other experimentally observable behavior of adsorbed CO overlayers on Pd(100) single crystal surfaces. Transfer matrix and Monte Carlo methods give accurate information regarding the lattice-gas model that often contradicts simple mean-field-like analysis. We demonstrate the usefulness of the model by reproducing experimental results over a large range of pressures and temperatures. (C) 2004 American Institute of Physics. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Liu, DJ (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 27 TC 10 Z9 10 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 1 PY 2004 VL 121 IS 9 BP 4352 EP 4357 DI 10.1063/1.1778134 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 850PB UT WOS:000223623800047 PM 15332986 ER PT J AU Pyda, M Bopp, RC Wunderlich, B AF Pyda, M Bopp, RC Wunderlich, B TI Heat capacity of poly(lactic acid) SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE heat capacity; poly(lactic acid); heats of fusion; glass transition; melting; crystallinity; rigid-amorphous fraction ID LINEAR MACROMOLECULES; ADDITION SCHEME; POLYMERS; POLY(L-LACTIDE); POLYETHYLENE; MICROSPHERES; WATER AB The heat capacity of poly(lactic acid) (PLA) is reported from T = (5 to 600) K as obtained by differential scanning calorimetry (d.s.c.) and adiabatic calorimetry. The heat capacity of solid PLA is linked to its group vibrational spectrum and the skeletal vibrations, the latter being described by a Tarasov equation with Theta(1) = 574 K, Theta(2) = Theta(3) = 52 K, and nine skeletal vibrations. The calculated and experimental heat capacities agree to +/- 3% between T= (5 and 300) K. The experimental heat capacity of liquid PLA can be expressed by C, (liquid) = (120.17 + 0.076T) J (.) K-1 (.) mol(-1) and has been compared to the ATHAS Data Bank, using contributions of other polymers with the same constituent groups. The glass transition temperature of amorphous PLA occurs at T = 332.5 K with a change in heat capacity of 43.8 J (.) K-1 (.) mol(-1). Depending on thermal history, semi-crystalline PLA has a melting endotherm between T= (418 and 432) K with variable heats of fusion. For 100% crystalline PLA, the heat of fusion is estimated to be (6.55 +/- 0.02) kJ (.) mol(-1) at T = 480 K. With these results, the enthalpy, entropy, and Gibbs function of crystalline and amorphous PLA were obtained. For semi-crystalline samples, one can check changes of crystallinity with temperature and judge the presence of rigid-amorphous fractions. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Cargill Dow LLD, Minnetonka, MN 55343 USA. RP Pyda, M (reprint author), Univ Tennessee, Dept Chem, 563 Buehler Hall, Knoxville, TN 37996 USA. EM mpyda@utk.edu NR 36 TC 115 Z9 117 U1 8 U2 55 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD SEP PY 2004 VL 36 IS 9 BP 731 EP 742 DI 10.1016/j.jet.2004.02.003 PG 12 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 851XF UT WOS:000223719100001 ER PT J AU Jepsen, R Roberts, J Gailani, J AF Jepsen, R Roberts, J Gailani, J TI Erosion measurements in linear, oscillatory, and combined oscillatory and linear flow regimes SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE waves; sediment; SEDflume ID BULK-DENSITY; BOTTOM AB Many contaminated sediments and dredged material mixtures of cohesive and non-cohesive sediments occur in wave-dominated environments. In-situ analysis is imperative in understanding the erosion and transport of these sediments. Recent research efforts have developed a flume with unidirectional flow that can measure in-situ sediment erosion with depth (SEDflume). However, the flow regime for the SEDflume has limited applicability to wave-dominated environments. Therefore, a unique device, called the SEAWOLF flume, was developed and used by Sandia National Laboratories to simulate high-shear stress erosion processes experienced in coastal waters where wave forcing dominates the system. The SEAWOLF is capable of testing in-situ or laboratory prepared cores. Erosion rates of cohesive and non-cohesive sediments prepared in the laboratory were determined in oscillatory and combined oscillatory and linear flow regimes. Results of these tests were compared to results from the unidirectional SEDflume. Although maximum shear stresses for oscillatory flows were as high as 7 Pa for the tests, the associated erosion rate for specific sediment over the entire wave cycle were comparable to much lower shear stresses found for constant, linear flows. For example, sediment exposed to a maximum of 7 Pa over a 15 s period resulted in erosion rates similar to results for a constant linear shear stress of 3.4 Pa. Analysis of results for all sediments tested led to a determination of values for an effective shear stress that relates wave-induced erosion to linear flow induced erosion. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Carlsbad Programs Grp, Carlsbad, NM 88220 USA. CEWES CC D, Coastal Hydraul Lab, Vicksburg, MS 39180 USA. RP Jepsen, R (reprint author), Sandia Natl Labs, POB 5800,MS 1135, Albuquerque, NM 87185 USA. NR 8 TC 4 Z9 5 U1 3 U2 7 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 2004 VL 20 IS 4 BP 1096 EP 1101 DI 10.2112/03-0003R.1 PG 6 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 873JW UT WOS:000225276900013 ER PT J AU Li, ZJ Pan, ZW Dai, S AF Li, ZJ Pan, ZW Dai, S TI Nitrogen adsorption characterization of aligned multiwalled carbon nanotubes and their acid modification SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE carbon nanotubes; nitrogen adsorption; surface modification; alpha s-plot ID SURFACE-AREA; ELECTRONIC-PROPERTIES; HYDROGEN STORAGE; PORE STRUCTURE; PURIFICATION; SENSITIVITY; ADSORBENTS; SIMULATION; GROWTH; ARRAYS AB Aligned multiwalled carbon nanotube (CNT) arrays were synthesized by using an iron-based sol-gel catalyst and acetylene as the precursor. These CNTs show high purity, uniform diameters and pore-wall thickness. Low temperature nitrogen adsorption was employed to characterize the structural and surface properties of the as-synthesized sample and that modified with boiling concentrated nitric acid. The adsorption characteristics of the as-synthesized and modified CNTs were thoroughly investigated. High-resolution comparative alpha(s)-plot showed that the nitrogen adsorption on CNTs takes place via a multistage mechanism closely related to their structures. It was also found that the acid modification significantly increased the adsorption energy and enhanced the adsorption capacity under low pressures. High-resolution comparative method provided valuable insights about the surface and pore structures of CNTs. Published by Elsevier Inc. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Sci, MS-6201, Oak Ridge, TN 37831 USA. EM dais@oml.gov RI Dai, Sheng/K-8411-2015; OI Dai, Sheng/0000-0002-8046-3931; Pan, Zhengwei/0000-0002-3854-958X NR 44 TC 41 Z9 41 U1 0 U2 12 PU ACADEMIC PRESS INC ELSEVIER SCIENCE 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 2004 VL 277 IS 1 BP 35 EP 42 DI 10.1016/j.jcis.2004.05.024 PG 8 WC Chemistry, Physical SC Chemistry GA 843HT UT WOS:000223070000005 PM 15276035 ER PT J AU McCabe, C Glotzer, SC Kieffer, J Neurock, M Cummings, PT AF McCabe, Clare Glotzer, Sharon C. Kieffer, John Neurock, Matthew Cummings, Peter T. TI Multiscale Simulation of the Synthesis, Assembly and Properties of Nanostructured Organic/Inorganic Hybrid Materials SO JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE LA English DT Article DE Polyhedral Oligomeric Silsequioxanes; POSS; Multiscale Simulation AB Polyhedral oligomeric silsesquioxane (POSS) molecules are unique nanometer-sized inorganic-organic hybrid structures based on a (SiO(1.5))(8) core. Depending on the functionalization of the POSS cages, the resulting systems can be solid or liquid, or, upon cross-linking, turned into a network. Although much is known experimentally about the chemical synthesis of POSS systems, very little theoretical understanding exists at the molecular level or beyond. In particular, the way in which individual POSS molecules can be assembled and manipulated at the nanoscale to form meso- and macroscale systems has not been investigated previously. The overall goal of our work is to develop a multiscale computational framework to simulate the synthesis and self- and guided-assembly of POSS systems. In this report we present an overview of the computational approach on which this framework is based, which combines simulation techniques at the electronic, atomistic, and mesoscale levels, and discuss progress in each of these areas. C1 [McCabe, Clare; Cummings, Peter T.] Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. [Glotzer, Sharon C.] Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. [Glotzer, Sharon C.; Kieffer, John] Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. [Neurock, Matthew] Univ Virginia, Dept Chem Engn, Charlottesville, VA 22904 USA. [Cummings, Peter T.] Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. [Cummings, Peter T.] Oak Ridge Natl Lab, Nanomat Theory Inst, Oak Ridge, TN 37831 USA. RP Cummings, PT (reprint author), Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013 OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216 FU National Science Foundation [DMR-0103399] FX This work is supported by the National Science Foundation (DMR-0103399). NR 59 TC 19 Z9 20 U1 1 U2 13 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1546-1955 J9 J COMPUT THEOR NANOS JI J. Comput. Theor. Nanosci. PD SEP PY 2004 VL 1 IS 3 BP 265 EP 279 DI 10.1166/jctn.2004.024 PG 15 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA V03TM UT WOS:000207013100004 ER PT J AU Windl, W Liang, T Lopatin, S Duscher, G AF Windl, Wolfgang Liang, Tao Lopatin, Sergei Duscher, Gerd TI Investigation of Nanostructured Germanium/Silicon Dioxide Interfaces SO JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE LA English DT Article DE Interface; Germanium; Silicon Dioxide; Electronic Devices; Ab Initio; Monte Carlo AB The precipitation of Ge nanoclusters in SiO2 after implantation arises from their immiscibility and is technologically interesting due to their luminescence and potential use for non-volatile memory devices. Exploiting the same immiscibility, we have recently found that oxidation of germanium-implanted Si surfaces can produce a pileup of Ge in front of the oxidation front and create an atomically sharp interface. In this paper, we examine the band structure and processing of such an interface. Based on ab initio band structure calculations, the band structure of the sharp interface seems to be more favorable for use in electronic devices than the usually diffuse interface in Si/SiO2. Furthermore, we propose an ab initio based Monte Carlo model to simulate such an oxidation of SiGe alloys. The model explains the formation of the sharp interface due to the repulsive interaction between O and Ge. In such cases, Ge is expelled from the oxide and O atoms do not enter the Ge region under the oxidation front, resulting in strong segregation. Furthermore, inclusion of Ge nanoparticles in the oxide is predicted for higher Ge concentrations, in agreement with experimental results. C1 [Windl, Wolfgang; Liang, Tao] Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. [Lopatin, Sergei; Duscher, Gerd] N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. [Duscher, Gerd] Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Windl, W (reprint author), Ohio State Univ, Dept Mat Sci & Engn, 2041 Coll Rd, Columbus, OH 43210 USA. RI Windl, Wolfgang/C-7255-2012; Duscher, Gerd/G-1730-2014 OI Windl, Wolfgang/0000-0001-5892-0684; Duscher, Gerd/0000-0002-2039-548X FU Semiconductor Research Corporation [2002-MJ-1018]; National Science Foundation [0244724]; U.S. Department of Energy [DE-AC05-00OR22725] FX This work was funded by the Semiconductor Research Corporation under contract number 2002-MJ-1018; the National Science Foundation under contract number 0244724; and the U.S. Department of Energy under contract number DE-AC05-00OR22725. We also thank the Ohio Supercomputer Center for supercomputer time under project number PAS0072. NR 38 TC 0 Z9 0 U1 0 U2 3 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1546-1955 EI 1546-1963 J9 J COMPUT THEOR NANOS JI J. Comput. Theor. Nanosci. PD SEP PY 2004 VL 1 IS 3 BP 288 EP 297 DI 10.1166/jctn.2004.030 PG 10 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA V03TM UT WOS:000207013100006 ER PT J AU Wang, LW AF Wang, Lin-Wang TI Effects of Stacking Faults on the Electronic Structures of Quantum Rods SO JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE LA English DT Article DE Nanorod; Stacking Fault; CdSe; Empirical Pseudopotential AB Atomistic semiempirical pseudopotential method is used to study the effects of stacking faults in a wurtzite structure quantum rod. It is found that a single stacking fault can cause a 10 to 50 meV change in the conduction-state eigen energy, and a localization in the electron wave function. However, the effects on the hole eigen energies and wave functions are very small. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. RP Wang, LW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, 1 Cyclotron Rd, Berkeley, CA 94720 USA. FU U.S. Department of Energy [DE-AC03-76DF00098] FX This work was supported by the U.S. Department of Energy, Contract No. DE-AC03-76DF00098. This research used the resources of the National Energy Research Scientific Computing Center. NR 15 TC 1 Z9 1 U1 0 U2 1 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1546-1955 J9 J COMPUT THEOR NANOS JI J. Comput. Theor. Nanosci. PD SEP PY 2004 VL 1 IS 3 BP 298 EP 302 DI 10.1166/jctn.2004.025 PG 5 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA V03TM UT WOS:000207013100007 ER PT J AU Barnard, AS AF Barnard, A. S. TI Shape and Energetics of TiN Nanoparticles SO JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE LA English DT Article DE Titanium Nitride (TiN); Density Functional Theory (DFT); Nanoparticles ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; AB-INITIO; PREFERRED ORIENTATION; ELASTIC-CONSTANTS; TITANIUM NITRIDE; PHASE-STABILITY; THIN-FILMS; DEPOSITION; SURFACE AB The properties of titanium nitride films have previously been found to be dependent upon the surface structure and crystallite orientation. Presented here are results of density functional theory calculations and a thermodynamic model that are used to predict the shape of isolated faceted TiN nanoparticles as a function of size. The model takes as input the surface free energies of the TiN (001) and (111) surfaces and compressibility of bulk TiN, which are be shown to in good agreement with experimental results and the results of other theoretical investigations. The optimization of the TiN nanocrystal shape resulted in a truncated cubic morphology which differs considerably from the truncated octahedral morphology for macroscopic crystals predicted by the Wulff construction. This study concludes that the Wulff construction is not satisfactory for predicting shapes at the nanoscale. C1 Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. RP Barnard, AS (reprint author), Argonne Natl Lab, Ctr Nanoscale Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Barnard, Amanda/A-7340-2011 OI Barnard, Amanda/0000-0002-4784-2382 FU U.S. Department of Energy; BES-Materials Sciences [W-31-109-ENG-38] FX This work has been supported by the U.S. Department of Energy, BES-Materials Sciences, under Contract W-31-109-ENG-38. Computational resources for this project have been supplied by the Victorian Partnership for Advanced Computing and the Australian Partnership for Advanced Computing supercomputer center. I would also like to thank Larry Curtiss for his support and assistance in preparing the manuscript. NR 38 TC 9 Z9 10 U1 2 U2 16 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1546-1955 J9 J COMPUT THEOR NANOS JI J. Comput. Theor. Nanosci. PD SEP PY 2004 VL 1 IS 3 BP 334 EP 339 DI 10.1166/jctn.2004.031 PG 6 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA V03TM UT WOS:000207013100012 ER PT J AU Li, ST Li, H AF Li, ST Li, H TI A novel approach of divergence-free reconstruction for adaptive mesh refinement SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE adaptive mesh refinement; divergence-free; magnetohydrodynamics; cylindrical geometry; spherical geometry; finite volume method ID FINITE-DIFFERENCE SCHEME; IDEAL MAGNETOHYDRODYNAMICS; NUMERICAL-SOLUTION; EQUATIONS; FLOWS AB A simple novel approach to maintain the divergence-free condition with adaptive mesh refinement is presented. This new approach uses reconstructions on the coarse faces together with the divergence-free condition to reconstruct the field values on the internal fine faces. It does not construct a global interpolation polynomial over a whole coarse cell. Therefore, it can be easily applied to any refinement ratio. It is implemented via a directionally splitting approach so that it can be applied to any kind of grids and in any dimensions. Implementation is presented in the Cartesian, cylindrical and spherical geometries. It is shown by several 2D magneto-hydrodynamic simulations that such a method can keep the divergence-free error of magnetic fields at the round-off level. (C) 2004 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Li, ST (reprint author), Los Alamos Natl Lab, Div Theoret, MS B284, Los Alamos, NM 87545 USA. EM sli@lanl.gov; hli@lanl.gov NR 20 TC 18 Z9 18 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE 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 2004 VL 199 IS 1 BP 1 EP 15 DI 10.1016/j.jcp.2004.01.027 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 851FW UT WOS:000223672000001 ER PT J AU Densmore, JD Larsen, EW AF Densmore, JD Larsen, EW TI Asymptotic equilibrium diffusion analysis of time-dependent Monte Carlo methods for grey radiative transfer SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE radiative transfer; Monte Carlo; asymptotic analysis ID MEAN FREE PATHS; NUMERICAL TRANSPORT PROBLEMS; OPTICALLY THICK; REGIMES; SCHEME; LIMIT AB The equations of nonlinear, time-dependent radiative transfer are known to yield the equilibrium diffusion equation as the leading-order solution of an asymptotic analysis when the mean-free path and mean-free time of a photon become small. We apply this same analysis to the Fleck-Cummings, Carter-Forest, and N'kaoua Monte Carlo approximations for grey (frequency-independent) radiative transfer. Although Monte Carlo simulation usually does not require the discretizations found in deterministic transport techniques, Monte Carlo methods for radiative transfer require a time discretization due to the nonlinearities of the problem. If an asymptotic analysis of the equations used by a particular Monte Carlo method yields an accurate time-discretized version of the equilibrium diffusion equation, the method should generate accurate solutions if a time discretization is chosen that resolves temperature changes, even if the time steps are much larger than the mean-free time of a photon. This analysis is of interest because in many radiative transfer problems, it is a practical necessity to use time steps that are large compared to a mean-free time. Our asymptotic analysis shows that: (i) the N'kaoua method has the equilibrium diffusion limit, (ii) the Carter-Forest method has the equilibrium diffusion limit if the material temperature change during a time step is small, and (iii) the Fleck-Cummings method does not have the equilibrium diffusion limit. We include numerical results that verify our theoretical predictions. (C) 2004 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Transport Methods Grp, Los Alamos, NM 87545 USA. Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RP Densmore, JD (reprint author), Los Alamos Natl Lab, Transport Methods Grp, Los Alamos, NM 87545 USA. EM jdd@lanl.gov; edlarsen@engin.umich.edu NR 18 TC 21 Z9 21 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2004 VL 199 IS 1 BP 175 EP 204 DI 10.1016/j.jcp.2004.02.004 PG 30 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 851FW UT WOS:000223672000009 ER PT J AU Barnum, H Saks, M AF Barnum, H Saks, M TI A lower bound on the quantum query complexity of read-once functions SO JOURNAL OF COMPUTER AND SYSTEM SCIENCES LA English DT Article DE quantum query complexity; quantum computation; query complexity; decision tree complexity; readonce functions; lower bounds AB We establish a lower bound of Omega(rootn) on the bounded-error quantum query complexity of read-once Boolean functions. The result is proved via an inductive argument, together with an extension of a lower bound method of Ambainis. Ambainis' method involves viewing a quantum computation as a mapping from inputs to quantum states (unit vectors in a complex inner-product space) which changes as the computation proceeds. Initially the mapping is constant (the state is independent of the input). If the computation evalutes the function f then at the end of the computation the two states associated with any f-distinguished pair of inputs (having different f values) are nearly orthogonal. Thus the inner product of their associated states must have changed from 1 to nearly 0. For any set off-distinguished pairs of inputs, the sum of the inner products of the corresponding pairs of states must decrease significantly during the computation, By deriving an upper bound on the decrease in such a sum, during a single step, for a carefully selected set of input pairs, one can obtain a lower bound on the number of steps. We extend Ambainis' bound by considering general weighted sums off-distinguished pairs. We then prove our result for read-once functions by induction on the number of variables, where the induction step involves a careful choice of weights depending on f to optimize the lower bound attained. (C) 2004 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Rutgers State Univ, Dept Math Hill Ctr, New Brunswick, NJ 08903 USA. DIMACS, Princeton, NJ USA. RP Los Alamos Natl Lab, CCS-3 Modelling Algorithms & Informat,MS B256, Los Alamos, NM 87545 USA. EM barnum@lanl.gov; saks@math.rutgers.edu NR 15 TC 23 Z9 23 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-0000 EI 1090-2724 J9 J COMPUT SYST SCI JI J. Comput. Syst. Sci. PD SEP PY 2004 VL 69 IS 2 BP 244 EP 258 DI 10.1016/j.jcss.2004.02.002 PG 15 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA 846CM UT WOS:000223292400006 ER PT J AU Wu, YS Liu, HH Bodvarsson, GS AF Wu, YS Liu, HH Bodvarsson, GS TI A triple-continuum approach for modeling flow and transport processes in fractured rock SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE naturally fractured reservoir; dual-continuum porous media; double-porosity; dual-permeability; triple-continuum model; numerical reservoir simulation; fractured unsaturated rock ID YUCCA MOUNTAIN; UNSATURATED ZONE; POROUS-MEDIA; HEAT-FLOW; RESERVOIRS; SIMULATION; NEVADA; FLUID; BEHAVIOR; TUFF AB This paper presents a triple-continuum conceptual model for simulating flow and transport processes in fractured rock. Field data collected from the unsaturated zone of Yucca Mountain, a repository site of high-level nuclear waste, show a large number of small-scale fractures. The effect of these small fractures has not been considered in previous modeling investigations within the context of a continuum approach. A new triple-continuum model (consisting of matrix, small-fracture, and large-fracture continua) has been developed to investigate the effect of these small fractures. This paper derives the model formulation and discusses the basic triple-continuum behavior of flow and transport processes under different conditions, using both analytical solutions and numerical approaches. The simulation results from the site-scale model of the unsaturated zone of Yucca Mountain indicate that these small fractures may have an important effect on radionuclide transport within the mountain. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. EM YSWu@lbl.gov RI Wu, Yu-Shu/A-5800-2011 NR 43 TC 61 Z9 70 U1 3 U2 14 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 2004 VL 73 IS 1-4 BP 145 EP 179 DI 10.1016/j.jconhyd.2004.01.002 PG 35 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 854DX UT WOS:000223882100007 PM 15336793 ER PT J AU Lenhard, RJ Oostrom, M Dane, JH AF Lenhard, RJ Oostrom, M Dane, JH TI A constitutive model for air-NAPL-water flow in the vadose zone accounting for immobile, non-occluded (residual) NAPL in strongly water-wet porous media (vol 71, pg 261, 2004) SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Correction ID HYDRAULIC CONDUCTIVITY; PRESSURE RELATIONS; MIXED-WETTABILITY; OIL-RECOVERY; SATURATION; BEHAVIOR; DRAINAGE; SYSTEMS AB A hysteretic constitutive model describing relations among relative permeabilities, saturations, and pressures in fluid systems consisting of air, nonaqueous-phase liquid (NAPL), and water is modified to account for NAPL that is postulated to be immobile in small pores and pore wedges and as films or lenses on water surfaces. A direct outcome of the model is prediction of the NAPL saturation that remains in the vadose zone after long drainage periods (residual NAPL). Using the modified model, water and NAPL (free, entrapped by water, and residual) saturations can be predicted from the capillary pressures and the water and total-liquid saturation-path histories. Relations between relative permeabilities and saturations are modified to account for the residual NAPL by adjusting the limits of integration in the integral expression used for predicting the NAPL relative permeability. When all of the NAPL is either residual or entrapped (i.e., no free NAPL), then the NAPL relative permeability will be zero. We model residual NAPL using concepts similar to those used to model residual water. As an initial test of the constitutive model, we compare predictions to published measurements of residual NAPL. Furthermore, we present results using the modified constitutive theory for a scenario involving NAPL imbibition and drainage. (C) 2003 Elsevier B.V. All rights reserved. C1 INEEL, Subsurface Sci Initiat, Idaho Falls, ID 83415 USA. PNNL, Environm Technol Div, Richland, WA USA. Auburn Univ, Dept Agron & Soils, Auburn, AL 36849 USA. RP Lenhard, RJ (reprint author), INEEL, Subsurface Sci Initiat, POB 1625,MS 2025, Idaho Falls, ID 83415 USA. EM lenhrj@inel.gov NR 28 TC 7 Z9 8 U1 0 U2 1 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 2004 VL 73 IS 1-4 BP 281 EP 304 DI 10.1016/j.jconhyd.2004.07.004 PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 854DX UT WOS:000223882100012 ER PT J AU Tsouris, C AF Tsouris, C TI Special Issue: From the 77(th) Colloid and Surface Science Symposium - Guest editorial SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. RP Tsouris, C (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM tsourisc@ornl.gov RI Tsouris, Costas/C-2544-2016 OI Tsouris, Costas/0000-0002-0522-1027 NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0193-2691 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PD SEP PY 2004 VL 25 IS 5 SI SI BP VII EP VII DI 10.1081/DIS-200027302 PG 1 WC Chemistry, Physical SC Chemistry GA 861TA UT WOS:000224440300001 ER PT J AU Benesch, T Yiacoumi, S Tsouris, C AF Benesch, T Yiacoumi, S Tsouris, C TI Like-charge attraction: A combined electrostatic-hydrodynamic approach SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 77th Colloid and Surface Science Symposium CY JUN 15-18, 2003 CL Georgia Inst Technol, Atlanta, GA SP Amer Chem Soc, Div Colloid & Surface Chem HO Georgia Inst Technol DE like-charge attraction; colloidal forces; electrostatic-hydrodynamic model ID COLLOIDAL SUSPENSIONS; PARTICLES; SURFACE; SPHERES AB This article discusses the like-charge attraction of colloidal spheres close to a charged plate and compares results produced by an electrostatic and a hydrodynamic model with experimental data. Hydrodynamic coupling is shown to be the dominating effect, while the electrostatic influence may often be neglected. Some observations, however, can be explained only by means of a combined electrostatic-hydrodynamic model, which is derived in this work. The combined model is able to predict not only the attractive force between particles of similar charge close to a charged plate but also the change to a purely repulsive force once the sphere-plate distance is further reduced. This prediction matches qualitatively results of experiments reported in the literature. C1 Georgia Inst Technol, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Georgia Inst Technol, 1311 Ferst Dr, Atlanta, GA 30332 USA. EM syiacoumi@ce.gatech.edu RI Tsouris, Costas/C-2544-2016 OI Tsouris, Costas/0000-0002-0522-1027 NR 26 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0193-2691 EI 1532-2351 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PD SEP PY 2004 VL 25 IS 5 SI SI BP 585 EP 592 DI 10.1081/DIS-200027308 PG 8 WC Chemistry, Physical SC Chemistry GA 861TA UT WOS:000224440300004 ER PT J AU Wang, W Gu, BH Liang, LY AF Wang, W Gu, BH Liang, LY TI Effect of surfactants on the formation, morphology, and surface property of synthesized SiO2 nanoparticles SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 77th Colloid and Surface Science Symposium CY JUN 15-18, 2003 CL Georgia Inst Technol, Atlanta, GA SP Amer Chem Soc, Div Colloid & Surface Chem HO Georgia Inst Technol DE silica; surfactant; nanoparticle; colloid; Raman spectra; synthesis ID COLLOIDAL SILICA SPHERES; RAMAN-SPECTRA; CETYLTRIMETHYLAMMONIUM BROMIDE; CATIONIC SURFACTANTS; PHASE-TRANSITION; AQUEOUS-SOLUTION; PARTICLES; CONFORMATIONS; FABRICATION; TEMPERATURE AB This study investigated the effect of cationic, anionic (saturated and unsaturated), and nonionic surfactants on the formation, morphology, and surface properties of silica nanoparticles synthesized by the ammonium-catalyzed hydrolysis of tetraethoxysilane in alcoholic media. Results indicate that at a relatively low surfactant concentration (1 x 10(-3)-1 x 10(-6)M), cationic surfactants significantly affected the growth of silica particles as measured by dynamic light scattering and transmission electron microscopic analyses. In contrast, the anionic and nonionic surfactants showed relatively minor effects in the low concentration range. The magnitude of negative zeta potential was reduced for silica colloids that were synthesized in the presence of cationic surfactant because of charge neutralization. The presence of anionic surfactants only slightly increased the negative zeta potential while the nonionic surfactant showed no obvious effects. At high surfactant concentrations (> 1 x 10(-3) M), cationic and anionic surfactants both induced colloid aggregation, while the nonionic surfactant showed no effect on particle size. Raman spectroscopic analysis suggests that molecules of cationic surfactants adsorb on silica surfaces via head groups, aided by favorable electrostatic attraction, while molecules of anionic and nonionic surfactants adsorb via their hydrophobic tails. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Wales Coll Cardiff, Sch Engn, Cardiff CF1 1XL, S Glam, Wales. RP Wang, W (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM wangw@ornl.gov RI Wang, Wei/B-5924-2012; Gu, Baohua/B-9511-2012; Liang, Liyuan/O-7213-2014 OI Gu, Baohua/0000-0002-7299-2956; Liang, Liyuan/0000-0003-1338-0324 NR 33 TC 10 Z9 10 U1 2 U2 7 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0193-2691 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PD SEP PY 2004 VL 25 IS 5 SI SI BP 593 EP 601 DI 10.1081/DIS-200027309 PG 9 WC Chemistry, Physical SC Chemistry GA 861TA UT WOS:000224440300005 ER PT J AU Martin, MZ Wullschleger, SD Garten, CT Palumbo, AV Smith, JG AF Martin, MZ Wullschleger, SD Garten, CT Palumbo, AV Smith, JG TI Elemental analysis of environmental and biological samples using laser-induced breakdown spectroscopy and pulsed Raman spectroscopy SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 77th Colloid and Surface Science Symposium CY JUN 15-18, 2003 CL Georgia Inst Technol, Atlanta, GA SP Amer Chem Soc, Div Colloid & Surface Chem HO Georgia Inst Technol DE LIBS; pulsed Raman spectroscopy; elemental analysis of environmental and biological samples ID SPECTROMETRY PY-MBMS; SOIL ORGANIC-MATTER; HUMIC ACIDS; FULVIC-ACID; SPECTRA; CARBON; C-13; FLUORESCENCE; ELECTRODES; FRACTIONS AB Laser-induced breakdown spectroscopy (LIBS) and a relatively new technique, pulsed Raman spectroscopy (P-RAMS) are used in this investigation to measure the elemental composition of soils and heterogeneous biological matrices. The LIBS method was used effectively to determine the elemental concentration of carbon and nitrogen in soils, and the presence of metal contaminants in invertebrates. The P-RAMS method was used in exploratory studies to assess prominent molecular vibration peaks from the same soils analyzed using LIBS. The P-RAMS spectra for the different soils show a close relationship to the fraction of organic carbon in soils. Our results demonstrate that these techniques greatly facilitate elemental analysis of heterogeneous environmental and biological matrices by reducing sample preparation and analysis times. These techniques can also provide semi-quantitative results on a regular basis and quantitative results in particular cases. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Martin, MZ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM martinm1@ornl.gov RI Palumbo, Anthony/A-4764-2011; Martin, Madhavi/A-5268-2011; Wullschleger, Stan/B-8297-2012; OI Palumbo, Anthony/0000-0002-1102-3975; Wullschleger, Stan/0000-0002-9869-0446; Martin, Madhavi/0000-0002-6677-2180 NR 24 TC 16 Z9 16 U1 0 U2 13 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0193-2691 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PD SEP PY 2004 VL 25 IS 5 SI SI BP 687 EP 694 DI 10.1081/DIS-200027329 PG 8 WC Chemistry, Physical SC Chemistry GA 861TA UT WOS:000224440300013 ER PT J AU Gabitto, J Riestenberg, D Lee, S Liang, LY Tsouris, C AF Gabitto, J Riestenberg, D Lee, S Liang, LY Tsouris, C TI Ocean disposal of CO2: Conditions for producing sinking CO2 hydrate SO JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 77th Colloid and Surface Science Symposium CY JUN 15-18, 2003 CL Georgia Inst Technol, Atlanta, GA SP Amer Chem Soc, Div Colloid & Surface Chem HO Georgia Inst Technol DE ocean carbon sequestration; CO2 hydrate; mass transfer ID LIQUID CO2-WATER INTERFACE; CARBON SEQUESTRATION; MASS-TRANSFER; COMPOSITE; MODEL; WATER; FILMS AB Carbon dioxide sequestration at intermediate ocean depths in the form of a sinking CO2 stream has been shown to be technically feasible. Buoyancy characteristics Of CO2 hydrate particles obtained from a coflow reactor operating under conditions that produce negatively buoyant CO2 hydrate composite particles were studied. Using a simplified process model, the limiting ratios Of CO2 to water to produce sinking hydrate composite streams were established for pressure and temperature conditions of intermediate ocean depths. A kinetic model involving a mass transfer step and a reaction step was proposed to explain experimental data using a seafloor process simulator. Results suggest that the reactor operates under mass-transfer controlled conditions. Although the density of freshwater is only a few percentage units less than that of seawater, operating conditions derived from freshwater-based studies are significantly different for ambient seawater. Owing to the higher density of seawater, greater conversion Of CO2 to hydrate is needed to obtain a sinking CO2 composite stream than at the same depth of freshwater. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Prairie View A&M Univ, Dept Chem Engn, Prairie View, TX USA. RP Tsouris, C (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM tsourisc@ornl.gov RI Liang, Liyuan/O-7213-2014; Tsouris, Costas/C-2544-2016 OI Liang, Liyuan/0000-0003-1338-0324; Tsouris, Costas/0000-0002-0522-1027 NR 19 TC 2 Z9 2 U1 1 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0193-2691 J9 J DISPER SCI TECHNOL JI J. Dispersion Sci. Technol. PD SEP PY 2004 VL 25 IS 5 SI SI BP 703 EP 712 DI 10.1081/DIS-200027332 PG 10 WC Chemistry, Physical SC Chemistry GA 861TA UT WOS:000224440300015 ER PT J AU Jellison, BJ Kess, HR Adams, DE Nelson, DC AF Jellison, BJ Kess, HR Adams, DE Nelson, DC TI Nondestructive evaluation of parts with degenerate modes using pseudorepeated roots SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article ID TOMOGRAPHY; DENSITY AB The modes of vibration of manufactured parts can be good indicators of the overall quality of the manufacturing process. That is, deviations in the modal frequencies or modal vectors of mechanical parts can help to identify v outlier or systemic problems in the raw materials or fabrication procedure. A novel method for characterizing nonuniformities in homogeneous symmetric parts using pseudorepeated modal frequencies is discussed in this paper It is demonstrated that the spacing between pseudorepeated roots in dominantly symmetric manufactured parts is a direct indicator of nonuniformities (i.e., inclusions, voids) in the stiffness or mass distributions. Smaller differences between split-peaks indicate less nonuniformity, and hence, higher quality parts. A simple fourth-order lumped parameter model is used to elaborate on this technique analytically, a representative finite element model is used to further this development, root locus techniques are used to study the sensitivity to nonuniformities, and acceleration response data from impact vibration tests on deep drawn hemispherical shells are used to verify the approach experimentally. C1 Purdue Univ, Sch Mech Engn, Ray W Herrick Labs, W Lafayette, IN 47907 USA. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Jellison, BJ (reprint author), Purdue Univ, Sch Mech Engn, Ray W Herrick Labs, 140 Intramural Dr, W Lafayette, IN 47907 USA. EM bjjellison@purdue.edu; hkess1@purdue.edu; deadams@purdue.edu; dnelson@lanl.gov NR 11 TC 1 Z9 1 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 2004 VL 126 IS 3 BP 498 EP 508 DI 10.1115/1.1789536 PG 11 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 879FX UT WOS:000225702900009 ER PT J AU Bement, M Jayasuriya, S AF Bement, M Jayasuriya, S TI Construction of a set of nonovershooting tracking controllers SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article ID LINEAR-SYSTEM; OVERSHOOT AB The problem of tracking a known reference without overshooting is of great practical importance in a number of applications. However nonminimum phase systems and systems with reference inputs other than steps have received very little attention. This paper proposes two different techniques for obtaining a continuous time, nonovershooting, feedback controller for a wide variety of linear single input, single output (SISO) systems, including nonminimum phase systems and systems whose reference input is something other than a step function. These techniques are then used to generate an initial nonovershooting controller from which a set of nonovershooting controllers is obtained. Examples are given to demonstrate all key concepts. C1 Los Alamos Natl Lab, ESA, WR, Los Alamos, NM 87545 USA. Texas A&M Univ, Dept Engn Mech, College Stn, TX 77843 USA. RP Bement, M (reprint author), Los Alamos Natl Lab, ESA, WR, MS PT080, Los Alamos, NM 87545 USA. NR 12 TC 13 Z9 15 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 2004 VL 126 IS 3 BP 558 EP 567 DI 10.1115/1.1789971 PG 10 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 879FX UT WOS:000225702900014 ER PT J AU Bement, M Jayasuriya, S AF Bement, M Jayasuriya, S TI Use of state feedback to achieve a nonovershooting step response for a class of nonminimum phase systems SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article ID LINEAR-SYSTEM; OVERSHOOT AB The problem of tracking a known reference without overshooting is of great practical importance in a number of applications. However nonminimum phase systems have received little attention in connection with obtaining a nonovershooting response. Using state feedback, this paper develops an eigenvector placement technique to construct an invariant set which guarantees a nonovershooting step response for a class of nonminimum phase SISO systems. C1 ESA, WR, Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. RP Bement, M (reprint author), ESA, WR, Los Alamos Natl Lab, MS PT080, Los Alamos, NM 87545 USA. NR 11 TC 17 Z9 18 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 2004 VL 126 IS 3 BP 657 EP 660 DI 10.1115/1.1790540 PG 4 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 879FX UT WOS:000225702900025 ER PT J AU Vianco, PT Rejent, JA Hlava, PF AF Vianco, PT Rejent, JA Hlava, PF TI Solid-state intermetallic compound layer growth between copper and 95.5Sn-3.9Ag-0.6Cu solder SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE Pb-free solder; intermetallic compound layer; solid-state growth; copper AB Long-term, solid-state intermetallic compound (IMC) layer growth was examined in 95.5Sn-3.9Ag-0.6Cu (wt.%)/copper (Cu) couples. Aging temperatures and times ranged from 70degreesC to 205degreesC and from 1 day to 400 days, respectively. The IMC layer thicknesses and compositions were compared to those investigated in 96.5Sn-3.5Ag/Cu, 95.5Sn-0.5Ag-4.0Cu/Cu, and 100Sn/Cu couples. The nominal Cu3Sn and Cu6Sn5 stoichiometries were observed. The Cu3Sn layer accounted for 0.4-0.6 of the total IMC layer thickness. The 95.5Sn-3.9Ag0.6Cu/Cu couples exhibited porosity development at the Cu3Sn/Cu interface and in the Cu3Sn layer as well as localized "plumes" of accelerated Cu3Sn growth into the Cu substrate when aged at 205 degreesC and t > 150 days. An excess of 3-5at.%Cu in the near-interface solder field likely contributed to IMC layer growth. The growth kinetics of the IMC layer in 95.5Sn-3.9Ag-0.6Cu/Cu couples were described by the equation x = x(o) + At(n)exp [-DeltaH/RT]. The time exponents, n, were 0.56 +/- 0.06, 0.54 +/- 0.07, and 0.58 +/- 0.07 for the Cu3Sn layer, the Cu6Sn5, and the total layer, respectively, indicating a diffusion-based mechanism. The apparent-activation energies (DeltaH) were Cu3Sn layer: 50 +/- 6 kJ/mol; Cu6Sn5 layer: 44 +/- 4 kJ/mol; and total layer: 50 +/- 4 kJ/mol, which suggested a fast-diffusion path along grain boundaries. The kinetics of Cu3Sn growth were sensitive to the Pb-free solder composition while those of Cu6Sn5 layer growth were not so. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Vianco, PT (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM ptvianco@sandia.gov NR 12 TC 58 Z9 59 U1 1 U2 14 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD SEP PY 2004 VL 33 IS 9 BP 991 EP 1004 DI 10.1007/s11664-004-0026-9 PG 14 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 857QQ UT WOS:000224133800009 ER PT J AU Wei, Y Chow, CL Lau, KJ Vianco, P Fang, HE AF Wei, Y Chow, CL Lau, KJ Vianco, P Fang, HE TI Behavior of lead-free solder under thermomechanical loading SO JOURNAL OF ELECTRONIC PACKAGING LA English DT Article ID ALLOY; FATIGUE AB This paper presents an investigation of lead-free Sn-Ag base alloy, 95.5Sn-3.9Ag-0.6Cu, both experimentally and analytically. Experimentally, the deformation behaviour of the material was measured for different temperatures (25degreesC and 1000degreesC) over a range of strain rates (10(-5) to 10(-3)/S) under isothermal and thermomechanical conditions. Development of a unified viscoplastic constitutive model followed, taking into account the effects of the measured strain rate and temperature changes. The temperature rate effects are considered in the evolution equation of back stress. In order to include material degradation in the solder the theory of damage mechanics is applied by introducing two damage variables in the viscoplastic constitutive model. Finally, the constitutive model is coded into a general-purpose finite element computer program (ABAQUS) through its user-defined material subroutine (UMAT). The damage-coupled finite element analysis (FEA) is then employed to monitor the condition of failure of a notched component. The predicted and measured maximum loads have been compared and found to be satisfactory In addition, the calculated damage distribution contours enable the identification of potential failure site for failure analysis. C1 Univ Michigan, Dept Mech Engn, Dearborn, MI 48128 USA. Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wei, Y (reprint author), Univ Michigan, Dept Mech Engn, Dearborn, MI 48128 USA. NR 10 TC 10 Z9 11 U1 0 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1043-7398 J9 J ELECTRON PACKAGING JI J. Electron. Packag. PD SEP PY 2004 VL 126 IS 3 BP 367 EP 373 DI 10.1115/1.1773197 PG 7 WC Engineering, Electrical & Electronic; Engineering, Mechanical SC Engineering GA 864KE UT WOS:000224631600012 ER PT J AU Gamey, TJ Doll, WE Beard, LP Bell, DT AF Gamey, TJ Doll, WE Beard, LP Bell, DT TI Analysis of correlated noise in airborne magnetic gradients for unexploded ordnance detection SO JOURNAL OF ENVIRONMENTAL AND ENGINEERING GEOPHYSICS LA English DT Article AB In this paper, we examine several field tests of correlated helicopter noise and demonstrate that measured vertical gradients can offer signal-to-noise improvements of 4:1 in rotor noise and 6:1 in maneuver noise over comparable total field measurements for unexploded ordnance (UXO) applications. This translates into an additional 1.5-2.0 m in acceptable survey height or ordnance depth. Horizontal gradients, both transverse and longitudinal to the helicopter flight path, are also examined. These offer smaller signal-to-noise improvements over the total field (approximately 1.5:1) and have other disadvantages not found in the vertical gradient. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gamey, TJ (reprint author), Oak Ridge Natl Lab, Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 4 TC 6 Z9 6 U1 0 U2 0 PU ENVIRONMENTAL ENGINEERING GEOPHYSICAL SOCIETY PI DENVER PA 1720 SOUTH BELLAIRE, STE 110, DENVER, CO 80222-433 USA SN 1083-1363 J9 J ENVIRON ENG GEOPH JI J. Environ. Eng. Geophys. PD SEP PY 2004 VL 9 IS 3 BP 115 EP 125 PG 11 WC Geochemistry & Geophysics; Engineering, Geological SC Geochemistry & Geophysics; Engineering GA 859YW UT WOS:000224305300001 ER PT J AU LaBrecque, DJ Heath, G Sharpe, R Versteeg, R AF LaBrecque, DJ Heath, G Sharpe, R Versteeg, R TI Autonomous monitoring of fluid movement using 3-D electrical resistivity tomography SO JOURNAL OF ENVIRONMENTAL AND ENGINEERING GEOPHYSICS LA English DT Article ID INVERSION AB The electrical resistivity tomography method (ERT) is seeing increasing use in long-term monitoring. Applications might include monitoring of advanced remediation methods, vadose zone fluid-flow monitoring, and monitoring below tanks at the Hanford reservation. For this method to be cost effective, future systems will need to be highly automated. This paper compares different strategies for collecting three-dimensional (3-D) data sets. We discuss the critical design aspects of the system and the importance of using integrated hardware for data collection, and software for data interpretation. An autonomous acquisition system was used to monitor a field experiment at the Idaho National Engineering and Environmental Laboratory. The system was successful at collecting data that were used to monitor infiltration of water into interbedded sediment and basalt layers. The results showed the advantages of autonomous systems for collecting data, and the need for robust operating systems designed specifically for autonomous operation. C1 Multi Phase Technol LLC, Sparks, NV USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP LaBrecque, DJ (reprint author), Multi Phase Technol LLC, Sparks, NV USA. NR 25 TC 26 Z9 26 U1 1 U2 5 PU ENVIRONMENTAL ENGINEERING GEOPHYSICAL SOCIETY PI DENVER PA 1720 SOUTH BELLAIRE, STE 110, DENVER, CO 80222-433 USA SN 1083-1363 J9 J ENVIRON ENG GEOPH JI J. Environ. Eng. Geophys. PD SEP PY 2004 VL 9 IS 3 BP 167 EP 176 PG 10 WC Geochemistry & Geophysics; Engineering, Geological SC Geochemistry & Geophysics; Engineering GA 859YW UT WOS:000224305300005 ER PT J AU Fuhrmann, M Fitts, JP AF Fuhrmann, M Fitts, JP TI Adsorption of trace metals on glass fiber filters SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article AB Filters, containing glass-fiber (GF) filter material, are commonly used as the primary filter or as the prefilter in sampling natural waters and laboratory experiments with high concentrations of suspended solids. We observed that GF filter material removed substantial quantities of trace metals from solutions of low ionic strength at near neutral and slightly acidic pH. The GF material sorbed essentially all Pb and Ag from 5-mL aliquots of solutions containing 0.054 and 0.093 mM, respectively. Somewhat less Ni was sorbed from a 0.099 mM solution. This material retained about 43 mumol of Ag per gram of GF material (4600 mug/g). The Ag and Ni sorption was highest at low KNO3 concentrations (as background electrolyte) and decreased to a constant concentration of sorbed metal at approximately 10 mM KNO3. Glass-fiber filter material should only be used with careful testing for the elements of concern under conditions that closely match expected environmental or experimental conditions. C1 Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Fuhrmann, M (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Bldg 830, Upton, NY 11973 USA. EM fuhrmann@bnl.gov RI Fitts, Jeffrey/J-3633-2012 NR 1 TC 3 Z9 3 U1 3 U2 9 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 2004 VL 33 IS 5 BP 1943 EP 1944 PG 2 WC Environmental Sciences SC Environmental Sciences & Ecology GA 855PU UT WOS:000223987000040 PM 15356258 ER PT J AU Cheng, MD AF Cheng, MD TI Effects of nanophase materials (<= 20 nm) on biological responses SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING LA English DT Article; Proceedings Paper CT International Symposium on Nanotechnology and Materials for the Environment CY MAR 26-27, 2003 CL Yokohama, JAPAN DE nanophase metals; nanoparticles; electrospray; differential mobility analyzer; interleukenes; cellular interaction ID INTERLEUKIN-8 GENE-EXPRESSION; BRONCHIAL EPITHELIAL-CELLS; INTERCELLULAR-ADHESION MOLECULE-1; DIESEL EXHAUST PARTICLES; ULTRAFINE PARTICLES; OXIDANT STRESS; SURFACE-AREA; IN-VITRO; LUNG; EXPOSURE AB Nanophase materials have enhanced properties (thermal, mechanical, electrical, surface reactivity, etc.) not found in bulk materials. lntuitively, the enhancement of material properties could occur when the materials encounter biological specimens. Previous investigations of biological interactions with nanometer-scale materials have been very limited. With the ability to manipulate atoms and molecules, we now can create predefined nanostructures with unprecedented precision. In parallel with this development, improved understanding of the biological effects of the nanophase materials, whatever those may be, should also deserve attention. In this study, we have applied precision aerosol technology to investigate cellular response to nanoparticles. We used synthetic. nanoparticles generated by an electrospray technique to produce nanoparticles in the size range of 8-13 nm with practically monodispersed aerosol particles and approximately the same number concentration. We report here on the potency of nano-metal particles with single or binary chemical components in eliciting interleukin-8 (IL-8) production from epithelial cell lines. For single-component nanoparticles, we found that nano-Cu particles were more potent in IL-8 production than nano-Ni and nano-V particles. However, the kinetics of IL-8 production by these three nanoparticles was different, the nano-Ni being the highest among the three. When sulfuric acid was introduced to form acidified nano-Ni particles, we found that the potency of such binary-component nanoparticles in eliciting IL-8 production was increased markedly, by about six times. However, the acidified binary nano-Na and -Mg nanoparticles did not exhibit the same effects as binary nano-Ni particles did. Since Ni, a transition metal, could induce free radicals on cell surfaces, while Na and Mg could not, the acidity might have enhanced the oxidative stress caused by radicals to the cells, leading to markedly higher IL-8 production. This result indicates the complexity of biological responses to nanoparticles. We believe that the exposure methodology and aerosol technology employed in our research will provide an effective means to systematically investigate cellular responses to nanoparticles, structured or unstructured, in ongoing research projects. Different cell lines, chemicals, and particle morphology can also be investigated using such a methodology. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6038, Oak Ridge, TN 37831 USA. EM chengmd@ornl.gov RI Cheng, Meng-Dawn/C-1098-2012; OI Cheng, Meng-Dawn/0000-0003-1407-9576 NR 32 TC 35 Z9 37 U1 1 U2 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1093-4529 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng. PD SEP PY 2004 VL 39 IS 10 BP 2691 EP 2705 DI 10.1081/LESA-200027028 PG 15 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 858AN UT WOS:000224162600010 PM 15509017 ER PT J AU Wijesinghe, HS Hornung, RD Garcia, AL Hadjiconstantinou, NG AF Wijesinghe, HS Hornung, RD Garcia, AL Hadjiconstantinou, NG TI Three-dimensional hybrid continuum-atomistic simulations for multiscale hydrodynamics SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID PARTIAL-DIFFERENTIAL EQUATIONS; RICHTMYER-MESHKOV INSTABILITY; NAVIER-STOKES EQUATIONS; MONTE-CARLO; ADAPTIVE MESH; ALGORITHM REFINEMENT; COUPLING BOLTZMANN; LENGTH SCALES; DYNAMICS; PARTICLE AB We present an adaptive mesh and algorithmic refinement (AMAR) scheme for modeling multi-scale hydrodynamics. The AMAR approach extends standard conservative adaptive mesh refinement (AMR) algorithms by providing a robust flux-based method for coupling an atomistic fluid representation to a continuum model. The atomistic model is applied locally in regions where the continuum description is invalid or inaccurate, such as near strong flow gradients and at fluid interfaces, or when the continuum grid is refined to the molecular scale. The need for such "hybrid" methods arises from the fact that hydrodynamics modeled by continuum representations are often under-resolved or inaccurate while solutions generated using molecular resolution globally are not feasible. In the implementation described herein, Direct Simulation Monte Carlo (DSMC) provides an atomistic description of the flow and the compressible two-fluid Euler equations serve as our continuum-scale model. The AMR methodology provides local grid refinement while the algorithm refinement feature allows the transition to DSMC where needed. The continuum and atomistic representations are coupled by matching fluxes at the continuum-atomistic interfaces and by proper averaging and interpolation of data between scales. Our AMAR application code is implemented in C++ and is built upon the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) framework developed at Lawrence Livermore National Laboratory. SAMRAI provides the parallel adaptive gridding algorithm and enables the coupling between the continuum and atomistic methods. C1 MIT, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. San Jose State Univ, San Jose, CA USA. RP Wijesinghe, HS (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 47 TC 58 Z9 59 U1 3 U2 13 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD SEP PY 2004 VL 126 IS 5 BP 768 EP 777 DI 10.1115/1.1792275 PG 10 WC Engineering, Mechanical SC Engineering GA 880QY UT WOS:000225805500009 ER PT J AU Intrator, T Nagata, M Hoffman, A Guo, H Steinhauer, L Ryutov, D Miller, R Okada, S AF Intrator, T Nagata, M Hoffman, A Guo, H Steinhauer, L Ryutov, D Miller, R Okada, S TI Summary of US-Japan exchange 2004: New directions and physics for compact toroids SO JOURNAL OF FUSION ENERGY LA English DT Article DE compact torus; fusion energy; plasma physics; fusion science; large beta; innovative confinement concept; magnetic reconnection; flux rope; field reversed configuration; spheromak; reversed field pinch; magnetized target fusion; spherical tokamak; helicity injection; kink stability; three-dimensional data visualization; magnetohydrodynamics; relaxation; self organization; flow; angular momentum; current drive; compact torus power plant; jet collimation ID FIELD-REVERSED CONFIGURATION; MAGNETIC RECONNECTION; RELAXED STATES; PLASMA; RELAXATION AB Scientists from research institutions in the United States of America and Japan attended a USA Department of Energy sponsored joint international workshop on the subject of Compact Toroids (CT) in Santa Fe, NM, USA in September 2004. We outline here a summary of the topics that were discussed, some of the implications, and new directions that are likely to follow from this research. Experimental, theoretical and computational results were presented. The experimental devices and concepts, along with the theory and computational models comprise investigations of fundamental plasma physics, fusion science, and approaches to fusion energy that require magnetized plasmas. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Washington, Redmond Plasma Phys Lab, Seattle, WA 98195 USA. Osaka Univ, Suita, Osaka 565, Japan. RP Intrator, T (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM intra-tor@lanl.gov NR 18 TC 3 Z9 3 U1 0 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0164-0313 J9 J FUSION ENERG JI J. Fusion Energy PD SEP PY 2004 VL 23 IS 3 BP 175 EP 182 DI 10.1007/s10894-005-5597-9 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 942DN UT WOS:000230263200002 ER PT J AU Ganguli, S Ganor, OJ Gill, J AF Ganguli, S Ganor, OJ Gill, J TI Twisted six dimensional gauge theories on tori, matrix models, and integrable systems SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE field theories in higher dimensions; integrable equations in physics; matrix models ID YANG-MILLS THEORY; STRING THEORIES; DUALITY; HAMILTONIANS; INSTANTONS; GEOMETRY; T-4 AB We use the Dijkgraaf-Vafa technique to study massive vacua of 6D SU(N) SYM theories on tori with R-symmetry twists. One finds a matrix model living on the compactification torus with a genus 2 spectral curve. The jacobian of this curve is closely related to a twisted four torus T in which the Seiberg-Witten curves of the theory are embedded. We also analyze R-symmetry twists in a bundle with nontrivial first Chern class which yields intrinsically 6D SUSY breaking and a novel matrix integral whose eigenvalues float in a sea of background charge. Next we analyze the underlying integrable system of the theory, whose phase space we show to be a system of N - 1 points on T. We write down an explicit set of Poisson commuting hamiltonians for this system for arbitrary N and use them to prove that equilibrium configurations with respect to all hamiltonians correspond to points in moduli space where the Seiberg-Witten curve maximally degenerates to genus 2, thereby recovering the matrix model spectral curve. We also write down a conjecture for a dual set of Poisson commuting variables which could shed light on a particle-like interpretation of the system. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM sganguli@socrates.berkeley.edu; origa@socrates.berkeley.edu; gill@socrates.berkeley.edu NR 43 TC 2 Z9 2 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 2004 IS 9 AR 014 PG 29 WC Physics, Particles & Fields SC Physics GA 873KR UT WOS:000225279400057 ER PT J AU Hall, LJ March-Russell, J Okui, T Smith, DR AF Hall, LJ March-Russell, J Okui, T Smith, DR TI Towards a theory of flavor from orbifold GUTs SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE field theories in higher dimensions; quark masses and SM parameters; GUT ID GRAND UNIFIED THEORIES; GAUGE COUPLING UNIFICATION; SYMMETRY-BREAKING; EXTRA DIMENSIONS; FERMION MASSES; MIXING-ANGLE; SUPERSYMMETRY; HIERARCHY; MODELS; QUARK AB We show that the recently constructed 5-dimensional supersymmetric S-1 /(Z(2) x Z(2)') orbifold GUT models allow an appealing explanation of the observed hierarchical structure of the quark and lepton masses and mixing angles. Flavor hierarchies arise from the geometrical suppression of some couplings when fields propagate in different numbers of dimensions, or on different fixed branes. Restrictions arising from locality in the extra dimension allow interesting texture zeroes to be easily generated. In addition the detailed nature of the SU(5)-breaking orbifold projections lead to simple theories where b - tau unification is maintained but similar disfavored SU(5) relations for the lighter generations are naturally avoided. We find that simple 5d models based on S-1/(Z(2) x Z'(2)) are strikingly successful in explaining many features of the masses and mixing angles of the 2nd and 3rd generation. Successful three generation models of flavor including neutrinos are constructed by generalizing the S-1/(Z(2) x Z'(2)) model to six dimensions. Large angle neutrino mixing is elegantly accommodated. Novel features of these models include a simple m(u) = 0 configuration leading to a solution of the strong CP problem. C1 LBNL, Div Phys, Theory Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP LBNL, Div Phys, Theory Grp, Berkeley, CA 94720 USA. EM ljhall@lbl.gov; j.march-russelll@physics.ox.ac.uk; okui@buphy.bu.edu; rsmith@lbl.gov NR 61 TC 17 Z9 17 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 2004 IS 9 AR 026 PG 20 WC Physics, Particles & Fields SC Physics GA 873KR UT WOS:000225279400045 ER PT J AU Hewett, JL Lillie, B Masip, M Rizzo, TG AF Hewett, JL Lillie, B Masip, M Rizzo, TG TI Signatures of long-lived gluinos in split supersymmetry SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE supersymmetry phenomenology; beyond standard model; supersymmetric standard model ID SEARCH; PARTICLES; PHENOMENOLOGY; COLLISIONS; LSP AB We examine the experimental signatures for the production of gluinos at colliders and in cosmic rays within the split supersymmetry scenario. Unlike in the MSSM, the gluinos in this model are relatively long-lived due to the large value of the squark masses which mediate their decay. Searches at colliders are found to be sensitive to the nature of gluino fragmentation as well as the gluino-hadron interactions with nuclei and energy deposition as it traverses the detector. We find that the worst-case scenario, where a neutral gluino-hadron passes through the detector with little energy deposition, is well described by a monojet signature. For this case, using Run I data we obtain a bound of m((g) over bar) > 170 GeV; this will increase to 210(1100) GeV at Run II(LHC) if no excess events are observed. In the opposite case, where a charged gluino-hadron travels through the detector, a significantly greater reach is obtained via stable charged particle search techniques. We also examine the production of gluino pairs in the atmosphere by cosmic rays and show they are potentially observable at IceCube; this would provide a cross-check for observations at hadron colliders. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Univ Granada, CAFPE, E-18071 Granada, Spain. Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain. RP Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM hewett@slac.stanford.edu; lillieb@slac.stanford.edu; masip@slac.stanford.edu; rizzo@slac.stanford.edu NR 40 TC 50 Z9 50 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 2004 IS 9 AR 070 PG 18 WC Physics, Particles & Fields SC Physics GA 873KR UT WOS:000225279400001 ER PT J AU Waichler, SR Wigmosta, MS AF Waichler, SR Wigmosta, MS TI Application of hydrograph shape and channel infiltration models to an arid watershed SO JOURNAL OF HYDROLOGIC ENGINEERING LA English DT Article DE streamflow; arid lands; water infiltration; hydrographs; watersheds; Washington AB Ephemeral streamflows measured during January 1995 at upstream and downstream locations in Cold Creek, near the and Hanford Site, in the state of Washington, were analyzed. Double triangle and composite hydrograph models fit these flow events relatively well, with mean efficiency approximate to 0.7, The composite hydrograph model is slightly preferable to the double triangle model for having one less parameter and a built-in method for quantifying base flow. A strong linear relationship was found between upstream and downstream flow volumes (R-2 = 0.99, p < 0.001), and a linearized exponential decay model for channel infiltration was used to estimate flow loss to infiltration as 19% of volume per km. As compared to the humid and semiarid environments where most of these techniques have been previously applied, the colder and more and setting of Hanford produces runoff much less. frequently and has greater channel infiltration capacity. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Waichler, SR (reprint author), Pacific NW Natl Lab, K9-36,POB 999, Richland, WA 99352 USA. EM scott.waichler@pnl.gov; mark.wigmosta@pnl.gov NR 15 TC 2 Z9 2 U1 1 U2 4 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 1084-0699 J9 J HYDROL ENG JI J. Hydrol. Eng. PD SEP-OCT PY 2004 VL 9 IS 5 BP 433 EP 439 DI 10.1061/(ASCE)1084-0699(2004)9:5(433) PG 7 WC Engineering, Civil; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA 847BO UT WOS:000223363900011 ER PT J AU Kyriakidis, PC Miller, NL Kim, J AF Kyriakidis, PC Miller, NL Kim, J TI A spatial time series framework for simulating daily precipitation at regional scales SO JOURNAL OF HYDROLOGY LA English DT Article DE rainfall modeling; geostatistics; cokriging; spatial time series; conditional stochastic simulation; daily precipitation; digital elevation model; NCAR/NCEP reanalysis ID EMPIRICAL ORTHOGONAL FUNCTIONS; UNGAUGED LOCATIONS; RIVER FLOW; MODEL; CALIFORNIA; GENERATION; VARIABLES; WINTER AB A spatiotemporal stochastic simulation approach for constructing maps of daily precipitation at regional scales in a hindcast mode is proposed in this paper. Parametric temporal trend models of precipitation are first established at the available rain gauges. Temporal trend model parameters are then regionalized in space accounting for their spatial auto- and cross-correlation, as well as for their relationships with auxiliary spatial information such as terrain elevation. The resulting residual values at the rain gauges are modeled as a realization of a stationary spatiotemporal process. Sequential simulation is then used to generate alternative synthetic realizations of daily precipitation fields, which reproduce: (i) the rain gauge measurements, and (ii) their histogram and a model for their spatiotemporal correlation over the entire study region and time period of interest. In addition, a post-processing transformation allows reproduction of the rainfall histogram at particular dates, while preserving the observed rain gauge data. A case study illustrates the applicability of the proposed methodology using daily precipitation measurements recorded at 77 rain gauges in the northern California coastal region from Nov 1, 1981 to Jan 31, 1982. Conditional stochastic simulation in space and time is performed for generating a 30-member ensemble of daily precipitation fields on a 300 x 360 grid of cell size 1 km(2) for the above time period. It is shown that simulated precipitation fields reproduce the spatiotemporal characteristics of the rain gauge measurements, thus providing realistic inputs of precipitation forcing for hydrologic impact assessment studies. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90024 USA. RP Kyriakidis, PC (reprint author), Univ Calif Santa Barbara, Dept Geog, Ellison Hall 5710, Santa Barbara, CA 93106 USA. EM phaedon@geog.ucsb.edu RI Miller, Norman/E-6897-2010; OI Kyriakidis, Phaedon/0000-0003-4222-8567 NR 31 TC 28 Z9 32 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD SEP 1 PY 2004 VL 297 IS 1-4 BP 236 EP 255 DI 10.1016/j.jhydrol.2004.04.022 PG 20 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 846CL UT WOS:000223292300015 ER PT J AU Hurtado, JE Robinett, RD Dohrmann, CR Goldsmith, SY AF Hurtado, JE Robinett, RD Dohrmann, CR Goldsmith, SY TI Decentralized control for a swarm of vehicles performing source localization SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE cooperative robots; decentralized control; distributed sensors AB In this paper, decentralized feedback controls are presented for a swarm of autonomous, robotic vehicles that is tasked with localizing a stationary, time-invariant source. The development of the feedback controls is motivated by classic function-minimization theory and the method is actually suited for a large collection of agents, where collection of agents may refer to, for example, a population of N design points in some variable space. We present the theory that supports the method, some example problems and their simulations to illustrate the method, and discuss some potential applications. C1 Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hurtado, JE (reprint author), Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. EM jehurtado@tamu.edu RI Hurtado, John/F-8280-2011 NR 20 TC 5 Z9 5 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0921-0296 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD SEP PY 2004 VL 41 IS 1 BP 1 EP 18 DI 10.1023/B:JINT.0000049161.62303.e5 PG 18 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 873RV UT WOS:000225299500001 ER PT J AU Matlachov, AN Volegov, PL Espy, MA George, JS Kraus, RH AF Matlachov, AN Volegov, PL Espy, MA George, JS Kraus, RH TI SQUID detected NMR in microtesla magnetic fields SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article ID ROOM-TEMPERATURE SAMPLES; INSIDE-OUT NMR; QUANTUM INTERFERENCE DEVICE; HUMAN BRAIN; DC SQUID; NEURONAL-ACTIVITY; RESONANCE; MRI; MAGNETOENCEPHALOGRAPHY; SENSITIVITY AB We have built an NMR system that employs a superconducting quantum interference device (SQUID) detector and operates in measurement fields of 2-25 muT. The system uses a pre-polarizing field from 4 to 30 mT generated by simple room-temperature wire-wound coils that are turned off during measurements. The instrument has an open geometry with samples located outside the cryostat at room-temperature. This removes constraints on sample size and allows us to obtain signals from living tissue. We have obtained I H NMR spectra from a variety of samples including water, mineral oil, and a live frog. We also acquired gradient encoded free induction decay (FID) data from a water-plastic phantom in the muT regime, from which simple projection images were reconstructed. NMR signals from samples inside metallic containers have also been acquired. This is possible because the penetration skin depth is much greater at the low operating frequencies of this system than for conventional systems. Advantages to ultra-low field NMR measurements include lower susceptibility artifacts caused by high strength polarizing and measurement fields, and negligible line width broadening due to measurement field inhomogeneity, reducing the burden of producing highly homogeneous fields. (C) 2004 Elsevier Inc. All rights reserved. C1 Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. RP Espy, MA (reprint author), Los Alamos Natl Lab, Biophys Grp, MS D454, Los Alamos, NM 87545 USA. EM espy@lanl.gov NR 30 TC 67 Z9 67 U1 2 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD SEP PY 2004 VL 170 IS 1 BP 1 EP 7 DI 10.1016/j.jmr.2004.05.015 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 849WU UT WOS:000223573000001 PM 15324752 ER PT J AU Mulford, R Asaro, RJ Sebring, RJ AF Mulford, R Asaro, RJ Sebring, RJ TI Spherical indentation of ductile power law materials SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID HARDNESS AB A procedure for extracting simple constitutive parameters from microindentation tests is described. The analysis used to interpret the indentation tests is based on the analysis of the spherical indentation test developed by Hill et al. for power law materials. Indentation tests are supplemented by scanning interference microscopy of the residual indented surface profiles and a method is suggested for using the residual surface profiles to estimate the actual contact surface. This, in turn, allows for the construction of the entire stress versus strain curve. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, Dept Struct Engn, La Jolla, CA 92093 USA. RP Mulford, R (reprint author), Los Alamos Natl Lab, NMT-15, Los Alamos, NM 87545 USA. NR 15 TC 15 Z9 15 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2004 VL 19 IS 9 BP 2641 EP 2649 DI 10.1557/JMR.2004.0363 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 851MK UT WOS:000223689000018 ER PT J AU Volinsky, AA Moody, NR Gerberich, WW AF Volinsky, AA Moody, NR Gerberich, WW TI Nanoindentation of Au and Pt/Cu thin films at elevated temperatures SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MECHANICAL-PROPERTIES; SINGLE-CRYSTALS; INDENTATION; DEFLECTION; STRESS AB This paper describes the nanoindentation technique for measuring sputter-deposited Au and Cu thin films' mechanical properties at elevated temperatures up to 130 degreesC. A thin, 5-nm Pt layer was deposited onto the Cu film to prevent its oxidation during testing. Nanoindentation was then used to measure elastic modulus and hardness as a function of temperature. These tests showed that elastic modulus and hardness decreased as the test temperature increased from 20 to 130 degreesC. Cu films exhibited higher hardness values compared to Au, a finding that is explained by the nanocrystalline structure of the film. Hardness was converted to the yield stress using both the Tabor relationship and the inverse method (based on the Johnson cavity model). The thermal component of the yield-stress dependence followed a second-order polynomial in the temperature range tested for Au and Pt/Cu films. The decrease in yield stress at elevated temperatures accounts for the increased interfacial toughness of Cu thin films. C1 Univ S Florida, Dept Mech Engn, Tampa, FL 33620 USA. Sandia Natl Labs, Livermore, CA 94550 USA. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RP Volinsky, AA (reprint author), Univ S Florida, Dept Mech Engn, Tampa, FL 33620 USA. EM volinsky@eng.usf.edu RI Volinsky, Alex/A-7974-2009; OI Volinsky, Alex/0000-0002-8520-6248 NR 34 TC 53 Z9 54 U1 1 U2 12 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 2004 VL 19 IS 9 BP 2650 EP 2657 DI 10.1557/JMR.2004.0331 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 851MK UT WOS:000223689000019 ER PT J AU Hsueh, CH Miranda, P AF Hsueh, CH Miranda, P TI Combined empirical-analytical method for determining contact radius and indenter displacement during Hertzian indentation on coating/substrate systems SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID FINITE-ELEMENT ANALYSIS; COATING SUBSTRATE; FILM; SPHERES; MODEL; FIELD AB An analytical model was developed in a previous work to relate the normalized indenter displacement to both the coating-to-substrate Young's modulus ratio and the coating-thickness-to-contact-radius ratio for Hertzian indentation on coating/substrate systems. However, application of this model is contingent upon the determination of the contact radius during indentation. Using the data from finite element analyses, an empirical equation is proposed in this paper to determine the normalized contact radius. Combining this empirical equation with the previous analytical equation, both the contact radius and the indenter displacement for Hertzian indentation on coating/substrate systems are predicted. The predictions obtained by this combined empirical-analytical method are shown to agree with the finite element results in general although the indenter displacement is over-estimated when the coating is stiffer than the substrate. Finally, the potential applications of this method to determine the elastic properties of coatings from the indentation data are envisaged. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Extremadura, Escuela Ingn Ind, Dept Elect & Ingn Electromecan, E-06071 Badajoz, Spain. RP Hsueh, CH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM hsuehc@ornl.gov RI Miranda, Pedro/C-4465-2008; Hsueh, Chun-Hway/G-1345-2011 OI Miranda, Pedro/0000-0003-4348-110X; NR 25 TC 18 Z9 19 U1 1 U2 9 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 2004 VL 19 IS 9 BP 2774 EP 2781 DI 10.1557/JMR.2004.0359 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 851MK UT WOS:000223689000038 ER PT J AU Amaya-Tapia, A Gasaneo, G Ovchinnikov, S Macek, JH Larsen, SY AF Amaya-Tapia, A Gasaneo, G Ovchinnikov, S Macek, JH Larsen, SY TI Integral representation of one-dimensional three particle scattering for delta function interactions SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID SHORT-RANGE POTENTIALS; BODY PROBLEM; RECOMBINATION; COLLISIONS; DYNAMICS; ATOMS; MODEL AB The Schrodinger equation, in hyperspherical coordinates, is solved in closed form for a system of three particles on a line, interacting via pair delta functions. This is for the case of equal masses and potential strengths. The interactions are replaced by appropriate boundary conditions. This leads then to requiring the solution of a free-particle Schrodinger equation subject to these boundary conditions. A generalized Kontorovich-Lebedev transformation is used to write this solution as an integral involving a product of Bessel functions and pseudo-Sturmian functions. The coefficient of the product is obtained from a three-term recurrence relation, derived from the boundary condition. The contours of the Kontorovich-Lebedev representation are fixed by the asymptotic conditions. The scattering matrix is then derived from the exact solution of the recurrence relation. The wavefunctions that are obtained are shown to be equivalent to those derived by McGuire. The method can clearly be applied to a larger number of particles and hopefully might be useful for unequal masses and potentials. (C) 2004 American Institute of Physics. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62251, Morelos, Mexico. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Nacl Sur, Dept Fis, RA-8000 Bahia Blanca, Buenos Aires, Argentina. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Temple Univ, Dept Phys, Philadelphia, PA 19122 USA. RP Amaya-Tapia, A (reprint author), Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, AP 48-3, Cuernavaca 62251, Morelos, Mexico. RI Ovchinnikov, Serguei/C-4994-2014 NR 27 TC 6 Z9 6 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 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD SEP PY 2004 VL 45 IS 9 BP 3533 EP 3545 DI 10.1063/1.1769613 PG 13 WC Physics, Mathematical SC Physics GA 849QP UT WOS:000223555200008 ER PT J AU Song, M Mitsuishi, K Furuya, K Allen, CW Birtcher, RC Donnelly, SE AF Song, M Mitsuishi, K Furuya, K Allen, CW Birtcher, RC Donnelly, SE TI Structure of nanometre-sized Xe particles embedded in Al crystals SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE Al; HREM; nanoparticles; Xe particles ID TRANSMISSION ELECTRON-MICROSCOPE; SOLID KRYPTON BUBBLES; IN-SITU; IMPLANTED ALUMINUM; 300 K; XENON; PRECIPITATION; COALESCENCE; IRRADIATION; CAVITIES AB The structure and lattice parameters of Xe particles about 1 nm to about 6 nm in size embedded in Al were investigated with off-Bragg condition high-resolution transmission electron microscopy. An Xe particle about I nm in size had different structural properties from those 2-6 nm in sizes. Some 1-nm Xe particles had an face-centred cubic (f.c.c.) structure with the same orientation as the Al matrix, whereas others of the same size had a non-f.c.c. structure. The lattice parameters of a 1-nm f.c.c. Xe particle were about 20% smaller than the average value obtained from electron diffraction, i.e. the particle was compressed by about 80%. The lattice parameters of Xe crystals about 2 nm to about 6 nm in size were almost the same as those obtained from diffraction results. One of the reasons for the extra compression seen with a 1-nm Xe particle is the increase in pressure inside an Xe particle with decreasing particle size. C1 Natl Inst Mat Sci, Tsukuba, Ibaraki 3050003, Japan. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Univ Salford, Joule Phys Lab, Salford M5 4WT, Lancs, England. RP Song, M (reprint author), Natl Inst Mat Sci, 3-13 Sakura, Tsukuba, Ibaraki 3050003, Japan. EM minghui.song@nims.go.jp OI Donnelly, Stephen/0000-0002-9749-5550 NR 25 TC 2 Z9 2 U1 0 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD SEP PY 2004 VL 215 BP 224 EP 229 DI 10.1111/j.0022-2720.2004.01369.x PN 3 PG 6 WC Microscopy SC Microscopy GA 853TB UT WOS:000223850700002 PM 15312186 ER PT J AU Masiello, T Vulpanovici, N Barber, J Chrysostom, ETH Nibler, JW Maki, A Blake, TA Sams, RL Weber, A AF Masiello, T Vulpanovici, N Barber, J Chrysostom, ETH Nibler, JW Maki, A Blake, TA Sams, RL Weber, A TI Analysis of high-resolution infrared and CARS spectra of (SO3)-S-32-O-18 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE infrared; CARS; spectrum; sulfur trioxide; oxygen-18; fermi resonance ID SULFUR-TRIOXIDE; COHERENT RAMAN; 2-NU(3) BANDS; HOT BANDS; (SO3)-S-34-O-16; NU(1); NU(2) AB As part of a series of investigations of isotopic forms of sulfur trioxide, high-resolution infrared and coherent anti-Stokes Raman spectroscopies were used to study the fundamental modes and several hot bands of (SO3)-S-32-O-18. Upper levels of hot bands originating from the v(2) and v(4) bending mode states have been found to couple strongly to the upper levels of the IR-inactive 1,1 symmetric stretch through indirect Coriolis interactions and Fermi resonances. Coriolis coupling effects are particularly noticeable in (SO3)-S-32-O-18 due to the close proximity of the v(2) and v(4) fundamental vibrations, whose deperturbed wavenumber values are 486.48813(4) and 504.28477(4) cm(-1). The uncertainties in the last digits are shown in parentheses and are two standard deviations. From the infrared transitions, accurate rovibrational constants are deduced for all of the mixed states, leading to deperturbed values for v(1), a(1)(beta), and alpha(1)(C) of 1004.68(2), 0.000713(2), and 0.000348(2) cm(-1), respectively. The B-e value is found to be 0.310820(2) cm(-1), yielding an equilibrium bond length r(e) of 141.7333(4) pm that is, within experimental uncertainty, identical to the value of 141,7339(3) pm reported previously for (SO3)-S-34-O-18. With this work, precise and accurate spectroscopic constants have now been determined in a systematic and consistent manner for all the fundamental vibrational modes of the sulfur trioxide D-3h isotopomeric forms (SO3)-S-32-O-16, (SO3)-S-34-O-16, (SO3)-S-32-O-18, and (SO3)-S-34-O-18. (C) 2004 Elsevier Inc. All rights reserved. C1 Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Sci Fdn, Arlington, VA 22230 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Nibler, JW (reprint author), Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. EM Niblerj@chem.orst.edu NR 13 TC 4 Z9 4 U1 1 U2 6 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 2004 VL 227 IS 1 BP 50 EP 59 DI 10.1016/j.jms.2004.05.007 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 844UF UT WOS:000223185400006 ER PT J AU Dillon, AC Yudasaka, M Dresselhaus, MS AF Dillon, AC Yudasaka, M Dresselhaus, MS TI Employing Raman spectroscopy to qualitatively evaluate the purity of carbon single-wall nanotube materials SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Review DE single-wall carbon nanotubes; Raman spectroscopy ID CHEMICAL-VAPOR-DEPOSITION; LARGE-SCALE; OPTICAL-PROPERTIES; VIBRATIONAL-MODES; CATALYTIC GROWTH; CVD SYNTHESIS; HIPCO PROCESS; SCATTERING; SPECTRA; SEPARATION AB Carbon single-wall nanotubes (SWNTs) have highly unique electronic, mechanical and adsorption properties, making them interesting for a variety of applications. Raman spectroscopy has been demonstrated to be one of the most important methods for characterizing SWNTs. For example, Raman spectroscopy may be employed to differentiate between metallic and semi-conducting nanotubes, and may also be employed to determine SWNT diameters and even the nanotube chirality. Single-wall carbon nanotubes are generated in a variety of ways, including arc-discharge, laser vaporization and various chemical vapor deposition (CVD) techniques. In all of these methods, a metal catalyst must be employed to observe SWNT formation. Also, all of the current synthesis techniques generate various non-nanotube carbon impurities, including amorphous carbon, fullerenes, multi-wall nanotubes (MWNTs) and nano-crystalline graphite, as well as larger mu-sized particles of graphite. For any of the potential nanotube applications to be realized, it is, therefore, necessary that purification techniques resulting in the recovery of predominantly SWNTs at high-yields be developed. It is, of course, equally important that a method for determining nanotube wt.% purity levels be developed and standardized. Moreover, a rapid method for qualitatively measuring nanotube purity could facilitate many laboratory research efforts. This review article discusses the application of Raman spectroscopy to rapidly determine if large quantities of carbon impurities are present in nanotube materials. Raman spectra of crude SWNT materials reveal tangential bands between 1500-1600 cm(-1), as well as a broad band at similar to1350 cm(-1), attributed to a convolution of the disorder-induced band (D-band) of carbon impurities and the D-band of the SWNTs; themselves. Since the full-width-at-half-maximum (FWHM) intensity of the various carbon impurity D-bands is generally much broader than that of the nanotube D-band, an indication of the SWNT purity level may be obtained by simply examining the line-width of the D-band. We also briefly discuss the effect of nanotube bundling on SWNT Raman spectra. Finally, sections on employing Raman spectroscopy, and Raman spectroscopy coupled with additional techniques, to identify the separation and possible isolation of a specific nanotube within purified SWNT materials is provided. Every SWNT can be considered to be a unique molecule, with different physical properties, depending on its (n, m) indices. The production of phase-pure (n, m) SWNTs may be essential for some nanotube applications. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. NEC Corp Ltd, Tsukuba, Ibaraki 3058501, Japan. MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 71 TC 92 Z9 92 U1 3 U2 86 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 EI 1533-4899 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD SEP PY 2004 VL 4 IS 7 BP 691 EP 703 DI 10.1166/jnn.2004.116 PG 13 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 864CS UT WOS:000224611300002 PM 15570946 ER PT J AU Anderson, AD Deluga, GA Moore, JT Vergne, MJ Hercules, DM Kenik, EA Lukehart, CM AF Anderson, AD Deluga, GA Moore, JT Vergne, MJ Hercules, DM Kenik, EA Lukehart, CM TI Preparation of Pt-Re/Vulcan carbon nanocomposites using a single-source molecular precursor and relative performance as a direct methanol fuel cell electrooxidation catalyst SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE Pt-Re/carbon nanocomposites; HR-EDS; direct methanol fuel cell; electrooxidation catalysis ID ANODE CATALYSTS; RHENIUM; COMPLEXES AB Pt-Re/Vulcan carbon powder nanocomposites have been prepared with total metal loadings of 18 wt.% and 40 wt.% using a new non-cluster (1:1)-PtRe bimetallic precursor as the source of metal. Pt-Re nanoparticles having an average diameter of ca. 6 nm and atomic stoichiometry near 1:1 are formed. TEM, on-particle HR-EDS, and powder XRD data are consistent with the formation of Pt-Re alloy nanoparticles having a hexagonal unit cell with cell constants of a = 2.70 Angstrom and c = 4.47 Angstrom. A nanocomposite prepared at higher total metal loading under more rigorous thermal treatment also contains Pt-Re alloy nanoparticles having a fcc unit cell structure (a = 3.95 Angstrom). The precise dependence of Pt-Re nanocrystal structure on the thermal history of the nanocomposite specimen has not been investigated in detail. While these Pt-Re/carbon nanocomposites are active as anode catalysts in operating direct methanol fuel cells, the measured performance is less than that of commercial Pt-Ru/carbon catalysts and has marginal practical importance. C1 Vanderbilt Univ, Dept Chem, Nashville, TN 37235 USA. Univ Minnesota, Dept Chem Engn, Minneapolis, MN 55455 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Lukehart, CM (reprint author), Vanderbilt Univ, Dept Chem, Box 1583, Nashville, TN 37235 USA. NR 22 TC 16 Z9 16 U1 1 U2 13 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD SEP PY 2004 VL 4 IS 7 BP 809 EP 816 DI 10.1166/jnn.2004.085 PG 8 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 864CS UT WOS:000224611300020 PM 15570964 ER PT J AU Doering, ER Havrilla, GJ Miller, TC AF Doering, ER Havrilla, GJ Miller, TC TI Disilicide diffusion coating inspection by micro X-ray fluorescence Imaging SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE coating; X-ray fluorescence; imaging ID SPECTROMETRY AB Space Shuttle orbiter thrusters fabricated from C-103 niobium alloy rely on a fused chromium disilicide coating as protection from high-temperature oxidation. Coating voids caused by high-temperature spalling, micrometeorite damage, or other impact damage must first be detected, and then characterized to measure the amount of remaining coating materials, since service life is directly proportional to coating thickness. Existing techniques to estimate the thickness of this diffusion layer are labor intensive, prone to error, and require contact with the coating. Alternative non-contact methods are sought that can automate the detection and characterization of coating defects. Micro X-ray fluorescence (MXRF) imaging is evaluated in this study as a potential NDE method to inspect the chromium disilicide coating. MXRF imaging, a relatively new technique to map the elemental composition of a surface, creates a high spatial resolution multispectral image that can be analyzed to detect coating voids and to quantify the remaining coating materials diffused in the alloy. Analysis of image data collected from sectioned thruster samples confirms that MXRF imaging is a viable detection and characterization method for the thruster coating inspection problem. C1 Rose Hulman Inst Technol, Dept Elect & Comp Engn, Terre Haute, IN 47803 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Doering, ER (reprint author), Rose Hulman Inst Technol, Dept Elect & Comp Engn, 5500 Wabash Ave, Terre Haute, IN 47803 USA. EM e.doering@ieee.org NR 22 TC 3 Z9 3 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD SEP PY 2004 VL 23 IS 3 BP 95 EP 105 DI 10.1023/B:JONE.0000048865.96417.bc PG 11 WC Materials Science, Characterization & Testing SC Materials Science GA 873RJ UT WOS:000225298300003 ER PT J AU Miller, GK Petti, DA Maki, JT AF Miller, GK Petti, DA Maki, JT TI Consideration of the effects of partial debonding of the IPyC and particle asphericity on TRISO-coated fuel behavior SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID IRRADIATION; PERFORMANCE AB The fundamental design for a gas-cooled reactor relies on the behavior of the coated particle fuel. The coating layers surrounding the fuel kernels in these spherical particles, consisting of pyrolytic carbon and silicon carbide layers, act as a pressure vessel that retains fission product gases. Many more fuel particles have failed in US irradiations than would be expected when only one-dimensional pressure vessel failures are considered. Post-irradiation examinations indicate that multi-dimensional effects may have contributed to these failures, such as (1) irradiation-induced shrinkage cracks in the inner pyrocarbon (IPyC) layer, (2) partial debonding between the IPyC and SiC layers, and (3) deviations from a perfectly spherical shape. An approach that was used previously to evaluate the effects of irradiation-induced shrinkage cracks is used herein to assess the effects of partial debonding and asphericity. Results of this investigation serve to identify circumstances where these mechanisms may contribute to particle failures. (C) 2004 Elsevier B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Miller, GK (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. EM gkm@inel.gov NR 13 TC 26 Z9 27 U1 1 U2 5 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 1 PY 2004 VL 334 IS 2-3 BP 79 EP 89 DI 10.1016/j.jnucmat.2004.04.330 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 853RH UT WOS:000223844600001 ER PT J AU Newton, TW Hobart, DE AF Newton, TW Hobart, DE TI Comment on 'Plutonium chemistry: A synthesis of experimental data and a quantitative model for plutonium oxide solubility' by J.M. Haschke and V.M. Oversby SO JOURNAL OF NUCLEAR MATERIALS LA English DT Editorial Material ID REDUCTION; PU(VI) AB In part of a recent paper [J. Nucl. Mater. 305 (2002) 187] the authors examined the published data on the disproportionation of Pu(V) and the self-reduction of Pu(VI) in aqueous solution. They conclude that alpha particle-induced reduction of Pu(VI) is contrary to the experimental observations. It is shown here that, with the exception of results at pH 6, the authors have misinterpreted the published data. It is also demonstrated that the published data are in agreement with the generally accepted alpha-reduction mechanism. (C) 2004 Published by Elsevier B.V. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Hobart, DE (reprint author), Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. EM dhobart@lanl.gov NR 8 TC 3 Z9 3 U1 1 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 1 PY 2004 VL 334 IS 2-3 BP 222 EP 224 DI 10.1016/j.jnucmat.2004.05.016 PG 3 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 853RH UT WOS:000223844600021 ER PT J AU Sheller, MR Crowther, RS Kinney, JH Yang, JP Di Jorio, S Breunig, T Carney, DH Ryaby, JT AF Sheller, MR Crowther, RS Kinney, JH Yang, JP Di Jorio, S Breunig, T Carney, DH Ryaby, JT TI Repair of rabbit segmental defects with the thrombin peptide, TP508 SO JOURNAL OF ORTHOPAEDIC RESEARCH LA English DT Article DE rabbit model; ulna; radius; segmental bone defect; thrombin related peptide; microtomography; synchrotron radiation; mechanical testing ID BONE MORPHOGENETIC PROTEIN-2; GROWTH-FACTOR; MODEL; REGENERATION; MEMBRANES; RHBMP-2; POLYMER; MARROW; FIBRIN AB The synthetic peptide, TP508 (Chrysalin(R)), was delivered to rabbit segmental bone defects in biodegradable controlled-release PLGA microspheres to determine its potential efficacy for enhancing healing of non-critically and critically sized segmental defects. Non-critically sized radial defects were created in the forelimbs of New Zealand White rabbits, which were randomized into three treatment groups receiving 10, 50 and 100 mug doses of TP508 in the right radius and control microspheres (without TP508) in the left radius. Torsional testing of the radii at six weeks showed a significant increase in ultimate torque, failure torque, ultimate energy, failure energy, and stiffness when treated with TP508 compared to controls (p < 0.01 for all measures). Thus, TP508 appeared to enhance or accelerate bone growth in these defects. In a second set of experiments, critically sized ulnar defects were created in the forelimbs of New Zealand White rabbits, which were randomized into two groups with each rabbit receiving microspheres with 100 or 200 mug of TP508 into the right ulnar defect and control microspheres (without TP508) alone into the left ulnar defect. Bone healing was evaluated with plain radiographs, synchrotron-based microtomography, and mechanical testing. Radiographs of the rabbit limbs scored by three blinded, independent reviewers demonstrated a significantly higher degree of healing when treated with TP508 than their untreated control limbs (p < 0.05). Three-dimensional synchrotron tomography of a limited number of samples showed that the new bone in TP508-treated samples had a less porous surface appearance and open marrow spaces, suggesting progression of bone remodeling. Torsional testing of the ulnae at nine weeks showed a significant increase in maximum torque and failure energy when treated with TP508 compared to controls (p < 0.01 for both measures). These results suggest that TP508 in a controlled release delivery vehicle has the potential to enhance healing of segmental defects in both critically and non-critically sized defects. (C) 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. C1 OrthoLog Corp, Res & Dev, Tempe, AZ 85281 USA. Chrysalis Biotechnol, Galveston, TX 77550 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Texas, Med Branch, Galveston, TX 77555 USA. Arizona State Univ, Tempe, AZ 85287 USA. RP Ryaby, JT (reprint author), OrthoLog Corp, Res & Dev, 1275 W Washington St, Tempe, AZ 85281 USA. EM jryaby@olgc.com FU NIAMS NIH HHS [2R44AR45508] NR 30 TC 52 Z9 56 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0736-0266 J9 J ORTHOPAED RES JI J. Orthop. Res. PD SEP PY 2004 VL 22 IS 5 BP 1094 EP 1099 DI 10.1016/j.orthres.2004.03.009 PG 6 WC Orthopedics SC Orthopedics GA 849TX UT WOS:000223564900024 PM 15304284 ER PT J AU Ozgokmen, TM Fischer, PF Duan, JQ Iliescu, T AF Ozgokmen, TM Fischer, PF Duan, JQ Iliescu, T TI Three-dimensional turbulent bottom density currents from a high-order nonhydrostatic spectral element model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID AVAILABLE POTENTIAL-ENERGY; DENMARK STRAIT OVERFLOW; COORDINATE OCEAN MODELS; NAVIER-STOKES EQUATIONS; FREE SHEAR LAYERS; GRAVITY CURRENTS; MEDITERRANEAN OUTFLOW; NORTH-ATLANTIC; RED-SEA; CONTINENTAL SLOPES AB Overflows are bottom gravity currents that supply dense water masses generated in high-latitude and marginal seas into the general circulation. Oceanic observations have revealed that mixing of overflows with ambient water masses takes place over small spatial and time scales. Studies with ocean general circulation models indicate that the strength of the thermohaline circulation is strongly sensitive to representation of overflows in these models. In light of these results, overflow-induced mixing emerges as one of the prominent oceanic processes. In this study, as a continuation of an effort to develop appropriate process models for overflows, nonhydrostatic 3D simulations of bottom gravity are carried out that would complement analysis of dedicated observations and large-scale ocean modeling. A parallel high-order spectral-element Navier-Stokes solver is used as the basis of the simulations. Numerical experiments are conducted in an idealized setting focusing on the startup phase of a dense water mass released at the top of a sloping wedge. Results from 3D experiments are compared with results from 2D experiments and laboratory experiments, based on propagation speed of the density front, growth rate of the characteristic head at the leading edge, turbulent overturning length scales, and entrainment parameters. Results from 3D experiments are found to be in general agreement with those from laboratory tank experiments. In 2D simulations, the propagation speed is approximately 20% slower than that of the 3D experiments and the head growth rate is 3 times as large, Thorpe scales are 1.3-1.5 times as large, and the entrainment parameter is up to 2 times as large as those in the 3D experiments. The differences between 2D and 3D simulations are entirely due to internal factors associated with the truncation of the Navier-Stokes equations for 2D approximation. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MPO, Div Meteorol & Phys Oceanog, Miami, FL 33149 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. IIT, Dept Appl Math, Chicago, IL 60616 USA. Virginia Polytech Inst & State Univ, Dept Math, Blacksburg, VA 24061 USA. RP Ozgokmen, TM (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MPO, Div Meteorol & Phys Oceanog, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM tozgokmen@rsmas.miami.edu NR 87 TC 49 Z9 49 U1 1 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2004 VL 34 IS 9 BP 2006 EP 2026 DI 10.1175/1520-0485(2004)034<2006:TTBDCF>2.0.CO;2 PG 21 WC Oceanography SC Oceanography GA 856WE UT WOS:000224075300005 ER PT J AU Klehe, AK Biggs, T Kuntscher, CA Kini, AM Schlueter, JA AF Klehe, AK Biggs, T Kuntscher, CA Kini, AM Schlueter, JA TI Comparative magnetotransport and T-c measurements on kappa-(BEDT-TTF)(2)Cu(SCN)(2) under pressure SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID ORGANIC SUPERCONDUCTOR KAPPA-(BEDT-TTF)(2)CU(NCS)(2); NORMAL-STATE PROPERTIES; HIGH MAGNETIC-FIELDS; CUPRATE SUPERCONDUCTORS; TRANSITION-TEMPERATURE; UNIAXIAL-STRESS; EFFECTIVE-MASS; SOLID HELIUM; DEPENDENCE; KAPPA-(ET)(2)CU(NCS)(2) AB We compare magnetotransport measurements under pressure on the organic superconductor kappa-(BEDT-TTF)(2)Cu(SCN)(2) (BEDT-TTF drop bis(ethylene-dithio) tetrathiafulvalene) with different pressure media and discover that the results are pressure media dependent. This pressure medium dependence is thought to originate from the difference in thermal contraction between the very soft and highly anisotropic sample and the isotropically contracting, but solid pressure medium, thus resulting in non-hydrostatic pressure on the sample. However, comparison of pressure measurements with different media reveals a pressure medium independent correlation between the superconducting transition temperature, T-c, and the size of the quasi-two-dimensional Fermi surface pocket and thus the quasi-two-dimensional carrier density in kappa-(BEDT-TTF)(2)Cu(SCN)(2). The observed pressure-induced increase in the quasi-two-dimensional carrier density can be interpreted as a transfer of carriers from quasi-one-dimensional Fermi surface sections, reminiscent of a mechanism in cuprate superconductors, where pressure is known to transfer carriers from the insulating charge reservoir layers into the conducting cuprate sheets. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM a.klehe1@physics.ox.ac.uk RI Kini, Aravinda/F-4467-2012 NR 33 TC 3 Z9 3 U1 0 U2 2 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 1 PY 2004 VL 16 IS 34 BP 6109 EP 6118 AR PII S0953-8984(04)80740-9 DI 10.1088/0953-8984/16/34/010 PG 10 WC Physics, Condensed Matter SC Physics GA 854LI UT WOS:000223904000012 ER PT J AU Leyer, S Barnes, RG Buschhaus, C Fischer, G Pilawa, B Pongs, B Tinner, A Dormann, E AF Leyer, S Barnes, RG Buschhaus, C Fischer, G Pilawa, B Pongs, B Tinner, A Dormann, E TI Low-temperature proton spin-lattice relaxation maxima of lanthanum hydrides doped with paramagnetic rare earth ions SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; ELECTRONIC-STRUCTURE; TRANSITIONS; DENSITY; TRIHYDRIDE; DIFFUSION; YTTRIUM; STATES; SYSTEM AB The low-temperature proton spin-lattice relaxation is analysed for lanthanum hydrides LaHx intentionally doped with Gd or Ce. These paramagnetic impurities were also characterized by static magnetic susceptibility and electron spin resonance measurements. A quantitative description of the proton relaxation rate maxima, as well as of the electron spin relaxation data, is presented. These analyses indicate that the density of states at the rare earth site disappears only for x greater than or similar to 2.9. C1 Univ Karlsruhe TH, Inst Phys, D-76128 Karlsruhe, Germany. Iowa State Univ, USDOE, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, USDOE, Ames Lab, Ames, IA 50011 USA. RP Leyer, S (reprint author), Univ Karlsruhe TH, Inst Phys, D-76128 Karlsruhe, Germany. NR 17 TC 6 Z9 6 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 1 PY 2004 VL 16 IS 34 BP 6147 EP 6158 AR PII S0953-8984(04)80920-2 DI 10.1088/0953-8984/16/34/014 PG 12 WC Physics, Condensed Matter SC Physics GA 854LI UT WOS:000223904000016 ER PT J AU Tomaselli, M Liu, LC Fritzsche, S Kuhl, T AF Tomaselli, M Liu, LC Fritzsche, S Kuhl, T TI Dressed bosons theory for nuclear structure SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID DYNAMIC-CORRELATION MODEL; REALISTIC EFFECTIVE INTERACTIONS; ELASTIC PROTON-SCATTERING; HALO NUCLEI; MATTER DISTRIBUTIONS; LIGHT-NUCLEI; INTERMEDIATE-ENERGY; INVERSE KINEMATICS; FINITE NUCLEI; SHELL NUCLEI AB The structure of nuclei of even number of nucleons is investigated in the boson-dynamic correlation model where valence-particle-excitation as well as core-excitation modes coexist. The model is nonperturbative and does not employ effective operators. The eigenstates of the model are the selfconsistent solution of a set of nonlinear dynamical equations, which represents valence-particle pairs dressed by their interactions with the nuclear medium. The model is applied to medium mass as well as light nuclei. Our study of O-18 reveals that the inclusion and the nonperturbative treatment of core excitations are the principal reasons for obtaining a correct ordering of the energy levels, a more complete spectrum and a much better agreement with the experimental low-lying as well as high-lying states than other published calculations. Our study of light nuclei He-6 and Li-6 shows that the halo formation in these nuclei is also a consequence of the excitation of the core protons and that halo can also be associated with valence proton-neutron pairs. The calculated matter distributions of these two nuclei reproduce well the differential cross sections obtained in proton elastic scattering experiments. The cluster-factorization method that expedites nonperturbative calculations is elucidated. C1 Tech Univ Darmstadt, Inst Nucl Phys, D-64289 Darmstadt, Germany. GSI Gessell Schwerionenforsch, D-64291 Darmstadt, Germany. Los Alamos Natl Lab, T Div, Los Alamos, NM 87545 USA. Univ Kassel, Inst Phys, D-34132 Kassel, Germany. RP Tech Univ Darmstadt, Inst Nucl Phys, D-64289 Darmstadt, Germany. RI Kuhl, Thomas/C-2243-2012 OI Kuhl, Thomas/0000-0001-6306-4579 NR 58 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 2004 VL 30 IS 9 BP 999 EP 1020 AR PII S0954-3899(04)78623-5 DI 10.1088/0954-3899/30/9/005 PG 22 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 859QA UT WOS:000224281800006 ER PT J AU Vergados, JD AF Vergados, JD TI Direct SUSY dark matter detection-theoretical rates due to the spin SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID NEUTRALINO-NUCLEUS SCATTERING; HIGGS-BOSON PRODUCTION; DIRECT SEARCH; MODULATION; MODEL; WIMPS; CONSTRAINTS; CANDIDATES; PARAMETERS; VELOCITY AB The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Thus direct dark matter detection, consisting of detecting the recoiling nucleus, is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). The relevant cross sections arise out of two mechanisms: (i) the coherent mode, due to the scalar interaction and (ii) the spin contribution arising from the axial current. In this paper we will focus on the spin contribution, which is expected to dominate for light targets. For both modes it is possible to obtain detectable rates, but in most models the expected rates are much lower than the present experimental goals. So one should exploit two characteristic signatures of the reaction, namely the modulation effect and in directional experiments the correlation of the event rates with the sun's motion. In standard non-directional experiments the modulation is small, less than 2 per cent. In the case of the directional event rates we would like to suggest that the experiments exploit two features of the process, which are essentially independent of the SUSY model employed, namely: (1) the forward-backward asymmetry, with respect to the sun's direction of motion, is very large and (2) the modulation is much larger, especially if the observation is made in a plane perpendicular to the sun's velocity. In this case the difference between maximum and minimum can be larger than 40 per cent and the phase of the earth at the maximum is direction dependent. C1 Univ Ioannina, Div Theoret Phys, GR-45110 Ioannina, Greece. Los Alamos Natl Lab, Div Theoret Phys, Los Alamos, NM 87545 USA. RP Univ Ioannina, Div Theoret Phys, GR-45110 Ioannina, Greece. EM Vergados@cc.uoi.gr NR 82 TC 27 Z9 27 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 2004 VL 30 IS 9 BP 1127 EP 1144 AR PII S0954-3899(04)79471-2 DI 10.1088/0954-3899/30/9/012 PG 18 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 859QA UT WOS:000224281800013 ER PT J AU Elliott, SR Engel, J AF Elliott, SR Engel, J TI Double-beta decay SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Review ID RANDOM-PHASE-APPROXIMATION; PROBE WMAP OBSERVATIONS; EXACTLY SOLVABLE MODEL; GRAN-SASSO 1990-2003; NUCLEAR-STRUCTURE; NEUTRINO MASS; PROTON-NEUTRON; SHELL-MODEL; MATRIX-ELEMENTS; CP-VIOLATION AB We review recent developments in double beta decay, focusing on what can be learned about the three light neutrinos in future experiments. We examine the effects of uncertainties in already measured neutrino parameters and in calculated nuclear matrix elements on, the interpretation of upcoming double-beta decay measurements. We then review a number of proposed experiments. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. RP Los Alamos Natl Lab, MS H803, Los Alamos, NM 87545 USA. NR 167 TC 186 Z9 186 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD SEP PY 2004 VL 30 IS 9 BP R183 EP R215 AR PII S0954-3899(04)62456-X DI 10.1088/0954-3899/30/9/R01 PG 33 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 859QA UT WOS:000224281800001 ER PT J AU Zagonel, AA Rohrbaugh, J Richardson, GP Andersen, DF AF Zagonel, AA Rohrbaugh, J Richardson, GP Andersen, DF TI Using simulation models to address "what if" questions about welfare reform SO JOURNAL OF POLICY ANALYSIS AND MANAGEMENT LA English DT Article; Proceedings Paper CT APPAM Research Conference CY 2002 CL Dallas, TX ID PRESIDENTIAL-ADDRESS; THINKING; SYSTEMS; SUPPORT; SCIENCE C1 Sandia Natl Labs, Crit Infrastruct Assur Grp, Livermore, CA 94550 USA. SUNY Albany, Rockefeller Coll Publ Affairs & Policy, Albany, NY 12222 USA. RP Zagonel, AA (reprint author), Sandia Natl Labs, Crit Infrastruct Assur Grp, Livermore, CA 94550 USA. NR 37 TC 23 Z9 23 U1 0 U2 6 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0276-8739 J9 J POLICY ANAL MANAG JI J. Policy Anal. Manage. PD FAL PY 2004 VL 23 IS 4 BP 890 EP 901 DI 10.1002/pam.20054 PG 12 WC Economics; Public Administration SC Business & Economics; Public Administration GA 852DX UT WOS:000223736500013 ER PT J AU Malwitz, MM Butler, PD Porcar, L Angelette, DP Schmidt, G AF Malwitz, MM Butler, PD Porcar, L Angelette, DP Schmidt, G TI Orientation and relaxation of polymer-clay solutions studied by rheology and small-angle neutron scattering SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE clay; poly(ethylene oxide) (PEO); shear; small-angle neutron scattering (SANS); solution; relaxation ID X-RAY-SCATTERING; LAYERED SILICATE NANOCOMPOSITES; RHEOMETRIC SHEARING APPARATUS; FLOW-BIREFRINGENCE; LAMELLAR PHASE; DIBLOCK COPOLYMER; BLOCK-COPOLYMERS; PEO MIXTURES; SANS; DISPERSIONS AB The influence of shear on viscoelastic solutions of poly(ethylene oxide) (PEO) and clay [montmorillonite, i.e., Cloisite NA+ (CNA)] was investigated with rheology and small-angle neutron scattering (SANS). The steady-state viscosity and SANS were used to measure the shear-induced orientation and relaxation of the polymer and clay platelets. Anisotropic scattering patterns developed at much lower shear rates than in pure clay solutions. The scattering anisotropy saturated at low shear rates, and the CNA clay platelets aligned with the flow, with the surface normal parallel to the gradient direction. The cessation of Shear led to partial and slow randomization of the CNA platelets, whereas extremely fast relaxation was observed for laponite (LRD) platelets. These PEO-CNA networklike solutions were compared with previously reported PEO-LRD networks, and the differences and similarities, with respect to the shear orientation, relaxation, and polymer-clay interactions, were examined. (C) 2004 Wiley Periodicals, Inc. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Schmidt, G (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. EM gudrun@lsu.edu RI Butler, Paul/D-7368-2011 NR 64 TC 30 Z9 30 U1 1 U2 24 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 2004 VL 42 IS 17 BP 3102 EP 3112 DI 10.1002/polb.20175 PG 11 WC Polymer Science SC Polymer Science GA 848OL UT WOS:000223476900007 ER PT J AU Arlen, MJ Dadmun, MD Hamilton, WA AF Arlen, MJ Dadmun, MD Hamilton, WA TI Using neutron reflectivity to determine the dynamic properties of a copolymer in a homopolymer matrix SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE copolymer; dynamics; neutron reflectivity; interfaces ID COMPRESSIBLE POLYMER BLENDS; SLOW MODE THEORIES; SPINODAL DECOMPOSITION; SURFACE SEGREGATION; SEGMENTAL DYNAMICS; POLY(METHYL METHACRYLATE); MOLECULAR-WEIGHT; PHASE-SEPARATION; DEUTERATED POLYSTYRENE; TEMPERATURE-DEPENDENCE AB A protocol for using neutron reflectivity to monitor the dynamic properties of a copolymer in a homopolymer matrix is described. This technique may be used to monitor a broad range of systems, as long as the copolymer and homopolymer form a miscible blend at low copolymer concentrations. Moreover, with knowledge of the Flory-Huggins interaction parameter between the copolymer and homopolymer, the molecular dynamic parameters of the copolymer, such as the tracer diffusion. coefficient, segmental friction factor, and longest relaxation time, can be quantitatively determined. This technique is demonstrated by the determination of these parameters for a series of styrene/methyl methacrylate alternating copolymers dispersed in a matrix of deuterated poly(methyl methacrylate). Interestingly, the segmental friction factor of these alternating copolymers is significantly different from that of similar diblock copolymers. (C) 2004 Wiley Periodicals, Inc. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Univ Tennessee, Dept Chem, Buehler Hall, Knoxville, TN 37996 USA. EM dad@utk.edu NR 76 TC 7 Z9 7 U1 0 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0887-6266 EI 1099-0488 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 2004 VL 42 IS 17 BP 3235 EP 3247 DI 10.1002/polb.20178 PG 13 WC Polymer Science SC Polymer Science GA 848OL UT WOS:000223476900016 ER PT J AU Smith, GS Skidmore, CB Howe, PM Majewski, J AF Smith, GS Skidmore, CB Howe, PM Majewski, J TI Diffusion, evaporation, and surface enrichment of a plasticizing additive in an annealed polymer thin film SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE additives; neutron reflectivity; surfaces; thin films ID GLYCOL MONODODECYL ETHER; NEUTRON REFLECTIVITY; SEGREGATION; BLEND; MIXTURES; SILICON; POLYSTYRENE; ADSORPTION; PARAMETERS; MODEL AB We present the first measurements of the simultaneous diffusion, surface enhancement, and evaporation of a plasticizer from a polymer, thin-film matrix using neutron reflection techniques. The reflectivity profiles as a function of the annealing time at an elevated temperature yield the time-dependent, plasticizer volume fraction profiles in a polyester-polyurethane (Estane) film. Thin, plasticizer-enriched layers form at both the polymer/substrate and polymer/air interfaces for annealed and unannealed samples. The diffusion equations for a material diffusing through a film and then evaporating into a vacuum at the free surface describe the loss of the plasticizer from the film for annealed samples. The loss of the plasticizer from the film is not limited by the movement of the plasticizer through the polymer matrix but is dominated by the plasticizer's rate of evaporation from the surface. The rate of evaporation and the volume fraction profiles for the plasticizer at the substrate interface are both consistent with surface attractions dominating over bulk attractions between the miscible plasticizer and the polymer. (C) 2004 Wiley Periodicals, Inc. C1 Oak Ridge Natl Lab, Ctr Neutron Scattering, Oak Ridge, TN 37831 USA. Los Alamos Natl Lab, Dynam Experimentat Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. RP Oak Ridge Natl Lab, Ctr Neutron Scattering, MS 6393, Oak Ridge, TN 37831 USA. EM smithgs1@ornl.gov RI Lujan Center, LANL/G-4896-2012; Smith, Gregory/D-1659-2016 OI Smith, Gregory/0000-0001-5659-1805 NR 34 TC 9 Z9 10 U1 2 U2 13 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0887-6266 EI 1099-0488 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 2004 VL 42 IS 17 BP 3258 EP 3266 DI 10.1002/polb.20171 PG 9 WC Polymer Science SC Polymer Science GA 848OL UT WOS:000223476900018 ER PT J AU Hamilton, WA Smith, GS Alcantar, NA Majewski, J Toomey, RG Kuhl, TL AF Hamilton, WA Smith, GS Alcantar, NA Majewski, J Toomey, RG Kuhl, TL TI Determining the density profile of confined polymer brushes with neutron reflectivity SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE confinement; diblocks; good solvent; neutron reflectivity; thin films; polystyrene ID ATOMIC-FORCE MICROSCOPY; DIBLOCK COPOLYMER MONOLAYERS; BLOCK-COPOLYMERS; GOOD SOLVENT; ADSORBED POLYMER; GRAFTED POLYMERS; TETHERED CHAINS; SURFACES; COMPRESSION; ADSORPTION AB Polymer molecules at solid or fluid interfaces have an enormous spectrum of applications in a wide variety of technologies as lubricants, adhesion modifiers, and protective surface coatings. Because polymer brushes have great potential to be used in such applications, there is a need to determine their structure and efficiency in reduced spaces. Using neutron reflectivity, we have directly quantified the density distribution of opposing polymer brushes under confinement in good solvent conditions under confinement. Our measurements show that the density profile in the overlap region between opposing polymer brushes flattens, consistent with predictions from molecular-dynamics simulations. In addition, a significant increase in the density at the anchoring surfaces due to the collapse of the brush layers was observed. This collapse of the brushes in restricted geometries suggests that high-density brushes do not interpenetrate significantly under good solvent conditions. (C) 2004 Wiley Periodicals, Inc. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Oak Ridge Natl Lab, Ctr Neutron Scattering, Oak Ridge, TN 37831 USA. Univ S Florida, Dept Chem Engn, Tampa, FL 33620 USA. Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Ctr Ocean Technol, St Petersburg, FL 33701 USA. RP Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. EM tlkuhl@ucdavis.edu RI Lujan Center, LANL/G-4896-2012; Smith, Gregory/D-1659-2016 OI Smith, Gregory/0000-0001-5659-1805 NR 48 TC 24 Z9 24 U1 3 U2 23 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0887-6266 EI 1099-0488 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 2004 VL 42 IS 17 BP 3290 EP 3301 DI 10.1002/polb.20170 PG 12 WC Polymer Science SC Polymer Science GA 848OL UT WOS:000223476900021 ER PT J AU Yim, H Kent, MS Satija, S Mendez, S Balamurugan, SS Balamurugan, S Lopez, CP AF Yim, H Kent, MS Satija, S Mendez, S Balamurugan, SS Balamurugan, S Lopez, CP TI Study of the conformational change of poly(N-isopropylacrylamide)-grafted chains in water with neutron reflection: Molecular weight dependence at high grafting density SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE poly-(N-isopropylacrylamide); grafted polymers; conformational analysis; neutron reflectivity ID POLY-N-ISOPROPYLACRYLAMIDE; SURFACE-PROPERTIES; PHASE-TRANSITION; SINGLE-CHAIN; TEMPERATURE; BRUSHES; BEHAVIOR; DETACHMENT; INTERFACES; SCATTERING AB The temperature-dependent conformational change of poly(N-isopropylacrylamide) (PNIPAM) brushes in D2O was investigated as a function of the molecular weight (M) at a high grafting density with neutron reflection. PNIPAM chains with three different M values were grafted at the same high surface density from a gold surface by atom transfer radical polymerization. A significant change in the segment concentration profile was observed for all three samples as the temperature passed through the lower critical solution temperature (similar to30 degreesC), in contrast to previous results obtained for samples with much lower surface density. Somewhat surprisingly, the fractional change in the first moment of the segment concentration profile () from 20 to 41 degreesC was weaker with increasing M. This is contrary to the trend for systems involving only van der Waals (VDW) interactions, in which higher M chains experience larger conformational changes with change in solvent quality. Indeed, the M dependence of the first moment of the segment concentration profile for the grafted PNIPAM chains at 20 degreesC was much weaker than has been reported previously for dense brushes involving only VDW interactions under good solvent conditions. At 20 degreesC, the form of the segment concentration profile varied systematically with M. A single-layer profile resulted for the highest M, but the profiles became more bilayer in character with decreasing M. At 41 degreesC, the profiles for all three samples were adequately described by a single dense layer with a smooth transition region to bulk D2O. The weak dependence of on M at 20 degreesC and the trend from a bilayer profile at lower M to a single-layer profile at higher M appear to be related. These results are interpreted in terms of concentration-dependent segment-segment interactions that result in a weak attraction for high segment densities at 20 degreesC. (C) 2004 Wiley Periodicals, Inc. C1 Sandia Natl Labs, Dept 1851, Albuquerque, NM 87185 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Kent, MS (reprint author), Sandia Natl Labs, Dept 1851, POB 5800, Albuquerque, NM 87185 USA. EM mskent@sandia.gov NR 47 TC 36 Z9 36 U1 2 U2 18 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 1 PY 2004 VL 42 IS 17 BP 3302 EP 3310 DI 10.1002/polb.20169 PG 9 WC Polymer Science SC Polymer Science GA 848OL UT WOS:000223476900022 ER PT J AU Strader, MB VerBerkmoes, NC Tabb, DL Connelly, HM Barton, JW Bruce, BD Pelletier, DA Davison, BH Hettich, RL Larimer, FW Hurst, GB AF Strader, MB VerBerkmoes, NC Tabb, DL Connelly, HM Barton, JW Bruce, BD Pelletier, DA Davison, BH Hettich, RL Larimer, FW Hurst, GB TI Characterization of the 70S ribosome from Rhodopseudomonas palustris using an integrated "top-down" and "bottom-up" mass spectrometric approach SO JOURNAL OF PROTEOME RESEARCH LA English DT Article DE bottom-up; top-down; Rhodopseudomonas palustris; protein complexes; 70S ribosome; post-translational modifications; proteomics; mass spectrometry ID AMINO-ACID-SEQUENCES; ESCHERICHIA-COLI; PROTEIN COMPLEXES; ANGSTROM RESOLUTION; INTACT PROTEINS; POSTTRANSLATIONAL MODIFICATIONS; SACCHAROMYCES-CEREVISIAE; BACTERIAL-RIBOSOMES; BREAST-CANCER; SPECTRAL DATA AB We present a comprehensive mass spectrometric approach that integrates intact protein molecular mass measurement ("top-down") and proteolytic fragment identification ("bottom-up") to characterize the 70S ribosome from Rhodopseudomonas palustris. Forty-two intact protein identifications were obtained by the top-down approach and 53 out of the 54 orthologs to Escherichia coli ribosomal proteins were identified from bottom-up analysis. This integrated approach simplified the assignment of post-translational modifications by increasing the confidence of identifications, distinguishing between isoforms, and identifying the amino acid positions at which particular post-translational modifications occurred. Our combined mass spectrometry data also allowed us to check and validate the gene annotations for three ribosomal proteins predicted to possess extended C-termini. In particular, we identified a highly repetitive C-terminal "alanine tail" on L25. This type of low complexity sequence, common to eukaryotic proteins, has previously not been reported in prokaryotic proteins. To our knowledge, this is the most comprehensive protein complex analysis to date that integrates two MS techniques. C1 Oak Ridge Natl Lab, Div Chem Sci, Organ & Biol Mass Spect Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Oak Ridge Natl Lab, Grad Sch Genome Sci & Technol, Oak Ridge, TN 37830 USA. Univ Tennessee, Dept Biochem Cellular & Mol Biol, Knoxville, TN 37996 USA. RP Hurst, GB (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Organ & Biol Mass Spect Grp, POB 2008, Oak Ridge, TN 37831 USA. EM hurstgb@ornl.gov RI Pelletier, Dale/F-4154-2011; Davison, Brian/D-7617-2013; Hettich, Robert/N-1458-2016; OI Davison, Brian/0000-0002-7408-3609; Hettich, Robert/0000-0001-7708-786X; Hurst, Gregory/0000-0002-7650-8009 NR 64 TC 63 Z9 121 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1535-3893 J9 J PROTEOME RES JI J. Proteome Res. PD SEP-OCT PY 2004 VL 3 IS 5 BP 965 EP 978 DI 10.1021/pr049940z PG 14 WC Biochemical Research Methods SC Biochemistry & Molecular Biology GA 865HR UT WOS:000224693800006 PM 15473684 ER PT J AU Coleman, MA Lao, VH Segelke, BW Beernink, PT AF Coleman, MA Lao, VH Segelke, BW Beernink, PT TI High-throughput, fluorescence-based screening for soluble protein expression SO JOURNAL OF PROTEOME RESEARCH LA English DT Article DE protein expression; high-throughput screening; fluorescence; green fluorescent protein (GFP); BODIPY-FL; protein microarray ID ESCHERICHIA-COLI; IN-VITRO; GENE-EXPRESSION; MICROARRAYS; SOLUBILITY; SYSTEM; SCALE; ASSAY; DNA AB Protein expression screening methods are essential for proteomic scale characterization of gene and cDNA expression libraries. Screening methods are also important for the identification of highly expressed protein targets, for example, in quantities suitable for high-throughput screening and protein structural studies. To address these needs, we describe the implementation of several rapid, fluorescence-based protein expression screening strategies using Escherichia coli or E. coli-based in vitro transcription/translation (IVT) systems. In vitro expression screening is fast, convenient and, as we show, correlates well with in vivo expression. For screening, expressed proteins are labeled either as fusions with green fluorescent protein (GFP) or through translational incorporation of a fluorescent amino acid derivative, BODIPY-FL-Lysine. Fluorescence-based detection of GFP fusions or BODIPY-labeled proteins is considerably faster than other common expression screening methods, such as immunological detection of gels or dot blots. Furthermore, in vitro and in vivo screening used together yield a larger set of expressed proteins than either method alone. Specifically labeled proteins in cellular lysates are detected in one of three formats: a microplate using a fluorescence plate reader, a dot-blot using a fluorescence scanner or a microarray using a laser scanner. We have established a correlation among the various detection formats, which validates the use of protein microarrays for expression screening. Production of expressed proteins detected through screening can be scaled up either using IVT reactions or with in vivo expression systems in the absence of a fluorophore for subsequent characterization of protein function or interactions. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Beernink, PT (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, 7000 E Ave,L-448, Livermore, CA 94550 USA. EM ptb@llnl.gov OI Coleman, Matthew/0000-0003-1389-4018 NR 41 TC 34 Z9 37 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1535-3893 J9 J PROTEOME RES JI J. Proteome Res. PD SEP-OCT PY 2004 VL 3 IS 5 BP 1024 EP 1032 DI 10.1021/pr049912g PG 9 WC Biochemical Research Methods SC Biochemistry & Molecular Biology GA 865HR UT WOS:000224693800014 PM 15473692 ER PT J AU Devi, VM Benner, DC Smith, MAH Rinsland, CP Sharpe, SW Sams, RL AF Devi, VM Benner, DC Smith, MAH Rinsland, CP Sharpe, SW Sams, RL TI A multispectrum analysis of the 2v(2) spectral region of (HCN)-C-12-N-14: intensities, broadening and pressure-shift coefficients SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE HCN; HCN 2v(2) band; infrared spectra; fourier transform infrared (FTIR) spectroscopy; absolute intensity; broadening and shifts ID INTEGRATED-INTENSITIES; WATER-VAPOR; V(1) BAND; HCN; TEMPERATURE; WIDTHS; TRANSITION; PARAMETERS; LINES; CM-1 AB High-resolution (0.005 cm(-1)) infrared absorption spectra of HCN in the 2v(2) band region near 1411 cm(-1) have been recorded at room temperature using the Bruker IFS120HR Fourier transform spectrometer located at Pacific Northwest National Laboratory. Four spectra of high-purity (99.8%) HCN together with three spectra of lean mixtures (similar to3%) of HCN in dry air were simultaneously fit using a multispectrum nonlinear least-squares procedure. The analysis yielded room temperature values for absolute intensities, self- and air-broadening coefficients, and self- and air-induced pressure shift coefficients for numerous lines in the 2v(2)(0) band of (HCN)-C-12-N-14. In addition, intensities, self- and air-broadening coefficients for several lines of the 3v(2)(1)-v(2)(1) hot band, as well as intensities for a number of lines in the 2v(0)(2) band of (HCN)-C-13-N-14, were also determined. Since there are no previous measurements of broadening and shift parameters reported in the 2v(2)(0) band, our results are compared with values recently determined in the v, band of (HCN)-C-12-N-14 and with current HITRAN values. (C) 2004 Elsevier Ltd. All rights reserved. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. PNNL, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Devi, VM (reprint author), Coll William & Mary, Dept Phys, Box 8795, Williamsburg, VA 23187 USA. EM m.d.venkataraman@larc.nasa.gov NR 24 TC 14 Z9 14 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD SEP 1 PY 2004 VL 87 IS 3-4 BP 339 EP 366 DI 10.1016/j.jqsrt.2004.03.002 PG 28 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 836KA UT WOS:000222553200009 ER PT J AU Felmy, AR Qafoku, O AF Felmy, AR Qafoku, O TI An aqueous thermodynamic model for the complexation of nickel with EDTA valid to high base concentration SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE nickel; EDTA; aqueous; complexation; solutions ID HIGH-IONIC-STRENGTH; NATURAL-WATERS; SOLUBILITY; PREDICTION; EQUILIBRIA; HYDROXIDE; STRONTIUM; SODIUM AB An aqueous thermodynamic model is developed which accurately describes the effects of high base concentration on the complexation of Ni2+ by ethylenedinitrilotetraacetic acid (EDTA). The model is primarily developed from an extensive dataset on the solubility of Ni(OH)(2)(cr) in the presence of EDTA and in the presence and absence of Ca2+ as the competing metal ion. The solubility data for Ni(OH)(2)(cr) were obtained in solutions ranging in NaOH concentration from 0.01 to 11.6 mol-kg(-1), and in Ca2+ concentrations extending to saturation with respect to portlandite, Ca(OH)(2). Owing to the inert nature of the Ni-EDTA complexation reactions, solubility experiments were approached from both the oversaturation and undersaturation direction and over time frames extending to 413 days. The final aqueous thermodynamic model is based upon the equations of Pitzer, accurately predicts the observed solubilities to concentrations as high as 11.6 mol-kg(-1) NaOH, and is consistent with UV-Vis spectroscopic studies of the complexes in solution. C1 Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. RP Felmy, AR (reprint author), Pacific NW Natl Lab, Div Chem Sci, 3335 Q Ave, Richland, WA 99352 USA. NR 26 TC 10 Z9 10 U1 0 U2 5 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD SEP PY 2004 VL 33 IS 9 BP 1161 EP 1180 DI 10.1023/B:JOSL.0000048051.48779.0c PG 20 WC Chemistry, Physical SC Chemistry GA 870NT UT WOS:000225065400007 ER PT J AU Jarzynski, C AF Jarzynski, C TI Nonequilibrium work theorem for a system strongly coupled to a thermal environment SO JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT LA English DT Article DE exact results; fluctuations (theory) ID FREE-ENERGY DIFFERENCES; FLUCTUATION-DISSIPATION RELATIONS; EQUILIBRIUM FREE-ENERGIES; STOCHASTIC-MODELS; THERMODYNAMICS; EQUALITY; EQUATION AB In a recent paper (2004 J. Stat. Mech.: Theor. Exp. P07006), Cohen and Mauzerall (CM) have argued that the derivation of the nonequilibrium work relation given in a previous work of Jarzynski (1997 Phys. Rev. Lett. 78 2690) is flawed. Here I attempt to answer their criticisms, both by presenting a detailed version of that derivation and by addressing specific objections raised by CM. The derivation presented here is in fact somewhat stronger than the one I gave in 1997, as it does not rely on the assumption of a weak coupling term connecting the system of interest and its thermal environment. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Jarzynski, C (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM chrisj@lanl.gov RI Jarzynski, Christopher/B-4490-2009 OI Jarzynski, Christopher/0000-0002-3464-2920 NR 27 TC 108 Z9 108 U1 3 U2 29 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1742-5468 J9 J STAT MECH-THEORY E JI J. Stat. Mech.-Theory Exp. PD SEP PY 2004 AR P09005 DI 10.1088/1742-5468/2004/09/P09005 PG 13 WC Mechanics; Physics, Mathematical SC Mechanics; Physics GA 901SI UT WOS:000227301800005 ER PT J AU Fischetti, R Stepanov, S Rosenbaum, G Barrea, R Black, E Gore, D Heurich, R Kondrashkina, E Kropf, AJ Wang, S Zhang, K Irving, TC Bunker, GB AF Fischetti, R Stepanov, S Rosenbaum, G Barrea, R Black, E Gore, D Heurich, R Kondrashkina, E Kropf, AJ Wang, S Zhang, K Irving, TC Bunker, GB TI The BioCAT undulator beamline 18ID: a facility for biological non-crystalline diffraction and X-ray absorption spectroscopy at the Advanced Photon Source SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray beamlines; non-crystalline diffraction; small-angle X-ray scattering; X-ray absorption spectroscopy; XAFS; XANES; EXAFS ID SOLUTION SCATTERING; FIBER DIFFRACTION; PROTEIN; DETECTOR; MACROMOLECULES; DESIGN; MUSCLE; ALPHA AB The 18ID undulator beamline of the Biophysics Collaborative Access Team at the Advanced Photon Source, Argonne, IL, USA, is a high-performance instrument designed for, and dedicated to, the study of partially ordered and disordered biological materials using the techniques of small-angle X-ray scattering, fiber diffraction, and X-ray absorption spectroscopy. The beamline and associated instrumentation are described in detail and examples of the representative experimental results are presented. C1 IIT, Dept Biol Chem & Phys Sci, Biophys Collaborat Access Team, Chicago, IL 60616 USA. Univ Georgia, SER CAT, Athens, GA 30602 USA. Argonne Natl Lab, CMT Div, Argonne, IL 60439 USA. RP Irving, TC (reprint author), Argonne Natl Lab, Div Biol, GMCA CAT, 9700 S Cass Ave, Argonne, IL 60439 USA. EM irving@biocat1.phys.iit.edu RI ID, BioCAT/D-2459-2012 FU NCRR NIH HHS [RR08630] NR 34 TC 78 Z9 79 U1 0 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD SEP PY 2004 VL 11 BP 399 EP 405 DI 10.1107/S0909049504016760 PN 5 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 846QJ UT WOS:000223330400006 PM 15310956 ER PT J AU Barrett, CL Marathe, MV Engelhart, DC Sivasubramaniam, A AF Barrett, CL Marathe, MV Engelhart, DC Sivasubramaniam, A TI Approximating the connectivity between nodes when simulating large-scale mobile ad hoc radio networks SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article; Proceedings Paper CT 36th Annual Simulation Symposium CY MAR 30-APR 02, 2003 CL ORLANDO, FLORIDA SP Soc Modeling & Simulat Int AB Simulation is a widely used technique in the design and evaluation of mobile ad hoc networks. However, time and space constraints can often limit the extent of the size, complexity and detail of the networks that can be simulated. Approximations in the system model can possibly alleviate this problem, but we need to be careful about how much accuracy is compromised when employing them. This paper specifically focuses on one aspect of simulation cost that is incurred in the computation of the connectivity graph that is used to describe what mobile nodes can communicate with whom. Since such a graph is re-computed frequently during the simulation, we explore alternatives to computing this graph exactly and their accuracy in capturing the actual graph properties. We investigate three approximation alternatives to compute graph connectivity, and propose metrics for expressing their deviations from the actual graph. In addition, the graphs generated by these approximations are compared to the original by examining several previously proposed graph measures-the degree distribution, clustering coefficient, shortest path distribution and eigen-value distribution. Such comparisons are conducted not only with static graphs, but also with dynamically changing graphs that are a consequence of clients moving. Results indicate that these approximations can be quite effective in avoiding repeated calculation of exact graph connectivity. (C) 2003 Elsevier Inc. All rights reserved. C1 Penn State Univ, University Pk, PA 16802 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Engelhart, DC (reprint author), Penn State Univ, 202 Pond, University Pk, PA 16802 USA. EM barrett@lanl.gov; marathe@lanl.gov; engelhar@cse.psu.edu; anand@cse.psu.edu NR 20 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0164-1212 J9 J SYST SOFTWARE JI J. Syst. Softw. PD SEP PY 2004 VL 73 IS 1 BP 63 EP 74 DI 10.1016/S0164-1212(03)00245-0 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 840DB UT WOS:000222836100006 ER PT J AU Chambers, DH Candy, JV Lehman, SK Kallman, JS Poggio, AJ Meyer, AW AF Chambers, DH Candy, JV Lehman, SK Kallman, JS Poggio, AJ Meyer, AW TI Time reversal and the spatio-temporal matched filter (L) SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB It is known that focusing of an acoustic field by a time-reversal mirror (TRM) is equivalent to a spatio-temporal matched filter under conditions where the Green's function of the field satisfies reciprocity and is time invariant, i.e., the Green's function is independent of the choice of time origin. In this letter, it is shown that both reciprocity and time invariance can be replaced by a more general constraint on the Green's function that allows a TRM to implement the spatio-temporal matched filter even when conditions are time varying. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Chambers, DH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM chambers2@llnl.gov NR 7 TC 12 Z9 13 U1 1 U2 1 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD SEP PY 2004 VL 116 IS 3 BP 1348 EP 1350 DI 10.1121/1.778839 PG 3 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 853OJ UT WOS:000223836600003 ER PT J AU Zielinska, B Sagebiel, J McDonald, JD Whitney, K Lawson, DR AF Zielinska, B Sagebiel, J McDonald, JD Whitney, K Lawson, DR TI Emission rates and comparative chemical composition from selected in-use diesel and gasoline-fueled vehicles SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article; Proceedings Paper CT 4th Colloquium on PM and Human Health CY MAR 31-APR 04, 2003 CL Pittsburgh, PA ID LIGHT CRUDE-OIL; PARTICULATE MATTER; ORGANIC-COMPOUNDS; BIOMARKER COMPOUNDS; AIR-POLLUTION; GC-MS; EXHAUST; CARBON; IDENTIFICATION; FRACTIONATION AB Emission samples for toxicity testing and detailed chemical characterization were collected from a variety of gasoline- and diesel-fueled in-use vehicles operated on the Unified Driving Cycle on a chassis dynamometer. Gasoline vehicles included normal particle mass (particulate matter [PM]) emitters (tested at 72 and 30 7), "black" and "white" smokers, and a new-technology vehicle (tested at 72 degreesF). Diesel vehicles included current-technology vehicles (tested at 72 and 30 degreesF) and a high PM emitter. Total PM emission rates ranged from below 3 mg/mi up to more than 700 mg/mi for the white smoker gasoline vehicle. Emission rates of organic and elemental carbon (OC/EC), elements (metals and associated analytes), ions, and a variety of particulate and semi-volatile organic compounds (polycyclic aromatic hydrocarbons [PAH], nitro-PAH, oxy-PAH, hopanes, and steranes) are reported for these vehicles. Speciated organic analysis also was conducted on the fuels and lube oils obtained from these vehicles after the emissions testing. The compositions of emissions were highly dependent on the fuel type (gasoline vs. diesel), the state of vehicle maintenance (low, average, or high emitters; white or black smokers), and ambient conditions (i.e., temperature) of the vehicles. Fuel and oil analyses from these vehicles showed that oil served as a repository for combustion byproducts (e.g., PAH), and oil-burning gasoline vehicles emitted PAH in higher concentrations than did other vehicles. These PAH emissions matched the PAH compositions observed in oil. C1 Desert Res Inst, Reno, NV 89512 USA. Lovelace Resp Res Inst, Albuquerque, NM USA. SW Res Inst, San Antonio, TX USA. Natl Renewable Energy Lab, Golden, CO USA. RP Zielinska, B (reprint author), Desert Res Inst, 2215 Raggio Pkwy, Reno, NV 89512 USA. EM barbz@dri.edu NR 26 TC 191 Z9 196 U1 11 U2 59 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD SEP PY 2004 VL 54 IS 9 BP 1138 EP 1150 PG 13 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 851RB UT WOS:000223701500011 PM 15468666 ER PT J AU Xu, Y Goyal, A Lian, J Rutter, NA Shi, I Sathyamurthy, S Paranthaman, M Wang, L Martin, PM Kroeger, DM AF Xu, Y Goyal, A Lian, J Rutter, NA Shi, I Sathyamurthy, S Paranthaman, M Wang, L Martin, PM Kroeger, DM TI Preparation of YBCO films on CeO2-buffered (001) YSZ substrates by a non-fluorine MOD method SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SUPERCONDUCTING THIN-FILMS; HIGH-TC SUPERCONDUCTORS; METALORGANIC DEPOSITION; TRIFLUOROACETATE PRECURSORS; YBA2CU3O7-DELTA; PRESSURE; SRTIO3; VAPOR AB YBa2Cu3O7-delta (YBCO) films were fabricated via a fluorine-free metal organic deposition (MOD) method followed by high-temperature, low oxygen partial pressure annealing. Trimethyl acetate salts of copper, yttrium, and barium hydroxide were used as the precursors, which were dissolved in proponic acid- and amine-based solvents. After spin-coating and burnout, samples were annealed at 740degreesC in 180 ppm oxygen partial pressure and exposed to humid atmosphere for different times. A critical transition temperature, T-c(R=O) of 90.2 K and a transport critical current density (J(c)) of 0.55 MA/cm(2) (77 K and self-field) were obtained for 0.2 mum YBCO films on CeO2-buffered yttria-stabilized zirconia (YSZ) substrates. X-ray studies shows that the YBCO films have sharp in-plane and out-of-plane texture for all samples; however, the porosity of the YBCO film varies with the time of exposure to the humid atmosphere. A reaction between YBCO and CeO2 during the high-temperature anneals and formation of the reaction product BaCeO3 was confirmed by X-ray diffraction (XRD) studies. The XRD and transmission electron microscopy analysis indicated that the epitaxial relations in the film were YBCO (001)HCeO2 (001)//YSZ (001) and YBCO [100]// CeO2 [110]//YSZ [110]. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Cincinnati, Dept Mat Sci, Cincinnati, OH 45221 USA. Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Xu, Y (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM xuy@ornl.gov RI Lian, Jie/A-7839-2010; Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 26 TC 28 Z9 29 U1 1 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2004 VL 87 IS 9 BP 1669 EP 1676 PG 8 WC Materials Science, Ceramics SC Materials Science GA 858LI UT WOS:000224192900009 ER PT J AU Muehleman, C Sumner, DR Zhong, Z AF Muehleman, C Sumner, DR Zhong, Z TI Refraction effects of diffraction enhanced radiographic imaging - A new look at bone SO JOURNAL OF THE AMERICAN PODIATRIC MEDICAL ASSOCIATION LA English DT Article ID ARTICULAR-CARTILAGE; TOMOGRAPHY AB The objective of this study was to demonstrate the ability of a novel radiographic technology-diffraction-enhanced imaging-to detect contrast in bone tissue through absorption, refraction, and scatter rejection. Diffraction-enhanced imaging uses a synchrotron x-ray beam to produce images of high contrast by measuring the object's refraction and ultra-small angle scattering of x-rays in addition to the attenuation measured by conventional radiography. We present evidence that diffraction-enhanced imaging provides contrast enhancement at the edges of cortical and cancellous bone and a three-dimensional appearance of trabeculae. C1 Rush Med Coll, Dept Anat & Cell Biol, Chicago, IL 60612 USA. Rush Med Coll, Dept Biochem, Chicago, IL 60612 USA. Rush Med Coll, Dept Orthoped Surg, Chicago, IL 60612 USA. Brookhaven Natl Lab, Natl Synchroton Light Source, Upton, NY 11973 USA. RP Muehleman, C (reprint author), Rush Med Coll, Dept Anat & Cell Biol, ACFAC 507,600 S Paulina St, Chicago, IL 60612 USA. FU NIAMS NIH HHS [AR48292] NR 12 TC 9 Z9 10 U1 0 U2 0 PU AMER PODIATRIC MED ASSN PI BETHESDA PA 9312 OLD GEORGETOWN ROAD, BETHESDA, MD 20814-1621 USA SN 8750-7315 J9 J AM PODIAT MED ASSN JI J. Am. Podiatr. Med. Assoc. PD SEP-OCT PY 2004 VL 94 IS 5 BP 453 EP 455 PG 3 WC Orthopedics SC Orthopedics GA 856XH UT WOS:000224078800003 PM 15377720 ER PT J AU Singpurwalla, ND Booker, JM AF Singpurwalla, ND Booker, JM TI Membership functions and probability measures of fuzzy sets SO JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION LA English DT Review DE decision making; expert testimony; fuzzy control; Laplace's genie; likelihood; machine learning; membership functions; subjective probability ID LOGIC; CAUSATION AB The notion of fuzzy sets has proven useful in the context of control theory, pattern recognition, and medical diagnosis. However, it has also spawned the view that classical probability theory is unable to deal with uncertainties in natural language and machine learning, so that alternatives to probability are needed. One such alternative is what is known as "possibility theory." Such alternatives have come into being because past attempts at making fuzzy set theory and probability theory work in concert have been unsuccessful. The purpose of this article is to develop a line of argument that demonstrates that probability theory has a sufficiently rich structure for incorporating fuzzy sets within its framework. Thus probabilities of fuzzy events can be logically induced. The philosophical underpinnings that make this happen are a subjectivistic interpretation of probability, an introduction of Laplace's famous genie, and the mathematics of encoding expert testimony. The benefit of making probability theory work in concert with fuzzy set theory is an ability to deal with different kinds of uncertainties that may arise within the same problem. C1 George Washington Univ, Washington, DC 20052 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Singpurwalla, ND (reprint author), George Washington Univ, Washington, DC 20052 USA. EM nozer@gwu.edu; jmb@lanl.gov OI SINGPURWALLA, Nozer Darabsha/0000-0003-3578-2308 NR 30 TC 70 Z9 71 U1 3 U2 19 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0162-1459 J9 J AM STAT ASSOC JI J. Am. Stat. Assoc. PD SEP PY 2004 VL 99 IS 467 BP 867 EP 877 DI 10.1198/016214504000001196 PG 11 WC Statistics & Probability SC Mathematics GA 853VR UT WOS:000223857500034 ER PT J AU Yang, XL Cai, LZ Liu, Q Liu, HK AF Yang, XL Cai, LZ Liu, Q Liu, HK TI Theoretical bandgap modeling of two-dimensional square photonic crystals fabricated by the interference of three noncoplanar laser beams SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LATTICES; GAPS AB We have investigated numerically the photonic bandgap (PBG) and spectral properties of two-dimensional (2-D) square structures fabricated by holographic lithography. Based on the block-iterative frequency-domain method and on the nonorthogonal finite-difference time-domain method, we have calculated band structure as a function of intensity threshold and shown that the PBG of 2-D titania arrays opens only for TM polarization and that directional PBGs can be obtained simultaneously for TE- and TM-polarized waves. In addition, we have shown that symmetry reduction of the atom introduced by holographic lithography can lift the band degeneracies and create an absolute PBG for a square lattice of dielectric rods in air. (C) 2004 Optical Society of America. C1 Shandong Univ, Dept Opt, Jinan 250100, Peoples R China. Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Peoples R China. Natl Taiwan Univ, Grad Inst Elect Opt Engn, Taipei 106, Taiwan. Natl Taiwan Univ, Dept Elect Engn, Taipei 106, Taiwan. Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37836 USA. RP Yang, XL (reprint author), Shandong Univ, Dept Opt, Jinan 250100, Peoples R China. NR 18 TC 4 Z9 4 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 2004 VL 21 IS 9 BP 1699 EP 1702 DI 10.1364/JOSAB.21.001699 PG 4 WC Optics SC Optics GA 851OA UT WOS:000223693200016 ER PT J AU Kageyama, A Ji, HT Goodman, J Chen, F Shoshan, E AF Kageyama, A Ji, HT Goodman, J Chen, F Shoshan, E TI Numerical and experimental investigation of circulation in short cylinders SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE magnetorotational instability; Taylor-Couette instability; jet flow; Ekman circulation; liquid metal experiment ID TAYLOR-COUETTE FLOW; SHROUDED COROTATING DISKS; SMALL ASPECT RATIO; BIFURCATION PHENOMENA; MAGNETOROTATIONAL INSTABILITY; ANOMALOUS MODES; MAGNETIC-FIELD; VISCOUS-FLUID; STEADY FLOWS; WAVE NUMBER AB In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we explore Couette flows having height comparable to the gap between cylinders, centrifugally stable rotation, and high Reynolds number. Experiments in water are compared with numerical simulations. Simulations show that endcaps corotating with the outer cylinder drive a strong poloidal circulation that redistributes angular momentum. Predicted azimuthal flow profiles agree well with experimental measurements. Spin-down times scale with Reynolds number as expected for laminar Ekman circulation; extrapolation from two-dimensional simulations at Re less than or equal to 3200 agrees remarkably well with experiment at Re similar to 10(6). This suggests that turbulence does not dominate the effective viscosity. Further detailed numerical studies reveal a strong radially inward flow near both endcaps. After turning vertically along the inner cylinder, these flows converge at the midplane and depart the boundary in a radial jet. To minimize this circulation in the MRI experiment, endcaps consisting of multiple, differentially rotating rings are proposed. Simulations predict that an adequate approximation to the ideal Couette profile can be obtained with a few rings. C1 Japan Agcy Marine Earth Sci & Technol, Earth Simulator Ctr, Yokohama, Kanagawa 2360001, Japan. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Rutgers State Univ, Piscataway, NJ 08854 USA. RP Kageyama, A (reprint author), Japan Agcy Marine Earth Sci & Technol, Earth Simulator Ctr, Yokohama, Kanagawa 2360001, Japan. EM kage@jamstec.go.jp; hji@pppl.gov; jeremy@astro.princeton.edu; fchen@pppl.gov RI Kageyama, Akira/H-4537-2013 OI Kageyama, Akira/0000-0003-0433-668X NR 36 TC 33 Z9 34 U1 1 U2 7 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 2004 VL 73 IS 9 BP 2424 EP 2437 DI 10.1143/JPSP.73.2424 PG 14 WC Physics, Multidisciplinary SC Physics GA 855WI UT WOS:000224005200016 ER PT J AU Poppa, H AF Poppa, H TI High resolution, high speed ultrahigh vacuum microscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Review ID TRANSMISSION ELECTRON-MICROSCOPY; IN-SITU TRANSMISSION; SUB-ANGSTROM RESOLUTION; SMALL METAL PARTICLES; EPITAXIAL THIN-FILMS; RECONSTRUCTED SURFACE; OXIDE SURFACES; PALLADIUM PARTICLES; GROWTH-PROCESSES; TEM OBSERVATION AB The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today's highly sophisticated UHV-TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, Auger electron spectroscopy, low-energy electron diffraction, temperature programmed desorption, high-resolution electron energy-loss and Fourier-transform infrared spectroscopies, and others. Material systems ranging from atomic layers of metals and semiconductors to biology related depositions are being investigated. In the case of biological materials, however, strict limitations to high-resolution applications are imposed by electron radiation damage considerations. (C) 2004 American Vacuum Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Poppa, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. EM hpoppa@comcast.net NR 131 TC 8 Z9 8 U1 5 U2 41 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD SEP-OCT PY 2004 VL 22 IS 5 BP 1931 EP 1947 DI 10.1116/1.1786304 PG 17 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 863VN UT WOS:000224591600002 ER PT J AU Sigman, J Bae, HJ Norton, DP Budai, J Boatner, LA AF Sigman, J Bae, HJ Norton, DP Budai, J Boatner, LA TI Dielectric response of asymmetric KNbO3/KTaO3 superlattices SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article; Proceedings Paper CT 50th AVS International Symposium CY NOV 02-07, 2003 CL Baltimore, MD SP AVS ID EPITAXIAL BATIO3/SRTIO3 SUPERLATTICES; PULSED-LASER ABLATION; THIN-FILMS; PHASE-TRANSITIONS; POLARIZATION; GROWTH; ENHANCEMENT; SIMULATION; NIOBATE AB The synthesis and properties of asymmetric KNbO3/KTaO3 superlattices is examined. Interdigitated electrodes are fabricated for temperature-dependent capacitance measurements. The nonlinear dielectric response of 1/N superlattice exhibits the anomalous positive tunability behavior indicative of antiferroelectricity. In contrast, the N/1 KNbO3/KTaO3 structures (N>1) appear to be either ferroelectric or paraelectric, depending on the temperature. Discussion of possible mechanisms for this behavior is given. (C) 2004 American Vacuum Society. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32606 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Norton, DP (reprint author), Univ Florida, Dept Mat Sci & Engn, POB 116400,Rhines Hall, Gainesville, FL 32606 USA. EM dnort@mse.ufl.edu RI Boatner, Lynn/I-6428-2013; OI Boatner, Lynn/0000-0002-0235-7594; Budai, John/0000-0002-7444-1306 NR 25 TC 8 Z9 8 U1 0 U2 4 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD SEP-OCT PY 2004 VL 22 IS 5 BP 2010 EP 2013 DI 10.1116/1.1778403 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 863VN UT WOS:000224591600013 ER PT J AU Berniard, TJ Albin, DS To, B Pankow, JW Young, M Asher, SE AF Berniard, TJ Albin, DS To, B Pankow, JW Young, M Asher, SE TI Effects of Cu at the device function on the properties of CdTe/CdS photovoltaic cells SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID CDS THIN-FILMS; SOLAR-CELLS; DIFFUSION AB Fabrication techniques used in processing cadmium telluride (CdTe) solar cell devices have been shown to introduce copper (Cu) into the cell structure. In fact, an accumulation of Cu in the cadmium sulfide (CdS) region has been seen, especially after back-contact processing. However, exactly how the presence of Cu near the device junction affects performance has yet to be determined. This study explores how CdS films are affected by Cu diffusion from a metallic layer and how these Cu-diffused layers (CdS:Cu) change the properties of thin-film CdS/CdTe devices. Spectrophotometric analysis shows the optical bandgap of CdS films was 2.31 eV following thermal diffusion of a 50 Angstrom Cu layer, compared to 2.43 eV for CdS films that did not contain Cu. Characterization of the CdS:Cu films using grazing incidence x-ray diffraction (GIXRD) also produced noticeable shifts in the CdS peaks, likely due to Cu incorporation in the films. GIXRD, supported by Auger electron spectroscopy data, indicate that a Cu gradient is present in the CdS films as a result of the Cu treatments. Devices were completed using the CdS:Cu films, and the resulting performance was compared with standard CdS / CdTe devices (i.e., no Cu evaporated at the interface). Standard devices had an open-circuit voltage (V-oc) of 825 mV, short-circuit current (J(sc)) of 21 mA/cm(2) fill factor (FF) of 64.2%, and efficiency (%eta) of 11. 1 %. A similar device stressed for 900 h had a V-oc of 726 mV, J(sc) of 21 mA/cm(2), FF of 29.2%, and efficiency of 6.9%. The device with a 10 Angstrom Cu layer diffused into the CdS (unstressed) had a V-oc of 651 mV, J(c), of 20.2 mA/cm(2), FF of 44.2%, and efficiency of 5.8%. Similar trends in the performance parameters are seen between the stressed cell and the cell containing CdS:Cu. Modeled quantum efficiency (QE) curves for CdTe devices showed a reduction and shifting of the QE response near 500 nm as the bandgap of the CdS is shifted to lower energy. This is consistent with trends in the QE curves, as a standard CdS/CdTe device goes from an unstressed to a stressed state. The presence of Cu at the interface, perhaps incorporated in the CdS layer, may help explain the degradation seen in standard CdTe devices. (C) 2004 American Vacuum Society. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Berniard, TJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM tracie_berniard@nrel.gov NR 11 TC 18 Z9 20 U1 1 U2 15 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD SEP-OCT PY 2004 VL 22 IS 5 BP 2423 EP 2428 DI 10.1116/1.1800311 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 870HN UT WOS:000225048300031 ER PT J AU Davenport, MP Ribeiro, RM Perelson, AS AF Davenport, MP Ribeiro, RM Perelson, AS TI Kinetics of virus-specific CD8(+) T cells and the control of human immunodeficiency virus infection SO JOURNAL OF VIROLOGY LA English DT Article ID LYMPHOCYTIC CHORIOMENINGITIS VIRUS; HIV-1 INFECTION; DISEASE PROGRESSION; RHESUS-MONKEYS; IN-VIVO; VIRAL REPLICATION; CD8-T-CELL MEMORY; TYPE-1 INFECTION; DNA VACCINATION; CD4-T-CELL HELP AB Several primate models indicate that cytotoxic T lymphocyte-inducing vaccines may be unable to prevent human immunodeficiency virus infection but may have a long-term benefit in controlling viral replication and delaying disease progression. Here we show that analysis of the kinetics of antigen-specific CD8(+) T-cell expansion suggests a delay in activation following infection that allows unimpeded early viral replication. Viral kinetics do not differ between controls and vaccinees during this delay phase. An increase in virus-specific CD8(+) T-cell numbers around day 10 postinfection coincides with a slowing in viral replication in vaccinees and reduces peak viral loads by around I log. However, this response is too little too late to prevent establishment of persistent infection. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New S Wales, Prince Wales Hosp, Dept Hematol, Kensington, NSW 2033, Australia. Univ New S Wales, Ctr Vasc Res, Kensington, NSW 2033, Australia. Univ Oxford, Dept Zool, Oxford OX1 3PS, England. RP Perelson, AS (reprint author), Los Alamos Natl Lab, MS-K710 T-10, Los Alamos, NM 87545 USA. EM asp@lanl.gov FU NCRR NIH HHS [RR06555, R01 RR006555]; NIAID NIH HHS [AI28433, R37 AI028433, R01 AI028433] NR 58 TC 67 Z9 67 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0022-538X J9 J VIROL JI J. Virol. PD SEP PY 2004 VL 78 IS 18 BP 10096 EP 10103 DI 10.1128/JVI.78.18.10096-10103.2004 PG 8 WC Virology SC Virology GA 851QY UT WOS:000223701100053 PM 15331742 ER PT J AU Batani, D Wootton, AJ AF Batani, D Wootton, AJ TI The International Conference on Ultrashort High-Energy Radiation and Matter - Guest editor's preface SO LASER AND PARTICLE BEAMS LA English DT Editorial Material C1 Univ Milan, Milan, Italy. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Batani, D (reprint author), Univ Milan, Milan, Italy. NR 0 TC 6 Z9 6 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2004 VL 22 IS 3 BP 197 EP 197 DI 10.1017/S026303460422300x PG 1 WC Physics, Applied SC Physics GA 874DB UT WOS:000225330000001 ER PT J AU Fukuda, Y Akahane, Y Aoyama, M Inoue, N Ueda, H Kishimoto, Y Yamakawa, K Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Abdallah, J Csanak, G Boldarev, AS Gasilov, VA AF Fukuda, Y Akahane, Y Aoyama, M Inoue, N Ueda, H Kishimoto, Y Yamakawa, K Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Abdallah, J Csanak, G Boldarev, AS Gasilov, VA TI Generation of X rays and energetic ions from superintense laser irradiation of micron-sized Ar clusters SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT International Conference on Ultrashort High-Energy Radiation and Matter CY OCT 07-10, 2003 CL Varenna, ITALY SP Piero Caldirola Int Ctr Promot Sci, Int Sch Plasma Phys, FEMTO Programme European Sci Fdn DE cluster; high power laser; isochoric heating; multiply charged ion; X ray ID ATOMIC CLUSTERS; PULSES; EMISSION AB High-resolution K-shell spectra of a plasma created by superintense laser irradiation of micron-sized At clusters have been measured with an intensity above 10(19) W/cm(2) and a pulse duration of 30 fs. The total photon flux of 2 X 10(8) photons/pulse was achieved for He-alpha1 resonant line of Ar (lambda = 3.9491 Angstrom, 3.14 keV). In parallel with X-ray measurements, energy distributions of emitted ions have been measured. The multiply charged ions with kinetic energies up to 800 keV were observed. It is found that hot electrons produced by high contrast laser pulses allow the isochoric heating of clusters and shift the ion balance toward the higher charge states, which enhances both the X-ray line yield of the He-like argon ion and the ion kinetic energy. C1 Japan Atom Energy Res Inst, Adv Photon Res Ctr, Kyoto 6190215, Japan. Japan Atom Energy Res Inst, Naka Fus Res Estab, Naka, Ibaraki 31101, Japan. VNIIFTRI, Multicharged Ions Spectra Data Ctr, Moscow, Russia. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. Russian Acad Sci, Inst Math Modeling, Moscow, Russia. RP Fukuda, Y (reprint author), Japan Atom Energy Res Inst, Adv Photon Res Ctr, Kyoto 6190215, Japan. EM fukuda@apr.jaeri.go.jp NR 16 TC 34 Z9 36 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2004 VL 22 IS 3 BP 215 EP 220 DI 10.1017/S0263034604223047 PG 6 WC Physics, Applied SC Physics GA 874DB UT WOS:000225330000005 ER PT J AU Hartemann, FV Tremaine, AM Anderson, SG Barty, CPJ Betts, SM Booth, R Brown, WJ Crane, JK Cross, RR Gibson, DJ Fittinghoff, DN Kuba, J Le Sage, GP Slaughter, DR Wootton, AJ Hartouni, EP Springer, PT Rosenzweig, JB Kerman, AK AF Hartemann, FV Tremaine, AM Anderson, SG Barty, CPJ Betts, SM Booth, R Brown, WJ Crane, JK Cross, RR Gibson, DJ Fittinghoff, DN Kuba, J Le Sage, GP Slaughter, DR Wootton, AJ Hartouni, EP Springer, PT Rosenzweig, JB Kerman, AK TI Characterization of a bright, tunable, ultrafast Compton scattering X-ray source SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT International Conference on Ultrashort High-Energy Radiation and Matter CY OCT 07-10, 2003 CL Varenna, ITALY SP Piero Caldirola Int Ctr Promot Sci, Int Sch Plasma Phys, FEMTO Programme European Sci Fdn DE calibrated foils; Compton scattering; relativistic electron beam; velocity compression; X-ray source ID DEGREES THOMSON SCATTERING; FREE-ELECTRON LASER; SYNCHROTRON-RADIATION; RELATIVISTIC ELECTRONS; STRUCTURAL DYNAMICS; LATTICE-DYNAMICS; CLASSICAL-THEORY; PULSES; DIFFRACTION; GENERATION AB The Compton scattering of a terawatt-class, femtosecond laser pulse by a high-brightness, relativistic electron beam has been demonstrated as a viable approach toward compact, tunable sources of bright, fermosecond, hard X-ray flashes. The main focus of this article is a detailed description of such a novel X-ray source, namely the PLEIADES (Picosecond Laser-Electron Inter-Action for the Dynamical Evaluation of Structures) facility at Lawrence Livermore National Laboratory. PLEIADES has produced first light at 70 keV, thus enabling critical applications, such as advanced backlighting for the National Ignition Facility and in situ time-resolved studies of high-Z materials. To date, the electron beam has been focused down to sigma(x) = sigma(y) = 27 mum rms, at 57 MeV, with 266 pC of charge, a relative energy spread of 0.2%, a normalized horizontal' emittance of 3.5 mm (.) mrad, a normalized vertical emittance of I I mm (.) mrad, and a duration of 3 ps rms. The compressed laser pulse energy at focus is 480 mJ, the pulse duration 54 fs Intensity Full Width at Half-Maximum (IFWHM), and the 1/e(2) radius 36 mum. Initial X rays produced by head-on collisions between the laser and electron beams at a repetition rate of 10 Hz were captured with a cooled CCD using a CsI scintillator; the peak photon energy was approximately 78 keV, and the observed angular distribution was found to agree very well with three-dimensional codes. The current X-ray dose is 3 X 106 photons per pulse, and the inferred peak brightness exceeds 10(15) photons/ (mm(2) X mrad(2) X s X 0. 1% bandwidth). Spectral measurements using calibrated foils of variable thickness are consistent with theory. Measurements of the X-ray dose as a function of the delay between the laser and electron beams show a 24-ps full width at half maximum (FWHM) window, as predicted by theory, in contrast with a measured timing jitter of 1.2 ps, which contributes to the stability of the source. In addition, K-edge radiographs of a Ta foil obtained at different electron beam energies clearly demonstrate the gamma(2)-tunability of the source and show very good agreement with the theoretical divergence-angle dependence of the X-ray spectrum. Finally, electron bunch shortening experiments using velocity compression have also been performed and durations as short as 300 A rms have been observed using coherent transition radiation; the corresponding inferred peak X-ray flux approaches 10(19) photons/s. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Hartemann, FV (reprint author), Lawrence Livermore Natl Lab, L-280,POB 808, Livermore, CA 94551 USA. EM hartemann1@llnl.gov OI Hartouni, Edward/0000-0001-9869-4351 NR 47 TC 18 Z9 18 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2004 VL 22 IS 3 BP 221 EP 244 DI 10.1017/S0263034604223059 PG 24 WC Physics, Applied SC Physics GA 874DB UT WOS:000225330000006 ER PT J AU Volegov, P Matlachov, AN Espy, MA George, JS Kraus, RH AF Volegov, P Matlachov, AN Espy, MA George, JS Kraus, RH TI Simultaneous magnetoencephalography and SQUID detected nuclear MR in microtesla magnetic fields SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article DE NMR; MEG; MRI; low magnetic field; SQUID ID ROOM-TEMPERATURE SAMPLES; NEURONAL-ACTIVITY; HUMAN BRAIN; RESONANCE; NMR AB A system that simultaneously measures magnetoencephalography (MEG) and nuclear magnetic resonance (NMR) signals from the human brain was designed and fabricated. A superconducting quantum interference device (SQUID) sensor coupled to a gradiometer pickup coil was used to measure the NMR and MEG signals. H-1 NMR spectra with typical Larmor frequencies from 100-1000 Hz acquired simultaneously with the evoked MEG response from a stimulus to the median nerve are reported. The single SQUID gradiometer was placed approximately over the somatosensory cortex of a human subject to noninvasively record the signals. These measurements demonstrate, for the first time, the feasibility of simultaneous MRI and MEG. NMR in the microtesla regime provides narrow line-widths and the potential for high spatial resolution imaging, while SQUID sensors enable direct measurement of neuronal activity with high temporal resolution via MEG. (C) 2004 Wiley-Liss, Inc. C1 Los Alamos Natl Lab, Biol & Quantum Phys Grp, Los Alamos, NM 87545 USA. RP Espy, MA (reprint author), Los Alamos Natl Lab, Biol & Quantum Phys Grp, Mail Stop D454, Los Alamos, NM 87545 USA. EM espy@lanl.gov NR 15 TC 56 Z9 56 U1 1 U2 8 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0740-3194 J9 MAGNET RESON MED JI Magn. Reson. Med. PD SEP PY 2004 VL 52 IS 3 BP 467 EP 470 DI 10.1002/mrm.20193 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 849HL UT WOS:000223529200004 PM 15334563 ER PT J AU Minard, KR Holtom, GR Kathmann, LE Majors, PD Thrall, BD Wind, RA AF Minard, KR Holtom, GR Kathmann, LE Majors, PD Thrall, BD Wind, RA TI Simultaneous H-1 PFG-NMR and confocal microscopy of monolayer cell cultures: Effects of apoptosis and necrosis on water diffusion and compartmentalization SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article DE apoptosis; cell; diffusion; necrosis; PFG ID WEIGHTED H-1-NMR SPECTROSCOPY; MAGNETIC-RESONANCE MICROSCOPE; IN-VIVO; INTRACELLULAR WATER; TREATMENT RESPONSE; TUMOR SPHEROIDS; DEATH; CONSTANTS; TIME; VOLUME AB We induced apoptosis and necrosis in monolayer cultures of Chinese hamster ovary cells using okadaic acid and hydrogen peroxide (H2O2), respectively, and examined the effect on water diffusion and compartmentalization using pulsed-field-gradient (PFG) H-1-NMR and simultaneous confocal microscopy. In PFG experiments characterized by a fixed diffusion time (<4.7 ms) and variable b-values (0-27000 s/mm(2)),H-1-NMR data collected with untreated cells exhibited multiexponential behavior. Analysis with a slow-exchange model revealed two distinct cellular water compartments with different apparent diffusion coefficients (ADCs; 0.56, 0.06 x 10(-3) mm(2)/s) and volume fractions (0.96 and 0.04). During the first 12 hr of necrosis or apoptosis, the amount of water in the smallest compartment increased twofold before significant changes in cell density or plasma membrane integrity occurred. Over the same period, water content in the largest compartment decreased by a factor of >2 in apoptotic cells, in accordance with observed cell shrinkage, and changed little in necrotic counterparts, where only slight swelling was evident. These results indicate that PFG H-1-NMR serves as a sensitive indicator of early cell death in monolayer cultures, and can be used to distinguish apoptosis from necrosis. Measurements of restricted diffusion and water exchange are presented to elucidate the compartment origins and justify the model assumptions. (C) 2004 Wiley-Liss, Inc. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Wind, RA (reprint author), Pacific NW Natl Lab, POB 999,Mail Stop K8-98, Richland, WA 99352 USA. EM Robert.Wind@pnl.gov FU NCI NIH HHS [R33 CA83230] NR 35 TC 11 Z9 11 U1 0 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0740-3194 J9 MAGNET RESON MED JI Magn. Reson. Med. PD SEP PY 2004 VL 52 IS 3 BP 495 EP 505 DI 10.1002/mrm.20179 PG 11 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 849HL UT WOS:000223529200008 PM 15334567 ER PT J AU Elder, JB AF Elder, JB TI Remote testing of underground high level radioactive waste storage tanks SO MATERIALS EVALUATION LA English DT Article C1 Savannah River Natl Lab, Mat Technol Sect, Aiken, SC 29808 USA. RP Elder, JB (reprint author), Savannah River Natl Lab, Mat Technol Sect, Aiken, SC 29808 USA. EM james.elder@srs.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD SEP PY 2004 VL 62 IS 9 BP 915 EP 920 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 853PM UT WOS:000223839500003 ER PT J AU Foo, ML Lee, WL Siegrist, T Lawes, G Ramirez, AP Ong, NP Cava, RJ AF Foo, ML Lee, WL Siegrist, T Lawes, G Ramirez, AP Ong, NP Cava, RJ TI Electronic characterization of alkali ruthenium hollandites: KRU4O8, RbRU4O8 and Cs0.8Li0.2RU4O8 SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; X-ray diffraction; electrical properties; magnetic properties; specific heat ID LAYERED PEROVSKITE; SUPERCONDUCTIVITY; DEPENDENCE; SR2RUO4; OXIDES AB Transport, specific heat, and magnetic measurements have been performed on three alkali hollandites: KRu4O8, RbRu4O8, and a newly synthesized Cs analog, Cs0.8Li0.2Ru4O8, which was determined to have space group I4/m (#87) and lattice parameters, a = 10.0850(4) and c = 3.12180(20). In contrast to the ruthenium perovskites, which display a wide range of electrical and magnetic behavior, the alkali hollandites are simple paramagnetic metals. (C) 2004 Elsevier Ltd. All rights reserved. C1 Princeton Univ, Dept Chem, Frick Lab, Princeton, NJ 08544 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Los Alamos Natl Lab, Dept Thermal Phys, Los Alamos, NM USA. RP Princeton Univ, Dept Chem, Frick Lab, Washington Rd, Princeton, NJ 08544 USA. EM mfoo@princeton.edu RI Foo, Maw Lin/H-9273-2012 NR 18 TC 14 Z9 14 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-5408 EI 1873-4227 J9 MATER RES BULL JI Mater. Res. Bull. PD SEP 1 PY 2004 VL 39 IS 11 BP 1663 EP 1670 DI 10.1016/j.matteresbull.2004.05.019 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 848CU UT WOS:000223445600010 ER PT J AU Nelson, PW Gilchrist, MA Coombs, D Hyman, JM Perelson, AS AF Nelson, PW Gilchrist, MA Coombs, D Hyman, JM Perelson, AS TI An age-structured model of HIV infection that allows for variations in the production rate of viral particles and the death rate of productively infected cells SO MATHEMATICAL BIOSCIENCES AND ENGINEERING LA English DT Article DE HIV; age-structured model; variable death; and production rates ID DYNAMICS IN-VIVO; INTRACELLULAR DELAY; MATHEMATICAL-ANALYSIS; IMMUNE-RESPONSE; CLEARANCE RATE; TUBERCULOSIS; DISEASES; THERAPY; DECAY AB Mathematical models of HIV-1 infection can help interpret drug treatment experiments and improve our understanding of the interplay between HIV-1 and the immune system. We develop and analyze an age-structured model of HIV-1 infection that allows for variations in the death rate of productively infected T cells and the production rate of viral particles as a function of the length of time a T cell has been infected. We show that this model is a generalization of the standard differential equation and of delay models previously used to describe HIV-1 infection, and provides a means for exploring fundamental issues of viral production and death. We show that the model has uninfected and infected steady states, linked by a transcritical bifurcation. We perform a local stability analysis of the nontrivial equilibrium solution and provide a general stability condition for models with age structure. We then use numerical methods to study solutions of our model focusing on the analysis of primary HIV infection. We show that the time to reach peak viral levels in the blood depends not only on initial conditions but also on the way in which viral production ramps up. If viral production ramps up slowly, we find that the time to peak viral load is delayed compared to results obtained using the standard (constant viral production) model of HIV infection. We find that data on viral load changing over time is insufficient to identify the functions specifying the dependence of the viral production rate or infected cell death rate on infected cell age. These functions must be determined through new quantitative experiments. C1 Univ Michigan, Dept Math, Ann Arbor, MI 48109 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Univ British Columbia, Dept Math, Vancouver, BC V6T 1Z2, Canada. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Nelson, PW (reprint author), Univ Michigan, Dept Math, 5860 E Hall, Ann Arbor, MI 48109 USA. EM pwn@umich.edu; mike@unm.edu; coombs@lanl.gov; hyman@lanl.gov; asp@t10.lanl.gov RI Gilchrist, Michael/A-8209-2008 OI Gilchrist, Michael/0000-0002-6936-0771 NR 32 TC 43 Z9 44 U1 0 U2 6 PU AMER INST MATHEMATICAL SCIENCES PI SPRINGFIELD PA PO BOX 2604, SPRINGFIELD, MO 65801-2604 USA SN 1547-1063 J9 MATH BIOSCI ENG JI Math. Biosci. Eng. PD SEP PY 2004 VL 1 IS 2 BP 267 EP 288 PG 22 WC Mathematical & Computational Biology SC Mathematical & Computational Biology GA 948CI UT WOS:000230693200004 PM 20369971 ER PT J AU Anitescu, M Hart, GD AF Anitescu, M Hart, GD TI A fixed-point iteration approach for multibody dynamics with contact and small friction SO MATHEMATICAL PROGRAMMING LA English DT Article; Proceedings Paper CT 3rd International Conference on Complementarity Problems CY JUL 29-AUG 02, 2002 CL Cambridge Univ, Cambridge, ENGLAND HO Cambridge Univ ID RIGID-BODY DYNAMICS; COULOMB-FRICTION AB Acceleration-force setups for multi-rigid-body dynamics are known to be inconsistent for some configurations and sufficiently large friction coefficients (a Painleve paradox). This difficulty is circumvented by time-stepping methods using impulse-velocity approaches, which solve complementarity problems with possibly nonconvex solution sets. We show that very simple configurations involving two bodies may have a nonconvex solution set for any nonzero value of the friction coefficient. We construct two fixed-point iteration algorithms that solve convex subproblems and that are guaranteed, for sufficiently small friction coefficients, to retrieve. at a linear convergence rate, the unique velocity solution of the nonconvex linear complementarity problem whenever the frictionless configuration can be disassembled. In addition, we show that one step of one of the iterative algorithms provides an excellent approximation to the velocity solution of the original, possibly nonconvex, problem if for all contacts we have that either the friction coefficient is small or the slip velocity is small. C1 Univ Pittsburgh, Dept Math, Pittsburgh, PA 15260 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Anitescu, M (reprint author), Univ Pittsburgh, Dept Math, Pittsburgh, PA 15260 USA. EM anitescu@math.pitt.edu; gdhart@pitt.edu NR 31 TC 26 Z9 27 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0025-5610 J9 MATH PROGRAM JI Math. Program. PD SEP PY 2004 VL 101 IS 1 BP 3 EP 32 DI 10.1007/s10107-004-0535-6 PG 30 WC Computer Science, Software Engineering; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Operations Research & Management Science; Mathematics GA 859FM UT WOS:000224248800002 ER PT J AU Ferris, MC Munson, TS AF Ferris, MC Munson, TS TI Semismooth support vector machines SO MATHEMATICAL PROGRAMMING LA English DT Article; Proceedings Paper CT 3rd International Conference on Complementarity Problems CY JUL 29-AUG 02, 2002 CL Cambridge Univ, Cambridge, ENGLAND HO Cambridge Univ ID NONMONOTONE STABILIZATION METHODS; BREAST-CANCER DIAGNOSIS; COMPLEMENTARITY-PROBLEMS; NONSMOOTH EQUATIONS; NEWTON METHOD AB Support vector machines can be posed as quadratic programming problems in a variety of ways. This paper investigates a formulation using the two-norm for the misclassification error that leads to a positive definite quadratic program with a single equality constraint under a duality construction. The quadratic term is a small rank update to a diagonal matrix with positive entries. The optimality conditions of the quadratic program are reformulated as a semismooth system of equations using the Fischer-Burmeister function and a damped Newton method is applied to solve the resulting problem. The algorithm is shown to converge from any starting point with a Q-quadratic rate of convergence. At each iteration, the Sherman-Morrison-Woodbury update formula is used to solve the key linear system. Results for a large problem with 60 million observations are presented demonstrating the scalability of the proposed method on a personal computer. Significant computational savings are realized as the inactive variables are identified and exploited during the solution process. Further results on a small problem separated by a nonlinear surface are given showing the gains in performance that can be made from restarting the algorithm as the data evolves. C1 Univ Wisconsin, Dept Comp Sci, Madison, WI 53706 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Ferris, MC (reprint author), Univ Wisconsin, Dept Comp Sci, 1210 W Dayton St, Madison, WI 53706 USA. EM ferris@cs.wisc.edu; tmunson@mcs.anl.gov NR 36 TC 15 Z9 16 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0025-5610 J9 MATH PROGRAM JI Math. Program. PD SEP PY 2004 VL 101 IS 1 BP 185 EP 204 DI 10.1007/s10107-004-0541-8 PG 20 WC Computer Science, Software Engineering; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Operations Research & Management Science; Mathematics GA 859FM UT WOS:000224248800008 ER PT J AU Ruggiero, EJ Park, G Inman, DJ AF Ruggiero, EJ Park, G Inman, DJ TI Multi-input multi-output vibration testing of an inflatable torus SO MECHANICAL SYSTEMS AND SIGNAL PROCESSING LA English DT Article ID SMART MATERIALS AB In this study, we investigate the feasibility of using a multiple-input multiple-output (MIMO) modal testing technique on an inflated torus. In particular, the refined modal testing methodology focuses on using Macro-Fiber Composite (MFC(R)) patches as both actuators and sensors. MFC(R) patches can be integrated in an unobtrusive way into the skin of the torus, and can be used to find a gossamer structure's modal parameters. Furthermore, MFC(R) excitation produces less interference with the suspension modes of the free-free torus than excitations from a conventional shaker. The use of multiple actuators is shown to properly excite the global modes of the structure and distinguish between pairs of modes at nearly identical resonant frequencies. Formulation of the MIMO test as well as the required post-processing techniques are studied and successfully applied to an inflated Kapton(R) torus. (C) 2004 Elsevier Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Mech Engn, Ctr Intelligent Mat Syst & Struct, Blacksburg, VA 24061 USA. Los Alamos Natl Lab, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. RP Inman, DJ (reprint author), Virginia Polytech Inst & State Univ, Dept Mech Engn, Ctr Intelligent Mat Syst & Struct, 310 Durham Hall, Blacksburg, VA 24061 USA. EM dinman@vt.edu NR 18 TC 12 Z9 13 U1 1 U2 4 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0888-3270 J9 MECH SYST SIGNAL PR JI Mech. Syst. Signal Proc. PD SEP PY 2004 VL 18 IS 5 BP 1187 EP 1201 DI 10.1016/j.ymssp.2004.01.003 PG 15 WC Engineering, Mechanical SC Engineering GA 828TF UT WOS:000221995400012 ER PT J AU Rivard, MJ Melhus, CS Kirk, BL AF Rivard, MJ Melhus, CS Kirk, BL TI Brachytherapy dosimetry parameters calculated for a new Pd-103 source SO MEDICAL PHYSICS LA English DT Article DE Monte Carlo calculations; brachytherapy dosimetry; TG-43; MCNP; Pd-103 ID MONTE-CARLO CALCULATIONS; I-125; PROTOCOL; SEED AB A new brachytherapy source having Pd-103 adsorbed onto silver beads has been designed. The dose distributions of this source have been characterized using version 5 of the MCNP Monte Carlo radiation transport code available from Oak Ridge National Laboratory. These results are presented in terms of the updated AAPM Task Group No. 43 (TG-43U1) formalism, dosimetry parameters, and recommended calculation methodology. (C) 2004 American Association of Physicists in Medicine. C1 Tufts Univ, Sch Med, Tufts New England Med Ctr, Dept Radiat Oncol, Boston, MA 02111 USA. Oak Ridge Natl Lab, Nucl Computat Informat Grp, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Rivard, MJ (reprint author), Tufts Univ, Sch Med, Tufts New England Med Ctr, Dept Radiat Oncol, Box 246,750 Washington St, Boston, MA 02111 USA. OI Melhus, Christopher/0000-0002-2017-1988 NR 26 TC 18 Z9 18 U1 0 U2 1 PU AMER ASSOC PHYSICISTS MEDICINE AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD SEP PY 2004 VL 31 IS 9 BP 2466 EP 2470 DI 10.1118/1.1781552 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 857LF UT WOS:000224117400012 PM 15487726 ER PT J AU Gray, GT Meyers, MA Thadhani, NN Vecchio, KS AF Gray, GT Meyers, MA Thadhani, NN Vecchio, KS TI Symposium on dynamic deformation: Constitutive modeling, grain size, and other effects - In honor of Prof. Ronald W. Armstrong SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Editorial Material C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. RP Gray, GT (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Meyers, Marc/A-2970-2016 OI Meyers, Marc/0000-0003-1698-5396 NR 0 TC 0 Z9 0 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2545 EP 2546 DI 10.1007/s11661-004-0200-y PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000001 ER PT J AU Cerreta, E Gray, GT Chen, SR Pollock, TM AF Cerreta, E Gray, GT Chen, SR Pollock, TM TI Dynamic deformation and damage in cast gamma-TiAl during Taylor cylinder impact: Experiments and model validation SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID BEHAVIOR; ALLOYS AB The dynamic deformation, damage evolution, and cracking in four cast gamma titanium aluminide alloys have been investigated experimentally and theoretically. In this study, the dynamic compressive constitutive properties of several cast TiAl alloys were measured at quasi-static and dynamic rates. Using the measured high-strain-rate constitutive properties, the deformation, damage evolution, and postmortem specimen geometries observed in Taylor cylinder experiments were predicted using the mechanical threshold stress (MTS) constitutive model. The utility of the Taylor impact test for validation of high-rate constitutive models for intermetallics is discussed. C1 Los Alamos Natl Lab, Santa Fe, NM 87501 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Los Alamos Natl Lab, Santa Fe, NM 87501 USA. EM ecerreta@lanl.gov NR 26 TC 9 Z9 9 U1 0 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2557 EP 2566 DI 10.1007/s11661-004-0202-9 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000003 ER PT J AU Schwartz, AJ Kumar, M Lassila, DH AF Schwartz, AJ Kumar, M Lassila, DH TI Analysis of intergranular impurity concentration and the effects on the ductility of copper-shaped charge jets SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID GRAIN-BOUNDARIES; SEGREGATION; BISMUTH; BI; CU AB Shaped charge liners (SCLs) are thin-walled metallic cones that are explosively driven to high pressures and strain rates. From a metallurgical point of view, the SCLs provide an excellent experimental test bed to evaluate the influence of microstructure on high strain rate deformation and failure. In this work, a geometrical analysis based on an assumed tetrakaidecahedron grain shape is applied to determine the relationship between grain size, overall impurity content, and ductility of the liners. The measured parameter for ductility in this case is the break-up time for sulfur-doped, oxygen-free electronic (ofe) copper SCLs after they are explosively driven. The calculations determine the number of impurity atoms as a function of grain size, the number of available sites at the intercrystalline defects, and the intercrystalline impurity concentration. Recent experiments have shown that larger grain size liners with low impurity contents exhibit better ductility than smaller grain size liners with higher impurity concentrations, which is contrary to conventional wisdom that the liner ductility scales directly with grain size or impurity content alone. Within the range of grain sizes and bulk impurity contents in this study, the analysis suggests that the quadruple nodes and triple lines are saturated with impurities. Over this same range of impurities and grain sizes, only a fraction of a monolayer of impurities exists at the grain boundaries if all boundaries are assumed to be equally susceptible to sulfur segregation. Modification of the analysis by assuming partitioning of the sulfur only to crystallographically random boundaries, however, suggests that there is a correlation between the jet break-up time and the transition to complete monolayer coverage of such boundaries. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Schwartz, AJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM mukul@llnl.gov NR 18 TC 4 Z9 6 U1 2 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2567 EP 2573 DI 10.1007/s11661-004-0203-8 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000004 ER PT J AU Remington, BA Bazan, G Belak, J Bringa, E Caturla, M Colvin, JD Edwards, MJ Glendinning, SG Ivanov, DS Kad, B Kalantar, DH Kumar, M Lasinski, BF Lorenz, KT McNaney, JM Meyerhofer, DD Meyers, MA Pollaine, SM Rowley, D Schneider, M Stolken, JS Wark, JS Weber, SV Wolfer, WG Yaakobi, B Zhigilei, LV AF Remington, BA Bazan, G Belak, J Bringa, E Caturla, M Colvin, JD Edwards, MJ Glendinning, SG Ivanov, DS Kad, B Kalantar, DH Kumar, M Lasinski, BF Lorenz, KT McNaney, JM Meyerhofer, DD Meyers, MA Pollaine, SM Rowley, D Schneider, M Stolken, JS Wark, JS Weber, SV Wolfer, WG Yaakobi, B Zhigilei, LV TI Materials science under extreme conditions of pressure and strain rate SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID ABSORPTION FINE-STRUCTURE; SOLID-STATE EXPERIMENTS; TAYLOR INSTABILITY; CONSTITUTIVE DESCRIPTION; PLASTIC-DEFORMATION; SHOCK COMPRESSION; PEIERLS MECHANISM; LASER; METALS; MODEL AB Solid-state dynamics experiments at very high pressures and strain rates are becoming possible with high-power laser facilities, albeit over brief intervals of time and spatially small scales. To achieve extreme pressures in the solid state requires that the sample be kept cool, with T-sample < T-melt. To this end, a shockless, plasma-piston "drive" has been developed on the Omega laser, and a staged shock drive was demonstrated on the Nova laser. To characterize the drive, velocity interferometer measurements allow the high pressures of 10 to 200 GPa (0.1 to 2 Mbar) and strain rates of 10(6) to 10(8) s(-1) to be determined. Solid-state strength in the sample is inferred at these high pressures using the Rayleigh-Taylor (RT) instability as a "diagnostic." Lattice response and phase can be inferred for single-crystal samples from time-resolved X-ray diffraction. Temperature and compression in polycrystalline samples can be deduced from extended X-ray absorption fine-structure (EXAFS) measurements. Deformation mechanisms and residual melt depth can be identified by examining recovered samples. We will briefly review this new area of laser-based materials-dynamics research, then present a path forward for carrying these solid-state experiments to much higher pressures, P > 10(3) GPa (10 Mbar), on the National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Dept Appl Phys, Alicante, Spain. Univ Virginia, Dept Mat Sci & Engn, Charlottesville, VA USA. Univ Calif San Diego, Dept Mech & Aerosp Engn, San Diego, CA USA. Laser Energet Lab, Rochester, NY USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. RP Remington, BA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM remingion2@llnl.gov RI Bringa, Eduardo/F-8918-2011; Caturla, Maria /D-6241-2012; Zhigilei, Leonid/E-2167-2012; McNaney, James/F-5258-2013; Bazan, Guillermo/B-7625-2014; Meyers, Marc/A-2970-2016 OI Caturla, Maria /0000-0002-4809-6553; Meyers, Marc/0000-0003-1698-5396 NR 56 TC 50 Z9 51 U1 2 U2 18 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2587 EP 2607 DI 10.1007/s11661-004-0205-6 PG 21 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000006 ER PT J AU Germann, TC Tanguy, D Holian, BL Lomdahl, PS Mareschal, M Ravelo, R AF Germann, TC Tanguy, D Holian, BL Lomdahl, PS Mareschal, M Ravelo, R TI Dislocation structure behind a shock front in Fcc perfect crystals: Atomistic simulation results SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID MOLECULAR-DYNAMICS SIMULATIONS; DEFORMATION; STRAIN; METALS; WAVES AB Large-scale molecular dynamics simulations are used to investigate the dislocation structure behind a shock front in perfect fcc crystals. Shock compression in both the (100) and (111) directions induces dislocation loop formation via a sequential emission of partial dislocations, but in the (100) case, this process is arrested after the first partial, resulting in stacking-fault loops. The large mobility of the bounding partial dislocations results in a plastic wave that is always overdriven in the (100) direction; the leading edges of the partials are traveling with the plastic front, as in the models of Smith and Hornbogen. In contrast, both partials are emitted in (111) shock compression, resulting in perfect dislocation loops bounded only by thin stacking fault ribbons due to the split partial dislocations. These loops grow more slowly than the plastic shock velocity, so new loops are periodically nucleated at the plastic front, as suggested by Meyers. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Ecole Mines St Etienne, CNRS, F-42023 St Etienne, France. Free Univ Brussels, B-1050 Brussels, Belgium. ENS, F-69007 Lyon, France. Univ Texas, Dept Phys, El Paso, TX 79968 USA. RP Germann, TC (reprint author), Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM tcg@lanl.gov NR 26 TC 46 Z9 47 U1 2 U2 14 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2609 EP 2615 DI 10.1007/s11661-004-0206-5 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000007 ER PT J AU Maloy, SA Gray, GT Cady, CM Rutherford, RW Hixson, RS AF Maloy, SA Gray, GT Cady, CM Rutherford, RW Hixson, RS TI The influence of explosive-driven "Taylor-Wave" shock prestraining on the structure/property behavior of 304 stainless steel SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID 304 STAINLESS-STEEL; DEFORMATION-INDUCED TRANSFORMATION; MECHANICAL-PROPERTIES; PULSE DURATION; STRAIN-RATE; STRESS AMPLITUDE; GRAIN-SIZE; MICROSTRUCTURE; SUBSTRUCTURE; TEMPERATURE AB The mechanical response of high-explosive (HE)-driven "Taylor-wave" (TW) shock-prestrained 304 stainless steel loaded to 35 to 45 GPa has been investigated in compression and tension at room temperature and compared to results from compressive testing of the annealed microstructure at a strain rate of 10(-3)/S. The microstructure and substructure evolution due to TW shock prestraining has been investigated using optical metallography and transmission electron microscopy. The mechanical behavior of 304 stainless steel following explosive shock prestraining is shown to exhibit a factor of 2 increase in yield stress and a significant reduction in ductility under tension. Microstructural analyses reveal a high density of twins after TW prestraining and very little production/retention of deformation-induced martensite. The current experimental results are shown to agree well with previous literature results on stainless steel samples shock-prestrained utilizing "square-topped" (ST) shock-pulse loading. This finding suggests that the peak shock pressure, which controls the total plastic strain that the sample must accommodate, is the dominant variable in shock-wave-loading defect generation and storage in 304 stainless steel. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM maloy@lanl.gov RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 43 TC 14 Z9 14 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2617 EP 2624 DI 10.1007/s11661-004-0207-4 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000008 ER PT J AU McNaney, JM Edwards, MJ Becker, R Lorenz, KT Remington, BA AF McNaney, JM Edwards, MJ Becker, R Lorenz, KT Remington, BA TI High-pressure, laser-driven deformation of an aluminum alloy SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID ISENTROPIC COMPRESSION EXPERIMENTS; Z-ACCELERATOR; SOLIDS AB Recent development of a laser-based experimental platform allows loading materials to high pressures in the solid state while controlling both strain rate and peak pressure. The drive utilizes momentum transfer from a plasma generated by the introduction of a strong shock in a reservoir of low-Z material. This study looks at the response of a commercial aluminum alloy (6061-T6) subjected to pressures of 18 and 40 GPa at strain rates of 10(7)/s and 5 x 10(7)/S, respectively. It was found that the depth of the crater formed on the sample surface is a good indicator of the general yield behavior of the material and that a relatively simple strength model prevails under the loading conditions considered here. Metallographic examination of recovered samples showed no evidence of shear-band formation or significant melting due to plasma-surface interactions. Crystal plasticity-based calculations were used to assess the effects of material texture. Lack of shear-band formation during the laser-based drive is rationalized by considering the strain gradient as compared to grain size and texture. C1 Lawrence Livermore Natl Lab, Mat Sci & Technol Div, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, AX Div, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, New Technol Engn Div, Livermore, CA 94550 USA. RP McNaney, JM (reprint author), Lawrence Livermore Natl Lab, Mat Sci & Technol Div, Livermore, CA 94550 USA. EM mcnaney1@llnl.gov RI McNaney, James/F-5258-2013; Becker, Richard/I-1196-2013 NR 15 TC 10 Z9 10 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2625 EP 2631 DI 10.1007/s11661-004-0208-3 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000009 ER PT J AU Schneider, MS Kad, BK Gregori, F Kalantar, D Remington, BA Meyers, MA AF Schneider, MS Kad, BK Gregori, F Kalantar, D Remington, BA Meyers, MA TI Laser-induced shock compression of copper: Orientation and pressure decay effects SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID CONSTITUTIVE DESCRIPTION; DYNAMIC DEFORMATION; NICKEL; METALS AB Pure copper monocrystals with [001] and [134] orientations were subjected to ultrashort shock pulses ranging in initial duration from 2.5 to 10 ns, induced by a laser at energies ranging from 10 to 70 MJ/m(2). The deformation structure was significantly dependent on the crystallographic orientation and depth from the laser-impacted surface, as characterized by transmission electron microscopy (TEM). The threshold pressure for twinning in the [001] direction was observed to be in the range of 20 to 40 GPa compared with 40 to 60 GPa for the [ 134] orientation. Dislocation densities were also different for the two orientations, under similar shock conditions. The [134] dislocation density was systematically lower. This is attributed to the activation of fewer slip systems resulting in a lower rate of hardening. The different results found for [001] and [134] copper single crystals are described and effects of pressure decay in [134] specimens are discussed. Differences in the mechanical response between the two orientations are responsible for differences in the shear stress in the specimens at the imposed pressures and associated strains. The [134] orientation is initially subjected to deformation by single slip, (111)[101], which has a Schmid factor of 0.4711 and a well-defined easy glide region followed by a cross-slip regime with secondary slip. The [001] orientation has eight slip systems {111} <110> with identical Schmid factors of 0.4082, which lead to immediate work hardening. At an imposed and prescribed pressure (that establishes the strain), the [134] orientation exhibits a lower shear stress. The orientation dependence of the twinning stress is much lower, as expressed by Schmid factors. This higher stress for [001] predisposes the onset of twinning in this orientation. The results are interpreted in terms of a criterion in which slip and twinning are considered as competing mechanisms. A constitutive description using a modified mechanical threshold stress (MTS) model is applied to the two orientations, incorporating both slip and twinning. The threshold pressure for twinning is calculated, considering the effect of shock heating. The constitutive description provides a rationale for the experimental results: the calculated thresholds are 17 GPa for [001] and 25 GPa for [134]. C1 Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. Univ Paris 13, F-93430 Villetaneuse, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. EM m1schneider@ucsd.edu RI Meyers, Marc/A-2970-2016 OI Meyers, Marc/0000-0003-1698-5396 NR 28 TC 19 Z9 19 U1 0 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2633 EP 2646 DI 10.1007/s11661-004-0209-2 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000010 ER PT J AU Minich, RW Cazamias, JU Kumar, M Schwartz, AJ AF Minich, RW Cazamias, JU Kumar, M Schwartz, AJ TI Effect of microstructural length scales on spall behavior of copper SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID DEFORMATION; FRACTURE; SOLIDS; STEEL AB A systematic study to quantify the effects of specific microstructural features on the spall behavior of 99.999 pct copper has revealed a strong dependence of the failure processes on length scale. Shock loading experiments with Cu flyer plates at velocities ranging from 300 to 2000 m/s (or impact pressures from 5 to 45 GPa) using a 35-mm single/two-stage light gas gun revealed that single crystals exhibit a higher spallation resistance than fine-grained polycrystals and internally oxidized single crystals. However, in contrast to previously reported results, the fine-grained (similar to8-mum) polycrystalline samples exhibit lower damage resistance than the coarse-grained (50- and 133-mum) samples. These observations have been analyzed in the context of the length scale inherent in each of these microstructures, and modeled using an analytical model developed recently. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM mukul@llnl.gov NR 20 TC 76 Z9 78 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2663 EP 2673 DI 10.1007/s11661-004-0212-7 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000013 ER PT J AU Kadau, K Germann, TC Lomdahl, PS Holian, BL Kadau, D Entel, P Kreth, M Westerhoff, F Wolf, DE AF Kadau, K Germann, TC Lomdahl, PS Holian, BL Kadau, D Entel, P Kreth, M Westerhoff, F Wolf, DE TI Molecular-dynamics study of mechanical deformation in nano-crystal line aluminum SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID NANOCRYSTALLINE METALS; SIMULATIONS; BEHAVIOR AB We report on molecular-dynamics (MD) simulations of tensile loading of nano-crystalline Al modeled by an embedded-atom method (EAM) potential. Usage of two different sample preparation methods of the nano-crystalline material allows us to compare mechanical properties for different sample qualities. A Voronoi-constructed polycrystal exhibits nearly no pores and has different mechanical properties compared to a material that is sintered under pressure and temperature from spherical nanoparticles, resulting in a lower-density sample. We found an inverse Hall-Petch relation for the flow stress for grain sizes smaller than 10 nm. Intergranular fracture was observed for the larger Al grain sizes, but not for nano-crystalline Cu. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Gerhard Mercator Univ, D-47048 Duisburg, Germany. RP Kadau, K (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM kkadau@lanl.gov RI Kadau, Dirk/B-4697-2010 NR 28 TC 36 Z9 38 U1 4 U2 23 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2719 EP 2723 DI 10.1007/s11661-004-0217-2 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000018 ER PT J AU Lassila, DH Shen, T Cao, BY Meyers, MA AF Lassila, DH Shen, T Cao, BY Meyers, MA TI Effect of low-temperature shock compression on the microstructure and strength of copper SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID CONSTITUTIVE RELATIONS; HIGH-STRAIN; BEHAVIOR; NICKEL; DEFORMATION AB Copper with two purities (99.8 and 99.995 pct) was subjected to shock compression from an initial temperature of 90 K. Shock compression was carried out by explosively accelerating flyer plates at velocities generating pressures between 27 and 77 GPa. The residual microstructure evolved from loose dislocation cells to mechanical twins and, at the 57 and 77 GPa pressures, to complete recrystallization, with a grain size larger than the initial one. The shock-compressed copper was mechanically tested in compression at a strain rate of 10(-3) s(-1) and temperature of 300 K; the conditions subjected to lower pressures (27 and 30 GPa) exhibited work softening, in contrast to the conventional work-hardening response. This work softening is due to the uniformly distributed dislocations and the formation of loose cells, evolving, upon plastic deformation at low strain rates, into well-defined cells, with a size of approximately 1 mum. The 99.995 pct copper subjected to the higher shock-compression pressures (57 and 77 GPa) exhibited a stress-strain response almost identical to the unshocked condition. This indicates that the residual temperature rise was sufficient to completely recrystallize the structure and eliminate the hardening due to shock compression. Thermodynamic calculations using the Hugoniot-Rankine conservation equations predict residual temperatures of 570 and 1000 K for the 57 and 77 GPa peak pressures, respectively. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Lassila, DH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM bucao@ucsd.edu RI Cao, Buyang/A-6136-2010; Meyers, Marc/A-2970-2016 OI Meyers, Marc/0000-0003-1698-5396 NR 20 TC 14 Z9 15 U1 1 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2729 EP 2739 DI 10.1007/s11661-004-0219-0 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000020 ER PT J AU Hammerberg, JE Holian, BL Germann, TC Ravelo, R AF Hammerberg, JE Holian, BL Germann, TC Ravelo, R TI Nonequilibrium molecular dynamics simulations of metallic friction at Ta/Al and Cu/Ag interfaces SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID CONSTITUTIVE MODEL; SHOCK-WAVES; DEFORMATION; PLASTICITY; CRYSTALS; SOLIDS; WEAR AB With the advent of large-scale parallel computers in the past decade, it has become possible to study the microphysics of complex nonlinear many-body systems at scales approaching the mesoscale. One of the areas where nonequilibrium deformation arises is that of dry sliding friction between ductile metals. We discuss the results of atomistic simulation studies of sliding friction in the velocity range 10 to 10(3) m/s in the high-pressure regime of 5 to 15 GPa for Ta/Al and Cu/Ag tribopairs. We discuss the velocity dependence and the near interface deformation seen in these simulations. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. RP Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. EM jeh@lanl.gov NR 44 TC 20 Z9 20 U1 1 U2 15 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2741 EP 2745 DI 10.1007/s11661-004-0220-7 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000021 ER PT J AU Teague, J Cerreta, E Stout, M AF Teague, J Cerreta, E Stout, M TI Tensile properties and microstructure of Haynes 25 alloy after aging at elevated temperatures for extended times SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM AB The tensile properties of Haynes 25 alloy have been measured after various aging treatments, time, and temperature: as received; and aged at 600 degreesC for three months; 800 degreesC for 6 and 12 months; and 1000 degreesC for 3 and 6 months. Contour plots in temperature-In (time) space were constructed based on the literature and our own data, detailing changes in yield strength, ultimate tensile strength, and tensile elongation. Scanning electron microscopy and transmission electron microscopy observations of the Haynes 25 alloy microstructure provided an explanation of why the properties changed with aging. Intense lattice distortions after aging at 600 degreesC, the presence of an alpha-Co3W, a L1(2)-ordered, fcc phase, a = 0.357 nm, after aging at 800 degreesC, and the nucleation and growth of W3Co3C carbides from aging at 800 T and 1000 T produced the changes in tensile properties. We did not observe either the Co2W Laves phase or CO7W6 gamma phase in any of the material conditions we examined, using TEM of thin foils: as received and aged at 600 degreesC, 800 degreesC, and 1000 degreesC. Other researchers believe these phases cause a loss of ductility in the Haynes 25 alloy with prolonged high-temperature exposure. C1 Los Alamos Natl Lab, Grp MST 8, Los Alamos, NM 87545 USA. RP Teague, J (reprint author), Los Alamos Natl Lab, Grp MST 8, Los Alamos, NM 87545 USA. EM mstout@lanl.gov NR 5 TC 13 Z9 14 U1 2 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2767 EP 2781 DI 10.1007/s11661-004-0223-4 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000024 ER PT J AU Leonard, JP Renk, TJ Thompson, MO Aziz, MJ AF Leonard, JP Renk, TJ Thompson, MO Aziz, MJ TI Solute diffusion in liquid nickel measured by pulsed ion beam melting SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT TMS/ASM Annual Meeting CY 2003 CL San Diego, CA SP TMS, ASM ID GROWTH; METALS AB Measurements of liquid-phase diffusion coefficients for dilute tungsten and molybdenum in molten nickel were made using a pulsed ion-beam melting technique. A high-intensity beam of nitrogen ions is focused on the surface of a nickel substrate that was implanted with known concentration profiles of W and Mo. Melting of the surface to a depth of similar to1 mum allows broadening of the implant profiles while molten. Solute concentration-depth profiles were determined before and after melting using Rutherford backscattering spectrometry. Using a series of numerical simulations to estimate the melt history and diffusional broadening for mean liquid temperatures in the range 1755 to 2022 K, an effective diffusion coefficient is determined in each case by comparison to the measured depth profiles. This is found to be (2.4 +/- 0.2) x 10(-5) cm(2)/s for W and (1.6 +/- 0.4) x 10(-5) cm(2)/s for Mo, with an additional systematic uncertainty of +/-0.5 x 10(-5) due to instrumental and surface effects. C1 Univ Pittsburgh, Pittsburgh, PA 15621 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Univ Pittsburgh, Pittsburgh, PA 15621 USA. EM jleonard@engr.pitt.edu OI Thompson, Michael/0000-0002-4933-009X NR 17 TC 16 Z9 16 U1 1 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD SEP PY 2004 VL 35A IS 9 BP 2803 EP 2807 DI 10.1007/s11661-004-0227-0 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 851IE UT WOS:000223678000028 ER PT J AU Graham, GA Grant, PG Chater, RJ Westphal, AJ Kearsley, AT Snead, C Dominguez, G Butterworth, AL McPhail, DS Bench, G Bradley, JP AF Graham, GA Grant, PG Chater, RJ Westphal, AJ Kearsley, AT Snead, C Dominguez, G Butterworth, AL McPhail, DS Bench, G Bradley, JP TI Investigation of ion beam techniques for the analysis and exposure of particles encapsulated by silica aerogel: Applicability for Stardust SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID INTERPLANETARY DUST PARTICLES; ENERGY-LOSS CONTRAST; SOLAR-SYSTEM; MICROSCOPY; EXTRACTION; MICROPROBE; SAMPLES; IMPACT; GRAINS; IDENTIFICATION AB In 2006, the StardLISt spacecraft will return to Earth with cometary and perhaps interstellar dust particles embedded in silica aerogel collectors for analysis in terrestrial laboratories. These particles will be the first sample return from a solid planetary body since the Apollo missions. In preparation for the return, analogue particles were implanted into a keystone of silica aerogel that had been extracted from bulk silica aerogel using the optical technique described in Westphal et al. (2004). These particles were subsequently analyzed using analytical techniques associated with the use of a nuclear microprobe. The particles have been analyzed using: a) scanning transmission ion microscopy (STIM) that enables quantitative density imaging; b) proton elastic scattering analysis (PESA) and proton backscattering (PBS) for the detection of light elements including hydrogen; and c) proton-induced X-ray emission (PIXE) for elements with Z > 11. These analytical techniques have enabled LIS to quantify the composition of the encapsulated particles. A significant observation from the study is the variable column density of the silica aerogel. We also observed organic contamination within the silica aerogel. The implanted particles were then subjected to focused ion beam (FIB) milling using a 30 keV gallium ion beam to ablate silica aerogel in site-specific areas to expose embedded particles. An ion polished flat surface of one of the particles was also prepared using the FIB. Here, we show that ion beam techniques have great potential in assisting with the analysis and exposure of Stardust particles. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. RP Graham, GA (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. EM graham42@llnl.gov NR 53 TC 18 Z9 18 U1 2 U2 9 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2004 VL 39 IS 9 BP 1461 EP 1473 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 856MR UT WOS:000224049800003 ER PT J AU Vaughan, DE Jacobson, SH AF Vaughan, DE Jacobson, SH TI Tabu guided generalized hill climbing algorithms SO METHODOLOGY AND COMPUTING IN APPLIED PROBABILITY LA English DT Article DE tabu search; local search; generalized hill climbing algorithms; Markov chains ID OPTIMIZATION; CONVERGENCE AB This paper formulates tabu search strategies that guide generalized hill climbing (GHC) algorithms for addressing NP-hard discrete optimization problems. The resulting framework, termed tabu guided generalized hill climbing (TG(2)HC) algorithms, uses a tabu release parameter that probabilistically accepts solutions currently on the tabu list. TG(2)HC algorithms are modeled as a set of stationary Markov chains, where the tabu list is fixed for each outer loop iteration. This framework provides practitioners with guidelines for developing tabu search strategies to use in conjunction with GHC algorithms that preserve some of the algorithms' known performance properties. In particular, sufficient conditions are obtained that indicate how to design iterations of problem-specific tabu search strategies, where the stationary distributions associated with each of these iterations converge to the distribution with zero weight on all non-optimal solutions. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Dept Mech & Ind Engn, Simulat & Optimizat Lab, Urbana, IL 61801 USA. RP Vaughan, DE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM dev@lanl.gov; shj@uiuc.edu OI Jacobson, Sheldon/0000-0002-9042-8750 NR 18 TC 2 Z9 2 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1387-5841 J9 METHODOL COMPUT APPL JI Methodol. Comput. Appl. Probab. PD SEP PY 2004 VL 6 IS 3 BP 343 EP 354 DI 10.1023/B:MCAP.0000026564.87435.66 PG 12 WC Statistics & Probability SC Mathematics GA 817WI UT WOS:000221207200006 ER PT J AU Li, SY Van Houtte, P Kalidindi, SR AF Li, SY Van Houtte, P Kalidindi, SR TI A quantitative evaluation of the deformation texture predictions for aluminium alloys from crystal plasticity finite element method SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID CRYSTALLOGRAPHIC TEXTURE; FCC METALS; POLYCRYSTAL PLASTICITY; EVOLUTION; SIMULATION; STRAIN; BRASS AB Crystal plasticity finite element (CPFE) models are useful tools in modelling the anisotropic stress-strain responses in large deformation of polycrystalline metals. In this study, a CPFE model is applied to simulate the evolution of crystallographic textures during cold rolling of hot-rolled aluminium plates and during uniaxial tensile, uniaxial compression and simple shear tests of annealed aluminium sheets. The performance of the model is critically evaluated through quantitative comparisons of the simulated textures with those predicted by the full constraints (FC) Taylor model and the experimentally measured textures. It is shown that the CPFE model performs better than the FC Taylor model in all the cases. However, the quality of the texture predictions deteriorates with increasing strain values. The CPFE model gives better texture predictions in the moderately deformed tensile and compression samples (similar to20% strain), compared to the more heavily deformed simple shear (0.85-0.95 shear strain) and cold-rolled (40-98% thickness reduction) samples. It is also shown that the CPFE predictions for cold rolling can be improved with finer discretization, i.e. by assigning multiple elements per grain instead of one element per grain in the finite element model. The improvement is mainly reflected in an improved prediction of the copper component and, in some cases, an improved prediction of the brass component. Inspection of the local deformation gradients reveals that these texture changes can be attributed to the increase of shear relaxations in the RD-ND and RD-TD planes. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Katholieke Univ Leuven, Dept Met & Mat Engn, B-3001 Louvain, Belgium. Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. RP Li, SY (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM Saiyi@lanl.gov RI Kalidindi, Surya/A-1024-2007; Li, Saiyi/J-3968-2012; OI Kalidindi, Surya/0000-0001-6909-7507 NR 27 TC 23 Z9 23 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD SEP PY 2004 VL 12 IS 5 BP 845 EP 870 AR PII S0965-0393(04)76559-6 DI 10.1088/0965-0393/12/5/006 PG 26 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 856LQ UT WOS:000224047100006 ER PT J AU Huamani, J McMahan, CA Herbert, DC Reddick, R McCarrey, JR MacInnes, MI Chen, DJ Walter, CA AF Huamani, J McMahan, CA Herbert, DC Reddick, R McCarrey, JR MacInnes, MI Chen, DJ Walter, CA TI Spontaneous mutagenesis is enhanced in Apex heterozygous mice SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID BASE EXCISION-REPAIR; DNA-POLYMERASE-BETA; GERM-CELL APOPTOSIS; APURINIC APYRIMIDINIC SITES; SPONTANEOUS MUTATION; TRANSGENIC MICE; MEIOTIC RECOMBINATION; SPERMATOGENIC CELLS; SECTORED PLAQUES; BINDING ACTIVITY AB Germ line DNA directs the development of the next generation and, as such, is profoundly different from somatic cell DNA. Spermatogenic cells obtained from young adult lacI transgenic mice display a lower spontaneous mutant frequency and greater in vitro base excision repair activity than somatic cells and tissues obtained from the same mice. However, spermatogenic cells from old lacI mice display a 10-fold higher mutant frequency. This increased spontaneous mutant frequency occurs coincidentally with decreased in vitro base excision repair activity for germ cell and testicular extracts that in turn corresponds to a decreased abundance of AP endonuclease. To directly test whether a genetic diminution of AP endonuclease results in increased spontaneous mutant frequencies in spermatogenic cell types, AP endonuclease heterozygous (Apex(+/-)) knockout mice were crossed with lacI transgenic mice. Spontaneous mutant frequencies were significantly elevated (approximately twofold) for liver and spleen obtained from 3-month-old Apex(+/-) lacI(+) mice compared to frequencies from Apex(+/+) lacI(+) littermates and were additionally elevated for somatic tissues from 9-month-old mice. Spermatogenic cells from 9-month-old Apex(+/+) lacI(+) mice were significantly elevated twofold compared to levels for 9-month-old Apex(+/+) lacI(+) control mice. These data indicate that diminution of AP endonuclease has a significant effect on spontaneous mutagenesis in somatic and germ line cells. C1 Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, San Antonio, TX 78229 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78229 USA. Univ Texas, Dept Biol, San Antonio, TX 78229 USA. S Texas Vet Hlth Care Syst, Div Res, San Antonio, TX USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Walter, CA (reprint author), Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, Mail Code 7762,7703 Floyd Curl Dr, San Antonio, TX 78229 USA. EM walter@uthscsa.edu FU NCI NIH HHS [R01 CA086936, CA86936]; NIA NIH HHS [P01 AG019316, AG19316, R01 AG021163, AG21163]; NIEHS NIH HHS [ES09136, R01 ES009136] NR 67 TC 40 Z9 43 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD SEP PY 2004 VL 24 IS 18 BP 8145 EP 8153 DI 10.1128/MCB.24.18.8145-8153 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 852MY UT WOS:000223760600030 PM 15340075 ER PT J AU Koopman, ME Schable, NA Glenn, TC AF Koopman, ME Schable, NA Glenn, TC TI Development and optimization of microsatellite DNA primers for boreal owls (Aegolius funereus) SO MOLECULAR ECOLOGY NOTES LA English DT Article DE Aegolius; boreal owl; cross-specific amplification; microsatellites; null alleles; Tengmalm's owl; Strigidae AB We developed 22 microsatellite loci for boreal owls (Aegolius funereus). We genotyped 275 unrelated boreal owls (Aegolius f. richardsoni) and 36 unrelated Tengmalm's owls (Aegolius f. funereus) using seven loci that were polymorphic and did not have detectable null alleles. Among North American and Scandinavian boreal owls, respectively, allelic diversity ranged from three to 11 alleles and from one to 11 alleles, observed heterozygosity ranged from 0.31 to 0.80 and from 0.00 to 0.81, and expected heterozygosity ranged from 0.28 to 0.81 and from 0.00 to 0.81. These markers appeared to amplify DNA in six other Strigidae species. C1 Univ Wyoming, Dept Zool & Physiol, Laramie, WY 82071 USA. Savannah River Ecol Lab, Aiken, GA USA. Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. RP Koopman, ME (reprint author), Univ Wyoming, Dept Zool & Physiol, Laramie, WY 82071 USA. EM marni.e.koopman@aphis.usda.gov RI Glenn, Travis/A-2390-2008 NR 4 TC 6 Z9 6 U1 1 U2 3 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1471-8278 J9 MOL ECOL NOTES JI Mol. Ecol. Notes PD SEP PY 2004 VL 4 IS 3 BP 376 EP 378 DI 10.1111/j.1471-8286.2004.00658.x PG 3 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 850YC UT WOS:000223649300019 ER PT J AU Schable, NA Faircloth, BC Palmer, WE Carroll, JP Burger, LW Brennan, LA Hagen, C Glenn, TC AF Schable, NA Faircloth, BC Palmer, WE Carroll, JP Burger, LW Brennan, LA Hagen, C Glenn, TC TI Tetranucleotide and dinucleotide microsatellite loci from the northern bobwhite (Colinus virginianus) SO MOLECULAR ECOLOGY NOTES LA English DT Article DE Colinus virginianus; galliformes; microsatellites; PCR; primer; quail; SSR AB We describe polymerase chain reaction (PCR) primers and conditions to amplify eight dinucleotide, one trinucleotide and 14 tetranucleotide microsatellite DNA loci isolated from the northern bobwhite (Colinus virginianus). The PCR primers were tested on 16 individuals collected from a population located within the Red Hills region of south Georgia and north Florida. The 23 primer pairs developed in this study yielded an average of 6.5 alleles per locus (range 2-11), an average observed heterozygosity of 0.47 (range 0.06-0.94) and average polymorphic information content of 0.60 (range 0.06-0.85). C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, DB Warnell Sch Forest Resources, Athens, GA 30602 USA. Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. Tall Timbers Res Stn, Tallahassee, FL 32312 USA. Mississippi State Univ, Dept Wildlife & Fisheries, Mississippi State, MS 39762 USA. Texas A&M Univ, Richard M Kleberg Jr Ctr Quail Res, Kingsville, TX 78363 USA. RP Schable, NA (reprint author), Univ Georgia, Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. EM schable@srel.edu RI Glenn, Travis/A-2390-2008; Burger, Loren/E-9228-2011; OI Faircloth, Brant/0000-0002-1943-0217 NR 11 TC 4 Z9 4 U1 0 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1471-8278 J9 MOL ECOL NOTES JI Mol. Ecol. Notes PD SEP PY 2004 VL 4 IS 3 BP 415 EP 419 DI 10.1111/j.1471-8286.2004.00670.x PG 5 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 850YC UT WOS:000223649300031 ER PT J AU Fritz, AH Schable, N AF Fritz, AH Schable, N TI Microsatellite loci from the Caribbean fruit fly, Anastrepha suspensa (Diptera : Tephritidae) SO MOLECULAR ECOLOGY NOTES LA English DT Article DE Anastrepha suspensa; microsatellite; PCR; primer; SSR AB The lack of polymorphic genetic markers suitable for genotyping sperm, eggs, and all life stages of the important agricultural pest, Anastrepha suspensa, have prevented detailed genetic studies of its breeding system, reproductive dynamics, and population dynamics. We describe polymerase chain reaction (PCR) primers and reaction conditions for amplifying nine polymorphic microsatellite DNA loci isolated from this species. The PCR primers were tested on four to five individuals each collected from five geographically distant locations in Florida. Heterozygosity values and the number of alleles per locus varied from 0.11 to 0.89, and from two to 12, respectively. C1 Eastern Illinois Univ, Dept Biol Sci, Charleston, IL 61920 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Fritz, AH (reprint author), Eastern Illinois Univ, Dept Biol Sci, Charleston, IL 61920 USA. EM cfahf@eiu.edu NR 7 TC 7 Z9 8 U1 1 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1471-8278 J9 MOL ECOL NOTES JI Mol. Ecol. Notes PD SEP PY 2004 VL 4 IS 3 BP 443 EP 445 DI 10.1111/j.1471-8286.2004.00699.x PG 3 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 850YC UT WOS:000223649300040 ER PT J AU Weston, JL Schable, NA Glenn, TC AF Weston, JL Schable, NA Glenn, TC TI Characterization of six microsatellite primers for the grey fox (Urocyon cinereoargenteus) SO MOLECULAR ECOLOGY NOTES LA English DT Article DE dinucleotide repeats; grey fox; microsatellite; polymerase chain reaction; primer; simple; sequence repeat; tetranucleotide repeats; Urocyon cinereoargenteus AB We describe polymerase chain reaction (PCR) primers and conditions to amplify one dinucleotide and five tetranucleotide microsatellite DNA loci isolated from the grey fox (Urocyon cinereoargenteus). The PCR primers were tested on nine to 12 individuals collected from the Department of Energy's Savannah River site (Aiken, SC, USA). The grey fox microsatellite primers developed had three to 10 alleles per locus that yielded observed heterozygosities ranging from 0.222 to 0.889. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ S Carolina, Dept Biol Sci, Peromyscus Genet Stock Ctr, Columbia, SC 29208 USA. RP Weston, JL (reprint author), Savannah River Ecol Lab, PO Drawer E, Aiken, SC 29802 USA. EM weston@biol.sc.edu RI Glenn, Travis/A-2390-2008 NR 7 TC 2 Z9 2 U1 0 U2 2 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1471-8278 J9 MOL ECOL NOTES JI Mol. Ecol. Notes PD SEP PY 2004 VL 4 IS 3 BP 503 EP 505 DI 10.1111/j.1471-8286.2004.00727-x PG 3 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 850YC UT WOS:000223649300059 ER PT J AU Ozawa, T Santos, RA Lamborn, KR Bauer, WF Koo, MS Kahl, SB Deen, DF AF Ozawa, Tomoko Santos, Raquel A. Lamborn, Kathleen R. Bauer, William F. Koo, Myoung-Seo Kahl, Stephen B. Deen, Dennis F. TI In vivo evaluation of the boronated porphyrin TABP-1 in U-87 MG intracerebral human glioblastoma xenografts SO MOLECULAR PHARMACEUTICS LA English DT Article DE boron neutron capture therapy; boronated porphyrin; U-87 MG human brain tumor xenografts; glioblastoma; convection-enhanced delivery AB Boron neutron capture therapy (BNCT) is an adjuvant therapy that has the potential to control local tumor growth. A selective delivery of sufficient amounts of boron to individual tumor cells, compared to surrounding normal tissues, is the key for successful BNCT. We have designed and synthesized a new highly water-soluble boronated porphyrin, TABP-1, as a possible BNCT agent. When we injected the maximum tolerated dose (MTD: 15 mg/kg) of TABP-1 systemically into the tail vein of athymic rats bearing intracerebral (ic) human glioblastoma U-87 MG xenografts, the compound accumulated preferentially in brain tumors compared to normal brain; however, the level of boron in the tumors was less than the 30 mu g/g of tissue that is generally considered necessary for BNCT. We next investigated whether convection -enhanced delivery (CED) could improve the boron distribution. The compound was administered directly into ic tumors using an osmotic minipump attached to a brain-infusion cannula. TABP-1 doses from 0.25 to 1.0 mg infused locally over 24 h produced tumor boron concentrations greater than those obtained by systemic administration at the MTD. For example, CED administration of 0.5 mg of TABP-1 produced a tumor boron level of 65.4 mu g/g of tumor, whereas the serum level was only 0.41 mu g/g (tumor to serum ratio of approximately 160:1). CED also produced relatively high tumor to normal brain ratios of approximately 5:1 for ipsilateral brain and approximately 26:1 for contralateral brain tissues at the 0.5 mg dose. Thus, we may be able to achieve therapeutic BNCT efficacy with minimal systemic toxicity or radiation-induced damage to normal tissue by administering TABP-1 using CED. C1 [Ozawa, Tomoko; Santos, Raquel A.; Lamborn, Kathleen R.; Deen, Dennis F.] Univ Calif San Francisco, Dept Neurol Surg, Brain Tumor Res Ctr, San Francisco, CA 94143 USA. [Deen, Dennis F.] Univ Calif San Francisco, Dept Radiat Oncol, San Francisco, CA 94143 USA. [Koo, Myoung-Seo; Kahl, Stephen B.] Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. [Bauer, William F.] Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Deen, DF (reprint author), Univ Calif San Francisco, Dept Neurol Surg, Brain Tumor Res Ctr, San Francisco, CA 94143 USA. EM ddeen@itsa.ucsf.edu RI Bauer, William/B-8357-2016 OI Bauer, William/0000-0002-7190-9700 FU NIH [CA-82478]; DOE [DE-AC03-76SF00098] FX This work was supported by NIH Grant CA-82478 and DOE Grant DE-AC03-76SF00098. The authors thank William McDonald, John Andrew McKay, and Sandeep Kunwar for helpful discussions, and we thank Sharon Reynolds for editorial assistance. NR 28 TC 15 Z9 16 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1543-8384 J9 MOL PHARMACEUT JI Mol. Pharm. PD SEP-OCT PY 2004 VL 1 IS 5 BP 368 EP 374 DI 10.1021/mp049933i PG 7 WC Medicine, Research & Experimental; Pharmacology & Pharmacy SC Research & Experimental Medicine; Pharmacology & Pharmacy GA V52IY UT WOS:000203538400006 PM 16026007 ER PT J AU Letant, SE van Buuren, TW Terminello, LJ AF Letant, SE van Buuren, TW Terminello, LJ TI Nanochannel arrays on silicon platforms by electrochemistry SO NANO LETTERS LA English DT Article ID NANOPOROUS MEMBRANES; MESOPOROUS SILICON; POROUS ALUMINA; DELIVERY; PORES AB Nanochannel arrays with diameters as small as 30 nm and aspect ratios up to 250 were prepared on silicon platforms for the first time by electrochemistry, which is a fast, reproducible, and inexpensive technique. Ionic diffusion through the arrays was investigated in order to demonstrate the open nature of the channels and the absence of defects in the devices. Possible applications for separation, drug release, and bio-encapsulation were also illustrated by following glucose and protein diffusion across the membranes. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Letant, SE (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. EM letant1@llnl.gov NR 16 TC 43 Z9 47 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 J9 NANO LETT JI Nano Lett. PD SEP PY 2004 VL 4 IS 9 BP 1705 EP 1707 DI 10.1021/nl049111c PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 853OP UT WOS:000223837200025 ER PT J AU Austin, CP Battey, JF Bradley, A Bucan, M Capecchi, M Collins, FS Dove, WF Duyk, G Dymecki, S Eppig, JT Grieder, FB Heintz, N Hicks, G Insel, TR Joyner, A Koller, BH Lloyd, KCK Magnuson, T Moore, MW Nagy, A Pollock, JD Roses, AD Sands, AT Seed, B Skarnes, WC Snoddy, J Soriano, P Stewart, DJ Stewart, F Stillman, B Varmus, H Varticovski, L Verma, IM Vogt, TF von Melchner, H Witkowski, J Woychik, RP Wurst, W Yancopoulos, GD Young, SG Zambrowicz, B AF Austin, CP Battey, JF Bradley, A Bucan, M Capecchi, M Collins, FS Dove, WF Duyk, G Dymecki, S Eppig, JT Grieder, FB Heintz, N Hicks, G Insel, TR Joyner, A Koller, BH Lloyd, KCK Magnuson, T Moore, MW Nagy, A Pollock, JD Roses, AD Sands, AT Seed, B Skarnes, WC Snoddy, J Soriano, P Stewart, DJ Stewart, F Stillman, B Varmus, H Varticovski, L Verma, IM Vogt, TF von Melchner, H Witkowski, J Woychik, RP Wurst, W Yancopoulos, GD Young, SG Zambrowicz, B CA Comprehensive Knockout Mouse Proje TI The knockout mouse project SO NATURE GENETICS LA English DT Article ID EMBRYONIC STEM-CELLS; GENE-TRAP MUTAGENESIS; GENOME; MICE; SEQUENCE; IDENTIFICATION; DEFICIENCY; PHENOTYPE; INSIGHTS; RESOURCE AB Mouse knockout technology provides a powerful means of elucidating gene function in vivo, and a publicly available genome-wide collection of mouse knockouts would be significantly enabling for biomedical discovery. To date, published knockouts exist for only about 10% of mouse genes. Furthermore, many of these are limited in utility because they have not been made or phenotyped in standardized ways, and many are not freely available to researchers. It is time to harness new technologies and efficiencies of production to mount a high-throughput international effort to produce and phenotype knockouts for all mouse genes, and place these resources into the public domain. C1 NHGRI, NIH, Bethesda, MD 20892 USA. Natl Inst Deafness & Other Commun Disorders, NIH, Bethesda, MD 20892 USA. Wellcome Trust Sanger Inst, Cambridge CB10 1SA, England. Univ Penn, Dept Genet, Philadelphia, PA 19104 USA. Univ Utah, Eccles Inst Human Genet, Salt Lake City, UT 85112 USA. Univ Wisconsin, McArdle Lab Canc Res, Madison, WI 53706 USA. TPG Ventures, San Francisco, CA 94104 USA. Harvard Univ, Sch Med, Dept Genet, Boston, MA 02115 USA. Jackson Lab, Bar Harbor, ME 04609 USA. NIH, Natl Ctr Res Resources, Bethesda, MD 20817 USA. Rockefeller Univ, Mol Biol Lab, New York, NY 10021 USA. Manitoba Inst Cell Biol, Winnipeg, MB R3E 0V9, Canada. NIMH, Bethesda, MD 20892 USA. Skirball Inst Biomol Med, New York, NY 10016 USA. Univ N Carolina, Dept Genet, Chapel Hill, NC 27599 USA. Univ Calif Davis, Sch Vet Med, Davis, CA 95616 USA. Deltagen, Redwood City, CA 94063 USA. Univ Toronto, Samuel Lumenfeld Res Inst, Toronto, ON M5G 1X5, Canada. Natl Inst Drug Abuse, Bethesda, MD 20892 USA. GlaxoSmithKline Inc, Res Triangle Pk, NC 27709 USA. Lexicon Genet, The Woodlands, TX 77381 USA. Massachusetts Gen Hosp, Dept Mol Biol, Boston, MA 02114 USA. Oak Ridge Natl Lab, Univ Tennessee ORNL Grad Sch Genome Sci & Technol, Oak Ridge, TN 37831 USA. Fred Hutchinson Canc Res Ctr, Div Basic Sci, Seattle, WA 98109 USA. Cold Spring Harbor Lab, Banbury Ctr, Cold Spring Harbor, NY 11724 USA. Univ Technol, Bioz, MPI CBG, D-1307 Dresden, Germany. Mem Sloan Kettering Canc Ctr, New York, NY 10021 USA. NCI, NIH, Bethesda, MD 20892 USA. Salk Inst Biol Studies, Mol Biol & Virol Lab, La Jolla, CA 92037 USA. Merck Res Labs, West Point, PA 19486 USA. Goethe Univ Frankfurt, Sch Med, Lab Mol Hematol, D-60590 Frankfurt, Germany. Jackson Lab, Bar Harbor, ME 04609 USA. Max Planck Inst Psychiat, GSF Res Ctr, Inst Dev Genet, D-85764 Munich, Germany. Regeneron Pharmaceut Inc, Tarrytown, NY 10591 USA. Univ Calif San Francisco, Gladstone Fdn Cardiovasc Dis, San Francisco, CA 94143 USA. RP Austin, CP (reprint author), NHGRI, NIH, Bldg 31,Room 4B09,31 Ctr Dr, Bethesda, MD 20892 USA. EM austinc@mail.nih.gov RI Pollock, Jonathan/B-1554-2009; Stewart, A. Francis/E-7789-2010; Nagy, Andras/G-6465-2013; Soriano, Philippe/E-5797-2015; OI Soriano, Philippe/0000-0002-0427-926X; Witkowski, Jan/0000-0002-8159-2874; Stillman, Bruce/0000-0002-9453-4091 FU Wellcome Trust [077188] NR 25 TC 359 Z9 385 U1 4 U2 30 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 1061-4036 J9 NAT GENET JI Nature Genet. PD SEP PY 2004 VL 36 IS 9 BP 921 EP 924 DI 10.1038/ng0904-921 PG 4 WC Genetics & Heredity SC Genetics & Heredity GA 851AY UT WOS:000223658100005 PM 15340423 ER PT J AU Chin, K de Solorzano, CO Knowles, D Jones, A Chou, W Rodriguez, EG Kuo, WL Ljung, BM Chew, K Myambo, K Miranda, M Krig, S Garbe, J Stampfer, M Yaswen, P Gray, JW Lockett, SJ AF Chin, K de Solorzano, CO Knowles, D Jones, A Chou, W Rodriguez, EG Kuo, WL Ljung, BM Chew, K Myambo, K Miranda, M Krig, S Garbe, J Stampfer, M Yaswen, P Gray, JW Lockett, SJ TI In situ analyses of genome instability in breast cancer SO NATURE GENETICS LA English DT Article ID MAMMARY EPITHELIAL-CELLS; TELOMERE DYSFUNCTION; HYBRIDIZATION; CARCINOMA; AMPLIFICATION; EXPRESSION; EVOLUTION; OCCURS; MICE AB Transition through telomere crisis is thought to be a crucial event in the development of most breast carcinomas. Our goal in this study was to determine where this occurs in the context of histologically defined breast cancer progression. To this end, we assessed genome instability (using fluorescence in situ hybridization) and other features associated with telomere crisis in normal ductal epithelium, usual ductal hyperplasia, ductal carcinoma in situ and invasive cancer. We modeled this process in vitro by measuring these same features in human mammary epithelial cell cultures during ZNF217-mediated transition through telomere crisis and immortalization. Taken together, the data suggest that transition through telomere crisis and immortalization in breast cancer occurs during progression from usual ductal hyperplasia to ductal carcinoma in situ. C1 Univ Calif San Francisco, Dept Lab Med, San Francisco, CA 94143 USA. Univ Calif San Francisco, Ctr Comprehens Canc, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Engn, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Pathol, San Francisco, CA 94143 USA. RP Gray, JW (reprint author), Univ Calif San Francisco, Dept Lab Med, San Francisco, CA 94143 USA. EM jwgray@lbl.gov RI Ortiz de Solorzano, Carlos/G-3278-2010 OI Ortiz de Solorzano, Carlos/0000-0001-8720-0205 FU NCI NIH HHS [R01 CA101359, R01 CA090421] NR 30 TC 232 Z9 242 U1 0 U2 4 PU NATURE PUBLISHING GROUP PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1061-4036 J9 NAT GENET JI Nature Genet. PD SEP PY 2004 VL 36 IS 9 BP 984 EP 988 DI 10.1038/ng1409 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA 851AY UT WOS:000223658100025 PM 15300252 ER PT J AU Brazhkin, V Dubrovinskaia, N Nicol, A Novikov, N Riedel, R Solozhenko, R Zhao, Y AF Brazhkin, V Dubrovinskaia, N Nicol, A Novikov, N Riedel, R Solozhenko, R Zhao, Y TI What-does 'harder than diamond' mean? SO NATURE MATERIALS LA English DT Letter C1 Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. Univ Bayreuth, Bayer Geoinst, D-95440 Bayreuth, Germany. Univ Nevada, High Pressure Sci & Engn Ctr, Las Vegas, NV 89154 USA. Inst Superhard Mat, UA-04074 Kiev, Ukraine. Tech Univ Darmstadt, D-64287 Darmstadt, Germany. Univ Paris 13, CNRS, LPMTM, F-93430 Villetaneuse, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Brazhkin, V (reprint author), Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. EM nicol@physics.unlv.edu RI Solozhenko, Vladimir/E-1975-2011; Lujan Center, LANL/G-4896-2012 NR 3 TC 93 Z9 97 U1 2 U2 37 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD SEP PY 2004 VL 3 IS 9 BP 576 EP 577 DI 10.1038/nmat1196 PG 2 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 850TS UT WOS:000223636200002 PM 15343282 ER PT J AU Koltover, I AF Koltover, I TI Biomolecular self-assembly - Stacks of viruses SO NATURE MATERIALS LA English DT News Item ID SURFACTANT COMPLEXES; DNA; POLYELECTROLYTES AB Self-assembly of soft materials has achieved structured periodicity of tens of nanometres. Layered superlattices prepared from viruses and lipid membranes could now be used as templates for organising macromolecules. C1 Sandia Natl Labs, Dept Biomol Mat & Interfaces, Albuquerque, NM 87123 USA. RP Koltover, I (reprint author), Sandia Natl Labs, Dept Biomol Mat & Interfaces, Albuquerque, NM 87123 USA. EM ikoltov@sandia.gov NR 10 TC 4 Z9 5 U1 2 U2 7 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD SEP PY 2004 VL 3 IS 9 BP 584 EP 586 DI 10.1038/nmat1200 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 850TS UT WOS:000223636200005 PM 15343286 ER PT J AU Duscher, G Chisholm, MF Alber, U Ruhle, M AF Duscher, G Chisholm, MF Alber, U Ruhle, M TI Bismuth-induced embrittlement of copper grain boundaries SO NATURE MATERIALS LA English DT Article ID SEGREGATION; CU; BI; ALLOYS; EDGE; BICRYSTALS; COHESION AB Catastrophic brittle fracture of crystalline materials is one of the best documented but most poorly understood fundamental phenomena in materials science. Embrittlement of copper by bismuth is a classic example of this phenomenon. Because brittle fracture in any structural material can involve human tragedy, a better understanding of the mechanisms behind it is of the highest interest. In this study, we use a combination of two state-of-the-art atomic characterization techniques and ab initio theoretical materials simulations to investigate the geometric and electronic structure of a copper grain boundary with and without bismuth. Only with this unique combination of methods are we able to observe the actual distribution of bismuth in the boundary and detect changes in the electronic structure caused by the bismuth impurity. We find that the copper atoms that surround the segregated bismuth in the grain boundary become embrittled by taking on a more zinc-like electronic structure. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27692 USA. Max Planck Inst Met Res, D-70569 Stuttgart, Germany. RP Chisholm, MF (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. EM chisholmmf@ornl.gov RI Duscher, Gerd/G-1730-2014 OI Duscher, Gerd/0000-0002-2039-548X NR 30 TC 128 Z9 128 U1 11 U2 69 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 J9 NAT MATER JI Nat. Mater. PD SEP PY 2004 VL 3 IS 9 BP 621 EP 626 DI 10.1038/nmat1191 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 850TS UT WOS:000223636200015 PM 15322533 ER PT J AU Eberling, JL Pivirotto, P Bringas, J Bankiewicz, KS AF Eberling, JL Pivirotto, P Bringas, J Bankiewicz, KS TI Comparison of two methods for the analysis of [F-18]6-fluoro-L-m-tyrosine PET data SO NEUROIMAGE LA English DT Article DE Parkinson disease; PET; FMT; input function ID POSITRON-EMISSION-TOMOGRAPHY; PARKINSONS-DISEASE; PRIMATE MODEL; HUMAN BRAIN; METABOLISM; KINETICS; MONKEYS AB PET and [F-18]fluoro-L-m-tyrosine (FMT) have been used to quantify presynaptic striatal dopamine (DA) function in Parkinson disease (PD) and in primate models of PD. While dynamic imaging and a metabolite-corrected blood input function can be used to determine striatal FMT uptake rate constants (K-i), a simpler analytic approach using shorter imaging times is desirable for clinical studies. We compared the utility of using striatal K-i values versus striatal count ratios in two groups of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. Striatal DA content was also measured in one of the groups to evaluate the relationship between the PET measures and an independent measure of striatal dopamine. Striatal K-i values were significantly correlated with striatal count ratios using the cerebellum as the denominator. Both K-i values and ratios were also correlated with striatal DA content. In addition, putamen-cerebellum ratios and putamen K-i values showed similar separation between baseline and post-MPTP values. These findings suggest that a simple ratio approach to analyzing FMT PET data may be a useful alternative to a kinetic approach especially for clinical applications. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Neurol, Davis, CA 95616 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. RP Eberling, JL (reprint author), 1 Cyclotron Rd,Mail Stop 55-121, Berkeley, CA 94720 USA. EM jleberling@lbl.gov NR 14 TC 5 Z9 5 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1053-8119 J9 NEUROIMAGE JI Neuroimage PD SEP PY 2004 VL 23 IS 1 BP 358 EP 363 DI 10.1016/j.neuroimage.2004.06.005 PG 6 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 850WL UT WOS:000223645000038 PM 15325383 ER EF