FN Thomson Reuters Web of Science™ VR 1.0 PT J AU McKenna, SA Doherty, J Hart, DB AF McKenna, SA Doherty, J Hart, DB TI Non-uniqueness of inverse transmissivity field calibration and predictive transport modeling SO JOURNAL OF HYDROLOGY LA English DT Article DE groundwater; geostatistics; inverse modeling; advective transport ID GROUNDWATER-FLOW MODEL; STOCHASTIC SIMULATION; PIEZOMETRIC DATA; AQUIFER AB Recent work with stochastic inverse modeling techniques has led to the development of efficient algorithms for the construction of transmissivity (T) fields conditioned to measurements of T and head. Small numbers of calibration targets and correlation between model parameters in these inverse solutions can lead to a relatively large region in parameter space that will produce a near optimal,, calibration of the T field to measured heads. Most applications of these inverse techniques have not considered the effects Of non-unique calibration on subsequent predictions made with the T fields. Use of these T fields in predictive contaminant transport modeling must take into account the non-uniqueness of the T field calibration. A recently developed 'predictive estimation' technique is presented and employed to create T fields that are conditioned to observed heads and measured T values while maximizing the conservatism of the associated predicted advective travel time. Predictive estimation employs confidence and prediction intervals calculated simultaneously on the flow and transport models, respectively. In an example problem, the distribution of advective transport results created with the predictive estimation technique is compared to the distribution of results created under traditional T field optimization where model non-uniqueness is not considered. The predictive estimation technique produces results with significantly shorter travel times relative to traditional techniques while maintaining near optimal calibration. Additionally, predictive estimation produces more accurate estimates of the fastest travel times. (C) 2003 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Dept Geophys, Albuquerque, NM 87187 USA. Watermark Numer Comp, Corinda 4075, Australia. Utah State Univ, Dept Comp Engn, Logan, UT 84322 USA. RP McKenna, SA (reprint author), Sandia Natl Labs, Dept Geophys, POB 5800 MS 0735, Albuquerque, NM 87187 USA. NR 19 TC 12 Z9 12 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD OCT 20 PY 2003 VL 281 IS 4 BP 265 EP 280 DI 10.1016/S0022-1694(03)00194-X PG 16 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 735EV UT WOS:000186100200003 ER PT J AU Schuh, CA Anderson, K Orme, C AF Schuh, CA Anderson, K Orme, C TI Rapid assessment of anisotropic surface processes: experiments on the corrosion of Inconel 600 SO SURFACE SCIENCE LA English DT Article DE surface structure, morphology, roughness, and topography; corrosion; atomic force microscopy ID NICKEL SINGLE-CRYSTALS; THIN OXIDE-FILMS; CRYSTALLOGRAPHIC ORIENTATION; OXIDATION-INHIBITION; REACTIVE ELEMENT; DISSOLUTION; GROWTH; COATINGS; BEHAVIOR; COPPER AB We present a general experimental method for rapid characterization of surface processes on crystals of many orientations. By correlating maps of crystallographic orientation (obtained by electron backscatter diffraction methods) with those of surface topography (obtained by atomic force microscopy), we illustrate how a surface property can be elucidated on many off-principle crystal surfaces from a single polycrystalline specimen. For the corrosion of Inconel 600 in a dilute aqueous solution of HCl, we find that corrosion rates scale with the deviation angle of the surface normal from an ideal (1 1 1) direction. The use of atomic force microscopy can also provide mechanistic details about the surface process in question. For Inconel 600, we correlate the surface oxide morphology directly to the orientation of the underlying crystal. (C) 2003 Elsevier B.V. All rights reserved. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Schuh, CA (reprint author), MIT, Dept Mat Sci & Engn, 77 Massachusetts Ave,Room 8-211, Cambridge, MA 02139 USA. RI Schuh, Christopher/C-7947-2009; Orme, Christine/A-4109-2009 NR 38 TC 18 Z9 18 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 20 PY 2003 VL 544 IS 2-3 BP 183 EP 192 DI 10.1016/j.susc.2003.07.009 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 733TZ UT WOS:000186017900012 ER PT J AU Ciobanu, CV Shenoy, VB Wang, CZ Ho, KM AF Ciobanu, CV Shenoy, VB Wang, CZ Ho, KM TI Structure and stability of the Si(105) surface SO SURFACE SCIENCE LA English DT Article DE molecular dynamics; semi-empirical models and model calculations; surface relaxation and reconstruction; surface energy; silicon; germanium ID STEPPED SURFACES; GROWTH; MORPHOLOGY; SILICON; SI; GE AB Recent experimental studies have shown that well-annealed, unstrained Si(1 0 5) surfaces appear disordered and atomically rough when imaged using scanning tunnelling microscopy. We construct new models for the Si(1 0 5) surface that are based on single- and double-height steps separated by Si(0 0 1) terraces, and propose that the observed surface disorder of Si(1 0 5) originates from the presence of several structural models with different atomic-scale features but similar energies. This degeneracy can be removed by applying compressive strains, a result that is consistent with recent observations of the structure of the Ge/Si(1 0 5) surface. (C) 2003 Elsevier B.V. All rights reserved. C1 Brown Univ, Div Engn, Providence, RI 02912 USA. Iowa State Univ, US Dept Energy, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Shenoy, VB (reprint author), Brown Univ, Div Engn, Providence, RI 02912 USA. RI Ciobanu, Cristian/B-3580-2009 NR 16 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 20 PY 2003 VL 544 IS 2-3 BP L715 EP L721 DI 10.1016/j.susc.2003.08.028 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 733TZ UT WOS:000186017900005 ER PT J AU Gallagher, ME Lucas, CA Stamenkovic, V Markovic, NM Ross, PN AF Gallagher, ME Lucas, CA Stamenkovic, V Markovic, NM Ross, PN TI Surface structure and relaxation at the Pt3Sn(111)/electrolyte interface SO SURFACE SCIENCE LA English DT Article DE X-ray scattering, diffraction, and reflection; catalysis; surface relaxation and reconstruction; alloys; solid-liquid interfaces ID BIMETALLIC SURFACES; ATOMIC-STRUCTURE; ALLOY SURFACES; CO; ADSORPTION; DIFFRACTION; OXIDATION; PT3SN(111); ELECTRODE AB In situ surface X-ray scattering (SXS) measurements have been performed to determine the surface structure of Pt3Sn(1 1 1) in sulfuric acid electrolyte. Potentiodynamic measurements indicate that the ultra high vacuum (UHV) prepared p(2x2) alloy surface structure is stable upon transfer to electrolyte and remains stable during subsequent cycling of the applied potential. A detailed structural study by crystal truncation rod (CTR) analysis shows that the surface layer of Pt and Sn atoms undergoes an expansion of similar to2% of the (1 1 1) layer spacing at low potential (0.05 V vs. reversible hydrogen electrode) in CO-free electrolyte. At 0.55 V the expansion of the Pt atoms is reduced to similar to0.6%, whereas the Sri atoms are expanded by similar to6% of the layer spacing, The potential-induced buckling of the surface layer is also observed in CO-saturated electrolyte and is a precursor to Sri dissolution which occurs at similar to1.0 V, causing irreversible roughening of the surface. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Lucas, CA (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Oxford St, Liverpool L69 7ZE, Merseyside, England. OI Lucas, Christopher/0000-0001-5743-3868 NR 17 TC 17 Z9 17 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD OCT 20 PY 2003 VL 544 IS 2-3 BP L729 EP L734 DI 10.1016/j.susc.2003.08.033 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 733TZ UT WOS:000186017900007 ER PT J AU Jennison, DR Mattsson, TR AF Jennison, DR Mattsson, TR TI Atomic understanding of strong nanometer-thin metal/alumina interfaces SO SURFACE SCIENCE LA English DT Article DE density functional calculations; adhesion; catalysis; interface states; aluminum oxide ID MOLECULAR-DYNAMICS METHODS; ALPHA-AL2O3 0001; OH GROUPS; SURFACE; MODEL; ADSORPTION; ADHESION; CU(111); ALUMINA; RHODIUM AB Chambers et al. [Science 297 (2002) 827] recently reported room temperature laminar growth of Co deposited in vacuum from an evaporation source on fully hydroxylated but otherwise clean alpha-Al2O3(0 0 0 1). We extend this work to a number of metals using first-principles calculations. The exothermicity of the suggested core reaction, 2OH(-) + M-(a) --> H-2 + 2O(2-) + M2+, where M represents any metal, is investigated for Cr, Fe, Ni, Cu, Mo, Ru, Rh, Pd, and Al. We find that the reactions are strongly exothermic for most metals. Rh is slightly endothermic, but has sufficient heat of adsorption to react immediately upon contact. The behavior of Cu cannot be determined within the current accuracy of density functional theory, and Pd is strongly endothermic. This suggests noble metals will not react. By first-principles molecular dynamics simulations of Rh, we show that the likelihood of a direct "hot" reaction, driven by the heat of adsorption, is significant. Published by Elsevier B.V. C1 Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Surface & Interface Sci Dept, Org 1114-MS 1415, Albuquerque, NM 87185 USA. EM drjenni@sandia.gov RI Mattsson, Thomas/B-6057-2009 NR 30 TC 14 Z9 14 U1 1 U2 11 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 OCT 20 PY 2003 VL 544 IS 2-3 BP L689 EP L696 DI 10.1016/j.susc.2003.07.012 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 733TZ UT WOS:000186017900001 ER PT J AU Mattsson, TR Paddison, SJ AF Mattsson, TR Paddison, SJ TI Methanol at the water-platinum interface studied by ab initio molecular dynamics SO SURFACE SCIENCE LA English DT Article DE alcohols; platinum; electrochemical methods; density functional calculations ID AUGMENTED-WAVE METHOD; DECOMPOSITION; TRANSITION; OXIDATION; METALS; ADSORPTION; HYDRATION; SURFACES; PT(111); GAS AB The adsorption and initial dehydrogenation of methanol on Pt(1 1 1) is examined using ab initio molecular dynamics. The simulations reveal that in solution the methanol molecule orientates with the CH3 group towards the surface, in contrast to the vacuum adsorption geometry. Our calculations also show that in vacuum the initial dehydrogenation step of CH3OH --> CH2OH + H has an energy barrier of only 0.45 eV, in good agreement with experimental results. We find a lowering and smearing of high-frequency hydrogen modes as a result of the methanol-surface interaction. The inclusion of hydration introduces additional effects and is necessary for a realistic treatment of the system. (C) 2003 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Theoret Chem & Mol Phys Grp, Los Alamos, NM 87545 USA. RP Mattsson, TR (reprint author), Sandia Natl Labs, HEDP Theory ICF Target Design, POB 5800, Albuquerque, NM 87111 USA. EM trmatts@sandia.gov RI Mattsson, Thomas/B-6057-2009; Paddison, Stephen/B-2935-2014 NR 28 TC 23 Z9 23 U1 1 U2 9 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 OCT 20 PY 2003 VL 544 IS 2-3 BP L697 EP L702 DI 10.1016/j.susc.2003.07.011 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 733TZ UT WOS:000186017900002 ER PT J AU Li, QB Jacob, DJ Yantosca, RM Heald, CL Singh, HB Koike, M Zhao, YJ Sachse, GW Streets, DG AF Li, QB Jacob, DJ Yantosca, RM Heald, CL Singh, HB Koike, M Zhao, YJ Sachse, GW Streets, DG TI A global three-dimensional model analysis of the atmospheric budgets of HCN and CH3CN: Constraints from aircraft and ground measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE biomass burning; pollution; nitriles; ocean uptake ID TRANSFORM INFRARED-SPECTROSCOPY; VERTICAL COLUMN ABUNDANCES; TRACE GAS MEASUREMENTS; MARINE BOUNDARY-LAYER; HYDROGEN-CYANIDE HCN; FREE TROPOSPHERIC CO; SEASONAL-VARIATIONS; PACIFIC-OCEAN; BIOGEOCHEMICAL CYCLES; NORTHERN JAPAN AB [1] We construct global atmospheric budgets of HCN and CH3CN through a three-dimensional (3-D) model simulation of the HCN-CH3CN-CO system constrained and evaluated with aircraft observations from the Transport and Chemical Evolution Over the Pacific (TRACE-P) mission over the NW Pacific in February - April 2001. Observed background vertical gradients of HCN and CH3CN imply a dominant ocean sink for both gases, with deposition velocity of 0.13 cm s(-1) for both and saturation ratios of 0.79 for HCN and 0.88 for CH3CN. Observations for both gases in the free troposphere imply a dominant source from biomass burning. Enhancement of HCN observed in Chinese urban plumes is attributed tentatively to residential coal burning. Biomass burning and residential coal burning emission ratios relative to CO of 0.27% and 1.6%, respectively, for HCN, and of 0.20% and 0.25%, respectively, for CH3CN, are consistent with observations in biomass burning and Chinese urban plumes. They provide the best model simulation of the ensemble of TRACE-P observations including vertical profiles and HCN- CH3CN- CO correlations. They also allow successful simulation of the long-term observations of HCN columns at sites in the Northern Hemisphere, and of the CH3CN vertical distribution observed over the northern Indian Ocean. Global biomass burning and Asian residential coal burning sources in the model are 0.63 and 0.2 Tg N yr(-1), respectively, for HCN and 0.47 and 0.03 Tg N yr(-1), respectively, for CH3CN. Ocean uptake is the dominant sink for both gases, with oxidation by OH representing an additional minor sink. The resulting tropospheric lifetimes are 5.3 months for HCN and 5.8 months for CH3CN. The model predicts very low HCN and CH3CN concentrations at high southern latitudes, reflecting the assumption of a uniform saturation ratio for ocean uptake; observations in that region are needed. In the free troposphere, the dominance of biomass burning sources ( 70 - 85% for HCN and 90 - 95% for CH3CN) implies that both gases can be used as biomass burning tracers. In the boundary layer, CH3CN appears to be a better biomass burning tracer. More work is needed to identify the origin of the Chinese urban source of HCN. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St,Pierce Hall,Room 107F, Cambridge, MA 02138 USA. EM qli@io.harvard.edu; djj@io.harvard.edu; heald@fas.harvard.edu; hanwant.b.singh@nasa.gov; koike@eps.s.u-tokyo.ac.jp; yzhao@mae.ucdavis.edu; g.w.sachse@larc.nasa.gov; dstreets@anl.gov RI Heald, Colette/A-6813-2011; Koike, Makoto/F-4366-2011; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014 OI Yantosca, Robert/0000-0003-3781-1870; NR 58 TC 75 Z9 75 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 18 PY 2003 VL 108 IS D21 AR 8827 DI 10.1029/2002JD003075 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZW UT WOS:000186088700001 ER PT J AU Morris, JP Lomov, IN Glenn, LA AF Morris, JP Lomov, IN Glenn, LA TI A constitutive model for stress-induced permeability and porosity evolution of Berea sandstone SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article DE berea sandstone; rocks; model; permeability; porosity; deformation ID CATACLASTIC FLOW; PORE PRESSURE; POROUS ROCKS; DEFORMATION; MICROMECHANICS; TRANSITION; DILATANCY; REDUCTION AB [1] Many applications in geophysics require good estimates of permeability evolution in response to deformation, pore collapse, dilatancy, and microfracturing. Simulations of the upper crust, oil well completion, and nuclear waste repositories depend upon reliable predictions of changes in rock permeability. For some applications, permeability can affect the strength of rock by influencing the pore pressure and effective stress. For example, the pore pressure during production from an oil bearing formation is controlled by the evolving permeability field. The rock strength, however, depends upon the effective stress which is influenced by the pore pressure. Accurate prediction of possible failure in such formations requires reliable estimates of permeability change. Ideally, such estimates could be obtained by directly simulating the changes in pore space connectivity at the microscale. In practice the system being studied is sufficiently large that constitutive models must be developed which address permeability evolution macroscopically. We develop a model for predicting porosity and permeability changes in Berea sandstone. The model has been kept as simple as possible in order to facilitate incorporation of the model into existing mechanics codes. For this reason we assume the existence of a separate material model capable of predicting the stress-strain response of the rock. In addition, the model assumes that the original pores and pores created by microfracturing can be treated separately with respect to permeability and porosity evolution. Despite these simplifying assumptions, the model is able to reproduce most of the key features observed in previously reported triaxial experiments performed on Berea sandstone. C1 Lawrence Livermore Natl Lab, Geophys & Global Secur Div, Livermore, CA 94551 USA. RP Morris, JP (reprint author), Lawrence Livermore Natl Lab, Geophys & Global Secur Div, POB 808,L-206, Livermore, CA 94551 USA. EM morris50@llnl.gov; lomov1@llnl.gov; glenn5@llnl.gov NR 21 TC 8 Z9 11 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD OCT 18 PY 2003 VL 108 IS B10 AR 2485 DI 10.1029/2001JB000463 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 735AN UT WOS:000186090300001 ER PT J AU Liu, Q Huang, QQ Teng, MK Weeks, CM Jelsch, C Zhang, RG Niu, LW AF Liu, Q Huang, QQ Teng, MK Weeks, CM Jelsch, C Zhang, RG Niu, LW TI The crystal structure of a novel, inactive, lysine 49 PLA2 from Agkistrodon acutus venom - An ultrahigh resolution, ab initio structure determination SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID RAY-DIFFRACTION DATA; X-RAY; PHOSPHOLIPASE A(2); CHARGE-DENSITY; ELECTRON-DENSITY; MYOTOXIN-II; PROTEINS; IMPLEMENTATION; REFINEMENT; PARAMETERS AB The crystal structure of acutohaemolysin, a lysine 49 phospholipase A2 protein with 1010 non-hydrogen protein atoms and 232 water molecules, has been determined ab initio using the program SnB at an ultrahigh resolution of 0.8 Angstrom. The lack of catalytic activity appears to be related to the presence of Phe(102), which prevents the access of substrate to the active site. The substitution of tryptophan for leucine at residue 10 interferes with dimer formation and may be responsible for the additional loss of hemolytic activity. The ultrahigh resolution of the experimental diffraction data permits alternative conformations to be modeled for disordered residues, many hydrogen atoms to be located, the protonation of the Nepsilon2 atom in the catalytic residue His(48) to be observed experimentally, and the density of the bonding electrons to be analyzed in detail. C1 Chinese Acad Sci, Key Lab Struct Biol, Hefei 230026, Anhui, Peoples R China. Univ Sci & Technol China, Sch Life Sci, Dept Mol & Cell Biol, Hefei 230026, Anhui, Peoples R China. Hauptman Woodward Med Res Inst, Buffalo, NY 14203 USA. Fac Sci, CNRS, Lab Cristallog & Modelisat Mat Mineraux & Biol, F-54506 Vandoeuvre Les Nancy, France. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP Niu, LW (reprint author), Chinese Acad Sci, Key Lab Struct Biol, 96 Jinzhai Rd, Hefei 230026, Anhui, Peoples R China. RI Liu, Qun/A-8757-2011 OI Liu, Qun/0000-0002-1179-290X FU NIBIB NIH HHS [EB-002057] NR 47 TC 33 Z9 35 U1 1 U2 5 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 OCT 17 PY 2003 VL 278 IS 42 BP 41400 EP 41408 DI 10.1074/jbc.M305210200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 730TX UT WOS:000185847200120 PM 12871974 ER PT J AU Sepulveda, J Jin, HL Sblattero, D Bradbury, A Burrone, OR AF Sepulveda, J Jin, HL Sblattero, D Bradbury, A Burrone, OR TI Binders based on dimerised immunoglobulin V-H domains SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE antibody engineering; binders; immunoglobulin domains ID CONFORMATIONAL-CHANGES; HYPERVARIABLE REGIONS; CANONICAL STRUCTURES; MONOCLONAL-ANTIBODY; VARIABLE DOMAINS; ESCHERICHIA-COLI; FAB FRAGMENT; LIGHT-CHAINS; FV FRAGMENT; ANTIGEN AB Antibody binding to antigen is mediated by the surface formed by the association of the two variable (V) regions of the L (V-L) and H (V-H) chains. The capacity Of V-L to dimerise and the high structural similarity Of V-L and V-H domains suggested the possibility that V-H could also associate. We show here that spontaneous formation of V-H dimers (VHD) is in many cases permissive, producing stable molecules with antigen binding specificity. VHD were displayed on filamentous phages for the selection of antigen-specific binders. VHD were expressed and secreted efficiently from both bacteria and mammalian cells in different formats, including single-chain (V-H(1)-linker-V-H(2)), double chain ((V-H)(2)) and IgG analogues having the V-L replaced by V-H. The affinity (K-d,K-app) achieved with a VH dimer expressed in the IgG format, specific for a glutenin subunit was around 30 nM measured by two different methods, which was about 20 times higher than that corresponding to the V-L/V-H counterpart. (C) 2003 Elsevier Ltd. All rights reserved. C1 Int Ctr Genet Engn & Biotechnol, I-34012 Trieste, Italy. Univ Trieste, Dept Biol, Trieste, Italy. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Burrone, OR (reprint author), Int Ctr Genet Engn & Biotechnol, Area Sci Pk,Padriciano 99, I-34012 Trieste, Italy. NR 48 TC 10 Z9 12 U1 0 U2 1 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 OCT 17 PY 2003 VL 333 IS 2 BP 355 EP 365 DI 10.1016/j.jmb.2003.08.033 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 730VZ UT WOS:000185852000011 PM 14529622 ER PT J AU Arslan, I Browning, ND AF Arslan, I Browning, ND TI Role of oxygen at screw dislocations in GaN SO PHYSICAL REVIEW LETTERS LA English DT Article AB Here we report the first direct atomic scale experimental observations of oxygen segregation to screw dislocations in GaN using correlated techniques in the scanning transmission electron microscope. The amount of oxygen present in each of the three distinct types of screw dislocation core is found to depend on the evolution and structure of the core, and thus gives rise to a varying concentration of localized states in the band gap. Contrary to previous theoretical predictions, the substitution of oxygen for nitrogen is observed to extend over many monolayers for the open core dislocation. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Arslan, I (reprint author), Univ Calif Davis, Dept Phys, 1 Shields Ave, Davis, CA 95616 USA. NR 13 TC 52 Z9 52 U1 2 U2 21 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 17 PY 2003 VL 91 IS 16 AR 165501 DI 10.1103/PhysRevLett.91.165501 PG 4 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300025 PM 14611410 ER PT J AU Aubert, B Barate, R Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Day, CT Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF Kukartsev, G LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Pelizaeus, M Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Cottingham, WN Mackay, C Wilson, FF Hearty, C Mattison, TS McKenna, JA Thiessen, D Kyberd, P McKemey, AK Blinov, VE Bukin, AD Golubev, VB Ivanchenko, VN Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Solodov, EP Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Mommsen, RK Roethel, W Stoker, DP Buchanan, C Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Heusch, CA Lockman, WS Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Albert, J Chen, E Dorsten, MP Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Blanc, F Bloom, P Clark, PJ Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Lacker, HM Maly, E Muller-Pfefferkorn, R Nogowski, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J Thiebaux, C Vasileiadis, G Verderi, M Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Taylor, GP Grenier, GJ Lee, SJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Bionta, RM Brigljevic, V Cheng, CH Lange, DJ Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R Kay, M Payne, DJ Sloane, RJ Touramanis, C Back, JJ Bellodi, G Harrison, PF Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Hart, PA Jackson, F Lafferty, GD Lyon, AJ Weatherall, JH Williams, JC Farbin, A Jawahery, A Kovalskyi, D Lae, CK Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Cowan, R Sciolla, G Taylor, F Yamamoto, RK Mangeol, DJJ Milek, M Patel, PM Lazzaro, A Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Godang, R Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, HW Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C Baak, MA Raven, G LoSecco, JM Gabriel, TA Brau, B Pulliam, T Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J T'Jampens, S Manfredi, PF Re, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Walsh, J Haire, M Judd, D Paick, K Wagoner, DE Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Smith, AJS Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Leonardi, E Mazzoni, MA Morganti, S Pierini, M Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Xella, SM Aleksan, R Emery, S Gaidot, A Ganzhur, SF Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Convery, MR Coupal, DP Dong, D Dorfan, J Dujmic, D Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges-Pous, E Hadig, T Halyo, V Hryn'ova, T Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Meyer, TI Roat, C Ahmed, S Ernst, JA Bugg, W Krishnamurthy, M Spanier, SM Eckmann, R Kim, H Ritchie, JL Schwitters, RF Izen, JM Kitayama, I Lou, XC Ye, S Bianchi, F Bona, M Gallo, F Gamba, D Borean, C Bosisio, L Della Ricca, G Dittongo, S Grancagnolo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, AK Pan, Y Prepost, R Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H AF Aubert, B Barate, R Boutigny, D Gaillard, JM Hicheur, A Karyotakis, Y Lees, JP Robbe, P Tisserand, V Zghiche, A Palano, A Pompili, A Chen, JC Qi, ND Rong, G Wang, P Zhu, YS Eigen, G Ofte, I Stugu, B Abrams, GS Borgland, AW Breon, AB Brown, DN Button-Shafer, J Cahn, RN Charles, E Day, CT Gill, MS Gritsan, AV Groysman, Y Jacobsen, RG Kadel, RW Kadyk, J Kerth, LT Kolomensky, YG Kral, JF Kukartsev, G LeClerc, C Levi, ME Lynch, G Mir, LM Oddone, PJ Orimoto, TJ Pripstein, M Roe, NA Romosan, A Ronan, MT Shelkov, VG Telnov, AV Wenzel, WA Harrison, TJ Hawkes, CM Knowles, DJ Penny, RC Watson, AT Watson, NK Deppermann, T Goetzen, K Koch, H Lewandowski, B Pelizaeus, M Peters, K Schmuecker, H Steinke, M Barlow, NR Bhimji, W Boyd, JT Chevalier, N Cottingham, WN Mackay, C Wilson, FF Hearty, C Mattison, TS McKenna, JA Thiessen, D Kyberd, P McKemey, AK Blinov, VE Bukin, AD Golubev, VB Ivanchenko, VN Kravchenko, EA Onuchin, AP Serednyakov, SI Skovpen, YI Solodov, EP Yushkov, AN Best, D Chao, M Kirkby, D Lankford, AJ Mandelkern, M McMahon, S Mommsen, RK Roethel, W Stoker, DP Buchanan, C Hadavand, HK Hill, EJ MacFarlane, DB Paar, HP Rahatlou, S Schwanke, U Sharma, V Berryhill, JW Campagnari, C Dahmes, B Kuznetsova, N Levy, SL Long, O Lu, A Mazur, MA Richman, JD Verkerke, W Beringer, J Eisner, AM Heusch, CA Lockman, WS Schalk, T Schmitz, RE Schumm, BA Seiden, A Turri, M Walkowiak, W Williams, DC Wilson, MG Albert, J Chen, E Dorsten, MP Dubois-Felsmann, GP Dvoretskii, A Hitlin, DG Narsky, I Porter, FC Ryd, A Samuel, A Yang, S Jayatilleke, S Mancinelli, G Meadows, BT Sokoloff, MD Barillari, T Blanc, F Bloom, P Clark, PJ Ford, WT Nauenberg, U Olivas, A Rankin, P Roy, J Smith, JG van Hoek, WC Zhang, L Harton, JL Hu, T Soffer, A Toki, WH Wilson, RJ Zhang, J Altenburg, D Brandt, T Brose, J Colberg, T Dickopp, M Dubitzky, RS Hauke, A Lacker, HM Maly, E Muller-Pfefferkorn, R Nogowski, R Otto, S Schubert, KR Schwierz, R Spaan, B Wilden, L Bernard, D Bonneaud, GR Brochard, F Cohen-Tanugi, J Thiebaux, C Vasileiadis, G Verderi, M Khan, A Lavin, D Muheim, F Playfer, S Swain, JE Tinslay, J Bozzi, C Piemontese, L Sarti, A Treadwell, E Anulli, F Baldini-Ferroli, R Calcaterra, A de Sangro, R Falciai, D Finocchiaro, G Patteri, P Peruzzi, IM Piccolo, M Zallo, A Buzzo, A Contri, R Crosetti, G Lo Vetere, M Macri, M Monge, MR Passaggio, S Pastore, FC Patrignani, C Robutti, E Santroni, A Tosi, S Bailey, S Morii, M Aspinwall, ML Bowerman, DA Dauncey, PD Egede, U Eschrich, I Morton, GW Nash, JA Sanders, P Taylor, GP Grenier, GJ Lee, SJ Mallik, U Cochran, J Crawley, HB Lamsa, J Meyer, WT Prell, S Rosenberg, EI Yi, J Davier, M Grosdidier, G Hocker, A Laplace, S Le Diberder, F Lepeltier, V Lutz, AM Petersen, TC Plaszczynski, S Schune, MH Tantot, L Wormser, G Bionta, RM Brigljevic, V Cheng, CH Lange, DJ Wright, DM Bevan, AJ Fry, JR Gabathuler, E Gamet, R Kay, M Payne, DJ Sloane, RJ Touramanis, C Back, JJ Bellodi, G Harrison, PF Shorthouse, HW Strother, P Vidal, PB Cowan, G Flaecher, HU George, S Green, MG Kurup, A Marker, CE McMahon, TR Ricciardi, S Salvatore, F Vaitsas, G Winter, MA Brown, D Davis, CL Allison, J Barlow, RJ Forti, AC Hart, PA Jackson, F Lafferty, GD Lyon, AJ Weatherall, JH Williams, JC Farbin, A Jawahery, A Kovalskyi, D Lae, CK Lillard, V Roberts, DA Blaylock, G Dallapiccola, C Flood, KT Hertzbach, SS Kofler, R Koptchev, VB Moore, TB Staengle, H Willocq, S Cowan, R Sciolla, G Taylor, F Yamamoto, RK Mangeol, DJJ Milek, M Patel, PM Lazzaro, A Palombo, F Bauer, JM Cremaldi, L Eschenburg, V Godang, R Kroeger, R Reidy, J Sanders, DA Summers, DJ Zhao, HW Hast, C Taras, P Nicholson, H Cartaro, C Cavallo, N De Nardo, G Fabozzi, F Gatto, C Lista, L Paolucci, P Piccolo, D Sciacca, C Baak, MA Raven, G LoSecco, JM Gabriel, TA Brau, B Pulliam, T Brau, J Frey, R Iwasaki, M Potter, CT Sinev, NB Strom, D Torrence, E Colecchia, F Dorigo, A Galeazzi, F Margoni, M Morandin, M Posocco, M Rotondo, M Simonetto, F Stroili, R Tiozzo, G Voci, C Benayoun, M Briand, H Chauveau, J David, P de la Vaissiere, C Del Buono, L Hamon, O Leruste, P Ocariz, J Pivk, M Roos, L Stark, J T'Jampens, S Manfredi, PF Re, V Gladney, L Guo, QH Panetta, J Angelini, C Batignani, G Bettarini, S Bondioli, M Bucci, F Calderini, G Carpinelli, M Forti, F Giorgi, MA Lusiani, A Marchiori, G Martinez-Vidal, F Morganti, M Neri, N Paoloni, E Rama, M Rizzo, G Sandrelli, F Walsh, J Haire, M Judd, D Paick, K Wagoner, DE Danielson, N Elmer, P Lu, C Miftakov, V Olsen, J Smith, AJS Varnes, EW Bellini, F Cavoto, G del Re, D Faccini, R Ferrarotto, F Ferroni, F Gaspero, M Leonardi, E Mazzoni, MA Morganti, S Pierini, M Piredda, G Tehrani, FS Serra, M Voena, C Christ, S Wagner, G Waldi, R Adye, T De Groot, N Franek, B Geddes, NI Gopal, GP Olaiya, EO Xella, SM Aleksan, R Emery, S Gaidot, A Ganzhur, SF Giraud, PF de Monchenault, GH Kozanecki, W Langer, M London, GW Mayer, B Schott, G Vasseur, G Yeche, C Zito, M Purohit, MV Weidemann, AW Yumiceva, FX Aston, D Bartoldus, R Berger, N Boyarski, AM Buchmueller, OL Convery, MR Coupal, DP Dong, D Dorfan, J Dujmic, D Dunwoodie, W Field, RC Glanzman, T Gowdy, SJ Grauges-Pous, E Hadig, T Halyo, V Hryn'ova, T Innes, WR Jessop, CP Kelsey, MH Kim, P Kocian, ML Langenegger, U Leith, DWGS Luitz, S Luth, V Lynch, HL Marsiske, H Menke, S Messner, R Muller, DR O'Grady, CP Ozcan, VE Perazzo, A Perl, M Petrak, S Ratcliff, BN Robertson, SH Roodman, A Salnikov, AA Schindler, RH Schwiening, J Simi, G Snyder, A Soha, A Stelzer, J Su, D Sullivan, MK Tanaka, HA Va'vra, J Wagner, SR Weaver, M Weinstein, AJR Wisniewski, WJ Wright, DH Young, CC Burchat, PR Meyer, TI Roat, C Ahmed, S Ernst, JA Bugg, W Krishnamurthy, M Spanier, SM Eckmann, R Kim, H Ritchie, JL Schwitters, RF Izen, JM Kitayama, I Lou, XC Ye, S Bianchi, F Bona, M Gallo, F Gamba, D Borean, C Bosisio, L Della Ricca, G Dittongo, S Grancagnolo, S Lanceri, L Poropat, P Vitale, L Vuagnin, G Panvini, RS Banerjee, S Brown, CM Fortin, D Jackson, PD Kowalewski, R Roney, JM Band, HR Dasu, S Datta, M Eichenbaum, AM Hu, H Johnson, JR Liu, R Di Lodovico, F Mohapatra, AK Pan, Y Prepost, R Sekula, SJ von Wimmersperg-Toeller, JH Wu, J Wu, SL Yu, Z Neal, H CA BABAR Collaboration TI Measurements of CP-violating asymmetries and branching fractions in B meson decays to eta ' K SO PHYSICAL REVIEW LETTERS LA English DT Article ID QCD AB We present measurements of the branching fractions of the decays B+-->eta(')K(+) and B-0-->eta(')K(0). For B-0-->eta(')K(S)(0) we also measure the time-dependent CP-violation parameters (SetaKS0)-K-' and (CetaKS0)-K-', and for B+-->eta(')K(+) the time-integrated charge asymmetry A(ch). The data sample corresponds to 88.9x10(6) B (B) over bar pairs produced by e(+)e(-) annihilation at the Y(4S). The results are B(B+-->eta(')K(+))=(76.9+/-3.5+/-4.4)x10(-6), B(B-0-->eta(')K(0))=(60.6+/-5.6+/-4.6)x10(-6), (SetaKS0)-K-'=0.02+/-0.34+/-0.03, (CetaKS0)-K-'=0.10+/-0.22+/-0.04, and A(ch)=0.037+/-0.045+/-0.011. C1 Phys Particules Lab, F-74941 Annecy Le Vieux, France. Univ Bari, Dipartmento Fis, I-70126 Bari, Italy. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Bergen, Inst Phys, N-5007 Bergen, Norway. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Ruhr Univ Bochum, Inst Phys Expt, D-44780 Bochum, Germany. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ British Columbia, Vancouver, BC V6T 1Z1, Canada. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. CALTECH, Pasadena, CA 91125 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. Univ Colorado, Boulder, CO 80309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Tech Univ Dresden, Inst Kern & Teilchenphys, D-01062 Dresden, Germany. Ecole Polytech, LLR, F-91128 Palaiseau, France. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. Univ Ferrara, Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Florida A&M Univ, Tallahassee, FL 32307 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Univ Genoa, Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Harvard Univ, Cambridge, MA 02138 USA. Univ London Imperial Coll Sci Technol & Med, London SW7 2BW, England. Univ Iowa, Iowa City, IA 52242 USA. Iowa State Univ, Ames, IA 50011 USA. Lab Accelerateur Lineaire, F-91898 Orsay, France. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Liverpool, Liverpool L69 3BX, Merseyside, England. Univ London, Queen Mary, London E1 4NS, England. Univ London Royal Holloway & Bedford New Coll, Egham TW20 0EX, Surrey, England. Univ Louisville, Louisville, KY 40292 USA. Univ Manchester, Manchester M13 9PL, Lancs, England. Univ Maryland, College Pk, MD 20742 USA. Univ Massachusetts, Amherst, MA 01003 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. McGill Univ, Montreal, PQ H3A 2T8, Canada. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Univ Milan, Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Mississippi, University, MS 38677 USA. Univ Montreal, Lab Rene JA Levesque, Montreal, PQ H3C 3J7, Canada. Mt Holyoke Coll, S Hadley, MA 01075 USA. Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy. Univ Naples Federico II, Ist Nazl Fis Nucl, I-80126 Naples, Italy. NIKHEF, Natl Inst Nucl Phys & High Energy Phys, NL-1009 DB Amsterdam, Netherlands. Univ Notre Dame, Notre Dame, IN 46556 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Univ Padua, Ist Nazl Fis Nucl, I-35131 Padua, Italy. Univ Paris 06, Lab Phys Nucl HE, F-75252 Paris, France. Univ Paris 07, Lab Phys Nucl HE, F-75252 Paris, France. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. Univ Pavia, Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Scuola Normale Super Pisa, Dipartimento Fis, I-56127 Pisa, Italy. Ist Nazl Fis Nucl, I-56127 Pisa, Italy. Prairie View A&M Univ, Prairie View, TX 77446 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Roma La Sapienza, Ist Nazl Fis Nucl, I-00185 Rome, Italy. Univ Rostock, D-18051 Rostock, Germany. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CEA Saclay, DSM Dapnia, F-91191 Gif Sur Yvette, France. Univ S Carolina, Columbia, SC 29208 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. SUNY Albany, Albany, NY 12222 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas, Richardson, TX 75083 USA. Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy. Univ Turin, Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Trieste, Dipartmento Fis, I-34127 Trieste, Italy. Univ Trieste, Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Victoria, Victoria, BC V8W 3P6, Canada. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. Univ Perugia, I-06100 Perugia, Italy. Univ Basilicata, I-85100 Potenza, Italy. Univ Valencia, CSIC, Inst Fis Corpuscular, IFIC, Valencia, Spain. RP Aubert, B (reprint author), Phys Particules Lab, F-74941 Annecy Le Vieux, France. RI Kravchenko, Evgeniy/F-5457-2015; Mir, Lluisa-Maria/G-7212-2015; Martinez Vidal, F*/L-7563-2014; Kolomensky, Yury/I-3510-2015; Lo Vetere, Maurizio/J-5049-2012; Lusiani, Alberto/N-2976-2015; Lusiani, Alberto/A-3329-2016; Morandin, Mauro/A-3308-2016; Della Ricca, Giuseppe/B-6826-2013; Di Lodovico, Francesca/L-9109-2016; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; Cavallo, Nicola/F-8913-2012; Patrignani, Claudia/C-5223-2009; Monge, Maria Roberta/G-9127-2012; Peters, Klaus/C-2728-2008; de Groot, Nicolo/A-2675-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Forti, Francesco/H-3035-2011; Rotondo, Marcello/I-6043-2012; de Sangro, Riccardo/J-2901-2012; Sarti, Alessio/I-2833-2012 OI Raven, Gerhard/0000-0002-2897-5323; Mackay, Catherine/0000-0003-4252-6740; Mir, Lluisa-Maria/0000-0002-4276-715X; Martinez Vidal, F*/0000-0001-6841-6035; Kolomensky, Yury/0000-0001-8496-9975; Lo Vetere, Maurizio/0000-0002-6520-4480; Lusiani, Alberto/0000-0002-6876-3288; Lusiani, Alberto/0000-0002-6876-3288; Morandin, Mauro/0000-0003-4708-4240; Della Ricca, Giuseppe/0000-0003-2831-6982; Di Lodovico, Francesca/0000-0003-3952-2175; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; Patrignani, Claudia/0000-0002-5882-1747; Monge, Maria Roberta/0000-0003-1633-3195; Peters, Klaus/0000-0001-7133-0662; Bellini, Fabio/0000-0002-2936-660X; Neri, Nicola/0000-0002-6106-3756; Forti, Francesco/0000-0001-6535-7965; Rotondo, Marcello/0000-0001-5704-6163; de Sangro, Riccardo/0000-0002-3808-5455; Sarti, Alessio/0000-0001-5419-7951 NR 23 TC 53 Z9 53 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 17 PY 2003 VL 91 IS 16 AR 161801 DI 10.1103/PhysRevLett.91.161801 PG 7 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300005 ER PT J AU Chung, P Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Cole, B Crowe, K Das, AC Draper, JE Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Holzmann, W Huo, L Issah, M Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, S Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Srivastava, B Stone, NTB Symons, TJM Taranenko, A Whitfield, J Witt, R Wood, L Zhang, WN Brown, D Pratt, S Wang, F Danielewicz, P AF Chung, P Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Cole, B Crowe, K Das, AC Draper, JE Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Holzmann, W Huo, L Issah, M Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, S Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Srivastava, B Stone, NTB Symons, TJM Taranenko, A Whitfield, J Witt, R Wood, L Zhang, WN Brown, D Pratt, S Wang, F Danielewicz, P CA E895 Collaboration TI Comparison of source images for protons, pi(-)'s, and Lambda's in 6A GeV Au+Au collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; ENERGY NUCLEAR COLLISIONS; PLUS AU COLLISIONS; ELLIPTIC FLOW; INTERFEROMETRY; DEPENDENCE; AGS; EQUATION; STATE AB Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs pLambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p. These observations suggest important differences in the space-time emission histories for protons, pions, and neutral strange baryons produced in the same events. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Ohio State Univ, Columbus, OH 43210 USA. Kent State Univ, Kent, OH 44242 USA. Univ Calif Davis, Davis, CA 95616 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Auckland, Auckland 1, New Zealand. Columbia Univ, New York, NY 10027 USA. St Marys Coll, Moraga, CA 94575 USA. Harbin Inst Technol, Harbin 150001, Peoples R China. Purdue Univ, W Lafayette, IN 47907 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Purdue Univ, W Lafayette, IN 47907 USA. RP Chung, P (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Witt, Richard/H-3560-2012 NR 32 TC 22 Z9 22 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 OCT 17 PY 2003 VL 91 IS 16 AR 162301 DI 10.1103/PhysRevLett.91.162301 PG 5 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300009 PM 14611394 ER PT J AU Demsar, J Averitt, RD Kabanov, VV Mihailovic, D AF Demsar, J Averitt, RD Kabanov, VV Mihailovic, D TI Comment on "Photoinduced changes of reflectivity in single crystals of YBa2Cu3O6.5 (Ortho II)" SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material ID SUPERCONDUCTORS; PARTICLE; DYNAMICS C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Jozef Stefan Inst, Ljubljana, Slovenia. RP Demsar, J (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Demsar, Jure/B-5578-2008; Demsar, Jure/F-7243-2016 OI Demsar, Jure/0000-0003-4551-7444; NR 12 TC 13 Z9 13 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 17 PY 2003 VL 91 IS 16 AR 169701 DI 10.1103/PhysRevLett.91.169701 PG 1 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300061 ER PT J AU Dillmann, I Kratz, KL Wohr, A Arndt, O Brown, BA Hoff, P Hjorth-Jensen, M Koster, U Ostrowski, AN Pfeiffer, B Seweryniak, D Shergur, J Walters, WB AF Dillmann, I Kratz, KL Wohr, A Arndt, O Brown, BA Hoff, P Hjorth-Jensen, M Koster, U Ostrowski, AN Pfeiffer, B Seweryniak, D Shergur, J Walters, WB CA ISOLDE Collaborators TI N=82 shell quenching of the classical r-process "waiting-point" nucleus C-130 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY PROPERTIES; MASS FORMULA; HALF-LIVES AB First beta- and gamma-spectroscopic decay studies of the N=82 r-process "waiting-point" nuclide Cd-130 have been performed at CERN/ISOLDE using the highest achievable isotopic selectivity. Several nuclear-physics surprises have been discovered. The first one is the unanticipatedly high energy of 2.12 MeV for the [pig(9/2)circle timesnug(7/2)] 1(+) level in In-130, which is fed by the main Gamow-Teller transition. The second surprise is the rather high Q(beta) value of 8.34 MeV, which is in agreement only with recent mass models that include the phenomenon of N=82 shell quenching. Possible implications of these new results on the formation of the Asimilar or equal to130 r-process abundance peak are presented. C1 Johannes Gutenberg Univ Mainz, Inst Kernchem, D-6500 Mainz, Germany. Univ Basel, Dept Phys & Astron, Basel, Switzerland. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, NSCL, E Lansing, MI 48824 USA. Univ Oslo, Dept Chem, Oslo, Norway. Univ Oslo, Dept Phys, Oslo, Norway. CERN, Geneva, Switzerland. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Dillmann, I (reprint author), Johannes Gutenberg Univ Mainz, Inst Kernchem, D-6500 Mainz, Germany. EM kl.kratz@uni-mainz.de RI Hjorth-Jensen, Morten/B-1417-2008 NR 30 TC 137 Z9 138 U1 0 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 17 PY 2003 VL 91 IS 16 AR 162503 DI 10.1103/PhysRevLett.91.162503 PG 4 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300012 PM 14611397 ER PT J AU Gedik, N Orenstein, J Liang, R Bonn, DA Hardy, WN AF Gedik, N Orenstein, J Liang, R Bonn, DA Hardy, WN TI Comment on "Photoinduced changes of reflectivity in single crystals of YBa2Cu3O6.5 (Ortho II)" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ British Columbia, Dept Phys, Vancouver, BC, Canada. RP Gedik, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Orenstein, Joseph/I-3451-2015 NR 4 TC 4 Z9 4 U1 1 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 OCT 17 PY 2003 VL 91 IS 16 AR 169702 DI 10.1103/PhysRevLett.91.169702 PG 1 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300062 ER PT J AU Simons, AJ Wadsworth, R Jenkins, DG Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Lane, GJ Lee, IY Macchiavelli, AO Stephens, FS Svensson, CE Vetter, K Ward, D Frauendorf, S AF Simons, AJ Wadsworth, R Jenkins, DG Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Lane, GJ Lee, IY Macchiavelli, AO Stephens, FS Svensson, CE Vetter, K Ward, D Frauendorf, S TI Evidence for a new type of shears mechanism in Cd-106 SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEI; BANDS AB Lifetimes of states in the lowest lying positive parity band in Cd-106 have been measured using the Doppler shift attenuation method. The deduced B(E2) transition rates show a marked decrease with increasing spin. Cranking and semiclassical model calculations suggest that the structure has the character of a shears-type band resulting from the coupling of g(9/2) proton holes to aligned pairs of h(11/2) and g(7/2) neutron particles. This is the first clear evidence for the phenomenon of "antimagnetic" rotation in nuclei. C1 Univ York, Dept Phys, York YO10 5DD, N Yorkshire, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Rossendorf Inc, Forschungszentrum, D-01314 Dresden, Germany. RP Simons, AJ (reprint author), Univ York, Dept Phys, York YO10 5DD, N Yorkshire, England. RI Lane, Gregory/A-7570-2011 OI Lane, Gregory/0000-0003-2244-182X NR 16 TC 39 Z9 41 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 OCT 17 PY 2003 VL 91 IS 16 AR 162501 DI 10.1103/PhysRevLett.91.162501 PG 4 WC Physics, Multidisciplinary SC Physics GA 734QP UT WOS:000186068300010 PM 14611395 ER PT J AU Nobrega, MA Ovcharenko, I Afzal, V Rubin, EM AF Nobrega, MA Ovcharenko, I Afzal, V Rubin, EM TI Scanning human gene deserts for long-range enhancers SO SCIENCE LA English DT Article ID DROSOPHILA DACHSHUND; EXPRESSION C1 US Dept Energy Joint Genome Inst, Walnut Creek, CA 94598 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Nobrega, MA (reprint author), US Dept Energy Joint Genome Inst, Walnut Creek, CA 94598 USA. FU NHLBI NIH HHS [HL66728] NR 6 TC 413 Z9 428 U1 3 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 17 PY 2003 VL 302 IS 5644 BP 413 EP 413 DI 10.1126/science.1088328 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 732UD UT WOS:000185963200032 PM 14563999 ER PT J AU Mao, WL Mao, HK Eng, PJ Trainor, TP Newville, M Kao, CC Heinz, DL Shu, JF Meng, Y Hemley, RJ AF Mao, WL Mao, HK Eng, PJ Trainor, TP Newville, M Kao, CC Heinz, DL Shu, JF Meng, Y Hemley, RJ TI Bonding changes in compressed superhard graphite SO SCIENCE LA English DT Article ID X-RAY-DIFFRACTION; HIGH-PRESSURE; HEXAGONAL DIAMOND; TRANSPARENT PHASE; ROOM-TEMPERATURE; CARBON; TRANSFORMATION; GPA AB Compressed under ambient temperature, graphite undergoes a transition at similar to17 gigapascals. The near K-edge spectroscopy of carbon using synchrotron x-ray inelastic scattering reveals that half of the pi-bonds between graphite layers convert to sigma-bonds, whereas the other half remain as pi-bonds in the high-pressure form. The x-ray diffraction pattern of the high-pressure form is consistent with a distorted graphite structure in which bridging carbon atoms between graphite layers pair and form sigma-bonds, whereas the nonbridging carbon atoms remain unpaired with pi-bonds. The high-pressure form is superhard, capable of indenting cubic-diamond single crystals. C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Argonne Natl Lab, Adv Photon Source, High Pressure Coolaborat Access Team, Argonne, IL 60439 USA. Univ Alabama, Dept Chem & Biochem, Fairbanks, AK 99775 USA. RP Mao, WL (reprint author), Univ Chicago, Dept Geophys Sci, 5734 S Ellis Ave, Chicago, IL 60637 USA. RI Mao, Wendy/D-1885-2009 NR 15 TC 312 Z9 315 U1 12 U2 107 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 17 PY 2003 VL 302 IS 5644 BP 425 EP 427 DI 10.1126/science.1089713 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 732UD UT WOS:000185963200036 PM 14564003 ER PT J AU Cheng, MD AF Cheng, MD TI Field measurement comparison of aerosol metals using aerosol beam focused laser-induced plasma spectrometer and reference methods SO TALANTA LA English DT Article DE metal-laden aerosol; Lorentzian model; aerosol measurements ID INDUCED-BREAKDOWN SPECTROSCOPY; SPECTROCHEMICAL ANALYSIS; SPARK; BERYLLIUM; WAVELENGTH; EMISSIONS; DROPLETS; PROBE; SOIL AB Several tests were conducted in July 2002 on an instrument developed by researchers at the Oak Ridge National Laboratory (ORNL) for in-situ, real-time measurement of metal-laden aerosol particles in flue gas from combustion facilities. Stock aqueous solutions of prepared metal concentrations were nebulized and injected into the flue gas to provide spikes for the instrument testing. Strengths of the solutions were designed such that a reference method (RM) was able to obtain a sufficient amount of material on filter samples in 30 min cycles; the collected filters were subsequently analyzed in an analytical laboratory using certified methods. Parallel aerosol measurements were performed by one operator using the ORNL instrument. The recorded signal of an individual element was analyzed using the Lorentzian model and the concentration calculated from a calibration curve that was established prior to the experiments. RM data were able to reflect the loads simulated in the spiked waste stream. However, data collected using the RM was unable to reflect the transient load condition in the flue gas and missed a sample containing beryllium. The possibility of bias in the RM determination of chromium could exist. With the real-time detection capability, the instrument was able to reveal the transient emission variation by making seven consecutive measurements within a 30 min cycle. The measurements for mercury by both techniques appeared to be in good agreement. Further improvement of the system includes the development of user-friendly software for modeling, data analysis tools, and packaging suitable for field transportation. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Cheng, Meng-Dawn/C-1098-2012; OI Cheng, Meng-Dawn/0000-0003-1407-9576 NR 21 TC 14 Z9 16 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD OCT 17 PY 2003 VL 61 IS 2 BP 127 EP 137 DI 10.1016/S0039-9140(03)00243-1 PG 11 WC Chemistry, Analytical SC Chemistry GA 735QZ UT WOS:000186127200008 PM 18969171 ER PT J AU Lu, YF McCaughey, BF Wang, DH Hampsey, JE Doke, N Yang, ZZ Brinker, CJ AF Lu, YF McCaughey, BF Wang, DH Hampsey, JE Doke, N Yang, ZZ Brinker, CJ TI Aerosol-assisted formation of mesostructured thin films SO ADVANCED MATERIALS LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; WATER-INTERFACE; SILICA SPHERES; COPOLYMER; TRIBLOCK; FIBERS AB A new aerosol-assisted surfactant self-assembly approach has been developed for large-scale mesostructured silica thin film fabrication. The formation mechanism involves coalescence of semisolid surfactant-silica mesostructured particles on substrates (see Figure) and subsequent reassembly of the mesostructures to adapt the morphology transformation from spherical to planar shape. C1 Tulane Univ, Dept Chem Engn, New Orleans, LA 70118 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Univ New Mexico, Sandia Natl Labs, Albuquerque, NM 87131 USA. Chinese Acad Sci, State Key Lab Polymer Phys & Chem, Ctr Mol Sci, Inst Chem, Beijing 100080, Peoples R China. RP Tulane Univ, Dept Chem Engn, New Orleans, LA 70118 USA. EM cjbrink@sandia.gov RI Wang, Donghai/L-1150-2013; 杨, 振忠/B-5929-2015 OI Wang, Donghai/0000-0001-7261-8510; NR 29 TC 27 Z9 27 U1 6 U2 20 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0935-9648 EI 1521-4095 J9 ADV MATER JI Adv. Mater. PD OCT 16 PY 2003 VL 15 IS 20 BP 1733 EP + DI 10.1002/adma.200305331 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 740WQ UT WOS:000186425600011 ER PT J AU Gordon, ML Tulumello, D Cooper, G Hitchcock, AP Glatzel, P Mullins, OC Cramer, SP Bergmann, U AF Gordon, ML Tulumello, D Cooper, G Hitchcock, AP Glatzel, P Mullins, OC Cramer, SP Bergmann, U TI Inner-shell excitation spectroscopy of fused-ring aromatic molecules by electron energy loss and X-ray Raman techniques SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CORE EXCITATION; GAS-PHASE; K-EDGE; SCATTERING; SPECTRA; BENZENE; CARBON; HYDROCARBONS; ABSORPTION; RESONANCES AB Oscillator strengths for C Is excitation spectra of gaseous benzene, naphthalene, anthracene, phenanthracene, triphenylene, pyrene, and 1,2-benzanthracene have been derived from inner-shell electron energy loss spectroscopy recorded under scattering conditions where electric dipole transitions dominate (2.5 keV residual energy, theta less than or equal to 2degrees corresponding to a product of momentum transfer and C 1s orbital size (qr) of 0.08). These spectra are interpreted with the aid of ab initio calculations on selected species. They are compared to the C 1s spectra of solid samples of benzene, naphththalene, anthracene, triphenylene, and 1,2-benzanthracene, recorded with inelastic X-ray Raman scattering in the dipole limit (qr < 0.5). When differences in resolution are taken into account, good agreement is found between the inelastic electron scattering spectra of the gases and the inelastic photon scattering spectra of the corresponding solid. Small differences are attributed to quenching of transitions to Rydberg states in the solids. Characteristic differences related to the degree of symmetry or spatial arrangement of the fused ring aromatic hydrocarbons (e.g., linear versus bent structures) indicate that C 1s X-ray Raman spectroscopy should be useful for characterizing aromatics in bulk samples that are opaque to soft X-rays, such as coals and heavy hydrocarbon deposits. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Univ Utrecht, Dept Chem, NL-3584 CA Utrecht, Netherlands. Schlumberger Doll Res Ctr, Ridgefield, CT 06877 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Hitchcock, AP (reprint author), McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. RI Glatzel, Pieter/E-9958-2010; Tulumello, David/F-2240-2013; ID, BioCAT/D-2459-2012; Tulumello, David/L-8960-2013 OI Glatzel, Pieter/0000-0001-6532-8144; NR 33 TC 26 Z9 26 U1 1 U2 15 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 OCT 16 PY 2003 VL 107 IS 41 BP 8512 EP 8520 DI 10.1021/jp035607r PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 730YH UT WOS:000185857400018 ER PT J AU Gresham, GL Gianotto, AK Harrington, PD Cao, LB Scott, JR Olson, JE Appelhans, AD Van Stipdonk, MJ Groenewold, GS AF Gresham, GL Gianotto, AK Harrington, PD Cao, LB Scott, JR Olson, JE Appelhans, AD Van Stipdonk, MJ Groenewold, GS TI Gas-phase hydration of U(IV), U(V), and U(VI) dioxo monocations SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ION MASS-SPECTROMETRY; COUPLED CHEMICAL-REACTIONS; ORGANOMETALLIC CHEMISTRY; AQUEOUS-SOLUTION; ACTINIDE IONS; METAL-IONS; URANYL-ION; TRAP; COORDINATION; HYDROLYSIS AB The formation of adduct ions consisting of uranium oxycations and water was studied using an ion trap-secondary ion mass spectrometer. The U(IV) and U(V) species [UO(OH)](+) and [UO2](+) were produced by bombarding the surface of UO3 using molecular primary ions, and the U(VI) species [UO2(OH)](+) was generated by O-2 oxidation of [UO(OH)](+) in the gas phase. All three ions formed H2O adducts by termolecular association reactions: [UO(OH)](+) (a U(IV) species) added three water molecules, for a total of five ligands; [UO2](+) (U(V)) added three or four water molecules, for a total of five or six ligands; and [UO2(OH)](+) (U(VI)) added four water molecules for a total of six ligands. Addition of a seventh ligand was not observed in any of the systems. These analyses showed that the optimum extent of ligation increased with increasing oxidation state of the uranium metal. Hard kinetic models were fit to the time-dependent mass spectral data using adaptive simulated annealing (ASA) to estimate reaction rates and rate constants from kinetic data sets. The values determined were validated using stochastic kinetic modeling and resulted in rate data for all forward and reverse reactions for the ensemble of reactive ions present in the ion trap. A comparison of the forward rate constants of the hydration steps showed that in general, formation of the monohydrates was slow, but that hydration efficiency increased upon addition of the second H2O. Addition of the third H2O was less efficient (except in the case Of [UO2](+)), and addition of the fourth H2O was even more inefficient and did not occur at all in the [UO2(OH)](+) system. Reverse rate constants also decreased with increasing ligation by H2O, except in the case of [UO(OH)(H2O)(4)](+), which prefers to quickly revert to the trihydrate. These findings indicate that stability of the hydrate complexes [UOyHz(H2O)(n)](+) increases with increasing n, until the optimum number of ligands is achieved. The results enable correlation of uranium hydration behavior with oxidation state. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Ohio Univ, Dept Chem & Biochem, Ctr Intelligent Chem Instrumentat, Athens, OH 45701 USA. Wichita State Univ, Dept Chem, Wichita, KS 67208 USA. RP Groenewold, GS (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RI Scott, Jill/G-7275-2012 NR 65 TC 41 Z9 41 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 16 PY 2003 VL 107 IS 41 BP 8530 EP 8538 DI 10.1021/jp035443e PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 730YH UT WOS:000185857400020 ER PT J AU Kopidakis, N Benkstein, KD van de Lagemaat, J Frank, AJ AF Kopidakis, N Benkstein, KD van de Lagemaat, J Frank, AJ TI Transport-limited recombination of photocarriers in dye-sensitized nanocrystalline TiO2 solar cells SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MODULATED PHOTOCURRENT SPECTROSCOPY; ELECTRIC-POTENTIAL DISTRIBUTION; TITANIUM-DIOXIDE FILMS; LI+ ION INSERTION; NANOPOROUS TIO2; LITHIUM INTERCALATION; CHARGE RECOMBINATION; ANATASE TIO2; POLYCRYSTALLINE TIO2; AMBIPOLAR DIFFUSION AB The effect of lithium intercalation on the transport dynamics and recombination kinetics in dye-sensitized nanoparticle TiO2 solar cells at lithium levels below 5 atom % was investigated by photocurrent and photovoltage transient and spectroelectrochemical techniques. Titanium dioxide films were doped electrochemically in the dark and under illumination. It was discovered that when Li+ is present in the electrolyte, lithium intercalates irreversibly into dye-sensitized TiO2 films at open circuit (ca. -0.7 V) under normal solar light intensities. Photocurrent transients of doped nonsensitized TiO2 films indicate that lithium doping decreases the diffusion coefficient of electrons through the nanoparticle network. Photocurrent and photovoltage transients of sensitized TiO2 films provide the first evidence that electron transport limits recombination with the redox electrolyte in working cells. As the Li density in the films increases, the diffusion and recombination times of photoelectrons increase proportionately, indicating a causal link between electron transport and recombination. The electron diffusion coefficient in dye-sensitized solar cells exhibits a power-law dependence on photocharge at all concentrations of inserted lithium in the TiO2 film. With increasing doping, the dependence of the electron diffusion coefficient on the photocharge becomes stronger, a phenomenon attributed to widening of the exponential conduction band tail resulting from disorder induced by randomly placed lithium defects in TiO2. The photovoltaic characteristics of dye-sensitized solar cells are largely unaffected by lithium intercalation, implying that intercalation has only a small effect on the charge collection efficiency and the rate of recombination. A simple model is presented that explains the observed transport-limited recombination. The results suggest that increasing the electron transport rate will not significantly improve the solar cell performance. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Frank, AJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI van de Lagemaat, Jao/J-9431-2012; Kopidakis, Nikos/N-4777-2015 NR 58 TC 340 Z9 342 U1 5 U2 86 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 OCT 16 PY 2003 VL 107 IS 41 BP 11307 EP 11315 DI 10.1021/jp0304475 PG 9 WC Chemistry, Physical SC Chemistry GA 730YJ UT WOS:000185857500008 ER PT J AU Jones, M Nedeljkovic, J Ellingson, RJ Nozik, AJ Rumbles, G AF Jones, M Nedeljkovic, J Ellingson, RJ Nozik, AJ Rumbles, G TI Photoenhancement of luminescence in colloidal CdSe quantum dot solutions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NANOCRYSTALS; PHOTOLUMINESCENCE; RELAXATION; EXCITATION; INP; SPECTROSCOPY; ABSORPTION; DISPERSION; SERIES; INTERMITTENCY AB Enhancement of the photoluminescence (PL) of colloidal CdSe and (core)shell (CdSe)ZnS quantum dots has been observed when the dots are illuminated above the band-gap energy. The effect occurs in dots suspended in a variety of organic,or aqueous environments. During periods of constant illumination, the exciton PL quantum yield was found to reach a value of up to 60 times that of the solution of as-prepared quantum dots and, if illumination continued, subsequently declined slowly because of photooxidation. When returned to the dark, the PL reverted to near its original value. The rate and magnitude of photoenhancement are found to depend on the illumination wavelength, the presence of a ZnS shell, the solvent environment, and the concentration of surfactant molecules. Time-resolved measurements of the fluorescence decay reveal multiexponential kinetics and an average lifetime that lengthens during the illumination period and shortens when quantum dots are returned to darkness. It is postulated that the stabilization of surface trap states, lengthening their average lifetime, could occur by a light-activated rearrangement of surfactant molecules, thus increasing the probability of thermalization back to the lowest emitting exciton state and enhancing the quantum dot PL. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM grumbles@nrel.gov RI Jones, Marcus/B-3291-2008; Ellingson, Randy/H-3424-2013; Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016; OI Jones, Marcus/0000-0001-9912-1168; Rumbles, Garry/0000-0003-0776-1462 NR 36 TC 249 Z9 252 U1 9 U2 75 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 OCT 16 PY 2003 VL 107 IS 41 BP 11346 EP 11352 DI 10.1021/jp035598m PG 7 WC Chemistry, Physical SC Chemistry GA 730YJ UT WOS:000185857500013 ER PT J AU Redfern, PC Zapol, P Curtiss, LA Rajh, T Thurnauer, MC AF Redfern, PC Zapol, P Curtiss, LA Rajh, T Thurnauer, MC TI Computational studies of catechol and water interactions with titanium oxide nanoparticles SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BI-ISONICOTINIC-ACID; X-RAY-ABSORPTION; TIO2 ANATASE 101; AB-INITIO; SURFACE COMPLEXATION; MOLECULAR ADSORPTION; GAUSSIAN-3 THEORY; RUTILE TIO2(110); BASIS-SET; ATOMS K AB The interaction of catechol and water with titanium oxide nanoparticles was investigated using ab initio molecular orbital theory and density functional theory. Hydrogen-terminated TiO2 clusters were used to model the surface of anatase nanoparticles. The calculations indicate that catechol reacts with a Ti=O defect site on the surface to form a bidentate structure that is favored over dissociative or molecular adsorption on the (101) anatase surface. The dissociative adsorption of catechol at the defect site leads to a much larger red shift in the TiO2 excitation energy than molecular adsorption on the (101) anatase surface on the basis of ZINDO/S calculations. This is consistent with recent experimental results on small (<2 mn) titania nanoparticles. The calculations on water adsorption indicate that it can also add to the Ti=O double bond site. However, molecular adsorption of water on the (101) anatase surface is more favorable. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zapol, Peter/G-1810-2012 OI Zapol, Peter/0000-0003-0570-9169 NR 32 TC 169 Z9 169 U1 5 U2 51 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 OCT 16 PY 2003 VL 107 IS 41 BP 11419 EP 11427 DI 10.1021/jp0303669 PG 9 WC Chemistry, Physical SC Chemistry GA 730YJ UT WOS:000185857500023 ER PT J AU Ramallo-Lopez, JM Santori, GF Giovanetti, L Casella, ML Ferretti, OA Requejo, FG AF Ramallo-Lopez, JM Santori, GF Giovanetti, L Casella, ML Ferretti, OA Requejo, FG TI XPS and XAFS Pt L-2,L-3-edge studies of dispersed metallic Pt and PtSn clusters on SiO2 obtained by organometallic synthesis: Structural and electronic characteristics SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-ABSORPTION; FINE-STRUCTURE; HYDROGEN ADSORPTION; SURFACE ALLOYS; CATALYSTS; PLATINUM; SPECTRA; PARTICLES; EXAFS; TIN AB In this work, well-defined silica-supported Pt and PtSn catalysts were prepared by surface organometallic reactions and were characterized by EXAFS-XANES at the Pt L-2,L-3 edge and XPS of the Pt 4f and Sn 3d levels. These catalysts were tested in the catalytic hydrogenation of cinnamaldehyde in the liquid phase. XPS results showed that in PtSn-OM* (not having butyl groups anchored on the surface), tin was present as Sn(0) adatoms "decorating" the metallic surface, isolating Pt atoms; in the PtSn-OM catalyst (Bu groups remain grafted on the surface), tin was found in the form of Sn(0) and Sn(II, IV) in similar proportions. EXAFS experiments do not provide evidence of the existence of PtSn alloys in any of these systems. In the bimetallic PtSn-BM systems, it was possible to observe by XPS that tin was found in the form of Sn(0) and Sn(II, IV). EXAFS experiments, in this case, allowed us to demonstrate the existence of a PtSn alloy diluting metallic Pt atoms. In tin-modified systems, when a fraction of ionic tin is present, the activation of the C=O group of the cinnamaldehyde is favored, increasing the selectivity to UOL. An increase in the number of Pt 5d holes measured by Pt-L-2,L-3 XANES could be indicating as a d --> s, p rehybridization process in the PtSn 3D small nanoclusters present in PtSn-BM catalysts. C1 Natl Univ La Plata, Ctr Invest & Desarrollo Ciencias Aplicadas Dr Jor, CINDECA, Fac Ciencias Exactas, RA-1900 La Plata, Argentina. Natl Univ La Plata, Fac Ciencias Exactas, Inst Fis La Plata, CONICET, RA-1900 La Plata, Argentina. Natl Univ La Plata, Fac Ciencias Exactas, Dept Fis, RA-1900 La Plata, Argentina. Natl Univ La Plata, Fac Ingn, Dept Ingn Quim, RA-1900 La Plata, Argentina. Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94706 USA. RP Ferretti, OA (reprint author), Natl Univ La Plata, Ctr Invest & Desarrollo Ciencias Aplicadas Dr Jor, CINDECA, Fac Ciencias Exactas, RA-1900 La Plata, Argentina. RI Ramallo-Lopez, Jose/N-1757-2016; Requejo, Felix/O-2260-2016; OI Ramallo-Lopez, Jose/0000-0002-8233-2644; Requejo, Felix/0000-0003-4439-864X; Giovanetti, Lisandro/0000-0001-5286-3463 NR 54 TC 58 Z9 58 U1 4 U2 37 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 OCT 16 PY 2003 VL 107 IS 41 BP 11441 EP 11451 DI 10.1021/jp030579y PG 11 WC Chemistry, Physical SC Chemistry GA 730YJ UT WOS:000185857500026 ER PT J AU Liu, W Bratko, D Prausnitz, JM Blanch, HW AF Liu, W Bratko, D Prausnitz, JM Blanch, HW TI Electrostatic interactions between peptides and the molecular chaperone DnaK SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PROTEIN-PROTEIN INTERACTIONS; SUBSTRATE-BINDING DOMAIN; DIPOLE POTENTIALS; FREE-ENERGIES; SPECIFICITY; MODELS AB The molecular chaperone DnaK prevents intracellular protein misfolding and aggregation by transiently binding with newly synthesized polypeptides and protein-folding intermediates. DnaK preferentially binds to peptides with basic residues (Arg/Lys) present on the outside of a hydrophobic core. The electrostatic contribution toward DnaK/peptide binding was determined by measuring the dissociation constant of DnaK complexes with two fluorescein-labeled peptides (f-NRLLLTG and f-NALLLTG) using fluorescence anisotropy. The measured dissociation constants, K-d, differ significantly at low ionic strength: at 20 mM phosphate buffer; K-d for DnaK and f-NRLLLTG is 0.2 muM while that for DnaK and f-NALLLTG is 1 muM. This difference, attributed to stronger Coulombic binding in the case of f-NRLLLTG, vanishes at high ionic strength due to electrostatic screening. For f-NRAAATG, no interaction with DnaK was apparent, showing that hydrophobic interactions are essential in chaperone/peptide binding. The ionic strength dependence of the electrostatic interaction between DnaK and NRLLLTG is interpreted in terms of an approximate analytic model for the potential of mean force between DnaK and dipolar peptide. The calculated electrostatic binding free energy, DeltaG(ele), of about -1 kcal/mol, is in good agreement with the experiment result for low salt concentration, as obtained from the ionic strength dependence of the measured dissociation constants. Our analytic model, here generalized to a pair of particles differing in size, charge, and dipole, provides a useful first estimate of electrostatic effects that can be exploited for control of protein-protein interactions. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Blanch, HW (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 45 TC 6 Z9 6 U1 1 U2 3 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 OCT 16 PY 2003 VL 107 IS 41 BP 11563 EP 11569 DI 10.1021/jp035872c PG 7 WC Chemistry, Physical SC Chemistry GA 730YJ UT WOS:000185857500039 ER PT J AU Rosner, R AF Rosner, R TI Solar physics - Heat exposure SO NATURE LA English DT Editorial Material ID CORONA C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. EM r-rosner@uchicago.edu NR 5 TC 6 Z9 6 U1 0 U2 1 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD OCT 16 PY 2003 VL 425 IS 6959 BP 672 EP 673 DI 10.1038/425672a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 732DA UT WOS:000185924500024 PM 14562084 ER PT J AU Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C 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 Wahl, M 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 Pegna, DL Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Ramirez, JE Rolke, WA Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M AF Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C 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 Wahl, M 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 Pegna, DL Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Ramirez, JE Rolke, WA Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M CA FOCUS Collaboration TI Search for rare and forbidden 3-body di-muon decays of the charmed mesons D+ and D-s(+) SO PHYSICS LETTERS B LA English DT Article ID SMALL SIGNALS AB Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report results of a search for eight rare and Standard-Model-forbidden decays: D+, D-S(+) --> h(+/-)mu(-/+)mu(+) (with h = pi, K). Improvement over previous results by a factor of 1.7-14 is realized. Our branching ratio upper limit D+ --> pi(+)mu(-)mu(+) of 8.8 x 10(-6) at the 90% C.L. is below the current MSSM R-parity violating constraint. (C) 2003 Published by Elsevier B.V. C1 Univ Calif Davis, Davis, CA 95616 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, RJ, 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. INFN, Milan, Italy. Univ Milan, Milan, Italy. Univ N Carolina, Asheville, NC 28804 USA. Dipartimento Fis Nucl & Teoria, Pavia, Italy. INFN, Pavia, Italy. Univ Puerto Rico, Mayaguez, PR 00681 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Tennessee, Knoxville, TN 37996 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Johns, WE (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014; Gobel Burlamaqui de Mello, Carla /H-4721-2016; Menasce, Dario Livio/A-2168-2016; Gianini, Gabriele/M-5195-2014 OI bianco, stefano/0000-0002-8300-4124; Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Menasce, Dario Livio/0000-0002-9918-1686; Gianini, Gabriele/0000-0001-5186-0199 NR 18 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 2003 VL 572 IS 1-2 BP 21 EP 31 DI 10.1016/j.physletb.2003.07.079 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 729ZH UT WOS:000185804400003 ER PT J AU Barone, V Calarco, T Drago, A Simani, MC AF Barone, V Calarco, T Drago, A Simani, MC TI Flavor asymmetry of the polarized light sea: models vs. data SO PHYSICS LETTERS B LA English DT Article ID N-C LIMIT; PARTON DISTRIBUTIONS; SPIN STRUCTURE; NUCLEON; CONFINEMENT AB The flavor asymmetry of the polarized light sea, Delta(u) over bar-Delta(d) over bar, discriminates between different model calculations of helicity densities. We show that the chiral chromodielectric model, differently from models based on a 1/N-C expansion, predicts a small value for this asymmetry, what seems in agreement with preliminary HERMES data. (C) 2003 Published by Elsevier B.V. C1 Univ Piemonte Orientale A Avogadro, DiSTA, I-15100 Alessandria, Italy. INFN, Grp Coll Alessandria, I-15100 Alessandria, Italy. ECT, I-38050 Trent, Italy. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. INFN, Sez Ferrara, I-44100 Ferrara, Italy. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Barone, V (reprint author), Univ Piemonte Orientale A Avogadro, DiSTA, I-15100 Alessandria, Italy. NR 22 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 16 PY 2003 VL 572 IS 1-2 BP 32 EP 36 DI 10.1016/j.physletb.2003.07.082 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 729ZH UT WOS:000185804400004 ER PT J AU McBride, MT Masquelier, D Hindson, BJ Makarewicz, AJ Brown, S Burris, K Metz, T Langlois, RG Tsang, KW Bryan, R Anderson, DA Venkateswaran, KS Milanovich, FP Colston, BW AF McBride, MT Masquelier, D Hindson, BJ Makarewicz, AJ Brown, S Burris, K Metz, T Langlois, RG Tsang, KW Bryan, R Anderson, DA Venkateswaran, KS Milanovich, FP Colston, BW TI Autonomous detection of aerosolized Bacillus anthracis and Yersinia pestis SO ANALYTICAL CHEMISTRY LA English DT Article ID BIOLOGICAL AEROSOLS; AIRBORNE BIOSENSOR; AGENT-DETECTION; FLUORESCENCE; BIOAEROSOLS; INSTRUMENT; BACTERIA; SPORES; SIZE AB We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system is designed to provide early warning to civilians in the event of a terrorist attack. The final APDS will be completely automated, offering aerosol sampling, in-fine sample preparation fluidics, multiplexed detection and identification immunoassays, and orthogonal, multiplexed PCR (nucleic acid) amplification and detection. The system performance (current capabilities include aerosol collection, multiplexed immunoassays, sample archiving, data reporting, and alarming) was evaluated in a field test conducted in a Biosafety Level 3 facility, where the system was challenged with, and detected, a series of aerosolized releases containing two live, virulent biological threat agents (Bacillus anthracis and Yersinia pestis). Results presented here represent the first autonomous, simultaneous measurement of these agents. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. USA Dugway Proving Grounds, W Desert Test Ctr, Dugway, UT 84022 USA. RP Colston, BW (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,POB 808, Livermore, CA 94550 USA. NR 24 TC 79 Z9 83 U1 1 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2003 VL 75 IS 20 BP 5293 EP 5299 DI 10.1021/ac034722v PG 7 WC Chemistry, Analytical SC Chemistry GA 733VZ UT WOS:000186022500001 PM 14710805 ER PT J AU Peterson, DS Rohr, T Svec, F Frechet, JMJ AF Peterson, DS Rohr, T Svec, F Frechet, JMJ TI Dual-function microanalytical device by in situ photolithographic grafting of porous polymer monolith: Integrating solid-phase extraction and enzymatic digestion for peptide mass mapping SO ANALYTICAL CHEMISTRY LA English DT Article ID MICROSCALE ELECTROSPRAY INTERFACE; CAPILLARY ELECTROCHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; PROTEIN IDENTIFICATION; SEPARATION MEDIA; LACTATE-DEHYDROGENASE; PHOTOGRAFTING PROCESS; MICROFLUIDIC DEVICES; SURFACE MODIFICATION; STATIONARY PHASES AB Microfluidic devices with a dual function containing both a solid-phase extractor and an enzymatic microreactor have been prepared, and their operation has been demonstrated. The devices were fabricated from a 25-mm-long porous poly(butyl methacrylate-co-ethylene dimethacrylate) monolith prepared within a 50-mum-i.d. capillary. This capillary with a pulled 9-12-mum needle tip was used as a nanoelectrospray emitter coupling the device to a mass spectrometer. Photografting with irradiation through a mask was then used to selectively functionalize a 20mm-long portion of the monolith, introducing reactive poly(2-vinyl-4,4-dimethylazlactone) chains to enable the subsequent attachment of trypsin, thereby creating an enzymatic microreactor with high proteolytic activity. The other 5 mm of unmodified hydrophobic monolith served as micro solid-phase extractor (muSPE). The dual-function devices were used in two different flow directions; concentration of myoglobin that was absorbed from its dilute solution, followed by elution and digestion or digestion, followed by concentration. Operations in both directions afforded equal sequence coverage. Different volumes of myoglobin solution ranging from 2 to 20 muL were loaded on the device. Very high sequence coverages of almost 80% were achieved for the highest loading. Despite the very short length of the extractor unit, the device operated in the digest-solid-phase extraction direction also enabled the separation of peaks that mostly contained undigested protein and peptides. C1 EO Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Frechet, JMJ (reprint author), EO Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. OI Peterson, Dominic/0000-0001-8244-565X; Frechet, Jean /0000-0001-6419-0163 FU NIGMS NIH HHS [GM-48364] NR 74 TC 161 Z9 168 U1 3 U2 40 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2003 VL 75 IS 20 BP 5328 EP 5335 DI 10.1021/ac034108j PG 8 WC Chemistry, Analytical SC Chemistry GA 733VZ UT WOS:000186022500005 PM 14710809 ER PT J AU Qian, WJ Gosche, MB Camp, DG Yu, LR Tang, KQ Smith, RD AF Qian, WJ Gosche, MB Camp, DG Yu, LR Tang, KQ Smith, RD TI Phosphoprotein isotope-coded solid-phase tag approach for enrichment and quantitative analysis of phosphopeptides from complex mixtures SO ANALYTICAL CHEMISTRY LA English DT Article ID PROTEIN IDENTIFICATION TECHNOLOGY; MASS-SPECTROMETRY; AFFINITY TAGS; PHOSPHORYLATED PROTEINS; YEAST PROTEOME; PEPTIDES; CHROMATOGRAPHY; FRAGMENTATION; DATABASE AB Many cellular processes are regulated by reversible protein phosphorylation, and the ability to broadly identify and quantify phosphoproteins from proteomes would provide a basis for gaining a better understanding of these dynamic cellular processes. However, such a sensitive, efficient, and global method capable of addressing the phosphoproteome has yet to be developed. Here we describe an improved stable-isotope labeling method using a phosphoprotein isotope-coded solid-phase tag (PhIST) for isolating and measuring the relative abundances of phosphorylated peptides from complex peptide mixtures resulting from the enzymatic digestion of extracted proteins. The PhIST approach is an extension of the previously reported phosphoprotein isotope-coded affinity tag (PhIAT) approach developed by our laboratory,(1,2) where phosphoseryl and phosphothreonyl residues were derivatized by hydroxide ion-mediated beta-elimination followed by the Michael addition of 1,2-ethanedithiol (EDT). Instead of using the biotin affinity tag, peptides containing the EDT moiety were captured and labeled in one step using isotope-coded solid-phase reagents containing either light (C-12(6), N-14) or heavy (C-13(6), N-15) stable isotopes. The captured peptides labeled with the isotope-coded tags were released from the solid-phase support by UV photocleavage and analyzed by capillary liquid chromatography-tandem mass spectrometry. The efficiency and sensitivity of the PhIST labeling approach for identification of phosphopeptides from mixtures were determined using casein proteins. Its utility for proteomic applications was demonstrated by the labeling of soluble phosphoproteins from a human breast cancer cell fine. C1 N Carolina State Univ, Dept Mol & Struct Biochem, Raleigh, NC 27695 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Qian, WJ (reprint author), N Carolina State Univ, Dept Mol & Struct Biochem, 128 Polk Hall,Campus Box 7622, Raleigh, NC 27695 USA. RI Qian, Weijun/C-6167-2011; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA93306] NR 32 TC 105 Z9 113 U1 1 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 OCT 15 PY 2003 VL 75 IS 20 BP 5441 EP 5450 DI 10.1021/ac0342774 PG 10 WC Chemistry, Analytical SC Chemistry GA 733VZ UT WOS:000186022500020 PM 14714534 ER PT J AU Steele, PT Tobias, HJ Fergenson, DP Pitesky, ME Horn, JM Czerwieniec, GA Russell, SC Lebrilla, CB Gard, EE Frank, M AF Steele, PT Tobias, HJ Fergenson, DP Pitesky, ME Horn, JM Czerwieniec, GA Russell, SC Lebrilla, CB Gard, EE Frank, M TI Laser power dependence of mass spectral signatures from individual bacterial spores in bioaerosol mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID ATMOSPHERIC AEROSOL-PARTICLES; REAL-TIME; SINGLE PARTICLES; DESORPTION/IONIZATION; CLASSIFICATION; ATOFMS; SPECTROSCOPY; FLUENCE; SIZE; IONS AB Bioaerosol mass spectrometry is being developed to analyze and identify biological aerosols in real time. Characteristic mass spectra from individual bacteria] endospores of Bacillus subtilis var. niger were obtained in a bipolar aerosol time-of-flight mass spectrometer using a pulsed 266-nm laser for molecular desorption and ionization. Spectra from single spores collected at an average fluence of similar to0.1 J/cm(2) frequently contain prominent peaks attributed to arginine, dipicolinic acid, and glutamic acid, but the shot-to-shot (spore-to-spore) variability in the data may make it difficult to consistently distinguish closely related Bacillus species with an automated routine. Fortunately, a study of the laser power dependence of the mass spectra reveals clear trends and a finite number of "spectral types" that span most of the variability. This, we will show, indicates that a significant fraction of the variability must be attributed to fluence variations in the profile of the laser beam. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Frank, M (reprint author), Lawrence Livermore Natl Lab, 700 East Ave,L-174, Livermore, CA 94550 USA. RI Frank, Matthias/O-9055-2014 NR 31 TC 46 Z9 47 U1 0 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 2003 VL 75 IS 20 BP 5480 EP 5487 DI 10.1021/ac034419u PG 8 WC Chemistry, Analytical SC Chemistry GA 733VZ UT WOS:000186022500025 PM 14710828 ER PT J AU Chen, DH Xu, WD Bales, E Colmenares, C Conacci-Sorrell, M Ishii, S Stavnezer, E Campisi, J Fisher, DE Ben-Ze'ev, A Medrano, EE AF Chen, DH Xu, WD Bales, E Colmenares, C Conacci-Sorrell, M Ishii, S Stavnezer, E Campisi, J Fisher, DE Ben-Ze'ev, A Medrano, EE TI SKI activates Wnt/beta-catenin signaling in human melanoma SO CANCER RESEARCH LA English DT Article ID TRANSFORMING-GROWTH-FACTOR; BETA-CATENIN; TRANSCRIPTION FACTOR; LIM-DOMAIN; NEURAL CREST; SMAD PROTEINS; CO-REPRESSOR; TARGET GENE; DNA-BINDING; CELL-LINES AB Overexpression of the oncoprotein SKI correlates with the progression of human melanoma in vivo. SKI is known to curtail the growth inhibitory activity of tumor growth factor beta through the formation of repressive transcriptional complexes with Smad2 and Smad3 at the p21(Waf-1) promoter. Here, we show that SKI also stimulates growth by activating the Wnt signaling pathway. From a yeast two-hybrid screen and immunoprecipitation studies, we identified the protein FHL2/DRAL as a novel SKI binding partner. FHL2, a LIM-only protein, binds beta-catenin and can function as either a transcriptional repressor or activator of the Wnt signaling pathway. SKI enhanced the activation of FHL2 and/or beta-catenin-regulated gene promoters in melanoma cells. Among the SKI targets were microphthalmia-associated transcription factor and Nr-CAM, two proteins associated with melanoma cell survival, growth, motility, and transformation. Transient overexpression of SKI and FHL2 in ski(-/-) melanocytes synergistically enhanced cell growth, and stable overexpression of SKI in a poorly clonogenic human melanoma cell line was sufficient to stimulate rapid proliferation, decreasing the number of cells in the G(1) phase of the cell cycle, and dramatically increasing clonogenicity, colony size and motility. Taken together, these results suggest that by targeting members of the tumor growth factor beta and beta-catenin pathways, SKI regulates crucial events required for melanoma growth, survival, and invasion. C1 Baylor Coll Med, Huffington Ctr Aging, Houston, TX 77030 USA. Baylor Coll Med, Dept Mol & Cellular Biol, Houston, TX 77030 USA. Baylor Coll Med, Dept Dermatol, Houston, TX 77030 USA. Cleveland Clin Fdn, Dept Canc Biol, Cleveland, OH 44195 USA. Weizmann Inst Sci, Dept Mol Cell Biol, IL-76100 Rehovot, Israel. Riken Tsukuba Inst, Tsukuba, Ibaraki 3050074, Japan. Case Western Reserve Univ, Dept Biochem, Cleveland, OH 44106 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Harvard Univ, Sch Med, Dana Farber Canc Inst, Dept Pediat Oncol, Boston, MA 02115 USA. RP Medrano, EE (reprint author), Baylor Coll Med, Huffington Ctr Aging, 1 Baylor Plaza M-320, Houston, TX 77030 USA. RI Ishii, Shunsuke/A-5271-2016 FU NCI NIH HHS [CA43600, R01 CA84282]; NIA NIH HHS [AG099909] NR 60 TC 78 Z9 82 U1 1 U2 7 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD OCT 15 PY 2003 VL 63 IS 20 BP 6626 EP 6634 PG 9 WC Oncology SC Oncology GA 737DJ UT WOS:000186213800009 PM 14583455 ER PT J AU Rodriguez, JA AF Rodriguez, JA TI Electronic and chemical properties of mixed-metal oxides: basic principles for the design of DeNO(x) and DeSO(x) catalysts SO CATALYSIS TODAY LA English DT Article DE mixed-metal oxides; electronic effects; DeNO(x) and DeSO(x) ID OXIDATIVE DEHYDROGENATION; ADSORPTION; SURFACES; NO; BEHAVIOR; SO2; MGO(100); CEO2; CO; CRXMG1-XO(100) AB Correlations between the electronic and chemical properties of perovskites, molybdates, and metal-doped MgO or CeO2 are examined. Simple models based on band-orbital mixing can explain trends found for the interaction of these catalytic materials with adsorbates: the less stable the occupied levels of a mixed-metal oxide, the higher its chemical reactivity. Metal <----> oxygen <----> metal interactions are common in mixed-metal oxides and can lead to substantial changes in the electronic and chemical properties of the cations. This is particularly true in the case of ABO(3) perovskites (A = Pb, Ca, Sr, Li, K, Na; B = Ti, Zr, Nb), and it is an important phenomenon that has to be considered when mixing AO and BO2 oxides for catalytic applications. In systems like Ce1-xZrxO2 and Ce1-xCaxO2, the structural stress induced by the dopant (Zr or Ca) leads to perturbations in the electronic properties of the Ce cations. The trends in the behavior of metal-doped MgO illustrate a basic principle in the design of mixed-metal oxide catalysts for DeNO(x), and DeSO(x) operations. The general idea is to find metal dopants that upon hybridization within an oxide matrix remain in a relatively low oxidation state and at the same time induce occupied electronic states located well above the valence band of the host oxide. Electronic effects should not be neglected a priori when explaining the behavior or dealing with the design of mixed-metal oxide catalysts. (C) 2003 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov NR 51 TC 23 Z9 23 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 EI 1873-4308 J9 CATAL TODAY JI Catal. Today PD OCT 15 PY 2003 VL 85 IS 2-4 BP 177 EP 192 DI 10.1016/S0920-5861(03)00385-7 PG 16 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 738FG UT WOS:000186275600010 ER PT J AU Henderson, MA Szanyi, J Peden, CHF AF Henderson, MA Szanyi, J Peden, CHF TI Conversion of N2O to N-2 on TiO2(110) SO CATALYSIS TODAY LA English DT Article DE TiO2(110); vacancy oxidation; N2O; N-2; temperature programmed desorption; X-ray photoelectron spectroscopy; electron energy loss spectroscopy ID MOLECULAR-BEAM; NITROUS-OXIDE; PHOTOCATALYTIC DECOMPOSITION; ELECTRON-TRANSFER; TITANIUM-DIOXIDE; ROOM-TEMPERATURE; TIO2 POWDER; ADSORPTION; NO; SURFACES AB In this study, we examine the interaction of N2O with TiO2(1 1 0) in an effort to better understand the conversion of NOx, species to N-2 over TiO2-based catalysts. The TiO2(1 1 0) surface was chosen as a model system because this material is commonly used as a support and because oxygen vacancies on this surface are perhaps the best available models for the role of electronic defects in catalysis. Annealing TiO2(0 1 0) in vacuum at high temperature (above about 800 K) generates oxygen vacancy sites that are associated with reduced surface cations (Ti3+ sites) and that are easily quantified using temperature programmed desorption (TPD) of water. Using TPD, X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS), we found that the majority of N2O molecules adsorbed at 90 K on TiO2 (1 1 0) are weakly held and desorb from the surface at 130 K. However, a small fraction of the N2O molecules exposed to TiO2(0 1 0) at 90 K decompose to N-2 via one of two channels, both of which are vacancy-mediated. One channel occurs at 90 K, and results in N-2 ejection from the surface and vacancy oxidation. We propose that this channel involves N2O molecules bound at vacancies with the O-end of the molecule in the vacancy. The second channel results from an adsorbed state of N2O that decomposes at 170 K to liberate N-2 in the gas phase and deposit oxygen adatoms at non-defect Ti4+ sites. The presence of these O adatoms is clearly evident in subsequent water TPD measurements. We propose that this channel involves N2O molecules that are bound at vacancies with the N-end of the molecule in the vacancy, which permits the O-end of the molecule to interact with an adjacent Ti4+ site. The partitioning between these two channels is roughly 1: 1 for adsorption at 90 K, but neither is observed to occur for moderate N2O exposures at temperatures above 200 K. EELS data indicate that vacancies readily transfer charge to N2O at 90 K, and this charge transfer facilitates N2O decomposition. Based on these results, it appears that the decomposition of N2O to N-2 requires trapping of the molecule at vacancies and that the lifetime of the N2O-vacancy interaction may be key to the conversion of N2O to N-2. (C) 2003 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Henderson, MA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999,KS K8-93, Richland, WA 99352 USA. OI Peden, Charles/0000-0001-6754-9928 NR 39 TC 22 Z9 25 U1 2 U2 33 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD OCT 15 PY 2003 VL 85 IS 2-4 BP 251 EP 266 DI 10.1016/S0920-5861(03)00392-4 PG 16 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 738FG UT WOS:000186275600017 ER PT J AU Jin, MH Ford, RM Cummings, PT AF Jin, MH Ford, RM Cummings, PT TI A numerical method for solving a scalar advection-dominated transport equation with concentration-dependent sources SO COMPUTERS & CHEMICAL ENGINEERING LA English DT Article DE Bott's scheme; numerical dispersion; advection-dispersion equation ID NONLINEAR RENORMALIZATION; SCHEME; FLUXES AB A numerical scheme, upstream biased Eulerian algorithm for transport equations with sources (UpBEATES), is developed for solving a scalar advective-dominated transport equation with concentration-independent and -dependent source terms. A control-volume method is used for spatial discretization. Time integration is invoked to yield a discrete system of integrated-flux-integrated-source form equations. The Bott's upstream-biased Eulerian advection scheme [Moneatry and Weakly Review 117 (1989a) 1006; Moneatry and Weakly Review 117 (1989b) 2633] is employed for approximating advective fluxes. A two-level time weighting scheme is employed for the dispersive fluxes. An upstream-biased Eulerian algorithm is proposed for the concentration-dependent source term. Flux and source limiters are developed to ensure non-negative evolution of the scalar concentration field. Numerical experiments were presented to illustrate its performance in comparison with theoretical solutions and those of conventional methods. The proposed scheme is mass-conservative, produces non-negative concentration values, exhibits low numerical dispersion, and is efficient for advection-dominated problems with concentration-dependent source terms. Like other Eulerian schemes, the Courant-Friedrich-Levy (CFL) stability criterion has to be met. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Univ Virginia, Dept Chem Engn, Charlottesville, VA 22903 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RP Ford, RM (reprint author), Univ Virginia, Dept Chem Engn, Charlottesville, VA 22903 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 18 TC 0 Z9 0 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-1354 J9 COMPUT CHEM ENG JI Comput. Chem. Eng. PD OCT 15 PY 2003 VL 27 IS 10 BP 1405 EP 1419 DI 10.1016/S0098-1354(03)00008-5 PG 15 WC Computer Science, Interdisciplinary Applications; Engineering, Chemical SC Computer Science; Engineering GA 715VZ UT WOS:000184994500004 ER PT J AU Sauras-Yera, T Tent, J Ivanov, Y Hinton, TG Rauret, G Vallejo, R AF Sauras-Yera, T Tent, J Ivanov, Y Hinton, TG Rauret, G Vallejo, R TI Reduction of crop contamination by soil resuspension within the 30-km zone of the Chernobyl Nuclear Power Plant SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID PASTURE GRASS; SURFACES; PARTICLES; NITROGEN; ADHESION; REQUIREMENTS; FERTILIZER; TRANSPORT; ANIMALS; TILLAGE AB A field experiment was conducted within the 30-km zone of the Chernobyl Nuclear Power Plant to analyze whether the application of mulching reduced resuspension of Cs-137 contaminated soil in oat (Avena sativa) crops. In 1993, we applied a mulch treatment at a dose of 200 g m(-2), and soil resuspension was measured by estimating soil loadings onto plant surfaces from Ti concentrations in plants. In 1994, two mulch doses were applied, 200 and 50 g m(-2), and we estimated the contribution of soil resuspension by using artificial resuspension collection devices (ARC). In the 1993 experiment between 4.6 and 34.4% of the plant's total Cs-137 contamination was attributed to external soil contamination. The mean amount of soil-derived Cs-137 attached to vegetation was 124.7 Bq kg(-1) plant in control plots and 53.7 Bq kg(-1) plant in mulched plots. In the 1994 experiment, covering the soil with a mulch layer decreased the radiocesium content in ARC by about 70%. Results obtained in these experiments suggest that soil resuspension was a significant mechanism for plant contamination and that mulching was effective in reducing that contamination. C1 Univ Barcelona, Dept Biol Vegetal, E-08028 Barcelona, Spain. Univ Barcelona, Dept Quim Analit, E-08028 Barcelona, Spain. Ukranian Inst Agr Radiol, Kiev, Ukraine. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29801 USA. CEAM, E-46980 Paterna, Spain. RP Sauras-Yera, T (reprint author), Univ Barcelona, Dept Biol Vegetal, Diagonal 645, E-08028 Barcelona, Spain. NR 27 TC 1 Z9 1 U1 0 U2 6 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 OCT 15 PY 2003 VL 37 IS 20 BP 4592 EP 4596 DI 10.1021/es026377h PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 735UM UT WOS:000186133000010 PM 14594366 ER PT J AU Fuller, CC Bargar, JR Davis, JA AF Fuller, CC Bargar, JR Davis, JA TI Molecular-scale characterization of uranium sorption by bone apatite materials for a permeable reactive barrier demonstration SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; ZERO-VALENT IRON; LEAD IMMOBILIZATION; COMPLEXES; HYDROXYAPATITE; GROUNDWATER; REMEDIATION; U(VI); PRODUCTS AB Uranium binding to bone charcoal and bone meal apatite materials was investigated using U L-III-edge EXAFS spectroscopy and synchrotron source XRD measurements of laboratory batch preparations in the absence and presence of dissolved carbonate. Pelletized bone char apatite recovered from a permeable reactive barrier (PRB) at Fry Canyon, UT, was also studied. EXAFS analyses indicate that U(VI) sorption in the absence of dissolved carbonate occurred by surface complexation of U(VI) for sorbed concentrations less than or equal to 5500 mug U(VI)/g for all materials with the exception of crushed bone char pellets. Either a split or a disordered equatorial oxygen shell was observed, consistent with complexation of uranyl by the apatite surface. A second shell of atoms at a distance of 2.9 Angstrom was required to fit the spectra of samples prepared in the presence of dissolved carbonate (4.8 mM total) and is interpreted as formation of ternary carbonate complexes with sorbed MO. A U-P distance at 3.5-3.6 Angstrom was found for most samples under conditions where uranyl phosphate phases did not form, which is consistent with monodentate coordination of uranyl by phosphate groups in the apatite surface. At sorbed concentrations greater than or equal to 5500 mug U(VI)/g in the absence of dissolved carbonate, formation of the uranyl phosphate solid phase, chernikovite, was observed. The presence of dissolved carbonate (4.8 mM total) suppressed the formation of chernikovite, which was not detected even with sorbed U(VI) up to 12 300 mug U(VI)/g in batch samples of bone meal, bone charcoal, and reagent-grade hydroxyapatite. EXAFS spectra of bone char samples recovered from the Fry Canyon PRB were comparable to laboratory samples in the presence of dissolved carbonate where U(VI) sorption occurred by surface complexation. Our findings demonstrate that uranium uptake by bone apatite will probably occur by surface complexation instead of precipitation of uranyl phosphate phases under the groundwater conditions found at many U-contaminated sites. C1 US Geol Survey, Menlo Pk, CA 94025 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Fuller, CC (reprint author), US Geol Survey, 345 Middlefield Rd,MS 465, Menlo Pk, CA 94025 USA. OI Fuller, Christopher/0000-0002-2354-8074 NR 34 TC 59 Z9 63 U1 3 U2 39 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 OCT 15 PY 2003 VL 37 IS 20 BP 4642 EP 4649 DI 10.1021/es0343959 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 735UM UT WOS:000186133000017 PM 14594373 ER PT J AU Kalabegishvili, TL Tsibakhashvili, NY Holman, HYN AF Kalabegishvili, TL Tsibakhashvili, NY Holman, HYN TI Electron spin resonance study of chromium(V) formation and decomposition by basalt-inhabiting bacteria SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SHEWANELLA-ONEIDENSIS MR-1; LOW-FREQUENCY EPR; CHROMATE REDUCTION; ARTHROBACTER-OXYDANS; AQUEOUS-SOLUTIONS; CR(VI); IDENTIFICATION; GLUTATHIONE; GENERATION; COMPLEXES AB Bacterial reduction of Cr(VI) to Cr(III) compounds may produce reactive intermediates Cr(V) and Cr(IV), which can affect the mobility and toxicity of chromium in environments. To address this important subject, we conducted an electron spin resonance (ESR) study to understand the kinetics of the formation and decomposition of Cr(V) during Cr(VI) reduction by different Gram-positive Cr(VI)-tolerant bacteria, which were isolated from polluted basalts from the United States of America and the Republic of Georgia. Results from our batch experiments show that during Cr(VI) reduction, the macromolecules at the cell wall of these bacteria could act as an electron donor to Cr(VI) to form a stable square-pyramidal Cr(V) complexes, which were reduced further probably via a one-electron transfer pathway to form Cr(IV) and Cr(III) Compounds. The Cr(V) peak at the ESR spectrum possessed superhyperfine splitting characteristic of the Cr(V) complexes with diol-containing molecules. It appears that the kinetics of Cr(V) formation and decomposition depended on the bacterial growth phase and on the species. Both formation and decomposition of Cr(V) occurred more quickly when Cr(VI) was added at the exponential phase. In comparison with other Gram-positive bacteria from the republic of Georgia, the formation and decomposition of Cr(V) in Arthrobacter species from the Unites States was significantly slower. C1 Georgian Acad Sci, Andronikashvili Inst Phys, GE-0177 Tbilisi, Rep of Georgia. Lawrence Berkeley Lab, Ctr Environm Biotechnol, Berkeley, CA 94720 USA. RP Tsibakhashvili, NY (reprint author), Georgian Acad Sci, Andronikashvili Inst Phys, GE-0177 Tbilisi, Rep of Georgia. RI Holman, Hoi-Ying/N-8451-2014 OI Holman, Hoi-Ying/0000-0002-7534-2625 NR 39 TC 25 Z9 25 U1 0 U2 5 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 OCT 15 PY 2003 VL 37 IS 20 BP 4678 EP 4684 DI 10.1021/es0343510 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 735UM UT WOS:000186133000022 PM 14594378 ER PT J AU Lunden, MM Thatcher, TL Hering, SV Brown, NJ AF Lunden, MM Thatcher, TL Hering, SV Brown, NJ TI Use of time- and chemically resolved particulate data to characterize the infiltration of outdoor PM2.5 into a residence in the San Joaquin Valley SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID AIRBORNE PARTICLES; AIR-POLLUTION; NITRIC-ACID; INDOOR; PENETRATION; DEPOSITION; NITRATE; MATTER; CALIFORNIA; EXPOSURE AB Recent studies associate particulate air pollution with adverse health effects. The indoor exposure to particles of outdoor origin is not well-characterized, particularly for individual chemical species. In response to this, a field study in an unoccupied, single-story residence in Clovis, CA, was conducted. Real-time particle monitors were used both outdoors and indoors to quantity PM2.5 nitrate, sulfate, and carbon. The aggregate of the highly time-resolved sulfate data, as well as averages, of these data, was fit using a time-averaged form of the infiltration equation, resulting in reasonable values for the penetration coefficient and deposition loss rate. In contrast, individual values of the indoor/outdoor ratio can vary significantly from that predicted by the model for time scales ranging from a few minutes to several hours. Measured indoor ammonium nitrate levels were typically significantly lower than expected solely on the basis of penetration and deposition losses. The additional reduction is due to the transformation of ammonium nitrate into ammonia and nitric acid gases indoors, which are subsequently lost by deposition and sorption to indoor surfaces. This result illustrates that exposure assessments based on total outdoor particle mass can obscure the actual causal relationships for indoor exposures to particles of outdoor origin. C1 Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Aerosol Dynam Inc, Berkeley, CA 94710 USA. RP Lunden, MM (reprint author), Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Hering, Susanne/B-1906-2012 NR 37 TC 34 Z9 35 U1 2 U2 13 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 OCT 15 PY 2003 VL 37 IS 20 BP 4724 EP 4732 DI 10.1021/es026387i PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 735UM UT WOS:000186133000028 PM 14594384 ER PT J AU Lee, SY De la Torre, A Yan, DL Kustu, S Nixon, BT Wemmer, DE AF Lee, SY De la Torre, A Yan, DL Kustu, S Nixon, BT Wemmer, DE TI Regulation of the transcriptional activator NtrC1: structural studies of the regulatory and AAA(+) ATPase domains SO GENES & DEVELOPMENT LA English DT Article DE AAA(+) ATPase; crystal structure; sigma(54); transcriptional activator; response regulator; two-component system ID ENHANCER-BINDING PROTEIN; RHIZOBIUM-MELILOTI DCTD; MIGRATION MOTOR PROTEIN; FORK JUNCTION DNA; CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; SIGMA(54)-DEPENDENT ACTIVATOR; CONFORMATIONAL-CHANGES; BRANCH MIGRATION; RECEIVER DOMAIN AB Transcription by sigma(54) RNA polymerase depends on activators that contain ATPase domains of the AAA(+) class. These activators, which are often response regulators of two-component signal transduction systems, remodel the polymerase so that it can form open complexes at promoters. Here, we report the first crystal structures of the ATPase domain of an activator, the NtrC1 protein from the extreme thermophile Aquifex aeolicus. This domain alone, which is active, crystallized as a ring-shaped heptamer. The protein carrying both the ATPase and adjacent receiver domains, which is inactive, crystallized as a dimer. In the inactive dimer, one residue needed for catalysis is far from the active site, and extensive contacts among the domains prevent oligomerization of the ATPase domain. Oligomerization, which completes the active site, depends on surfaces that are buried in the dimer, and hence, on a rearrangement of the receiver domains upon phosphorylation. A motif in the ATPase domain known to be critical for coupling energy to remodeling of polymerase forms a novel loop that projects from the middle of an alpha helix. The extended, structured loops from the subunits of the heptamer localize to a pore in the center of the ring and form a surface that could contact sigma(54). C1 Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol Cellular Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Penn State Univ, Dept Biochem & Mol Biol, University Pk, PA 16802 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM38361, GM62163, R01 GM038361, R01 GM062163, R37 GM038361] NR 59 TC 137 Z9 141 U1 0 U2 3 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI WOODBURY PA 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2924 USA SN 0890-9369 J9 GENE DEV JI Genes Dev. PD OCT 15 PY 2003 VL 17 IS 20 BP 2552 EP 2563 DI 10.1101/gad.1125603 PG 12 WC Cell Biology; Developmental Biology; Genetics & Heredity SC Cell Biology; Developmental Biology; Genetics & Heredity GA 733TT UT WOS:000186017300009 PM 14561776 ER PT J AU Vassiliadis, D Klimas, AJ Weigel, RS Baker, DN Rigler, EJ Kanekal, SG Nagai, T Fung, SF Friedel, RWH Cayton, TE AF Vassiliadis, D Klimas, AJ Weigel, RS Baker, DN Rigler, EJ Kanekal, SG Nagai, T Fung, SF Friedel, RWH Cayton, TE TI Structure of Earth's outer radiation belt inferred from long-term electron flux dynamics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; RELATIVISTIC ELECTRONS; MAGNETOSPHERE; ACCELERATION; SAMPEX; ZONE AB [1] We map the spatial structure of the electron belts over their radial range (L = 1 - 11 R-E) using a total of 25 years of observations by NASA, ISAS, and GPS spacecraft. Correlation analysis reveals significant radial structuring of the outer belt and identifies three regions, while earlier single-spacecraft studies are used to interpret the results. The central region P-1 ( L = 4.1 - 7.5 R-E) has a well-known slow response ( 2 - 3 days) most probably due to shear-hydrodynamic effects of the interplanetary medium, which excite ULF waves at low latitudes. In the innermost region P-0 (L = 3.0 - 4.1 R-E) the electron response is rapid (<1 day). It appears related to solar wind ram-hydrodynamic inputs (compressions) and/or time-varying interplanetary electric and magnetic fields. Region P-2 (L > 7.5 R-E) has a much weaker brief response to magnetic field orientation and low interplanetary plasma velocities, anticorrelated with the other two regions. The findings and, in addition, the solar-cycle modulation of the region size strongly suggest that the solar wind excites nonlinear response modes in the inner magnetosphere which are prototypically revealed in the three regions. Given this spatial variability, the optimal approach to next-generation modeling and electron storm forecasting may differ considerably for each region. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Colorado, Lab Astrophys & Space Phys, Boulder, CO 80309 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Tokyo Inst Technol, Tokyo 152, Japan. Los Alamos Natl Lab, NIS Div 2, Los Alamos, NM USA. RP Vassiliadis, D (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RI Fung, Shing/F-5647-2012; Friedel, Reiner/D-1410-2012 OI Friedel, Reiner/0000-0002-5228-0281 NR 17 TC 17 Z9 17 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 2003 VL 30 IS 19 AR 2015 DI 10.1029/2003gl017328 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 734YT UT WOS:000186086100001 ER PT J AU Streets, DG Yarber, KF Woo, JH Carmichael, GR AF Streets, DG Yarber, KF Woo, JH Carmichael, GR TI Biomass burning in Asia: Annual and seasonal estimates and atmospheric emissions SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE Asia; atmospheric emissions; biomass burning ID INDIA; COMBUSTION; AEROSOL; FIRES AB [1] Estimates of biomass burning in Asia are developed to facilitate the modeling of Asian and global air quality. A survey of national, regional, and international publications on biomass burning is conducted to yield consensus estimates of "typical'' (i.e., non-year-specific) estimates of open burning ( excluding biofuels). We conclude that 730 Tg of biomass are burned in a typical year from both anthropogenic and natural causes. Forest burning comprises 45% of the total, the burning of crop residues in the field comprises 34%, and 20% comes from the burning of grassland and savanna. China contributes 25% of the total, India 18%, Indonesia 13%, and Myanmar 8%. Regionally, forest burning in Southeast Asia dominates. National, annual totals are converted to daily and monthly estimates at 1degrees x 1degrees spatial resolution using distributions based on AVHRR fire counts for 1999 - 2000. Several adjustment schemes are applied to correct for the deficiencies of AVHRR data, including the use of moving averages, normalization, TOMS Aerosol Index, and masks for dust, clouds, landcover, and other fire sources. Good agreement between the national estimates of biomass burning and adjusted fire counts is obtained (R-2 = 0.71 - 0.78). Biomass burning amounts are converted to atmospheric emissions, yielding the following estimates: 0.37 Tg of SO2, 2.8 Tg of NOx, 1100 Tg of CO2, 67 Tg of CO, 3.1 Tg of CH4, 12 Tg of NMVOC, 0.45 Tg of BC, 3.3 Tg of OC, and 0.92 Tg of NH3. Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of +/- 65% for CO2 emissions in Japan to a high of +/- 700% for BC emissions in India. C1 Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52240 USA. RP Streets, DG (reprint author), Argonne Natl Lab, Decis & Informat Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 42 TC 285 Z9 318 U1 16 U2 106 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD OCT 15 PY 2003 VL 17 IS 4 AR 1099 DI 10.1029/2003GB002040 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 734ZC UT WOS:000186087000001 ER PT J AU Yoo, K Zhang, ZY Wendelken, JF AF Yoo, K Zhang, ZY Wendelken, JF TI A novel growth approach of ultrasmall Ge and Si nanoclusters on a Si(100) substrate without a wetting layer SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE nanoclusters; growth; Ge islands; silicon; low-temperature synthesis; STM; MBE ID ISLAND FORMATION; HUT CLUSTERS; SI(001); PHOTOLUMINESCENCE; NANOCRYSTALS; INTERFACES; SURFACES; COVERAGE; DOTS AB Growth of ultrasmall Ge and Si nanoclusters has been achieved on a Si(100) substrate in the use of Xe buffer layer. The temporary use of Xe buffer layer, which has the low surface free energy, leads to nanoclusters formation on Si(100) due to the indirect interaction between deposited Ge or Si atoms and a Si(100) substrate. The formation of Ge and Si nanoclusters on Si(100) surface without a wetting layer was confirmed by the scanning tunneling microscope observation. Ge nanoclusters are much smaller and denser than that are grown by the Stranski-Krastanov mode. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tokyo, Inst Solid State Phys, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. RP Yoo, K (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. NR 25 TC 9 Z9 9 U1 1 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 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD OCT 15 PY 2003 VL 42 IS 10B BP L1232 EP L1234 DI 10.1143/JJAP.42.L1232 PG 3 WC Physics, Applied SC Physics GA 749UW UT WOS:000186948100004 ER PT J AU Wright, AF Myers, SM AF Wright, AF Myers, SM TI Configurations, energies, and thermodynamics of the neutral MgH complex in GaN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID P-TYPE GAN; DOPED GAN; MOLECULAR-DYNAMICS; GALLIUM NITRIDE; HYDROGEN; COMPENSATION; DEFECTS AB Atomic configurations corresponding to local-energy minima for the neutral MgH complex in wurtzite GaN are identified using density-functional theory and the generalized-gradient approximation for exchange and correlation. MgH binding energies, H local-mode vibration frequencies, and configurational degeneracies for the six lowest-energy configurations are used, along with corresponding results for isolated H+, to compute equilibrium H state populations in Mg-doped GaN as a function of temperature. For a Mg concentration of 1x10(19)/cm(3) and a H/Mg concentration ratio of 0.99, MgH is found to be the majority H species at room temperature with isolated H+ becoming the majority species at Tapproximate to550 degreesC. Among the MgH states, one is found to dominate at all temperatures. The dominant configuration consists of H at an antibonding site of a N neighbor of the substitutional Mg, with the Mg-N and N-H bonds nearly aligned and the N-H bond oriented at an angle of similar to109degrees with the c axis. The H stretch-mode frequency of the dominant state is consistent with the peak observed in Fourier-transform infrared reflection spectra from Mg-doped GaN samples. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM afwrigh@sandia.gov NR 28 TC 16 Z9 16 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2003 VL 94 IS 8 BP 4918 EP 4922 DI 10.1063/1.1610232 PG 5 WC Physics, Applied SC Physics GA 727NE UT WOS:000185664300030 ER PT J AU Zhang, DZ AF Zhang, DZ TI Modeling plate impact response of particle-polymer composite SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DYNAMIC-MECHANICAL BEHAVIOR; FILLED POLYMERS; SIMULATIONS AB A recently obtained constitutive relation [Zhang , Phys. Rev. E 66, 051806 (2002)] is used for polymers to model plate impact experiments on a composite material consisting of elastic particles and a polymer binder. The stress relaxation in the polymer is described by a kernel in a history integral. The kernel implies a 1/roott stress relaxation for a short time t, and an exponential stress relaxation for a long time. It is found that the binder behavior, especially the stress relaxation at a short-time scale, plays an essential role in the wave dispersion observed during the experiments. Although it is difficult to implement the history dependent constitutive relation directly into a numerical calculation, a mathematical approximation of the kernel is found in the form resembling a prony series. The approximation enables easy implementation of the constitutive relation into numerical calculations. While the conventional use of a prony series requires a series of experiments to determine the parameters, in the present article, the parameters in the series expansion are uniquely determined by the kernel. Furthermore, not all the terms in the series are needed for a specific problem of interest. Only those terms with the relaxation times in the range of the time scales of the physical process are important. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Zhang, DZ (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,B216, Los Alamos, NM 87545 USA. NR 14 TC 3 Z9 3 U1 2 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2003 VL 94 IS 8 BP 4938 EP 4945 DI 10.1063/1.1610235 PG 8 WC Physics, Applied SC Physics GA 727NE UT WOS:000185664300033 ER PT J AU Augustsson, A Schmitt, T Duda, LC Nordgren, J Nordlinder, S Edstrom, K Gustafsson, T Guo, JH AF Augustsson, A Schmitt, T Duda, LC Nordgren, J Nordlinder, S Edstrom, K Gustafsson, T Guo, JH TI The electronic structure and lithiation of electrodes based on vanadium-oxide nanotubes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RAY EMISSION-SPECTROSCOPY; TRANSITION-METAL COMPOUNDS; EXCITATIONS; PERFORMANCE; SCATTERING; BATTERIES; SYSTEMS; V2O3; VO2 AB The effect of lithium insertion (lithiation) in electrodes of vanadium oxide nanotubes has been studied using resonant soft-x-ray emission spectroscopy (RSXES) and soft x-ray absorption spectroscopy (SXAS). Spectra at the V L edges were recorded ex-situ on a series of cycled electrodes that had been discharged to different potentials (3.0, 2.5, 2.0, and 1.8 V). Different chemical states upon discharge effectively correspond to different doping levels: the lower the cell potential, the higher the lithiation. The RSXES and SXAS spectra reflect the occupied and unoccupied electronic states, respectively. Spectral changes are observed as a function of the reduction process of vanadium by the electrochemical process. Lithiation induces a gradual enhancement of features attributed to occupied V 3d states in the RSXES spectra, indicating that the intercalated charges occupy bands of V 3d. Both SXAS and RSXES results suggest a partial reduction to V3+ at potentials below 2.0 V and the presence of a mixture of three different oxidation states. RSXES spectra also reveal the low energy-loss feature of 1 eV, suggesting strong correlation of the V 3d orbitals. (C) 2003 American Institute of Physics. C1 Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Chem Mat, S-75121 Uppsala, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Augustsson, A (reprint author), Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. RI Schmitt, Thorsten/A-7025-2010; OI Edstroem, Kristina/0000-0003-4440-2952 NR 25 TC 15 Z9 15 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2003 VL 94 IS 8 BP 5083 EP 5087 DI 10.1063/1.1611626 PG 5 WC Physics, Applied SC Physics GA 727NE UT WOS:000185664300054 ER PT J AU Peterson, KA Li, YM Francisco, JS Zou, P Webster, CE Perez, LM Hall, MB North, SW AF Peterson, KA Li, YM Francisco, JS Zou, P Webster, CE Perez, LM Hall, MB North, SW TI The role of triplet states in the long wavelength absorption region of bromine nitrate SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; CORRELATED MOLECULAR CALCULATIONS; CORRECT ASYMPTOTIC-BEHAVIOR; COUPLED-CLUSTER THEORY; GAUSSIAN-BASIS SETS; EXCITED-STATES; EXCITATION-ENERGIES; CONFIGURATION-INTERACTION; SINGLE SUBSTITUTIONS; CHLORINE NITRATE AB A theoretical study of the low-lying singlet and triplet electronic states of BrONO2 is presented. Calculations of excitation energies and oscillator strengths are reported using excited-state coupled cluster response methods, as well as the complete active space self-consistent field method with the full Breit-Pauli spin-orbit operator. The calculations predict that there is only one singlet state for BrONO2, the (A) over tilde (1)A(') state, that is accessible at wavelengths longer than 300 nm. At energies below the first singlet state, i.e., lambda>330 nm, the calculations reveal two triplet states with significant oscillator strength. Therefore, we propose that the origin of absorption in the long wavelength region from 350 to 500 nm, responsible for the majority of atmospheric photolysis, is due to transitions to triplet states and not singlet states. A comparison of the reported benchmark coupled cluster calculations (CCSD) with the results of (1) configuration interaction with all single substitutions and a perturbative correction for the double substitutions [CIS(D)] and (2) time-dependent density-functional (TDDF) calculations is provided. For the lowest energy excitations, CIS(D) calculations provide quantitative agreement with the CCSD results, while TDDF calculations yield qualitative agreement. (C) 2003 American Institute of Physics. C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. Texas A&M Univ, Supercomp Facil, College Stn, TX 77843 USA. Texas A&M Univ, Lab Mol Simulat, College Stn, TX 77843 USA. RP Peterson, KA (reprint author), Washington State Univ, Dept Chem, Pullman, WA 99164 USA. RI Hall, Michael/B-9118-2013; North, Simon/G-5054-2012; OI Hall, Michael/0000-0003-3263-3219; North, Simon/0000-0002-0795-796X; Webster, Charles Edwin/0000-0002-6917-2957 NR 59 TC 2 Z9 2 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 OCT 15 PY 2003 VL 119 IS 15 BP 7864 EP 7870 DI 10.1063/1.1604374 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 728EK UT WOS:000185703100028 ER PT J AU Leontyev, IV Vener, MV Rostov, IV Basilevsky, MV Newton, MD AF Leontyev, IV Vener, MV Rostov, IV Basilevsky, MV Newton, MD TI Continuum level treatment of electronic polarization in the framework of molecular simulations of solvation effects SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CAVITY MODEL FRCM; LIQUID WATER; NONEQUILIBRIUM SOLVATION; DYNAMICS SIMULATIONS; FLUCTUATING CHARGE; POLAR-SOLVENTS; FREE-ENERGIES; TETRAHEDRAL QUADRUPOLES; REORGANIZATION ENERGIES; COMPUTER-SIMULATIONS AB The hybrid molecular-continuum model for polar solvation considered in this paper combines the dielectric continuum approximation for treating fast electronic (inertialess) polarization effects and a molecular dynamics (MD) simulation for the slow (inertial) polarization component, including orientational and translational solvent modes. The inertial polarization is generated by average charge distributions of solvent particles, composed of permanent and induced (electronic) components. MD simulations are performed in a manner consistent with the choice of solvent and solute charges such that all electrostatic interactions are scaled by the factor 1/epsilon(infinity), where epsilon(infinity) is the optical dielectric permittivity. This approach yields an ensemble of equilibrium solvent configurations adjusted to the electric field created by a charged or strongly polar solute. The electrostatic solvent response field is found as the solution of the Poisson equation including both solute and explicit solvent charges, with accurate account of electrostatic boundary conditions at the surfaces separating spatial regions with different dielectric permittivities. Both equilibrium and nonequilibrium solvation effects can be studied by means of this model, and their inertial and inertialess contributions are naturally separated. The methodology for computation of charge transfer reorganization energies is developed and applied to a model two-site dipolar system in the SPC water solvent. Three types of charge transfer reactions are considered. The standard linear-response approach yields high accuracy for each particular reaction, but proves to be significantly in error when reorganization energies of different reactions were compared. This result has a purely molecular origin and is absent within a conventional continuum solvent model. (C) 2003 American Institute of Physics. C1 LY Karpov Phys Chem Res Inst, Moscow 103064, Russia. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP LY Karpov Phys Chem Res Inst, Ul Vorontsovo Pole 10, Moscow 103064, Russia. RI Leontyev, Igor/B-6981-2013 NR 62 TC 35 Z9 36 U1 0 U2 7 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 OCT 15 PY 2003 VL 119 IS 15 BP 8024 EP 8037 DI 10.1063/1.1605944 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 728EK UT WOS:000185703100045 ER PT J AU Chialvo, AA Simonson, JM AF Chialvo, AA Simonson, JM TI The structure of CaCl2 aqueous solutions over a wide range of concentration. Interpretation of diffraction experiments via molecular simulation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-DIFFRACTION; NEUTRON-SCATTERING; DYNAMICS SIMULATION; CHLORIDE SOLUTIONS; LITHIUM BROMIDE; HYDRATION; ION; WATER; SOLVATION; EXAFS AB A detailed analysis of the water structure around the ionic species in aqueous CaCl2 solutions is performed by molecular dynamics over a wide range of concentration (0 Al2O3, the solubility of hafnia is linearly and positively correlated with Na2O/(Na2O + Al2O3) or Na2O - Al2O3 (excess sodium), despite the presence of 5-16 mol% B2O3. The results of this solubility study are comparable to other studies of high-valence cation solubility in B-free silicate melts. For peralkaline B-bearing glasses, it is shown that, although the solubility limits are higher, the solution behavior of hafnia is the same as in B-free silicate melts previously studied by other workers. By comparison, it is shown that in peraluminous melts there must be a different solution mechanism for hafnia, different than that for peralkaline sodium-boro-aluminosilicate glasses in this study and different than that for B-free silicate melts studied by others. The formation of moieties in the peralkaline glasses/melts, with approximate stoichiometries of Na4HfO4, Na6Hf2O7 or NaHfO3 (most likely with associated Si and B), appears to be responsible for the incorporation of large amounts of Hf in the glass matrix, and therefore high HfO2 solubility. (C) 2003 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. RP Davis, LL (reprint author), Washington & Lee Univ, Dept Geol, Lexington, VA 24450 USA. NR 32 TC 11 Z9 11 U1 1 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD OCT 15 PY 2003 VL 328 IS 1-3 BP 102 EP 122 DI 10.1016/S0022-3093(03)00479-4 PG 21 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 734VU UT WOS:000186079300009 ER PT J AU Tian, ZRR Voigt, JA Liu, J McKenzie, B Xu, HF AF Tian, ZRR Voigt, JA Liu, J McKenzie, B Xu, HF TI Large oriented arrays and continuous films of TiO2-based nanotubes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TITANIUM-OXIDE NANOTUBES; ALIGNED CARBON NANOTUBES; LONG TIO2 NANOTUBES; LOW-TEMPERATURE; ZNO NANORODS; NANOWIRES; GROWTH C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Liu, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Tian, Z. Ryan /R-6671-2016 OI Tian, Z. Ryan /0000-0002-5644-8483 NR 33 TC 400 Z9 410 U1 11 U2 100 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 OCT 15 PY 2003 VL 125 IS 41 BP 12384 EP 12385 DI 10.1021/ja0369461 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 730YF UT WOS:000185857200010 PM 14531662 ER PT J AU Farrar, CD Sorey, ML Roeloffs, E Galloway, DL Howle, JF Jacobson, R AF Farrar, CD Sorey, ML Roeloffs, E Galloway, DL Howle, JF Jacobson, R TI Inferences on the hydrothermal system beneath the resurgent dome in Long Valley caldera, east-central California, USA, from recent pumping tests and geochemical sampling SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE Long Valley caldera; hydrothermal systems; hydrology; hydraulic properties; geochemistry; thermal history ID MAMMOTH MOUNTAIN AB Quaternary volcanic unrest has provided heat for episodic hydrothermal circulation in the Long Valley caldera, including the present-day hydrothermal system, which has been active over the past 40 kyr. The most recent period of crustal unrest in this region of east-central California began around 1980 and has included periods of intense seismicity and ground deformation. Uplift totaling more than 0.7 m has been centered on the caldera's resurgent dome, and is best modeled by a near-vertical ellipsoidal source centered at depths of 6-7 km. Modeling of both deformation and microgravity data now suggests that (1) there are two inflation sources beneath the caldera, a shallower source 7-10 km beneath the resurgent dome and a deeper source similar to 15 km beneath the caldera's south moat and (2) the shallower source may contain components of magmatic brine and gas. The Long Valley Exploration Well (LVEW), completed in 1998 on the resurgent dome, penetrates to a depth of 3 km directly above this shallower source, but bottoms in a zone of 100degreesC fluid with zero vertical thermal gradient. Although these results preclude extrapolations of temperatures at depths below 3 km, other information obtained from flow tests and fluid sampling at this well indicates the presence of magmatic volatiles and fault-related permeability within the metamorphic basement rocks underlying the volcanic fill. In this paper, we present recently acquired data from LVEW and compare them with information from other drill holes and thermal springs in Long Valley to delineate the likely flow paths and fluid system properties under the resurgent dome. Additional information from mineralogical assemblages in core obtained from fracture zones in LVEW documents a previous period of more vigorous and energetic fluid circulation beneath the resurgent dome. Although this system apparently died off as a result of mineral deposition and cooling (and/or deepening) of magmatic heat sources, flow testing and tidal analyses of LVEW water level data show that relatively high permeability and strain sensitivity still exist in the steeply dipping principal fracture zone penetrated at a depth of 2.6 km. The hydraulic properties of this zone would allow a pressure change induced at distances of several kilometers below the well to be observable within a matter of days. This indicates that continuous fluid pressure monitoring in the well could provide direct evidence of future intrusions of magma or high-temperature fluids at depths of 5-7 km. (C) 2003 Elsevier B.V. All rights reserved. C1 US Geol Survey, Carnelian Bay, CA 96140 USA. US Geol Survey, Vancouver, WA USA. US Geol Survey, Sacramento, CA USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Farrar, CD (reprint author), US Geol Survey, 5229 N Lake Blvd, Carnelian Bay, CA 96140 USA. OI Galloway, Devin/0000-0003-0904-5355 NR 36 TC 8 Z9 8 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD OCT 15 PY 2003 VL 127 IS 3-4 BP 305 EP 328 DI 10.1016/S0377-0273(03)00174-4 PG 24 WC Geosciences, Multidisciplinary SC Geology GA 730GW UT WOS:000185821800007 ER PT J AU Ng, DHL Cho, KS Wong, ML Chan, SLI Ma, XY Lo, CCH AF Ng, DHL Cho, KS Wong, ML Chan, SLI Ma, XY Lo, CCH TI Study of microstructure, mechanical properties, and magnetization process in low carbon steel bars by Barkhausen emission SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE Barkhausen emission; low carbon steels; microstructures; stress and strain ID GRAIN-SIZE; MAGNETOACOUSTIC EMISSION; PEARLITIC STEELS; NOISE; STRESS; DEFORMATION; IRON; DEPENDENCE; MODEL; FIELD AB Correlation between Barkhausen emission (BE) signal, microstructure and mechanical properties of a series of low carbon steel bars after receiving different heat treatments are studied for the purpose of further developing the nondestructive BE technique to monitor the stress-strain characteristics of steel components. It is found that the BE signal, which is proportional to the number of unpinning events of domain walls (DW), is more intense in samples with small grains which have been annealed at lower temperatures, than in those with large grains which have been annealed at higher temperatures. The small-grain samples have larger BE signals, because they have large fractional volume of grain boundaries that act as sites for the DW unpinning. A qualitative model is proposed to describe the BE signal obtained from these ferritic steel samples. BE measurements are also made in-situ on each sample while it is under increasing tension. The BE signal increases in sample under tension. In the case of small-grain sample, the increase is mainly due to the re-orientation of domain configurations that facilitates the magnetization process. In the case of large-grain sample, tensile stress re-orients the domain configurations as well as creating new DWs that increase the number of unpinning events. In this work, it is also found that the BE-strain plots of the steel bars annealed at temperatures ranging from room temperature to 600 degreesC exhibit behaviors which are similar to their corresponding stress-strain curves. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Chinese Univ Hong Kong, Dept Phys, Shatin, Hong Kong, Peoples R China. Natl Taiwan Univ, Inst Mat Sci & Engn, Taipei 10764, Taiwan. Hauzhong Univ Sci & Technol, Dept Mat, Wuhan, Peoples R China. Iowa State Univ, Ames Lab, Ctr Nondestruct Evaluat, Ames, IA 50011 USA. RP Ng, DHL (reprint author), Chinese Univ Hong Kong, Dept Phys, Shatin, Hong Kong, Peoples R China. RI Chan, Sammy/B-4812-2011; OI Chan, Sammy/0000-0001-8271-3351 NR 40 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2003 VL 358 IS 1-2 BP 186 EP 198 DI 10.1016/S0921-5093(03)00295-8 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 713FE UT WOS:000184845800026 ER PT J AU Brady, MP Anderson, IM Weaver, ML Meyer, HM Walker, LR Miller, MK Larson, DJ Wright, IG Sikka, VK Rar, A Pharr, GM Keiser, JR Walls, CA AF Brady, MP Anderson, IM Weaver, ML Meyer, HM Walker, LR Miller, MK Larson, DJ Wright, IG Sikka, VK Rar, A Pharr, GM Keiser, JR Walls, CA TI Nitrogen impurity gettering in oxide dispersion ductilized chromium SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE powder processing; ODS; composites; mechanical properties; segregation; embrittlement; Cr ID HIGH-PURITY CHROMIUM; MECHANICAL-PROPERTIES; PURE CHROMIUM; TRANSITION; ALLOYS AB Work by Scruggs in the 1960s demonstrated that tensile ductility could be achieved at room temperature in powder metallurgically-produced Cr alloyed with MgO. During consolidation, much of the MgO converted to the MgCr2O4 spinel phase, which was hypothesized to getter nitrogen from the Cr, rendering it ductile. We have duplicated this effect, achieving room temperature tensile elongations of 4% for hot-pressed Cr-6MgO-(0-1)Ti (wt.%) and 10% for hot-pressed and extruded Cr-6MgO-0.75Ti. Direct incorporation of nitrogen into the MgCr2O4 phase was not detected; however, impurities, particularly nitrogen and sulfur, were observed to segregate to and/or precipitate at interfaces between the MgO/MgCr2O4 phases and the Cr matrix. Exploratory studies of other non-spinel forming oxide dispersions (La2O3, TiO2 and Y2O3) showed a similar pattern of impurity segregation/precipitation, suggesting that there is nothing unique about spinel dispersions in Cr with regards to impurities. However, none of these other dispersions resulted in similar levels of tensile elongation. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Alabama, Tuscaloosa, AL USA. Univ Tennessee, Knoxville, TN USA. RP Brady, MP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Brady, Michael/A-8122-2008 OI Brady, Michael/0000-0003-1338-4747 NR 26 TC 13 Z9 13 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2003 VL 358 IS 1-2 BP 243 EP 254 DI 10.1016/S0921-5093(03)00324-1 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 713FE UT WOS:000184845800033 ER PT J AU Sharif, AA Misra, A Mitchell, TE AF Sharif, AA Misra, A Mitchell, TE TI Deformation mechanisms of polycrystalline MoSi2 alloyed with 1 at.% Nb SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE solid solution softening/hardening; MoSi2; yield strength; dislocations; slip ID MOLYBDENUM DISILICIDE COMPOSITES; SINGLE-CRYSTALS; PLASTIC-DEFORMATION; TEMPERATURE; OXIDATION; SILICIDES; DUCTILITY; ELEMENTS; CREEP AB Molybdenum disilicide (MoSi2) is a high Peierls stress material with a strong temperature dependence of the yield stress at low homologous temperatures. We have investigated the effects of alloying with I at.% Nb on the mechanisms of deformation of polycrystalline MoSi2 by compression testing from room temperature to 1600 degreesC. While polycrystalline unalloyed MoSi2 fractured before plastic yield at temperatures less than or equal to900degreesC, the Nb-alloyed MoSi2 could be deformed in compression even at room temperature. Transmission electron microscopy (TEM) investigations indicated that the presence of I at.% Nb increased the stacking fault width of 1/2<111> dislocations and promoted 1/2<111> slip at low temperatures. The solution softening is interpreted in terms of easier kink nucleation on partial dislocations (especially in the vicinity of solute atoms) with increasing partial spacing. With increasing deformation temperature, thermal activation makes kink nucleation easy, and presumably, kink migration is hindered by the solute atoms leading to the expected solid solution hardening at elevated temperatures. At very high temperatures (similar to1600degreesC), the yield strengths of Nb-containing alloys may be up to an order of magnitude higher than;pure MoSi2; the related hardening mechanisms are discussed. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Ctr Mat Sci, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Calif State Univ Los Angeles, Dept Engn Mech, Los Angeles, CA 90032 USA. RP Misra, A (reprint author), Los Alamos Natl Lab, Ctr Mat Sci, Div Mat Sci & Technol, MS K765, Los Alamos, NM 87545 USA. RI Misra, Amit/H-1087-2012 NR 38 TC 23 Z9 26 U1 3 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2003 VL 358 IS 1-2 BP 279 EP 287 DI 10.1016/S0921-5093(03)00307-1 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 713FE UT WOS:000184845800037 ER PT J AU Tsang, M Psaltis, D Omenetto, FG AF Tsang, M Psaltis, D Omenetto, FG TI Reverse propagation of femtosecond pulses in optical fibers SO OPTICS LETTERS LA English DT Article ID PHASE CONJUGATION AB We present a numerical technique for reversing femtosecond pulse propagation in an optical fiber, such that given any output pulse it is possible to obtain the input pulse shape by numerically undoing all dispersion and nonlinear effects. The technique is tested against experimental results, and it is shown that it can be used for fiber output pulse optimization in both the anomalous and normal dispersion regimes. U 2003 Optical Society of America. C1 CALTECH, Dept Elect Engn, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Tsang, M (reprint author), CALTECH, Dept Elect Engn, Pasadena, CA 91125 USA. RI Tsang, Mankei/B-2926-2011 OI Tsang, Mankei/0000-0001-7173-1239 NR 8 TC 37 Z9 38 U1 1 U2 3 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 OCT 15 PY 2003 VL 28 IS 20 BP 1873 EP 1875 DI 10.1364/OL.28.001873 PG 3 WC Optics SC Optics GA 728ZM UT WOS:000185746300005 PM 14587760 ER PT J AU Lin, SY Fleming, JG El-Kady, I AF Lin, SY Fleming, JG El-Kady, I TI Three-dimensional photonic-crystal emission through thermal excitation SO OPTICS LETTERS LA English DT Article ID ENHANCEMENT; BAND AB A three-dimensional tungsten photonic crystal is thermally excited and shown to emit light at a narrow band, lambda = 3.3-4.25 mum. The emission is experimentally observed to exceed that of the free-space Planck radiation over a wide temperature range, T = 475-850 K. It is proposed that an enhanced density of state associated with the propagating electromagnetic Bloch waves in the photonic crystal is responsible for this experimental finding. (C) 2003 Optical Society of America. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lin, SY (reprint author), Sandia Natl Labs, MS 0603,POB 5800, Albuquerque, NM 87185 USA. RI El-Kady, Ihab/D-2886-2013 OI El-Kady, Ihab/0000-0001-7417-9814 NR 14 TC 65 Z9 66 U1 1 U2 8 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 OCT 15 PY 2003 VL 28 IS 20 BP 1909 EP 1911 DI 10.1364/OL.28.001909 PG 3 WC Optics SC Optics GA 728ZM UT WOS:000185746300017 PM 14587772 ER PT J AU Abdullaev, B Ortiz, G Rossler, U Musakhanov, M Nakamura, A AF Abdullaev, B Ortiz, G Rossler, U Musakhanov, M Nakamura, A TI Approximate ground state of a confined Coulomb anyon gas in an external magnetic field SO PHYSICAL REVIEW B LA English DT Article ID OBEYING FRACTIONAL STATISTICS; QUANTUM DOTS; WAVE-FUNCTIONS; MONTE-CARLO; BOSONIC END; PERTURBATIVE EQUATION; SPECTRA; MECHANICS; PARTICLES; ELECTRONS AB We derive an analytic, albeit approximate, expression for the ground state energy of N Coulomb interacting anyons with fractional statistics nu, 0less than or equal to\nu\less than or equal to1, confined in a two-dimensional well (with characteristic frequency omega(0)) and subjected to an external magnetic field (with cyclotron frequency omega(c)). We apply a variational principle combined with a regularization procedure which consists of fitting a cutoff parameter to existing exact analytical results in the noninteracting case, and to numerical calculations for electrons in quantum dots in the interacting case. The resulting expression depends upon parameters of the system \nu\,N,omega(0),r(0),a(B) and omega(c), where r(0) represents a characteristic unit length and a(B) the Bohr radius. Validity of the result is critically assessed by a comparison with exact, approximate, and numerical results from the literature. C1 Uzbekistan Natl Univ, Dept Theoret Phys, Tashkent 700174, Uzbekistan. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Hiroshima Univ, RIISE, Hiroshima 730, Japan. RP Abdullaev, B (reprint author), Uzbekistan Natl Univ, Dept Theoret Phys, Tashkent 700174, Uzbekistan. NR 69 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165105 DI 10.1103/PhysRevB.68.165105 PG 9 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800019 ER PT J AU Alfonso, DR Jaffe, JE Hess, AC Gutowski, M AF Alfonso, DR Jaffe, JE Hess, AC Gutowski, M TI Formation of the c(1x1) Cu monolayer on CaO(100): A theoretical study SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; AB-INITIO; MGO(001) SURFACE; FIRST-PRINCIPLES; MGO; ADSORPTION; MGO(100); ENERGY; GROWTH; METALS AB The Cu overlayer adsorbed on CaO(100) was studied at the density functional level of theory using a gradient-corrected exchange-correlation functional of Perdew and collaborators. Following an experimental suggestion of Waltenburg and Moller [Surf. Sci. 439, 139 (1999)], we examined a c(1x1) structure with copper atoms adsorbed on every O-O bridging site of CaO(100). The calculated binding energy/atom for this structure is 2.60 eV. However, another c(1x1) structure proposed by us, with copper atoms on every surface Ca and O atom, displayed a larger binding energy of 3.08 eV. Both energies are smaller than the calculated cohesive energy of bulk copper (3.54 eV/atom). Our results confirm that the experimentally observed monolayer film of Cu is unstable with respect to formation of three-dimensional metallic islands on the CaO substrate. With the copper coverage reduced by half, the preferred adsorption site for the Cu overlayer is above the O site, but even for this coverage that lateral interaction among copper atoms is larger than their interaction with the CaO substrate. The dominant mechanism for the Cu interaction with CaO(100) is rehybridization of the metal 3d and surface O 2p bands. C1 Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. PARSONS, South Pk, PA 15129 USA. Pacific NW Natl Lab, Energy Sci & Technol Directorate, Richland, WA 99352 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. RP Gutowski, M (reprint author), Pacific NW Natl Lab, Div Chem Sci, Richland, WA 99352 USA. NR 42 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155411 DI 10.1103/PhysRevB.68.155411 PG 7 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600105 ER PT J AU Bussmann-Holder, A Bishop, AR AF Bussmann-Holder, A Bishop, AR TI Optical response of oxide dielectrics SO PHYSICAL REVIEW B LA English DT Article ID FERROELECTRIC PHASE-TRANSITIONS; LATTICE-DYNAMICS; POLARIZABILITY MODEL; CUBIC PHASE; BATIO3; ORIGIN; SUPERCONDUCTIVITY; LIXK1-XTAO3; PEROVSKITES; CRYSTALS AB The optical response of oxide dielectrics is calculated by using a combination of self-consistent phonon theory together with results obtained from exactly solving a nonlinear electron-phonon interaction model in the continuum limit. The model is based on the unusual oxygen ion polarizability which induces multiphonon density-density interactions. The damping of optic modes together with an increase in oscillator strength and the development of line shape anomalies with decreasing temperature, is obtained in agreement with experimental data. Unusual mass dependences of optic modes are observed, and the origin of the damping of these phonon modes is identified. The results may provide a fundamental understanding of sum rule violations observed in many dielectrics. C1 Max Planck Inst Solid State Res, D-70569 Stuttgart, Germany. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bussmann-Holder, A (reprint author), Max Planck Inst Solid State Res, Heisenbergstr 1, D-70569 Stuttgart, Germany. NR 32 TC 3 Z9 3 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155104 DI 10.1103/PhysRevB.68.155104 PG 5 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600033 ER PT J AU Choi, IH Yu, PY AF Choi, IH Yu, PY TI Pressure dependence of phonons and excitons in InSe films prepared by metal-organic chemical vapor deposition SO PHYSICAL REVIEW B LA English DT Article AB The pressure dependence of the Raman spectra of phase-pure InSe thin films prepared by the low-pressure metal-organic chemical vapor deposition technique has been studied using a diamond-anvil high-pressure cell. Enhancement in the intensities of the Raman modes has been observed as a result of pressure-induced "tuning" of the energy of the M-1-type hyperbolic exciton in InSe at similar to2.54 eV through discrete incident laser photon energies. The pressure coefficients of the phonon modes and of the hyperbolic exciton in InSe have been determined. C1 Chung Ang Univ, Dept Phys, Seoul, South Korea. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Yu, PY (reprint author), Chung Ang Univ, Dept Phys, Seoul, South Korea. NR 10 TC 11 Z9 11 U1 0 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165339 DI 10.1103/PhysRevB.68.165339 PG 6 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800070 ER PT J AU Inyushkin, AV Taldenkov, AN Ozhogin VI Itoh, KM Haller, EE AF Inyushkin, AV Taldenkov, AN Ozhogin, VI Itoh, KM Haller, EE TI Isotope effect on the phonon-drag component of the thermoelectric power of germanium SO PHYSICAL REVIEW B LA English DT Article ID THERMAL-CONDUCTIVITY; LOW-TEMPERATURES; SINGLE-CRYSTALS; SEMICONDUCTORS; SCATTERING AB We have measured the thermoelectric power of several germanium single crystals with different isotopic compositions: natural, 96.3%, and 99.99% enriched (70)Ge. N- and p-type Ge samples with the net concentration of electrically active impurities <2x10(13) cm(3) were studied. Our experimental data show a decrease of thermopower with an increase in isotopic mass disorder. This isotope effect is evident at temperatures below approximately 70 K where a phonon-drag part of the thermopower dominates. At high temperatures, in the diffusion regime, the thermopower does not correlate with the isotopic composition within experimental error. The observed isotope effect can be explained with a special phonon-drag contribution induced by a momentum transfer from thermal phonons to low-energy phonons in the enriched samples. C1 Russian Res Ctr, Kurchatov Inst, Inst Mol Phys, Moscow 123182, Russia. Keio Univ, Fac Sci & Technol, Dept Appl Phys & Physicoinformat, Kohoku Ku, Yokohama, Kanagawa 223, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Inyushkin, AV (reprint author), Russian Res Ctr, Kurchatov Inst, Inst Mol Phys, Moscow 123182, Russia. EM inyushkin@imp.kiae.ru RI Itoh, Kohei/C-5738-2014 NR 23 TC 12 Z9 12 U1 2 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 153203 DI 10.1103/PhysRevB.68.153203 PG 4 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600010 ER PT J AU Li, ZY Ho, KM AF Li, ZY Ho, KM TI Light propagation in semi-infinite photonic crystals and related waveguide structures SO PHYSICAL REVIEW B LA English DT Article ID BAND-GAP STRUCTURES; INTEGRATED-OPTICS; TRANSMISSION; BENDS; SLABS; FORMULATION; GRATINGS AB A transfer-matrix method (TMM) that employs the plane-wave expansion of electromagnetic (EM) fields has been developed to handle EM wave propagation in semi-infinite photonic crystal and related waveguide structures. The major aim is to account for wave scattering only at the concerned boundary and to completely remove multiple reflections in the presence of other structural boundaries. It turns out that the scattering problem is closely connected to the eigenmodes of the transfer matrix for the unit cell of the crystal. A natural boundary condition is imposed to describe the asymptotic propagation behavior of scattered EM waves in a region far away from the interface. Theories for a variety of important structures have been systematically set up. These include wave propagation in a semi-infinite photonic crystal, a coated semi-infinite photonic crystal, a heterostructure formed by two different semi-infinite photonic crystals face to face, and a complex sandwiched structure formed by two semi-infinite photonic crystals separated by a general grating slab. In combination with a supercell technique, the developed formulations can also be used to handle photonic crystal waveguide structures. We have applied the developed TMM to two-dimensional photonic crystal and related waveguide structures. The first is the coupling of an external wave into a photonic crystal (photonic crystal waveguide) and the related inverse problems of coupling of a Bloch's wave (guided wave) out of the photonic crystal (photonic crystal waveguide). The second is scattering of a guided wave by a cavity introduced into a photonic crystal waveguide. The developed TMM can help to understand optical properties and design optimal structures of individual functional elements in an optical integrated circuit built in a photonic crystal environment. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Li, ZY (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM lizy@axel.ameslab.gov NR 33 TC 73 Z9 76 U1 2 U2 23 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155101 DI 10.1103/PhysRevB.68.155101 PG 15 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600030 ER PT J AU Magri, R Zunger, A AF Magri, R Zunger, A TI Predicting interband transition energies for InAs/GaSb superlattices using the empirical pseudopotential method SO PHYSICAL REVIEW B LA English DT Article ID ANTIMONIDE-BASED HETEROSTRUCTURES; OPTICAL-PROPERTIES; COMMON-ATOM; INTERFACE; SEMICONDUCTORS; LASERS; SCATTERING; PARAMETERS; GROWTH; GAP AB Recent measurements surprisingly show that the lowest valence-to-conduction confined transitions in narrow (InAs)(8)/(GaSb)(n) and (InAs)(6)/(GaSb)(n) superlattices increase in energy as the barrier thickness n increases. We show that in addition to the mesoscopic geometric quantities (well and barrier sizes), an atomic-scale description of interdiffused interfaces is needed to correctly reproduce the observed spectroscopic trend. The interdiffused interface is modeled via diffusion equations. We compare our atomistic empirical pseudopotential calculation in which only the bulk binary data are fit to experiment, with contemporary methods in which agreement with experiment is forced using ideally abrupt interfaces. C1 Univ Modena & Reggio Emilia, S3, Ist Nazl Fis Mat, Modena, Italy. Univ Modena & Reggio Emilia, Dipartimento Fis, Modena, Italy. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Magri, R (reprint author), Univ Modena & Reggio Emilia, S3, Ist Nazl Fis Mat, Via Campi 213-A, Modena, Italy. RI Zunger, Alex/A-6733-2013; Magri, Rita/O-5267-2016 OI Magri, Rita/0000-0003-2945-0374 NR 37 TC 11 Z9 11 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155329 DI 10.1103/PhysRevB.68.155329 PG 8 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600089 ER PT J AU Noh, H Lilly, MP Tsui, DC Simmons, JA Hwang, EH Das Sarma, S Pfeiffer, LN West, KW AF Noh, H Lilly, MP Tsui, DC Simmons, JA Hwang, EH Das Sarma, S Pfeiffer, LN West, KW TI Interaction corrections to two-dimensional hole transport in the large-r(s) limit SO PHYSICAL REVIEW B LA English DT Article ID METAL-INSULATOR-TRANSITION; DIMENSIONAL ELECTRON-GAS; SILICON INVERSION-LAYERS; PARALLEL MAGNETIC-FIELD; TEMPERATURE-DEPENDENCE; ALXGA1-XAS/GAAS HETEROJUNCTIONS; PHONON-SCATTERING; MOBILITY; SYSTEMS; GAAS AB The metallic conductivity of dilute two-dimensional holes in a GaAs heterojunction insulated-gate field-effect transistor with extremely high mobility and large r(s) is found to have a linear dependence on temperature, consistent with the theory of interaction corrections in the ballistic regime. Phonon scattering contributions are negligible in the temperature range of our interest, allowing comparison between our measured data and theory without any phonon subtraction. The magnitude of the Fermi liquid interaction parameter F-0(sigma) determined from the experiment, however, decreases with increasing r(s) for r(s)greater than or similar to22, a behavior unexpected from theoretical calculations valid for small r(s). C1 Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Maryland, Dept Phys, Condensed Matter Theory Ctr, College Pk, MD 20742 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Noh, H (reprint author), Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. RI Hwang, Euyheon/A-6239-2013; Noh, Hwayong/A-9196-2013; Das Sarma, Sankar/B-2400-2009 OI Das Sarma, Sankar/0000-0002-0439-986X NR 34 TC 56 Z9 57 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165308 DI 10.1103/PhysRevB.68.165308 PG 6 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800039 ER PT J AU Reichhardt, C Reichhardt, CJO AF Reichhardt, C Reichhardt, CJO TI Temperature and ac effects on charge transport in arrays of metallic dots SO PHYSICAL REVIEW B LA English DT Article ID GOLD-CLUSTER STRUCTURES; 2-DIMENSIONAL ARRAYS; ISLANDS AB We investigate the effects of finite temperature, dc pulse, and ac drives on the charge transport in metallic arrays using numerical simulations. For finite temperatures there is a finite conduction threshold which decreases linearly with temperature. Additionally we find a quadratic scaling of the current-voltage curves which is independent of temperature for finite thresholds. These results are in excellent agreement with recent experiments on 2D metallic dot arrays. We have also investigated the effects of an ac drive as well as a suddenly applied dc drive. With an ac drive the conduction threshold decreases for fixed frequency and increasing amplitude and saturates for fixed amplitude and increasing frequency. For sudden applied dc drives below threshold we observe a long time power-law conduction decay. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. OI Reichhardt, Cynthia/0000-0002-3487-5089 NR 23 TC 6 Z9 6 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165305 DI 10.1103/PhysRevB.68.165305 PG 5 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800036 ER PT J AU Sanati, M Hart, GLW Zunger, A AF Sanati, M Hart, GLW Zunger, A TI Ordering tendencies in octahedral MgO-ZnO alloys SO PHYSICAL REVIEW B LA English DT Article ID TOTAL-ENERGY CALCULATIONS; II-VI SEMICONDUCTORS; WAVE BASIS-SET; ELECTRONIC-STRUCTURE; D-BANDS; MGXZN1-XO; STABILITY; FILMS; FORMALISM; STATES AB Isostructural II-VI alloys whose components are either rocksalt stable (e.g., CaO-MgO) or zincblende stable (e.g., ZnS-ZnSe) are known to be thermodynamically unstable at low temperatures, showing a miscibility gap and no bulk ordering. In contrast, we show that heterostructural MgO-ZnO is stable, under certain conditions, in the sixfold-coordinated structure for Zn concentrations below 67%, giving rise to spontaneously ordered alloys. Using first-principles calculations, we explain the origin of this stability, the structures of their low-temperature ordered phases, short-range-order patterns, and their optical band-gap properties. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA. RP Sanati, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013; OI Hart, Gus L. W./0000-0002-6149-9234 NR 29 TC 42 Z9 46 U1 2 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155210 DI 10.1103/PhysRevB.68.155210 PG 5 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600060 ER PT J AU Saniz, R Barbiellini, B Denison, AB Bansil, A AF Saniz, R Barbiellini, B Denison, AB Bansil, A TI Spontaneous magnetization and electron momentum density in three-dimensional quantum dots SO PHYSICAL REVIEW B LA English DT Article ID SIMPLE-METAL NANOWIRES; ENERGY-LEVELS; ATOMS AB We discuss an exactly solvable model Hamiltonian for describing the interacting electron gas in a quantum dot. Results for a spherical square-well confining potential are presented. The ground state is found to exhibit striking oscillations in spin polarization with dot radius at a fixed electron density. These oscillations are shown to induce characteristic signatures in the momentum density of the electron gas, providing a route for direct experimental observation of the dot magnetization via spectroscopies sensitive to the electron momentum density. C1 Univ Catolica Boliviana, Dept Ciencias Exactas, Cochabamba, Bolivia. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Saniz, R (reprint author), Univ Catolica Boliviana, Dept Ciencias Exactas, Casilla 5381, Cochabamba, Bolivia. RI Barbiellini, Bernardo/K-3619-2015 OI Barbiellini, Bernardo/0000-0002-3309-1362 NR 25 TC 9 Z9 9 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165326 DI 10.1103/PhysRevB.68.165326 PG 5 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800057 ER PT J AU Segev, D Wei, SH AF Segev, D Wei, SH TI Effects of covalency, p-d coupling, and epitaxial strain on the band offsets of II-VI semiconductors SO PHYSICAL REVIEW B LA English DT Article ID CHEMICAL TRENDS; D-ORBITALS; LINEUPS; ALLOYS; MODEL; PHASE; STATE; MGTE; BAS AB Using the first-principles all-electrons method, we have systematically studied the natural band offsets among zinc blende BeX, MgX, and ZnX (X=S, Se, Te). We show that ZnX, which has large anion p-cation d repulsion, always has higher natural valence band maximum (VBM) than BeX and MgX, whereas BeX, which shows strong covalency, has higher natural VBM than MgX due to kinetic-energy-induced valence band broadening. However, epitaxial strain could reverse these trends. We found that for these isovalent semiconductors, the band offset is not sensitive to interface atomic compositions. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Segev, D (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 28 TC 10 Z9 10 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165336 DI 10.1103/PhysRevB.68.165336 PG 5 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800067 ER PT J AU Singley, EJ Burch, KS Kawakami, R Stephens, J Awschalom, DD Basov, DN AF Singley, EJ Burch, KS Kawakami, R Stephens, J Awschalom, DD Basov, DN TI Electronic structure and carrier dynamics of the ferromagnetic semiconductor Ga1-xMnxAs SO PHYSICAL REVIEW B LA English DT Article ID TEMPERATURE-GROWN GAAS; METAL-INSULATOR-TRANSITION; PLASTICALLY DEFORMED GAAS; MAGNETIC SEMICONDUCTORS; TUNNELING SPECTROSCOPY; INTENSITY MEASUREMENTS; OPTICAL CONDUCTIVITY; GALLIUM-ARSENIDE; DEFECT; MODEL AB Infrared spectroscopy is used to study the doping and temperature dependence of the intragap absorption in the ferromagnetic semiconductor Ga1-xMnxAs, from a paramagnetic, x=0.017 sample to a heavily doped, x=0.079 sample. Transmission and reflectance measurements coupled with a Kramers-Kronig analysis allow us to determine the optical constants of the thin films. All ferromagnetic samples show a broad absorption resonance near 200 meV, within the GaAs band gap. We present a critical analysis of possible origins of this feature, including a Mn-induced impurity band and intervalence band transitions. The overall magnitude of the real part of the frequency dependent conductivity grows with increasing Mn doping, and reaches a maximum in the x=0.052 sample where T-C saturates at the highest value (similar to70 K) for the series. We observe spectroscopic signatures of compensation and track its impact on the electronic and magnetic state across the Mn phase diagram. The temperature dependence of the far infrared spectrum reveals a significant decrease in the effective mass of itinerant carriers in the ferromagnetic state. A simple scaling relation between changes in the mass and the sample magnetization suggest that the itinerant carriers play a key role in producing the ferromagnetism in this system. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Singley, EJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source Div, 1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Burch, Kenneth/0000-0002-7541-0245 NR 72 TC 63 Z9 63 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 165204 DI 10.1103/PhysRevB.68.165204 PG 14 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800026 ER PT J AU Smith, S Mascarenhas, A Olson, JM AF Smith, S Mascarenhas, A Olson, JM TI Magnetophotoluminescence of quantum confined states in ordered GaxIn1-xP with 200 nanometer resolution SO PHYSICAL REVIEW B LA English DT Article ID GAINP2 ALLOYS; EXCITONS; DOTS AB We observe the diamagnetic shift and Zeeman splitting of ultra-sharp photoluminescence lines which appear in an ordered-GaInP epilayer using a micro-photoluminescence technique in fields up to 5 T. These transitions show many signatures of a fully quantum-confined state, however, a detailed description of the origin of these states is not known. Under a magnetic field, these states show behavior similar to other III-V quantum dot systems, with large variations in diamagnetic shift and exciton g factor. By noting their variation with energy, one can make inferences about possible confinement geometries. These results are compared to previous work. C1 NREL, Golden, CO 80401 USA. RP Smith, S (reprint author), NREL, 1617 Cole Blvd, Golden, CO 80401 USA. NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 153202 DI 10.1103/PhysRevB.68.153202 PG 4 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600009 ER PT J AU Tobin, JG Chung, BW Schulze, RK Terry, J Farr, JD Shuh, DK Heinzelman, K Rotenberg, E Waddill, GD van der Laan, G AF Tobin, JG Chung, BW Schulze, RK Terry, J Farr, JD Shuh, DK Heinzelman, K Rotenberg, E Waddill, GD van der Laan, G TI Resonant photoemission in f-electron systems: Pu and Gd SO PHYSICAL REVIEW B LA English DT Article ID X-RAY PHOTOEMISSION; MAGNETIC CIRCULAR-DICHROISM; PHOTOELECTRON-SPECTROSCOPY; DELTA-PU; LIGHT-SOURCE; ACTINIDE MATERIALS; 5F ELECTRONS; PLUTONIUM; ALPHA; SURFACE AB Resonant photoemission in the Pu 5f and Pu 6p states is compared to that in the Gd 4f and Gd 5p states. Spectral simulations, based upon an atomic model with angular momentum coupling, are compared to the Gd and Pu results. Additional spectroscopic measurements of Pu, including core level photoemission and x-ray absorption, are also presented. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Missouri, Rolla, MO 65401 USA. SERC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. RP Tobin, JG (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Rotenberg, Eli/B-3700-2009; Chung, Brandon/G-2929-2012; Tobin, James/O-6953-2015; van der Laan, Gerrit/Q-1662-2015 OI Rotenberg, Eli/0000-0002-3979-8844; van der Laan, Gerrit/0000-0001-6852-2495 NR 49 TC 49 Z9 49 U1 1 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 15 AR 155109 DI 10.1103/PhysRevB.68.155109 PG 11 WC Physics, Condensed Matter SC Physics GA 740VQ UT WOS:000186422600038 ER PT J AU Akerib, DS Alvaro-Dean, J Armel, MS Attisha, MJ Baudis, L Bauer, DA Bolozdynya, AI Brink, PL Bunker, R Cabrera, B Caldwell, DO Castle, JP Chang, CL Clarke, RM Crisler, MB Cushman, P Davies, AK Dixon, R Driscoll, DD Duong, L Emes, J Ferril, R Gaitskell, RJ Golwala, SR Haldeman, M Hellmig, J Hennessey, M Holmgren, D Huber, ME Kamat, S Kurylowicz, M Lu, A Mahapatra, R Mandic, V Martinis, JM Meunier, P Mirabolfathi, N Nam, SW Nelson, H Nelson, R Ogburn, RW Perales, J Perera, TA Isaac, MCI Rau, W Reisetter, A Ross, RR Saab, T Sadoulet, B Sander, J Savage, C Schnee, RW Seitz, DN Shutt, TA Smith, G Spadafora, AL Thompson, JPF Tomada, A Wang, G Yellin, S Young, BA AF Akerib, DS Alvaro-Dean, J Armel, MS Attisha, MJ Baudis, L Bauer, DA Bolozdynya, AI Brink, PL Bunker, R Cabrera, B Caldwell, DO Castle, JP Chang, CL Clarke, RM Crisler, MB Cushman, P Davies, AK Dixon, R Driscoll, DD Duong, L Emes, J Ferril, R Gaitskell, RJ Golwala, SR Haldeman, M Hellmig, J Hennessey, M Holmgren, D Huber, ME Kamat, S Kurylowicz, M Lu, A Mahapatra, R Mandic, V Martinis, JM Meunier, P Mirabolfathi, N Nam, SW Nelson, H Nelson, R Ogburn, RW Perales, J Perera, TA Isaac, MCI Rau, W Reisetter, A Ross, RR Saab, T Sadoulet, B Sander, J Savage, C Schnee, RW Seitz, DN Shutt, TA Smith, G Spadafora, AL Thompson, JPF Tomada, A Wang, G Yellin, S Young, BA CA CDMS Collaboration TI New results from the Cryogenic Dark Matter Search experiment SO PHYSICAL REVIEW D LA English DT Article ID WIMP SEARCH; LIMITS; SITE AB Using improved Ge and Si detectors, better neutron shielding, and increased counting time, the Cryogenic Dark Matter Search (CDMS) experiment has obtained stricter limits on the cross section of weakly interacting massive particles (WIMPs) elastically scattering from nuclei. Increased discrimination against electromagnetic backgrounds and reduction of the neutron flux confirm WIMP-candidate events previously detected by CDMS were consistent with neutrons and give limits on spin-independent WIMP interactions which are >2x lower than previous CDMS results for high WIMP mass, and which exclude new parameter space for WIMPs with mass between 8 and 20 GeV/c(2). C1 Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Santa Clara Univ, Dept Phys, Santa Clara, CA 95053 USA. Univ Minnesota, Dept Phys & Astron, Minneapolis, MN 55455 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Colorado, Dept Phys, Denver, CO 80217 USA. RP Akerib, DS (reprint author), Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. RI Huber, Martin/B-3354-2011 NR 19 TC 102 Z9 102 U1 0 U2 4 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 OCT 15 PY 2003 VL 68 IS 8 AR 082002 DI 10.1103/PhysRevD.68.082002 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800002 ER PT J AU Anchordoqui, L Hojvat, C McCauley, T Paul, T Reucroft, S Swain, J Widom, A AF Anchordoqui, L Hojvat, C McCauley, T Paul, T Reucroft, S Swain, J Widom, A TI Full-sky search for ultrahigh energy cosmic ray anisotropies SO PHYSICAL REVIEW D LA English DT Article ID AIR-SHOWER ARRAY; ARRIVAL DIRECTIONS; EXTRAGALACTIC OBJECTS; STATISTICAL-ANALYSIS; SPECTRUM; AKENO; CATALOGS; QUASARS AB Using data from the Sydney University Giant Air-Shower Recorder and the Akeno Giant Air-Shower Array experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for large-scale anisotropy patterns in the arrival directions of cosmic rays with energies >10(19.6) eV. We determine the angular power spectrum from an expansion in spherical harmonics for modes out to l=5. Based on available statistics, we find no significant deviation from isotropy. We compare the rather modest results which can be extracted from existing data samples with the results that should be forthcoming as new full-sky observatories begin operation. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Northeastern Univ, Dept Phys, Boston, MA 02115 USA. NR 32 TC 11 Z9 11 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 2003 VL 68 IS 8 AR 083004 DI 10.1103/PhysRevD.68.083004 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800006 ER PT J AU Curtright, T Zachos, C AF Curtright, T Zachos, C TI Classical and quantum Nambu mechanics SO PHYSICAL REVIEW D LA English DT Article ID POISSON STRUCTURES; DEFORMATION QUANTIZATION; SIGMA-MODELS; ALGEBRAS; EQUATIONS; BRACKET; COHOMOLOGY; DIRAC AB The classical and quantum features of Nambu mechanics are analyzed and fundamental issues are resolved. The classical theory is reviewed and developed utilizing varied examples. The quantum theory is discussed in a parallel presentation and illustrated with detailed specific cases. Quantization is carried out with standard Hilbert space methods. With the proper physical interpretation, obtained by allowing for different time scales on different invariant sectors of a theory, the resulting non-Abelian approach to quantum Nambu mechanics is shown to be fully consistent. C1 Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Curtright, T (reprint author), Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. RI zachos, cosmas/C-4366-2014; Curtright, Thomas/B-6840-2015; OI zachos, cosmas/0000-0003-4379-3875; Curtright, Thomas/0000-0001-7031-5604 NR 55 TC 70 Z9 73 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 2003 VL 68 IS 8 AR 085001 DI 10.1103/PhysRevD.68.085001 PG 29 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800051 ER PT J AU Linder, EV AF Linder, EV TI Baryon oscillations as a cosmological probe SO PHYSICAL REVIEW D LA English DT Article ID POWER SPECTRUM; SUPERNOVAE; UNIVERSE AB Mapping the expansion of the Universe gives clues to the underlying physics causing the recently discovered acceleration of the expansion, and enables discrimination among cosmological models. We examine the utility of measuring the rate of expansion, H(z), at various epochs, both alone and in combination with distance measurements. Because of parameter degeneracies, it proves most useful as a complement to precision distance-redshift data. Using the baryon oscillations in the matter power spectrum as a standard rod allows determination of H(z)/(Omega(m)h(2))(1/2) free of most major systematics, and thus provides a window on dark energy properties. We discuss the addition of this data from a next generation galaxy redshift survey such as KAOS to precision distance information from a next generation supernova survey such as SNAP. This can provide useful crosschecks as well as lead to improvement on estimation of a time variation in the dark energy equation of state by factors ranging from 15-50 %. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. NR 21 TC 100 Z9 101 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 OCT 15 PY 2003 VL 68 IS 8 AR 083504 DI 10.1103/PhysRevD.68.083504 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800010 ER PT J AU Linder, EV AF Linder, EV TI Cosmic shear with next generation redshift surveys as a cosmological probe SO PHYSICAL REVIEW D LA English DT Article ID SUPERNOVAE; CONSTANT AB The expansion of the Universe causes spacetime curvature, distinguishing between distances measured along and transverse to the line of sight. The ratio of these distances, e.g., the cosmic shear distortion of a sphere defined by observations of large scale structure as suggested by Alcock and Paczynski, provides a method for exploring the expansion as a function of redshift. The theoretical sensitivity to cosmological parameters, including the dark energy equation of state, is presented. Remarkably, sensitivity to the time variation of the dark energy equation of state is best achieved by observations at redshifts zless than or similar to1. While systematic errors greatly degrade the theoretical sensitivity, this probe may still offer useful parameter estimation, especially in complementarity with a distance measure such as the type Ia supernova method implemented by SNAP. Possible future observations of the Alcock-Paczynski distortion by the KAOS project on an 8-meter ground-based telescope are considered. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. NR 11 TC 25 Z9 27 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 OCT 15 PY 2003 VL 68 IS 8 AR 083503 DI 10.1103/PhysRevD.68.083503 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800009 ER PT J AU Kletzing, CA Scudder, JD Dors, EE Curto, C AF Kletzing, CA Scudder, JD Dors, EE Curto, C TI Auroral source region: Plasma properties of the high-latitude plasma sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE plasma sheet; aurora; temperature; density; solar wind correlation ID SOLAR-WIND; MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; DISTANT MAGNETOTAIL; ELECTRON; ION; TEMPERATURE; AVERAGE; DISTRIBUTIONS; SPACECRAFT AB [1] Statistical results from a survey of 93 passes through the high-latitude extension of the plasma sheet of electron data from the Hydra instrument on the Polar spacecraft show that the values for electron density can range from 0.01 to 0.5 cm(-3) with an average value around 0.1 cm(-3) on the poleward side and 0.3 cm(-3) on the equatorward side. Electron mean energy is found to have an average value near 900 eV on the equatorward side and 400 eV on the poleward side but varies from 100 eV to 4 keV. These values for density and mean energy are similar to those reported for measurements made in the equatorial plasma sheet by several previous spacecraft. The character of the electron distributions has been compared with Maxwellian and kappa-distributions with the result that the kappa-distribution with kappa less than or equal to 10 yields an acceptable fit to the data twice as often as a Maxwellian distribution. This is similar to results found in the equatorial plasma sheet for both electrons and ions. The variation of electron density and mean energy around their average values have been compared with several solar wind parameters which have been developed to correlate solar wind variation with magnetospheric activity level. Few of these parameters are found to provide significant correlation with high-latitude plasma sheet electron density or temperature with the notable exception of solar wind density and solar wind particle flux which correlate with plasma sheet density. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, Dept Math, Durham, NC 27708 USA. RP Kletzing, CA (reprint author), Univ Iowa, Dept Phys & Astron, 203 Van Allen Hall, Iowa City, IA 52242 USA. RI Scudder, Jack/D-8417-2013; OI Scudder, Jack/0000-0001-7975-5630; Kletzing, Craig/0000-0002-4136-3348 NR 32 TC 41 Z9 42 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 14 PY 2003 VL 108 IS A10 AR 1360 DI 10.1029/2002JA009678 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735AR UT WOS:000186090600001 ER PT J AU Johal, MS Casson, JL Chiarelli, PA Liu, DG Shaw, JA Robinson, JM Wang, HL AF Johal, MS Casson, JL Chiarelli, PA Liu, DG Shaw, JA Robinson, JM Wang, HL TI Polyelectrolyte trilayer combinations using spin-assembly and ionic self-assembly SO LANGMUIR LA English DT Article ID GRAPHITE OXIDE NANOPLATELETS; MULTILAYER FILMS; THIN-FILMS; 2ND-HARMONIC GENERATION; RELEASE PROPERTIES; ULTRATHIN FILMS; CHARGE-DENSITY; FABRICATION; ORIENTATION; ADSORPTION AB Water-soluble, cationic, anionic, and neutral polymers are used to form various repeat trilayer films via ionic self-assembly (ISA) and spin-assembly. These multilayer thin films assemble through physical entanglement, electrostatic, and/or H-bonding interactions. Spin assembly has the advantage over ISA in constructing stable multilayers when polyelectrolytes with like charge are assembled in adjacent layers. These multilayers do not desorb in water over a long period of time. In contrast to spin assembly, the ISA method deposits only a minimal amount of polyelectrolyte on top of a like-charged layer. The mechanical entanglement that is responsible for the deposition of like-charged species in spin assembly is probably lacking in ISA. The ability to construct repeated trilayers or multilayers composed of polycations, polyanions, and neutral polymers allows the fabrication of multilayer thin films with the desired interfacial structure and interactions. In this work, polyelectrolytes with NLO chromophores are used because the deposition can be easily monitored through UV-visible spectroscopy and they have potential utility for NLO thin film devices. The adsorption kinetics of an ISA trilayer was studied, and it was found that the adsorption reaches equilibrium in 15 s to 5 min, depending on the structure and specific interaction between layers. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. New Coll Florida, Div Nat Sci, Sarasota, FL 34243 USA. Pomona Coll, Dept Chem, Claremont, CA 91711 USA. RP Wang, HL (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663, Los Alamos, NM 87545 USA. NR 38 TC 30 Z9 30 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 14 PY 2003 VL 19 IS 21 BP 8876 EP 8881 DI 10.1021/la034788l PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 730LG UT WOS:000185831800040 ER PT J AU Blankenbecler, R Ohlsson, M Peterson, C Ringner, M AF Blankenbecler, R Ohlsson, M Peterson, C Ringner, M TI Matching protein structures with fuzzy alignments SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE algorithm; dynamical programming; fuzzy assignment; mean field annealing ID CLASSIFICATION; SIMILARITIES; CORE; SCOP AB Unraveling functional and ancestral relationships between proteins as well as structure-prediction procedures require powerful protein-alignment methods. A structure-alignment method is presented where the problem is mapped onto a cost function containing both fuzzy (Potts) assignment variables and atomic coordinates. The cost function is minimized by using an iterative scheme, where at each step mean field theory methods at finite "temperatures" are used for determining fuzzy assignment variables followed by exact translation and rotation of atomic coordinates weighted by their corresponding fuzzy assignment variables. The approach performs very well when compared with other methods, requires modest central processing unit consumption, and is robust with respect to choice of iteration parameters for a wide range of proteins. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Lund Univ, Dept Theoret Phys, Complex Syst Div, S-22362 Lund, Sweden. RP Ohlsson, M (reprint author), Stanford Linear Accelerator Ctr, POB 4349, Stanford, CA 94309 USA. RI Ohlsson, Mattias/G-5790-2011; Ringner, Markus/G-3641-2011; OI Ringner, Markus/0000-0001-5469-8940; Ohlsson, Mattias/0000-0003-1145-4297 NR 18 TC 17 Z9 19 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 14 PY 2003 VL 100 IS 21 BP 11936 EP 11940 DI 10.1073/pnas.1635048100 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 733WU UT WOS:000186024300005 PM 14526099 ER PT J AU Tan, SY Guschin, D Davalos, A Lee, YL Snowden, AW Jouvenot, Y Zhang, HS Howes, K McNamara, AR Lai, A Ullman, C Reynolds, L Moore, M Isalan, M Berg, LP Campos, B Qi, H Spratt, SK Case, CC Pabo, CO Campisi, J Gregory, PD AF Tan, SY Guschin, D Davalos, A Lee, YL Snowden, AW Jouvenot, Y Zhang, HS Howes, K McNamara, AR Lai, A Ullman, C Reynolds, L Moore, M Isalan, M Berg, LP Campos, B Qi, H Spratt, SK Case, CC Pabo, CO Campisi, J Gregory, PD TI Zinc-finger protein-targeted gene regulation: Genomewide single-gene specificity SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ENGINEERED TRANSCRIPTION FACTORS; GROWTH-FACTOR-A; INDUCED PHOSPHORYLATION; IONIZING-RADIATION; CHECKPOINT KINASE; TELOMERE LENGTH; HUMAN-CELLS; CDS1 CHK2; IN-VIVO; ACTIVATION AB Zinc-finger protein transcription factors (ZFP TFs) can be designed to control the expression of any desired target gene, and thus provide potential therapeutic tools for the study and treatment of disease. Here we report that a ZFP TF can repress target gene expression with single-gene specificity within the human genome. A ZFP TF repressor that binds an 18-bp recognition sequence within the promoter of the endogenous CHK2 gene gives a >10-fold reduction in CHK2 mRNA and protein. This level of repression was sufficient to generate a functional phenotype, as demonstrated by the loss of DNA damage-induced CHK2-dependent p53 phosphorylation. We determined the specificity of repression by using DNA microarrays and found that the ZFP TF repressed a single gene (CHK2) within the monitored genome in two different cell types. These data demonstrate the utility of ZFP TFs as precise tools for target validation, and highlight their potential as clinical therapeutics. C1 Sangamo Biosci Inc, Point Richmond Tech Ctr 2, Richmond, CA 94804 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gregory, PD (reprint author), Sangamo Biosci Inc, Point Richmond Tech Ctr 2, 501 Canal Blvd, Richmond, CA 94804 USA. FU NCI NIH HHS [9R44 CA 94795-02]; NIA NIH HHS [T32 AG000266, AG 11658, R01 AG011658, AG 00266] NR 40 TC 115 Z9 116 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 OCT 14 PY 2003 VL 100 IS 21 BP 11997 EP 12002 DI 10.1073/pnas.2035056100 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 733WU UT WOS:000186024300016 PM 14514889 ER PT J AU Hsu, T Hingley-Wilson, SM Chen, B Chen, M Dai, AZ Morin, PM Marks, CB Padiyar, J Goulding, C Gingery, M Eisenberg, D Russell, RG Derrick, SC Collins, FM Morris, SL King, CH Jacobs, WR AF Hsu, T Hingley-Wilson, SM Chen, B Chen, M Dai, AZ Morin, PM Marks, CB Padiyar, J Goulding, C Gingery, M Eisenberg, D Russell, RG Derrick, SC Collins, FM Morris, SL King, CH Jacobs, WR TI The primary mechanism of attenuation of bacillus Calmette-Guerin is a loss of secreted lytic function required for invasion of lung interstitial tissue SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MYCOBACTERIUM-TUBERCULOSIS H37RV; EPITHELIAL-CELLS; BOVIS BCG; VIRULENCE; PATHOGENESIS; SMEGMATIS; INFECTION; DELETION; GENOMICS; DELIVERY AB Tuberculosis remains a leading cause of death worldwide, despite the availability of effective chemotherapy and a vaccine. Bacillus Calmette-Guerin (BCG), the tuberculosis vaccine, is an attenuated mutant of Mycobacterium bovis that was isolated after serial subcultures, yet the functional basis for this attenuation has never been elucidated. A single region (RD1), which is absent in all BCG substrains, was deleted from virulent M. bovis and Mycobacterium, tuberculosis strains, and the resulting DeltaRD1 mutants were significantly attenuated for virulence in both immunocompromised and immunocompetent mice. The M. tuberculosis DeltaRD1 mutants were also shown to protect mice against aerosol challenge, in a similar manner to BCG. Interestingly, the DeltaRD1 mutants failed to cause cytolysis of pneumocytes, a phenotype that had been previously used to distinguish virulent M. tuberculosis from BCG. A specific transposon mutation, which disrupts the Rv3874 Rv3875 (cfp-10 esat-6) operon of RD1, also caused loss of the cytolytic phenotype in both pneumocytes and macrophages. This mutation resulted in the attenuation of virulence in mice, as the result of reduced tissue invasiveness. Moreover, specific deletion of each transcriptional unit of RD1 revealed that three independent transcriptional units are required for virulence, two of which are involved in the secretion of ESAT-6 (6-kDa early secretory antigenic target). We conclude that the primary attenuating mechanism of bacillus Calmette-Guerin is the loss of cytolytic activity mediated by secreted ESAT-6, which results in reduced tissue invasiveness. C1 Yeshiva Univ Albert Einstein Coll Med, Howard Hughes Med Inst, Dept Pathol, Bronx, NY 10461 USA. Yeshiva Univ Albert Einstein Coll Med, Dept Microbiol & Immunol, Bronx, NY 10461 USA. Yeshiva Univ Albert Einstein Coll Med, Analyt Imaging Facil, Bronx, NY 10461 USA. Univ Calif Los Angeles, UCLA DOE Inst Genom & Proteom, Los Angeles, CA 90095 USA. US FDA, Ctr Biol Evaluat & Res, Bethesda, MD 20892 USA. Emory Univ, Sch Med, Ctr Dept Med, Atlanta, GA 30303 USA. RP Jacobs, WR (reprint author), Yeshiva Univ Albert Einstein Coll Med, Howard Hughes Med Inst, Dept Pathol, Bronx, NY 10461 USA. FU NIAID NIH HHS [AI 26170, AI 52356, R01 AI026170, R37 AI026170]; NIGMS NIH HHS [GM 62410, P50 GM062410] NR 31 TC 397 Z9 413 U1 4 U2 20 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 OCT 14 PY 2003 VL 100 IS 21 BP 12420 EP 12425 DI 10.1073/pnas.1635213100 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 733WU UT WOS:000186024300087 PM 14557547 ER PT J AU Lee, JK Hochbauer, T Averitt, RD Nastasi, M AF Lee, JK Hochbauer, T Averitt, RD Nastasi, M TI Role of boron for defect evolution in hydrogen-implanted silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID CRYSTALLINE SILICON; DIFFUSION; ACTIVATION; MECHANISMS; GERMANIUM; CUT; SI AB The mechanism underlying the exfoliation phenomenon in B+H coimplanted Si is presented. Compared with only H implantation, H-implanted Si samples that received a B preimplant were observed to have a decrease in implantation-induced lattice damage, in spite of enhanced blistering behavior, which was more pronounced for nonactivated B. Infrared spectroscopy showed that the concentration of Si-H multivacancy defects was also decreased in the B+H coimplanted Si relative to H-only-implanted Si. These decreases in the damage and H-defect density suggest that the lower damage in the B+H coimplanted Si results from a reduction in H-trap density, which in turn enhances H diffusion and the kinetics of blistering. This reduction in lattice damage and H-Si-defect complexes is attributed to the formation of a kinetically active B-Si interstitial complex that is prevalent in nonactivated B-implanted Si. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Lee, JK (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 24 TC 9 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3042 EP 3044 DI 10.1063/1.1616979 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400018 ER PT J AU Amitay-Sadovsky, E Komvopoulos, K Ward, R Somorjai, GA AF Amitay-Sadovsky, E Komvopoulos, K Ward, R Somorjai, GA TI Effects of copolymer segment length and reversible deformation on the molecular surface structure of polyurethane SO APPLIED PHYSICS LETTERS LA English DT Article ID GENERATION VIBRATIONAL SPECTROSCOPY; FORCE MICROSCOPY; ALIGNMENT; FILMS AB The surface molecular structure and the deformation mechanisms of two polyurethane (PUR) short-segmented copolymers were studied by sum frequency generation (SFG) vibrational spectroscopy. These PURs differ only in the length of their hard segment. Surface deformation was induced by cyclically stretching the PUR films to a macroscopic elastic elongation. Results for both PUR compositions indicate that the upward orientation of the methylene groups increases with elongation and decreases upon relaxation. The surface of the stretched PUR films with shorter hard segments exhibited irreversible deformation at the molecular level. This produced a surface composition similar to that of PUR with longer hard segments that deformed only elastically after three stretching cycles. This behavior indicates that the surface structure of PUR copolymers can be controlled by mechanical manipulation or by modification of the copolymer segment length. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Polymer Technol Grp Inc, Berkeley, CA 94710 USA. RP Amitay-Sadovsky, E (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NR 14 TC 3 Z9 3 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3066 EP 3068 DI 10.1063/1.1610249 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400026 ER PT J AU Wang, H Zhang, X Gupta, A Tiwari, A Narayan, J AF Wang, H Zhang, X Gupta, A Tiwari, A Narayan, J TI Growth and characteristics of TaN/TiN superlattice structures SO APPLIED PHYSICS LETTERS LA English DT Article ID DIFFUSION BARRIER; EPITAXIAL-GROWTH; TAN; CU; TANTALUM; METALLIZATION; FILMS; SI AB Epitaxial B1 NaCl-structured TaN(3 nm)/TiN(2 nm) superlattice structures were grown on Si(100) substrates with a TiN buffer layer, using pulsed-laser deposition. A special target assembly was used to manipulate the thickness of each layer. X-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy (Z contrast) studies confirmed the single-crystalline nature of the superlattice with a uniform layer structure. Nanoindentation results suggest the high hardness of these superlattice structures. Four-point-probe resistivity measurements show low resistivity of the heterostructures and a Cu diffusion characteristic study proved this superlattice system can be a promising diffusion barrier and can withstand 700 degreesC annealing for 30 min. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. RP Wang, H (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Narayan, Jagdish/D-1874-2009; Zhang, Xinghang/H-6764-2013; Wang, Haiyan/P-3550-2014 OI Zhang, Xinghang/0000-0002-8380-8667; Wang, Haiyan/0000-0002-7397-1209 NR 10 TC 10 Z9 10 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3072 EP 3074 DI 10.1063/1.1616656 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400028 ER PT J AU Stemmer, S Li, YL Foran, B Lysaght, PS Streiffer, SK Fuoss, P Seifert, S AF Stemmer, S Li, YL Foran, B Lysaght, PS Streiffer, SK Fuoss, P Seifert, S TI Grazing-incidence small angle x-ray scattering studies of phase separation in hafnium silicate films SO APPLIED PHYSICS LETTERS LA English DT Article ID SPINODAL DECOMPOSITION; GATE DIELECTRICS; THIN-FILMS AB Grazing-incidence small-angle x-ray scattering (GISAXS) and high-resolution transmission electron microscopy (HRTEM) were used to investigate phase separation in hafnium silicate films after rapid thermal annealing between 700 and 1000 degreesC. 4-nm-thick Hf-silicate films with 80 and 40 mol % HfO(2), respectively, were prepared by metalorganic vapor deposition. Films of the two compositions showed distinctly different phase-separated microstructures, consistent with two limiting cases of microstructural evolution: nucleation/growth and spinodal decomposition. Films with 40 mol % HfO(2) phase separated in the amorphous by spinodal decomposition and exhibited a characteristic wavelength in the plane of the film. Decomposition with a wavelength of similar to3 nm could be detected at 800 degreesC. At 1000 degreesC the films rapidly demixed with a wavelength of 5 nm. In contrast, films with 80 mol % HfO(2) phase separated by nucleation and growth of crystallites, and showed a more random microstructure. The factors determining specific film morphologies and phase separation kinetics are discussed. (C) 2003 American Institute of Physics. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Int Sematech, Austin, TX 78741 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Stemmer, S (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. EM stemmer@mrl.ucsb.edu RI Streiffer, Stephen/A-1756-2009; Stemmer, Susanne/H-6555-2011 OI Stemmer, Susanne/0000-0002-3142-4696 NR 13 TC 80 Z9 80 U1 2 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 OCT 13 PY 2003 VL 83 IS 15 BP 3141 EP 3143 DI 10.1063/1.1617369 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400051 ER PT J AU Hu, J Ward, S Wang, Q AF Hu, J Ward, S Wang, Q TI Field-induced electric switching in sol-gel-derived SiO2 films SO APPLIED PHYSICS LETTERS LA English DT Article ID CONDUCTIVITY; BREAKDOWN AB The switching dynamics of sol-gel-derived SiO2 films is investigated using voltage pulses over durations from 300 ns to 1 s and amplitudes from 1 to 20 V. The SiO2 film was fabricated using a spin-coating technique and annealed at 100 degreesC. The shortest switching transit time is found to be on the order of 10 ns. A delay time ranging from 100 ns to 500 ms is usually observed prior to switching, which changes exponentially with the electric field at switching, and also depends strongly on the area of the device. (C) 2003 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Hu, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 10 TC 5 Z9 5 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 OCT 13 PY 2003 VL 83 IS 15 BP 3153 EP 3155 DI 10.1063/1.1618950 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400055 ER PT J AU Pan, ZW Dai, S Beach, DB Lowndes, DH AF Pan, ZW Dai, S Beach, DB Lowndes, DH TI Liquid gallium ball/crystalline silicon polyhedrons/aligned silicon oxide nanowires sandwich structure: An interesting nanowire growth route SO APPLIED PHYSICS LETTERS LA English DT Article ID SEMICONDUCTOR NANOWIRES; SOLID MECHANISM; NANOSTRUCTURES; CRYSTALS AB We demonstrate the growth of silicon oxide nanowires through a sandwich-like configuration, i.e., Ga ball/Si polyhedrons/silicon oxide nanowires, by using Ga as the catalyst and SiO powder as the source material. The sandwich-like structures have a carrot-like morphology, consisting of three materials with different morphologies, states, and crystallographic structures. The "carrot" top is a liquid Ga ball with diameter of similar to10-30 mum; the middle part is a Si ring usually composed of about 10 mum-sized, clearly faceted, and crystalline Si polyhedrons that are arranged sequentially in a band around the lower hemisphere surface of the Ga ball; the bottom part is a carrot-shaped bunch of highly aligned silicon oxide nanowires that grow out from the downward facing facets of the Si polyhedrons. This study reveals several interesting nanowire growth phenomena that enrich the conventional vapor-liquid-solid nanowire growth mechanism. (C) 2003 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RI Dai, Sheng/K-8411-2015; OI Dai, Sheng/0000-0002-8046-3931; Pan, Zhengwei/0000-0002-3854-958X NR 14 TC 34 Z9 34 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3159 EP 3161 DI 10.1063/1.1617378 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400057 ER PT J AU Wang, ZW Zhao, YS Schiferl, D Zha, CS Downs, RT Sekine, T AF Wang, ZW Zhao, YS Schiferl, D Zha, CS Downs, RT Sekine, T TI Critical pressure for weakening of size-induced stiffness in spinel-structure Si3N4 nanocrystals SO APPLIED PHYSICS LETTERS LA English DT Article ID X-RAY-DIFFRACTION; SEMICONDUCTOR NANOCRYSTALS; ELASTIC-MODULI; BULK MODULUS; TRANSFORMATIONS; COMPRESSIBILITY; HARDNESS; NITRIDE; DIAMOND; PHASE AB We demonstrate that the compressibility of spinel Si3N4 nanocrystals increases when the pressure is raised above similar to40 GPa. Si3N4 nanocrystals initially exhibit an extremely high bulk modulus of 685(45) GPa. But, above 40 GPa, the bulk modulus is reduced to 415(10) GPa. Thus, a critical pressure of similar to40 GPa was determined that signifies the onset of size-induced weakening of elastic stiffness in nanocrystalline Si3N4. Enhanced surface energy contributions to the shell layers of nanoparticles and the resulting effect on the corresponding large d-spacing planes are used to explain the observed phenomenon. Upon decompression, the bulk modulus of the Si3N4 spinel remained at its lower value of 415 GPa. This study provides a reasonable explanation for the different compressibility properties of numerous nanocrystals. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Cornell Univ, Cornell High Energy Synchrotron Source, Ithaca, NY 14853 USA. Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. Natl Inst Mat Sci, Tsukuba, Ibaraki, Japan. RP Wang, ZW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. EM z_wang@lanl.gov RI Lujan Center, LANL/G-4896-2012 NR 20 TC 19 Z9 20 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3174 EP 3176 DI 10.1063/1.16183650 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400062 ER PT J AU Li, DY Wu, Y Fan, R Yang, PD Majumdar, A AF Li, DY Wu, Y Fan, R Yang, PD Majumdar, A TI Thermal conductivity of Si/SiGe superlattice nanowires SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH; TRANSPORT; DEVICES AB The thermal conductivities of individual single crystalline Si/SiGe superlattice nanowires with diameters of 58 and 83 nm were measured over a temperature range from 20 to 320 K. The observed thermal conductivity shows similar temperature dependence as that of two-dimensional Si/SiGe superlattice films. Comparison with the thermal conductivity data of intrinsic Si nanowires suggests that alloy scattering of phonons in the Si-Ge segments is the dominant scattering mechanism in these superlattice nanowires. In addition, boundary scattering also contributes to thermal conductivity reduction. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mech 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. RP Li, DY (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RI Wu, Yiying/A-3949-2011; Li, Deyu/D-2938-2012; Fan, Rong/B-1613-2014; OI Li, Deyu/0000-0001-8364-0924; Wu, Yiying/0000-0001-9359-1863 NR 19 TC 251 Z9 252 U1 8 U2 55 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 13 PY 2003 VL 83 IS 15 BP 3186 EP 3188 DI 10.1063/1.1619221 PG 3 WC Physics, Applied SC Physics GA 730LN UT WOS:000185832400066 ER PT J AU Vega-Arroyo, M LeBreton, PR Rajh, T Zapol, P Curtiss, LA AF Vega-Arroyo, M LeBreton, PR Rajh, T Zapol, P Curtiss, LA TI Theoretical study of the ionization potential of thymine: effect of adding conjugated functional groups SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ELECTRON-AFFINITIES; AQUEOUS-SOLUTION; DENSITY; NANOPARTICLES AB The ionization potential of thymine functionalized at the C5 position with the truncated linker groups, -CH=CHCO2CH3 and -CH=CHCONHCH3, was examined using density functional theory. Results indicate that the addition of the carboxyl group to thymine lowers the adiabatic ionization potential by 0.4 eV. Further, modification of the carboxyl group by an amino group lowers the ionization potential by another 0.2 eV. The effect of solvation and base pairing with adenine on the modified thymine ionization energies was also investigated. The results provide evidence that linker groups can dampen the influence of adenine base pairing on thymine charge transfer. (C) 2003 Published by Elsevier B.V. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Zapol, P (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zapol, Peter/G-1810-2012 OI Zapol, Peter/0000-0003-0570-9169 NR 29 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 13 PY 2003 VL 380 IS 1-2 BP 54 EP 62 DI 10.1016/j.cplett.2003.08.072 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 733RT UT WOS:000186015000009 ER PT J AU Sigurdson, AJ Jones, IM AF Sigurdson, AJ Jones, IM TI Second cancers after radiotherapy: any evidence for radiation-induced genomic instability? SO ONCOGENE LA English DT Article DE second primary cancer; radiation therapy; genomic instability; chromosomal instability; review ID DNA-REPAIR GENES; THERAPY-RELATED LEUKEMIA; HODGKINS-DISEASE; IONIZING-RADIATION; LUNG-CANCER; P53 MUTATIONS; SOLID TUMORS; MICROSATELLITE INSTABILITY; CHROMOSOMAL-ABERRATIONS; MARROW TRANSPLANTATION AB Do second primary cancers in humans arise from radiation-induced somatic genomic instability after radiotherapy for the first malignancy? The amount of truly pertinent human information on this issue is sparse, leading to the conclusion that we cannot confirm or refute that instability induction by radiation is involved. However, the in vitro findings of radiation-induced genomic instability through bystander effects or increased mutation rates in cell progeny of apparently normal but irradiated cells are provocative and their transferability to human in vivo biology deserves further investigation. We describe possible animal and human studies to stimulate ideas, but the collaborative commitment of multiple large institutions to tumor tissue procurement and retrieval will be essential. In addition, detecting the temporal progression of genomic instability and identifying the salient genetic events as being radiation-induced will be pivotal. Execution of some of the studies suggested is not possible now, but applying next-generation methods could bring the concepts to fruition. As nearly one in 10 cancer diagnoses are second (or higher) malignancies, it is important to understand the contribution of radiotherapy to second cancer induction and pursue well-coordinated efforts to determine the role of induced genomic instability. C1 NCI, Radiat Epidemiol Branch, Div Canc Epidemiol & Genet, NIH,DHHS, Bethesda, MD 20892 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Sigurdson, AJ (reprint author), NCI, Radiat Epidemiol Branch, Div Canc Epidemiol & Genet, NIH,DHHS, 6120 Execut Blvd,EPS 7092,MSC 7238, Bethesda, MD 20892 USA. NR 61 TC 34 Z9 36 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0950-9232 J9 ONCOGENE JI Oncogene PD OCT 13 PY 2003 VL 22 IS 45 BP 7018 EP 7027 DI 10.1038/sj.onc.1206989 PG 10 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA 731UB UT WOS:000185903900006 PM 14557806 ER PT J AU Rocco, D Critchlow, T AF Rocco, D Critchlow, T TI Automatic discovery and classification of bioinformatics Web sources SO BIOINFORMATICS LA English DT Article; Proceedings Paper CT International Conference in Bioinformatics CY NOV 13-16, 2003 CL ATLANTA, GEORGIA AB Motivation: The World Wide Web provides an incredible resource to genomics researchers in the form of query access to distributed data sources-e.g. BLAST sequence homology search interfaces. The number of these autonomous sources and their rate of change outpaces the speed at which they can be manually classified, meaning that the available data is not being utilized to its full potential. Manually maintaining a wrapper library will not scale to accommodate the growth of genomics data sources on the Web, challenging us to produce an automated system that can find, classify and wrap new sources without constant human intervention. Previous research has not addressed the problem of automatically locating, classifying and integrating classes of bioinformatics data sources. Results: This paper presents an overview of a system for finding classes of bioinformatics data sources and integrating them behind a unified interface. We describe our approach for automatic classification of new Web sources into relevance categories that eliminates the human effort required to maintain a current repository of sources. Our approach is based on a meta-data description of classes of interesting sources that describes the important features of an entire class of services without tying that description to any particular Web source. We examine the features of this format in the context of BLAST sources to show how it relates to Web sources that are being described. We then show how a description can be used to determine if an arbitrary Web source is an instance of the described service. To validate the effectiveness of this approach, we have constructed a prototype that correctly classifies approximately two-thirds of the BLAST sources we tested. We conclude with a discussion of these results, the factors that affect correct automatic classification and areas for future study. C1 Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Rocco, D (reprint author), Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD OCT 12 PY 2003 VL 19 IS 15 BP 1927 EP 1933 DI 10.1093/bioinformatics/btg353 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 736PJ UT WOS:000186179000009 PM 14555625 ER PT J AU Narasimhan, C LoCascio, P Uberbacher, E AF Narasimhan, C LoCascio, P Uberbacher, E TI Background rareness-based iterative multiple sequence alignment algorithm for regulatory element detection SO BIOINFORMATICS LA English DT Article ID YEAST SACCHAROMYCES-CEREVISIAE; CELL-CYCLE; BINDING-SITES; EXPECTATION MAXIMIZATION; GENE-EXPRESSION; DNA; IDENTIFICATION; TRANSCRIPTION; PATTERNS; GENOME AB Motivation: Experimental methods capable of generating sets of co-regulated genes have become commonplace, however, recognizing the regulatory motifs responsible for this regulation remains difficult. As a result, computational detection of transcription factor binding sites in such data sets has been an active area of research. Most approaches have utilized either Gibbs sampling or greedy strategies to identify such elements in sets of sequences. These existing methods have varying degrees of success depending on the strength and length of the signals and the number of available sequences. We present a new deterministic iterative algorithm for regulatory element detection based on a Markov chain background. As in other methods, sequences in the entire genome and the training set are taken into account in order to discriminate against commonly occurring signals and produce patterns, which are significant in the training set. Results: The results of the algorithm compare favorably with existing tools on previously known and newly compiled data sets. The iteration based search appears rather rigorous, not only finding the binding sites, but also showing how the binding site stands out from genomic background. The approach used to score the results is critical and a discussion of various scoring schemes and options is also presented. Benchmarking of several methods shows that while most tools are good at detecting strong signals, Gibbs sampling algorithms give inconsistent results when the regulatory element signal becomes weak. A Markov chain based background model alleviates the drawbacks of MAP (maximum a posteriori log likelihood) scores. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. RP Uberbacher, E (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 3480, Oak Ridge, TN 37830 USA. NR 46 TC 10 Z9 11 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD OCT 12 PY 2003 VL 19 IS 15 BP 1952 EP 1963 DI 10.1093/bioinformatics/btg266 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 736PJ UT WOS:000186179000013 PM 14555629 ER PT J AU Shah, M Passovets, S Kim, DS Ellrott, K Wang, L Vokler, I LoCascio, P Xu, D Xu, Y AF Shah, M Passovets, S Kim, DS Ellrott, K Wang, L Vokler, I LoCascio, P Xu, D Xu, Y TI A computational pipeline for protein structure prediction and analysis at genome scale SO BIOINFORMATICS LA English DT Article ID 3-DIMENSIONAL STRUCTURE; DATA-BANK; SEQUENCES; DATABASE; CLASSIFICATION; CONFORMATIONS; PROSPECT; DESIGN; MODEL; FOLD AB Motivation: Experimental techniques alone cannot keep up with the production rate of protein sequences, while computational techniques for protein structure predictions have matured to such a level to provide reliable structural characterization of proteins at large scale. Integration of multiple computational tools for protein structure prediction can complement experimental techniques. Results: We present an automated pipeline for protein structure prediction. The centerpiece of the pipeline is our threading-based protein structure prediction system PROSPECT. The pipeline consists of a dozen tools for identification of protein domains and signal peptide, protein triage to determine the protein type (membrane or globular), protein fold recognition, generation of atomic structural models, prediction result validation, etc. Different processing and prediction branches are determined automatically by a prediction pipeline manager based on identified characteristics of the protein. The pipeline has been implemented to run in a heterogeneous computational environment as a client/server system with a web interface. Genome-scale applications on Caenorhabditis elegans, Pyrococcus furiosus and three cyanobacterial genomes are presented. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37830 USA. Univ Tennessee, Sch Genome Sci & Technol, Knoxville, TN 37922 USA. RP Xu, Y (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. EM xyn@ornl.gov RI Kim, Dongsup/C-1612-2011; OI Ellrott, Kyle/0000-0002-6573-5900 NR 38 TC 15 Z9 17 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD OCT 12 PY 2003 VL 19 IS 15 BP 1985 EP 1996 DI 10.1093/bioinformatics/btg262 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 736PJ UT WOS:000186179000017 PM 14555633 ER PT J AU Wheatley, PJ Mauche, CW Mattei, JA AF Wheatley, PJ Mauche, CW Mattei, JA TI The X-ray and extreme-ultraviolet flux evolution of SS Cygni throughout outburst SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : close; stars : dwarf novae; stars : individual : SS Cygni; novae, cataclysmic variables ID DWARF-NOVA OUTBURSTS; U-GEMINORUM; OY CARINAE; CATACLYSMIC VARIABLES; EUVE OBSERVATIONS; VW-HYDRI; EXOSAT OBSERVATIONS; DELAY; SUPEROUTBURST; QUIESCENCE AB We present the most complete multiwavelength coverage of any dwarf nova outburst: simultaneous optical, Extreme Ultraviolet Explorer and Rossi X-ray Timing Explorer observations of SS Cygni throughout a narrow asymmetric outburst. Our data show that the high-energy outburst begins in the X-ray waveband 0.9-1.4 d after the beginning of the optical rise and 0.6 d before the extreme-ultraviolet rise. The X-ray flux drops suddenly, immediately before the extreme-ultraviolet flux rise, supporting the view that both components arise in the boundary layer between the accretion disc and white dwarf surface. The early rise of the X-ray flux shows that the propagation time of the outburst heating wave may have been previously overestimated. The transitions between X-ray and extreme-ultraviolet dominated emission are accompanied by intense variability in the X-ray flux, with time-scales of minutes. As detailed by Mauche & Robinson, dwarf nova oscillations are detected throughout the extreme-ultraviolet outburst, but we find they are absent from the X-ray light curve. X-ray and extreme-ultraviolet luminosities imply accretion rates of 3 x 10(15) g s(-1) in quiescence, 1 x 10(16) g s(-1) when the boundary layer becomes optically thick, and 10(18) g s(-1) at the peak of the outburst. The quiescent accretion rate is two and a half orders of magnitude higher than predicted by the standard disc instability model, and we suggest this may be because the inner accretion disc in SS Cyg is in a permanent outburst state. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Amer Assoc Variable Star Observers, Cambridge, MA 02138 USA. RP Wheatley, PJ (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. OI Wheatley, Peter/0000-0003-1452-2240 NR 59 TC 56 Z9 56 U1 0 U2 1 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 11 PY 2003 VL 345 IS 1 BP 49 EP 61 DI 10.1046/j.1365-8711.2003.06936.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 728UW UT WOS:000185735600006 ER PT J AU Kozlova, JP Bowles, TJ Eremin, VK Gavrin, VN Koshelev, OG Markov, AV Morozova, VA Polyakov, AJ Verbitskaya, EM Veretenkin, EP AF Kozlova, JP Bowles, TJ Eremin, VK Gavrin, VN Koshelev, OG Markov, AV Morozova, VA Polyakov, AJ Verbitskaya, EM Veretenkin, EP TI A comparative study of EL2 and other deep centers in undoped SIGaAs using optical absorption spectra and photoconductivity measurements SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 9th European Symposium on Semiconductor Detectors CY JUN 23-27, 2002 CL SCHLOSS ELMAU, GERMANY SP Hamamatsu Photon Deutschland GmbH, iseg Spezialelektronik GmbH, Konica Business Machines, Rontec GmbH, SINTEF Elect & Cybernet, STMicroelectronics DE gallium arsenide; radiation detector; deep levels; optical absorption ID SEMIINSULATING GAAS DETECTORS AB The performance of radiation detectors fabricated from semi-insulating (SI) GaAs is highly sensitive to EL2(+)-concentration in the material. Near-infrared optical absorption measurements are commonly used to determine the EL2-concentration and to roughly estimate the EL2(+)-concentration under the assumption that the optical absorption is mainly determined by the photoionization and the photoneutralization of EL2(0) and EL2(+), respectively. However, the presence of different native defects can contribute to optical absorption and reduce the precision of determination of EL2-concentration. In this work, we evaluate the contributions into optical absorption from EL2 and other deep center namely EL3 defect (0.55 eV) using near-infrared optical absorption and photoconductivity (PC) measurements in the photon energy interval 0.5-1.4 eV for SI GaAs crystals grown by the liquid encapsulated Czochralski method from melts with As content changing from 50% to about 46%. The photoelectrical spectra were measured on p-i-n structure detectors with heavily doped p(+) and n(+) layers grown by Liquid Phase Epitaxy and on Schottky diodes. The short circuit photocurrent spectra were registered for all detectors in the energy interval 0.65-1.4 eV. Unexpectedly, the current sensitivities in the regions of the extrinsic and intrinsic absorption were comparable. A comparative study of optical absorption, PC and short circuit photocurrent spectra resulted in determination of EL2+-concentration. It was concluded that contribution of additional deep centers, particularly the ionized EL3+ defect could be comparable to the EL2-contribution. The EL3 centers were attributed to oxygen-related defects based on published results and on some indirect evidence in our experimental data. (C) 2003 Elsevier B.V. All rights reserved. C1 Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. Los Alamos Natl Lab, Los Alamos, NM USA. Ioffe Inst, St Petersburg, Russia. Moscow MV Lomonosov State Univ, Dept Phys, Moscow, Russia. Inst Rare Met, Moscow, Russia. RP Kozlova, JP (reprint author), Russian Acad Sci, Inst Nucl Res, 60th October Anniversary Pr 7A, Moscow 117312, Russia. RI Verbitskaya, Elena/D-1521-2014 NR 10 TC 6 Z9 7 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 OCT 11 PY 2003 VL 512 IS 1-2 BP 1 EP 7 DI 10.1016/S0168-9002(03)01871-0 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 738LU UT WOS:000186290000002 ER PT J AU Houdayer, A Lebel, C Leroy, C Li, Z Verbitskaya, E AF Houdayer, A Lebel, C Leroy, C Li, Z Verbitskaya, E TI Improved radiation hardness to low-energy protons for oxygenated Si detectors with thermal donors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 9th European Symposium on Semiconductor Detectors CY JUN 23-27, 2002 CL SCHLOSS ELMAU, GERMANY SP Hamamatsu Photon Deutschland GmbH, iseg Spezialelektronik GmbH, Konica Business Machines, Rontec GmbH, SINTEF Elect & Cybernet, STMicroelectronics DE silicon detectors; oxygen; 10 MeV proton irradiation; radiation hardness ID SILICON DETECTORS; IRRADIATION AB Silicon detectors have been made on oxygenated silicon with the incorporation of thermal donors during the oxidation process based on BNL's high-temperature long-time (thermal donor) (HTLT(TD)) technology. The initial doping concentration in HTLT(TD) silicon detectors is twice more than that of standard silicon detectors (same starting material, but no HTLT process), with TD being the dominant donor. Standard and HTLT(TD) silicon detectors have been irradiated by 10 MeV protons up to 2.5 x 10(14) p/cm(2). It has been found that the increase rate (beta) of the space charge concentration (N-eff) after space charge sign inversion (SCSI) in HTLT(TD) silicon detectors is about half of that in standard silicon detectors. Further improvement in proton radiation hardness has been observed in terms of the SCSI fluence. The SCSI fluence for HTLT(TD) silicon detectors is more than four times higher than that of standard detectors, although the corresponding ratio of initial space charge concentrations between the two groups of detectors is about two. This result implies that the SCSI is greatly delayed in HTLT(TD) silicon detector compared with. silicon detectors with similar initial space charge (all phosphorus) concentration (lower resistivity standard silicon detectors). (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Montreal, Montreal, PQ H3C 3J7, Canada. Brookhaven Natl Lab, Upton, NY 11973 USA. Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Lebel, C (reprint author), Univ Montreal, CP 6128,Succursale Ctr Ville, Montreal, PQ H3C 3J7, Canada. RI Verbitskaya, Elena/D-1521-2014 NR 6 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD OCT 11 PY 2003 VL 512 IS 1-2 BP 92 EP 97 DI 10.1016/S0168-9002(03)01882-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 738LU UT WOS:000186290000012 ER PT J AU Castoldi, A Galimberti, A Guazzoni, C Rehak, P Struder, L AF Castoldi, A Galimberti, A Guazzoni, C Rehak, P Struder, L TI X-ray imaging and spectroscopy with Controlled-Drift Detectors: experimental results and perspectives SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 9th European Symposium on Semiconductor Detectors CY JUN 23-27, 2002 CL SCHLOSS ELMAU, GERMANY SP Hamamatsu Photon Deutschland GmbH, iseg Spezialelektronik GmbH, Konica Business Machines, Rontec GmbH, SINTEF Elect & Cybernet, STMicroelectronics DE time resolved X-ray imaging; X-ray radiography; Controlled-Drift Detectors; energy-resolved X-ray imaging AB The Controlled-Drift Detector (CDD) is a fully depleted silicon detector that allows 2-D position sensing and energy spectroscopy of X-rays in the range 1-30 keV with excellent time resolution. Its distinctive feature is the simultaneous readout of the charge packets stored in the detector by means of a uniform electrostatic field leading to readout times of few mus/cm. The achieved room temperature energy resolution at the Mn Kalpha line is better than 300 eV FWHM at 60 kHz and improves at higher frame frequencies thanks to the short integration time. In this paper, we present the characterization of the imaging and timing properties of two CDD prototypes. Time resolved 2-D images in the microsecond range as well as X-ray radiographies will be presented. Details of the design of a new 6 x 6 mm(2) prototype will be presented and the preliminary measurements will be discussed. (C) 2003 Elsevier B.V. All rights reserved. C1 Politecn Milan, Dip Ingn Nucl, CeSNEF, I-20133 Milan, Italy. Politecn Milan, Dip Elettron & Informaz, I-20133 Milan, Italy. Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. Max Planck Inst Halbleiterlab, D-81739 Munich, Germany. Sincrotrone Trieste, SYRMEP Beamline, Trieste, Italy. RP Castoldi, A (reprint author), Politecn Milan, Dip Ingn Nucl, CeSNEF, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy. RI Guazzoni, Chiara/A-5070-2008 OI Guazzoni, Chiara/0000-0001-6399-8670 NR 8 TC 15 Z9 14 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 OCT 11 PY 2003 VL 512 IS 1-2 BP 250 EP 256 DI 10.1016/S0168-9002(03)01901-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 738LU UT WOS:000186290000032 ER PT J AU Chen, W De Geronimo, G Li, Z O'Connor, P Radeka, V Rehak, P Smith, GC Wall, JS Yu, B AF Chen, W De Geronimo, G Li, Z O'Connor, P Radeka, V Rehak, P Smith, GC Wall, JS Yu, B TI High resistivity silicon active pixel sensors for recording data from STEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 9th European Symposium on Semiconductor Detectors CY JUN 23-27, 2002 CL SCHLOSS ELMAU, GERMANY SP Hamamatsu Photon Deutschland GmbH, iseg Spezialelektronik GmbH, Konica Business Machines, Rontec GmbH, SINTEF Elect & Cybernet, STMicroelectronics DE pixel sensor; electron microscope; silicon detector; direct conversion ID DETECTORS AB An X-ray Active Matrix Pixel Sensor (XAMPS) for recording Data from the Scanning Transmission Electron Microscope (STEM) was designed, produced and tested. The reason for measuring scattering angle of all STEM electrons is given together with the requirement on the performance of the XAMPS. Principles of the measurement of the number of STEM electrons scattered in a particular direction are summarized. Results of tests performed on, a produced detector are described and the problem with the formation of an insulation layer between silicon and aluminum is identified. A change in the design of the pixel is proposed which results in a fully functioning XAMPS even with the insulation layer present. (C) 2003 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Instrumentat Div, Bldg 535 B, Upton, NY 11973 USA. EM rehak2@bnl.gov NR 8 TC 6 Z9 6 U1 0 U2 2 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 OCT 11 PY 2003 VL 512 IS 1-2 BP 368 EP 377 DI 10.1016/S0168-9002(03)01915-6 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 738LU UT WOS:000186290000046 ER PT J AU Poyneer, LA AF Poyneer, LA TI Scene-based Shack-Hartmann wave-front sensing: analysis and simulation SO APPLIED OPTICS LA English DT Article ID ADAPTIVE OPTICS SYSTEMS; IMAGE-RESTORATION; REGISTRATION AB In many situations it is not possible for an adaptive optics system to use a point source to measure the phase derivative, such as imaging along slant paths through the atmosphere and observation of the earth from space with a lightweight optic. Instead, small subimages of the observed scene can be used in a scene-based wave-front sensing technique. This study presents three important advances in the understanding of this technique. Rigorous analysis shows how slope estimation performance depends precisely on scene content and illumination. Scaling laws for changes in illumination are derived. The technique, when applied to point sources, is more robust to detect size changes and background levels than current methods. (C) 2003 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Poyneer, LA (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94551 USA. EM poyneer1@llnl.gov RI Tippie, Abbie/A-1106-2007 NR 15 TC 67 Z9 70 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 10 PY 2003 VL 42 IS 29 BP 5807 EP 5815 DI 10.1364/AO.42.005807 PG 9 WC Optics SC Optics GA 732EN UT WOS:000185928000001 PM 14577533 ER PT J AU Hui, L Haiman, Z AF Hui, L Haiman, Z TI The thermal memory of reionization history SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : theory; intergalactic medium; quasars : absorption lines ID LY-ALPHA FOREST; PHOTOIONIZED INTERGALACTIC MEDIUM; PROBE WMAP OBSERVATIONS; POPULATION-III STARS; RADIATIVE-TRANSFER; COSMOLOGICAL REIONIZATION; DARK-MATTER; INHOMOGENEOUS UNIVERSE; REDSHIFT EVOLUTION; B-DISTRIBUTION AB The recent measurement by WMAP of a large electron-scattering optical depth tau(e) = 0.17 +/- 0.04 is consistent with a simple model of reionization in which the intergalactic medium (IGM) is ionized at redshift z similar to 15 and remains highly ionized thereafter. Here we show that existing measurements of the IGM temperature from the Lyalpha forest at z similar to 2-4 rule out this "vanilla" model. Under reasonable assumptions about the ionizing spectrum, as long as the universe is reionized before z = 10 and remains highly ionized thereafter, the IGM reaches an asymptotic thermal state that is too cold compared to observations. To simultaneously satisfy the cosmic microwave background and Lyalpha forest constraints, the reionization history must be complex: reionization begins early at z e 15, but there must have been significant (order-of-unity) changes in fractions of neutral hydrogen and/or helium at 6 < z < 10 and/or singly ionized helium at 4 < z < 10. We describe a physically motivated reionization model that satisfies all current observations. We also explore the impact of a stochastic reionization history and show that a late epoch of (He II --> He III) reionization induces a significant scatter in the IGM temperature, but the scatter diminishes with time quickly. Finally, we provide an analytic formula for the thermal asymptote and discuss possible additional heating mechanisms that might evade our constraints. C1 Fermilab Natl Accelerator Lab, Theoret Astrophys Dept, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Fermilab Natl Accelerator Lab, Theoret Astrophys Dept, POB 500,500 Wilson Rd, Batavia, IL 60510 USA. EM lhui@fnal.gov; zoltan@astro.columbia.edu NR 68 TC 163 Z9 163 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 9 EP 18 DI 10.1086/377229 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300002 ER PT J AU Scharf, C Smail, I Ivison, R Bower, R van Breugel, W Reuland, M AF Scharf, C Smail, I Ivison, R Bower, R van Breugel, W Reuland, M TI Extended X-ray emission around 4C 41.17 at z=3.8 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : high-redshift; galaxies : individual (4C 41.17) galaxies : jets; radiation mechanisms : nonthermal; X-rays : galaxies ID INVERSE COMPTON-SCATTERING; REDSHIFT RADIO GALAXIES; DEEP FIELD-SOUTH; INTRACLUSTER MEDIUM; STAR-FORMATION; CHANDRA; CLUSTERS; JETS; EVOLUTION; SEARCH AB We present sensitive, high-resolution, X-ray imaging from Chandra of the high-redshift radio galaxy 4C 41.17 (z = 3.8). Our 150 ks Chandra exposure detects strong X-ray emission from a point source coincident with the nucleus of the radio galaxy. In addition, we identify extended X-ray emission with a luminosity of similar to10(45) ergs s(-1) covering a 100 kpc (15") diameter region around the radio galaxy. The extended X-ray emission follows the general distribution of radio emission in the radio lobes of this source and the distribution of a giant Lyalpha emission-line halo, while the spectrum of the X-ray emission is nonthermal and has a power-law index consistent with that of the radio synchrotron. We conclude that the X-ray emission is most likely inverse Compton scattering of far-infrared photons from a relativistic electron population probably associated with past and current activity from the central object. Assuming an equipartition magnetic field, the cosmic microwave background energy density at z = 3.8 can account for at most only 40% of the inverse Compton emission. Published submillimeter maps of 4C 41.17 have detected an apparently extended and extremely luminous far-infrared emission around the radio galaxy. We demonstrate that this photon component and its spatial distribution, in combination with the cosmic microwave background, can reproduce the observed X-ray luminosity. We propose that photoionization by these inverse Compton X-ray photons plays a significant role in this system and provides a new physical feedback mechanism to preferentially affect the gas within the most massive halos at high redshift. This is the highest redshift example of extended X-ray emission around a radio galaxy currently known and points toward an extraordinary halo around such systems, where cool dust, relativistic electrons, neutral and ionized gas, and intense infrared and X-ray radiation all appear to coexist. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Univ Durham, Inst Computat Cosmol, Durham, England. Royal Observ, Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. RP Scharf, C (reprint author), Columbia Univ, Columbia Astrophys Lab, MC 5247,550 W 120th St, New York, NY 10027 USA. RI Smail, Ian/M-5161-2013; Ivison, R./G-4450-2011 OI Smail, Ian/0000-0003-3037-257X; Ivison, R./0000-0001-5118-1313 NR 58 TC 41 Z9 41 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 105 EP 113 DI 10.1086/377531 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300009 ER PT J AU Sako, M Kahn, SM Branduardi-Raymont, G Kaastra, JS Brinkman, AC Page, MJ Behar, E Paerels, F Kinkhabwala, A Liedahl, DA den Herder, JW AF Sako, M Kahn, SM Branduardi-Raymont, G Kaastra, JS Brinkman, AC Page, MJ Behar, E Paerels, F Kinkhabwala, A Liedahl, DA den Herder, JW TI Can a dusty warm absorber model reproduce the soft X-ray spectra of MCG-6-30-15 and Markarian 766? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : Seyfert; X; rays : galaxies ID ACTIVE GALACTIC NUCLEI; REFLECTION GRATING SPECTROMETER; SEYFERT-1 GALAXY MCG-6-30-15; K-ALPHA LINES; XMM-NEWTON; ACCRETION DISK; EMISSION-LINES; BLACK-HOLE; ATOMIC OXYGEN; IRON AB XMM-Newton RGS spectra of MCG -6-30-15 and Mrk 766 exhibit complex discrete structure, which was interpreted in a paper by Branduardi-Raymont and coworkers as evidence for the existence of relativistically broadened Lyalpha emission from carbon, nitrogen, and oxygen, produced in the innermost regions of an accretion disk around a Kerr black hole. This suggestion was subsequently criticized in a paper by Lee and coworkers, who argued that for MCG -6-30-15, the Chandra HETG spectrum, which is partially overlapping the RGS in spectral coverage, is adequately fitted by a dusty warm absorber model, with no relativistic line emission. We present a reanalysis of the original RGS data sets in terms of the model by Lee and coworkers. Specifically, we show that (1) the explicit model given by Lee and coworkers differs markedly from the RGS data, especially at longer wavelengths, beyond the region sampled by the HETG; (2) generalizations of the Lee and coworkers model, with all parameters left free, do provide qualitatively better fits to the RGS data, but are still incompatible with the detailed spectral structure; (3) the ionized oxygen absorption-line equivalent widths are well measured with the RGS for both sources, and place very tight constraints on both the column densities and turbulent velocity widths of O VII and O VIII. The derived column densities are well below those posited by Lee and coworkers and are insufficient to play any role in explaining the observed edge-like feature near 17.5 Angstrom; (4) the lack of a significant neutral oxygen edge near 23 Angstrom places very strong limits on any possible contribution of absorption to the observed structure by dust embedded in a warm medium; and (5) the original relativistic line model with warm absorption proposed by Branduardi-Raymont and coworkers provides a superior fit to the RGS data, both in the overall shape of the spectrum and in the discrete absorption lines. We also discuss a possible theoretical interpretation for the putative relativistic Lyalpha line emission in terms of the photoionized surface layers of the inner regions of an accretion disk. While there are still a number of outstanding theoretical questions about the viability of such a model, it is interesting to note that simple estimates of key parameters are roughly compatible with those derived from the observed spectra. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Natl Inst Space Res, SRON, NL-3584 CA Utrecht, Netherlands. Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. RP CALTECH, Theoret Astrophys & Space Radiat Lab, MC 130-33, Pasadena, CA 91125 USA. EM masao@tapir.caltech.edu; skahn@astro.columbia.edu; gbr@mssl.ucl.ac.uk; J.S.Kaastra@sron.nl; A.C.Brinkman@sron.nl; mjp@mssl.ucl.ac.uk; behar@astro.columbia.edu; frits@astro.columbia.edu; ali@astro.columbia.edu; duane@virgo.llnl.gov; J.W.A.den.Herder@sronl.nl NR 87 TC 62 Z9 62 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 114 EP 128 DI 10.1086/377575 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300010 ER PT J AU Chisholm, JR Dodelson, S Kolb, EW AF Chisholm, JR Dodelson, S Kolb, EW TI Stellar-mass black holes in the solar neighborhood SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; solar neighborhood; stars : fundamental parameters ID DIGITAL SKY SURVEY; ADIABATIC ACCRETION FLOW; HIGH-RESOLUTION CAMERA; GALACTIC DISTRIBUTION; SPHERICAL ACCRETION; BINARY-SYSTEMS; NEUTRON-STARS; RADIATION; DISKS; M82 AB We search for nearby, isolated, accreting, "stellar-mass'' (3-100 M-circle dot) black holes. Models suggest a synchrotron spectrum in visible wavelengths and some emission in X-ray wavelengths. Of 3.7 million objects in the Sloan Digital Sky Survey Early Data Release, about 150,000 objects have colors and properties consistent with such a spectrum, and 87 of these objects are X-ray sources from the ROSAT All-Sky Survey. Thirty-two of these have been confirmed not to be black holes using optical spectra. We give the positions and colors of these 55 black hole candidates and quantitatively rank them on their likelihood to be black holes. We discuss uncertainties in the expected number of sources and the contribution of black holes to local dark matter. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Chisholm, JR (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 57 TC 7 Z9 7 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 437 EP 450 DI 10.1086/377628 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300037 ER PT J AU Koller, J Li, H Lin, DNC AF Koller, J Li, H Lin, DNC TI Vortices in the co-orbital region of an embedded protoplanet SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; hydrodynamics; planetary systems : protoplanetary disks ID PRIMORDIAL SOLAR NEBULA; COROTATION TORQUE; TIDAL INTERACTION; GIANT PLANETS; VISCOUS DISK; MIGRATION; ACCRETION; SIMULATIONS AB We present global two-dimensional inviscid disk simulations with an embedded planet, emphasizing the nonlinear dynamics in its co-orbital region. We find that the potential vorticity of the flow in this region is not conserved because of the presence of two spiral shocks produced by the planet. As the system evolves, the potential vorticity profile develops extrema ( inflection points) that eventually render the flow unstable. Vortices are produced in association with the potential vorticity minima. Born in the separatrix region, these vortices experience close encounters with the planet, consequently exerting strong torques on the planet. The existence of these vortices have important implications for understanding the migration rates of low-mass planets. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. RP Koller, J (reprint author), Los Alamos Natl Lab, Div Appl Phys, X-1,MS P225, Los Alamos, NM 87545 USA. RI Koller, Josef/C-5591-2009 OI Koller, Josef/0000-0002-6770-4980 NR 19 TC 50 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP L91 EP L94 DI 10.1086/379032 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500023 ER PT J AU Torres, DF Romero, GE Barcons, X Lu, YJ AF Torres, DF Romero, GE Barcons, X Lu, YJ TI Testing the binary black hole paradigm through the FeK alpha line profile: Application to 3C 273 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; line : profiles; quasars : individual (3C 273) ID ACTIVE GALACTIC NUCLEI; 3C 273; EMISSION-LINE; INNER JET; GALAXIES; PRECESSION; CORONA; RADIO; 3C273 AB We propose the study of long-term variations in the Fe Kalpha line profile as a discriminator for binary black hole (BH) systems. The existence of a binary BH in the center of an active galaxy will produce a particular signature in the evolution of the line profile, as a result of disk precession. This signature is a periodic variation of the position of the blue edge of the profile, accompanied by periodic change of its intensity. We show that detection of the former is clearly within the observational capabilities of planned X-ray missions. Detecting a periodic variation of line profiles would provide the first direct evidence for precessing disks in active galactic nuclei, as opposed to the existing evidence supporting only the precession of jets. We apply these ideas to 3C 273. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Inst Argentino Radioastron, RA-1894 Buenos Aires, DF, Argentina. UC, CSIC, Inst Fis Cantabria, Santander 39005, Spain. Univ Toronto, Canadian Inst Theoret Astrophys, McLennan Labs, Toronto, ON M5S 3H8, Canada. Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, Peoples R China. RP Torres, DF (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-413, Livermore, CA 94550 USA. RI Barcons, Xavier/L-3335-2014; Torres, Diego/O-9422-2016 OI Barcons, Xavier/0000-0003-1081-8861; Torres, Diego/0000-0002-1522-9065 NR 28 TC 6 Z9 6 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP L31 EP L34 DI 10.1086/379108 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500008 ER PT J AU Kolling, DRJ Samoilova, RI Holland, JT Berry, EA Dikanov, SA Crofts, AR AF Kolling, DRJ Samoilova, RI Holland, JT Berry, EA Dikanov, SA Crofts, AR TI Exploration of ligands to the Q(i) site semiquinone in the bc(1) complex using high-resolution EPR SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PURE QUADRUPOLE-RESONANCE; RHODOBACTER-SPHAEROIDES; AMINO-ACIDS; ELECTRON-TRANSFER; CYTOCHROME-B; QUINONE; N-14; UBIQUINOL; OXIDOREDUCTASE; MECHANISM AB Pulsed EPR spectroscopy was used to explore the structural neighborhood of the semiquinone (SQ) stabilized at the Q(i) site of the bc(1) complex of Rhodobacter sphaeroides (EC 1.10.2.2) and to demonstrate that the nitrogen atom of a histidine imidazole group donates an H-bond to the SQ. Crystallographic structures show two different configurations for the binding of ubiquinone at the Q(i) site of mitochondrial bc1 complexes in which histidine (His-201 in bovine sequence) is either a direct H-bond donor or separated by a bridging water. The paramagnetic properties of the SQ formed at the site provide an independent method for studying the liganding of this intermediate species. The antimycin-sensitive SQ formed at the Q(i) site by either equilibrium redox titration, reduction of the oxidized complex by ascorbate, or addition of decylubihydroquinone to the oxidized complex in the presence of myxothiazol all showed similar properties. The electron spin echo envelope modulation spectra in the N-14 region were dominated by lines with frequencies at 1.7 and 3.1 MHz. Hyperfine sublevel correlation spectroscopy spectra showed that these were contributed by a single nitrogen. Further analysis showed that the N-14 nucleus was characterized by an isotropic hyperfine coupling of similar to0.8 MHz and a quadrupole coupling constant of similar to0.35 MHz. The nitrogen was identified as the N-epsilon or N-delta imidazole nitrogen of a histidine (it is likely to be His-217, or His-201 in bovine sequence). A distance of 2.5-3.1 Angstrom for the O-N distance between the carbonyl of SQ and the nitrogen was estimated. The mechanistic significance is discussed in the context of a dynamic role for the movement of His-217 in proton transfer to the site. C1 Univ Illinois, Dept Biochem, Roger Adams Lab 419, Urbana, IL 61801 USA. Univ Illinois, Dept Vet Clin Med, Urbana, IL 61801 USA. Univ Illinois, Ctr Biophys & Computat Biol, Urbana, IL 61801 USA. Russian Acad Sci, Inst Chem Kinet & Combust, Novosibirsk 630090, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Crofts, AR (reprint author), Univ Illinois, Dept Biochem, Roger Adams Lab 419, 600 S Mathews Ave, Urbana, IL 61801 USA. FU FIC NIH HHS [1 R03 TW01495]; NCRR NIH HHS [S10-RR15878]; NIGMS NIH HHS [GM 35438, GM 62954] NR 34 TC 36 Z9 38 U1 0 U2 9 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 OCT 10 PY 2003 VL 278 IS 41 BP 39747 EP 39754 DI 10.1074/jbc.M305913200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 728JJ UT WOS:000185713800060 PM 12874282 ER PT J AU Szabelski, P Liu, XD Guiochon, G AF Szabelski, P Liu, XD Guiochon, G TI Pressure-induced effects in the heterogeneous adsorption of insulin on chromatographic surfaces SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption; hydrophobic surfaces; heterogeneous interactions; insulin ID PERFORMANCE LIQUID-CHROMATOGRAPHY; RANDOM SEQUENTIAL ADSORPTION; PROTEIN ADSORPTION; BEHAVIOR; RETENTION; DYNAMICS; KINETICS; HPLC AB The effect of increasing the average column pressure (ACP) on the heterogeneous adsorption of insulin variants on a C-18-bonded silica was studied in isocratic reversed-phase HPLC. Adsorption isotherm data of lispro and porcine insulin obtained for values of the ACP ranging from 57 to 237 bar were fitted to the Langmuir-Freundlich and the Toth equation. The resulting isotherm parameters, including the equilibrium adsorption constant and the heterogeneity index, were next used for the calculation of distribution functions characterizing the energy of interactions between the adsorbed insulin molecules and the stationary phase. It was observed that increasing the pressure by 180 bar causes a broadening of the distribution functions and a shift of the position of their maximum toward lower interaction energies. These findings suggest that, under high pressures, the insulin molecules interact with the stationary phase in a more diversified way than under low pressures. Additionally, the most probable value of the energy of the insulin-surface interactions becomes lower when the ACP increases. The pressure-induced changes in the interaction of insulin variants with the hydrophobic surface are attributed to a possible conformational flexibility of the molecular structure of this protein. (C) 2003 Elsevier B.V. All rights reserved. C1 Marie Curie Sklodowska Univ, Dept Theoret Chem, PL-20031 Lublin, Poland. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN USA. RP Guiochon, G (reprint author), Beijing Inst Transfus Med, 27 9 Taiping Rd, Beijing 100850, Peoples R China. NR 35 TC 5 Z9 5 U1 2 U2 11 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 OCT 10 PY 2003 VL 1015 IS 1-2 BP 43 EP 52 DI 10.1016/S0021-9673(03)01286-X PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 727YZ UT WOS:000185689600005 PM 14570318 ER PT J AU Zhou, DM Kaczmarski, K Guiochon, G AF Zhou, DM Kaczmarski, K Guiochon, G TI Comparison of the binary equilibrium isotherms of the 1-indanol enantiomers on three high-performance liquid chromatography columns of different sizes SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE adsorption isotherms; enantiomer separation; indanol; cellulose tribenzoate ID CHIRAL STATIONARY-PHASE; SIMULATED MOVING-BED; CAPILLARY-ELECTROPHORESIS; BAND PROFILES; ADSORPTION BEHAVIOR; MICROBORE COLUMNS; BETA-CYCLODEXTRIN; SEPARATION; 1-PHENYL-1-PROPANOL; PREDICTION AB The competitive isotherm data for the enantiomers of 1-indanol were measured on three columns, a microbore column (15 cm x 0.1 cm), a conventional analytical column (15 cm x 0.46 cm), and a semi-preparative column (20 cm x 1.0 cm), packed with Chiralcel OB. The sets of isotherm data measured on each one of these three columns could be fitted well by a bi-Langmuir isotherm model. The experimental elution band profiles of mixtures of the 1-indanol isomers were recorded on the three columns. The isotherm model, combined with the equilibrium dispersive model of chromatography, gave calculated profiles that are in excellent agreement with the experimental profiles in all cases investigated. It was found that the value of the inner diameter of the column is an important parameter in the calculation of the isotherm parameters from the measured isotherm data. In order to use isotherm data obtained on one column to account for the phase equilibrium on another one, the inner diameters of these columns must be measured accurately. The diameters of the three columns were all slightly off their nominal value. Without correction, an important systematic error was made on the isotherm data obtained with the microbore column while only negligible errors were made on the data obtained with the other two columns. After due correction for this effect, the relative difference between the isotherm data for the microbore and the semi-preparative column is still, on the average, about 10%, a difference that might be explained by the limited precision of the measurement of the microbore column diameter. The relative difference between the isotherm data for the analytical and the semi-preparative columns was about 1%, a reasonable value, since the two columns came from different batches of the same packing material. (C) 2003 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 USA. Rzeszow Univ Technol, Fac Chem, PL-35959 Rzeszow, Poland. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, 552 Buehler Hall, Knoxville, TN 37996 USA. NR 37 TC 8 Z9 9 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 OCT 10 PY 2003 VL 1015 IS 1-2 BP 73 EP 87 DI 10.1016/S0021-9673(03)01214-7 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 727YZ UT WOS:000185689600008 PM 14570321 ER PT J AU Tartakovsky, DM Guadagnini, A Riva, M AF Tartakovsky, DM Guadagnini, A Riva, M TI Stochastic averaging of nonlinear flows in heterogeneous porous media SO JOURNAL OF FLUID MECHANICS LA English DT Article ID STEADY-STATE FLOW; UNSATURATED FLOW; LOCALIZED ANALYSES; BROOKS-COREY; TRANSPORT; DIFFUSION; EQUATIONS; DOMAINS; DISPERSION; SOLUTE AB We consider flow in partially saturated heterogeneous porous media with uncertain hydraulic parameters. By treating the saturated conductivity of the medium as a random field, we derive a set of deterministic equations for the statistics (ensemble mean and variance) of fluid pressure. This is done for three constitutive models that describe the nonlinear dependence of relative conductivity on pressure. We use the Kirchhoff transform to map Richards equation into a linear PDE and explore alternative closures for the resulting moment equations. Regardless of the type of nonlinearity, closure by perturbation is more accurate than closure based on the non-perturbative Gaussian mapping. We also demonstrate that predictability of unsaturated flow in heterogeneous porous media is enhanced by choosing either the Brooks-Corey or van Genuchten constitutive model over the Gardner model. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Politecn Milan, DIIAR, I-20133 Milan, Italy. RP Tartakovsky, DM (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013; Riva, Monica/A-9974-2015; OI Riva, Monica/0000-0002-7304-4114 NR 35 TC 28 Z9 28 U1 0 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD OCT 10 PY 2003 VL 492 BP 47 EP 62 DI 10.1017/S002211200300538X PG 16 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 735EM UT WOS:000186099500003 ER PT J AU Amini, JM Gould, H AF Amini, JM Gould, H TI High precision measurement of the static dipole polarizability of cesium SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALKALI-METAL ATOMS; DISPERSION COEFFICIENTS; LIFETIME MEASUREMENTS; STARK SHIFT; CS; CONSTANTS; CS-133; BEAM AB The cesium 6(2)S(1/2) scalar dipole polarizability alpha(0) has been determined from the time-of-flight of laser cooled and launched cesium atoms traveling through an electric field. We find alpha(0)=6.611+/-0.009x10(-39) C m(2)/V=59.42+/-0.08x10(-24) cm(3)=401.0+/-0.6a(0)(3). The 0.14% uncertainty is a factor of 14 improvement over the previous measurement. Values for the 6(2)P(1/2) and 6(2)P(3/2) lifetimes and the 6(2)S(1/2) cesium-cesium dispersion coefficient C-6 are determined from alpha(0) using the procedure of Derevianko and Porsev [Phys. Rev. A 65, 053403 (2002)10.1103/PhysRevA.65.053403 (2002)]. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Amini, JM (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 33 TC 90 Z9 90 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 OCT 10 PY 2003 VL 91 IS 15 AR 153001 DI 10.1103/PhysRevLett.91.153001 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500014 PM 14611463 ER PT J AU Dewey, MS Gilliam, DM Nico, JS Wietfeldt, FE Fei, X Snow, WM Greene, GL Pauwels, J Eykens, R Lamberty, A Van Gestel, J AF Dewey, MS Gilliam, DM Nico, JS Wietfeldt, FE Fei, X Snow, WM Greene, GL Pauwels, J Eykens, R Lamberty, A Van Gestel, J TI Measurement of the neutron lifetime using a proton trap SO PHYSICAL REVIEW LETTERS LA English DT Article ID (LIF)-LI-6 REFERENCE DEPOSITS; INELASTICALLY SCATTERED NEUTRONS; STORING ULTRACOLD NEUTRONS; CHARGED-PARTICLE REACTIONS; B-10; DECAY AB We report a new measurement of the neutron decay lifetime by the absolute counting of in-beam neutrons and their decay protons. Protons were confined in a quasi-Penning trap and counted with a silicon detector. The neutron beam fluence was measured by capture in a thin (LiF)-Li-6 foil detector with known absolute efficiency. The combination of these simultaneous measurements gives the neutron lifetime: tau(n)=(886.8+/-1.2[stat]+/-3.2[syst]) s. The systematic uncertainty is dominated by uncertainties in the mass of the (LiF)-Li-6 deposit and the Li-6(n,t) cross section. This is the most precise measurement of the neutron lifetime to date using an in-beam method. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Tulane Univ, New Orleans, LA 70118 USA. Indiana Univ, Bloomington, IN 47408 USA. Univ Tennessee, Oak Ridge Natl Lab, Knoxville, TN 37996 USA. Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. RP Dewey, MS (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 31 TC 36 Z9 37 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 OCT 10 PY 2003 VL 91 IS 15 AR 152302 DI 10.1103/PhysRevLett.91.152302 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500012 PM 14611461 ER PT J AU Guo, JH Luo, Y Augustsson, A Kashtanov, S Rubensson, JE Shuh, DK Agren, H Nordgren, J AF Guo, JH Luo, Y Augustsson, A Kashtanov, S Rubensson, JE Shuh, DK Agren, H Nordgren, J TI Molecular structure of alcohol-water mixtures SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIQUID METHANOL; DIFFRACTION; SIMULATION; CLUSTERS; NEUTRON AB We use x-ray emission spectroscopy to elucidate the molecular structure of liquid methanol, water, and methanol-water solutions. We find that molecules in the pure liquid methanol predominantly persist as hydrogen-bonded chains and rings with six and/or eight molecules of equal abundance. For water-methanol solutions we find evidence of incomplete mixing at the microscopic level. Our results provide a new explanation for a smaller entropy increase in the solution due to water molecules bridging methanol chains to form rings. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Royal Inst Technol, SCFAB, S-10691 Stockholm, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Guo, JH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RI Luo, Yi/B-1449-2009; Agren, Hans/H-7715-2016; OI Luo, Yi/0000-0003-0007-0394; Augustsson, Andreas/0000-0002-9463-3700 NR 19 TC 238 Z9 243 U1 9 U2 83 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 10 PY 2003 VL 91 IS 15 AR 157401 DI 10.1103/PhysRevLett.91.157401 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500043 PM 14611492 ER PT J AU Johnson, SL Heimann, PA Lindenberg, AM Jeschke, HO Garcia, ME Chang, Z Lee, RW Rehr, JJ Falcone, RW AF Johnson, SL Heimann, PA Lindenberg, AM Jeschke, HO Garcia, ME Chang, Z Lee, RW Rehr, JJ Falcone, RW TI Properties of liquid silicon observed by time-resolved x-ray absorption spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID AMORPHOUS-SILICON; LASER-ABLATION; DIFFRACTION; GERMANIUM; SI; TEMPERATURE; DISORDER; SPECTRA AB Time-resolved x-ray spectroscopy at the Si L edges is used to probe the electronic structure of an amorphous Si foil as it melts following absorption of an ultrafast laser pulse. Picosecond temporal resolution allows observation of the transient liquid phase before vaporization and before the liquid breaks up into droplets. The melting causes changes in the spectrum that match predictions of molecular dynamics and ab initio x-ray absorption codes. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Free Univ Berlin, Inst Theoret Phys, D-14195 Berlin, Germany. Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. RP Johnson, SL (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM Steve.Johnson@mailaps.org RI Garcia, Martin/D-2697-2009; Johnson, Steven/B-3252-2008; Chang, Zenghu/K-8143-2012; Jeschke, Harald/C-3507-2009 OI Johnson, Steven/0000-0001-6074-4894; Chang, Zenghu/0000-0001-9015-0747; Jeschke, Harald/0000-0002-8091-7024 NR 27 TC 64 Z9 65 U1 0 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 OCT 10 PY 2003 VL 91 IS 15 AR 157403 DI 10.1103/PhysRevLett.91.157403 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500045 PM 14611494 ER PT J AU Liang, JF Shapira, D Gross, CJ Beene, JR Bierman, JD Galindo-Uribarri, A del Campo, JG Hausladen, PA Larochelle, Y Loveland, W Mueller, PE Peterson, D Radford, DC Stracener, DW Varner, RL AF Liang, JF Shapira, D Gross, CJ Beene, JR Bierman, JD Galindo-Uribarri, A del Campo, JG Hausladen, PA Larochelle, Y Loveland, W Mueller, PE Peterson, D Radford, DC Stracener, DW Varner, RL TI Enhanced fusion-evaporation cross sections in neutron-rich Sn-132 on Ni-64 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION FUSION; EVEN-EVEN NUCLIDES; SUPERHEAVY ELEMENTS; RADIOACTIVE BEAMS; NUCLEI; MODEL; BARRIERS AB Evaporation residue cross sections have been measured with neutron-rich radioactive Sn-132 beams on Ni-64 in the vicinity of the Coulomb barrier. The average beam intensity was 2x10(4) particles per second and the smallest cross section measured was less than 5 mb. Large sub-barrier fusion enhancement was observed. Coupled-channel calculations taking into account inelastic excitation significantly underpredict the measured cross sections below the barrier. The presence of several neutron transfer channels with large positive Q values suggests that multinucleon transfer may play an important role in enhancing the fusion of Sn-132 and Ni-64. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Gonzaga Univ, Phys dept AD51, Spokane, WA 99258 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37966 USA. Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. RP Liang, JF (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI radford, David/A-3928-2015 NR 26 TC 53 Z9 56 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 OCT 10 PY 2003 VL 91 IS 15 AR 152701 DI 10.1103/PhysRevLett.91.152701 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500013 PM 14611462 ER PT J AU Louca, D Sarrao, JL AF Louca, D Sarrao, JL TI Dynamical disorder of spin-induced Jahn-Teller orbitals with the insulator-metal transition in cobaltites SO PHYSICAL REVIEW LETTERS LA English DT Article ID OXIDES; FLUCTUATIONS; LATTICE; LACOO3; ORDER AB Using elastic and inelastic neutron scattering, we investigated the evolution of the local atomic structure and lattice dynamics of La1-xSrxCoO3 (x=0-0.5) as it crosses over with x from an insulator to a ferromagnetic metal (FMM). Our pair density function analysis indicates that, in the paramagnetic insulating phase for all x, spin activation of Co3+ ions induces local static Jahn-Teller (JT) distortions. The size of the JT lattice increases almost linearly with x. However, in the FMM phase, static JT distortions are absent for xless than or equal to30%. This coincides with narrowing of homega=22 and 24 meV modes in the phonon spectrum which we argue is due to localized dynamical JT fluctuations. For x>30%, static JT distortions reappear along with broadening of the phonon modes because of weakened charge-lattice interactions. C1 Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Louca, D (reprint author), Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA. NR 29 TC 74 Z9 76 U1 1 U2 23 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 10 PY 2003 VL 91 IS 15 AR 155501 DI 10.1103/PhysRevLett.91.155501 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500024 PM 14611473 ER PT J AU Puzder, A Williamson, AJ Reboredo, FA Galli, G AF Puzder, A Williamson, AJ Reboredo, FA Galli, G TI Structural stability and optical properties of nanomaterials with reconstructed surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM DOTS; ELECTRONIC-STRUCTURE; POROUS SILICON; NANOPARTICLES; NANOCLUSTERS AB We present density functional and quantum Monte Carlo calculations of the stability and optical properties of semiconductor nanomaterials with reconstructed surfaces. We predict the relative stability of silicon nanostructures with reconstructed and unreconstructed surfaces, and we show that surface step geometries unique to highly curved surfaces dramatically reduce the optical gaps and decrease excitonic lifetimes. These predictions provide an explanation of both the variations in the photoluminescence spectra of colloidally synthesized nanoparticles and observed deep gap levels in porous silicon. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Puzder, A (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Reboredo, Fernando/B-8391-2009 NR 21 TC 100 Z9 101 U1 2 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 10 PY 2003 VL 91 IS 15 AR 157405 DI 10.1103/PhysRevLett.91.157405 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500047 PM 14611496 ER PT J AU Zhang, Y Fluegel, B Mascarenhas, A AF Zhang, Y Fluegel, B Mascarenhas, A TI Total negative refraction in real crystals for ballistic electrons and light SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXPERIMENTAL-VERIFICATION; TRANSMISSION; INDEX AB It is found that there exists a category of material interfaces, readily available, that not only can provide total refraction (i.e., zero reflection) but can also give rise to amphoteric refraction (i.e., both positive and negative refraction) for electromagnetic waves in any frequency domain as well as for ballistic electron waves. These two unusual phenomena are demonstrated experimentally for the propagation of light through such an interface. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 22 TC 132 Z9 141 U1 2 U2 9 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 OCT 10 PY 2003 VL 91 IS 15 AR 157404 DI 10.1103/PhysRevLett.91.157404 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500046 PM 14611495 ER PT J AU Zhou, CS Kurths, J Neufeld, Z Kiss, IZ AF Zhou, CS Kurths, J Neufeld, Z Kiss, IZ TI Noise-sustained coherent oscillation of excitable media in a chaotic flow SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPATIOTEMPORAL STOCHASTIC RESONANCE; PHASE SYNCHRONIZATION; PHYTOPLANKTON BLOOM; SUBEXCITABLE MEDIA; SYSTEM; IRON; PATTERNS AB Constructive effects of noise in spatially extended systems have been well studied in static reaction-diffusion media. We study a noisy two-dimensional Fitz Hugh-Nagumo excitable model under the stirring of a chaotic flow. We find a regime where a noisy excitation can induce a coherent global excitation of the medium and a noise-sustained oscillation. Outside this regime, noisy excitation is either diluted into homogeneous background by strong stirring or develops into noncoherent patterns at weak stirring. These results explain some experimental findings of stirring effects in chemical reactions and are relevant for understanding the effects of natural variability in oceanic plankton bloom. C1 Univ Potsdam, Inst Phys, D-14415 Potsdam, Germany. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Leeds, Dept Appl Math, Leeds LS2 9JT, W Yorkshire, England. RP Univ Potsdam, Inst Phys, PF 601553, D-14415 Potsdam, Germany. RI Zhou, Changsong /F-4707-2010; Neufeld, Zoltan/C-3008-2011; Kiss, Istvan/C-7392-2014 OI Kiss, Istvan/0000-0003-1473-6644 NR 39 TC 18 Z9 19 U1 2 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 10 PY 2003 VL 91 IS 15 AR 150601 DI 10.1103/PhysRevLett.91.150601 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500009 PM 14611458 ER PT J AU Zhu, JX Grempel, DR Si, QM AF Zhu, JX Grempel, DR Si, QM TI Continuous quantum phase transition in a Kondo lattice model SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LIQUID BEHAVIOR; SPIN-GLASS; SPATIAL CORRELATIONS; METALS; ANTIFERROMAGNETISM; FLUCTUATIONS; HEAVY; FIELD AB We study the magnetic quantum phase transition in an anisotropic Kondo lattice model. The dynamical competition between the RKKY and Kondo interactions is treated using an extended dynamic mean field theory appropriate for both the antiferromagnetic and paramagnetic phases. A quantum Monte Carlo approach is used, which is able to reach very low temperatures, of the order of 1% of the bare Kondo scale. We find that the finite-temperature magnetic transition, which occurs for sufficiently large RKKY interactions, is first order. The extrapolated zero-temperature magnetic transition, on the other hand, is continuous and locally critical. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. CEA Saclay, DRECAM, SPCSI, F-91191 Gif Sur Yvette, France. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. RP Zhu, JX (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 26 TC 39 Z9 39 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 10 PY 2003 VL 91 IS 15 AR 156404 DI 10.1103/PhysRevLett.91.156404 PG 4 WC Physics, Multidisciplinary SC Physics GA 731AN UT WOS:000185862500034 PM 14611483 ER PT J AU Joly, AG Beck, KM Henyk, M Hess, WP Sushko, PV Shluger, AL AF Joly, AG Beck, KM Henyk, M Hess, WP Sushko, PV Shluger, AL TI Surface electronic spectra detected by atomic desorption SO SURFACE SCIENCE LA English DT Article ID RARE-GAS SOLIDS; ALKALI-HALIDES; LASER-DESORPTION; IONIC SURFACES; EXCITATION; EXCITONS; PHOTODESORPTION; FLUORIDES; BULK AB Using Continuously tunable laser excitation of KI we measure the desorption yield of hyperthermal iodine atoms as a function of photon energy. Based on a theoretical model of desorption we demonstrate that these spectra display a signature of a surface exciton and constitute a new sensitive method of surface electronic spectroscopy detected by atomic desorption. Our results not only demonstrate that creation of surface excitons call be a much more general phenomenon than was previously thought, based on measurements made using established spectroscopic techniques, but extend the classes of material amenable to surface spectroscopic interrogation. (C) 2003 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Shluger, AL (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM shluger@ucl.ac.uk RI Sushko, Peter/F-5171-2013 OI Sushko, Peter/0000-0001-7338-4146 NR 30 TC 13 Z9 13 U1 0 U2 4 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 OCT 10 PY 2003 VL 544 IS 1 BP L683 EP L688 DI 10.1016/j.susc.2003.08.009 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 729ZF UT WOS:000185804200002 ER PT J AU Szoke, A Scott, WG Hajdu, J AF Szoke, A Scott, WG Hajdu, J TI Catalysis, evolution and life SO FEBS LETTERS LA English DT Article DE catalysis; evolution; self-replication; replication ID SARCOPLASMIC-RETICULUM CA2+-ATPASE; ISOPENICILLIN-N-SYNTHASE; CRYSTAL-STRUCTURE; HEAT-PRODUCTION; ATP HYDROLYSIS; PYROPHOSPHATASE; RESOLUTION; PATHWAY AB Living organisms are unique in their ability to generate and replicate ordered systems from disordered components. Generation of order, replication of the individual, and evolution of the species all depend on the successful utilization of external energy derived from chemicals and light. The information for reproduction is encoded in nucleic acids, but evolution depends on a limited variability in replication, and proceeds through the selection of individuals with altered biochemistry. Essentially all biochemistry is catalyzed; therefore, altered biochemistry implies altered or new catalysts. In that sense catalysis is the medium of evolution. We propose that a basic property of enzymes, at least as fundamental as reaction rate enhancement, is to adjust the reaction path by altering and eventually optimizing the reversible interchange of chemical, electrical and mechanical energy among themselves and their reactants. (C) 2003 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies. C1 Uppsala Univ, ICM Mol Biophys, S-75124 Uppsala, Sweden. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Ctr Mol Biol RNA Sinsheimer Labs, Santa Cruz, CA 95064 USA. RP Szoke, A (reprint author), Uppsala Univ, ICM Mol Biophys, Box 596, S-75124 Uppsala, Sweden. NR 17 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD OCT 9 PY 2003 VL 553 IS 1-2 BP 18 EP 20 DI 10.1016/S0014-5793(03)01008-1 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 731HE UT WOS:000185877600004 PM 14550539 ER PT J AU Chen, WW Liu, JB Ng, CY AF Chen, WW Liu, JB Ng, CY TI Vacuum ultraviolet pulsed field ionization-photoelectron study for (NO+)-O-2 in the energy range of 16.3-21.0 eV SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID HIGH-RESOLUTION THRESHOLD; BEAM LASER SPECTROSCOPY; NITROUS-OXIDE; SYNCHROTRON-RADIATION; EMISSION-SPECTRUM; PHOTOION COINCIDENCE; QUANTUM YIELDS; N2O; STATE; BANDS AB The vacuum ultraviolet pulsed field ionization-photoelectron (PFI-PE) spectra for N2O have been measured in the energy range of 16.3-21.0 eV, covering the vibronic bands of N2O+(A(2)Sigma(+), B(2)Pi, and C(2)Sigma(+)). Many vibronic bands, which were not resolved in previous photoelectron studies, are identified in the present measurement. As observed in the HeI photoelectron spectra of N2O, the PFI-PE spectra for N2O+(A(2)Sigma(+) and C(2)Sigma(+)) are dominated by excitation of the nu(1)(+) (symmetric stretching) and nu(3)(+) (antisymmetric stretching) modes, along with weak bands due to excitation of both even and odd quanta of the nu(2)(+) (bending) mode. The simulation of the rotational contours resolved in the PFI-PE bands associated with excitation to N2O+(A(2)Sigma(+), nu(1)(+) = 0-1, nu(2)(+) = 0, and nu(3)(+) = 0-1) has revealed the orbital angular momentum of the outgoing photoelectrons and yielded accurate ionization energies for the formation of these states from N2O(X(1)Sigma(+)). C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ng, CY (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. NR 58 TC 14 Z9 15 U1 0 U2 0 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 OCT 9 PY 2003 VL 107 IS 40 BP 8086 EP 8091 DI 10.1021/jp022389d PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 729DQ UT WOS:000185757100010 ER PT J AU Buschmann, WE McGrane, SD Shreve, AP AF Buschmann, WE McGrane, SD Shreve, AP TI Chemical tuning of nonlinearity leading to intrinsically localized modes in halide-bridged mixed-valence platinum materials SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-METAL COMPLEXES; ONE-DIMENSIONAL SYSTEM; DISCRETE BREATHERS; ANTIFERROMAGNETIC LATTICE; QUANTUM BREATHERS; JOSEPHSON LADDERS; 2-BAND MODEL; ACETANILIDE; GENERATION; CRYSTALS AB The appearance of nonlinearity in multiphonon excitations is compared in the series of [Pt(en)(2)X-2][Pt(en)(2)](ClO4)(4) (X = Cl, Br, I; en = ethylenediamine) mixed-valence, linear-chain, charge-density-wave compounds. This comparison is made for crystals obtained under new synthetic conditions that minimize chemical defects incorporated during crystal growth. The single-crystal resonance Raman spectra collected at 77 K on this series (with natural isotope abundances) show strong red-shifting of the X-Pt-X symmetric stretch overtone peaks for X = Cl, modest red-shifting for X = Br, and no anharmonicity for X = I. When X = Cl, by the sixth overtone of the Cl-35-Pt-Cl-35 stretch, red shifts significantly larger than 10% of the fundamental frequency are observed. In addition, evolution of spectral line shapes corresponding to formation of dynamically localized vibrational states (intrinsically localized modes) is apparent, even by the second overtone. When X = Br, observed red shifts are less than 7% up to the eighth overtone, and there is no spectral evidence for intrinsically localized modes at 77 K. Further study of X = Br at 4 K yields spectra up to the 11th overtone having similar red shifts and narrower line shapes than at 77 K but provides only very ambiguous indications of resolved combination bands that could correspond to intrinsically localized modes. When X = 1, the lack of any observed anharmonicity indicates linear phonon excitations, which likely correspond to highly delocalized small amplitude motions. The series of data presented here demonstrate how nonlinearities in vibrational degrees of freedom, and the corresponding existence of localized modes, can be tuned chemically by adjusting the competing effects of electron delocalization and electron-phonon interactions in low-dimensional materials. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Dynam Experimentat Div, Los Alamos, NM 87545 USA. RP Shreve, AP (reprint author), Los Alamos Natl Lab, Biosci Div, MS G755, Los Alamos, NM 87545 USA. NR 55 TC 9 Z9 9 U1 0 U2 0 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 OCT 9 PY 2003 VL 107 IS 40 BP 8198 EP 8207 DI 10.1021/jp034038k PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 729DQ UT WOS:000185757100024 ER PT J AU Farrell, D Majetich, SA Wilcoxon, JP AF Farrell, D Majetich, SA Wilcoxon, JP TI Preparation and characterization of monodisperse Fe nanoparticles SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MAGNETIC-PROPERTIES; IRON; PARTICLES; NANOCLUSTERS; CONTRAST; COBALT AB Fe nanoparticles prepared by iron carbonyl decomposition using different methods are compared structurally, chemically, and magnetically. The specific magnetization of the particles was determined from the magnetic moment, the particle size observed by transmission electron microscopy, and the total iron concentration found from calibrated X-ray fluorescence. The volume fraction of oxide is reported for particles of different sizes and for particles made by slightly different techniques. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Dept 1122, Albuquerque, NM 87185 USA. RP Majetich, SA (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI Majetich, Sara/B-1022-2015 OI Majetich, Sara/0000-0003-0848-9317 NR 25 TC 165 Z9 170 U1 4 U2 57 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 OCT 9 PY 2003 VL 107 IS 40 BP 11022 EP 11030 DI 10.1021/jp0351831 PG 9 WC Chemistry, Physical SC Chemistry GA 729DP UT WOS:000185756900010 ER PT J AU Budarz, TE Prohofsky, EW Durbin, SM Sjodin, T Sage, JT Sturhahn, W Alp, EE AF Budarz, TE Prohofsky, EW Durbin, SM Sjodin, T Sage, JT Sturhahn, W Alp, EE TI Determination of the complete set of iron normal modes in the heme model compound Fe-III(OEP)C1 from nuclear resonance vibrational spectroscopic data SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PORPHYRIN FORCE-FIELD; LYING SPIN STATES; NICKEL OCTAETHYLPORPHYRIN; SYNCHROTRON-RADIATION; INFRARED-SPECTRA; ISOTOPE SHIFTS; RAMAN-SPECTRA; SCATTERING; MYOGLOBIN; DYNAMICS AB The vibrational spectrum of Fe-57 in chloro iron octaethylporphyrin, Fe(OEP)Cl, has been calculated by normal-mode analysis refined to absorption data from nuclear resonance vibrational spectroscopy. This technique directly measures the amplitudes and frequencies for all modes that have significant iron participation, providing rigorous constraints to the best-fit values for the force constants. The calculated normal modes reveal the importance of Fe displacements perpendicular to the heme plane for both the lowest frequency modes and the ligand modes. The actual normal modes of Fe(OEP)Cl are not well described by single modes of the core porphyrin; instead they are hybrids of multiple core modes and ethyl and chlorine displacements. C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Budarz, TE (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NR 37 TC 17 Z9 17 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD OCT 9 PY 2003 VL 107 IS 40 BP 11170 EP 11177 DI 10.1021/jp027348w PG 8 WC Chemistry, Physical SC Chemistry GA 729DP UT WOS:000185756900028 ER PT J AU Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C 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, E Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Segoni, I Wahl, M 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, M 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, E Malvezzi, S Menasce, D Mazzadri, 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 Pegna, DL Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Ramirez, JE Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M AF Link, JM Yager, PM Anjos, JC Bediaga, I Gobel, C 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, E Agostino, L Cinquini, L Cumalat, JP O'Reilly, B Segoni, I Wahl, M 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, M 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, E Malvezzi, S Menasce, D Mazzadri, 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 Pegna, DL Merlo, MM Pantea, D Ratti, SP Riccardi, C Vitulo, P Hernandez, H Lopez, AM Luiggi, E Mendez, H Paris, A Quinones, J Ramirez, JE Zhang, Y Wilson, JR Handler, T Mitchell, R Engh, D Hosack, M Johns, WE Nehring, M Sheldon, PD Stenson, K Vaandering, EW Webster, M Sheaff, M CA FOCUS TI Measurements of Xi(+)(c) branching ratios SO PHYSICS LETTERS B LA English DT Article ID BARYON DECAYS; SPECTROMETER; FOCUS AB Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo-favored decays Xi(c)(+) --> Sigma(+)K(-)pi(+), Xi(c)(+) --> Sigma(+)(K) over bar*(892)(0), and Xi(c)(+) --> Lambda(0)K(-)pi(+)pi(+) relative to Xi(c)(+) --> Xi(-)pi(+)pi(+) to be 0.91 +/- 0.11 +/- 0.04, 0.78 +/- 0.16 +/- 0.06, and 0.28 +/- 0.06 +/- 0.06, respectively. We report the first observation of the Cabibbo-suppressed decay Xi(c)(+) --> Sigma(+)K(+)K(-) and we measure the branching ratio relative to Xi(c)(+) --> Sigma(+)K(-)pi(+) to be 0.16 +/- 0.06 +/- 0.01. We also set 90% confidence level upper limits for Xi(c)(+) --> Sigma(+)phi and Xi(c)(+) --> Xi*(1690)(0)(Sigma(+)K(-))K+ relative to Xi(c)(+) --> Sigma(+)K(-)pi(+) to be 0.12 and 0.05, respectively. We find an indication of the decays Xi(c)(+) --> Omega(-)K(+)pi(+) and Xi(c)(+) --> Sigma*(1385)(+)(K) over bar (0) and set 90% confidence level upper limits for the branching ratios with respect to Xi(c)(+) --> Xi(-)pi(+)pi(+) to be 0.12 and 1.72, respectively. Finally, we determine the 90% C.L. upper limit for the resonant contribution Xi(c)(+) --> Xi*(1530)(0)pi(+) relative to Xi(c)(+) --> Xi(-)pi(+)pi(+) to be 0.10. (C) 2003 Elsevier B.V. All rights reserved. C1 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, Nazl Frascati Lab, I-00044 Frascati, Italy. Univ Guanajuato, Leon 37150, Guanajuato, 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. INFM, Milan, Italy. Univ Milan, 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. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Link, JM (reprint author), Univ Calif Davis, Davis, CA 95616 USA. RI Bonomi, Germano/G-4236-2010; Kwak, Jungwon/K-8338-2012; Anjos, Joao/C-8335-2013; Link, Jonathan/L-2560-2013; Benussi, Luigi/O-9684-2014; Gobel Burlamaqui de Mello, Carla /H-4721-2016 OI Kryemadhi, Abaz/0000-0002-1240-2803; Bonomi, Germano/0000-0003-1618-9648; Link, Jonathan/0000-0002-1514-0650; Benussi, Luigi/0000-0002-2363-8889; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X NR 14 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 9 PY 2003 VL 571 IS 3-4 BP 139 EP 147 DI 10.1016/S0370-2693(03)00809-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 725ZR UT WOS:000185573100004 ER PT J AU Wuosmaa, AH Wiedenhover, I Caggiano, J Carpenter, MP Devlin, M Heinz, A Janssens, RVF Kondev, F Lauritsen, T Sarantites, DG Sobotka, LG Battacharyya, P AF Wuosmaa, AH Wiedenhover, I Caggiano, J Carpenter, MP Devlin, M Heinz, A Janssens, RVF Kondev, F Lauritsen, T Sarantites, DG Sobotka, LG Battacharyya, P TI Angular correlation, spin alignment, and systematics of mis-matched C-12+C-12 inelastic scattering resonances SO PHYSICS LETTERS B LA English DT Article DE resonances; angular correlations ID NUCLEAR-MOLECULES; EXCITED-STATES; C-12; BEHAVIOR; MODEL; MG-24 AB Particle gamma-ray angular correlation measurements have been used to study the spin alignment and magnetic-substate population parameters for the 2(1)(+) (4.443 MeV) state in C-12, populated in the C-12(C-12,C-12[0(2)(+)])C-12(2(1)(+)) inelastic scattering reaction in the vicinity of a prominent, narrow peak in the scattering excitation function. The data show a strong alignment of the spin with the orbital angular momentum, and suggest that the cross section peak corresponds to a spin 14(+) resonance at E-c.m. = 28.0 MeV. This energy is close to that where a strong peak is also observed in the 0(1)(+) + 0(2)(+) excitation function. A comparison between the data for these two channels lends some support to recent theoretical calculations of resonance behavior for angular-momentum-mismatched channels in C-12 + C-12 inelastic scattering. (C) 2003 Published by Elsevier B.V. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RP Wuosmaa, AH (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RI Heinz, Andreas/E-3191-2014; Carpenter, Michael/E-4287-2015; Devlin, Matthew/B-5089-2013 OI Carpenter, Michael/0000-0002-3237-5734; Devlin, Matthew/0000-0002-6948-2154 NR 34 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 9 PY 2003 VL 571 IS 3-4 BP 155 EP 162 DI 10.1016/j.physletb.2003.07.074 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 725ZR UT WOS:000185573100006 ER PT J AU Mazumdar, S Dallakyan, S Chandross, M AF Mazumdar, S Dallakyan, S Chandross, M TI Designing pi-conjugated polymers with light emission in the infrared SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT 5th International Topical Conference on Optical Probes of Conjugated Polymers, Organic and Inorganic Nanostructure CY FEB 09-14, 2003 CL VENICE, ITALY DE polyacetylene and derivatives; semi-empirical models and model calculations; light sources ID EXCITED-STATES; CONFINEMENT; POLYENES; CHAINS AB There is currently a great need for solid state lasers that emit in the infrared. Whether or not conjugated polymers that emit in the IR can be synthesized is an interesting theoretical challenge. We show that emission in the IR can be achieved in designer polymers in which the effective Coulomb correlation is smaller than that in existing systems. We also show that the structural requirement for having small effective Coulomb correlations is that there exist transverse pi-conjugation over a few bonds in addition to longitudinal conjugation with large conjugation lengths. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mazumdar, S (reprint author), Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD OCT 9 PY 2003 VL 139 IS 3 BP 769 EP 772 DI 10.1016/S0379-6779(03)00260-1 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA 721EG UT WOS:000185303600053 ER PT J AU Baer, R Kouri, DJ Baer, M Hoffman, DK AF Baer, R Kouri, DJ Baer, M Hoffman, DK TI General Born-Oppenheimer-Huang approach to systems of electrons and nuclei SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NONADIABATIC COUPLING TERMS; MOLECULAR-SYSTEMS; CONICAL INTERSECTIONS; CHEMICAL-REACTIONS; POTENTIALS; STATES; MATRIX AB We reconsider the Born-Oppenheimer-Huang treatment of systems of electrons and nuclei for the case of their interaction with time-dependent fields. Initially, we present a framework in which all expressions derived are formally exact since no truncations are introduced. The objective is to explore the general structure of the equations under the most unrestricted conditions, including the possibility that the electronic basis is dependent both on the nuclear coordinates and on time. We then derive an application of the theory applicable to cases of interaction with strong time-dependent fields. The method truncates the electronic basis only after the time-dependent interaction is taken into account in the electronic wave functions. This leads to theory which is similar to a Born-Oppenheimer-type truncation within the interaction picture. (C) 2003 American Institute of Physics. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Soreq Nucl Res Ctr, IL-81800 Yavne, Israel. Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Lise Meitner Ctr Computat Quantum Chem, IL-91904 Jerusalem, Israel. Univ Houston, Dept Math, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Baer, M (reprint author), Soreq Nucl Res Ctr, IL-81800 Yavne, Israel. NR 21 TC 21 Z9 21 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2003 VL 119 IS 14 BP 6998 EP 7002 DI 10.1063/1.1606433 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726AT UT WOS:000185575700003 ER PT J AU Clegg, SM Parsons, BF Klippenstein, SJ Osborn, DL AF Clegg, SM Parsons, BF Klippenstein, SJ Osborn, DL TI Photodissociation dynamics of dicyclopropyl ketone at 193 nm: Isomerization of the cyclopropyl ligand SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR-PHASE PHOTOLYSIS; VIBRATIONAL-STATE DISTRIBUTIONS; N-3S RYDBERG STATE; DISSOCIATION DYNAMICS; EMISSION-SPECTROSCOPY; ULTRAFAST PHOTODISSOCIATION; UNIMOLECULAR DISSOCIATION; STEPWISE DISSOCIATION; ENERGY-DISTRIBUTION; ROTATIONAL-STATE AB The photodissociation dynamics of dicyclopropyl ketone are investigated using time-resolved Fourier transform infrared spectroscopy and photofragment ion imaging spectroscopy. The photodissociation products are C3H5+CO+C3H5, and the isomerization dynamics of C3H5 are the focus of this paper. Electronic structure calculations are used to define the potential energy surface, while a two-step phase space theory model predicts excitation in the CO product. The vibrational energy distribution of the CO product is not described by this statistical distribution, and is more excited than that observed in the analogous dissociation of acetone. The translational energy distribution of CO indicates an exit barrier on the potential energy surface. Contrary to expectations based on the photodissociation of other aliphatic ketones, the hydrocarbon products are not cyclopropyl radicals. Instead, the excited dicyclopropyl ketone undergoes a ring-opening isomerization to form diallyl ketone, followed by dissociation producing allyl radicals and carbon monoxide. Some of the allyl radicals have sufficient internal energy to decompose to allene+H. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Osborn, DL (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RI Osborn, David/A-2627-2009; OI Klippenstein, Stephen/0000-0001-6297-9187 NR 68 TC 15 Z9 15 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2003 VL 119 IS 14 BP 7222 EP 7236 DI 10.1063/1.1606445 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726AT UT WOS:000185575700031 ER PT J AU Sewell, TD Menikoff, R Bedrov, D Smith, GD AF Sewell, TD Menikoff, R Bedrov, D Smith, GD TI A molecular dynamics simulation study of elastic properties of HMX SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CRYSTAL-STRUCTURE; OCTAHYDRO-1,3,5,7-TETRANITRO-1,3,5,7-TETRAZOCINE HMX; HYDROSTATIC COMPRESSION; BETA-HMX; PETN; DIFFRACTION; SHEAR; FORMS AB Atomistic simulations were used to calculate the isothermal elastic properties for beta-, alpha-, and delta-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The room-temperature isotherm for each polymorph was computed in the pressure interval 0less than or equal topless than or equal to10.6 GPa and was used to extract the initial isothermal bulk modulus K-o and its pressure derivative using equations of state employed previously in experimental studies of the beta-HMX isotherm. The complete elastic tensor for each polymorph was calculated at room temperature and atmospheric pressure. For the case of beta-HMX, the calculated elastic tensor is compared to one based on a fit to sound speed data yielding reasonably good agreement. The bulk modulus of beta-HMX obtained from equation-of-state fits to the room-temperature isotherm agrees well with that determined from the complete elastic tensor and from volume fluctuations at atmospheric pressure. However, the value of K-o obtained from the isotherm is sensitive to choice of equation of state fitting form and to the weighting scheme employed in the fit. Based upon simulation results and reanalysis of experimental data, the commonly accepted value of the initial isothermal bulk modulus for beta-HMX should be revised from a value of similar to12.4-13.5 GPa to similar to15-16 GPa. The present report provides the first accurate determination of the elastic tensors and isotropic moduli for alpha- and delta-HMX. Predicted values of the shear moduli for alpha- and delta-HMX are more than a factor of 2 smaller than for beta-HMX. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Detonat Theory & Applicat Grp, Los Alamos, NM 87545 USA. Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem & Fuels Engn, Salt Lake City, UT 84112 USA. RP Sewell, TD (reprint author), Los Alamos Natl Lab, Div Theoret, Detonat Theory & Applicat Grp, Los Alamos, NM 87545 USA. NR 42 TC 101 Z9 112 U1 7 U2 35 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 OCT 8 PY 2003 VL 119 IS 14 BP 7417 EP 7426 DI 10.1063/1.1599273 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726AT UT WOS:000185575700048 ER PT J AU Thompson, AP AF Thompson, AP TI Nonequilibrium molecular dynamics simulation of electro-osmotic flow in a charged nanopore SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SHEARED DOUBLE-LAYERS; PORES; FLUIDS; SINGLE; MODEL AB Nonequilibrium molecular dynamics simulations were performed for Poiseuille and electro-osmotic flow in a charged cylindrical nanopore. The goal was to examine any deviations from continuum flow behavior and to compare and contrast the Poiseuille and electro-osmotic flow situations. The fluid was composed of cationic counterions and nonpolar monatomic solvent molecules. The cylindrical surface of the pore wall was represented by a stochastic scattering boundary condition. The lack of any surface roughness and the computational efficiency of the fluid model enabled the velocity profile near the wall to be measured at very high spatial resolution. The simulation results indicate that both Poiseuille and electro-osmotic flow conform to continuum transport theories except in the first monolayer of fluid at the pore wall. The apparent viscosity in this region was highly nonuniform and exhibited singularities. Despite this, the viscosity profiles obtained from Poiseuille and electro-osmotic flow were in good mutual agreement at all locations. The singularities were caused by a local maximum in the solvent and counterion velocity profiles occurring at the edge of the first monolayer of liquid. This apparent channeling of fluid near the pore wall has been observed in previous studies of Poiseuille flow. The exact cause is not clear, but it may be due to cooperative transport of the fluid molecules facilitated by two-dimensional ordering at the wall. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Thompson, AP (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 52 Z9 52 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 2003 VL 119 IS 14 BP 7503 EP 7511 DI 10.1063/1.1609194 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726AT UT WOS:000185575700059 ER PT J AU Ellis, WW Ciancanelli, R Miller, SM Raebiger, JW DuBois, MR DuBois, DL AF Ellis, WW Ciancanelli, R Miller, SM Raebiger, JW DuBois, MR DuBois, DL TI Thermodynamic hydride donor abilities of [HW(CO)(4)L](-) complexes (L = PPh3, P(OMe)(3), CO) and their reactions with [C5Me5Re(PMe3)(NO)(CO)](+) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL COMPLEXES; MONONUCLEAR PENTACARBONYL HYDRIDES; COORDINATED CARBON-MONOXIDE; FE-ONLY HYDROGENASE; DIHYDROGEN COMPLEXES; ACTIVE-SITE; ELECTRODE-POTENTIALS; ANGSTROM RESOLUTION; CRYSTAL-STRUCTURE; NIFE HYDROGENASE AB The thermodynamic hydride donor abilities of [HW(CO)(5)](-) (40 kcal/mol), [HW(CO)(4)P(OMe3)](-) (37 kcal/mol), and [HW(CO)(4)(PPh3)](-) (36 kcal/mol) have been measured in acetonitrile by either equilibrium or calorimetric methods. The hydride donor abilities of these complexes-are compared with other complexes for which similar thermodynamic measurements have been made. [HW(CO)(5)](-), [HW(CO)(4)P(OMe3)](-), and [HW(CO)(4)(PPh3)](-) all react rapidly with [Cp*Re(PMe3)(NO)(CO)](+) to form dinuclear intermediates with bridging formyl ligands. These intermediates slowly form [Cp*Re(PMe3)(NO)(CHO)] and [W(CO)(4)(L)(CH3-CN)]. The structure of cis-[HW(CO)(4)(PPh3)](-) has been determined and has the expected octahedral structure. The hydride ligand bends away from the CO ligand trans to PPh3 and toward PPh3. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP DuBois, DL (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. NR 78 TC 42 Z9 42 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD OCT 8 PY 2003 VL 125 IS 40 BP 12230 EP 12236 DI 10.1021/ja036524r PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 729QG UT WOS:000185784700039 PM 14519008 ER PT J AU Baumann, TF Satcher, JH AF Baumann, TF Satcher, JH TI Homogeneous incorporation of metal nanoparticles into ordered macroporous carbons SO CHEMISTRY OF MATERIALS LA English DT Article ID PHOTONIC CRYSTALS; ELECTROCHEMICAL DEPOSITION; 3-DIMENSIONAL ARRAYS; POLYSTYRENE SPHERES; COLLOIDAL SPHERES; SPHERICAL PORES; POROUS SILICA; TEMPLATES; FABRICATION; TITANIA C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Baumann, TF (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-092, Livermore, CA 94551 USA. NR 42 TC 55 Z9 59 U1 2 U2 17 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 OCT 7 PY 2003 VL 15 IS 20 BP 3745 EP 3747 DI 10.1021/cm0343960 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 728ZW UT WOS:000185747100004 ER PT J AU Boyle, TJ Rodriguez, MA Ingersoll, D Headley, TJ Bunge, SD Pedrotty, DM De'Angeli, SM Vick, SC Fan, HY AF Boyle, TJ Rodriguez, MA Ingersoll, D Headley, TJ Bunge, SD Pedrotty, DM De'Angeli, SM Vick, SC Fan, HY TI A novel family of structurally characterized lithium cobalt double aryloxides and the nanoparticles and thin films generated therefrom SO CHEMISTRY OF MATERIALS LA English DT Article ID SOL-GEL SYNTHESIS; ELECTROCHEMICAL PROPERTIES; CRYSTAL-STRUCTURES; CATHODE MATERIALS; MANGANESE OXIDES; METAL ALKOXIDES; SOLUTION ROUTES; ION BATTERY; PRECURSORS; TIO2 AB The reaction between LiN(SiMe3)(2) and Co(N(SiMe3)(2))(2) in THF followed by the addition of an aryl alcohol (HOAr) yielded: [Co[(mu-OAr)(2)Li(THF)(x)](2) [where x = 2: OAr =: OC6H4Me-2 (oMP, 1), OC6H4(OCHMe2)-2 (oPP, 2), OC6H3(Me)(2)-2,6 (DMP, 3); where x = 1: OAr = OC6H3(OCHMe2)(2)-2,6 (DIP, 4)]. Undertaking the same synthesis in pyridine (py) led to the same general structure with py molecules substituted for the THF solvent molecules: [Co[(muOAr)(2)Li(py)(2)](2) (OAr = oMP (5), oPP (6)]. For 1-6, the tetrahedrally (Td) bound Co atom bridges two OAr ligands to each of the Li atoms. The Li atom adopts a Td or trigonal bipyramidal (TBP) geometry, as determined by the number of bound solvent molecules. For the more sterically demanding ligands with py as the solvent, the mononuclear monometallic species [Co[(mu-OAr)(2)(py)(x)](2) (OAr = DMP (7), x = 2; DIP (8), x = 3) were observed adopting a Td or TBP geometry, respectively, based on the number of bound solvent molecules. Increasing the steric bulk of the OAr to OC6H3Bu2t-2,6 (DBP) in either THF or py led to the isolation of the previously characterized [Li(DBP)(solv)](2). Calculated XRD powder patterns were generated from the single-crystal structure of 1-8 and used to verify the identity of the bulk powder. Attempts to use these compounds for MOCVD applications were not successful due to low volatility of these compounds. Attempts to generate nanoparticles of the spinel phase of LiCoO2 by injecting a py solution of 5 or 6 into boiling methyl-imidazole (Melm)/H2O 95:5) led to nanoparticles of Co(OH)2 only, as characterized by XRD and TEM. Thin films of the spinel phase of LiCoO2 were formed by spin-cast deposition methods using 5 or 6 dissolved in a py/toluene mixture onto platinized silicon wafers followed by firing at 700 degreesC. Cyclic voltammetry revealed two irreversible oxidation processes followed by one reversible process, the latter of which is found to occur at about 4.2 V. XRD analysis of the thin film, both before and after electrochemical cycling, revealed only minimal variations in the crystal structure of the film after cycling. This family of compounds, even though stoichiometrically incorrect, have been shown to be useful for single-source applications in the solid and liquid techniques. 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. NR 52 TC 32 Z9 32 U1 2 U2 11 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 OCT 7 PY 2003 VL 15 IS 20 BP 3903 EP 3912 DI 10.1021/cm020902u PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 728ZW UT WOS:000185747100027 ER PT J AU Nachimuthu, P Thevuthasan, S Kim, YJ Lea, AS Shutthanandan, V Engelhard, MH Baer, DR Chambers, SA Shuh, DK Lindle, DW Gullikson, EM Perera, RCC AF Nachimuthu, P Thevuthasan, S Kim, YJ Lea, AS Shutthanandan, V Engelhard, MH Baer, DR Chambers, SA Shuh, DK Lindle, DW Gullikson, EM Perera, RCC TI Investigation of copper(I) oxide quantum dots by near-edge X-ray absorption fine structure spectroscopy SO CHEMISTRY OF MATERIALS LA English DT Article ID ELECTRONIC-STRUCTURE; HIGH-RESOLUTION; THIN-FILMS; CUO; CU2O; SURFACES; GROWTH; SIZE; NANOPARTICLES; NANOCRYSTALS AB Copper(I) oxide quantum dots (OQDs) were grown in various thicknesses on different SrTiO3(001) surfaces and were investigated by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The experimental growth conditions for the OQDs were optimized to obtain Cu2O as the major phase. The OQDs grown on clean SrTiO3(001) surfaces at 825 K and higher with p(O-2) of 9.0 x 10(-7) Torr or greater contain mostly CuO, contrasting to OQDs grown at 800 K with p(O-2) of similar to7.0 x 10(-7) Torr that contain primarily Cu2O. Furthermore, there is a strong interaction between the SrTiO3(001) surface and the first few monolayers of the OQDs, which induces the formation of Cu(II). However, this interaction is mitigated with increasing thickness of OQDs, resulting in the exclusive formation of Cu2O in the topmost layers. The influence of the SrTiO3(001) substrate on the formation of OQDs can be minimized by modifying the substrate surface using chemical treatment and/or energetic Au2+ ion-beam irradiation. Examination of the photochemical properties of these OQDs shows that prolonged soft X-ray irradiation under vacuum reduces Cu(II), which is present as a minor impurity in the Cu(I) OQDs. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Hanbat Natl Univ, Dept Chem Technol, Taejon, South Korea. RP Thevuthasan, S (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM theva@pnl.gov RI Engelhard, Mark/F-1317-2010; Baer, Donald/J-6191-2013; OI Baer, Donald/0000-0003-0875-5961; Lea, Alan/0000-0002-4232-1553; Engelhard, Mark/0000-0002-5543-0812 NR 42 TC 18 Z9 18 U1 1 U2 32 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 OCT 7 PY 2003 VL 15 IS 20 BP 3939 EP 3946 DI 10.1021/cm021757n PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 728ZW UT WOS:000185747100031 ER PT J AU Kuehl, CJ Simpson, CK John, KD Sattelberger, AP Carlson, CN Hanusa, TP AF Kuehl, CJ Simpson, CK John, KD Sattelberger, AP Carlson, CN Hanusa, TP TI Monomeric f-element chemistry with sterically encumbered allyl ligands SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article; Proceedings Paper CT 224th ACS National Meeting CY AUG 11-22, 2002 CL Boston, MA SP ACS DE allyl; lanthanide; tetrahydrofuran; complex; crystal structure; bulley ligands ID STEREOSPECIFIC BUTADIENE POLYMERIZATION; NUCLEAR-MAGNETIC-RESONANCE; PARAMAGNETIC-SUSCEPTIBILITY; DONOR LIGANDS; M(ALLYL)(3) M; COMPLEXES; CATALYSIS; METALLOCENES; DYNAMICS; PRECATALYSTS C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Vanderbilt Univ, Dept Chem, Nashville, TN 37235 USA. RP Hanusa, TP (reprint author), Los Alamos Natl Lab, Div Chem, MS J582, Los Alamos, NM 87545 USA. EM kjohn@lanl.gov; t.hanusa@vanderbilt.edu OI John, Kevin/0000-0002-6181-9330 NR 32 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD OCT 7 PY 2003 VL 683 IS 1 BP 149 EP 154 DI 10.1016/S0022-328X(03)00558-8 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 732QP UT WOS:000185957300019 ER PT J AU Fu, CL Schneibel, JH AF Fu, CL Schneibel, JH TI Reducing the thermal expansion anisotropy in Mo5Si3 by Nb and V additions: theory and experiment SO ACTA MATERIALIA LA English DT Article DE intermetallic compounds; Ab initio calculation; theory and modeling (structural behavior); thermal expansion ID SINGLE-CRYSTALS; PHASE AB Mo5Si3 exhibits a high anisotropy of its coefficients of thermal expansion (CTEs) in the a and c directions, i.e., CTE(c)/CTE(a) = 2.0. The high CTE anisotropy is due to the existence of prominent atom chains along the c-axis. Ternary alloying additions that effectively stretch the atom chains are likely to reduce the bonding directionality/strength and CTE anisotropy. First-principles local-density-functional calculations were carried out for two alloy systems, MoNb4Si3 and Mo4VSi3. Indeed, we find a significant reduction of the CTE ratio to a value of 1.5 for MoNb4Si3 and a value close to 1.0 for Mo4VSi3. The decrease in the CTE anisotropy mainly comes from the reduction in CTE in the c-direction. While a conventional approach to reduce the CTE would involve an increase in lattice rigidity by increasing the bond strength, our strategy focuses on the reduction of driving force for thermal expansion by decreasing the bond directionality. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Fu, CL (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 9 TC 25 Z9 27 U1 0 U2 6 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 OCT 6 PY 2003 VL 51 IS 17 BP 5083 EP 5092 DI 10.1016/S1359(03)00358-6 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 730CL UT WOS:000185811600012 ER PT J AU Zhang, SL Johnson, HT Wagner, GJ Liu, WK Hsia, KJ AF Zhang, SL Johnson, HT Wagner, GJ Liu, WK Hsia, KJ TI Stress generation mechanisms in carbon thin films grown by ion-beam deposition SO ACTA MATERIALIA LA English DT Article DE carbon thin films; residual stress; interstitial; vacancy ID DIAMOND-LIKE CARBON; MOLECULAR-DYNAMICS; COMPRESSIVE STRESS; SURFACE; DISPLACEMENT; BOMBARDMENT; RADIATION AB A three-dimensional molecular dynamics (MD) simulation is performed to study the stress generation mechanisms in carbon thin films grown by ion-beam deposition. The relationship between the kinetic energy of incident ions and the steady-state film stress is established. Examination of the atomic stress and film microstructures reveals that the grown films contain a significant fraction of vacancies, contradicting the presumption of the subplantation model. By taking into account both interstitials and vacancies, an analytical model is developed, in which the formation of the compressive stress is attributed to competing mechanisms between generation and recovery of the defects. This model can satisfactorily explain the numerical observation in which compressive stress prevails in films in the presence of vacancies. The present study provides useful insights into tailoring residual stress to control thin film curvature in microelectromechanical systems (MEMS) by ion-beam machining. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 60801 USA. Sandia Natl Labs, Livermore, CA 94551 USA. Univ Illinois, Dept Theoret & Appl Mech, Urbana, IL 60801 USA. RP Zhang, SL (reprint author), Northwestern Univ, Dept Mech Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI Liu, Wing/B-7599-2009; Zhang, Sulin /E-6457-2010; Wagner, Gregory/I-4377-2015 NR 24 TC 46 Z9 46 U1 0 U2 13 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 OCT 6 PY 2003 VL 51 IS 17 BP 5211 EP 5222 DI 10.1016/S1359-6454(03000385-9 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 730CL UT WOS:000185811600023 ER PT J AU Tian, Y Bastawros, AF Lo, CCH Constant, AP Russell, AM Cook, BA AF Tian, Y Bastawros, AF Lo, CCH Constant, AP Russell, AM Cook, BA TI Superhard self-lubricating AlMgB14 films for microelectromechanical devices SO APPLIED PHYSICS LETTERS LA English DT Article ID BORON-CARBIDE; COATINGS; DEPOSITION; LIGA; MEMS AB Performance and reliability of microelectromechanical system (MEMS) components can be enhanced dramatically through the incorporation of protective thin-film coatings. Current-generation MEMS devices prepared by the lithographie-galvanoformung-abformung (LIGA) technique employ transition metals such as Ni, Cu, Fe, or alloys thereof, and hence lack stability in oxidizing, corrosive, and/or high-temperature environments. Fabrication of a superhard self-lubricating coating based on a ternary boride compound AlMgB14 described in this letter has great potential in protective coating technology for LIGA microdevices. Nanoindentation tests show that the hardness of AlMgB14 films prepared by pulsed laser deposition ranges from 45 GPa to 51 GPa, when deposited at room temperature and 573 K, respectively. Extremely low friction coefficients of 0.04-0.05, which are thought to result from a self-lubricating effect, have also been confirmed by nanoscratch tests on the AlMgB14 films. Transmission electron microscopy studies show that the as-deposited films are amorphous, regardless of substrate temperature; however, analysis of Fourier transform infrared spectra suggests that the higher substrate temperature facilitates the formation of the B-12 icosahedral framework, therefore leading to the higher hardness. (C) 2003 American Institute of Physics. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Aerosp Engn & Engn Mech, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Tian, Y (reprint author), Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RI Bastawros, Ashraf/L-8057-2013; OI Bastawros, Ashraf/0000-0003-4547-8588; Russell, Alan/0000-0001-5264-0104 NR 21 TC 37 Z9 42 U1 0 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 OCT 6 PY 2003 VL 83 IS 14 BP 2781 EP 2783 DI 10.1063/1.1615677 PG 3 WC Physics, Applied SC Physics GA 727NB UT WOS:000185664000017 ER PT J AU Jasinski, J Liliental-Weber, Z Paduano, QS Weyburne, DW AF Jasinski, J Liliental-Weber, Z Paduano, QS Weyburne, DW TI Inversion domains in AlN grown on (0001) sapphire SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; ELECTRON-DIFFRACTION; GAN FILMS; POLARITY; BOUNDARIES; LAYERS AB Al-polarity inversion domains formed during AlN layer growth on (0001) sapphire were identified using transmission electron microscopy (TEM). They resemble columnar inversion domains reported for GaN films grown on (0001) sapphire. However, for AlN, these columns have a V-like shape with boundaries that deviate by 2degrees+/-0.5degrees from the c axis. TEM identification of these defects agrees with the post-growth surface morphology as well as with the microstructure revealed by etching in hot aqueous KOH. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. USAF, Res Lab, Sensors Directorate, Hanscom AFB, MA 01731 USA. RP Jasinski, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012 NR 17 TC 84 Z9 85 U1 6 U2 56 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 6 PY 2003 VL 83 IS 14 BP 2811 EP 2813 DI 10.1063/1.1616191 PG 3 WC Physics, Applied SC Physics GA 727NB UT WOS:000185664000027 ER PT J AU Yu, KM Walukiewicz, W Wu, J Shan, W Beeman, JW Scarpulla, MA Dubon, OD Ridgway, MC Mars, DE Chamberlin, DR AF Yu, KM Walukiewicz, W Wu, J Shan, W Beeman, JW Scarpulla, MA Dubon, OD Ridgway, MC Mars, DE Chamberlin, DR TI Mutual passivation of group IV donors and nitrogen in diluted GaNxAs1-x alloys SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; BAND-GAP ENERGY; GAAS; SEMICONDUCTORS; DEPENDENCE; DEFECTS; SULFUR AB We demonstrate the mutual passivation phenomenon of Ge donors and isovalent N in highly mismatched alloy GaNxAs1-x doped with Ge. Layers of this alloy were formed by the sequential implantation of Ge and N ions followed by pulsed laser melting and rapid thermal annealing. The mutual passivation effect results in the electrical deactivation of Ge-Ga donors (Ge on Ga sites) and suppression of the N-As (N on As sites) induced band gap narrowing through the formation of Ge-Ga-N-As nearest neighbor pairs. These results in combination with the analogous effect observed in Si-doped GaNxAs1-x provide clear evidence of the general nature of the mutual passivation phenomenon in highly mismatched semiconductor alloys. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT, Australia. Agilent Labs, Palo Alto, CA 94304 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM kmyu@lbl.gov RI Scarpulla, Michael/C-7941-2009; Wu, Junqiao/G-7840-2011; Yu, Kin Man/J-1399-2012; Ridgway, Mark/D-9626-2011; OI Wu, Junqiao/0000-0002-1498-0148; Yu, Kin Man/0000-0003-1350-9642; Ridgway, Mark/0000-0002-0642-0108; Scarpulla, Michael/0000-0002-6084-6839 NR 24 TC 16 Z9 16 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 6 PY 2003 VL 83 IS 14 BP 2844 EP 2846 DI 10.1063/1.1616980 PG 3 WC Physics, Applied SC Physics GA 727NB UT WOS:000185664000038 ER PT J AU Li, DY Wu, YY Kim, P Shi, L Yang, PD Majumdar, A AF Li, DY Wu, YY Kim, P Shi, L Yang, PD Majumdar, A TI Thermal conductivity of individual silicon nanowires SO APPLIED PHYSICS LETTERS LA English DT Article ID NANOSCALE ELECTRONIC DEVICES; CONFINED ACOUSTIC PHONONS; QUANTUM WIRES; WELL AB The thermal conductivities of individual single crystalline intrinsic Si nanowires with diameters of 22, 37, 56, and 115 nm were measured using a microfabricated suspended device over a temperature range of 20-320 K. Although the nanowires had well-defined crystalline order, the thermal conductivity observed was more than two orders of magnitude lower than the bulk value. The strong diameter dependence of thermal conductivity in nanowires was ascribed to the increased phonon-boundary scattering and possible phonon spectrum modification. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Texas, Dept Mech Engn, Austin, TX 78712 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Li, DY (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RI Wu, Yiying/A-3949-2011; Li, Deyu/D-2938-2012; Shi, Li/C-8123-2013; Kim, Philip/N-1886-2013; OI Li, Deyu/0000-0001-8364-0924; Shi, Li/0000-0002-5401-6839; Wu, Yiying/0000-0001-9359-1863 NR 19 TC 977 Z9 996 U1 23 U2 173 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 6 PY 2003 VL 83 IS 14 BP 2934 EP 2936 DI 10.1063/1.1616981 PG 3 WC Physics, Applied SC Physics GA 727NB UT WOS:000185664000068 ER PT J AU Li, ADQ Wang, W Wang, LQ AF Li, ADQ Wang, W Wang, LQ TI Folding versus self-assembling SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE foldable polymer; protein engineering; protein folding; self-assembly; synthesis design ID SEMICONDUCTING POLYMERS; CONJUGATED POLYMERS; DNA; ELECTROLUMINESCENCE; TRITYLATION; OLIGOMERS; STACKING; SOLVENT AB Model foldable polymers with sequences of rigid hydrophobic chromophores and flexible hydrophilic tetra(ethylene glycol) were synthesized and used as a paradigm for studying molecular-folding and self-assembly phenomena. Our results demonstrate that intramolecular association or folding prevails over intermolecular interaction or self-assembling in the concentration region from 1 mum to 0.1m. Importantly, folded polymeric nanostructures have absorption and fluorescence properties that are distinct from those of unfolded polymers or free monomers. We hypothesize that the origins of folding and self-assembly come from interactions between molecular units, and that the key parameter that regulates the on-and-off of such interactions is the distance R separating the two molecular units. Each molecular unit produces a characteristic force field, and when another molecular unit enters this field, the probability that the two units will interact increases significantly. A preliminary estimate of the radius of such a force field for the perylene tetracarboxylic diimide chromophore is about 90-120 Angstrom. As a result, phenomena associated with folding or self-assembly of molecular species are observed when these conditions are met in solution. C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Washington State Univ, Mat Res Ctr, Pullman, WA 99164 USA. Pacific NW Natl Lab, Div Mat Sci, Richland, WA 99352 USA. RP Li, ADQ (reprint author), Washington State Univ, Dept Chem, Pullman, WA 99164 USA. NR 31 TC 142 Z9 141 U1 0 U2 35 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD OCT 6 PY 2003 VL 9 IS 19 BP 4594 EP 4601 DI 10.1002/chem.200305025 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 732GU UT WOS:000185933100003 PM 14566864 ER PT J AU Liang, BY Andrews, L Li, J Bursten, BE AF Liang, BY Andrews, L Li, J Bursten, BE TI Bonding of multiple noble-gas atoms to CUO in solid neon: CUO(Ng)(n) (Ng = Ar, Kr, Xe; n=1, 2, 3, 4) complexes and the singlet-triplet crossover point SO CHEMISTRY-A EUROPEAN JOURNAL LA English DT Article DE density functional calculations; matrix-isolation; noble gases; uranium ID ENERGY-ADJUSTED PSEUDOPOTENTIALS; METAL-CARBONYL-COMPLEXES; MICROWAVE-SPECTRA; ACTINIDE COMPOUNDS; INFRARED-SPECTRA; CONSTANTS; MOLECULES; MATRICES; SETS; MO AB Laser-ablated U atoms co-deposited with CO in excess neon produce the novel CUO molecule, which forms distinct Ng complexes (Ng = Ar, Kr, Xe) with the heavier noble gases. The CUO(Ng) complexes are identified through CO isotopic and Ng reagent substitution and comparison to results of DFr frequency calculations. The U-C and U-O stretching frequencies of CUO(Ng) complexes are slightly red-shifted from neon matrix (1)Sigma(+) CUO values, which indicates a (1)A' ground state for the CUO(Ng) complexes. The CUO(Ng)(2) complexes in excess neon are likewise singlet molecules. However, the CUO(Ng)(3) and CUO(Ng)(4) complexes exhibit very different stretching frequencies and isotopic behaviors that are similar to those of CUO(Ar)(n) in a pure argon matrix, which has a (3)A" ground state based on DFT vibrational frequency calculations. This work suggests a coordination sphere model in which CUO in solid neon is initially solvated by four or more Ne atoms. Up to four heavier Ng atoms successively displace the Ne atoms leading ultimately to CUO(Ng)(4) complexes. The major changes in the CUO stretching frequencies from CUO(Ng)(2) to CUO(Ng)(3) provides evidence for the crossover from a singlet ground state to a triplet ground state. C1 Univ Virginia, Dept Chem, Charlottesville, VA 22904 USA. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Andrews, L (reprint author), Univ Virginia, Dept Chem, Charlottesville, VA 22904 USA. RI Li, Jun/E-5334-2011 OI Li, Jun/0000-0002-8456-3980 NR 24 TC 18 Z9 18 U1 1 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0947-6539 J9 CHEM-EUR J JI Chem.-Eur. J. PD OCT 6 PY 2003 VL 9 IS 19 BP 4781 EP 4788 DI 10.1002/chem.200304946 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 732GU UT WOS:000185933100025 PM 14566886 ER PT J AU Zhuravleva, MA Pcionek, RJ Wang, XP Schultz, AJ Kanatzidis, MG AF Zhuravleva, MA Pcionek, RJ Wang, XP Schultz, AJ Kanatzidis, MG TI REMGa3Ge and RE3Ni3Ga8Ge3 (M = Ni, Co; RE = rare-earth element): New intermetallics synthesized in liquid gallium. X-ray, electron, and neutron structure determination and magnetism SO INORGANIC CHEMISTRY LA English DT Article ID EXPLORATORY SYNTHESIS; MOLTEN ALUMINUM; SM; SILICIDES; SOLVENT; GA; DIFFRACTION; TB; TM; ER AB New quaternary intermetallic phases REMGa3Ge (1) (RE = Y, Sm, Tb, Gd, Er, Tm; M = Ni, Co) and RE3Ni3Ga8Ge3 (2) (RE = Sm, Gd) were obtained from exploratory reactions involving rare-earth elements (RE), transition metal (M), Ge, and excess liquid Ga the reactive solvent. The crystal structures were solved with single-crystal X-ray and electron diffraction. The crystals of 1 and 2 are tetragonal. Single-crystal X-ray data: YNiGa3Ge, a = 4.1748(10) Angstrom, c = 23.710(8) Angstrom, V = 413.24(2) Angstrom(3), 14/mmm, Z = 4; Gd3Ni3Ga8Ge3, a = 4.1809(18) Angstrom, c = 17.035(11) Angstrom, V = 297.8(3) Angstrom(,)(3) P4/mmm, Z = 1. Both compounds feature square nets of Ga atoms. The distribution of Ga and Ge atoms in the REMGa3Ge was determined with neutron diffraction. The neutron experiments revealed that in 1 the Ge atoms are specifically located at the 4e crystallographic site, while Ga atoms are at 4d and 8g. The crystal structures of these compounds are related and could, be derived from the consecutive stacking of disordered [MGa](2) puckered layers, monatomic RE-Ge planes and [MGa4Ge2] slabs. Complex superstructures with modulations occurring in the ab-plane and believed to be associated with the square nets of Ga atoms were found by electron diffraction. The magnetic measurements show antiferromagnetic ordering of the moments located on the RE atoms at low temperature, and Curie-Weiss behavior at higher temperatures with the values of mu(eff) close to those expected for RE3+ free ions. C1 Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Kanatzidis, MG (reprint author), Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA. RI Wang, Xiaoping/E-8050-2012 OI Wang, Xiaoping/0000-0001-7143-8112 NR 27 TC 32 Z9 32 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 OCT 6 PY 2003 VL 42 IS 20 BP 6412 EP 6424 DI 10.1021/ic0341892 PG 13 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 728CH UT WOS:000185697300032 PM 14514317 ER PT J AU Vogt, R Gutierrez, TD AF Vogt, R Gutierrez, TD TI Xi and Omega distributions in hadron-nucleus interactions SO NUCLEAR PHYSICS A LA English DT Article ID PI-P-INTERACTIONS; PARTON DISTRIBUTIONS; PARTICLE-PRODUCTION; INTRINSIC CHARM; HYPERON BEAM; 400-GEV PROTONS; LEADING CHARM; 116 GEV/C; CERN SPS; ASYMMETRIES AB Strange baryons have long been known to exhibit a leading particle effect. A recent comparison of Theta(-) production in pi(-), n, and Sigma(-) interactions with nuclei show this effect clearly. These data are supplemented by earlier measurements of Theta(-) and Omega production by a Theta(-) beam. We calculate the Theta(-) and Omega (xF) distributions and nuclear dependence in hA interactions using the intrinsic model. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. EM vogt@lbl.gov NR 45 TC 0 Z9 0 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 OCT 6 PY 2003 VL 726 IS 1-2 BP 134 EP 156 DI 10.1016/j.nuclphysa.2003.07.003 PG 23 WC Physics, Nuclear SC Physics GA 718PH UT WOS:000185155300007 ER PT J AU Ahn, J Efimov, AV Averitt, RD Taylor, AJ AF Ahn, J Efimov, AV Averitt, RD Taylor, AJ TI Terahertz waveform synthesis via optical rectification of shaped ultrafast laser pulses SO OPTICS EXPRESS LA English DT Article ID LARGE-APERTURE PHOTOCONDUCTORS; POLED LITHIUM-NIOBATE; ELECTROMAGNETIC PULSES; ELECTROOPTIC DETECTION; GENERATION; RADIATION; ALGORITHM; PHASE; THZ AB We demonstrate the use of optical pulse-shaping technique in conjunction with difference frequency generation in a non-linear optoelectronic crystal for generating synthesized waveforms at terahertz frequencies. Spectral phase modulations, programmed using Gerchberg-Saxton algorithm and prepared in a spatial light Fourier filter, produce tailored terahertz pulses, including chirped pulses, zero-area pulses, and trains of multiple pulses for tunable narrow-band terahertz radiation up to 2.0 THz. (C) 2003 Optical Society of America. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Ahn, J (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM jwahn@lanl.gov RI Ahn, Jaewook/C-1637-2011 NR 26 TC 85 Z9 88 U1 0 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 6 PY 2003 VL 11 IS 20 BP 2486 EP 2496 DI 10.1364/OE.11.002486 PG 11 WC Optics SC Optics GA 729GK UT WOS:000185764700005 PM 19471361 ER PT J AU Efimov, A Taylor, AJ Omenetto, FG Knight, JC Wadsworth, WJ Russell, PS AF Efimov, A Taylor, AJ Omenetto, FG Knight, JC Wadsworth, WJ Russell, PS TI Phase-matched third harmonic generation in microstructured fibers SO OPTICS EXPRESS LA English DT Article ID OPTICAL 2ND-HARMONIC GENERATION; FREQUENCY LIGHT GENERATION; MODES AB Strong guiding provided by the high-delta microstructured fibers allows for efficient intermodally phase-matched harmonic generation with femtosecond pumping at telecom wavelengths. Visible harmonics are generated in a number of distinct transverse modes of the structure. We present a detailed experimental and theoretical study of the third harmonic generation in such fibers including phase-matching wavelengths, far-field intensity distributions and polarization dependence. Good agreement between the theory and experiment is achieved. (C) 2003 Optical Society of America. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. Univ Bath, Dept Phys, Bath BA2 7AY, Avon, England. RP Efimov, A (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MST-10,MS K764, Los Alamos, NM 87545 USA. EM efimov@lanl.gov RI Wadsworth, William/A-1317-2012; Knight, Jonathan/D-3879-2011; Russell, Philip/G-5132-2012; OI Knight, Jonathan/0000-0002-0802-8804; Russell, Philip/0000-0002-8972-2477; Efimov, Anatoly/0000-0002-5559-4147 NR 16 TC 90 Z9 96 U1 2 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD OCT 6 PY 2003 VL 11 IS 20 BP 2567 EP 2576 DI 10.1364/OE.11.002567 PG 10 WC Optics SC Optics GA 729GK UT WOS:000185764700014 PM 19471370 ER PT J AU Sims, KWW Blichert-Toft, J Fornari, DJ Perfit, MR Goldstein, SJ Johnson, P DePaolo, DJ Hart, SR Murrell, PJ Michael, PJ Layne, GD Ball, LA AF Sims, KWW Blichert-Toft, J Fornari, DJ Perfit, MR Goldstein, SJ Johnson, P DePaolo, DJ Hart, SR Murrell, PJ Michael, PJ Layne, GD Ball, LA TI Aberrant youth: Chemical and isotopic constraints on the origin of off-axis lavas from the East Pacific Rise, 9 degrees-10 degrees N SO GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS LA English DT Article DE mantle source composition; U-series disequilibria; mid-ocean ridge processes; isotope geochemistry; off-axis volcanism; melt generation and magma transport ID SPREADING MIDOCEAN RIDGES; JUAN-DE-FUCA; CRUSTAL EMPLACEMENT PROCESSES; IONIZATION MASS-SPECTROMETRY; RA-226 TH-230 DISEQUILIBRIUM; RECENT VOLCANIC-ERUPTIONS; U-SERIES DISEQUILIBRIA; COLLECTOR ICP-MS; SEISMIC LAYER 2A; SEA-FLOOR AB [1] We report measurements of U-series disequilibria, Sr, Nd, Hf, and Pb isotopic compositions and major and trace element abundances in a suite of well-located, off-axis MORBs that span the East Pacific Rise (EPR) ridge crest from 9degrees48'-52'N and across it for similar to4 km on either side. The geological context of the samples are well constrained as they were collected by submersible in an area that has been extensively imaged by remote sensing techniques. Sr, Nd, Hf and Pb-208/Pb-206 isotopic compositions of the off-axis N-MORB are identical to the axial lavas from this same region, suggesting that their sources are similar and that melting processes are the dominant influence in establishing the U-Th-Ra disequilibria and trace element fractionations. A majority of off-axis samples have U-Th and Th-Ra disequilibria that are larger, and model ages that are younger, than would be predicted from their off-axis distance and the time-integrated spreading rate. There are, however, a few off-axis samples with U-Th ages that are consistent with their spreading rate ages. It is likely that these samples erupted within or close to the axial summit trough (AST) and aged at a rate proportional to the spreading rate. The anomalously young ages determined for most of the off-axis lavas suggest that volcanic construction along this region is occurring over a zone that is wider (at least 4 km) than the AST (10s to 100s of meters). The combined observational, chemical and isotopic data support a model for the 9degrees0'N area that includes a significant component of crustal accumulation resulting from lavas that breach the AST and flow down the flanks of the EPR ridge crest. However, these data also require a minor component of off-axis eruptions that occur on distinct pillow mounds and ridges. This suggests that MOR construction involves several volcanic and tectonic processes acting in concert to form a complex patchwork of lava ages and compositions along, and across, this fast spreading ridge crest. C1 Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA. Ecole Normale Super Lyon, CNRS, UMR 5570, Lab Sci Terre, F-69364 Lyon 7, France. Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA. Los Alamos Natl Lab, Grp C INC, Los Alamos, NM 87545 USA. Univ Hawaii, SOEST, Hawaii Mapping Res Grp, Honolulu, HI 96822 USA. Univ Calif Berkeley, Dept Earth & Planetary Sci, Ctr Isotope Geochem, Berkeley, CA 94720 USA. Univ Tulsa, Dept Geosci, Tulsa, OK 74104 USA. Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. RP Sims, KWW (reprint author), Woods Hole Oceanog Inst, Dept Geol & Geophys, MS 22 Woods Hole Rd, Woods Hole, MA 02543 USA. RI Blichert-Toft, Janne/C-8280-2012; Facility, NENIMF/B-8811-2015 OI Blichert-Toft, Janne/0000-0002-4932-4079; NR 66 TC 42 Z9 42 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1525-2027 J9 GEOCHEM GEOPHY GEOSY JI Geochem. Geophys. Geosyst. PD OCT 4 PY 2003 VL 4 AR 8621 DI 10.1029/2002GC000443 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 731LA UT WOS:000185884500001 ER PT J AU Reid, CD Maherali, H Johnson, HB Smith, SD Wullschleger, SD Jackson, RB AF Reid, CD Maherali, H Johnson, HB Smith, SD Wullschleger, SD Jackson, RB TI On the relationship between stomatal characters and atmospheric CO2 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ELEVATED CO2; ANATOMICAL CHARACTERISTICS; DENSITY; LEAVES; INDEX; CONDUCTANCE; ENRICHMENT; CLIMATE; SENSITIVITY; FREQUENCY AB [1] Leaf stomatal characters influence the response of terrestrial evapotranspiration to climate change and are used as proxies for the reconstruction of past atmospheric [CO2]. We examined the phenotypic response of stomatal index (SI), density (SD) and aperture (AP) to rising atmospheric CO2 in 15 species after four years exposure to a field CO2 gradient (200 to 550 mumol mol(-1) atmospheric [CO2]) or at three Free Air CO2 Enrichment ( FACE) sites. Along the CO2 gradient, SI and SD showed no evidence of a decline to increasing [CO2], while AP decreased slightly. There was no significant change in SI, SD or AP with CO2 across FACE experiments. Without evolutionary changes, SI and SD may not respond to atmospheric [CO2] in the field and are unlikely to decrease in a future high CO2 world. C1 Duke Univ, Dept Biol, Durham, NC 27708 USA. ARS, USDA, Temple, TX 76502 USA. Univ Nevada, Dept Biol Sci, Las Vegas, NV 89154 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC USA. RP Reid, CD (reprint author), Duke Univ, Dept Biol, Durham, NC 27708 USA. RI Wullschleger, Stan/B-8297-2012 OI Wullschleger, Stan/0000-0002-9869-0446 NR 32 TC 23 Z9 24 U1 1 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 4 PY 2003 VL 30 IS 19 AR 1983 DI 10.1029/2003GL017775 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 731MG UT WOS:000185888700001 ER PT J AU Chigaev, A Zwartz, G Graves, SW Dwyer, DC Tsuji, H Foutz, TD Edwards, BS Prossnitz, ER Larson, RS Sklar, LA AF Chigaev, A Zwartz, G Graves, SW Dwyer, DC Tsuji, H Foutz, TD Edwards, BS Prossnitz, ER Larson, RS Sklar, LA TI alpha(4)beta(1) integrin affinity changes govern cell adhesion SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID MULTIPLE ACTIVATION STATES; MOLECULE-1 ICAM-1; P-SELECTIN; PHYSIOLOGICAL FLOW; ENDOTHELIAL-CELLS; ALPHA-4 INTEGRINS; T-CELLS; RECEPTOR; BINDING; LIGAND AB Integrin alpha(4)beta(1) is a receptor for vascular cell adhesion molecule-1 and fibronectin. It is important in lymphopoiesis, inflammatory recruitment of leukocytes, and other situations that require cell adhesion to the vascular endothelium. The avidity of the cells expressing alpha(4)beta(1) integrin can be rapidly changed by chemokines and chemoattractants. Different mechanisms, including changes in the number of interacting molecules due to the alteration of the receptor topology or changes in the affinity of the individual bonds, have been proposed to explain the nature of these fast changes in avidity. Recently, we described a fluorescent LDV- containing small molecule, which we used to monitor the affinity changes on live cells in real time (Chigaev, A., Blenc, A. M., Braaten, J. V., Kumaraswamy, N., Kepley, C. L., Andrews, R. P., Oliver, J. M., Edwards, B. S., Prossnitz, E. R., Larson, R. S. et al. (2001) J. Biol. Chem. 276, 48670 48678). Here we show that the affinity of the small molecule probe as well as the native ligand vascular cell adhesion molecule-1 varies in parallel when the integrin is modulated with divalent cations and that the affinity modulation leads to the changes in cell avidity. Using formyl peptide receptor-transfected U937 cells, we further show that the time course of avidity changes in response to the receptor activation coincides with the time course of the affinity changes. Taken together, these data are consistent with the idea that affinity regulation is a major factor that governs the avidity of cell adhesion mediated by the alpha(4) integrin. C1 Univ New Mexico, Dept Pathol, HSC, Albuquerque, NM 87131 USA. Univ New Mexico, Ctr Canc, HSC, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Natl Flow Cytometry Resource, Los Alamos, NM 87545 USA. RP Sklar, LA (reprint author), Univ New Mexico, Dept Pathol, HSC, Albuquerque, NM 87131 USA. RI Chigaev, Alexandre/A-3103-2010; Prossnitz, Eric/B-4543-2008; OI Chigaev, Alexandre/0000-0002-7726-638X; Prossnitz, Eric/0000-0001-9190-8302 FU NCRR NIH HHS [RR01315, RR14175]; NHLBI NIH HHS [HL56384] NR 49 TC 59 Z9 62 U1 1 U2 11 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 OCT 3 PY 2003 VL 278 IS 40 BP 38174 EP 38182 DI 10.1074/jbc.M210472200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 726AM UT WOS:000185575100012 PM 12844491 ER PT J AU Almog, O Gonzalez, A Klein, D Greenblatt, HM Braun, S Shoham, G AF Almog, O Gonzalez, A Klein, D Greenblatt, HM Braun, S Shoham, G TI The 0.93 angstrom crystal structure of sphericase: A calcium-loaded serine protease from Bacillus sphaericus SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE sphericase; serine protease; subtilisin; cold adaptation; mesophilic ID COLD ADAPTATION; ALPHA-AMYLASE; MACROMOLECULAR STRUCTURES; LABORATORY EVOLUTION; STRUCTURE REFINEMENT; DIRECTED EVOLUTION; ATOMIC-RESOLUTION; BINDING-SITES; SUBTILISIN; PROTEINS AB We have previously isolated sphericase (Sph), an extracellular mesophilic serine protease produced by Bacillus sphaericus. The Sph amino acid sequence is highly homologous to two cold-adapted subtilisins from Antarctic bacilli S39 and S41 (76% and 74% identity, respectively). Sph is calcium-dependent, 310 amino acid residues long and has optimal activity at pH 10.0. S41 and S39 have not as yet been structurally analysed. In the present work, we determined the crystal structure of Sph by the Eu/multiwavelength anomalous diffraction method. The structure was extended to 0.93 Angstrom resolution and refined to a crystallographic R-factor of 9.7%. The final model included all 310 amino acid residues, one disulfide bond, 679 water molecules and five calcium ions. Although Sph is a mesophilic subtilisin, its amino acid sequence is similar to that of the psychrophilic subtilisins, which suggests that the crystal structure of these subtilisins is very similar. The presence of five calcium ions bound to a subtilisin molecule, as found here for Sph, has not been reported for the subtilisin superfamily. None of these calcium-binding sites correlates with the well-known high-affinity calcium-binding site (site I or site A), and only one site has been described previously. This calcium-binding pattern suggests that a reduction in the flexibility of the surface loops of Sph by calcium binding may be responsible for its adaptation to mesophilic organisms. (C) 2003 Elsevier Ltd. All rights reserved. C1 Ben Gurion Univ Negev, Fac Hlth Sci, Dept Clin Biochem, IL-84105 Beer Sheva, Israel. EMBL, Hamburg Outstn, D-22603 Hamburg, Germany. Hebrew Univ Jerusalem, Dept Biol Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Inst Life Sci, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Dept Inorgan Chem, IL-91904 Jerusalem, Israel. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Almog, O (reprint author), Ben Gurion Univ Negev, Fac Hlth Sci, Dept Clin Biochem, IL-84105 Beer Sheva, Israel. EM almogo@bgumail.bgu.ac.il NR 56 TC 25 Z9 25 U1 0 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 OCT 3 PY 2003 VL 332 IS 5 BP 1071 EP 1082 DI 10.1016/j.jmb.2003.07.011 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 726AP UT WOS:000185575300009 PM 14499610 ER PT J AU Zhang, RG Andersson, CE Skarina, T Evdokimova, E Edwards, AM Joachimiak, A Savchenko, A Mowbray, SL AF Zhang, RG Andersson, CE Skarina, T Evdokimova, E Edwards, AM Joachimiak, A Savchenko, A Mowbray, SL TI The 2.2 angstrom resolution structure of RpiB/AlsB from Escherichia coli illustrates a new approach to the ribose-5-phosphate isomerase reaction SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE ribose-5-phosphate isomerase; pentose phosphate pathway; galactose-6-phosphate isomerase; MAD; X-ray crystallography ID TAGATOSE 6-PHOSPHATE PATHWAY; D-RIBOSE-5-PHOSPHATE ISOMERASE; PROTEIN STRUCTURES; CRYSTAL-STRUCTURE; STAPHYLOCOCCUS-AUREUS; ISOMERIZATION; METABOLISM; LACTOSE; RIBOSE; MODELS AB Ribose-5-phosphate isomerases (EC 5.3.1.6) interconvert ribose 5-phosphate and ribulose 5-phosphate. This reaction permits the synthesis of ribose from other sugars, as well as the recycling of sugars from nucleotide breakdown. Two unrelated types of enzyme can catalyze the reaction. The most common, RpiA, is present in almost all organisms (including Escherichia coli), and is highly conserved. The second type, RpiB, is present in some bacterial and eukaryotic species and is well conserved. In E. coli, RpiB is sometimes referred to as AlsB, because it can take part in the metabolism of the rare sugar, allose, as well as the much more common ribose sugars. We report here the structure of RpiB/AlsB from E. coli, solved by multi-wavelength anomalous diffraction (MAD) phasing, and refined to 2.2 Angstrom resolution. RpiB is the first structure to be solved from pfam02502 (the RpiB/LacAB family). It exhibits a Rossmann-type alphabetaalpha-sandwich fold that is common to many nucleotide-binding proteins, as well as other proteins with different functions. This structure is quite distinct from that of the previously solved RpiA; although both are, to some extent, based on the Rossmann fold, their tertiary and quaternary structures are very different. The four molecules in the RpiB asymmetric unit represent a dimer of dimers. Active-site residues were identified at the interface between the subunits, such that each active site has contributions from both subunits. Kinetic studies indicate that RpiB is nearly as efficient as RpiA, despite its completely different catalytic machinery. The sequence and structural results further suggest that the two homologous components of LacAB (galactose-6-phosphate isomerase) will compose a bi-functional enzyme; the second activity is unknown. (C) 2003 Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Struct Biol Ctr, Biosci Div, Argonne, IL 60439 USA. Uppsala Univ, Dept Cell & Mol Biol, Biomed Ctr, S-75124 Uppsala, Sweden. Univ Toronto, Hlth Network, Toronto, ON M5G 2C4, Canada. Univ Toronto, Banting & Best Dept Med Res, Toronto, ON M5G 1L7, Canada. Swedish Univ Agr Sci, Ctr Biomed, Dept Mol Biosci, Div Struct Biol, S-75124 Uppsala, Sweden. RP Joachimiak, A (reprint author), Argonne Natl Lab, Struct Biol Ctr, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Mowbray, Sherry/D-2141-2013 FU NIGMS NIH HHS [P50 GM062414, GM 62414, P50 GM062414-02] NR 44 TC 40 Z9 42 U1 0 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 OCT 3 PY 2003 VL 332 IS 5 BP 1083 EP 1094 DI 10.1016/j.jmb.2003.08.009 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 726AP UT WOS:000185575300010 PM 14499611 ER PT J AU Peleg, A Chung, Y AF Peleg, A Chung, Y TI Stationary solutions to the nonlinear Schrodinger equation in the presence of third-order dispersion SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID MODE OPTICAL FIBERS; SOLITON PROPAGATION; PERTURBATIONS; WAVELENGTH AB We study stationary solutions of the nonlinear Schrodinger equation in the presence of small but non-zero third-order dispersion (TOD). Using a singular perturbation theory around the ideal soliton we calculate these solutions up to the second order in the TOD coefficient. The existence and linear stability of the stationary solutions is proved for any finite order of the perturbation theory. The results obtained by our numerical simulations of the nonlinear Schrodinger equation are in very good agreement with theory. The significance of these results for fibre optic communication systems is discussed. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Peleg, A (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 19 TC 7 Z9 7 U1 0 U2 4 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 OCT 3 PY 2003 VL 36 IS 39 BP 10039 EP 10051 AR PII S0305-4470(03)63240-3 DI 10.1088/0305-4470/36/39/305 PG 13 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 736CG UT WOS:000186152500008 ER PT J AU Lambregts, MJ Frank, SM AF Lambregts, MJ Frank, SM TI Characterization of cesium containing glass-bonded ceramic waste forms SO MICROPOROUS AND MESOPOROUS MATERIALS LA English DT Article DE cesium; sodalite; analcime; pollucite; aluminosilicate ID SOLID-STATE NMR; NUCLEAR-MAGNETIC-RESONANCE; ALKALI SILICATE-GLASSES; EXCHANGED ZEOLITE-A; MAS NMR; CRYSTAL-STRUCTURES; CATION; ALUMINOSILICATE; DIFFRACTION; POLLUCITE AB High cesium containing glass-bonded ceramic waste form samples were prepared and characterized to identify possible cesium phases present in glass-bonded ceramic waste forms developed for the containment of fission product bearing salts. Major phases of the waste forms are sodalite and glass. A combination of powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance spectroscopy (NMR) were used to study the multiphase nature of these waste forms. Cesium was found to be present in the higher loaded waste forms in a cesium aluminosilicate phase with an analcime structure and a 1:1 Si:Al ratio, a pollucite phase, and also in the glass phase. The glass phase contains the majority of the cesium at lower loadings, however some pollucite also remains. Cesium was not detected in the sodalite phase of any of the samples. (C) 2003 Elsevier Inc. All rights reserved. C1 Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Lambregts, MJ (reprint author), Argonne Natl Lab, POB 2528, Idaho Falls, ID 83403 USA. RI Bala, Marsha/I-4459-2016; Frank, Steven/B-9046-2017 OI Bala, Marsha/0000-0002-7936-416X; Frank, Steven/0000-0001-8259-6722 NR 38 TC 21 Z9 21 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-1811 J9 MICROPOR MESOPOR MAT JI Microporous Mesoporous Mat. PD OCT 3 PY 2003 VL 64 IS 1-3 BP 1 EP 9 DI 10.1016/S1387-1811(03)00486-4 PG 9 WC Chemistry, Applied; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 728RN UT WOS:000185730300001 ER PT J AU Blunden, PG Melnitchouk, W Tjon, JA AF Blunden, PG Melnitchouk, W Tjon, JA TI Two-photon exchange and elastic electron-proton scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID ONE-LOOP INTEGRALS; RADIATIVE-CORRECTIONS; FORM-FACTORS; EP AB Two-photon exchange contributions to elastic electron-proton scattering cross sections are evaluated in a simple hadronic model including the finite size of the proton. The corrections are found to be small in magnitude, but with a strong angular dependence at fixed Q(2). This is significant for the Rosenbluth technique for determining the ratio of the electric and magnetic form factors of the proton at high Q(2), and partly reconciles the apparent discrepancy with the results of the polarization transfer technique. C1 Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Jefferson Lab, Newport News, VA 23606 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Blunden, PG (reprint author), Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. NR 21 TC 221 Z9 222 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 OCT 3 PY 2003 VL 91 IS 14 AR 142304 DI 10.1103/PhysRevLett.91.142304 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500011 PM 14611520 ER PT J AU Goldhaber, AS Nieto, MM AF Goldhaber, AS Nieto, MM TI Problems with the rotating-torsion-balance limit on the photon mass SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material ID EXTRAGALACTIC MAGNETIC-FIELDS C1 MIT, Cambridge, MA 02138 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Goldhaber, AS (reprint author), MIT, Cambridge, MA 02138 USA. NR 9 TC 16 Z9 16 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 OCT 3 PY 2003 VL 91 IS 14 AR 149101 DI 10.1103/PhysRevLett.91.149101 PG 1 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500056 PM 14611565 ER PT J AU Jin, R Onose, Y Tokura, Y Mandrus, D Dai, P Sales, BC AF Jin, R Onose, Y Tokura, Y Mandrus, D Dai, P Sales, BC TI In-plane thermal conductivity of Nd2CuO4: Evidence for magnon heat transport SO PHYSICAL REVIEW LETTERS LA English DT Article ID YBCO SINGLE-CRYSTALS; SPIN REORIENTATION; MAGNETIC-FIELDS; ND; PR; TRANSITIONS; WAVES; SM AB We report the temperature and magnetic field dependence of the in-plane thermal conductivity (kappa(ab)) of high-quality monocrystalline Nd2CuO4. Isothermal measurements of the field dependence of kappa(ab) at low temperatures (2 Kless than or equal toTless than or equal to5 K) show no change in kappa(ab) below a critical magnetic field H-c (H(c)approximate to4.5 T for Hparallel to[100]) and H(c)approximate to2.5 T for Happroximate toparallel to[110]). Above H-c, kappa(ab) more than doubles as H is increased to 9 T. At H-c, there is a transition from a noncollinear to a collinear arrangement of the Nd and Cu spins and a collapse of the gap, Delta, in an acoustic magnon branch at k=0. Closure of this gap appears to allow the conduction of substantial amounts of heat by acoustic magnons. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Japan Sci & Technol, ERATO, Spin Superstruct Project, Tsukuba, Ibaraki 3058562, Japan. Correlated Electron Res Ctr, Tsukuba, Ibaraki 3058562, Japan. Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Jin, R (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Onose, Yoshinori/F-1977-2010; Dai, Pengcheng /C-9171-2012; Tokura, Yoshinori/C-7352-2009; Mandrus, David/H-3090-2014 OI Dai, Pengcheng /0000-0002-6088-3170; NR 28 TC 28 Z9 29 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 3 PY 2003 VL 91 IS 14 AR 146601 DI 10.1103/PhysRevLett.91.146601 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500033 PM 14611542 ER PT J AU Klein, SR Vogt, R AF Klein, SR Vogt, R TI Inhomogeneous shadowing effects on J/psi production in dA collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; PARTON DISTRIBUTIONS; QUARKONIUM PRODUCTION; DEPENDENCE; EVOLUTION; NUCLEON; PP AB We study the effect of spatially homogeneous and inhomogeneous shadowing on J/psi production in deuterium-nucleus collisions. We discuss how the shadowing and its spatial dependence can be measured by comparing central and peripheral dA collisions. These event classes may be selected by using gray protons from heavy ion breakup and events where the proton or neutron in the deuterium does not interact. We find that inhomogeneous shadowing has a significant effect on central dA collisions, larger than expected in central AA collisions. Results are presented for dAu collisions at roots(NN)=200 GeV and dPb collisions at roots(NN)=6.2 TeV. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 31 TC 57 Z9 60 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 OCT 3 PY 2003 VL 91 IS 14 AR 142301 DI 10.1103/PhysRevLett.91.142301 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500008 PM 14611517 ER PT J AU Stephenson, EJ Bacher, AD Allgower, CE Gardestig, A Lavelle, CM Miller, GA Nann, H Olmsted, J Pancella, PV Pickar, MA Rapaport, J Rinckel, T Smith, A Spinka, HM van Kolck, U AF Stephenson, EJ Bacher, AD Allgower, CE Gardestig, A Lavelle, CM Miller, GA Nann, H Olmsted, J Pancella, PV Pickar, MA Rapaport, J Rinckel, T Smith, A Spinka, HM van Kolck, U TI Observation of the charge symmetry breaking d+d -> He-4+pi(0) reaction near threshold SO PHYSICAL REVIEW LETTERS LA English DT Article ID VIOLATION AB We report the first observation of the charge symmetry breaking d+d--> He-4 +pi(0) reaction near threshold. Measurements using a magnetic channel (gated by two photons) of the He-4 scattering angle and momentum (from time of flight) permitted reconstruction of the pi(0) "missing mass," the quantity used to separate He-4 +pi(0) events from the continuum of double radiative capture 4He +gamma+gamma events. We measured total cross sections for neutral pion production of 12.7+/-2.2 pb at 228.5 MeV and 15.1+/-3.1 pb at 231.8 MeV. The uncertainty is dominated by statistical errors. These cross sections arise fundamentally from the down-up quark mass difference and quark electromagnetic effects that contribute in part through meson mixing (e.g., pi(0)-eta) mechanisms. C1 Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. Indiana Univ, Ctr Nucl Theory, Bloomington, IN 47408 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Mankato State Univ, Dept Phys & Astron, Mankato, MN 56001 USA. Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Hillsdale Coll, Dept Phys, Hillsdale, MI 49242 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. RP Stephenson, EJ (reprint author), Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. NR 17 TC 57 Z9 57 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 3 PY 2003 VL 91 IS 14 AR 142302 DI 10.1103/PhysRevLett.91.142302 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500009 PM 14611518 ER PT J AU Won, C Wu, YZ Scholl, A Doran, A Kurahashi, N Zhao, HW Qiu, ZQ AF Won, C Wu, YZ Scholl, A Doran, A Kurahashi, N Zhao, HW Qiu, ZQ TI Magnetic phase transition in Co/Cu/Ni/Cu(100) and Co/Fe/Ni/Cu(100) SO PHYSICAL REVIEW LETTERS LA English DT Article ID ULTRATHIN FILMS; FERROMAGNETISM; TEMPERATURE; SURFACES; CU(100); MODEL; RANGE AB Magnetic phase transitions in coupled magnetic sandwiches of Cu/Co/Cu/Ni/Cu(100) and Cu/Co/Fe/Ni/Cu(100) are investigated by photoemission electron microscopy. Element-specific magnetic domains are taken at room temperature to reveal the critical thickness at which the magnetic phase transition occurs. The results show that a coupled magnetic sandwich undergoes three types of magnetic phase transitions depending on the two ferromagnetic films' thickness. A phase diagram is constructed and explained in the process of constructing Monte Carlo simulations, which corroborate the experimental results. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Chinese Acad Sci, Int Ctr Quantum Struct, Beijing 100080, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Won, C (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI 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 18 TC 13 Z9 13 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 3 PY 2003 VL 91 IS 14 AR 147202 DI 10.1103/PhysRevLett.91.147202 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500041 PM 14611550 ER PT J AU Gibson, EA Paul, A Wagner, N Tobey, R Gaudiosi, D Backus, S Christov, IP Aquila, A Gullikson, EM Attwood, DT Murnane, MM Kapteyn, HC AF Gibson, EA Paul, A Wagner, N Tobey, R Gaudiosi, D Backus, S Christov, IP Aquila, A Gullikson, EM Attwood, DT Murnane, MM Kapteyn, HC TI Coherent soft x-ray generation in the water window with quasi-phase matching SO SCIENCE LA English DT Article ID HIGH-HARMONIC-GENERATION; RARE-GASES; FEMTOSECOND PULSES; ATTOSECOND PULSES; LASER-PULSES; IONIZATION; RADIATION; WAVELENGTHS; CONVERSION; BARRIER AB We demonstrate enhanced generation of coherent light in the "water window" region of the soft x-ray spectrum at 4.4 nanometers, using quasi-phase-matched frequency conversion of ultrafast laser pulses. By periodically modulating the diameter of a gas-filled hollow waveguide, the phase mismatch normally present between the laser light and the generated soft x-ray light can be partially compensated. This makes it possible to use neon gas as the nonlinear medium to coherently convert light up to the water window, illustrating that techniques of nonlinear optics can be applied effectively in the soft x-ray region of the spectrum. These results advance the prospects for compact coherent soft x-ray sources for applications in biomicroscopy and in chemical spectroscopy. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Sofia, Dept Phys, BU-1126 Sofia, Bulgaria. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Kapteyn, HC (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. EM kapteyn@jila.colorado.edu RI Backus, Sterling/C-2506-2008; Wagner, Nicholas/E-7437-2010; Kapteyn, Henry/H-6559-2011; Christov, Ivan/D-4446-2014 OI Kapteyn, Henry/0000-0001-8386-6317; Christov, Ivan/0000-0002-9146-6708 NR 31 TC 243 Z9 246 U1 3 U2 41 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 3 PY 2003 VL 302 IS 5642 BP 95 EP 98 DI 10.1126/science.1088654 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 727UD UT WOS:000185678500042 PM 14526077 ER PT J AU Guo, SC Shu, D Simon, MN Guo, PX AF Guo, SC Shu, D Simon, MN Guo, PX TI Gene cloning, purification, and stoichiometry quantification of phi29 anti-receptor gp12 with potential use as special ligand for gene delivery SO GENE LA English DT Article DE stoichiometry; receptor; receptor mediated endocytosis; gene delivery; gene therapy ID DNA PACKAGING MOTOR; BACTERIAL-VIRUS PHI29; NECK APPENDAGE PROTEIN; BACILLUS-SUBTILIS; BACTERIOPHAGE-PHI-29 DNA; PHAGE PHI-29; VIRAL-RNA; DNA-GP3; MORPHOGENESIS; HEXAMER AB Bacterial virus phi29 is the most efficient in vitro DNA packaging system, with which up to 90% of the added DNA can be packaged into purified recombinant procapsid in vitro. The findings that phi29 virions can be assembled with the exclusive use of cloned gene products have bred a thought that phi29 has a potential to be a gene delivery vector since it is a nonpathogenic virus. gp12 of bacterial virus phi29 has been reported to be the anti-receptor that is responsible for binding the virus particle to the host cell. We cloned the gene coding gp12, overexpressed it in Escherichia coli, and purified the gene product to study the properties and functions of gp12 in virus assembly. According to SDS PloyAcrylamide Gel Electrophoresis (SDS-PAGE) analysis and N-terminal sequencing, recombinant gp12 isolated from E. coli bad a molecular mass of 80 kDa, and 24 amino acids at N-terminal were cleaved after expression. The purified recombinant gp12 was incorporated into phi29 particles and converted the gp12-lacking assembly intermediates of phi29 into infectious virions in vitro. This purified protein gp12 was able to compete with infectious phi29 virions for binding to the host cell, thus inhibiting the infection by phi29. Scanning Transmission Electron Microscopy (STEM) analysis and sedimentation studies revealed that recombinant gp12 products were assembled into biologically active dimers. Analysis of the dose-response curve showed that 12 dimeric gp12 complexes were assembled onto viral particles and that each virion contained 24 copies of gp12 molecules. The results provide a basis for future research into bacteriophage-host interaction by modifying the anti-receptor protein. The ultimate goal is to re-target the bacteriophage to new host cells for the purpose of gene delivery. (C) 2003 Elsevier B.V. All rights reserved. C1 Purdue Univ, Purdue Canc Res Ctr, Dept Pathobiol, Lab Mol Virol & Gene Therapy, W Lafayette, IN 47907 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Guo, PX (reprint author), Purdue Univ, Purdue Canc Res Ctr, Dept Pathobiol, Lab Mol Virol & Gene Therapy, B-36 Hansen Life Sci Res Bldg, W Lafayette, IN 47907 USA. RI Guo, Peixuan/I-7184-2015 FU NCRR NIH HHS [P41-RR01777]; NIGMS NIH HHS [GM60529, GM59944] NR 37 TC 8 Z9 8 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD OCT 2 PY 2003 VL 315 BP 145 EP 152 DI 10.1016/S0378-1119(03)00729-7 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA 737HU UT WOS:000186225000016 PM 14557074 ER PT J AU Miller, JA Klippenstein, SJ AF Miller, JA Klippenstein, SJ TI The recombination of propargyl radicals and other reactions on a C6H6 potential SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PHENOMENOLOGICAL RATE COEFFICIENTS; WELL MASTER EQUATION; KASSEL-MARCUS THEORY; STOCHASTIC-MODELS; THERMAL-ISOMERIZATION; THEORETICAL-ANALYSIS; CHEMICAL-REACTION; REACTION-KINETICS; MOLECULAR-OXYGEN; ENERGY SURFACE AB Using a combination of electronic-structure methods, we have explored in some detail the regions of the C6H6 potential that are important for describing the recombination of propargyl (C3H3) radicals. Using this information in an RRKM-based master equation, we have been able to predict rate coefficients for a variety of elementary reactions, including the C3H3 + C3H3 recombination itself. Generally, the agreement between the theory and the limited amount of experimental information available is very good, although some discrepancies remain. The most important new feature of the present analysis (over our previous one) is the inclusion of a path on the potential that connects 1,2,4,5-hexatetraene to 1,3-hexadien-5-yne and then goes on to benzene and phenyl + H without passing through fulvene. The inclusion of this path in the analysis allows a number of experimental observations to be accounted for by the theory. From the results of the master equation calculations, we propose a simple, contracted model for describing the rate coefficient and product distribution of the C3H3 + C3H3 recombination reaction (and subsequent isomerizations) for use in flame modeling. Modified Arrhenius expressions are provided for the rate coefficients of the reactions appearing in the simplified model. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Miller, JA (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. OI Klippenstein, Stephen/0000-0001-6297-9187 NR 57 TC 206 Z9 207 U1 7 U2 73 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 OCT 2 PY 2003 VL 107 IS 39 BP 7783 EP 7799 DI 10.1021/jp030375h PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726QB UT WOS:000185609500016 ER PT J AU Gibson, JK AF Gibson, JK TI Role of atomic electronics in f-element bond formation: Bond energies of lanthanide and actinide oxide molecules SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DISSOCIATION-ENERGIES; THERMODYNAMIC PROPERTIES; OXIDATION REACTIONS; PERIODIC TRENDS; METAL-OXIDE; REACTIVITY; CATIONS; CONFIGURATIONS; HYDROCARBONS; COMPLEXES AB Metal oxide molecules are of particular interest from both a scientific and technological perspective in view of their elementary nature and role in such processes as high-temperature vaporization. A fundamental and important property is the bond energy between the metal center and the oxygen in neutral and ionic monoxide molecules, BDE[MO] and BDE[MO(+)]. For the 4f-block lanthanide (Ln) and 5f-block actinide (An) inner transition metals, it has been demonstrated that many chemical properties can be rationalized from the electronic structures and energetics of the isolated metal atom or ion. In the present work, a relationship is developed to reliably predict known BDE[LnO], BDE[LnO(+)], BDE[AnO], and BDE[AnO(+)] energies from spectroscopically determined electronic properties; this relationship is employed to estimate unknown bond energies. A notable implication of the results is that effective bonding between the metal center and the oxygen atom in these species requires two unpaired valence d electrons. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. EM gibsonjk@ornl.gov NR 38 TC 46 Z9 47 U1 2 U2 24 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 OCT 2 PY 2003 VL 107 IS 39 BP 7891 EP 7899 DI 10.1021/jp035003n PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726QB UT WOS:000185609500030 ER PT J AU Lymar, SV Poskrebyshev, GA AF Lymar, SV Poskrebyshev, GA TI Rate of ON-OO- bond homolysis and the Gibbs energy of formation of peroxynitrite SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PULSE-RADIOLYSIS; AQUEOUS-SOLUTION; NITRIC-OXIDE; HYDROXYL RADICALS; METHYL VIOLOGEN; REDUCTION POTENTIALS; BIOLOGICAL-ACTIVITY; ACID DISSOCIATION; DECOMPOSITION; SUPEROXIDE AB Oxidation of the methyl viologen radical, MV.+, by the peroxynitrite anion, ONOO-, occurs through an indirect pathway, which includes reversible homolytic dissociation of ONOO- into a pair of the NO. and O-2(.-) radicals (rate-determining step, k(h) = 0.017 +/- 0.001 s(-1)) followed by rapid oxidation of MV.+ by O-2(.+) with k(so) = (3.5 +/- 0.2) x 10(9) M-1 s(-1) at zero ionic strength. Direct oxidation of MV.+ radical through a bimolecular reaction with ONOO- is immeasurably slow (k < 1 x 10(3) M-1 s(-1)). The MV.+ radical does not rapidly reduce NO., suggesting that the one-electron reduction potential of the latter is significantly below -0.45 V (NHE), consistent with the recently reported reevaluations of NO. reduction energetics. The equilibrium constant K-h = (3.6 +/- 0.3) x 10(-12) M for the dissociation of ONOO- into NO. and O-2(.-) is determined from the measurements of rate constants for the forward and reverse (recombination of NO. and O-2(.-), k(-h) = (4.8 +/- 0.3) x 101 M-1 s-1) reactions. The free energies of formation in aqueous solution Delta(f)Gdegrees(ONOO-) = 68.5 +/- 1.4 kJ/mol and Delta(f)Gdegrees(ONOOH) = 30.8 +/- 1.5 kJ/mol are derived from these data. The last value is fully consistent with the major role of the ONOOH homolytic dissociation into a pair of the NO2. and OH. radicals in oxidations by peroxynitrite. Collectively, these results help to resolve disputes in the literature over the values for k(h), k(-h), K-h, Delta(f)Gdegrees(ONOO-), and Delta(f)Gdegrees(ONOOH); measurements of all these quantities in this work disagree with their recent reevaluations, but largely agree with earlier reports. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Lymar, SV (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Poskrebyshev, Gregory/I-9122-2016 OI Poskrebyshev, Gregory/0000-0002-8920-7037 NR 58 TC 17 Z9 17 U1 2 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 OCT 2 PY 2003 VL 107 IS 39 BP 7991 EP 7996 DI 10.1021/jp0354245 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 726QB UT WOS:000185609500043 ER PT J AU Sutin, N Brunschwig, BS Creutz, C AF Sutin, N Brunschwig, BS Creutz, C TI Using the Marcus inverted region for rectification in donor-bridge-acceptor "wire" assemblies SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID ELECTRON-TRANSFER REACTIONS; TRANSFER KINETICS; MOLECULAR WIRES; CONDUCTANCE; JUNCTIONS; TRANSPORT AB We examine the properties of a system in which a hopping mechanism can exploit the nuclear factors, along with the field resulting from the applied voltage, to control the current through a donor-bridge-acceptor (D-B-A) system inserted between two metal electrodes. We find that, by utilizing D/A couples with small lambda values, switching can be achieved at modest applied potentials. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Beckman Inst CALTECH, Pasadena, CA 91125 USA. RP Sutin, N (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brunschwig, Bruce/G-4249-2011 NR 23 TC 9 Z9 9 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 OCT 2 PY 2003 VL 107 IS 39 BP 10687 EP 10690 DI 10.1021/jp035542s PG 4 WC Chemistry, Physical SC Chemistry GA 726QC UT WOS:000185609600002 ER PT J AU McKnight, TE Melechko, AV Guillorn, MA Merkulov, VI Doktycz, MJ Culbertson, CT Jacobson, SC Lowndes, DH Simpson, ML AF McKnight, TE Melechko, AV Guillorn, MA Merkulov, VI Doktycz, MJ Culbertson, CT Jacobson, SC Lowndes, DH Simpson, ML TI Effects of microfabrication processing on the electrochemistry of carbon nanofiber electrodes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID GROWTH AB We describe the fabrication and electrochemical characterization of as-grown and postprocessed vertically aligned carbon nanofiber forest electrodes at macroscopic (5 mm) and microscopic dimensions (250 mum). We examine the impact of a variety of microfabrication processes that are typically employed during nanofiber-based device synthesis including refractory metal reactive ion etch, oxide coating and removal, and several oxygen-based etch processes-all of which dramatically impact microscale electrode response. We also demonstrate that the high electrochemically active surface area of larger scale, macroscopic nanofiber forest electrodes can provide a buffering capacity against surface activation/inactivation. Under diffusion-limited transport conditions, this may preserve the electrochemical response of the electrode during storage and against the impacts of processing techniques used during nanofiber-based device fabrication. C1 Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. RP McKnight, TE (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Melechko, Anatoli/B-8820-2008; Doktycz, Mitchel/A-7499-2011; Simpson, Michael/A-8410-2011; McKnight, Tim/H-3087-2011; OI Doktycz, Mitchel/0000-0003-4856-8343; Simpson, Michael/0000-0002-3933-3457; McKnight, Tim/0000-0003-4326-9117; Culbertson, Christopher/0000-0002-6833-3237 NR 20 TC 26 Z9 26 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 OCT 2 PY 2003 VL 107 IS 39 BP 10722 EP 10728 DI 10.1021/jp034872+ PG 7 WC Chemistry, Physical SC Chemistry GA 726QC UT WOS:000185609600008 ER PT J AU Pinnaduwage, LA Gehl, A Hedden, DL Muralidharan, G Thundat, T Lareau, RT Sulchek, T Manning, L Rogers, B Jones, M Adams, JD AF Pinnaduwage, LA Gehl, A Hedden, DL Muralidharan, G Thundat, T Lareau, RT Sulchek, T Manning, L Rogers, B Jones, M Adams, JD TI A microsensor for trinitrotoluene vapour SO NATURE LA English DT Editorial Material ID MICROCANTILEVERS; SENSORS C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Transportat Secur Adm, US Dept Homeland Secur, Atlantic City, NJ 08405 USA. Univ Nevada, Dept Mech Engn, Reno, NV 89557 USA. Univ Nevada, Nevada Ventures Nanosci Program, Reno, NV 89557 USA. RP Pinnaduwage, LA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 9 TC 124 Z9 124 U1 0 U2 20 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 2 PY 2003 VL 425 IS 6957 BP 474 EP 474 DI 10.1038/425474a PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 727FN UT WOS:000185648100034 PM 14523436 ER PT J AU Krutilina, RI Smirnova, AN Mudrak, OS Pleskach, NM Svetlova, MP Oei, SL Yau, PM Bradbury, EM Zalensky, AO Tomilin, NV AF Krutilina, RI Smirnova, AN Mudrak, OS Pleskach, NM Svetlova, MP Oei, SL Yau, PM Bradbury, EM Zalensky, AO Tomilin, NV TI Protection of internal (TTAGGG)n repeats in Chinese hamster cells by telomeric protein TRF1 SO ONCOGENE LA English DT Article DE internal telomeric repeats; instability; TRF1; wortmannin; tankyrase 1 ID DOUBLE-STRAND BREAK; ATM-DEPENDENT PHOSPHORYLATION; ATAXIA-TELANGIECTASIA CELLS; DNA-DAMAGE RESPONSE; END-JOINING FACTORS; OVARY CELLS; CHROMOSOMAL INSTABILITY; L1 ENDONUCLEASE; MAMMALIAN-CELLS; TTAGGG REPEATS AB Chinese hamster cells have large interstitial ( TTAGGG) bands (ITs) which are unstable and should be protected by an unknown mechanism. Here, we expressed in Chinese hamster V79 cells green fluorescent protein (GFP)-tagged human TRF1, and found that a major fraction of GFP-TRF1 bound to ITs is diffusionally mobile. This fraction strongly decreases after treatment of cells with wortmannin, a protein kinase inhibitor, and this drug also increases the frequency of chromosome aberrations. Ionizing radiation does not induce detectable translocation of GFP-TRF1 to the sites of random double-strand breaks visualized using antibodies against histone gamma-H2AX. TRF1 is known to be eliminated from telomeres by overexpression of tankyrase 1 which induces TRF1 poly(ADP-ribosyl) ation. We transfected V79 cells by plasmid encoding tankyrase 1 and found that the frequency of chromosome rearrangements is increased in these cells independently of their treatment by IR. Taken together, our results suggest that TRF1 is involved in sequence-specific protection of internal nontelomeric (TTAGGG) n repeats. C1 Russian Acad Sci, Inst Cytol, Lab Chromosome Stabil, St Petersburg 194064, Russia. Free Univ Berlin, Inst Biochem, D-14195 Berlin, Germany. Univ Calif Davis, Sch Med, Dept Biol Chem, Davis, CA 95616 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Tomilin, NV (reprint author), Russian Acad Sci, Inst Cytol, Lab Chromosome Stabil, St Petersburg 194064, Russia. FU NICHD NIH HHS [5R01-HD39830-02] NR 69 TC 14 Z9 14 U1 3 U2 6 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0950-9232 J9 ONCOGENE JI Oncogene PD OCT 2 PY 2003 VL 22 IS 43 BP 6690 EP 6698 DI 10.1038/sj.onc.1206745 PG 9 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA 729XA UT WOS:000185799300004 PM 14555982 ER PT J AU Maayan, G Fish, RH Neumann, R AF Maayan, G Fish, RH Neumann, R TI Polyfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents SO ORGANIC LETTERS LA English DT Article ID MANGANESE-CONTAINING POLYOXOMETALATE; LIQUID/SOLID PHASE-SEPARATION; CHIRAL ALLYLIC ALCOHOLS; HYDROGEN-PEROXIDE; AEROBIC OXIDATION; ALKENE FUNCTIONALIZATION; M(C8F17(CH2)(2)CO2)(2) M; PERFLUORINATED SOLVENTS; SOLUBLE CATALYSTS; EPOXIDATION AB Polyfluorinated quaternary ammonium cations, [CF3(CF2)(7)(CH2)(3)](3)CH3N+ (RFN+), were synthesized and used as countercations for the [WZnM2(H2O)(2)(ZnW9O34)(2)](12-) (M = Mn(II), Zn(II)) polyoxometalate. The (RFN+)(12)[WZnM2(H2O)(2)(ZnW9O34)(2)] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected by both the hydrophobicity of the solvent and the substrate. C1 Univ Calif, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Maayan, G (reprint author), Weizmann Inst Sci, Dept Organ Chem, IL-76100 Rehovot, Israel. NR 45 TC 49 Z9 49 U1 0 U2 11 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 OCT 2 PY 2003 VL 5 IS 20 BP 3547 EP 3550 DI 10.1021/ol0348598 PG 4 WC Chemistry, Organic SC Chemistry GA 725WN UT WOS:000185565500001 PM 14507169 ER PT J AU Barone, V Calarco, T Drago, A Simani, MC AF Barone, V Calarco, T Drago, A Simani, MC TI Flavor asymmetry of the polarized light sea: models vs. data SO PHYSICS LETTERS B LA English DT Article ID N-C LIMIT; PARTON DISTRIBUTIONS; SPIN STRUCTURE; NUCLEON; CONFINEMENT AB The flavor asymmetry of the polarized light sea, Delta(u) over bar - Delta(d) over bar, discriminates between different model calculations of helicity densities. We show that the chiral chromodielectric model, differently from models based on a 1/N-c expansion, predicts a small value for this asymmetry, what seems in agreement with preliminary HERMES data. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Piemonte Orientale A Avogadro, DISTA, I-15100 Alessandria, Italy. Ist Nazl Fis Nucl, Grp Coll Alessandria, I-15100 Alessandria, Italy. ECT, I-38050 Villazzano, Trento, Italy. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Barone, V (reprint author), Univ Piemonte Orientale A Avogadro, DISTA, I-15100 Alessandria, Italy. RI Drago, Alessandro/F-6347-2012 NR 22 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD OCT 2 PY 2003 VL 571 IS 1-2 BP 50 EP 54 DI 10.1016/j.physletb.2003.07.068 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 723CB UT WOS:000185413900007 ER PT J AU DePaoli, DW Tsouris, C Hu, MZC AF DePaoli, DW Tsouris, C Hu, MZC TI EHD micromixing reactor for particle synthesis SO POWDER TECHNOLOGY LA English DT Article DE electrohydrodynamic mixing; ultrafine particles; zirconia particles; electrohydrodynamic flow; EHD; particle production ID ELECTROSTATIC DISPERSION; NONCONDUCTIVE FLUIDS; UNIPOLAR INJECTION; INSULATING LIQUIDS; CONDUCTIVE FLUIDS; OXIDE PARTICLES; FINE PARTICLES; ZIRCONIA; HYDROLYSIS; ELECTRODISPERSION AB This paper presents a liquid-phase approach to particle production using electrohydrodynamic (EHD) mixing. EHD flows are used to disperse one miscible, reactive fluid into another, based on the capability to develop significant fluid velocities and turbulence by charge injection into dielectric fluids. Alcohol solvents, commonly used for sol-gel reactions, are very suitable for applying this EHD mixing approach. The rapid micromixing in the vicinity of the electrified injector allows the liquid-phase reactions to be conducted uniformly at high rates. This approach allows continuous production of non-agglomerated, monodispersed, submicron-sized particles. Experiments aimed at investigating the capability for EHD mixing to improve particle production were conducted in a continuous-flow system using the hydrolysis and condensation of zirconium tetra-n-butoxide in alcohols. Because of the rapid kinetics of this reaction system, the quality of ultrafine particles produced is greatly affected by the degree of early-stage mixing. Mixing of the reactant streams was shown to improve with increasing applied voltage, and a corresponding improvement in the homogeneity of the produced particles was determined. The EHD mixing approach was shown to have several possible advantages in comparison with batch reactions. The reaction can be conducted to produce quality particles at higher concentrations, and the particles produced by EHD mixing are more homogeneous. In addition, under the rapid micromixing conditions, it is possible to manipulate nucleation rates through the introduction of concentrated reactants, resulting in the capability to produce significantly smaller particles. This study indicates that reactors utilizing EHD mixing could be used for continuous, rapid production of homogeneous, ultrafine particles. (C) 2003 Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP DePaoli, DW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Tsouris, Costas/C-2544-2016; OI Tsouris, Costas/0000-0002-0522-1027; Hu, Michael/0000-0001-8461-9684 NR 36 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD OCT 2 PY 2003 VL 135 SI SI BP 302 EP 309 DI 10.1016/j.powtec.2003.08.022 PG 8 WC Engineering, Chemical SC Engineering GA 745KR UT WOS:000186688300034 ER PT J AU Deitz, SJ Chamberlain, BL Choi, SE Snyder, L AF Deitz, SJ Chamberlain, BL Choi, SE Snyder, L TI The design and implementation of a parallel array operator for the arbitrary remapping of data SO ACM SIGPLAN NOTICES LA English DT Article; Proceedings Paper CT 9th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming CY JUN 11-13, 2003 CL SAN DIEGO, CALIFORNIA SP ACM, SIGPLAN DE languages; parallel programming; gather; scatter; array languages; ZPL AB Gather and scatter are data redistribution functions of long-standing importance to high performance computing. In this paper, we present a highly-general array operator with powerful gather and scatter capabilities unmatched by other array languages. We discuss an efficient parallel implementation, introducing three new optimizations-schedule compression, dead array reuse, and direct communication-that reduce the costs associated with the operator's wide applicability. In our implementation of this operator in ZPL, we demonstrate performance comparable to the hand-coded Fortran + MPI versions of the NAS FT and CC benchmarks. C1 Univ Washington, Seattle, WA 98195 USA. Cray Inc, Seattle, WA 98104 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Deitz, SJ (reprint author), Univ Washington, Seattle, WA 98195 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 USA SN 0362-1340 J9 ACM SIGPLAN NOTICES JI ACM Sigplan Not. PD OCT PY 2003 VL 38 IS 10 BP 154 EP 165 PG 12 WC Computer Science, Software Engineering SC Computer Science GA 755BA UT WOS:000187366900014 ER PT J AU Terwilliger, TC AF Terwilliger, TC TI Statistical density modification using local pattern matching SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID 2-DIMENSIONAL HISTOGRAM; PYROBACULUM-AEROPHILUM; PHASE-IMPROVEMENT; CRYSTAL-STRUCTURE; PROTEIN MODELS; MAIN-CHAIN; RESOLUTION; MAPS; EXTENSION; REFINEMENT AB A method for improving crystallographic phases is presented that is based on the preferential occurrence of certain local patterns of electron density in macromolecular electron-density maps. The method focuses on the relationship between the value of electron density at a point in the map and the pattern of density surrounding this point. Patterns of density that can be superimposed by rotation about the central point are considered equivalent. Standard templates are created from experimental or model electron-density maps by clustering and averaging local patterns of electron density. The clustering is based on correlation coefficients after rotation to maximize the correlation. Experimental or model maps are also used to create histograms relating the value of electron density at the central point to the correlation coefficient of the density surrounding this point with each member of the set of standard patterns. These histograms are then used to estimate the electron density at each point in a new experimental electron-density map using the pattern of electron density at points surrounding that point and the correlation coefficient of this density to each of the set of standard templates, again after rotation to maximize the correlation. The method is strengthened by excluding any information from the point in question from both the templates and the local pattern of density in the calculation. A function based on the origin of the Patterson function is used to remove information about the electron density at the point in question from nearby electron density. This allows an estimation of the electron density at each point in a map, using only information from other points in the process. The resulting estimates of electron density are shown to have errors that are nearly independent of the errors in the original map using model data and templates calculated at a resolution of 2.6 Angstrom. Owing to this independence of errors, information from the new map can be combined in a simple fashion with information from the original map to create an improved map. An iterative phase-improvement process using this approach and other applications of the image-reconstruction method are described and applied to experimental data at resolutions ranging from 2.4 to 2.8 Angstrom. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Terwilliger, TC (reprint author), Los Alamos Natl Lab, Mail Stop M888, Los Alamos, NM 87545 USA. RI Terwilliger, Thomas/K-4109-2012 OI Terwilliger, Thomas/0000-0001-6384-0320 NR 40 TC 31 Z9 31 U1 0 U2 4 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 OCT PY 2003 VL 59 BP 1688 EP 1701 DI 10.1107/S0907444903015142 PN 10 PG 14 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 723VA UT WOS:000185451200002 PM 14501107 ER PT J AU Soares, AS Caspar, DLD Weckert, E Heroux, A Holzer, K Schroer, K Zellner, J Schneider, D Nolan, W Sweet, RM AF Soares, AS Caspar, DLD Weckert, E Heroux, A Holzer, K Schroer, K Zellner, J Schneider, D Nolan, W Sweet, RM TI Three-beam interference is a sensitive measure of the efficacy of macromolecular refinement techniques SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID X-RAY-DIFFRACTION; CUBIC INSULIN CRYSTALS; TRIPLET PHASES; REFLECTION PHASES; PROTEIN; CRYSTALLOGRAPHY; DENSITY; FEASIBILITY; VALIDATION; SOLVATION AB Triplet phases recorded from insulin crystals were used to measure the improvement of phases during model refinement and to quantify the contribution made by each step in the refinement. Conventional amplitude data were recorded to 1.5 Angstrom resolution from rhombohedral pig insulin crystals using 1.54 Angstrom Cu Kalpha radiation. An initial atomic model and starting phases were obtained from a published structure and the atomic model was refined against the amplitude data using CNS. The refined phases were compared with 800 triplet phases that were measured from similar crystals using a three-beam interference technique and 1.1 Angstrom wavelength synchrotron radiation. The solvent region was improved further using a novel density-modification procedure. Calculated triplet phases were obtained from the model after each step in the refinement and were compared with the recorded triplet phases. The average difference between the recorded triplet phases and the calculated triplet phases was used as an unbiased measure of the correctness of the model at each stage in the refinement. The average individual phase error was estimated from discrepancies from triplet phases after each refinement step. Conventional atomic refinement of an approximate starting model reduced the average individual phase error from 21.6 to 14.7degrees. Improvement of the solvent region, including the difference-map flattening procedure, reduced the individual phase error by a further 2.6degrees. Modeling the discrete disorder of four amino acids accounted for an additional 0.5degrees improvement and the final individual phase error was 11.6degrees. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Florida State Univ, Inst Mol Biophys, Tallahassee, FL 32306 USA. DESY, HASYLAB, D-22603 Hamburg, Germany. RP Sweet, RM (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RI Soares, Alexei/F-4800-2014 OI Soares, Alexei/0000-0002-6565-8503 NR 35 TC 8 Z9 8 U1 0 U2 2 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 OCT PY 2003 VL 59 BP 1716 EP 1724 DI 10.1107/S0907444903015403 PN 10 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 723VA UT WOS:000185451200004 PM 14501109 ER PT J AU Ogawa, H Zhang, X Qiu, Y Ogata, CM Misono, KS AF Ogawa, H Zhang, X Qiu, Y Ogata, CM Misono, KS TI Crystallization and preliminary X-ray analysis of the atrial natriuretic peptide (ANP) receptor extracellular domain complex with ANP: use of ammonium sulfate as the cryosalt SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID VASORELAXANT ACTIVITY; PURIFICATION; DIFFRACTION; BINDING AB Atrial natriuretic peptide (ANP) plays a major role in blood pressure and volume regulation owing to its natriuretic and vasodilatory activities. The ANP receptor is a single-span transmembrane receptor coupled to its intrinsic guanylyl cyclase activity. The extracellular hormone-binding domain of rat ANP receptor (ANPR) was overexpressed by permanent transfection in CHO cells and purified. ANPR complexed with ANP was crystallized at 301 K by the hanging-drop vapor-diffusion method. The crystals were frozen in 3.4 M ammonium sulfate used as a cryoprotectant. The crystals diffracted to 3.1 Angstrom resolution using synchrotron radiation and belonged to the hexagonal space group P6(1), with unit-cell parameters a = b = 100.3, c = 258.6 Angstrom. C1 Cleveland Clin Fdn, Dept Mol Cardiol, Lerner Res Inst, Cleveland, OH 44195 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Misono, KS (reprint author), Cleveland Clin Fdn, Dept Mol Cardiol, Lerner Res Inst, 9500 Euclid Ave, Cleveland, OH 44195 USA. FU NHLBI NIH HHS [HL54329] NR 14 TC 6 Z9 6 U1 0 U2 0 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 OCT PY 2003 VL 59 BP 1831 EP 1833 DI 10.1107/S0907444903016445 PN 10 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 723VA UT WOS:000185451200024 PM 14501129 ER PT J AU Wielopolski, L Ramirez, LM Coyle, P Heymsfield, S Zimman, J AF Wielopolski, L Ramirez, LM Coyle, P Heymsfield, S Zimman, J TI Some aspects of measuring levels of potassium in the brain SO ACTA DIABETOLOGICA LA English DT Article; Proceedings Paper CT 6th International Symposium on In Vivo Body Composition Studies CY OCT 03-05, 2002 CL ROME, ITALY DE potassium; brain; in vivo; multiple sclerosis; edema ID BODY AB The general aim of this work is to measure brain potassium (K) levels as a marker of intracellular water content and to test the hypothesis of whether edema in multiple sclerosis (MS) is associated with increased intracellular brain water. For that purpose, a system to measure K in brain is being developed. Our specific aim is to assess the potential contribution to the K photopeak from cranial K located outside the brain. For this, a simplified spherical phantom to represent the brain, a square box to represent the cranium, and a K point source to assess the contributions due to K outside the brain were used. It is estimated that only about 1-2% of the K photopeak might be attributable to K outside the brain. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. St Lukes Roosevelt Hosp, New York, NY 10025 USA. Univ Hosp Stony Brook, Stony Brook, NY USA. RP Wielopolski, L (reprint author), Brookhaven Natl Lab, Bldg 490-D, Upton, NY 11973 USA. FU NIDDK NIH HHS [P01 DK042618]; PHS HHS [4261844] NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0940-5429 J9 ACTA DIABETOL JI Acta Diabetol. PD OCT PY 2003 VL 40 SU 1 BP S73 EP S75 DI 10.1007/s00592-003-0031-0 PG 3 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 739UX UT WOS:000186365800016 PM 14618438 ER PT J AU Niu, Y Hou, Y AF Niu, Y Hou, Y TI Characterization of pore development at Al2O3/FeAl interface during high temperature oxidation SO ACTA METALLURGICA SINICA LA Chinese DT Article DE pore; interface; oxidation; FeAl; A1(2)O(3) ID AL ALLOYS; BEHAVIOR; SCALE; FEAL; INTERMETALLICS; ZR AB Engineering alloys of heat resistance often generate pores at the scale/alloy interface during high temperature oxidation. The accumulation and growth of those pores greatly weaken scale adhesion. The purpose of this study is to observe pore development in Fe-40%Al (atomic fraction) and measure the change in pore volume with oxidation time. Experimental results are then compared to a theoretical calculation where all vacancies are allowed to condense as voids. After removing the oxide scales formed after various times of oxidation at 1000 degreesC in oxygen, the alloy surface was analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) to determine the size and depth of interfacial pores. Results are discussed in light of possible mechanisms involved in pore formation at scale/alloy interfaces. C1 Chinese Acad Sci, Inst Met Res, State Key Lab Corros & Protect, Shenyang 110016, Peoples R China. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Hou, Y (reprint author), Chinese Acad Sci, Inst Met Res, State Key Lab Corros & Protect, Shenyang 110016, Peoples R China. EM yniu@icpm.syb.ac.cn NR 23 TC 1 Z9 5 U1 0 U2 1 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0412-1961 J9 ACTA METALL SIN JI Acta Metall. Sin. PD OCT PY 2003 VL 39 IS 10 BP 1065 EP 1070 PG 6 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 741GX UT WOS:000186451300011 ER PT J AU Maziasz, P Pollard, M AF Maziasz, P Pollard, M TI High-temperature cast stainless steel SO ADVANCED MATERIALS & PROCESSES LA English DT Article C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Caterpillar Inc, Ctr Tech, Peoria, IL USA. RP Maziasz, P (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Maziasz, Philip/0000-0001-8207-334X NR 0 TC 13 Z9 13 U1 1 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD OCT PY 2003 VL 161 IS 10 BP 57 EP 59 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 731WM UT WOS:000185909500008 ER PT J AU Sajwan, KS Paramasivam, S Alva, AK Adriano, DC Hooda, PS AF Sajwan, KS Paramasivam, S Alva, AK Adriano, DC Hooda, PS TI Assessing the feasibility of land application of fly ash, sewage sludge and their mixtures SO ADVANCES IN ENVIRONMENTAL RESEARCH LA English DT Article DE biomass; fly ash; groundwater; leaching; metals; sewage sludge ID SOILS; TURFGRASS; RESIDUES; QUALITY; RATES; TIME AB Land disposal of fly ash (FA) and sewage sludge (SS) is a major problem due largely to their potentially harmful constituents. Combined use of FA and SS however may help reduce the associated pollution potential. In this paper we summarize the results of several case studies designed to assess the feasibility of land application of FA with and without SS. A wide range of application rates was tested under laboratory, greenhouse and field conditions. The leaching of metals from soil columns amended with moderate rates of FA applications (8-16 Mg ha(-1)) generally had no significant impact on the metal content of leachate or their downward migration in the soil. The application of FA or SS at a much high rate (74.1 Mg ha(-1)) significantly increased both leaching and downward migration of metals. The use of 1:1 FA+SS mixture at 148.2 Mg ha(-1) reduced metal leaching compared to the combined metal quantities leached when FA or SS applied at 74.1 Mg ha(-1). The results indicate that combined use of FA and SS at a rational rate of application should not cause any significant effect on drainage water quality. Plant studies conducted using FA and SS mixtures indicated that these materials could be beneficial for biomass production, without contributing significant metal uptake or leaching. The application of FA as high as 560 Mg ha(-1) in a long-term field trial had no detectable deterioration in soil or groundwater quality and no substantial increases in plant uptake of metals and other trace elements were observed. Low to moderate rates of FA and SS therefore could be successfully used as soil amendments, particularly so when used as a mixture. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Savannah State Univ, Ctr Marine Environm Sci Biotechnol Res, Savannah, GA 31404 USA. ARS, USDA, PWA, Vegetable & Forage Crops Res, Prosser, WA 99350 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Kingston Univ, Ctr Earth & Environm Sci Res, Kingston upon Thames KT1 2EE, Surrey, England. RP Sajwan, KS (reprint author), Savannah State Univ, Ctr Marine Environm Sci Biotechnol Res, POB 20600, Savannah, GA 31404 USA. EM sajwank@savstate.edu NR 42 TC 41 Z9 45 U1 1 U2 15 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1093-0191 J9 ADV ENVIRON RES JI Adv. Environ. Res. PD OCT PY 2003 VL 8 IS 1 BP 77 EP 91 DI 10.1016/S1093-0191(02)00137-5 PG 15 WC Engineering, Environmental; Engineering, Chemical SC Engineering GA 760FZ UT WOS:000187802100007 ER PT J AU Maxwell, RM Welty, C Tompson, AFB AF Maxwell, RM Welty, C Tompson, AFB TI Streamline-based simulation of virus transport resulting from long term artificial recharge in a heterogeneous aquifer SO ADVANCES IN WATER RESOURCES LA English DT Article DE virus transport; colloid transport; geologic heterogeneity; artificial aquifer recharge; streamline numerical methods ID CRYPTOSPORIDIUM-PARVUM OOCYSTS; POROUS-MEDIA; SOLUTE TRANSPORT; SANDY SOILS; BACTERIOPHAGE TRANSPORT; CHEMICAL PERTURBATIONS; HYDRAULIC CONDUCTIVITY; GRADIENT EXPERIMENT; STOCHASTIC-ANALYSIS; COLLOID TRANSPORT AB The likelihood for viruses, protozoan oocysts, and other human pathogens to enter groundwater, and in particular, sensitive or vulnerable water supplies, has increased as the numbers of anthropogenic sources such as septic systems, leaking sewers, animal farming operations, and artificial recharge of treated wastewater have proliferated. In this paper, we utilize a detailed numerical model of groundwater flow in a region encompassing a large artificial groundwater recharge operation in Orange County, California to evaluate the potential for transport of viruses and protozoan oocysts in such a system, as dictated by a transport model that includes colloid filtration and microbial inactivation components. The purpose of the model is not oriented towards the analysis of any perceived or real microbial contamination, but rather is directed at understanding the influence of aquifer heterogeneity within the modeled system. The transport model is based upon a novel representation of geologic heterogeneity, a high-resolution flow simulator, and an efficient streamline-based transport algorithm. Example virus transport simulations illustrate a large degree of variability in virus breakthrough across water supply pumping wells, with shallower wells providing less than two orders of magnitude of virus removal, and deeper wells indicating many orders of magnitude of virus removal. Simulation results also show variability among pathogens modeled, with Cryptosporidium parvum filtered to a much greater degree than other pathogens. Comparison to transport of an abiotic colloid and a conservative chemical tracer are provided to illustrate the influence of filtration and inactivation on the transport process. The results emphasize the need for improved microbial transport models in realistic aquifer systems, more reliable virus characterization methods and monitoring networks, and their ultimate integration into a broader epidemiological and regulatory framework for aquifer management. (C) 2003 Elsevier Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Div Environm Sci, Livermore, CA 94550 USA. Drexel Univ, Dept Civil Environm & Architectural Engn, Philadelphia, PA 19104 USA. RP Maxwell, RM (reprint author), Lawrence Livermore Natl Lab, Div Environm Sci, L-208,7000 E Ave, Livermore, CA 94550 USA. RI Maxwell, Reed/D-7980-2013 OI Maxwell, Reed/0000-0002-1364-4441 NR 71 TC 26 Z9 28 U1 2 U2 13 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 OCT PY 2003 VL 26 IS 10 BP 1075 EP 1096 DI 10.1016/S0309-1708(03)00074-5 PG 22 WC Water Resources SC Water Resources GA 727QV UT WOS:000185670700003 ER PT J AU Klepeis, NE Apte, MG Gundel, LA Sextro, RG Nazaroff, WW AF Klepeis, NE Apte, MG Gundel, LA Sextro, RG Nazaroff, WW TI Determining size-specific emission factors for environmental tobacco smoke particles SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID SIDESTREAM CIGARETTE-SMOKE; CHEMICAL-COMPOSITION; AEROSOL; MAINSTREAM; DEPOSITION; EXPOSURE; NICOTINE; MASS AB Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides - in addition to estimates of the emissions size distribution and integrated emission factors estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ mum diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01 - 1+ mum diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange-rate 20 m(3) chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1 - 2 h after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle emission factors were fit with log-normal distributions, yielding an average mass median diameter of 0.2 mum and an average geometric standard deviation of 2.3 with no systematic differences between cigars and cigarettes. The equivalent total particle emission rate, obtained by integrating each size distribution, was 0.2 - 0.7 mg/min for cigars and 0.7 - 0.9 mg/min for cigarettes. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Indoor Environm Dept, Berkeley, CA USA. Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA 94720 USA. RP Klepeis, NE (reprint author), 16475 Tarpey Rd, Watsonville, CA 95076 USA. RI Nazaroff, William/C-4106-2008; OI Nazaroff, William/0000-0001-5645-3357; Klepeis, Neil/0000-0002-6934-3242 NR 36 TC 73 Z9 83 U1 3 U2 20 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD OCT PY 2003 VL 37 IS 10 BP 780 EP 790 DI 10.1080/02786820390220254 PG 11 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 746YF UT WOS:000186775900001 ER PT J AU Marshall, SL AF Marshall, SL TI Generalized least-squares parameter estimation from multiequation implicit models SO AICHE JOURNAL LA English DT Article ID VAPOR-LIQUID-EQUILIBRIUM; MAXIMUM-LIKELIHOOD PRINCIPLE; OCTANE PLUS TOLUENE; THERMODYNAMIC PROPERTIES; FUNCTION MINIMIZATION; GLOBAL OPTIMIZATION; MULTIRESPONSE DATA; NONLINEAR MODELS; EFFICIENT METHOD; ADMITTANCE DATA AB Maximum likelihood fit of nonlinear, implicit, multiple-response models to data containing normally distributed random errors can be carried out by a combination of the Gauss-Newton generalized nonlinear least-square algorithm first described by Britt and Luecke in 1973, with a Fletcher-Reeves conjugate gradient search for initial parameter estimates. The convergence of the algorithm is further improved by adding a step-limiting procedure that ensures a reduction in the objective function for each iteration. Multiple-equation regression methods appropriate to the solution of explicit fixed-regressor models are derived from this general treatment as special cases. These include weighted nonlinear least squares (where the covariance matrix of the response is known), and uniformly weighted nonlinear least squares (where the responses are uncorrelated and characterized by a single common variance). Alternative methods for fixed-regressor fits of explicit multiequation models with an unknown covariance matrix of the responses are also considered. The moment-matrix determinant criterion appropriate in such situations is also efficiently minimized by use of the conjugate-gradient algorithm, which is considerably less sensitive to the accuracy of the initial parameter estimate than the more usual Gauss-Newton methods. The performance of the new algorithm for models defined by one, two, and three implicit functional constraints per point is illustrated by random-regressor fits of isothermal p - X and p - X - Y vapor-liquid equilibrium data, and ternary liquid -liquid equilibrium data, respectively. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Marshall, SL (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Marshall, Simon/E-9518-2010 NR 78 TC 6 Z9 6 U1 6 U2 12 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD OCT PY 2003 VL 49 IS 10 BP 2577 EP 2594 DI 10.1002/aic.690491012 PG 18 WC Engineering, Chemical SC Engineering GA 731JF UT WOS:000185880000011 ER PT J AU Marshall, SL AF Marshall, SL TI New maximum-likelihood method for reduction of distribution-coefficient data SO AICHE JOURNAL LA English DT Article ID VAPOR-LIQUID-EQUILIBRIUM; PARAMETERS; MODELS AB The sampling distributions for the activity coefficient gamma and distribution ratio (or K-value) in binary fluid mixtures are derived from the assumptions that the pressure errors are negligible, and that the vapor and liquid composition measurements from which they are derived are normally distributed with known mean and variance. The distribution of K is shown to be not normal, with deviations from normality becoming particularly pronounced at the extremes of the composition range. The dispersion of this distribution is considerably greater than that predicted by the classic error-propagation formula. Deviation from normality invalidates the most important assumption implicit in the use of the least-squares criterion as the basis for parameter estimation from activity-coefficient data. This has important implications for the estimation of Henry's law constants for solutes in very dilute solutions, as well as for Raoult's law-based infinite-dilution activity coefficients. The use of the exact distributions of gamma and K as the basis for a more rigorous maximum-likelihood method for parameter estimation in excess Gibbs energy models based on either Henry's law or Raoult's law standard states is demonstrated. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Marshall, SL (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Marshall, Simon/E-9518-2010 NR 29 TC 0 Z9 0 U1 0 U2 2 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0001-1541 J9 AICHE J JI AICHE J. PD OCT PY 2003 VL 49 IS 10 BP 2595 EP 2608 DI 10.1002/aic.690491013 PG 14 WC Engineering, Chemical SC Engineering GA 731JF UT WOS:000185880000012 ER PT J AU Stewart, AJ Ryon, MG AF Stewart, AJ Ryon, MG TI Supercharged snails for stream ecology & water-quality studies SO AMERICAN BIOLOGY TEACHER LA English DT Editorial Material ID LIMITATION; RESPONSES C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Stewart, AJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. OI stewart, arthur/0000-0003-1968-5997 NR 5 TC 0 Z9 0 U1 1 U2 3 PU NATL ASSOC BIOLOGY TEACHERS INC PI RESTON PA 12030 SUNRISE VALLEY DR, #110, RESTON, VA 20191 USA SN 0002-7685 J9 AM BIOL TEACH JI Am. Biol. Teach. PD OCT PY 2003 VL 65 IS 8 BP 620 EP 626 PG 7 WC Biology; Education, Scientific Disciplines SC Life Sciences & Biomedicine - Other Topics; Education & Educational Research GA 734UE UT WOS:000186075700010 ER PT J AU Glaser, RL Broman, KW Schulman, RL Eskenazi, B Wyrobek, AJ Jabs, EW AF Glaser, RL Broman, KW Schulman, RL Eskenazi, B Wyrobek, AJ Jabs, EW TI The paternal-age effect in Apert syndrome is due, in part, to the increased frequency of mutations in sperm SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID CROUZON-SYNDROME; FGFR2 MUTATIONS; PARENTAL AGE; ORIGIN; PREVALENCE; REPAIR AB A paternal-age effect and the exclusive paternal origin of mutations have been reported in Apert syndrome (AS). As the incidence of sporadic AS births increases exponentially with paternal age, we hypothesized that the frequency of AS mutations in sperm would also increase. To determine the frequency of two common FGFR2 mutations in AS, we developed allele-specific peptide nucleic acid-PCR assays. Analyzing sperm DNA from 148 men, age 21-80 years, we showed that the number of sperm with mutations increased in the oldest age groups among men who did not have a child with AS. These older men were also more likely to have both mutations in their sperm. However, this age-related increase in mutation frequency was not sufficient to explain the AS-birth frequency. In contrast, the mutation frequency observed in men who were younger and had children with AS was significantly greater. In addition, our data suggest selection for sperm with specific mutations. Therefore, contributing factors to the paternal-age effect may include selection and a higher number of mutant sperm in a subset of men ascertained because they had a child with AS. No age-related increase in the frequency of these mutations was observed in leukocytes. Selection and/or quality-control mechanisms, including DNA repair and apoptosis, may contribute to the cell-type differences in mutation frequency. C1 Johns Hopkins Univ, Sch Med, Dept Pediat,CMSC 1004, Ctr Craniofacial Dev & Disorders,Inst Genet Med, Baltimore, MD 21287 USA. Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Biostat, Baltimore, MD 21287 USA. Univ Calif Berkeley, Sch Publ Hlth, Div Epidemiol, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. RP Jabs, EW (reprint author), Johns Hopkins Univ, Sch Med, Dept Pediat,CMSC 1004, Ctr Craniofacial Dev & Disorders,Inst Genet Med, 600 N Wolfe St, Baltimore, MD 21287 USA. OI Jabs, Ethylin/0000-0001-8983-5466 FU NIDCR NIH HHS [P60 DE013078, P60 DE13078, R01 DE1441]; NIEHS NIH HHS [P42 ES004705, P42 ES04705]; NIGMS NIH HHS [T32 GM007814, T32 GM07814] NR 24 TC 89 Z9 94 U1 4 U2 9 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 2003 VL 73 IS 4 BP 939 EP 947 DI 10.1086/378419 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA 727TL UT WOS:000185676100019 PM 12900791 ER PT J AU Fiedler, N Weisel, C Lynch, R Kelly-McNeil, K Wedeen, R Jones, K Udasin, I Ohman-Strickland, P Gochfeld, M AF Fiedler, N Weisel, C Lynch, R Kelly-McNeil, K Wedeen, R Jones, K Udasin, I Ohman-Strickland, P Gochfeld, M TI Cognitive effects of chronic exposure to lead and solvents SO AMERICAN JOURNAL OF INDUSTRIAL MEDICINE LA English DT Article DE lead exposure; bone lead; solvent exposure; neurobehavioral; occupational exposure ID X-RAY-FLUORESCENCE; LONG-TERM EXPOSURE; BONE LEAD; OCCUPATIONAL EXPOSURE; ORGANIC-SOLVENTS; INORGANIC LEAD; UNITED-STATES; BLOOD LEAD; WORKERS; PAINTERS AB Background. Occupational exposure to lead and solvents has declined steadily over the past 20 years, however construction workers continue to be exposed to these neurotoxicants. The purpose of this study was to investigate the cognitive effects of chronic occupational exposure to lead and solvents. Method. Based on K-XRF of tibial bone lead and occupational history of solvent exposure, subjects were classified into four exposure groups: lead (N = 40), solvent (N = 39), lead/ solvent (N = 45), and control (N = 33). All subjects completed tests to assess concentration, motor skills, memory, and mood. Results. Relative to controls, the lead, solvent, and lead/solvent groups performed significantly more poorly on a test of verbal memory, while the lead and lead/solvent groups were slower than the solvent and control groups on a task of processing speed. Bone lead was a significant predictor of information processing speed and latency of response while solvent exposure was a significant predictor of verbal learning and memory. Conclusions. Bone lead was associated with slower speed of processing while exposure to lead and/or solvents reduced efficiency of verbal learning. (C) 2003 Wiley-Liss, Inc. C1 Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Community & Environm Med, Piscataway, NJ 08854 USA. Rutgers State Univ, Edward J Bloustein Sch Planning & Publ Safety, Piscataway, NJ 08855 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Div Biometr, Piscataway, NJ 08854 USA. RP Fiedler, N (reprint author), Univ Med & Dent New Jersey, Robert Wood Johnson Med Sch, Dept Community & Environm Med, 170 Frelinghuysen Rd,Room 210, Piscataway, NJ 08854 USA. FU NIEHS NIH HHS [P30 ES05022]; NIOSH CDC HHS [5R01 OH03691] NR 52 TC 27 Z9 27 U1 2 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0271-3586 J9 AM J IND MED JI Am. J. Ind. Med. PD OCT PY 2003 VL 44 IS 4 BP 413 EP 423 DI 10.1002/ajim.10287 PG 11 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 727YW UT WOS:000185689300011 PM 14502770 ER PT J AU Sanati, M Saxena, A AF Sanati, M Saxena, A TI Landau theory of domain walls for one-dimensional asymmetric potentials SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID STRUCTURAL PHASE-TRANSITIONS; MEAN-FIELD THEORY; HYDROGEN-BONDED SOLIDS; TRAFFIC CONGESTION; MODEL; ORDER; TRANSFORMATION; THERMODYNAMICS; DEFORMATION; SIMULATION AB Investigation of a great number of physical systems shows that a Landau free energy of the form F(phi) =Hphi+ (A/2) phi(2) + (B/3) phi(3)+ (C/4) phi(4) describes a first-order phase transition in an internal or external field H. To study the formation of static domain walls in these systems we include a spatial gradient (Ginzburg) term of the scalar order parameter phi. From the variational derivative of the total free energy we obtain a static equilibrium condition. By solving this equation exactly for different physical parameters and boundary conditions, we obtained different quasi-one-dimensional soliton-like solutions. These solutions correspond to three different types of domain walls between the two different phases which are created in the system. In addition, we obtain soliton lattice (domain wall array) solutions, calculate their formation energy and the asymptotic interaction between the solitons. By introducing certain transformations, we show that the solutions obtained here can be used to study domain walls in other physical systems such as described by asymmetric double Morse potentials. Finally, we apply our results to the specific cases of liquid crystals and the jam phenomena in traffic flows. (C) 2003 American Association of Physics Teachers. C1 Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sanati, M (reprint author), Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. NR 42 TC 7 Z9 7 U1 0 U2 7 PU AMER ASSOC PHYSICS TEACHERS AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD OCT PY 2003 VL 71 IS 10 BP 1005 EP 1012 DI 10.1119/1.1578064 PG 8 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 723YH UT WOS:000185458800006 ER PT J AU Barnes, JH Hieftje, GM Denton, MB Sperline, R Koppenaal, DW Barinaga, C AF Barnes, JH Hieftje, GM Denton, MB Sperline, R Koppenaal, DW Barinaga, C TI A mass spectrometry detector array that provides truly simultaneous detection SO AMERICAN LABORATORY LA English DT Article ID SPECTROGRAPH AB Over the nearly century-long existence of mass spectrometry, the technique has evolved from a research-laboratory novelty to a well-characterized, widely employed method of analysis. With currently available technology, it is possible to dissect a sample and determine its composition, both qualitatively and quantitatively, in bulk and at trace levels, with a great deal of sensitivity and precision. However, the majority of recent advances in MS technology have focused on improving sample introduction methods and mass analyzer performance, with relatively little attention paid to ion detection. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Pacific NW Natl lab, Environm Mol Sci Lab, Richland, WA USA. RP Barnes, JH (reprint author), Indiana Univ, Dept Chem, 800 E Kirkwood Ave, Bloomington, IN 47405 USA. NR 5 TC 3 Z9 3 U1 0 U2 2 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 USA SN 0044-7749 J9 AM LAB JI Am. Lab. PD OCT PY 2003 VL 35 IS 20 BP 15 EP + PG 7 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 739QC UT WOS:000186357100004 ER PT J AU Dera, P Prewitt, CT Japel, S Bish, DL Johnston, CT AF Dera, P Prewitt, CT Japel, S Bish, DL Johnston, CT TI Pressure-controlled polytypism in hydrous layered materials SO AMERICAN MINERALOGIST LA English DT Article ID POWDER NEUTRON-DIFFRACTION; SAN-ANDREAS FAULT; PHASE-TRANSITIONS; DICKITE; KAOLINITE; MUSCOVITE; BRUCITE; CLAYS; DEPTH; GPA AB An isosymmetric displacive structural transformation in the hydrous layer silicate dickite [Al2Si2O5(OH)(4), monoclinic Cc, a = 5.161(3), b = 8.960(6), c = 14.459(10) Angstrom, beta = 96.77(l)degrees], occurring under hydrostatic compression above 2.0 GPa, has been studied using single-crystal X-ray diffraction and diamond-anvil cell techniques. The structure of the high-pressure phase, determined in situ, is monoclinic with space group Cc with unit-cell parameters a = 5.082(3), b = 8.757(6), c = 13.771(9) Angstrom, and beta = 89.60(2)degrees at 4.1 GPa. The positions of all hydrogen atoms at both ambient and high pressure have been determined by a combination of simulated annealing and energy minimization. The mechanism of the transformation, which may be general for other hydrous layered materials, involves a shift of the 1: 1 layers with respect to each other by the vector [1/6, 1/6, 0] and is accompanied by the formation of new hydrogen bonds. C1 Carnegie Inst Sci, Geophys Lab, Washington, DC 20015 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Purdue Univ, Birck Nanotechnol Ctr, W Lafayette, IN 47907 USA. RP Dera, P (reprint author), Carnegie Inst Sci, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. EM pdera@gl.ciw.edu RI Dera, Przemyslaw/F-6483-2013; Johnston, Cliff/B-2215-2009 OI Johnston, Cliff/0000-0002-8462-9724 NR 45 TC 29 Z9 30 U1 0 U2 7 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD OCT PY 2003 VL 88 IS 10 BP 1428 EP 1435 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 731PK UT WOS:000185895500007 ER PT J AU Ross, NL Gibbs, GV Rosso, KM AF Ross, NL Gibbs, GV Rosso, KM TI Potential docking sites and positions of hydrogen in high-pressure silicates SO AMERICAN MINERALOGIST LA English DT Article ID NOMINALLY ANHYDROUS MINERALS; X-RAY-DIFFRACTION; ELECTRON LOCALIZATION FUNCTION; SINGLE-CRYSTAL; AB-INITIO; WADSLEYITE BETA-MG2SIO4; MOLECULAR-GEOMETRY; TRANSITION ZONE; EARTHS MANTLE; GAMMA-PHASE AB A method based on an analysis of the Laplacian of the electron density distribution is used to locate positions of nonbonding electron-pairs and favorable docking sites for hydrogen in high-pressure silicates, including stishovite, akimotoite, wadsleyite, ringwoodite, MgSiO3, and CaSiO3 perovskite. In stishovite, model hydrogen positions (h) are located off the shared O...O edge of the octahedra with the Oh vector oriented perpendicular to [001]. In akimotoite, two model positions for hydrogen are found, one along an edge of the MgO6 octahedron with an Oh vector aligned close to [00 1] and the other within the face of the MgO6 octahedra, with Oh vectors oriented perpendicular to [001]. Geometric and electrostatic considerations suggest that both of these sites would require vacant Mg sites. In wadsleyite, potential sites for protonation exist for all 0 atoms. Hydrogen bonded to 01 resides in a cage-like site with the Oh dipole oriented parallel to [001]. Two symmetrically equivalent sites for hydrogen exist at 02 in a second cage-like structure with Oh vectors aligned approximately along [100]. The calculations also identify potential sites for hydrogen at 03 and 04, but suggest that these could only be occupied by hydrogen if vacancies exist at adjacent Mg sites. Model hydrogen positions in ringwoodite are predicted along O...O edges of the MgO6 octahedron, and, if occupied, would require vacancies at adjacent Mg sites. MgSiO3 perovskite is distinguished by having only one potential site for hydrogen. The Oh vector lies within the (I 10) plane and geometric and electrostatic considerations suggest that a vacancy is required at the Mg site if this site is protonated. No localized sites for hydrogen are found in CaSiO3 perovskite. We suggest that non-bonded electron pairs associated with oxide anions involved in octahedral frameworks with tilt angles of less than 180degrees provide more favorable docking sites for protons than those involved in wider angles. The results from the electron density calculations show very good agreement with available crystallographic and spectroscopic data and demonstrate that the strategy used in this study can be useful in locating protons in Earth materials. C1 Virginia Tech, Dept Geol Sci, Blacksburg, VA 24061 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Ross, NL (reprint author), Virginia Tech, Dept Geol Sci, Blacksburg, VA 24061 USA. NR 49 TC 27 Z9 27 U1 1 U2 5 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD OCT PY 2003 VL 88 IS 10 BP 1452 EP 1459 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 731PK UT WOS:000185895500010 ER PT J AU Putirka, KD Mikaelian, H Ryerson, F Shaw, H AF Putirka, KD Mikaelian, H Ryerson, F Shaw, H TI New clinopyroxene-liquid thermobarometers for maric, evolved, and volatile-bearing lava compositions, with applications to lavas from Tibet and the Snake River Plain, Idaho SO AMERICAN MINERALOGIST LA English DT Article ID MEDICINE LAKE VOLCANO; OCEAN ISLAND BASALTS; HIGH-ALUMINA BASALTS; LOW-CA PYROXENE; EXPERIMENTAL CONSTRAINTS; TECTONIC IMPLICATIONS; NORTHERN CALIFORNIA; MELTING EXPERIMENTS; MAGMATIC PROCESSES; MANTLE PERIDOTITE AB Our ability to calculate the depths and temperatures at which magmas partially crystallize can prove crucial as petrologists test hypotheses of magma transport and evolution. Yet whereas numerous magma transport arguments involve hydrous and SiO2-rich volcanic products, current clinopyroxene-liquid thermobarometers have been calibrated only from basaltic liquid compositions. To remedy this deficiency, new thermobarometers have been calibrated using new experiments that include hydrated (water-undersaturated) and SiO2-rich liquids ranging to 71.3 wt% SiO2. with prior models, the new calibrations are based on jadeite crystallization and jadeite-diopside + hedenbergite exchange equilibria: p(kbar) = -88.3 +2.82 x 10(-3) T(K) ln[[JD(cpx)]/[(NaAlliq)-Al-liq(Si-liq)(2)]] + 2.19 x 10(-2) T(K) - 25.1 ln[(CaSiliq)-Si-liq] + 7.03 [Mg' (liq)] + 12.4 ln [Ca-liq] 10(4)/T(K) = 4.60 - 4.37 x 10(-1) ln[[Jd(cpx)Ca(liq)Fm(liq)]/[DiHd(cpx)Na(liq)Al(liq)]] - 6.54 x 10(-1) ln[Mg'(liq)] - 3.26 x 10(-1) ln[Na-liq] - 6.32 x 10(-3) [P(kbar)] - 0.92 ln[Si-liq] + 2.74 x 10(-1) ln[Jd(cdx)] Here, T is in Kelvins and P is in kbar. Jd(cpx) is the mole fraction of jadeite in clinopyroxene, where pyroxene cations are calculated on the basis of 6 0 atoms, and Jd is the lesser of Na or Al-VI; remaining Al is used to form CaTs. DiHd(cpx) is the mole fraction of diopside + hedenbergite in clinopyroxene, calculated as the fraction of Ca remaining after forming CaTs (= Al-VI - Jd), CaTiAl2O6 [= (Al-VI - CaTs)/2], and CaCr2SiO6 (=Cr/2). Terms such as Al-liq refer to the cation fraction of AlO1.5 in the liquid, Fm-liq is the sum FeOliq + MgOliq, and Mg'(liq) is the cation fraction ratio MgOliq/(MgOliq + FeOliq). Errors are similar to earlier models that utilize basalt compositions only. For the barometer, R-2 = 0.97 and the standard error of estimate (SEE) is 1.7 kbar for the regression data; for the thermometer R-2 = 0.96 and the SEE is 33 K. The models are applied to Neogene lavas from the Tibetan Plateau, and Neogene-Quternary lavas from the eastern Snake River Plain (SRP), Idaho. Crystallization depths for Tibet cluster at the middle/lower crust boundary. Magma-crust density relationships suggest that the middle crust may act as a level of neutral buoyancy. In the SRP, however, magmas appear to bypass several possible density traps. We suggest that fracture properties, such as dike size and aspect ratio, control magma transport in the SRR. C1 Calif State Univ Fresno, Dept Earth & Environm Sci, Fresno, CA 93720 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94566 USA. RP Putirka, KD (reprint author), Calif State Univ Fresno, Dept Earth & Environm Sci, 2345 E San Ramon Ave,MS-MH24, Fresno, CA 93720 USA. EM kputirka@csufresno.edu RI Shaw, Henry/B-6445-2012 OI Shaw, Henry/0000-0003-0681-5430 NR 92 TC 206 Z9 225 U1 1 U2 22 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD OCT PY 2003 VL 88 IS 10 BP 1542 EP 1554 PG 13 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 731PK UT WOS:000185895500018 ER PT J AU Fayek, M Utsunomiya, S Ewing, RC Riciputi, LR Jensen, KA AF Fayek, M Utsunomiya, S Ewing, RC Riciputi, LR Jensen, KA TI Oxygen isotopic composition of nano-scale uraninite at the Oklo-Okelobondo natural fission reactors, Gabon SO AMERICAN MINERALOGIST LA English DT Article ID CIGAR LAKE DEPOSIT; FRANCEVILLE BASIN; ATHABASCA BASIN; MINERALS; SASKATCHEWAN; SYSTEM; PHASES; AGES AB High spatial resolution (10-30 mum), in situ oxygen isotopic analyses by secondary ion mass spectrometry (SIMS), coupled with high-resolution transmission electron microscopy (HRTEM), were used to show that uraninite from the Oklo-Okelobondo natural fission reactors that occur in near surface environments, have low delta O-18 values and nanotextures that are consistent with interaction with ground water. These low delta(18)O values (-14.4 to -8.5parts per thousand) suggest that the minerals exchanged with meteoric groundwater. In contrast, reactor zones that occur at depth have largely retained their original O isotopic composition (-10.2 to -5.6parts per thousand) and uraninites are well-crystallized and essentially defect-free. These observations clearly demonstrate that by combining both HRTEM and in situ O isotopic analyses by SIMS, it is possible to characterize the nano-scale porosity and post-depositional alteration of U-bearing phases. C1 Univ Tennessee, Knoxville, TN 37996 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Natl Inst Occupat Hlth, DK-2100 Copenhagen, Denmark. RP Fayek, M (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 28 TC 8 Z9 8 U1 3 U2 6 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD OCT PY 2003 VL 88 IS 10 BP 1583 EP 1590 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 731PK UT WOS:000185895500022 ER PT J AU Krueger, BJ Grassian, VH Iedema, MJ Cowin, JP Laskin, A AF Krueger, BJ Grassian, VH Iedema, MJ Cowin, JP Laskin, A TI Probing heterogeneous chemistry of individual atmospheric particles using scanning electron microscopy and energy-dispersive X-ray analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID SEA-SALT PARTICLES; ATOMIC-FORCE MICROSCOPY; MARINE BOUNDARY-LAYER; GASEOUS NITRIC-ACID; AEROSOL-PARTICLES; KNUDSEN CELL; NORTH-SEA; CHEMICAL-CHARACTERIZATION; AIR MASSES; NITRATE AB In this paper, we demonstrate the utility of single-particle analysis to investigate the chemistry of isolated, individual particles of atmospheric relevance such as NaCl, sea salt, CaCO3, and SiO2. A variety of state-of-the-art scanning electron microscopy techniques, including environmental scanning electron microscopy and computer-controlled scanning electron microscopy/energy-dispersive X-ray analysis, were utilized for monitoring and quantifying phase transitions of individual particles, morphology, and compositional changes of individual particles as they react with nitric acid. Clear differences in reaction mechanisms were observed between SiO2, CaCO3, NaCl, and sea salt particles. SiO2 particles exposed to HNO3 showed no change, indicating that the reaction of SiO2 particles is limited to the particle surface and would not involve bulk atoms in its reactivity. Calcium carbonate was seen to convert to aqueous calcium nitrate droplets while sodium chloride formed microcrystallites of sodium nitrate on top of the particle. Sea salt particles showed morphology changes that could be described as a combination of these as both spherical droplets and microcrystallites were observed. This is consistent with the multicomponent composition of sea salt. Further differences were found in the reaction rates for sea salt and sodium chloride with nitric acid. Sea salt yielded a significant increase in reactivity when compared to the NaCl particles under similar conditions. The reaction of nitric acid with calcium carbonate was found to be strongly enhanced at higher relative humidity. C1 Univ Iowa, Dept Chem, Iowa City, IA 52242 USA. Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Grassian, VH (reprint author), Univ Iowa, Dept Chem, Iowa City, IA 52242 USA. RI Laskin, Alexander/I-2574-2012 OI Laskin, Alexander/0000-0002-7836-8417 NR 60 TC 80 Z9 81 U1 2 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 2003 VL 75 IS 19 BP 5170 EP 5179 DI 10.1021/ac034455t PG 10 WC Chemistry, Analytical SC Chemistry GA 728LB UT WOS:000185717700034 ER PT J AU Anderson, RT Vrionis, HA Ortiz-Bernad, I Resch, CT Long, PE Dayvault, R Karp, K Marutzky, S Metzler, DR Peacock, A White, DC Lowe, M Lovley, DR AF Anderson, RT Vrionis, HA Ortiz-Bernad, I Resch, CT Long, PE Dayvault, R Karp, K Marutzky, S Metzler, DR Peacock, A White, DC Lowe, M Lovley, DR TI Stimulating the in situ activity of Geobacter species to remove uranium from the groundwater of a uranium-contaminated aquifer SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; DISSIMILATORY METAL REDUCTION; MICROBIAL-POPULATIONS; IRON REDUCTION; FE(III) OXIDE; FERRIC IRON; SEDIMENTS; BIOREMEDIATION; ENVIRONMENTS; INHIBITION AB The potential for removing uranium from contaminated groundwater by stimulating the in situ activity of dissimilatory metal-reducing microorganisms was evaluated in a uranium-contaminated aquifer located in Rifle, Colo. Acetate (1 to 3 mM) was injected into the subsurface over a 3-month period via an injection gallery composed of 20 injection wells, which was installed upgradient from a series of 15 monitoring wells. U(VI) concentrations decreased in as little as 9 days after acetate injection was initiated, and within 50 days uranium had declined below the prescribed treatment level of 0.18 muM in some of the monitoring wells. Analysis of 16S ribosomal DNA (rDNA) sequences and phospholipid fatty acid profiles demonstrated that the initial loss of uranium from the groundwater was associated with an enrichment of Geobacter species in the treatment zone. Fe(II) in the groundwater also increased during this period, suggesting that U(VI) reduction was coincident with Fe(III) reduction. As the acetate injection continued over 50 days there was a loss of sulfate from the groundwater and an accumulation of sulfide and the composition of the microbial community changed. Organisms with 16S rDNA sequences most closely related to those of sulfate reducers became predominant, and Geobacter species became a minor component of the community. This apparent switch from Fe(III) reduction to sulfate reduction as the terminal electron accepting process for the oxidation of the injected acetate was associated with an increase in uranium concentration in the groundwater. These results demonstrate that in situ bioremediation of uranium-contaminated groundwater is feasible but suggest that the strategy should be optimized to better maintain long-term activity of Geobacter species. C1 Univ Massachusetts, Dept Microbiol, Morrill Sci Ctr IVN, Amherst, MA 01003 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. SM Stoller Corp, Lafayette, CO 80026 USA. MFG Inc, Boulder, CO 80301 USA. US DOE, Grand Junction, CO 81503 USA. Univ Tennessee, Ctr Biomarker Anal, Knoxville, TN 37932 USA. Loyola Coll, Dept Phys, Baltimore, MD 21210 USA. RP Anderson, RT (reprint author), Univ Massachusetts, Dept Microbiol, Morrill Sci Ctr IVN, Amherst, MA 01003 USA. RI Long, Philip/F-5728-2013 OI Long, Philip/0000-0003-4152-5682 NR 45 TC 569 Z9 591 U1 14 U2 183 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 OCT PY 2003 VL 69 IS 10 BP 5884 EP 5891 DI 10.1128/AEM.69.10.5884-5891.2003 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 731JV UT WOS:000185881300020 PM 14532040 ER PT J AU Eschenfeldt, WH Zhang, YY Samaha, H Stols, L Eirich, LD Wilson, CR Donnelly, MI AF Eschenfeldt, WH Zhang, YY Samaha, H Stols, L Eirich, LD Wilson, CR Donnelly, MI TI Transformation of fatty acids catalyzed by cytochrome P450 monooxygenase enzymes of Candida tropicalis SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID STRAIGHT CHAIN ACIDS; ASSOCIATION EQUILIBRIA; MONOCARBOXYLIC ACIDS; ALKALI SALTS; N-ALKANE; MALTOSA; CODON; GENE; IDENTIFICATION; FAMILY AB Candida tropicalis ATCC 20336 can grow on fatty acids or alkanes as its sole source of carbon and energy, but strains blocked in beta-oxidation convert these substrates to long-chain alpha,omega-dicarboxylic acids (diacids), compounds of potential commercial value (Picataggio et al., Biotechnology 10:894-898, 1992). The initial step in the formation of these diacids, which is thought to be rate limiting, is omega-hydroxylation by a cytochrome P450 (CYP) monooxygenase. C tropicalis ATCC 20336 contains a family of CYP genes, and when ATCC 20336 or its derivatives are exposed to oleic acid (C-18:1), two cytochrome P450s, CYP52A13 and CYP52A17, are consistently strongly induced (Craft et al., this issue). To determine the relative activity of each of these enzymes and their contribution to diacid formation, both cytochrome P450s were expressed separately in insect cells in conjunction with the C. tropicalis cytochrome P450 reductase (NCP). Microsomes prepared from these cells were analyzed for their ability to oxidize fatty acids. CYP52A13 preferentially oxidized oleic acid and other unsaturated acids to omega-hydroxy acids. CYP52A17 also oxidized oleic acid efficiently but converted shorter, saturated fatty acids such as myristic acid (C-14:0) much more effectively. Both enzymes, in particular CYP52A17, also oxidized w-hydroxy fatty acids, ultimately generating the alpha,omega-diacid. Consideration of these different specificities and selectivities will help determine which enzymes to amplify in strains blocked for beta-oxidation to enhance the production of dicarboxylic acids. The activity spectrum also identified other potential oxidation targets for commercial development. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Cognis Corp, Biotechnol Grp, Cincinnati, OH 45232 USA. RP Donnelly, MI (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 202,Rm BE111,9700 S Cass Ave, Argonne, IL 60439 USA. NR 27 TC 45 Z9 46 U1 2 U2 18 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 OCT PY 2003 VL 69 IS 10 BP 5992 EP 5999 DI 10.1128/AEM.69.10.5992-5999.2003 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 731JV UT WOS:000185881300034 PM 14532054 ER PT J AU Liu, XD Bagwell, CE Wu, LY Devol, AH Zhou, JH AF Liu, XD Bagwell, CE Wu, LY Devol, AH Zhou, JH TI Molecular diversity of sulfate-reducing bacteria from two different continental margin habitats SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID DISSIMILATORY SULFITE REDUCTASE; MARINE ORGANIC-MATTER; SPARTINA-ALTERNIFLORA; CARBON OXIDATION; SHELF SEDIMENTS; SEASONAL-CHANGES; RIBOSOMAL-RNA; GENES; COMMUNITIES; NITROGEN AB This study examined the natural diversity and distributions of sulfate-reducing bacteria along a natural carbon gradient extending down the shelf-slope transition zone of the eastern Pacific continental margin. Dissimilatory (bi)sulfite reductase gene sequences (dsrAB) were PCR amplified and cloned from five different sampling sites, each at a discrete depth, from two different margin systems, one off the Pacific coast of Mexico and another off the coast of Washington State. A total of 1,762 clones were recovered and evaluated by restriction fragment length polymorphism (RFLP) analysis. The majority of the gene sequences recovered showed site and depth restricted distributions; however, a limited number of gene sequences were widely distributed within and between the margin systems. Cluster analysis identified 175 unique RFLP patterns, and nucleotide sequences were determined for corresponding clones. Several different continental margin DsrA sequences clustered with those from formally characterized taxa belonging to the delta subdivision of the class Proteobacteria (Desulfobulbus propionicus, Desulfosarcina variabilis) and the Bacillus-Clostridium (Desulfotomaculum putei) divisions, although the majority of the recovered sequences were phylogenetically divergent relative to all of the other DsrA sequences available for comparison. This study revealed extensive new genetic diversity among sulfate-reducing bacteria in continental margin sedimentary habitats, which appears to be tightly coupled to slope depth, specifically carbon bioavailability. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Hunan Agr Univ, Dept Plant Pathol, Changsha, Hunan, Peoples R China. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. RP Zhou, JH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Bldg 1505 MS 6038,Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 57 TC 36 Z9 38 U1 1 U2 8 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 OCT PY 2003 VL 69 IS 10 BP 6073 EP 6081 DI 10.1128/AEM.69.10.6073-6081.2003 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 731JV UT WOS:000185881300044 PM 14532064 ER PT J AU Rushford, MC Britten, JA Dixit, SN Hoaglan, CR Aasen, MD Summers, LJ AF Rushford, MC Britten, JA Dixit, SN Hoaglan, CR Aasen, MD Summers, LJ TI Wet-etch figuring for precision optical contouring SO APPLIED OPTICS LA English DT Article ID DRYING PROCESS; MARANGONI; MRF AB Wet-etch figuring utilizes free surface flows driven by surface tension gradients (the Marangoni effect) to confine and stabilize the size and shape of an etchant droplet attached to the underside of a glass surface. This droplet, or wetted zone, is translated on the surface, etching where it contacts and leaving behind no residue, to facilitate an etching-based small-tool figuring process that is free of mechanical and thermal stresses. The optic needs no backing plate, and its back side is free for inspection by optical means. When transmissive optics is figured, the optical thickness between the front and the rear surfaces of the optic is measured interferometrically and used in real time to control the local dwell time of the etchant zone. This truly closed-loop figuring process is robust, environmentally insensitive, and fully automated. It is particularly suited for figuring patterns such as phase plates, corrective elements, and optical flats on very thin (much less than1-mm) substrates that are difficult to figure with traditional abrasive polishing methods. (C) 2003 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rushford, MC (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM britten1@llnl.gov NR 24 TC 6 Z9 8 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD OCT 1 PY 2003 VL 42 IS 28 BP 5706 EP 5713 DI 10.1364/AO.42.005706 PG 8 WC Optics SC Optics GA 726EB UT WOS:000185584600012 PM 14528933 ER PT J AU Bajt, SA Chapman, HN Nguyen, N Alameda, J Robinson, JC Malinowski, M Gullikson, E Aquila, A Tarrio, C Grantham, S AF Bajt, SA Chapman, HN Nguyen, N Alameda, J Robinson, JC Malinowski, M Gullikson, E Aquila, A Tarrio, C Grantham, S TI Design and performance of capping layers for extreme-ultraviolet multilayer mirrors SO APPLIED OPTICS LA English DT Article ID ENGINEERING TEST STAND; ENVIRONMENTAL DATA; MO/SI-MULTILAYERS; LITHOGRAPHY; RADIATION; OPTICS; CONTAMINATION; REFLECTANCE; RESOLUTION; COATINGS AB Multilayer lifetime has emerged as one of the major issues for the commercialization of extreme-ultraviolet lithography (EUVL). We describe the performance of an oxidation-resistant capping layer of Ru atop multilayers that results in a reflectivity above 69% at 13.2 nm, which is suitable for EUVL projection optics and has been tested with accelerated electron-beam and extreme-ultraviolet (ELTV) light in a water-vapor environment. Based on accelerated exposure results, we calculated multilayer lifetimes for all reflective mirrors in a typical commercial EUVL tool and concluded that Ru-capped multilayers have similar to40X longer lifetimes than Si-capped multilayers, which translates to 3 months to many years, depending on the mirror dose. (C) 2003 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Sandia Natl Labs, Livermore, CA 94550 USA. Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. NIST, Gaithersburg, MD 20899 USA. RP Bajt, SA (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. EM bajt@llnl.gov RI Chapman, Henry/G-2153-2010; Bajt, Sasa/G-2228-2010 OI Chapman, Henry/0000-0002-4655-1743; NR 22 TC 59 Z9 61 U1 2 U2 14 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 OCT 1 PY 2003 VL 42 IS 28 BP 5750 EP 5758 DI 10.1364/AO.42.005750 PG 9 WC Optics SC Optics GA 726EB UT WOS:000185584600019 PM 14528939 ER PT J AU Wilcox, BP Chrysostom, ETH McIlroy, A Daily, JW Kennedy, IM AF Wilcox, BP Chrysostom, ETH McIlroy, A Daily, JW Kennedy, IM TI Measurement of CrO in flames by cavity ringdown spectroscopy SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID ROTATIONAL ANALYSIS; CHROMIUM; TRANSITION; LASER; INCINERATION; SPECTROMETER; EMISSIONS; OXIDES; GAS AB CrO is an important intermediate in the high temperature oxidation chemistry of chromium containing species. This work reports the first detection of CrO in a flame. The B(5)Pi-X(5)Pi electronic transition was probed by cavity ringdown spectroscopy (CRDS) in a lean (phi = 0.38), lowpressure, flat, laminar hydrogen-oxygen-argon flame seeded with Cr(CO)(6). The previous B(5)Pi-X(5)Pi CrO spectrum of Hocking et al. (605.0 nm-606.5 nm) is extended from the band head located at 605.6 nm to 614.4 nm. The temperature profiles of the doped and undoped flames were obtained from measurements of OH laser-induced fluorescence. Seeding the flame with Cr(CO)6 increased the flame temperature by approximately 150 K. The concentration profile of CrO was measured as a function of height above the burner. CrO absorption signals were converted to concentration using the measured temperature profile and absorption cross-section calculated from lifetimes by Hedgecock et al. A lower limit peak CrO concentration of 1.6 ppb was found in the flame. Some uncertainty in the cross-section remains. Comparisons to calculations using STANJAN indicate that CrO is present in flames at super equilibrium concentrations. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. RP McIlroy, A (reprint author), Sandia Natl Labs, MS 9051, Livermore, CA 94551 USA. NR 33 TC 2 Z9 2 U1 0 U2 9 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD OCT PY 2003 VL 77 IS 5 BP 535 EP 540 DI 10.1007/s00340-003-1275-7 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA 743HN UT WOS:000186566500011 ER PT J AU Silver, GL AF Silver, GL TI Work and disproportionation for aqueous plutonium SO APPLIED RADIATION AND ISOTOPES LA English DT Article DE plutonium; disproportionation; balanced equations; work; free energy ID EQUATIONS; INTEGRALS AB The relation of two plutonium work integrals has recently been illustrated. One of the integrals applies to the work of disproportionation of tetravalent plutonium in 1 M acid and the other to the work of oxidation of plutonium from the trivalent to a higher oxidation state. This paper generalizes the disproportionation work integral so that it can be applied to tetravalent plutonium at any acid concentration. An equation is provided that can be used to verify work estimations obtained by integration. It applies to oxidation and disproportionation processes and it is easy to use. Published by Elsevier Ltd. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Silver, GL (reprint author), Los Alamos Natl Lab, MS E500,POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 12 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD OCT PY 2003 VL 59 IS 4 BP 217 EP 220 DI 10.1016/S0969-8043(03)00171-4 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 732JY UT WOS:000185941300001 PM 14522227 ER PT J AU McCarthy, JF Burrus, LW Tolbert, VR AF McCarthy, JF Burrus, LW Tolbert, VR TI Bioaccumulation of benzo(a)pyrene from sediment by fathead minnows: Effects of organic content, resuspension and metabolism SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; FUNCTION OXIDASE SYSTEM; BLUEGILL SUNFISH; LEPOMIS-MACROCHIRUS; RAINBOW-TROUT; ACCUMULATION; TEMPERATURE; INDUCTION; BEHAVIOR; SORPTION AB The accumulation of C-14-benzo(a)pyrene (BaP) sorbed to sediment was examined in fathead minnows (Pimephales promelas) to compare uptake from sediment with a high organic carbon (OC) content (7.7%), to that with a low OC content (2%). Ingestion of sediments was quantified by co-labeling the sediment with (141)Cerium, which was not assimilated by the fish. Results of this study indicated that (1) significantly greater quantities of BaP were dissolved in water over low-OC sediment, compared to water over high-OC sediment, (2) fish disturbed the sediment and increased the concentration of BaP in centrifuged (particle-free) water, (3) fish ingested significantly more of the low-OC sediment than high-OC sediment, perhaps in response to the lower food quality of the low-OC sediment, and (4) uptake of BaP from sediment ingestion contributed <3% of the total flux of BaP into the fish. Primarily as a result of the greater concentration of BaP in water, fish from the low-OC exposures had significantly higher rates of BaP accumulation. However, after 48 h the body burdens in these fish declined by 50%, likely due to the induction of MFO enzymes in response to accumulation of BaP. A smaller effect was apparent in the fish from the high-OC exposures, consistent with the lower dose of BaP they experienced. These results illustrate the complex, and sometime counter-intuitive, interactions that affect the uptake and bioaccumulation of sediment-associated contaminants. C1 Univ Tennessee, Dept Geol Sci, Knoxville, TN 37996 USA. San Francisco State Univ, Dept Dev Biol, San Francisco, CA 94132 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP McCarthy, JF (reprint author), Univ Tennessee, Dept Geol Sci, 306 Geol Bldg, Knoxville, TN 37996 USA. NR 19 TC 10 Z9 10 U1 0 U2 14 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD OCT PY 2003 VL 45 IS 3 BP 364 EP 370 DI 10.1007/s00244-003-2148-0 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 722HY UT WOS:000185370400011 PM 14674590 ER PT J AU Kintner-Meyer, M Goldman, C Sezgen, O Pratt, D AF Kintner-Meyer, M Goldman, C Sezgen, O Pratt, D TI Dividends with demand response SO ASHRAE JOURNAL LA English DT Article AB A new wave of demand response (DR) programs offers commercial facilities the opportunity to earn money by managing electrical loads in response to market prices. The DR programs are offered by independent system operators (ISOs), which are entities that operate transmission grids, preserve system reliability, and operate spot market auctions where buyers and sellers can meet to complete their obligations. Programs are designed to integrate load curtailments directly into system operations. ISOs typically pay participants amounts equivalent to what generators are paid for equivalent services. C1 Pacific NW Natl Lab, Richland, WA USA. Lawrence Berkeley Lab, Elect Markets & Policy Grp, Berkeley, CA USA. Neenan Assoc, Implement Serv, Syracuse, NY USA. RP Kintner-Meyer, M (reprint author), Pacific NW Natl Lab, Richland, WA USA. NR 3 TC 1 Z9 1 U1 0 U2 1 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 OCT PY 2003 VL 45 IS 10 BP 37 EP + PG 7 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 731JM UT WOS:000185880600012 ER PT J AU Dieckmann, J Roth, KW Brodrick, J AF Dieckmann, J Roth, KW Brodrick, J TI Small centrifugal compressors SO ASHRAE JOURNAL LA English DT Article C1 TIAX, HVAC & Refrigerat Technol Sector, Cambridge, MA USA. US DOE, Bldg Technol Program, Washington, DC USA. RP Dieckmann, J (reprint author), TIAX, HVAC & Refrigerat Technol Sector, Cambridge, MA USA. NR 4 TC 0 Z9 0 U1 1 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 OCT PY 2003 VL 45 IS 10 BP 67 EP 67 PG 1 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 731JM UT WOS:000185880600017 ER PT J AU Smith, JA Tucker, DL Allam, SS Rodgers, CT AF Smith, JA Tucker, DL Allam, SS Rodgers, CT TI Local u ' g ' r ' i ' z ' standard stars in the Chandra Deep Field South SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; standards; stars : fundamental parameters ID DIGITAL SKY SURVEY; ESO IMAGING SURVEY; SYSTEM; CATALOG AB Because several observing programs are under way in various spectral regimes to explore the Chandra Deep Field South (CDF-S), the value of local photometric standards is obvious. As part of an NOAO Survey Program to establish u'g'r'i'z' standard stars in the southern hemisphere, we have observed the central region of the CDF-S to create local standards for use by other investigators using these filters. As a courtesy, we present the CDF-S standards to the public now, although the main program will not finish until mid-2005. C1 Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Smith, JA (reprint author), Los Alamos Natl Lab, Mail Stop D-448,POB 1663, Los Alamos, NM 87545 USA. OI Smith, J. Allyn/0000-0002-6261-4601; Tucker, Douglas/0000-0001-7211-5729 NR 20 TC 9 Z9 9 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 2037 EP 2047 DI 10.1086/378052 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200032 ER PT J AU Abazajian, K Adelman-McCarthy, JK Agueros, MA Allam, SS Anderson, SF Annis, J Bahcall, NA Baldry, IK Bastian, S Berlind, A Bernardi, M Blanton, MR Blythe, N Bochanski, JJ Boroski, WN Brewington, H Briggs, JW Brinkmann, J Brunner, RJ Budavari, T Carey, LN Carr, MA Castander, FJ Chiu, K Collinge, MJ Connolly, AJ Covey, KR Csabai, I Dalcanton, JJ Dodelson, S Doi, M Dong, F Eisenstein, DJ Evans, ML Fan, XH Feldman, PD Finkbeiner, DP Friedman, SD Frieman, JA Fukugita, M Gal, RR Gillespie, B Glazebrook, K Gonzalez, CF Gray, J Grebel, EK Grodnicki, L Gunn, JE Gurbani, VK Hall, PB Hao, L Harbeck, D Harris, FH Harris, HC Harvanek, M Hawley, SL Heckman, TM Helmboldt, JF Hendry, JS Hennessy, GS Hindsley, RB Hogg, DW Holmgren, DJ Holtzman, JA Homer, L Hui, L Ichikawa, SI Ichikawa, T Inkmann, JP Ivezic, Z Jester, S Johnston, DE Jordan, B Jordan, WP Jorgensen, AM Juric, M Kauffmann, G Kent, SM Kleinman, SJ Knapp, GR Kniazev, AY Kron, RG Krzesinski, J Kunszt, PZ Kuropatkin, N Lamb, DQ Lampeitl, H Laubscher, BE Lee, BC Leger, RF Li, N Lidz, A Lin, H Loh, YS Long, DC Loveday, J Lupton, RH Malik, T Margon, B McGehee, PM McKay, TA Meiksin, A Miknaitis, GA Moorthy, BK Munn, JA Murphy, T Nakajima, R Narayanan, VK Nash, T Neilsen, EH Newberg, HJ Newman, PR Nichol, RC Nicinski, T Nieto-Santisteban, M Nitta, A Odenkirchen, M Okamura, S Ostriker, JP Owen, R Padmanabhan, N Peoples, J Pier, JR Pindor, B Pope, AC Quinn, TR Rafikov, RR Raymond, SN Richards, GT Richmond, MW Rix, HW Rockosi, CM Schaye, J Schlegel, DJ Schneider, DP Schroeder, J Scranton, R Sekiguchi, M Seljak, U Sergey, G Sesar, B Sheldon, E Shimasaku, K Siegmund, WA Silvestri, NM Sinisgalli, AJ Sirko, E Smith, JA Smolcic, V Snedden, SA Stebbins, A Steinhardt, C Stinson, G Stoughton, C Strateva, IV Strauss, MA Subbarao, M Szalay, AS Szapudi, I Szkody, P Tasca, L Tegmark, M Thakar, AR Tremonti, C Tucker, DL Uomoto, A Vanden Berk, DE Vandenberg, J Vogeley, MS Voges, W Vogt, NP Walkowicz, LM Weinberg, DH West, AA White, SDM Wilhite, BC Willman, B Xu, YZ Yanny, B Yarger, J Yasuda, N Yip, CW Yocum, DR York, DG Zakamska, NL Zehavi, I Zheng, W Zibetti, S Zucker, DB AF Abazajian, K Adelman-McCarthy, JK Agueros, MA Allam, SS Anderson, SF Annis, J Bahcall, NA Baldry, IK Bastian, S Berlind, A Bernardi, M Blanton, MR Blythe, N Bochanski, JJ Boroski, WN Brewington, H Briggs, JW Brinkmann, J Brunner, RJ Budavari, T Carey, LN Carr, MA Castander, FJ Chiu, K Collinge, MJ Connolly, AJ Covey, KR Csabai, I Dalcanton, JJ Dodelson, S Doi, M Dong, F Eisenstein, DJ Evans, ML Fan, XH Feldman, PD Finkbeiner, DP Friedman, SD Frieman, JA Fukugita, M Gal, RR Gillespie, B Glazebrook, K Gonzalez, CF Gray, J Grebel, EK Grodnicki, L Gunn, JE Gurbani, VK Hall, PB Hao, L Harbeck, D Harris, FH Harris, HC Harvanek, M Hawley, SL Heckman, TM Helmboldt, JF Hendry, JS Hennessy, GS Hindsley, RB Hogg, DW Holmgren, DJ Holtzman, JA Homer, L Hui, L Ichikawa, SI Ichikawa, T Inkmann, JP Ivezic, Z Jester, S Johnston, DE Jordan, B Jordan, WP Jorgensen, AM Juric, M Kauffmann, G Kent, SM Kleinman, SJ Knapp, GR Kniazev, AY Kron, RG Krzesinski, J Kunszt, PZ Kuropatkin, N Lamb, DQ Lampeitl, H Laubscher, BE Lee, BC Leger, RF Li, N Lidz, A Lin, H Loh, YS Long, DC Loveday, J Lupton, RH Malik, T Margon, B McGehee, PM McKay, TA Meiksin, A Miknaitis, GA Moorthy, BK Munn, JA Murphy, T Nakajima, R Narayanan, VK Nash, T Neilsen, EH Newberg, HJ Newman, PR Nichol, RC Nicinski, T Nieto-Santisteban, M Nitta, A Odenkirchen, M Okamura, S Ostriker, JP Owen, R Padmanabhan, N Peoples, J Pier, JR Pindor, B Pope, AC Quinn, TR Rafikov, RR Raymond, SN Richards, GT Richmond, MW Rix, HW Rockosi, CM Schaye, J Schlegel, DJ Schneider, DP Schroeder, J Scranton, R Sekiguchi, M Seljak, U Sergey, G Sesar, B Sheldon, E Shimasaku, K Siegmund, WA Silvestri, NM Sinisgalli, AJ Sirko, E Smith, JA Smolcic, V Snedden, SA Stebbins, A Steinhardt, C Stinson, G Stoughton, C Strateva, IV Strauss, MA Subbarao, M Szalay, AS Szapudi, I Szkody, P Tasca, L Tegmark, M Thakar, AR Tremonti, C Tucker, DL Uomoto, A Vanden Berk, DE Vandenberg, J Vogeley, MS Voges, W Vogt, NP Walkowicz, LM Weinberg, DH West, AA White, SDM Wilhite, BC Willman, B Xu, YZ Yanny, B Yarger, J Yasuda, N Yip, CW Yocum, DR York, DG Zakamska, NL Zehavi, I Zheng, W Zibetti, S Zucker, DB TI The first data release of the Sloan Digital Sky Survey SO ASTRONOMICAL JOURNAL LA English DT Article DE atlases; catalogs; surveys ID SPECTROSCOPIC TARGET SELECTION; GALAXY SAMPLE; SYSTEM AB The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its First Data Release. This consists of 2099 deg(2) of five-band (u, g, r, i, z) imaging data, 186,240 spectra of galaxies, quasars, stars and calibrating blank sky patches selected over 1360 deg(2) of this area, and tables of measured parameters from these data. The imaging data go to a depth of r approximate to 22.6 and are photometrically and astrometrically calibrated to 2% rms and 100 mas rms per coordinate, respectively. The spectra cover the range 3800-9200 Angstrom, with a resolution of 1800-2100. This paper describes the characteristics of the data with emphasis on improvements since the release of commissioning data (the SDSS Early Data Release) and serves as a pointer to extensive published and on-line documentation of the survey. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. NYU, Dept Phys, Ctr Cosmol & Particle Phys, New York, NY 10003 USA. Apache Point Observ, Sunspot, NM 88349 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. CSIC, Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Eotvos Lorand Univ, Dept Phys, H-1518 Budapest, Hungary. Univ Tokyo, Sch Sci, Inst Astron, Tokyo 1810015, Japan. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Tokyo 1810015, Japan. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Microsoft Res, San Francisco, CA 94105 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Lucent Technol, Naperville, IL 60566 USA. Pontificia Univ Catolica Chile, Fac Fis, Dept Astron & Astrofis, Santiago 22, Chile. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. USN Observ, Washington, DC 20392 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Natl Astron Observ, Tokyo 1818588, Japan. Tohoku Univ, Astron Inst, Sendai, Miyagi 9808578, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Max Planck Inst Astrophys, D-85748 Garching, Germany. Akad Pedag Krakowie, Obserwatorium Astron Suhorze, PL-30084 Krakow, Poland. CERN, IT Div, CH-1211 Geneva 23, Switzerland. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Edinburgh, Royal Observ, Astron Inst, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Penn, Dept Phys, Philadelphia, PA 19104 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. Lucent Technol, Lisle, IL 60532 USA. Univ Tokyo, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Univ Zagreb, Dept Phys, HR-10000 Zagreb, Croatia. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Abazajian, K (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Padmanabhan, Nikhil/A-2094-2012; Margon, Bruce/B-5913-2012; Yasuda, Naoki/A-4355-2011; Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; West, Andrew/H-3717-2014; Agueros, Marcel/K-7998-2014; Glazebrook, Karl/N-3488-2015; Helmboldt, Joseph/C-8105-2012; OI Murphy, Tara/0000-0002-2686-438X; Csabai, Istvan/0000-0001-9232-9898; /0000-0002-1891-3794; Hogg, David/0000-0003-2866-9403; Covey, Kevin/0000-0001-6914-7797; Smith, J. Allyn/0000-0002-6261-4601; Baldry, Ivan/0000-0003-0719-9385; Tucker, Douglas/0000-0001-7211-5729; Schaye, Joop/0000-0002-0668-5560; McKay, Timothy/0000-0001-9036-6150; Agueros, Marcel/0000-0001-7077-3664; Glazebrook, Karl/0000-0002-3254-9044; Meiksin, Avery/0000-0002-5451-9057; Kunszt, Peter/0000-0003-0933-4763; PINDOR, BARTOSZ/0000-0003-3240-2437; Holmgren, Donald/0000-0001-6701-7737; Tan, Joshua/0000-0003-3835-8115 NR 22 TC 713 Z9 719 U1 2 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 2081 EP 2086 DI 10.1086/378165 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200035 ER PT J AU Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM AF Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM TI A spectroscopic and photometric survey of stars in the field of L1457: A new distance determination (vol 124, pg 2164,2002) SO ASTRONOMICAL JOURNAL LA English DT Correction C1 Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Andersson, BG (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 2087 EP 2087 DI 10.1086/378167 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200036 ER PT J AU Dougherty, SM Pittard, JM Kasian, L Coker, RF Williams, PM Lloyd, HM AF Dougherty, SM Pittard, JM Kasian, L Coker, RF Williams, PM Lloyd, HM TI Radio emission models of colliding-wind binary systems SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : binaries : general; stars : early-type; stars : individual : WR147; stars : Wolf-Rayet; radio continuum : stars ID EARLY-TYPE STARS; X-RAY-EMISSION; PARTICLE-ACCELERATION; STELLAR WINDS; NONTHERMAL EMISSION; MAGNETIC-FIELD; OBLIQUE SHOCKS; LIGHT CURVES; HOT STARS; WR-147 AB We present calculations of the spatial and spectral distribution of the radio emission from a wide WR + OB colliding-wind binary system based on high-resolution hydrodynamical simulations and solutions to the radiative transfer equation. We account for both thermal and synchrotron radio emission, free-free absorption in both the unshocked stellar wind envelopes and the shocked gas, synchrotron self-absorption, and the Razin effect. To calculate the synchrotron emission several simplifying assumptions are adopted: the relativistic particle energy density is a simple fraction of the thermal particle energy density, in equipartition with the magnetic energy density, and a power-law in energy. We also assume that the magnetic field is tangled such that the resulting emission is isotropic. The applicability of these calculations to modelling radio images and spectra of colliding-wind systems is demonstrated with models of the radio emission from the wide WR + OB binary WR147. Its synchrotron spectrum follows a power-law between 5 and 15 GHz but turns down to below this at lower and higher frequencies. We find that while free-free opacity from the circum-binary stellar winds can potentially account for the low-frequency turnover, models that also include a combination of synchrotron self-absorption and Razin effect are favoured. We argue that the high-frequency turn down is a consequence of inverse-Compton cooling. We present our resulting spectra and intensity distributions, along with simulated MERLIN observations of these intensity distributions. From these we argue that the inclination of the WR147 system to the plane of the sky is low. We summarise by considering extensions of the current model that are important for models of the emission from closer colliding wind binaries, in particular the dramatically varying radio emission of WR 140. C1 Natl Res Council Canada, Herzberg Inst Astrophys, Domin Radio Astrophys Observ, Penticton, BC V2A 6J9, Canada. Univ Leeds, Dept Phys & Astron, Leeds LS2 9JT, W Yorkshire, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Edinburgh, Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. Blade Interact Studios, Manchester M3 4JB, Lancs, England. RP Dougherty, SM (reprint author), Natl Res Council Canada, Herzberg Inst Astrophys, Domin Radio Astrophys Observ, POB 248, Penticton, BC V2A 6J9, Canada. OI Pittard, Julian/0000-0003-2244-5070 NR 50 TC 60 Z9 60 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 409 IS 1 BP 217 EP 233 DI 10.1051/0004-6361:20031048 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721LQ UT WOS:000185318200020 ER PT J AU Bartelmann, M Meneghetti, M Perrotta, F Baccigalupi, C Moscardini, L AF Bartelmann, M Meneghetti, M Perrotta, F Baccigalupi, C Moscardini, L TI Arc statistics in cosmological models with dark energy SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : clusters : general; cosmology : theory; cosmology : dark matter; cosmology : gravitational lensing ID REALISTIC CLUSTER POTENTIALS; GRAVITATIONAL LENSING STATISTICS; BACKGROUND ANISOTROPY DATA; ANGULAR POWER SPECTRUM; RAY-SELECTED CLUSTERS; EXTRAGALACTIC SURVEYS; HIERARCHICAL-MODELS; HALO CONCENTRATIONS; GALAXY FORMATION; MERGER RATES AB We investigate how the probability of the formation of giant arcs in galaxy clusters is expected to change in cosmological models dominated by dark energy with an equation of state p = omegarhoc(2) compared to cosmological-constant or open models. To do so, we use a simple analytic model for arc cross sections based on the Navarro-Frenk-White density profile which we demonstrate reproduces essential features of numerically determined arc cross sections. Since analytic lens models are known to be inadequate for accurate absolute quantifications of arc probabilities, we use them only for studying changes relative to cosmological-constant models. Our main results are (1) the order of magnitude difference between the arc probabilities in low density, spatially flat and open CDM models found numerically is reproduced by our analytic model, and (2) dark-energy cosmologies with omega > -1 increase the arc optical depth by at most a factor of two and are thus unlikely to reconcile arc statistics with spatially flat cosmological models with low matter density. C1 Max Planck Inst Astrophys, D-85741 Garching, Germany. Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. Osserv Astron Padova, I-35122 Padua, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. SISSA, ISAS, I-34014 Trieste, Italy. Dipartimento Astron, I-40127 Bologna, Italy. RP Bartelmann, M (reprint author), Max Planck Inst Astrophys, POB 1317, D-85741 Garching, Germany. RI Bartelmann, Matthias/A-5336-2014; OI Meneghetti, Massimo/0000-0003-1225-7084 NR 60 TC 48 Z9 48 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 409 IS 2 BP 449 EP 457 DI 10.1051/0004-6361:20031158 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 725FW UT WOS:000185534000010 ER PT J AU Atkins, R Benbow, W Berley, D Blaufuss, E Bussons, J Coyne, DG Delay, RS DeYoung, T Dingus, BL Dorfan, DE Ellsworth, RW Falcone, A Fleysher, L Fleysher, R Gisler, G Gonzalez, MM Goodman, JA Haines, TJ Hays, E Hoffman, CM Kelley, LA Laird, RW McCullough, J McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Noyes, D Ryan, JM Samuelson, FW Schneider, M Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Tumer, OT Wang, K Wascko, M Williams, DA Westerhoff, S Wilson, ME Xu, X Yodh, GB AF Atkins, R Benbow, W Berley, D Blaufuss, E Bussons, J Coyne, DG Delay, RS DeYoung, T Dingus, BL Dorfan, DE Ellsworth, RW Falcone, A Fleysher, L Fleysher, R Gisler, G Gonzalez, MM Goodman, JA Haines, TJ Hays, E Hoffman, CM Kelley, LA Laird, RW McCullough, J McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Noyes, D Ryan, JM Samuelson, FW Schneider, M Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Tumer, OT Wang, K Wascko, M Williams, DA Westerhoff, S Wilson, ME Xu, X Yodh, GB TI Observation of TeV gamma rays from the Crab Nebula with Milagro using a new background rejection technique SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; instrumentation : detectors; ISM : individual (Crab Nebula); stars : neutron; supernova remnants ID AIR-SHOWER ARRAY; ASTRONOMY; SEARCH; SPECTRUM; ENERGIES AB The recent advances in TeV gamma-ray astronomy are largely the result of the ability to differentiate between extensive air showers generated by gamma rays and hadronic cosmic rays. Air Cerenkov telescopes have developed and perfected the "imaging '' technique over the past several decades. However, until now no background rejection method has been successfully used in an air shower array to detect a source of TeV gamma rays. We report on a method to differentiate hadronic air showers from electromagnetic air showers in the Milagro gamma-ray observatory, based on the ability to detect the energetic particles in an extensive air shower. The technique is used to detect TeV emission from the Crab Nebula. The flux from the Crab Nebula is estimated to be 2.68 (+/-0.42(stat) +/- 1.4(sys)) x 10(-7) (E/1 TeV)(-2.59) m(-2) s(-1) TeV-1, where the spectral index is assumed to be as given by the HEGRA collaboration. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Calif Irvine, Irvine, CA 92717 USA. George Mason Univ, Fairfax, VA 22030 USA. Univ New Hampshire, Durham, NH 03824 USA. NYU, New York, NY 10003 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Sinnis, G (reprint author), Los Alamos Natl Lab, MS 803, Los Alamos, NM 87545 USA. RI Hays, Elizabeth/D-3257-2012; OI Dingus, Brenda/0000-0001-8451-7450 NR 18 TC 108 Z9 108 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 803 EP 811 DI 10.1086/377498 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800019 ER PT J AU Tournear, D Raffauf, E Bloom, ED Focke, W Giebels, B Godfrey, G Parkinson, PMS Reilly, KT Wood, KS Ray, PS Wolff, MT Bandyopadhyay, RM Lovellette, MN Scargle, JD AF Tournear, D Raffauf, E Bloom, ED Focke, W Giebels, B Godfrey, G Parkinson, PMS Reilly, KT Wood, KS Ray, PS Wolff, MT Bandyopadhyay, RM Lovellette, MN Scargle, JD TI X-ray bursts in neutron star and black hole binaries from Unconventional Stellar Aspect experiment and Rossi X-Ray Timing Explorer data: Detections and upper limits SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : neutron; X-rays : binaries; X-rays : bursts ID RAPID-BURSTER; PROPORTIONAL COUNTER; XTE J1118+480; EVENT-HORIZON; CYGNUS X-2; MASS; FLASHES; TRANSIENTS; QUIESCENCE; SPECTRUM AB Narayan & Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. However, no appropriate observational limit exists in the literature. In this paper we survey 2101.2 ks of data from the Unconventional Stellar Aspect (USA) X-ray timing experiment and 5142 ks of data from the Rossi X-Ray Timing Explorer (RXTE) experiment to obtain a formal constraint of this type. We find that 1122 ks of neutron star data yield a population-averaged mean burst rate of (1.7 +/- 0.4) x 10(-5) bursts s(-1), while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10(-7) bursts s(-1). This is the first published limit of this type for BHCs. Applying the theoretical framework of Narayan & Heyl, we calculate regions of unstable luminosity, where the neutron stars are expected to burst and the BHCs would be expected to burst if they had a surface. In this unstable luminosity region, 464 ks of neutron star data yield an averaged mean burst rate of (4.1 +/- 0.8) x 10(-5) bursts s(-1), and 1512 ks of BHC data yield a 95% confidence level upper limit of 2.0 x 10(-6) bursts s(-1) and a strong limit that BHCs do not burst with a rate similar to the rate of neutron stars in these unstable regions. This gives further evidence that BHCs do not have surfaces unless there is some new physics occurring on their surface. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Tournear, D (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. OI Ray, Paul/0000-0002-5297-5278 NR 57 TC 12 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 1058 EP 1065 DI 10.1086/377431 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800038 ER PT J AU Schmidt, GD Harris, HC Liebert, J Eisenstein, DJ Anderson, SF Brinkmann, J Hall, PB Harvanek, M Hawley, S Kleinman, SJ Knapp, GR Krzesinski, J Lamb, DQ Long, D Munn, JA Neilsen, EH Newman, PR Nitta, A Schlegel, DJ Schneider, DP Silvestri, NM Smith, JA Snedden, SA Szkody, P Berk, DV AF Schmidt, GD Harris, HC Liebert, J Eisenstein, DJ Anderson, SF Brinkmann, J Hall, PB Harvanek, M Hawley, S Kleinman, SJ Knapp, GR Krzesinski, J Lamb, DQ Long, D Munn, JA Neilsen, EH Newman, PR Nitta, A Schlegel, DJ Schneider, DP Silvestri, NM Smith, JA Snedden, SA Szkody, P Berk, DV TI Magnetic white dwarfs from the Sloan Digital Sky Survey: The first data release SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : magnetic fields; white dwarfs ID DOUBLE-DEGENERATE BINARY; HYDROGEN-RICH; RE J0317-853; FIELDS; DISCOVERY; SYSTEM; CARBON; CALIBRATION; EVOLUTION; LINES AB Beyond its goals related to the extragalactic universe, the Sloan Digital Sky Survey (SDSS) is an effective tool for identifying stellar objects with unusual spectral energy distributions. Here we report on the 53 new magnetic white dwarfs discovered during the first two years of the survey, including 38 whose data are made public in the 1500 deg(2) First Data Release. Discoveries span the magnitude range 16.3 less than or equal to g less than or equal to 20.5, and based on the recovery rate for previously known magnetic white dwarfs, the completeness of the SDSS appears to be high for reasonably hot stars with B greater than or similar to 3 MG and g greater than or similar to 15. The new objects nearly double the total number of known magnetic white dwarfs and include examples with polar field strengths B-p > 500 MG, as well as several with exotic atmospheric compositions. The improved sample statistics and uniformity indicate that the distribution of magnetic white dwarfs has a broad peak in the range similar to5-30 MG and a tail extending to nearly 10(9) G. Degenerates with polar fields B-p greater than or similar to 50 MG are consistent with being descendents of magnetic Ap/Bp main-sequence stars, but low- and moderate-field magnetic white dwarfs appear to imply another origin. Yet-undetected magnetic F-type stars with convective envelopes that destroy the ordered underlying field are attractive candidates. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. USN Observ, Flagstaff, AZ 86002 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Apache Point Observ, Sunspot, NM 88349 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Pontificia Univ Catolica Chile, Fac Fis, Dept Astron & Astrofis, Santiago 22, Chile. Akad Pedag Krakowie, Obserwatorium Astron Suhorze, PL-30084 Krakow, Poland. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Penn State Univ, Dept Phys & Astron, Davey Lab 525, University Pk, PA 16802 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. RP Schmidt, GD (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. OI Smith, J. Allyn/0000-0002-6261-4601 NR 44 TC 98 Z9 98 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 1101 EP 1113 DI 10.1086/377476 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800043 ER PT J AU Bahcall, NA McKay, TA Annis, J Kim, RSJ Dong, F Hansen, S Goto, T Gunn, JE Miller, C Nichol, RC Postman, M Schneider, D Schroeder, J Voges, W Brinkmann, J Fukugita, M AF Bahcall, NA McKay, TA Annis, J Kim, RSJ Dong, F Hansen, S Goto, T Gunn, JE Miller, C Nichol, RC Postman, M Schneider, D Schroeder, J Voges, W Brinkmann, J Fukugita, M TI A merged catalog of clusters of galaxies from early Sloan digital sky survey data SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; cosmology : observations; cosmology : theory; galaxies : clusters : general; large-scale structure of universe ID SPECTROSCOPIC TARGET SELECTION; RICH CLUSTERS; REDSHIFT SURVEY; EVOLUTION; UNIVERSE; SAMPLE; COSMOLOGY; ALGORITHM; OMEGA(M); DENSITY AB We present a catalog of 799 clusters of galaxies in the redshift range z(est) = 0.05-0.3 selected from similar to400 deg(2) of early Sloan Digital Sky Survey (SDSS) commissioning data along the celestial equator. The catalog is based on merging two independent selection methods-a color-magnitude red-sequence maxBCG technique (B), and a hybrid matched filter method (H). The BH catalog includes clusters with richness Lambda greater than or equal to 40 (matched filter) and N-gal greater than or equal to 13 (maxBCG), corresponding to typical velocity dispersion of sigma(upsilon) greater than or similar to 400 km s(-1) and mass (within 0.6 h(-1) Mpc radius) greater than or similar to5 x 10(13) h(-1) M.. This threshold is below Abell richness class 0 clusters. The average space density of these clusters is 2 x 10(-5) h(3) Mpc(-3). All NORAS X-ray clusters and 53 of the 58 Abell clusters in the survey region are detected in the catalog; the five additional Abell clusters are detected below the BH catalog cuts. The cluster richness function is determined and found to exhibit a steeply decreasing cluster abundance with increasing richness. We derive observational scaling relations between cluster richness and observed cluster luminosity and cluster velocity dispersion; these scaling relations provide important physical calibrations for the clusters. The catalog can be used for studies of individual clusters, for comparisons with other sources such as X-ray clusters and active galactic nuclei, and, with proper correction for the relevant selection functions, also for statistical analyses of clusters. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Apache Point Observ, Sunspot, NM 88349 USA. Univ Tokyo, Inst Cosm Ray Res, Midori Ku, Tokyo 1888502, Japan. RP Bahcall, NA (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI McKay, Timothy/C-1501-2009; OI McKay, Timothy/0000-0001-9036-6150; Tan, Joshua/0000-0003-3835-8115 NR 59 TC 88 Z9 88 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2003 VL 148 IS 2 BP 243 EP 274 DI 10.1086/377167 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TN UT WOS:000185676300001 ER PT J AU Calvert, JG Lindberg, SE AF Calvert, JG Lindberg, SE TI A modeling study of the mechanism of the halogen-ozone-mercury homogeneous reactions in the troposphere during the polar spring SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE Arctic O-3 depletion in troposphere; Arctic Hg depletion in troposphere; computer simulations BrO-Br-ClO-Cl-O-3 chemistry ID SUNRISE EXPERIMENT 1992; GAS-PHASE REACTION; BR-ATOM CHEMISTRY; BOUNDARY-LAYER; SURFACE OZONE; ATMOSPHERIC CHEMISTRY; ARCTIC TROPOSPHERE; MOLECULAR HALOGENS; RATE COEFFICIENTS; GASEOUS MERCURY AB Computer simulations are described for the homogeneous portion of the chemistry of the ozone and mercury depletion observed in the troposphere during the polar spring. Conditions chosen are similar to those of a clear day (17 March) at the location of Barrow, Alaska. 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 ozone and gaseous atomic mercury depletion are both strong functions of two important variables: (1) the concentrations of Br-2 and BrCl present during the day; and (2) the concentrations of reactive trace gases such as CH2O present in the air mass. The simulated rate of Hg depletion and the expected product distribution are also functions of the size of the rate coefficient for the Hg + BrO reaction (k(17)). The relatively small extent Of O-3 and Hg depletion rates that result from Cl-ClO chemistry and the major effects that result from the Br-BrO chemistry are rationalized in terms of the significant differences in the reaction mechanisms for the two halogens. (C) 2003 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. RI Mason, Robert/A-6829-2011 NR 48 TC 48 Z9 49 U1 0 U2 7 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 OCT PY 2003 VL 37 IS 32 BP 4467 EP 4481 DI 10.1016/j.atmosenv.2003.07.001 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 727QP UT WOS:000185670200001 ER PT J AU Barton, TS Wyrobek, AJ Hills, FS Robaire, B Hales, BF AF Barton, TS Wyrobek, AJ Hills, FS Robaire, B Hales, BF TI Numerical chromosomal abnormalities in rat epididymal spermatozoa following chronic cyclophosphamide exposure SO BIOLOGY OF REPRODUCTION LA English DT Article DE meiosis; sperm; spermatogenesis; testis; toxicology ID IN-SITU HYBRIDIZATION; HUMAN SPERM NUCLEI; MOUSE GERM-CELLS; ADULT MALE-RATS; MULTICOLOR FISH; MEIOTIC RECOMBINATION; GENETIC-DAMAGE; INFERTILE MEN; PROPHASE-I; ANEUPLOIDY AB Chronic, low-dose treatment of male rats with cyclophosphamide, a chemotherapeutic agent, is known to affect progeny outcome adversely in a dose-dependent and time-specific manner, resulting in increased pre- and postimplantation loss as well as malformations. Concern exists regarding the genetic quality of mature gametes exposed to cyclophosphamide during mitosis and meiosis. The goal of the present study was to determine the effect of chronic cyclophosphamide treatment during spermatogenesis on the frequency of numerical chromosomal anomalies in epididymal spermatozoa. Male rats were treated with either saline or cyclophosphamide (6 mg kg(-1) day(-1)) for 6 or 9 wk, and cauda epididymal spermatozoa were collected. The rat sperm Y-4 fluorescence in situ hybridization assay was used to assess the induction of spermatozoal disomy, nullisomy, and diploidy involving chromosomes Y and 4. The overall frequency of numerically abnormal spermatozoa was elevated approximately 2-fold (P < 0.001) after 9 wk of cyclophosphamide treatment. Exposure for 9 wk, but not for 6 wk, significantly increased the frequency of spermatozoa with chromosome 4 disomy (P < 0.02) and nullisomy (P < 0.05), but disomy Y and diploidy were not significantly increased with treatment compared to corresponding controls. Independent of treatment, only 27% of aneuploid spermatozoa presented with morphological abnormalities, but all diploid spermatozoa were approximately twice the size of normal cells. Thus, cyclophosphamide disrupts meiotic events before pachynema during spermatogenesis, emphasizing the potential for adverse progeny outcomes following genotoxic damage. C1 McGill Univ, Dept Pharmacol & Therapeut, Montreal, PQ H3G 1Y6, Canada. McGill Univ, Dept Obstet & Gynecol, Montreal, PQ H3G 1Y6, Canada. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Hales, BF (reprint author), McGill Univ, Dept Pharmacol & Therapeut, 3655 Promenade Sir William Osler, Montreal, PQ H3G 1Y6, Canada. FU NIEHS NIH HHS [Y01-ES-8016, P42 ES04705] NR 57 TC 19 Z9 21 U1 0 U2 1 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD OCT PY 2003 VL 69 IS 4 BP 1150 EP 1157 DI 10.1095/biolreprod.103.016261 PG 8 WC Reproductive Biology SC Reproductive Biology GA 723XQ UT WOS:000185457200007 PM 12773405 ER PT J AU Nalla, RK Kinney, JH Ritchie, RO AF Nalla, RK Kinney, JH Ritchie, RO TI Effect of orientation on the in vitro fracture toughness of dentin: the role of toughening mechanisms SO BIOMATERIALS LA English DT Article DE collagen; fracture toughness; tubules; orientation; toughening mechanisms; dentin ID FATIGUE-CRACK-PROPAGATION; HUMAN CORTICAL BONE; BRITTLE SOLIDS; DIFFUSE DAMAGE; HUMAN-ENAMEL; GROWTH; MICROCRACKING; COMPOSITES; COLLAGEN; CERAMICS AB Toughening mechanisms based on the presence of collagen fibrils have long been proposed for mineralized biological tissues like bone and dentin: however, no direct evidence for their precise role has ever been provided. Furthermore, although the anisotropy of mechanical properties of dentin with respect to orientation has been suggested in the literature, accurate measurements to support the effect of orientation on the fracture toughness of dentin are not available. To address these issues, the in vitro fracture toughness of dentin. extracted from elephant tusk, has been characterized using fatigue-precracked compact-tension specimens tested in Hank's balanced salt solution at ambient temperature, with fracture paths perpendicular and parallel to the tubule orientations (and orientations in between) specifically being evaluated. It was found that the fracture toughness was lower where cracking occurred in the plane of the collagen fibers, as compared to crack paths perpendicular to the fibers. The origins of this effect on the toughness of dentin are discussed primarily in terms of the salient toughening mechanisms active in this material; specifically, the role of crack bridging. both from uncracked ligaments and by individual collagen fibrils, is considered. Estimates for the contributions from each of these mechanisms are provided from theoretical models available in the literature. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 USA. RP Ritchie, RO (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Div Sci Mat, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 FU NIDCR NIH HHS [P01DE09859] NR 40 TC 135 Z9 140 U1 3 U2 34 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD OCT PY 2003 VL 24 IS 22 BP 3955 EP 3968 DI 10.1016/S0142-9612(03)00278-3 PG 14 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 700FD UT WOS:000184101200011 PM 12834591 ER PT J AU Leonhard, K Prausnitz, JM Radke, CJ AF Leonhard, K Prausnitz, JM Radke, CJ TI 3D-lattice Monte Carlo simulations of model proteins. Size effects on folding thermodynamics and kinetics SO BIOPHYSICAL CHEMISTRY LA English DT Article DE lattice simulation; interaction energies; protein folding; solvation; size effects ID LATTICE MODEL; SEQUENCES AB Recently, we devised an energy scale to vary systematically amino-acid residue-solvent interactions for Monte Carlo simulations of lattice-model proteins in water. For 27-mer proteins, the folding behavior varies appreciably with the choice of interaction parameters. We now perform similar simulations with 64-mers to study the size dependence of the optimal energy parameter set for representing realistic behavior typical of many real proteins (i.e. fast folding and high cooperativity for single chains). We find that 64-mers are considerably more stable and more cooperative compared to 27-mers. The optimal interfacial-interaction-energy parameter set, however, is relatively size independent. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Radke, CJ (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Leonhard, Kai/B-2127-2009 NR 16 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-4622 J9 BIOPHYS CHEM JI Biophys. Chem. PD OCT 1 PY 2003 VL 106 IS 1 BP 81 EP 89 DI 10.1016/S0301-4622(03)00185-6 PG 9 WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA 730EL UT WOS:000185816200009 PM 14516915 ER PT J AU Mobley, DL Cox, DL Singh, RRP Kulkarni, RV Slepoy, A AF Mobley, DL Cox, DL Singh, RRP Kulkarni, RV Slepoy, A TI Simulations of oligomeric intermediates in prion diseases SO BIOPHYSICAL JOURNAL LA English DT Article ID BOVINE SPONGIFORM ENCEPHALOPATHY; PROTEIN; TRANSMISSION; REPLICATION; SPIN; MICE; BSE AB We extend our previous stochastic cellular automata-based model for two-dimensional (areal) aggregation of prion proteins on neuronal surfaces. The new anisotropic model allows us to simulate both strong beta-sheet and weaker attachment bonds between proteins. Constraining binding directions allows us to generate aggregate structures with the hexagonal lattice symmetry found in recently observed in vitro experiments. We argue that these constraints on rules may correspond to underlying steric constraints on the aggregation process. We find that monomer-dominated growth of the areal aggregate is too slow to account for some observed doubling-time-to-incubation-time ratios inferred from data, and so consider aggregation dominated by relatively stable but noninfectious oligomeric intermediates. We compare a kinetic theory analysis of oligomeric aggregation to spatially explicit simulations of the process. We find that with suitable rules for misfolding of oligomers, possibly due to water exclusion by the surrounding aggregate, the resulting oligomeric aggregation model maps onto our previous monomer aggregation model. Therefore it can produce some of the same attractive features for the description of prion incubation time data. We propose experiments to test the oligomeric aggregation model. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mobley, DL (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. EM mobley@physics.ucdavis.edu RI Mobley, David/C-3885-2009 OI Mobley, David/0000-0002-1083-5533 NR 17 TC 6 Z9 7 U1 0 U2 2 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 2003 VL 85 IS 4 BP 2213 EP 2223 DI 10.1016/S0006-3495(03)74647-5 PG 11 WC Biophysics SC Biophysics GA 726AQ UT WOS:000185575400013 PM 14507687 ER PT J AU Brewer, LR Friddle, R Noy, A Baldwin, E Martin, SS Corzett, M Balhorn, R Baskin, RJ AF Brewer, LR Friddle, R Noy, A Baldwin, E Martin, SS Corzett, M Balhorn, R Baskin, RJ TI Packaging of single DNA molecules by the yeast mitochondrial protein Abf2p SO BIOPHYSICAL JOURNAL LA English DT Article ID MOBILITY GROUP PROTEIN; HMG-BOX PROTEIN; TRANSCRIPTIONAL ACTIVATOR; SACCHAROMYCES-CEREVISIAE; HISTONE HM; NUCLEAR; RECOMBINATION; NUCLEOIDS; BINDING; DAMAGE AB Mitochondrial and nuclear DNA are packaged by proteins in a very different manner. Although protein-DNA complexes called "nucleoids'' have been identified as the genetic units of mitochondrial inheritance in yeast and man, little is known about their physical structure. The yeast mitochondrial protein Abf2p was shown to be sufficient to compact linear dsDNA, without the benefit of supercoiling, using optical and atomic force microscopy single molecule techniques. The packaging of DNA by Abf2p was observed to be very weak as evidenced by a fast Abf2p off-rate (k(off) = 0.014 +/- 0.001 s(-1)) and the extremely small forces (< 0.6 pN) stabilizing the condensed protein-DNA complex. Atomic force microscopy images of individual complexes showed the 190-nm structures are loosely packaged relative to nuclear chromatin. This organization may leave mtDNA accessible for transcription and replication, while making it more vulnerable to damage. C1 Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Div Chem & Mat Sci, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Div, Livermore, CA 94550 USA. Univ Calif Davis, Dept Mol & Cellular Biol, Davis, CA 95616 USA. Univ Calif Davis, Grad Grp Biophys, Davis, CA 95616 USA. RP Brewer, LR (reprint author), Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. RI Brewer, Laurence/G-4056-2012 NR 31 TC 34 Z9 34 U1 0 U2 2 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 2003 VL 85 IS 4 BP 2519 EP 2524 DI 10.1016/S0006-3495(03)74674-8 PG 6 WC Biophysics SC Biophysics GA 726AQ UT WOS:000185575400040 PM 14507714 ER PT J AU Hendriks, BS Wiley, HS Lauffenburger, D AF Hendriks, BS Wiley, HS Lauffenburger, D TI HER2-mediated effects on EGFR endosomal sorting: Analysis of biophysical mechanisms SO BIOPHYSICAL JOURNAL LA English DT Article ID EPIDERMAL-GROWTH-FACTOR; LIGAND-RECEPTOR COMPLEXES; ERBB SIGNALING NETWORK; QUANTITATIVE-ANALYSIS; BREAST-CANCER; INTRACELLULAR TRAFFICKING; POSTENDOCYTIC TRAFFICKING; ENDOCYTIC SYSTEM; TYROSINE KINASES; DOWN-REGULATION AB Overexpression of HER2, a receptor-like tyrosine kinase and signaling partner for the epidermal growth factor receptor (EGFR), has been implicated in numerous experimental and clinical studies as promoting the progression of many types of cancer. One avenue by which HER2 overexpression may dysregulate EGFR-mediated cell responses, such as proliferation and migration, downstream of EGF family ligand binding, is by its modulation on EGFR endocytic trafficking dynamics. EGFR signaling is regulated by downregulation and compartmental relocalization arising from endocytic internalization and endosomal sorting to degradation versus recycling fates. HER2 overexpression influences both of these processes. At the endosomal sorting stage, increased HER2 levels elicit enhanced EGFR recycling outcomes, but the mechanism by which this transpires is poorly understood. Here, we determine whether alternative mechanisms for HER2-mediated enhancement of EGFR recycling can be distinguished by comparison of corresponding mathematical models to experimental literature data. Indeed, we find that the experimental data are clearly most consistent with a mechanism in which HER2 directly competes with EGFR for a stoichiometrically-limited quantity of endosomal retention components (ERCs), thereby reducing degradation of ERC-coupled EGFR. Model predictions based on this mechanism exhibited qualitative trends highly similar to data on the fraction of EGF/EGFR complexes sorted to recycling fate as a function of the amount of internalized EGF/EGFR complexes. In contrast, model predictions for alternative mechanisms-blocking of EGFR/ERC coupling, or altering EGF/EGFR dissociation-were inconsistent with the qualitative trends of the experimental data. C1 MIT, Dept Chem Engn, Cambridge, MA 02139 USA. MIT, Dept Biol, Biol Engn Div, Cambridge, MA USA. MIT, Ctr Canc Res, Cambridge, MA 02139 USA. Pacific NW Natl Lab, Div Biol Sci, Richland, WA USA. RP Lauffenburger, D (reprint author), MIT, Dept Chem Engn, Bldg 56,Rm 341, Cambridge, MA 02139 USA. OI Wiley, Steven/0000-0003-0232-6867 NR 58 TC 44 Z9 45 U1 0 U2 5 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD OCT PY 2003 VL 85 IS 4 BP 2732 EP 2745 DI 10.1016/S0006-3495(03)74696-7 PG 14 WC Biophysics SC Biophysics GA 726AQ UT WOS:000185575400062 PM 14507736 ER PT J AU Gizeli, E Bender, F Rasmusson, A Saha, K Josse, F Cernosek, R AF Gizeli, E Bender, F Rasmusson, A Saha, K Josse, F Cernosek, R TI Sensitivity of the acoustic waveguide biosensor to protein binding as a function of the waveguide properties SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE acoustic waveguide device; love wave; biosensor ID IMMUNOSENSOR; LIQUID; LAYER; INTERFACE; SENSORS; DEVICE AB The aim of this work is to study the effect of operating frequency, piezoelectric substrate and waveguide layer thickness on the sensitivity of the acoustic waveguide sensor during the specific binding of an antibody by a protein. Shear horizontal (SH) wave devices consisting of (a) a LiTaO3 substrate operating at 104 MHz, (b) a quartz substrate operating at 108 MHz and (c) a quartz substrate operating at 155 MHz were coated with a photoresist polymer layer in order to produce acoustic waveguide devices supporting a Love wave. The effect of the thickness of the polymer layer on the Love wave was assessed by measuring the amplitude and phase of the wave before and after coating. The sensitivity of the above three biosensors was compared during the detection of the specific binding of different concentrations of Immunoglobulin G in the range of 0.7-667 nM to a protein A modified surface. Results indicate that the thickness of the polymer guiding layer is critical for obtaining the maximum sensitivity for a given geometry but a trade-off has to be made between the theoretically determined optimum thickness for waveguiding and the device insertion loss. It was also found that increasing the frequency of operation results in a further increase in the device sensitivity to protein detection. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Cambridge, Inst Biotechnol, Cambridge CB2 1QT, England. Marquette Univ, Microsensors Res Lab, Milwaukee, WI 53201 USA. Marquette Univ, Dept Elect & Comp Engn, Milwaukee, WI 53201 USA. Sandia Natl Labs, Microsensor Res & Dev Dept, Albuquerque, NM 87185 USA. RP Gizeli, E (reprint author), Univ Cambridge, Inst Biotechnol, Tennis Court Rd, Cambridge CB2 1QT, England. RI Saha, Krishanu/J-3980-2014 OI Saha, Krishanu/0000-0003-2837-0858 NR 21 TC 64 Z9 69 U1 1 U2 14 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD OCT 1 PY 2003 VL 18 IS 11 BP 1399 EP 1406 DI 10.1016/S0956-5663(03)00080-0 PG 8 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 719FT UT WOS:000185193500012 PM 12896842 ER PT J AU Gottardo, R Pannucci, JA Kuske, CR Brettin, T AF Gottardo, R Pannucci, JA Kuske, CR Brettin, T TI Statistical analysis of microarray data: a Bayesian approach SO BIOSTATISTICS LA English DT Article DE differential gene expression; hierarchical Bayes; multiple testing; posterior probabilities; replicated cDNA microarrays ID BACILLUS-ANTHRACIS; GENE; TRANSCRIPTION; VIRULENCE AB The potential of microarray data is enormous. It allows us to monitor the expression of thousands of genes simultaneously. A common task with microarray is to determine which genes are differentially expressed between two samples obtained under two different conditions. Recently, several statistical methods have been proposed to perform such a task when there are replicate samples under each condition. Two major problems arise with microarray data. The first one is that the number of replicates is very small (usually 2-10), leading to noisy point estimates. As a consequence, traditional statistics that are based on the means and standard deviations, e.g. t-statistic, are not suitable. The second problem is that the number of genes is usually very large (similar to10000), and one is faced with an extreme multiple testing problem. Most multiple testing adjustments are relatively conservative, especially when the number of replicates is small. In this paper we present an empirical Bayes analysis that handles both problems very well. Using different parametrizations, we develop four statistics that can be used to test hypotheses about the means and/or variances of the gene expression levels in both one- and two-sample problems. The methods are illustrated using experimental data with prior knowledge. In addition, we present the result of a simulation comparing our methods to well-known statistics and multiple testing adjustments. C1 Univ Washington, Dept Stat, Seattle, WA 98195 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Gottardo, R (reprint author), Univ Washington, Dept Stat, Box 354322, Seattle, WA 98195 USA. NR 22 TC 42 Z9 44 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1465-4644 J9 BIOSTATISTICS JI Biostatistics PD OCT PY 2003 VL 4 IS 4 BP 597 EP 620 DI 10.1093/biostatistics/4.4.597 PG 24 WC Mathematical & Computational Biology; Statistics & Probability SC Mathematical & Computational Biology; Mathematics GA 734DL UT WOS:000186039900008 PM 14557114 ER PT J AU Stolken, JS Kinney, JH AF Stolken, JS Kinney, JH TI On the importance of geometric nonlinearity in finite-element simulations of trabecular bone failure SO BONE LA English DT Article DE bone; trabecular bone; finite element modeling; fracture; failure; stability theory; bifurcation ID VERTEBRAL CANCELLOUS BONE; DISTAL RADIUS FAILURE; FRACTURE-TOUGHNESS; CORTICAL BONE; MICRO-FE; STRENGTH; MODELS; STIFFNESS; DAMAGE; COMPRESSION AB The finite element method, which has been successfully applied to studies of the elastic properties of trabecular bone, is now being used to simulate its failure. These simulations have used a geometrically linear (linear kinematic) approximation to the total stiffness matrix; nonlinear terms in the total stiffness matrix have been excluded from the computation in order to achieve efficiency. Because trabecular bone appears to be a slender (i.e., geometrically nonlinear) structure, we studied the validity of the linear kinematic approximation for simulating its failure. Two cases, designed to bracket the extremes of stability behavior, were explored: a single representative spicule of trabecular bone (case 1) and a volume of trabecular bone consisting of relatively low aspect ratio members (case 2). For case 1, geometrically linear (GL) and nonlinear (GNL) analyses were performed with two different materials models: a plastic damage model and a brittle damage model. When GNL terms were included in the total stiffness matrix, we found that load-path bifurcation preceded tissue failure regardless of the form of the damage model. This bifurcation was the result of a complex coupling between material yield and structural instability. The nature of this coupling was highly sensitive to the form of the damage model. None of these behaviors was observed in the linear analyses, where failure was insensitive to the form of the damage model and where structural instabilities were prevented from occurring. For case 2, compressive loading of a volume of trabecular bone, geometric nonlinear effects were pronounced. There was a bifurcation in load response that resulted in large apparent strain to failure. The GL simulations, on the other hand, precluded this bifurcation. We hypothesize that trabecular bone is a geometric nonlinear structure; nonlinear terms must be included in the total stiffness matrix to accurately simulate its failure. (C) 2003 Elsevier Inc. All rights reserved. C1 Lawrence Livermore Natl Lab, Dept Mech Engn, Livermore, CA 94551 USA. RP Kinney, JH (reprint author), Lawrence Livermore Natl Lab, Dept Mech Engn, L-333, Livermore, CA 94551 USA. NR 32 TC 69 Z9 72 U1 0 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 8756-3282 J9 BONE JI Bone PD OCT PY 2003 VL 33 IS 4 BP 494 EP 504 DI 10.1016/S875603282(03)00214-X PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 733FZ UT WOS:000185990400005 PM 14555252 ER PT J AU Huang, RY Miller, LM Carlson, CS Chance, MR AF Huang, RY Miller, LM Carlson, CS Chance, MR TI In situ chemistry of osteoporosis revealed by synchrotron infrared microspectroscopy SO BONE LA English DT Article DE infrared microspectroscopy; cynomolgus monkeys; fluorochrome; postmenopausal osteoporosis; hydroxyapatite; nandrolone decanoate ID MONKEYS MACACA-FASCICULARIS; CYNOMOLGUS MONKEYS; NANDROLONE DECANOATE; TRABECULAR BONE; OVARIECTOMIZED RATS; CANCELLOUS BONE; MINERAL-CONTENT; CORTICAL BONE; COLLAGEN; SPECTROSCOPY AB Reduced bone density is a well-known feature of osteoporosis, yet little is known about the changes in the chemical composition of bone or the impact of such chemical changes on fracture risks. Using ovariectomized cynomolgus monkeys (Macaca fascicularis) as a model for the menopausal onset of osteoporosis, we examined the microscopic chemical changes of bone measured by synchrotron infrared microspectroscopy as a function of time after ovariectomy. The results demonstrate that cortical bone formed I or 2 years after ovariectomy, as identified by fluorochrome labeling, has a higher phosphate content (PO(4)(3-/)matrix ratio), a lower carbonate content (CO32-/matrix ratio), and more mature collagen cross-links (nonreducible cross-link/reducible cross-link ratio) than that formed in sham-operated controls. Trabecular bone after ovariectomy shows no changes in phosphate content, a lower carbonate content, and immature collagen cross-linking. Treatment with a bone turnover suppressor, (nandrolone decanoate) reverses most of the ovariectomy-induced chemical changes in the cortical bone to the levels of the ovary-intact controls, but has little effect on the trabecular bone. These results demonstrate that bone newly synthesized after ovariectomy is chemically different from healthy bone within specific bone regions, which may contribute to reduced bone quality in osteoporosis. (C) 2003 Elsevier Inc. All rights reserved. C1 Albert Einstein Coll Med, Ctr Synchrotron Biosci, Dept Physiol & Biophys, Bronx, NY 10461 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Univ Minnesota, Coll Vet Med, Dept Vet Diagnost Med, St Paul, MN 55108 USA. RP Chance, MR (reprint author), Albert Einstein Coll Med, Ctr Synchrotron Biosci, Dept Physiol & Biophys, Ullmann 315,1300 Morris Pk Ave, Bronx, NY 10461 USA. OI Huang, Raymond/0000-0001-7661-797X FU NCRR NIH HHS [P41-RR01633, RR-14099] NR 41 TC 49 Z9 50 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 8756-3282 J9 BONE JI Bone PD OCT PY 2003 VL 33 IS 4 BP 514 EP 521 DI 10.1016/S8756-3282(03)00233-3 PG 8 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 733FZ UT WOS:000185990400007 PM 14555254 ER PT J AU Petersen, OW Gudjonsson, T Villadsen, R AF Petersen, OW Gudjonsson, T Villadsen, R TI Epithelial progenitor cell lines as models of normal, breast morphogenesis and neoplasia SO CELL PROLIFERATION LA English DT Article ID RECONSTITUTED BASEMENT-MEMBRANE; HUMAN MAMMARY EPITHELIUM; STEM-CELL; MYOEPITHELIAL CELLS; MONOCLONAL-ANTIBODIES; KERATIN EXPRESSION; IN-VITRO; DIFFERENTIATION; GLAND; ANTIGEN AB The majority of human breast carcinomas exhibit luminal characteristics and as such, are most probably derived from progenitor cells within the luminal epithelial compartment. This has been subdivided recently into at least three luminal subtypes based on gene expression patterns. The value of knowing the cellular origin of individual tumours is clear and should aid in designing effective therapies. To do this, however, we need strategies aimed at defining the nature of stem and progenitor cell populations in the normal breast. In this review, we will discuss our technical approach for delineating the origin of the epithelial cell types. A major step forward was the purification of each cell type by the application of immunomagnetic cell sorting based on expression of lineage-specific surface antigens. We then developed chemically defined media that could support either the luminal epithelial or the myoepithelial cell phenotype in primary cultures. Having succeeded in continuous propagation presumably without loss of markers, we could show that a subset of the luminal epithelial cells could convert to myoepithelial cells, signifying the possible existence of a progenitor cell population. By combining the information on marker expression and in situ localization with immunomagnetic sorting and subsequent immortalization, we have identifed and isolated a cytokeratin 19-positive suprabasal putative precursor cell in the luminal epithelial compartment and established representative cell lines. This suprabasal-derived epithelial cell line is able to generate both itself and differentiated luminal epithelial and myoepithelial cells, and in addition, is able to form elaborate terminal duct lobular unit (TDLU)-like structures within a reconstituted basement membrane. As more than 90% of breast cancers arise in TDLUs and more than 90% are also cytokeratin 19-positive, we suggest that this cell population contains a breast-cancer progenitor. C1 Univ Copenhagen, Panum Inst, Dept Anat & Med, Struct Cell Biol Unit,Inst Med Anat, DK-2200 Copenhagen, Denmark. Univ Copenhagen, August Krogh Inst, Zoophysiol Lab, DK-2100 Copenhagen, Denmark. Icelandic Canc Soc, Mol & Cell Biol Res Lab, Reykjavik, Iceland. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Univ Copenhagen, Panum Inst, Dept Anat & Med, Struct Cell Biol Unit,Inst Med Anat, Blegdamsvej 3, DK-2200 Copenhagen, Denmark. EM o.w.petersen@mai.ku.dk RI Ronnov-Jessen OR Ronnovjessen, Lone/A-5981-2013 FU NCI NIH HHS [R37 CA064786, R01 CA064786-04A1, CA-64786-02, R01 CA064786] NR 61 TC 43 Z9 44 U1 1 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0960-7722 EI 1365-2184 J9 CELL PROLIFERAT JI Cell Prolif. PD OCT PY 2003 VL 36 SU 1 BP 33 EP 44 DI 10.1046/j.1365-2184.36.s.1.4.x PG 12 WC Cell Biology SC Cell Biology GA 739RT UT WOS:000186360800004 PM 14521514 ER PT J AU Corr, DJ Monteiro, PJM Bastacky, J AF Corr, DJ Monteiro, PJM Bastacky, J TI Observations of ice lens formation and frost heave in young Portland cement paste SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE freezing and thawing; microstructure; permeability; SEM; frost heave ID MORPHOLOGY AB As part of a research program to image frozen cement past specimens, abnormal microstructural formations are seen in specimens frozen after 10-h hydration. The formations are areas of loose microstructure with aspect ratios of 6-10, which appear perpendicular to the direction of cooling in the specimen. After sublimation of the water in the specimens during the imaging process, these formations collapse, indicating that ice is instrumental to their structure. These formations coincide with longitudinal cracks in the specimen, which do not appear to be due to specimen preparation and are consistent with an internal tensile strain. The authors have hypothesized that ice lens fort-nation and frost heave, or a similar freezing mechanism, is responsible for these microstructural features, which are seen in 10-h specimens and are absent in all other cement paste specimens. Triaxial permeability tests have also shown that the cement paste mix used in this study has a permeability at 10-h age of similar to 10(-6) cm/s. This permeability is similar to that of silty soil, some of the most susceptible to frost heave. (C) 2003 Elsevier Ltd. All rights reserved. C1 Northwestern Univ, Dept Civil & Environm Engn, Ctr Adv Cement Based Mat, Technol Inst A130, Evanston, IL 60208 USA. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Corr, DJ (reprint author), Northwestern Univ, Dept Civil & Environm Engn, Ctr Adv Cement Based Mat, Technol Inst A130, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM d-corr2@northwestern.edu RI Corr, David/B-6930-2009; Chen, Wei/A-5694-2010 NR 12 TC 4 Z9 4 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD OCT PY 2003 VL 33 IS 10 BP 1531 EP 1537 DI 10.1016/S0008-8846(03)00103-0 PG 7 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 807GB UT WOS:000220488900005 ER PT J AU Williams, PJ Biernacki, JJ Bai, JM Rawn, CJ AF Williams, PJ Biernacki, JJ Bai, JM Rawn, CJ TI Assessment of a synchrotron X-ray method for quantitative analysis of calcium hydroxide SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE synchrotron XRD; X-ray diffraction; calcium hydroxide; fly ash; quantitative ID FLY-ASH PASTES; CEMENT PASTE; MICROSTRUCTURE; DIFFRACTION AB Thermogravimetric analysis (TGA) and quantitative X-ray diffraction (QXRD) are widely used to determine the calcium hydroxide (CH) content in cementitious systems containing blends of Portland cement, fly ash, blast furnace slag, silica fume and other pozzolanic and hydraulic materials. These techniques, however, are destructive to cement samples and subject to various forms of error. While precise weight losses can be measured by TGA, extracting information from samples with multiple overlapping thermal events is difficult. And, however, while QXRD can offer easier deconvolution, the accuracy for components below about 5 wt.% is typically poor when a laboratory X-ray source is used. Furthermore, the destructive nature of both techniques prevents using them to study the in situ hydration of a single contiguous sample for kinetic analysis. In an attempt to overcome these problems, the present research evaluated the use of synchrotron X-rays for quantitative analysis of CH. A synchrotron X-ray source was used to develop calibration data for quantification of the amount of CH in mixtures with fly ash. These data were compared to conventional laboratory XRD data for like samples. While both methods were found to offer good quantification, synchrotron XRD (SXRD) provided a broader range of delectability and higher accuracy than laboratory diffraction and removed the subjectivity as compared to TGA analysis. Further, the sealed glass capillaries used with the synchrotron source provided a nondestructive closed, in situ environment for tracking hydrating specimens from zero to any desired age. (C) 2003 Elsevier Ltd. All rights reserved. C1 Tennessee Technol Univ, Dept Chem Engn, Cookeville, TN 38505 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Biernacki, JJ (reprint author), Tennessee Technol Univ, Dept Chem Engn, Box 5013, Cookeville, TN 38505 USA. EM jbiernacki@tntech.edu RI Chen, Wei/A-5694-2010; Bai, Jianming/O-5005-2015 NR 22 TC 2 Z9 3 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD OCT PY 2003 VL 33 IS 10 BP 1553 EP 1559 DI 10.1016/S0008-8846(03)00105-4 PG 7 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 807GB UT WOS:000220488900009 ER PT J AU Cizmas, PG Palacios, A O'Brien, T Syamlal, M AF Cizmas, PG Palacios, A O'Brien, T Syamlal, M TI Proper-orthogonal decomposition of spatio-temporal patterns in fluidized beds SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE fluidization; multiphase flow; model reduction; nonlinear dynamics ID EQUATIONS; DYNAMICS; VELOCITY; BUBBLE; FLOWS; JET AB Numerical simulations of the hydrodynamics of a fluidized bed are carried Out to investigate the complex interaction between the gas and the solid particles, and to explore the utility of a reduced-order model based on the proper orthogonal decomposition (POD). The behavior of a fluidized bed is modeled using a "two-fluid" theory, which involves conservation of mass, momentum, energy and species equations for the two interpenetrating continua. These equations are solved using a numerical algorithm that employs a conservative discretization scheme with mixed implicit and explicit formulations. We conducted simulations of gas-solid interaction in a narrow (two-dimensional) bed filled with sand particles which was uniformly fluidized at minimum fluidization but with additional air flow through a central nozzle. Aided by the proper orthogonal decomposition, spatial dominant features arc identified and separated from the spatio-temporal dynamics of the simulations. The most dynamic region of the gas-solid interaction is confined to the central channel caused by the jet. The flow within this structure is successfully captured by a few POD eigenfunctions. Phase-space plots further indicate the existence of low-dimensional dynamics within the central channel. This conclusion supports the validity of a reduced-order model for fluidized beds, which can then be constructed by projecting the governing equations onto the POD modes, as it is commonly done in the Galerkin method. (C) 2003 Elsevier Ltd. All rights reserved. C1 San Diego State Univ, Dept Math & Stat, Nonlinear Dynam Grp, San Diego, CA 92182 USA. Texas A&M Univ, Dept Aerosp Engn, College Stn, TX 77843 USA. Dept Energy, Natl Energy Technol Lab, Morgantown, WV 26507 USA. Fluent Inc, Morgantown, WV 26507 USA. RP Palacios, A (reprint author), San Diego State Univ, Dept Math & Stat, Nonlinear Dynam Grp, San Diego, CA 92182 USA. NR 33 TC 28 Z9 31 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD OCT PY 2003 VL 58 IS 19 BP 4417 EP 4427 DI 10.1016/S0009-2509(03)00323-3 PG 11 WC Engineering, Chemical SC Engineering GA 730EV UT WOS:000185817000010 ER PT J AU Hang, B Singer, B AF Hang, B Singer, B TI Protein-protein interactions involving DNA glycosylases SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Review ID BASE-EXCISION-REPAIR; CELL NUCLEAR ANTIGEN; TRANSCRIPTION-COUPLED REPAIR; STRUCTURE-SPECIFIC ENDONUCLEASE; OXIDATIVELY DAMAGED DNA; HUMAN MISMATCH REPAIR; HUMAN MUTY HOMOLOG; APURINIC-APYRIMIDINIC ENDONUCLEASES; COCKAYNE-SYNDROME PATIENTS; PURIFIED HUMAN PROTEINS C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Hang, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA47723, CA72079] NR 224 TC 12 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD OCT PY 2003 VL 16 IS 10 BP 1181 EP 1195 DI 10.1021/tx030020p PG 15 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 735GC UT WOS:000186103200001 PM 14565759 ER PT J AU Kumar, KS Bowerman, WW DeVault, TL Takasuga, T Rhodes, OE Brisbin, IH Masunaga, S AF Kumar, KS Bowerman, WW DeVault, TL Takasuga, T Rhodes, OE Brisbin, IH Masunaga, S TI Chlorinated hydrocarbon contaminants in blood of blackand turkey vultures from Savannah River Site, South Carolina, USA SO CHEMOSPHERE LA English DT Article DE black vulture; turkey vulture; 2,3,7,8-PCDD/DFs; dioxin-like PCBs; Di-ortho PCBs; toxic equivalent quantities (TEQs) ID DIBENZO-P-DIOXINS; DOUBLE-CRESTED CORMORANTS; POLYCHLORINATED BIPHENYL CONGENERS; FISH-EATING BIRDS; PHALACROCORAX-CARBO; GREAT-LAKES; ORGANOCHLORINE CONTAMINANTS; HALIAEETUS-ALBICILLA; STERNA-HIRUNDO; COMMON TERNS AB Blood of adult and juvenile black and turkey vultures in the Savannah River Site of South Carolina, USA was analyzed for the presence of 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins (2,3,7,8-PCDDs), dibenzofurans (2,3,7,8-PCDFs), -dioxin-like and -di-ortho polychlorinated biphenyls. Concentration ranges of 2,3,7, 8-PCDD/DFs in blood of black and turkey vultures were 14.2-34.6 and 8.7-56.2 pg/ml wet wt., respectively. Dioxin-like PCBs were in the ranges of 815-4627 and 753-3611 pg/ml wet wt. respectively, in black and turkey vultures. Considerable concentrations of two congeners of di-ortho PCBs were noticed in the ranges of 141510325 and 663-7500 pg/ml respectively, in black and turkey vultures. Comparatively, greater toxic equivalency (TEQ) were observed in blood of turkey vultures with the ranges of 3.2-20, whereas black vulture contained 1.88.4 pg TEQ/ml wet wt. basis. The species-specific accumulation profiles of PCDD/DFs and dioxin-like PCBs may reflect the different feeding habits, ecology, metabolic capacity and migratory movements of these two. scavenging species. (C) 2003 Elsevier Ltd. All. rights reserved. C1 Shimadzu Technol Res Inst, Nakagyo Ku, Kyoto 6048436, Japan. Yokohama Natl Univ, Grad Sch Environm & Informat Sci, Hodogaya Ku, Yokohama, Kanagawa 2408501, Japan. Clemson Univ, Dept Environm Toxicol, Pendleton, SC 29670 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Purdue Univ, Dept Forestry & Nat Resources, W Lafayette, IN 47907 USA. RP Kumar, KS (reprint author), Shimadzu Technol Res Inst, Nakagyo Ku, 1,Nishinokyo Shimoaicho, Kyoto 6048436, Japan. RI Masunaga, Shigeki/F-1315-2011 OI Masunaga, Shigeki/0000-0003-0608-2337 NR 31 TC 5 Z9 7 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD OCT PY 2003 VL 53 IS 2 BP 173 EP 182 DI 10.1016/S0045-6535(03)00304-7 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA 715VX UT WOS:000184994300009 ER PT J AU Cheng, MD Malone, B Storey, JME AF Cheng, MD Malone, B Storey, JME TI Monitoring cellular responses of engine-emitted particles by using a direct air-cell interface deposition technique SO CHEMOSPHERE LA English DT Article DE aerosol; aerosol deposition; air-cell interface; human lung cells; internal combustion engines; cytokines ID DIESEL EXHAUST PARTICLES; BRONCHIAL EPITHELIAL-CELLS; IN-VITRO; EXPOSURE; INFLAMMATION; EXPRESSION; A549; MACROPHAGES; ACTIVATION; STRESS AB The impacts of ultrafine airborne particles generated by diesel or gasoline engines on human lung cells have been investigated using a new in vitro cellular exposure technique. This technique enables direct deposition of the gasoline engine exhaust particles (GEP) and diesel engine exhaust particles (DEP) on human lung cells located at the air-cell interface on a transwell membrane in an exposure apparatus. The cellular responses to particle exposure were measured by the levels of IL-8 chemokines produced as a function of exposure time. The findings suggest that GEP and high-sulfur DEP induced the production of similar levels of IL-8 by unprimed A549 cells. The level of IL-8 produced by unprimed A549 cells in response to low-sulfur DEP was found lower than that produced in response to high-sulfur DEP and GEP. When cells were primed, simulating predisposed conditions, significant levels of IL-8 were produced. GEP triggered a much higher level of IL-8 production than DEP did. Furthermore, the time profile of IL-8 production induced by GEP was markedly different from that induced by DEP. The findings indicate that GEP could induce the production of higher levels of chemokines (i.e., IL-8) than DEP did, implying that exposure to GEP could be a greater health risk than exposure to DEP. (C) 2003 Elsevier Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Engn Technol & Sci Div, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,MS 6038, Oak Ridge, TN 37831 USA. RI Cheng, Meng-Dawn/C-1098-2012; OI Cheng, Meng-Dawn/0000-0003-1407-9576 NR 26 TC 33 Z9 33 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD OCT PY 2003 VL 53 IS 3 BP 237 EP 243 DI 10.1016/S0045-6535(03)00555-1 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA 719UK UT WOS:000185223300005 PM 12919783 ER PT J AU Stephen, JM Davis, LE Aine, CJ Ranken, D Herman, M Hudson, D Huang, MX Poole, J AF Stephen, JM Davis, LE Aine, CJ Ranken, D Herman, M Hudson, D Huang, MX Poole, J TI Investigation of the normal proximal somatomotor system using magnetoencephalography SO CLINICAL NEUROPHYSIOLOGY LA English DT Article DE magnetoencephalography; proximal arm; ipsilateral motor cortex; somatosensory; deltoid; bicep ID TRANSCRANIAL MAGNETIC STIMULATION; PRIMARY SOMATOSENSORY CORTEX; IPSILATERAL MOTOR CORTEX; POSITRON EMISSION TOMOGRAPHY; CEREBRAL BLOOD-FLOW; HEMISPHERIC-ASYMMETRY; FUNCTIONAL RECOVERY; SOURCE LOCALIZATION; EVOKED RESPONSES; FINGER MOVEMENTS AB Objective: The role of the ipsilateral cortex in proximal muscle control in normal human subjects is still under debate. One clinical finding, rapid recovery of proximal muscle relative to distal muscle use following stroke, has led to the suggestion that the ipsilateral as well as the contralateral motor cortex may be involved in normal proximal muscle control. The primary goal of this project was to identify contralateral and ipsilateral motor cortex activation associated with proximal muscle movement in normal subjects using magnetoencephalography (MEG). Methods: We developed protocols for a self-paced bicep motor task and a deltoid, electrical-stimulation somatosensory task. The MEG data were analyzed using automated multi-dipole spatiotemporal modeling techniques to localize the sources and characterize the associated timing of these sources. Results: Reliable contralateral primary motor and somatosensory sources localized to areas consistent with the homunculus. Ipsilateral M1 activation was only found in 2/12 hemispheres. Conclusions: Robust contralateral motor cortex activation and sparse ipsilateral motor cortex activation suggest that the ipsilateral motor cortex is not involved in normal proximal muscle control. Significance: The results suggest that proximal and distal muscle control is similar in normal subjects in the sense that proximal muscle control is primarily governed by the contralateral motor cortex. (C) 2003 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. C1 Univ New Mexico, Sch Med, Dept Radiol, Albuquerque, NM 87131 USA. New Mexico VA Healthcare Syst, Ctr Funct Brain Imaging, Albuquerque, NM 87108 USA. Univ New Mexico, Sch Med, Dept Neurol, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Div Phys, Biophys Grp, Los Alamos, NM 87545 USA. Univ New Mexico, Sch Med, Occupat Therapy Grad Program, Albuquerque, NM 87131 USA. RP Stephen, JM (reprint author), Univ New Mexico, Sch Med, Dept Radiol, Albuquerque, NM 87131 USA. OI Stephen, Julia/0000-0003-2486-747X FU NCRR NIH HHS [5-P20RR15636-02] NR 72 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 1388-2457 J9 CLIN NEUROPHYSIOL JI Clin. Neurophysiol. PD OCT PY 2003 VL 114 IS 10 BP 1781 EP 1792 DI 10.1016/S1388-2457(03)00150-0 PG 12 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 733CL UT WOS:000185982300002 PM 14499739 ER PT J AU Stompor, R Hanany, S Abroe, ME Borrill, J Ferreira, PG Jaffe, AH Johnson, B Lee, AT Rabii, B Richards, PL Smoot, G Winant, C Wu, JHP AF Stompor, R Hanany, S Abroe, ME Borrill, J Ferreira, PG Jaffe, AH Johnson, B Lee, AT Rabii, B Richards, PL Smoot, G Winant, C Wu, JHP TI The MAXIMA experiment: latest results and consistency tests SO COMPTES RENDUS PHYSIQUE LA English DT Article DE MAXIMA; cosmic microwave background anisotropy; cosmology; early Universe ID ANGULAR POWER SPECTRUM; BOOMERANG AB The MAXIMA cosmic microwave background anisotropy experiment had a significant impact on cosmology. Results from the program have played a significant role in determining the geometry of the universe, given strong supporting evidence to inflation, and, in combination with other astrophysical data, showed that the universe is filled with dark matter and energy. We present a subset of the internal consistency checks that were carried out on the MAXIMA-1 data prior to their release, which demonstrate that systematics errors were much smaller than statistical errors. We also discuss the MAXIMA-2 flight and data, compare the maps of MAXIMA-1 and -2 in areas where they overlap and show that the two independent experiments confirm each other. All of these results demonstrate that MAXIMA mapped the cosmic microwave background anisotropy with high accuracy. (C) 2003 Academie des sciences. Published by Elsevier SAS. All rights reserved. C1 Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. Natl Taiwan Univ, Dept Phys, Taipei, Taiwan. Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2BW, England. Univ Oxford, Oxford, England. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Stompor, R (reprint author), Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. RI Jaffe, Andrew/D-3526-2009; OI WU, JIUN-HUEI/0000-0001-9608-7662 NR 23 TC 2 Z9 2 U1 0 U2 0 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1631-0705 J9 CR PHYS JI C. R. Phys. PD OCT PY 2003 VL 4 IS 8 BP 841 EP 852 DI 10.1016/j.crhy.2003.09.003 PG 12 WC Astronomy & Astrophysics; Physics, Multidisciplinary SC Astronomy & Astrophysics; Physics GA 769CC UT WOS:000188608000004 ER PT J AU Kuprat, A George, D Straub, G Demirel, MC AF Kuprat, A George, D Straub, G Demirel, MC TI Modeling microstructure evolution in three dimensions with Grain3D and LaGriT SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Software Development for Process and Materials Disign CY SEP 15-16, 2002 CL MOSCOW, RUSSIA DE microstructure evolution; motion by mean curvature; gradient-weighted moving finite elements; unstructured tetrahedral meshes; deforming grids; changing grid topology ID MOVING FINITE-ELEMENTS; BOUNDARY; DESIGN AB This paper will describe modeling microstructure evolution using a combination of our gradient-weighted moving finite elements code, Grain3D and our 3-D unstructured grid generation and optimization code, LaGriT. Grain boundaries evolve by mean curvature motion, and Grain3D allows for the incorporation of grain boundary orientation dependence modeled as anisotropic mobility and energy. We also describe the process of generating an initial computational grid from images obtained from electron backscatter diffraction. We present the grid optimization operations developed to respond to changes in the physical topology such as the collapse of grains and to maintain uniform computational grid quality. For 3-D columnar microstructures, validation of the method is demonstrated by comparison with experiments. For large systems of fully 3-D micro structures, simulations compare favorably to the parabolic law of normal grain growth. (C) 2003 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Kuprat, A (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. RI Demirel, Melik/E-4495-2010; Demirel, Melik/E-3775-2016; OI Kuprat, Andrew/0000-0003-4159-918X NR 20 TC 21 Z9 21 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD OCT PY 2003 VL 28 IS 2 BP 199 EP 208 DI 10.1016/S0927-0256(03)00107-1 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 739RJ UT WOS:000186360000010 ER PT J AU Apra, E Bylaska, EJ Dean, DJ Fortunelli, A Gao, F Krstic, PS Wells, JC Windus, TL AF Apra, E Bylaska, EJ Dean, DJ Fortunelli, A Gao, F Krstic, PS Wells, JC Windus, TL TI NWChem for materials science SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Software Development for Process and Materials Disign CY SEP 15-16, 2002 CL MOSCOW, RUSSIA DE DFT; cluster; defects; molecular electronics; electronic structure; parallel computing ID DENSITY-FUNCTIONAL CALCULATIONS; INITIO QUANTUM-CHEMISTRY; WALLED CARBON NANOTUBES; MANY-ELECTRON SYSTEMS; AB-INITIO; COMPUTATIONAL CHEMISTRY; MOLECULAR-DYNAMICS; ENERGY; SINGLE; APPROXIMATION AB This paper focuses on describing the computational chemistry software, NWChem, and its use in materials science research. The current functionalities and capabilities are outlined, as well as future features. Specific computational examples are given to show the flexibility and usefulness of NWChern to answering materials science problems. (C) 2003 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, MS IN, Richland, WA 99352 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. IPCF, Mol Modeling Lab, CNR, I-56010 Ghezzano, PI, Italy. Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. RP Apra, E (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS IN, K8-91,POB 999, Richland, WA 99352 USA. RI Apra, Edoardo/F-2135-2010; Gao, Fei/H-3045-2012; Wells, Jack/D-3675-2016; OI Apra, Edoardo/0000-0001-5955-0734; Wells, Jack/0000-0002-5083-3030; Dean, David/0000-0002-5688-703X NR 76 TC 16 Z9 16 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD OCT PY 2003 VL 28 IS 2 BP 209 EP 221 DI 10.1016/S0927-0256(03)00108-3 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 739RJ UT WOS:000186360000011 ER PT J AU Krstic, PS Dean, DJ Zhang, XG Keffer, D Leng, YS Cummings, PT Wells, JC AF Krstic, PS Dean, DJ Zhang, XG Keffer, D Leng, YS Cummings, PT Wells, JC TI Computational chemistry for molecular electronics SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Software Development for Process and Materials Disign CY SEP 15-16, 2002 CL MOSCOW, RUSSIA DE molecular electronic; conductance; SAM formation; MD; DFT ID RELATIVISTIC EFFECTIVE POTENTIALS; SCANNING-TUNNELING-MICROSCOPY; DENSITY-FUNCTIONAL THEORY; SPIN-ORBIT OPERATORS; VALENCE BASIS-SETS; AU(111) SURFACE; DYNAMICS SIMULATIONS; TRANSPORT-PROPERTIES; GOLD NANOCRYSTALS; PHASE AB We present a synergetic effort of a group of theorists to characterize a molecular electronics device through a multiscale modeling approach. We combine electronic-structure calculations with molecular dynamics and Monte Carlo simulations to predict the structure of self-assembled molecular monolayers on a metal surface. We also develop a novel insight into molecular conductance, with a particular resolution of its fundamental channels, which stresses the importance of a complete molecular structure description of all components of the system, including the leads, the molecule, and their contacts. Both molecular dynamics and electron transport simulations imply that knowledge of detailed molecular structure and system geometry are critical for successful comparison with carefully performed experiments. We illustrate our findings with benzenedithiolate molecules in contact with gold. (C) 2003 Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Keffer, David/C-5133-2014; Wells, Jack/D-3675-2016; Cummings, Peter/B-8762-2013; OI Keffer, David/0000-0002-6246-0286; Wells, Jack/0000-0002-5083-3030; Cummings, Peter/0000-0002-9766-2216; Dean, David/0000-0002-5688-703X NR 63 TC 32 Z9 32 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 EI 1879-0801 J9 COMP MATER SCI JI Comput. Mater. Sci. PD OCT PY 2003 VL 28 IS 2 BP 321 EP 341 DI 10.1016/S0927-0256(03)00116-2 PG 21 WC Materials Science, Multidisciplinary SC Materials Science GA 739RJ UT WOS:000186360000019 ER PT J AU Dube, DH Bertozzi, CR AF Dube, DH Bertozzi, CR TI Metabolic oligosaccharide engineering as a tool for glycobiology SO CURRENT OPINION IN CHEMICAL BIOLOGY LA English DT Review ID UNNATURAL SIALIC ACIDS; CELL-ADHESION MOLECULE; ACYL SIDE-CHAIN; CARBOHYDRATE ANTIGENS; GLCNAC 2-EPIMERASE; TUMOR-CELLS; O-GLCNAC; GLYCOSYLATION; BIOSYNTHESIS; LIPOOLIGOSACCHARIDES AB Oligosaccharides transact information exchange at the cell surface and modulate the activities and distribution of proteins within cells. Recently, the ability to modify monosaccharicle structures within cellular glycans through metabolic processes has offered a new avenue for biological studies. The technique of metabolic oligosaccharide engineering has been used to disrupt glycan biosynthesis, chemically modify cell surfaces, probe metabolic flux inside cells, and to identify specific glycoprotein subtypes from the proteome. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Dube, DH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM 58867, GM 66047] NR 46 TC 116 Z9 116 U1 5 U2 27 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1367-5931 J9 CURR OPIN CHEM BIOL JI Curr. Opin. Chem. Biol. PD OCT PY 2003 VL 7 IS 5 BP 616 EP 625 DI 10.1016/j.cbpa.2003.08.006 PG 10 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 741FM UT WOS:000186448100015 PM 14580567 ER PT J AU Viallet, PM Vo-Dinh, T AF Viallet, PM Vo-Dinh, T TI Monitoring intracellular proteins using fluorescence techniques: From protein synthesis and localization to activity SO CURRENT PROTEIN & PEPTIDE SCIENCE LA English DT Review DE intracellular fluorescence imaging; green fluorescence protein; protein synthesis and translocation; intracellular protein localization and activity; inter and/or intramolecular fluorescent rulers ID LIFETIME IMAGING MICROSCOPY; RESONANCE ENERGY-TRANSFER; FIELD OPTICAL MICROSCOPY; ACTIN-BINDING PROTEIN; LIVING CELLS; ENDOPLASMIC-RETICULUM; SACCHAROMYCES-CEREVISIAE; MESSENGER-RNA; LIVE CELLS; CYTOPLASMIC MICROTUBULES AB The recent breakthroughs in genomics and proteomics and improvements of optical methods have made it possible to obtain localized, real-time information on intracellular proteins dynamics, through dynamic three-dimensional (3D) maps of the living cell with nanometric resolution of individual molecules. On one side, brighter variants of the Green Fluorescence Protein (GFP) have been engineered that have different excitation and/or emission spectra that better match available light sources. Like their parent molecule, these variants retain their fluorescence when fused to heterologous proteins on the N- and C- terminals, and this binding generally does not affect the functionality of the tagged protein leading the way to their use as an intracellular reporter. On the other side, optical methods have been improved to allow reaching the level of single-molecule detection inside living cells. Nevertheless some limitations exist for the use of GFP variants for probing 3D conformational changes of proteins. First, these variants are fused to the N and/or C terminals of the studied protein, which are generally not the best location to detect conformational changes resulting from the binding to other proteins or enzyme substrates. Then their own relatively large size makes them unusable for tagging small proteins. These limitations suggest that new tagging processes, permitting the location of the right fluorescent markers at the right places, must be found to built up inter- and/or intra-molecular rulers allowing one to monitor conformational changes resulting from intracellular protein-protein, protein-membrane, and enzyme-substrate binding. These specific locations can be obtained from in vitro studies of 3D conformational changes that occur during protein docking. C1 Univ Perpignan, Lab Physicochem Biol Integrated Syst, Quantitat Microfluorimetry Grp, F-66840 Perpignan, France. Oak Ridge Natl Lab, Adv Biomed Sci & Technol Grp, Oak Ridge, TN 37831 USA. RP Viallet, PM (reprint author), Univ Perpignan, Lab Physicochem Biol Integrated Syst, Quantitat Microfluorimetry Grp, F-66840 Perpignan, France. EM viallet@univ-perp.fr NR 140 TC 12 Z9 12 U1 0 U2 13 PU BENTHAM SCIENCE PUBL LTD PI SHARJAH PA EXECUTIVE STE Y26, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES SN 1389-2037 J9 CURR PROTEIN PEPT SC JI Curr. Protein Pept. Sci. PD OCT PY 2003 VL 4 IS 5 BP 375 EP 388 DI 10.2174/1389203033487045 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 731XD UT WOS:000185911000006 PM 14529531 ER PT J AU Polyakov, VI Rukovishnikov, AI Rossukanyi, NM Pereverzev, VG Pimenov, SM Carlisle, JA Gruen, DM Loubnin, EN AF Polyakov, VI Rukovishnikov, AI Rossukanyi, NM Pereverzev, VG Pimenov, SM Carlisle, JA Gruen, DM Loubnin, EN TI Charge-based deep level transient spectroscopy of undoped and nitrogen-doped ultrananocrystalline diamond films SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 8th International Conference on New Diamond Science and Technology CY JUL 21-26, 2002 CL VICTORIA, AUSTRALIA DE nanocrystalline diamond film; nitrogen; electrical properties; deep and shallow levels ID CVD DIAMOND; POLYCRYSTALLINE DIAMOND; EMISSION; BORON AB A comparative study of electrically active defects has been performed for undoped and nitrogen-doped nanocrystalline diamond thin films deposited on Si substrates from CH4/Ar/H-2 and CH4/Ar/N-2 gas mixtures using microwave and d.c. plasma CVD techniques. The method of charge-based deep level transient spectroscopy (Q-DLTS) was applied to obtain information on the concentration, activation energy and capture cross-section of native and nitrogen-induced defects. A common feature in Q-DLTS spectra of undoped films was the presence of a deep level with the activation energy of 0.13-0.22 eV. The Q-DLTS spectra of nitrogen-doped films, however, exhibited a shallow level peak with the activation energy of approximately 0.05 eV. The density of the shallow defects was found to increase with increasing concentration of incorporated nitrogen. The photoelectrical properties of the films were also studied. The kinetics of photoresponse to a high intensity light pulse (in open circuit condition at zero bias) was measured. These photoresponse data were obtained at saturation conditions and were used for designing the energy band diagram for the p-Si/UNCD film/metal and n-Si/UNCD film/metal heterostructures studied. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Radio Engn & Elect, Moscow 103907, Russia. Inst Gen Phys, Moscow 119991, Russia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Russian Acad Sci, Inst Phys Chem, Moscow 117915, Russia. RP Polyakov, VI (reprint author), Russian Acad Sci, Inst Radio Engn & Elect, 11 Mohovaya St, Moscow 103907, Russia. NR 19 TC 20 Z9 22 U1 1 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD OCT-NOV PY 2003 VL 12 IS 10-11 BP 1776 EP 1782 DI 10.1016/S0925-9635(03)00203-6 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 755TJ UT WOS:000187427300028 ER PT J AU Cudnik, BM Dunham, DW Palmer, DM Cook, A Venable, R Gural, PS AF Cudnik, BM Dunham, DW Palmer, DM Cook, A Venable, R Gural, PS TI The observation and characterization of lunar meteoroid impact phenomena SO EARTH MOON AND PLANETS LA English DT Article DE hypervelocity impacts; Leonid meteors; lunar impact phenomena; moon; professional-amateur collaboration; signal detection technology ID MOON; FLASHES AB Confirmed observations of meteoroids from the Leonid stream impacting the Moon in 1999 and 2001 have opened up new opportunities in observational and theoretical astronomy. These opportunities could help bridge the gap between the ground-based ( atmospheric) sampling of the smallest meteoroids and the larger objects observable with ground-based telescopes. The Moon provides a laboratory for the study of hypervelocity impacts, with collision velocities not yet possible in ground-based laboratories. Development of automatic detection software removes the time-intensive activity of laboriously reviewing data for impact event signatures, freeing the observer to engage in other activities. The dynamics of professional-amateur astronomer collaboration have the promise of advancing the study of lunar meteoritic phenomenon considerably. These three factors will assist greatly in the development of a systematic, comprehensive program for monitoring the Moon for meteoroid impacts and determining the physical nature of these impacts. C1 Prairie View A&M Univ, Dept Phys, Prairie View, TX 77446 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. Sci Appl Intl Corp, Chantilly, VA 20151 USA. RP Cudnik, BM (reprint author), Prairie View A&M Univ, Dept Phys, Prairie View, TX 77446 USA. NR 16 TC 2 Z9 2 U1 2 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD OCT PY 2003 VL 93 IS 2 BP 97 EP 106 DI 10.1023/B:MOON.0000034498.32831.3c PG 10 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 837CG UT WOS:000222604200002 ER PT J AU Breshears, DD Whicker, JJ Johansen, MP Pinder, JE AF Breshears, DD Whicker, JJ Johansen, MP Pinder, JE TI Wind and water erosion and transport in semi-arid shrubland, grassland and forest ecosystems: Quantifying dominance of horizontal wind-driven transport SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article; Proceedings Paper CT Joint Meeting of the 5th International Conference on Aeolian Research/Global Change and Terrestrial Ecosystems-Soil Erosion Network CY JUL 22-25, 2002 CL LUBBOCK, TEXAS DE wind erosion; water erosion; aeolian sediment transport; drylands semi-arid ecosystems ID SOUTHERN NEW-MEXICO; AEOLIAN TRANSPORT; ERODED SEDIMENT; CLIMATE-CHANGE; UNITED-STATES; ROCKY FLATS; SOIL; DUST; MANAGEMENT; THRESHOLD AB Soil erosion is an important process in dryland ecosystems, yet measurements and comparisons of wind and water erosion within and among such ecosystems are lacking. Here we compare wind erosion and transport field measurements with water erosion and transport from rainfall-simulation for three different semi-arid ecosystems: a shrubland near Carlsbad, New Mexico; a grassland near Denver, Colorado; and a forest near Los Alamos, New Mexico. In addition to comparing erosion loss from an area, we propose a framework for comparing horizontal mass transport of wind- and water-driven materials as a metric for local soil redistribution. Median erosion rates from wind for vertical mass flux measurements (g m(-2) d(-1)) were 1.5 X 10(-2) for the shrubland, 8.3 x 10(-3) for the grassland, and 9.1 x 10(-3) for the forest. Wind-driven transport from horizontal mass flux measurements was greatest in the shrubland (15.0 g m(-2) d(-1)) followed by the grassland (1-5 g m(-2) d(-1)) and the forest sites (0.17 g m(-2) d(-1)). Annual projections accounting for longer-term site meteorology suggest that wind erosion exceeds water erosion at the shrubland by c. 33 times and by c. five times at the forest, but not the grassland site, where the high clay content of the soils contributed to greater amounts of water erosion: water erosion exceeded wind erosion by about three times. Horizontal transport by wind was greater than that by water for all three systems, overwhelmingly so in the shrubland (factor of c. 2200). Our results, which include some of the only wind erosion measurements to date for semi-arid grasslands and forests, provide a basis for hypothesizing trends in wind and water erosion among ecosystems, highlight the importance of wind erosion and transport in semi-arid ecosystems, and have implications for land surface geomorphology, contaminant transport, and ecosystem biogeochemistry. Copyright (C) 2003 John Wiley Sons, Ltd. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Hlth Safety & Radiat Protect Div, Hlth Phys Measurements Grp, Los Alamos, NM 87545 USA. Colorado State Univ, Dept Environm & Radiol Hlth Sci, Ft Collins, CO 80523 USA. Los Alamos Area Org, Dept Energy, Los Alamos, NM 87544 USA. RP Breshears, DD (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, Mail Stop J495, Los Alamos, NM 87545 USA. RI Johansen, Mathew/D-7049-2012; Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 84 TC 101 Z9 111 U1 2 U2 42 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 OCT PY 2003 VL 28 IS 11 BP 1189 EP 1209 DI 10.1002/esp.1034 PG 21 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 740EE UT WOS:000186388700003 ER PT J AU Kszos, LA Beauchamp, JJ Stewart, AJ AF Kszos, LA Beauchamp, JJ Stewart, AJ TI Toxicity of lithium to three freshwater organisms and the antagonistic effect of sodium SO ECOTOXICOLOGY LA English DT Article DE lithium; sodium; toxicity; Pimephales promelas; Ceriodaphnia dubia; Elimia clavaeformis ID RAINBOW-TROUT; ANTIPORTER; RESPONSES; EXCHANGER; CLEARANCE; CHLORIDE; EXPOSURE; VESICLES; SILVER; METALS AB Lithium (Li) is the lightest metal and occurs primarily in stable minerals and salts. Concentrations of Li in surface water are typically <0.04 mg l(-1) but can be elevated in contaminated streams. Because of the general lack of information concerning the toxicity of Li to common toxicity test organisms, we evaluated the toxicity of Li to Pimephales promelas (fathead minnow), Ceriodaphnia dubia, and a freshwater snail (Elimia clavaeformis). In the laboratory, the concentration of Li that inhibited P. promelas growth or C. dubia reproduction by 25% (IC25) was dependant upon the dilution water. In laboratory control water containing little sodium (&SIM;2.8 mg l(-1)), the IC25s were 0.38 and 0.32 mg Li l(-1) and in ambient stream water containing &SIM;17 mg Na l(-1), the IC25s were 1.99 and 3.33, respectively. A Li concentration of 0.15 mg l(-1) inhibited the feeding of E. clavaeformis in laboratory tests. Toxicity tests conducted to evaluate the effect of sodium on the toxicity of Li were conducted with fathead minnows and C. dubia. The presence of sodium greatly affected the toxicity of Li. Fathead minnows and Ceriodaphnia, for example, tolerated concentrations of Li as great as 6 mg l(-1) when sufficient Na was present. The interaction of Li and Na on the reproduction of Ceriodaphnia was investigated in depth and can be described using an exponential model. The model predicts that C. dubia reproduction would not be affected when animals are exposed to combinations of lithium and sodium with a log ratio of mmol Na to mmol Li equal to at least 1.63. The results of this study indicate that for most natural waters, the presence of sodium is sufficient to prevent Li toxicity. However, in areas of historical disposal or heavy processing or use, an evaluation of Li from a water quality perspective would be warranted. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Lipscomb Univ, Dept Math, Nashville, TN 37204 USA. RP Kszos, LA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,Bethel Valley Rd, Oak Ridge, TN 37831 USA. OI Kszos, Lynn/0000-0002-8218-9032; stewart, arthur/0000-0003-1968-5997 NR 41 TC 16 Z9 16 U1 1 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD OCT PY 2003 VL 12 IS 5 BP 427 EP 437 DI 10.1023/A:1026160323594 PG 11 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 732TQ UT WOS:000185962000006 PM 14649425 ER PT J AU Kszos, LA Stewart, AJ AF Kszos, LA Stewart, AJ TI Review of lithium in the aquatic environment: Distribution in the united states, toxicity and case example of groundwater contamination SO ECOTOXICOLOGY LA English DT Review DE lithium; distribution; toxicity; groundwater ID MOUNTAIN STREAM; TRACER; WATER; RIVER AB Lithium is found at low concentrations in the major rivers of the United States (about 0.002 mg l(-1)) and as a mineral or salt in pegmatites and brines. The United States produces many lithium materials and consumes the greatest amount of Li in the world for use in ceramics, glass, aluminum, pharmaceuticals, batteries, etc. From 1950 to 1970, Li was central to many nuclear-related US Department of Energy (DOE) activities. The historical and current use of Li has not prompted many studies of the toxicity of this element to aquatic organisms. Here, we review the distribution and use of Li in the US with emphasis on usage by DOE. We also summarize information on the toxicity of lithium to aquatic biota. A case-example is provided which demonstrates the potential for contamination of groundwater with Li, evaluates the toxicity of the Li-contaminated groundwater, and identifies a treatment alternative. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Kszos, LA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,Bethel Valley Rd, Oak Ridge, TN 37831 USA. OI Kszos, Lynn/0000-0002-8218-9032; stewart, arthur/0000-0003-1968-5997 NR 51 TC 25 Z9 25 U1 4 U2 30 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD OCT PY 2003 VL 12 IS 5 BP 439 EP 447 DI 10.1023/A:1026112507664 PG 9 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 732TQ UT WOS:000185962000007 PM 14649426 ER PT J AU Doeff, MM Hu, YQ McLarnon, F Kostecki, R AF Doeff, MM Hu, YQ McLarnon, F Kostecki, R TI Effect of surface carbon structure on the electrochemical performance of LiFePO4 SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID FILMS; GRAPHITE; CATHODE AB The electrochemical performance of LiFePO4 samples synthesized by sol-gel or solid-state routes varies considerably, although their physical characteristics are similar. Raman microprobe spectroscopic analysis indicated that the structure of the residual carbon present on the surfaces of the powders differs significantly and accounts for the performance variation. Higher utilization is associated with a larger ratio of sp(2)-coordinated carbon, which exhibits better electronic properties than disordered or sp(3)-coordinated carbonaceous materials. Incorporation of naphthalenetetracarboxylic dianhydride during synthesis results in a more graphitic carbon coating and improves utilization of LiFePO4 in lithium cells, although the total carbon content is not necessarily higher than that of samples prepared without the additive. This result suggests that practical energy density need not be sacrificed for power density, provided that carbon coatings are optimized by carefully choosing additives. (C) 2003 The Electrochemical Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, 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. OI Doeff, Marca/0000-0002-2148-8047 NR 17 TC 310 Z9 333 U1 21 U2 154 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD OCT PY 2003 VL 6 IS 10 BP A207 EP A209 DI 10.1149/1.1601372 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 716BA UT WOS:000185007900001 ER PT J AU Yang, ZG Walker, MS Singh, P Stevenson, JW AF Yang, ZG Walker, MS Singh, P Stevenson, JW TI Anomalous corrosion behavior of stainless steels under SOFC interconnect exposure conditions SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID HIGH-TEMPERATURE CORROSION; OXIDE FUEL-CELLS; ENVIRONMENTS; OXIDATION; HYDROGEN; ALLOY; IRON AB In low and intermediate temperature solid oxide fuel cell (SOFC) stacks, ferritic stainless steels are among the most promising materials to construct the interconnect, which is simultaneously exposed to a fuel on the anode side and an oxidant on the cathode side. However, the corrosion behavior of stainless steels under the interconnect exposure condition was unclear and thus was investigated in a specifically designed apparatus. It was discovered that, under the simultaneous exposure, the oxide scale formed on the air side of the sample was significantly different from the scales formed when the alloy was exposed to air only. It appeared that the anomalous corrosion behavior during the simultaneous dual exposure was due to hydrogen transport through the bulk alloy from the fuel side to the air side. (C) 2003 The Electrochemical Society. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Yang, ZG (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Singh, Prabhakar/M-3186-2013 NR 20 TC 44 Z9 44 U1 1 U2 14 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD OCT PY 2003 VL 6 IS 10 BP B35 EP B37 DI 10.1149/1.1603012 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 716BA UT WOS:000185007900005 ER PT J AU Chaudhry, C Farr, GW Todd, MJ Rye, HS Brunger, AT Adams, PD Horwich, AL Sigler, PB AF Chaudhry, C Farr, GW Todd, MJ Rye, HS Brunger, AT Adams, PD Horwich, AL Sigler, PB TI Role of the gamma-phosphate of ATP in triggering protein folding by GroEL-GroES: function, structure and energetics SO EMBO JOURNAL LA English DT Article DE aluminium fluoride; beryllium fluoride; chaperonin; transition-state analogue ID CYTOPLASMIC CHAPERONIN; MACROMOLECULAR STRUCTURES; ANISOTROPIC REFINEMENT; CRYSTAL-STRUCTURE; MECHANISM; BINDING; HYDROLYSIS; COMPLEX; CYCLE; POLYPEPTIDE AB Productive cis folding by the chaperonin GroEL is triggered by the binding of ATP but not ADP, along with cochaperonin GroES, to the same ring as non-native polypeptide, ejecting polypeptide into an encapsulated hydrophilic chamber. We examined the specific contribution of the gamma-phosphate of ATP to this activation process using complexes of ADP and aluminium or beryllium fluoride. These ATP analogues supported productive cis folding of the substrate protein, rhodanese, even when added to already-formed, folding-inactive cis ADP ternary complexes, essentially introducing the gamma-phosphate of ATP in an independent step. Aluminium fluoride was observed to stabilize the association of GroES with GroEL, with a substantial release of free energy (-46 kcal/mol). To understand the basis of such activation and stabilization, a crystal structure of GroEL-GroES-ADP.AlF3 was determined at 2.8 Angstrom. A trigonal AlF3 metal complex was observed in the gamma-phosphate position of the nucleotide pocket of the cis ring. Surprisingly, when this structure was compared with that of the previously determined GroEL-GroES-ADP complex, no other differences were observed. We discuss the likely basis of the ability of gamma-phosphate binding to convert preformed GroEL-GroES-ADP-polypeptide complexes into the folding-active state. C1 Yale Univ, Sch Med, Dept Genet, New Haven, CT 06510 USA. Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT USA. Yale Univ, Howard Hughes Med Inst, New Haven, CT 06511 USA. Three Dimens Pharmaceut Inc, Yardley, PA USA. Stanford Univ, Dept Cellular & Mol Physiol, Stanford, CA 94305 USA. Stanford Univ, Dept Neurol & Neurol Sci, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Horwich, AL (reprint author), Yale Univ, Sch Med, Dept Genet, New Haven, CT 06510 USA. RI Adams, Paul/A-1977-2013 OI Adams, Paul/0000-0001-9333-8219 NR 43 TC 81 Z9 82 U1 0 U2 10 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0261-4189 J9 EMBO J JI Embo J. PD OCT 1 PY 2003 VL 22 IS 19 BP 4877 EP 4887 DI 10.1093/emboj/cdg477 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 728RZ UT WOS:000185731300001 PM 14517228 ER PT J AU Klara, SM Srivastava, RD McIlvried, HG AF Klara, SM Srivastava, RD McIlvried, HG TI Integrated collaborative technology, development program for CO2 sequestration in geologic formations - United States Department of Energy R&D SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE carbon dioxide sequestration; geological media; sedimentary basins AB A major contributor to increased atmospheric CO2 levels is fossil fuel combustion. Roughly one third of the carbon emissions in the United States comes from power plants. Since electric generation is expected to grow and fossil fuels will continue to be the dominant fuel source, there is growing recognition that the energy industry can be part of the solution to reducing greenhouse gas emissions by capturing and permanently sequestering CO2. Consequently, an important component of the United States Department of Energy's (DOE) research and development program is dedicated to reducing CO2 emissions from power plants by developing technologies for capturing CO2 and for subsequent utilization and/or sequestration. Injection Of CO2 into geologic formations is being practiced today by the petroleum industry for enhanced oil recovery, but it is not yet possible to predict with confidence storage volumes, formation integrity and permanence over long time periods. Many important issues dealing with geologic storage, monitoring and verification of fluids (including CO2) in underground oil and gas reservoirs, coal beds and saline formations must be addressed. Field demonstrations are needed to confirm practical considerations, such as economics, safety, stability, permanence and public acceptance. This paper presents an overview of DOE's research program in the area Of CO2 sequestration and storage in geologic formations and specifically addresses the status of new knowledge, improved tools and enhanced technology for cost optimization, monitoring, modeling and capacity estimation. This paper also highlights those fundamental and applied studies, including field tests, sponsored by DOE that are measuring the degree to which Co-2 can be. injected and remain safely and permanently sequestered in geologic formations while concurrently assuring no adverse long term ecological impacts. Published by Elsevier Science Ltd. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Sci Applicat Int Corp, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Klara, SM (reprint author), US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. NR 8 TC 54 Z9 58 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD OCT PY 2003 VL 44 IS 17 BP 2699 EP 2712 DI 10.1016/S0196-8904(03)00042-6 PG 14 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA 698WE UT WOS:000184021700002 ER PT J AU Wiel, S McMahon, JE AF Wiel, S McMahon, JE TI Governments should implement energy-efficiency standards and labels - cautiously SO ENERGY POLICY LA English DT Article DE standards and labels; energy efficiency; appliances AB Energy-efficiency standards and labels can be the most effective long-term energy-efficiency policy any government call implement. This paper describes: (1) the benefits that can be obtained through this policy, (2) which countries are implementing standards and labels and for which products, (3) the processes they are using at each step along the way including the reasons why each step must be done carefully and thoroughly, and (4) the relationship of standard-setting and labeling to other energy-efficiency policies. Published by Elsevier Science Ltd. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Wiel, S (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,Mail Stop 90-4000, Berkeley, CA 94720 USA. NR 14 TC 17 Z9 17 U1 0 U2 1 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 OCT PY 2003 VL 31 IS 13 BP 1403 EP 1415 AR PII S0301-4215(02)00199-4 DI 10.1016/S0301-4215(02)00199-4 PG 13 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 681VP UT WOS:000183056500009 ER PT J AU Lavine, A Gardner, JN Reneau, SL AF Lavine, A Gardner, JN Reneau, SL TI Total station geologic mapping: an innovative approach to analyzing surface-faulting hazards SO ENGINEERING GEOLOGY LA English DT Article DE total station; seismic hazards; digital mapping; surface rupture; faults ID RIO-GRANDE RIFT; ZONE AB We have developed an innovative application of high-precision geologic mapping with an electronic total station to assess the potential for seismic surface rupture in areas of Los Alamos National Laboratory (LANL). Our method of total station mapping enables recognition of secondary faults, with as little as 30 cm of vertical displacement that are not exposed at the surface, have no topographic expression, and would otherwise likely go unnoticed. It has been applied to preclude the presence of faulting in large areas (several km(2)) of proposed and existing critical facilities at LANL. The method involves surveying of points on geologic features, and detailed computer-aided and field analyses of anomalies in the elevations of surveyed points. We examine vertical anomalies in elevations that are the result of dominantly normal and reverse faulting; however, the method could also be applied to strike-slip faulting. Surveying of geologic contacts allows for easy integration of geologic data into a Geographical Information System (GIS) and detailed 3D analysis of small-scale structures. Field data are analyzed in profiles, 3D surface diagrams, and maps that are constructed with a variety of commercially available software packages. We apply the method to delineate volcanic map-unit boundaries in the 1.2-million-year-old Tshirege Member of the Bandelier Tuff to characterize portions of the Pajarito fault system. The ability of this method to identify faults with very small displacements that otherwise might be unrecognizable allows for discrimination of varying styles of deformation, decreases in displacement along strike through splaying into many smaller faults, monoclinal flexures, and cross structures between faults. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Lavine, A (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, EES-9,Mailstop D462, Los Alamos, NM 87545 USA. NR 53 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0013-7952 J9 ENG GEOL JI Eng. Geol. PD OCT PY 2003 VL 70 IS 1-2 BP 71 EP 91 DI 10.1016/S0013-7952(03)00083-8 PG 21 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA 727DK UT WOS:000185641200006 ER PT J AU Castorina, R Bradman, A McKone, TE Barr, DB Harnly, ME Eskenazi, B AF Castorina, R Bradman, A McKone, TE Barr, DB Harnly, ME Eskenazi, B TI Cumulative organophosphate pesticide exposure and risk assessment among pregnant women living in an agricultural community: A case study from the CHAMACOS cohort SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article DE cumulative dose; exposure; mixtures; organophosphate pesticides; pregnancy; prenatal; risk; urinary metabolites; women ID 24-HOUR CREATININE CLEARANCE; CONTEMPORARY-USE PESTICIDES; DEVELOPMENTAL NEUROTOXICITY; CELLULAR MECHANISMS; PRENATAL EXPOSURE; YOUNG-CHILDREN; CHLORPYRIFOS; URINE; RATS; METABOLITES AB Approximately 230,000 kg of organophosphate (OP) pesticides are applied annually in California's Salinas Valley. These activities have raised concerns about exposures to area residents. We collected three spot urine samples from pregnant women (between 1999 and 2001) enrolled in CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas), a longitudinal birth cohort study, and analyzed them for six dialkyl phosphate metabolites. We used urine from 446 pregnant women to estimate OP pesticide doses with two deterministic steady-state modeling methods: method 1, which assumed the metabolites were attributable entirely to a single diethyl or dimethyl OP pesticide; and method 2, which adapted U.S. Environmental Protection Agency (U.S. EPA) draft guidelines for cumulative risk assessment to estimate dose from a mixture of OP pesticides that share a common mechanism of toxicity. We used pesticide use reporting data for the Salinas Valley to approximate the mixture to which the women were exposed. Based on average OP pesticide dose estimates that assumed exposure to a single OP pesticide (method 1), between 0% and 36.1% of study participants' doses failed to attain a margin of exposure (MOE) of 100 relative to the U.S. EPA oral benchmark dose(10) (BMD10), depending on the assumption made about the parent compound. These BMD10 values are doses expected to produce a 10% reduction in brain cholinesterase activity compared with background response in rats. Given the participants' average cumulative OP pesticide dose estimates (method 2) and regardless of the index chemical selected, we found that 14.8% of the doses failed to attain an MOE of 100 relative to the BMD10 of the selected index. An uncertainty analysis of the pesticide mixture parameter, which is extrapolated from pesticide application data for the study area and not directly quantified for each individual, suggests that this point estimate could range from 1 to 34%. In future analyses, we will use pesticide-specific urinary metabolites, when available, to evaluate cumulative OP pesticide exposures. C1 Univ Calif Berkeley, Ctr Childrens Environm Hlth Res, CHAMACOS, Sch Publ Hlth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ctr Dis Control & Prevent, Natl Ctr Environm Hlth, Atlanta, GA USA. Calif Dept Hlth Serv, Environm Hlth Invest Branch, Oakland, CA USA. RP Eskenazi, B (reprint author), Univ Calif Berkeley, Ctr Childrens Environm Hlth Res, CHAMACOS, Sch Publ Hlth, 2150 Shattuck Ave,Ste 600, Berkeley, CA 94720 USA. RI Barr, Dana/E-6369-2011; Barr, Dana/E-2276-2013 FU NIEHS NIH HHS [P01ES09605] NR 48 TC 57 Z9 60 U1 1 U2 11 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD OCT PY 2003 VL 111 IS 13 BP 1640 EP 1648 DI 10.1289/ehp.5887 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 732JU UT WOS:000185940800031 PM 14527844 ER PT J AU Chang, LY AF Chang, LY TI Alternative chromium reduction and heavy metal precipitation methods for industrial wastewater SO ENVIRONMENTAL PROGRESS LA English DT Article ID ZERO-VALENT IRON; SUBSURFACE REMEDIATION; CHROMATE REDUCTION; CR(VI) REDUCTION; ZEROVALENT IRON; KINETICS; REMOVAL; TRANSPORT; CORROSION; BARRIER AB A study of alternative chromium-reduction and heavy-metal precipitation methods was performed on wastewater generated by a metal-cleaning facility. Four existing chromium-reduction treatment methods were tested on the wastewater samples: treatment with (1) sodium metabisulfite, (2) ferrous sulfate, (3) zero-valent iron, and (4) dimethyl dithio carbamate, ferrous sulfate, and aluminum/chloride. We found that the first two methods are more effective in chrome reduction, while the last method achieved similar reduction results but produced more sludge than any of the other methods. Our results also indicated that when ferrous sulfate was used as a chrome reduction reagent at a low initial pH (2 to 3), the competitive oxidation reaction of ferrous ions with dissolved oxygen in solution is insignificant. When iron powder was used to reduce hexavalent chromium to trivalent chromium, we found that (a) when the sample containing low levels of total chromium (less than or equal to1.54 x 10(-4) mole/liter) was mixed properly with zero-valent iron powders at a low pH (4 to 5), the total chromium concentration could be reduced to 1 mg/l in 3 hours; and (b) the chrome absorption-reduction efficiency is limited by the transport process of Cr(VI)from the bulk of the wastewater to the surface of the iron powder. In a leaching test of used iron powder filtered from the treated wastewater, we also found that most of chromium absorbed on the iron powder was very stable, and only low Cr(VI) was detected in the leachate. C1 Lawrence Berkeley Natl Lab, EH&S Div, Berkeley, CA 94720 USA. RP Chang, LY (reprint author), Lawrence Berkeley Natl Lab, EH&S Div, MS85B,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 25 TC 17 Z9 19 U1 3 U2 19 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD OCT PY 2003 VL 22 IS 3 BP 174 EP 182 DI 10.1002/ep.670220315 PG 9 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 733EJ UT WOS:000185986700006 ER PT J AU Love, AH Hunt, JR Knezovich, JP AF Love, AH Hunt, JR Knezovich, JP TI Reconstructing tritium exposure using tree rings at Lawrence Berkeley National Laboratory, California SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY AB Annual tritium exposures were reconstructed using tree cores from Pinus jeffreyi and Eucalyptus globulus near a tritiated water vapor release stack. Both tritium (H-3) and carbon-14 (C-14) from the wood were measured from milligram samples using accelerator mass spectrometry. Because the annual nature of the eucalyptus tree rings was in doubt, C-14 measurements provided growth rates used to estimate the age for H-3 determinations. A 30-yr comparison of organically bound tritium (OBT) levels to reported H-3 release data is achieved using OBT measurements from three trees near the stack. The annual average H-3,determined from atmospheric water vapor monitoring stations, is comparable to the OBT in proximal trees. For situations without adequate historical monitoring data, this measurement-based historical assessment provides the only independent means of assessing exposure as compared to fate and transport models that require prior knowledge of environmental conditions and H-3 discharge patterns. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Hunt, JR (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. FU NIEHS NIH HHS [P42 ES004705, P42 ES04705, P42 ES004705-180026] NR 18 TC 3 Z9 3 U1 3 U2 11 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 OCT 1 PY 2003 VL 37 IS 19 BP 4330 EP 4335 DI 10.1021/es034278d PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 728BZ UT WOS:000185696500023 PM 14572081 ER PT J AU Kim, AG Kazonich, G Dahlberg, M AF Kim, AG Kazonich, G Dahlberg, M TI Relative solubility of cations in Class F fly ash SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article AB Coal utilization byproducts (CUB), such as fly ash, contain cations that may be released during exposure to fluids such as acid rain or acid mine drainage. Researchers at the Department of Energy's National Energy Technology Laboratory (DOE/NETL) have conducted a long-term column leaching study of 32 Class F fly ash samples from pulverized coal (PC) combustion, and quantified the release of 19 cations in four leachants with a pH between 1.2 and 12. The relative solubility(M-L/T) of each cation was defined as the total mass leached (M-L) relative to the concentration (M-T) of that element in the fly ash sample. A frequency distribution of relative solubility values was computed with ranges defined as insoluble, slightly soluble, moderately soluble, and very soluble. On the basis of this sample set, Ba, Cd, Fe, Pb, Sb, and Se in PC fly ash are insoluble. The elements Al, Be, Ca, Co, Cr, Cu, K, Mg, Mn, Na, Ni, and Zn are slightly to moderately acid soluble. Only Ca and Na are water soluble; As and Ca are soluble in the basic solution. The results of this study indicate that the extent to which cations in Class F PC fly ash can be leached by naturally occurring fluids is very limited. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15235 USA. RP Kim, AG (reprint author), US DOE, Natl Energy Technol Lab, 626 Cochrans Mill Rd,POB 10940, Pittsburgh, PA 15235 USA. NR 4 TC 45 Z9 47 U1 1 U2 8 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 OCT 1 PY 2003 VL 37 IS 19 BP 4507 EP 4511 DI 10.1021/es0263691 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 728BZ UT WOS:000185696500050 PM 14572108 ER PT J AU Adams, SM Greeley, MS Law, JM Noga, EJ Zelikoff, JT AF Adams, SM Greeley, MS Law, JM Noga, EJ Zelikoff, JT TI Application of multiple sublethal stress indicators to assess the health of fish in Pamlico Sound following extensive flooding SO ESTUARIES LA English DT Article ID SOUTHEASTERN UNITED-STATES; AQUATIC ECOSYSTEMS; ICTALURUS-PUNCTATUS; DISSOLVED-OXYGEN; CHANNEL CATFISH; HYPOXIA; CONTAMINANTS; HURRICANES; ORGANISMS; RESPONSES AB Multiple indicators of sublethal stress (bioindicators) were used to assess the health and condition of two important estuarine fish species in the Pamlico Sound estuary following extensive flooding from three sequential hurricanes that occurred during early fall 1999. Bioindicators ranging from the biochemical to the reproductive and organism-level were used to assess the health of southern flounder and spot in Pamlico Sound compared to the health of these same species sampled from a relatively unaffected reference site in lower Core Sound. Many of the physiological, reproductive, immunological, histopathological, and general condition indices suggested that both species, and particularly spot, in Pamlico Sound were sublethally stressed and in poorer condition than fish sampled from Core Sound. The major environmental stressors causing these sublethal stress responses in Pamlico Sound fish appears to be those related to episodic hypoxic exposure or a combination of effects associated with hypoxic conditions such as alterations in preferred habitat and food availability. Although fish populations in Pamlico Sound do not appear to be severely damaged or impaired at this time, organisms that are sublethally stressed can incur increased vulnerability to additional or future stressors such as modified physicochemical regimes, changes in food and habitat availability, and increases in infectious pathogens. Because of the low flushing rate (similar to1 yr) of Pamlico Sound, recovery rate may be exceptionally slow, prolonging any adverse effects of altered nutrient regimes (such as hypoxia) on the health and fitness of resident fish populations. Flooding from the 1999 hurricanes may have contributed to the short-term health and condition of finfish species in Pamlico Sound and also influenced longer-term recovery and ecological status of this system. Longer-term manifestation of effects from flooding may be of particular concern as the frequency of hurricanes is expected to increase over the next few years and the accelerated uses of the coastal zone places further stress on estuarine resources. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. N Carolina State Univ, Coll Vet Med, Raleigh, NC 27606 USA. NYU, Sch Med, Nelson Inst Environm Med, Tuxedo Pk, NY 10987 USA. RP Adams, SM (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RI Greeley, Mark/D-2330-2016 OI Greeley, Mark/0000-0002-6088-5942 NR 70 TC 18 Z9 18 U1 0 U2 4 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD OCT PY 2003 VL 26 IS 5 BP 1365 EP 1382 DI 10.1007/BF02803638 PG 18 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 756JY UT WOS:000187463000014 ER PT J AU Heister, A Schael, S Barate, R Bruneliere, R De Bonis, I Decamp, D Goy, C Jezequel, S Lees, JP Martin, F Merle, E Minard, MN Pietrzyk, B Trocme, B Bravo, S Casado, MP Chmeissani, M Crespo, JM Fernandez, E Fernandez-Bosman, M Garrido, L Martinez, M Pacheco, A Ruiz, H Colaleo, A Creanza, D De Filippis, N de Palma, M Iaselli, G Maggi, G Maggi, M Nuzzo, S Ranieri, A Raso, G Ruggieri, F Selvaggi, G Silvestris, L Tempesta, P Tricomi, A Zito, G Huang, X Lin, J Ouyang, Q Wang, T Xie, Y Xu, R Xue, S Zhang, J Zhang, L Zhao, W Abbaneo, D Azzurri, P Barklow, T Buchmuller, O Cattaneo, M Cerutti, F Clerbaux, B Drevermann, H Forty, RW Frank, M Gianotti, F Hansen, JB Harvey, J Hutchcroft, DE Janot, P Jost, B Kado, M Mato, P Moutoussi, A Ranjard, F Rolandi, L Schlatter, D Sguazzoni, G Tejessy, W Teubert, F Valassi, A Videau, I Ward, JJ Badaud, F Dessagne, S Falvard, A Fayolle, D Gay, P Jousset, J Michel, B Monteil, S Pallin, D Pascolo, JM Perret, P Hansen, JD Hansen, JR Hansen, PH Nilsson, BS Kyriakis, A Markou, C Simopoulou, E Vayaki, A Zachariadou, K Blondel, A Brient, JC Machefert, F Rouge, A Swynghedauw, M Tanaka, R Ciulli, V Focardi, E Parrini, G Antonelli, A Antonelli, M Bencivenni, G Bossi, F Capon, G Cerutti, F Chiarella, V Laurelli, P Mannocchi, G Murtas, GP Passalacqua, L Kennedy, J Lynch, JG Negus, P O'Shea, V Thompson, AS Wasserbaech, S Cavanaugh, R Dhamotharan, S Geweniger, C Hanke, P Hepp, V Kluge, EE Leibenguth, G Putzer, A Stenzel, H Tittel, K Wunsch, M Beuselinck, R Cameron, W Davies, G Dornan, PJ Girone, M Hill, RD Marinelli, N Nowell, J Rutherford, SA Sedgbeer, JK Thompson, JC White, R Ghete, VM Girtler, P Kneringer, E Kuhn, D Rudolph, G Bouhova-Thacker, E Bowdery, CK Clarke, DP Ellis, G Finch, AJ Foster, F Hughes, G Jones, RWL Pearson, MR Robertson, NA Smizanska, M van der Aa, O Delaere, C Lemaitre, V Blumenschein, U Holldorfer, F Jakobs, K Kayser, F Kleinknecht, K Muller, AS Renk, B Sander, HG Schmeling, S Wachsmuth, H Zeitnitz, C Ziegler, T Bonissent, A Coyle, P Curtil, C Ealet, A Fouchez, D Payre, P Tilquin, A Ragusa, F David, A Dietl, H Ganis, G Huttmann, K Lutjens, G Manner, W Moser, HG Settles, R Wolf, G Boucrot, J Callot, O Davier, M Duflot, L Grivaz, JF Heusse, P Jacholkowska, A Serin, L Veillet, JJ Yuan, C Bagliesi, G Boccali, T Foa, L Giammanco, A Giassi, A Ligabue, F Messineo, A Palla, F Sanguinetti, G Sciaba, A Spagnolo, P Tenchini, R Venturi, A Verdini, PG Awunor, O Blair, GA Cowan, G Garcia-Bellido, A Green, MG Jones, LT Medcalf, T Misiejuk, A Strong, JA Teixeira-Dias, P Clifft, RW Edgecock, TR Norton, PR Tomalin, IR Bloch-Devaux, B Boumediene, D Colas, P Fabbro, B Lancon, E Lemaire, MC Locci, E Perez, P Rander, J Tuchming, B Vallage, B Konstantinidis, N Litke, AM Taylor, G Booth, CN Cartwright, S Combley, F Hodgson, PN Lehto, M Thompson, LF Bohrer, A Brandt, S Grupen, C Hess, J Ngac, A Prange, G Borean, C Giannini, G He, H Putz, J Rothberg, J Armstrong, SR Berkelman, K Cranmer, K Ferguson, DPS Gao, Y Gonzalez, S Hayes, OJ Hu, H Jin, S Kile, J McNamara, PA Nielsen, J Pan, YB von Wimmersperg-Toeller, JH Wiedenmann, W Wu, J Wu, SL Wu, X Zobernig, G Dissertori, G AF Heister, A Schael, S Barate, R Bruneliere, R De Bonis, I Decamp, D Goy, C Jezequel, S Lees, JP Martin, F Merle, E Minard, MN Pietrzyk, B Trocme, B Bravo, S Casado, MP Chmeissani, M Crespo, JM Fernandez, E Fernandez-Bosman, M Garrido, L Martinez, M Pacheco, A Ruiz, H Colaleo, A Creanza, D De Filippis, N de Palma, M Iaselli, G Maggi, G Maggi, M Nuzzo, S Ranieri, A Raso, G Ruggieri, F Selvaggi, G Silvestris, L Tempesta, P Tricomi, A Zito, G Huang, X Lin, J Ouyang, Q Wang, T Xie, Y Xu, R Xue, S Zhang, J Zhang, L Zhao, W Abbaneo, D Azzurri, P Barklow, T Buchmuller, O Cattaneo, M Cerutti, F Clerbaux, B Drevermann, H Forty, RW Frank, M Gianotti, F Hansen, JB Harvey, J Hutchcroft, DE Janot, P Jost, B Kado, M Mato, P Moutoussi, A Ranjard, F Rolandi, L Schlatter, D Sguazzoni, G Tejessy, W Teubert, F Valassi, A Videau, I Ward, JJ Badaud, F Dessagne, S Falvard, A Fayolle, D Gay, P Jousset, J Michel, B Monteil, S Pallin, D Pascolo, JM Perret, P Hansen, JD Hansen, JR Hansen, PH Nilsson, BS Kyriakis, A Markou, C Simopoulou, E Vayaki, A Zachariadou, K Blondel, A Brient, JC Machefert, F Rouge, A Swynghedauw, M Tanaka, R Ciulli, V Focardi, E Parrini, G Antonelli, A Antonelli, M Bencivenni, G Bossi, F Capon, G Cerutti, F Chiarella, V Laurelli, P Mannocchi, G Murtas, GP Passalacqua, L Kennedy, J Lynch, JG Negus, P O'Shea, V Thompson, AS Wasserbaech, S Cavanaugh, R Dhamotharan, S Geweniger, C Hanke, P Hepp, V Kluge, EE Leibenguth, G Putzer, A Stenzel, H Tittel, K Wunsch, M Beuselinck, R Cameron, W Davies, G Dornan, PJ Girone, M Hill, RD Marinelli, N Nowell, J Rutherford, SA Sedgbeer, JK Thompson, JC White, R Ghete, VM Girtler, P Kneringer, E Kuhn, D Rudolph, G Bouhova-Thacker, E Bowdery, CK Clarke, DP Ellis, G Finch, AJ Foster, F Hughes, G Jones, RWL Pearson, MR Robertson, NA Smizanska, M van der Aa, O Delaere, C Lemaitre, V Blumenschein, U Holldorfer, F Jakobs, K Kayser, F Kleinknecht, K Muller, AS Renk, B Sander, HG Schmeling, S Wachsmuth, H Zeitnitz, C Ziegler, T Bonissent, A Coyle, P Curtil, C Ealet, A Fouchez, D Payre, P Tilquin, A Ragusa, F David, A Dietl, H Ganis, G Huttmann, K Lutjens, G Manner, W Moser, HG Settles, R Wolf, G Boucrot, J Callot, O Davier, M Duflot, L Grivaz, JF Heusse, P Jacholkowska, A Serin, L Veillet, JJ Yuan, C Bagliesi, G Boccali, T Foa, L Giammanco, A Giassi, A Ligabue, F Messineo, A Palla, F Sanguinetti, G Sciaba, A Spagnolo, P Tenchini, R Venturi, A Verdini, PG Awunor, O Blair, GA Cowan, G Garcia-Bellido, A Green, MG Jones, LT Medcalf, T Misiejuk, A Strong, JA Teixeira-Dias, P Clifft, RW Edgecock, TR Norton, PR Tomalin, IR Bloch-Devaux, B Boumediene, D Colas, P Fabbro, B Lancon, E Lemaire, MC Locci, E Perez, P Rander, J Tuchming, B Vallage, B Konstantinidis, N Litke, AM Taylor, G Booth, CN Cartwright, S Combley, F Hodgson, PN Lehto, M Thompson, LF Bohrer, A Brandt, S Grupen, C Hess, J Ngac, A Prange, G Borean, C Giannini, G He, H Putz, J Rothberg, J Armstrong, SR Berkelman, K Cranmer, K Ferguson, DPS Gao, Y Gonzalez, S Hayes, OJ Hu, H Jin, S Kile, J McNamara, PA Nielsen, J Pan, YB von Wimmersperg-Toeller, JH Wiedenmann, W Wu, J Wu, SL Wu, X Zobernig, G Dissertori, G CA ALEPH Collaboration TI Search for supersymmetric particles with R-parity violating decays in e(+)e(-) collisions at root s up to 209 GeV SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID OF-MASS ENERGIES; MONTE-CARLO; PAIR PRODUCTION; LEP; PHYSICS; GENERATION; DETECTOR; ALEPH; TEV AB Searches for the pair production of supersymmetric particles under the assumption that R-parity is violated via a single dominant LL (E) over bar, LQ (D) over bar or (UDD) over bar coupling are performed using the data collected by the ALEPH detector at LEP at centre-of-mass energies from 189 to 209 GeV. The numbers of observed candidate events in the data are in agreement with the Standard Model expectation, and limits on the production cross sections and on the masses of charginos, sleptons, squarks and sneutrinos are derived. C1 Rhein Westfal TH Aachen, Inst Phys, D-52056 Aachen, Germany. LAPP, IN2P3, CNRS, F-74019 Annecy Le Vieux, France. Univ Autonoma Barcelona, Inst Fis Altes Energies, Bellaterra, Barcelona, Spain. Ist Nazl Fis Nucl, Sez Bari, Dipartimento Fis, I-70126 Bari, Italy. Acad Sinica, Inst High Energy Phys, Beijing, Peoples R China. CERN, European Lab Particle Phys, CH-1211 Geneva 23, Switzerland. Univ Clermont Ferrand, Phys Corpusculaire Lab, CNRS, IN2P3, F-63177 Clermont Ferrand, Aubiere, France. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. NRCD, Athens 15310, Greece. Ecole Polytech, CNRS, IN2P3, Lab Leprince Ringuet, F-91128 Palaiseau, France. Univ Florence, Dipartimento Fis, Sez Firenze, Ist Nazl Fis Nucl, I-50125 Florence, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Haverford Coll, Dept Phys, Haverford, PA 19041 USA. Univ Heidelberg, Kirchhoff Inst Phys, D-69120 Heidelberg, Germany. Univ London Imperial Coll Sci Technol & Med, Dept Phys, London SW7 2BZ, England. Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria. Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England. Catholic Univ Louvain, Inst Phys Nucl, Dept Phys, B-1348 Louvain, Belgium. Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany. Univ Aix Marseille 2, CNRS, IN2P3, Ctr Phys Particules Marseille, F-13288 Marseille, France. Univ Milan, Dipartimento Fis, Sez Milano, Ist Nazl Fis Nucl, I-20133 Milan, Italy. Max Planck Inst Phys & Astrophys, Werner Heisenberg Inst, D-80805 Munich, Germany. Univ Paris 11, Accelerateur Lineaire Lab, CNRS, IN2P3, F-91898 Orsay, France. Ist Nazl Fis Nucl, Sez Pisa & Scuola Norm Super, Dipartimento Fis, I-56010 Pisa, Italy. Univ London Royal Holloway & Bedford New Coll, Dept Phys, Egham TW20 0EX, Surrey, England. Rutherford Appleton Lab, Particle Phys Dept, Didcot OX11 0QX, Oxon, England. CEA Saclay, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Univ Siegen, Fachbereich Phys, D-57068 Siegen, Germany. Univ Trieste, Ist Nazl Fis Nucl, Dipartimento Fis, Sez Trieste, I-34127 Trieste, Italy. Univ Washington, Expt Elementary Particle Phys, Seattle, WA 98195 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. ETH Honggerberg, Inst Particle Phys, CH-8093 Zurich, Switzerland. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Dipartimento Fis, I-95129 Catania, Italy. Ist Nazl Fis Nucl, Sez Catania, I-95129 Catania, Italy. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. CNR, Ist Cosmo Geofis, Turin, Italy. Univ Montpellier 2, Grp Astroparticules, F-34095 Montpellier, France. Univ Geneva, Dept Phys Corpusculaire, CH-1211 Geneva 4, Switzerland. Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. Univ Barcelona, Barcelona 08208, Spain. SAP AG, D-69185 Walldorf, Germany. BNP Paribas, D-60325 Frankfurt, Germany. Free Univ Brussels, ITHE, B-1050 Brussels, Belgium. Univ Palermo, Dipartimento Fis & Tecnol Relat, Palermo, Italy. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Roma Tor Vergata, Dipartimento Fis, Ist Nazl Fis Nucl, Sez Roma 2, I-00133 Rome, Italy. RP Heister, A (reprint author), Rhein Westfal TH Aachen, Inst Phys, D-52056 Aachen, Germany. RI ANTONELLI, ANTONELLA/C-6238-2011; Hansen, John/B-9058-2015; Passalacqua, Luca/F-5127-2011; Venturi, Andrea/J-1877-2012; Valassi, Andrea/K-7506-2012; Rolandi, Luigi (Gigi)/E-8563-2013; Colas, Paul/F-2876-2013; Ruiz, Hugo/H-4141-2013; Jones, Roger/H-5578-2011; O'Shea, Val/G-1279-2010; Fernandez, Enrique/L-5387-2014; Bosman, Martine/J-9917-2014; Chmeissani, Mokhtar/G-4346-2015; Sguazzoni, Giacomo/J-4620-2015; Booth, Christopher/B-5263-2016; Pacheco Pages, Andres/C-5353-2011; Casado, Pilar/H-1484-2015; Ligabue, Franco/F-3432-2014; OI Hansen, John/0000-0002-8422-5543; Valassi, Andrea/0000-0001-9322-9565; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Jones, Roger/0000-0002-6427-3513; O'Shea, Val/0000-0001-7183-1205; Fernandez, Enrique/0000-0002-6405-9488; Bosman, Martine/0000-0002-7290-643X; Chmeissani, Mokhtar/0000-0002-2287-4791; Ciulli, Vitaliano/0000-0003-1947-3396; Finch, Alexander/0000-0002-5433-6031; Sguazzoni, Giacomo/0000-0002-0791-3350; Booth, Christopher/0000-0002-6051-2847; Pacheco Pages, Andres/0000-0001-8210-1734; Casado, Pilar/0000-0002-0394-5646; Boccali, Tommaso/0000-0002-9930-9299; Ligabue, Franco/0000-0002-1549-7107; Bloch-Devaux, Brigitte/0000-0002-2463-1232; Awunor, Onuora/0000-0002-2636-9709; Tricomi, Alessia Rita/0000-0002-5071-5501; RASO, Giuseppe/0000-0002-5660-3711 NR 30 TC 42 Z9 42 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD OCT PY 2003 VL 31 IS 1 BP 1 EP 16 DI 10.1140/epjc/s2003-01311-5 PG 16 WC Physics, Particles & Fields SC Physics GA 743ZX UT WOS:000186604400001 ER PT J AU Freeman, RR Anderson, C Hill, JM King, J Snavely, R Hatchett, S Key, M Koch, J MacKinnon, A Stephens, R Cowan, T AF Freeman, RR Anderson, C Hill, JM King, J Snavely, R Hatchett, S Key, M Koch, J MacKinnon, A Stephens, R Cowan, T TI High-intensity lasers and controlled fusion SO EUROPEAN PHYSICAL JOURNAL D LA English DT Article ID TRANSPORT; IGNITION; PLASMA; GAIN AB The use of high-intensity lasers to cause ignition in inertial confinement fusion is presented, with emphasis on current experimental programs and physical concepts that are at the forefront of the field. In particular, we highlight the issues of fast electron transport through dense materials, an essential element of the "Fast Ignitor" concept. C1 Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Gen Atom Co, San Diego, CA USA. RP Freeman, RR (reprint author), Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RI MacKinnon, Andrew/P-7239-2014; Cowan, Thomas/A-8713-2011; OI MacKinnon, Andrew/0000-0002-4380-2906; Cowan, Thomas/0000-0002-5845-000X; Stephens, Richard/0000-0002-7034-6141 NR 15 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6060 J9 EUR PHYS J D JI Eur. Phys. J. D PD OCT PY 2003 VL 26 IS 1 BP 73 EP 77 DI 10.1140/epjd/e2003-00246-x PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 731ZB UT WOS:000185915400013 ER PT J AU Hakem, IF Lal, J AF Hakem, IF Lal, J TI Polyelectrolyte-like behaviour of poly(ethylene-oxide) solutions with added monovalent salt SO EUROPHYSICS LETTERS LA English DT Article ID OXIDE); SCATTERING AB Solvent effects on the conformation of poly(ethylene-oxide) (PEO) and complexation of PEO by monovalent cations have been examined by using small-angle neutron scattering. In methanol and acetonitrile, a big change in interchain interaction, osmotic compressibility and local chain conformation have been observed upon addition of small amounts of potassium iodide. The amplitude of the total intensity decreases significantly and a peak at a certain value of the wave vector q* appears as signature of a polyelectrolyte-like behaviour. With further addition of salt, the ionic strength of the solution increases and potassium binding becomes less favorable: the binding constant decreases with the ionic strength and PEO behaves as a neutral polymer with excluded volume. No association between PEO and potassium iodide was observed in aqueous solutions. C1 Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. Tlemcen Univ, Fac Sci, Dept Phys, Tilimsen 13000, Algeria. RP Hakem, IF (reprint author), Argonne Natl Lab, IPNS, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hakem, Ilhem F. /C-8374-2014 NR 16 TC 17 Z9 17 U1 2 U2 16 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD OCT PY 2003 VL 64 IS 2 BP 204 EP 210 DI 10.1209/epl/i2003-00294-2 PG 7 WC Physics, Multidisciplinary SC Physics GA 729PB UT WOS:000185781400009 ER PT J AU Hickerson, MJ Gilchrist, MA Takebayashi, N AF Hickerson, MJ Gilchrist, MA Takebayashi, N TI Calibrating a molecular clock from phylogeographic data: Moments and likelihood estimators SO EVOLUTION LA English DT Article DE ancestral population size; coalescent; DNA substitution rate; geminate species; phylogeography ID MITOCHONDRIAL-DNA; MODERN HUMANS; SEA-URCHINS; POPULATION-STRUCTURE; EVOLUTIONARY RATES; GENETIC-DIVERGENCE; EASTERN PACIFIC; SPECIATION; ISTHMUS; PANAMA AB We present moments and likelihood methods that estimate a DNA substitution rate from a group of closely related sister species pairs separated at an assumed time. and we test these methods with simulations. The methods also estimate ancestral population size and can test whether there is a significant difference among the ancestral population sizes of the sister species pairs. Estimates presented in the literature often ignore the ancestral coalescent prior to speciation and therefore should be biased upward. The simulations show that both methods yield accurate estimates given sample sizes of five or more species pairs and that better likelihood estimates are obtained if there is no significant difference among ancestral population sizes. The model presented here indicates that the larger than expected variation found in multitaxa datasets can be explained by variation in the ancestral coalescence and the Poisson mutation process. In this context, observed variation can often be accounted for by variation in ancestral population sizes rather than invoking variation in other parameters, such as divergence time or mutation rate. The methods are applied to data from two groups of species pairs (sea urchins and Alpheus snapping shrimp) that are thought to have separated by the rise of Panama three million years ago. C1 Duke Univ, Dept Biol, Durham, NC 27708 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Hickerson, MJ (reprint author), Univ New Mexico, Dept Biol, 167A Castetter Hall, Albuquerque, NM 87131 USA. EM mjh2@duke.edu; mike@unm.edu; ntakebay@duke.edu RI Gilchrist, Michael/A-8209-2008 OI Gilchrist, Michael/0000-0002-6936-0771 NR 61 TC 20 Z9 20 U1 0 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0014-3820 EI 1558-5646 J9 EVOLUTION JI Evolution PD OCT PY 2003 VL 57 IS 10 BP 2216 EP 2225 PG 10 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 740PG UT WOS:000186410300002 PM 14628910 ER PT J AU Cao, WS Baniecki, ML McGrath, WJ Bao, C Deming, CB Rade, JJ Lowenstein, CJ Mangel, WF AF Cao, WS Baniecki, ML McGrath, WJ Bao, C Deming, CB Rade, JJ Lowenstein, CJ Mangel, WF TI Nitric oxide inhibits the adenovirus proteinase in vitro and viral infectivity in vivo SO FASEB JOURNAL LA English DT Article DE S-nitrosylation; antiviral agent; proteinase inhibitor; cysteine proteinase; diethylamine NONOate ID CYTOKERATIN NETWORK; SYNTHASE ACTIVITY; VIRUS-PARTICLES; REPLICATION; COFACTOR; PROTEASE; MECHANISM; PEPTIDE; BINDING; PAPAIN AB Nitric oxide (NO) is an antiviral effector of the innate immune system, but few of the viral targets of NO have been identified. We now show that NO inhibits adenovirus replication by targeting the adenovirus proteinase (AVP). NO generated from diethylamine NONOate (DEA-NONOate) or spermine NONOate (Sp-NONOate) inhibited the AVP. Inhibition was reversible with dithiothreitol. The equilibrium dissociation constant for reversible binding to the AVP by Sp-NONOate, or K-i, was 0.47 mM, and the first-order rate constant for irreversible inhibition of the AVP by Sp-NONOate, or k(i), was 0.0036 s(-1). Two hallmarks of a successful adenovirus infection were abolished by the NO donors: the appearance of E1A protein and the cleavage of cytokeratin 18 by AVP. Treatment of infectious virus by DEA-NONOate dramatically decreased viral infectivity. These data suggest that NO may be a useful antiviral agent against viruses encoding a cysteine proteinase and in particular may be an antiadenovirus agent. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Johns Hopkins Univ, Sch Med, Dept Med, Div Cardiol, Baltimore, MD 21205 USA. SUNY Stony Brook, Dept Pharmacol Sci, Stony Brook, NY 11794 USA. RP Mangel, WF (reprint author), Brookhaven Natl Lab, Dept Biol, 50 Bell Ave, Upton, NY 11973 USA. EM Mangel@BNL.Gov NR 34 TC 16 Z9 17 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD OCT PY 2003 VL 17 IS 13 BP 2345 EP + DI 10.1096/fj.03-0396fje PG 19 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 739KH UT WOS:000186343300009 PM 14525937 ER PT J AU Ebert, TA Southon, JR AF Ebert, TA Southon, JR TI Red sea urchins (Strongylocentrotus franciscanus) can live over 100 years: confirmation with A-bomb (14)carbon SO FISHERY BULLETIN LA English DT Article ID POPULATION-DYNAMICS; ARCTICA-ISLANDICA; AGE-DETERMINATION; GROWTH ZONES; KELP FOREST; ECHINOIDEA; ECHINODERMATA; RADIOCARBON; RECRUITMENT; MORTALITY C1 Oregon State Univ, Dept Zool, Corvallis, OR 97331 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Oregon State Univ, Dept Zool, Corvallis, OR 97331 USA. EM ebertt@sciences.oregonstate.edu NR 58 TC 80 Z9 80 U1 0 U2 14 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 EI 1937-4518 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2003 VL 101 IS 4 BP 915 EP 922 PG 8 WC Fisheries SC Fisheries GA 746FE UT WOS:000186735700019 ER PT J AU Sharp, JA Krawitz, DC Gardner, KA Fox, CA Kaufman, PD AF Sharp, JA Krawitz, DC Gardner, KA Fox, CA Kaufman, PD TI The budding yeast silencing protein Sir1 is a functional component of centromeric chromatin SO GENES & DEVELOPMENT LA English DT Article DE chromatin assembly; centromere; kinetochore; yeast; silencing ID ASSEMBLY FACTOR-I; ORIGIN RECOGNITION COMPLEX; SACCHAROMYCES-CEREVISIAE; CHROMOSOME SEGREGATION; HIR PROTEINS; HISTONE H3; GENE-EXPRESSION; HETEROCHROMATIN; DOMAIN; KINETOCHORES AB In fission yeast and multicellular organisms, centromere-proximal regions of chromosomes are heterochromatic, containing proteins that silence gene expression. In contrast, the relationship between heterochromatin proteins and kinetochore function in the budding yeast Saccharomyces cerevisiae remains largely unexplored. Here we report that the yeast heterochromatin protein Sir1 is a component of centromeric chromatin and contributes to mitotic chromosome stability. Sir1 recruitment to centromeres occurred through a novel mechanism independent of its interaction with the origin recognition complex (ORC). Sir1 function at centromeres was distinct from its role in forming heterochromatin, because the Sir2-4 proteins were not associated with centromeric regions. Sir1 bound to Cac1, a subunit of chromatin assembly factor I (CAF-I), and helped to retain Cac1 at centromeric loci. These studies reveal that although budding yeast and mammalian cells use fundamentally different mechanisms of forming heterochromatin, they both use silencing proteins to attract the histone deposition factor CAF-I to centromeric chromatin. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Wisconsin, Sch Med, Dept Biomol Chem, Madison, WI 53706 USA. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM pdkaufman@lbl.gov OI Kaufman, Paul/0000-0003-3089-313X FU NIGMS NIH HHS [R01 GM055712] NR 32 TC 33 Z9 36 U1 0 U2 1 PU COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT PI COLD SPRING HARBOR PA 1 BUNGTOWN RD, COLD SPRING HARBOR, NY 11724 USA SN 0890-9369 EI 1549-5477 J9 GENE DEV JI Genes Dev. PD OCT 1 PY 2003 VL 17 IS 19 BP 2356 EP 2361 DI 10.1101/gad.1131103 PG 6 WC Cell Biology; Developmental Biology; Genetics & Heredity SC Cell Biology; Developmental Biology; Genetics & Heredity GA 729DW UT WOS:000185757800003 PM 12975325 ER PT J AU Templeton, AS Trainor, TP Spormann, AM Brown, GE AF Templeton, AS Trainor, TP Spormann, AM Brown, GE TI Selenium speciation and partitioning within Burkholderia cepacia biofilms formed on alpha-Al2O3 surfaces SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; ELEMENTAL SELENIUM; SELENATE REDUCTION; STANDING WAVES; BACTERIUM; INTERFACES; SORPTION; TRANSFORMATION; FLUORESCENCE; RESPIRATION AB The distribution and speciation of Se within aerobic Burkholderia cepacia biofilms formed on alpha-Al2O3 (1-102) surfaces have been examined using grazing-angle X-ray spectroscopic techniques. We present quantitative information on the partitioning of 10(-6) M to 10(-3) M selenate and selenite between the biofilms and underlying alumina surfaces derived from long-period X-ray standing wave (XSW) data. Changes in the Se partitioning behavior over time are correlated with microbially induced reduction of Se(VI) and Se(IV) to Se(0), as observed from X-ray absorption near edge structure (XANES) spectroscopy. Selenite preferentially binds to the alumina surfaces, particularly at low [Se], and is increasingly partitioned into the biofilms at higher [Se]. When B. cepacia is metabolically active, B. cepacia rapidly reduces a fraction of the SeO32- to red elemental Se(0). In contrast, selenate is preferentially partitioned into the B. cepacia biofilms at all [Se] tested due to a lower affinity for binding to the alumina surface. Rapid reduction of SeO42- by B. cepacia to Se(IV) and Se(0) subsequently results in a vertical segregation of Se species at the B. cepacia/alpha-Al2O3 interface. Elemental Se(0) accumulates within the biofilm with Se(VI), whereas Se(IV) intermediates preferentially sorb to the alumina surface. B. cepacia/alpha-Al2O3 samples incubated with SeO42- and SeO32- when the bacteria were metabolically active result in a significant reduction in the mobility of Se vs. X-ray treated biofilms. Remobilization experiments show that a large fraction of the insoluble Se(0) produced within the biofilm is retained during exchange with Se-free solutions. In addition, Se(IV) intermediates generated during Se(VI) reduction are preferentially bound to the alumina surface and do not fully desorb. In contrast, Se(VI) is rapidly and extensively remobilized. Copyright (C) 2003 Elsevier Ltd. C1 Stanford Univ, Dept Geol & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94035 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60439 USA. Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. SLAC, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Templeton, AS (reprint author), Univ Calif San Diego, Div Marine Biol Res, Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM atempleton@ucsd.edu OI TEMPLETON, ALEXIS/0000-0002-9670-0647 NR 52 TC 29 Z9 30 U1 2 U2 11 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 OCT PY 2003 VL 67 IS 19 BP 3547 EP 3557 DI 10.1016/S0016-7037(03)00212-6 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 728UK UT WOS:000185734600002 ER PT J AU Gu, BH Chen, J AF Gu, BH Chen, J TI Enhanced microbial reduction of Cr(VI) and U(VI) by different natural organic matter fractions SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HUMIC SUBSTANCES; FLUORESCENCE SPECTROSCOPY; DISSIMILATORY REDUCTION; ELECTRON-ACCEPTORS; REDUCING BACTERIA; REDOX PROPERTIES; FULVIC-ACID; IRON; CHROMIUM(VI); GROUNDWATER AB Although direct microbial reduction of Cr(VI) and U(VI) is known, few studies have examined the kinetics and the underlying mechanisms of the reduction of these contaminants by different natural organic matter (NOM) fractions in the presence or absence of microorganisms. In this study, NOM was found to chemically reduce Cr(VI) at pH 3, but the reduction rates were negligible at pH similar to7. The abiotic reduction of U(VI) by NOM was not observed, possibly because of the presence of small amounts of nitrate in the reactant solution. However, all NOM fractions, particularly the soil humic acid (HA), enhanced the bioreduction of Cr(VI) or U(VI) in the presence of Shewanella putrefaciens CN32. The reduction rates varied greatly among NOM fractions with different chemical and structural properties: the polyphenolic-rich NOM-PP fraction appeared to be the most reactive in abiotically reducing Cr(VI) at a low pH, but soil HA was more effective in mediating the microbial reduction of Cr(VI) and U(VI) under anaerobic, circumneutral pH conditions. These observations are attributed to an increased solubility and conformational changes of the soil HA with pH and, more importantly, its relatively high contents of polycondensed and conjugated aromatic organic moieties. An important implication of this study is that, depending on chemical and structural properties, different NOM components may play different roles in enhancing the bioreduction of Cr(VI) and U(VI) by microorganisms. Polycondensed aromatic humic materials may be particularly useful in mediating the bioreduction and rapid immobilization of these contaminant metals in soil. Copyright (C) 2003 Elsevier Ltd. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Gu, BH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,MS 6036, Oak Ridge, TN 37831 USA. RI Gu, Baohua/B-9511-2012 OI Gu, Baohua/0000-0002-7299-2956 NR 48 TC 99 Z9 112 U1 4 U2 41 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 OCT PY 2003 VL 67 IS 19 BP 3575 EP 3582 DI 10.1016/S0016-7037(03)00162-5 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 728UK UT WOS:000185734600004 ER PT J AU Wilson, JE Goodwin, LB Lewis, CJ AF Wilson, JE Goodwin, LB Lewis, CJ TI Deformation bands in nonwelded ignimbrites: Petrophysical controls on fault-zone deformation and evidence of preferential fluid flow SO GEOLOGY LA English DT Article ID RIO-GRANDE RIFT; NEW-MEXICO; PERMEABILITY STRUCTURE; POROUS SANDSTONES; ARCHITECTURE; CALIFORNIA; COUNTY; GROWTH; NEVADA AB The impact of faults on fluid flow and transport through thick vadose zones depends in part on the nature of fault-zone deformation. Both fractures and deformation bands occur in ignimbrite sequences at Los Alamos, New Mexico, and Busted Butte, Nevada. The primary controls on mode of failure are grain-contact area and strength, which are directly related to degree of welding and crystallization and inversely proportional to porosity. Low-porosity welded units deform by transgranular fracture; high-porosity, glassy, nonwelded units deform by cataclasis within deformation bands. Moderately high porosity, nonwelded units that have undergone devitrification and/or vapor-phase crystallization form either deformation bands or fractures, depending on local variations in the degree and nature of crystallization. Grain- and pore-size reduction in deformation bands commonly produces indurated, tabular zones of clay-sized fault material. Many of these bands are locally rich in smectite and/or cemented by carbonate. Preferential wetting of deformation bands is inferred to promote alteration and cementation. We therefore interpret variably altered fault-zone material as evidence of preferential fluid flow in the vadose zone, which we infer to result from enhanced unsaturated permeability due to pore-size reduction in deformation bands. C1 New Mexico Inst Min & Technol, Earth & Environm Sci Dept, Socorro, NM 87801 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, EES 9, Los Alamos, NM 87545 USA. RP Wilson, JE (reprint author), New Mexico Inst Min & Technol, Earth & Environm Sci Dept, 801 Leroy Pl, Socorro, NM 87801 USA. NR 27 TC 30 Z9 30 U1 0 U2 1 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD OCT PY 2003 VL 31 IS 10 SU 1 BP 837 EP 840 DI 10.1130/G19667R.1 PG 4 WC Geology SC Geology GA 728AC UT WOS:000185692200002 ER PT J AU Kang, SY Doh, S Lee, D Lee, D Jin, VL Kimball, JS AF Kang, SY Doh, S Lee, D Lee, D Jin, VL Kimball, JS TI Topographic and climatic controls on soil respiration in six temperate mixed-hardwood forest slopes, Korea SO GLOBAL CHANGE BIOLOGY LA English DT Article DE climate; microtopography; spatial heterogeneity; soil respiration; soil water content ID WATER-RETENTION; CO2 EVOLUTION; LITTER DECOMPOSITION; NUMERICAL EVALUATION; ECOSYSTEM PROCESSES; TEMPORAL PATTERNS; AIR-TEMPERATURE; BULK-DENSITY; CLEAR-CUT; CARBON AB To better understand the effects of local topography and climate on soil respiration, we conducted field measurements and soil incubation experiments to investigate various factors influencing spatial and temporal variations in soil respiration for six mixed-hardwood forest slopes in the midst of the Korean Peninsula. Soil respiration and soil water content (SWC) were significantly greater (P=0.09 and 0.003, respectively) on north-facing slopes compared to south-facing slopes, while soil temperature was not significantly different between slopes (P>0.5). At all sites, soil temperature was the primary factor driving temporal variations in soil respiration (r(2)=0.84-0.96) followed by SWC, which accounted for 30% of soil respiration spatial and temporal variability. Results from both field measurements and incubation experiments indicate that variations in soil respiration due to aspect can be explained by a convex-shaped function relating SWC to normalized soil respiration rates. Annual soil respiration estimates (1070-1246 g C m(-2) yr(-1)) were not closely related to mean annual air temperatures among sites from different climate regimes. When soils from each site were incubated at similar temperatures in a laboratory, respiration rates for mineral soils from wetter and cooler sites were significantly higher than those for the drier and warmer sites (n=4, P<0.01). Our results indicate that the application of standard temperature-based Q(10) models to estimate soil respiration rates for larger geographic areas covering different aspects or climatic regimes are not adequate unless other factors, such as SWC and total soil nitrogen, are considered in addition to soil temperature. C1 Seoul Natl Univ, Grad Sch Environm Studies, Environm Planning Inst, Seoul 151742, South Korea. Univ Montana, Numer Terradynam Simulat Grp, Missoula, MT USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Dept Plant Biol, Aiken, SC 29802 USA. Univ Montana, Flathead Lake Biol Stn, Polson, MT 59860 USA. RP Kang, SY (reprint author), Univ Montana, Sch Forestry, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA. NR 45 TC 88 Z9 150 U1 2 U2 41 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD OCT PY 2003 VL 9 IS 10 BP 1427 EP 1437 DI 10.1046/j.1365-2486.2003.00668.x PG 11 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 730QR UT WOS:000185841900007 ER PT J AU Tolstykh, EI Shishkina, EA Degteva, MO Ivanov, DV Shved, VA Bayankin, SN Anspaugh, LR Napier, BA Wieser, A Jacob, P AF Tolstykh, EI Shishkina, EA Degteva, MO Ivanov, DV Shved, VA Bayankin, SN Anspaugh, LR Napier, BA Wieser, A Jacob, P TI Age dependencies of Sr-90 incorporation in dental tissues: Comparative analysis and interpretation of different kinds of measurements obtained for residents on the Techa River SO HEALTH PHYSICS LA English DT Article DE biokinetics; bones, human; contamination, environmental; Sr-90 ID EPR DOSE RECONSTRUCTION; DOSIMETRY SYSTEM; URALS POPULATION; TOOTH ENAMEL; TEETH; SPECTROSCOPY; STRONTIUM-90 AB Human teeth have been considered as dosimeters for decades. Methods include the in vivo measurement of Sr-90/Y-90 in teeth,with a tooth-beta counter, the radiochemical determination of Sr-90 in whole teeth, and the measurement of dose in teeth by use of electron paramagnetic resonance. Presented in this paper are results of 2,514 tooth-beta counter measurements, 334 radiochemical measurements, and 218 electron paramagnetic resonance measurements for residents living in settlements along the Techa River. All three kinds of measurements indicate a sharp peak that corresponds to the uptake of Sr-90 by tooth tissue. The results can be interpreted in terms of an intake function for Sr-90 only if the period of calcification of each individual tooth is considered-such detail on a tooth-by-tooth basis is presented in this paper. The conclusion is reached that the tooth-beta counter data are the most reliable in terms of reconstruction of Sr-90 intake; this is due in part to the fact that the tooth-beta counter measures four teeth (all at position 1) with essentially the same time periods of mineralization and because there are a large number of tooth-beta counter measurements. The main utility of electron paramagnetic resonance measurements is considered to be the validation of estimates of external dose; but for this purpose teeth with Sr-90 taken up into enamel must be avoided. C1 Urals Res Ctr Radiat Med, Chelyabinsk 454076, Russia. Inst Phys Met, Ekaterinburg 620219, Russia. Univ Utah, Dept Radiol, Div Radiobiol, Salt Lake City, UT 84108 USA. Battelle Mem Inst, Pacific NW Natl Lab, Richland, WA 99352 USA. GSF, Natl Res Ctr Environm & Hlth, D-85764 Neuherberg, Germany. RP Tolstykh, EI (reprint author), Urals Res Ctr Radiat Med, Chelyabinsk 454076, Russia. EM evgenia@urcrm.chel.su RI Ivanov, Denis/J-3235-2013; Shishkina, Elena/G-4595-2016 OI Ivanov, Denis/0000-0001-6757-5587; Shishkina, Elena/0000-0003-4464-0889 NR 47 TC 18 Z9 18 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 OCT PY 2003 VL 85 IS 4 BP 409 EP 419 DI 10.1097/00004032-200310000-00004 PG 11 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 721FJ UT WOS:000185306100004 PM 13678281 ER PT J AU Rooney, W AF Rooney, W TI MRI: From picture to proton SO HEALTH PHYSICS LA English DT Book Review C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Rooney, W (reprint author), Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. NR 1 TC 2 Z9 2 U1 1 U2 15 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 OCT PY 2003 VL 85 IS 4 BP 504 EP 505 DI 10.1097/00004032-200310000-00020 PG 2 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 721FJ UT WOS:000185306100020 ER PT J AU Golia, P Powers, K Dorante, G Cunningham-Rundles, S Ribeiro, R Shata, MT Perelson, AS Talal, AH AF Golia, P Powers, K Dorante, G Cunningham-Rundles, S Ribeiro, R Shata, MT Perelson, AS Talal, AH TI Pharmacodynamics and pharmacokinetics of hepatitis C virus (HCV) and pegylated interferon-alfa2b in human immunodeficiency virus (HIV)/HCV co-infected patients. SO HEPATOLOGY LA English DT Meeting Abstract CT 54th Annual Meeting of the American-Association-for-the-Study-of-Liver-Disease CY OCT 24-28, 2003 CL BOSTON, MASSACHUSETTS SP Amer Assoc Study Liver Diseases C1 Cornell Univ, Weill Med Coll, New York, NY USA. Los Alamos Nat Lab, Los Alamos, NM USA. New York Blood Ctr, New York, NY 10021 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0270-9139 J9 HEPATOLOGY JI Hepatology PD OCT PY 2003 VL 38 IS 4 SU 1 MA 385 BP 345A EP 345A PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 730ER UT WOS:000185816700386 ER PT J AU Zhou, LJ Ma, WX Liu, LC AF Zhou, LJ Ma, WX Liu, LC TI On the tensor glueball content of soft pomeron SO HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION LA English DT Article DE pomeron; glueballs; mesons ID DEEP-INELASTIC-SCATTERING; J/PSI RADIATIVE DECAYS; QUANTUM CHROMODYNAMICS; ELASTIC-SCATTERING; MODEL; MESONS; STATE; GEV/C AB We study the gluonic content of the pomeron through relating the pomeron trajectory to the observed I(G)J(PC) = 0(+) 2(++) isoscalar tensor mesons. Four of these mesons satisfy the spin-mass relation of the pomeron. These pomeronian candidates may be hybrid states. One of them, the f(2) (2220) meson, can have a predominant glueball component. We address the unsettled experimental situation about the width of this meson and give a theoretical lower bound for it. We also show why this meson may not be seen in (p) over barp experiments. C1 Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China. CAS, Inst High Energy Phys, Beijing 100039, Peoples R China. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Zhou, LJ (reprint author), Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China. EM MAWX@mail.ihep.ac.cn NR 43 TC 0 Z9 0 U1 0 U2 0 PU SCIENCE CHINA PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0254-3052 J9 HIGH ENERG PHYS NUC JI High Energy Phys. Nucl. Phys.-Chin. Ed. PD OCT PY 2003 VL 27 IS 10 BP 857 EP 865 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 732HT UT WOS:000185935300004 ER PT J AU Healy, WM Lutz, JD Lekov, AB AF Healy, WM Lutz, JD Lekov, AB TI Variability in energy factor test results for residential electric water heaters SO HVAC&R RESEARCH LA English DT Article AB Recent modifications to the minimum energy efficiency requirements for residential water heaters have spurred an investigation into the variability in testing high-efficiency electric water heaters. nile initial interlaboratory comparisons showed excellent agreement between test results from different labs, subsequent interlaboratory comparisons show differences between measured energy factors of up to 0.040. To determine the source of these differences, analyses of various parts of the test procedure are performed For one case studied, the uncertainty in test results can be as high as +/-0.028 if instrument accuracies reach the minimum level allowed in the test procedure. Other areas of the test procedure where variability is introduced are the optional use of pre-draws, the location of the lower tank temperature-measuring device, the use of insulation on tank fittings, and the use of a warm-up period before the simulated-use test commences. The implications of these issues on test results are discussed. C1 Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Engn Technol Div, Berkeley, CA 94720 USA. RP Healy, WM (reprint author), Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. NR 8 TC 3 Z9 3 U1 1 U2 5 PU AMER SOC HEATING REFRIGERATING AIR-CONDITIONING ENG, INC, PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 USA SN 1078-9669 J9 HVAC&R RES JI HVAC&R Res. PD OCT PY 2003 VL 9 IS 4 BP 435 EP 449 DI 10.1080/10789669.2003.10391079 PG 15 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 754NX UT WOS:000187324200005 ER PT J AU Roberto, FF AF Roberto, FF TI Nucleotide sequence of a small cryptic plasmid from Acidithiobacillus ferrooxidans strain A-6 SO HYDROMETALLURGY LA English DT Article; Proceedings Paper CT International Biohydeometallurgy Symposium CY SEP 16-19, 2001 CL OURO PRETO, BRAZIL DE Acidithiobacillus ferrooxidans; plasmid; DNA sequence; RepA; pAYS homology ID THIOBACILLUS-FERROOXIDANS; ESCHERICHIA-COLI; MOBILIZATION; RESISTANCE; CLONING; ORIGIN; DNA AB A 2.1 kb cryptic plasmid from Acidithiobacillus ferrooxidans strain A-6 was isolated and cloned into the Escherichia coli vector plasmid, pUC128. The cloned plasmid was mapped by restriction enzyme fragment analysis and subsequently sequenced. Much of the plasmid remains cryptic, but substantial nucleotide and protein sequence similarities have been observed to the putative replication protein, RepA, of the small cryptic plasmids pAYS and pAYL found in the ammonia-oxidizing Nitrosomonas sp. strain ENI-11. These results suggest that an entirely new class of plasmid is maintained in at least one strain of A. ferrooxidans and other acidophilic bacteria, and raises interesting questions about the origin of this plasmid in acidic environments. Published by Elsevier B.V. C1 Idaho Natl & Environm Engn Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Roberto, FF (reprint author), Idaho Natl & Environm Engn Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. EM ffr@inel.gov NR 22 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-386X J9 HYDROMETALLURGY JI Hydrometallurgy PD OCT PY 2003 VL 71 IS 1-2 BP 133 EP 137 DI 10.1016/S0304-386X(03)00149-X PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 739QL UT WOS:000186357900017 ER PT J AU Sharma, PK Das, A Rao, KH Forssberg, KSE AF Sharma, PK Das, A Rao, KH Forssberg, KSE TI Surface characterization of Acidithiobacillus ferrooxidans cells grown under different conditions SO HYDROMETALLURGY LA English DT Article; Proceedings Paper CT International Biohydeometallurgy Symposium CY SEP 16-19, 2001 CL OURO PRETO, BRAZIL DE surface characterization; acidithiobacillus ferrooxidans; infrared spectroscopy; zeta-potential ID THIOBACILLUS-FERROOXIDANS; MINERAL SURFACES; ADHESION; BACTERIA; PYRITE; PROTEIN; SULFUR AB The growth characteristics of a strain of Acidithiobacillus ferrooxidans isolated from mine water with ferrous ion, sulfur, or pyrite mineral as sole source of energy have been established. The electrokinetic behaviour of the bacterial cells was investigated and the cell surface groups were characterized by diffuse reflectance FT-IR and FT-Raman spectroscopies. The surface charge on the iron-grown cells (i.e.p., pH 2.0) is different from that on the solid-substrate-grown cells (i.e.p., pH 3.0-3.5) and the surface charge depends on the growth history of the bacteria. The FT-IR and FT-Raman spectra revealed a higher amount of protein content on the surface of the sulfur- and pyrite-grown cells compared to the iron-grown cells. These results suggest that the altered surface charge on the cells is due to differences in the protein content synthesized by bacteria exposed to different growth conditions. (C) 2003 Elsevier B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sharma, PK (reprint author), Univ Groningen, Dept Biomed Engn, A Deusinglaan 1, NL-9713 AV Groningen, Netherlands. NR 31 TC 59 Z9 67 U1 2 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-386X J9 HYDROMETALLURGY JI Hydrometallurgy PD OCT PY 2003 VL 71 IS 1-2 BP 285 EP 292 DI 10.1016/S0304-386X(03)00167-1 PG 8 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 739QL UT WOS:000186357900035 ER PT J AU Moses, WW AF Moses, WW TI Time of flight in PET revisited SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Editorial Material DE nuclear medicine; positron emission tomography (PET); time of flight; timing resolution ID POSITRON-EMISSION-TOMOGRAPHY; IMAGE-RECONSTRUCTION; ACCIDENTAL COINCIDENCES; SCINTILLATOR; INFORMATION; LUALO3-CE; SYSTEM; LSO AB PET scanners based on LSO have the potential for significantly better coincidence timing resolution than the 6 ns FWHM typically achieved with BGO. This study analyzes the performance enhancements made possible by improved timing as a function of the coincidence time resolution. If 500 ps FWHM coincidence timing. resolution can be achieved in a complete PET camera, the following four benefits can be realized for whole-body FDG imaging: 1) the random event rate can be reduced by using a narrower coincidence timing window, increasing the peak NECR by similar to50%; 2) using time-of-flight (TOF) in the reconstruction algorithm will reduce the noise variance by a factor of 5; 3) emission and transmission data can be acquired simultaneously, reducing the total scan time; and 4) axial blurring can be reduced by using TOF to determine the correct axial plane of origin for each event. While TOF was extensively studied in the 1980s, practical factors limited its effectiveness at that time and little attention has been paid to timing in PET since then. As these potential improvements are substantial and the advent of LSO PET cameras gives us the means to obtain them without other sacrifices, efforts to improve PET timing should resume after their long dormancy. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 34 TC 188 Z9 194 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1325 EP 1330 DI 10.1109/TNS.2003.817319 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200002 ER PT J AU Shokouhi, S Stoll, SP Villanueva, A Vaska, P Schlyer, DJ Woody, CL Yu, B O'Connor, P Pratte, JF Radeka, V Volkow, N Fowler, JS AF Shokouhi, S Stoll, SP Villanueva, A Vaska, P Schlyer, DJ Woody, CL Yu, B O'Connor, P Pratte, JF Radeka, V Volkow, N Fowler, JS TI A noninvasive LSO-APD blood radioactivity monitor for PET imaging studies SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE blood monitor; input function; modeling; radiation detector ID POSITRON-EMISSION-TOMOGRAPHY; ARTERIAL INPUT FUNCTION; DETECTOR SYSTEM; METABOLIC-RATE; FLOW AB A study has been carried out to investigate the possibility of using a pair of LSO + APD detector arrays to obtain a noninvasive measurement of the arterial input function for use in PET. The main focus of this study was to determine the spatial resolution and sensitivity required to obtain a high quality image that would permit a precise determination of the region of interest around the wrist artery. From these data a quantitative arterial input function that has minimal interference from the tissue and vein background can be obtained. The detector arrays were operated in coincidence counting mode to obtain planar images of various phantoms to demonstrate the feasibility of the concept. C1 SUNY Stony Brook, Dept Biomed Engn, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11974 USA. RP Shokouhi, S (reprint author), SUNY Stony Brook, Dept Biomed Engn, Stony Brook, NY 11794 USA. NR 17 TC 0 Z9 0 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1457 EP 1461 DI 10.1109/TNS.2003.817284 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200024 ER PT J AU Bal, H DiBella, EVR Gullberg, GT AF Bal, H DiBella, EVR Gullberg, GT TI Parametric image formation using clustering for dynamic cardiac SPECT SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE clustering methods; compartment modeling; dynamic cardiac SPECT ID TL-201; TEBOROXIME; PET AB Dynamic cardiac SPECT imaging can provide quantitative and possibly even absolute measures of physiological parameters. However, a dynamic cardiac SPECT study involves a number of steps to obtain estimates of physiological parameters of interest. One of the key steps involves the selection of regions of interest. In the past, this has been done manually or by using a semiautomatic method. We propose to use cluster analysis to segment the data to obtain improved parameter estimates. The algorithm consists of using a standard k-means clustering followed by a blood input fine-tuning procedure using fuzzy k-means performed to obtain a more accurate blood input function. Computer simulations were used to test the algorithm and to compute bias in kinetic rate parameters with and without the use of blood input fine-tuning. This was followed by performing eight studies in three canines and three studies in two patients with a dynamic cardiac perfusion SPECT protocol. The short-axis slice image data were used as input for the cluster analysis program as well as for a previously validated semi-automatic method. All of the time activity curves were fit to a two-compartment model. Parametric images of the wash-in rate parameter were obtained after cluster analysis. The wash-in rate estimates from the selected regions of interest with both of the methods were compared using microsphere derived flows as a gold standard in the case of canine studies. Our results suggest that in regions with low noise, cluster analysis provides parameter estimates comparable to the semi-automatic method in addition to providing improved visual defect localization and contrast. Moreover, the clustered curves have less noise and yield reasonable fits where with the semi-automatic method the fitting routine sometimes failed to converge. The use of clustering also required less manual intervention than the semi-automatic method. These results indicate that use of clustering may bring dynamic cardiac SPECT closer to clinical feasibility. C1 Univ Utah, Dept Bioengn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Radiol, Salt Lake City, UT 84108 USA. Lawrence Berkeley Lab, Dept Nucl Med & Funct Imaging, Berkeley, CA 94720 USA. RP Bal, H (reprint author), Univ Utah, Dept Bioengn, Salt Lake City, UT 84112 USA. OI DiBella, Edward/0000-0001-9196-3731 NR 11 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1584 EP 1589 DI 10.1109/TNS.2003.817955 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200045 ER PT J AU More, MJ Narayanan, D Goodale, PJ Majewski, S Welch, B Wojcik, R Williams, MB AF More, MJ Narayanan, D Goodale, PJ Majewski, S Welch, B Wojcik, R Williams, MB TI X-ray stereotactic lesion localization in conjunction with dedicated scintimammography SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE breast imaging; multimodality; scintimammography; stereotactic localization; technetium-99m sestamibi uptake ID BREAST-LESIONS; BIOPSY AB We are developing a dual modality system that combines digital X-ray mammography with gamma emission scintigraphy on an upright mammography gantry. The breast is held under mild compression by a support structure that is independent of the detectors. The X-ray source and detectors can be rotated around a fixed rotation axis permitting multiple views of the breast with fixed compression. Two such views can be combined as a stereotactic pair to obtain the three-dimensional location of breast lesions. Information about the location of the lesion within the breast permits corrections for attenuation and detector spatial resolution, resulting in more accurate estimation of the true lesion-to-background concentration ratio, based on the image lesion-to-background counts ratio. In this paper, we describe the model used to make these corrections, and present the results of the phantom experiments designed to test the accuracy of our calculations. C1 Univ Virginia, Charlottesville, VA 22908 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP More, MJ (reprint author), Univ Virginia, Charlottesville, VA 22908 USA. NR 11 TC 14 Z9 14 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1636 EP 1642 DI 10.1109/TNS.2003.817303 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200053 ER PT J AU Williams, MB Narayanan, D More, MJ Goodale, PJ Majewski, S Kieper, DA AF Williams, MB Narayanan, D More, MJ Goodale, PJ Majewski, S Kieper, DA TI Analysis of position-dependent Compton scatter in scintimammography with mild compression SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE breast imaging; Compton scatter; multimodality; scintimammography AB In breast scintigraphy using Tc-99m-sestamibi the relatively low radiotracer uptake in the breast compared to that in other organs such as the heart results in a large fraction of the detected events being Compton scattered gamma-rays. In this study, our goal was to determine whether generalized conclusions regarding scatter-to-primary ratios at various locations within the breast image are possible, and if so, to use them to make explicit scatter corrections to the breast scintigrams. Energy spectra were obtained from patient scans for contiguous regions of interest (ROIs) centered left to right within the image of the breast, and extending from the chest wall edge of the image to the anterior edge. An anthropomorphic torso phantom with fillable internal organs and a compressed-shape breast containing water only was used to obtain realistic position-dependent scatter-only spectra. For each ROI, the measured patient energy spectrum was fitted with a linear combination of the scatter-only spectrum from the anthropomorphic phantom and the scatter-free spectrum from a point source. We found that although there is a very strong dependence on location within the breast of the scatter-to-primary ratio, the spectra are well modeled by a linear combination of position-dependent scatter-only spectra and a position-independent scatter-free spectrum, resulting in a set of position-dependent correction factors. These correction factors can be used along with measured emission spectra from a given breast to correct for the Compton scatter in the scintigrams. However, the large variation among patients in the magnitude of the position-dependent scatter makes the success of universal correction approaches unlikely. C1 Univ Virginia, Charlottesville, VA 22908 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Hampton Univ, Hampton, VA 23668 USA. RP Williams, MB (reprint author), Univ Virginia, Charlottesville, VA 22908 USA. NR 3 TC 10 Z9 10 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1643 EP 1649 DI 10.1109/TNS.2003.817297 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200054 ER PT J AU Huber, JS Choong, WS Wang, J Maltz, JS Qi, J Mandelli, E Moses, WW AF Huber, JS Choong, WS Wang, J Maltz, JS Qi, J Mandelli, E Moses, WW TI Development of the LBNL positron emission mammography camera SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE biomedical imaging; detectors; positron emission tomography (PET) ID PET DETECTOR MODULE; DEPTH; RECONSTRUCTION; SCINTILLATOR; DESIGN AB We present the construction status of the LBNL positron emission mammography (PEM) camera, which utilizes a positron emission tomography (PET) detector module with depth of interaction measurement consisting of 64 LSO crystals (3 x 3 x 30 mm(3)) coupled on one end to a single photomultiplier tube (PMT) and on the opposite end to a 64 pixel array of silicon photodiodes (PDs). The PMT provides an accurate timing pulse, the PDs identify the crystal of interaction, the sum provides a total energy signal, and the PD/(PD + PMT) ratio determines the depth of interaction. We have completed construction of all 42 PEM detector modules. All data acquisition electronics have been completed, fully tested and loaded onto the gantry. We have demonstrated that all functions of the custom IC work using the production rigid-flex boards and data acquisition system. Preliminary detector module characterization and coincidence data have been taken using the production system, including initial images. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Huber, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Qi, Jinyi/A-1768-2010 OI Qi, Jinyi/0000-0002-5428-0322 NR 12 TC 19 Z9 20 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1650 EP 1653 DI 10.1109/TNS.2003.817941 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CA UT WOS:000185922200055 ER PT J AU Steinwart, I AF Steinwart, I TI On the optimal parameter choice for nu-support vector machines SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article DE pattern recognition; PAC model; support vector machines; parameter selection AB We determine the asymptotically optimal choice of the parameter v for classifiers of v-support vector machine (v-SVM) type which has been introduced by Scholkopf et al. [14]. It turns out that v should be a close upper estimate of twice the optimal Bayes risk provided that the classifier uses a so-called universal kernel such as the Gaussian RBF kernel. Moreover, several experiments show that this result can be used to implement some modified cross validation procedures which improve standard cross validation for v-SVMs. C1 Los Alamos Natl Lab, Modeling Algorithms & Informat Grp, Los Alamos, NM 87545 USA. RP Steinwart, I (reprint author), Los Alamos Natl Lab, Modeling Algorithms & Informat Grp, CCS-3, Los Alamos, NM 87545 USA. OI Steinwart, Ingo/0000-0002-4436-7109 NR 18 TC 19 Z9 22 U1 0 U2 5 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD OCT PY 2003 VL 25 IS 10 BP 1274 EP 1284 DI 10.1109/TPAMI.2003.1233901 PG 11 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 723ZE UT WOS:000185460800007 ER PT J AU Struve, KW AF Struve, KW TI Special issue on vacuum discharge plasmas - Introduction SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Struve, KW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 2003 VL 31 IS 5 BP 798 EP 798 DI 10.1109/TPS.2003.819621 PN 1 PG 1 WC Physics, Fluids & Plasmas SC Physics GA 735KB UT WOS:000186111500001 ER PT J AU Anders, A AF Anders, A TI Tracking down the origin of arc plasma science I. Early pulsed and oscillating discharges SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE arc; Capacitor discharges; cathodic arc deposition; history; Priestley Rings; spark discharges AB The early development of are plasma physics is closely related to the development of suitable sources of electrical energy. The harnessing of electrostatic charge in Leyden jars (early capacitors) enabled the controlled production of sparks and pulsed arcs. A contemporary introduction to sparks and arcs gives the foundation for critically assessing the early development, when observation and discovery of phenomena were still far from understanding. The modern development of discharge physics can be traced back to the 18th century. Notably, and generally unnoticed by the scientific community until today, Joseph Priestley observed cathode erosion and film deposition of cathode material as early as 1766. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 36 TC 5 Z9 5 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 2003 VL 31 IS 5 BP 1052 EP 1059 DI 10.1109/TPS.2003.815476 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 735KF UT WOS:000186112000007 ER PT J AU Anders, A AF Anders, A TI Tracking down the origin of arc plasma science - 2. Early continuous discharges SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE arcs; carbon arc lamp; history; Humphry Davy; electrochemical cell; Vasilii Petrov; voltaic battery AB Continuous discharges could only be obtained after enduring energy sources became available, namely in the form of a battery of electrochemical cells, invented by Volta in late 1799. Humphry Davy is often credited with the discovery of the arc discharge, which later led to the development of the carbon arc lamp. Indeed, as early as 1800, he obtained short pulsed arcs with his Voltaic pile. Independently, and earlier than Davy in the sense of continuous discharges, the Russian Vasilii Petrov of St. Petersburg made carbon arcs in 1802. Petrov used a pile of 4200 electrochemical cells to drive what was the most powerful discharge at that time. Petrov's publication of 1803 appeared only in Russian, and his work was ignored and forgotten for over a century. Davy pursued highly successful electrochemical experiments and was unaware of Petrov's work. He increased the size of his battery in several steps, which led to increasingly powerful discharges, most likely an undesired side effect. After 1808, using the new battery of the Royal Institution, Davy demonstrated continuous arc discharges. The exact dates and circumstances of early arc demonstrations around 1810 are still the subject of research, but later arc experiments such as those at the London Institution of 1821 are well documented. While Petrov could claim priority for continuous carbon arcs, it was Davy who made a lasting impact on further development. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 39 TC 8 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 2003 VL 31 IS 5 BP 1060 EP 1069 DI 10.1109/TPS.2003.815477 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 735KF UT WOS:000186112000008 ER PT J AU Chutopa, Y Yotsombat, B Brown, IG AF Chutopa, Y Yotsombat, B Brown, IG TI Measurement of secondary electron emission yields SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE ion beam bombardment; ion beams; secondary electron yield; secondary emission; vacuum arc ion source; vacuum arc plasma ID DISCHARGE CATHODE MATERIALS; IMMERSION ION-IMPLANTATION; PLASMA EXPOSED SURFACES; VACUUM; BOMBARDMENT; DEPENDENCE; ALUMINUM; AU AB The authors describe a method for the measurement of secondary electron emission coefficients and demonstrate the use of this approach for the measurement of secondary electron yields for titanium, copper, and carbon ions incident upon an aluminum target. The method is time-resolved in that a series of measurements can be obtained within a single ion beam pulse of several hundred microseconds duration. The metal ion beams were produced with a vacuum arc ion source, and the ratio of secondary electron current to incident ion current was determined using a Faraday cup with fast control of the electron suppressor voltage. The method is relatively simple and readily applied and is suitable for measurements over a wide parameter range. The secondary yields obtained in the present work are of relevance to the measurement of ion current and implantation dose in plasma immersion ion implantation. C1 Chiang Mai Univ, Dept Phys, Chiang Mai 50200, Thailand. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Chutopa, Y (reprint author), Chiang Mai Univ, Dept Phys, Chiang Mai 50200, Thailand. NR 23 TC 6 Z9 7 U1 3 U2 20 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 2003 VL 31 IS 5 BP 1095 EP 1099 DI 10.1109/TPS.2003.818764 PN 2 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 735KF UT WOS:000186112000013 ER PT J AU Parvin, B Yang, Q Fontenay, G Barcellos-Hoff, MH AF Parvin, B Yang, Q Fontenay, G Barcellos-Hoff, MH TI BioSig: An imaging bioinformatics system for phenotypic analysis SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS LA English DT Article DE cell segmentation; imaging bioinfomatics; phenotypic analysis ID HYPERQUADRICS; MODEL AB Organisms express their genomes in a cell-specific manner, resulting in a variety of cellular. phenotype's or phenomes. Mapping cell phenomes under a variety of experimental conditions is necessary in order to understand the responses, of organisms to stimuli. Representing such data requires an integrated view of experimental and informatic protocols. The proposed system, named BioSig, provides the foundation for cataloging cellular responses as a function of specific conditioning, treatment, staining, etc., for either fixed tissue or living cell studies. A data model has been developed to capture experimental variables and map them to image collections and their computed representation. This representation is hierarchical and spans across sample tissues, cells, and organelles, which are imaged with light microscopy. At each layer, content is represented with an attributed graph, which contains information about cellular morphology, protein localization, and cellular organization in tissue or cell culture. The Web-based multilayer informatics architecture uses the data model to provide guided workflow access for content exploration. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Parvin, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 23 TC 15 Z9 15 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1083-4419 J9 IEEE T SYST MAN CY B JI IEEE Trans. Syst. Man Cybern. Part B-Cybern. PD OCT PY 2003 VL 33 IS 5 BP 814 EP 824 DI 10.1109/TSMCB.2003.816929 PG 11 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics SC Automation & Control Systems; Computer Science GA 724PN UT WOS:000185496100010 PM 18238234 ER PT J AU Telschow, KL Deason, VA Cottle, DL Larson, JD AF Telschow, KL Deason, VA Cottle, DL Larson, JD TI Full-field imaging of gigahertz film bulk acoustic resonator motion SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID INTERFEROMETER; WAVES AB A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates by using dynamic holography with photorefractive interferometric detection. By extending the approach to ultra high frequencies, an acoustic microscope has been developed that is capable of operation at Gigahertz frequency and micron length scales. Both acoustic amplitude and phase are recorded, allowing full calibration and determination of phases to within a single arbitrary constant. Results are presented of measurements at frequencies of 800-900 MHz, illustrating a multitude of normal mode behavior in electrically driven thin film acoustic resonators. Coupled with microwave electrical impedance measurements, this imaging mode provides an exceptionally fast method for evaluation of electric-to-acoustic coupling of these devices and their performance. Images of 256 x 240 pixels are recorded at 18 fps rates synchronized to obtain both in-phase and quadrature detection of the acoustic motion. Simple averaging provides sensitivity to the subnanometer level at each pixel calibrated over the image using interferometry. Identification of specific acoustic modes and their relationship to electrical impedance characteristics show the advantages and overall high speed of the technique. C1 Idaho Natl Engn & Environm Lab, Dept Phys, Idaho Falls, ID 83415 USA. Agilent Technol Inc, Palo Alto, CA 94304 USA. RP Telschow, KL (reprint author), Idaho Natl Engn & Environm Lab, Dept Phys, Idaho Falls, ID 83415 USA. NR 9 TC 42 Z9 42 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD OCT PY 2003 VL 50 IS 10 BP 1279 EP 1285 DI 10.1109/TUFFC.2003.1244744 PG 7 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 736UT UT WOS:000186192100008 PM 14609067 ER PT J AU Bonnell, KS Duchaineau, MA Schikore, DR Hamann, B Joy, KI AF Bonnell, KS Duchaineau, MA Schikore, DR Hamann, B Joy, KI TI Material interface reconstruction SO IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS LA English DT Article DE Eulerian flow; material boundaries; material interfaces; finite elements; barycentric coordinates; volume fraction; isosurface extraction AB This paper presents an algorithm for material interface reconstruction for data sets where fractional material information is given as a percentage for each element of the underlying grid. The reconstruction problem is transformed to a problem that analyzes a dual grid, where each vertex in the dual grid has an associated barycentric coordinate tuple that represents the fraction of each material present. Material boundaries are constructed by analyzing the barycentric coordinate tuples of a tetrahedron in material space and calculating intersections with Voronoi cells that represent the regions where one material dominates. These intersections are used to calculate intersections in the Euclidean coordinates of the tetrahedron. By triangulating these intersection points, one creates the material boundary. The algorithm can treat data sets containing any number of materials. The algorithm can also create nonmanifold boundary surfaces if necessary. By clipping the generated material boundaries against the original cells, one can examine the error in the algorithm. Error analysis shows that the algorithm preserves volume fractions within an error range of 0.5 percent per material. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Computat Engn Int, Apex, NC 27502 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Dept Comp Sci, Ctr Image Proc & Integrated Comp, Davis, CA 95616 USA. RP Lawrence Livermore Natl Lab, POB 808,L-312, Livermore, CA 94550 USA. EM bonnell2@llnl.gov; duchaineau1@llnl.gov; schikore@ceintl.com; hamann@cs.ucdavis.edu; joy@cs.ucdavis.edu NR 13 TC 25 Z9 25 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1077-2626 EI 1941-0506 J9 IEEE T VIS COMPUT GR JI IEEE Trans. Vis. Comput. Graph. PD OCT-DEC PY 2003 VL 9 IS 4 BP 500 EP 511 DI 10.1109/TVCG.2003.1260744 PG 12 WC Computer Science, Software Engineering SC Computer Science GA 734FZ UT WOS:000186045500006 ER PT J AU Krupin, PJ AF Krupin, PJ TI Getting the good stuff on the net SO INDUSTRIAL ENGINEER LA English DT Article C1 US DOE, Washington, DC 20585 USA. RP Krupin, PJ (reprint author), US DOE, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST INDUSTRIAL ENGINEERS PI NORCROSS PA 25 TECHNOLOGY PARK/ATLANTA, NORCROSS, GA 30092 USA SN 1085-1259 J9 IND ENG JI Ind. Eng PD OCT PY 2003 VL 35 IS 10 BP 42 EP 42 PG 1 WC Engineering, Industrial SC Engineering GA 728NN UT WOS:000185723400021 ER PT J AU Majumdar, A Choi, KK Reno, JL Rokhinson, LP Tsui, DC AF Majumdar, A Choi, KK Reno, JL Rokhinson, LP Tsui, DC TI Electron transfer based voltage tunable two-color quantum-well infrared photodetectors SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Quantum Well Infrared Photodetectors (QWIP 2002) CY OCT 13-17, 2002 CL TURIN, ITALY DE quantum-well infrared photodetectors; two-color; voltage tunable detectors; coupled quantum wells ID FOCAL-PLANE ARRAY; INTERSUBBAND TRANSITIONS; DARK CURRENT; DETECTOR; SENSITIVITY AB We present a detailed investigation of the temperature T dependence of photoresponse of voltage tunable two-color quantum-well infrared photodetectors (QWIPs) that are based on the transfer of electrons between coupled QWs under an applied bias V-b. For T less than or equal to 40 K, the peak detection wavelength switches from 7.2 mum under positive bias to 8.6 mum under large negative bias as electrons are transferred from the right QW (RQW) to the left QW (LQW). For T greater than or equal to 50 K, the short wavelength peak is not only present for both bias polarities but also increases rapidly with T while the long wavelength peak decreases rapidly with T. We investigate this temperature dependence by extracting absorption coefficient a and photoconductive gain g using corrugated QWIPs with different corrugation periods. The deduced absorption spectra indicate that the LQW population first increases and then decreases with increasing negative bias for T greater than or equal to 50 K. The deduced gain spectra show that short and long wavelength gain under negative bias exhibit a strong enhancement and reduction, respectively, with T above 50 K. We show that both these temperature dependences are caused by large thermal currents from the LQWs, which are designed for long wavelength detection and, therefore, have a significantly lower activation energy than the RQWs. (C) 2003 Elsevier B.V. All rights reserved. C1 Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. USA, Res Lab, Electroopt & Photon Div, Adelphi, MD 20783 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Majumdar, A (reprint author), Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. RI Choi, Kwong-Kit/K-9205-2013 NR 28 TC 3 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT-DEC PY 2003 VL 44 IS 5-6 BP 337 EP 346 DI 10.1016/S1350-4495(03)00153-1 PG 10 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 736GT UT WOS:000186163600005 ER PT J AU Gertsman, VY Henager, CH AF Gertsman, VY Henager, CH TI Grain boundary junctions in microstructure generated by multiple twinning SO INTERFACE SCIENCE LA English DT Article DE grain boundaries; triple junctions; annealing twinning; recrystallization ID TRIPLE JUNCTIONS; ANNEALING TWINS; FCC CRYSTALS; TEXTURE; METALS; ALLOYS; DISTRIBUTIONS; POLYCRYSTALS; STATISTICS; STEELS AB The microstructure of a Cu-Ni alloy after static recrystallization was investigated using electron backscatter diffraction in a scanning electron microscope and the existence of orientationally related clusters of crystallites formed by multiple twinning has been established. Grain boundary and triple junction character within the clusters are analyzed. While the outer boundaries of the cluster are crystallographically random, all the inner boundaries have Sigma3(n) misorientations. A newly developed crystallographic theory of triple junctions and multicrystallite ensembles consisting of CSL boundaries is used to describe the structure of the cluster. The presence of an alphanot equal1 triple junction is confirmed. Apparently, the microstructure of recrystallized materials susceptible to annealing twinning consists of multiple-twinned clusters. The cluster size cannot be reduced to the "grain size excluding twins." C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gertsman, VY (reprint author), Nat Resources Canada, Mat Technol Lab, 568 Booth St, Ottawa, ON K1A 0G1, Canada. OI Henager, Chuck/0000-0002-8600-6803 NR 29 TC 39 Z9 47 U1 2 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD OCT PY 2003 VL 11 IS 4 BP 403 EP 415 DI 10.1023/A:1026191810431 PG 13 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 732YR UT WOS:000185973600005 ER PT J AU Nyeki, J Erdelyi, G Lograsso, TA Schlagel, DL Beke, DL AF Nyeki, J Erdelyi, G Lograsso, TA Schlagel, DL Beke, DL TI Ni volume diffusion in Ni2MnGa SO INTERMETALLICS LA English DT Article DE volume diffusion; shape-memory effect; intermetallics; Heusler alloy; ferromagnetic alloy ID SELF-DIFFUSION; NICKEL; TEMPERATURES; ALLOYS; SINGLE AB Ni-63 volume diffusion in monocrystalline Ni2MnGa shape-memory ferromagnetic alloy was investigated in the temperature range of 700-1033 K. The composition of the alloy was slightly Ni rich and the direction of diffusion was perpendicular to the (100) plane. The temperature dependence of the volume diffusion coefficient can be described by the following Arrhenius function: D(T) = 5.49 (+8.65)(-3.36) x 10(-8) exp[-(146,000 6600)/RT]m(2)/s. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Debrecen, Dept Solid State Phys, H-4010 Debrecen, Hungary. Univ Aix Marseille 3, Fac Sci St Jerome, UMR 6637, Lab Mat & Microelect Provence, F-13397 Marseille, France. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Univ Debrecen, Dept Solid State Phys, POB 2, H-4010 Debrecen, Hungary. EM erdelyi@tigris.klte.hu NR 12 TC 4 Z9 4 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD OCT PY 2003 VL 11 IS 10 BP 1075 EP 1077 DI 10.1016/S0966-9795(03)00124-9 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 733WQ UT WOS:000186024000011 ER PT J AU LaVan, DA Boyce, BL Buchheit, TE AF LaVan, DA Boyce, BL Buchheit, TE TI Size and frequency of defects in silicon MEMS SO INTERNATIONAL JOURNAL OF DAMAGE MECHANICS LA English DT Article DE silicon; polysilicon; defects; fracture; failure; prediction; mechanical; testing; thin film; notch ID POLYSILICON; STRENGTH; MODULUS AB Mechanical testing of thin films for MEMS has progressed from a developmental stage to a point where validated techniques are used to study the behavior of devices and materials at a very fine scale. Tensile data covering a range of sizes and test techniques have been analyzed to examine the distribution of defects that would be responsible for the observed fracture strengths. For each sample, a critical defect size was calculated based on a published fracture toughness and a half-circular surface crack fracture toughness model. For polysilicon produced using the SUMMiT V process in the period 1998-1999, the calculated mean defect size was 115 nm. For polysilicon produced using the MUMPS process, the calculated mean defect size was 389 nm. C1 Harvard Univ, MIT, Div Hlth Sci & Technol, Cambridge, MA 02139 USA. Childrens Hosp, Dept Surg Res, Boston, MA 02115 USA. Sandia Natl Labs, Microsyst Mat Tribol & Technol Dept, Albuquerque, NM 87185 USA. RP LaVan, DA (reprint author), Harvard Univ, MIT, Div Hlth Sci & Technol, Cambridge, MA 02139 USA. RI LaVan, David/C-3943-2012; Boyce, Brad/H-5045-2012 OI LaVan, David/0000-0002-1952-0028; Boyce, Brad/0000-0001-5994-1743 NR 17 TC 4 Z9 4 U1 0 U2 5 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1056-7895 J9 INT J DAMAGE MECH JI Int. J. Damage Mech. PD OCT PY 2003 VL 12 IS 4 BP 357 EP 363 DI 10.1177/105678903036226 PG 7 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 876HB UT WOS:000225486300004 ER PT J AU Misra, A Kung, H Hammon, D Hoagland, RG Nastasi, M AF Misra, A Kung, H Hammon, D Hoagland, RG Nastasi, M TI Damage mechanisms in nanolayered metallic composites SO INTERNATIONAL JOURNAL OF DAMAGE MECHANICS LA English DT Article DE nanostructured materials; metallic multilayers; dislocations; ultra-high strength materials AB The strengths of metallic multilayers, composed of alternating layers of soft metals such as Cu and Nb, approach the theoretical limit of material strength when the bilayer periods are on the order of a few nanometers. We have investigated the damage mechanisms in these ultra-high strength nanolayered composite materials subjected to monotonic deformation. Large strain plastic deformation such as room temperature rolling does not lead to any dislocation cell structure formation within the layers indicating that the deformation and dislocation storage mechanisms in nanostructured materials are completely different from the bulk. In bulk metals, dislocation pile-ups lead to heterogeneous slip, but in nano-materials, deformation by single dislocations on closely spaced glide planes results in more homogeneously distributed slip. The implications of the high tensile strengths and homogeneous slip on the fatigue properties of nanolayered materials are also discussed. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. US DOE, Washington, DC 20585 USA. RP Misra, A (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. RI Hoagland, Richard/G-9821-2012; Misra, Amit/H-1087-2012 NR 11 TC 31 Z9 31 U1 2 U2 16 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1056-7895 J9 INT J DAMAGE MECH JI Int. J. Damage Mech. PD OCT PY 2003 VL 12 IS 4 BP 365 EP 376 DI 10.1177/105678903036227 PG 12 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 876HB UT WOS:000225486300005 ER PT J AU Knapp, JA Follstaedt, DM Myers, SM AF Knapp, JA Follstaedt, DM Myers, SM TI Evaluating micromechanical properties at surfaces using nanoindentation with finite-element modeling SO INTERNATIONAL JOURNAL OF DAMAGE MECHANICS LA English DT Article DE nanoindentation; mechanical properties; finite-element modeling ID MECHANICAL-PROPERTIES; HARDNESS; NICKEL AB Detailed finite-element modeling of nanoindentation data is used to obtain accurate mechanical properties of very thin films or surface-modified layers independently of the properties of the underlying substrates. These procedures accurately deduce the yield strength, elastic modulus, and layer hardness, and greatly increase the usefulness of indentation testing with very thin surface layers. Moreover, extraction of the effective Young's modulus in the near surface region should enable mechanical damage studies on a small scale. This paper presents a brief overview of the procedures involved and illustrates them with He-implanted Ni. C1 Sandia Natl Labs, Radiat Solid Interact & Proc Dept, Albuquerque, NM 87185 USA. RP Knapp, JA (reprint author), Sandia Natl Labs, Radiat Solid Interact & Proc Dept, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 5 Z9 5 U1 0 U2 2 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1056-7895 EI 1530-7921 J9 INT J DAMAGE MECH JI Int. J. Damage Mech. PD OCT PY 2003 VL 12 IS 4 BP 377 EP 387 DI 10.1177/105678903036228 PG 11 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 876HB UT WOS:000225486300006 ER PT J AU Christensen, RM AF Christensen, RM TI The brittle versus the ductile nature of fracture Modes I and II SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE fracture; Modes I and II; ductile; brittle AB Failure surface orientations are determined for states of uniaxial tensile stress and shear stress appropriate to fracture Modes I and H. The method uses a newly developed failure criterion along with the associated flow rule. The failure angles show a sharp demarcation between ductile and brittle material types. Only the brittle materials class show consistency with Mode I conditions. Mode II behavior only occurs for perfectly ductile materials and likely represents a shear localization effect rather than explicit fracture. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Christensen, RM (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. EM christensen6@llnl.gov NR 4 TC 3 Z9 3 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PD OCT PY 2003 VL 123 IS 3-4 BP L157 EP L164 DI 10.1023/B:FRAC.0000007386.16848.fb PG 8 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 769LA UT WOS:000188650500007 ER PT J AU Fincke, JR Crawford, DM Snyder, SC Swank, WD Haggard, DC Williamson, RL AF Fincke, JR Crawford, DM Snyder, SC Swank, WD Haggard, DC Williamson, RL TI Entrainment in high-velocity, high-temperature plasma jets. Part I: experimental results SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE thermal plasma; plasma spray; jets; entrainment; laser diagnostics ID LASER-INDUCED FLUORESCENCE; TURBULENT SHEAR-LAYER; ENTHALPY PROBE; LIGHT SCATTERING; O-ATOMS; GAS; COMBUSTION; NITROGEN; OXYGEN; ARGON AB The development of a high-velocity, high-temperature argon plasma jet issuing into air has been investigated. In particular the entrainment of the surrounding air, its effect on the temperature and velocity profiles and the subsequent mixing and dissociation of oxygen has been examined in detail. The total concentration of oxygen and the velocity and temperature profiles in the jet were obtained from an enthalpy probe. High-resolution Thomson scattering provided an independent measure of plasma velocity and temperature, validating enthalpy probe measurements and providing non-intrusive measurements near the nozzle exit. The concentration of atomic oxygen was obtained from 2-photon laser induced fluorescence. Molecular oxygen concentration and temperature was obtained from coherent anti-Stokes Raman spectroscopy. It was found that both the incompleteness of mixing at the molecular scale and the rate of oxygen dissociation and recombination affects jet behavior. (C) 2003 Elsevier Ltd. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Williamson, RL (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. OI Williamson, Richard/0000-0001-7734-3632 NR 34 TC 27 Z9 32 U1 2 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD OCT PY 2003 VL 46 IS 22 BP 4201 EP 4213 DI 10.1016/S0017-9310(03)00272-2 PG 13 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 711QT UT WOS:000184753100006 ER PT J AU Williamson, RL Fincke, JR Crawford, DM Snyder, SC Swank, WD Haggard, DC AF Williamson, RL Fincke, JR Crawford, DM Snyder, SC Swank, WD Haggard, DC TI Entrainment in high-velocity, high-temperature plasma jets. Part II: computational results and comparison to experiment SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE thermal plasma; plasma spray; modeling; jets; entrainment ID THERMAL PLASMAS; MOLYBDENUM PARTICLES; MASS-TRANSFER; CARRIER-GAS; FLOW; DYNAMICS; TORCH; ARGON; MODEL; INJECTION AB The development of a turbulent high-velocity, high-temperature argon plasma jet issuing into air has been computationally modeled using the computer program LAVA. LAVA is a comprehensive computational software program developed for flowing thermal plasmas in the absence of electromagnetic fields, with particular emphasis on plasma jets. The plasma is represented as a multicomponent chemically reacting ideal gas with temperature-dependent thermodynamic and transport properties. The plasma flow is governed by the complete transient, compressible Navier-Stokes equations in two-dimensions in the current simulation. Turbulence is represented by the k-epsilon model. Neutrals, ions and electrons are considered as separate components of species of the mixture. General kinetic and equilibrium chemistry algorithms compute ionization, dissociation, recombination and other chemical reactions. Computational results and extensive comparisons with experimental data are presented. In particular the influence of inflow boundary conditions and the ability of the k-epsilon turbulence model to describe entrainment with chemistry are examined. (C) 2003 Elsevier Ltd. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Williamson, RL (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. OI Williamson, Richard/0000-0001-7734-3632 NR 43 TC 29 Z9 32 U1 4 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD OCT PY 2003 VL 46 IS 22 BP 4215 EP 4228 DI 10.1016/S0017-9310(03)00271-0 PG 14 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 711QT UT WOS:000184753100007 ER PT J AU Forsberg, CW AF Forsberg, CW TI Hydrogen, nuclear energy, and the advanced high-temperature reactor SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE hydrogen; nuclear energy; advanced high-temperature reactor ID DESIGN AB Nuclear energy has been proposed as an energy source to produce hydrogen (H-2) from water. An examination of systems issues in this paper indicates that the infrastructure of H-2 consumption is now compatible with the production of H-2 by nuclear reactors. Alternative H-2 production processes were examined to define the requirements such processes would impose on the nuclear reactor. These requirements include supplying heat at a near-constant high temperature, providing a low-pressure interface with the H-2 production processes, isolating the nuclear plant from the chemical plant, and avoiding tritium contamination of the H-2 product. A reactor concept-the advanced high-temperature reactor-was developed to match these requirements for H-2 production. Published by Elsevier Science Ltd on behalf of the International Association for Hydrogen Energy. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Forsberg, CW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 53 Z9 54 U1 0 U2 0 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 OCT PY 2003 VL 28 IS 10 BP 1073 EP 1081 AR PII S0360-3199(02)00232-X PG 9 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 687DN UT WOS:000183360900005 ER PT J AU Schefer, RW AF Schefer, RW TI Hydrogen enrichment for improved lean flame stability SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article ID NATURAL-GAS; ENGINE AB The stability characteristics of a premixed, swirl-stabilized flame were studied to determine the effects of hydrogen addition on flame stability under fuel-lean conditions. The burner configuration consisted of a centerbody with an annular, premixed methane/air jet introduced through five, 45degrees swirl vanes. Flame stability was studied over a range of operating conditions. Under fuel-rich conditions the flame was lifted from the burner surface due to the mixing with entrained ambient air that was needed to form a flammable mixture. As the fuel/air mixture ratio was decreased toward stoichiometric, the resulting increase in flame speed allowed the flame to propagate upstream through the low-velocity wake region and attach to the centerbody face. The maximum blowout velocity occurred at stoichiometric conditions, and decreased as the mixture became leaner. OH PLIF measurements were used to study the behavior of OH mole fraction as the lean stability limit was approached. Near the lean stability limit the overall OH mole fraction decreased, the flame decreased in size and the high OH region took on a more shredded appearance. The addition of up to 20% hydrogen to the methane/air mixture resulted in a significant increase in the OH concentration and extended the lean stability limits of the burner. Published by Elsevier Science Ltd on behalf of the International Association for Hydrogen Energy. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Schefer, RW (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RI Schefer, Jurg/G-3960-2012 NR 13 TC 136 Z9 145 U1 1 U2 18 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 OCT PY 2003 VL 28 IS 10 BP 1131 EP 1141 AR PII S0360-3199(02)00199-4 DI 10.1016/S0360-3199(02)00199-4 PG 11 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 687DN UT WOS:000183360900013 ER PT J AU Khalakdina, A Selvin, S Merrill, DW Erdmann, CA Colford, JM AF Khalakdina, A Selvin, S Merrill, DW Erdmann, CA Colford, JM TI Analysis of the spatial distribution of cryptosporidiosis in AIDS patients in San Francisco using density equalizing map projections (DEMP) SO INTERNATIONAL JOURNAL OF HYGIENE AND ENVIRONMENTAL HEALTH LA English DT Article DE density equalizing transformation; spatial analysis; spatial epidemiology; cryptosporidiosis; AIDS ID INFECTION; TRANSMISSION; EPIDEMIOLOGY; CALIFORNIA; COUNTIES; DISEASE; CANCER AB Environmental transmission of cryptosporidiosis has occurred repeatedly in defined spatial areas during outbreaks of disease attributed, for example, to drinking water contamination. Little work has been done to investigate the possibility of cryptosporicliosis infection in defined spatial areas in non-outbreak (i.e., endemic) settings. This study applies a novel approach to the investigation of the spatial distribution of cryptosporicliosis in AIDS patients in San Francisco. Density equalizing map projection (DEMP) maps were created for nine race/ethnicity-age groups of AIDS patients based on census tract of residence. Additionally, census tracts with a "high density" of cryptosporicliosis cases were identified by applying smoothing techniques to the DEMP maps, and included as a covariate in multivariate Poisson regression analyses of other known risk factors for cryptosporidiosis. These analyses suggest: (1) cases of cryptosporidiosis among Black and Hispanic AIDS patients, but not among Whites, show a statistically significant non-random spatial distribution (p < 0.05) even after adjustment for the underlying spatial distribution of AIDS patients for these demographic groups, and (2) the risk of residence in these high density census tracts, adjusted for other known risk factors, was not statistically significant (relative risk = 1.27, 95% confidence interval 0.15, 10.53). These results do not support an independent effect of spatial distribution on the transmission of cryptosporicliosis among AIDS patients. C1 Univ Calif Berkeley, Sch Publ Hlth, Div Publ Hlth Biol & Epidemiol, Ctr Family & Community Hlth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Sch Publ Hlth, Div Publ Hlth Biol & Epidemiol, Ctr Occupat & Environm Hlth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Sch Publ Hlth, Div Publ Hlth Biol & Epidemiol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA USA. RP Colford, JM (reprint author), Univ Calif Berkeley, Sch Publ Hlth, Div Publ Hlth Biol & Epidemiol, Ctr Family & Community Hlth, 140 Warren Hall, Berkeley, CA 94720 USA. NR 32 TC 3 Z9 4 U1 0 U2 3 PU URBAN & FISCHER VERLAG PI JENA PA BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY SN 1438-4639 J9 INT J HYG ENVIR HEAL JI Int. J. Hyg. Environ. Health. PD OCT PY 2003 VL 206 IS 6 BP 553 EP 561 DI 10.1078/1438-4639-00245 PG 9 WC Public, Environmental & Occupational Health; Infectious Diseases SC Public, Environmental & Occupational Health; Infectious Diseases GA 744KM UT WOS:000186628500009 PM 14626902 ER PT J AU Duffey, TA Romero, C AF Duffey, TA Romero, C TI Strain growth in spherical explosive chambers subjected to internal blast loading SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article DE containment vessel; dynamic response; spherical shell; beating ID VIBRATIONS AB Spherical pressure vessels are used to fully contain the effects of high explosions. In this paper, the vibrations of a spherical containment vessel undergoing elastic response are investigated. Vibration modes of containment vessels are of particular interest, as it is the superposition and interaction of different modes of response with closely spaced frequencies (beating) that has been reported to be the mechanism of 'strain growth'. The modal frequencies of a complete spherical shell for both axisymmetric and nonaxisymmetric response modes are discussed, based on a sequence of papers that have appeared in the open literature. Analytical predictions are then compared with finite element numerical simulations. It is found that the numerical simulations accurately predict both the axisymmetric and nonaxisymmetric modal frequencies for the complete spherical shell. Next, numerical simulations of modal frequencies for the more complex spherical containment vessel (with nozzles) are compared with the spherical shell results. These simulations for the spherical containment vessel reveal that frequencies are similar to the complete spherical shell, although a splitting of the degenerate frequencies (associated with nonaxisymmetric modes) occurs when progressing from a perfect spherical shell to the containment vessel. As a result, the vibrational response of the spherical containment vessel can be interpreted as a perturbation on the response of a perfect spherical shell. Limited comparisons with experimentally recorded frequencies for participating modes of vessel dynamic response during high explosive containment testing are presented as well. Participating modes potentially capable of beating together to produce 'strain growth' are isolated and are found to agree within 4 percent with frequencies determined from beating frequency measurements. Published by Elsevier Science Ltd. C1 Los Alamos Natl Lab, Grp DX 5, Los Alamos, NM 87545 USA. RP Duffey, TA (reprint author), POB 1239, Tijeras, NM 87059 USA. NR 24 TC 25 Z9 34 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD OCT PY 2003 VL 28 IS 9 BP 967 EP 983 DI 10.1016/S0734-743X(02)00169-0 PG 17 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 674RT UT WOS:000182650300003 ER PT J AU Johnson, KB Delmore, JE Appelhans, AD AF Johnson, KB Delmore, JE Appelhans, AD TI High intensity perrhenate anion (ReO4-) emitters SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE ion emitters; SIMS; perrhenate; polyatomic primary ions ID ION MASS-SPECTROMETRY; SURFACE-IONIZATION; STATIC SIMS; POLYMER SURFACES; BEAM; EMISSION; BOMBARDMENT; YIELD; SOIL; VX AB Various materials have been investigated for ReO4- (perrhenate anion) emission with the goal of producing a high output emitter for application as a primary ion source in secondary ion mass spectrometry (SIMS) analysis. A new emitter consisting of Re powder/BaSO4 packed in Pt tubes has been found to have superior properties. This system produces in the order of 200 nA/mm(2) for over 100 h when heated between 1100 and 1300 degreesC. Total currents of over several hundred nano-amperes have been sustained (three orders of magnitude higher than previous emitters, >100 h). Lower currents (5-100 nA) persist for hundreds of hours. These emitters have been used in several SIMS guns for over a year, and have proven to be extremely reliable and relatively easy to operate. As the ReO4- ion has previously been shown to be a highly effective projectile for many SIMS applications, the development of this improved high output emitter makes it feasible to extend the range of its application to imaging and depth profiling. (C) 2003 Elsevier B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Johnson, KB (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 36 TC 6 Z9 6 U1 0 U2 0 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 OCT PY 2003 VL 229 IS 3 BP 157 EP 166 DI 10.1016/S1387-3806(03)00303-8 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 733PB UT WOS:000186008900004 ER PT J AU Richter, S Goldberg, SA AF Richter, S Goldberg, SA TI Improved techniques for high accuracy isotope ratio measurements of nuclear materials using thermal ionization mass spectrometry SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE isotope ratios; total evaporation; multi-dynamic measurements; TIMS ID CALIBRATION; LINEARITY; URANIUM AB A set of new techniques with significantly improved accuracy and precision has been developed and qualified for isotope ratio measurements of nuclear material using thermal ionization mass spectrometry (TIMS). First, we have modified the classical total evaporation technique to provide both high precision and high accuracy for a broader range of isotope ratios. This NBL-modified total evaporation technique acquires isotope ratio data until the entire sample is consumed, similar to the classical total evaporation technique, but also corrects the usually low abundances of isotopes such as U-234 and U-236 for peak tailing contributions originating from the isotope intensities of U-235 and U-238. Using the NBL-modified total evaporation technique, we have analyzed a series of NIST/NBL certified reference materials (CRMs) and report new results. For the U-235/U-238 isotope ratio, the relative standard deviation (RSD) between sample turrets is below 0.01%, based on the analysis of 5-10 samples per sample turret. As a second new development, the NBL-modified total evaporation technique is combined with a multi-dynamic measurement routine that further improves the accuracy of the U-234/U-238 and U-236/U-238 isotope ratio measurements. Multi-dynamic isotope ratio measurements combine the simultaneous detection of multiple isotopes with dynamic cycling of mass in two or more steps. This technique is applied on a new mass spectrometer equipped with a dispersion quadrupole, which for the first time allows the necessary fast switching of the ion beam dispersion during multi-dynamic measurements. The advantage of multi-dynamic compared to static measurements is that the dependence of the isotope ratio results on both the cup efficiencies and the current amplifier gains is eliminated. The result is a higher degree of accuracy for nuclear materials analyses. The impact of the NBL-modified total evaporation and the multi-dynamic measurement techniques on several recent certification projects at NBL is demonstrated for uranium. These techniques have significantly improved reproducibility and accuracy for nuclear safeguards measurements and certification of nuclear materials. They have the potential to improve precision and accuracy for other mass spectrometric applications as well. (C) 2003 Elsevier B.V. All rights reserved. C1 US DOE, New Brunswick Lab, Argonne, IL 60439 USA. RP Richter, S (reprint author), Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. NR 12 TC 99 Z9 100 U1 2 U2 20 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 OCT PY 2003 VL 229 IS 3 BP 181 EP 197 DI 10.1016/S1387-3806(03)000338-5 PG 17 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 733PB UT WOS:000186008900006 ER PT J AU Creutz, M AF Creutz, M TI Direct simulations of small multi-fermion systems SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE fermion simulations; Hubbard model ID NARROW ENERGY BANDS; ELECTRON CORRELATIONS; TRANSITION; COMPUTER AB I explore computer simulations of the dynamics of small multi-fermion lattice systems. The method is more general, but I concentrate on Hubbard type models where the fermions hop between a small number of connected sites. I use the natural mapping of fermion occupation numbers onto computer bits. Signs from fermion interchange are reduced to bit counting. The technique inherently requires computer resources growing exponentially with the system volume; so, it restricted to modestly small systems. Large volume results would require combining these techniques with further approximations, perhaps in a recursive renormalization group manner. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Creutz, M (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM creutz@bnl.gov NR 11 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD OCT PY 2003 VL 14 IS 8 BP 1027 EP 1040 DI 10.1142/S0129183103005169 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 805DO UT WOS:000220347200004 ER PT J AU Yin, E Nelson, DO Coleman, MA Peterson, LE Wyrobek, AJ AF Yin, E Nelson, DO Coleman, MA Peterson, LE Wyrobek, AJ TI Gene expression changes in mouse brain after exposure to low-dose ionizing radiation SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID RAT-BRAIN; MICROARRAY DATA; MESSENGER-RNA; IN-VIVO; INDUCED APOPTOSIS; X-IRRADIATION; DNA-DAMAGE; CELL-DEATH; NEURONS; INDUCTION AB Purpose: To characterize the cellular functions associated with the altered transcript profiles of mouse brain exposed to low-dose in vivo gamma-irradiation. Materials and methods: Cerebral RNA was isolated at 30 min and 4 h after whole-body irradiation at 0.1 or 2 Gy, hybridized to random oligonucleotide arrays, and evaluated for time and dose-response patterns by multifactorial analyses. Results: Brain irradiation modulated the expression patterns of 1574 genes, of which 855 showed more than 1.5-fold variation. about 30% of genes showed dose-dependent variations, including genes exclusively affected by 0.1 Gy. About 60% of genes showed time-dependent variation with more genes affected at 30 min than at 4 h. Early changes involved signal transduction, ion regulation and synaptic signalling. Later changes involved metabolic functions including myelin and protein synthesis. Low-dose radiation also modulated the expression of genes involved in stress response, cell-cycle control and DNA synthesis/repair. Conclusions: Doses of 0.1 Gy induced changes in gene expression that were qualitatively different from those at 2 Gy. The findings suggest that low-dose irradiation of the brain induces the expression of genes involved in protective and reparative functions, while down-modulating genes involved in neural signalling activity. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Baylor Coll Med, Dept Med, Houston, TX 77030 USA. RP Wyrobek, AJ (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. OI Coleman, Matthew/0000-0003-1389-4018; Peterson, Leif/0000-0002-1187-0883 NR 85 TC 121 Z9 133 U1 0 U2 7 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD OCT PY 2003 VL 79 IS 10 BP 759 EP 775 DI 10.1080/0955300310001610961 PG 17 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 745HN UT WOS:000186683400001 PM 14630535 ER PT J AU Bronkhorst, CA AF Bronkhorst, CA TI Modelling paper as a two-dimensional elastic-plastic stochastic network SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE paper; Stochastic; network; tension; cyclic; inelastic; failure zone; stress distribution ID FIBER NETWORKS; SIMULATION; BEHAVIOR AB Stochastic two-dimensional elastic-plastic network models are used to represent the inelastic deformation behavior of well-bonded paper. Linear kinematic hardening is employed with an initial non-zero back stress to represent anisotropic fiber yield. Network models are used to simulate simple monotonic tension and simple cyclic tension of paper materials. The performance of the models is compared to experimental results and found to perform reasonably well. The results suggest that interfiber bonding must be explicitly accounted for to adequately describe the material. Some discrepancy between the model and experimental cyclic tension results is believed to be due to time-dependent strain recovery in the material which is not represented in the network models. Experimental results are also presented which show that simple tension failure in these materials occurs along a line of localized deformation in a majority of the samples. This line is generally observed to form immediately prior to failure and is oriented at a well-defined angle with respect to the loading direction. (C) 2003 Elsevier Ltd. All rights reserved. C1 Weyerhaeuser Co, Federal Way, WA 98063 USA. RP Bronkhorst, CA (reprint author), Los Alamos Natl Lab, Div Theoret, T-3,POB 1663,Mail Stop B216, Los Alamos, NM 87545 USA. RI Bronkhorst, Curt/B-4280-2011 OI Bronkhorst, Curt/0000-0002-2709-1964 NR 30 TC 36 Z9 37 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD OCT PY 2003 VL 40 IS 20 BP 5441 EP 5454 DI 10.1016/S0020-7683(03)00281-6 PG 14 WC Mechanics SC Mechanics GA 720CN UT WOS:000185244100015 ER PT J AU Borcea, L Gray, GA Zhang, Y AF Borcea, L Gray, GA Zhang, Y TI Variationally constrained numerical solution of electrical impedance tomography SO INVERSE PROBLEMS LA English DT Review ID INVERSE CONDUCTIVITY PROBLEM; CURRENT COMPUTED-TOMOGRAPHY; PARAMETER-ESTIMATION PROBLEMS; BOUNDARY-VALUE PROBLEM; ILL-POSED PROBLEMS; RECONSTRUCTION ALGORITHM; REGULARIZING PROPERTIES; RESISTANCE TOMOGRAPHY; GLOBAL UNIQUENESS; STATE ESTIMATION AB We propose a novel, variational inversion methodology for the electrical impedance tomography (EIT) problem, where we seek electrical conductivity a inside a bounded, simply connected domain Omega, given simultaneous measurements of electric currents I and corresponding potentials V at the boundary. Explicitly, we make use of natural, variational constraints on the space of admissible functions sigma, to obtain efficient reconstruction methods which make best use of the data. We give a detailed analysis of the variational constraints; we propose a variety of reconstruction algorithms for the static problem in a simple continuum model. We discuss their advantages and disadvantages and we assess the performance of our algorithms through numerical simulations and comparisons with other, well established, numerical reconstruction methods. C1 Rice Univ, Houston, TX 77005 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Borcea, L (reprint author), Rice Univ, MS 134,6100 Main St, Houston, TX 77005 USA. EM borcea@caam.rice.edu; gagray@sandia.gov; zhang@caam.rice.edu NR 107 TC 10 Z9 11 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD OCT PY 2003 VL 19 IS 5 BP 1159 EP 1184 AR PII S0266-5611(03)57791-7 DI 10.1088/0266-5611/19/5/309 PG 26 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 733WB UT WOS:000186022700009 ER PT J AU Han, SW AF Han, SW TI Local structural properties in the terahertz semiconductor Zn1-xCdxTe SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE ZnCdTe; terahertz; local structure; disorder; XAFS; semiconductor ID ABSORPTION FINE-STRUCTURE; ZNTE; DETECTORS; RADIATION; CRYSTALS; DEFECTS; PULSES AB Local structural properties of wide-band-gap semiconductors, Zn1-xCdxTe (ZCT) crystals (x = 0-0.25), were studied using X-ray absorption fine structure (XAFS) measurements at the Te L-1 - and Zn K-edges. A previous study by Liu et al. (1)) reported that ZCT emits or absorbs terahertz (THz) signals with a best efficiency when x similar or equal to 0.05. The XAFS studies show that the disorder and the bond length of Te-Zn pairs have maximum values at about x = 0.05. We discuss that these structural transitions are relevant to the efficiency of THz emission and absorption in ZCT crystals. We also find that the distance of Te-Cd pairs is at least similar to0.2 Angstrom longer than that of Te-Zn pairs and that Cd doping causes disorder/distortion in both Te and Zn sites in the crystals. C1 Lawrence Berkeley Lab, Chem Sci Div, Berkeley, CA 94720 USA. RP Han, SW (reprint author), Lawrence Berkeley Lab, Chem Sci Div, Berkeley, CA 94720 USA. NR 23 TC 6 Z9 6 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 OCT PY 2003 VL 42 IS 10 BP 6303 EP 6307 DI 10.1143/JJAP.42.6303 PG 5 WC Physics, Applied SC Physics GA 749UZ UT WOS:000186948400012 ER PT J AU Muramatsu, Y Motoyama, M Denlinger, JD Gullikson, EM Perera, RCC AF Muramatsu, Y Motoyama, M Denlinger, JD Gullikson, EM Perera, RCC TI Characterization of carbon films on the Japanese smoked roof tile "Ibushi-Kawara" by high-resolution soft x-ray spectroscopy SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE carbon; roof tile; soft X-ray; synchrotron radiation; X-ray emission; X-ray absorption ID GRAPHITE AB Carbon films on the Japanese smoked roof tile "Ibushi-Kawara" were characterized by high-resolution soft X-ray spectroscopy using synchrotron radiation. By comparing the soft X-ray emission and absorption spectra of Kawara with the reference carbon compounds, it was determined that the carbon films on Kawara consist of mostly carbon-black-like sp(2) carbon atoms and that the surface also contains polyethylene-like sp(3) carbon atoms. The take-off/incident-angle dependence on the X-ray emission/absorption spectra of Kawara shows that the carbon-black-like sp(2) carbon atoms partially form a layer structure oriented parallel to the basal clay plane, and that the degree of orientation of the carbon films is estimated to be 50% that of highly oriented pyrolytic graphite (HOPG). The microstructure of the carbon films on Kawara is one in which half of the carbon-black-like sp(2) carbon atoms form layer-structured clusters parallel to the basal clay plane and the rest of the carbon atoms form random-structured clusters which rigidly connect the layer-structured clusters. C1 Japan Atom Energy Res Inst, Kansai Res Estab, Mikazuki, Hyogo 6795148, Japan. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Hyogo Prefectural Inst Technol, Kobe, Hyogo 6540037, Japan. RP Muramatsu, Y (reprint author), Japan Atom Energy Res Inst, Kansai Res Estab, 1-1-1 Kouto, Mikazuki, Hyogo 6795148, Japan. NR 10 TC 5 Z9 5 U1 0 U2 1 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 OCT PY 2003 VL 42 IS 10 BP 6551 EP 6555 DI 10.1143/JJAP.42.6551 PG 5 WC Physics, Applied SC Physics GA 749UZ UT WOS:000186948400061 ER PT J AU Saxena, A Lookman, T Bishop, AR Shenoy, SR AF Saxena, A Lookman, T Bishop, AR Shenoy, SR TI Computational modeling of martensite: Emerging new paradigms SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID SHAPE-MEMORY ALLOYS; LEAD ORTHO-VANADATE; ELECTRON-MICROSCOPY; PHASE-TRANSITIONS; PREMARTENSITIC PHENOMENA; TRANSFORMATIONS; DIFFRACTION; SOLIDS; FLUIDS AB We present a brief review of spatial variations of the order parameter (e.g. strain, shuffle, etc.) in materials undergoing transitions such as ferroelastic martensites, shape memory alloys and magnetoelastics. We emphasize the usefulness of strain tensor and elastic compatibility constraint in providing key physical insights as well as a full description (including microstructure) of these materials. We outline applications of these ideas, in conjunction with recent experiments and computer simulations, in understanding strain textures such as twinning and transformation precursors. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. RP Saxena, A (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 41 TC 1 Z9 1 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 85 EP 91 DI 10.1051/jp4:2003841 PN 1 PG 7 WC Physics, Multidisciplinary SC Physics GA 742EG UT WOS:000186503200010 ER PT J AU Lookman, T Shenoy, SR Rasmussen, KO Saxena, A Bishop, AR AF Lookman, T Shenoy, SR Rasmussen, KO Saxena, A Bishop, AR TI On dynamics of ferroelastic transitions SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID STRAIN AB Simulating microstructure evolution requires an understanding of the validity of various dynamical schemes. We show how underdamped and overdamped equations can be obtained for ferroelastic transitions and, in particular, demonstrate that the widely used time dependent Ginzburg-Landau (TDGL) equations correspond to an appropriate limit of the dynamics. C1 Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. RP Lookman, T (reprint author), Los Alamos Natl Lab, Theoret Div, POB 1663, Los Alamos, NM 87545 USA. RI Rasmussen, Kim/B-5464-2009 OI Rasmussen, Kim/0000-0002-4029-4723 NR 17 TC 4 Z9 4 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 195 EP 199 DI 10.1051/jp4:2003864 PN 1 PG 5 WC Physics, Multidisciplinary SC Physics GA 742EG UT WOS:000186503200033 ER PT J AU Gavriljuk, VG Tyshchenko, AI Rawers, J Berns, H AF Gavriljuk, VG Tyshchenko, AI Rawers, J Berns, H TI Thermodynamic stability, structure and properties of Fe-based C plus N austenite and martensite SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID NITROGEN; CARBON; ALLOYS AB Atomic distribution in C+N austenites and martensites is studied using Mossbauer spectroscopy and Monte Carlo simulation. It is shown that interaction of interstitial atoms is characterised by a strong repulsion within the first two coordination spheres, so that they do not occupy neighbouring interstitial sites in the fcc as well as in the bcc lattice. Such behaviour is not typical either for nitrogen or for carbon atoms. A high stability of C+N solid solutions in relation to martensitic transformation and precipitation during tempering is found and attributed to these peculiarities of atomic distribution. C1 Inst Phys Met, UA-03142 Kiev, Ukraine. US DOE, Albany Res Ctr, Albany, OR 97321 USA. Ruhr Univ Bochum, Chair Mat Technol, D-44780 Bochum, Germany. RP Gavriljuk, VG (reprint author), Inst Phys Met, Vernadsky Blvd 36, UA-03142 Kiev, Ukraine. RI Tyshchenko, Andrii/F-8296-2016 NR 10 TC 1 Z9 1 U1 3 U2 5 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 259 EP 262 DI 10.1051/jp4:2003878 PN 1 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EG UT WOS:000186503200047 ER PT J AU Xie, Z Liu, Y Stach, E AF Xie, Z Liu, Y Stach, E TI In situ TEM study of the shape recovery process in predeformed NiTi shape memory alloy SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID MARTENSITE DEFORMATION; COMPRESSION; TENSION AB Shape recovery of pre-deformed martensitic NiTi shape memory alloy was studied by TEM during insitu heating up to 300degreesC, a temperature significantly higher than the A(f) temperature of the same material in bulk. Special attention has been paid to the microstructure variation upon subsequent heating and cooling. It is found that, although both forward and reverse phase transformations have taken place, the morphology of pre-deformed microstructure remains unchanged. The subsequently formed martensite upon re-cooling to room temperature consists of no lattice twins. C1 Nanyang Technol Univ, Sch Mat Engn, Singapore 639798, Singapore. Nanyang Technol Univ, Sch Mech & Prod Engn, Singapore 639798, Singapore. Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA USA. RP Xie, Z (reprint author), Nanyang Technol Univ, Sch Mat Engn, Nanyang Ave, Singapore 639798, Singapore. RI Stach, Eric/D-8545-2011; Liu, Yong/G-5084-2010 OI Stach, Eric/0000-0002-3366-2153; NR 8 TC 0 Z9 0 U1 1 U2 6 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 769 EP 772 DI 10.1051/jp4:2003995 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EH UT WOS:000186503400034 ER PT J AU Vaidyanathan, R Bourke, MAM Dunand, DC AF Vaidyanathan, R Bourke, MAM Dunand, DC TI An in situ neutron diffraction mechanical study of superelastic NiTi and NiTi-TiC composites SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID PHASE-FRACTION; TEXTURE; STRAIN AB Superelastic NiTi and NiTi-TiC composites were subjected to static uniaxial compressive loading while neutron diffraction spectra were simultaneously acquired. A methodology was established to obtain quantitative strain, texture and phase volume fraction information during the forward and reverse stress-induced martensitic transformation. Despite the presence of 10 vol.% of stiff TiC particles, a macroscopic compressive strain of 3% was obtained in the composite on loading and was fully recovered on unloading. The observed behavior suggests that the martensite accommodates the mismatch with the transforming austenite (while they co-exist) and the TiC particles (in the case of the composite). Superelastic NiTi was also subjected to simultaneous neutron diffraction and uniaxial compressive cycling. The average phase strain in the mechanically-loaded austenite (at a given stress) remained unaltered during the load-unload cycles. However, differences in both volume fraction and texture of austenite and martensite were noted as cycling progressed, suggesting that these factors are responsible for the changes in the macroscopic stress-strain response of NiTi with mechanical cycling. C1 Univ Cent Florida, AMPAC, Orlando, FL 32816 USA. Univ Cent Florida, MMAE, Orlando, FL 32816 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RP Vaidyanathan, R (reprint author), Univ Cent Florida, AMPAC, Orlando, FL 32816 USA. RI Dunand, David/B-7515-2009; OI Dunand, David/0000-0001-5476-7379 NR 8 TC 2 Z9 2 U1 1 U2 6 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 823 EP 826 DI 10.1051/jp4:20031008 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EH UT WOS:000186503400047 ER PT J AU De Graef, M Kishi, Y Zhu, Y Wuttig, M AF De Graef, M Kishi, Y Zhu, Y Wuttig, M TI Lorentz study of magnetic domains in Heusler-type ferromagnetic shape memory alloys SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID PHASE AB We report on magnetic domain observations using in-situ Lorentz microscopy of the ferromagnetic shape memory alloys of the type Ni2MnGa and Co2NiGa. The domain configurations are analyzed by means of the Transport-of-Intensity phase reconstruction method. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. RP De Graef, M (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. RI DeGraef, Marc/G-5827-2010 OI DeGraef, Marc/0000-0002-4721-6226 NR 8 TC 10 Z9 10 U1 2 U2 10 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 993 EP 996 DI 10.1051/jp4:20031048 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EH UT WOS:000186503400087 ER PT J AU Kishi, Y De Graef, M Craciunescu, C Lograsso, TA Neumann, DA Wuttig, M AF Kishi, Y De Graef, M Craciunescu, C Lograsso, TA Neumann, DA Wuttig, M TI Microstructures and transformation behavior of CoNiGa ferromagnetic shape memory alloys SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID PHASE-TRANSFORMATIONS; SYSTEM; GA AB TEM observations and transformation characteristics of Co2Ni1-xGa1+x ferromagnetic shape memory alloys will be presented. The dependence of the martensitic transformation start temperatures on the valance-electron atom ratio is identical to that of NiMnGa alloys. Optical microstructures show typical self-accommodated structures. The domain boundaries are straight indicating only elastic distortions in the product phase. High-density striations are observed in the TEM bright field images of the martensite-phase. Selected area electron diffraction patterns and TEM dark field images revealed that they are thin twin plates. Tweed or striated contrast is observed in the TEM bright field images of the parent phase at temperatures about 70 K higher than the M, temperature. C1 Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Iowa State Univ, Ames Lab, Ames, IA USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Kishi, Y (reprint author), Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA. RI Craciunescu, Corneliu/B-8890-2011; DeGraef, Marc/G-5827-2010 OI DeGraef, Marc/0000-0002-4721-6226 NR 9 TC 8 Z9 8 U1 0 U2 12 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 1021 EP 1024 DI 10.1051/jp4:20031055 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EH UT WOS:000186503400094 ER PT J AU Shapiro, SM Winn, BL Schlagel, DL Lograsso, TA Erwin, RL AF Shapiro, SM Winn, BL Schlagel, DL Lograsso, TA Erwin, RL TI Phonon precursors to the high temperature martensitic transformation in Ti50Pd42Cr8 SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 10th International Conference on Martensitic Transformations CY JUN 10-14, 2002 CL ESPOO, FINLAND SP Metso, Minist Trade & Ind, ESPOO, Fdn Technol, AvestaPolarti Stainless, IMATRA STEEL, Bodycote Metal Technol, Outokumpu, RAUTARUUKKI, KONE, COMPONENTA, AdaptaMat, Finnair, Nordea ID ALLOYS AB Inelastic neutron scattering measurements were carried out on the Ti50Pd50-xCrx alloy, which is a high temperature shape memory material. For x=0, the transformation temperature is similar to800K and for the composition studied (x=8 at.%) M-s similar to 400K. The majority of the measurements were performed in the parent, B2-phase, up to 873K. Most of the phonons propagating along the three symmetry directions [zeta00], [zetazetazeta], and [zetazeta0] were well defined with the exception of the [zetazeta0] transverse acoustic mode with displacements along the [-zetazeta0] corresponding to the C'=1/2(C-11-C-12) elastic constant in the zeta-->0 limit. These phonons are well defined for small zeta, but for zeta > 0.10 they are strongly overdamped near the transition temperature and become better defined at higher temperatures. An elastic peak develops in the cubic phase at zeta=0.22 and increases in intensity as M, is approached. However, the dispersion curves show no anomaly at this particular wavevector, in marked contrast to the lattice dynamic studies of other systems exhibiting Martensitic transformations. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NIST, Gaithersburg, MD 20899 USA. RP Shapiro, SM (reprint author), Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. RI Winn, Barry/A-5065-2016 OI Winn, Barry/0000-0001-6383-4318 NR 8 TC 4 Z9 4 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD OCT PY 2003 VL 112 BP 1047 EP 1050 DI 10.1051/jp4:20031061 PN 2 PG 4 WC Physics, Multidisciplinary SC Physics GA 742EH UT WOS:000186503400100 ER PT J AU Zhao, J AF Zhao, J TI General-case data interpretation of spin-echo small-angle neutron scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID INSTRUMENT AB Following previous works on data interpretation in the case of a one-dimensionally encoded spin-echo small-angle neutron scattering instrument when the scattering data are collected along a single direction, further studies for the more general case of data collection in two dimensions are presented. A mathematical relationship between the correlation function measured in two dimensions and the pair-distance distribution function of the scattering sample is established. The relationship between the correlation function measured in one and two dimensions is also examined. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Zhao, J (reprint author), Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. RI Zhao, Jinkui/B-7872-2013 OI Zhao, Jinkui/0000-0002-7756-1952 NR 7 TC 0 Z9 0 U1 0 U2 2 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT PY 2003 VL 36 BP 1177 EP 1181 DI 10.1107/S0021889803013736 PN 5 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 718ZV UT WOS:000185178600010 ER PT J AU Zhang, Y Wilkinson, AP Nolas, GS Lee, PL Hodges, JP AF Zhang, Y Wilkinson, AP Nolas, GS Lee, PL Hodges, JP TI Strategies for solving neighboring-element problems: a case study using resonant X-ray diffraction and pulsed neutron diffraction to examine Sr8Ga16Ge30 SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID POWDER DIFFRACTION; RIETVELD REFINEMENT; SITE OCCUPANCIES; SYNCHROTRON RADIATION; ANOMALOUS SCATTERING; STRUCTURAL DISORDER; CRYSTAL-STRUCTURE; CLATHRATE; DISTRIBUTIONS; COLLECTION AB The distribution of gallium and germanium over the available framework sites in the type-I clathrate Sr8Ga16Ge30 (Pm (3) over barn) has been determined by powder diffraction using several different combinations of resonant scattering data sets, collected at energies close to both the Ga and Ge K-edges, and time-of-flight (TOF) neutron diffraction data. Based on a combined refinement using three X-ray data sets and a composition restraint, the fractional occupancies of the 6c, 16i and 24k sites by gallium are estimated to be 0.705 ( 5), 0.181 ( 3) and 0.376 ( 2), respectively. The required resonant scattering factors were determined by Kramers - Kronig transformation from X-ray absorption spectra. The results from refinements using single data sets and various combinations of data sets are compared. The high degree of scattering contrast that resonant diffraction can provide leads to very precise site occupancies. However, systematic errors in the resonant diffraction intensity data can considerably degrade the accuracy of the results. The use of a carefully chosen multiple-data-set strategy can minimize bias in the refinement results by reducing the correlations between site occupancies, atomic displacement parameters and histogram scale factors. The effect of errors in the resonant scattering factors on the refinement results was also examined. C1 Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Univ S Florida, Dept Phys, Tampa, FL 33620 USA. Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Wilkinson, AP (reprint author), Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. EM angus.wilkinson@chemistry.gatech.edu RI Wilkinson, Angus/C-3408-2008; Hodges, Jason/K-1421-2013; OI Wilkinson, Angus/0000-0003-2904-400X; Hodges, Jason/0000-0003-3016-4578 NR 34 TC 17 Z9 17 U1 2 U2 12 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT PY 2003 VL 36 BP 1182 EP 1189 DI 10.1107/S0021889803013955 PN 5 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 718ZV UT WOS:000185178600011 ER PT J AU Savytskii, DI Trots, DM Vasylechko, LO Tamura, N Berkowski, M AF Savytskii, DI Trots, DM Vasylechko, LO Tamura, N Berkowski, M TI Twinning in La0.95Sr0.05Ga0.9Mg0.1O2.92 crystal studied by white-beam (Laue) X-ray microdiffraction SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID FERROELASTIC DOMAIN-WALLS; SINGLE-CRYSTALS; TOPOGRAPHY; CONDUCTIVITY; PHASE; OXIDE AB The investigation of twin structure in La0.95Sr0.05Ga0.9Mg0.1O2.92 perovskite-type crystals has been undertaken using the technique of white-beam X-ray microdiffraction. The sample shows definite twinning which is reflected in the Laue patterns as apparent splitting of the peaks. Reflections from the different domains were indexed separately. Positional shifts of twin domain spots with respect to the reference matrix spot, arising from the mutual misorientation of diffraction vectors, were measured on Laue patterns and compared with calculated values in order to solve the twin laws in this system. The dominant twin operations were found to be (12 (1) over bar) and (10 (1) over bar) mirror reflections. C1 Lviv Polytech Natl Univ, UA-79013 Lvov, Ukraine. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. RP Savytskii, DI (reprint author), Lviv Polytech Natl Univ, 12 Bandera St, UA-79013 Lvov, Ukraine. EM crystal@polynet.lviv.ua RI Savytskii, Dmytro/A-4152-2012; Berkowski, Marek/K-9465-2016 NR 18 TC 13 Z9 14 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT PY 2003 VL 36 BP 1197 EP 1203 DI 10.1107/S002188980301433X PN 5 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 718ZV UT WOS:000185178600013 ER PT J AU Toby, BH Von Dreele, RB Larson, AC AF Toby, BH Von Dreele, RB Larson, AC TI CIF applications. XIV. Reporting of Rietveld results using pdCIF: GSAS2CIF SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID CRYSTALLOGRAPHIC INFORMATION FILE AB A discussion of the process of creating powder diffraction CIF documents (pdCIF) from Rietveld results is presented, with particular focus on the computer program GSAS2CIF. The data structures used within GSAS2CIF are described, as well as how the program implements template files for descriptive information. Two graphical user interface utilities are also discussed. C1 Natl Inst Stand & Technol, NISt Ctr Neutron Res, Gaithersburg, MD 20899 USA. Argonne Natl Lab, IPNS APS Div, Argonne, IL 60439 USA. RP Toby, BH (reprint author), Natl Inst Stand & Technol, NISt Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Toby, Brian/F-3176-2013 OI Toby, Brian/0000-0001-8793-8285 NR 7 TC 7 Z9 7 U1 2 U2 6 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD OCT PY 2003 VL 36 BP 1290 EP 1294 DI 10.1107/S0021889803016819 PN 5 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 718ZV UT WOS:000185178600030 ER PT J AU Pfister, G McKenzie, RL Liley, JB Thomas, A Forgan, BW Long, CN AF Pfister, G McKenzie, RL Liley, JB Thomas, A Forgan, BW Long, CN TI Cloud coverage based on all-sky imaging and its impact on surface solar irradiance SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID B RADIATION; UV-B; SKIES; HAZE AB In Lauder, Central Otago, New Zealand, two all-sky imaging systems have been in operation for more than 1 yr, measuring the total, opaque, and thin cloud fraction, as well as indicating whether the sun is obscured by clouds. The data provide a basis for investigating the impact of clouds on the surface radiation field. The all-sky cloud parameters were combined with measurements of global, direct, and diffuse surface solar irradiance over the spectral interval from 0.3 to 3 mum. Here, the results of ongoing analysis of this dataset are described. As a reference for the magnitude of the cloud influence, clear-sky irradiance values are estimated as a simple function of solar zenith angle and the earth-sun distance. The function is derived from a least squares fit to measurements taken when available cloud images show clear-sky situations. Averaged over a longer time period, such as 1 month, cloud fraction and surface irradiance are clearly negatively correlated. Monthly means in the ratio of the measured surface irradiance to the clear-sky value had a correlation coefficient of about -0.9 with means of cloud fraction for the months from July 2000 to June 2001. In the present work reductions in the surface irradiance and situations in which clouds cause radiation values to exceed the expected clear-sky amount are analyzed. Over 1 yr of observations, 1-min-averaged radiation measurements exceeding the expected clear-sky value by more than 10% were observed with a frequency of 5%. In contrast, a reduction of more than 10% below estimated clear-sky values occurred in 66% of the cases, while clear-sky irradiances ( measured irradiance within +/-10% of estimated clear-sky value) were observed 29% of the time. Low cloud fractions frequently lead to moderate enhancement, because the sun is often unobscured and the clouds are brighter than the sky that they hide. As cloud fraction increases the sun is likely to be obscured, causing irradiance values to fall well below clear-sky values. However, in the case of unobscured sun, there is a tendency for strongest enhancements when cloud fractions are highest. Enhancements, especially at high solar zenith angle, are also often observed in association with thin clouds. C1 Natl Inst Water & Atmospher Res, Central Otago, New Zealand. Bur Meteorol, Melbourne, Vic, Australia. Pacific NW Natl Lab, Richland, WA USA. RP Pfister, G (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. RI Pfister, Gabriele/A-9349-2008; OI Liley, Ben/0000-0002-8844-7928 NR 17 TC 111 Z9 125 U1 2 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2003 VL 42 IS 10 BP 1421 EP 1434 DI 10.1175/1520-0450(2003)042<1421:CCBOAI>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 727NP UT WOS:000185665200006 ER PT J AU Gao, F Weber, WJ AF Gao, F Weber, WJ TI Recovery of close Frenkel pairs produced by low energy recoils in SiC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SILICON-CARBIDE; DISPLACEMENT CASCADES; MOLECULAR-DYNAMICS; METALS; EVOLUTION; DISORDER; DEFECTS; DAMAGE; IRON AB Simulations of displacement cascades in silicon carbide (SiC) indicate that most defects created are point defects, where interstitials are displaced only a small distance from the nearest vacancies. Of the interstitial defects produced in SiC, about 40% survive as freely migrating interstitials that can contribute to microstructural evolution during irradiation of SiC. The stable defect configurations in this study were created with low-energy recoils using molecular dynamics (MD) simulation. These stable Frenkel pairs have been annealed at different temperatures, using MD methods, to determine the time required for interstitials to recombine with vacancies. The MD data have been analyzed using an Arrhenius relation, and the activation energies for defect recombination processes range from 0.22 to 1.6 eV for C Frenkel pairs and from 0.28 to 0.9 eV for Si Frenkel pairs. These low activation energies for spontaneous recovery of Frenkel pairs in SiC are qualitatively consistent with the recovery processes observed experimentally on both the Si and C sublattices below room temperature. Based on the data analysis, the spontaneous recombination distance is estimated to be 0.66 and 0.70 a(o) for the C and Si sublattices, respectively. (C) 2003 American Institute of Physics. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gao, F (reprint author), Pacific NW Natl Lab, MS K8-93,POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012 OI Weber, William/0000-0002-9017-7365; NR 33 TC 65 Z9 67 U1 4 U2 22 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 2003 VL 94 IS 7 BP 4348 EP 4356 DI 10.1063/1.1605254 PG 9 WC Physics, Applied SC Physics GA 723FC UT WOS:000185420900019 ER PT J AU Knudson, MD Lemke, RW Hayes, DB Hall, CA Deeney, C Asay, JR AF Knudson, MD Lemke, RW Hayes, DB Hall, CA Deeney, C Asay, JR TI Near-absolute Hugoniot measurements in aluminum to 500 GPa using a magnetically accelerated flyer plate technique SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHOCK-WAVE EXPERIMENTS; HIGH-PRESSURE; STATE MEASUREMENTS; IMPACT VELOCITIES; COMPRESSION; EQUATION; COPPER; KM/S; IRON; TANTALUM AB Hugoniot measurements were performed on aluminum (6061-T6) in the stress range of 100-500 GPa (1-5 Mbar) using a magnetically accelerated flyer plate technique. This method of flyer plate launch utilizes the high currents, and resulting magnetic fields produced at the Sandia Z Accelerator to accelerate macroscopic aluminum flyer plates (approximately 12x25 mm in lateral dimension and similar to300 mum in thickness) to velocities in excess of 20 km/s. This technique was used to perform plate-impact shock-wave experiments on aluminum to determine the high-stress equation of state (EOS). Using a near-symmetric impact method, Hugoniot measurements were obtained in the stress range of 100-500 GPa. The results of these experiments are in excellent agreement with previously reported Hugoniot measurements of aluminum in this stress range. The agreement at lower stress, where highly accurate gas gun data exist, establishes the magnetically accelerated flyer plate technique as a suitable method for generating EOS data. Furthermore, the present results exhibit increased accuracy over the previous techniques used to obtain data in the higher-stress range. This improved accuracy enhances our understanding of the response of aluminum to 500 GPa, and lends increased confidence to the use of aluminum as a standard material in future impedance matching experiments. (C) 2003 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Knudson, MD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mdknuds@sandia.gov NR 58 TC 74 Z9 91 U1 3 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 2003 VL 94 IS 7 BP 4420 EP 4431 DI 10.1063/1.1604967 PG 12 WC Physics, Applied SC Physics GA 723FC UT WOS:000185420900030 ER PT J AU Zhong, Y Ashkenazy, Y Albe, K Averback, RS AF Zhong, Y Ashkenazy, Y Albe, K Averback, RS TI Ion beam smoothening of metal surfaces SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EMBEDDED-ATOM-METHOD; MOLECULAR-DYNAMICS; FCC METALS; IRRADIATION; FILMS; SEMICONDUCTORS; NANOPARTICLES; BOMBARDMENT; INSTABILITY; RELAXATION AB Ion beam induced smoothening of crystalline and amorphous substrates were investigated using molecular dynamics simulations. Rough surfaces created by depositing small nanoparticles, 2-3 nm in diameter, onto flat substrates were subjected to repeated impacts with 40 keV Xe atoms. Two smoothening processes are identified: The nanoparticle either burrows into the substrate, with the underlying substrate atoms flowing around it to the surface, or it flows over the substrate surface, wetting it. Generally, these two mechanisms operate simultaneously in both amorphous and crystalline substrates. The burrowing mechanism in amorphous substrates was additionally investigated by creating low energy recoils, 20 or 200 eV in the substrate beneath the nanoparticle. Roughening of initially smooth amorphous substrates during ion impact was also studied for comparison with the smoothening process. (C) 2003 American Institute of Physics. C1 Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. RP Zhong, Y (reprint author), Argonne Natl Lab, Adv Photon Source, Bldg 401, Argonne, IL 60540 USA. RI ashkenazy, yinon/D-1257-2012; Albe, Karsten/F-1139-2011 NR 27 TC 12 Z9 12 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 2003 VL 94 IS 7 BP 4432 EP 4439 DI 10.1063/1.1604933 PG 8 WC Physics, Applied SC Physics GA 723FC UT WOS:000185420900031 ER PT J AU Wu, J Walukiewicz, W Shan, W Yu, KM Ager, JW Li, SX Haller, EE Lu, H Schaff, WJ AF Wu, J Walukiewicz, W Shan, W Yu, KM Ager, JW Li, SX Haller, EE Lu, H Schaff, WJ TI Temperature dependence of the fundamental band gap of InN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; HEXAGONAL INN; OPTICAL-PROPERTIES; INDIUM NITRIDE; BUFFER LAYER; THIN-FILMS; ALLOYS; ENERGY AB The fundamental band gap of InN films grown by molecular beam epitaxy have been measured by transmission and photoluminescence spectroscopy as a function of temperature. The band edge absorption energy and its temperature dependence depend on the doping level. The band gap variation and Varshni parameters of InN are compared with other group III nitrides. The energy of the photoluminescence peak is affected by the emission from localized states and cannot be used to determine the band gap energy. Based on the results obtained on two samples with distinctly different electron concentrations, the effect of degenerate doping on the optical properties of InN is discussed. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Cornell Univ, Dept Elect & Comp Engn, Ithaca, NY 14853 USA. RP Walukiewicz, W (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM w_walukiewicz@lbl.gov RI Wu, Junqiao/G-7840-2011; Yu, Kin Man/J-1399-2012; OI Wu, Junqiao/0000-0002-1498-0148; Yu, Kin Man/0000-0003-1350-9642; Ager, Joel/0000-0001-9334-9751 NR 20 TC 273 Z9 282 U1 2 U2 41 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 2003 VL 94 IS 7 BP 4457 EP 4460 DI 10.1063/1.1605815 PG 4 WC Physics, Applied SC Physics GA 723FC UT WOS:000185420900034 ER PT J AU Shapiro, NA Feick, H Hong, W Cich, M Armitage, R Weber, ER AF Shapiro, NA Feick, H Hong, W Cich, M Armitage, R Weber, ER TI Luminescence energy and carrier lifetime in InGaN/GaN quantum wells as a function of applied biaxial strain SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELASTIC-CONSTANTS; PIEZOELECTRIC POLARIZATION; MACROSCOPIC POLARIZATION; GALLIUM NITRIDE; GAN; ALN; HETEROSTRUCTURES; RECOMBINATION; SPECTROSCOPY; TEMPERATURE AB Continuous-wave and time-resolved photoluminescence of InGaN quantum wells are measured as a function of applied biaxial strain, which provides a unique means of altering the built-in polarization field in these structures. The direction and magnitude of the shift of the luminescence-peak energy are quantitatively analyzed within an analytical carrier separation model. It is found that the presently used piezoelectric coefficients of InGaN are not entirely consistent with our experimental results. Instead, consistent interpretation of our data requires the e(13) and e(33) piezoelectric coefficients of InN to be similar to15% larger than the commonly accepted values. Our analysis allows the assignment of an effective carrier-separation parameter to each investigated quantum-well sample, which quantifies the shift of the luminescence peak energy with the change in the polarization field. The effective carrier separation is found to be zero for narrow quantum wells (<1.5 nm) and asymptotically approaches the full quantum well width for increasing well width. However, heavy doping or increased indium content are found to reduce the effective carrier separation, which is ascribed to screening of the polarization field or localization effects, respectively. A reduction of the carrier lifetime with the application of strain supports the carrier separation model and allows the derivation of a quantity related to the change of the wave function shape with the polarization field. (C) 2003 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. RP Shapiro, NA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 28 TC 22 Z9 27 U1 3 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 OCT 1 PY 2003 VL 94 IS 7 BP 4520 EP 4529 DI 10.1063/1.1607521 PG 10 WC Physics, Applied SC Physics GA 723FC UT WOS:000185420900044 ER PT J AU Opdahl, A Kim, SH Koffas, TS Marmo, C Somorjai, GA AF Opdahl, A Kim, SH Koffas, TS Marmo, C Somorjai, GA TI Surface mechanical properties of pHEMA contact lenses: Viscoelastic and adhesive property changes on exposure to controlled humidity SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A LA English DT Article DE atomic force microscopy; surface mechanical properties; hydrogel; contact lens material ID FORCE MICROSCOPY; GLASS-TRANSITION; POLYMERS; FRICTION; AFM AB The surface mechanical properties of poly(hydroxyethyl)methacrylate (pHEMA)-based contact lenses were monitored as a function of humidity by atomic force microscopy (AFM). Surface viscoelastic and adhesion values were extracted from AFM force versus distance interaction curves and were found to be strongly dependent on the bulk water content of the lens and on the relative humidity. At low relative humidity, 40-50%, the dehydration rate from the surface is faster than the hydration rate from the bulk, leading to a rigid surface region that has mechanical properties similar to those measured on totally dehydrated lenses. At relative humidity values > 60%, the dehydration rate from the lens surface rapidly decreases, leading to higher surface water content and a softer surface region. The results indicate that, in an ocular environment, although the bulk of the pHEMA contact lens is hydrated, the surface region may be in a transition between a dehydrated glassy state and a hydrated rubbery state. (C) 2003 Wiley Periodicals, Inc. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA. Ocular Sci Inc, San Francisco, CA 94080 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 15 TC 44 Z9 45 U1 4 U2 26 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES A JI J. Biomed. Mater. Res. Part A PD OCT 1 PY 2003 VL 67A IS 1 BP 350 EP 356 DI 10.1002/jbm.a.10054 PG 7 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 729ER UT WOS:000185760300041 PM 14517895 ER PT J AU Nguyen, TN Wemmer, DE AF Nguyen, TN Wemmer, DE TI Complete resonance assignments for the nudix hydrolase DR2356 of Deinococcus radiodurans SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE homeostasis; NMR; nudix; radiation resistant C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 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 OCT PY 2003 VL 27 IS 2 BP 181 EP 182 DI 10.1023/A:1024934325331 PG 2 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 705WM UT WOS:000184419100009 PM 12913415 ER PT J AU Zheng, DY Cort, JR Chiang, YW Acton, T Kennedy, MA Montelione, GT AF Zheng, DY Cort, JR Chiang, YW Acton, T Kennedy, MA Montelione, GT TI H-1, C-13 and N-15 resonance assignments for methionine sulfoxide reductase B from Bacillus subtilis SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE AutoAssign; methionine sulfoxide reductase; structural genomics C1 Rutgers State Univ, Dept Biochem & Mol Biol, Ctr Adv Biotechnol, Piscataway, NJ 08854 USA. Rutgers State Univ, NE Struct Genom Consortium, Piscataway, NJ 08854 USA. Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. Pacific NW Natl Lab, NE Struct Genom Consortium, Richland, WA 99352 USA. RP Montelione, GT (reprint author), Rutgers State Univ, Dept Biochem & Mol Biol, Ctr Adv Biotechnol, Piscataway, NJ 08854 USA. FU NIGMS NIH HHS [P50 GM 62413] NR 9 TC 4 Z9 4 U1 0 U2 0 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 OCT PY 2003 VL 27 IS 2 BP 183 EP 184 DI 10.1023/A:1024991310929 PG 2 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 705WM UT WOS:000184419100010 PM 12913416 ER PT J AU Babikov, D AF Babikov, D TI Entrance channel localized states in ozone: Possible application to helium nanodroplet isolation spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; DISSOCIATION THRESHOLD; METASTABLE STATES; SCATTERING; SPECTRUM; HO2 AB Accurate calculations of the bound ro-vibrational states of ozone are performed in the region of high vibrational excitation. Two unusual vibrational states localized in the far van der Waals region are discovered. They can be considered as the ground vibrational states of even and odd symmetries bound in the shallow van der Waals well. Properties of these states are presented and discussed, which opens possibilities for experimental realization of the helium nanodroplet isolation ro-vibrational spectroscopy of ozone. (C) 2003 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Babikov, D (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 22 TC 15 Z9 15 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 2003 VL 119 IS 13 BP 6554 EP 6559 DI 10.1063/1.1604771 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 723FH UT WOS:000185421400020 ER PT J AU McLain, SE Siewenie, JE Benmore, CJ Turner, JFC AF McLain, SE Siewenie, JE Benmore, CJ Turner, JFC TI On the structure of boron trifluoride in liquid and supercritical phase investigated with neutron diffraction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID REVERSE MONTE-CARLO; DER-WAALS COMPLEXES; SHORT-RANGE ORDER; NITROUS-OXIDE COMPLEX; LIGAND CLOSE-PACKING; INFRARED-SPECTRUM; AB-INITIO; SOLID PARAHYDROGEN; LEWIS ACIDITY; DISORDERED STRUCTURES AB The results and reverse Monte Carlo analysis of diffraction measurements of BF3 in the liquid and supercritical state are presented. Liquid BF3 displays order only in the first coordination sphere around the average molecule and there is no intermediate range order. Liquid BF3 is thus not a layered liquid. Angular analysis using reverse Monte Carlo modeling shows that the dominant structural motif in the solid state, that of pseudo trigonal bipyramidal [3+2] coordination at B is partially retained in both the liquid and supercritical phase, though in the latter, this structural preference is greatly reduced. The structure of the supercritical phase retains the same intermolecular contact as the liquid phase, though the structural sites and population of these sites is much more widely distributed. (C) 2003 American Institute of Physics. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Agronne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL USA. Univ Tennessee, Neutron Sci Consortium, Knoxville, TN 37996 USA. RP Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. EM jturner@atom.chem.utk.edu OI McLain, Sylvia/0000-0002-3347-7759; Benmore, Chris/0000-0001-7007-7749 NR 73 TC 2 Z9 2 U1 0 U2 3 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 OCT 1 PY 2003 VL 119 IS 13 BP 6671 EP 6679 DI 10.1063/1.1604382 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 723FH UT WOS:000185421400033 ER PT J AU Kimmel, GA Persson, M Dohnalek, Z Kay, BD AF Kimmel, GA Persson, M Dohnalek, Z Kay, BD TI Temperature independent physisorption kinetics and adsorbate layer compression for Ar adsorbed on Pt(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NON-REGISTERED MONOLAYER; THERMAL-DESORPTION; SURFACE; FILMS; ARGON; TRANSITION; ADSORPTION; AG(111); KRYPTON; SYSTEM AB The influence of adlayer compression on the physisorption of Ar on Pt(111) is investigated using temperature programmed desorption and modulated molecular beams. We find that the difference in coverage between the compressed and uncompressed first layers is similar to10-15%. For coverages near one monolayer, this compression causes nearly temperature independent desorption kinetics over a wide temperature range (32-41 K). We present a theory that includes the effects of the compression on the desorption kinetics and explains the observed kinetics in terms of a competition between adsorbate-substrate and adsorbate-adsorbate interactions resulting in a continuous increase in the chemical potential near the completion of each successive layer. (C) 2003 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Chalmers Goteborg Univ, Dept Appl Phys, SE-41296 Gothenburg, Sweden. RP Kimmel, GA (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Persson, Mats/A-7514-2011; OI Persson, Mats/0000-0002-1443-9490; Kimmel, Greg/0000-0003-4447-2440; Dohnalek, Zdenek/0000-0002-5999-7867 NR 28 TC 27 Z9 27 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 2003 VL 119 IS 13 BP 6776 EP 6783 DI 10.1063/1.1604111 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 723FH UT WOS:000185421400045 ER PT J AU Kachru, S Kallosh, R Linde, A Maldacena, J McAllister, L Trivedi, SP AF Kachru, S Kallosh, R Linde, A Maldacena, J McAllister, L Trivedi, SP TI Towards inflation in string theory SO JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS LA English DT Article DE inflation; string theory and cosmology ID BRANE INFLATION; UNIVERSE AB We investigate the embedding of brane inflation into stable compactifications of string theory. At first sight a warped compactification geometry seems to produce a naturally flat inflaton potential, evading one well known difficulty of brane-antibrane scenarios. Careful consideration of the closed string moduli reveals a further obstacle: superpotential stabilization of the compactification volume typically modifies the inflaton potential and renders it too steep for inflation. We discuss the non-generic conditions under which this problem does not arise. We conclude that brane inflation models can only work if restrictive assumptions about the method of volume stabilization, the warping of the internal space, and the source of inflationary energy are satisfied. We argue that this may not be a real problem, given the large range of available fluxes and background geometries in string theory. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Inst Adv Study, Princeton, NJ 08540 USA. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. RP Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM skachru@stanford.edu; kallosh@stanford.edu; alinde@stanford.edu; malda@ias.edu; lpm@itp.stanford.edu; sandip@tifr.res.in NR 59 TC 768 Z9 769 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1475-7516 J9 J COSMOL ASTROPART P JI J. Cosmol. Astropart. Phys. PD OCT PY 2003 IS 10 AR 013 DI 10.1088/1475-7516/2003/10/013 PG 32 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 741PP UT WOS:000186466700003 ER PT J AU Kallosh, R Kratochvil, J Linde, A Linder, EV Shmakova, M AF Kallosh, R Kratochvil, J Linde, A Linder, EV Shmakova, M TI Observational bounds on cosmic doomsday SO JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS LA English DT Article DE dark energy theory; cosmological constant experiments ID COSMOLOGICAL CONSTANT; DARK ENERGY; CONSEQUENCES; SUPERNOVAE; EQUATION; UNIVERSE; STATE; FATE AB Recently it was found, in a broad class of models, that the dark energy density may change its sign during the evolution of the universe. This may lead to a global collapse of the universe within the time t(c)similar to10(10)-10(11) years. Our goal is to find what bounds on the future lifetime of the universe can be placed by the next generation of cosmological observations. As an example, we investigate the simplest model of dark energy with a linear potential V (phi)=V-0(1+alpha(phi)). This model can describe the present stage of acceleration of the universe if alpha is small enough. However, eventually the field phi rolls down, V (phi) becomes negative, and the universe collapses. The existing observational data indicate that the universe described by this model will collapse not earlier than t(c)greater than or similar to10 billion years from the present moment. We show that the data from SNAP and Planck satellites may extend the bound on the 'doomsday' time to t(c)greater than or similar to40 billion years at the 95% confidence level. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM kallosh@stanford.edu; jank@Stanford.EDU; alinde@stanford.edu; evlinder@lbl.gov; shmakova@slac.stanford.edu NR 51 TC 61 Z9 61 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1475-7516 J9 J COSMOL ASTROPART P JI J. Cosmol. Astropart. Phys. PD OCT PY 2003 IS 10 AR 015 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 741PP UT WOS:000186466700001 ER PT J AU Wang, H Gupta, A Tiwari, A Zhang, X Narayan, J AF Wang, H Gupta, A Tiwari, A Zhang, X Narayan, J TI TaN-TiN binary alloys and superlattices as diffusion barriers for copper interconnects SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials and Processes for Submicron Technologies III CY MAR 03, 2003 CL SAN DIEGO, CALIFORNIA DE TaN; TiN; superlattice; alloy; Cu diffusion barrier ID TANTALUM NITRIDES; VAPOR-DEPOSITION; EPITAXIAL-GROWTH; FILMS; METALLIZATION; SILICON; CU AB Binary alloys and superlattices of TaN-TiN thin films were grown on Si(100) substrates with a TiN buffer layer using pulsed laser deposition. A special target assembly was used to manipulate the concentrations of these binary component films. The 60% TaN resulted in a TaN (3 nm)/TiN (2 nm) superlattice, while 30% and 70% TaN generated uniform TaxTi1-xN alloys. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) confirmed the single-crystalline nature of these films. Four-point probe resistivity measurements suggest that these alloy and superlattice films have a lower resistivity than pure single-crystalline TaN films. The Cu-diffusion characteristic studies showed that these materials would have the potential as high-temperature diffusion barriers for Cu in ultra-large-scale integration technology. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Wang, H (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. RI Narayan, Jagdish/D-1874-2009; Zhang, Xinghang/H-6764-2013; Wang, Haiyan/P-3550-2014 OI Zhang, Xinghang/0000-0002-8380-8667; Wang, Haiyan/0000-0002-7397-1209 NR 15 TC 7 Z9 7 U1 0 U2 7 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 OCT PY 2003 VL 32 IS 10 BP 994 EP 999 DI 10.1007/s11664-003-0081-7 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 734VJ UT WOS:000186078400004 ER PT J AU Minor, AM Stach, EA Morris, JW Petrov, I AF Minor, AM Stach, EA Morris, JW Petrov, I TI In-situ nanoindentation of epitaxial TiN/MgO (001) in a transmission electron microscope SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials and Processes for Submicron Technologies III CY MAR 03, 2003 CL SAN DIEGO, CALIFORNIA DE nanoindentation; in situ; transmission electron microscopy; epitaxial film; plasticity; dislocation ID HARD COATINGS; ION-BEAM; MORPHOLOGY; LAYERS; MICROSTRUCTURE; GROWTH AB The deformation behavior of the epitaxial TiN/MgO (001) thin film/substrate system was studied through in-situ nanoindentation in a transmission electron microscope (TEM). The required sample geometry was prepared using Ga+ focused ion beam (FIB) etching. During room-temperature indentation, both the TiN film and the MgO substrate deformed through the motion of dislocations. The result was a localized hemispherical plastic zone in the TiN film directly under the indentation contact area, forming an 8degrees tilt boundary. These results show directly that small-scale plasticity in TiN can occur at room temperature through the motion of dislocations. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Illinois, Dept Mat Sci, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. RP Minor, AM (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Stach, Eric/D-8545-2011; Petrov, Ivan/D-4910-2011 OI Stach, Eric/0000-0002-3366-2153; Petrov, Ivan/0000-0002-2955-4897 NR 17 TC 28 Z9 28 U1 1 U2 15 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 OCT PY 2003 VL 32 IS 10 BP 1023 EP 1027 DI 10.1007/s11664-003-0084-4 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 734VJ UT WOS:000186078400007 ER PT J AU Sopori, B AF Sopori, B TI Silicon nitride processing for control of optical and electronic properties of silicon solar cells SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials and Processes for Submicron Technologies III CY MAR 03, 2003 CL SAN DIEGO, CALIFORNIA DE silicon nitride; solar cells; defects; impurities; passivation; metallization; antireflection coatings AB Thin films of SiN are well suited as antireflection (AR) coatings for Si solar cells because their optical properties, such as refractive index and absorption coefficient, can be tailored during deposition to match those of Si solar cells. The SiN layers, particularly those deposited by a plasma-enhanced chemical vapor deposition (PECVD) process, can serve other functions in Si solar-cell fabrication. They can be excellent buffer layers through which the front metal contact can be fired. The PECVD nitridation also introduces H into the Si surface, which diffuses deep into the solar cell and passivates residual impurities and defects during metal-contact firing. The optimization of SiN properties and processing conditions may have conflicting demands based on its multifunctional role. To fully exploit these multiple functions, the SiN processing sequence must be optimized based on the properties of the nitride, the diffusion behavior of H, and the interactions of metal with the SiN/Si composite substrate. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sopori, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 15 TC 37 Z9 38 U1 4 U2 13 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 OCT PY 2003 VL 32 IS 10 BP 1034 EP 1042 DI 10.1007/s11664-003-0086-2 PG 9 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 734VJ UT WOS:000186078400009 ER PT J AU Ravindra, NM Ravindra, K Mahendra, S Sopori, B Fiory, AT AF Ravindra, NM Ravindra, K Mahendra, S Sopori, B Fiory, AT TI Modeling and simulation of emissivity of silicon-related materials and structures SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Symposium on Materials and Processes for Submicron Technologies III CY MAR 03, 2003 CL SAN DIEGO, CALIFORNIA DE si; emissivity; Hotliner; SIMOX ID SI WAFERS; TEMPERATURE AB A brief review of the models that have been proposed in the literature to simulate the emissivity of silicon-related materials and structures is presented. The models discussed in this paper include ray tracing, numerical, phenomenological, and semi-quantitative approaches. A semi-empirical model, known as Multi-Rad, based on the matrix method of multilayers is used to evaluate the reflectance, transmittance, and emittance for Si, SiO2/Si, Si3N4/SiO2/Si/SiO2/Si3N4 (Hotliner), and separation by implantation of oxygen (SIMOX) wafers. The influence of doping concentration and dopant type as well as the effect of the angle of incidence on the radiative properties of silicon is examined. The results of these simulations lead to the following conclusions: (1) at least within the limitations of the Multi-Rad model, near the absorption edge, the radiative properties of Si are not affected significantly by the angle of incidence unless the angle is very steep; (2) at low temperatures, the emissivity of silicon shows complex structure as a function of wavelength; (3) for SiO2/Si, changes in emissivity are dominated by substrate effects; (4) Hotliner has peak transmittance at 1.25 mum, and its emissivity is almost temperature independent; and (5) SIMOX exhibits significant changes in emissivity in the wavelength range of 1-20 mum. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Union Cty Magnet High Sch, Scotch Plains, NJ 07076 USA. Millburn High Sch, Millburn, NJ 07041 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ravindra, NM (reprint author), New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. NR 13 TC 14 Z9 14 U1 3 U2 16 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 OCT PY 2003 VL 32 IS 10 BP 1052 EP 1058 DI 10.1007/s11664-003-0088-0 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 734VJ UT WOS:000186078400011 ER PT J AU Geist, DR Brown, RS Cullinan, VI Mesa, MG Vanderkooi, SP McKinstry, CA AF Geist, DR Brown, RS Cullinan, VI Mesa, MG Vanderkooi, SP McKinstry, CA TI Relationships between metabolic rate, muscle electromyograms and swim performance of adult chinook salmon SO JOURNAL OF FISH BIOLOGY LA English DT Article DE Columbia River; electromyogram; hydroelectric dams; metabolic rate; spring chinook salmon; swim speed ID SOCKEYE-SALMON; ONCORHYNCHUS-NERKA; OXYGEN CONSUMPTION; DIFFICULT PASSAGE; COLUMBIA-RIVER; AMERICAN SHAD; ENERGY USE; FISH; SPEEDS; TEMPERATURE AB Oxygen consumption rates of adult spring chinook salmon Oncorhynchus tshawytscha increased with swim speed and, depending on temperature and fish mass, ranged from 609 mg O-2 h(-1) at 30 cm s(-1) (c. 0.5 BL s(-1)) to 3347 mg O-2 h(-1) at 170 cm s(-1) (c. 2.3 BL s(-1)). Corrected for fish mass, these values ranged from 122 to 670 mg O-2 kg(-1) h(-1), and were similar to other Oncorhynchus species. At all temperatures (8, 12.5 and 17degrees C), maximum oxygen consumption values levelled off and slightly declined with increasing swim speed > 170 cm s(-1), and a third-order polynomial regression model fitted the data best. The upper critical swim speed (U-crit) of fish tested at two laboratories averaged 155 cm s(-1) (2.1 BL s(-1)), but U-crit of fish tested at the Pacific Northwest National Laboratory were significantly higher (mean 165 cm s(-1)) than those from fish tested at the Columbia River Research Laboratory (mean 140 cm s(-1)). Swim trials using fish that had electromyogram (EMG) transmitters implanted in them suggested that at a swim speed of c. 135 cm s(-1), red muscle EMG pulse rates slowed and white muscle EMG pulse rates increased. Although there was significant variation between individual fish, this swim speed was c. 80% of the U(cri)t for the fish used in the EMG trials (mean U-crit 168.2 cm s(-1)). Bioenergetic modelling of the upstream migration of adult chinook salmon should consider incorporating an anaerobic fraction of the energy budget when swim speeds are greater than or equal to80% of the U-crit. (C) 2003 The Fisheries Society of the British Isles. C1 Pacific NW Natl Lab, Ecol Grp, Richland, WA 99352 USA. Pacific NW Natl Lab, Marine Ecol Proc Grp, Sequim, WA 98382 USA. US Geol Survey, Western Fisheries Res Ctr, Columbia River Res Lab, Cook, WA 98605 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Geist, DR (reprint author), Pacific NW Natl Lab, Ecol Grp, Mail Stop K6-85,POB 999, Richland, WA 99352 USA. NR 55 TC 17 Z9 17 U1 2 U2 12 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD OCT PY 2003 VL 63 IS 4 BP 970 EP 989 DI 10.1046/j.1095-8649.2003.00217.x PG 20 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 734GQ UT WOS:000186047000012 ER PT J AU Shawky, MA Marathe, A Barrett, CL AF Shawky, MA Marathe, A Barrett, CL TI A first look at the empirical relation between spot and futures electricity prices in the United States SO JOURNAL OF FUTURES MARKETS LA English DT Article ID CONDITIONAL HETEROSKEDASTICITY; FINANCING POLICIES; MARKET POWER; NATURAL-GAS; CRUDE-OIL; RISK; EQUILIBRIUM; REGRESSION; INVESTMENT; PREMIUMS AB In this article we investigate the statistical properties of wholesale electricity spot and futures prices traded on the New York Mercantile Exchange for delivery at the California-Oregon Border. Using daily data for the years 1998 and 1999, we find that many of the characteristics of the electricity market can be viewed to be broadly consistent with efficient markets. The futures risk premium for 6-month futures contracts is estimated to be 0.1328% per day or about 4% per month. Using a GARCH specification, we estimate minimum variance hedge ratios for electricity futures. Finally, we study the dynamic relation between spot and futures prices using an Exponential GARCH model and between the spot and futures returns series using a vector autoregression. (C) 2003 Wiley Periodicals, Inc. C1 SUNY Albany, Sch Business, Albany, NY 12222 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Shawky, MA (reprint author), SUNY Albany, Sch Business, Albany, NY 12222 USA. NR 36 TC 9 Z9 9 U1 0 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0270-7314 J9 J FUTURES MARKETS JI J. Futures Mark. PD OCT PY 2003 VL 23 IS 10 BP 931 EP 955 DI 10.1002/fut.10093 PG 25 WC Business, Finance SC Business & Economics GA 712DQ UT WOS:000184782200002 ER PT J AU Shi, L Li, DY Yu, CH Jang, WY Kim, D Yao, Z Kim, P Majumdar, A AF Shi, L Li, DY Yu, CH Jang, WY Kim, D Yao, Z Kim, P Majumdar, A TI Measuring thermal and thermoelectric properties of one-dimensional nanostructures using a microfabricated device SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE heat transfer; measurement techniques; microscale; nanoscale; thermoelectric ID WALLED CARBON NANOTUBES; TRANSPORT-PROPERTIES; CONDUCTIVITY; NANOWIRES; PHONONS; QUANTUM; POWER; HEAT AB We have batch-fabricated a microdevice consisting of two adjacent symmetric silicon nitride membranes suspended by long silicon nitride beams for measuring thermophysical properties of one-dimensional nanostructures (nanotubes, nanowires, and nanobelts) bridging the two membranes. A platinum resistance heater/thermometer is fabricated on each membrane. One membrane can be Joule heated to cause heat conduction through the sample to the other membrane. Thermal conductance, electrical conductance, and Seebeck coefficient can be measured using this microdevice in the temperature range of 4-400 K of an evacuated Helium cryostat. Measurement sensitivity, errors, and uncertainty are discussed. Measurement results of a 148 nm and a 10 nm-diameter single wall carbon nanotube bundle (ire presented. C1 Univ Texas, Ctr Nano & Mol Sci & Technol, Dept Mech Engn, Austin, TX 78712 USA. Univ Calif Berkeley, Dept Mech Engn, Dept Phys, Berkeley, CA 94720 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mech Engn, Div Sci Mat, Berkeley, CA 94720 USA. RP Univ Texas, Ctr Nano & Mol Sci & Technol, Dept Mech Engn, Austin, TX 78712 USA. EM lishi@mail.utexas.edu RI Li, Deyu/D-2938-2012; Shi, Li/C-8123-2013; Kim, Philip/N-1886-2013 OI Li, Deyu/0000-0001-8364-0924; Shi, Li/0000-0002-5401-6839; NR 26 TC 337 Z9 339 U1 18 U2 127 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-1481 EI 1528-8943 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD OCT PY 2003 VL 125 IS 5 BP 881 EP 888 DI 10.1115/1.1597619 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 728JR UT WOS:000185714500015 ER PT J AU Burgess, CP Filotas, E Klein, M Quevedo, F AF Burgess, CP Filotas, E Klein, M Quevedo, F TI Low-energy brave-world effective actions and partial supersymmetry breaking SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE D-braves; supersymmetry breaking ID HETEROTIC STRING THEORY; GAUGINO CONDENSATION; GLOBAL SUPERSYMMETRY; SOFT TERMS; SUPERGRAVITY; COUPLINGS; BRANE; N=1; FORMULATION; UNITARITY AB As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brave-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N=2 to N=1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N=1 theory perturbatively in powers of kappa=1/M-Planck. We show that the way the massive gravitino and spin-1 fields assemble into N=1 multiplets implies the existence of direct brave-brave contact interactions at order O(kappa). This result is contrary to the O(kappa(2)) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries. C1 McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Cambridge, DAMTP, Ctr Math Sci, Cambridge CB3 0WA, England. RP McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada. EM cliff@physics.mcgill.ca; filotas@hep.physics.mcgill.ca; mklein@slac.stanford.edu; f.quevedo@damtp.cam.ac.uk NR 60 TC 43 Z9 43 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 OCT PY 2003 IS 10 AR 041 PG 27 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500041 ER PT J AU Friedland, A Lunardini, C AF Friedland, A Lunardini, C TI Do many-particle neutrino interactions cause a novel coherent effect? SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE neutrino and gamma astronomy; neutrino physics ID BIG-BANG NUCLEOSYNTHESIS; LARGE LEPTON ASYMMETRY; EARLY UNIVERSE; FLAVOR OSCILLATIONS; BOUNDS; MATTER AB We investigate whether coherent flavor conversion of neutrinos in a neutrino background is substantially modified by many-body effects, with respect to the conventional one-particle effective description. We study the evolution of a system of interacting neutrino plane waves in a box. Using its equivalence to a system of spins, we determine the character of its behavior completely analytically. We find that, if the neutrinos are initially in flavor eigenstates, no coherent flavor conversion is realized, in agreement with the effective one-particle description. This result does not depend on the size of the neutrino wavepackets and therefore has a general character. The validity of the several important applications of the one-particle formalism is thus confirmed. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. RP Los Alamos Natl Lab, Div Theoret, T-8,MS B285, Los Alamos, NM 87545 USA. EM friedland@lanl.gov; lunardi@ias.edu NR 24 TC 35 Z9 35 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 OCT PY 2003 IS 10 AR 043 PG 22 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500043 ER PT J AU Hewett, JL Petriello, FJ Rizzo, TG AF Hewett, JL Petriello, FJ Rizzo, TG TI Constraining the littlest Higgs SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE beyond standard model; technicolor and composite models ID COMPOSITE HIGGS; STANDARD MODEL; DIMENSIONS; MILLIMETER; HIERARCHY; SYMMETRY; BREAKING; PHYSICS; SEARCH; SU(2) AB Little Higgs models offer a new way to address the hierarchy problem, and give rise to a weakly-coupled Higgs sector. These theories predict the existence of new states which are necessary to cancel the quadratic divergences of the Standard Model. The simplest version of these models, the Littlest Higgs, is based on an SU(5)/SO(5) non-Linear sigma model and predicts that four new gauge bosons, a weak isosinglet quark, t', with Q=2/3, as well as an isotriplet scalar field exist at the TeV scale. We consider the contributions of these new states to precision electroweak observables, and examine their production at the Tevatron. We thoroughly explore the parameter space of this model and find that small regions are allowed by the precision data where the model parameters take on their natural values. These regions are, however, excluded by the Tevatron data. Combined, the direct and indirect effects of these new states constrain the 'decay constant' fgreater than or similar to3.5 TeV and m(t)'greater than or similar to7 TeV. These bounds imply that significant fine-tuning be present in order for this model to resolve the hierarchy problem. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM hewett@slac.stanford.edu; frankp@stanford.edu; rizzo@slac.stanford.edu NR 38 TC 195 Z9 195 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 OCT PY 2003 IS 10 AR 062 PG 24 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500062 ER PT J AU Kachru, S Schulz, M Trivedi, SP AF Kachru, S Schulz, M Trivedi, SP TI Moduli stabilization from fluxes in a simple IIB orientifold SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE superstrings and heterotic strings; superstring vacua ID STRING COMPACTIFICATIONS; SUPERGRAVITY; REDUCTION AB We study novel type-IIB compactifications on the T-6/Z(2) orientifold. This geometry arises in the T-dual description of type-I theory on T-6, and one normally introduces 16 space-filling D3-branes to cancel the RR tadpoles. Here, we cancel the RR tadpoles either partially or fully by turning on three-form flux in the compact geometry. The resulting (super) potential for moduli is calculable. We demonstrate that one can find many examples of N = 1 supersymmetric vacua with greatly reduced numbers of moduli in this system. A few examples with N > 1 supersymmetry or complete supersymmetry breaking are also discussed. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford, CA 94305 USA. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. RP Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM skachru@stanford.edu; mschulz@stanford.edu; sandip@tifr.res.in NR 52 TC 158 Z9 158 U1 1 U2 1 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 OCT PY 2003 IS 10 AR 007 PG 43 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500007 ER PT J AU Klein, M Sang-Jin, SB AF Klein, M Sang-Jin, SB TI On effective superpotentials and Kutasov duality SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE nonperturbative effects; supersymmetry and duality; supersymmetric effective theories ID ELECTRIC-MAGNETIC DUALITY; ABELIAN GAUGE-THEORIES; SEIBERG DUALITY; MATRIX MODELS AB We derive the effective superpotential for an N=1 SU(N-c) gauge theory with one massless adjoint field and N-f massless fundamental flavors and cubic tree-level superpotential for the adjoint field. This is a generalization of the Affleck-Dine-Seiberg superpotential to gauge theories with one massless adjoint matter field. Using Kutasov's generalization of Seiberg duality, we then find the effective superpotential for a related theory with massive fundamental flavors. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Theory Grp, Stanford, CA 94309 USA. Hanyang Univ, Dept Phys, Seoul 133791, South Korea. RP Stanford Univ, Stanford Linear Accelerator Ctr, Theory Grp, Stanford, CA 94309 USA. EM mklein@slac.stanford.edu; sjsin@hanyang.ac.kr NR 31 TC 3 Z9 3 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 OCT PY 2003 IS 10 AR 050 PG 19 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500050 ER PT J AU Stephon, HSA AF Stephon, HSA TI Brane gas cosmology, M-theory and little string theory SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE m-theory; cosmology of theories beyond the SM AB We generalize the Brane Gas Cosmological Scenario to M-theory degrees of freedom, namely M5 and M2 branes. Without brane intersections, the Brandenberger Vafa(BV) arguments applied to M-theory degrees of freedom generically predict a large 6 dimensional spacetime. We show that intersections of M5 and M2 branes can instead lead to a large 4 dimensional spacetime. One dimensional intersections in 111) is related to (2,0) little strings (LST) on NS5 branes in type IIA. The gas regime of membranes in M-theory corresponds to the thermodynamics of LST obtained from holography. We propose a mechanism whereby LST living on the worldvolume of NS5 (M5)-branes wrapping a five dimensional torus, annihilate most efficiently in 3+1 dimensions leading to a large 3+1 dimensional spacetime. We also show that this picture is consistent with the gas approximation in M-theory. C1 Stanford Univ, SLAC, Stanford, CA 94305 USA. Stanford Univ, Inst Theoret Phys, Stanford, CA 94305 USA. RP Stanford Univ, SLAC, Stanford, CA 94305 USA. EM stephon@itp.stanford.edu NR 20 TC 0 Z9 0 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 OCT PY 2003 IS 10 AR 013 PG 15 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500013 ER PT J AU Stump, D Huston, J Pumplin, J Tung, WK Lai, HL Kuhlmann, S Owens, JF AF Stump, D Huston, J Pumplin, J Tung, WK Lai, HL Kuhlmann, S Owens, JF TI Inclusive jet production, parton distributions, and the search for new physics SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE QCD; jets; parton model; hadronic colliders ID DIJET ANGULAR-DISTRIBUTIONS; DEEP-INELASTIC SCATTERING; (P)OVER-BAR-P COLLISIONS; QUARK COMPOSITENESS; CROSS-SECTION; ROOT-S=1.8TEV; TEVATRON; PROTON AB Jet production at the Tevatron probes some of the smallest distance scales currently accessible. A gluon distribution that is enhanced at large x compared to previous determinations provides a better description of the Run 1b jet data from both CDF and Dempty set. However, considerable uncertainty still remains regarding the gluon distribution at high x. In this paper, we examine the effects of this uncertainty, and of the remaining uncertainties in the NLO QCD theory, on jet cross section comparisons to Run 1b data. We also calculate the range of contributions still possible from any new physics. Predictions are also made for the expanded kinematic range expected for the ongoing Run 2 at the Tevatron and for the LHC. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Taipei Municipal Teachers Coll, Dept Sci Educ, Taipei, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RP Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. EM stump@pa.msu.edu; huston@msupa.pa.msu.edu; pumplin@msupa.pa.msu.edu; tung@pa.msu.edu; hllai@tmtc.edu.tw; stk@hep.anl.gov; owens@hep.fsu.edu NR 29 TC 332 Z9 332 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 OCT PY 2003 IS 10 AR 046 DI 10.1088/1126-6708/2003/10/046 PG 36 WC Physics, Particles & Fields SC Physics GA 761ML UT WOS:000187912500046 ER PT J AU Aronchik, I Behne, MJ Leypoldt, L Crumrine, D Epstein, E Ikeda, S Mizoguchi, M Bench, G Pozzan, T Mauro, T AF Aronchik, I Behne, MJ Leypoldt, L Crumrine, D Epstein, E Ikeda, S Mizoguchi, M Bench, G Pozzan, T Mauro, T TI Actin reorganization is abnormal and cellular ATP is decreased in Hailey-Hailey keratinocytes SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Article DE calcium; adhesion ID E-CADHERIN; DARIERS-DISEASE; IN-VITRO; CALCIUM; CA2+; LOCALIZATION; MITOCHONDRIA; MUTATIONS; GTPASES; CATENIN AB Actin reorganization and the formation of adherens junctions are necessary for normal cell-to-cell adhesion in keratinocytes. Hailey-Hailey disease (HHD) is blistering skin disease, resulting from mutations in the Ca2+ ATPase ATP2C1, which controls Ca2+ concentrations in the cytoplasm and Golgi of human keratinocytes. Because actin reorganization is among the first responses to raised cytoplasmic Ca2+, we examined Ca2+-induced actin reorganization in normal and HHD keratinocytes. Even though HHD keratinocytes display raised baseline cytoplasmic Ca2+, we found that actin reorganization in response to Ca2+ was impaired in HHD keratinocytes. Defects in actin reorganization were linked to a marked decrease in cellular ATP in HHD keratinocytes, which persists, in vivo, in HHD epidermis. Defective actin reorganization was reproduced in normal keratinocytes in which the intracellular ATP concentration had been lowered pharmacologically. ATP concentrations in undifferentiated keratinocytes markedly declined after extracellular Ca2+ was increased, but then recovered to a new baseline that was approximately 150% of the previous baseline. In contrast, ATP concentrations in HHD keratinocytes did not change in response to increased extracellular Ca2+. This report provides new insights into how the ATP2C1-controlled ATP metabolism mediates Ca2+-induced cell-to-cell adhesion in normal keratinocytes. In addition, these findings implicate inadequate ATP stores as an additional cause in the pathogenesis of HHD and suggest novel therapeutic options. C1 Univ Calif San Francisco, Dept Dermatol, San Francisco, CA 94143 USA. VA Med Ctr, Dermatol Serv, San Francisco, CA USA. San Francisco Gen Hosp, Dept Dermatol, San Francisco, CA 94110 USA. Univ Padua, Dept Biomed Sci, Padua, Italy. Univ Padua, CNR, Ctr Study Biomembranes, Padua, Italy. Juntendo Univ, Sch Med, Dept Dermatol, Tokyo 113, Japan. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Behne, MJ (reprint author), Vet Affairs Med Ctr, Dermatol Serv 190, 4150 Clement St, San Francisco, CA 94121 USA. FU NIAMS NIH HHS [AR44341] NR 31 TC 21 Z9 23 U1 0 U2 0 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0022-202X J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD OCT PY 2003 VL 121 IS 4 BP 681 EP 687 DI 10.1046/j.1523-1747.2003.12472.x PG 7 WC Dermatology SC Dermatology GA 729UT UT WOS:000185793900010 PM 14632182 ER PT J AU Behne, MJ Tu, CL Aronchik, I Epstein, E Bench, G Bikle, DD Pozzan, T Mauro, TM AF Behne, MJ Tu, CL Aronchik, I Epstein, E Bench, G Bikle, DD Pozzan, T Mauro, TM TI Human keratinocyte ATP2C1 localizes to the Golgi and controls Golgi Ca2+ stores SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Article DE Hailey-Hailey disease; aequorin; adhesion; epidermal permeability barrier ID HAILEY-HAILEY-DISEASE; TARGETED RECOMBINANT AEQUORIN; CALCIUM-SENSING RECEPTOR; YEAST SECRETORY PATHWAY; ENDOPLASMIC-RETICULUM; TERMINAL DIFFERENTIATION; EXTRACELLULAR CALCIUM; INOSITOL 1,4,5-TRISPHOSPHATE; MURINE KERATINOCYTES; PROPERTIES DISTINCT AB Hailey-Hailey disease (MIM16960) is a blistering skin disease caused by mutations in the Ca2+ ATPase ATP2C1. We found that the abnormal Ca2+ signaling seen in Hailey-Hailey disease keratinocytes correlates with decreased protein levels of ATP2C1. Human ATP2C1 protein approximated 115 kDa in size. The ATP2C1 is localized to the Golgi apparatus in human keratinocytes, similar to its localization in yeast and Caenorhabditis elegans. To test whether the ATP2C1 controls Golgi Ca2+ stores, we measured intraorganelle Ca2+ concentrations using specifically targeted aequorins. Whereas normal keratinocytes display Golgi Ca2+ levels comparable to other epithelial cells, Hailey-Hailey disease keratinocyte Golgi Ca2+ refill is slower, and the maximum Ca2+ concentration reached is significantly lower. These findings were replicated in vivo, because clinically normal Hailey-Hailey disease epidermis contained lower Ca2+ stores and displayed an abnormal Ca2+ gradient. In this report we localize the ATP2C1, demonstrate its physiologic relevance in mammalian cells, and measure intraorganelle Golgi Ca2+ in keratinocytes. C1 Univ Calif San Francisco, Dept Dermatol, San Francisco, CA 94143 USA. VA Med Ctr, Dept Med, Endocrine Unit, San Francisco, CA USA. San Francisco Gen Hosp, Dept Dermatol, San Francisco, CA 94110 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Padua, Dept Biomed Sci, I-35121 Padua, Italy. Univ Padua, CNR, Ctr Study Biomembranes, I-35121 Padua, Italy. RP Vet Affairs Med Ctr, Dermatol Serv 190, 4150 Clement St, San Francisco, CA 94121 USA. EM behnemj@itsa.ucsf.edu FU NIAMS NIH HHS [AR44341] NR 53 TC 87 Z9 93 U1 0 U2 3 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 0022-202X EI 1523-1747 J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD OCT PY 2003 VL 121 IS 4 BP 688 EP 694 DI 10.1046/j.1523-1747.2003.12528.x PG 7 WC Dermatology SC Dermatology GA 729UT UT WOS:000185793900011 PM 14632183 ER PT J AU Gegenwart, P Custers, J Tayama, T Tenya, K Geibel, C Sparn, G Harrison, N Kerschl, P Eckert, D Muller, KH Steglich, F AF Gegenwart, P Custers, J Tayama, T Tenya, K Geibel, C Sparn, G Harrison, N Kerschl, P Eckert, D Muller, KH Steglich, F TI Tuning heavy fermion systems into quantum criticality by magnetic field SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article DE heavy fermion; magnetic field; CeNi2Ge2; YbRh2Si2 ID LIQUID BEHAVIOR; COMPOUND CENI2GE2; AMBIENT-PRESSURE; YBRH2SI2; METALS; SUPERCONDUCTIVITY; RESISTIVITY; TEMPERATURE; CECU6-XAUX; TRANSITION AB We discuss a series of thermodynamic, magnetic, and electrical transport experiments on the two heavy fermion compounds CeNi2Ge2 and YbRh2Si2 in which magnetic fields, B, are used to tune the systems from a non-Fermi liquid (NFL) into a field-induced FL state. Upon approaching the quantum-critical points from the FL side by reducing B we analyze the heavy quasi-particle (QP) mass and QP-QP scattering cross sections. For CeNi2Ge2 the observed behavior agrees well with the predictions of the spin-density wave (SDW) scenario for three-dimensional (3D) critical spin-fluctuations. By contrast, the observed singularity in YbRh2Si2 cannot be explained by the itinerant SDW theory for neither 3D nor 2D critical spinfluctuations. Furthermore, we investigate the magnetization M(B) at high magnetic fields. For CeNi2Ge2 a metamagnetic transition is observed at 43 T, whereas for YbRh2Si2 a kink-like anomaly occurs at 10 T in M vs B (applied along the easy basal plane) above which the heavy fermion state is completely suppressed. C1 Max Planck Inst Chem Phys Solids, D-01187 Dresden, Germany. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Leibniz Inst Solid State & Mat Res, D-01187 Dresden, Germany. RP Gegenwart, P (reprint author), Max Planck Inst Chem Phys Solids, D-01187 Dresden, Germany. RI Sparn, Guenter/F-5120-2013; Custers, Jeroen/D-8011-2016; Gegenwart, Philipp/A-7291-2017 OI Custers, Jeroen/0000-0001-6974-1489; NR 36 TC 18 Z9 18 U1 1 U2 14 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD OCT PY 2003 VL 133 IS 1-2 BP 3 EP 15 DI 10.1023/A:1025624831341 PG 13 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 719WW UT WOS:000185228900002 ER PT J AU Boebinger, GS Lacerda, AH AF Boebinger, GS Lacerda, AH TI The National High Magnetic Field Laboratory at Los Alamos National Laboratory SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article DE LANL; NHMFL; hall resistivity AB Los Alamos National Laboratory (LANL) is the home institution of the Pulsed Field Facility of the National High Magnetic Field Laboratory (NHMFL). The NHMFL laboratories are the only facilities in the US (among a few worldwide) to host qualified users while running strong in-house science programs related to high magnetic field research. At Los Alamos, the NHMFL advances the frontiers of condensed matter physics at extreme conditions of high magnetic field, low temperature and pressure, utilizing start-of-the-art pulsed magnets and unique experimental capabilities. This paper will describe the current and future plans of pulsed magnet technology and science at the NHMFL Pulsed Field Facility at LANL. C1 Los Alamos Natl Lab, Pulsed Field Facil, NHMFL, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Pulsed Field Facil, NHMFL, POB 1663, Los Alamos, NM 87545 USA. EM lacerda@lanl.gov NR 7 TC 3 Z9 3 U1 0 U2 5 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 EI 1573-7357 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD OCT PY 2003 VL 133 IS 1-2 BP 121 EP 138 DI 10.1023/A:1025637201299 PG 18 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 719WW UT WOS:000185228900008 ER PT J AU Scholz, W Guslienko, KY Novosad, V Suess, D Schrefl, T Chantrell, RW Fidler, J AF Scholz, W Guslienko, KY Novosad, V Suess, D Schrefl, T Chantrell, RW Fidler, J TI Transition from single-domain to vortex state in soft magnetic cylindrical nanodots SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 4th International Conference on Fine Particle Magnetism (ICFPM) CY AUG 14-16, 2002 CL PITTSBURGH, PA DE magnetic nanodot; magnetic vortex; micromagnetics ID PERMALLOY NANODISKS; DOTS; ANNIHILATION; NUCLEATION; STABILITY; VORTICES; CYLINDER AB We have investigated the magnetic properties of submicron soft magnetic cylindrical nanodots using an analytical model as well as three dimensional numerical finite element simulations. A detailed comparison of the magnetic vortex state shows the differences between these two models. It appears that the magnetic surface charges play a crucial role in the equilibrium magnetization distribution especially for shifted vortices. Finally, the magnetic phase diagram for soft magnetic particles with varying aspect ratio is presented. (C) 2003 Elsevier B.V. All rights reserved. C1 Vienna Univ Technol, Inst Appl & Tech Phys, A-1040 Vienna, Austria. Seagate Res, Pittsburgh, PA 15222 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Scholz, W (reprint author), Vienna Univ Technol, Inst Appl & Tech Phys, Wiedner Hauptstr 8-10, A-1040 Vienna, Austria. EM werner.scholzo@tuwien.ac.at; konstantin.guslienko@seagate.com RI Scholz, Werner/F-2473-2013; Novosad, Valentyn/C-2018-2014; Novosad, V /J-4843-2015; Suess, Dieter/H-7475-2012; Chantrell, Roy/J-9898-2015 OI Suess, Dieter/0000-0001-5453-9974; Chantrell, Roy/0000-0001-5410-5615 NR 20 TC 75 Z9 76 U1 2 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD OCT PY 2003 VL 266 IS 1-2 BP 155 EP 163 DI 10.1016/S0304-8853(03)00466-9 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 730VU UT WOS:000185851500020 ER PT J AU Itoh, M Bissell, MJ AF Itoh, M Bissell, MJ TI The organization of tight junctions in epithelia: Implications for mammary gland biology and breast tumorigenesis SO JOURNAL OF MAMMARY GLAND BIOLOGY AND NEOPLASIA LA English DT Article DE tight junctions; barrier; permeability; fence; polarity; PDZ domain; mammary gland ID TUMOR-SUPPRESSOR PROTEIN; BLOOD-BRAIN-BARRIER; ADHESION MOLECULE JAM; CELL-POLARITY; PDZ DOMAIN; KINASE-C; MEMBRANE-PROTEINS; GUANYLATE KINASE; OVARIAN-CANCER; DIRECT BINDING AB Tight junctions (TJs), the most apical components of the cell-cell junctional complexes, play a crucial role in the establishment and maintenance of cell polarity within tissues. In secretory glandular tissues, such as the mammary gland, TJs are crucial for separating apical and basolateral domains. TJs also create the variable barrier regulating paracellular movement of molecules through epithelial sheets, thereby maintaining tissue homeostasis. Recent advances reveal that TJs exist as macromolecular complexes comprised of several types of membrane proteins, cytoskeletal proteins, and signaling molecules. Many of these components are regulated during mammary gland development and pregnancy cycles, and several have received much attention as possible "tumor suppressors" during progression to breast cancer. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Itoh, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd Mail Stop 83-101, Berkeley, CA 94720 USA. EM mitoh@lbl.gov FU NCI NIH HHS [R37 CA064786, CA57621, CA64786, R01 CA057621, R01 CA057621-07, R01 CA064786, R01 CA064786-04A1] NR 93 TC 61 Z9 63 U1 0 U2 1 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1083-3021 J9 J MAMMARY GLAND BIOL JI J. Mammary Gland Biol. Neoplasia PD OCT PY 2003 VL 8 IS 4 BP 449 EP 462 DI 10.1023/B:JOMG.0000017431.45314.07 PG 14 WC Oncology; Endocrinology & Metabolism; Physiology SC Oncology; Endocrinology & Metabolism; Physiology GA 778JE UT WOS:000189235400007 PM 14985640 ER PT J AU Ong, RJ Dawley, JT Clemk, PG AF Ong, RJ Dawley, JT Clemk, PG TI Chemical solution deposition of biaxially oriented (Ba,Sr)TiO3 thin films on < 100 > Ni SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRITICAL-CURRENT DENSITY; PULSED-LASER DEPOSITION; DIELECTRIC-PROPERTIES; YBCO FILMS; GROWTH; MICROSTRUCTURE; TEMPERATURE; YBA2CU3O7; CERAMICS AB Biaxially oriented Ba1-xSrxTiO3 (BST) thin films were fabricated under a highly reducing atmosphere (oxygen partial pressure similar to10(-18) atm) on base metal substrates (<100> Ni) using a fluorinated chemical solution deposition method. The degree of film orientation was investigated with respect to film annealing temperature and composition (x = 0, 0.33, 0.5, 0.67, 1). The solution synthesis route included fluorinated solvents, donor-dopants, and chelating agents for control of orientation, defect chemistry, and morphology. Free-energy and phase diagrams guided solution development using halide addition to avoid intermediate BaCO3 formation and instead produce direct crystallization of BaTiO3-type materials from BaF2. The degree of (200) orientation of BST films deposited on <100> Ni substrates displayed a compositional dependence for 0 < x < 1, with a maximum orientation Lotgering factor approaching unity. Low-temperature (500 degreesC) crystallization of highly oriented films was demonstrated for solution-derived BST on Ni, which may have enabling materials integration implications for capacitors and other applications. C1 Sandia Natl Labs, Microsyst Mat Tribol & Technol Dept, Albuquerque, NM 87185 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RP Ong, RJ (reprint author), Sandia Natl Labs, Microsyst Mat Tribol & Technol Dept, POB 5800, Albuquerque, NM 87185 USA. NR 32 TC 17 Z9 17 U1 0 U2 4 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 OCT PY 2003 VL 18 IS 10 BP 2310 EP 2317 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 730GN UT WOS:000185821000008 ER PT J AU Cantoni, C Christen, DK Varela, M Thompson, JR Pennycook, SJ Specht, ED Goyal, A AF Cantoni, C Christen, DK Varela, M Thompson, JR Pennycook, SJ Specht, ED Goyal, A TI Deposition and characterization of YBa(2)Cu(3)O(7-delta)/LaMnO(3)/MgO/TiN heterostructures on Cu metal substrates for development of coated conductors SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRITICAL-CURRENT DENSITY; SCANNING-TUNNELING-MICROSCOPY; SUPERCONDUCTING TAPES; COPPER; SURFACE; GROWTH; FILMS; RECONSTRUCTION; DIFFUSION; OXIDATION AB In this paper a novel buffer layer architecture consisting of LaMnO(3)/MgO/TiN is proposed as a suitable structural and chemical template for the epitaxial growth of high-transition temperature (T(c)) superconductors on Cu metal surfaces. Using techniques such as high-energy electron diffraction and scanning transmission electron microscopy, we present in situ and ex situ analyses of the buffer-layer and superconductor growth with focus on structural properties of the interfaces formed. While MgO is a good barrier to oxygen diffusion, we find that MgO alone is not a suitable buffer layer due to rapid Cu diffusion. Further, growth of MgO with a single epitaxy can be hindered by the presence of impurities such as S, which form strongly bonded superstructures on the metal surface. With the addition of a TiN layer as a barrier to Cu diffusion, oxide formation is suppressed, interfaces are clean, and a single cube-on-cube epitaxy is observed. While the Cu/TiN and TiN/MgO interfaces are rough, the MgO and LaMnO(3) layers planarize the material, leading to growth of smooth YBa(2)CU(3)O(7-delta) (YBCO). Residual strain in the YBCO film is 0.25% or less and does not lead to apparent cracking. The superconducting properties of the samples were investigated by electrical transport and magnetization measurements. For the first time, high critical current density (J(c)) values are reported for YBCO films grown on (001) single-crystal and {100}<100> textured Cu surfaces without intervening metal coatings. Jc on single crystal-like substrates is as high as 3.5 MA/cm(2). Reduced J(c) of approximately 1 MA/cm(2) on rolled Cu tapes is limited by damage to the tape surface during the rolling process. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Cantoni, C (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Varela, Maria/H-2648-2012; Varela, Maria/E-2472-2014; Specht, Eliot/A-5654-2009; Cantoni, Claudia/G-3031-2013 OI Varela, Maria/0000-0002-6582-7004; Specht, Eliot/0000-0002-3191-2163; Cantoni, Claudia/0000-0002-9731-2021 NR 39 TC 14 Z9 15 U1 1 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 2003 VL 18 IS 10 BP 2387 EP 2400 DI 10.1557/JMR.2003.0334 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 730GN UT WOS:000185821000018 ER PT J AU Specht, ED Rar, A Pharr, GM George, EP Zschack, P Hong, H Ilavsky, J AF Specht, ED Rar, A Pharr, GM George, EP Zschack, P Hong, H Ilavsky, J TI Rapid structural and chemical characterization of ternary phase diagrams using synchrotron radiation SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID NI; DISCOVERY; CR; FE AB A technique based on synchrotron radiation was developed that allows for rapid structural and chemical characterization of ternary alloys over a wide range of composition. The technique was applied to isothermal sections of the Cr-Fe-Ni system grown on Al2O3(0001) sapphire substrates by sequential deposition of layers of graded thickness followed by annealing to interdiffuse the elements. A film spanning the Cr-Fe-Ni ternary system was measured in 4 h at a resolution of 2 at.% by rastering the sample under a focused beam of synchrotron radiation while simultaneously measuring the diffraction pattern with a charge-coupled device detector to determine crystallographic phases, texture, and lattice parameters and also measuring the x-ray fluorescence with an energy-dispersive detector to determine elemental composition. Maps of phase composition and lattice parameter as a function of composition for several annealing treatments were found to be consistent with equilibrium values. The technique will be useful in combinatorial materials design. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. NIST, Gaithersburg, MD 20899 USA. RP Specht, ED (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RI Ilavsky, Jan/D-4521-2013; George, Easo/L-5434-2014; Specht, Eliot/A-5654-2009 OI Ilavsky, Jan/0000-0003-1982-8900; Specht, Eliot/0000-0002-3191-2163 NR 18 TC 12 Z9 12 U1 2 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD OCT PY 2003 VL 18 IS 10 BP 2522 EP 2527 DI 10.1557/JMR.2003.0351 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 730GN UT WOS:000185821000035 ER PT J AU Juenger, MCG Lamour, VHR Monteiro, PJM Gartner, EM Denbeaux, GP AF Juenger, MCG Lamour, VHR Monteiro, PJM Gartner, EM Denbeaux, GP TI Direct observation of cement hydration by soft X-ray transmission microscopy SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article C1 Univ Texas, Dept Civil Engn, Austin, TX 78712 USA. Ecole Normale Super, Dept Genie Civil, Cachan, France. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Lafarge, Cent Rech Lab, F-38291 St Quentin Fallavier, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Juenger, MCG (reprint author), Univ Texas, Dept Civil Engn, Austin, TX 78712 USA. RI Gartner, Ellis/P-9420-2015 OI Gartner, Ellis/0000-0002-4009-8466 NR 3 TC 21 Z9 21 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD OCT 1 PY 2003 VL 22 IS 19 BP 1335 EP 1337 DI 10.1023/A:1025731210337 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 722DH UT WOS:000185359800010 ER PT J AU Kasap, SO Gunes, M Johanson, RE Wang, Q Yang, Y Guha, S AF Kasap, SO Gunes, M Johanson, RE Wang, Q Yang, Y Guha, S TI Conductance fluctuations in a-Si : H: effects of alloying and device structure SO JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS LA English DT Article; Proceedings Paper CT 12th International School on Condensed Matter Physics CY SEP 01-06, 2002 CL VARNA, BULGARIA ID HYDROGENATED AMORPHOUS-SILICON; 1/F NOISE; THIN-FILMS AB We present measurements of conductance noise in undoped a-Si : H and a-SiGe : H thin films in both a transverse and coplanar electrode geometry. For a-Si : H with coplanar electrodes, the noise spectrum is not a pure f(-alpha) power law but consists of two linear regions with different slope parameters a. The spectral shape and its temperature dependence are similar for all samples, regardless of the growth technique. Adding Ge results in qualitatively similar spectra; however, alpha at high frequencies and the temperature dependence are altered. For both a-Si : H and a-SiGe : H with transverse electrodes, the noise spectra are pure f(-alpha) power laws, and alpha decreases with the Ge content. (C) 2003 Kluwer Academic Publishers. C1 Univ Saskatchewan, Dept Elect Engn, Saskatoon, SK S7N 5A9, Canada. Natl Renewable Energy Lab, Golden, CO 80401 USA. United Solar Syst Corp, Troy, MI 48084 USA. RP Kasap, SO (reprint author), Univ Saskatchewan, Dept Elect Engn, Saskatoon, SK S7N 5A9, Canada. NR 15 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0957-4522 J9 J MATER SCI-MATER EL JI J. Mater. Sci.-Mater. Electron. PD OCT-DEC PY 2003 VL 14 IS 10-12 BP 693 EP 696 DI 10.1023/A:1026127020267 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA 732TV UT WOS:000185962400022 ER PT J AU Dyer, G Sheppherd, R Kuba, J Fill, E Wootton, A Patel, P Price, D Ditmire, T AF Dyer, G Sheppherd, R Kuba, J Fill, E Wootton, A Patel, P Price, D Ditmire, T TI Isochoric heating of solid aluminium with picosecond X-ray pulses SO JOURNAL OF MODERN OPTICS LA English DT Article ID LASER; PLASMAS AB High-energy-density matter in quite unique parameter regimes can be studied using an intense laser pulse to heat isochorically an initially cold solid density target. Such isochoric heating experiments permit study of the properties, such as the equation of state, of heated matter. One of the principal challenges of these experiments is to heat sufficiently thick layers so that they will be inertially confined over times scales sufficient for equilibration, times that are often many picoseconds, even at these high densities. One approach to this problem is to heat a solid target not with the laser pulse directly, which deposits its energy only over a few nanometres, but to heat with penetrating X-rays. In this paper, we present preliminary results where such ultrafast X-ray heating is demonstrated using a short-pulse laser-driven silicon Kalpha source to heat a layer of solid density aluminium. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94550 USA. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. RP Univ Texas, Dept Phys, Austin, TX 78712 USA. EM tditmire@physics.utexas.edu RI Patel, Pravesh/E-1400-2011 NR 23 TC 3 Z9 3 U1 1 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0950-0340 EI 1362-3044 J9 J MOD OPTIC JI J. Mod. Opt. PD OCT-NOV PY 2003 VL 50 IS 15-17 BP 2495 EP 2505 DI 10.1080/09500340310001598101 PG 11 WC Optics SC Optics GA 735LU UT WOS:000186116200018 ER PT J AU Boyd, RW Heebner, JE Lepeshkin, NN Park, QH Schweinsberg, A Wicks, GW Baca, AS Fajardo, JE Hancock, RR Lewis, MA Boysel, RM Quesada, M Welty, R Bleier, AR Treichler, J Slusher, RE AF Boyd, RW Heebner, JE Lepeshkin, NN Park, QH Schweinsberg, A Wicks, GW Baca, AS Fajardo, JE Hancock, RR Lewis, MA Boysel, RM Quesada, M Welty, R Bleier, AR Treichler, J Slusher, RE TI Nanofabrication of optical structures and devices for photonics and biophotonics SO JOURNAL OF MODERN OPTICS LA English DT Article ID SURFACE-PLASMON RESONANCE; MICRORING RESONATORS; WAVE-GUIDES; SOLITONS; RING AB Nanofabrication offers promise for the design of artificial materials with optical properties unlike those of materials occurring in nature and for the design of new and exotic optical devices. We describe some specific ideas for applications in this area, and present some laboratory results on the development of these applications. C1 Univ Rochester, Inst Opt, Rochester, NY 14627 USA. Corning Inc, New York, NY USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Cornell Nanoscale Sci & Technol Facil, Ithaca, NY USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Korea Univ, Dept Phys, Seoul 136701, South Korea. RP Boyd, RW (reprint author), Univ Rochester, Inst Opt, Rochester, NY 14627 USA. RI Heebner, John/C-2411-2009; Nikolic, Rebecca/C-3618-2009; Schweinsberg, Aaron/D-7488-2012 NR 22 TC 14 Z9 14 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD OCT-NOV PY 2003 VL 50 IS 15-17 BP 2543 EP 2550 DI 10.1080/0950034032000120849 PG 8 WC Optics SC Optics GA 735LU UT WOS:000186116200022 ER PT J AU Shvets, G Tushentsov, M AF Shvets, G Tushentsov, M TI Nonlinear propagation of electromagnetic waves in a plasma by means of electromagnetically induced transparency SO JOURNAL OF MODERN OPTICS LA English DT Article ID SELF-MODULATION; LIGHT; ULTRASLOW; STATES; GAS AB Magnetized plasma can be made transparent at the cyclotron frequency by addition of a helical undulator. The purpose of the undulator is to couple the transverse (propagating) and longitudinal (non-propagating) electromagnetic waves in the plasma. The coupling is particularly strong when the electron cyclotron and plasma frequencies are equal. It is demonstrated that this coupling gives rise to ultra-slow electromagnetic waves with group velocity upsilong much less than c (where c is the speed of light in vacuum), resulting in the extreme energy compression in the plasma. A linear propagation equation for the electromagnetic wave envelope is derived, and its group velocity and group velocity dispersion are calculated. Relativistic corrections to the plasma electron motion are included to derive the nonlinear propagation equation. It is shown that, in comparison with unmagnetized plasma, an enhancement of non-linearities of order 1/upsilon(g)(2) is expected. Implications for relativistic self-focusing in the plasma are discussed. C1 IIT, Chicago, IL 60302 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60520 USA. RP Shvets, G (reprint author), IIT, Chicago, IL 60302 USA. NR 21 TC 5 Z9 5 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD OCT-NOV PY 2003 VL 50 IS 15-17 BP 2583 EP 2594 DI 10.1080/0950034032000121091 PG 12 WC Optics SC Optics GA 735LU UT WOS:000186116200025 ER PT J AU Dou, YS Torralva, BR Allen, RE AF Dou, YS Torralva, BR Allen, RE TI Semiclassical electron-radiation-ion dynamics (SERID) and cis-trans photoisomerization of butadiene SO JOURNAL OF MODERN OPTICS LA English DT Article ID ULTRAFAST INTERNAL-CONVERSION; CONICAL INTERSECTION; STATE; RELAXATION; SPECTRA; 1,3,5-HEXATRIENE; PHOTOIONIZATION; PHOTOCHEMISTRY; FLUORESCENCE; PHOTOPHYSICS AB Detailed simulations are reported for the dynamics of electrons and nuclei during the cis-trans isomerization of butadiene following a femtosecond-scale laser pulse. Our technique, semiclassical electron-radiation-ion dynamics (SERID), is fully described in the text. The one-electron Hamiltonian and ion-ion interactions employed in the present work are density-functional based. Following excitation of electrons by the laser pulse, all three C-C bonds in the butadiene molecule become longer, as electrons are promoted from the HOMO to both the LUMO and LUMO+1 levels. In the excited electronic state, the molecule rotates about all of its three C-C bonds. There are then non-adiabatic events near avoided crossings, with electronic transitions to the ground state via creation of vibrational excitations. The molecule continues to twist around the central bond and one of the terminal C-C bonds, until the trans-conformation is achieved. Various features in the behaviour of the vibrational modes can also be observed, including initial excitations due to the laser pulse, further excitations at avoided crossings and the redistribution of vibrational energy between modes. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Dou, YS (reprint author), Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. NR 41 TC 67 Z9 69 U1 0 U2 15 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD OCT-NOV PY 2003 VL 50 IS 15-17 BP 2615 EP 2643 DI 10.1080/0950034032000120759 PG 29 WC Optics SC Optics GA 735LU UT WOS:000186116200028 ER PT J AU Yang, NYC Jian, KQ Kulaots, I Crawford, GP Hurt, RH AF Yang, NYC Jian, KQ Kulaots, I Crawford, GP Hurt, RH TI Template synthesis of nanophase mesocarbon SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE discotic liquid crystal; carbon nanomaterial; mesophase pitch; self-assembly; porous media ID NEMATIC LIQUID-CRYSTALS; AREA MICROPOROUS CARBON; MESOPOROUS CARBON; NANOFIBERS; ZEOLITE; CHROMATOGRAPHY; PERFORMANCE; PITCH AB Templating techniques are used increasingly to create carbon materials with precisely engineered pore systems. This article presents a new templating technique that achieves simultaneous control of pore structure and molecular (crystal) structure in a single synthesis step. With the use of discotic liquid crystalline precursors, unique carbon structures can be engineered by selecting the size and geometry of the confining spaces and selecting the template material to induce edge-on or face-on orientation of the discotic precursor. Here mesophase pitch is infiltrated by capillary forces into a nanoporous glass followed by slow carbonization and NaOH etching. The resulting porous carbon material exhibits interconnected solid grains about 100 nm in size, a monodisperse pore size of 60 nm, 42% total porosity, and an abundance of edge-plane inner surfaces that reflect the favored edge-on anchoring of the mesophase precursor on glass. This new carbon form is potentially interesting for a number of important applications in which uniform large pores, active-site-rich surfaces, and easy access to interlayer spaces in nanometric grains are advantageous. C1 Brown Univ, Providence, RI 02912 USA. Sandia Natl Labs, Livermore, CA USA. RP Hurt, RH (reprint author), Brown Univ, Providence, RI 02912 USA. NR 27 TC 12 Z9 12 U1 0 U2 5 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 OCT PY 2003 VL 3 IS 5 BP 386 EP 391 DI 10.1166/jnn.2003.216 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 751KU UT WOS:000187066500007 PM 14733148 ER PT J AU Moon, P Sandi, G Kizilel, R Stevens, D AF Moon, P Sandi, G Kizilel, R Stevens, D TI Computational simulation of lithium ion transport through polymer nanocomposite membranes SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE lithium battery; clay-polymer; nanocomposite membrane; electrochemical model; transference number ID BATTERY APPLICATIONS; ELECTROLYTES; CELLS; MODEL AB Presented here are the macroscopic transport mechanisms of lithium ion in clay-polymer nanocomposites membranes with potential use in lithium rechargeable batteries. Computational simulations of the lithium ion transport across the interface of an anode and a cathode provide information to tailor single ion conductors and, thus to enhance ionic conductivity of the membrane. These transport simulations demonstrate that the lithium concentration profile in the nanocomposite membranes decreases linearly as a function of time and position. This finding is surprising because the membranes are single ion conductor with transferences numbers approaching one. Thus, a deeper understanding is needed of the transport properties in a real system, in order to be able to tailor materials with high conductivity and high transference numbers. It is shown that a battery cell with a thinner clay-polymer membrane can deliver a much higher capacity than that of a thicker membrane while the cell voltage remain almost unchanged and under 4 volts. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. IIT, Dept Chem & Environm Engn, Chicago, IL 60616 USA. RP Moon, P (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 2 Z9 2 U1 1 U2 9 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C P 6079, SUCC CENTRE-VILLE, MONTREAL, PQ H3C 3A7, CANADA SN 1480-2422 J9 J NEW MAT ELECTR SYS JI J. New Mat.Electrochem. Syst. PD OCT PY 2003 VL 6 IS 4 BP 237 EP 244 PG 8 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 754LC UT WOS:000187317700005 ER PT J AU Petrovich, MN Favre, A Hewak, DW Rutt, HN Grippo, AC Gubeli, JF Jordan, KC Neil, GR Shinn, MD AF Petrovich, MN Favre, A Hewak, DW Rutt, HN Grippo, AC Gubeli, JF Jordan, KC Neil, GR Shinn, MD TI Near-IR absorption of Ga : La : S and Ga : La : S : O glasses by free-electron laser-based laser calorimetry SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th International Symposium on Non-Oxide Glasses and New Optical Glasses CY SEP 09-13, 2002 CL PARDUBICE, CZECH REPUBLIC SP Univ Pardubice, Res Ctr & Dept Gen & Inorgan Chem, Acad Sci Czech Republic Lab Solid State Chem, Univ Pardubice Acad Sci Lab Solid State Chem, Czech Glass Soc ID OPTICAL-FIBER AB The optical absorption of bulk Ga:La:S and Ga:La:S:O glasses in the near infrared was investigated by laser calorimetry using the free-electron laser source at the Thomas Jefferson National Accelerator Facility. An absorption coefficient of 1.2x10(-2) and 2.3 x 10(-2) cm(-1) was measured at 1.55 mum for Ga:La:S and Ga:La:S:O respectively. Comparing this result with conventional transmission measurements, we show that absorption is the prevailing loss mechanism in the near-IR region. Although not conclusive, our measurements suggest that the absorption is due to impurities and to the weak absorption tail. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Southampton, Optoelect Res Ctr, Southampton SO17 1BJ, Hants, England. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Petrovich, MN (reprint author), Univ Southampton, Optoelect Res Ctr, Mountbatten Bldg, Southampton SO17 1BJ, Hants, England. NR 8 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD OCT 1 PY 2003 VL 326 BP 93 EP 97 DI 10.1016/S0022-3093(03)00384-3 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 721YT UT WOS:000185346600017 ER PT J AU Kaban, I Halm, T Hoyer, W Jovari, P Neuefeind, J AF Kaban, I Halm, T Hoyer, W Jovari, P Neuefeind, J TI Short-range order in amorphous germanium-tellurium alloys SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th International Symposium on Non-Oxide Glasses and New Optical Glasses CY SEP 09-13, 2002 CL PARDUBICE, CZECH REPUBLIC SP Univ Pardubice, Res Ctr & Dept Gen & Inorgan Chem, Acad Sci Czech Republic Lab Solid State Chem, Univ Pardubice Acad Sci Lab Solid State Chem, Czech Glass Soc ID NEUTRON-DIFFRACTION; GETE; FILMS AB The atomic structure of Te-rich amorphous germanium tellurides has been investigated experimentally with high-energy synchrotron radiation and modeled by means of the reverse Monte Carlo technique. Total and partial structure factors and pair correlation functions were simulated. It is shown that the structure of Ge20Te80 and Ge15Te85 glasses can be described by GeTe4 tetrahedra as structural units which are bridged by Te-Te bonds. (C) 2003 Elsevier B.V. All rights reserved. C1 Tech Univ Chemnitz, Inst Phys, D-09107 Chemnitz, Germany. DESY, Hamburger Synchrontronstschlungslab HASYLAB, D-22607 Hamburg, Germany. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Hoyer, W (reprint author), Tech Univ Chemnitz, Inst Phys, Reichenhainer Str 70, D-09107 Chemnitz, Germany. RI Neuefeind, Joerg/D-9990-2015 OI Neuefeind, Joerg/0000-0002-0563-1544 NR 16 TC 24 Z9 24 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD OCT 1 PY 2003 VL 326 BP 120 EP 124 DI 10.1016/S0022-3093(03)00389-2 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 721YT UT WOS:000185346600022 ER PT J AU Chen, G Jain, H Vlcek, M Li, J Drabold, DA Khalid, S Elliott, SR AF Chen, G Jain, H Vlcek, M Li, J Drabold, DA Khalid, S Elliott, SR TI Study of light-induced vector changes in the local atomic structure of As-Se glasses by EXAFS SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 13th International Symposium on Non-Oxide Glasses and New Optical Glasses CY SEP 09-13, 2002 CL PARDUBICE, CZECH REPUBLIC SP Univ Pardubice, Res Ctr & Dept Gen & Inorgan Chem, Acad Sci Czech Republic Lab Solid State Chem, Univ Pardubice Acad Sci Lab Solid State Chem, Czech Glass Soc ID CHALCOGENIDE GLASSES; AMORPHOUS CHALCOGENIDES; PHOTOSTRUCTURAL CHANGES; SEMICONDUCTORS; ANISOTROPY; AS2SE3; MODEL AB We have observed light-induced vector changes in the local structure of As-Se glasses using extended X-ray absorption fine structure (EXAFS) experiments with in situ laser illumination. Local structure around As and Se atoms was determined for as-prepared as well as annealed a-As40Se60 films, which were exposed to bandgap light of polarization parallel and perpendicular to that of the X-rays. For the as-prepared film, the nearest neighbor bond distance around Se atoms increases, the magnitude of which varies with the polarization of light, thus confirming our previous observations on a-As50Se50 films. These results give an atomistic indication of a light-induced vector expansion in any material, and provide insight of the mechanisms of the light-induced atom displacements. (C) 2003 Elsevier B.V. All rights reserved. C1 Lehigh Univ, Dept Mat Sci & Engn, Whitaker Lab, Bethlehem, PA 18015 USA. Univ Pardubice, Dept Gen & Inorgan Chem, Pardubice 53210, Czech Republic. Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England. RP Jain, H (reprint author), Lehigh Univ, Dept Mat Sci & Engn, Whitaker Lab, 5 E Packer Ave, Bethlehem, PA 18015 USA. RI Li, Jun /D-1948-2010; VLCEK, Miroslav/G-1673-2015; OI Drabold, David/0000-0001-5344-5837 NR 21 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD OCT 1 PY 2003 VL 326 BP 257 EP 262 DI 10.1016/S0022-3093(03)00403-4 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 721YT UT WOS:000185346600046 ER PT J AU Paffett, MT Kelly, D Joyce, SA Morris, J Veirs, K AF Paffett, MT Kelly, D Joyce, SA Morris, J Veirs, K TI A critical examination of the thermodynamics of water adsorption on actinide oxide surfaces SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID TEMPERATURE-PROGRAMMED DESORPTION; PLUTONIUM DIOXIDE; THERMAL DESORPTION; VAPOR ADSORPTION; POROUS CATALYSTS; URANIUM; COEFFICIENT; PARAMETERS; MASS AB The reversible adsorption of water from actinide oxide surfaces is examined from several viewpoints in this article. A reinterpretation and critical look at the previously published thermodynamic values for desorption of water from PuO2 [J. Phys. Chem. 77 (1973) 581] are reexamined in light of more recent mathematical treatments of thermal desorption data from high surface area materials. In addition, the time and temperature dependent process of water adsorption/ desorption in closed system experiments is examined using chemical kinetics modeling. A simple experimental method and mathematical treatment of determining adsorption enthalpies based upon a closed system is also described. The desorption enthalpy for reversibly adsorbed water from PuO2 is determined to be a function of adsorbate coverage with values ranging from 51 to 44 kJ mol(-1) for coverages of one to several monolayers (MLs). Consistent desorption enthalpy values are obtained using either approach thus highlighting the importance of proper interpretation of adsorption parameters determined from high surface area powders. Reversible adsorption/desorption equilibrium of water with actinide oxide materials is discussed from the practical standpoint of storage and subsequent pressurization of containers. These results obtained from PuO2 surfaces are consistent with desorption enthalpies of water from a low surface area UO2, that has been measured using ultra-high vacuum thermal desorption mass spectroscopy to be 42.2 kJ mol(-1). (C) 2003 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Paffett, MT (reprint author), Los Alamos Natl Lab, Div Chem, MS J964 POB 1663, Los Alamos, NM 87545 USA. RI Joyce, Stephen/Q-7804-2016 OI Joyce, Stephen/0000-0003-1330-7362 NR 33 TC 21 Z9 23 U1 1 U2 13 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 OCT 1 PY 2003 VL 322 IS 1 BP 45 EP 56 DI 10.1016/S0022-3115(03)00315-5 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 725MM UT WOS:000185547000005 ER PT J AU Aladyshkin, AY Mel'nikov, AS Ryzhov, DA AF Aladyshkin, AY Mel'nikov, AS Ryzhov, DA TI The Little-Parks effect and multiquanta vortices in a hybrid superconductor-ferromagnet system SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID II SUPERCONDUCTOR; VORTEX STRUCTURE; MAGNETIC DOTS; THIN-FILM; MESOSCOPIC SUPERCONDUCTORS; PHASE-TRANSITIONS; LATTICE; ARRAYS; ANTIVORTICES; NUCLEATION AB Within the phenomenological Ginzburg-Landau theory we investigate the phase diagram of a thin superconducting film with ferromagnetic nanoparticles. We study the oscillatory dependence of the critical temperature on an external magnetic field, similar to the Little-Parks effect, and formation of multiquantum vortex structures. The structure of a superconducting state is studied both analytically and numerically. C1 Russian Acad Sci, Inst Phys Microstruct, Nizhnii Novgorod, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Aladyshkin, AY (reprint author), Russian Acad Sci, Inst Phys Microstruct, GSP 105, Nizhnii Novgorod, Russia. RI Mel'nikov, Alexander/E-8099-2017 OI Mel'nikov, Alexander/0000-0002-4241-467X NR 48 TC 14 Z9 14 U1 3 U2 7 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 OCT 1 PY 2003 VL 15 IS 38 BP 6591 EP 6597 AR PII S0953-8984(03)63629-5 DI 10.1088/0953-8984/15/38/024 PG 7 WC Physics, Condensed Matter SC Physics GA 735RM UT WOS:000186128400025 ER PT J AU Bass, SA Muller, B Srivastava, DK AF Bass, SA Muller, B Srivastava, DK TI Transverse momentum distribution of net baryon number at RHIC SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID PLUS AU COLLISIONS; PARTON-CASCADES; EVOLUTION; COHERENT; QCD AB We calculate the transverse momentum distribution of net quarks (quarks minus antiquarks) in Au+Au collisions at the Relativistic Heavy Ion Collider in the framework of the parton cascade model at two different rapidities. Parton re-scattering and fragmentation are seen to lead to a substantial difference in the slopes of these distributions between mid- and forward-rapidities, in qualitative agreement with the corresponding data for the net baryon distribution. C1 Duke Univ, Dept Phys, Durham, NC 27708 USA. RIKEN, Res Ctr, Brookhaven Natl Lab, Upton, NY 11973 USA. Ctr Variable Energy Cyclotron, Kolkata 700064, W Bengal, India. RP Duke Univ, Dept Phys, Durham, NC 27708 USA. EM bass@phy.duke.edu OI Bass, Steffen/0000-0002-9451-0954 NR 36 TC 0 Z9 0 U1 0 U2 1 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 OCT PY 2003 VL 29 IS 10 BP L51 EP L58 AR PII S0954-3899(03)65712-9 DI 10.1088/0954-3899/29/10/101 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 745KZ UT WOS:000186689000001 ER PT J AU Bender, G Zawodzinski, TA Saab, AP AF Bender, G Zawodzinski, TA Saab, AP TI Fabrication of high precision PEFC membrane electrode assemblies SO JOURNAL OF POWER SOURCES LA English DT Article DE PEMFC; PEFC; fuel cell; membrane electrode assembly; fabrication; catalyst ink; Kapton ID FUEL-CELLS; PERFORMANCE AB Membrane electrode assemblies (MEAs) for polymer electrolyte fuel cells (PEFCs) are commonly prepared in the research laboratory by hand painting liquid catalyst material onto Teflon supports, then transferring the dried catalyst to a membrane separator by hot pressing. This hand application of the catalyst is a time consuming process of modest precision with respect to catalyst loading, producing samples not ideally suited for controlled experimentation. We report the results of a method for preparing MEA catalyst layers in a faster and highly reproducible fashion. This method relies on catalyst inks that have been modified to increase their coating reproducibility, and the use of a support material that improves the hot press transfer of the catalyst to the membrane separator. The result is a process which is not only significantly more precise and faster than hand painting, but which produces cells with nearly 25% higher current density in the critical voltage operating region. Published by Elsevier B.V. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bender, G (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 45 Z9 45 U1 5 U2 30 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 OCT 1 PY 2003 VL 124 IS 1 BP 114 EP 117 DI 10.1016/S0378-7753(03)00735-3 PG 4 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 725VV UT WOS:000185563800016 ER PT J AU Thomas, EV Case, HL Doughty, DH Jungst, RG Nagasubramanian, G Roth, EP AF Thomas, EV Case, HL Doughty, DH Jungst, RG Nagasubramanian, G Roth, EP TI Accelerated power degradation of Li-ion cells SO JOURNAL OF POWER SOURCES LA English DT Article DE accelerated power degradation; pulse power characterization test; statistical experimental design AB A statistically designed accelerated aging experiment was conducted to investigate the effects of aging time, temperature, and state-of-charge (SOC) on the performance of lithium-ion cells. In this experiment, a number of cells were stored in a variety of static aging environments ranging from 25 degreesC and 60% SOC to 55 degreesC and 100% SOC. The power output of each cell was monitored regularly over the course of 44 weeks via a low current level hybrid pulse power characterization test. A single empirical model of power fade, involving two concurrent degradation processes, was found to be applicable over a wide range of experimental conditions. The first degradation process is relatively rapid (nearly complete within 4 weeks) and is accelerated by temperature with unknown kinetics. The second degradation process (accelerated by temperature and SOC) is less rapid and exhibits time(3/2) kinetics. (C) 2003 Elsevier B.V. All rights reserved. C1 Sandia Natl Labs, Independent Surveillance Assessment & Stat Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Lithium Battery R&D Dept, Albuquerque, NM 87185 USA. RP Thomas, EV (reprint author), Sandia Natl Labs, Independent Surveillance Assessment & Stat Dept, POB 5800, Albuquerque, NM 87185 USA. NR 5 TC 48 Z9 51 U1 3 U2 13 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 OCT 1 PY 2003 VL 124 IS 1 BP 254 EP 260 DI 10.1016/S0378-7753(03)00729-8 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA 725VV UT WOS:000185563800037 ER PT J AU Dewberry, RA Boyce, WT Kinard, WF AF Dewberry, RA Boyce, WT Kinard, WF TI Chemical treatment of US Department of Energy high level and low level waste to obtain a pure radiochemical fraction for determination of californium alpha-decay content SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB We have developed a chemical separation technique that allows the radiochemical determination of the californium alpha-decay content in Department of Energy (DOE) high level wastes from the Hanford and Savannah River sites. The chemical separation technique uses a series of column extraction chromatography steps that use Eichrom Industries' lanthanide and actinide +3 oxidation state selective Ln-resin(R) and the transuranic selective +4 oxidation state TRU-resin(R) to obtain intermediate product phases in dilute nitric acid. The technique has been demonstrated on three types of authentic DOE high and low level waste samples. We obtain discrimination from Pu alpha-activity by a factor of over 200 and from Cm-244 cc-activity by a factor approaching 1700. Californium recoveries are measured by addition of a Cf-249 spike and are in the range of 50% to 90% in the synthetic samples and are in the range of 1.4% to 48% for the authentic DOE waste samples. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29801 USA. Coll Charleston, Dept Chem, Charleston, SC 29401 USA. RP Dewberry, RA (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, 773-41A, Aiken, SC 29801 USA. NR 11 TC 0 Z9 0 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD OCT PY 2003 VL 258 IS 2 BP 287 EP 298 DI 10.1023/A:1026233704227 PG 12 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 734FP UT WOS:000186044600013 ER PT J AU Ling, F Brahmachary, E Xu, MC Svec, F Frechet, JMJ AF Ling, F Brahmachary, E Xu, MC Svec, F Frechet, JMJ TI Polymer-bound cellulose phenylcarbamate derivatives as chiral stationary phases for enantioselective HPLC SO JOURNAL OF SEPARATION SCIENCE LA English DT Article DE polymeric support; stationary phase; enantioselective separation; HPLC; cellulose derivatives ID PERFORMANCE LIQUID-CHROMATOGRAPHY; SILICA-GEL; OPTICAL RESOLUTION; SEPARATION MEDIA; AMINO-ACID; COMBINATORIAL APPROACH; RACEMIC DRUGS; RECOGNITION; ENANTIOMERS; SELECTORS AB Novel chiral stationary phases (CSP) have been prepared by coating the internal surface of monodisperse macroporous poly(2-aminoethyl methacrylate-co-ethylene dimethacrylate) beads with dimethylphenylcarbamate derivatives of regenerated cellulose. The coating was achieved either by simple adsorption or by chemical bonding using a diisocyanate linker. Separation of enantiomers in normal-phase HPLC mode was used to evaluate the enantioselectivity of all CSPs. The influence of the properties of the polymer support such as pore size, pore volume, and content of the amine functionalities, reaction and separation conditions such as weight ratio of modified cellulose selector to polymer beads, amount of diisocyanate crosslinker, and the composition of the mobile phase on chiral discrimination and chromatographic resolution were also systematically investigated. The CSPs prepared by chemical anchoring were more stable and a wider range of solvents including dichloromethane could be used for the separations. Compared to the coated-type CSPs, the chemically bonded stationary phases enabled the enantioseparations of a larger number of racemates and exhibited enantioselectivity fully comparable to their counterparts prepared using porous silica as a support. However, the benefits of tailored macroporous polymer supports demonstrated earlier with brush-type CSPs did not enhance the performance of the chiral stationary phases prepared from cellulose-based selectors. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Div Mat Sci, EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Svec, F (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Frechet, Jean /0000-0001-6419-0163 NR 45 TC 21 Z9 22 U1 0 U2 9 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1615-9314 J9 J SEP SCI JI J. Sep. Sci. PD OCT PY 2003 VL 26 IS 15-16 BP 1337 EP 1346 DI 10.1002/jssc.200301539 PG 10 WC Chemistry, Analytical SC Chemistry GA 739ZE UT WOS:000186375800004 ER PT J AU Tripathi, A Medvedev, DG Nyman, M Clearfield, A AF Tripathi, A Medvedev, DG Nyman, M Clearfield, A TI Selectivity for Cs and Sr in Nb-substituted titanosilicate with sitinakite topology SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Metal Oxides held at the 224th National Meeting of the American-Chemical-Society CY AUG 18-22, 2002 CL BOSTON, MASSACHUSETTS SP Natl Sci Fdn, Amer Chem Soc Petr Res Fund DE titanosilicate; niobium; structure; rietveld analysis; ion exchange; selectivity; distribution constant; uptake; cesium; strontium ID ION-EXCHANGE PROPERTIES; CRYSTAL-STRUCTURES; WASTES AB The 25% mobium substituted crystalline titanosilicate with the composition Na1.5Nb0.5Ti1.5O3SiO4.2H(2)O (Nb-TS) was synthesized under hydrothermal conditions. Its selectivity for radioactive Cs-137 and Sr-89 was compared with the TS, Na2Ti2O3SiO4.2H(2)O, having sitinakite topology. The Nb-TS shows significantly higher uptake value for Cs-137 but lower for Sr-89 than the TS. To investigate the origin of selectivity, the ion exchanged Cs+ and Sr2+ forms with the composition, CsxNaHyNb0.5Ti1.5O3SiO4.zH(2)O(x = 0.1, 0.2 and 0.3, x + y = 0.5 and z = 1-2) and Sr0.2Na0.6H0.5Nb0.5Ti1.5O3SiO4 . H2O, respectively, were structurally characterized from the X-ray powder diffraction data using the Rietveld refinement technique. Simultaneously the kinetics of Cs-137 and Sr-89 uptake was investigated for the Nb-v free and doped samples. While the Cs+ and Sr2+ exchanged form of Nb-TS and the Cs+ exchanged form of TS retain the symmetry of the parent compound, the Sr2+ exchanged form of TS undergoes a symmetry change. The differences in the uptake of Cs+ and Sr2+ result from the different coordination environments of cesium and strontium in the eight-ring channel, that result from various hydration sites in the tunnel. The origin of selectivity appears to arise from the higher coordination number of cesium or strontium. Other effects due to Nb-v substitution are reflected in the increase of both, the a- and c-dimensions and thus the unit cell volume, and the population of water vs. Na+ in the channel to charge-balance the Nb5+ <----> Ti4+ substitution. (C) 2003 Elsevier Science (USA). All rights reserved. C1 Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Clearfield, A (reprint author), Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. RI Clearfield, Abraham/D-4184-2015 OI Clearfield, Abraham/0000-0001-8318-8122 NR 25 TC 36 Z9 37 U1 6 U2 16 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD OCT PY 2003 VL 175 IS 1 BP 72 EP 83 DI 10.1016/S0022-4596(03)00145-2 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 722ZN UT WOS:000185408100012 ER PT J AU Spence, JCH Weierstall, U Fricke, TT Glaeser, RM Downing, KH AF Spence, JCH Weierstall, U Fricke, TT Glaeser, RM Downing, KH TI Three-dimensional diffractive imaging for crystalline monolayers with one-dimensional compact support SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE electron crystallography; diffraction; protein structure; phase determination ID PHASE RETRIEVAL; X-RAY; CRYSTALLOGRAPHY; RECONSTRUCTION; SCATTERING; ALGORITHMS; REFINEMENT; RECOVERY; OBJECT AB The use of a compact support constraint along the beam direction is considered as a solution to the phase problem for diffraction by two-dimensional protein crystals. Specifically we apply the iterative Gerchberg-Saxton-Fienup algorithm to simulated three-dimensional transmission electron diffraction data from monolayer organic crystals. We find that oversampling along the reciprocal-lattice rods (relrods) normal to the monolayer alone does not solve the phase problem in this geometry in general. However, based on simulations for a crystalline protein monolayer (lysozyme), we find that convergence is obtained in three dimensions if phases are supplied from a few high resolution electron microscope images recorded at small tilts to the beam direction. In the absence of noise, amplitude-weighted phase residuals of around 5degrees, and a cross-correlation coefficient of 0.96 between the true and estimated potential are obtained if phases are included from images at tilts of up to 15degrees. The performance is almost as good in the presence of noise at a level that is comparable to that commonly observed in electron crystallography of proteins. The method should greatly reduce the time and labor needed for data acquisition and analysis in cryo-electron microscopy of organic thin crystals by avoiding the need to record images at high tilt angles. (C) 2003 Elsevier Inc. All rights reserved. C1 Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Spence, JCH (reprint author), Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. RI Weierstall, Uwe/B-3568-2011 FU NIGMS NIH HHS [GM51487] NR 30 TC 7 Z9 7 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 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD OCT-NOV PY 2003 VL 144 IS 1-2 BP 209 EP 218 DI 10.1016/j.jsb.2003.09.019 PG 10 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 750VH UT WOS:000187018800020 PM 14643223 ER PT J AU Huldt, G Szoke, A Hajdu, J AF Huldt, G Szoke, A Hajdu, J TI Diffraction imaging of single particles and biomolecules SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE single molecule diffraction; single particle diffraction; image classification; averaging; orientation; 3D reconstruction ID RECONSTRUCTION; MICROSCOPY; RESOLUTION AB Theory predicts that with a very short and very intense X-ray pulse, the image of a single diffraction pattern may be recorded from a large macromolecule, a virus, or a nanocluster of proteins without the need for a crystal. A three-dimensional data set can be assembled from such images when many copies of the molecule are exposed to the beam one by one in random orientations. We outline a method for structure reconstruction from such a data set in which no independent information is available about the orientation of the images. The basic requirement for reconstruction and/or signal averaging is the ability to tell whether two noisy diffraction patterns represent the same view of the sample or two different views. With this knowledge, averaging techniques can be used to enhance the signal and extend the resolution in a redundant data set. Based on statistical properties of the diffraction pattern, we present an analytical solution to the classification problem. The solution connects the number of incident X-ray photons with the particle size and the achievable resolution. The results are surprising in that they show that classification can be done with less than one photon per pixel in the limiting resolution shell, assuming Poisson-type photon noise in the image. The results can also be used to provide criteria for improvements in other image classification procedures, e.g., those used in electron tomography or diffraction. (C) 2003 Elsevier Inc. All rights reserved. C1 Uppsala Univ, Biomed Ctr, ICM Mol Biophys, SE-75124 Uppsala, Sweden. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Hajdu, J (reprint author), Uppsala Univ, Biomed Ctr, ICM Mol Biophys, Box 596, SE-75124 Uppsala, Sweden. NR 27 TC 98 Z9 98 U1 3 U2 16 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD OCT-NOV PY 2003 VL 144 IS 1-2 BP 219 EP 227 DI 10.1016/j.jsb.2003.09.025 PG 9 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 750VH UT WOS:000187018800021 PM 14643224 ER PT J AU Gardner, DL Swift, GW AF Gardner, DL Swift, GW TI A cascade thermoacoustic engine SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DRIVEN ACOUSTIC OSCILLATIONS; WAVE HEAT ENGINE; TUBES AB A cascade thermoacoustic engine is described, consisting of one standing-wave stage plus two traveling-wave stages in series. Most of the acoustic power is produced in the efficient traveling-wave stages. The straight-line series configuration is easy to build and allows no Gedeon streaming. The engine delivers up to 2 kW of acoustic power, with an efficiency (the ratio of acoustic power to heater power) of up to 20%. An understanding of the pressure and volume-velocity waves is very good. The agreement between measured and calculated powers and temperatures is reasonable. Some of the measured thermal power that cannot be accounted for by calculation can be attributed to Rayleigh streaming in the two thermal buffer tubes with the largest aspect ratios. A straightforward extension of this work should yield cascade thermoacoustic engines with efficiencies of around 35-40% of the Carnot efficiency. (C) 2003 Acoustical Society of America. C1 Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Gardner, DL (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. NR 35 TC 58 Z9 71 U1 2 U2 14 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 OCT PY 2003 VL 114 IS 4 BP 1905 EP 1919 DI 10.1121/1.1612483 PN 1 PG 15 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 733GU UT WOS:000185992200018 PM 14587591 ER PT J AU Chow, JC Watson, JG Herzog, A Benson, SM Hidy, GM Gunter, WD Penkala, SJ White, CM AF Chow, JC Watson, JG Herzog, A Benson, SM Hidy, GM Gunter, WD Penkala, SJ White, CM TI Separation and capture of CO2 from large stationary in sources and sequestration in geological formations SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Editorial Material ID CLIMATE ALTERATION C1 Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. Nat Resources Def Council, Washington, DC USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. ENVAIR Aerochem, Placitas, NM USA. Alberta Res Council, Edmonton, AB, Canada. Air Sci Consultants Inc, Bridgeville, PA USA. Natl Energy Technol Lab, Pittsburgh, PA USA. RP Chow, JC (reprint author), Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. RI Watson, John/E-6869-2010 OI Watson, John/0000-0002-1752-6899 NR 21 TC 11 Z9 12 U1 1 U2 13 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 OCT PY 2003 VL 53 IS 10 BP 1172 EP 1182 PG 11 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 729GT UT WOS:000185765500002 PM 14604326 ER PT J AU Ziegler, A Kisielowski, C Hoffmann, MJ Ritchie, RO AF Ziegler, A Kisielowski, C Hoffmann, MJ Ritchie, RO TI Atomic resolution transmission electron microscopy of the intergranular structure of aY(2)O(3)-containing silicon nitride ceramic SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID WAVE-FUNCTION RECONSTRUCTION; GRAIN-BOUNDARY FILMS; EQUILIBRIUM THICKNESS; SI3N4-SIO2 CERAMICS; ANGSTROM RESOLUTION; PHASE-RETRIEVAL; FOCUS-VARIATION; FOCAL-SERIES; GLASSY FILM; HRTEM AB High-resolution transmission electron microscopy (HRTEM) employing focus-variation phase-reconstruction methods is used to image the atomic structure of grain boundaries in a silicon nitride ceramic at subangstrom resolution. Complementary energy-dispersive X-ray emission spectroscopy experiments revealed the presence of yttrium ions segregated to the 0.5-0.7-nm thin amorphous boundary layers that separate individual grains. Our objective here is probing if yttrium ions attach to the prismatic planes of the Si3N4 at the interface toward the amorphous layer, using Scherzer and phase-reconstruction imaging, as well as image simulation. Crystal structure images of grain boundaries in thin sample (<100 Angstrom) areas do not reveal the attachment of yttrium at these positions, although lattice images from thicker areas do suggest the presence of yttrium at these sites. It is concluded that most of the yttrium atoms are located in the amorphous phase and only a few atoms may attach to the terminating prism plane. In this case, the line concentrations of such yttrium in the latter location are estimated to be at most one yttrium atom every 17 Angstrom. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Karlsruhe, Inst Keram Maschinenbau, D-76131 Karlsruhe, Germany. RP Ziegler, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 43 TC 35 Z9 35 U1 0 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 2003 VL 86 IS 10 BP 1777 EP 1785 PG 9 WC Materials Science, Ceramics SC Materials Science GA 732CE UT WOS:000185922600021 ER PT J AU Buchanan, AC Kidder, MK Britt, PF AF Buchanan, AC Kidder, MK Britt, PF TI Free-radical reactions under diffusional constraints: Orientation does matter in hydrogen transfer SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RESTRICTED MASS-TRANSPORT; CHAIN DECOMPOSITION; MODEL COMPOUNDS; PHENYL ETHER; SURFACE; POLYMERIZATION; PYROLYSIS; REARRANGEMENT; MECHANISM; PATHWAYS C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Buchanan, AC (reprint author), Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. NR 20 TC 8 Z9 8 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 OCT 1 PY 2003 VL 125 IS 39 BP 11806 EP 11807 DI 10.1021/ja036435e PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 726BQ UT WOS:000185578500017 PM 14505388 ER PT J AU Hayashi, Y Kita, S Brunschwig, BS Fujita, E AF Hayashi, Y Kita, S Brunschwig, BS Fujita, E TI Involvement of a binuclear species with the Re-C(O)O-Re moiety in CO2 reduction catalyzed by tricarbonyl rhenium(I) complexes with diimine ligands: Strikingly slow formation of the Re-Re and Re-C(O)O-Re species from Re(dmb)(CO)(3)S (dmb=4,4 '-dimethyl-2,2 '-bipyridine, S = solvent) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RESOLVED INFRARED-SPECTROSCOPY; TRANSITION-METAL COMPLEXES; LOWEST EXCITED-STATE; THIN POLYMERIC FILMS; CARBON-DIOXIDE; CHARGE-TRANSFER; ELECTROCATALYTIC REDUCTION; PHOTOCATALYTIC REDUCTION; PHOTOINDUCED REDUCTION; HOMOGENEOUS CATALYSTS AB Excited-state properties of fac-[Re(dmb)(CO)(3)(CH3CN)]PF6, [Re(dmb)(CO)(3)](2) (where dmb = 4,4'-dimethyl-2,2'-bipyridine), and other tricarbonyl rhenium(l) complexes were investigated by transient FTIR and UV-vis spectroscopy in CH3CN or THF. The one-electron reduced monomer, Re(dmb)(CO)(3)S (S = CH3CN or THF), can be prepared either by reductive quenching of the excited states of fac-[Re(dmb)(CO)(3)(CH3CN)]PF6 or by homolysis of [Re(dmb)(CO)(3)](2). In the reduced monomer's ground state, the odd electron resides on the dmb ligand rather than on the metal center. Re(dmb)(CO)(3)S dimerizes slowly in THF, k(d) = 40 +/- 5 M-1 s(-1). This rate constant is much smaller than those of other organometallic radicals which are typically 10(9) M-1 s(-1). The slower rate suggests that the equilibrium between the ligand-centered and metal-centered radicals is very unfavorable (K approximate to 10(-4)). The reaction of Re(dmb)(CO)(3)S with CO2 is slow and competes with the dimerization. Photolysis of [Re(dmb)(CO)(3)](2) in the presence of CO2 produces CO with a 25-50% yield based on [Re]. A CO2 bridged dimer, (CO)(3)(dmb)Re-CO(O)-Re(dmb)(CO)(3) is identified as an intermediate. Both [Re(dmb)(CO)(3)](2)(OCO2) and Re(dmb)(CO)(3)(OC(O)OH) are detected as oxidation products; however, the previously reported formato-rhenium species is not detected. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Fujita, E (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brunschwig, Bruce/G-4249-2011; Fujita, Etsuko/D-8814-2013 NR 67 TC 153 Z9 153 U1 8 U2 67 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 OCT 1 PY 2003 VL 125 IS 39 BP 11976 EP 11987 DI 10.1021/ja035960a PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 726BQ UT WOS:000185578500048 PM 14505419 ER PT J AU Gianotto, AK Hodges, BDM Harrington, PDB Appelhans, AD Olson, JE Groenewold, GS AF Gianotto, AK Hodges, BDM Harrington, PDB Appelhans, AD Olson, JE Groenewold, GS TI Ion-molecule reactions of gas-phase chromium oxyanions: CrxOyHZ-+O-2 SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID MICROPROBE MASS-SPECTROMETRY; ALKALINE-EARTH CHROMATE; CLUSTER IONS; LASER ABLATION/IONIZATION; SPECIATION ANALYSIS; SODIUM-NITRATE; METAL-OXIDES; OXYGEN; TRAP; SIMS AB Chromium oxyanions, CrxOyHz-, were generated in the gas-phase using a quadrupole ion trap secondary ion mass spectrometer (IT-SIMS), where they were reacted with O-2. Only CrO2- of the Cr1OyHz- envelope was observed to react with oxygen, producing primarily CrO3-. The rate constant for the reaction of CrO2- with O-2 was similar to38% of the Langevin collision constant at 310 K. CrO3-, CrO4-, and CrO4H- were unreactive with O-2 in the ion trap. In contrast, Cr2O4- was observed to react with O-2 producing CrO3- + CrO3 via oxidative degradation at a rate that was similar to15% efficient. The presence of background water facilitated the reaction of Cr2O4- + H2O to form Cr2O5H2-; the hydrated product ion Cr2O5H2 reacted with O-2 to form Cr2O6- (with concurrent elimination of H2O) at a rate that was 6% efficient. Cr2O5- also reacted with O-2 to form Cr2O7- (4% efficient) and Cr2O6- + O (2% efficient); these reactions proceeded in parallel. By comparison, Cr2O6- was unreactive with O-2, and in fact, no further 02 addition could be observed for any of the Cr2O6Hz- anions. Generalizing, CrxOyHz- species that have low coordinate, low oxidation state metal centers are susceptible to O-2 oxidation. However, when the metal coordination is >3, or when the formal oxidation state is greater than or equal to5, reactivity stops. C1 INEEL, Dept Chem, Idaho Falls, ID 83415 USA. Ohio Univ, Dept Chem & Biochem, Ctr Intelligent Chem Instrumentat, Athens, OH 45701 USA. RP Groenewold, GS (reprint author), INEEL, Dept Chem, POB 1625 MS 2208, Idaho Falls, ID 83415 USA. OI Harrington, Peter/0000-0003-0268-8630 NR 56 TC 13 Z9 13 U1 0 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD OCT PY 2003 VL 14 IS 10 BP 1067 EP 1075 DI 10.1016/S1044-0305(03)00410-0 PG 9 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 732CG UT WOS:000185922800001 PM 14530087 ER PT J AU Fritts, DC Nappo, C Riggin, DM Balsley, BB Eichinger, WE Newsom, RK AF Fritts, DC Nappo, C Riggin, DM Balsley, BB Eichinger, WE Newsom, RK TI Analysis of ducted motions in the stable nocturnal boundary layer during CASES-99 SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INTERNAL GRAVITY-WAVE; INTERMITTENT TURBULENCE; NEIGHBORING PYCNOCLINES; ATMOSPHERE; FIELD; FLOW; STATISTICS; EVOLUTION; LIDAR AB Data obtained with multiple instruments at the main site of the 1999 Cooperative Atmosphere - Surface Exchange Study (CASES-99) are employed to examine the character and variability of wave motions occurring in the stable nocturnal boundary layer during the night of 14 October 1999. The predominant motions are surprisingly similar in character throughout the night, exhibiting largely westward propagation, horizontal wavelengths of; 1 to 10 km, phase speeds slightly greater than the mean wind in the direction of propagation, and highly coherent vertical motions with no apparent phase progression with altitude. Additionally, vertical and horizontal velocities are in approximate quadrature and the largest amplitudes occur at elevated altitudes of maximum stratification. These motions are interpreted as ducted gravity waves that propagate along maxima of stratification and mean wind and that are evanescent above, and occasionally below, the altitudes at which they are ducted. Modal structures for ducted waves are computed for mean wind and stratification profiles for three specific cases and are seen to provide a plausible explanation of the observed motions. C1 NW Res Associates Inc, Colorado Res Associates, Boulder, CO 80301 USA. NOAA, Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Iowa, Dept Civil & Environm Engn, Iowa City, IA 52242 USA. NOAA, Environm Technol Lab, Boulder, CO USA. RP Fritts, DC (reprint author), NW Res Associates Inc, Colorado Res Associates, 3380 Mitchell Lane, Boulder, CO 80301 USA. OI Riggin, Dennis/0000-0001-5094-7620 NR 31 TC 39 Z9 39 U1 3 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD OCT PY 2003 VL 60 IS 20 BP 2450 EP 2472 DI 10.1175/1520-0469(2003)060<2450:AODMIT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 727NK UT WOS:000185664800003 ER PT J AU Ramanathan, S McIntyre, PC Luning, J Lysaght, PS Yang, Y Chen, ZQ Stemmer, S AF Ramanathan, S McIntyre, PC Luning, J Lysaght, PS Yang, Y Chen, ZQ Stemmer, S TI Phase separation in hafnium silicates for alternative gate dielectrics - Influence on the unoccupied states SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL OXIDES; THIN-FILMS; ELECTRONIC-STRUCTURE; ALPHA-QUARTZ; SPECTRA; ZIRCON; DEPOSITION; INTERFACE; KINETICS; DIOXIDE AB We have used X-ray absorption near-edge fine-structure (XANES) analysis of oxygen K-edges in combination with high-resolution transmission electron microscopy to investigate phase separation in Hf-silicate thin films subjected to high temperature anneals. We show that the oxygen K-edge fine structures can, in a first approximation, be interpreted as an overlap of features from amorphous silica and crystalline hafnia phases in the phase separated microstructures. Increasing amounts of silica in the samples resulted in an increase of bulk silica-like features in the oxygen K-edges. The lowest conduction band levels are determined by the Hf d states of hafnia for all compositions investigated. XANES was not able to detect silicate-type bonding that is expected to be present in some of the films. (C) 2003 The Electrochemical Society. C1 Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94025 USA. Int Sematech, Austin, TX 78741 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RP Ramanathan, S (reprint author), Intel Corp, Components Res, Hillsboro, OR 97124 USA. RI Stemmer, Susanne/H-6555-2011 OI Stemmer, Susanne/0000-0002-3142-4696 NR 28 TC 41 Z9 41 U1 0 U2 7 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD OCT PY 2003 VL 150 IS 10 BP F173 EP F177 DI 10.1149/1.1604115 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 727CX UT WOS:000185639800045 ER PT J AU Norton, SJ Vo-Dinh, T AF Norton, SJ Vo-Dinh, T TI Optoacoustic diffraction tomography: analysis of algorithms SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID TISSUE CHARACTERIZATION; ULTRASOUND; LIGHT AB We consider the problem of using the photoacoustic effect to image the optical properties of tissue. A region of tissue is assumed to be illuminated by frequency-modulated light that creates an ultrasonic wave of the same frequency. This wave is detected on a passive array of receiving transducers distributed over a circular or a cylindrical aperture. If the frequency is swept over a broad band (or, equivalently, if we illuminate with a pulse and Fourier transform the response), then a spatial map of a parameter that depends on the optical absorption coefficient of the tissue can be recovered. Analytical inversion formulas are derived in both two and three dimensions. The effects of band-limited data on image quality are also investigated. (C) 2003 Optical Society of America. C1 Geophex Ltd, Raleigh, NC 27603 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Norton, SJ (reprint author), 605 Mercury St, Raleigh, NC 27603 USA. NR 15 TC 47 Z9 47 U1 3 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD OCT PY 2003 VL 20 IS 10 BP 1859 EP 1866 DI 10.1364/JOSAA.20.001859 PG 8 WC Optics SC Optics GA 725AW UT WOS:000185521300003 PM 14570099 ER PT J AU Pack, MV Armstrong, DJ Smith, AV AF Pack, MV Armstrong, DJ Smith, AV TI Measurement of the chi((2)) tensor of the potassium niobate crystal SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID NONLINEAR-OPTICAL-CRYSTALS; 2ND-HARMONIC GENERATION; REFRACTIVE-INDEXES; ORTHORHOMBIC KNBO3; MAKER FRINGES; PHASE; DISPERSION; COEFFICIENTS AB We use the separated-beams, second-harmonic method to measure the full second-order nonlinear optical tensor of KNbO3 relative to d(zxy) of KDP for a fundamental wavelength of 1064 nm. Assuming d(zxy)(KDP) = 0.39 pm/V, we find for KNbO3 that d(xxx) = 21.9 pm/V, d(xyy) = 8.9 pm/V, d(xzz) = 12.4 pm/V, d(yxy) = 9.2 pm/V, and d(zxz) = 13.0 pm/V with estimated uncertainties of +/-2-5%. (C) 2003 Optical Society of America. C1 Sandia Natl Labs, Dept Lasers Opt & Remote Sensing 1118, Albuquerque, NM 87185 USA. RP Smith, AV (reprint author), Sandia Natl Labs, Dept Lasers Opt & Remote Sensing 1118, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 8 Z9 8 U1 0 U2 1 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 OCT PY 2003 VL 20 IS 10 BP 2109 EP 2116 DI 10.1364/JOSAB.20.002109 PG 8 WC Optics SC Optics GA 730MM UT WOS:000185834600012 ER PT J AU Kaneshita, E Ichioka, M Machida, K AF Kaneshita, E Ichioka, M Machida, K TI Fermi arc of metallic diagonal stripes in high-temperature superconducting cuprates SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE incommensurate spin-density wave; spectral weight; Hubbard model; high-temperature superconductor ID 2-DIMENSIONAL HUBBARD-MODEL; SPIN-DENSITY-WAVE; MAGNETISM; PHASE AB Spectral weight is investigated for the metallic diagonal stripe state in a two-dimensional Hubbard model, and the Fermi arc observed by the angle-resolved photoemission spectroscopy of La2-xSrxCuO4 is discussed. The Fermi arc coming from the midgap state of a diagonal stripe appears near (pi/2, pi/2) and at the equivalent positions in the reciprocal space, and the gap opens below the midgap state. We show how this spectral weight structure depends on the phasing of stripes, i.e., site- or bond-centered stripes. C1 Okayama Univ, Dept Phys, Okayama 7008530, Japan. RP Kaneshita, E (reprint author), Los Alamos Natl Lab, MS-B262,T-11, Los Alamos, NM 87545 USA. EM eiji@viking.lan1.gov RI ICHIOKA, Masanori/B-2136-2011 OI ICHIOKA, Masanori/0000-0003-3616-806X NR 20 TC 4 Z9 4 U1 1 U2 2 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 OCT PY 2003 VL 72 IS 10 BP 2441 EP 2444 DI 10.1143/JPSJ.72.2441 PG 4 WC Physics, Multidisciplinary SC Physics GA 735CX UT WOS:000186095800010 ER PT J AU Koler-Matznick, J Brisbin, IL Feinstein, M Bulmer, S AF Koler-Matznick, J Brisbin, IL Feinstein, M Bulmer, S TI An updated description of the New Guinea singing dog (Canis hallstromi, Troughton 1957) SO JOURNAL OF ZOOLOGY LA English DT Article DE Canis; Canis hallstromi; New Guinea; dingo; dog ID WOLF; DOMESTICATION; FAMILIARIS; MULTIPLE; ORIGIN AB In 1957, Troughton described the wild dog of New Guinea, naming it Canis hallstromi. Here the description given by Troughton is expanded by the addition of morphological, molecular and behavioural information collected from both captive and wild New Guinea singing dogs subsequent to the original description. The data support Troughton's identification of this canid as a unique taxon, although further studies are needed to clarify the exact level of taxonomic differentiation of this rare and possibly highly endangered canid. C1 New Guinea Singing Dog Conservat Soc, Central Point, OR 97502 USA. Savannah River Ecol Lab, Aiken, SC USA. Hampshire Coll, Sch Cognit Sci, Amherst, MA USA. Bulmer & Associates, Auckland, New Zealand. RP Koler-Matznick, J (reprint author), New Guinea Singing Dog Conservat Soc, 5265 Old Stage Rd, Central Point, OR 97502 USA. NR 78 TC 18 Z9 20 U1 2 U2 11 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0952-8369 J9 J ZOOL JI J. Zool. PD OCT PY 2003 VL 261 BP 109 EP 118 DI 10.1017/S0952836903004060 PN 2 PG 10 WC Zoology SC Zoology GA 739DV UT WOS:000186327700001 ER PT J AU Kim, WT Hong, KH Jhon, MS VanOsdol, JG Smith, DH AF Kim, WT Hong, KH Jhon, MS VanOsdol, JG Smith, DH TI Forced convection in a circular pipe with a partially filled porous medium SO KSME INTERNATIONAL JOURNAL LA English DT Article DE forced convection; porous medium; Brinkman-Forchheimer equation; Darcy model ID GAS FILTER VESSEL; FLOW; CHANNEL; DEPOSITION; TRANSPORT AB A study of forced convection in a circular pipe with a partially filled porous medium was numerically investigated. The Brinkman-Forchheimer extension of the Darcy model was used to analyze the and temperature distribution in the porous medium. Our study includes two types of porous layer configurations : (1) a layer attached at the tube wall extending inward towards the centerline and (2) a layer at the centerline extending outward. The effect of several parameters, such as Darcy number, effective viscosity, effective thermal conductivity, and inertia parameter, as well as the effect of geometric parameters, were investigated. C1 Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Ctr Data Storage Syst, Pittsburgh, PA 15213 USA. US DOE, Natl Energy Technol Lab, Morgantown, WV 26509 USA. RP Kim, WT (reprint author), Carnegie Mellon Univ, Dept Chem Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. NR 17 TC 4 Z9 4 U1 0 U2 1 PU KOREAN SOC MECHANICAL ENGINEERS PI SEOUL PA KSTC NEW BLD. 7TH FLOOR, 635-4 YEOGSAM-DONG KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 1226-4865 J9 KSME INT J JI KSME Int. J. PD OCT PY 2003 VL 17 IS 10 BP 1583 EP 1595 PG 13 WC Engineering, Mechanical SC Engineering GA 729CK UT WOS:000185753600019 ER PT J AU Yang, JC Bradley, S Gibson, JM AF Yang, JC Bradley, S Gibson, JM TI The oblate morphology of supported PtRu5 on carbon black SO MATERIALS CHARACTERIZATION LA English DT Article DE oblate morphology; supported nanoparticles; carbon black ID ELECTRON-MICROSCOPY; CATALYSTS; CLUSTERS; PLATINUM; STEM; RU AB We have examined supported PtRu5 nanoparticles by a variety of electron microscopy techniques, including high-resolution, analytical and a unique mass-spectroscopic electron microscopy technique. The absolute intensity from very high angle annular dark-field images in a dedicated scanning transmission electron microscope can be quantified to determine the number of atoms in a nanoparticle on a support material. Analytical electron microscopy results revealed that the relative Pt:Ru atomic concentration in a nanoparticle does not vary significantly from particle to particle. The average diameter of the nanoparticles was 1.56 nm, and the average number of atoms was measured to be 24 atoms per nanoparticle. The combination of these techniques indicates that the PtRu5 nanoparticles are oblate on the carbon black support. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Pittsburgh, Dept Mat Sci & Engn, Pittsburgh, PA 15261 USA. UOP, Des Plaines, IL 60017 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Yang, JC (reprint author), Univ Pittsburgh, Dept Mat Sci & Engn, 848 Benedum Hall, Pittsburgh, PA 15261 USA. EM jyang@engrng.pitt.edu RI Gibson, Murray/E-5855-2013 OI Gibson, Murray/0000-0002-0807-6224 NR 14 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD OCT PY 2003 VL 51 IS 2-3 BP 101 EP 107 DI 10.1016/j.matchar.2003.09.013 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA 774BA UT WOS:000188958800002 ER PT J AU Difilippo, F Papiez, L Moskvin, V Peplow, D DesRosiers, C Johnson, J Timmerman, R Randall, M Lillie, R AF Difilippo, F Papiez, L Moskvin, V Peplow, D DesRosiers, C Johnson, J Timmerman, R Randall, M Lillie, R TI Contamination dose from photoneutron processes in bodily tissues during therapeutic radiation delivery SO MEDICAL PHYSICS LA English DT Article DE photoneutron; neutron dosimetry; whole body dose; dose from heavy charged particles; Monte Carlo simulation; internal dosimetry; MCNPX ID FAST-NEUTRONS; SOLID CANCER; BEAM AB Dose to the total body from induced radiation resulting from primary exposure to radiotherapeutic beams is not detailed in routine treatment planning though this information is potentially important for better estimates of health risks including secondary cancers. This information can also allow better management of patient treatment logistics, suggesting better timing, sequencing, and conduct of treatment. Monte Carlo simulations capable of taking into account all interactions contributing to the dose to the total body, including neutron scattering and induced radioactivity, provide the most versatile and accurate tool for investigating these effects. MCNPX code version 2.2.6 with full IAEA library of photoneutron cross sections is particularly suited to trace not only photoneutrons but also protons and heavy ion particles that result from photoneutron interactions. Specifically, the MCNPX code is applied here to the problem of dose calculations in traditional (non-IMRT) photon beam therapy. Points of calculation are located in the head, where the primary irradiation has been directed, but also in the superior portion of the torso of the ORNL Mathematical Human Phantom. We calculated dose contributions from neutrons, protons, deutrons, tritons and He-3 that are produced at the time of photoneutron interactions in the body and that would not have been accounted for by conventional radiation oncology dosimetry. (C) 2003 American Association of Physicists in Medicine. C1 Oak Ridge Natl Lab, Radiat Transport & Phys Grp, Oak Ridge, TN 37831 USA. Indiana Univ, Dept Radiat Oncol, Indianapolis, IN 46202 USA. RP Papiez, L (reprint author), Oak Ridge Natl Lab, Radiat Transport & Phys Grp, Oak Ridge, TN 37831 USA. RI Timmerman, Robert/C-2222-2013; Moskvin, Vadim/C-3839-2016 OI Moskvin, Vadim/0000-0002-4969-669X NR 15 TC 14 Z9 15 U1 0 U2 4 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 OCT PY 2003 VL 30 IS 10 BP 2849 EP 2854 DI 10.1118/1.1612947 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 732PA UT WOS:000185953700029 PM 14596320 ER PT J AU Totemeier, TC Wright, RN Swank, WD AF Totemeier, TC Wright, RN Swank, WD TI Mechanical and physical properties of high-velocity oxy-fuel-sprayed iron aluminide coatings SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Fundamentals of Structural Intermetallics CY FEB 17-21, 2002 CL SEATTLE, WASHINGTON ID RESIDUAL-STRESSES; X-RAY; METALS AB Tensile tests and thermal-expansion measurements were performed on free-standing, high-velocity oxy-fuel (HVOF)-sprayed Fe3Al coatings produced at spray-particle velocities of 390, 560, and 620 m/s. To examine the relationship between properties and spray conditions, the microstructures of the coatings were characterized in terms of the fractions of unmelted particles, porosity, and oxide inclusions, as well as the dislocation density assessed by X-ray diffraction (XRD) line-broadening analysis. Residual coating stresses were determined as a function of coating thickness using curvature measurements. The tensile behavior was entirely brittle at room temperature; fracture strengths increased with spray-particle velocity; and the increase in fracture-strength results from decreasing fractions of microstructural defects and better interparticle bonding. The mean thermal-expansion coefficients for the coatings were lower than those for an equivalent wrought material; the differences were attributed to a 7 to 15 vol pct fraction of oxide inclusions. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Totemeier, TC (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 17 TC 17 Z9 17 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 OCT PY 2003 VL 34A IS 10 BP 2223 EP 2231 DI 10.1007/s11661-003-0286-7 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 728PK UT WOS:000185725400019 ER PT J AU Zhu, YM Wu, LJ Tafto, J AF Zhu, YM Wu, LJ Tafto, J TI Accurate measurements of valence electron distribution and interfacial lattice displacement using quantitative electron diffraction SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE charge density; charge distribution; interfacial displacement; quantitative electron diffraction; YBa2Cu3O7; Bi2Sr2CaCu2O8+delta; MgB2; superconductors ID OXIDE SUPERCONDUCTORS; CHARGE-TRANSFER; REFINEMENT; BI2SR2CACU2O8; TEMPERATURE; CRYSTAL; DENSITY; OXYGEN; HOLES; MODULATION AB We developed a novel electron-diffraction technique by focusing a small probe above (or below), the sample in an electron microscope to measure charge density and lattice displacement in technologically important materials. The method features the simultaneous acquisition of shadow images within many Bragg reflections, resulting in parallel recording of dark-field images (PARODI). Because it couples diffraction with images, it is thus suitable for studying crystals as well as their defects. We used this technique to accurately locate the charge-carrying holes in superconducting crystals, and to determine displacement vectors across planar faults by comparing the experiments with calculations, and by using fitting and error analyses. Examples are given for complex YBa2Cu3O7 and Bi2Sr2CaCu2O8+delta oxides and the newly discovered MgB2 superconductor. C1 Brookhaven Natl Lab, Div Sci Mat, Upton, NY 11973 USA. Univ Oslo, Dept Phys, Blindern, Norway. RP Zhu, YM (reprint author), Brookhaven Natl Lab, Div Sci Mat, Upton, NY 11973 USA. EM zhu@bnl.gov NR 42 TC 6 Z9 6 U1 1 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD OCT PY 2003 VL 9 IS 5 BP 442 EP 456 DI 10.1017/S143192760303037X PG 15 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 728RU UT WOS:000185730800008 PM 19771700 ER PT J AU Maldonado-Rodriguez, R Espinosa-Lara, M Barrera-Leon, O Colin-Tovar, C Gonzalez-Yebra, B Salcedo-Vargas, M Santiago-Hernandez, JC Mendez-Tenorio, A Beattie, KL AF Maldonado-Rodriguez, R Espinosa-Lara, M Barrera-Leon, O Colin-Tovar, C Gonzalez-Yebra, B Salcedo-Vargas, M Santiago-Hernandez, JC Mendez-Tenorio, A Beattie, KL TI Detection of mutations in RET proto-oncogene codon 634 through double tandem hybridization SO MOLECULAR BIOTECHNOLOGY LA English DT Article DE DNA chips; mutation detection; DNA probes; mismatched hybridization ID CENTER-DOT-A; NEAREST-NEIGHBOR THERMODYNAMICS; TETHERED OLIGONUCLEOTIDE PROBES; MEDULLARY-THYROID CARCINOMA; STACKING HYBRIDIZATION; MASS-SPECTROMETRY; GENE-EXPRESSION; T MISMATCHES; DNA; ARRAYS AB We developed a procedure to detect the 7 point mutations at Cys634 of the proto-oncogene RET, which is responsible for medullary thyroid carcinoma (MTC). Genomic DNA was prepared from blood samples obtained from normal and MTC-affected individuals belonging to a family with a history of the disease. The RET genotype for each individual was first established by performing restriction and sequencing analyses. Single-stranded target DNA was prepared by asymmetric polymerase chain reaction (PCR) amplification of a 93-bp fragment containing Cys634. The target was annealed with pairs of prelabeled stacking oligonucleotides designed to create appropriate 7-nucleotide gaps, which served as the sites of subsequent hybridization with glass-immobilized 7-mer probes. The target-stacking oligonucleotide duplexes were hybridized with DNA chips containing a set of eight 7-mer probes designed to detect the wild-type sequence and the seven point mutations described. We tested two sets of immobilized probes containing internal or 5'-terminal codon-634 single-base variations. Both groups of probes were able to discriminatively identify the mutations. The hybridization patterns indicated that the disease in this family was due to the C634Y mutation, in accord with the original sequence analysis. The hybridization-based mutation assignment was additionally supported by determination of the control homozygous and heterozygous hybridization patterns produced with synthetic targets having the normal or codon 634 mutant sequences. The effects of mismatch type and nearest-neighbor sequences on the occurrence of false-positive (mismatched) hybridizations are discussed. C1 IMSS, CNM SXXI, Hosp Cancerol, Mexico City, DF, Mexico. IPN, CINVESTAV, Mol Biochem Dept, Mexico City, DF, Mexico. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Maldonado-Rodriguez, R (reprint author), IPN, Escuela Nacl Ciencias Biol, Mexico City 11340, DF, Mexico. NR 48 TC 3 Z9 3 U1 1 U2 6 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA SN 1073-6085 J9 MOL BIOTECHNOL JI Mol. Biotechnol. PD OCT PY 2003 VL 25 IS 2 BP 113 EP 129 DI 10.1385/MB:25:2:113 PG 17 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 729VX UT WOS:000185796700002 PM 14526122 ER PT J AU Gardner, SN Fernandes, M AF Gardner, SN Fernandes, M TI New tools for cancer chemotherapy: computational assistance for tailoring treatments SO MOLECULAR CANCER THERAPEUTICS LA English DT Review ID DRUG-RESISTANCE; MATHEMATICAL-MODEL; BREAST-CANCER; CELL-PROLIFERATION; GENE-EXPRESSION; DOSE INTENSITY; DOXORUBICIN; TOXICITY; THERAPY; TRIAL AB Computational models of cancer chemotherapy have the potential to streamline clinical trial design, contribute to the design of rational, tailored treatments, and facilitate our understanding of experimental results. Mechanistic models based on functional data from tumor biopsies will enable physicians to predict response to treatment for a specific patient, in contrast to statistical models in which the probability of response for a given patient may differ substantially from the population average. While microarray analyses of gene expression also show promise for guiding individualized treatments, it may be difficult to link statistical mining of microarray data with mechanistic, tailored treatments. Furthermore, gene expression does not identify how drugs should be scheduled. This review summarizes mechanistic mathematical models developed to improve the design of chemotherapy regimens. Mechanistic models that incorporate both genetic resistance and cell cycle-mediated resistance during treatment with multiple drugs will be most useful in designing treatment regimens tailored for individuals. Because there are already a number of papers that address the applications of microarray technology, we will limit our discussion to the contrasts between mechanistic computational models and microarray technology, and how these two approaches may complement one another. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Medbase LLC, Princeton, NJ USA. RP Gardner, SN (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-448, Livermore, CA 94551 USA. NR 54 TC 13 Z9 13 U1 1 U2 1 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 1535-7163 J9 MOL CANCER THER JI Mol. Cancer Ther. PD OCT PY 2003 VL 2 IS 10 BP 1079 EP 1084 PG 6 WC Oncology SC Oncology GA 734KK UT WOS:000186054800016 PM 14578473 ER PT J AU Hill, F Marchetti, F Liechty, M Bishop, J Hozier, J Wyrobek, AJ AF Hill, F Marchetti, F Liechty, M Bishop, J Hozier, J Wyrobek, AJ TI A new FISH assay to simultaneously detect structural and numerical chromosomal abnormalities in mouse sperm SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE mouse sperm; aneuploidy; structural aberrations; fluorescence in situ hybridization ID IN-SITU HYBRIDIZATION; MULTICOLOR FISH; RECIPROCAL TRANSLOCATIONS; HEALTHY-MEN; GERM-CELLS; MALE-MICE; ANEUPLOIDY; SEGREGATION; ORIGIN AB De novo aberrations in chromosome structure represent important categories of paternally transmitted genetic damage. Unlike numerical abnormalities the majority of de novo structural aberrations among human offspring are of paternal origin. We report the development of a three-color fluorescence in situ hybridization (FISH) assay (CT8) to detect mouse sperm carrying structural and numerical chromosomal abnormalities. The CT8 assay uses DNA probes for the centromeric and telomeric regions of chromosome 2, and a probe for the subcentromeric region of chromosome 8. The CT8 assay was used to measure the frequencies of sperm carrying certain structural aberrations involving chromosome 2 (del2ter, dup2ter, del2cen, dup2cen), disomy 2, disomy 8, and sperm diploidy. Analysis of similar to80,000 sperm from eight B6C3F1 mice revealed an average baseline frequency of 2.5 per 10,000 sperm carrying partial duplications and deletions of chromosome 2. Extrapolated to the entire haploid genome, similar to0.4% of mouse sperm are estimated to carry structural chromosomal aberrations, which is more than fivefold lower than the spontaneous frequencies of sperm with chromosome structural aberrations in man. We validated the CT8 assay by comparing the frequencies of abnormal segregants in sperm of T(2;14) translocation carriers detected by this assay against those detected by chromosome painting cytogenetic analysis of meiosis II spermatocytes. The CT8 sperm FISH assay is a promising method for detecting structural chromosome aberrations in mouse sperm with widespread applications in genetics, physiology, and genetic toxicology. (C) 2003 Wiley-Liss, Inc. C1 Appl Genet Labs, Melbourne, FL USA. Lawrence Livermore Natl Lab, Hlth Effects Genet Div, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NIEHS, Res Triangle Pk, NC 27709 USA. RP Wyrobek, AJ (reprint author), Lawrence Livermore Natl Lab, Hlth Effects Genet Div, Biol & Biotechnol Res Program, L-448, Livermore, CA 94550 USA. OI Marchetti, Francesco/0000-0002-9435-4867 FU NIEHS NIH HHS [Y01-ES-8016] NR 30 TC 9 Z9 10 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD OCT PY 2003 VL 66 IS 2 BP 172 EP 180 DI 10.1002/mrd.10299 PG 9 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA 717RP UT WOS:000185104200009 PM 12950105 ER PT J AU Ackerman, DM Skoulidas, AI Sholl, DS Johnson, JK AF Ackerman, DM Skoulidas, AI Sholl, DS Johnson, JK TI Diffusivities of Ar and Ne in carbon nanotubes SO MOLECULAR SIMULATION LA English DT Article; Proceedings Paper CT Yangtze Conference on Fluids and Interfaces CY OCT 12-18, 2002 CL NANJING, PEOPLES R CHINA SP Nanjing Univ Chem Technol, Univ Hong Kong, Brigham Young Univ, China Natl Nat Sci Fdn, Univ Utah, Henry Eyring Ctr Theoret Chem, US Natl Sci Fdn, Davis M Kennedy Ctr Int Studies, Taylor & Francis Ltd, Jiangsu Assoc Sci & Technol, Nanjing Ideas Software Co DE argon diffusivity; carbon nanotube membranes; neon diffusivity; silicalite membranes ID MOLECULAR-DYNAMICS SIMULATIONS; ATOMISTIC SIMULATIONS; TRANSPORT DIFFUSIVITIES; BOUNDARY-CONDITIONS; ZEOLITE MEMBRANES; MATERIALS SCIENCE; FLUID-FLOW; DIFFUSION; SILICALITE; EQUILIBRIUM AB Atomically detailed simulations are used to compute the self-diffusivity and transport diffusivity of Ar and Ne through single walled carbon nanotube (SWNT) pores at room temperature. The diffusivities are computed over a range of loadings, corresponding to external equilibrium bulk pressures ranging from 0 to 100 bar. The diffusivities in carbon nanotubes are compared with diffusivities of the same gases in silicalite, a common zeolite, under the same conditions. We find that self-diffusivities are one to three orders of magnitude faster in carbon nanotubes than in silicalite, depending on loading. The transport diffusivities are about three orders of magnitude faster in nanotubes than in silicalite over all loadings studied. The equilibrium adsorption isotherms and computed diffusivities are used to predict fluxes through hypothetical membranes of nanotubes and silicalite. The fluxes for both Ar and Ne are predicted to be four orders of magnitude greater through nanotube membranes than through silicalite membranes of the same thickness. C1 Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Univ London Imperial Coll Sci Technol & Med, Dept Chem, Kensington SW7 2AY, England. RP Johnson, JK (reprint author), Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 USA. EM karlj@pitt.edu RI Johnson, Karl/E-9733-2013 OI Johnson, Karl/0000-0002-3608-8003 NR 54 TC 127 Z9 130 U1 2 U2 24 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0892-7022 J9 MOL SIMULAT JI Mol. Simul. PD OCT-NOV PY 2003 VL 29 IS 10-11 BP 677 EP 684 DI 10.1080/0892702031000103239 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 721MQ UT WOS:000185320500012 ER PT J AU Lyons, WA Nelson, TE Williams, ER Cummer, SA Stanley, MA AF Lyons, WA Nelson, TE Williams, ER Cummer, SA Stanley, MA TI Characteristics of sprite-producing positive cloud-to-ground lightning during the 19 July 2000 STEPS mesoscale convective systems SO MONTHLY WEATHER REVIEW LA English DT Article ID CONTIGUOUS UNITED-STATES; STRATIFORM REGIONS; ELECTRIC-FIELD; THUNDERSTORMS; CURRENTS; CHARGE; ELVES; ELECTRIFICATION; SIMULATIONS; DISCHARGES AB During the summer of 2000, the Severe Thunderstorm Electrification and Precipitation Study (STEPS) program deployed a three-dimensional Lightning Mapping Array (LMA) near Goodland, Kansas. Video confirmation of sprites triggered by lightning within storms traversing the LMA domain were coordinated with extremely low frequency (ELF) transient measurements in Rhode Island and North Carolina. Two techniques of estimating changes in vertical charge moment (M-q) yielded averages of similar to800 and similar to950 C km for 13 sprite-parent positive polarity cloud-to-ground strokes (+CGs). Analyses of the LMA's very high frequency (VHF) lightning emissions within the two mesoscale convective systems (MCSs) show that +CGs did not produce sprites until the centroid of the maximum density of lightning radiation emissions dropped from the upper part of the storm (7-11.5 km AGL) to much lower altitudes (2-5 km AGL). The average height of charge removal (Z(q)) from 15 sprite-parent +CGs during the late mature phase of one MCS was 4.1 km AGL. Thus, the total charges lowered by sprite-parent +CGs were on the order of 200 C. The regional 0degreesC isotherm was located at about 4.0 km AGL. This suggests a possible linkage between sprite-parent CGs and melting-layer/brightband charge production mechanisms in MCS stratiform precipitation regions. These cases are supportive of the conceptual MCS sprite-production models previously proposed by two of the authors (Lyons and Williams). C1 FMA Res Inc, Yucca Ridge Field Stn, Ft Collins, CO 80524 USA. MIT, Ralph M Parsons Lab, Cambridge, MA 02139 USA. Duke Univ, Dept Elect Engn, Durham, NC 27706 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Lyons, WA (reprint author), FMA Res Inc, Yucca Ridge Field Stn, 46050 Weld Cty Rd 13, Ft Collins, CO 80524 USA. RI Cummer, Steven/A-6118-2008 OI Cummer, Steven/0000-0002-0002-0613 NR 47 TC 81 Z9 82 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2003 VL 131 IS 10 BP 2417 EP 2427 DI 10.1175/1520-0493(2003)131<2417:COSPCL>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722AX UT WOS:000185353100013 ER PT J AU Chambers, SA Yoo, YK AF Chambers, SA Yoo, YK TI New materials for spintronics SO MRS BULLETIN LA English DT Editorial Material DE ferromagnetic semiconductors; spin-polarized transport; spintronics ID MAGNETIC SEMICONDUCTORS; FERROMAGNETISM; INJECTION AB This article introduces the October 2003 issue of MRS Bulletin on "New Materials for Spintronics." As a result of quantum mechanics, the carriers in ferromagnetic metals such as Fe, Co, and Ni are spin-polarized due to an imbalance at the Fermi level in the number of spin-up and spin-down electrons. A carrier maintains its spin polarization as long as it does not encounter a magnetic impurity or interact with the host lattice by means of spin-orbit coupling. The discovery of optically induced, long-lived quantum coherent spin states in semiconductors has created a range of possibilities for a new class of devices that utilize spin. This discovery also points to the need for a wider range of spin-polarized materials that will be required for different device configurations. In this issue of MRS Bulletin, we focus on three classes of candidate spintronic materials and review the current state of our understanding of them: III-V and II-VI semiconductors, oxides, and Heusler alloys. The field of spin-polarized materials is growing very rapidly, and the search for new magnetic semiconductors and other suitable spin-injection materials with higher Curie temperatures is bringing spintronics closer to the realm of being practical. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Intematix Corp, Moraga, CA USA. RP Chambers, SA (reprint author), Pacific NW Natl Lab, POB 999,MS K8-93, Richland, WA 99352 USA. NR 7 TC 51 Z9 52 U1 0 U2 13 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD OCT PY 2003 VL 28 IS 10 BP 706 EP 708 DI 10.1557/mrs2003.210 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 732NX UT WOS:000185953400003 ER PT J AU Dillon, AC Mahan, AH Parilla, PA Alleman, JL Heben, MJ Jones, KM Gilbert, KEH AF Dillon, AC Mahan, AH Parilla, PA Alleman, JL Heben, MJ Jones, KM Gilbert, KEH TI Continuous hot wire chemical vapor deposition of high-density carbon multiwall nanotubes SO NANO LETTERS LA English DT Article ID LOW-TEMPERATURE; FIELD-EMISSION; HIGH-YIELD; GROWTH; PURIFICATION; ARRAYS; GLASS; MICROTUBULES; SPECTROSCOPY; MICROSCOPY AB Hot wire chemical vapor deposition (HWCVD) has been adapted to be a continuous growth process for high-density carbon multiwall nanotubes (MWNTs). MWNT growth is optimized in 1:5 CH4:Ar at 150 Torr with reactor temperatures of 400 and 550 degreesC for static and flowing gases, respectively. Ferrocene is employed to provide a gas-phase catalyst. Highly graphitic nanotubes can be continuously deposited with iron content as low as 15 wt % and carbon impurities below thermal gravimetric analysis detection limits. The MWNTs are simply purified to similar to99.5 wt % with minimal structural damage and with a 75 wt % yield. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dillon, AC (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 38 TC 37 Z9 40 U1 0 U2 5 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 OCT PY 2003 VL 3 IS 10 BP 1425 EP 1429 DI 10.1021/nl0342038 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 731AZ UT WOS:000185863500022 ER PT J AU Chakraborty, AK Dustin, ML Shaw, AS AF Chakraborty, AK Dustin, ML Shaw, AS TI In silico models for cellular and molecular immunology: successes, promises and challenges SO NATURE IMMUNOLOGY LA English DT Editorial Material ID 2-PHOTON MICROSCOPY; T-CELLS; ACTIVATION; SYNAPSE; RECOGNITION; DYNAMICS 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, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NYU, Sch Med, Skirball Inst Biomol Med, New York, NY 10016 USA. NYU, Sch Med, Dept Pathol, New York, NY 10016 USA. Washington Univ, Sch Med, Dept Pathol & Immunol, St Louis, MO 63110 USA. RP Chakraborty, AK (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM arup@uclink.berkeley.edu OI Dustin, Michael/0000-0003-4983-6389 NR 23 TC 46 Z9 46 U1 0 U2 7 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 1529-2908 J9 NAT IMMUNOL JI Nat. Immunol. PD OCT PY 2003 VL 4 IS 10 BP 933 EP 936 DI 10.1038/ni1003-933 PG 4 WC Immunology SC Immunology GA 726GG UT WOS:000185590100004 PM 14515121 ER PT J AU DeLaBarre, B Brunger, AT AF DeLaBarre, B Brunger, AT TI Complete structure of p97/valosin-containing protein reveals communication between nucleotide domains SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID SENSITIVE FUSION PROTEIN; X-RAY-DIFFRACTION; AAA-ATPASE P97; CRYSTAL-STRUCTURE; TERMINAL DOMAIN; THERMOPLASMA-ACIDOPHILUM; MEMBRANE-FUSION; VCP; TRANSPORT; HOMOLOG AB The ATPase p97/VCP affects multiple events within the cell. These events include the alteration of both nuclear and mitotic Golgi membranes, the dislocation of ubiquitylated proteins from the endoplasmic reticulum and regulation of the NF-kappab pathway. Here we present the crystal structure of full-length Mus musculus p97/VCP in complex with a mixture of ADP and ADP-AlFx at a resolution of 4.7 Angstrom. This is the first complete hexameric structure of a protein containing tandem AAA ( ATPases associated with a variety of cellular activities) domains. Comparison of the crystal structure and cryo-electron microscopy ( EM) reconstructions reveals large conformational changes in the helical subdomains during the hydrolysis cycle. Structural and functional data imply a communication mechanism between the AAA domains. A Zn2+ occludes the central pore of the hexamer, suggesting that substrate does not thread through the pore of the molecule. C1 Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. Stanford Univ, Dept Cellular & Mol Physiol, Stanford, CA 94305 USA. Stanford Univ, Dept Neurol & Neurol Sci, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Brunger, AT (reprint author), Stanford Univ, Howard Hughes Med Inst, James H Clark Ctr E300-C,318 Campus Dr, Stanford, CA 94305 USA. OI Brunger, Axel/0000-0001-5121-2036 NR 46 TC 236 Z9 239 U1 1 U2 12 PU NATURE PUBLISHING GROUP PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD OCT PY 2003 VL 10 IS 10 BP 856 EP 863 DI 10.1038/nsb972 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 726WQ UT WOS:000185624900019 PM 12949490 ER PT J AU Caparelli, EC Tomasi, D Arnold, S Chang, L Ernst, T AF Caparelli, EC Tomasi, D Arnold, S Chang, L Ernst, T TI k-space based summary motion detection for functional magnetic resonance imaging SO NEUROIMAGE LA English DT Article DE fMRl; brain movement; motion detector; k-space data ID FMRI TIME-SERIES; CORRECTION ALGORITHMS; REAL-TIME; IMAGES; MRI AB Functional MRI studies are very sensitive to motion; head movements of as little as I-mm translations or V rotations may cause spurious signals. An algorithm was developed that uses k-space MRI data to monitor subject motion during functional MRI time series. A k-space weighted average of squared difference between the initial scan and subsequent scans is calculated, which summarizes subject motion in a single quality parameter; however, the quality parameter cannot be used for motion correction. The evolution of this quality parameter throughout a time series indicates whether head motion is within a predetermined limit. Fifty functional MRI studies were used to calibrate the sensitivity of the algorithm, using the six rigid-body registration parameters (three translations and three rotations) from the statistical parametric mapping (SPM99) package as a reference. The average correlation coefficient between the new quality parameter and the reference value from SPM was 0.84. The simple algorithm correctly classified acceptable or excessive motion with 90% accuracy, with the remaining 10% being borderline cases. This method makes it possible to evaluate brain motion within seconds after a scan and to decide whether a study needs to be repeated. (C) 2003 Elsevier Inc. All rights reserved. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Nacl Gen San Martin, Excuela Ciencia & Tecnol, RA-1651 Buenos Aires, DF, Argentina. RP Caparelli, EC (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490, Upton, NY 11973 USA. EM caparelli@bnl.gov RI Tomasi, Dardo/J-2127-2015 FU NIDA NIH HHS [K24 DA16170]; PHS HHS [1R01 61427-01] NR 14 TC 37 Z9 38 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 1053-8119 J9 NEUROIMAGE JI Neuroimage PD OCT PY 2003 VL 20 IS 2 BP 1411 EP 1418 DI 10.1016/S1053-8119(03)00339-2 PG 8 WC Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging SC Neurosciences & Neurology; Radiology, Nuclear Medicine & Medical Imaging GA 737YV UT WOS:000186260700072 PM 14568510 ER PT J AU Jester, S AF Jester, S TI What ignites optical jets? SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT International Meeting on the Physics of Relativistic Jets in the Chandra and XMM Era CY SEP 23-27, 2002 CL BOLOGNA, ITALY DE galaxies : jets; radiation mechanisms : non-thermal; acceleration of particles ID LUMINOSITY RADIO-GALAXIES; M87 JET; SPECTRUM; 3C-273 AB The properties of radio galaxies and quasars with and without optical or X-ray jets are compared. The majority of jets from which high-frequency emission has been detected so far (13 with optical emission, 11 with X-rays, 13 with both) are associated with the most powerful radio sources at any given redshift. It is found that optical/X-ray jet sources are more strongly beamed than the average population of extragalactic radio sources. This suggests that the detection or non-detection of optical emission from jets has so far been dominated by surface brightness selection effects, not by jet physics. It implies that optical jets are much more common than is currently appreciated. (C) 2003 Elsevier B.V. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Jester, S (reprint author), Fermilab Natl Accelerator Lab, POB 500,MS 127, Batavia, IL 60510 USA. NR 16 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD OCT PY 2003 VL 47 IS 6-7 BP 427 EP 430 DI 10.1016/S1387-6473(03)00064-2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 737CH UT WOS:000186210600004 ER PT J AU Lao, LL Chan, VS Chu, MS Evans, T Humphreys, DA Leuer, JA Mahdavi, MA Petrie, TW Snyder, PB St John, HE Staebler, GM Stambaugh, RD Taylor, TS Turnbull, AD West, WP Brennan, DP AF Lao, LL Chan, VS Chu, MS Evans, T Humphreys, DA Leuer, JA Mahdavi, MA Petrie, TW Snyder, PB St John, HE Staebler, GM Stambaugh, RD Taylor, TS Turnbull, AD West, WP Brennan, DP TI Physics and control of ELMing H-mode negative-central-shear advanced tokamak ITER scenario based on experimental profiles from DIII-D SO NUCLEAR FUSION LA English DT Article ID MHD MODES; STABILIZATION; STABILITY; PLASMAS; TRANSPORT; FEEDBACK; FEAT AB Key DIII-D advanced tokamak (AT) experimental and modelling results are applied to examine the physics and control issues for ITER to operate in a negative central shear (NCS) AT scenario. The effects of a finite edge pressure pedestal and current density are included based on the DIII-D experimental profiles. Ideal and resistive stability analyses demonstrate that feedback control of resistive wall modes by rotational drive or flux conserving intelligent coils is crucial for these AT configurations to operate at attractive beta(N) values in the range 3.0-3.5. Vertical stability and halo cur-rent analyses show that reliable disruption mitigation is essential and mitigation control using an impurity gas can significantly reduce the local mechanical stress to an acceptable level. Core transport and turbulence analyses indicate that control of the rotational shear profile is essential to reduce the pedestal temperature required for high beta. Consideration of edge stability and core transport suggests that a sufficiently wide pedestal is necessary for the projected fusion performance. Heat flux analyses indicate that, with core-only radiation enhancement, the outboard peak divertor heat load is near the design limit of 10 MW m(-2). Detached operation may be necessary to reduce the heat flux to a more manageable level. Evaluation of the ITER pulse length using a local step response approach indicates that the 3000 s ITER long-pulse scenario is probably both necessary and sufficient for demonstration of local current profile control. C1 Gen Atom Co, San Diego, CA 92186 USA. Oak Ridge Inst Sci Educ, Oak Ridge, TN USA. RP Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 25 TC 4 Z9 4 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0029-5515 EI 1741-4326 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1023 EP 1030 AR PII S0029-5515(03)67096-1 DI 10.1088/0029-5515/43/10/002 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800004 ER PT J AU Sanchez, R Newman, DE Carreras, BA Woodard, R Ferenbaugh, W Hicks, HR AF Sanchez, R Newman, DE Carreras, BA Woodard, R Ferenbaugh, W Hicks, HR TI Modelling of ELM-like phenomena via mixed SOC-diffusive dynamics SO NUCLEAR FUSION LA English DT Article ID SELF-ORGANIZED CRITICALITY; TURBULENT TRANSPORT; SANDPILE MODEL; H TRANSITION; PLASMA EDGE; CONFINEMENT; PARADIGM; FLUCTUATIONS; SIMILARITY; DEVICES AB A sandpile model describing some of the features of plasma turbulent transport dynamics in the L-mode is extended, by adding appropriate new dynamics, to exhibit a transition to enhanced confinement modes. As a result, H-modes with and without edge localized modes (ELMs) can both be obtained by varying the appropriate parameters. Each exhibits features reminiscent of what is observed in confined plasmas. The interplay between an avalanche and a diffusive transport mechanism is shown to be essential, in this context, for the system to display periodic edge ELMing. C1 Univ Carlos III Madrid, Madrid 28911, Spain. Univ Alaska Fairbanks, Fairbanks, AK 99775 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Univ Carlos III Madrid, Madrid 28911, Spain. EM rsanchez@fis.uc3m.es RI Sanchez, Raul/C-2328-2008 NR 24 TC 13 Z9 13 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0029-5515 EI 1741-4326 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1031 EP 1039 AR PII S0029-5515(03)67186-3 DI 10.1088/0029-5515/43/10/003 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800005 ER PT J AU Hudson, SR Monticello, DA Reiman, AH Strickler, DJ Hirshman, SP Ku, LP Lazarus, E Brooks, A Zarnstorff, MC Boozer, AH Fu, GY Neilson, GH AF Hudson, SR Monticello, DA Reiman, AH Strickler, DJ Hirshman, SP Ku, LP Lazarus, E Brooks, A Zarnstorff, MC Boozer, AH Fu, GY Neilson, GH TI Constructing integrable high-pressure full-current free-boundary stellarator magnetohydrodynamic equilibrium solutions SO NUCLEAR FUSION LA English DT Article ID 3-DIMENSIONAL MHD EQUILIBRIA; ISLANDS; FIELDS; COILS AB For the (non-axisymmetric) stellarator class of plasma confinement devices lobe feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schluter currents, diamagnetic currents and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver (Reiman and Greenside 1986 Comput. Phys. Commun. 43 157) which iterates the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and the plasma simultaneously converge to an equilibrium in which the island content is negligible, the plasma is stable to ideal kink modes, and the coils satisfy engineering constraints. The method is applied to a candidate plasma and coil design for the National Compact Stellarator experiment (Reiman et al 2001 Phys. Plasma 8 2083). C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Columbia Univ, New York, NY 10027 USA. RP Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM shudson@pppl.gov RI Hudson, Stuart/H-7186-2013 OI Hudson, Stuart/0000-0003-1530-2733 NR 19 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0029-5515 EI 1741-4326 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1040 EP 1046 AR PII S0029-5515(03)67270-4 DI 10.1088/0029-5515/43/10/004 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800006 ER PT J AU Ichiguchi, K Nakajima, N Wakatani, M Carreras, BA Lynch, VE AF Ichiguchi, K Nakajima, N Wakatani, M Carreras, BA Lynch, VE TI Nonlinear MHD analysis for LHD plasmas SO NUCLEAR FUSION LA English DT Article ID LARGE HELICAL DEVICE; FREE-BOUNDARY; STABILITY; PRESSURE; INSTABILITIES; STELLARATORS; HELIOTRON AB For the large helical device (LHD), the nonlinear evolution of equilibria that are linearly unstable to ideal interchange modes is studied using the reduced MHD equations. At sufficiently low beta, each individual mode saturates without affecting directly the evolution of the other modes. They only couple through the modification of the averaged pressure profile. The change of the averaged pressure profile is limited to the local flattening near the resonant surfaces. At higher beta values and for the same initial pressure profile, a bursting phenomenon in the kinetic energy is observed. This bursting activity is caused by the overlap of multiple modes, which results in a global reduction of the pressure. However, increasing beta and using a pressure profile obtained from the nonlinear evolution at the lower beta suppress this bursting behaviour. This result indicates that the pressure profile can be self-organized so that the LHD plasma could reach a high beta regime through a stable path. C1 Natl Inst Fus Sci, Toki 5095292, Japan. Kyoto Univ, Grad Sch Energy Sci, Kyoto 6110011, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Natl Inst Fus Sci, Toki 5095292, Japan. EM ichiguch@nifs.ac.jp RI Lynch, Vickie/J-4647-2012 OI Lynch, Vickie/0000-0002-5836-7636 NR 16 TC 25 Z9 25 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0029-5515 EI 1741-4326 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1101 EP 1109 AR PII S0029-5515(03)67925-1 DI 10.1088/0029-5515/43/10/011 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800013 ER PT J AU Chen, Y Parker, SE Cohen, BI Dimits, AM Nevins, WM Shumaker, D Decyk, VK Leboeuf, JN AF Chen, Y Parker, SE Cohen, BI Dimits, AM Nevins, WM Shumaker, D Decyk, VK Leboeuf, JN TI Simulations of turbulent transport with kinetic electrons and electromagnetic effects SO NUCLEAR FUSION LA English DT Article ID TEMPERATURE-GRADIENT TURBULENCE; SHEAR-ALFVEN WAVES; PARTICLE SIMULATION; MODEL; DRIVEN; TOKAMAKS; CLOSURES; PLASMAS; DRIFT AB A new electromagnetic kinetic electron simulation model that uses a generalized split-weight scheme, where the adiabatic part is adjustable, along with a parallel canonical momentum formulation has been developed in three-dimensional toroidal flux-tube geometry. This model includes electron-ion collisional effects and has been linearly benchmarked. It is found that for H-mode parameters, the nonadiabatic effects of kinetic electrons increase linear growth rates of the ion-temperature-gradient-driven (ITG) modes, mainly due to trapped-electron drive. The ion heat transport is also increased from that obtained with adiabatic electrons. The linear behaviour of the zonal flow is not significantly affected by kinetic electrons. The ion heat transport decreases to below the adiabatic electron level when finite plasma beta is included due to finite-beta stabilization of the ITG modes. This work is being carried out using the 'Summit Framework'. C1 Univ Colorado, Boulder, CO 80309 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Calif Los Angeles, Los Angeles, CA USA. RP Chen, Y (reprint author), Univ Colorado, Boulder, CO 80309 USA. NR 26 TC 36 Z9 36 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1121 EP 1127 AR PII S0029-5515(03)67914-7 DI 10.1088/0029-5515/43/10/013 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800015 ER PT J AU Prater, R La Haye, RJ Lohr, J Luce, TC Petty, CC Ferron, JR Humphreys, DA Strait, EJ Perkins, FW Harvey, RW AF Prater, R La Haye, RJ Lohr, J Luce, TC Petty, CC Ferron, JR Humphreys, DA Strait, EJ Perkins, FW Harvey, RW TI Discharge improvement through control of neoclassical tearing modes by localized ECCD in DIII-D SO NUCLEAR FUSION LA English DT Article ID CURRENT DRIVE; ASDEX UPGRADE; STABILIZATION AB Neoclassical tearing modes (NTMs) are magnetohydrodynamic modes that can limit the performance of high beta discharges in tokamaks, in some cases leading to a major disruption. The destabilizing effect that results in NTM growth is a helical decrease in the bootstrap current caused by a local reduction of the plasma pressure gradient by 'seed' magnetic islands. The NTM is particularly well suited to control since the mode is linearly stable although nonlinearly unstable, so if the island amplitude can be decreased below a threshold size the mode will decay and vanish. One means of shrinking the island is the replacement of the 'missing' bootstrap current by a localized current generated by electron cyclotron current drive (ECCD). This method has been applied to the m = 3/n = 2 NTM in DIII-D, in H-mode plasmas with ongoing edge localized modes and sawteeth, both of which generate seed islands periodically. In the case of the 3/2 mode, full suppression was obtained robustly by applying about 1.5 MW of ECCD very near the rational surface of the mode. When the mode first appears in the plasma, the stored energy decreases by 30%, but after the mode is stabilized by the ECCD, the beta may be raised above the initial threshold pressure by 20% by additional neutral beam heating, thereby generating an improvement in the limiting beta of nearly a factor of 2. An innovative automated search algorithm was implemented to find and retain the optimum location for the ECCD in the presence of the mode. C1 Gen Atom Co, San Diego, CA 92186 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. CompX, Del Mar, CA USA. RP Prater, R (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 16 TC 42 Z9 43 U1 2 U2 14 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1128 EP 1134 AR PII S0029-5515(03)67258-3 DI 10.1088/0029-5515/43/10/014 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800016 ER PT J AU Counsell, GF Alm, JW Cohen, RH Kirk, A Helander, P Martin, R Ryutov, DD Tabasso, A Wilson, HR Yang, Y AF Counsell, GF Alm, JW Cohen, RH Kirk, A Helander, P Martin, R Ryutov, DD Tabasso, A Wilson, HR Yang, Y CA MAST Team TI Exhaust, ELM, and halo physics using the MAST tokamak SO NUCLEAR FUSION LA English DT Article ID DIVERTOR; PLASMA AB The scrape-off layer (SOL) and divertor target plasma of a large spherical tokamak (ST) are characterized in detail for the first time. Scalings for the SOL heat flux width in MAST are developed and compared with conventional tokamaks. Modelling reveals the significance of the mirror force to the ST SOL. Core energy losses, including during ELMs, in MAST arrive predominantly (>80%) at the outboard targets in all geometries. Convective transport dominates energy losses during ELMs, and MHD analysis suggests ELMs in MAST are Type III even at auxiliary heating powers well above the L-H threshold. ELMs are associated with a poloidally and/or toroidally localized radial efflux at similar to1 km s(-1) well into the far SOL but not with any broadening of the target heat flux width. Toroidally asymmetric divertor biasing experiments have been conducted in an attempt to broaden the target heat flux width, with promising results. During vertical displacement events, the maximum product of the toroidal peaking factor and halo current fraction remains below 0.3, around half the ITER design limit. Evidence is presented to demonstrate that the resistance of the halo current path may have an impact on the distribution of the halo current. C1 UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Inst Plasma Phys, Hefei 230031, Peoples R China. RP Counsell, GF (reprint author), UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. NR 17 TC 17 Z9 17 U1 1 U2 5 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1197 EP 1203 AR PII S0029-5515(03)68135-4 DI 10.1088/0029-5515/43/10/022 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800024 ER PT J AU Cohen, RH Berk, HL Cohen, BI Fowler, TK Hooper, EB LoDestro, LL Morse, EC Pearlstein, LD Rognlien, TD Ryutov, DD Sovinec, CR Woodruff, S AF Cohen, RH Berk, HL Cohen, BI Fowler, TK Hooper, EB LoDestro, LL Morse, EC Pearlstein, LD Rognlien, TD Ryutov, DD Sovinec, CR Woodruff, S TI Theoretical investigation of field-line quality in a driven spheromak SO NUCLEAR FUSION LA English DT Article ID SUSTAINMENT; RELAXATION; TRANSPORT; PLASMA; MODEL AB Theoretical studies aimed at predicting and diagnosing field-line quality in a spheromak are described. These include nonlinear three-dimensional MHD simulations and analyses of confinement in spheromaks dominated by either open (stochastic) field lines or approximate flux surfaces. Three-dimensional nonlinear MHD simulations confirm that field lines are predominantly open when there is a large-amplitude toroidal-mode-number n = 1 mode. However, an appreciable volume of good flux surfaces can be obtained either during the drive-off phase of a scheme with periodic pulsed drive or for an extended period under driven conditions, with oscillating volume, when the odd-n modes are suppressed. If a configuration with radially localized perturbations can be achieved, a scaling analysis for a Rosenbluth-Bussac spheromak equilibrium indicates a favourable (1/Lundquist number) scaling to larger, higher-field devices. A hyper-resistivity analysis, which also assumes small-scale perturbations, reproduces well magnetic probe data in the sustained spheromak physics experiment, while an analysis of the same experiment based on one-dimensional transport along open field lines contradicts experimental observations in several key ways. The scaling analysis is also applied to reversed-field pinches and indicates that a completely determined scaling can be obtained with less approximation to the resistive MHD equations than indicated in the previous literature. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Cohen, RH (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 23 TC 9 Z9 9 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1220 EP 1234 AR PII S0029-5515(03)68601-1 DI 10.1088/0029-5515/43/10/025 PG 15 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800027 ER PT J AU Takenaga, H Higashijima, S Oyama, N Bruskin, LG Koide, Y Ide, S Shirai, H Sakamoto, Y Suzuki, T Hill, KW Rewoldt, G Kramer, GJ Nazikian, R Takizuka, T Fujita, T Sakasai, A Kamada, Y Kubo, H AF Takenaga, H Higashijima, S Oyama, N Bruskin, LG Koide, Y Ide, S Shirai, H Sakamoto, Y Suzuki, T Hill, KW Rewoldt, G Kramer, GJ Nazikian, R Takizuka, T Fujita, T Sakasai, A Kamada, Y Kubo, H CA JT-60 Team TI Relationship between particle and heat transport in JT-60U plasmas with internal transport barrier SO NUCLEAR FUSION LA English DT Article ID IMPURITY BEHAVIOR; BOOTSTRAP CURRENT; SHEAR PLASMAS; ASDEX UPGRADE; TOKAMAK; DISCHARGES; CONFINEMENT; REFLECTOMETRY; REACTOR; ENERGY AB The relationship between particle and heat transport in an internal transport barrier (ITB) has been systematically investigated in reversed shear (RS) and high beta(p) mode plasmas of JT-60U. The electron effective diffusivity is well correlated with the ion thermal diffusivity in the ITB region. The ratio of particle flux to electron heat flux, calculated on the basis of the linear stability analysis, shows a similar tendency to an experiment in the RS plasma with a strong ITB. However, the calculated ratio of ion anomalous heat flux to electron heat flux is smaller than the experiment in the ITB region. Helium and carbon are not accumulated inside the ITB even with ion heat transport close to a neoclassical level, but argon is accumulated. The helium diffusivity (D-He) and the ion thermal diffusivity (Xi) are 5-15 times higher than the neoclassical level in the high beta(p) mode plasma. In the RS plasma, D-He is reduced from 6-7 times to a 1.4-2 times higher level than the neoclassical level when chi(i) is reduced from 7-18 times to a 1.2-2.6 times higher level than the neoclassical level. The carbon and argon diffusivities estimated assuming the neoclassical inward convection velocity are 4-5 times larger than the neoclassical value, even when chi(i) is close to the neoclassical level. Argon exhaust from the inside of the ITB is demonstrated by applying electron cyclotron heating (ECH) in the high Pp mode plasma, where both electron and argon density profiles become flatter. The flattening of the argon density profile is consistent with the reduction of the neoclassical inward convection velocity due to the reduction of the bulk plasma density gradient. In the RS plasma, the density gradient is not decreased by ECH and argon is not exhausted. These results suggest the importance of density gradient control in suppressing impurity accumulation. C1 Naka Fus Res Estab, Japan Atom Energy Res Inst, Naka, Ibaraki 3110193, Japan. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Takenaga, H (reprint author), Naka Fus Res Estab, Japan Atom Energy Res Inst, Naka, Ibaraki 3110193, Japan. RI Kikuchi, Mitsuru/O-1036-2015 OI Kikuchi, Mitsuru/0000-0002-5485-8737 NR 29 TC 51 Z9 51 U1 1 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1235 EP 1245 AR PII S0029-5515(03)68824-1 DI 10.1088/0029-5515/43/10/026 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800028 ER PT J AU Fredrickson, E Chen, L White, R AF Fredrickson, E Chen, L White, R TI Bounce precession fishbones in the national spherical torus experiment SO NUCLEAR FUSION LA English DT Article ID ENERGETIC PARTICLES; INTERNAL KINK; TOKAMAKS; MODES; INSTABILITIES; OSCILLATIONS; PARAMETERS; PLASMAS; IONS AB Bursting modes, which are identified as bounce precession frequency fishbone modes, are observed on a low aspect ratio tokamak, the national spherical torus experiment (Ono M. et al 2000 Nucl. Fusion 40 557). They are predicted to be important in high current, low shear discharges with a significant population of trapped particles with a large mean bounce angle, such as produced by near tangential beam injection into a small aspect ratio device. Such a distribution is often stable to the usual precession-resonance fishbone mode. These modes could be important in ignited plasmas, driven by the trapped alpha particle population. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RP Fredrickson, E (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI White, Roscoe/D-1773-2013; chen, liu/I-2297-2013 OI White, Roscoe/0000-0002-4239-2685; NR 20 TC 40 Z9 42 U1 0 U2 5 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD OCT PY 2003 VL 43 IS 10 BP 1258 EP 1264 AR PII S0029-5515(03)68954-4 DI 10.1088/0029-5515/43/10/029 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 740KP UT WOS:000186401800031 ER PT J AU Reijonen, J Eardley, M Gough, R Leung, K Thomae, R AF Reijonen, J Eardley, M Gough, R Leung, K Thomae, R TI Microwave ion source for low charge state ion production SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE microwave ion source; ECR plasma heating; charge state; ion optics; emittance ID EXTRACTION AB The Plasma and Ion Source Technology Group at LBNL have developed a microwave ion source. The source consists of a stainless-steel plasma chamber, a permanent-magnet dipole structure and a coaxial microwave feed. Measurements were carried out to characterize the plasma and the ion beam produced in the ion source. These measurements included current density, charge state distribution, gas efficiency and accelerated beam emittance measurements. Using a computer controlled data acquisition system a new method of determining the saturation ion current was developed. Current density of 3-6 mA/cm(2) was measured with the source operating in the over dense mode. The highest measured charge-states were Ar5+, O3+ and Xe7+. Gas efficiency was measured using a calibrated argon leak. Depending on the source pressure and discharge power, more than 20% total gas efficiency was achieved. The emittance of the ion beam was measured by using a pepper-pot device. Certain spread was noticed in the beam emittance in the perpendicular direction to the source dipole field. For the parallel direction to the magnetic field, the normalized rr' emittance of 0.032 pi-mm-mrad at 13 kV of acceleration voltage and beam exit aperture of 3-mm-in-diameter was measured. This compares relatively well with the simulated value of 4 rms, normalized emittance value of 0.024 pi-mm-mrad. Published by Elsevier B.V. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Reijonen, J (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 5-119, Berkeley, CA 94720 USA. NR 6 TC 4 Z9 4 U1 0 U2 2 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 OCT 1 PY 2003 VL 511 IS 3 BP 301 EP 310 DI 10.1016/S0168-9002(03)01931-4 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 726GF UT WOS:000185590000001 ER PT J AU Hazen, E Lawlor, C Rohlf, JW Wu, SX Baumbaugh, A Elias, JE Freeman, J Green, D Lazic, D Los, S Ronzhin, A Sergueev, S Shaw, T Vidal, R Whitmore, J Zimmerman, T Adams, M Burchesky, K Qian, W Baden, A Bard, R Breden, H Grassi, T Skuja, A Fisher, W Mans, J Tully, C Barnes, V Laasanen, A de Barbaro, P Budd, H AF Hazen, E Lawlor, C Rohlf, JW Wu, SX Baumbaugh, A Elias, JE Freeman, J Green, D Lazic, D Los, S Ronzhin, A Sergueev, S Shaw, T Vidal, R Whitmore, J Zimmerman, T Adams, M Burchesky, K Qian, W Baden, A Bard, R Breden, H Grassi, T Skuja, A Fisher, W Mans, J Tully, C Barnes, V Laasanen, A de Barbaro, P Budd, H TI Radioactive source calibration technique for the CMS hadron calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE hadron sampling calorimeter; radioactive source calibration AB Relative calibration of the scintillator tiles used in the hadronic calorimeter for the Compact Muon Solenoid detector at the CERN Large Hadron Collider is established and maintained using a radioactive source technique. A movable source can be positioned remotely to illuminate each scintillator tile individually, and the resulting photo-detector current is measured to provide the relative calibration. The unique measurement technique described here makes use of the normal high-speed data acquisition system required for signal digitization at the 40 MHz collider frequency. The data paths for collider measurements and source measurements are then identical, and systematic uncertainties associated with having different signal paths are avoided. In this high-speed mode, the source signal is observed as a Poisson photo-electron distribution with a mean that is smaller than the width of the electronics noise (pedestal) distribution. We report demonstration of the technique using prototype electronics for the complete readout chain and show the typical response observed with a 144 channel test beam system. The electronics noise has a root-mean l-square of 1.6 least counts, and a 1 mCi source produces a shift of the mean value of 0.1 least counts. Because of the speed of the data acquisition system, this shift can be measured to a statistical precision better than a fraction of a percent on a millisecond time scale. The result is reproducible to better than 2% over a time scale of 1 month. (C) 2003 Elsevier B.V. All rights reserved. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. Univ Maryland, College Pk, MD 20742 USA. Princeton Univ, Princeton, NJ 08540 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. RP Rohlf, JW (reprint author), Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. RI Fisher, Wade/N-4491-2013 NR 20 TC 7 Z9 7 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 OCT 1 PY 2003 VL 511 IS 3 BP 311 EP 327 DI 10.1016/S0168-9002(03)01971-5 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 726GF UT WOS:000185590000002 ER PT J AU Helmer, RG Hardy, JC Iacob, VE Sanchez-Vega, M Neilson, RG Nelson, J AF Helmer, RG Hardy, JC Iacob, VE Sanchez-Vega, M Neilson, RG Nelson, J TI The use of Monte Carlo calculations in the determination of a Ge detector efficiency curve SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Ge detector; efficiency; Monte Carlo calculations ID RAY RESPONSE CHARACTERISTICS; GE(LI) DETECTORS; SEMICONDUCTOR DETECTORS; HPGE DETECTOR; INTENSITY DISTRIBUTIONS; RELATIVE EFFICIENCY; PEAK EFFICIENCIES; CALIBRATION; SPECTRA; STATE AB Precise measured data and an extensive set of Monte Carlo calculations have been combined to optimize the parameters for a 280 cm(3) n-type Ge semiconductor photon detector, with the outcome that the Monte Carlo calculations now provide a very precise detector efficiency curve. The detector position and its length were determined from a set of measurements that included an axial scan. Measurements of the relative efficiencies based on radionuclides with accurately known relative photon emission rates were combined with efficiencies calculated by a Monte Carlo photon and electron transport code to adjust the detector diameter, internal deadlayer thickness, and the effective external deadlayer thickness. Our results show that, in a well-studied situation, it is possible to use Monte Carlo calculations to aid in the determination of a Ge detector's efficiency with an accuracy of about 0.2% from 50 to 1400 keV. (C) 2003 Elsevier B.V. All rights reserved. C1 Idaho State Univ, Idaho Accelerator Ctr, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. RP Helmer, RG (reprint author), Idaho State Univ, Idaho Accelerator Ctr, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 40 TC 98 Z9 103 U1 0 U2 13 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 OCT 1 PY 2003 VL 511 IS 3 BP 360 EP 381 DI 10.1016/S0168-9002(03)01942-9 PG 22 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 726GF UT WOS:000185590000008 ER PT J AU Gehrke, RJ Baker, JD Hartwell, JK Riddle, CL McGrath, CA AF Gehrke, RJ Baker, JD Hartwell, JK Riddle, CL McGrath, CA TI Measurement of neutron-to-gamma-ray production ratios from (alpha, n) reactions for their application to assay TRU waste SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE (alpha, n) reactions; (n, gamma) reactions; CaF2; gamma-ray spectrometry AB We report on the measurement of neutron-to-gamma-ray production ratios from (alpha, n) reactions for three matrices CaF2, Al2O3, and MgO using alpha-emitting Cm-244 deposited in the respective matrix. These ratios allow the determination of neutron emission rates from (alpha, n) reactions on the target nuclides from gamma-ray spectra. These measurements may be useful in correcting neutron singles counts of transuranic waste for the neutrons produced from alpha-reactions with the matrix materials. (C) 2003 Elsevier B.V. All rights reserved. C1 INEEL, Idaho Falls, ID 83415 USA. RP Hartwell, JK (reprint author), INEEL, POB 1625 MS 2114, Idaho Falls, ID 83415 USA. RI McGrath, Christopher/E-8995-2013 NR 17 TC 4 Z9 4 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 OCT 1 PY 2003 VL 511 IS 3 BP 444 EP 456 DI 10.1016/S0168-9002(03)02011-4 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 726GF UT WOS:000185590000017 ER PT J AU Heinrichs, DP Wofford, SC AF Heinrichs, DP Wofford, SC TI A brief history of the Lawrence Radiation Laboratory Criticality Facility SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Thousands of critical and high-multiplication subcritical experiments were performed at the Lawrence Radiation Laboratory (LRL) Critical Facility throughout the 1950s and 1960s. This paper presents a brief history of the origins of the LRL and the critical facility with a synopsis of those experiments that have been evaluated and published or will soon appear in the International Handbook of Evaluated Criticality Safely Benchmark Experiments. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Heinrichs, DP (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 2003 VL 145 IS 2 BP 173 EP 180 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 729KF UT WOS:000185771800003 ER PT J AU Elam, KR Rearden, BT AF Elam, KR Rearden, BT TI Use of sensitivity and uncertainty analysis to select benchmark experiments for the validation of computer codes and data SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID RATIOS AB Sensitivity and uncertainty analysis methodologies under development at Oak Ridge National Laboratory were applied to determine whether existing benchmark experiments adequately cover the area of applicability for the criticality code and data validation of PuO2 and mixed-oxide (MOX) powder systems. The study examined three PuO2 powder systems and four MOX powder systems that would be useful for establishing mass limits for a MOX fuel fabrication facility. Using traditional methods to choose experiments for criticality analysis validation, 46 benchmark critical experiments were identified as applicable to the PuO2 powder systems. However, only 14 experiments were thought to be within the area of applicability for dry MOX powder systems. The applicability of 318 benchmark critical experiments, including the 60 experiments initially identified, was assessed. Each benchmark and powder system was analyzed using the Tools for Sensitivity and UNcertainty Analysis Methodology Implementation (TSUNAMI) one-dimensional (TSUNAMI-ID) or TSUNAMI three-dimensional (TSUNAMI-3D) sensitivity analysis sequences, which will be included in the next release of the SCALE code system. This sensitivity data and cross-section uncertainty data were then processed with TSUNAMI-IP to determine the correlation of each application to each experiment in the benchmarking set. Correlation coefficients are used to assess the similarity between systems and determine the applicability of one system for the code and data validation of another. The applicability of most of the experiments identified using traditional methods was confirmed by the TSUNAMI analysis. In addition, some PuO2 and MOX powder systems were determined to be within the area of applicability of several other benchmarks that would not have been considered using traditional methods. Therefore, the number of benchmark experiments useful for the validation of these systems exceeds the number previously expected. The TSUNAMI analysis also emphasized some areas where more benchmark data are needed, indicating the need for further evaluation of existing experiments, or possibly the completion of new experiments to fill these gaps. This lack of evaluated data is particularly important for very dry and dense MOX powder systems. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Elam, KR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 29 TC 10 Z9 10 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 2003 VL 145 IS 2 BP 196 EP 212 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 729KF UT WOS:000185771800006 ER PT J AU Loaiza, DJ Sanchez, R AF Loaiza, DJ Sanchez, R TI Examination of the 2x2 SiO2, Al, and Fe experiments mixed with highly enriched uranium on the thermal energy region SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB The basic characteristics of waste materials such as silicon dioxide, aluminum, and iron fueled with highly enriched uranium (HEU) and moderated and reflected by polyethylene were investigated. These critical experiments were performed at the Los Alamos Criticality Experiments Facility. The primary intention of these experiments is to provide supplementary data that can be used to validate and improve criticality data for the Yucca Mountain and the Hanford Storage Waste Tanks Projects. The secondary intention of the 2x2 experiments is to reduce the H/U ratio and increase the waste material/U ratio from previously published experiments. These experiments were designed to supply data for interlaced waste material/fuel/moderator systems on the thermal region. The experiments contained silicon dioxide (SiO2), aluminum (Al), and iron (Fe) mixed with 93.23% enriched uranium and moderated and reflected by polyethylene. This analysis systematically examines uncertainties associated with the critical experiments as they affect the calculated multiplication factor. The systematic analysis is separated into uncertainties due to mass measurements, uncertainties due to fabrication, and uncertainties due to composition. Each type of uncertainty is analyzed individually, and a total combined uncertainty is derived. The SiO2-HEU experiment had a measured k(eff) of 0.993, the Al-HEU experiment had a measured keff of 0.990, and the Fe-HEU experiment had a measured k(eff) of 1.000. The calculated k(eff) values tend to agree well with the experimental values. The sensitivity analysis of these critical experiments yielded a total combined uncertainty on the measured keff of +/-0.0044 for SiO2, of +/-0.0048 for Al, and of +/-0.0046 for Fe. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Loaiza, DJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 2003 VL 145 IS 2 BP 256 EP 266 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 729KF UT WOS:000185771800011 ER PT J AU Hoffman, EA Stacey, WM AF Hoffman, EA Stacey, WM TI Comparative fuel cycle analysis of critical and subcritical fast reactor transmutation systems SO NUCLEAR TECHNOLOGY LA English DT Article DE transmutation; repository performance; nuclear fuel cycle ID WASTE TRANSMUTATION; NEUTRON SOURCE AB Fuel cycle analyses are performed to evaluate the impacts of further transmutation of spent nuclear fuel on high-level and low-level waste mass flows into repositories, on the composition and toxicity of the high-level waste, on the capacity of high-level waste repositories, and on the proliferation resistance of the high-level waste. Storage intact of light water reactor (LWR) spent nuclear fuel, a single recycle in a LWR of the plutonium as mixed-oxide fuel, and the repeated recycle of the transuranics in critical and subcritical fast reactors are compared with the focus on the waste management performance of these systems. Other considerations such as cost and technological challenges were beyond the scope of this study. The overall conclusion of the studies is that repeated recycling of the transuranics from spent nuclear fuel would significantly increase the capacity of high-level waste repositories per unit of nuclear energy produced, significantly increase the nuclear energy production per unit mass of uranium ore mined, significantly reduce the radiotoxicity of the waste streams per unit of nuclear energy produced, and significantly enhance the proliferation resistance of the material stored in high-level waste repositories. C1 Georgia Inst Technol, Nucl & Radiol Engn Program, Atlanta, GA 30332 USA. RP Hoffman, EA (reprint author), Argonne Natl Lab, Bldg 208,Room C130,9700 S Cass Ave, Argonne, IL 60439 USA. NR 41 TC 24 Z9 24 U1 1 U2 3 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD OCT PY 2003 VL 144 IS 1 BP 83 EP 106 PG 24 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 722MA UT WOS:000185377500007 ER PT J AU Wilde, EW Berry, CJ Goli, MB AF Wilde, EW Berry, CJ Goli, MB TI Method for removing gadolinium from used heavy water reactor moderator SO NUCLEAR TECHNOLOGY LA English DT Article DE gadolinium; nitrate; heavy water AB A novel process is described that treats used heavy water moderator (D2O) contaminated with high concentrations of the neutron poison gadolinium nitrate, Gd(NO3)(3). Gadolinium is removed by precipitation. The resultant precipitate, GdPO4.6H(2)O, represents an extremely rare compound of considerable potential value. The resultant supernatant consisting of residual nitrate, NaNO3 or KNO3, is less toxic and easier to process than the original waste. Thus, the alkali metal waste handling can be done with considerably less environmental concern. This waste can potentially be treated by a combination of electrochemical and biological methods. C1 Westinghouse Savannah River Co, Aiken, SC 29808 USA. Mississippi Valley State Univ, Itta Bena, MS 38941 USA. RP Wilde, EW (reprint author), Westinghouse Savannah River Co, Savannah River Site, Aiken, SC 29808 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD OCT PY 2003 VL 144 IS 1 BP 141 EP 143 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 722MA UT WOS:000185377500010 ER PT J AU Xu, D Olman, V Wang, L Xu, Y AF Xu, D Olman, V Wang, L Xu, Y TI EXCAVATOR: a computer program for efficiently mining gene expression data SO NUCLEIC ACIDS RESEARCH LA English DT Article ID CYCLE-REGULATED GENES; SACCHAROMYCES-CEREVISIAE; TRANSCRIPTIONAL PROGRAM; MICROARRAY ANALYSIS; CLUSTER-ANALYSIS; BUDDING YEAST; SCALE; PATTERNS AB Massive amounts of gene expression data are generated using microarrays for functional studies of genes and gene expression data clustering is a useful tool for studying the functional relationship among genes in a biological process. We have developed a computer package EXCAVATOR for clustering gene expression profiles based on our new framework for representing gene expression data as a minimum spanning tree. EXCAVATOR uses a number of rigorous and efficient clustering algorithms. This program has a number of unique features, including capabilities for: (i) data- constrained clustering; (ii) identification of genes with similar expression profiles to pre-specified seed genes; (iii) cluster identification from a noisy background; (iv) computational comparison between different clustering results of the same data set. EXCAVATOR can be run from a Unix/Linux/DOS shell, from a Java interface or from a Web server. The clustering results can be visualized as colored figures and 2-dimensional plots. Moreover, EXCAVATOR provides a wide range of options for data formats, distance measures, objective functions, clustering algorithms, methods to choose number of clusters, etc. The effectiveness of EXCAVATOR has been demonstrated on several experimental data sets. Its performance compares favorably against the popular K-means clustering method in terms of clustering quality and computing time. C1 Oak Ridge Natl Lab, Div Life Sci, Prot Informat Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Xu, D (reprint author), Univ Missouri, Dept Comp Sci, 201 Engn Bldg W, Columbia, MO 65211 USA. NR 27 TC 11 Z9 12 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD OCT 1 PY 2003 VL 31 IS 19 BP 5582 EP 5589 DI 10.1093/nar/gkg783 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 726LK UT WOS:000185600400020 PM 14500821 ER PT J AU Sims, GE Kim, SH AF Sims, GE Kim, SH TI Global mapping of nucleic acid conformational space: dinucleoside monophosphate conformations and transition pathways among conformational classes SO NUCLEIC ACIDS RESEARCH LA English DT Article ID B-DNA; A-DNA; MOLECULAR-STRUCTURE; ATOMIC RESOLUTION; CRYSTAL-STRUCTURE; HELIX GEOMETRY; RNA; NUCLEOTIDES; REPRESENTATIONS; HYDRATION AB A global conformational space of 6253 dinucleoside monophosphate (DMP) units consisting of RNA and DNA (free and protein/drug-bound) was 'mapped' using high resolution crystal structures cataloged in the Nucleic Acid Database (NDB). The torsion angles of each DMP were clustered in a reduced three-dimensional space using a classical multi-dimensional scaling method. The mapping of the conformational space reveals nine primary clusters which distinguish among the common A-, B- and Z-forms and their various substates, plus five secondary clusters for kinked or bent structures. Conformational relationships and possible transitional pathways among the substates are also examined using the conformational states of DNA and RNA bound with proteins or drugs as potential pathway intermediates. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM0829515] NR 38 TC 17 Z9 18 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD OCT 1 PY 2003 VL 31 IS 19 BP 5607 EP 5616 DI 10.1093/nar/gkg750 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 726LK UT WOS:000185600400023 PM 14500824 ER PT J AU Mandel, J Dohrmann, CR AF Mandel, J Dohrmann, CR TI Convergence of a balancing domain decomposition by constraints and energy minimization SO NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS LA English DT Article DE iterative substructuring; FETI; balancing domain decomposition; Neumann-Neumann; additive Schwarz; non-overlapping domain decomposition ID ELLIPTIC PROBLEMS; PRECONDITIONERS; CONSTRUCTION; COEFFICIENTS; PLATE AB A convergence theory is presented for a substructuring preconditioner based on constrained energy minimization concepts. The substructure spaces consist of local functions with zero values of the constraints, while the coarse space consists of minimal energy functions with the constraint values continuous across substructure interfaces. In applications, the constraints include values at corners and optionally averages on edges and faces. The preconditioner is reformulated as an additive Schwarz method and analysed by building on existing results for balancing domain decomposition. The main result is a bound on the condition number based on inequalities involving the matrices of the preconditioner. Estimates of the form C(1 + log(2)(H/h)) are obtained under the standard assumptions of substructuring theory. Computational results demonstrating the performance of method are included. Published in 2003 by John Wiley Sons, Ltd. C1 Univ Colorado, Dept Math, Denver, CO 80217 USA. Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA. Sandia Natl Labs, Struct Dynam Res Dept, Albuquerque, NM 87185 USA. RP Mandel, J (reprint author), Univ Colorado, Dept Math, Denver, CO 80217 USA. RI Mandel, Jan/A-2281-2009 OI Mandel, Jan/0000-0002-8489-5766 NR 23 TC 105 Z9 105 U1 2 U2 6 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1070-5325 J9 NUMER LINEAR ALGEBR JI Numer. Linear Algebr. Appl. PD OCT-NOV PY 2003 VL 10 IS 7 BP 639 EP 659 DI 10.1002/nla.341 PG 21 WC Mathematics, Applied; Mathematics SC Mathematics GA 737VU UT WOS:000186253100007 ER PT J AU Deng, LG Liu, HK AF Deng, LG Liu, HK TI Nonlinear optical limiting of the azo dye methylred doped nematic liquid crystalline films SO OPTICAL ENGINEERING LA English DT Article DE nonlinear optical limiting; doped nematic liquid crystal; eye and sensor protection; liquid crystal limiters; methyl-red-doped liquid crystalline films ID SELF-PHASE MODULATION; CORED FIBER ARRAY; LASER-PULSES; POWER; PROTECTION; MEDIA AB We describe the nonlinear optical limiting behaviors of the azo dye methyl-red-doped nematic liquid crystalline (NLC) films and report the phenomena of the formation of an interesting dark spot and a dynamic self-action diffraction ring pattern in the far field beyond the sample cell. We present the method of measuring the optical limiting characteristics of the methyl-red-dye-doped NLC; films with typical test results obtained in the experiments. We theoretically analyze the optical limiting mechanisms of the methyl-red-dye-doped NLC films and discuss the advantages and restrictions of the methyl-red dye doped liquid crystal limiters, and propose several possible solutions to overcome these restrictions. (C) 2003 Society of Photo-Optical Instrumentation Engineers. C1 Beijing Inst Technol, Fac Sci, Dept Appl Phys, Beijing 100081, Peoples R China. Natl Taiwan Univ, Grad Inst Electroopt Engn, Dept Elect Engn, Taipei 10764, Taiwan. Oak Ridge Natl Lab, Ctr Engn Adv Res, Oak Ridge, TN 37831 USA. RP Deng, LG (reprint author), Beijing Inst Technol, Fac Sci, Dept Appl Phys, Beijing 100081, Peoples R China. RI Deng, Luogen /C-8402-2009 NR 29 TC 16 Z9 17 U1 0 U2 11 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD OCT PY 2003 VL 42 IS 10 BP 2936 EP 2941 DI 10.1117/1.1607332 PG 6 WC Optics SC Optics GA 733CM UT WOS:000185982400029 ER PT J AU Horchani, K Gacon, JC Ferid, M Trabelsi-Ayedi, M Krachni, O Liu, GK AF Horchani, K Gacon, JC Ferid, M Trabelsi-Ayedi, M Krachni, O Liu, GK TI Energy levels of Pr3+ in CsPrP4O12 and RbPrP4O12 cyclotetraphosphates SO OPTICAL MATERIALS LA English DT Article; Proceedings Paper CT 5th French-Israeli Workshop on Optical Properties of Inorganic Materials CY DEC 08-12, 2002 CL CLAUDE BERNARD LYON UNIV 1, VILLEURBANNE, FRANCE SP Min foreign Affairs France, French Embassy Israel, CNRS, Dept Chem, France-Israel Rhone Alpea Chamber Commerce, Reg Rhone Alpes HO CLAUDE BERNARD LYON UNIV 1 ID SINGLE-CRYSTAL; LASER; IONS AB Single crystals of CsPrP4O12 and RbPrP4O12 cyclotetraphosphates were grown using the flux method. CsPrP4O12 crystallizes in the cubic I-43d space group whereas RbPrP4O12 crystallizes either in the cubic I-43d or monoclinic C2/c space group. The Pr3+ ions occupy sites of S-4 and C-2 symmetries in the cubic and monoclinic phases, respectively, with an eightfold coordination in both phases. The present work reports on an analysis of the Pr3+ 4f(2) energy level diagram based on the low temperature fluorescence spectra under laser selective excitation in the P-3(2) states of the cubic CsPrP4O12 and monoclinic RbPrP4O12 compounds. The experimental energy levels are fitted using the SPECTRA program available on the Argonne National Laboratory website. The best fits lead to standard deviations in the order of 28 and 21 cm(-1) for the CsPrP4O12 and RbPrP4O12 materials, respectively. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Lyon 1, CNRS, UMR 5620, Lab Physicochim Mat Luminescents, F-69622 Villeurbanne, France. Inst Natl Rech Sci & Tech, Lab Proc Chim, Hammam Lif 2050, Tunisia. Fac Sci Bizerte, Lab Physicochim Min, Bizerte, Tunisia. Univ Ferhat Abbas, Inst Phys, Setif, Algeria. Argonne Natl Lab, Argonne, IL 60439 USA. RP Horchani, K (reprint author), Univ Lyon 1, CNRS, UMR 5620, Lab Physicochim Mat Luminescents, F-69622 Villeurbanne, France. OI karima, Horchani-Naifer/0000-0001-8156-2870 NR 10 TC 26 Z9 27 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-3467 J9 OPT MATER JI Opt. Mater. PD OCT-NOV PY 2003 VL 24 IS 1-2 BP 169 EP 174 DI 10.1016/S0925-3467(03)00121-6 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA 736VV UT WOS:000186194600026 ER PT J AU Toth, C Faure, J van Tilborg, J Geddes, CGR Schroeder, CB Esarey, E Leemans, WP AF Toth, C Faure, J van Tilborg, J Geddes, CGR Schroeder, CB Esarey, E Leemans, WP TI Tuning of laser pulse shapes in grating-based compressors for optimal electron acceleration in plasmas SO OPTICS LETTERS LA English DT Article ID WAKEFIELD ACCELERATORS; OPTICAL PULSES; PHASE-CONTROL; AMPLIFICATION; AMPLITUDE; SYSTEMS AB The temporal shape (rise time, fall time, skewness) of 50-200-fs Ti:sapphire laser pulses has been controlled by appropriate adjustment of a grating-pair compressor. it was found that the skewness of the laser pulse envelope is particularly sensitive to the third-order component of the spectral phase. Introducing such a third-order phase offset by detuning the grating pair relative to the optimum pulse compression settings allowed the generation of skewed pulses. As an example of an application, these skewed pulses were used to optimize a laser-plasma electron accelerator. (C) 2003 Optical Society of America. C1 Lawrence Berkeley Natl Lab, LOASIS Grp, Accelerator & Fus Res Div, Berkeley, CA 94720 USA. RP Toth, C (reprint author), Lawrence Berkeley Natl Lab, LOASIS Grp, Accelerator & Fus Res Div, Bldg 71R0259,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Schroeder, Carl/0000-0002-9610-0166 NR 16 TC 16 Z9 16 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD OCT 1 PY 2003 VL 28 IS 19 BP 1823 EP 1825 DI 10.1364/OL.28.001823 PG 3 WC Optics SC Optics GA 723MQ UT WOS:000185436500031 PM 14514113 ER PT J AU Xiong, YL AF Xiong, YL TI Predicted equilibrium constants for solid and aqueous selenium species to 300 degrees C: applications to selenium-rich mineral deposits SO ORE GEOLOGY REVIEWS LA English DT Review DE selenium; hydrothermal; aqueous speciation; solubility; geochemistry; mineral deposits ID MOLAL THERMODYNAMIC PROPERTIES; HYDROTHERMAL SOLUTIONS; ELEVATED-TEMPERATURES; NICKEL DISELENIDE; IRON DISELENIDE; HEAT-CAPACITIES; PHASE-RELATIONS; HIGH-PRESSURES; STANDARD; ELECTROLYTES AB In this study, an attempt has been made to assess aqueous speciation of selenium and solubility product constants of common selenides at elevated temperatures (up to 300degreesC) by using various extrapolation methods. This study predicts that reduced selenium species are dominant species in many geological processes even under relatively oxidized conditions such as those dictated by the magnetite-hematite buffer. On the basis of extrapolated equilibrium constants and solubility product constants for common Se-bearing mineral phases, critical SigmaSe/SigmaS ratios (molal ratios) in mineralizing fluids are proposed for independent selenium mineralization. The minimum SigmaSe/SigmaS ratios in mineralizing fluids for independent selenium mineralization should be at least similar to 10(-6), similar to 10(-5) and similar to 10(-4) at 100, 200 and 300degreesC, respectively. For giant independent selenium deposits such as the La'erma and Qiongmo Au-Se deposits in the western Qingling mountains, and Yutangba Se deposits in Hubei Province, China, the mineralizing fluids have reached much higher SigmaSe/SigmaS ratios ranging from similar to 10(-1) to similar to 10(-3) at 200degreesC. This study also suggests that the equilibrium assemblage of pyrite-ferroselite among the common ore minerals requires the highest SigmaSe/SigmaS ratios in mineralizing fluids, followed in decreasing order by the assemblages of stibnite-antimonselite, galena-clausthalite, cinnabar-tiemannite, and acanthite/argentite-naumannite. The assemblage of pyrite-ferroselite can also be formed under relatively oxidizing conditions where [SigmaH(2)Se]/[SigmaH(2)S] ratios can be high enough for the formation of independent ferroselite. (C) 2003 Elsevier B.V. All rights reserved. C1 Rutgers State Univ, Dept Geol Sci, Piscataway, NJ 08854 USA. RP Xiong, YL (reprint author), Sandia Natl Labs, 4100 Natl Parks Highway, Carlsbad, NM 88220 USA. NR 68 TC 32 Z9 38 U1 2 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-1368 J9 ORE GEOL REV JI Ore Geol. Rev. PD OCT PY 2003 VL 23 IS 3-4 BP 259 EP 276 DI 10.1016/S0169-1368(03)00038-6 PG 18 WC Geology; Mineralogy; Mining & Mineral Processing SC Geology; Mineralogy; Mining & Mineral Processing GA 745LQ UT WOS:000186690500008 ER PT J AU Scheuring, I Czaran, T Szabo, P Karolyi, G Toroczkai, Z AF Scheuring, I Czaran, T Szabo, P Karolyi, G Toroczkai, Z TI Spatial models of prebiotic evolution: Soup before pizza? SO ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES LA English DT Article DE coexistence; early evolution; Eigen's paradox; prebiotic soup; open chaotic flow; prebiotic pizza; parasites; RNA-world ID OPEN HYDRODYNAMICAL FLOWS; CATALYZED RNA POLYMERIZATION; LEAPFROGGING VORTEX PAIRS; OPEN CHAOTIC FLOWS; ADVECTION; SYSTEMS; REPLICATORS; SCATTERING; TEMPLATES; LIGATION AB The problem of information integration and resistance to the invasion of parasitic mutants in prebiotic replicator systems is a notorious issue of research on the origin of life. Almost all theoretical studies published so far have demonstrated that some kind of spatial structure is indispensable for the persistence and/or the parasite resistance of any feasible replicator system. Based on a detailed critical survey of spatial models on prebiotic information integration, we suggest a possible scenario for replicator system evolution leading to the emergence of the first protocells capable of independent life. We show that even the spatial versions of the hypercycle model are vulnerable to selfish parasites in heterogeneous habitats. Contrary, the metabolic system remains persistent and coexistent with its parasites both on heterogeneous surfaces and in chaotically mixing flowing media. Persistent metabolic parasites can be converted to metabolic cooperators, or they can gradually obtain replicase activity. Our simulations show that, once replicase activity emerged, a gradual and simultaneous evolutionary improvement of replicase functionality ( speed and fidelity) and template efficiency is possible only on a surface that constrains the mobility of macromolecule replicators. Based on the results of the models reviewed, we suggest that open chaotic flows ('soup') and surface dynamics ('pizza') both played key roles in the sequence of evolutionary events ultimately concluding in the appearance of the first living cell on Earth. C1 Eotvos Lorand Univ, Dept Plant Taxonomy & Ecol, Res Grp Ecol & Theoret Biol, H-1117 Budapest, Hungary. Int Inst Appl Syst Anal, Adapt Dynam Network, A-2361 Laxenburg, Austria. Univ Arizona, Program Appl Math, Tucson, AZ 85721 USA. Budapest Univ Technol & Econ, Dept Struct Mech, H-1521 Budapest, Hungary. Budapest Univ Technol & Econ, Ctr Appl Math & Computat Phys, H-1521 Budapest, Hungary. Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. RP Scheuring, I (reprint author), Eotvos Lorand Univ, Dept Plant Taxonomy & Ecol, Res Grp Ecol & Theoret Biol, Pazmany P Setany 1-C, H-1117 Budapest, Hungary. EM shieazsf@ludens.elte.hu RI Toroczkai, Zoltan/A-3421-2008; Karolyi, Gyorgy/A-5073-2008; Scheuring, Istvan/A-5368-2011; Czaran, Tamas/A-1169-2008; OI Toroczkai, Zoltan/0000-0002-6602-2849; Scheuring, Istvan/0000-0002-8108-8897; Czaran, Tamas/0000-0002-2722-6208; Karolyi, Gyorgy/0000-0002-1021-9554 NR 69 TC 37 Z9 38 U1 1 U2 16 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-6149 J9 ORIGINS LIFE EVOL B JI Orig. Life Evol. Biosph. PD OCT PY 2003 VL 33 IS 4-5 BP 319 EP 355 DI 10.1023/A:1025742505324 PG 37 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 721VX UT WOS:000185340100002 PM 14604181 ER PT J AU Chervenak, A Deelman, E Kesselman, C Allcock, B Foster, I Nefedova, V Lee, J Sim, A Shoshahi, A Drach, B Williams, D Middleton, D AF Chervenak, A Deelman, E Kesselman, C Allcock, B Foster, I Nefedova, V Lee, J Sim, A Shoshahi, A Drach, B Williams, D Middleton, D TI High-performance remote access to climate simulation data: a challenge problem for data grid technologies SO PARALLEL COMPUTING LA English DT Article DE grid computing; Globus Toolkit (R); GridFTP; Earth System Grid AB In numerous scientific disciplines, terabyte and petabyte-scale data collections are emerging as critical community resources. A new class of "data grid" infrastructure is required to support management, transport, distributed access to, and analysis of these datasets by potentially thousands of users. Researchers who face this challenge include the climate modeling community, which performs long-duration computations accompanied by frequent output of very large files that must be further analyzed. We describe the Earth System Grid-I prototype, which brings together advanced analysis, replica management, data transfer, request management, and other technologies to support high-performance, interactive analysis of replicated data. We present performance results that demonstrate our ability to manage the location and movement of large datasets from the user's desktop. We report on experiments conducted over SciNET at SC'2000, where we achieved peak performance of 1.55 Gb/s and sustained performance of 512.9 Mb/s for data transfers between Texas and California. Finally, we describe the development of the next-generation Earth System Grid-II (ESG-II) project. Important issues for ESG-II include security requirements for production environments, efficient data filtering and transport, metadata services for discovery of relevant climate datasets, and sophisticated request or workflow management for complex tasks. (C) 2003 Published by Elsevier B.V. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ So Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Ctr Atmospher Res, Boulder, CO 80305 USA. RP Foster, I (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Kesselman, Carl/0000-0003-0917-1562 NR 27 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD OCT PY 2003 VL 29 IS 10 BP 1335 EP 1356 DI 10.1016/j.parco.2003.06.001 PG 22 WC Computer Science, Theory & Methods SC Computer Science GA 732JM UT WOS:000185939900004 ER PT J AU Ahmadi, G He, CH Smith, DH Ramer, E AF Ahmadi, G He, CH Smith, DH Ramer, E TI Gas flow and particle transport and deposition in a pilot-scale furnace SO PARTICULATE SCIENCE AND TECHNOLOGY LA English DT Article DE furnace flow; furnace temperature; particle transport; particle deposition; simulations ID COAL COMBUSTION; ASH DEPOSITION; SIMULATION; REACTOR; GROWTH; TUBE AB The present work describes a computer simulation study of gas flow and particle transport and deposition in a pilot-scale furnace with cooling system. The Gambit code is used to generate the geometry and the computational grid. An unstructured mesh is generated for the pilot-scale boiler. The FLUENT code is used for evaluating the gas mean velocity, turbulence fluctuation energy, and mean pressure, as well as temperature fields and chemical species concentrations. The particle equation of motion includes the nonlinear drag, gravity, Brownian, lift, and thermophoretic forces. The gas velocity and thermal conditions in the furnace are studied. Ensembles of particle trajectories are generated and statistically analyzed. Particle deposition rates on different walls are evaluated, and the effect of particle size is studied. C1 Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. US DOE, Natl Energy Technol Lab, Morgantown, WV USA. RP Ahmadi, G (reprint author), Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0272-6351 J9 PARTICUL SCI TECHNOL JI Part. Sci. Technol. PD OCT-DEC PY 2003 VL 21 IS 4 BP 375 EP 386 DI 10.1080/02726350390240223 PG 12 WC Engineering, Chemical SC Engineering GA 740TH UT WOS:000186417300007 ER PT J AU Adiga, PSU Flint, J AF Adiga, PSU Flint, J TI An efficient tool for genetic experiments: agarose gel image analysis SO PATTERN RECOGNITION LA English DT Article DE agarose; gel; allele; DNA; segmentation; classification; filtering AB Repeatability of many genetic analysis experiments can be improved by the application of signal processing and image-processing tools. Most of the experiments in genetics result in some sort of digital signal or image patterns that are subjectively analyzed by the geneticists. This paper presents an example project where image-processing techniques are applied for automation of most of the routine processes of agarose gel image analysis. Result of applying this program has shown that the time taken for the analysis has been reduced by about 70% and the result is reproducible. (C) 2003 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Oxford, Wellcome Trust Ctr Human Genet, Psychiat Genet Grp, Oxford, England. RP Adiga, PSU (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 50A-1148,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-3203 J9 PATTERN RECOGN JI Pattern Recognit. PD OCT PY 2003 VL 36 IS 10 BP 2453 EP 2461 DI 10.1016/S0031-3203(03)00129-8 PG 9 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 707KN UT WOS:000184510000019 ER PT J AU Jackiewicz, JA Blagoev, KB Bedell, KS AF Jackiewicz, JA Blagoev, KB Bedell, KS TI A model for coexistent superconductivity and ferromagnetism SO PHILOSOPHICAL MAGAZINE LA English DT Article ID SPIN CORRELATIONS; UGE2; METALS AB We explore the various temperature dependences and thermodynamic quantities of a mean-field model of a ferromagnetic-superconducting system. The starting point for this model is based on an s-wave pairing scheme in the singlet channel of the superconducting state and a spontaneously broken-symmetry phase in the ferromagnetic state. We show numerically and analytically that a state of coexistence reveals itself and is favoured energetically over other possible states, and a simple phase diagram is developed. Finally, a comparison of the specific heat with experiment is shown. C1 Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Jackiewicz, JA (reprint author), Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. EM Jackiewi@mail.bc.edu NR 17 TC 3 Z9 3 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1478-6435 J9 PHILOS MAG JI Philos. Mag. PD OCT 1 PY 2003 VL 83 IS 28 BP 3247 EP 3254 DI 10.1080/14786430310001606145 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 732AE UT WOS:000185918000005 ER PT J AU Kalosakas, G Bishop, AR AF Kalosakas, G Bishop, AR TI Intrinsic inhomogeneity due to nonlinearity SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 6th International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media CY JUL 15-19, 2002 CL SNOWBIRD, UT SP Natl Sci Fdn, USA Res Off, Univ Utah, Opt Soc Amer, Amer Phys Soc, Soc Ind & Appl Math DE intrinsic localization; Raman red-shifts; charge trapping in DNA ID DNA DENATURATION; STATISTICAL-MECHANICS; LOCALIZED MODES; BREATHERS; LATTICES; SUPERCONDUCTORS; TRANSITION; EXISTENCE; SPECTRUM; DYNAMICS AB Presence of strong nonlinearity in a material, either explicit, or effective (resulting from the interaction of coupled degrees of freedom), can lead to intrinsic inhomogeneity even in a periodic extended system. We briefly discuss two examples where such a breaking of the translational symmetry due to nonlinearity (i) determines the optical features (in particular the resonance Raman scattering spectra) of a quasi-one-dimensional halogen-bridged mixed-valence transition metal complex, and (ii) enhances the trapping of a charge in a model of DNA, which is likely to affect the long-range transport properties in this biomolecule. (C) 2003 Elsevier B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Bishop, AR (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM georgek@lanl.gov; arb@lanl.gov RI Kalosakas, George/L-6211-2013 OI Kalosakas, George/0000-0001-7763-718X NR 36 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD OCT PY 2003 VL 338 IS 1-4 BP 87 EP 91 DI 10.1016/S0921-4526(03)00466-6 PG 5 WC Physics, Condensed Matter SC Physics GA 747PB UT WOS:000186812200019 ER PT J AU Pletzer, A Shvets, G AF Pletzer, A Shvets, G TI Simulating photons and plasmons in a three-dimensional lattice SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 6th International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media CY JUL 15-19, 2002 CL SNOWBIRD, UTAH SP Natl Sci Fdn, USA Res Off, Univ Utah, Opt Soc Amer, Amer Phys Soc, Soc Ind & Appl Math DE band structure; Helmholtz equation; 3-D; mixed FE-FD; perfect conductor AB Three-dimensional metallic photonic structures are studied using a newly developed mixed finite element-finite difference (FE-FD) code, Curly3d. The code solves the vector Helmholtz equation as an eigenvalue problem in the unit cell of a triply periodic lattice composed of conductors and/or dielectrics. The mixed FE-FD discretization scheme ensures rapid numerical convergence of the eigenvalue and allows the code to run at low resolution. Plasmon and photonic band structure calculations are presented. (C) 2003 Elsevier B.V. All rights reserved. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. IIT, Chicago, IL 60616 USA. RP Pletzer, A (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 10 TC 1 Z9 1 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 OCT PY 2003 VL 338 IS 1-4 BP 190 EP 195 DI 10.1016/S0921-4526(03)00485-X PG 6 WC Physics, Condensed Matter SC Physics GA 747PB UT WOS:000186812200038 ER PT J AU Berryman, JG AF Berryman, JG TI Electrokinetic effects and fluid permeability SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 6th International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media CY JUL 15-19, 2002 CL SNOWBIRD, UTAH SP Natl Sci Fdn, USA Res Off, Univ Utah, Opt Soc Amer, Amer Phys Soc, Soc Ind & Appl Math DE electrical impedance tomography; electrokinetic phenomena; fluid permeability ID FREQUENCY AC ELECTROKINETICS; SATURATED POROUS-MEDIA; ELASTIC WAVES; PROPAGATION; CONVERSIONS; TOMOGRAPHY; TRANSPORT; RANGE; ROCK AB Fluid permeability of porous media depends mainly on connectivity of the pore space and two physical parameters: porosity and a pertinent length-scale parameter. Electrical imaging methods typically establish connectivity and directly measure electrical conductivity, which can then often be related to porosity by Archie's law. When electrical phase measurements are made in addition to the amplitude measurements, information about the pertinent length scale can then be obtained. Since fluid permeability controls the ability to flush unwanted fluid contaminants from the subsurface, inexpensive maps of permeability could improve planning strategies for remediation efforts. Detailed knowledge of fluid permeability is also important for oil field exploitation, where knowledge of permeability distribution in three dimensions is a common requirement for petroleum reservoir simulation and analysis, as well as for estimates on the economics of recovery. (C) 2003 Elsevier B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berryman, JG (reprint author), Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. RI Berryman, James/A-9712-2008 NR 26 TC 2 Z9 3 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 OCT PY 2003 VL 338 IS 1-4 BP 270 EP 273 DI 10.1016/j.physb.2003.08.006 PG 4 WC Physics, Condensed Matter SC Physics GA 747PB UT WOS:000186812200056 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Transparency threshold in the insulating phase of layered copper oxides SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID SUPERCONDUCTIVITY; SINGULARITY; YBA2CU4O8 AB The dielectric function of the insulating antiferromagnetic phase of high-T-c layered cuprates is calculated, as function of frequency, at different dopings and temperatures. It is shown that at frequencies below the energy gap the dielectric constant is real but can change its sign. This means that there exists a transparency threshold. The corresponding frequency is calculated. as function of temperature at different dopings. It vanishes in both limits: T --> 0, and T --> T-N, if the transition at T-N is a second order transition. In case of a first order transition the threshold frequency remains finite at T-N. (C) 2003 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Abrikosov, AA (reprint author), Argonne Natl Lab, Div Mat Sci, Bldg 223,9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 1 PY 2003 VL 397 IS 1-2 BP 71 EP 76 DI 10.1016/S0921-4534(03)01328-5 PG 6 WC Physics, Applied SC Physics GA 732ZP UT WOS:000185975700009 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Antiferromagnetic bubbles around nonmagnetic impurities SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article AB An explanation is proposed for the experimentally observed phenomenon of an antiferromagnetic spin polarization around nonmagnetic impurities, Zn and Li, in the metallic state of layered copper oxides. The explanation is based on the idea that the impurity ion, creating an excess positive charge at the copper site, reduces the hole concentration in its vicinity, and this leads to the appearance of a bubble of a an insulating spin-density wave phase around the impurity. (C) 2003 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Abrikosov, AA (reprint author), Argonne Natl Lab, Div Mat Sci, Bldg 223,9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT 1 PY 2003 VL 397 IS 1-2 BP 77 EP 79 DI 10.1016/S0921-4534(03)01251-6 PG 3 WC Physics, Applied SC Physics GA 732ZP UT WOS:000185975700010 ER PT J AU Balachandran, U Ma, B Li, M Fisher, BL Koritala, RE Miller, DJ Dorris, SE AF Balachandran, U Ma, B Li, M Fisher, BL Koritala, RE Miller, DJ Dorris, SE TI Development of coated conductors by inclined substrate deposition SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 15th International Symposium on Superconductivity (ISS 2002) CY NOV 11-13, 2002 CL YOKOHAMA, JAPAN DE YBCO thin film; coated conductor; inclined substrate deposition; biaxial texture ID YTTRIA-STABILIZED-ZIRCONIA; BEAM-ASSISTED DEPOSITION; THIN-FILMS; LASER DEPOSITION; BUFFER LAYERS; BICRYSTALS; YBA2CU3O7; TAPES; MGO AB Inclined substrate deposition (ISD) offers the potential for rapid production of high-quality biaxially textured buffer layers suitable for YBa2Cu3O7-delta (YBCO)-coated conductors. We have grown biaxially textured magnesium oxide (MgO) films on Hastelloy C276 (HC) substrates by ISD at deposition rates of 20-100 Angstrom/s. Scanning electron microscopy of the ISD MgO films showed columnar grain structures with a roof-tile-shaped surface. X-ray pole figure analysis revealed that the c-axis of the ISD MgO films is titled at an angle approximate to32degrees from the substrate normal. A small full-width at half maximum of approximate to9degrees was observed for the phi-scan of MgO films. YBCO films were grown on ISD MgO buffered HC substrates by pulsed laser deposition and were determined to be biaxially aligned with the c-axis parallel to the substrate normal. The orientation relationship between the ISD template and the top YBCO film was investigated by X-ray pole figure analysis and transmission electron microscopy. A transport critical current density of J(c) = 5.5 x 10(5) A/cm(2) at 77 K in self-field was measured on a YBCO film that was 0.46-mum thick, 4-mm wide, 10-mm long. (C) 2003 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Balachandran, U (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Koritala, Rachel/F-1774-2011; Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 17 TC 17 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT PY 2003 VL 392 BP 806 EP 814 DI 10.1016/S0921-4534(03)00790-1 PN 2 PG 9 WC Physics, Applied SC Physics GA 726PG UT WOS:000185607600006 ER PT J AU Tsukui, S Koritala, RE Li, M Goretta, KC Adachi, A Baker, JE Routbort, JL AF Tsukui, S Koritala, RE Li, M Goretta, KC Adachi, A Baker, JE Routbort, JL TI Oxygen and cation diffusion in YBCO coated conductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 15th International Symposium on Superconductivity (ISS 2002) CY NOV 11-13, 2002 CL YOKOHAMA, JAPAN DE oxygen diffusion; interdiffusion; YBCO; thin film ID TRACER DIFFUSION; TEXTURE DEVELOPMENT; SUPERCONDUCTORS; HG AB Biaxially textured YBa2Cu3Ox (YBCO) films 0.3 mum thick were deposited on single-crystal LaAlO3 and buffered Hastelloy C276 substrates. After annealing in O-18 at 400 degreesC, secondary-ion mass spectrometry was used to determine oxygen-diffusion profiles and several cation-diffusion profiles within the various layers of the conductors. Oxygenation in the YBCO/LaAlO3 specimen was relatively slow and hours would be required for full oxygenation of the YBCO. Oxygen diffusion was rapid in the coated conductor. It was dominated by diffusion along a-b planes and full oxygenation of a 0.3-mum-thick YBCO layer was achieved in several minutes. Cation interdiffusion was limited in the YBCO/LaAlO3 specimen, but was significant within the coated conductor. Although Cu diffused out of the superconductor, an SrTiO3 layer between textured MgO and YBCO limited diffusion of cations from the various substrate layers into the superconductor. (C) 2003 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Univ Osaka Prefecture, Osaka 5998570, Japan. Univ Illinois, Ctr Microanal Mat, Urbana, IL 61801 USA. RP Routbort, JL (reprint author), Argonne Natl Lab, Div Energy Technol, ET-212, Argonne, IL 60439 USA. RI Koritala, Rachel/F-1774-2011 NR 18 TC 9 Z9 9 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT PY 2003 VL 392 BP 841 EP 846 DI 10.1016/S0921-4534(03)01132-8 PN 2 PG 6 WC Physics, Applied SC Physics GA 726PG UT WOS:000185607600011 ER PT J AU Gouge, MJ Cole, MJ Demko, JA Fisher, PW Foster, CA Grabovickic, R Lindsay, DT Lue, JW Roden, ML Tolbert, JC AF Gouge, MJ Cole, MJ Demko, JA Fisher, PW Foster, CA Grabovickic, R Lindsay, DT Lue, JW Roden, ML Tolbert, JC TI High-temperature superconducting tri-axial power cable SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 15th International Symposium on Superconductivity (ISS 2002) CY NOV 11-13, 2002 CL YOKOHAMA, JAPAN DE superconducting cable; superconducting power applications ID HTS CABLES AB Encouraged by the positive test results of a 1.5-m long prototype tri-axial cable, the Southwire/ORNL team has conceived, designed and built a 5-m tri-axial cable with three-phase terminations. The three concentric superconducting phases are made of BSCCO-2223 HTS tapes, separated by layers of cold-dielectric tape. A copper braid is added as the grounding shield. The completed tri-axial cable is enclosed in a flexible cryostat. Cooling of the cable and terminations is achieved by liquid nitrogen flowing through the annulus between the cable and the cryostat. The terminations used in the cable tests are cooled by a separate liquid nitrogen stream. The resulting three-phase, cold dielectric, cable and termination design is nearly as compact as the single-phase, co-axial design developed previously by Southwire/ORNL and represents the highest known cable current density achievable in an electric AC power cable. DC testing of the 5-m cable includes V-I curves for each of the concentric HTS phases, cable heat loads at varying DC currents, liquid nitrogen flow-pressure measurements, and over-current tests. AC testing of the cable includes ac loss measurements, induced-current in the Cu-shield measurements and operation at the line voltage test. The ac losses are measured calorimetrically by measuring the temperature differential of the coolant across the cable length due to the ac loss in the superconductors. Both balanced and un-balanced currents among the three phases are used in ac loss and induced current measurements. (C) 2003 Elsevier B.V. All rights reserved. C1 Oak Ridge Natl Lab, Appl Superconduct Grp, Oak Ridge, TN 37831 USA. Southwire Co, Carrollton, GA 30119 USA. RP Gouge, MJ (reprint author), Oak Ridge Natl Lab, Appl Superconduct Grp, POB 2009,MS 8071, Oak Ridge, TN 37831 USA. NR 12 TC 9 Z9 10 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD OCT PY 2003 VL 392 BP 1180 EP 1185 DI 10.1016/S0921-4534(03)00788-3 PN 2 PG 6 WC Physics, Applied SC Physics GA 726PG UT WOS:000185607600075 ER PT J AU Paul, MR Chiam, KH Cross, MC Fischer, PF Greenside, HS AF Paul, MR Chiam, KH Cross, MC Fischer, PF Greenside, HS TI Pattern formation and dynamics in Rayleigh-Benard convection: Numerical simulations of experimentally realistic geometries SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article; Proceedings Paper CT Conference on Complexity and Nonlinearity in Physical Systems held in Honor of Alan Newell CY NOV, 2001 CL UNIV ARIZONA, TUCSON, ARIZONA HO UNIV ARIZONA DE Rayleigh-Benard convection; nonequilibrium systems; Boussinesq equations ID WAVE-NUMBER SELECTION; SPIRAL DEFECT CHAOS; MEAN FLOW; TURBULENCE; EQUILIBRIUM; INSTABILITY; EQUATIONS; SYSTEMS; MODEL; ONSET AB Rayleigh-Benard convection is studied and quantitative comparisons are made, where possible, between theory and experiment by performing numerical simulations of the Boussinesq equations for a variety of experimentally realistic situations. Rectangular and cylindrical geometries of varying aspect ratios for experimental boundary conditions, including fins and spatial ramps in plate separation, are examined with particular attention paid to the role of the mean flow. A small cylindrical convection layer bounded laterally either by a rigid wall, fin, or a ramp is investigated and our results suggest that the mean flow plays an important role in the observed wavenumber. Analytical results are developed quantifying the mean flow sources, generated by amplitude gradients, and its effect on the pattern wavenumber for a large-aspect-ratio cylinder with a ramped boundary. Numerical results are found to agree well with these analytical predictions. We gain further insight into the role of mean flow in pattern dynamics by employing a novel method of quenching the mean flow numerically. Simulations of a spiral defect chaos state where the mean flow is suddenly quenched is found to remove the time dependence, increase the wavenumber and make the pattern more angular in nature. Published by Elsevier B.V. C1 CALTECH, Dept Phys, Pasadena, CA 91125 USA. Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. RP Paul, MR (reprint author), CALTECH, Dept Phys, 114-36, Pasadena, CA 91125 USA. RI Paul, Mark/E-3567-2014 OI Paul, Mark/0000-0002-0701-1955 NR 29 TC 22 Z9 22 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD OCT 1 PY 2003 VL 184 IS 1-4 BP 114 EP 126 DI 10.1016/S0167-2789(03)00216-1 PG 13 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 735PK UT WOS:000186123600008 ER PT J AU Jupen, C Denne-Hinnov, B Martinson, I Curtis, LJ AF Jupen, C Denne-Hinnov, B Martinson, I Curtis, LJ TI Additions to the spectra of highly ionized molybdenum, Mo XXIV-Mo XXVIII SO PHYSICA SCRIPTA LA English DT Article ID I ISOELECTRONIC SEQUENCE; MAGNETIC DIPOLE LINES; PRINCETON LARGE TORUS; TOKAMAK DISCHARGES; PLT TOKAMAK; COPPER; TRANSITIONS; KR; IDENTIFICATION; WAVELENGTHS AB We have observed radiation from highly charged molybdenum ions in the JET tokamak plasmas. Spectra were recorded in the wavelength range 70-110 Angstrom, resulting in the classification of 15 new n = 3. Deltan = 0 transitions in Mo XXIV-Mo XXVIII. C1 Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. Lund Univ, SE-22100 Lund, Sweden. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Curtis, LJ (reprint author), Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. NR 22 TC 3 Z9 3 U1 0 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PD OCT PY 2003 VL 68 IS 4 BP 230 EP 232 DI 10.1238/Physica.Regular.068a00230 PG 3 WC Physics, Multidisciplinary SC Physics GA 737XA UT WOS:000186256000007 ER PT J AU Meloni, G Ferguson, MJ Neumark, DM AF Meloni, G Ferguson, MJ Neumark, DM TI Negative ion photodetachment spectroscopy of the Al3O2, Al3O3, Al4Ox, Al5Ox, (x=3-5), Al6O5, and Al7O5 clusters SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID ANION PHOTOELECTRON-SPECTROSCOPY; INDIUM-PHOSPHIDE CLUSTERS; ELECTRONIC-STRUCTURE; SPECTRA; PHOTOISOMERIZATION AB The Al3O2, Al3O3, Al4Ox, Al5Ox (x = 3-5), Al6O5, and Al7O5 clusters are studied using negative ion photoelectron spectroscopy. At 266 nm (4.661 eV) laser photodetachment wavelength the spectra of Al3O2 and Al3O3 present vibrationally resolved features. They show three electronic transitions, due to two different isomers. From Franck-Condon simulations of the Al3O2 and Al3O3 photoelectron spectra, several vibrational frequencies together with the normal coordinate changes were derived. We obtained approximate electron affinities for Al3O2 and Al3O3 using the Gaussian 2 model, and calculated isomerization energies for both the anionic and neutral geometries and the experimental adiabatic detachment energies (ADE) of bands X' and X. The larger aluminum oxide clusters present several structureless bands which likely also result from multiple isomers. The ADEs for the larger clusters increase with size within a cluster series, with the exception of Al5O5. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Meloni, G (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 26 TC 29 Z9 29 U1 1 U2 9 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PD OCT 1 PY 2003 VL 5 IS 19 BP 4073 EP 4079 DI 10.1039/b308119b PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 736LY UT WOS:000186173300003 ER PT J AU Arenz, M Stamenkovic, V Schmidt, TJ Wandelt, K Ross, PN Markovic, NM AF Arenz, M Stamenkovic, V Schmidt, TJ Wandelt, K Ross, PN Markovic, NM TI The electro-oxidation of formic acid on Pt-Pd single crystal bimetallic surfaces SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID MODIFIED STEPPED ELECTRODES; SMALL ORGANIC-MOLECULES; INFRARED-SPECTROSCOPY; PLATINUM-ELECTRODES; PT(111) ELECTRODES; RU ALLOYS; ELECTROCHEMICAL-BEHAVIOR; CARBON-MONOXIDE; CO ADSORPTION; OXIDATION AB The interrelationship between the macroscopic kinetic rate of HCOOH oxidation in 0.1 M HClO4 solution and the morphology/composition of the electrode is studied on Pt(111) modified by Pd (denoted hereafter as the Pt(111)-Pd-xML system, 0 < x < 1) and on Pt-Pd bulk single crystal alloy surfaces (denoted hereafter as the PtPdxat%(111) system, x = 6 and x = 25). The Pd surface composition of the Pt(111)-Pd-xML and PtPdxat%(111) electrodes was established previously ex-situ by low energy ion scattering (LEIS) measurements. The nature of adsorbed intermediates (COad) and the electrocatalytic properties (the onset of CO2 formation) at the Pt(111)-Pd-xML and the PtPdxat%(111) interface were studied by FTIR spectroscopy. The results show that Pd atoms either on the Surface or in the Surface have an unique catalytic activity for HCOOH oxidation, with Pd atoms being three (bulk alloys) or five times (Pd films) more active than Pt atoms at 0.4 V. FTIR spectra reveal that on Pt atoms adsorbed CO is produced from dehydration of HCOOH, whereas no CO adsorbed on Pd can be detected although a high production rate of CO, is observed at low potentials, indicating that the reaction can proceed on Pd at low potentials without the Pt typical "poison" formation. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Bonn, Inst Phys & Theoret Chem, D-53115 Bonn, Germany. RP Arenz, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Schmidt, Thomas/A-2586-2010; Arenz, Matthias/C-7385-2009; Arenz, Matthias/C-3195-2016 OI Schmidt, Thomas/0000-0002-1636-367X; Arenz, Matthias/0000-0001-9765-4315; Arenz, Matthias/0000-0001-9765-4315 NR 46 TC 147 Z9 153 U1 7 U2 62 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PD OCT 1 PY 2003 VL 5 IS 19 BP 4242 EP 4251 DI 10.1039/b306307k PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 736LY UT WOS:000186173300028 ER PT J AU Ballard, JB Arrowsmith, AN Huwel, L Dai, XC Leone, SR AF Ballard, JB Arrowsmith, AN Huwel, L Dai, XC Leone, SR TI Inducing a sign inversion in one state of a two-state superposition using ultrafast pulse shaping SO PHYSICAL REVIEW A LA English DT Article ID FEMTOSECOND WAVE-PACKET; QUANTUM COMPUTATION; LI-2; ALGORITHM; IMPLEMENTATION; OPTIMIZATION; SPECTROSCOPY; COHERENCES; COMPUTER; PHASE AB An ultrafast pulse shaping scheme is presented that transiently modifies a two-state superposition on the E(l)Sigma(g)(+) curve of the lithium dimer. At short time delays, the wave-function amplitude of one of the states is forced to undergo a sign change, while the sign of the second state is programmed to remain static, analogous to the operation of a quantum-computational Z gate. This is observed as a pi phase shift in the time-dependent wave-packet signal for pump-probe delays <1.5 ps, relative to longer time. delays, greater than 2.5 ps. This shift in sign is accomplished by taking advantage of the separability of the resonant and nonresonant light field effects in the creation of the excited-state wave function. The results show that, for a single state, the resonant and nonresonant light field effects can either be added or subtracted to create the total time evolution of the excited-state wave-function coefficient. If the nonresonant contributions are subtracted from the resonant ones at a time delay when the nonresonant term dominates, then for a short time the excited-state coefficient will have a sign opposite to that at long time, where the resonant term dominates. A desired phase function is derived to produce the opposition in sign of resonant versus nonresonant contributions, and the experimental transient Z-gate matrix elements are quantified. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Ballard, JB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Dai, Xingcan/B-3556-2014 NR 31 TC 6 Z9 8 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 043409 DI 10.1103/PhysRevA.68.043409 PN B PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 770EZ UT WOS:000188711400009 ER PT J AU Bannister, AE Krause, HF Vane, CR Djuric, N Popovic, DB Stepanovic, M Dunn, GH Chung, YS Smith, ACH Wallbank, B AF Bannister, AE Krause, HF Vane, CR Djuric, N Popovic, DB Stepanovic, M Dunn, GH Chung, YS Smith, ACH Wallbank, B TI Electron-impact dissociation of CH(+) ions: Measurement of C(+) fragment ions SO PHYSICAL REVIEW A LA English DT Article ID ABSOLUTE CROSS-SECTIONS; MOLECULAR-IONS; STATE; RECOMBINATION; IONIZATION; TRANSITION; COLLISION; PLASMA; EXCITATION; B3-SIGMA AB Absolute cross sections for electron-impact dissociation of CH(+) producing C(+) fragment ions were measured in the 3-100 eV range using a crossed electron-ion beams technique with total uncertainties of about 10% near the cross-section peak. Although the measured energy dependence agrees well with two sets of storage ring measurements, the magnitude of the present results lies about 15-25 % below the other results at the cross-section peak near 40 eV. Below 10 eV, the present data tend to exceed the storage ring data, consistent with the presence of excited states in the CH(+) ion beam. For energies above 29 eV, the cross sections should also include contributions from dissociative ionization, though no clear onset of this channel is evident in any of the three sets of measured data. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Chungnam Natl Univ, Dept Phys, Taejon 305764, South Korea. UCL, Dept Phys & Astron, London WC1E 6BT, England. St Francis Xavier Univ, Dept Phys, Antigonish, NS B2G 2W5, Canada. RP Bannister, AE (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM bannisterme@ornl.gov NR 32 TC 3 Z9 3 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 042714 DI 10.1103/PhysRevA.68.042714 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 750PJ UT WOS:000187004700072 ER PT J AU Gurvits, L Barnum, H AF Gurvits, L Barnum, H TI Separable balls around the maximally mixed multipartite quantum states SO PHYSICAL REVIEW A LA English DT Article ID ENTANGLEMENT AB We show that for an m-partite quantum system, there is a ball of radius 2(-(m/2-1)) in Frobenius norm, centered at the identity matrix, of separable (unentangled) positive semidefinite matrices. This can be used to derive an epsilon below which mixtures of epsilon of any density matrix with 1 - epsilon of the maximally mixed state will be separable. The epsilon thus obtained is exponentially better (in the number of systems) than existing results. This gives a number of qubits below which nuclear magnetic resonance with standard pseudopure-state preparation techniques can access only unentangled states; with parameters realistic for current experiments, this is 23 qubits (compared to 13 qubits via earlier results). A ball of radius 1 is obtained for multipartite states separable over the reals. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, CCS-3,Mail Stop B256, Los Alamos, NM 87545 USA. NR 11 TC 50 Z9 50 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 042312 DI 10.1103/PhysRevA.68.042312 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 750PJ UT WOS:000187004700031 ER PT J AU Peshkin, M AF Peshkin, M TI Reply to "Comment on 'Spin and statistics in nonrelativistic quantum mechanics: The spin-zero case"' SO PHYSICAL REVIEW A LA English DT Editorial Material ID INDISTINGUISHABILITY; PARTICLES AB The preceding Comment states that I have assumed the conclusion in my proof from nonrelativistic quantum mechanics that spin-zero particles must be bosons, and that the theory presented is different from standard quantum mechanics. I show here that neither of those statements is true. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. EM peshkin@anl.gov RI Peshkin, Michael/B-7604-2009 NR 5 TC 7 Z9 7 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 046102 DI 10.1103/PhysRevA.68.046102 PN B PG 2 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 770EZ UT WOS:000188711400078 ER PT J AU Sapirstein, J Cheng, KT AF Sapirstein, J Cheng, KT TI Vacuum polarization calculations for hydrogenlike and alkali-metal-like ions SO PHYSICAL REVIEW A LA English DT Article ID LAMB-SHIFT; POTENTIALS; ACCURATE; ENERGY; FIELD; U89+ AB Complete vacuum polarization calculations incorporating finite nuclear size are presented for hydrogenic ions with principal quantum numbers n = 1 -5. Lithiumlike, sodiumlike, and copperlike ions are also treated starting with Kohn-Sham potentials, and including first-order screening corrections. In both cases dominant Uehling terms are calculated with high accuracy, and smaller Wichmann-Kroll terms are obtained using numerical electron Green's functions. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sapirstein, J (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 22 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 042111 DI 10.1103/PhysRevA.68.042111 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 750PJ UT WOS:000187004700017 ER PT J AU Takabayashi, Y Ito, T Azuma, T Komaki, K Yamazaki, Y Tawara, H Takada, E Murakami, T Seliger, M Tokesi, K Reinhold, CO Burgdorfer, J AF Takabayashi, Y Ito, T Azuma, T Komaki, K Yamazaki, Y Tawara, H Takada, E Murakami, T Seliger, M Tokesi, K Reinhold, CO Burgdorfer, J TI Excited-state evolution probed by convoy-electron emission in relativistic heavy-ion collisions SO PHYSICAL REVIEW A LA English DT Article ID THIN FOILS; H-IONS; ANGULAR-DISTRIBUTIONS; CONTINUUM CUSPS; ATOM COLLISIONS; HYDROGEN; CAPTURE; CARBON; SOLIDS; TRANSMISSION AB We present a joint experimental and theoretical study of convoy-electron emission resulting from highly-charged-ion transport through carbon foils at moderately relativistic speeds. Energy spectra of electrons ejected at 0degrees have been measured for 390 MeV/u hydrogen-like Ar17+ ions and 460 MeV/u (beta=nu/c=0.74,gamma = 1.49) Fe25+ (1s), Fe24+ (1s(2)), and Fe23+ (1s(2) 2s) incident on carbon foils with thicknesses from 25 to 8700 mug/cm(2). Due to this unprecedented wide range of thicknesses, the sequential excitation and ionization of initially deeply bound electrons to highly excited states and continuum states can be followed in considerable detail. The analysis of the spectra is aided by simulations based on the classical transport theory which has been extended to relativistic energies and to multielectron projectiles. The motion of the projectile electron inside the solid target is calculated taking into account the Coulomb potential of the projectile ion and the multiple stochastic collisions with target cores and target electrons. Different phases of the convoy-electron emissions can be disentangled: direct ejection to the continuum, the transient buildup of an excited-state wave packet followed by ionization, and postionization modification of the continuum spectrum. We find good agreement between experiment and simulation for the evolution of charge states and the emission spectrum. C1 Univ Tokyo, Grad Sch Arts & Sci, Inst Phys, Meguro Ku, Tokyo 1538902, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 1920397, Japan. RIKEN, Atom Phys Lab, Wako, Saitama 3510198, Japan. Natl Inst Fus Sci, Gifu 5095292, Japan. Natl Inst Radiol Sci, Inage Ku, Chiba 2638555, Japan. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. Hungarian Acad Sci, Inst Nucl Res, ATOMKI, H-4001 Debrecen, Hungary. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Takabayashi, Y (reprint author), Univ Tokyo, Grad Sch Arts & Sci, Inst Phys, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan. RI Azuma, Toshiyuki/B-7471-2015; Yamazaki, Yasunori/N-8018-2015 OI Yamazaki, Yasunori/0000-0001-5712-0853 NR 34 TC 6 Z9 6 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 042703 DI 10.1103/PhysRevA.68.042703 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 750PJ UT WOS:000187004700061 ER PT J AU Trabert, E Beiersdorfer, P Lepson, JK Chen, H AF Trabert, E Beiersdorfer, P Lepson, JK Chen, H TI Extreme ultraviolet spectra of highly charged Xe ions SO PHYSICAL REVIEW A LA English DT Article ID BORON ISOELECTRONIC SEQUENCE; MANY-BODY CALCULATIONS; MG-LIKE IONS; CONFIGURATION-INTERACTION CALCULATION; PERTURBATION-THEORY CALCULATIONS; ENERGY-LEVEL SCHEME; ZN-LIKE IONS; CU-LIKE IONS; TRANSITION-PROBABILITIES; NA-LIKE AB Using the SuperEBIT electron-beam ion trap and a flat-field spectrometer, we observed extreme ultraviolet spectra of highly charged ions of Xe and measured the wavelengths of prominent lines from Li-, Be-, B-, Na-, and Mg-like ions. Our results for Li- and Na-like ions are as precise as the best available elsewhere. The results for Be-, B-, and Mg-like ions are much more precise than available data or extend those available from lower-Z ions and reveal significant shortcomings of the various theoretical predictions. C1 Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, High Temp & Astrophys Div, Livermore, CA 94550 USA. Univ Calif Berkeley, Berkeley, CA 94039 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. RP Trabert, E (reprint author), Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, High Temp & Astrophys Div, Livermore, CA 94550 USA. NR 61 TC 31 Z9 31 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD OCT PY 2003 VL 68 IS 4 AR 042501 DI 10.1103/PhysRevA.68.042501 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 750PJ UT WOS:000187004700051 ER PT J AU Aselage, TL Emin, D McCready, SS Venturini, EL Rodriguez, MA Voigt, JA Headley, TJ AF Aselage, TL Emin, D McCready, SS Venturini, EL Rodriguez, MA Voigt, JA Headley, TJ TI Metal-semiconductor and magnetic transitions in compensated polycrystalline La1-xCaxMnO3-delta (x=0.20,0.25) SO PHYSICAL REVIEW B LA English DT Article ID DOUBLE EXCHANGE; PHASE-DIAGRAM; FERROMAGNETIC SEMICONDUCTOR; COLOSSAL MAGNETORESISTANCE; THERMOELECTRIC-POWER; TRANSPORT-PROPERTIES; RESISTIVITY; MOTION; LA1-XSRXMNO3; CONDUCTIVITY AB The structures, magnetizations, conductivities, and Seebeck coefficients of single-phase polycrystalline La0.75Ca0.25MnO3-delta and La0.80Ca0.20MnO3-delta samples have been investigated as a function of the oxygen-vacancy concentration. Electrons from oxygen vacancies compensate holes introduced by Ca cations. Thus, by altering the oxygen deficiency delta the carrier concentration is changed while the calcium concentration remains constant. The effects of carrier and calcium concentrations on transport and magnetism are thereby separated from one another. We find the conductivity to be very sensitive to oxygen vacancies while the magnetization is not. In particular, oxygen vacancies decrease the conductivity and can eliminate low-temperature metal-like conduction. Thus ferromagnetism in La0.75Ca0.25MnO3-delta and La0.80Ca0.20MnO3-delta can occur without the concomitant occurrence of metallic conduction. However, electronic properties are sensitive to magnetic order. In particular, the temperature dependence of the Seebeck coefficient changes at the Curie temperature. These results are consistent with Jonker's suggestion that ferromagnetism in these manganites is induced by dopant-induced strains rather than by dopant-induced charge carriers. Loss of magnetic order fosters mobile charge carriers' collapse to localized dopant-related polaron states. Thus, the magnetically induced metal-semiconductor transitions in doped manganites are analogous to those of suitably doped ferromagnetic EuO. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Aselage, TL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 44 TC 20 Z9 21 U1 2 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134448 DI 10.1103/PhysRevB.68.134448 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400102 ER PT J AU Bai, JM AF Bai, JM TI Atomic scattering factor for a spherical wave and near-field effects in x-ray fluorescence holography SO PHYSICAL REVIEW B LA English DT Article ID RESOLUTION AB A formula for calculating the atomic scattering factor for spherical x-ray waves is derived and used to solve the near field effects problem in x-ray fluorescence holography theory. A rigorous formalism to calculate the x-ray fluorescence hologram is then given so that quantitative structural information can be obtained from these holographic measurements. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bai, JM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Bai, Jianming/O-5005-2015 NR 14 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 144109 DI 10.1103/PhysRevB.68.144109 PG 7 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500025 ER PT J AU Bill, A Morawitz, H Kresin, VZ AF Bill, A Morawitz, H Kresin, VZ TI Electronic collective modes and superconductivity in layered conductors SO PHYSICAL REVIEW B LA English DT Article ID ZIRCONIUM NITRIDE CHLORIDE; HIGH-TC SUPERCONDUCTIVITY; MANY-BODY PROBLEM; ORGANIC SUPERCONDUCTOR; PAIRING MECHANISM; PLASMON MECHANISM; HAFNIUM NITRIDE; BAND-STRUCTURE; GAS; TEMPERATURE AB A distinctive feature of layered conductors is the presence of low-energy electronic collective modes of the conduction electrons. This affects the dynamic screening properties of the Coulomb interaction in a layered material. We study the consequences of the existence of these collective modes for superconductivity. General equations for the superconducting order parameter are derived within the strong-coupling phonon-plasmon scheme that accounts for the screened Coulomb interaction. Specifically, we calculate the superconducting critical temperature T-c taking into account the full temperature, frequency, and wave-vector dependence of the dielectric function. We show that low-energy plasmons may contribute constructively to superconductivity. Three classes of layered superconductors are discussed within our model: metal-intercalated halide nitrides, layered organic materials, and high-T-c oxides. In particular, we demonstrate that the plasmon contribution (electronic mechanism) is dominant in the first class of layered materials. The theory shows that the description of so-called "quasi-two-dimensional superconductors" cannot be reduced to a purely two-dimensional model, as commonly assumed. While the transport properties are strongly anisotropic, it remains essential to take into account the screened interlayer Coulomb interaction to describe the superconducting state of layered materials. C1 Paul Scherrer Inst, CH-5232 Villigen, Switzerland. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Ulm, Inst Theoret Phys, D-89069 Ulm, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Paul Scherrer Inst, CH-5232 Villigen, Switzerland. NR 77 TC 60 Z9 60 U1 2 U2 16 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 144519 DI 10.1103/PhysRevB.68.144519 PG 12 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500087 ER PT J AU Caux, JS Essler, FHL Low, U AF Caux, JS Essler, FHL Low, U TI Dynamical structure factor of the anisotropic Heisenberg chain in a transverse field SO PHYSICAL REVIEW B LA English DT Article ID SPIN-CORRELATION-FUNCTIONS; MAGNETIC-FIELD; XY-MODEL; STATISTICAL MECHANICS; COPPER BENZOATE; ENERGY; TEMPERATURE; ZERO AB We consider the anisotropic Heisenberg spin-1/2 chain in a transverse magnetic field at zero temperature. We first determine all components of the dynamical structure factor by combining exact results with a mean-field approximation recently proposed by Dmitriev et al. [JETP 95, 538 (2002)]. We then turn to the small anisotropy limit, in which we use field theory methods to obtain exact results. We discuss the relevance of our results to neutron scattering experiments on the one-dimensional Heisenberg chain compound Cs2CoCl4. C1 Univ Amsterdam, ITFA, NL-1018 XE Amsterdam, Netherlands. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Cologne, Inst Theoret Phys, D-50937 Cologne, Germany. RP Univ Amsterdam, ITFA, Valckenierstr 65, NL-1018 XE Amsterdam, Netherlands. NR 39 TC 38 Z9 38 U1 1 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134431 DI 10.1103/PhysRevB.68.134431 PG 12 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400085 ER PT J AU Chung, EML Paul, DM Balakrishnan, G Lees, MR Ivanov, A Yethiraj, M AF Chung, EML Paul, DM Balakrishnan, G Lees, MR Ivanov, A Yethiraj, M TI Role of electronic correlations on the phonon modes of MnO and NiO SO PHYSICAL REVIEW B LA English DT Article ID ANTIFERROMAGNETIC TRANSITION; LATTICE-DYNAMICS; SPIN-WAVES; ABSORPTION AB The possibility of magnetic-order induced phonon anisotropy in single crystals of MnO and NiO is investigated using inelastic neutron scattering. Below T-N both compounds exhibit a splitting in their transverse-optical phonon spectra of approximately 10%. This behavior illustrates that, contrary to general assumption, the dynamic properties of MnO and NiO are substantially noncubic. C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Chung, EML (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RI Lees, Martin/D-9584-2013; Balakrishnan, Geetha/P-5977-2016 OI Lees, Martin/0000-0002-2270-2295; Balakrishnan, Geetha/0000-0002-5890-1149 NR 17 TC 18 Z9 18 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 140406 DI 10.1103/PhysRevB.68.140406 PG 4 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500010 ER PT J AU Coldea, R Tennant, DA Tylczynski, Z AF Coldea, R Tennant, DA Tylczynski, Z TI Extended scattering continua characteristic of spin fractionalization in the two-dimensional frustrated quantum magnet Cs2CuCl4 observed by neutron scattering SO PHYSICAL REVIEW B LA English DT Article ID ANISOTROPIC TRIANGULAR LATTICE; RESONATING-VALENCE-BOND; HEISENBERG-ANTIFERROMAGNET; SQUARE-LATTICE; PHASE-DIAGRAM; GROUND-STATES; LINEAR-CHAIN; 2 DIMENSIONS; FIELD; MAGNETIZATION AB The magnetic excitations of the quasi-2D spin-1/2 frustrated Heisenberg antiferromagnet Cs2CuCl4 are explored throughout the 2D Brillouin zone using high-resolution time-of-flight inelastic neutron scattering. Measurements are made both in the magnetically ordered phase, stabilized at low temperatures by the weak interlayer couplings, as well as in the spin liquid phase above the ordering temperature T-N, when the 2D magnetic layers are decoupled. In the spin liquid phase the dynamical correlations are dominated by highly dispersive excitation continua, a characteristic signature of fractionalization of S=1 spin waves into pairs of deconfined S=1/2 spinons and the hallmark of a resonating-valence-bond (RVB) state. The boundaries of the excitation continua have strong 2D-modulated incommensurate dispersion relations. Upon cooling below T-N magnetic order in an incommensurate spiral forms due to the 2D frustrated couplings. In this phase sharp magnons carrying a small part of the total scattering weight are observed at low energies, but the dominant continuum scattering which occurs at medium to high energies is essentially unchanged compared to the spin liquid phase. Linear spin-wave theory including one- and two-magnon processes can describe the sharp magnon excitation, but not the dominant continuum scattering, which instead is well described by a parametrized two-spinon cross section. Those results suggest a crossover in the nature of the excitations from S=1 spin waves at low energies to deconfined S=1/2 spinons at medium to high energies, which could be understood if Cs2CuCl4 was in the close proximity of transition between a fractional RVB spin liquid and a magnetically ordered state. A large renormalization factor of the excitation energies [R=1.63(5)], indicating strong quantum fluctuations in the ground state, is obtained using the exchange couplings determined from saturation-field measurements. We provide an independent consistency check of this quantum renormalization factor using measurements of the second moment of the paramagnetic scattering. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS Facil, Didcot OX11 0QX, Oxon, England. Adam Mickiewicz Univ, Inst Phys, PL-61614 Poznan, Poland. RP Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI Tennant, David/Q-2497-2015 OI Tennant, David/0000-0002-9575-3368 NR 49 TC 153 Z9 153 U1 3 U2 28 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134424 DI 10.1103/PhysRevB.68.134424 PG 16 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400078 ER PT J AU Granado, E Ling, CD Neumeier, JJ Lynn, JW Argyriou, DN AF Granado, E Ling, CD Neumeier, JJ Lynn, JW Argyriou, DN TI Inhomogeneous magnetism in La-doped CaMnO3. II. Nanometric-scale spin clusters and long-range spin canting SO PHYSICAL REVIEW B LA English DT Article ID DOUBLE-EXCHANGE MODEL; FERROMAGNETIC KONDO MODEL; PHASE-SEPARATION; NEUTRON-SCATTERING; ELECTRONIC MODELS; MANGANITES; DIAGRAM; ANTIFERROMAGNETISM; MAGNETORESISTANCE; RESISTIVITY AB Neutron measurements on Ca1-xLaxMnO3 (0.00less than or equal toxless than or equal to0.20) reveal the development of magnetic droplets showing a liquidlike intercluster spatial distribution. The average size of the droplets is similar to10 Angstrom, the concentration of which in the G-AFM matrix being proportional to x (one cluster per similar to60 doped electrons). In addition, a long-range ordered ferromagnetic component is observed for 0.05less than or similar toxless than or similar to0.14. This component is perpendicularly coupled to the simple G-type antiferromagnetic (G-AFM) structure of the undoped compound, which is a signature of a G-AFM+FM spin-canted state. The possible relationship between cluster formation and the stabilization of a long-range spin canting for intermediate doping is discussed. C1 Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. Lab Nacl Luz Sincrotron, BR-13084971 Campinas, SP, Brazil. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. EM granado@lnls.br RI Ling, Chris D/B-2228-2009; Granado, Eduardo/F-5389-2012 OI Ling, Chris D/0000-0003-2205-3106; NR 32 TC 70 Z9 70 U1 0 U2 17 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134440 DI 10.1103/PhysRevB.68.134440 PG 6 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400094 ER PT J AU Jung, MH Kim, HC Migliori, A Galli, F Mydosh, JA AF Jung, MH Kim, HC Migliori, A Galli, F Mydosh, JA TI Magnetic-field and pressure effects on charge-density-wave, superconducting, and magnetic states in Lu5Ir4Si10 and Er5Ir4Si10 SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL; TRANSITION AB We have studied the charge-density-wave (CDW) state for the superconducting Lu5Ir4Si10 and the antiferromagnetic Er5Ir4Si10 as variables of temperature, magnetic field, and hydrostatic pressure. There is monotonic suppression of the CDW state in Lu5Ir4Si10, while there is complex pressure effect on the CDW states of Er5Ir4Si10. In addition, Er5Ir4Si10 shows negative magnetoresistance at low temperatures, compared with the positive magnetoresistance of Lu5Ir4Si10. The present results suggest that the CDW and magnetism could be coupled because of the presence of f electrons with the local magnetic moment in Er5Ir4Si10. C1 Korea Basic Sci Inst, Mat Sci Lab, Taejon 305333, South Korea. Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. RP Jung, MH (reprint author), Korea Basic Sci Inst, Mat Sci Lab, Taejon 305333, South Korea. NR 14 TC 8 Z9 8 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 132102 DI 10.1103/PhysRevB.68.132102 PG 4 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400002 ER PT J AU Krcmar, M Fu, CL AF Krcmar, M Fu, CL TI First-principles study of point-defect structures in C15 ZrCo2 and ZrCr2 and B2 ZrCo SO PHYSICAL REVIEW B LA English DT Article ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; LAVES-PHASE; INTERMETALLIC COMPOUNDS; ELECTRONIC-STRUCTURE; ENTHALPIES; SYSTEM; ALLOYS AB Two intermetallic compounds ZrCo2 and ZrCr2 with the same close-packed C15 structure but significantly different heat-of-formation values are chosen to examine any possible differences in the point defect structures from the first-principles calculations. Although there is a substantial mismatch in the atomic size between constituent atoms, we find no evidence for the existence of constitutional vacancies for both compounds on either side of stoichiometry. By contrast, in ZrCo compound with the open B2 structure and a heat-of-formation nearly as high as that of ZrCo2, the point defect structure is characterized by the existence of triple defects (two vacancies at the Co sites accompanied by the Co antisite defect at the Zr sublattice), typical for the strongly ordered systems. Our analysis shows that, regardless of the degree of ordering, maintaining high coordination number is a preferred bonding mode for atoms in a topologically close-packed structure. On the other hand, the defect structure in the open B2 structure appears to be governed by the atomic size factor once the bonding states are fully occupied. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Krcmar, M (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 26 TC 2 Z9 2 U1 1 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134110 DI 10.1103/PhysRevB.68.134110 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400038 ER PT J AU Latyshev, YI Koshelev, AE Bulaevskii, LN AF Latyshev, YI Koshelev, AE Bulaevskii, LN TI Probing quasiparticle dynamics in Bi2Sr2CaCu2O8+delta with a driven Josephson vortex lattice SO PHYSICAL REVIEW B LA English DT Article ID D-WAVE SUPERCONDUCTORS; PARALLEL MAGNETIC-FIELDS; SINGLE-CRYSTAL WHISKERS; T-C SUPERCONDUCTORS; THERMAL-CONDUCTIVITY; UNCONVENTIONAL SUPERCONDUCTORS; PENETRATION DEPTH; TRANSPORT; IMPURITIES; JUNCTIONS AB We show that the flux-flow transport of the Josephson vortex lattice (JVL) in layered high-temperature superconductors provides a convenient probe for both components of quasiparticle conductivity, sigma(c) and sigma(ab). We found that the JVL flux-flow resistivity, rho(ff), in a wide range of magnetic fields is mainly determined by the in-plane dissipation. In the dense lattice regime (B>1 T) the rho(ff)(B) dependence is well fitted by the theoretical formula for that limit. That allows us to independently extract from the experimental data the values of sigma(c) and of the ratio sigma(ab)/(sigma(c)gamma(4)). The extracted temperature dependence sigma(ab)(T) is consistent with microwave data. The shape of the current-voltage characteristics is also sensitive to the frequency dependence of sigma(ab), which allows us to estimate the quasiparticle relaxation time and relate it to the impurity bandwidth using data obtained for the same crystal. C1 Russian Acad Sci, Inst Radioengn & Elect, Moscow 101999, Russia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Latyshev, YI (reprint author), Russian Acad Sci, Inst Radioengn & Elect, Mokhovaya 11-7, Moscow 101999, Russia. RI Koshelev, Alexei/K-3971-2013 OI Koshelev, Alexei/0000-0002-1167-5906 NR 52 TC 27 Z9 27 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134504 DI 10.1103/PhysRevB.68.134504 PG 10 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400111 ER PT J AU Lee, BJ Shim, JH Baskes, MI AF Lee, BJ Shim, JH Baskes, MI TI Semiempirical atomic potentials for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, Al, and Pb based on first and second nearest-neighbor modified embedded atom method SO PHYSICAL REVIEW B LA English DT Article ID SURFACE FREE-ENERGIES; SILICON; ALLOYS; ELEMENTS AB Modified embedded atom method (MEAM) potentials for fcc elements Cu, Ag, Au, Ni, Pd, Pt, Al, and Pb have been newly developed using the original first nearest-neighbor MEAM and the recently developed second nearest-neighbor MEAM formalisms. It was found that the original MEAM potentials for fcc elements show some critical shortcomings such as structural instability and incorrect surface reconstructions on (100), (110), and/or (111) surfaces. The newly developed MEAM potentials solve most of the problems and describe the bulk properties (elastic constants, structural energy differences), point defect properties (vacancy and interstitial formation energy and formation volume, activation energy of vacancy diffusion), planar defect properties (stacking fault energy, surface energy, surface relaxation and reconstruction), and thermal properties (thermal expansion coefficients, specific heat, melting point, heat of melting) of the fcc elements considered, in good agreement with relevant experimental information. It has been shown that in the MEAM the degree of many-body screening (C-min) is an important material property and that structural stability at finite temperatures should be included as a checkpoint during development of semiempirical potentials. C1 Pohang Inst Sci & Technol, Dept Mat Sci & Engn, Pohang 790784, South Korea. Korea Inst Sci & Technol, Div Mat Sci & Technol, Seoul 136791, South Korea. Los Alamos Natl Lab, Struct Properties Relat Grp, Los Alamos, NM 87545 USA. RP Lee, BJ (reprint author), Pohang Inst Sci & Technol, Dept Mat Sci & Engn, Pohang 790784, South Korea. EM calphad@postech.ac.kr NR 43 TC 217 Z9 223 U1 13 U2 82 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 144112 DI 10.1103/PhysRevB.68.144112 PG 11 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500028 ER PT J AU Levitas, VI Preston, DL Lee, DW AF Levitas, VI Preston, DL Lee, DW TI Three-dimensional Landau theory for multivariant stress-induced martensitic phase transformations. III. Alternative potentials, critical nuclei, kink solutions, and dislocation theory SO PHYSICAL REVIEW B LA English DT Article ID SHAPE-MEMORY ALLOYS; SOLITONS; MODEL AB In part III of this paper, alternative Landau potentials for the description of stress-and temperature-induced martensitic phase transformations under arbitrary three-dimensional loading are obtained. These alternative potentials include a sixth-degree (2-4-6) polynomial in Cartesian order parameters and a potential in hyperspherical order parameters. Each satisfies all conditions for the correct description of experiments. The unique features of the potentials are pointed out and a detailed comparison of the potentials is made for NiAl alloy. Analytic solutions of the one-dimensional time-independent Ginzburg-Landau equations for the 2-3-4 and 2-4-6 potentials for a constant-stress tensor and invariant-plane strain are obtained and compared. Solutions include martensitic and austenitic critical nuclei and diffuse martensite-austenite and martensite-martensite interfaces. The widths and energies of the nuclei and interfaces are functions of the thermodynamic driving force, the gradient energy coefficient, and a parameter that characterizes the stability of austenite. The splitting of a martensite-martensite interface into two austenite-martensite interfaces is interpreted as a potentially new mechanism-namely, barrierless austenite nucleation-which might be observed experimentally at the interface between two invariant-plane-strain variants. The widths, energies, and gradient energy coefficients of the martensite-martensite and austenite-martensite interfaces are estimated for NiAl. Finally, we outline a version of phase field theory for dislocations based on our theoretical framework for phase transformations. C1 Texas Tech Univ, Ctr Mechanochem & Synth New Mat, Dept Mech Engn, Lubbock, TX 79409 USA. Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Levitas, VI (reprint author), Texas Tech Univ, Ctr Mechanochem & Synth New Mat, Dept Mech Engn, Lubbock, TX 79409 USA. RI Lee, Dong-Wook /D-2630-2011 NR 14 TC 75 Z9 75 U1 0 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134201 DI 10.1103/PhysRevB.68.134201 PG 24 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400039 ER PT J AU Lian, J Chen, J Wang, LM Ewing, RC Farmer, JM Boatner, LA Helean, KB AF Lian, J Chen, J Wang, LM Ewing, RC Farmer, JM Boatner, LA Helean, KB TI Radiation-induced amorphization of rare-earth titanate pyrochlores SO PHYSICAL REVIEW B LA English DT Article ID STRUCTURAL-CHANGE; ION IRRADIATION; ZIRCON; OXIDES; DISORDER; TEMPERATURE; CONDUCTION AB Single crystals of the entire series of A(2)Ti(2)O(7) (A=Sm to Lu, and Y) pyrochlore compounds were irradiated by 1-MeV Kr+ ions at temperatures from 293 to 1073 K, and the microstructure evolution, as a function of increasing radiation fluence, was characterized using in situ transmission electron microscopy (TEM). The critical amorphization temperature, T-c, generally increases from similar to480 to similar to1120 K with increasing A-site cation size (e.g., 0.977 Angstrom for Lu3+ to 1.079 Angstrom for Sm3+). An abnormally high susceptibility to ion beam damage was found for Gd2Ti2O7 (with the highest T-c of similar to1120 K). Factors influencing the response of titanate pyrochlores to ion irradiation-induced amorphization are discussed in terms of cation radius ratio, defect formation, and the tendency to undergo an order-disorder transition to the defect-fluorite structure. The resistance of the pyrochlore structure to ion beam-induced amorphization is not only affected by the relative sizes of the A- and B-site cations, but also the cation electronic configuration and the structural disorder. Pyrochlore compositions that have larger structural deviations from the ideal fluorite structure, as evidenced by the smaller 48f oxygen positional parameter, x, are more sensitive to ion beam-induced amorphization. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. RP Ewing, RC (reprint author), Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RI Lian, Jie/A-7839-2010; Farmer, Matt/C-2571-2016; Boatner, Lynn/I-6428-2013 OI Farmer, Matt/0000-0002-7279-1847; Boatner, Lynn/0000-0002-0235-7594 NR 31 TC 169 Z9 172 U1 4 U2 56 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134107 DI 10.1103/PhysRevB.68.134107 PG 9 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400035 ER PT J AU Lima, AL Gschneidner, KA Pecharsky, VK Pecharsky, AO AF Lima, AL Gschneidner, KA Pecharsky, VK Pecharsky, AO TI Disappearance and reappearance of magnetic ordering upon lanthanide substitution in (Er1-xDyx)Al-2 SO PHYSICAL REVIEW B LA English DT Article AB Multiple magnetic ordering phenomena, when substituting Dy for Er in (Er1-xDyx)Al-2 over a broad range of concentrations 0less than or equal toxless than or equal to0.85, observed in low-temperature heat capacity measurements have been explained theoretically. The Hamiltonian that describes the system includes crystalline electric field effects, exchange interaction, and second-order contributions such as quadrupolar and magnetoelastic effects. We show that the discontinuity in the heat capacity, which arises at certain concentrations of the alloying element Dy, is the result of the competition between the magnetoelastic coupling and quadrupolar effects. The existence of the disappearance and reappearance of the magnetic phases in other lanthanide-lanthanide systems is also discussed. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Gschneidner, KA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 18 TC 31 Z9 31 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134409 DI 10.1103/PhysRevB.68.134409 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400063 ER PT J AU Ling, CD Granado, E Neumeier, JJ Lynn, JW Argyriou, DN AF Ling, CD Granado, E Neumeier, JJ Lynn, JW Argyriou, DN TI Inhomogeneous magnetism in La-doped CaMnO3. I. Mesoscopic phase separation due to lattice-coupled ferromagnetic interactions SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; MANGANITES; PEROVSKITE; MAGNETORESISTANCE; MAROKITE; ANTIFERROMAGNETISM; CAMN2O4 AB A detailed investigation of mesoscopic magnetic and crystallographic phase separation in Ca1-xLaxMnO3, 0.00less than or equal toxless than or equal to0.20, is reported. Neutron powder diffraction and dc-magnetization techniques have been used to isolate the different roles played by electrons doped into the e(g) level as a function of their concentration x. The presence of multiple low-temperature magnetic and crystallographic phases within individual polycrystalline samples is argued to be an intrinsic feature of the system that follows from the shifting balance between competing ferromagnetic (FM) and antiferromagnetic (AFM) interactions as a function of temperature. FM double-exchange interactions associated with doped e(g) electrons are favored over competing AFM interactions at higher temperatures, and couple more strongly with the lattice via orbital polarization. These FM interactions thereby play a privileged role, even at low e(g) electron concentrations, by virtue of structural modifications induced above the AFM transition temperatures. C1 Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. Lab Nacl Luz Sincrotron, BR-13084971 Campinas, SP, Brazil. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. RP Ling, CD (reprint author), Inst Max Von Laue Paul Langevin, BP 156, F-38042 Grenoble 9, France. RI Ling, Chris D/B-2228-2009; Granado, Eduardo/F-5389-2012 OI Ling, Chris D/0000-0003-2205-3106; NR 31 TC 83 Z9 83 U1 0 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134439 DI 10.1103/PhysRevB.68.134439 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400093 ER PT J AU Lorenz, B Cmaidalka, J Meng, RL Chu, CW AF Lorenz, B Cmaidalka, J Meng, RL Chu, CW TI Effect of hydrostatic pressure on the superconductivity in NaxCoO2 center dot yH(2)O SO PHYSICAL REVIEW B LA English DT Article AB The effect of hydrostatic pressure on the superconducting transition temperature of Na0.35CoO2.yH(2)O was investigated by ac susceptibility measurements up to 1.6 GPa. The pressure coefficient of T-c is negative and the dependence T-c(p) is nonlinear over the pressure range investigated. The magnitude of the average d ln T-c/dpapproximate to-0.07 GPa(-1) is comparable to the pressure coefficient of electron-doped high-T-c copper oxide superconductors with a similar value of T-c. Our results provide support to the assumption of two-dimensional superconductivity in Na0.35CoO2.yH(2)O, which is similar to the cuprate systems, and suggest that intercalation of larger molecules may lead to an enhancement of T-c. C1 Univ Houston, Dept Phys, Houston, TX 77204 USA. Univ Houston, TCSAM, Houston, TX 77204 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Hong Kong Univ Sci & Technol, Hong Kong, Hong Kong, Peoples R China. RP Univ Houston, Dept Phys, Houston, TX 77204 USA. NR 10 TC 33 Z9 34 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 132504 DI 10.1103/PhysRevB.68.132504 PG 3 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400023 ER PT J AU Luo, SN Ahrens, TJ Cagin, T Strachan, A Goddard, WA Swift, DC AF Luo, SN Ahrens, TJ Cagin, T Strachan, A Goddard, WA Swift, DC TI Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments SO PHYSICAL REVIEW B LA English DT Article ID STABILITY LIMIT; CRYSTAL NUCLEATION; SHOCK TEMPERATURES; PHASE; COMPRESSION; CATASTROPHE; MOLYBDENUM; ALUMINUM; ENTROPY; LIQUIDS AB The maximum superheating and undercooling achievable at various heating (or cooling) rates were investigated based on classical nucleation theory and undercooling experiments, molecular dynamics (MD) simulations, and dynamic experiments. The highest (or lowest) temperature T-c achievable in a superheated solid (or an undercooled liquid) depends on a dimensionless nucleation barrier parameter beta and the heating (or cooling) rate Q. beta depends on the material: betaequivalent to16pigamma(sl)(3)/(3kT(m)DeltaH(m)(2)) where gamma(sl) is the solid-liquid interfacial energy, DeltaH(m) the heat of fusion, T-m the melting temperature, and k Boltzmann's constant. The systematics of maximum superheating and undercooling were established phenomenologically as beta=(A(0)-b log(10)Q)theta(c)(1-theta(c))(2) where theta(c)=T-c/T-m, A(0)=59.4, b=2.33, and Q is normalized by 1 K/s. For a number of elements and compounds, beta varies in the range 0.2-8.2, corresponding to maximum superheating theta(c) of 1.06-1.35 and 1.08-1.43 at Qsimilar to1 and 10(12) K/s, respectively. Such systematics predict that a liquid with certain beta cannot crystallize at cooling rates higher than a critical value and that the smallest theta(c) achievable is 1/3. MD simulations (Qsimilar to10(12) K/s) at ambient and high pressures were conducted on close-packed bulk metals with Sutton-Chen many-body potentials. The maximum superheating and undercooling resolved from single- and two-phase simulations are consistent with the theta(c)-beta-Q systematics for the maximum superheating and undercooling. The systematics are also in accord with previous MD melting simulations on other materials (e.g., silica, Ta and epsilon-Fe) described by different force fields such as Morse-stretch charge equilibrium and embedded-atom-method potentials. Thus, the theta(c)-beta-Q systematics are supported by simulations at the level of interatomic interactions. The heating rate is crucial to achieving significant superheating experimentally. We demonstrate that the amount of superheating achieved in dynamic experiments (Qsimilar to10(12) K/s), such as planar shock-wave loading and intense laser irradiation, agrees with the superheating systematics. C1 CALTECH, Seismol Lab, Lindhurst Lab Expt Geophys, Pasadena, CA 91125 USA. CALTECH, Beckman Inst, Mat & Proc Simulat Ctr, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM sluo@lanl.gov RI Luo, Sheng-Nian /D-2257-2010 OI Luo, Sheng-Nian /0000-0002-7538-0541 NR 49 TC 153 Z9 154 U1 6 U2 47 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134206 DI 10.1103/PhysRevB.68.134206 PG 11 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400044 ER PT J AU Majer, G Gottwald, J Kaess, U Peterson, DT Barnes, RG AF Majer, G Gottwald, J Kaess, U Peterson, DT Barnes, RG TI Nuclear relaxation in the dideuterides of hafnium and titanium SO PHYSICAL REVIEW B LA English DT Article ID SPIN-LATTICE-RELAXATION; HYDROGEN DIFFUSION; TRANSLATIONAL DIFFUSION; MAGNETIC-RESONANCE; HYDRIDE; ZIRCONIUM; SYSTEMS; SOLIDS; MODEL; TIME AB The deuteron spin-lattice relaxation in the substoichiometric dideuterides HfDx(1.68less than or equal toxless than or equal to1.90) and TiDx(x=1.91) has been measured at temperatures between 300 and 830 K. The results are compared with previous proton NMR measurements on dihydrides of similar hydrogen contents. The deuteron relaxation rate Gamma(1), which consists of quadrupolar (Gamma(1,quad)), dipolar (Gamma(1,dip)), and electronic (Gamma(1,e)) contributions, is dominated by Gamma(1,quad). The deuterium atoms jump predominantly from occupied tetrahedral sites (T sites) to nearest-neighbor vacant T sites. The fluctuations in the electric field gradients are related to the jumps of the vacancies on the deuterium sublattice. The Gamma(1,quad) maximum occurs at a lower temperature than the Gamma(1,dip) maximum, reflecting the higher jump frequency of the vacancies compared to that of the deuterium atoms. The temperature dependence of Gamma(1,quad) yields the activation enthalpy H-a of the deuterium vacancies and thus that of the deuterium atoms in the dideuterides. These H-a values are in good agreement with the activation enthalpies of hydrogen atoms in corresponding dihydrides. C1 Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Iowa State Univ, Dept Phys, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Majer, G (reprint author), Max Planck Inst Met Res, Heisenbergstr 3, D-70569 Stuttgart, Germany. NR 25 TC 4 Z9 4 U1 2 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134304 DI 10.1103/PhysRevB.68.134304 PG 6 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400053 ER PT J AU Marchesini, S He, H Chapman, HN Hau-Riege, SP Noy, A Howells, MR Weierstall, U Spence, JCH AF Marchesini, S He, H Chapman, HN Hau-Riege, SP Noy, A Howells, MR Weierstall, U Spence, JCH TI X-ray image reconstruction from a diffraction pattern alone SO PHYSICAL REVIEW B LA English DT Article ID PHASE RETRIEVAL; ITERATIVE ALGORITHMS; OBJECT; CRYSTALLOGRAPHY; ELECTRON; SUPPORT AB A solution to the inversion problem of scattering would offer aberration-free diffraction-limited three-dimensional images without the resolution and depth-of-field limitations of lens-based tomographic systems. Powerful algorithms are increasingly being used to act as lenses to form such images. Current image reconstruction methods, however, require the knowledge of the shape of the object and the low spatial frequencies unavoidably lost in experiments. Diffractive imaging has thus previously been used to increase the resolution of images obtained by other means. Here we experimentally demonstrate an inversion method, which reconstructs the image of the object without the need for any such prior knowledge. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. RP Marchesini, S (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. RI Marchesini, Stefano/A-6795-2009; Chapman, Henry/G-2153-2010; Weierstall, Uwe/B-3568-2011 OI Chapman, Henry/0000-0002-4655-1743; NR 23 TC 351 Z9 355 U1 5 U2 54 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 140101 DI 10.1103/PhysRevB.68.140101 PG 4 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500001 ER PT J AU Matsuura, M Dai, PC Kang, HJ Lynn, JW Argyriou, DN Prokes, K Onose, Y Tokura, Y AF Matsuura, M Dai, PC Kang, HJ Lynn, JW Argyriou, DN Prokes, K Onose, Y Tokura, Y TI Effect of a magnetic field on the long-range magnetic order in insulating Nd2CuO4 and nonsuperconducting and superconducting Nd1.85Ce0.15CuO4 SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTOR; T-C SUPERCONDUCTIVITY; ANTIFERROMAGNETIC ORDER; SINGLE-CRYSTALS; ND2-XCEXCUO4; TRANSITIONS; DEPENDENCE; SYMMETRY; VORTEX; STATE AB We have measured the effect of a c-axis-aligned magnetic field on the long-range magnetic order of insulating Nd2CuO4, as-grown nonsuperconducting and superconducting Nd1.85Ce0.15CuO4. On cooling from room temperature, Nd2CuO4 goes through a series of antiferromagnetic (AF) phase transitions with different noncollinear spin structures. In all phases of Nd2CuO4, we find that the applied c-axis field induces a canting of the AF order but does not alter the basic zero-field noncollinear spin structures. A similar behavior is also found in as-grown nonsuperconducting Nd1.85Ce0.15CuO4. These results contrast dramatically with those of superconducting Nd1.85Ce0.15CuO4, where the c-axis-aligned magnetic field induces a static, anomalously conducting, long-range ordered AF state. We confirm that the annealing process necessary to make superconducting Nd1.85Ce0.15CuO4 also induces epitaxial, three-dimensional long-range-ordered cubic (Nd,Ce)(2)O-3 as a small impurity phase. In addition, the annealing process makes a series of quasi-two-dimensional superlattice reflections associated with lattice distortions of Nd1.85Ce0.15CuO4 in the CuO2 plane. While the application of a magnetic field will induce a net moment in the impurity phase, we determine its magnitude and eliminate this as a possibility for the observed magnetic-field-induced effect in superconducting Nd1.85Ce0.15CuO4. This is confirmed by measurements of the (1/2,1/2,3) peak, which is not lattice matched to the impurity phase. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. Charles Univ, Dept Elect Struct, Prague 12116 2, Czech Republic. Japan Sci & Technol, ERATO, Spin Superstruct Project, Tsukuba, Ibaraki 3058562, Japan. Correlated Electron Res Ctr, Tsukuba, Ibaraki 3058562, Japan. Univ Tokyo, Dept Appl Phys, Tokyo 1138656, Japan. RP Matsuura, M (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Onose, Yoshinori/F-1977-2010; Dai, Pengcheng /C-9171-2012; Tokura, Yoshinori/C-7352-2009; Matsuura, Masato/C-2827-2013 OI Dai, Pengcheng /0000-0002-6088-3170; Matsuura, Masato/0000-0003-4470-0271 NR 37 TC 40 Z9 40 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 144503 DI 10.1103/PhysRevB.68.144503 PG 13 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500071 ER PT J AU Pecharsky, AO Mozharivskyj, Y Dennis, KW Gschneidner, KA McCallum, RW Miller, GJ Pecharsky, VK AF Pecharsky, AO Mozharivskyj, Y Dennis, KW Gschneidner, KA McCallum, RW Miller, GJ Pecharsky, VK TI Preparation, crystal structure, heat capacity, magnetism, and the magnetocaloric effect of Pr5Ni1.9Si3 and PrNi SO PHYSICAL REVIEW B LA English DT Article AB Single-phase Pr5Ni1.9Si3 and PrNi were prepared and characterized by using differential thermal analysis, single crystal, and powder x-ray diffraction. Their thermal and magnetic properties were studied by measuring heat capacity as a function of temperature in magnetic fields up to 100 kOe and magnetization as a function of magnetic field up to 50 kOe over the temperature range from 5 to 400 K. Pr5Ni1.9Si3 orders magnetically at 50 K, and it undergoes a second transition at 25 K. As inferred from the behavior of the magnetization and magnetocaloric effect (MCE), both ferromagnetic and antiferromagnetic components are present in the magnetic ground state of the material. The heat capacity and magnetocaloric effect of PrNi confirm that it orders ferromagnetically at 19 K. Both Pr5Ni1.9Si3 and PrNi exhibit moderate magnetocaloric effects. The maximum MCE for Pr5Ni1.9Si3 is 3.4 K and it is observed at 50 K for a magnetic field change from 0 to 75 kOe. The maximum MCE for PrNi is 4.2 K, which occurs at 19 K for a magnetic field change from 0 to 100 kOe. C1 Iowa State Univ, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Pecharsky, AO (reprint author), Iowa State Univ, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA. NR 17 TC 36 Z9 36 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134452 DI 10.1103/PhysRevB.68.134452 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400106 ER PT J AU Smith, NV AF Smith, NV TI Memory effects in the magnetotransport properties of the classical Drude metal SO PHYSICAL REVIEW B LA English DT Article AB Memory effects are incorporated into the classical Drude model by use of a current-decay function that deviates from a simple exponential. In the hypothetical case where velocity persists after one collision but is totally lost after subsequent collisions, the magnetoresistance is negative, the Hall coefficient can occur with either sign, and both vary with magnetic field. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Smith, NV (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. NR 7 TC 2 Z9 2 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 132406 DI 10.1103/PhysRevB.68.132406 PG 2 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400014 ER PT J AU Soignard, E McMillan, PF Chaplin, TD Farag, SM Bull, CL Somayazulu, MS Leinenweber, K AF Soignard, E McMillan, PF Chaplin, TD Farag, SM Bull, CL Somayazulu, MS Leinenweber, K TI High-pressure synthesis and study of low-compressibility molybdenum nitride (MoN and MoN1-x) phases SO PHYSICAL REVIEW B LA English DT Article AB We report the compressibility of the stoichiometric hexagonal delta phase of MoN that is a well-known hard material that becomes superconducting below T-c=12 K. The measured bulk modulus is K-0=345(9) GPa and K'(0)=3.5(3). We also report the compressibility of the non-stoichiometric cubic B1 structured gamma-Mo2N phase, that has a lower bulk modulus [K-0=301(7) GPa, assuming K'(0)=4]. The difference in bulk modulus is due to the difference in structure and the cohesive energy between the two phases. C1 UCL, Dept Chem, Christopher Ingold Labs, London WC1H 0AJ, England. Royal Inst Great Britain, Davy Faraday Res Lab, London W1X 4BS, England. Argonne Natl Labs, Adv Photon Source, HPCAT, Argonne, IL 60439 USA. Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. RP UCL, Dept Chem, Christopher Ingold Labs, 20 Gordon St, London WC1H 0AJ, England. EM p.f.mcmillan@ucl.ac.uk RI Bul, Craig/F-4383-2010 NR 19 TC 48 Z9 50 U1 8 U2 24 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 132101 DI 10.1103/PhysRevB.68.132101 PG 4 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400001 ER PT J AU Strassle, T Janssen, S Juranyi, F Furrer, A Moze, O Pecharsky, AO Pecharsky, VK Gschneidner, KA AF Strassle, T Janssen, S Juranyi, F Furrer, A Moze, O Pecharsky, AO Pecharsky, VK Gschneidner, KA TI Inelastic neutron scattering study of the intra-lanthanide alloys ErxPr1-x (x=0.6,0.8) SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL FIELDS; ER; LU AB Neutron spectroscopy has been applied in order to elucidate the magnetothermal properties of the lanthanide alloys ErxPr1-x (x=0.6,0.8). The observed crystal-field splittings are in accordance with the arithmetically weighted crystal fields of the two pure metals. A mean-field approach is presented, which couples the two effective internal fields originating from the Er and Pr ions. The model is successful in explaining many of the observed magnetic properties, including the ferrimagnetic arrangement of the Er and Pr moments, the values of the respective moments, the magnetocaloric effect for x=0.7 and the large increase of the magnetic entropy at low temperatures due to the addition of Pr. A large single-ion anisotropy is derived and it is predicted that an enhanced magnetocaloric effect should be observed in single-crystal samples for xsimilar to0.7 with the external magnetic field applied along the c axis. Additional magnetization measurements under pressure up to 0.72 GPa have shown no evidence for a pronounced sensitivity of the magnetic ordering temperature upon pressure in Er0.6Pr0.4. C1 ETH, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Strassle, T (reprint author), Univ Paris 06, B77 4 Pl Jussieu, F-75252 Paris, France. NR 14 TC 2 Z9 2 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134411 DI 10.1103/PhysRevB.68.134411 PG 6 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400065 ER PT J AU Tanguy, D Mareschal, M Lomdahl, PS Germann, TC Holian, BL Ravelo, R AF Tanguy, D Mareschal, M Lomdahl, PS Germann, TC Holian, BL Ravelo, R TI Dislocation nucleation induced by a shock wave in a perfect crystal: Molecular dynamics simulations and elastic calculations SO PHYSICAL REVIEW B LA English DT Article ID SURFACE AB We study the nucleation mechanism of the defects responsible for plastic flow in a <100> fcc perfect single crystal submitted to a shock wave. In the large-scale nonequilibrium molecular dynamics simulation, small dislocation loops are created from thermal fluctuations just behind the shock front, in a narrow region of a few lattice parameters width. Their critical size is measured. The activation energy for the formation of an edge dipole, under high pressure, is computed within the Peierls framework. The elastic constants and the generalized stacking fault energy are computed from the interatomic potential. This model enables a qualitative discussion of the influence of material parameters such as intrinsic and unstable stacking faults versus elastic energy release. C1 Ecole Normale Super Lyon, Ctr Europeen Calcul Atom & Mol, FR-69007 Lyon, France. Ecole Mines St Etienne, CNRS, URA 1884, FR-42023 St Etienne, France. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. RP Tanguy, D (reprint author), Ecole Normale Super Lyon, Ctr Europeen Calcul Atom & Mol, 46 Allee Italie, FR-69007 Lyon, France. EM tanguy@emse.fr NR 20 TC 45 Z9 46 U1 1 U2 18 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 14 AR 144111 DI 10.1103/PhysRevB.68.144111 PG 10 WC Physics, Condensed Matter SC Physics GA 740VP UT WOS:000186422500027 ER PT J AU Wesolowski, R Haraldsen, JT Musfeldt, JL Barnes, T Mas-Torrent, M Rovira, C Henriques, RT Almeida, M AF Wesolowski, R Haraldsen, JT Musfeldt, JL Barnes, T Mas-Torrent, M Rovira, C Henriques, RT Almeida, M TI Infrared investigation of the low-temperature structural and magnetic transitions in the spin-ladder candidate (DT-TTF)(2)Au(mnt)(2) SO PHYSICAL REVIEW B LA English DT Article ID EXCITATION SPECTRUM; SUPERCONDUCTIVITY; SUSCEPTIBILITY; SCATTERING; BEHAVIOR; FAMILY AB We report measurements of the variable temperature infrared response of the organic spin-ladder candidate dithiophentelrathiafulvalene gold maleonitrile dithiolate [(DT-TTF)(2)Au(mnt)(2)]. The 220 K structural transition is driven by massive symmetry breaking along the rung direction, whereas the 70 K magnetic transition is associated with a change in symmetry of the vibronically activated A(g) modes in the rail direction. From molecular dynamics simulations, we assign the most important intramolecular vibrational modes involved in each transition. From an analysis of the charge-transfer behavior, we find that the localization of unpaired electrons in the interacting DT-TTF double chains is modified at these transition temperatures as well. To motivate future inelastic neutron-scattering studies, we have also calculated the spectrum of low-lying magnon excitations expected in this material, assuming an isotropic Heisenberg spin-ladder model. We estimate a gap of 0.6 meV for the one-magnon mode. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. CSIC, Inst Ciencia Mat Barcelona, E-08193 Barcelona, Spain. ITN, Dept Quim, P-2686 Sacavem, Portugal. RP Wesolowski, R (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RI Haraldsen, Jason/B-9809-2012; ROVIRA, Concepcio*/F-3155-2011; Mas-Torrent, Marta/A-3485-2013; Almeida, Manuel/B-5227-2011 OI Haraldsen, Jason/0000-0002-8641-5412; ROVIRA, Concepcio*/0000-0002-2365-9479; Mas-Torrent, Marta/0000-0002-1586-005X; Almeida, Manuel/0000-0003-2222-5641 NR 34 TC 14 Z9 14 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134405 DI 10.1103/PhysRevB.68.134405 PG 8 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400059 ER PT J AU Westfahl, H Schmalian, J Wolynes, PG AF Westfahl, H Schmalian, J Wolynes, PG TI Dynamical mean-field theory of quantum stripe glasses SO PHYSICAL REVIEW B LA English DT Article ID SPIN-GLASS; TRANSITION; STATE; SYSTEMS; THERMODYNAMICS; LA2-XSRXCUO4; DIMENSIONS; PARAMETER; MODEL; NMR AB We present a many body approach for nonequilibrium behavior and self-generated glassiness in strongly correlated quantum systems. It combines the dynamical mean-field theory of equilibrium systems with the replica theory for classical glasses without quenched disorder. We apply this approach to study a quantized version of the Brazovskii model and find a self-generated quantum glass that remains in a quantum mechanically mixed state as T-->0. This quantum glass is formed by a large number of competing states spread over an energy region which is determined within our theory. C1 Lab Nacl Luz Sncrotron ABTLuS, BR-13084971 Campinas, SP, Brazil. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. RP Lab Nacl Luz Sncrotron ABTLuS, BR-13084971 Campinas, SP, Brazil. RI Schmalian, Joerg/H-2313-2011 NR 44 TC 23 Z9 23 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134203 DI 10.1103/PhysRevB.68.134203 PG 10 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400041 ER PT J AU Wiebe, CR Greedan, JE Kyriakou, PP Luke, GM Gardner, JS Fukaya, A Gat-Malureanu, IM Russo, PL Savici, AT Uemura, YJ AF Wiebe, CR Greedan, JE Kyriakou, PP Luke, GM Gardner, JS Fukaya, A Gat-Malureanu, IM Russo, PL Savici, AT Uemura, YJ TI Frustration-driven spin freezing in the S=1/2 fcc perovskite Sr2MgReO6 SO PHYSICAL REVIEW B LA English DT Article ID PYROCHLORE ANTIFERROMAGNET; KAGOME ANTIFERROMAGNET; MAGNETIC FRUSTRATION; LATTICE; RELAXATION; DYNAMICS; Y2MO2O7; RHENIUM; CUMN AB The ordered perovskite Sr2MgReO6 of tetragonal symmetry [I4/m, a=5.5670(1) Angstrom, c=7.9318(2) Angstrom at T=295 K] has been synthesized and characterized by x-ray and neutron diffraction, thermal gravimetric analysis dc susceptibility, heat capacity, and muon spin relaxation (muSR) experiments. The B site cations Re6+ and Mg2+ appear to be ordered due the large difference in formal charge. The Re6+ magnetic ions form a distorted fcc lattice of S=1/2 spins providing a frustrated topology of edge-shared tetrahedra. The material exhibits a weak magnetic glassiness shown by a cusp at similar to50 K in the dc susceptibility, a weak but broad heat capacity anomaly, and a low-temperature muSR line shape characteristic of a spin-glass state. A broad and strongly field- dependent maximum in the dc susceptibility suggests that magnetic correlations persist to similar to175 K, accompanied by a divergence in the field-cooled and zero-field-cooled susceptibility. The anisotropic nature of the superexchange pathways due to the tetragonal distortion is thought to disrupt the ideal frustrated environment and lead to weaker glassiness than Sr2CaReO6, which has T(G)similar to14 K, and a large specific heat anomaly. In contrast, Sr2MgReO6 has a small anomaly, and only about 3% of the entropy is released at T(G)similar to50 K, which is comparable to other unconventional spin glasses such as the jarosite (H3O)Fe-3(SO4)(2)(OH)(6)(similar to6%). T(G)similar to50 K is unusually high for this class of materials. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. RP Greedan, JE (reprint author), McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. RI Savici, Andrei/F-2790-2013; Luke, Graeme/A-9094-2010; Gardner, Jason/A-1532-2013 OI Savici, Andrei/0000-0001-5127-8967; NR 34 TC 53 Z9 54 U1 1 U2 23 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134410 DI 10.1103/PhysRevB.68.134410 PG 10 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400064 ER PT J AU Zaliznyak, IA AF Zaliznyak, IA TI Heisenberg magnet with modulated exchange SO PHYSICAL REVIEW B LA English DT Article ID TRIANGULAR XY MODEL; VALENCE-BOND STATE; RARE-EARTH-METALS; PHASE-TRANSITIONS; GROUND-STATE; SPIN SYSTEM; ANTIFERROMAGNETIC CHAIN; LINEAR-CHAIN; LATTICE; SUPERCONDUCTIVITY AB A modification of the ground state of the classical-spin Heisenberg Hamiltonian in the presence of a weak superstructural distortion of an otherwise Bravais lattice is examined. It is shown that a slight modulation of the crystal lattice with wave vector Q(c) results in a corresponding modulation of the exchange interaction which, in the leading order, is parametrized by no more than two constants per bond, and perturbs the spin Hamiltonian by adding the "umklapp" terms similar toS(q)(alpha)S(q+/-Qc)(alpha). As a result, for a general spin-spiral ground state of the nonperturbed exchange Hamiltonian, an incommensurate shift of the propagation vector Q and additional new magnetic Bragg peaks, at Q+/-nQ(c), n=1,2,..., appear, and its energy is lowered as it adapts to the exchange modulation. Consequently, the lattice distortion may open a region of stability of the incommensurate spiral phase which otherwise does not win the competition with the collinear Neel state. Such is the case for the frustrated square-lattice antiferromagnet. In addition, the umklapp terms provide a commensuration mechanism, which may lock the spin structure to the lattice modulation vector Q(c), if there is sufficient easy-axis anisotropy, or a magnetic field in an easy plane. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Upton, NY 11973 USA. RI Zaliznyak, Igor/E-8532-2014 OI Zaliznyak, Igor/0000-0002-9886-3255 NR 66 TC 5 Z9 5 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134451 DI 10.1103/PhysRevB.68.134451 PG 13 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400105 ER PT J AU Zheludev, A Honda, Z Broholm, CL Katsumata, K Shapiro, SM Kolezhuk, A Park, S Qiu, Y AF Zheludev, A Honda, Z Broholm, CL Katsumata, K Shapiro, SM Kolezhuk, A Park, S Qiu, Y TI Massive triplet excitations in a magnetized anisotropic Haldane spin chain SO PHYSICAL REVIEW B LA English DT Article ID S=1 HEISENBERG-ANTIFERROMAGNET; GAP ANTIFERROMAGNET; NEUTRON-SCATTERING; FIELD-THEORY; DYNAMICS; MODEL; PHASE AB Inelastic neutron scattering experiments on the Haldane-gap quantum antiferromagnet Ni(C5D14N2)(2)N-3(PF6) are performed at mK temperatures in magnetic fields of almost twice the critical field H-c applied perpendicular to the spin chains. Above H-c a reopening of the spin gap is clearly observed. In the high-field Neel-ordered state the spectrum is dominated by three distinct excitation branches. A theoretical model consistently describing the experimental data is proposed. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. Saitama Univ, Fac Engn, Urawa, Saitama 3388570, Japan. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. RIKEN, Harima Inst, Sayo, Hyogo 6795148, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Hannover, Inst Theoret Phys, D-30167 Hannover, Germany. Natl Acad Sci, Inst Magnetism, UA-03142 Kiev, Ukraine. Minist Educ Ukraine, UA-03142 Kiev, Ukraine. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20743 USA. RP Zheludev, A (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Broholm, Collin/E-8228-2011; Kolezhuk, Alexei/A-3311-2009 OI Broholm, Collin/0000-0002-1569-9892; Kolezhuk, Alexei/0000-0002-9739-0986 NR 26 TC 32 Z9 32 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 2003 VL 68 IS 13 AR 134438 DI 10.1103/PhysRevB.68.134438 PG 4 WC Physics, Condensed Matter SC Physics GA 740VN UT WOS:000186422400092 ER EF