FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Straub, TM Daly, DS Wunshel, S Rochelle, PA DeLeon, R Chandler, DP AF Straub, TM Daly, DS Wunshel, S Rochelle, PA DeLeon, R Chandler, DP TI Genotyping Cyptospoildium parvum with an hsp70 single-nucleotide polymorphism microarray SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID CRYPTOSPORIDIUM-PARVUM; OLIGONUCLEOTIDE ARRAYS; HYBRIDIZATION; MICROCHIPS; GENE AB We investigated the application of an oligonucleotide microarray to (i) specifically detect Cryptosporidium spp., (ii) differentiate between closely related C. parvum isolates and Cryptosporidium species, and (iii) differentiate between principle genotypes known to infect humans. A microarray of 68 capture probes targeting seven single-nucleotide polymorphisms (SNPs) within a 190-bp region of the hsp70 gene of Ctyptosporidium parvum was constructed. Labeled hsp70 targets were generated by PCR with biotin- or Cy3-labeled primers. Hybridization conditions were optimized for hybridization time, temperature, and salt concentration. Two genotype I C. parvum isolates (TU502 and UG502), two C. parvum genotype II isolates (Iowa and GCH1), and DNAs from 22 non-Cryptosporidium sp. organisms were used to test method specificity. Only DNAs from C. parvum isolates produced labeled amplicons that could be hybridized to and detected on the array. Hybridization patterns between genotypes were visually distinct, but identification of SNPs required statistical analysis of the signal intensity data. The results indicated that correct mismatch discrimination could be achieved for all seven SNPs for the UG502 isolate, five of seven SNPs for the TU502 isolate., and six of seven SNPs for both the Iowa and GCH1 isolates. Even without perfect mismatch discrimination, the microarray method unambiguously distinguished between genotype I and genotype II isolates and demonstrated the potential to differentiate between other isolates and species on a single microarray. This method may provide a powerful new tool for water utilities and public health officials for assessing point and nonpoint source contamination of water supplies. C1 Pacific NW Natl Lab, Analyt Microbiol Grp, Richland, WA 99352 USA. Pacific NW Natl Lab, Appl Stat Grp, Richland, WA 99352 USA. Metropolitan Water Dist So Calif, La Verne, CA 91750 USA. RP Straub, TM (reprint author), 902 Battelle Blvd,Mail Stop P7-50, Richland, WA 99352 USA. NR 24 TC 36 Z9 37 U1 0 U2 0 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 APR PY 2002 VL 68 IS 4 BP 1817 EP 1826 DI 10.1128/AEM.68.4.1817-1826.2002 PG 10 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 538YF UT WOS:000174842200043 PM 11916701 ER PT J AU Kuske, CR Ticknor, LO Miller, ME Dunbar, JM Davis, JA Barns, SM Belnap, J AF Kuske, CR Ticknor, LO Miller, ME Dunbar, JM Davis, JA Barns, SM Belnap, J TI Comparison of soil bacterial communities in rhizospheres of three plant species and the interspaces in an arid grassland SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SOUTHWESTERN UNITED-STATES; BROMUS-TECTORUM L; MICROBIAL BIOMASS; NORTH-AMERICA; DIVERSITY; NITROGEN; CRUSTS; DESERT; LENGTH; RNA AB Soil bacteria are important contributors to primary productivity and nutrient cycling in and land ecosystems, and their populations may be greatly affected by changes in environmental conditions. In parallel studies, the composition of the total bacterial community and of members of the Acidobacterium division were assessed in and grassland soils using terminal restriction fragment length polymorphism (TRF, also known as T-RFLP) analysis of 16S rRNA, genes amplified from soil DNA. Bacterial communities associated with the rhizospheres of the native bunchgrasses Stipa hymenoides and Hilaria jamesii, the invading annual grass Bromus tectorum, and the interspaces colonized by cyanobacterial soil crusts were compared at three depths. When used in a replicated field-scale study, TRF analysis was useful for identifying broad-scale, consistent differences in the bacterial communities in different soil locations, over the natural microscale heterogeneity of the soil. The compositions of the total bacterial community and Acidobacterium division in the soil crust interspaces were significantly different from those of the plant rhizospheres. Major differences were also observed in the rhizospheres of the three plant species and were most apparent with analysis of the Acidobacterium division. The total bacterial community and the Acidobacterium division bacteria were affected by soil depth in both the interspaces and plant rhizospheres. This study provides a baseline for monitoring bacterial community structure and dynamics with changes in plant cover and environmental conditions in the and grasslands. C1 Los Alamos Natl Lab, Environm Mol Biol Grp, Biosci Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Decis Applicat Div, Los Alamos, NM 87545 USA. Bur Land Management, Grand Staircase Escalante Natl Monument, Kanab, UT USA. US Geol Survey, Moab, UT USA. RP Kuske, CR (reprint author), Los Alamos Natl Lab, Environm Mol Biol Grp, Biosci Div, POB 1663,B-N1,M888, Los Alamos, NM 87545 USA. NR 45 TC 192 Z9 214 U1 8 U2 70 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 APR PY 2002 VL 68 IS 4 BP 1854 EP 1863 DI 10.1128/AEM.68.4.1854-1863.2002 PG 10 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 538YF UT WOS:000174842200047 PM 11916705 ER PT J AU Henson, VE Yang, UM AF Henson, VE Yang, UM TI BoomerAMG: A parallel algebraic multigrid solver and preconditioner SO APPLIED NUMERICAL MATHEMATICS LA English DT Article; Proceedings Paper CT 16th IMACS World Congress CY 2000 CL LAUSANNE, SWITZERLAND SP IMACS DE algebraic multigrid; parallel computing AB Driven by the need to solve linear systems arising from problems posed on extremely large, unstructured grids, there has been a recent resurgence of interest in algebraic multigrid (AMG). AMG is attractive in that it holds out the possibility of multigrid-like performance on unstructured grids. The sheer size of many modem physics and simulation problems has led to the development of massively parallel computers, and has sparked much research into developing algorithms for them. Parallelizing AMG is a difficult task, however. While much of the AMG method parallelizes readily, the process of coarse-grid selection, in particular, is fundamentally, sequential in nature. We have previously introduced a parallel algorithm [A.J. Cleary, R.D. Falgout, V.E. Henson, J.E. Jones, in: Proceedings of the Fifth International Symposium on Solving Irregularly Structured Problems in Parallel, Springer, New York, 1998] for the selection of coarse-grid points, based on modifications of certain parallel independent set algorithms and the application of heuristics designed to insure the quality of the coarse grids, and shown results from a prototype serial version of the algorithm. In this paper we describe an implementation of a parallel ANIG code, using the algorithm of A.J. Cleary, R.D. Falgout, V.E. Henson, J.E. Jones [in: Proceedings of the Fifth International Symposium on Solving Irregularly Structured Problems in Parallel, Springer, New York, 1998] as well as other approaches to parallelizing the coarse-grid selection. We consider three basic coarsening schemes and certain modifications to the basic schemes, designed to address specific performance issues. We present numerical results for a broad range of problem sizes and descriptions, and draw conclusions regarding the efficacy of the method. Finally, we indicate the current directions of the research. (C) 2002 IMACS. Published by Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Yang, UM (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Box 808,L-560, Livermore, CA 94551 USA. NR 19 TC 259 Z9 270 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 J9 APPL NUMER MATH JI Appl. Numer. Math. PD APR PY 2002 VL 41 IS 1 BP 155 EP 177 AR PII S0168-9274(01)00115-5 DI 10.1016/S0168-9274(01)00115-5 PG 23 WC Mathematics, Applied SC Mathematics GA 531KP UT WOS:000174414800011 ER PT J AU Demos, SG Staggs, M AF Demos, SG Staggs, M TI Application of fluorescence microscopy for noninvasive detection of surface contamination and precursors to laser-induced damage SO APPLIED OPTICS LA English DT Article ID OPTICAL-MATERIALS; INDUCED BREAKDOWN; KH2PO4 CRYSTALS; FUSED-SILICA; THRESHOLD AB We present an experimental investigation to evaluate fluorescence microscopy as a tool to detect surface contamination as well as reveal surface damage precursors on optical components for large-aperture laser systems. We performed fluorescence imaging experiments using 351-nm laser excitation, whereas in situ damage testing was performed at laser fluences well below the dielectric breakdown threshold of the pure material. The experimental results demonstrated the potential of this technique to address both aforementioned technical issues. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Demos, SG (reprint author), Lawrence Livermore Natl Lab, POB 808,L-411, Livermore, CA 94551 USA. EM Demos1@llnl.gov NR 18 TC 24 Z9 24 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 2002 VL 41 IS 10 BP 1977 EP 1983 DI 10.1364/AO.41.001977 PG 7 WC Optics SC Optics GA 538JK UT WOS:000174812200022 PM 11936799 ER PT J AU Zhukov, AA Purnell, A Miyoshi, Y Bugoslavsky, Y Lockman, Z Berenov, A Zhai, HY Christen, HM Paranthaman, MP Lowndes, DH Jo, MH Blamire, MG Hao, L Gallop, J MacManus-Driscoll, JL Cohen, LF AF Zhukov, AA Purnell, A Miyoshi, Y Bugoslavsky, Y Lockman, Z Berenov, A Zhai, HY Christen, HM Paranthaman, MP Lowndes, DH Jo, MH Blamire, MG Hao, L Gallop, J MacManus-Driscoll, JL Cohen, LF TI Microwave surface resistance of MgB2 SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTORS AB The microwave power and frequency dependence of the surface resistance of MgB2 films and powder samples were studied. Sample quality is relatively easy to identify by the breakdown in the omega(2) law for poor-quality samples at all temperatures. The performance of MgB2 at 10 GHz and 21 K was compared directly with that of high-quality YBCO films. The surface resistance of MgB2 was found to be approximately three times higher at low microwave power and showed an onset of nonlinearity at microwave surface fields ten times lower than the YBCO film. It is clear that MgB2 films are not yet optimized for microwave applications. (C) 2002 American Institute of Physics. C1 Univ London Imperial Coll Sci Technol & Med, Ctr High Temp Superconduct, London SW7 2BZ, England. Oak Ridge Natl Lab, Oak Ridge, TN 37931 USA. Univ Cambridge, Dept Mat Sci, Cambridge CB2 3QZ, England. Natl Phys Lab, Teddington TW11 0LW, Middx, England. RP Zhukov, AA (reprint author), Univ London Imperial Coll Sci Technol & Med, Ctr High Temp Superconduct, Prince Consort Rd, London SW7 2BZ, England. RI Berenov, Andrey/A-3020-2011; Lockman, Zainovia/F-5260-2011; So Young, Jang/H-9164-2012; Christen, Hans/H-6551-2013; Zhukov, Alexey/J-3730-2013; Paranthaman, Mariappan/N-3866-2015; Jo, Moon-Ho/B-9860-2017 OI Christen, Hans/0000-0001-8187-7469; Paranthaman, Mariappan/0000-0003-3009-8531; Jo, Moon-Ho/0000-0002-3160-358X NR 20 TC 30 Z9 30 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 1 PY 2002 VL 80 IS 13 BP 2347 EP 2349 DI 10.1063/1.1465129 PG 3 WC Physics, Applied SC Physics GA 535BB UT WOS:000174623300037 ER PT J AU Asayama, G Lettieri, J Zurbuchen, MA Jia, Y Trolier-McKinstry, S Schlom, DG Streiffer, SK Maria, JP Bu, SD Eom, CB AF Asayama, G Lettieri, J Zurbuchen, MA Jia, Y Trolier-McKinstry, S Schlom, DG Streiffer, SK Maria, JP Bu, SD Eom, CB TI Growth of (103) fiber-textured SrBi2Nb2O9 films on Pt-coated silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID SRBI2TA2O9 THIN-FILMS; FERROELECTRIC CAPACITORS; ELECTRICAL-PROPERTIES; ORIENTATION; SIO2/SI; LAYER; PT/TI AB (103) fiber-textured SrBi2Nb2O9 thin films have been grown on Pt-coated Si substrates using a SrRuO3 buffer layer. High-resolution transmission electron microscopy reveals that the fiber texture arises from the local epitaxial growth of (111) SrRuO3 grains on (111) Pt grains and in turn (103) SrBi2Nb2O9 grains on (111) SrRuO3 grains. The films exhibit remanent polarization values of 9 muC/cm(2). The uniform grain orientation (fiber texture) should minimize grain-to-grain variations in the remanent polarization, which is important to continued scaling of ferroelectric memory device structures. (C) 2002 American Institute of Physics. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16803 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Asayama, G (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16803 USA. RI Bu, Sang Don/B-1576-2008; Streiffer, Stephen/A-1756-2009; Zurbuchen, Mark/H-1664-2012; Schlom, Darrell/J-2412-2013; Eom, Chang-Beom/I-5567-2014; OI Bu, Sang Don/0000-0003-4883-1308; Zurbuchen, Mark/0000-0002-8947-6309; Schlom, Darrell/0000-0003-2493-6113; Trolier-McKinstry, Susan/0000-0002-7267-9281 NR 26 TC 40 Z9 40 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 1 PY 2002 VL 80 IS 13 BP 2371 EP 2373 DI 10.1063/1.1463697 PG 3 WC Physics, Applied SC Physics GA 535BB UT WOS:000174623300045 ER PT J AU Mikhailovsky, AA Malko, AV Hollingsworth, JA Bawendi, MG Klimov, VI AF Mikhailovsky, AA Malko, AV Hollingsworth, JA Bawendi, MG Klimov, VI TI Multiparticle interactions and stimulated emission in chemically synthesized quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID SEMICONDUCTOR NANOCRYSTALS; OPTICAL NONLINEARITIES; GAIN; DYNAMICS AB We study the effect of multiparticle interactions on optical gain and stimulated emission in close-packed solids of chemically synthesized CdSe nanocrystals (nanocrystal quantum dots). An analysis of pump-dependent nonlinear absorption signals indicates that the band-edge optical gain is due to multiparticle states with a dominant contribution from doubly excited nanocrystals (quantum-confined biexcitons). We observe that optical gain dynamics are due to the competition between ultrafast hole surface trapping and multiparticle Auger decay. We analyze the effect of intrinsic Auger recombination on optical gain lifetimes and gain pump intensity thresholds. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Klimov, VI (reprint author), Los Alamos Natl Lab, Div Chem, C-PCS,MS-J585, Los Alamos, NM 87545 USA. NR 13 TC 71 Z9 73 U1 5 U2 19 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 APR 1 PY 2002 VL 80 IS 13 BP 2380 EP 2382 DI 10.1063/1.1463704 PG 3 WC Physics, Applied SC Physics GA 535BB UT WOS:000174623300048 ER PT J AU Jones, RW McClelland, JF AF Jones, RW McClelland, JF TI Quantitative depth profiling using saturation-equalized photoacoustic spectra SO APPLIED SPECTROSCOPY LA English DT Article DE depth profiling; photoacoustic spectroscopy; PAS; spectrum saturation ID INVERSE SCATTERING-THEORY; PHASE-ANALYSIS; THIN-FILMS; SPECTROSCOPY; TRANSFORM; ABSORPTION; STRATIFICATION; SURFACE; TISSUE; ATR AB Depth profiling using photoacoustic spectra taken at multiple scanning speeds or modulation frequencies is normally impaired by the increase in spectral saturation that occurs with decreasing speed or frequency. Photothermal depth profiling in general is also impeded by the ill conditioned nature of the mathematical problem of determining a depth profile from photothermal data. This paper describes a method for reducing the saturation level in low-speed or low-frequency spectra to the level at high speed or frequency so that all spectra have the same saturation. The conversion method requires only magnitude spectra, so it is applicable to both conventional and phase-modulation photoacoustic spectra. This paper also demonstrates a method for quantitative depth profiling with these converted spectra that makes use of prior knowledge about the type of profile existing in a sample to reduce the instabilities associated with the mathematically ill conditioned task. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. MTEC Photoacoust Inc, Ames, IA 50014 USA. RP Jones, RW (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 38 TC 9 Z9 9 U1 0 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD APR PY 2002 VL 56 IS 4 BP 409 EP 418 DI 10.1366/0003702021954926 PG 10 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 543YE UT WOS:000175130300002 ER PT J AU Anglos, D Melesanaki, K Zafiropulos, V Gresalfi, MJ Miller, JC AF Anglos, D Melesanaki, K Zafiropulos, V Gresalfi, MJ Miller, JC TI Laser-induced breakdown spectroscopy for the analysis of 150-year-old daguerreotypes SO APPLIED SPECTROSCOPY LA English DT Article DE laser-induced breakdown spectroscopy; LIBS; daguerreotypes; depth profiling; laser ablation ID 19TH-CENTURY DAGUERREOTYPES; PIGMENT IDENTIFICATION; PAINTED ARTWORKS; RAMAN MICROSCOPY; DEPTH-PROFILE; SPECTROMETRY; POLYCHROMES; COATINGS; GLASS; STEEL AB Laser-induced breakdown spectroscopy, or LIBS, has been used to characterize the elemental composition of the surface and interior of nineteenth-century, metal-based photographs called daguerreotypes. A surface plasma was produced by the infrared beam of a nanosecond Nd:YAG laser and the emitted light was dispersed in a monochromator to yield the spectroscopic identification of elements. Major components of the daguerreotype surface included silver, copper, and gold. The gold was only, present on the surface, as evidenced by its absence after the first one or two laser shots. Minor components such as silicon, aluminum, calcium, and magnesium reflect contaminant particles arising primarily from the cover glass. Several "colored" or "tinted" daguerreotypes were analyzed and the pigments identified. Depth profiling, accomplished by monitoring the spectra as a function of multiple laser shots, allowed the thickness of the silver layer to be measured as the ablation laser "drilled" into the surface. The LIBS technique is shown to be useful in understanding the composition of daguerreotypes and for identifying the specific pigments used by the photographer. These data also provide a scientific basis for attempts to optimize laser cleaning of tarnished daguerreotypes and may also provide clues to the provenance of particular examples. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. Inst Elect Struct & Laser, Laser & Applicat Div, FORTH, GR-71110 Iraklion, Greece. RP Oak Ridge Natl Lab, Div Life Sci, POB 2008, Oak Ridge, TN 37830 USA. RI Anglos, Demetrios/A-2548-2014 NR 48 TC 34 Z9 34 U1 2 U2 6 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0003-7028 EI 1943-3530 J9 APPL SPECTROSC JI Appl. Spectrosc. PD APR PY 2002 VL 56 IS 4 BP 423 EP 432 DI 10.1366/0003702021955079 PG 10 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 543YE UT WOS:000175130300004 ER PT J AU Losinger, WC Traub-Dargatz, JL Garber, LP Fedorka-Cray, PJ Ladely, S Ferris, KE Morgan, K AF Losinger, WC Traub-Dargatz, JL Garber, LP Fedorka-Cray, PJ Ladely, S Ferris, KE Morgan, K TI Factors associated with fecal-shedding of Salmonella spp by horses on US operations SO ARQUIVO BRASILEIRO DE MEDICINA VETERINARIA E ZOOTECNIA LA English DT Article DE equine operations; national survey; risk factor analysis; logistic regression ID OUTBREAK AB In a cross-sectional national study that included 972 operations with greater than or equal to 3 horses on 1/1/98 in 28 states in the USA, 8,417 fecal specimens were collected from horses and cultured to test for the presence of Salmonella spp. Operations were characterized as Salmonella spp-positive if at least one fecal specimen tested positive for Salmonella spp. Percentages of Salmonella spp-positive operations were computed by management and other factors (collected from operation-level questionnaires) that were hypothesized to be related to fecal shedding of Salmonella spp. A logistic-regression model was constructed to identify factors associated with horses' shedding Salmonella spp in feces on an operation. The odds of an operation being Salmonella spp positive increased as the number of resident horses increased. In addition, the following factors were found to be associated with increased odds of an operation being Salmonella spp positive: horses were used primarily for breeding; operation cleanliness was characterized as poor by the data collector; and new resident equids had been added to the operation without routine quarantine. C1 US DOE, New Brunswick Lab, Argonne, IL 60439 USA. Colorado State Univ, Coll Vet Med & Biomed Sci, Ft Collins, CO 80523 USA. USDA, Washington, DC 20250 USA. RP Losinger, WC (reprint author), US DOE, New Brunswick Lab, 9800 S Cass Ave,Bldg 350, Argonne, IL 60439 USA. NR 25 TC 2 Z9 2 U1 0 U2 0 PU ARQUIVO BRASILEIRO MEDICINA VETERINARIA ZOOTECNIA PI MINAS GERAIS PA FEDERAL MINAS GERAIS CAIXA POSTAL 567-BELO HORIZ, MINAS GERAIS, BRAZIL SN 0102-0935 J9 ARQ BRAS MED VET ZOO JI Arq. Bras. Med. Vet. Zootec. PD APR PY 2002 VL 54 IS 2 BP 109 EP 116 DI 10.1590/S0102-09352002000200001 PG 8 WC Veterinary Sciences SC Veterinary Sciences GA 564QV UT WOS:000176325800001 ER PT J AU Kumar, S Fisk, WJ AF Kumar, S Fisk, WJ TI IEQ and the impact on building occupants SO ASHRAE JOURNAL LA English DT Article ID RESPIRATORY HEALTH; CO2 CONCENTRATIONS; HOME; SYMPTOMS; CHILDREN C1 Lawrence Berkeley Natl Lab, Energy Anal Dept, Washington, DC USA. Lawrence Berkeley Natl Lab, Indoor Environm Dept, Washington, DC USA. RP Kumar, S (reprint author), Lawrence Berkeley Natl Lab, Energy Anal Dept, Washington, DC USA. NR 26 TC 2 Z9 2 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 APR PY 2002 VL 44 IS 4 BP 50 EP 52 PG 3 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA 540DU UT WOS:000174914700016 ER PT J AU Goto, T Sekiguchi, M Nichol, RC Bahcall, NA Kim, RSJ Annis, J Ivezic, Z Brinkmann, J Hennessy, GS Szokoly, GP Tucker, DL AF Goto, T Sekiguchi, M Nichol, RC Bahcall, NA Kim, RSJ Annis, J Ivezic, Z Brinkmann, J Hennessy, GS Szokoly, GP Tucker, DL TI The cut-and-enhance method: Selecting clusters of galaxies from the Sloan Digital Sky Survey commissioning data SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : clusters : general; methods : analytical ID COLOR-MAGNITUDE RELATION; DISTANT CLUSTERS; MATCHED-FILTER; RICH CLUSTERS; DARK CLUSTER; EVOLUTION; CATALOG; LUMINOSITY; PHOTOMETRY; MORPHOLOGY AB We describe an automated method, the cut-and-enhance (CE) method, for detecting clusters of galaxies in multicolor optical imaging surveys. This method uses simple color cuts, combined with a density enhancement algorithm, to up-weight pairs of galaxies that are close in both angular separation and color. The method is semiparametric, since it uses minimal assumptions about cluster properties in order to minimize possible biases. No assumptions are made about the shape of clusters, their radial profile, or their luminosity function. The method is successful in finding systems ranging from poor to rich clusters of galaxies, of both regular and irregular shape. We determine the selection function of the CE method via extensive Monte Carlo simulations that use both the real, observed background of galaxies and a randomized background of galaxies. We use position-shuffled and color-shuffled data to perform false-positive tests. We have also visually checked all the clusters detected by the CE method. We apply the CE method to the 350 deg(2) of the Sloan Digital Sky Survey ( SDSS) commissioning data and construct an SDSS CE galaxy cluster catalog with an estimated redshift and richness for each cluster. The CE method is compared with other cluster selection methods used on SDSS data such as the matched filter, "maxBCG", and Voronoi tessellation techniques. The CE method can be adopted for cluster selection in any multicolor imaging survey. C1 Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Apache Point Observ, Sunspot, NM 88349 USA. USN Observ, Washington, DC 20392 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. RP Goto, T (reprint author), Univ Tokyo, Inst Cosm Ray Res, 5-1-5 Kashiwa, Kashiwa, Chiba 2778582, Japan. RI Brinkmann, Jonathan/H-2779-2014; OI Brinkmann, Jonathan/0000-0001-6128-659X; Tucker, Douglas/0000-0001-7211-5729 NR 60 TC 140 Z9 141 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 2002 VL 123 IS 4 BP 1807 EP 1825 DI 10.1086/339303 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 537JX UT WOS:000174756400001 ER PT J AU Smith, JA Tucker, DL Kent, S Richmond, MW Fukugita, M Ichikawa, T Ichikawa, S Jorgensen, AM Uomoto, A Gunn, JE Hamabe, M Watanabe, M Tolea, A Henden, A Annis, J Pier, JR McKay, TA Brinkmann, J Chen, B Holtzman, J Shimasaku, K York, DG AF Smith, JA Tucker, DL Kent, S Richmond, MW Fukugita, M Ichikawa, T Ichikawa, S Jorgensen, AM Uomoto, A Gunn, JE Hamabe, M Watanabe, M Tolea, A Henden, A Annis, J Pier, JR McKay, TA Brinkmann, J Chen, B Holtzman, J Shimasaku, K York, DG TI The u ' g ' r ' i ' z ' standard-star system SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; standards; stars : fundamental parameters ID PROPER-MOTION STARS; DIGITAL SKY SURVEY; HUBBLE-SPACE-TELESCOPE; SPECTRAL CLASSIFICATIONS; INFRARED PHOTOMETRY; SOLAR NEIGHBORHOOD; HOT SUBDWARFS; WHITE-DWARFS; SPECTROPHOTOMETRY; CATALOG AB We present the 158 standard stars that de ne the u' g' r' i' z' photometric system. These stars form the basis for the photometric calibration of the Sloan Digital Sky Survey. The de ning instrument system and filters, the observing process, the reduction techniques, and the software used to create the stellar network are all described. We briefly discuss the history of the star selection process, the derivation of a set of transformation equations for the UBVRCIC system, and plans for future work. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. Inst Adv Study, Princeton, NJ 08540 USA. Tohoku Univ, Inst Astron, Sendai, Miyagi 9808578, Japan. Natl Astron Observ, Tokyo 1818588, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Japan Womens Univ, Dept Math & Phys Sci, Tokyo 1128681, Japan. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Apache Point Observ, Sunspot, NM 88349 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Univ Tokyo, Dept Astron, Tokyo 1130033, Japan. Univ Tokyo, Res Ctr Early Universe, Tokyo 1130033, Japan. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Smith, JA (reprint author), Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. RI McKay, Timothy/C-1501-2009; OI McKay, Timothy/0000-0001-9036-6150; Smith, J. Allyn/0000-0002-6261-4601; Tucker, Douglas/0000-0001-7211-5729 NR 65 TC 1186 Z9 1189 U1 1 U2 14 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 APR PY 2002 VL 123 IS 4 BP 2121 EP 2144 DI 10.1086/339311 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 537JX UT WOS:000174756400027 ER PT J AU Israel, GL Hummel, W Covino, S Campana, S Appenzeller, I Gassler, W Mantel, KH Marconi, G Mauche, CW Munari, U Negueruela, I Nicklas, H Rupprecht, G Smart, RL Stahl, O Stella, L AF Israel, GL Hummel, W Covino, S Campana, S Appenzeller, I Gassler, W Mantel, KH Marconi, G Mauche, CW Munari, U Negueruela, I Nicklas, H Rupprecht, G Smart, RL Stahl, O Stella, L TI RX J0806.3+1527: A double degenerate binary with the shortest known orbital period (321s) SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual; RX J0806.3+1527, 1BMW J080622.8+152732 binaries : close; stars : white dwarfs; stars : emission-line; X-rays : stars ID OBJECTS; STARS AB We carried out optical observations of the field of the X-ray pulsator RX J0806.3+1527. A blue V = 21.1 star was found to be the only object consistent with the X-ray position. VLT FORS spectra revealed a blue continuum with no intrinsic absorption lines. Broad (v similar to 1500 km s(-1)), low equivalent width (similar to -1 divided by -6 Angstrom) emission lines from the HeII Pickering series were clearly detected. B, V and R time-resolved photometry revealed the presence of similar to15% pulsations at the similar to321 s X-ray period, confirming the identification. These findings, together with the period stability and absence of any additional modulation in the 1 min-5 hr period range, argue in favour of the orbital interpretation of the 321 s pulsations. The most likely scenario is thus that RX J0806.3+1527 is a double degenerate system of the AM CVn class. This would make RX J0806.3+1527 the shortest orbital period binary currently known and one of the best candidates for gravitational wave detection. C1 INAF, Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. European So Observ, D-85748 Garching, Germany. INAF, Osservatorio Astron Brera, I-23807 Merate, Italy. Landessternwarte Heidelberg, D-69117 Heidelberg, Germany. Univ Sternwarte Munchen, Inst Phys, D-81673 Munich, Germany. NAOJ, Subaru Telescope, Hilo, HI 96720 USA. European So Observ, Santiago 19, Chile. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. INAF, Osservatorio Astron Padova, I-36012 Asiago, Italy. Observ Astron, F-67000 Strasbourg, France. Univ Sternwarte Gottingen, D-37083 Gottingen, Germany. INAF, Osservatorio Astron Torino, I-10025 Pino Torinese, To, Italy. RP INAF, Osservatorio Astron Roma, V Frascati 33, I-00040 Monte Porzio Catone, Italy. EM gianluca@mporzio.astro.it RI Negueruela, Ignacio/L-5483-2014; OI Negueruela, Ignacio/0000-0003-1952-3680; Smart, Richard/0000-0002-4424-4766; Covino, Stefano/0000-0001-9078-5507 NR 13 TC 64 Z9 65 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR PY 2002 VL 386 IS 1 BP L13 EP L17 DI 10.1051/0004-6361:20020314 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 543YU UT WOS:000175132100004 ER PT J AU Korn, AJ Keller, SC Kaufer, A Langer, N Przybilla, N Stahl, O Wolf, B AF Korn, AJ Keller, SC Kaufer, A Langer, N Przybilla, N Stahl, O Wolf, B TI Pristine CNO abundances from Magellanic Cloud B stars - I. The LMC cluster NGC 2004 with UVES SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : abundances; stars : atmospheres; stars : early type; galaxies : Magellanic Clouds; galaxies : clusters : individual : NGC 2004 ID STELLAR EVOLUTION; YOUNG CLUSTERS; GALACTIC DISK; MODELS; NGC-2004 AB We present chemical abundances for four main sequence B stars in the young cluster NGC2004 in the Large Magellanic Cloud (LMC). Apart from H II regions, unevolved OB-type stars are currently the only accessible source of present-day CNO abundances for the MCs not altered by stellar evolution. Using UVES on the VLT, we obtained spectra of sufficient resolution (R=20 000) and signal-to-noise (S/N greater than or equal to 100) to derive abundances for a variety of elements (He, C, N, O, Mg and Si) with NLTE line formation. This study doubles the number of main sequence B stars in the LMC with detailed chemical abundances. More importantly and in contrast to previous studies, we find no CNO abundance anomalies brought on by e.g. binary interaction or rotational mixing. Thus, this is the first time that abundances from H II regions in the LMC can sensibly be cross-checked against those from B stars by excluding evolutionary effects. We confirm the H II-region CNO abundances to within the errors, in particular the extraordinarily low nitrogen abundance of epsilon(N) similar or equal to 7.0. Taken at face value, the nebular carbon abundance is 0.16 dex below the B-star value which could be interpreted in terms of interstellar dust depletion. Oxygen abundances from the two sources agree to within 0.03 dex. In comparison with the Galactic thin disk at MC metallicities, the Magellanic Clouds are clearly nitrogen-poor environments. C1 Univ Sternwarte Munchen, D-81679 Munich, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. European So Observ, Santiago 19, Chile. Univ Utrecht, Astron Inst, NL-3584 CC Utrecht, Netherlands. Landessternwarte Heidelberg, D-69115 Heidelberg, Germany. RP Korn, AJ (reprint author), Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany. NR 42 TC 59 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 APR PY 2002 VL 385 IS 1 BP 143 EP 151 DI 10.1051/0004-6361:20020116 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 535BW UT WOS:000174626200014 ER PT J AU Revnivtsev, MG Trudolyubov, SP Borozdin, KN AF Revnivtsev, MG Trudolyubov, SP Borozdin, KN TI Localization of X-ray sources in six galactic globular clusters from Chandra data SO ASTRONOMY LETTERS-A JOURNAL OF ASTRONOMY AND SPACE ASTROPHYSICS LA English DT Article DE X-ray and gamma-ray sources ID BINARIES AB We present our observations of six Galactic globular clusters where the following bright Xray sources were observed: NGC 6440, NGC 6441, NGC 6624, Terzan 1, Terzan 2, and Terzan 6. Using the Chandra observatory, we were able to achieve a localization accuracy of 0''.6 for X-ray sources in the globular clusters. The error circle considerably decreased compared to the observations of other observatories, by more than a factor of 10 for some clusters. We detected at least one X-ray source in each of the globular clusters studied and 12 sources in the globular cluster NGC 6440. The source XB1733-30 in Terzan I was not detected by the Chandra observatory; we obtained an upper limit on its luminosity. (C) 2002 MAIK 'Nauka/Interperiodica". C1 Russian Acad Sci, Space Res Inst, Moscow 117810, Russia. Max Planck Inst Astrophys, D-85740 Garching, Germany. Los Alamos Natl Lab, NIS 2, Los Alamos, NM 87545 USA. RP Revnivtsev, MG (reprint author), Russian Acad Sci, Space Res Inst, Profsoyuznaya Ul 84-32, Moscow 117810, Russia. NR 15 TC 3 Z9 3 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PUBL PI MELVILLE PA C/O AMERICAN INST PHYSICS, 2 HUNTINGTON QUANDRANGLE, STE 1NO1, MELVILLE, NY 11747-4502 USA SN 1063-7737 J9 ASTRON LETT+ JI Astron. Lett.-J. Astron. Space Astrophys. PD APR PY 2002 VL 28 IS 4 BP 237 EP 240 DI 10.1134/1.1467258 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 545PC UT WOS:000175225400004 ER PT J AU Wheeler, JC Meier, DL Wilson, JR AF Wheeler, JC Meier, DL Wilson, JR TI Asymmetric supernovae from magnetocentrifugal jets SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; ISM : jets and outflows; pulsars : general; supernovae : general ID GAMMA-RAY BURSTS; 25 APRIL 1998; ACCRETION DISKS; CORE-COLLAPSE; STELLAR COLLAPSE; NEUTRON-STARS; BLACK-HOLES; GRB 970228; R-PROCESS; EXPLOSIONS AB Strong toroidal magnetic fields generated in stellar collapse can generate magnetocentrifugal jets in analogy to those found in simulations of black hole accretion. Magnetocentrifugal jets may explain why all core collapse supernovae are found to be substantially asymmetric and predominantly bipolar. We describe two phases: the initial LeBlanc-Wilson jet and a subsequent protopulsar or toroidal jet that propagates at about the core escape velocity. The prompt LeBlanc-Wilson jets will produce an excess of neutron-rich matter and hence cannot be the common origin of supernova explosions; similar but less severe problems arise with the protopulsar jet that may be alleviated by partial evacuation along the axis by rotation. The jets will produce bow shocks that tend to expel matter, including iron and silicon, into equatorial tori. This may help to account for observations of the element distribution in Cas A. A magnetic switch mechanism may apply in rare instances ( when there is low density and large magnetic field), with subsequent increase in the speed and collimation of the toroidal jet. The conditions that turn the magnetic switch on would yield a jet that propagates rapidly and with small opening angle through the star, depositing relatively little momentum. The result could be enough infall to form a black hole. A third, highly relativistic jet from the rotating black hole could catch up to the protopulsar jet after it has emerged from the star. The interaction of these two jets plausibly could be the origin of the internal shocks thought to produce gamma-ray bursts and could explain the presence of iron lines in the afterglow. Recent estimates that typical gamma-ray burst energy is similar to3 x 10(50) ergs imply either a very low efficiency for conversion of rotation into jets by the Blandford-Znajek mechanism or a rather rapid turnoff of the jet process even though the black hole still rotates rapidly. Magnetars and hypernovae might arise in an intermediate parameter regime of energetic jets that yield larger magnetic fields and provide more energy than the routine case, but that are not so tightly collimated that they yield failed supernova. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wheeler, JC (reprint author), Univ Texas, Dept Astron, RLM 15308, Austin, TX 78712 USA. EM wheel@astro.as.utexas.edu; dlm@sgra.jpl.nasa.gov; wilson@ricker.llnl.gov NR 81 TC 108 Z9 109 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 2002 VL 568 IS 2 BP 807 EP 819 DI 10.1086/338953 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 535BQ UT WOS:000174625700029 ER PT J AU Thatcher, TL Lai, ACK Moreno-Jackson, R Sextro, RG Nazaroff, WW AF Thatcher, TL Lai, ACK Moreno-Jackson, R Sextro, RG Nazaroff, WW TI Effects of room furnishings and air speed on particle deposition rates indoors SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE aerosol; deposition; indoor; particle; air speed; furnishings ID PENETRATION; POLLUTION; EXPOSURE; OUTDOOR; FLOW; TIME AB Particle deposition to surfaces plays an important role in determining exposures to indoor particles. However, the effects of furnishings and air speed on these rates have not been well characterized. In this study, experiments were performed in an isolated room (volume = 14.2 m(3)) using three different indoor furnishing levels (bare, carpeted, and fully furnished) and four different air flow conditions. Deposition loss rates were determined by generating a short burst of polydispersed particles, then measuring the size-resolved (0.5-10 mum) concentration decay rate using an aerodynamic particle sizer. Increasing the surface area from bare (35 m(2) nominal surface area) to fully furnished (12 m(2) additional surface area) increased the deposition loss rate by as much as a factor of 2.6 with the largest increase seen for the smallest particles. Increasing the mean airspeed from < 5 to 19 cm/s, by means of increasing fan speed, increased the deposition rate for all particle sizes studied by factors ranging from 1.3 to 2.4 with larger particles exhibiting greater effects than smaller particles. The significant effect of particle size and room conditions on deposition loss rates argues against using a single first-order loss-rate coefficient to represent deposition for integrated mass measurements (PM2.5 or PM10). (C) 2002 Published by Elsevier Science Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Thatcher, TL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Lai, Alvin/G-8409-2011; Nazaroff, William/C-4106-2008 OI Lai, Alvin/0000-0002-6202-1988; Nazaroff, William/0000-0001-5645-3357 NR 20 TC 160 Z9 168 U1 5 U2 47 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 APR PY 2002 VL 36 IS 11 BP 1811 EP 1819 AR PII S1352-2310(02)00157-7 DI 10.1016/S1352-2310(02)00157-7 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 560CW UT WOS:000176065200010 ER PT J AU Bhupathiraju, VK Krauter, P Holman, HYN Conrad, ME Daley, PF Templeton, AS Hunt, JR Hernandez, M Alvarez-Cohen, L AF Bhupathiraju, VK Krauter, P Holman, HYN Conrad, ME Daley, PF Templeton, AS Hunt, JR Hernandez, M Alvarez-Cohen, L TI Assessment of in-situ bioremediation at a refinery waste-contaminated site and an aviation gasoline contaminated site SO BIODEGRADATION LA English DT Article DE aviation gasoline; biodegradation; bioremediation; direct microscopy; petroleum hydrocarbons; radioisotopes ID INTRINSIC BIOREMEDIATION; PETROLEUM-HYDROCARBONS; NATURAL ATTENUATION; GROUND WATER; BACTERIA; AQUIFER; BIODEGRADATION; METHANE; ALKANES; CARBON AB A combination of geochemical, microbiological and isotopic methods were used to evaluate in-situ bioremediation of petroleum hydrocarbons at one site contaminated with refinery waste and a second site contaminated with aviation gasoline at Alameda Point, California. At each site, geochemical and microbiological characteristics from four locations in the contaminated zone were compared to those from two uncontaminated background locations. At both sites, the geochemical indicators of in-situ biodegradation included depleted soil gas and groundwater oxygen, elevated groundwater alkalinity, and elevated soil gas carbon dioxide and methane in the contaminated zone relative to the background. Radiocarbon content of methane and carbon dioxide measured in soil gas at both sites indicated that they were derived from hydrocarbon contaminant degradation. Direct microscopy of soil core samples using cell wall stains and activity stains, revealed elevated microbial numbers and enhanced microbial activities in contaminated areas relative to background areas, corroborating geochemical findings. While microbial plate counts and microcosm studies using soil core samples provided laboratory evidence for the presence of some microbial activity and contaminant degradation abilities, they did not correlate well with either contaminant location, geochemical, isotopic, or direct microscopy data. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Environm Restorat Ctr, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Alvarez-Cohen, L (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. EM alvarez@ce.berkeley.edu RI Conrad, Mark/G-2767-2010; Holman, Hoi-Ying/N-8451-2014; OI Holman, Hoi-Ying/0000-0002-7534-2625; TEMPLETON, ALEXIS/0000-0002-9670-0647 FU NIEHS NIH HHS [P42-ES04705] NR 33 TC 22 Z9 24 U1 1 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0923-9820 J9 BIODEGRADATION JI Biodegradation PD APR PY 2002 VL 13 IS 2 BP 79 EP 90 DI 10.1023/A:1020415626554 PG 12 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 599GQ UT WOS:000178326100001 PM 12449311 ER PT J AU Kane, SR Beller, HR Legler, TC Anderson, RT AF Kane, SR Beller, HR Legler, TC Anderson, RT TI Biochemical and genetic evidence of benzylsuccinate synthase in toluene-degrading, ferric iron-reducing Geobacter metallireducens SO BIODEGRADATION LA English DT Article DE anaerobic; benzylsuccinate synthase; bssA; Geobacter metallireducens; toluene ID SP STRAIN-T; ANAEROBIC TOLUENE; DENITRIFYING BACTERIUM; DESULFOBACTERIUM-CETONICUM; ENRICHMENT CULTURE; THAUERA-AROMATICA; INITIAL REACTIONS; M-XYLENE; METABOLISM; OXIDATION AB In vitro assays demonstrated that toluene-grown cells of Geobacter metallireducens catalyzed the addition of toluene to fumarate to form benzylsuccinate under anaerobic conditions. The specific in vitro rate of benzylsuccinate formation was ca. 45% of the specific in vivo rate of toluene consumption. In addition, bssA and bssB, which code for the alpha and beta subunits of benzylsuccinate synthase (BSS), respectively, were found to have sequences in G. metallireducens similar to the only sequences heretofore available (for three denitrifying strains). This is the first report of the presence of BSS in a ferric iron-reducing bacterium; BSS activity has previously been reported in denitrifying, sulfate-reducing, and anoxygenic phototrophic toluene degraders, as well as in a highly enriched methanogenic, toluene-degrading culture. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Massachusetts, Dept Microbiol, Amherst, MA 01003 USA. RP Beller, HR (reprint author), Lawrence Livermore Natl Lab, POB 808,L-542, Livermore, CA 94551 USA. RI Beller, Harry/H-6973-2014 NR 26 TC 46 Z9 47 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-9820 J9 BIODEGRADATION JI Biodegradation PD APR PY 2002 VL 13 IS 2 BP 149 EP 154 DI 10.1023/A:1020454831407 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 599GQ UT WOS:000178326100007 PM 12449317 ER PT J AU Xu, Y Olman, V Xu, D AF Xu, Y Olman, V Xu, D TI Clustering gene expression data using a graph-theoretic approach: an application of minimum spanning trees SO BIOINFORMATICS LA English DT Article ID PATTERNS AB Motivation: Gene expression data clustering provides a powerful tool for studying functional relationships of genes in a biological process. Identifying correlated expression patterns of genes represents the basic challenge in this clustering problem. Results: This paper describes a new framework for representing a set of multi-dimensional gene expression data as a Minimum Spanning Tree (MST), a concept from the graph theory. A key property of this representation is that each cluster of the expression data corresponds to one subtree of the MST, which rigorously converts a multi-dimensional clustering problem to a tree partitioning problem. We have demonstrated that though the inter-data relationship is greatly simplified in the MST representation, no essential information is lost for the purpose of clustering. Two key advantages in representing a set of multi-dimensional data as an MST are: (1) the simple structure of a tree facilitates efficient implementations of rigorous clustering algorithms, which otherwise are highly computationally challenging; and (2) as an MST-based clustering does not depend on detailed geometric shape of a cluster, it can overcome many of the problems faced by classical clustering algorithms. Based on the MST representation, we have developed a number of rigorous and efficient clustering algorithms, including two with guaranteed global optimality. We have implemented these algorithms as a computer software EXpression data Clustering Analysis and VisualizATiOn Resource (EXCAVATOR), To demonstrate its effectiveness, we have tested it on three data sets, i.e. expression data from yeast Saccharomyces cerevisiae, expression data in response of human fibroblasts to serum, and Arabidopsis expression data in response to chitin elicitation. The test results are highly encouraging. Availability: EXCAVATOR is available on request from the authors. Contact: xyn@ornl.gov. C1 Oak Ridge Natl Lab, Prot Informat Grp, Div Life Sci, Oak Ridge, TN 37831 USA. RP Xu, Y (reprint author), Oak Ridge Natl Lab, Prot Informat Grp, Div Life Sci, MS 6480, Oak Ridge, TN 37831 USA. NR 18 TC 111 Z9 120 U1 1 U2 9 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD APR PY 2002 VL 18 IS 4 BP 536 EP 545 DI 10.1093/bioinformatics/18.4.536 PG 10 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 551CP UT WOS:000175542200005 PM 12016051 ER PT J AU Kim, SH Opdahl, A Marmo, C Somorjai, GA AF Kim, SH Opdahl, A Marmo, C Somorjai, GA TI AFM and SFG studies of pHEMA-based hydrogel contact lens surfaces in saline solution: adhesion, friction, and the presence of non-crosslinked polymer chains at the surface SO BIOMATERIALS LA English DT Article DE contact lens; hydrogel; AFM; SFG; friction; adhesion ID SCANNING FORCE MICROSCOPY; HUMAN SERUM-ALBUMIN; POLY(2-HYDROXYETHYL METHACRYLATE); MICROMECHANICAL PROPERTIES; BACTERIAL ADHESION; FUNCTIONAL-GROUPS; ADSORBED POLYMER; HYDRATION FORCES; DRYNESS RATINGS; WATER-CONTENT AB The Surfaces of two types of soft contact lenses neutral and ionic hydrogels-were characterized by atomic force microscopy (AFM) and sum-frequency-generation (SFG) vibrational spectroscopy. AFM measurements in saline solution showed that the presence of ionic functional groups at the surface lowered the friction and adhesion to a hydrophobic polystyrene tip. This was attributed to the specific interactions of water and the molecular orientation of hydrogel chains at the surface. Friction and adhesion behavior also revealed the presence of domains of non-crosslinked polymer chains at the lens surface. SFG showed that the lens surface became partially dehydrated upon exposure to air. On this partially dehydrated lens surface, the non-crosslinked domains exhibited low friction and adhesion in AFM. Fully hydrated in saline solution, the non-crosslinked domains extended more than tens of nanometers into solution and were mobile. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Ocular Sci Inc, San Francisco, CA 94080 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 54 TC 87 Z9 87 U1 3 U2 58 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 APR PY 2002 VL 23 IS 7 BP 1657 EP 1666 AR PII S0142-9612(01)00292-7 DI 10.1016/S0142-9612(01)00292-7 PG 10 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 527PX UT WOS:000174196100012 PM 11922469 ER PT J AU Anderson, BC Bloom, PD Baikerikar, KG Sheares, VV Mallapragada, SK AF Anderson, BC Bloom, PD Baikerikar, KG Sheares, VV Mallapragada, SK TI At-Cu-Fe quasicrystal/ultra-high molecular weight polyethylene composites as biomaterials for acetabular cup prosthetics SO BIOMATERIALS LA English DT Article DE quasicrystal; reduced wear; polymer composite; joint replacement; biocompatible ID QUASI-CRYSTAL; WEAR; OXIDATION; SURFACE AB Polymer composites of Al-Cu Fe quasicrystals and ultra-high molecular weight polyethylene (UHMWPE) were investigated for use in acetabular cup prosthetics. The wear properties of the Al Cu-Fe/UHMWPE samples and a 440 steel ball counterface were measured. The mechanical strength of the Al Cu Fe/UHMWPE composites was compared to UHMWPE and alumina/UHMWPE. The biocompatibility of the composite material was tested using a direct contact cytotoxicity assay. At-Cu-Fe/UHMWPE demonstrated lower volume loss after wear and higher mechanical strength than UHMWPE. This composite material also showed no increase in counterface wear or cytotoxicity relative to UHMWPE. These combined results demonstrate that Al Cu Fe/UHMWPE composites are promising candidate materials for acetabular cup prosthetics. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Iowa State Univ Sci & Technol, Dept Chem Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Mallapragada, SK (reprint author), Iowa State Univ Sci & Technol, Dept Chem Engn, 2114 Sweeney Hall, Ames, IA 50011 USA. RI Mallapragada, Surya/F-9375-2012 NR 27 TC 57 Z9 61 U1 1 U2 9 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 APR PY 2002 VL 23 IS 8 BP 1761 EP 1768 AR PII S0142-9612(01)00301-5 DI 10.1016/S0142-9612(01)00301-5 PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 536FD UT WOS:000174689300005 PM 11950046 ER PT J AU Wofsy, C Goldstein, B AF Wofsy, C Goldstein, B TI Effective rate models for receptors distributed in a layer above a surface: Application to cells and biacore SO BIOPHYSICAL JOURNAL LA English DT Article ID PLASMON RESONANCE BIOSENSORS; MASS-TRANSPORT; KINETIC-ANALYSIS; POLYMER MATRIX; RATE CONSTANTS; BINDING; DIFFUSION; CONVECTION AB In the Biacore biosensor, a widely used tool for studying the kinetics of ligand/receptor binding, receptors are commonly localized to the sensor surface through attachment to polymers that extend from the surface to form a layer. The importance of the polymeric layer in analyzing data is controversial. The question of the effect of a binding layer also arises in the case of ligands interacting with binding sites distributed in the extracellular matrix of cells. To identify and quantify the effects of a binding layer on the estimation of association and dissociation rate constants, we derived effective rate coefficients. The expressions show that rate constants determined under the standard assumption that binding takes place on a two-dimensional surface underestimate the true reaction rate constants by a factor that depends on the ratio of the height of the layer to the mean free path of the ligand within the layer. We show that, for typical biological ligands, receptors, cells, and Biacore conditions, the binding layer will affect the interpretation of data only if transport of the ligand in the layer is slowed substantially - by one or two orders of magnitude-relative to transport outside the layer. From existing experiments and theory, it is not clear which Biacore experiments, if any, have transport within the dextran layer reduced to such an extent. We propose a method, based on the effective rate coefficients we have derived, for the experimental determination of ligand diffusion coefficients in a polymeric matrix. C1 Los Alamos Natl Lab, Div Theoret, Theoret Biol & Biophys Grp, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM 87131 USA. RP Goldstein, B (reprint author), Los Alamos Natl Lab, Div Theoret, Theoret Biol & Biophys Grp, T-10,MS K710, Los Alamos, NM 87545 USA. FU NIGMS NIH HHS [GM35556] NR 25 TC 35 Z9 35 U1 1 U2 4 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD APR PY 2002 VL 82 IS 4 BP 1743 EP 1755 PG 13 WC Biophysics SC Biophysics GA 540MH UT WOS:000174932400006 PM 11916835 ER PT J AU Ji, HF Thundat, T AF Ji, HF Thundat, T TI In situ detection of calcium ions with chemically modified microcantilevers SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE microcantilevers; calcium ion detection; selective coatings; self assembled monolayers ID INDUCED SURFACE STRESS; SELECTIVE ELECTRODE; RESONATING MICROCANTILEVERS; FORCE MICROSCOPE; NEUTRAL CARRIER; SENSORS; IONOPHORES; COMPONENT; COATINGS; DESIGN AB We report a novel technique of micromechanical detection of trace amounts of calcium ions by using microcantilevers modified with ion-selective self-assembled monolayers (SAMs). The SAM-modified microcantilevers undergo bending due to selective adsorption of calcium ions. Experiments conducted under flow conditions show that the modified cantilevers respond sensitively to calcium ions (Ca2+); a Ca2+ concentration of 10(-9) M can be detected with this technique. Other cations, such as Na+ and K+, do not have any effect on the deflection of these cantilevers. We demonstrate two different kinds of SAMs having selectivity for calcium ions. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Thundat, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NR 27 TC 45 Z9 47 U1 1 U2 11 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 APR PY 2002 VL 17 IS 4 SI SI BP 337 EP 343 AR PII S0956-5663(01)00270-6 DI 10.1016/S0956-5663(01)00270-6 PG 7 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 536GX UT WOS:000174693300012 PM 11849931 ER PT J AU Cooke, BM Glenister, FK Mohandas, N Coppel, RL AF Cooke, BM Glenister, FK Mohandas, N Coppel, RL TI Assignment of functional roles to parasite proteins in malaria-infected red blood cells by competitive flow-based adhesion assay SO BRITISH JOURNAL OF HAEMATOLOGY LA English DT Article DE malaria; Plasmodium falciparum; erythrocyte; membrane skeleton; cell adhesion ID ERYTHROCYTE SURFACE-ANTIGEN; PLASMODIUM-FALCIPARUM; ULTRASTRUCTURAL ANALYSIS; CEREBRAL MALARIA; CYTOADHERENCE; MEMBRANE; CD36; KNOBS; GENE; SEQUESTRATION AB Adhesion of parasitized red blood cells (PRBCs) to endothelial cells and subsequent accumulation in the microvasculature are pivotal events in the pathogenesis of falciparum malaria. During intraerythrocytic development, numerous proteins exported from the parasite associate with the RBC membrane skeleton but the precise function of many of these proteins remain unknown. Their cellular location, however, suggests that some may play a role in adhesion. The adhesive properties of PRBCs are best studied under flow conditions in vitro ; however, experimental variation in levels of cytoadherence in currently available assays make subtle alterations in adhesion difficult to quantify. Here, we describe a flow-based assay that can quantify small differences in adhesion and document the extent to which a number of parasite proteins influence adhesion using parasite lines that no longer express specific proteins. Loss of parasite proteins ring-infected erythrocyte surface antigen (RESA), knob-associated histidine-rich protein (KAHRP) or Plasmodium falciparum erythrocyte membrane protein 3 (PfEMP3) had a significant effect on the ability of PRBCs to adhere, whereas loss of mature parasite-infected erythrocyte surface antigen (MESA) had no effect. Our studies indicate that a number of membrane skeleton-associated parasite proteins, although not exposed on the RBC surface, can collectively affect the adhesive properties of PRBCs and further our understanding of pathophysiologically relevant structure/function relationships in malaria-infected RBCs. C1 Monash Univ, Dept Microbiol, Clayton, Vic 3800, Australia. Lawrence Berkeley Lab, Berkeley, CA USA. RP Cooke, BM (reprint author), Monash Univ, Dept Microbiol, POB 53, Clayton, Vic 3800, Australia. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK32094-10] NR 42 TC 32 Z9 32 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0007-1048 J9 BRIT J HAEMATOL JI Br. J. Haematol. PD APR PY 2002 VL 117 IS 1 BP 203 EP 211 DI 10.1046/j.1365-2141.2002.03404.x PG 9 WC Hematology SC Hematology GA 549GK UT WOS:000175436000031 PM 11918556 ER PT J AU Allwine, KJ Shinn, JH Streit, GE Clawson, KL Brown, M AF Allwine, KJ Shinn, JH Streit, GE Clawson, KL Brown, M TI Overview of urban 2000 - A multiscale field study of dispersion through an urban environment SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SKY-VIEW-FACTORS; WIND-TUNNEL; MODEL CUBE; TRACER; DIFFUSION; FLOW; AREA; WAKE C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Allwine, KJ (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Clawson, Kirk/C-5910-2016 OI Clawson, Kirk/0000-0002-8789-9607 NR 29 TC 124 Z9 137 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 2002 VL 83 IS 4 BP 521 EP 536 DI 10.1175/1520-0477(2002)083<0521:OOUAMF>2.3.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 547RZ UT WOS:000175346800017 ER PT J AU Doran, JC Fast, JD Horel, J AF Doran, JC Fast, JD Horel, J TI The VTMX 2000 campaign SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID OZONE LAYERS ALOFT; BOUNDARY-LAYER; COMPLEX TERRAIN; VALLEY; LIDAR; BASIN; MODEL; CLOUD; FLUX; AREA C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Utah, Salt Lake City, UT 84112 USA. RP Doran, JC (reprint author), Pacific NW Natl Lab, POB 999,MSIN K9-30, Richland, WA 99352 USA. NR 26 TC 84 Z9 84 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 2002 VL 83 IS 4 BP 537 EP 551 DI 10.1175/1520-0477(2002)083<0537:TVC>2.3.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 547RZ UT WOS:000175346800018 ER PT J AU Weber, PK Hutcheon, ID McKeegan, KD Ingram, BL AF Weber, PK Hutcheon, ID McKeegan, KD Ingram, BL TI Otolith sulfur isotope method to reconstruct salmon (Oncorhynchus tshawytscha) life history SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID CARBON AB We report a new ion microprobe method to reconstruct aspects of fish life history based on sulfur isotopes (S-34/S-32, expressed as delta(34)S). Selected hatchery raised and naturally spawned juvenile chinook salmon (Oncorhynchus tshawytscha) are shown to have a 12.96 +/- 0.27parts per thousand (mean +/- 2 standard errors) difference in muscle delta(34)S values, corresponding to delta(34)S differences between the hatchery and freshwater diets. Isotopic microanalyses of otoliths demonstrate that this 13parts per thousand difference is preserved in the otoliths. We interpret the otolith delta(34)S record to be a chronology of dietary delta(34)S, with approximately one-week temporal resolution, preserved in these banded calcium carbonate structures. Potential applications of this method include identifying hatchery raised fish and reconstructing nutrition sources, migration, and other aspects of fish life history. C1 Univ Calif Berkeley, Dept Geog, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Analyt & Nucl Chem Div, Livermore, CA 94551 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. RP Weber, PK (reprint author), Univ Calif Berkeley, Dept Geog, Berkeley, CA 94720 USA. RI McKeegan, Kevin/A-4107-2008; UCLA, SIMS/A-1459-2011 OI McKeegan, Kevin/0000-0002-1827-729X; NR 12 TC 47 Z9 51 U1 2 U2 14 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD APR PY 2002 VL 59 IS 4 BP 587 EP 591 DI 10.1139/F02-038 PG 5 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 564KH UT WOS:000176313200001 ER PT J AU Payzant, EA King, HW AF Payzant, EA King, HW TI A high temperature X-ray diffraction investigation of the beta-(Bi2O3)(1-x)(SrO)(x) solid solution SO CANADIAN METALLURGICAL QUARTERLY LA English DT Article ID MIXED OXIDES; CRYSTAL-CHEMISTRY; PHASE-EQUILIBRIA; SYSTEM; DIFFRACTOMETRY AB The incidence of phase transitions in the beta-(Bi2O3)(1-x)(SrO)(x) solid solution was examined over the composition range x = 0.18-0.42 using in situ high temperature X-ray diffraction. The a lattice parameter of the rhombohedral structure (referenced to hexagonal axes) is approximately constant across the entire composition range of the beta-phase. The c parameter also remains approximately constant at compositions of x less than or equal to 0.28, but at x > 0.28 this parameter shows a marked increase in compositional dependence. The temperature dependence of the a and c lattice parameters exhibits discrete discontinuities at distinct temperatures T-0 which occur between 600 and 710 degreesC depending on the composition. These fully reversible effects confirm previous reports of structural discontinuities, and are consistent with observations of enhanced ionic conductivity, differential thermal analysis (DTA) peaks and transmission electron microscope (TEM) superlattice reflections indicative of an order:disorder transition in the beta-phase. The maximum magnitude of the associated discontinuity in the volume of the unit cell occurs at the stoichiometric composition of x = 0.28 which represents an equal number of Bi3+ and Sr2+ ions. The c parameter/temperature plot for the composition x = 0.42 shows a distinct increase in slope at a temperature T-1 which is close to 490 degreesC. This effect is attributed to the relief of localized microdomains of order or the progressive disorder of a superlattice with a considerable defect structure. The transition temperatures T-0 and T-1 correlate closely with previously reported temperatures of discrete increases in oxygen ion conductivity and of DTA peaks and enable an effective composition/temperature boundary to be defined between the disordered and ordered beta-phase structures. C1 Univ Western Ontario, Dept Mat Engn, London, ON N6A 5B9, Canada. RP Payzant, EA (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Payzant, Edward/B-5449-2009 OI Payzant, Edward/0000-0002-3447-2060 NR 32 TC 1 Z9 1 U1 1 U2 3 PU MANEY PUBLISHING PI LEEDS PA STE 1C, JOSEPHS WELL, HANOVER WALK, LEEDS LS3 1AB, W YORKS, ENGLAND SN 0008-4433 J9 CAN METALL QUART JI Can. Metall. Q. PD APR PY 2002 VL 41 IS 2 BP 263 EP 271 PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 544HE UT WOS:000175151500014 ER PT J AU Kennel, SJ Brechbiel, MW Milenic, DE Schlom, J Mirzadeh, S AF Kennel, SJ Brechbiel, MW Milenic, DE Schlom, J Mirzadeh, S TI Actinium-225 conjugates of MAb CC49 and humanized Delta CH(2)CC49 SO CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS LA English DT Article DE MAb CC49; Ac-225; HEHA; micro-distribution; therapy; radiotoxicity ID SINGLE-CHAIN FV; MONOCLONAL-ANTIBODY; TUMOR-CELLS; RADIOIMMUNOTHERAPY; RADIOTOXICITY; BI-213; MICROMETASTASES; IMMUNOGLOBULIN; PROTEINS; THERAPY AB Radioisotopes With Moderate half-lives arc essential for conventional radioimmunotherapy using tumor selective MAbs which require days for localization. Actinium-225, with a half-life of 10 days and a yield of 4 alpha particles in its decal, Chain, may be all ideal choice for tumor-targeted radioimmunotheraphy. Release of daughter radioisotopes from the primary chelator after the first decay has been a complication With the use Of Ac-225. It has been reported that the domain-deleted product of MAb CC49, Hu-DeltaCH(2) CC49, is able to extravasate and penetrate more deeply into tumors than the parent IgG molecule. We reasoned that once the Ac-225-chelate-MAb had penetrated into the tumor, the daughter radioisotopes would remain trapped even if they had been released from the primary chelator. Actinium-225 HEHA MAb CC49 conjugates were tested for distribution, micro-distribution and therapy in immunocompromised mice which had LS174T tumors growing at subcutaneous Or intramuscular sites. Both I-125 and Ac-225 CC49 and Hu-DeltaCH(2) CC49 were efficient in delivery of the radioisotopes to tumor sites. Tissue micro-autoradiography for the two antibody forms did not demonstrate ally differences in micro-distribution of either I-125 or Ac-225 ill the tumor. Furthermore, there was no detectable difference for the two carriers ill the tumor retention of daughter radio isotopes from Ac-225. Therapy experiments with Ac-225 were complicated by radiotoxicity of the conjugates. The lethal dose was about 0.5 muCi ill two strains of mice regardless of the carrier. At injected closes of 0.5 and 0.25 muCi, CC49 was slightly active ill tumor stasis, whereas 170 consistent significant effect of Ac-225-Hu-DeltaCH(2) CC49 oil growth of tumors was observed. The potential of Ac-225 in radioimmunotherapy is limited by the radiotoxicity of its daughter radioisotopes. Its potential will only be realized if stable conjugates, capable of daughter radioisotope retention, call be devised. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NCI, Ctr Canc Res, NIH, Bethesda, MD 20892 USA. RP Kennel, SJ (reprint author), Oak Ridge Natl Lab, Div Life Sci, Bldg 4500S,Rm F150, Oak Ridge, TN 37831 USA. NR 31 TC 12 Z9 12 U1 2 U2 4 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1084-9785 J9 CANCER BIOTHER RADIO JI Cancer Biother. Radiopharm. PD APR PY 2002 VL 17 IS 2 BP 219 EP 231 DI 10.1089/108497802753773847 PG 13 WC Oncology; Medicine, Research & Experimental; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Research & Experimental Medicine; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging GA 552ZW UT WOS:000175651300010 PM 12030116 ER PT J AU Cherry, RS AF Cherry, RS TI Where are chemical engineers headed? SO CHEMICAL ENGINEERING PROGRESS LA English DT Letter C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83401 USA. RP Cherry, RS (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83401 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0360-7275 J9 CHEM ENG PROG JI Chem. Eng. Prog. PD APR PY 2002 VL 98 IS 4 BP 10 EP 10 PG 1 WC Engineering, Chemical SC Engineering GA 541AD UT WOS:000174962300003 ER PT J AU Karbowiak, M Edelstein, NM Drozdynski, J AF Karbowiak, M Edelstein, NM Drozdynski, J TI Spectroscopic studies and dynamics of Nd3+ ions in RbY2Cl7 single crystals. Part I. Analysis of site-selective excitation and emission spectra SO CHEMICAL PHYSICS LA English DT Article ID UP-CONVERSION; RBGD2BR7 AB Single crystals of Nd3+ :RbY2Cl7 were grown by the Bridgman-Stockbarger method. The host crystal contains two slightly inequivalent Y3+ ions, each with an approximate C-2v site symmetry. The crystal-field energy levels of the Nd 31 ion doped in the two slightly inequivalent sites of the host crystal have been measured by optical absorption spectroscopy as well as by laser-selective excitation and emission experiments. As many as 151 and 156 energy levels have been ascribed to the Nd(l) and Nd(2) sites, respectively. Emission transients of a number of the levels were determined. Strong fluorescence and upconversion transitions were recorded and some mechanisms involving excited state absorption and energy transfer between Nd3+ ions were proposed as explanatory for the results of the present investigations. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Wroclaw B Beirut Univ, Fac Chem, PL-50383 Wroclaw, Poland. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Drozdynski, J (reprint author), Wroclaw B Beirut Univ, Fac Chem, Ul F Joliot Curie 14, PL-50383 Wroclaw, Poland. NR 12 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD APR 1 PY 2002 VL 277 IS 3 BP 341 EP 359 AR PII S0301-0104(02)00324-5 DI 10.1016/S0301-0104(02)00324-5 PG 19 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 538RH UT WOS:000174828500008 ER PT J AU Karbowiak, M Edelstein, NM Drozdzynski, J Kossowski, K AF Karbowiak, M Edelstein, NM Drozdzynski, J Kossowski, K TI Spectroscopic studies and dynamics of Nd3+ ions in RbY2Cl7 single crystals. Part II. Crystal-field analysis SO CHEMICAL PHYSICS LA English DT Article ID ENERGY-LEVEL STRUCTURES; ND-3+; LANTHANIDES; ACTINIDES; RBGD2BR7; HOSTS AB Crystal-field energy levels of Nd3+ ions doped in the two slightly inequivalent sites of the RbY2Cl7 host crystal were assigned and fitted to the parameters of a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions. Using the one-electron crystal-field formalism 151 levels of the Nd(1) site and 156 levels of the Nd(2) site were assigned with a r.m.s. deviation of 17.5 and 15.4 cm(-1), respectively. Including correlation crystal-field terms into the semiempirical Hamiltonian we could obtain an improvement of the r.m.s. deviation for the Nd(1) and Nd(2) site up to 11.4 and 10.3 cm(-1), respectively, as well as the elimination of major discrepancies between the calculated and observed energy levels within the anomalous H-2(2)(11/2) and F-2(2)(5/2) multiplets. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Wroclaw B Beirut Univ, Fac Chem, PL-50383 Wroclaw, Poland. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Drozdzynski, J (reprint author), Wroclaw B Beirut Univ, Fac Chem, Ul F Joliot Curie 14, PL-50383 Wroclaw, Poland. NR 21 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD APR 1 PY 2002 VL 277 IS 3 BP 361 EP 372 AR PII S0301-0104(02)00323-3 DI 10.1016/S0301-0104(02)00323-3 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 538RH UT WOS:000174828500009 ER PT J AU Marquez, M Robinson, J Van Nostrand, V Schaefer, D Ryzhkov, LR Lowe, W Suib, SL AF Marquez, M Robinson, J Van Nostrand, V Schaefer, D Ryzhkov, LR Lowe, W Suib, SL TI Atomic force microscopy, electron paramagnetic resonance and X-ray fluorescence investigations of self-assembled lines from colloidal solutions of lamellar MnOx SO CHEMISTRY OF MATERIALS LA English DT Article ID OCTAHEDRAL MOLECULAR-SIEVES; MANGANESE OXIDE; MAGNETORESISTANCE; NUCLEATION; FRAMEWORKS; PROSPECTS; SOLIDS; SILICA; PORES; FILMS AB In this article, we report AFM, EPR, and X-ray fluorescence studies of well-ordered linear patterns of manganese oxide deposited onto glass and quartz surfaces. The patterns reported here were generated from newly described colloidal solutions of manganese oxide nanoparticles of composition [N(CH3)(4)]+0.93Mn2.14+Mn1.93+O7(OH)(1.03).5H(2)O. Qualitative studies, and quantitative analysis of the concentration dependence of the width, frequency, and height of the ordered lines of Nino, (average Mn oxidation state of 3.52) were performed. These results provide information about the morphology of the patterns, the distribution of Mn within the lines, and the nature of free-radicals detected in this material. C1 Towson State Univ, Dept Chem, Towson, MD 21252 USA. Univ Connecticut, Dept Chem, Storrs, CT 06269 USA. Towson State Univ, Dept Phys Astron & Geosci, Towson, MD 21252 USA. Howard Univ, Dept Phys, MHATT CAT, Washington, DC 20059 USA. Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Kraft Gen Foods Inc, Nanotechnol Lab Res & Dev, Glenview, IL 60025 USA. RP Ryzhkov, LR (reprint author), Towson State Univ, Dept Chem, Towson, MD 21252 USA. NR 43 TC 8 Z9 8 U1 1 U2 5 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 APR PY 2002 VL 14 IS 4 BP 1493 EP 1499 DI 10.1021/cm010285u PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 542DR UT WOS:000175028700009 ER PT J AU Boxall, DL Kenik, EA Lukehart, CM AF Boxall, DL Kenik, EA Lukehart, CM TI Synthesis of PtSn/carbon nanocomposites using trans-PtCl(PEt3)2(SnCl3) as the source of metal SO CHEMISTRY OF MATERIALS LA English DT Article ID SN/PT(111) SURFACE ALLOYS; PT-SN; REFORMING CATALYSTS; DEHYDROGENATION; PRECURSOR; SILICA; REACTIVITY; ACTIVATION; OXIDATION; CHEMISTRY AB Five Pt-Sn/Vulcan carbon nanocomposites containing metal nanoclusters highly dispersed on a carbon powder support have been prepared using trans-PtCl(PEt3)(2)(SnCl3) as the source of metal. Thermal gravimetric analysis of the decomposition of this complex in air reveals a single-step loss of all nonmetallic elements centered at 243 degreesC. X-ray diffraction (XRD) analysis confirms formation of PtSn (niggliite) nanocrystals as the only crystalline phase present in the nanocomposite products, excluding trace contamination by Pt metal in one sample. Pt/Sn atomic ratios determined from on-particle high-resolution energy-dispersive spectroscopy (HR-EDS) measurements are consistent with the formation of PtSn nanocrystals and provide no evidence for the formation of phase-separated compositions. Metal nanoclusters are formed using single or multiple depositions of precursor with average sizes of 7-26 nm even at metal loadings as high as 40 wt %. C1 Vanderbilt Univ, Dept Chem, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Lukehart, CM (reprint author), Vanderbilt Univ, Dept Chem, Box 1583, Nashville, TN 37235 USA. NR 26 TC 24 Z9 24 U1 0 U2 6 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 APR PY 2002 VL 14 IS 4 BP 1715 EP 1720 DI 10.1021/cm010952j PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 542DR UT WOS:000175028700039 ER PT J AU Huang, JY Zhu, YT AF Huang, JY Zhu, YT TI Atomic-scale structural investigations on the nucleation of cubic boron nitride from amorphous boron nitride under high pressures and temperatures SO CHEMISTRY OF MATERIALS LA English DT Article ID DIAMOND-LIKE CARBON; DEPOSITED DIAMOND; THIN-FILMS; BN; GROWTH; PHASES AB By controlling the microstructure of the starting materials, i.e., by ball-milling a commercial hexagonal boron nitride (h-BN) to an amorphous boron nitride (a-BN), the subsequent high-pressure and high-temperature (HP-HT) induced phase transformation has been significantly facilitated. Namely, cubic boron nitride (c-BN) forms at 900 degreesC and achieves accomplishment at 1350 degreesC under 7.7 GPa, which are significantly less-extreme conditions than that of crystalline h-BN under similar HP-HT treatments. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) clarified the nucleation mechanism at an atomic scale. It demonstrated that the c-BN phase nucleates directly from the sp(3)-hybridized amorphous matrix, which is originally induced by ball-milling and is therefore responsible for the reduced HP-HT conditions. This c-BN nucleation mechanism is completely different from the so-called diffusionless "puckering" mechanism involved in the HP-HT experiments starting from crystalline h-BN but very similar to one of the proposed mechanisms involved in the chemical vapor deposition (CVD) of diamond and c-BN. It turns out that the present experimental results provide not only a less-extreme way to synthesize nanocrystalline c-BN material but also key clues to the understanding of the nucleation mechanisms involved in the CVD diamond or c-BN, which are still under controversy. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Huang, JY (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MS G755, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Huang, Jianyu/C-5183-2008 OI Zhu, Yuntian/0000-0002-5961-7422; NR 34 TC 24 Z9 26 U1 0 U2 14 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 APR PY 2002 VL 14 IS 4 BP 1873 EP 1878 DI 10.1021/cm0109645 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 542DR UT WOS:000175028700062 ER PT J AU Chorpening, BT Brewster, MQ AF Chorpening, BT Brewster, MQ TI Emission imaging of AP/HTPB propellant sandwich combustion SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article DE solid propellant rockets; laminar diffusion flames ID FLAME AB Ultraviolet emission imaging (305-315 nm) was used to study the combustion of sandwiches of ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) in nitrogen at pressures up to 32 atm. with binder layers from 50 to 450 mum in thickness. The emission imaging was combined with a novel backlighting technique to allow determination of the corresponding surface shape during combustion, The results indicated that the interface regression rate of IPDI-cured samples undergoing laser-assisted deflagration (120 W/cm(2) average flux) is nearly independent of the binder thickness for binders thicker than 100 pm. The pressure exponent of the regression rate is 0,31 up to 15 atm, then increases with pressure from 15 to 32 atm. Two primary flame regimes were identified: a regime of high Peclet and Damkohler numbers which exhibits a split base in the ultraviolet flame emission, and a regime of low Peclet and Damkohler numbers which exhibits a merged flame base, A third. "lifted" flame region, in which the strongest flame emission starts several hundred microns above the solid surface, occurs with low Damkohler numbers and high Peclet numbers, The effects of Pe and binder oxygenation (by fine-AP) on the size of the diffusion flame and the C1 Natl Energy Technol Lab, Morgantown, WV USA. Dept Mech & Ind Engn, Urbana, IL USA. RP Chorpening, BT (reprint author), Natl Energy Technol Lab, Morgantown, WV USA. NR 25 TC 10 Z9 12 U1 0 U2 9 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PD APR PY 2002 VL 174 IS 4 BP 39 EP 60 DI 10.1080/00102200290021146 PG 22 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA 572XY UT WOS:000176801300003 ER PT J AU Smith, RD AF Smith, RD TI Advanced mass spectrometric methods for the rapid and quantitative characterization of proteomes SO COMPARATIVE AND FUNCTIONAL GENOMICS LA English DT Review DE Fourier transform ion cyclotron resonance; mass spectrometry; proteome; proteins; D radiodurans ID CAPILLARY LIQUID-CHROMATOGRAPHY; PROTEIN IDENTIFICATION; POLYACRYLAMIDE GELS; AFFINITY TAGS; EXPRESSION AB Progress is reviewed towards the development of a global strategy that aims to extend the sensitivity, dynamic range, comprehensiveness and throughput of proteomic measurements based upon the use of high performance separations and mass spectrometry. The approach uses high accuracy mass measurements from Fourier transform ion cyclotron resonance mass spectrometry (FTICR) to validate peptide 'accurate mass tags' (AMTs) produced by global protein enzymatic digestions for a specific organism, tissue or cell type from 'potential mass tags' tentatively identified using conventional tandem mass spectrometry (MS/MS). This provides the basis for subsequent measurements without the need for MS/MS. High resolution capillary liquid chromatography separations combined with high sensitivity, and high resolution accurate FTICR measurements are shown to be capable of characterizing peptide mixtures of more than 10(5) components. The strategy has been initially demonstrated using the microorganisms Saccharomyces cerevisiae and Deinococcus radiodurans. Advantages of the approach include the high confidence of protein identification, its broad proteome coverage, high sensitivity, and the capability for stable-isotope labeling methods for precise relative protein abundance measurements. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Pacific NW Natl Lab, MSIN, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, MSIN, Environm & Mol Sci Lab, K8-98,POB 999, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 15 TC 35 Z9 35 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1531-6912 J9 COMPAR FUNCT GENOM JI Compar. Funct. Genom. PD APR PY 2002 VL 3 IS 2 BP 143 EP 150 DI 10.1002/cfg.159 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 548LF UT WOS:000175388900010 PM 18628837 ER PT J AU Haslam, AJ Moldovan, D Phillpot, SR Wolf, D Gleiter, H AF Haslam, AJ Moldovan, D Phillpot, SR Wolf, D Gleiter, H TI Combined atomistic and mesoscale simulation of grain growth in nanocrystalline thin films SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Meeting of the International Union of Matierals Research Societies (IUMRS) CY JUL 24-26, 2000 CL HONG KONG, PEOPLES R CHINA DE grain growth; grain rotation; grain-boundary migration; atomistic simulation; mesoscale simulation; multiscale simulation; nanocrystalline materials ID MOLECULAR-DYNAMICS SIMULATION; COMPUTER-SIMULATION; 2 DIMENSIONS; VARIATIONAL APPROACH; BOUNDARY ENERGIES; DIFFUSION; METALS; KINETICS; ROTATION; SYSTEMS AB We have combined molecular-dynamics (MD) simulations with mesoscale simulations to elucidate the mechanism and kinetics of grain growth in nanocrystalline palladium with a columnar grain structure. The conventional picture of grain growth assumes that the process is governed by curvature-driven grain-boundary (GB) migration. Out, MD simulations demonstrate that, at least in a nanocrystalline material. grain growth can also be triggered by the coordinated rotations of neighboring grains so its to eliminate the common GB between them. Such rotation-coalescence events result in the formation of highly elongated. unstable grains which then grow via the GB migration mechanism. These insights can be incorporated into mesoscale simulations in which, instead of the atoms, the objects that evoke in space and time are discretized GBs. grain junctions and the grain orientations. with a time scale controlled by that associated with grain rotation and GB migration and with a length scale given by the grain size. These mesoscale simulations. with physical insight and input materials parameters obtained by MD simulation. enable the investigation of the topology and long-time grain-growth behavior in a physically more realistic manner than via mesoscale simulations alone. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Forschungszentrum Karlsruhe, Inst Nanotechnol, D-76021 Karlsruhe, Germany. RP Wolf, D (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 74 TC 48 Z9 49 U1 0 U2 16 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 APR PY 2002 VL 23 IS 1-4 BP 15 EP 32 AR PII S0927-0256(01)00218-X DI 10.1016/S0927-0256(01)00218-X PG 18 WC Materials Science, Multidisciplinary SC Materials Science GA 556VW UT WOS:000175870500003 ER PT J AU Zhang, QM Wu, SY Zhang, ZY AF Zhang, QM Wu, SY Zhang, ZY TI Energetics of Ge addimers on the Si(100) and Ge(100) surfaces: a comparative study SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Meeting of the International Union of Matierals Research Societies (IUMRS) CY JUL 24-26, 2000 CL HONG KONG, PEOPLES R CHINA DE Si(100) surface; Ge(100) surface; Ge adsorption; Ge/Si heterostructures; simulated STM images ID SI AD-DIMERS; SCANNING-TUNNELING-MICROSCOPY; AB-INITIO; SI(001); GROWTH; DIFFUSION; DYNAMICS; NUCLEATION; BINDING; GE(001) AB The adsorption energetics of Ge dimers on the (10 0) surfaces of Ge and Si has been investigated using the first-principles Molecular dynamics method. Four high-symmetry configurations have been considered and fully relaxed. The most stable configuration for Ge dimers on Si(1 0 0) is found to be in the trough between two surface dimer rows, oriented parallel to the substrate Si dimers, These results are consistent with recent experimental studies of the system using the scanning tunneling microscope (STM). and help to clarify some existing controversies on the interpretation of the STM images. In contrast. for Ge dinners on Ge( 10 0). the most stable configuration is on top of the substrate dimer row. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Dept Phys, Arlington, TX 76019 USA. Univ Louisville, Dept Phys, Louisville, KY 40292 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN USA. RP Univ Texas, Dept Phys, POB 19059, Arlington, TX 76019 USA. EM zhang@uta.edn NR 33 TC 0 Z9 0 U1 1 U2 4 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 APR PY 2002 VL 23 IS 1-4 BP 48 EP 54 AR PII S0927-0256(01)00210-5 DI 10.1016/S0927-0256(01)00210-5 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 556VW UT WOS:000175870500007 ER PT J AU Chang, JP Cai, W Bulatov, VV Yip, S AF Chang, JP Cai, W Bulatov, VV Yip, S TI Molecular dynamics simulations of motion of edge and screw dislocations in a metal SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Meeting of the International Union of Matierals Research Societies (IUMRS) CY JUL 24-26, 2000 CL HONG KONG, PEOPLES R CHINA DE dislocation mobility; molecular dynamics; periodic image effect ID TRANSITION-METALS AB Motions of a straight edge dislocation and a kinked screw dislocation in BCC Mo. described by the Finnis-Sinclair potential, are Studied in periodic simulation cells subjected to an applied shear stress. Procedures for setting tip the initial atomic configurations in each case are described. and estimate is made of the local driving force due to the image interactions. Preliminary results show that at low temperature the edge dislocation moves primarily through kink nucleation. whereas the mobility of the screw dislocation is strongly facilitated by the presence of a kink. (C) 2002 Elsevier Science B.V. All rights reserved. C1 MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chang, JP (reprint author), MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. OI Cai, Wei/0000-0001-5919-8734 NR 15 TC 46 Z9 49 U1 4 U2 22 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 APR PY 2002 VL 23 IS 1-4 BP 111 EP 115 AR PII S0927-0256(01)00221-X DI 10.1016/S0927-0256(01)00221-X PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 556VW UT WOS:000175870500015 ER PT J AU Cai, W Bulatov, VV Justo, JF Argon, AS Yip, S AF Cai, W Bulatov, VV Justo, JF Argon, AS Yip, S TI Kinetic Monte Carlo approach to modeling dislocation mobility SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Meeting of the International Union of Matierals Research Societies (IUMRS) CY JUL 24-26, 2000 CL HONG KONG, PEOPLES R CHINA DE dislocation; kinetic Monte Carlo; silicon; BCC metals ID SINGLE-CRYSTALS; SCREW DISLOCATIONS; MOLECULAR-DYNAMICS; BCC METALS; SILICON; MOTION; KINKS; SIMULATIONS; ASYMMETRY; BARRIER AB We describe a kinetic Monte Carlo (kMC) approach to modeling dislocation motion. directly linking the energetics of dislocation kink nucleation and migration on the atomistic scale with the experimental data on the microscale. A study of planar glide of screw dislocation in St. an ideal test-bed for our method is first discussed, followed by preliminary results for a more complicated problem. three-dimensional motion of screw dislocation in BCC metals. We find that accuracy of the model predictions. even in the favorable case of Si. cannot claim to be quantitative because of uncertainties in the atomistic results for kink energetics. On the other hand. the kMC method is useful for qualitatively probing the mechanisms controlling dislocation motion. and it is capable of providing plausible explanation of some puzzling features of the experimental data. (C) 2002 Elsevier Science B.V. All rights reserved. C1 MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. RP MIT, Dept Nucl Engn, 77 Mass Ave, Cambridge, MA 02139 USA. EM syip@mit.edu OI Cai, Wei/0000-0001-5919-8734 NR 41 TC 11 Z9 11 U1 0 U2 7 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 APR PY 2002 VL 23 IS 1-4 BP 124 EP 130 AR PII S0927-0256(01)00223-3 DI 10.1016/S0927-0256(01)00223-3 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 556VW UT WOS:000175870500017 ER PT J AU Wang, EG Liu, BG Wu, J Li, MZ Zhong, JX Wendelken, J Niu, Q Zhang, ZY AF Wang, EG Liu, BG Wu, J Li, MZ Zhong, JX Wendelken, J Niu, Q Zhang, ZY TI Novel formation and decay mechanisms of nanostructures on surface SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Meeting of the International Union of Matierals Research Societies (IUMRS) CY JUL 24-26, 2000 CL HONG KONG, PEOPLES R CHINA DE nanostructures on surface; formation and decay; kinetic Monte Carlo; rate-equation analysis ID INTERLAYER MASS-TRANSPORT; EPITAXIAL-GROWTH; MEDIATED EPITAXY; ADSORPTION; DIFFUSION; EXCHANGE; PT(111); MOUNDS AB For decades research on thin-film growth has attracted a lot of attention as these kinds of materials hake the potential in new generation device application. It is known that the nuclei at initial stage of the islands are more stable than others and certain atoms are inert while others are active, In this paper, we will show that. when a surfactant layer is used to mediate the growth, a counter-intuitive fractal-to-compact island shape transition can be induced by increasing deposition flux or decreasing growth temperature. Specifically. we introduce a react ion-limited aggregation (RLA) theory, where the physical process controlling the island shape transition is the shielding effect of adatoms stuck to stable islands on incoming adatoms. Also discussed are the origin of a transition from triangular to hexagonal then to inverted triangular and the decay characteristics of 3D islands on surface, and connections of our unique predictions with recent experiments. Furthermore. we will present a noel idea to make use of the condensation energy of adatoms to control the island evolution along special direction. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China. Chinese Acad Sci, Ctr Condensed Matter Phys, Beijing 100080, Peoples R China. CAS, Int Ctr Quantum Struct, Beijing, Peoples R China. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. RP Wang, EG (reprint author), Chinese Acad Sci, Inst Phys, POB 603, Beijing 100080, Peoples R China. RI Niu, Qian/G-9908-2013; OI Liu, Bang-Gui/0000-0002-6030-6680 NR 23 TC 1 Z9 1 U1 1 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 APR PY 2002 VL 23 IS 1-4 BP 197 EP 203 AR PII S0927-0256(01)00214-2 DI 10.1016/S0927-0256(01)00214-2 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 556VW UT WOS:000175870500025 ER PT J AU Duchovic, RJ Volobuev, YL Lynch, GC Truhlar, DG Allison, TC Wagner, AF Garrett, BC Corchado, JC AF Duchovic, RJ Volobuev, YL Lynch, GC Truhlar, DG Allison, TC Wagner, AF Garrett, BC Corchado, JC TI POTLIB 2001: A potential energy surface library for chemical systems SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID REACTION-RATES; COMPUTER-PROGRAM; POLYATOMICS; VERSION AB POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born-Oppenheimer potential energy of chemical systems as a function of the internal coordinates. The accompanying test data allow users to verify local implementations of this library. Finally, the utility programs permit use of this library in conjunction with a variety of chemical dynamics and chemical kinetics computer codes. Interface routines are provided for the POLYRATE and ABCRATE program packages of Truhlar and co-workers, the VENUS96 program package of Hase and co-workers, and the VARIFLEX program package of Klippenstein and co-workers; the routines in this library can also be used in conjunction with the DYNASOL program package of Zhang and co-workers. This article describes the library and the utility programs and outlines the systematic conventions used for interfaces in the computer programs contained in the library. Adherence to these conventions will allow future PESs to be compatible with this library. (C) 2001 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem, Theoret Chem Grp, Argonne, IL 60439 USA. Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Minnesota, Inst Superconduct, Minneapolis, MN 55455 USA. NIST, Gaithersburg, MD 20899 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Extremadura, Fac Ciencias, Dept Quim Fis, Badajoz 06071, Spain. RP Duchovic, RJ (reprint author), Indiana Univ Purdue Univ, Dept Chem, Ft Wayne, IN 46805 USA. RI Garrett, Bruce/F-8516-2011; Truhlar, Donald/G-7076-2015; Corchado, Jose C./H-6053-2015 OI Truhlar, Donald/0000-0002-7742-7294; Corchado, Jose C./0000-0002-8463-3168 NR 26 TC 23 Z9 24 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD APR 1 PY 2002 VL 144 IS 2 BP 169 EP 187 AR PII S0010-4655(01)00437-4 DI 10.1016/S0010-4655(01)00437-4 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 535ZG UT WOS:000174675800005 ER PT J AU De Chant, LJ AF De Chant, LJ TI Impulsive displacement of a quasi-linear viscoelastic material through accurate numerical inversion of the laplace transform SO COMPUTERS & MATHEMATICS WITH APPLICATIONS LA English DT Article DE numerical inversion; Laplace transform; quasi-linear model; displacement of material ID RESPONSES AB An analytical model for the one-dimensional, impulsive displacement of a quasi-linear viscoelastic material has been developed. The quasi-linear model of Fung [1] has been used successfully for a wide range of soft biological tissues. Due to the integral definition of linear viscoelastic materials, solutions are conveniently performed in the Laplace transform plane. Complex kernels like the quasilinear model are challenging to invert back to the real plane. Here, the method of Gaver (2] and Stehfest (3] is used to numerically carry Laplace space solutions to the real plane. Parametric results for a basic impulsive disturbance problem are presented. Results indicate that stress wave propagation is weakly dependent on the fast time, slow time ratio and more strongly dependent on the logarithmic damping parameter. Limitations of the numerical inversion method in the face of discontinuities are discussed as well using asymptotic methods. As an alternative to the numerical/polynomial-based Gaver-Stehfest method, a semianalytical regularization function useful near large gradient regions method is developed. A composite method that utilizes both the fully numerical and sernianalytical convolution-based method is also described. The composite model provides improved results in terms of reducing computational undershoot and overshoot (wiggles) which limit both the fully numerical and the sernianalytical models alone. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP De Chant, LJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 21 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0898-1221 J9 COMPUT MATH APPL JI Comput. Math. Appl. PD APR-MAY PY 2002 VL 43 IS 8-9 BP 1161 EP 1170 AR PII S0898-12210(10)0352-2 DI 10.1016/S0898-1221(02)80020-7 PG 10 WC Mathematics, Applied SC Mathematics GA 541FV UT WOS:000174975300019 ER PT J AU Reed, RN Shine, R AF Reed, RN Shine, R TI Lying in wait for extinction: Ecological correlates of conservation status among Australian elapid snakes SO CONSERVATION BIOLOGY LA English DT Article ID SEXUAL SIZE DIMORPHISM; INDEPENDENT CONTRASTS; MOLECULAR PHYLOGENY; HISTORY; ALLOMETRY; VULNERABILITY; EXPLOITATION; ATTRIBUTES; EVOLUTION; BEHAVIOR AB Why do some species decline rapidly with anthropogenic disturbance, whereas others readily exploit disturbed habitats? It is possible that the ecological characteristics of some species render them especially vulnerable to extinction. Previous analyses of a diverse array of taxa have identified a number of intrinsic ecological predictors of vulnerability, but snakes have not been studied in this respect, We collated ecological data on Australian venomous snake species in the family Elapidae, based primarily on examination of preserved specimens in museums, to investigate possible differences between threatened and nonthreatened taxa. We also used comparative (phylogenetically based) analyses to identify functional associations with endangerment. Correlates of conservation vulnerability identified in previous studies did not discriminate successfully between threatened and nonthreatened elapid species. However, threatened and nonthreatened elapids differed significantly in two main respects. First, threatened species tended to rely on ambush foraging rather than actively searching for prey. Sit-and-wait foragers may be vulnerable because (1) they rely on sites with specific types of ground cover, and anthropogenic activities disrupt these habitat features, and (2) ambush foraging is associated with a suite of life-history traits that involve low, rates of feeding, growth, and reproduction. The second major correlate of endangerment involves the mating system. Endangered species typically lacked mate-male combat: In such taxa, females grow, larger than males and are more vulnerable to human predation (as judged by the composition of museum collections). Our analysis also identified taxa that, although not currently listed as threatened, share many of the ecological traits of the endangered group. Our results may facilitate future attempts to prioritize conservation actions for Australian snakes. C1 Univ Sydney, Sch Biol Sci A08, Sydney, NSW 2006, Australia. RP Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. EM reed@srel.edu RI Shine, Richard/B-8711-2008 NR 73 TC 64 Z9 67 U1 0 U2 16 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD APR PY 2002 VL 16 IS 2 BP 451 EP 461 DI 10.1046/j.1523-1739.2002.02283.x PG 11 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 537GP UT WOS:000174750800023 ER PT J AU Hampton, MA Karl, HA Murray, CJ AF Hampton, MA Karl, HA Murray, CJ TI Acoustic profiles and images of the Palos Verdes margin: implications concerning deposition from the White's Point outfall SO CONTINENTAL SHELF RESEARCH LA English DT Article AB Subbottom profiles and sidescan-sonar images collected on and around the Palos Verdes Shelf show a surficial deposit interpreted to contain effluent from the White's Point diffusers, as well as showing several geologic features that affect the deposit's distribution. The effluent-affected deposit is visible in high-resolution subbottom profiles on the shelf and the adjacent San Pedro basin slope to water depths of 170 m. It has a maximum thickness of 75 cm and was mapped acoustically over an area of 10.8 km(2), which encompasses a volume of about 3.2 million m(3). The deposit's basal reflector is acoustically distinct over most of the mapped area, implying that the deposit has not been extensively mixed across its base, perhaps being relatively free of reworking since its initial deposition. Nearshore, the basal reflector is weak and fades away toward land, which could result from syndepositional intermixing of coarse native sediment (particularly from the Portuguese Bend landslide) with effluent in the high-energy nearshore zone, or postdepositionally by physical (wave) or biological mixing across the interface. The geometry of the deposit implies that effluent is dispersed primarily in a northwesterly and seaward direction from the diffusers. Dispersal across the shelf break is in some places strongly affected by topography, particularly by submarine canyons. The deposit overlies stratified and unstratified Quaternary sediment, up to 30 m thick, that in turn overlies the irregular erosional surface of deformed Miocene bedrock that crops out in places on the shelf and upper basin slope. The effluent-affected deposit rests on potentially unstable landslide deposits on the San Pedro basin slope. The acoustic profiles and side-scan images show evidence for active and inactive vents, probably of hot water and gas, some of which are within the boundary of the effluent-affected sediment deposit and could disrupt it if seepage occurs. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 US Geol Survey, Menlo Pk, CA 94025 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hampton, MA (reprint author), US Geol Survey, 345 Middlefield Rd, Menlo Pk, CA 94025 USA. NR 20 TC 19 Z9 19 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR-MAY PY 2002 VL 22 IS 6-7 BP 841 EP 857 AR PII S0278-4343(01)00107-8 DI 10.1016/S0278-4343(01)00107-8 PG 17 WC Oceanography SC Oceanography GA 560MZ UT WOS:000176087000002 ER PT J AU Murray, CJ Lee, HJ Hampton, MA AF Murray, CJ Lee, HJ Hampton, MA TI Geostatistical mapping of effluent-affected sediment distribution on the Palos Verdes shelf SO CONTINENTAL SHELF RESEARCH LA English DT Article DE geostatistics; pollution maps; geophysical data; cores; DDE; sewage disposal; outfalls; regional terms; USA; California; Palos Verdes Margin ID CALIFORNIA; MARGIN AB Geostatistical techniques were used to study the spatial continuity of the thickness of effluent-affected sediment in the offshore Palos Verdes Margin area. The thickness data were measured directly from cores and indirectly from high-frequency subbottom profiles collected over the Palos Verdes Margin. Strong spatial continuity of the sediment thickness data was identified, with a maximum range of correlation in excess of 1.4 km. The spatial correlation showed a marked anisotropy, and was more than twice as continuous in the alongshore direction as in the cross-shelf direction. Sequential indicator simulation employing models fit to the thickness data variograms was used to map the distribution of the sediment, and to quantify the uncertainty in those estimates. A strong correlation between sediment thickness data and measurements of the mass of the contaminant p,p'-DDE per unit area was identified. A calibration based on the bivariate distribution of the thickness and pp-DDE data was applied using Markov-Bayes indicator simulation to extend the geostatistical study and map the contamination levels in the sediment. Integrating the map grids produced by the geostatistical study of the two variables indicated that 7.8 million in 3 of effluent-affected sediment exist in the map area, containing approximately 61-72 Mg (metric tons) of p,p-DDE. Most of the contaminated sediment (about 85% of the sediment and 89% of the p,p'-DDE) occurs in water depths < 100 m. The geostatistical study also indicated that the samples available for mapping are well distributed and the uncertainty of the estimates of the thickness and contamination level of the sediments is lowest in areas where the contaminated sediment is most prevalent. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. US Geol Survey, Menlo Pk, CA 94025 USA. RP Murray, CJ (reprint author), Pacific NW Natl Lab, POB 999,MS K6-81, Richland, WA 99352 USA. EM chris.murray@pnl.gov NR 16 TC 14 Z9 15 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR-MAY PY 2002 VL 22 IS 6-7 BP 881 EP 897 AR PII S0278-4343(01)00109-1 DI 10.1016/S0278-4343(01)00109-1 PG 17 WC Oceanography SC Oceanography GA 560MZ UT WOS:000176087000004 ER PT J AU Danielson, MJ AF Danielson, MJ TI Use of the Devanathan-Stachurski cell to measure hydrogen permeation in aluminum alloys SO CORROSION SCIENCE LA English DT Article DE aluminum; hydrogen permeation ID ALKALINE-MEDIUM; CORROSION AB The Devanathan-Stachurski (DS) cell has been successfully used to determine hydrogen permeation behavior in a wide variety of metals, but the DS cell has been much less successful with aluminum alloys. The DS literature is critically reviewed for aluminum alloys. An improved DS method is described and demonstrated for use with aluminum alloys (and probably M.-based alloys). Experimental results are reported for the hydrogen diffusion coefficient, solubility, and trapping in the AA5083 aluminum alloy. The diffusion coefficient is reported for AA6061. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Danielson, MJ (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 12 TC 29 Z9 30 U1 1 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0010-938X J9 CORROS SCI JI Corrosion Sci. PD APR PY 2002 VL 44 IS 4 BP 829 EP 840 DI 10.1016/S0010-938X(01)00103-2 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 517VB UT WOS:000173629900014 ER PT J AU Callow, MJ Rubin, EM AF Callow, MJ Rubin, EM TI Expression profiling and comparative sequence derived insights into lipid metabolism SO CURRENT OPINION IN LIPIDOLOGY LA English DT Review ID BINDING CASSETTE TRANSPORTER-1; DENSITY-LIPOPROTEIN DEFICIENCY; TANGIER-DISEASE; LOADED MACROPHAGES; GENE; CHOLESTEROL; MUTATIONS; MICE; ACCUMULATION; MICROARRAY AB Expression profiling and genomic DNA sequence comparisons are increasingly being applied to the identification and analysis of the genes that are involved in lipid metabolism. Not only has genome-wide expression profiling aided in the identification of novel genes that are involved in important processes in lipid metabolism such as sterol efflux, but also the utilization of information from these studies has added to our understanding of the regulation of pathways that participate in the process. Coupled with these gene expression studies, cross-species comparison (a technique used to search for sequences that are conserved through evolution) has proven to be a powerful tool to identify important noncoding regulatory sequences and novel genes that are relevant to lipid biology. An example of the value of this approach was the recent chance discovery of a new apolipoprotein gene (that which encodes apolipoprotein AV) that has dramatic effects on triglyceride metabolism in mice and humans. Curr Opin Lipidol 13:173-179, (C) 2002 Lippincott Williams Wilkins. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Callow, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, 1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [5U01 HL66681-02, HL63897-02] NR 35 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0957-9672 J9 CURR OPIN LIPIDOL JI Curr. Opin. Lipidology PD APR PY 2002 VL 13 IS 2 BP 173 EP 179 DI 10.1097/00041433-200204000-00009 PG 7 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Peripheral Vascular Disease SC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Cardiovascular System & Cardiology GA 540BW UT WOS:000174909400009 PM 11891420 ER PT J AU Saibil, HR Brunger, AT AF Saibil, HR Brunger, AT TI Macromolecular assemblages machines and networks - Editorial overview SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Editorial Material C1 Univ London Birkbeck Coll, Dept Crystallog, London WC1E 7HX, England. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA. Stanford Univ, Dept Mol & Cellular Physiol, Stanford, CA 94305 USA. Stanford Univ, Dept Neurol & Neurol Sci, Stanford, CA 94305 USA. RP Saibil, HR (reprint author), Univ London Birkbeck Coll, Dept Crystallog, Malet St, London WC1E 7HX, England. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD APR PY 2002 VL 12 IS 2 BP 215 EP 216 DI 10.1016/S0959-440X(02)00312-3 PG 2 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 542KQ UT WOS:000175043000011 ER PT J AU Jeruzalmi, D O'Donnell, M Kuriyan, J AF Jeruzalmi, D O'Donnell, M Kuriyan, J TI Clamp loaders and sliding clamps SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Article ID DNA-POLYMERASE-III; CHROMOSOMAL REPLICATION MACHINE; ONE HOLOENZYME PARTICLE; ESCHERICHIA-COLI; CRYSTAL-STRUCTURE; PROCESSIVITY FACTOR; ACCESSORY PROTEINS; ATP HYDROLYSIS; FACTOR-C; COMPLEX AB A coherent view of the structure and function of DNA polymerase processivity factors (sliding clamps and clamp loaders) is emerging from recent structural studies. Crystal structures of sliding clamps from the T4 and RB69 bacteriophages, and from an archaebacterium expand the gallery of ring-shaped processivity factors and clarify how the clamp interacts with the DNA polymerase. Crystallographic and electron microscopic views of clamp loaders from bacteria, archaebacteria and eukaryotes emphasize their common architecture and have produced models of how ATP binding might be coupled to clamp opening/loading. C1 Univ Calif Berkeley, Howard Hughes Med Inst, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Dept Chem, Berkeley, CA 94720 USA. Rockefeller Univ, Howard Hughes Med Inst, New York, NY 10021 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Jeruzalmi, D (reprint author), Univ Calif Berkeley, Howard Hughes Med Inst, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM RO1-38839, GMRO1-45547] NR 62 TC 102 Z9 103 U1 2 U2 4 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD APR PY 2002 VL 12 IS 2 BP 217 EP 224 DI 10.1016/S0959-440X(02)00313-5 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 542KQ UT WOS:000175043000012 PM 11959500 ER PT J AU Brofferio, C Arnaboldi, C Capelli, S Carbone, L Cremonesi, O Fiorini, E Giugni, D Negri, P Nucciotti, A Pavan, M Pessina, G Pirro, S Previtali, E Sisti, M Vanzini, M Zanotti, L Beeman, J McDonald, RJ Haller, EE Norman, EB Smith, AR Giuliani, A Pedretti, M Barucci, M Ventura, G Balata, M Bucci, C Pobes, C Palmieri, V Frossati, G de Waard, A Avignone, FT Creswick, RJ Farach, HA Rosenfeld, C Cebrian, S Irastorz, IG Morales, A AF Brofferio, C Arnaboldi, C Capelli, S Carbone, L Cremonesi, O Fiorini, E Giugni, D Negri, P Nucciotti, A Pavan, M Pessina, G Pirro, S Previtali, E Sisti, M Vanzini, M Zanotti, L Beeman, J McDonald, RJ Haller, EE Norman, EB Smith, AR Giuliani, A Pedretti, M Barucci, M Ventura, G Balata, M Bucci, C Pobes, C Palmieri, V Frossati, G de Waard, A Avignone, FT Creswick, RJ Farach, HA Rosenfeld, C Cebrian, S Irastorz, IG Morales, A TI Present and future cryogenic experiments on double-beta decay SO CZECHOSLOVAK JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Calculation of Double-Beta-Decay Matrix Elements (MEDEX 01) CY JUL 11-15, 2001 CL PRAGUE, CZECH REPUBLIC DE double-beta decay; neutrino mass; cryogenic detectors ID PARTICLE DETECTORS AB Thermal detectors are introduced and their possible impact on neutrinoless double-beta-decay (2beta0sigma) search is discussed. The thermal experiment MIBETA is described, reporting the up-to-date limits on Te-130 and Te-128. A new generation experiment, consisting in a large expansion of MIBETA and known as CUORE, is presented and discussed. C1 Univ Milan, Dipartimento Fis, I-20126 Milan, Italy. Ist Nazl Fis Nucl, Sez Milano, I-20126 Milan, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Insubria, Dipartimento Sci Chim Fis & Matemat, I-22100 Como, Italy. Ist Nazl Fis Nucl, Sez Milano, I-22100 Como, Italy. Univ Florence, Dipartimento Fis, I-50125 Florence, Italy. Ist Nazl Fis Nucl, Sez Firenze, I-50125 Florence, Italy. Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, I-67010 Assergi, Italy. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Univ Zaragoza, Lab Nucl & High Energy Phys, E-50009 Zaragoza, Spain. RP Univ Milan, Dipartimento Fis, Via Celoria 16, I-20126 Milan, Italy. RI Nucciotti, Angelo/I-8888-2012; Barucci, Marco/D-4209-2012; Sisti, Monica/B-7550-2013; capelli, silvia/G-5168-2012; OI Nucciotti, Angelo/0000-0002-8458-1556; Barucci, Marco/0000-0003-0381-3376; Sisti, Monica/0000-0003-2517-1909; capelli, silvia/0000-0002-0300-2752; pavan, maura/0000-0002-9723-7834; Pessina, Gianluigi Ezio/0000-0003-3700-9757 NR 8 TC 2 Z9 2 U1 0 U2 1 PU INST PHYSICS ACAD SCI CZECH REPUBLIC PI PRAGUE PA NA SLOVANCE 2, PRAGUE 182 21, CZECH REPUBLIC SN 0011-4626 J9 CZECH J PHYS JI Czech. J. Phys. PD APR PY 2002 VL 52 IS 4 BP 531 EP 540 DI 10.1023/A:1015361411086 PG 10 WC Physics, Multidisciplinary SC Physics GA 563QQ UT WOS:000176267400010 ER PT J AU Cheyette, BNR Waxman, JS Miller, JR Takemaru, KI Sheldahl, LC Khlebtsova, N Fox, EP Earnest, T Moon, RT AF Cheyette, BNR Waxman, JS Miller, JR Takemaru, KI Sheldahl, LC Khlebtsova, N Fox, EP Earnest, T Moon, RT TI Dapper, a Dishevelled-associated antagonist of beta-catenin and JNK signaling, is required for notochord formation SO DEVELOPMENTAL CELL LA English DT Article ID GLYCOGEN-SYNTHASE KINASE-3; XENOPUS-EMBRYOS; WNT; PROTEIN; PATHWAYS; WINGLESS; AXIN; DVL; EXPRESSION; ACTIVATION AB Dapper was isolated in a screen for proteins interacting with Dishevelled, a key factor in Wnt signaling. Dapper and Dishevelled colocalize intracellularly and form a complex with Axin, GSK-3, CKI, and beta-catenin. Overexpression of Dapper increases Axin and GSK-3 in this complex, resulting in decreased soluble beta-catenin and decreased activation of beta-catenin-responsive genes. Dapper also inhibits activation by Dishevelled of c-Jun N-terminal kinase (JNK), a component of beta-catenin-independent Frizzled signaling. Inhibition of Dapper activates both beta-catenin-responsive genes and an AP1-responsive promoter, demonstrating that Dapper is a general Dishevelled antagonist. Depletion of maternal Dapper RNA from Xenopus embryos results in loss of notochord and head structures, demonstrating that Dapper is required for normal vertebrate development. C1 Univ Washington, Sch Med, Dept Pharmacol, Howard Hughes Med Inst, Seattle, WA 98195 USA. Univ Washington, Sch Med, Ctr Dev Biol, Seattle, WA 98195 USA. Univ Washington, Sch Med, Dept Psychiat & Behav Sci, Seattle, WA 98195 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley Ctr Struct Biol, Berkeley, CA 94720 USA. RP Moon, RT (reprint author), Univ Washington, Sch Med, Dept Pharmacol, Howard Hughes Med Inst, Seattle, WA 98195 USA. RI Moon, Randall/B-1743-2014; Cheyette, Benjamin/K-5535-2014 OI Moon, Randall/0000-0002-9352-1408; Cheyette, Benjamin/0000-0001-9934-7941 FU NICHD NIH HHS [R01 HD27525, T32 HD007183, 2T32 HD07183-21]; NIMH NIH HHS [K08 MH01750] NR 50 TC 160 Z9 171 U1 0 U2 2 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE,, CAMBRIDGE, MA 02138 USA SN 1534-5807 J9 DEV CELL JI Dev. Cell PD APR PY 2002 VL 2 IS 4 BP 449 EP 461 DI 10.1016/S1534-5807(02)00140-5 PG 13 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA 548KA UT WOS:000175386100012 PM 11970895 ER PT J AU Peng, TZ Cheng, Q Cheng, Q AF Peng, TZ Cheng, Q Cheng, Q TI Determination of short DNA oligomers using an electrochemical biosensor with a conductive self-assembled membrane SO ELECTROANALYSIS LA English DT Article DE DNA sequence; hybridization; intercalation; biosensor ID HUMAN-IMMUNODEFICIENCY-VIRUS; QUARTZ-CRYSTAL MICROBALANCE; GENE DETECTION; HYBRIDIZATION; SENSOR; PROBES; OLIGONUCLEOTIDE; RECOGNITION; SEQUENCES AB A new conductive modifier N-[6-(thien-3-yl)acetoxy]-pyrrolidine-2,5-dione (TAPD), which can self-assemble on a gold surface and react with amino groups is synthesized to immobilize a probe DNA on gold electrodes. The hybridization of the probe with a target DNA in sample solutions is monitored by a self-synthesized electroactive indicator, which specifically intercalates in (he hybrids on the electrode surface. The current signal of the modified electrode is proportional to the concentration of the target DNA in samples, and a detection limit of 2 x 10(-9) molL(-1) was found. The biosensor has been used to detect short oligomers containing HIV-1 and mycobacterrium nucleotide sequences. C1 Zhejiang Univ, Dept Chem, Hangzhou 310028, Peoples R China. Jiaxing Coll, Dept Chem Engn, Jiaxing 314001, Zhejiang, Peoples R China. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Peng, TZ (reprint author), Zhejiang Univ, Dept Chem, Xixi Campus, Hangzhou 310028, Peoples R China. RI Cheng, Jason/C-6345-2011 NR 19 TC 5 Z9 6 U1 1 U2 8 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD APR PY 2002 VL 14 IS 6 BP 455 EP 458 DI 10.1002/1521-4109(200203)14:6<455::AID-ELAN455>3.0.CO;2-T PG 4 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 538UF UT WOS:000174832900011 ER PT J AU Norin, L Kostecki, R McLarnon, F AF Norin, L Kostecki, R McLarnon, F TI Study of membrane degradation in high-power lithium-ion cells SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID BATTERIES; SEPARATORS AB Impedance spectra of Celgard(R) 2300 membranes that were removed from high-power Li-ion cells showed a significant rise in membrane ionic resistivity for cells that were cycled or stored at elevated temperatures. Atomic force microscopy images revealed dramatic changes in membrane surface morphology. Swelling of the membrane polypropylene fibers and the presence of particles of electrode active material in the membrane pores effectively reduced the membrane porosity, and thereby account for the membrane impedance rise and part of the cell power loss. These results not only indicate that membrane degradation can contribute significantly to Li-ion cell power loss at elevated temperatures, but also reveal mechanisms of membrane degradation. (C) 2002 The Electrochemical Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy & Technol Div, Berkeley, CA 94720 USA. RP Norin, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy & Technol Div, Berkeley, CA 94720 USA. NR 8 TC 10 Z9 10 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 APR PY 2002 VL 5 IS 4 BP A67 EP A69 DI 10.1149/1.1457206 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 547CB UT WOS:000175314300002 ER PT J AU Sun, YK Hong, KJ Prakash, J Amine, K AF Sun, YK Hong, KJ Prakash, J Amine, K TI Electrochemical performance of nano-sized ZnO-coated LiNi0.5Mn1.5O4 spinel as 5 V materials at elevated temperatures SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE lithium secondary batteries; spinel; ZnO coating; HF; Mn dissolution ID SURFACE MODIFICATION; LITHIUM BATTERIES; CATHODE MATERIALS; LI/LIMN2O4 CELLS; ION BATTERIES; DEGRADATION AB ZnO-coated LiNi0.5Mn1.5O4 powders with excellent electrochemical cyclability and structural stability have been synthesized. The electrochemical performance and structural stability of ZnO-coated LiNi0.5Mn1.5O4 electrodes in the 5 V region at elevated temperature has been studied as function of the level of ZnO coating. The 1.5 wt% ZnO-coated LiNi0.5Mn1.5O4 electrode delivers all initial discharge capacity of 137 mAh g(-1) with excellent cyclability at elevated temperature even at 55degreesC. The reason for the excellent cycling performance of ZnO-coated LiNi0.5Mn1.5O4 electrode is largely attributed to ZnO playing an important role of HF getting in the electrolyte. (C) 2002 Published by Elsevier Science B.V. C1 IIT, Dept Environm Chem & Engn, Chicago, IL 60616 USA. Hanyang Univ, Dept Chem Engn, Seoul 133791, South Korea. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Sun, YK (reprint author), IIT, Dept Environm Chem & Engn, Chicago, IL 60616 USA. RI Sun, Yang-Kook/B-9157-2013; Amine, Khalil/K-9344-2013 OI Sun, Yang-Kook/0000-0002-0117-0170; NR 17 TC 217 Z9 225 U1 19 U2 206 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1388-2481 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD APR PY 2002 VL 4 IS 4 BP 344 EP 348 AR PII S1388-2481(02)00277-1 DI 10.1016/S1388-2481(02)00277-1 PG 5 WC Electrochemistry SC Electrochemistry GA 571QZ UT WOS:000176729600015 ER PT J AU Vine, E AF Vine, E TI Promoting emerging energy-efficiency technologies and practices by utilities in a restructured energy industry: a report from California SO ENERGY LA English DT Article AB The potential energy savings from emerging technologies (i.e. those technologies emerging from research and development) represent a significant resource to California and the US. This paper describes how California's investor-owned utilities (IOUs) have been promoting emerging technologies over the past three years to increase energy efficiency in the buildings sector. During these years, the IOUs have experienced significant changes in their regulatory environment as part of the restructuring of the energy industry in California. These regulatory changes have impacted the way emerging technologies are treated by the regulatory community and the IOUs. After reviewing these changes, the paper concludes by discussing potential opportunities to improve the market penetration of emerging technologies. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Tech Div, Energy Anal Dept, Berkeley, CA 94720 USA. RP Vine, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Tech Div, Energy Anal Dept, Bldg 90-4000,1 Cyclotron Rd,MS 90-2000, Berkeley, CA 94720 USA. NR 24 TC 0 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD APR PY 2002 VL 27 IS 4 BP 317 EP 328 AR PII S0360-5442(01)00087-1 DI 10.1016/S0360-5442(01)00087-1 PG 12 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA 525JN UT WOS:000174065900001 ER PT J AU Kadam, KL AF Kadam, KL TI Environmental benefits on a life cycle basis of using bagasse-derived ethanol as a gasoline oxygenate in India SO ENERGY POLICY LA English DT Article DE bagasse; ethanol; gasoline oxygenate; India; life cycle assessment AB Bagasse is the fibrous residue generated during sugar production and can be a desirable feedstock for fuel ethanol production. Excess bagasse left after satisfying the mills' energy requirements can be used in a bioconvesion process to make ethanol. A life cycle assessment (LCA) was conducted to quantify the environmental benefits of diverting excess bagasse to ethanol production as opposed to disposing it through the current practice of open-field burning. The LCA results demonstrated lower net values for the ethanol scenario for the following: carbon monoxide, hydrocarbons (except methane), SOx, NOx, particulates, carbon dioxide, methane, and fossil energy consumption. Reduced carbon dioxide and methane emissions for the ethanol scenario also lower its greenhouse potential. Additional drivers are the lower values observed for the following impact assessment categories for the ethanol scenario: depletion of natural resources, air acidification potential. eutrophication potential, human toxicity potential, and air odor potential. Specifically, deployment of the bioethanol option, due to its significantly lower greenhouse potential, can be facilitated via the Clean Development Mechanism, as specified under the Kyoto Protocol. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kadam, KL (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 32 TC 48 Z9 50 U1 1 U2 7 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 APR PY 2002 VL 30 IS 5 BP 371 EP 384 AR PII S0301-4215(01)00104-5 DI 10.1016/S0301-4215(01)00104-5 PG 14 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 534XJ UT WOS:000174614800002 ER PT J AU Liu, CX Zachara, JM Fredrickson, JK Kennedy, DW Dohnalkova, A AF Liu, CX Zachara, JM Fredrickson, JK Kennedy, DW Dohnalkova, A TI Modeling the inhibition of the bacterial reduction of U(VI) by beta-MnO2(S)(g) SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID NUCLEAR-FUEL; OXIDATIVE DISSOLUTION; CANDU FUEL; URANIUM; UO2; PERCHLORATE; MANGANESE; CORROSION; KINETICS; DIOXIDE AB Pyrolusite (beta-MnO2(s)) was used to assess the influence of a competitive electron acceptor on the kinetics of reduction of aqueous uranyl carbonate by a dissimilatory metal-reducing bacterium (DMRB), Shewanella putrefaciens strain CN32. The enzymatic reduction of U(VI) and beta-MnO2(s) and the abiotic redox reaction between beta-MnO2(s) and biogenic uraninite (UO2(s)) were independently investigated to allow for interpretation of studies of U(VI) bioreduction in the presence of beta-MnO2(s). Uranyl bioreduction to UO2(s) by CN32 with H-2 as the electron donor followed Monod kinetics, with a maximum specific reduction rate of 110 muM/h/10(8) cells/mL and a half-saturation constant of 370 muM. The bioreduction rate of beta-MnO2(s) by CN32 was described by a pseudo-first-order model with respect to beta-MnO2(s) surface sites, with a rate constant of 7.92 x 10(-2) h(-1)/10(8) cells/mL. Uraninite that precipitated as a result of microbial U(VI) reduction was abiotically reoxidized to U(VI) by beta-MnO2(s), with concomitant reduction to Mn(II). The oxidation of biogenic UO2(s) coupled with beta-MnO2(s) reduction was well-described by an electrochemical model. However, a simple model that coupled the bacterial reduction of U(VI) and beta-MnO2(s) with an abiotic redox reaction between UO2(s) and beta-MnO2(s) failed to describe the mass loss of U(VI) in the presence of beta-MnO2(s). Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) revealed that the particle size and spatial distribution of the biogenic UO2(s) changed dynamically in systems with, as compared to without, beta-MnO2(s). These observations suggested that the surface properties and localization of UO2(s) in relation to the cell and beta-MnO2(s) surfaces was an important factor controlling the abiotic oxidation of UO2(s) and, thus, the overall rate and extent of U(VI) bioreduction. The coupled model that was modified to account for the "effective" contact surface area between UO2(s) and beta-MnO2(s) significantly improved the simulation of microbial reduction of U(VI) in the presence of beta-MnO2(s). C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liu, CX (reprint author), Pacific NW Natl Lab, POB 999,MSIN K8-96, Richland, WA 99352 USA. RI Liu, Chongxuan/C-5580-2009 NR 31 TC 44 Z9 45 U1 5 U2 28 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR 1 PY 2002 VL 36 IS 7 BP 1452 EP 1459 DI 10.1021/es011159u PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 537ZH UT WOS:000174789200027 PM 11999050 ER PT J AU Chertock, A AF Chertock, A TI On the stability of a class of self-similar solutions to the filtration-absorption equation SO EUROPEAN JOURNAL OF APPLIED MATHEMATICS LA English DT Article ID DEGENERATE PARABOLIC EQUATION; VISCOSITY SOLUTIONS AB We consider the one-dimensional and two-dimensional filtration-absorption equation u(t) = uDeltau-(c-1)(delu)(2). The one-dimensional case was considered previously by Barenblatt et al. [4], where a special class of self-similar solutions was introduced. By the analogy with the ID case we construct a family of axisymmetric solutions in 2D. We demonstrate numerically that the self-similar solutions obtained attract the solutions of non-self-similar Cauchy problems having the initial condition of compact support. The main analytical result we provide is the linear stability of the above self-similar solutions both in the 1D case and in the 2D case. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Chertock, A (reprint author), Univ Calif Berkeley, Dept Math, MS 50A-1148,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM alina@math.lbl.gov RI Chertock, Alina/I-3676-2013 OI Chertock, Alina/0000-0003-4978-1314 NR 16 TC 9 Z9 11 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0956-7925 EI 1469-4425 J9 EUR J APPL MATH JI Eur. J. Appl. Math. PD APR PY 2002 VL 13 BP 179 EP 194 DI 10.1017/S095679250100482X PN 2 PG 16 WC Mathematics, Applied SC Mathematics GA 546UA UT WOS:000175291800003 ER PT J AU Gnanasekar, KI Rambabu, B Langry, KC AF Gnanasekar, KI Rambabu, B Langry, KC TI Unusual high sensitivity in highly oriented laser ablated thin films of SnO2 on (1102) sapphire and (100) LaAlO3 SO EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS LA English DT Article ID TIN OXIDE; GAS; RESISTIVITY; GROWTH AB A systematic investigation on growth and sensor characteristics of SnO2 thin films of different orientations is reported for the first time. Thin films were grown by pulsed laser (KrF; lambda = 248 nm) ablation technique under in-situ conditions. Films deposited at 525 C on ( 1102) sapphire were predominantly (101) orientated whereas those deposited on (100) LaAlO3 were highly a-axis orientated. Sensors made of predominantly (101) oriented films exhibited more than two orders magnitude change in resistance even for 100 ppm of H-2 in air at 310 degreesC. The response and retracing times of the sensor were remarkably short respectively 30 and 200 s. Sensors made of a-axis oriented films also exhibited similar sensitivity and response time for the same quantity of both H-2 and LPG. However, the retrace time was very long typically about 20 min. Atomic force microscopic (AFM) investigation reveals that the films are highly granular with an average size of about 100 150 nm which is ten times larger than the critical size of 6 nm, a criterion required for high sensitivity. (The Debye length of SnO2 congruent to 3.07 nm at 293 K and the critical grain size is therefore 2 x Debye length, which is 6 nm.). C1 So Univ & A&M Coll, Dept Phys, Surface Sci Spect & Solid State Ion Lab, Baton Rouge, LA 70813 USA. Lawrence Livermore Natl Lab, Chem & Biol Detect Grp, Livermore, CA 94550 USA. RP Gnanasekar, KI (reprint author), So Univ & A&M Coll, Dept Phys, Surface Sci Spect & Solid State Ion Lab, Baton Rouge, LA 70813 USA. NR 23 TC 2 Z9 2 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 1286-0042 J9 EUR PHYS J-APPL PHYS JI Eur. Phys. J.-Appl. Phys PD APR PY 2002 VL 18 IS 1 BP 9 EP 15 DI 10.1051/epjap:2002021 PG 7 WC Physics, Applied SC Physics GA 544FD UT WOS:000175146800002 ER PT J AU Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wessoleck, H Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Paganis, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Grabowska-Bold, I Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Bauerdick, LAT Behrens, U Borras, K Chiochia, V Dannheim, D Desler, K Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Labes, H Lelas, D Lohr, B Mankel, R Martens, J Martinez, M Moritz, M Notz, D Petrucci, MC Polini, A Schneekloth, U Selonke, F Stonjek, S Surrow, B Whitmore, JJ Wichmann, R Wolf, G Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Bodmann, B Holm, U Salehi, H Wick, K Ziegler, A Ziegler, A Carli, T Gialas, I Klimek, K Lohrmann, E Milite, M Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Llee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG Laurent, MS Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Adamczyk, L Oh, BY Saull, PRB Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Hayes, ME Heaphy, EA Jones, TW Lane, JB Lightwood, MS West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Breitweg, J Chapin, D Cross, R Kcira, D Lammers, S Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J AF Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Bartsch, D Brock, I Crittenden, J Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Renner, R Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wessoleck, H Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Helbich, M Liu, X Mellado, B Paganis, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Grabowska-Bold, I Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Szuba, J Kotanski, A Slominski, W Bauerdick, LAT Behrens, U Borras, K Chiochia, V Dannheim, D Desler, K Drews, G Fourletova, J Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hillert, S Kotz, U Kowalski, H Labes, H Lelas, D Lohr, B Mankel, R Martens, J Martinez, M Moritz, M Notz, D Petrucci, MC Polini, A Schneekloth, U Selonke, F Stonjek, S Surrow, B Whitmore, JJ Wichmann, R Wolf, G Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Genta, C Pelfer, PG Bamberger, A Benen, A Coppola, N Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Hanlon, S Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Bodmann, B Holm, U Salehi, H Wick, K Ziegler, A Ziegler, A Carli, T Gialas, I Klimek, K Lohrmann, E Milite, M Collins-Tooth, C Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Llee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG Laurent, MS Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Koffeman, E Kooijman, P Maddox, E Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Garfagnini, A Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Adamczyk, L Oh, BY Saull, PRB Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Heusch, C Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Hayes, ME Heaphy, EA Jones, TW Lane, JB Lightwood, MS West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Smalska, B Sztuk, J Tymieniecka, T Ukleja, A Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Breitweg, J Chapin, D Cross, R Kcira, D Lammers, S Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Fourletov, S Menary, S Soares, M Standage, J TI Dijet photoproduction at HERA and the structure of the photon SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID STRUCTURE-FUNCTION F-2(GAMMA); JET CROSS-SECTIONS; TO-LEADING ORDER; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; PARTON DISTRIBUTIONS; HADRON-COLLISIONS; LOW-X; Q(2) EVOLUTION; SCATTERING AB The dijet cross section in photoproduction ha's been measured with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb(-1). The events were required to have a virtuality of the incoming photon, Q(2), of less than 1 GeV2 and a photon-proton centre-of-mass energy in the range 131 < W-yp < 277 GeV. Each event contains at least two jets satisfying transverse-energy requirements of E-T(jet1) > 14 GeV and E-T(jet2) > 11 GeV and pseudorapidity requirements of -1 < eta(jet1,2) < 2.4. The measurements arc compared to next-to-loading-order QCD predictions. The data show particular sensitivity to the density of partons in the photon, allowing the validity of the current parameterisations to be tested. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Irvington, NY 10027 USA. Inst Nucl Phys, Krakow, Poland. Univ Min & Met Krakow, Fac Phys & Nucl Techniques, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY Zeuthen, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Freiburg, Fak Phys, D-7800 Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Hamburg, Inst Expt Phys 1, Hamburg, Germany. Univ Hamburg, Inst Expt Phys 2, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, D-5170 Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow MV Lomonosov State Univ, Inst Phys Nucl, Moscow, Russia. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Seoul Natl Univ, Seoul, South Korea. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, IL-69978 Tel Aviv, Israel. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. York Univ, Dept Phys, N York, ON M3J 1P3, Canada. Univ Lodz, PL-90131 Lodz, Poland. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Solomin, Anatoly/C-3072-2016; Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; Wiggers, Leo/B-5218-2015; De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; collins-tooth, christopher/A-9201-2012; Ferrando, James/A-9192-2012; Golubkov, Yury/E-1643-2012; Levchenko, B./D-9752-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; OI Gladilin, Leonid/0000-0001-9422-8636; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Graciani Diaz, Ricardo/0000-0001-7166-5198; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Longhin, Andrea/0000-0001-9103-9936; Wiggers, Leo/0000-0003-1060-0520; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Ferrando, James/0000-0002-1007-7816; Katz, Uli/0000-0002-7063-4418; PAGANIS, STATHES/0000-0002-1950-8993 NR 78 TC 63 Z9 63 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6044 EI 1434-6052 J9 EUR PHYS J C JI Eur. Phys. J. C PD APR PY 2002 VL 23 IS 4 BP 615 EP 631 DI 10.1007/s100520200936 PG 17 WC Physics, Particles & Fields SC Physics GA 555UC UT WOS:000175810800002 ER PT J AU Haslinger, R Abanov, A Chubukov, A AF Haslinger, R Abanov, A Chubukov, A TI ARPES in the normal state of the cuprates: Comparing the marginal Fermi-liquid and spin-fluctuation scenarios SO EUROPHYSICS LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; SCATTERING; PHENOMENOLOGY; BEHAVIOR; SPECTRA; MODEL AB We address the issue whether ARPES measurements of the spectral function A(k) (omega) near the Fermi surface in the normal state of near optimally doped cuprates can distinguish between the marginal Fermi-liquid scenario and the spin-fluctuation scenario. We argue that the data for momenta near the Fermi surface are equally well described by both theories, but this agreement is nearly meaningless as in both cases one has to add to Sigma" (omega) a large constant of yet unknown origin. We show that the data can be well fitted by keeping only this constant term in the self-energy. To distinguish between the two scenarios, one has to analyze the data away from the Fermi surface, when the intrinsic piece in Sigma(omega) becomes dominant. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Haslinger, R (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 27 TC 5 Z9 5 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 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD APR PY 2002 VL 58 IS 2 BP 271 EP 277 DI 10.1209/epl/i2002-00633-9 PG 7 WC Physics, Multidisciplinary SC Physics GA 546JF UT WOS:000175270400018 ER PT J AU Holland, B AF Holland, B TI Sexual selection fails to promote adaptation to a new environment SO EVOLUTION LA English DT Article DE adaptation; antagonistic seduction; good genes; intersexual conflict; sexual selection; thermal stress ID ACCESSORY-GLAND PRODUCTS; DROSOPHILA-MELANOGASTER; SPERM COMPETITION; RECEIVER BIASES; MATING SUCCESS; FEMALE CHOICE; FRUIT-FLIES; EVOLUTION; CONFLICT; FITNESS AB Selection can be divided into sexual and nonsexual components. Some work finds that a component of sexual selection, adaptive female selection for good genes, can promote nonsexual fitness. Less studied is the benefit from sexual selection in tote, that is, when intra- and intersexual selection are both present and able to affect females directly and indirectly. Here an upper bound for the net benefit of sexual selection is estimated for Drosophila melanogaster. Replicate populations were allowed to adapt to low-grade thermal stress, with or with out the operation of sexual selection. Because proteins and lipids are highly sensitive to temperature, low-grade thermal stress will select broadly across the genome for alternative alleles. Such broad, directional selection for thermal tolerance should increase the measurable benefits of sexual selection far beyond that available under stabilizing selection. Sexual selection was removed by enforced monogamy without mate choice and retained by enforced polyandry (four males per female). After 36 generations of thermal stress exposure, there was substantial adaptation to the new environment (the net reproductive rate increased six standard deviations relative to thermal controls). However, sexual selection did not affect the rate of adaptation. Therefore, adaptive female selection for thermal tolerance either was insignificant or negated by other aspects of sexual selection, for example, male-induced female harm, which has been shown to diminish under monogamy. This experiment employed two parameters that reduced the opportunity for divergence in such harm: a truncated intersexual interaction period and strong directional selection for thermal tolerance. No divergence in male-induced harm was observed. C1 Univ Calif Santa Cruz, Dept Biol Nat Sci 4, Santa Cruz, CA 95064 USA. RP Holland, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, I Cyclotron Rd,Mailstop 84-171, Berkeley, CA 94720 USA. NR 50 TC 58 Z9 60 U1 0 U2 40 PU SOC STUDY EVOLUTION PI LAWRENCE PA 810 E 10TH STREET, LAWRENCE, KS 66044 USA SN 0014-3820 J9 EVOLUTION JI Evolution PD APR PY 2002 VL 56 IS 4 BP 721 EP 730 DI 10.1554/0014-3820(2002)056[0721:SSFTPA]2.0.CO;2 PG 10 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 552HQ UT WOS:000175614400007 PM 12038530 ER PT J AU Redfield, E Barns, SM Belnap, J Daane, LL Kuske, CR AF Redfield, E Barns, SM Belnap, J Daane, LL Kuske, CR TI Comparative diversity and composition of cyanobacteria in three predominant soil crusts of the Colorado Plateau SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE biological soil crust; cyanobacterium; terminal restriction fragment analysis; arid land soil; cyanobacterial diversity; 16S rRNA sequencing; desert soil ID 16S RIBOSOMAL-RNA; POLYMORPHISM T-RFLP; SURFACE DISTURBANCES; SEQUENCE-ANALYSIS; DESERT CRUSTS; GENES; COMMUNITY; REGIONS AB Terminal restriction fragment length polymorphism (TRF or T-RFLP) analysis and 16S rDNA sequence analysis from clone libraries were used to examine cyanobacterial diversity in three types of predominant soil crusts in an and grassland. Total DNA was extracted from cyanobacteria-, lichen-, or moss-dominated crusts that represent different successional stages in crust development, and which contribute different amounts of carbon and nitrogen into the ecosystem. Cyanobacterial 16S rRNA genes were amplified by PCR using cyanobacteria-specific 16S rDNA primers. Both TRF and clone sequence analyses indicated that the cyanobacterial crust type is dominated by strains of Microcoleus vaginatus, but also contains other cyanobacterial genera. In the moss crust, M. vaginatus-related sequences were also the most abundant types, together with sequences from moss chloroplasts. In contrast, sequences obtained from the lichen crust were surprisingly diverse, representing numerous genera, but including only two from W. vaginatus relatives. By obtaining clone sequence information, we were able to infer the composition of many peaks observed in TRF profiles, and all peaks predicted for clone sequences were observed in TRF analysis. This Study provides the first TRF analysis of biological soil crusts and the first DNA-based comparison of cyanobacterial diversity between lichen-, cyano- and moss-dominated crusts, Results indicate that for this phylogenetic group, TRF analysis, in conjunction with limited sequence analysis, can provide accurate information about the composition and relative abundance of cyanobacterial types in soil crust communities. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. US Geol Survey, Forest & Rangeland Ecosyst Sci Ctr, Moab, UT 84532 USA. RP Kuske, CR (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663,M888, Los Alamos, NM 87545 USA. NR 41 TC 44 Z9 47 U1 1 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD APR PY 2002 VL 40 IS 1 BP 55 EP 63 AR PII S0168-6496(02)00197-6 DI 10.1111/j.1574-6941.2002.tb00936.x PG 9 WC Microbiology SC Microbiology GA 556XC UT WOS:000175873400007 PM 19709211 ER PT J AU Baltrus, JP Diehl, JR Soong, Y Sands, W AF Baltrus, JP Diehl, JR Soong, Y Sands, W TI Triboelectrostatic separation of fly ash and charge reversal SO FUEL LA English DT Article DE fly ash; triboelectrostatic separation; triboelectrification ID ELECTROSTATIC SEPARATION; BENEFICIATION AB Triboelectrostatic separation has been investigated as a method for separating unburned carbon from coal combustion fly ash. It was found that when a fly ash is exposed to moisture before it undergoes separation, the charging properties of the components of the fly ash change significantly. The mineral and carbon components of the fly,ash appear to charge oppositely to how they were charged before exposure to moisture. A correlation was found between the degree of charge reversal and the relative amounts of leachable ions, especially calcium and sodium ions, present on the surface of the ash. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Baltrus, JP (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 18 TC 19 Z9 21 U1 2 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0016-2361 J9 FUEL JI Fuel PD APR PY 2002 VL 81 IS 6 BP 757 EP 762 AR PII S0016-2361(01)00196-X DI 10.1016/S0016-2361(01)00196-X PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 539HT UT WOS:000174865000006 ER PT J AU Berket, K Agarwal, DA Chevassut, O AF Berket, K Agarwal, DA Chevassut, O TI A practical approach to the InterGroup protocols SO FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF GRID COMPUTING AND ESCIENCE LA English DT Article DE distributed systems; group communication; reliable multicast; security ID GROUP COMMUNICATION-SYSTEM; TOTEM AB Existing reliable ordered group communication protocols have been developed for local-area networks and do not in general scale well to a large number of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces an unusual approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable timestamp ordered. We also present a secure group layer that builds on InterGroup to provide SSL-like security for groups. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Berket, K (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 50B-2239, Berkeley, CA 94720 USA. EM kberket@lbl.gov; daagarwal@lbl.gov; ochevassut@lbl.gov NR 24 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-739X J9 FUTURE GENER COMP SY JI Futur. Gener. Comp. Syst. PD APR PY 2002 VL 18 IS 5 BP 709 EP 719 AR PII S0167-739X(02)00036-5 DI 10.1016/S0167-739X(02)00036-5 PG 11 WC Computer Science, Theory & Methods SC Computer Science GA 548XW UT WOS:000175416000012 ER PT J AU Anderson, OD Larka, L Christoffers, MJ McCue, KF Gustafson, JP AF Anderson, OD Larka, L Christoffers, MJ McCue, KF Gustafson, JP TI Comparison of orthologous and paralogous DNA flanking the wheat high molecular weight glutenin genes: sequence conservation and divergence, transposon distribution, and matrix-attachment regions SO GENOME LA English DT Article DE wheat; glutenins; evolution; matrix-attachment regions; transposable elements ID TRITICUM-AESTIVUM L; HEXAPLOID BREAD WHEAT; NUCLEAR MATRIX; SUBUNIT GENE; GENOME; RETROTRANSPOSONS; FAMILY; EXPRESSION; CHROMATIN; ELEMENTS AB Extended flanking DNA sequences were characterized for five members of the wheat high molecular weight (HMW) glutenin gene family to understand more of the structure, control, and evolution of these genes. Analysis revealed more sequence conservation among orthologous regions than between paralogous regions, with differences mainly owing to transposition events involving putative retrotransposons and several miniature inverted transposable elements (MITEs). Both gyspy-like long terminal repeat (LTR) and non-LTR retrotransposon sequences are represented in the flanking DNAs. One of the MITEs is a novel class, but another MITE is related to the maize Stowaway family and is widely represented in Triticeae express sequence tags (ESTs). Flanking DNA of the longest sequence, a 20 425-bp fragment including and surrounding the HMW-glutenin Bx7 gene, showed additional cereal gene-like sequences both immediately 5' and 3' to the HMW-glutenin coding region. The transcriptional activities of sequences related to these flanking putative genes and the retrotransposon-related regions were indicated by matches to wheat and other Triticeae ESTs. Predictive analysis of matrix-attachment regions (MARs) of the HMW glutenin and several alpha, gamma-, and omega-gliadin flanking DNAs indicate potential MARs immediately flanking each of the genes. Matrix binding activity in the predicted regions was confirmed for two of the HMW-glutenin genes. C1 ARS, Western Reg Res Ctr, USDA, Albany, CA 94710 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. N Dakota State Univ, Dept Plant Sci, Fargo, ND 58105 USA. Univ Missouri, Dept Agron, USDA ARS, Columbia, MO 65211 USA. RP Anderson, OD (reprint author), ARS, Western Reg Res Ctr, USDA, 800 Buchanan St, Albany, CA 94710 USA. RI McCue, Kent/A-8973-2009 NR 50 TC 24 Z9 24 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0831-2796 J9 GENOME JI Genome PD APR PY 2002 VL 45 IS 2 BP 367 EP 380 DI 10.1139/G01-137 PG 14 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 530AM UT WOS:000174333500018 PM 11962634 ER PT J AU Chittenden, L Lu, XC Cacheiro, NLA Cain, KT Generoso, W Bryda, EC Stubbs, L AF Chittenden, L Lu, XC Cacheiro, NLA Cain, KT Generoso, W Bryda, EC Stubbs, L TI A new mouse model for autosomal recessive polycystic kidney disease SO GENOMICS LA English DT Article DE autosomal recessive polycystic kidney disease; experimental animal models; mice; fluorescence in situ hybridization ID 2ND GENE; MICE; MUTATIONS; LOCUS; CHLORAMBUCIL; PATHOGENESIS; LOCALIZATION; KINASE; PKHD1; JCPK AB In the course of large-scale mutagenesis studies, we discovered a mutant that provides a new mouse model for human autosomal recessive polycystic kidney disease. Animals homozygous for this mutation, T(2;10)67Gso, present evidence of grossly cystic renal and hepatic tissue at birth and a limited survival time of 3-4 days. The recessively expressed phenotype is associated with inheritance of a reciprocal translocation involving mouse chromosomes 2 and 10. Here we describe the pathology and phenotype of this new mutation. The mapping of the chromosomal breakpoint to the 1.0-cM critical region defined for another mouse autosomal recessive polycystic kidney disease model, juvenile congenital polycystic kidney disease (jcpk), led us to undertake the complementation testing that confirmed T(2;10)67Gso and jcpk are allelic. Because of the strong resemblance between the phenotype associated with these mouse mutations and early childhood polycystic kidney disease, and because of advantages offered by reciprocal translocations for gene mapping and cloning, T(2;10)67Gso should prove a valuable asset for studies concerning this fatal disease. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Tennessee, Grad Sch Genome Sci Technol, Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Marshall Univ, Joan C Edwards Sch Med, Dept Microbiol Immunol & Mol Genet, Huntington, WV 25704 USA. RP Stubbs, L (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, L-452,7000 E Ave, Livermore, CA 94550 USA. OI Stubbs, Lisa/0000-0002-9556-1972 FU NIDDK NIH HHS [DK54732] NR 47 TC 5 Z9 6 U1 1 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD APR PY 2002 VL 79 IS 4 BP 499 EP 504 DI 10.1006/geno.2002.6731 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 537ED UT WOS:000174744600009 PM 11944981 ER PT J AU Waychunas, GA Fuller, CC Davis, JA AF Waychunas, GA Fuller, CC Davis, JA TI Surface complexation and precipitate geometry for aqueous Zn(II) sorption on ferrihydrite I: X-ray absorption extended fine structure spectroscopy analysis SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HYDROUS FERRIC-OXIDE; UNIT-CELL DIMENSIONS; BASIC ZINC SULFATES; CRYSTAL-STRUCTURE; STRUCTURE REFINEMENT; EXAFS; ADSORPTION; HYDROXIDE; ZN; SOLUBILITY AB "Two-line" ferrihydrite samples precipitated and then exposed to a range of aqueous Zn solutions (10(-5) to 10(-3) M), and also coprecipitated in similar Zn solutions (pH 6.5), have been examined by Zn and Fe K-edge X-ray absorption spectroscopy. Typical Zn complexes on the surface have Zn-O distances of 1.97(.02) Angstrom and coordination numbers of about 4.0(0.5), consistent with tetrahedral oxygen coordination. This contrasts with Zn-O distances of 2,11(.02) Angstrom and coordination numbers of 6 to 7 in the aqueous Zn solutions used in sample preparation. X-ray absorption extended fine structure spectroscopy (EXAFS) fits to the second shell of cation neighbors indicate as many as 4 Zn-Fe neighbors at 3.44(.04) Angstrom in coprecipitated samples, and about two Zn-Fe neighbors at the same distance in adsorption samples. In both sets of samples, the fitted coordination number of second shell cations decreases as sorption density increases. indicating changes in the number and type of available complexing sites or the onset of competitive precipitation processes. Comparison of our results with the possible geometries for surface complexes and precipitates suggests that the Zn sorption complexes are inner sphere and at lowest adsorption densities are bidentate, sharing apical oxygens with adjacent edge-sharing Fe(O,OH)(6) octahedra. Coprecipitation samples have complexes with similar geometry, but these are polydentate, sharing apices with more than two adjacent edge-sharing Fe(,O,OH)(6) polyhedra. The results are inconsistent with Zn entering the ferrihydrite structure (i.e., solid solution formation) or formation of other Zn-Fe precipitates. The fitted Zn-Fe coordination numbers drop with increasing Zn density with a minimum of about 0.8(.2) at Zn/(Zn + Fe) of 0.08 or more. This change appears to be attributable to the onset of precipitation of zinc hydroxide polymers with mainly tetrahedral Zn coordination. At the highest loadings studied, the nature of the complexes changes further, and a second type of precipitate forms. This has a structure based on a brucite layer topology, with mainly octahedral Zn coordination. Amorphous zinc hydroxide samples prepared for comparison had a closely similar local structure. Analysis of the Fe K-edge EXAFS is consistent with surface complexation reactions and surface precipitation at high Zn loadings with little or no Fe-Zn solid solution formation. The formation of Zn-containing precipitates at solution conditions two or more orders of magnitude below their solubility limit is compared with other sorption and spectroscopic studies that describe similar behavior. Copyright (C) 2002 Elsevier Science Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Dept Geochem, Berkeley, CA 94720 USA. US Geol Survey, Div Water Resources, Menlo Pk, CA 94025 USA. RP Waychunas, GA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Dept Geochem, MS 70-108B, Berkeley, CA 94720 USA. EM gawaychunas@lbl.gov OI Fuller, Christopher/0000-0002-2354-8074 NR 86 TC 104 Z9 108 U1 1 U2 32 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 APR PY 2002 VL 66 IS 7 BP 1119 EP 1137 DI 10.1016/S0016-7037(01)00853-5 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 534QR UT WOS:000174598600002 ER PT J AU Vaniman, DT Chipera, SJ Bish, DL Duff, MC Hunter, DB AF Vaniman, DT Chipera, SJ Bish, DL Duff, MC Hunter, DB TI Crystal chemistry of clay-Mn oxide associations in soils, fractures, and matrix of the Bandelier Tuff, Pajarito Mesa, New Mexico SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID YUCCA MOUNTAIN; BEHAVIOR; WATER; EDGE; SPECTROSCOPY; LANTHANIDES; PARTICLES; ACTINIDES; OXIDATION; MINERALS AB The upper 25 m of Bandelier Tuff at Pajarito Mesa, New Mexico, include soils, shallow fractures, deeper fractures. and tuff matrices in which clays provide a record of transport and alteration, The principal pathways within this system are fractures that penetrate the tuff. Large fractures that host deep root penetration provide a setting in which clay deposits accumulate through particulate or colloidal migration from the soil zone. Clays throughout the system are predominantly expandable interstratified illite/smectites (I/S), but clays of the tuff matrix at depth are distinctly Fe-rich and are not mixed with clays transported from the surface into fractures. Chemical alteration superimposed on clay particles transported into fractures results in clays with lower Al : Si ratios, higher Na, and higher lanthanide content with increasingly negative Eu anomalies with depth. These changes are accompanied by invasion and precipitation of Mn oxides, principally birnessite, within clay bodies. Investigation of the Mn oxides by synchrotron X-ray fluorescence (SXRF) shows that Mn is associated with Ba, Cc, Ni, and Pb. In addition, synchrotron X-ray absorption near-edge structure (XANES) spectra show that Ce in Mn oxides occurs as Ce(3+) and Ce(4+), with average Ce oxidation state of similar to3.75. The Mn oxides intergrown with clays actively participate in removal of Ce from solution, accompanied by oxidation of Ce(3+) to Ce(4+). Other lanthanides are accumulated by the clays but are not concentrated along with Cc in the Mn oxides. Extraction of Ce from solution by Mn oxides is more effective than lanthanide accumulation in clay, a process that is variable and likely influenced by defects, extent of recrystallization, and particle sizes. This dichotomy in lanthanide interaction results in locally constant Ce content but either negative or positive Ce anomalies in the clay-Mn oxide system as a consequence of variability in the abundance of the other lanthanides. Nevertheless, the net lanthanide pattern for the sum of all clay-Mn oxide samples in either shallow or deep fractures has no Ce anomaly, indicating that other lanthanides segregated from Ce are not transported beyond the range of either the shallow or deep fracture systems. Evidence from Eu anomalies indicates that lanthanides accumulated in the fracture clays are acquired from the local tuff. The clay-Mn oxide assemblage is more effective than clay alone in accumulating of a wide variety of heavy metals. Copyright (C) 2002 Elsevier Science Ltd. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Vaniman, DT (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. EM vaniman@lanl.gov NR 42 TC 21 Z9 22 U1 2 U2 7 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 APR PY 2002 VL 66 IS 8 BP 1349 EP 1374 AR PII S0016-7037(01)00826-2 DI 10.1016/S0016-7037(01)00826-2 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 543JV UT WOS:000175099600005 ER PT J AU Murphy, MA Yin, A Kapp, P Harrison, TM Manning, CE Ryerson, FJ Ding, L Guo, JH AF Murphy, MA Yin, A Kapp, P Harrison, TM Manning, CE Ryerson, FJ Ding, L Guo, JH TI Structural evolution of the Gurla Mandhata detachment system, southwest Tibet: Implications for the eastward extent of the Karakoram fault system SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE Himalayas; kinematics; metamorphic core complex; strike-slip faults; Tibetan plateau ID INDO-ASIAN COLLISION; SOUTHERN TIBET; ACTIVE DEFORMATION; TECTONIC IMPLICATIONS; ISOTOPIC CONSTRAINTS; PASSIVE MARGIN; OROGENIC BELT; HIMALAYA; PLATEAU; AGE AB Field mapping and geochronologic and thermobarometric analyses of the Gurla Mandhata area, in southwest Tibet, reveal major middle to late Miocene, east-west extension along a normal-fault system, termed the Gurla Mandhata detachment system. The maximum fault slip occurs along a pair of low-angle normal faults that have caused significant tectonic denudation of the Tethyan Sedimentary Sequence, resulting in juxtaposition of weakly metamorphosed Paleozoic rocks and Tertiary sedimentary rocks in the hanging wall over amphibolite-facies mylonitic schist, marble, gneisses, and variably deformed leucogranite bodies in the footwall. The footwall of the detachment fault system records a late Miocene intrusive event, in part contemporaneous with top-to-the-west ductile normal shearing. The consistency of the mean shear direction within the mylonitic footwall rocks and its correlation with structurally higher brittle normal faults suggest that they represent an evolving low-angle normal-fault system. Ar-40/Ar-39 data from muscovite and biotite from the footwall rocks indicate that it cooled below 400 degreesC by ca. 9 Ma. Consideration of the original depth and dip angle of the detachment fault prior to exhumation of the footwall yields total slip estimates between 66 and 35 km across the Gurla Mandhata detachment system. The slip estimates and timing constraints on the Gurla Mandhata detachment system are comparable to those estimated on the right-slip Karakoram fault system, to which it is interpreted to be kinematically linked. Moreover, the mean shear-sense direction on both the Karakoram fault and the Gurla Mandhata detachment system overlap along the intersection line between the mean orientations of the faults, which further supports a kinematic association. If valid, this interpretation extends previous results that the Karakoram fault extends to mid-crustal depths. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China. RP Murphy, MA (reprint author), Univ Houston, Dept Geosci, Houston, TX 77204 USA. RI Harrison, Timothy/E-7443-2012; Manning, Craig/A-1118-2009; Yin, An/B-3050-2014; UCLA, SIMS/A-1459-2011; OI Manning, Craig/0000-0002-1463-3701; Kapp, Paul/0000-0002-7173-9908 NR 64 TC 119 Z9 131 U1 2 U2 15 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD APR PY 2002 VL 114 IS 4 BP 428 EP + DI 10.1130/0016-7606(2002)114<0428:SEOTGM>2.0.CO;2 PG 22 WC Geosciences, Multidisciplinary SC Geology GA 538YJ UT WOS:000174842500004 ER PT J AU Baker, SN Baker, GA Bright, FV AF Baker, SN Baker, GA Bright, FV TI Temperature-dependent microscopic solvent properties of 'dry' and 'wet' 1-butyl-3-methylimidazolium hexafluorophosphate: correlation with ET(30) and Kamlet-Taft polarity scales SO GREEN CHEMISTRY LA English DT Article ID SOLVATOCHROMIC COMPARISON METHOD; DIELS-ALDER REACTIONS; NONAQUEOUS IONIC LIQUIDS; FRIEDEL-CRAFTS REACTIONS; GAS-CHROMATOGRAPHY; SOLUTE-SOLVENT; CLEAN TECHNOLOGY; CARBON-DIOXIDE; PHASE-BEHAVIOR; HECK REACTION AB As a result of heightened awareness of a wealth of potential in clean manufacturing processes, room temperature ionic liquids (RTILs) have been the target of increased investigation. As an integral part of the green chemistry movement, RTILs have found application in synthesis, catalysis, polymerization, industrial cleaning, liquid/liquid extraction, and separations. While some groundwork has been laid, the optimal utilization and tailoring of these solvents has been hobbled by an incomplete understanding of their solvent properties, particularly at the molecular level. In this work, we use solvatochromic measurements to determine 'energy of transition' E-T(30) values and Kamlet-Taft solvent parameters (alpha,beta,pi*) for the relatively hydrophobic RTIL 1-butyl-3-methylimidazolium hexafluorophosphate, [bmin](+)[PF6](-), as a function of temperature (10-70degreesC) and water content (50 ppm or less water, 'dry' or 2% water (v/v), 'wet'). The results of these experiments demonstrate that dry [bmim]+[PF6]exhibits a hydrogen bond donor strength on the order of short chain alcohols with a linear temperature dependence. Dry and wet [bmim](+)[PF6](-) exhibit hydrogen bond acceptor abilities, which are weak functions of temperature, intermediate between that of water and acetonitrile. The pi* parameter for wet and dry [bmim](+)[PF6](-) is higher than short chain alcohols, but lower than water or dimethylsulfoxide at ambient conditions, and it exhibits a strong linear temperature dependence. Finally, the addition of water to [bmim](+)[PF6](-) does not affect the beta and pi* values significantly. C1 SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Bright, FV (reprint author), SUNY Buffalo, Dept Chem, Nat Sci Complex, Buffalo, NY 14260 USA. RI Baker, Gary/H-9444-2016 OI Baker, Gary/0000-0002-3052-7730 NR 79 TC 201 Z9 201 U1 3 U2 39 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9262 J9 GREEN CHEM JI Green Chem. PD APR PY 2002 VL 4 IS 2 BP 165 EP 169 DI 10.1039/b111285f PG 5 WC Chemistry, Multidisciplinary; GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY SC Chemistry; Science & Technology - Other Topics GA 551FA UT WOS:000175547900021 ER PT J AU Nasedkina, T Domer, P Zharinov, V Hoberg, J Lysov, Y Mirzabekov, A AF Nasedkina, T Domer, P Zharinov, V Hoberg, J Lysov, Y Mirzabekov, A TI Identification of chromosomal translocations in leukemias by hybridization with oligonucleotide microarrays SO HAEMATOLOGICA LA English DT Article DE oligonucleotide microarray; RT-PCR; multiplex PCR; leukemia; chromosomal translocations; diagnostics ID POLYMERASE CHAIN-REACTION; RT-PCR; MICROCHIPS; DNA; TRANSCRIPTS; IMMOBILIZATION; ABERRATIONS; DIAGNOSIS; ARRAYS; RNA AB Background and Objectives. Identification of chromosomal rearrangements is important for a precise risk-stratified diagnosis of hematologic malignancies. As the number of known translocations, specific for different types of leukemia increases, it takes ever more time and increasing amounts of patient's material to screen a single patient with individual polymerase chain reactions (PCR). The aim of this study was to develop a new approach combining specificity with high-throughput sufficient for rapid screening of clinical samples for the presence of numerous translocations. Design and Methods, We designed an oligonucleotide microarray and used hybridization with microarrays in combination with multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay for accurate and rapid identification of some major leukemias. The following translocations were used as prototypic: t(9;22) p210 and p190, t(4;11), t(12;21), and t(15;17). This approach was tested on five different cell cultures carrying translocations and on 22 clinical samples from leukemic patients. Results. Distinctive hybridization signals were obtained for all types of chimeric transcripts from cell lines with translocations. Both the type of translocation and the splice variant were determined. The data demonstrated high specificity and reproducibility of the method. Analysis of the 22 clinical samples using the microarray-based approach showed complete agreement with standard PCR analysis. Interpretation and Conclusions. Our data suggest that oligonucleotide microarrays can be used as an efficient, alternative approach to the traditional post-PCR Southern blot analysis. The oligonucleotide microarray approach appears suitable for clinical screening of major risk-stratifying translocations in patients with leukemia. (C)2002, Ferrata Storti Foundation. C1 Russian Acad Sci, Engelhardt Inst Mol Biol, Moscow 119991, Russia. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. Res Inst Pediat Hematol, Moscow, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Mirzabekov, A (reprint author), Russian Acad Sci, Engelhardt Inst Mol Biol, Vavilov Str 32, Moscow 119991, Russia. NR 29 TC 20 Z9 23 U1 0 U2 1 PU FERRATA STORTI FOUNDATION PI PAVIA PA STRADA NUOVA 134, 27100 PAVIA, ITALY SN 0390-6078 J9 HAEMATOLOGICA JI Haematologica PD APR PY 2002 VL 87 IS 4 BP 363 EP 372 PG 10 WC Hematology SC Hematology GA 537TJ UT WOS:000174775400007 PM 11940480 ER PT J AU Potter, CA Culp, TA AF Potter, CA Culp, TA TI Development of a routine I-125 bioassay program for athyrotic individuals using a pseudo uptake retention function SO HEALTH PHYSICS LA English DT Article DE dosimetry, internal; bioassay; excretion, urinary; I-125 AB Individuals working in iodine production require bioassay to determine if intakes have occurred. This is both to determine dose received for regulatory purposes and to verify whether workplace controls limiting the spread of contamination are adequate. Thyroid monitoring is commonly used as a bioassay technique to detect isotopes of iodine. If an individual performing iodine processing does not have a thyroid gland, other means must be used to determine intake and infer dose. Data was obtained from a previously published thesis that attempted to verify a model for absorption and retention of iodine by athyrotic individuals. These data were reevaluated to determine a pseudo uptake retention function. This analysis does not attempt to identify a biokinetic model, only to describe excretion of iodine and calculate an intake. Once the pseudo uptake retention function was derived, it was combined with the standard respiratory and gastrointestinal tract models as an inhalation intake retention function. A periodic urine bioassay protocol has been designed using the intake retention function described above and a conservative dose coefficient derived using organ dose coefficients for reference man, excluding the thyroid, and the appropriate weighting factors. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Potter, CA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 0 Z9 0 U1 0 U2 2 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 APR PY 2002 VL 82 IS 4 BP 533 EP 538 DI 10.1097/00004032-200204000-00015 PG 6 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 531XU UT WOS:000174443200015 PM 11906143 ER PT J AU Briggs, SLK AF Briggs, SLK TI ISO 14001: Positioning your organization for environmental success SO HEALTH PHYSICS LA English DT Book Review C1 Brookhaven Natl Lab, Environm Serv Div, Upton, NY 11973 USA. RP Briggs, SLK (reprint author), Brookhaven Natl Lab, Environm Serv Div, POB 5000, Upton, NY 11973 USA. NR 1 TC 0 Z9 0 U1 2 U2 2 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 APR PY 2002 VL 82 IS 4 BP 539 EP 539 DI 10.1097/00004032-200204000-00016 PG 1 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 531XU UT WOS:000174443200016 ER PT J AU Zhang, JB Huo, L Zhang, WN Liu, YM Xu, N AF Zhang, JB Huo, L Zhang, WN Liu, YM Xu, N TI Radial flow in Au plus Au central collisions at RHIC energy SO HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION LA English DT Letter DE heavy-ion collisions; radial flow; transverse mass spectra ID HEAVY-ION COLLISIONS; COLLECTIVE FLOW AB Using the dynamical transport approach RQMD, the radial collective expansion in relativistic heavy-ion collisions is studied at RHIC energy. The prediction of the radial flow is presented by analyzing the transverse mass spectra for Au + Au central collisions at the center of mass energy roots = 200 A GeV. We conclude that the average radial flow velocity is 0.6c and the freeze-out temperature is 160MeV in Au + Au reactions. C1 Harbin Inst Technol, Dept Phys, Harbin 150001, Peoples R China. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Zhang, JB (reprint author), Harbin Inst Technol, Dept Phys, Harbin 150001, Peoples R China. NR 10 TC 1 Z9 1 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 APR PY 2002 VL 26 IS 4 BP 305 EP 308 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 540RN UT WOS:000174942400002 ER PT J AU Ma, WX Zhou, LJ Liu, LC AF Ma, WX Zhou, LJ Liu, LC TI Does the tensor glueball xi (2230) exist? SO HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION LA English DT Letter DE tensor glueball; pp scattering; p(p)over-bar scattering ID J/PSI RADIATIVE DECAYS; XI(2230); MASSES; MESON AB We show that the xi(2230) must have a width much broader than the reported 20MeV. A broader width does not necessarily rule out the xi(2230) as a glueball, but it does explain why the meson cannot be seen in p (p) over bar experiments. Therefore, the controversy between different experimental results does not rule out the existence of the tensor glueball xi(2230). C1 Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China. Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China. Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ma, WX (reprint author), Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China. NR 17 TC 3 Z9 3 U1 0 U2 1 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 APR PY 2002 VL 26 IS 4 BP 309 EP 312 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 540RN UT WOS:000174942400003 ER PT J AU Nellis, WJ AF Nellis, WJ TI Metallization of hydrogen and other small molecules at 100 GPa pressures SO HIGH PRESSURE RESEARCH LA English DT Article; Proceedings Paper CT 39th European High Pressure Research Group Meeting on Advanves on High Pressure Research (EHPRHG'39) CY SEP 16-19, 2001 CL SANTANDER, SPAIN DE hydrogen; metallization; shock pressure; fluid; Mott transition ID ELECTRICAL-CONDUCTIVITY; MEGABAR PRESSURES; FLUID HYDROGEN; 1.4 MBAR; METAL; WATER; H-2 AB Fluid hydrogen, oxygen, and nitrogen become metallic at 100 GPa (1 Mbar) pressures. Disorder is the primary reason for observing a metal at lower pressures in the fluid than expected for the ordered solid. This metallic transition is similar to those observed in fluid Cs and Rb by Hensel et al. All five undergo a Mott transition from a semiconducting to metallic fluid with the same electrical conductivities. In contrast, water is a proton conductor at pressures up to 200 GPa. Extreme conditions were achieved for similar to100ns with a reverberating shock wave generated with a two-stage light-gas gun. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nellis, WJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 19 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0895-7959 J9 HIGH PRESSURE RES JI High Pressure Res. PD APR PY 2002 VL 22 IS 1 SI SI BP 1 EP 4 DI 10.1080/08957950290007126 PG 4 WC Physics, Multidisciplinary SC Physics GA 572WX UT WOS:000176798900002 ER PT J AU Lorenzana, HE Lipp, MJ Evans, WJ AF Lorenzana, HE Lipp, MJ Evans, WJ TI Anomalous molecular phase of nitrogen: Implications to the phase diagram SO HIGH PRESSURE RESEARCH LA English DT Article; Proceedings Paper CT 39th European High Pressure Research Group Meeting on Advanves on High Pressure Research (EHPRHG'39) CY SEP 16-19, 2001 CL SANTANDER, SPAIN DE high pressure; nitrogen; molecular solid; phase transformation; Raman spectroscopy ID HIGH-PRESSURE PHASES; SOLID NITROGEN; RAMAN-SPECTROSCOPY; DELTA-PHASE; GPA; TEMPERATURES; TRANSITIONS; SCATTERING; SPECTRUM; BEHAVIOR AB Despite their simplicity, diatomic molecules of first row elements can exhibit very complex phase diagrams. Determination of the phase diagrams can be further complicated by the existence of hysteretic molecular phases that can be observed over large regions of coexistence. Here we present evidence for a previously unreported molecular phase of nitrogen existing at room temperature at least over the range of 33-74GPa. Our measurements show that sample history may have a significant impact on the thermodynamic states accessed by the molecular nitrogen solid and, by extension, also on the established phase diagram. C1 Lawrence Livermore Natl Lab, H Div, Phys & Adv Technol Directorate, Livermore, CA 94551 USA. RP Lorenzana, HE (reprint author), Lawrence Livermore Natl Lab, H Div, Phys & Adv Technol Directorate, Livermore, CA 94551 USA. NR 15 TC 2 Z9 2 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0895-7959 J9 HIGH PRESSURE RES JI High Pressure Res. PD APR PY 2002 VL 22 IS 1 SI SI BP 5 EP 8 DI 10.1080/08957950290008657 PG 4 WC Physics, Multidisciplinary SC Physics GA 572WX UT WOS:000176798900003 ER PT J AU Sparn, G Borth, R Lengyel, E Pagliuso, PG Sarrao, J Steglich, F Thompson, JD AF Sparn, G Borth, R Lengyel, E Pagliuso, PG Sarrao, J Steglich, F Thompson, JD TI Pressure studies of the unconventional superconductors CeTIn5 (T : Co, Ir) SO HIGH PRESSURE RESEARCH LA English DT Article; Proceedings Paper CT 39th European High Pressure Research Group Meeting on Advanves on High Pressure Research (EHPRHG'39) CY SEP 16-19, 2001 CL SANTANDER, SPAIN DE heavy fermion; superconductivity; heat capacity; pressure ID MAGNETICALLY MEDIATED SUPERCONDUCTIVITY; CEIRIN5 AB In the quest for new superconductor compounds which adopt the superconducting state at increasingly higher transition temperatures T-c, a non-phonon mediated coupling between the charge carriers seems to play a key role. In order to enhance our understanding of such unconventional coupling mechanisms, we studied a new family of heavy fermion (HF) superconductors CeTIn5 (T: transition metal) whose properties point toward the realization of unconventional superconductivity (SC): the specific beat, thermal conductivity and nuclear spin-lattice relaxation rate of CeIrIn5 and CeCoIn5 decrease as a power law of temperature instead of exponentially for T < T-c. We report on measurements of the heat capacity of CeIrIn5 and CeCoIn5 at hydrostatic pressures p less than or equal to 1.6 GPa. In both compounds, T. increases with increasing pressure, while the mass of the quasi-particles m(eff) decreases, as indicated by the ratio C/T\(Tc). As a working hypothesis based on theories of a nearly antiferromagnetic Fermi-liquid (NAFFL), this may be interpreted as the stabilization of the superconducting state by an increase of the characteristic spin fluctuation temperature T-SF (T-SF proportional to k(F)(2)/m(eff)). C1 Max Planck Inst Chem Phys Solids, Dresden, Germany. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sparn, G (reprint author), Max Planck Inst Chem Phys Solids, Dresden, Germany. RI Pagliuso, Pascoal/C-9169-2012; Sparn, Guenter/F-5120-2013 NR 10 TC 1 Z9 1 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0895-7959 J9 HIGH PRESSURE RES JI High Pressure Res. PD APR PY 2002 VL 22 IS 1 SI SI BP 163 EP 165 DI 10.1080/0895795020003003 PG 3 WC Physics, Multidisciplinary SC Physics GA 572WX UT WOS:000176798900035 ER PT J AU Lengyel, E Borth, R Pagliuso, PG Sarrao, J Sparn, G Steglich, F Thompson, JD AF Lengyel, E Borth, R Pagliuso, PG Sarrao, J Sparn, G Steglich, F Thompson, JD TI Heat capacity under pressure of CeCoIn5 SO HIGH PRESSURE RESEARCH LA English DT Article; Proceedings Paper CT 39th European High Pressure Research Group Meeting on Advanves on High Pressure Research (EHPRHG'39) CY SEP 16-19, 2001 CL SANTANDER, SPAIN DE heavy fermion; superconductivity; heat capacity; pressure ID MAGNETICALLY MEDIATED SUPERCONDUCTIVITY AB Among heavy-fermion (HF) superconductors, CeCoIn5 exhibits a record high value of T-c = 2.3 K at ambient pressure [1]. CeCoIn5 belongs to a new class of HF-superconductors that crystallize in the tetragonal HoCoGa5-structure. This structure can be regarded as alternating layers of CeIn3 and CoIn2. Bulk CeIn3 undergoes a transition from an antiferromagnetic (AFM) state at ambient pressure (T-N = 10.2 K) to a superconducting state with very low T-C = 0.15 K at a critical pressure p(c) = 2.8 GPa [2] at which long range magnetic order vanishes. It is, therefore, regarded as a possible candidate for magnetically mediated superconductivity (SC). We report on measurements of the heat capacity of CeCoIn5 at hydrostatic pressures p less than or equal to 1.5 GPa. While T-c increases with increasing pressure, the effective mass of the quasi-particles m(eff) decreases, as indicated by the ratio C/T\(Tc). As a working hypothesis based on theories of a nearly antiferromagnetic Fermi-liquid (NAFFL), this may be interpreted as the stabilization of the superconducting state by an increase of the characteristic spin fluctuation temperature T-SF (T-SF proportional tok(F)(2)/m(eff)). C1 Max Planck Inst Chem Phys Solids, Dresden, Germany. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lengyel, E (reprint author), Max Planck Inst Chem Phys Solids, Dresden, Germany. RI Pagliuso, Pascoal/C-9169-2012; Sparn, Guenter/F-5120-2013 NR 11 TC 6 Z9 6 U1 1 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0895-7959 J9 HIGH PRESSURE RES JI High Pressure Res. PD APR PY 2002 VL 22 IS 1 SI SI BP 185 EP 187 DI 10.1080/08957950290010627 PG 3 WC Physics, Multidisciplinary SC Physics GA 572WX UT WOS:000176798900040 ER PT J AU Oomi, G Minamitake, I Ohashi, M Eto, T Cho, BK Canfield, PC AF Oomi, G Minamitake, I Ohashi, M Eto, T Cho, BK Canfield, PC TI Relation between the superconducting transition temperature and the axial ratio in RNi2B2C (R=Y, Ho, Er, Tm, Lu) under high pressure SO HIGH PRESSURE RESEARCH LA English DT Article; Proceedings Paper CT 39th European High Pressure Research Group Meeting on Advanves on High Pressure Research (EHPRHG'39) CY SEP 16-19, 2001 CL SANTANDER, SPAIN DE RNi2B2C; lattice parameter; superconductivity; axial ratio; high pressure ID STATE AB The effect of pressure on the lattice parameters of RNi2B2C (R = Y, Ho, Er, Tm, Lu) has been measured in order to investigate the relation of T-C to axial ratio c/a in the tetragonal lattice or the cohesive properties of these materials. The large anisotropies are observed in the lattice compression curves especially for R Ho and Tm; the c-axis is more compressible than the a-axis. On the other hand, the anisotropy in the lattice compression is found to be relatively small for R = Y and Lu. The close relation between T-C and c/a is pointed out particularly for R = Ho. C1 Kyushu Univ, Dept Phys, Chuo Ku, Fukuoka 8108560, Japan. Kyushu Univ, Res Ctr Higher Educ, Chuo Ku, Fukuoka 8108560, Japan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Oomi, G (reprint author), Kyushu Univ, Dept Phys, Chuo Ku, Fukuoka 8108560, Japan. RI Canfield, Paul/H-2698-2014 NR 10 TC 4 Z9 4 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0895-7959 J9 HIGH PRESSURE RES JI High Pressure Res. PD APR PY 2002 VL 22 IS 1 SI SI BP 195 EP 198 DI 10.1080/08957950290010645 PG 4 WC Physics, Multidisciplinary SC Physics GA 572WX UT WOS:000176798900042 ER PT J AU Beck, BD Slayton, TM Farr, CH Sved, DW Crecelius, EA Holson, JF AF Beck, BD Slayton, TM Farr, CH Sved, DW Crecelius, EA Holson, JF TI Systemic uptake of inhaled arsenic in rabbits SO HUMAN & EXPERIMENTAL TOXICOLOGY LA English DT Article DE arsenic; inhalation; plasma; rabbits ID MONOMETHYLARSONOUS ACID MMA(III); COPPER SMELTER WORKERS; LUNG-CANCER MORTALITY; DRINKING-WATER; DIMETHYLARSINIC ACID; RESPIRATORY CANCER; MAIN METABOLITE; METHYLATED ARSENICALS; INORGANIC ARSENICS; DOSE-RESPONSE AB Human occupational exposure to sufficiently high levels of arsenic in air has been associated with lung cancer, but generally not other types of cancer. Thus, a better understanding of the relationship between airborne arsenic exposures and systemic uptake is essential. In this study, rabbits were exposed to one of four levels of arsenic trioxide in air for 8 h/day, 7 days/week, for 8 weeks (0.05, 0.1, 0.22, or 1.1 mg/m(3)). Plasma levels of inorganic arsenic, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were measured following the last exposure. Although there was a dose-related increase in plasma levels of methylated arsenic metabolites, statistically significant increases in mean inorganic arsenic levels in plasma were observed only in male rabbits exposed to 0.22 mg/m(3), and in both males and females exposed to 1.1 mg/m(3). Mean inorganic arsenic levels in plasma in males and females exposed to 0.05 and 0.1 mg/m(3), and 3 females exposed to 0.22 mg/m(3), were not significantly elevated compared to controls. These results suggest that arsenic inhalation has a negligible impact on body burden of inorganic arsenic until air levels are significantly elevated. Based on plasma measurements of inorganic arsenic, the two lowest exposure levels in this study (0.05 and 0.1 mg/m(3)) are indistinguishable from background. C1 Gradient Corp, Cambridge, MA 02142 USA. WIL Res Labs, Ashland, OR USA. Atofina Chem, Philadelphia, PA USA. Battelle Marine Sci Lab, Washington, DC USA. RP Beck, BD (reprint author), Gradient Corp, 238 Main St, Cambridge, MA 02142 USA. NR 76 TC 0 Z9 0 U1 0 U2 0 PU ARNOLD, HODDER HEADLINE PLC PI LONDON PA 338 EUSTON ROAD, LONDON NW1 3BH, ENGLAND SN 0960-3271 J9 HUM EXP TOXICOL JI Hum. Exp. Toxicol. PD APR PY 2002 VL 21 IS 4 BP 205 EP 215 DI 10.1191/0960327102ht237oa PG 11 WC Toxicology SC Toxicology GA 566CK UT WOS:000176409100006 PM 12099622 ER PT J AU Cook, CB Orlob, GT Huston, DW AF Cook, CB Orlob, GT Huston, DW TI Simulation of wind-driven circulation in the Salton Sea: implications for indigenous ecosystems SO HYDROBIOLOGIA LA English DT Article DE transient CFD modeling; finite element method; acoustic Doppler current profiler; terminal basin lake; RMA10; thermohaline stratification ID TURBULENCE AB The Salton Sea, the largest 'man-made' water body wholly within California, was formed in 1904 as the result of a levee failure along the Colorado River. Initially, flow into the Salton `Sink' created a fresh water lake about 24 m deep with a water surface about 85 m below the level of the ocean. Salinity of the water body, at first roughly the same as the river, rose rapidly due to solution of previously accumulated residual salt, then following levee repair, adjusted to the combined influence of agricultural drainage accretions and evaporative losses. Water levels adjusted accordingly, at first declining then rising slowly until the mid 1930s when a level about 75 m below ocean level was reached. Thereafter, both water levels and salinity gradually rose, so that at present the surface elevation of the Sea stands near -69.5 m and salinity is approaching 45 g l(-1), about 30% above ocean salinity. The Salton Sea Authority is seeking practical methods for reducing water levels and controlling salinity within ranges that will protect beneficial uses of the Sea, its adjacent lands, and its indigenous ecosystems, both aquatic and avian. Proposed solutions include various physical changes in the bathymetry and configuration of the Sea, especially its southern basin. Because circulation in the Sea is driven primarily by wind stresses imposed on the water surface, and circulation changes are likely to affect the Sea's quality and ecology, a methodology for quantifying the effects of specific alternatives is required. For this purpose a mathematical model for simulation of the hydrodynamic behavior of the Sea has been developed, calibrated to data gathered by a field investigation conducted in 1997, and applied to alternative schemes that will isolate sections of the southern basin, thus changing the natural wind induced circulation in areas that are ecologically sensitive. The Salton Sea Hydrodynamic/Water Quality Model is constructed using the finite element method to represent the bathymetry of the Sea as it currently exists, or may subsequently be modified, in a three-dimensional grid. Given certain boundary conditions, for example wind stresses imposed on the surface, the model solves the three dimensional equations of motion and continuity, the advection-dispersion equation, and an equation of state dependent upon temperature and salinity, to obtain temporal and spatial descriptions of velocities and temperatures over a specified period of time. Using data derived from 1997 field measurements of velocities using acoustic Doppler current profilers and temperature sensors, the model was calibrated to reproduce mathematically the historic experience of field observation. The model successfully replicated principal features of the Sea's behavior, especially the persistence of a counterclockwise gyre in the southern basin and seasonal stratification. Once calibrated, the model was applied to evaluate the possible effects of changing water surface elevations in the Sea and altering its configuration to isolate sections for evaporative concentration of salts. These effects, evident in changes in velocity, were quantified with regard to their possible impacts on the aquatic habitat and the health of the Salton Sea ecology. A comparative evaluation of alternatives is presented. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Calif Davis, Dept Civil & Environm Engn, Davis, CA 95616 USA. Dept Water Resources, Sacramento, CA 95816 USA. RP Cook, CB (reprint author), Pacific NW Natl Lab, POB 999 K9-33, Richland, WA 99352 USA. NR 12 TC 24 Z9 24 U1 1 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD APR PY 2002 VL 473 IS 1-3 BP 59 EP 75 DI 10.1023/A:1016517331869 PG 17 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 576MF UT WOS:000177008500005 ER PT J AU Frana, PL AF Frana, PL TI A well-intentioned query and the Halloween problem SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Article C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Frana, PL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 19 TC 1 Z9 1 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 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD APR-JUN PY 2002 VL 24 IS 2 BP 86 EP 89 DI 10.1109/MAHC.2002.1010071 PG 4 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA 560CQ UT WOS:000176064700008 ER PT J AU Fitzpatrick, A Malinovsky, BN AF Fitzpatrick, A Malinovsky, BN TI The MESM and the monastery SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Article C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Fitzpatrick, A (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD APR-JUN PY 2002 VL 24 IS 2 BP 91 EP 93 DI 10.1109/MAHC.2002.1010073 PG 3 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA 560CQ UT WOS:000176064700010 ER PT J AU Chow, WW Schneider, HC Koch, SW Chang, CH Chrostowski, L Chang-Hasnain, CJ AF Chow, WW Schneider, HC Koch, SW Chang, CH Chrostowski, L Chang-Hasnain, CJ TI Nonequilibrium model for semiconductor laser modulation response SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE nonequilibrium laser dynamics; optical hole burning; quantum-well lasers; semiconductor lasers; surface-emitting lasers ID MICROCAVITY LASERS; DYNAMICS AB This paper presents a laser model for describing the effects of nonequilibrium carrier distributions. The approach is based on the coupled Maxwell-semiconductor-Bloch equations, with carrier-carrier and carrier-phonon collisions treated in the relaxation rate approximation. Using examples involving relaxation oscillation, current modulation, and optical injection, we demonstrate how the model can be used to study the influences of spectral hole burning, dynamic carrier population bottleneck, and plasma heating on semiconductor laser modulation response. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Marburg, Dept Phys, D-35032 Marburg, Germany. Univ Marburg, Ctr Mat Sci, D-35032 Marburg, Germany. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Chow, WW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Schneider, Hans Christian/B-9450-2009; Chrostowski, Lukas/B-5014-2011 OI Schneider, Hans Christian/0000-0001-7656-4919; NR 15 TC 34 Z9 34 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD APR PY 2002 VL 38 IS 4 BP 402 EP 409 AR PII S0018-9197(02)02646-5 DI 10.1109/3.992554 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 535DU UT WOS:000174630600011 ER PT J AU Rao, HL Scarmozzino, R Osgood, RM AF Rao, HL Scarmozzino, R Osgood, RM TI An improved ADI-FDTD method and its application to photonic simulations SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE ADI technique; courant stability; FDTD method; numerical dispersion; PML-BC ID DOMAIN AB When ADI-FDTD is applied to simulating photonic devices, full efficiency can not be achieved if reasonable accuracy is to be kept, due to numerical errors such as numerical dispersion. A simple modification to ADI-FDTD is proposed by calculating the envelope rather than the fast-varying field, so that errors are minimized. A factor of two-five in speed can usually be gained while retaining the same level of accuracy compared with the conventional FDTD. C1 Columbia Univ, Microelect Sci Labs, New York, NY 10027 USA. RSoft Inc, Ossining, NY 10562 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Rao, HL (reprint author), Columbia Univ, Microelect Sci Labs, New York, NY 10027 USA. NR 8 TC 43 Z9 43 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD APR PY 2002 VL 14 IS 4 BP 477 EP 479 AR PII S1041-1135(02)01849-9 DI 10.1109/68.992583 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 535VB UT WOS:000174666100015 ER PT J AU Nichols, TE Qi, JY Asma, E Leahy, RM AF Nichols, TE Qi, JY Asma, E Leahy, RM TI Spatiotemporal reconstruction of list-mode PET data SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE calibration; conjugate gradient methods; estimation; poisson processes; smoothing methods; spline functions ID BAYESIAN IMAGE-RECONSTRUCTION; EMISSION-TOMOGRAPHY; MAXIMUM-LIKELIHOOD; LEAST-SQUARES; EM ALGORITHM; 3-D PET; RESOLUTION AB We describe a method for computing a continuous time estimate of tracer density using list-mode positron emission tomography data. The rate function in each voxel is modeled as an inhomogeneous Poisson process whose rate function can be represented using a cubic B-spline basis. The rate functions are estimated by maximizing the likelihood of the arrival times of detected photon pairs over the control vertices of the spline, modified by quadratic spatial and temporal smoothness penalties and a penalty term to enforce nonnegativity. Randoms rate functions are estimated by assuming independence between the spatial and temporal randoms distributions. Similarly, scatter rate functions are estimated by assuming spatiotemporal independence and that the temporal distribution of the scatter is proportional to the temporal distribution of the trues. A quantitative evaluation was performed using simulated data and the method is also demonstrated in a human study using C-11-raclopride. C1 Univ So Calif, Signal & Image Proc Inst, Los Angeles, CA 90089 USA. Univ Michigan, Dept Biostat, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Functional Imaging, Berkeley, CA 94720 USA. RP Leahy, RM (reprint author), Univ So Calif, Signal & Image Proc Inst, 3740 McClintock Ave EEB400, Los Angeles, CA 90089 USA. RI Qi, Jinyi/A-1768-2010; OI Qi, Jinyi/0000-0002-5428-0322; Nichols, Thomas/0000-0002-4516-5103 FU NCI NIH HHS [R01 CA59794] NR 29 TC 110 Z9 112 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD APR PY 2002 VL 21 IS 4 BP 396 EP 404 AR PII S0278-0062(02)04687-6 DI 10.1109/TMI.2002.1000263 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA 550LZ UT WOS:000175505700011 PM 12022627 ER PT J AU Perazzo, A O'Grady, C Swain, J AF Perazzo, A O'Grady, C Swain, J TI Vertical Monitoring: A data acquisition application for the BaBar experiment SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 12th IEEE/NPSS Real-Time Conference (RTC 2001) CY JUN 04-08, 2001 CL VALENCIA, SPAIN SP IEEE, NPSS DE data acquisition (DAQ); HEP; monitor AB Online Dataflow (ODF) handles data acquisition and processing from the BaBar detector front end electronics through the delivery of complete events to a farm of UNIX nodes. To understand the system, a monitor application, Vertical Monitoring (VMON), has been developed. VMON multicasts UDP packets with performance information from each CPU of the Dataflow system. This information is currently received by a single client on one UNIX node and archived. A ROOT-based GUI is provided on the UNIX application side to control VMON, display the performance of the ODF system in real time and retrieve archived data. VMON is currently used successfully in BaBar to provide diagnostics in the dataflow system and help with projections of future performance. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Edinburgh, Edinburgh, Midlothian, Scotland. RP Perazzo, A (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 2002 VL 49 IS 2 BP 437 EP 442 AR PII S0018-9499(02)03931-X DI 10.1109/TNS.2002.1003768 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 555YP UT WOS:000175820900020 ER PT J AU White, CG Jones, TD Luebke, WR Chen, YC Cheng, KC Choong, WS Kaplan, DM Nelson, K Rubin, HA Turko, B Zyla, P AF White, CG Jones, TD Luebke, WR Chen, YC Cheng, KC Choong, WS Kaplan, DM Nelson, K Rubin, HA Turko, B Zyla, P TI Tripling the data set for the HyperCP experiment SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE acquisition; data-acquisition (DAQ); E871; HyperCP; hyperon ID DIRECT CP VIOLATION; SEARCH; DECAYS AB FNAL E871 (HyperCP) collected over 38 terabytes of data during the 1997 fixed-target run at Fermilab. The data-acquisition (DAQ) system wrote data to tape with a typical rate of 13 MB/s. A second data collection period in 1999 allowed for the collection of a further 82 terabytes of data. However, changes in the spill structure and an increase in primary beam intensity necessitated an upgrade of the 1997 DAQ system. The 1999 run of HyperCP featured a DAQ system which recorded data on 20,421 8 mm tapes at a sustainable rate of 27 MB/s. The rationale and methods for this upgrade are detailed within. C1 IIT, Dept Biol Chem & Phys Sci, Div Phys, Chicago, IL 60616 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP White, CG (reprint author), IIT, Dept Biol Chem & Phys Sci, Div Phys, Chicago, IL 60616 USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 2002 VL 49 IS 2 BP 568 EP 576 AR PII S0018-9499(02)03897-2 DI 10.1109/TNS.2002.1003675 PN 2 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 555YR UT WOS:000175821100005 ER PT J AU Ahn, JK Akikawa, H Arvieux, J Bassalleck, B Chung, MS En'yo, H Fukuda, T Funahashi, H Golovkin, SV Gorin, AM Goto, Y Hanabata, M Hayakawa, T Ichikawa, A Ieiri, M Imai, K Ishino, M Kanda, H Kim, YD Kondo, Y Kozarenko, EN Kreslo, IE Lee, JM Masaike, A Mihara, S Nakai, K Nakazawa, K Ozawa, K Sato, A Sato, HD Sim, KS Tabaru, T Takeutchi, F Tlusty, P Torii, H Yamamoto, K Yokkaichi, S Yoshida, M AF Ahn, JK Akikawa, H Arvieux, J Bassalleck, B Chung, MS En'yo, H Fukuda, T Funahashi, H Golovkin, SV Gorin, AM Goto, Y Hanabata, M Hayakawa, T Ichikawa, A Ieiri, M Imai, K Ishino, M Kanda, H Kim, YD Kondo, Y Kozarenko, EN Kreslo, IE Lee, JM Masaike, A Mihara, S Nakai, K Nakazawa, K Ozawa, K Sato, A Sato, HD Sim, KS Tabaru, T Takeutchi, F Tlusty, P Torii, H Yamamoto, K Yokkaichi, S Yoshida, M TI Active target with plastic scintillating fibers for hyperon-proton scattering experiments SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE active target; hyperon-proton scattering; scintillating fibers ID ELASTIC-SCATTERING; REGION AB An active target with plastic scintillating fibers has been constructed. This active target serves as a production target of hyperons, as well as a scattering target, and works as a 4pi-detector for charged particles. This system is designed for measurements of hyperon-proton scattering for hyperon momenta of several hundred MeV/c. A spectrometer system for the incident beam and outgoing particles of the hyperon production reaction is linked with this target-detector in order to provide triggers for the imaging device of this detector system. As a control of this detector, the decay constant of Sigma(-) hyperon has been evaluated. C1 Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan. Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Univ Paris 11, Inst Nucl Phys, F-91406 Orsay, France. Univ New Mexico, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. KEK, High Energy Accelerator Res Org, IPNS, Tsukuba, Ibaraki 3050801, Japan. Inst High Energy Phys, RU-142284 Protvino, Russia. Gifu Univ, Dept Phys, Gifu 50111, Japan. Cent Japan Railway Co, Nagoya, Aichi 4506101, Japan. Univ Tokyo, Int Ctr Elementary Particle Phys, Tokyo 1130033, Japan. Tohoku Univ, Grad Sch Sci, Dept Phys, Sendai, Miyagi 9808578, Japan. Sejong Univ, Dept Phys, Seoul 143747, South Korea. Joint Nucl Res Inst, RU-141980 Dubna, Russia. Korea Rs Inst Stand & Sci, Taejon 305600, South Korea. Fukui Univ Technol, Fukui 9108505, Japan. Sci Univ Tokyo, Dept Phys, Noda, Chiba 2788510, Japan. Univ Tokyo, Ctr Nucl Study, Tokyo 1130033, Japan. Korea Univ, Dept Phys, Seoul 136701, South Korea. Kyoto Sangyo Univ, Dept Phys, Kyoto 6038555, Japan. Acad Sci Czech Republ, Inst Nucl Phys, CZ-25068 Rez, Czech Republic. Osaka City Univ, Dept Phys, Sumiyoshi Ku, Osaka 5588585, Japan. RP Ahn, JK (reprint author), Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan. RI Ahn, Jung Keun/C-1293-2008; En'yo, Hideto/B-2440-2015; Yokkaichi, Satoshi/C-6215-2017 NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 2002 VL 49 IS 2 BP 592 EP 596 AR PII S0018-9499(02)03900-X DI 10.1109/TNS.2002.1003680 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 555YR UT WOS:000175821100009 ER PT J AU Phlips, BF Johnson, WN Kroeger, RA Kurfess, JD Phillips, G Wulf, EA Luke, PN AF Phlips, BF Johnson, WN Kroeger, RA Kurfess, JD Phillips, G Wulf, EA Luke, PN TI Development of germanium strip detectors for environmental remediation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Annual Nuclear Science Symposium (NSS) CY OCT 15-20, 2000 CL LYON, FRANCE SP IEEE, CEA, IN2P3, CERN DE germanium radiation detectors; imaging; radiation detectors; semiconductor radiation detectors ID POSITION AB We present the initial results of the first germanium strip detector array for the imaging and high-resolution spectroscopy of gamma-ray sources. The array consists of four detectors, 5 x 5 x 1 cm. each, with 25 strips on each side. The detectors are daisy chained to hybrid preamplifiers to reduce the number of channels of electronics. Good spectroscopy and imaging are achieved. We also present results from the development of an amorphous germanium contact technology as an alternative to the lithium contact technology. A prototype 25 x 25 strip detector was manufactured with this new technology and demonstrates good spectroscopy and imaging. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Phlips, BF (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Wulf, Eric/B-1240-2012; Johnson, Neil/G-3309-2014 NR 6 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 2002 VL 49 IS 2 BP 597 EP 600 AR PII S0018-9499(02)03899-6 DI 10.1109/TNS.2002.1003681 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 555YR UT WOS:000175821100010 ER PT J AU Douglas, MR Baksht, RB AF Douglas, MR Baksht, RB TI Special issue on Z pinch plasmas SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Editorial Material C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. RP Douglas, MR (reprint author), Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 458 EP 459 AR PII S0093-3813(02)06408-1 DI 10.1109/TPS.2002.1024276 PN 1 PG 2 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600001 ER PT J AU Oliver, BV Mehlhorn, TA AF Oliver, BV Mehlhorn, TA TI Nonideal MHD plasma regimes in the study of dynamic Z pinches SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE dynamic Z pinch; EMHD; hall current; wire initiation ID ARRAY Z-PINCHES; WIRE-NUMBER; INSTABILITY; IMPLOSIONS; STABILITY; POWER; FLOW; MASS AB Detailed simulations of wire-array Z pinches with Radiation MHD codes require calculations which span a broad range of plasma parameters. An introductory study of the various regimes accessed by nonequilibrium Z pinches of the type fielded on the Z accelerator at Sandia National Laboratories is presented. In particular, the physics of wire initiation and breakdown and liner implosion are considered. The conditions for ideal and some nonideal MHD dynamics, including fluid viscosity, resistivity, and Hall current dynamics are reviewed. A discussion of the relevance of MHD simulations and modeling to the various plasma regimes is given. C1 Mission Res Corp, Albuquerque, NM 87110 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Oliver, BV (reprint author), Mission Res Corp, Albuquerque, NM 87110 USA. NR 28 TC 3 Z9 3 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 517 EP 523 AR PII S0093-3813(02)05316-X DI 10.1109/TPS.2002.1024284 PN 1 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600009 ER PT J AU Sze, HM Levine, JS Banister, JW Coleman, PL Failor, BH Song, Y Apruzese, JP Davis, J Coverdale, CA Deeney, C Bell, D AF Sze, HM Levine, JS Banister, JW Coleman, PL Failor, BH Song, Y Apruzese, JP Davis, J Coverdale, CA Deeney, C Bell, D TI K-shell radiation from nickel wire arrays at 18 MA SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE K-shell X-ray production; plasma radiation sources; wire array z pinch; z pinch plasma ID Z-PINCH; IMPLOSIONS AB A series of nickel z pinch experiments was conducted at 18 MA current on the Z accelerator producing up to 13 kJ of K-shell radiation at 7.8 keV and above. Double-shell wire arrays were used, with the diameter of the outer array of the nested structure varied from 55 to 70 mm. By using Cr and Mn dopants in conjunction with a streak spectrograph, the interaction of the outer and inner array could be investigated. The radiation from the outer array started slightly after the inner array and lasted longer, producing comparable energy per atom at lower power. This indicates that the arrays were well mixed for most of the radiation pulse, in contrast to the observed behavior of a double-shell gas puff. C1 Titan Syst Corp, Pulse Sci Div, San Leandro, CA 94577 USA. USN, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Def Threat Reduct Agcy, Alexandria, VA 22310 USA. RP Sze, HM (reprint author), Titan Syst Corp, Pulse Sci Div, San Leandro, CA 94577 USA. EM jlevine@titan.com NR 10 TC 9 Z9 9 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 532 EP 537 AR PII S0093-3813(02)05328-6 DI 10.1109/TPS.2002.1024286 PN 1 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600011 ER PT J AU Sanford, TWL Roderick, NF Mock, RC Struve, KW Peterson, DL AF Sanford, TWL Roderick, NF Mock, RC Struve, KW Peterson, DL TI Azimuthal structure in wire-array Z pinch experiments SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE ICF; plasma pinch; z pinch ID X-RAY POWER; 2-DIMENSIONAL SIMULATIONS; DIAGNOSTIC PACKAGE; INSTABILITY; DYNAMICS; INSIGHTS; FLOW AB Nested wire-array loads on Z with a high degree of azimuthal symmetry in the outside current-return-shell (which surrounds a z pinch) exhibit a 6 +/- 2 azimuthal mode structure in the axial X-ray emission near stagnation when the pinch is viewed from above through a small radiation-exit-hole in the anode. MACH3 numerical simulations show that if a low-number mode like 6 does exist in the initial density distribution, it will remain throughout the implosion, amplifying near the time of stagnation. And if a random-density pattern initially exists with a significantly higher mode number, it will coalesce to a reduced mode number of about 4 to 8 by the time stagnation is neared, in agreement with experiment. Current-return-shells with a nine-fold periodic slot structure (which permit side-on viewing of the pinch) are used as examples of loads that develop azimuthal mode structures in their X-ray emission. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sanford, TWL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 26 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 538 EP 546 AR PII S0093-3813(02)05319-5 DI 10.1109/TPS.2002.1024287 PN 1 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600012 ER PT J AU Failor, BH Deeney, C LePell, PD Riordan, JC Apruzese, JP Thornhill, JW Whitney, KG Nash, TJ Yadlowsky, EJ Moschella, JJ AF Failor, BH Deeney, C LePell, PD Riordan, JC Apruzese, JP Thornhill, JW Whitney, KG Nash, TJ Yadlowsky, EJ Moschella, JJ TI Time-resolved spectroscopy and energy-resolved imaging of coated wire arrays as the interwire spacing is decreased SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE K-shell X-ray production; plasma radiation sources; wire array z pinch; z pinch plasma ID SIMILAR ATOMIC NUMBERS; LASER-PRODUCED PLASMAS; X-RAY-EMISSION; Z-PINCHES; POWER; TEMPERATURE; IMPLOSIONS; GENERATORS; ELEMENTS AB We have spectroscopically observed, as suggested by Sanford et al. (1996), a transition from discrete wire implosions to the implosion of a more continuous plasma shell in aluminum-wire-array z pinches driven by a 7-TW electrical generator. The time history of magnesium dopant K-shell X-ray emission depended on the interwire spacing, as well as whether the dopant was introduced as an alloy in or a coating on the aluminum wires. We diagnose the final assembly of the hot, dense K-shell emitting core, a region of the pinch not accessible to laser interferometry or optical/UV emission measurements. C1 Maxwell Phys Int, San Leandro, CA 94577 USA. USN, Res Lab, Washington, DC 20375 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Hytect Res Corp, Radford, VA 24141 USA. RP Failor, BH (reprint author), Titan Syst Corp, Pulse Sci Div, San Leandro, CA 94577 USA. NR 21 TC 1 Z9 1 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 547 EP 551 AR PII S0093-3813(02)05314-6 DI 10.1109/TPS.2002.1024288 PN 1 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600013 ER PT J AU Shelkovenko, TA Pikuz, SA Sinars, DB Chandler, KM Hammer, DA AF Shelkovenko, TA Pikuz, SA Sinars, DB Chandler, KM Hammer, DA TI X pinch plasma development as a function of wire material and current pulse parameters SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE point X-ray source; short pulse X-ray source; X pinch; X-ray radiography; X-ray spectroscopy; Z pinch ID EXPLODING WIRES; RAY SOURCE; POINT; DYNAMICS AB An X pinch plasma is produced using two or more fine metal wires arranged so that they cross and touch at a single point, in the form of an-"X," as the load of a pulsed power generator (pulser). X pinches produce very bright, small, short-lived sources of X-rays in the 1-10 keV range. The X-ray source size, pulse duration and photon energy spectra depend upon the wire material and diameter, and the current waveform from the pulser. Those with similar to1 mum source size can be used as, point sources,of X-ray radiation for point-projection radiography with high spatial resolution. We report experiments with a variety of different wire materials, including Al, Ti, Mo, W, among others, all of which produced high resolution images, and all of which have subnanosecond X-ray pulses for X-rays greater than or equal to 3 keV. X pinches produced using all of these materials had common development stages. However, the wire material and the rate of rise of the current pulse influenced the details of the dynamics, leading to variation in the timing of the X-ray burst(s) relative to the start of the current pulse. For a given wire material, wire diameter had only a small effect on X-ray emission timing. Final X pinch neck implosion speeds as high as 66-75 mum/ns were estimated. C1 PN Lebedev Phys Inst, Moscow 119991, Russia. Cornell Univ, Plasma Studies Lab, Ithaca, NY 14853 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA. RP Shelkovenko, TA (reprint author), PN Lebedev Phys Inst, Leninsky Prospect 53, Moscow 119991, Russia. RI Pikuz, Sergey/M-8231-2015; Shelkovenko, Tatiana/M-8254-2015 NR 21 TC 23 Z9 23 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 567 EP 576 AR PII S0093-3813(02)05325-0 DI 10.1109/TPS.2002.1024291 PN 1 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600016 ER PT J AU Chandler, KM Hammer, DA Sinars, DB Pikuz, SA Shelkovenko, TA AF Chandler, KM Hammer, DA Sinars, DB Pikuz, SA Shelkovenko, TA TI The relationship between exploding wire expansion rates and wire material properties near the boiling temperature SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE dense Z pinches; exploding wires; pulsed-power applications; X-ray backlighting ID PLASMA FORMATION; TUNGSTEN WIRE; X-PINCH; ARRAY; RAYS AB The energy deposited by a submicrosecond, similar to1-kA current pulse in a 25-mum diameter metal wire prior to its explosion, correlates directly with the expansion rate of the wire after the explosion. Energy deposition by resistive heating is terminated by the formation of plasma around the wire and a collapse of the voltage along the wire, and is evidently facilitated by the desorption of gases from the wire and/or the evaporation of the wire material (or impurities within it) as it heats up. Data presented here implies that the relationship between materials with the lowest resistivities and high exploding wire expansion rates found in earlier work (D. B. Sinars et al. 2000) is a result of the reduced voltage delaying the gas breakdown along such wires. This, in turn, increases the energy deposited resistively in the wire before the current shifts to the surrounding plasma. If gas breakdown does not occur until close to the full vaporization energy is deposited in the wire, the expansion rate will be more rapid than if a small fraction of the vaporization energy is deposited before voltage collapse. C1 Cornell Univ, Plasma Studies Lab, Ithaca, NY 14853 USA. Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. PN Lebedev Phys Inst, Moscow 119991, Russia. RP Chandler, KM (reprint author), Cornell Univ, Plasma Studies Lab, Ithaca, NY 14853 USA. RI Pikuz, Sergey/M-8231-2015; Shelkovenko, Tatiana/M-8254-2015 NR 24 TC 28 Z9 30 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 577 EP 587 AR PII S0093-3813(02)05322-5 DI 10.1109/TPS.2002.1024292 PN 1 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600017 ER PT J AU Frese, MH Frese, SD Rosenthal, SE Douglas, MR Roderick, NF AF Frese, MH Frese, SD Rosenthal, SE Douglas, MR Roderick, NF TI Computational simulation of initiation and implosion of circular arrays of wires in two and three dimensions SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE computational simulations; MHD; Rayleigh-Taylor instability; wire-array; Z pinches ID Z-PINCHES; MODEL; CONDUCTIVITY; ENHANCEMENT; INSTABILITY; PLASMAS; NUMBER; POWER; LINER; FLOW AB We have performed realistic two-dimensional (2-D) r-theta resistive MHD simulations of high-current aluminum wire array initiation and implosion. These show only a moderate differentiation of wire plasma into a warm dense core and a hot diffuse corona. Wire plasmas in 28-wire array simulations implode without forming a shell; those in 56-wire simulations first merge,but then separate. As both implode, thread-like plasmas settle into valleys formed across the field lines by the thread mass. Thus, shell formation does not smooth the initial wire asymmetry, because the r-theta Rayleigh-Taylor instability amplifies it. This argues against shell-formation as the primary explanation for the observed effect of increased wire number on radiation power. We have also performed three-dimensional (3-D) ideal MHD simulations that continue those 2-D simulations; they start with a fully consistent MHD state. These simulations, perturbed between the 2-D and 3-D phases, show that azimuthally uncorrelated 3-D perturbations-appropriate for wires-grow more slowly than fully azimuthally correlated 2-D r-z perturbations. Further, the uncorrelated perturbation growth rate is smaller for 56 wires than for the 28, as the magnetic field couples more plasma threads over the same distance. These 3-D effects may explain the observed radiation power improvement with increased wire number. C1 NumerEx, Albuquerque, NM 87111 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Frese, MH (reprint author), NumerEx, Albuquerque, NM 87111 USA. NR 25 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 2002 VL 30 IS 2 BP 593 EP 603 AR PII S0093-3813(02)05313-4 DI 10.1109/TPS.2002.1024294 PN 1 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 585QT UT WOS:000177536600019 ER PT J AU Eick, SG Graves, TL Karr, AF Mockus, A Schuster, P AF Eick, SG Graves, TL Karr, AF Mockus, A Schuster, P TI Visualizing software changes SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE visualization; software changes; reengineering; code structure; change management ID ANIMATION; GRAPHS; TOOL AB A key problem in software engineering is changing the code. We present a sequence of visualizations and visual metaphors designed to help engineers understand and manage the software change process. The principal metaphors are matrix views, cityscapes, bar and pie charts, data sheets, and networks. Linked by selection mechanisms, multiple views are combined to form perspectives that both enable discovery of high-level structure in software change data and allow effective access to details of those data. Use of the views and perspectives is illustrated in two important contexts: understanding software change by exploration of software change data and management of software development, Our approach complements existing visualizations of software structure and software execution. C1 Visual Insights, Naperville, IL 60566 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Inst Stat Sci, Durham, NC 27707 USA. Bell Labs, Naperville, IL 60566 USA. RP Visual Insights, 215 Shuman Blvd, Naperville, IL 60566 USA. EM eick@visualinsights.com; tgraves@lanl.gov; karr@niss.org; audris@research.bell-labs.com NR 40 TC 39 Z9 39 U1 0 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0098-5589 EI 1939-3520 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD APR PY 2002 VL 28 IS 4 BP 396 EP 412 DI 10.1109/TSE.2002.995435 PG 17 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 538KA UT WOS:000174814100006 ER PT J AU Gulgun, MA Voytovych, R Maclaren, I Ruhle, M Cannon, RM AF Gulgun, MA Voytovych, R Maclaren, I Ruhle, M Cannon, RM TI Cation segregation in an oxide ceramic with low solubility: Yttrium doped alpha-alumina SO INTERFACE SCIENCE LA English DT Article DE alpha-alumina; grain boundary; segregation; adsorption; precipitation ID GRAIN-BOUNDARY SEGREGATION; TEMPERATURE CREEP RESISTANCE; PHASE-SINTERED ALUMINA; POLYCRYSTALLINE AL2O3; DOPANT DISTRIBUTIONS; PLASTIC-DEFORMATION; MICROSTRUCTURE; CHEMISTRY; TENSILE; FILMS AB The segregation behaviour of a cation (yttrium) with a low solubility in the polycrystalline oxide host (alpha-Al(2)O(3)) has been investigated at temperatures between 1450 and 1650degreesC using analytical scanning transmission electron microscopy. Three distinct segregation regimes were identified. In the first, the yttrium adsorbs to all grain boundaries with a high partitioning coefficient, and this can be modelled using a simple McLean-Langmuir type absorption isotherm. In the second, a noticeable deviation from this isotherm is observed and the grain boundary excess reaches a maximum of 9 Y-cat/nm(2) and precipitates of a second phase (yttrium aluminate garnet, YAG) start to form. In the third regime, the grain boundary excess of the cation settles down to a value of 6-7 Y-cat/nm(2) that is in equilibrium with the YAG precipitates. In a material (accidentally) co-doped with Zr, the Zr seems to behave in a similar way to the Y and the Y + Zr grain boundary excess behaves in the same way as the Y grain boundary excess in the pure Y-doped system. In this latter system, Y-stabilised cubic zirconia is precipitated in addition to YAG at higher Y + Zr concentrations. C1 Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI MacLaren, Ian/C-1773-2010 OI MacLaren, Ian/0000-0002-5334-3010 NR 56 TC 50 Z9 51 U1 0 U2 18 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0927-7056 J9 INTERFACE SCI JI Interface Sci. PD APR PY 2002 VL 10 IS 1 BP 99 EP 110 DI 10.1023/A:1015268232315 PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 542UA UT WOS:000175061600014 ER PT J AU Zhu, JH Liu, CT AF Zhu, JH Liu, CT TI Intermediate-temperature mechanical properties of Ni-Si alloys: oxygen embrittlement and its remedies SO INTERMETALLICS LA English DT Article DE silicides; various; alloy design; environmental embrittlement; mechanical properties at high temperatures ID BORON-DOPED NI3AL; LL2-TYPE NI3(SI,TI) INTERMETALLICS; LOW-EXPANSION SUPERALLOY; GRAIN-BOUNDARY FRACTURE; ENVIRONMENTAL EMBRITTLEMENT; DUCTILITY; NI3SI; 600-DEGREES-C; OXIDATION; BEHAVIOR AB With good corrosion resistance, reasonable room-temperature ductility, and excellent strength up to temperatures of 700 degreesC, Ni3Si-based alloys show considerable potential for structural applications. The Ni-Si alloys used for acid-corrosion resistance suffer from a dynamic environmental embrittlement when tested at intermediate temperatures around 600 degreesC. To assess these Ni-Si alloys for elevated-temperature structural application, the mechanical properties of these alloys strengthened by Ni3Si precipitates were systematically evaluated at different temperatures in various test environments. Oxygen was identified as the embrittling species responsible for the low ductility and premature fracture of the Ni-Si alloys. A strong dependence of elongation and fracture mode on strain rate was observed. Based on the understanding of the embrittlement mechanism, some unique approaches for improving the intermediate-temperature ductility, strength and fabricability of Ni-Ni3Si alloys were identified: reactive element doping (such as Zr and Y) to change the grain boundary chemistry; preoxidation to form adherent oxide layers; and thermomechanical processing to tailor the grain structure/shape. Some other properties such as creep resistance and weldability of these alloys were also briefly evaluated and are discussed in this paper. (C) 2002 Published by Elsevier Science Ltd. C1 Tennessee Technol Univ, Dept Mech Engn, Cookeville, TN 38505 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Zhu, JH (reprint author), Tennessee Technol Univ, Dept Mech Engn, TTU Box 5041, Cookeville, TN 38505 USA. NR 34 TC 15 Z9 16 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD APR PY 2002 VL 10 IS 4 BP 309 EP 316 AR PII S0966-9795(01)00134-0 DI 10.1016/S0966-9795(01)00134-0 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 540HB UT WOS:000174922500002 ER PT J AU Bakac, A AF Bakac, A TI Kinetics of the reaction of NO2 with a macrocyclic nickel complex SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID ELECTRON-TRANSFER REACTIONS; AQUEOUS-SOLUTION; RATE CONSTANTS; RADICALS; HOMOLYSIS; NITRITE AB The kinetics of the reaction between NO2 and ([14]aneN(4))Ni2+ were determined by laser flash photolysis. The NO2 was generated in two independent reactions, one of which is based on the photochemistry of (NH3)(5)CoNO22+, and the other on the photochemistry of HNO2/NO2-. The results from both sets of experiments yielded a consistent value for the rate constant, k(1) = 1.2 x 10(8) M-1 s(-1) in aqueous solutions at pH 1-4. There was no evidence for the reverse reaction. NO2 reacts with Fe-aq(2+) more slowly, k(Fe) similar to 2 x 10(5) M-1 s(-1). (C) 2002 Wiley Periodicals, Inc. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Bakac, A (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 25 TC 2 Z9 2 U1 0 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD APR PY 2002 VL 34 IS 4 BP 278 EP 281 DI 10.1002/kin.10048 PG 4 WC Chemistry, Physical SC Chemistry GA 535CT UT WOS:000174628200007 ER PT J AU Woodcraft, AL Sudiwala, RV Griffin, MJ Wakui, E Maffei, B Tucker, CE Haynes, CV Gannaway, F Ade, PAR Bock, JJ Turner, AD Sethuraman, S Beeman, JW AF Woodcraft, AL Sudiwala, RV Griffin, MJ Wakui, E Maffei, B Tucker, CE Haynes, CV Gannaway, F Ade, PAR Bock, JJ Turner, AD Sethuraman, S Beeman, JW TI High precision characterisation of semiconductor bolometers SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE cryogenic detectors; bolometers; characterisation; submillimeter; NTD ID INFRARED DETECTORS; NOISE; GE AB We describe techniques for testing and characterising semiconductor bolometers, using the bolometer model presented in Sudiwalia et. al. [1]. The procedures are illustrated with results from a prototype bolometer for the high frequency instrument (HFI) in the Planck Surveyor cosmic microwave background mission. This is a bolometer using spider-web geometry and a neutron transmutation doped (NTD) germanium thermistor, designed for operation at 100 mK. Details are given of the laboratory facility used to take data at temperatures from 70 mK to 350 mK. This employs an adiabatic demagnetisation refrigerator to cool the detector and optics. The spatial and spectral properties of the optical system are controlled using feedhorns and edge filters. To characterise the bolometer, blanked and optically loaded load curves were measured over a range of temperatures, and the response to modulated radiation was measured as a function of modulation frequency, temperature and bias current. Results for the prototype bolometer show that its behaviour is well represented by an ideal thermal detector down to a temperature of approximately 100 mK. Below this, non-thermal effects such as electron-phonon decoupling or electric field dependent resistance appear to lead to departure from ideal behaviour. The performance was in good agreement with the design goals for the bolometer. C1 Univ Wales Coll Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Univ London Queen Mary & Westfield Coll, Dept Phys, London E1 4NS, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Woodcraft, AL (reprint author), Univ Wales Coll Cardiff, Dept Phys & Astron, 5 Parade, Cardiff CF24 3YB, S Glam, Wales. NR 21 TC 12 Z9 12 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD APR PY 2002 VL 23 IS 4 BP 575 EP 595 AR UNSP 0195-9271/02/0400-0575/0 DI 10.1023/A:1015757810970 PG 21 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 554JJ UT WOS:000175731800004 ER PT J AU Knight, AK Sperline, RP Hieftje, GM Young, E Barinaga, CJ Koppenaal, DW Denton, MB AF Knight, AK Sperline, RP Hieftje, GM Young, E Barinaga, CJ Koppenaal, DW Denton, MB TI The development of a micro-Faraday array for ion detection SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE array; infrared; mass spectrometry; Faraday cup; Faraday plate; Faraday finger; ion; ion detector; ion detection ID MASS-SPECTROMETRY; SPECTROSCOPY; MS AB A micro-Faraday array detector was evaluated for use as an ion detector for mass spectrometry. This charge-integrating detector was based upon the merging of technologies from the fields of CCDs and infrared (IR) multiplexers. Measurements were performed by exposing the detector to an Ar+ ion beam of low flux. The array detector responds to both positive and negative charges and preliminary results indicate a detection limit of 100 ions. Current data indicate that the linear dynamic range of the device is over five orders of magnitude. The capability of the device to perform specialized charge read out modes could theoretically both lower the detection limit by a factor of seven and increase the linear dynamic range to nine orders of magnitude using non-destructive read outs. (Int J Mass Spectrom 215 (2002) 131-139) (C) 2002 Published by Elsevier Science B.V. C1 Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Denton, MB (reprint author), Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. NR 22 TC 36 Z9 39 U1 0 U2 4 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 APR 1 PY 2002 VL 215 IS 1-3 SI SI BP 131 EP 139 AR PII S1387-3806(02)00528-6 DI 10.1016/S1387-3806(02)00528-6 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 542BE UT WOS:000175023000011 ER PT J AU Calhoun, RJ Street, RL AF Calhoun, RJ Street, RL TI Patterns on a free surface caused by underwater topography: a laboratory-scale study SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID SUBMARINE SAND WAVES; SYNTHETIC-APERTURE RADAR; MULTIBAND IMAGING RADAR; NAVIER-STOKES EQUATIONS; BOTTOM TOPOGRAPHY; MODEL; IMAGERY; SEA; SIGNATURES; TURBULENCE AB The motivation of this paper is to deepen the theoretical foundations of the interpretation of Synthetic Aperature Radar (SAR) imagery of the coastal seas. The approach uses large-eddy simulations (LES) to study the link between bottom topography and its expression on a free surface. In particular, the focus is on situations where the flow cannot be well approximated using simple conservation of mass arguments. The full Navier-Stokes equations are solved for laboratory-scale domains. Free surface patterns are presented for three configurations: neutral flow over wavy topography, stratified flow over wavy topography, and neutral flow over three-dimensional sinusoidal topography. The extent to which each configuration produces unique and identifiable surface patterns is explored. The focus is on the fluid mechanics near the surface, for example, attachment and persistence of vortical structures, upwelling, and zones of convergence. Neutral flow over wavy topography creates a large number of powerful upwellings on the free surface. These upwellings appear to overwhelm the coherency of pre-existing vortices and vortex pairs. Consequently, the persistence of organized vortical motions on the free surface is reduced. In contrast, in stably stratified flow over a wavy boundary, upwellings are weakened, and more vortex pairs are observed. The surface signature of three-dimensional underwater topography shows elongated streaks in the streamwise direction. The above features allow these underwater topographies (at the depths presented) to be uniquely differentiated based solely on their surface signatures. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Environm Fluid Mech Lab, Stanford, CA USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM calhoun7@llnl.gov; street@ce.stanford.edu NR 27 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0143-1161 EI 1366-5901 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD APR PY 2002 VL 23 IS 8 BP 1609 EP 1620 DI 10.1080/01431160110070672 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 540YC UT WOS:000174957600004 ER PT J AU Dorn, O Bertete-Aguirre, H Berryman, JG Papanicolaou, GC AF Dorn, O Bertete-Aguirre, H Berryman, JG Papanicolaou, GC TI Sensitivity analysis of a nonlinear inversion method for 3D electromagnetic imaging in anisotropic media SO INVERSE PROBLEMS LA English DT Article ID MEASUREMENT DENSITY-FUNCTIONS; OPTICAL TOMOGRAPHY; FREQUENCY-DOMAIN; ADJOINT FIELDS; SCATTERING; ABSORPTION; WAVES AB We present a detailed sensitivity analysis for a nonlinear electromagnetic inversion method which was introduced earlier by the authors. Whereas the earlier work was restricted to the 3D imaging of isotropic structures in the earth from cross-borehole electromagnetic data, the analysis presented here is focused on the imaging of anisotropic structures which often have to be taken into account in practical situations. The inversion scheme considered can be described as a single-step adjoint field scheme. It avoids calculating huge sensitivity matrices (which we call linearized residual operators) during the inversion and uses only the data corresponding to one source position at a time. Doing so, the action of the adjoint linearized residual operator on the corresponding (filtered) residual vector can be calculated very efficiently by just running one forward and one adjoint Maxwell problem on the most recent best guess for the parameters. The outcome of these two runs is combined to find a correction to the latest best guess. The anisotropic sensitivity functions have the property that they decompose the linearized residual operator as well as the corresponding adjoint linearized residual operator. Playing this dual role, they provide useful information about how sources and receivers should be arranged in a given experiment, and which structures in the earth can be expected to be resolved in the inversion from a given data set. In the paper, we present numerical examples of 3D anisotropic sensitivity functions for homogeneous as well as for inhomogeneous background parameter distributions, and discuss their dual role in the nonlinear adjoint field inversion scheme. C1 Univ British Columbia, Dept Comp Sci, Vancouver, BC V6T 1Z4, Canada. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Stanford Univ, Dept Math, Stanford, CA 94305 USA. RP Dorn, O (reprint author), Univ British Columbia, Dept Comp Sci, 301-2366 Main Mall, Vancouver, BC V6T 1Z4, Canada. RI Berryman, James/A-9712-2008 NR 48 TC 15 Z9 15 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD APR PY 2002 VL 18 IS 2 BP 285 EP 317 AR PII S0266-5611(02)25099-6 DI 10.1088/0266-5611/18/2/301 PG 33 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 549NP UT WOS:000175450700002 ER PT J AU Avdonin, S Lenhart, S Protopopescu, V AF Avdonin, S Lenhart, S Protopopescu, V TI Solving the dynamical inverse problem for the Schrodinger equation by the boundary control method SO INVERSE PROBLEMS LA English DT Article ID BC-METHOD; CONTROLLABILITY AB We consider the inverse problem of determining the potential in the one-dimensional Schrodinger equation from dynamical boundary observations, which are the range values of the Neumann-to-Dirichlet map. Dynamical boundary data have not been used in the inverse problem for the Schrodinger equation, since the traditional Gelfand-Levitan-Marchenko approach reconstructs the potential from spectral or scattering data. Here we show that one can completely recover the spectral data from the dynamical boundary data. The construction of the spectral data uses new results on exact and spectral controllability for the Schrodinger equation, which we obtain by using the properties of exponential Riesz bases (nonharmonic Fourier series). From the spectral data, we solve the inverse problem using the boundary control method, which-unlike other identification methods based on control and optimization-is consistently linear and, in principle, independent of dimensionality. C1 Univ Alaska, Dept Math Sci, Fairbanks, AK 99775 USA. Univ Tennessee, Dept Math, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 USA. RP Avdonin, S (reprint author), Univ Alaska, Dept Math Sci, Fairbanks, AK 99775 USA. NR 31 TC 20 Z9 20 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 J9 INVERSE PROBL JI Inverse Probl. PD APR PY 2002 VL 18 IS 2 BP 349 EP 361 AR PII S0266-5611(02)25082-0 DI 10.1088/0266-5611/18/2/304 PG 13 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 549NP UT WOS:000175450700005 ER PT J AU Santarsiero, BD Yegian, DT Lee, CC Spraggon, G Gu, J Scheibe, D Uber, DC Cornell, EW Nordmeyer, RA Kolbe, WF Jin, J Jones, AL Jaklevic, JM Schultz, PG Stevens, RC AF Santarsiero, BD Yegian, DT Lee, CC Spraggon, G Gu, J Scheibe, D Uber, DC Cornell, EW Nordmeyer, RA Kolbe, WF Jin, J Jones, AL Jaklevic, JM Schultz, PG Stevens, RC TI An approach to rapid protein crystallization using nanodroplets SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID CRYSTAL-GROWTH; MICROCRYSTALS AB An approach that enables up to a two order of magnitude reduction in the amount of protein required and a tenfold reduction in the amount of time required for vapor-diffusion protein crystallization is reported. A prototype high-throughput automated system was used for the production of diffraction-quality crystals for a variety of proteins from a screen of 480 conditions using drop volumes as small as 20 nL. This approach results in a significant reduction in the time and cost of protein structure determination, and allows for larger and more efficient screens of crystallization parameter space. The ability to produce diffraction-quality crystals rapidly with minimal quantities of protein enables high-throughput efforts in structural genomics and structure-based drug discovery. C1 Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Novartis Res Fdn, Genom Inst, San Diego, CA 92121 USA. EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Scripps Res Inst, Dept Chem, La Jolla, CA 92037 USA. Joint Ctr Struct Genom, La Jolla, CA 92037 USA. RP Stevens, RC (reprint author), Scripps Res Inst, Dept Mol Biol, 10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. EM stevens@scripps.edu RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 18 TC 205 Z9 212 U1 0 U2 15 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 APR PY 2002 VL 35 BP 278 EP 281 DI 10.1107/S0021889802001474 PN 2 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 536XK UT WOS:000174727000020 ER PT J AU Salem, A Ravat, D Gamey, TJ Ushijima, K AF Salem, A Ravat, D Gamey, TJ Ushijima, K TI Analytic signal approach and its applicability in environmental magnetic investigations SO JOURNAL OF APPLIED GEOPHYSICS LA English DT Article DE magnetic; analytic signal; depth estimation; environmental ID POLYGONAL CROSS-SECTION; POTENTIAL-FIELD DATA; ANOMALIES; BODIES; DEPTH AB We investigate the analytic signal method and its applicability in obtaining source locations of compact environmental magnetic objects. Previous investigations have shown that, for two-dimensional magnetic sources, the shape and location of the maxima of the amplitude of the analytic signal (AAS) are independent of the magnetization direction. In this study, we show that the shape of the AAS over magnetic dipole or sphere source is dependent on the direction of magnetization and, consequently, the maxima of the AAS are not always located directly over the dipolar sources. Maximum shift in the horizontal location is obtained for magnetic inclination of 30degrees. The shifts of the maxima are a function of the source-to-observation distance and they can be up to 30% of the distance. We also present a method of estimating the depths of compact magnetic objects based on the ratio of the AAS of the magnetic anomaly to the AAS of the vertical gradient of the magnetic anomaly. The estimated depths are independent of the magnetization direction. With the help of magnetic anomalies over environmental targets of buried steel drums, we show that the depths can be reliably estimated in most cases. Therefore, the analytic signal approach can be useful in estimating source locations of compact magnetic objects. However, horizontal locations of the targets derived from the maximum values of the AAS must be verified using other techniques. (C) 2002 Elsevier Science B.V All rights reserved. C1 Kyushu Univ, Fac Engn, Dept Earth Resources Engn, Higashi Ku, Fukuoka 8128581, Japan. So Illinois Univ, Dept Geol, Carbondale, IL 62901 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Salem, A (reprint author), Kyushu Univ, Fac Engn, Dept Earth Resources Engn, Higashi Ku, 6-10-1, Fukuoka 8128581, Japan. RI U-ID, Kyushu/C-5291-2016; OI Ravat, Dhananjay/0000-0003-1962-4422 NR 21 TC 43 Z9 44 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-9851 J9 J APPL GEOPHYS JI J. Appl. Geophys. PD APR PY 2002 VL 49 IS 4 BP 231 EP 244 AR PII S0926-9851(02)00125-8 DI 10.1016/S0926-9851(02)00125-8 PG 14 WC Geosciences, Multidisciplinary; Mining & Mineral Processing SC Geology; Mining & Mineral Processing GA 582HL UT WOS:000177344500003 ER PT J AU Tallant, DR Seager, CH Simpson, RL AF Tallant, DR Seager, CH Simpson, RL TI Energy transfer and relaxation in europium-activated Y2O3 after excitation by ultraviolet photons SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHOSPHORS; IONS AB We present persistence data from the D-5 manifolds of europium (3+)-activated Y2O3, after excitation by ultraviolet photons. For europium concentrations below 1 at. %, the persistence is largely consistent with multiphonon relaxation. For europium concentrations at and above 1 at. %, the persistence shows evidence for energy transfer interactions between europium activators. Interactions involving one activator in an upper (D-5(3), D-5(2) or D-5(1)) manifold and another in a ground state (F-7) manifold affect the kinetics of the relaxation of the upper D-5 manifolds but do not degrade phosphor efficiency. Interactions involving two activators in excited manifolds ultimately dissipate, by phonon emission, excitation that might be emitted as photons. The interactions involving two activators in excited manifolds appear to be related to both concentration quenching and the reduction of phosphor efficiency at high excitation density. (C) 2002 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tallant, DR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 23 TC 42 Z9 42 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 APR 1 PY 2002 VL 91 IS 7 BP 4053 EP 4064 DI 10.1063/1.1452770 PG 12 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900013 ER PT J AU Li, T Balk, JW Ruden, PP Campbell, IH Smith, DL AF Li, T Balk, JW Ruden, PP Campbell, IH Smith, DL TI Channel formation in organic field-effect transistors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILM TRANSISTORS; ANALYTICAL MODEL; SEMICONDUCTORS; INJECTION AB Results of two-dimensional electrostatic modeling of organic field-effect transistors, focusing on the formation of the conductive channel, are reported. The effect on channel formation of the choice of the source and drain contact metal is investigated for both top- and bottom-contact device structures. High-work-function metal (e.g., gold) source and drain contacts produce a conducting p-type region near these contacts. In contrast, low-work-function metal source and drain contacts (e.g., magnesium) lead to depleted regions. In the center of the device, between the source and drain contacts, the channel carrier density at a fixed gate bias is determined by the work function of the gate contact material, and is essentially independent of the metal used to form the source and drain contacts. The principal difference between top- and bottom-contact structures is the spatial variation of the charge density in the vicinity of the source and drain contacts. The channel carrier density for a fixed gate bias (and gate contact material) between the source and drain electrodes is essentially the same for the two structures. Finally, the dependence of the transistor threshold voltage on the gate contact metal work function and the device implications of the spatial variation of the induced charge density are discussed. (C) 2002 American Institute of Physics. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Li, T (reprint author), Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. RI Caironi, Mario/O-2745-2013 OI Caironi, Mario/0000-0002-0442-4439 NR 22 TC 74 Z9 75 U1 0 U2 19 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 APR 1 PY 2002 VL 91 IS 7 BP 4312 EP 4318 DI 10.1063/1.1453509 PG 7 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900055 ER PT J AU Baylor, LR Merkulov, VI Ellis, ED Guillorn, MA Lowndes, DH Melechko, AV Simpson, ML Whealton, JH AF Baylor, LR Merkulov, VI Ellis, ED Guillorn, MA Lowndes, DH Melechko, AV Simpson, ML Whealton, JH TI Field emission from isolated individual vertically aligned carbon nanocones SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NANOTUBE; EMITTERS; DISPLAY; GROWTH AB Field emission from isolated individual vertically aligned carbon nanocones (VACNCs) has been measured using a small-diameter moveable probe. The probe was scanned parallel to the sample plane to locate the VACNCs, and perpendicular to the sample plane to measure the emission turn-on electric field of each VACNC. Individual VACNCs can be good field emitters. The emission threshold field depends on the geometric aspect ratio (height/tip radius) of the VACNC and is lowest when a sharp tip is present. VACNCs exposed to a reactive ion etch process demonstrate a lowered emission threshold field while maintaining a similar aspect ratio. Individual VACNCs can have low emission thresholds, carry high current densities, and have long emission lifetime. This makes them very promising for various field emission applications for which deterministic placement of the emitter with submicron accuracy is needed. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. RP Baylor, LR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Melechko, Anatoli/B-8820-2008; Simpson, Michael/A-8410-2011; OI Simpson, Michael/0000-0002-3933-3457; Baylor, Larry/0000-0002-0325-7771 NR 21 TC 54 Z9 56 U1 1 U2 19 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 APR 1 PY 2002 VL 91 IS 7 BP 4602 EP 4606 DI 10.1063/1.1455138 PG 5 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900101 ER PT J AU Majumdar, A Choi, KK Rokhinson, LP Reno, JL Tsui, DC AF Majumdar, A Choi, KK Rokhinson, LP Reno, JL Tsui, DC TI Electron transfer in voltage tunable two-color infrared photodetectors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID QUANTUM-WELLS; DETECTOR AB Two-color quantum-well infrared photodetectors (QWIPs) that are based on electron transfer between coupled QWs suffer from the presence of the shorter wavelength peak at all bias voltages. We investigate this problem in such detectors with 50 or 200 Angstrom AlGaAs barriers between the QW pair. We deduce the absorption coefficient alpha and photoconductive gain g of the detectors with 50 Angstrom barriers using corrugated QWIPs with different corrugation periods. We find that alpha has a number of small peaks in its spectrum but its value remains almost constant between 0.1 and 0.2 mum(-1) in the 6-12 mum range for most experimental conditions. The wavelength dependence of g, which always has a pronounced peak at the shorter detection wavelength, determines the responsivity line shape. These results are attributed to insufficient electron transfer between the coupled QWs and to low tunneling probability of the longer wavelength photoelectrons. A comparison of measured responsivity and calculated absorption spectrum of the detectors with 200 Angstrom barriers indicates that there is significant electron transfer between the coupled wells. Despite efficient electron transfer, these detectors have a shorter wavelength detection peak at all bias voltages because of significant short wavelength absorption in both the QWs. (C) 2002 American Institute of Physics. C1 Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. USA, Res Lab, 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 20 TC 3 Z9 3 U1 2 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 APR 1 PY 2002 VL 91 IS 7 BP 4623 EP 4630 DI 10.1063/1.1455684 PG 8 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900105 ER PT J AU Bernstein, A Wang, Y Gratta, G West, T AF Bernstein, A Wang, Y Gratta, G West, T TI Nuclear reactor safeguards and monitoring with antineutrino detectors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NEUTRON FISSION-PRODUCTS; SPECTRA AB Cubic-meter-sized antineutrino detectors can be used to non intrusively, robustly, and automatically monitor and safeguard a wide variety of nuclear reactor types, including power reactors, research reactors, and plutonium production reactors. Since the antineutrino spectra and relative yields of fissioning isotopes depend on the isotopic composition of the core, changes in composition can be observed without ever directly accessing the core itself. Information from a modest-sized antineutrino detector, coupled with the well-understood principles that govern the core's evolution in time, can be used to determine whether the reactor is being operated in an illegitimate way. A group at Sandia is currently constructing a 1 m(3) antineutrino detector at the San Onofre reactor site in California to demonstrate these principles. (C) 2002 American Institute of Physics. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Sandia Natl Labs, Livermore, CA 94551 USA. EM abernst@sandia.gov NR 15 TC 41 Z9 42 U1 0 U2 2 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 APR 1 PY 2002 VL 91 IS 7 BP 4672 EP 4676 DI 10.1063/1.1452775 PG 5 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900112 ER PT J AU Passian, A Muralidharan, G Kouchekian, S Mehta, A Cherian, S Ferrell, TL Thundat, T AF Passian, A Muralidharan, G Kouchekian, S Mehta, A Cherian, S Ferrell, TL Thundat, T TI Dynamics of self-driven microcantilevers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC-FORCE MICROSCOPE; FREQUENCY-RESPONSE; CANTILEVERS; FLUIDS AB The small amplitude thermal vibrations of the microcantilever of an atomic force microscope can be enhanced via a delayed feedback system. This is verified experimentally for a triangular cantilever, and modeled theoretically as a boundary value problem resulting in a second order functional differential equation for the temporal behavior of the cantilever. The eigenvalues of the resulting delay differential equation describing the transverse vibrations of the cantilever are calculated and analyzed. These values are compared with the corresponding resonant frequencies predicted by a point mass model and with the experimentally observed values. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Virginia Polytech Inst & State Univ, Dept Math, Blacksburg, VA 24061 USA. RP Passian, A (reprint author), Oak Ridge Natl Lab, Bethel Valley Rd, Oak Ridge, TN 37830 USA. RI Muralidharan, Govindarajan/J-6155-2015 NR 17 TC 18 Z9 18 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 APR 1 PY 2002 VL 91 IS 7 BP 4693 EP 4700 DI 10.1063/1.1452771 PG 8 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900115 ER PT J AU Strauss, M Kaufman, Y Sapir, M Amendt, PA London, RA Glinsky, ME AF Strauss, M Kaufman, Y Sapir, M Amendt, PA London, RA Glinsky, ME TI Self-consistent coupling of cavitation bubbles in aqueous systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LASER-ABLATION; DYNAMICS; THROMBOLYSIS; SPALLATION; PICOSECOND; TRANSIENT; EVOLUTION; LIQUIDS; MEDIA AB The dynamics of an ensemble of cavitation voids initiated by laser-produced stress waves in aqueous systems is considered. Aqueous systems have large similarity to soft tissues. Laser-initiated stress waves are reflected from tissue boundaries, thereby inducing a tensile stress that is responsible for tissue damage. The early stage of damage is represented by an ensemble of voids or bubbles that nucleate and grow around impurities under stress wave tension. For impurity densities larger than 10(5) cm(-3) the bubbles growth reduces the tensile wave component and causes the pressure to oscillate between tension and compression. For impurity densities below 10(8) cm(-3) the bubbles grow on a long time scale (similar to10 mus) relative to the wave interaction time (similar to100 ns). For bubble densities above 10(8) cm(-3) the bubble lifetime is greatly shortened because of the reduced tensile component. On a long time scale the growing bubbles cause a significant reduction in the liquid average compression pressure below the ambient atmospheric pressure. This effect increases the bubble lifetime by almost a factor of 2 relative to the low impurity density case when the bubbles are growing independently, in agreement with experiment [Paltauf and Schmidt-Kloiber, Appl. Phys. A: Mater. Sci. Process. 62, 303 (1996)]. As the collapse stage starts, small bubbles collapse first and the compression pressure screening becomes less effective, thereby accelerating the collapse of the larger bubbles and reducing the spread of the bubble lifetimes. (C) 2002 American Institute of Physics. C1 Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. BHP Petr, Houston, TX 77056 USA. RP Strauss, M (reprint author), Nucl Res Ctr Negev, POB 9001, IL-84190 Beer Sheva, Israel. NR 34 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 1 PY 2002 VL 91 IS 7 BP 4720 EP 4725 DI 10.1063/1.1456247 PG 6 WC Physics, Applied SC Physics GA 535UC UT WOS:000174663900119 ER PT J AU Campbell, JR Hlavka, DL Welton, EJ Flynn, CJ Turner, DD Spinhirne, JD Scott, VS Hwang, IH AF Campbell, JR Hlavka, DL Welton, EJ Flynn, CJ Turner, DD Spinhirne, JD Scott, VS Hwang, IH TI Full-time, eye-safe cloud and aerosol lidar observation at atmospheric radiation measurement program sites: Instruments and data processing SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID CLIMATE AB Atmospheric radiative forcing, surface radiation budget, and top-of-the-atmosphere radiance interpretation involve knowledge of the vertical height structure of overlying cloud and aerosol layers. During the last decade, the U. S. Department of Energy, through the Atmospheric Radiation Measurement (ARM) program, has constructed four long-term atmospheric observing sites in strategic climate regimes (north-central Oklahoma; Barrow, Alaska; and Nauru and Manus Islands in the tropical western Pacific). Micropulse lidar (MPL) systems provide continuous, autonomous observation of nearly all significant atmospheric clouds and aerosols at each of the central ARM facilities. These systems are compact, and transmitted pulses are eye safe. Eye safety is achieved by expanding relatively low-powered outgoing pulse energy through a shared, coaxial transmit/receive telescope. ARM MPL system specifications and specific unit optical designs are discussed. Data normalization and calibration techniques are presented. These techniques, in tandem, represent an operational value-added processing package used to produce normalized data products for ARM cloud and aerosol research. C1 Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20708 USA. Sci & Engn Serv Inc, Burtonsville, MD USA. RP Campbell, JR (reprint author), NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Code 912, Greenbelt, MD 20708 USA. RI Welton, Ellsworth/A-8362-2012; Campbell, James/C-4884-2012; Scott, Vibart/B-5086-2013; OI Campbell, James/0000-0003-0251-4550; Hlavka, Dennis/0000-0002-2976-7243 NR 14 TC 183 Z9 191 U1 5 U2 19 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 2002 VL 19 IS 4 BP 431 EP 442 DI 10.1175/1520-0426(2002)019<0431:FTESCA>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 534UH UT WOS:000174605000002 ER PT J AU Connolly, KM Iwahara, M Clubb, RT AF Connolly, KM Iwahara, M Clubb, RT TI Xis protein binding to the left arm stimulates excision of conjugative transposon Tn916 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SITE-SPECIFIC RECOMBINATION; INTEGRATION HOST FACTOR; GRAM-POSITIVE BACTERIA; DNA-BINDING; ESCHERICHIA-COLI; BACILLUS-SUBTILIS; IN-VITRO; ENTEROCOCCUS-FAECALIS; LAMBDA-INTEGRASE; ATTACHMENT SITE AB Tn916 and related conjugative transposons are clinically significant vectors for the transfer of antibiotic resistance among human pathogens, and they excise from their donor organisms using the transposon-encoded integrase ((Tn916)Int) and excisionase ((Tn916)XiS) proteins. In this study, we have investigated the role of the (Tn916)XiS protein in stimulating excisive recombination. The functional relevance of (Tn916)Xis binding sites on the arms of the transposon has been assessed in vivo using a transposon excision assay. Our results indicate that in Escherichia coli the stimulatory effect of the (Tn916)Xis protein is mediated by sequence-specific binding to either of its two binding sites on the left arm of the transposon. These sites lie in between the core and arm sites recognized by (Tn916)Int, suggesting that the (Tn916)Xis protein enhances excision in a manner similar to the excisionase protein of bacteriophage lambda, serving an architectural role in the stabilization of protein-nucleic acid structures required for strand synapsis. However, our finding that excision in E. coli is significantly enhanced by the host factor HU, but does not depend on the integration host factor or the factor for inversion stimulation, defines clear mechanistic differences between Tn916 and bacteriophage lambda recombination. C1 Univ Calif Los Angeles, DOE Lab Struct Biol & Mol Med, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Mol Biol Inst, Los Angeles, CA 90095 USA. RP Clubb, RT (reprint author), Univ Calif Los Angeles, DOE Lab Struct Biol & Mol Med, Dept Chem & Biochem, 405 Hilgard Ave, Los Angeles, CA 90095 USA. EM rclubb@mbi.ucla.edu FU NIGMS NIH HHS [GM57487, R01 GM057487] NR 64 TC 9 Z9 10 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD APR PY 2002 VL 184 IS 8 BP 2088 EP 2099 DI 10.1128/JB.184.8.2088-2099.2002 PG 12 WC Microbiology SC Microbiology GA 535WJ UT WOS:000174669100005 PM 11914339 ER PT J AU Sarti, A Mikula, K Sgallari, F Lamberti, C AF Sarti, A Mikula, K Sgallari, F Lamberti, C TI Evolutionary partial differential equations for biomedical image processing SO JOURNAL OF BIOMEDICAL INFORMATICS LA English DT Article DE medical imaging; echo-cardiography; motion based image filtering; image multi-scale analysis; non-linear partial differential equations; numerical solution ID NONLINEAR DIFFUSION-EQUATIONS; FINITE-VOLUME SCHEME; MEAN-CURVATURE; EDGE-DETECTION; SUBJECTIVE SURFACES; VISCOSITY SOLUTIONS; GEOMETRIC MODEL; ALGORITHMS; SPEED; INTERFACES AB We are presenting here a model for processing space-time image sequences and applying them to 3D echo-cardiography. The non-linear evolutionary equations filter the sequence with keeping space-time coherent structures. They have been developed using ideas of regularized Perona-Malik an-isotropic diffusion and geometrical diffusion of mean curvature flow type (Malladi-Sethian), combined with Galilean invariant movie multi-scale analysis of Alvarez et al. A discretization of space-time filtering equations by means of finite volume method is discussed in detail. Computational results in processing of 3D echo-cardiographic sequences obtained by rotational acquisition technique and by real-time 3D echo volumetrics acquisition technique are presented. Quantitative error estimation is also provided. (C) 2002 Elsevier Science (USA). All rights reserved. C1 Univ Calif Berkeley, Dept Math, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Bologna, DEIS, I-40136 Bologna, Italy. Slovak Univ Technol Bratislava, Dept Math, Bratislava, Slovakia. Univ Bologna, Dept Math, Bologna, Italy. RP Sarti, A (reprint author), Univ Calif Berkeley, Dept Math, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM asarti@deis.unibo.it OI LAMBERTI, CLAUDIO/0000-0002-0039-1369 NR 54 TC 4 Z9 5 U1 1 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1532-0464 J9 J BIOMED INFORM JI J. Biomed. Inform. PD APR PY 2002 VL 35 IS 2 BP 77 EP 91 AR PII S1532-0464(02)00502-6 DI 10.1016/S1532-0464(02)00502-6 PG 15 WC Computer Science, Interdisciplinary Applications; Medical Informatics SC Computer Science; Medical Informatics GA 617AW UT WOS:000179337900001 PM 12474422 ER PT J AU Wei, LP Liu, YY Dubchak, I Shon, J Park, J AF Wei, LP Liu, YY Dubchak, I Shon, J Park, J TI Comparative genomics approaches to study organism similarities and differences SO JOURNAL OF BIOMEDICAL INFORMATICS LA English DT Review ID MICROBIAL GENE IDENTIFICATION; CONSERVED NONCODING SEQUENCES; DNA-SEQUENCE; REGULATORY ELEMENTS; HELICOBACTER-PYLORI; ESCHERICHIA-COLI; DRAFT SEQUENCE; MOUSE GENOME; WEB SERVER; SCL LOCI AB Comparative genomics is a large-scale, holistic approach that compares two or more genomes to discover the similarities and differences between the genomes and to study the biology of the individual genomes. Comparative studies can be performed at different levels of the genomes to obtain multiple perspectives about the organisms. We discuss in detail the type of analyses that offer significant biological insights in the comparisons of (1) genome structure including overall genome statistics, repeats, genome rearrangement at both DNA and gene level, synteny, and breakpoints; (2) coding regions including gene content, protein content, orthologs, and paralogs; and (3) noncoding regions including the prediction of regulatory elements. We also briefly review the currently available computational tools in comparative genomics such as algorithms for genome-scale sequence alignment, gene identification, and nonhomology-based function prediction. (C) 2002 Elsevier Science (USA). All rights reserved. C1 Nexus Genom Inc, Mountain View, CA 94043 USA. Beijing Genom Inst, Hang Zhou Ctr, Hangzhou, Peoples R China. Stanford Univ, Stanford, CA 94305 USA. Lawrence Berkeley Natl Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Wei, LP (reprint author), Nexus Genom Inc, 229 Polaris Ave,Suite 6, Mountain View, CA 94043 USA. EM wei@nexusgenomics.com NR 78 TC 15 Z9 19 U1 0 U2 9 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1532-0464 J9 J BIOMED INFORM JI J. Biomed. Inform. PD APR PY 2002 VL 35 IS 2 BP 142 EP 150 AR PII S1532-0464(02)00506-3 DI 10.1016/S1532-0464(02)00506-3 PG 9 WC Computer Science, Interdisciplinary Applications; Medical Informatics SC Computer Science; Medical Informatics GA 617AW UT WOS:000179337900006 PM 12474427 ER PT J AU Stoller, P Kim, BM Rubenchik, AM Reiser, KM Da Silva, LB AF Stoller, P Kim, BM Rubenchik, AM Reiser, KM Da Silva, LB TI Polarization-dependent optical second-harmonic imaging of a rat-tail tendon SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE second harmonic generation; confocal microscopy; ultrashort pulse laser; rat-tail tendon; collagen structure ID HARMONIC-GENERATION; LASER-PULSES; I COLLAGEN; TISSUES; SCATTERING; 2ND AB Using scanning confocal microscopy, we measure the backscattered second harmonic signal generated by a 100 fs laser in rat-tail tendon collagen. Damage to the sample is avoided by using a continuous scanning technique, rather than measuring the signal at discrete points. The second harmonic signal varies by about a factor of 2 across a single cross section of the rat-tail tendon fascicle. The signal intensity depends both on the collagen organization and the backscattering efficiency. This implies that we cannot use intensity measurements alone to characterize collagen structure. However, we can infer structural information from the polarization dependence of the second harmonic signal. Axial and transverse scans for different linear polarization angles of the input beam show that second harmonic generation (SHG) in the rat-tail tendon depends strongly on the polarization of the input laser beam. We develop an analytical model for the SHG as a function of the polarization angle in the rat-tail tendon. We apply this model in determining the orientation of collagen fibrils in the fascicle and the ratio gamma between the two independent elements of the second-order nonlinear susceptibility tensor. There is a good fit between our model and the measured data. (C) 2002 Society of Photo-Optical Instrumentation Engineers. C1 Yonsei Univ, Dept Biomed Engn, Kangwan Do 220710, South Korea. Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94550 USA. Univ Calif Davis, Dept Neurol Sci, Sch Med, Davis, CA 95616 USA. RP Kim, BM (reprint author), Yonsei Univ, Dept Biomed Engn, 234 Heungup, Kangwan Do 220710, South Korea. EM beopmkim@dragon.yonsei.ac.kr OI Stoller, Patrick/0000-0002-6620-1249 NR 25 TC 142 Z9 142 U1 3 U2 22 PU SPIE-SOC PHOTOPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 1083-3668 J9 J BIOMED OPT JI J. Biomed. Opt. PD APR PY 2002 VL 7 IS 2 BP 205 EP 214 DI 10.1117/1.1431967 PG 10 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA 550AJ UT WOS:000175480500005 PM 11966305 ER PT J AU Newman, GC Hospod, FE Patlak, TS Trowbridge, SD Wilke, TJ Fuhrmann, T Jones, KW AF Newman, GC Hospod, FE Patlak, TS Trowbridge, SD Wilke, TJ Fuhrmann, T Jones, KW TI Calcium compartments in brain SO JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM LA English DT Article DE calcium; brain; kinetics ID CEREBROSPINAL-FLUID; PYRAMIDAL NEURONS; SLICES; RAT; CA-2+; ACCUMULATION; HISTOLOGY; MEMBRANES; DIFFUSION; ISCHEMIA AB Excellent progress has been made toward understanding the physiology and pharmacology of specific calcium-related cellular processes of the brain, but few studies have provided an integrated view of brain calcium kinetics. To further the knowledge of the size and binding properties of brain calcium compartments, the authors have conducted a series of experiments in hippocampal brain slices exposed to high and low extracellular calcium. Slices were incubated in buffers containing 0.001 to 4.5 mmol/L calcium for up to 75 minutes. Slice calcium content was analyzed by three methods: exchange equilibrium with Ca-45, synchrotron-radiation-induced x-ray emission, and inductively coupled plasma. Data were analyzed using a model based on a Langmuir isotherm for two independent sites, with additional extracellular and bound compartments. In parallel experiments, altered low calcium had no effect on slice histology and only mild effects on slice adenylates. When combined with prior Ca-45 and fluorescent probe binding experiments, these results suggest that there are at least five kinetically distinct calcium compartments: (1) free extracellular (similar to10%); (2) loosely associated extracellular plasma membrane (similar to55%); (3) intracellular compartment with moderate avidity (similar to17%); (4) tightly bound, nonexchangeable intracellular compartment (similar to15%); and (5) free cytoplasmic (<0.01%). If only the third compartment is considered a potential calcium buffer, then the buffering ratio is calculated to be similar to2,700:1, but if the second compartment is also included, then the buffering ratio would be similar to13,000:1. This may explain the wide range of estimates observed by fluorescent probe studies. C1 SUNY Stony Brook, Dept Neurol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Surg, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Environm Sci Dept, Upton, NY USA. RP Newman, GC (reprint author), SUNY Stony Brook, Dept Neurol, HSC T12-020, Stony Brook, NY 11794 USA. FU NINDS NIH HHS [NS28429-01A1] NR 36 TC 5 Z9 5 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0271-678X J9 J CEREBR BLOOD F MET JI J. Cereb. Blood Flow Metab. PD APR PY 2002 VL 22 IS 4 BP 479 EP 489 PG 11 WC Endocrinology & Metabolism; Hematology; Neurosciences SC Endocrinology & Metabolism; Hematology; Neurosciences & Neurology GA 538EY UT WOS:000174802900012 PM 11919519 ER PT J AU Liu, XH Gross, RL Suits, AG AF Liu, XH Gross, RL Suits, AG TI Differential cross sections for O(P-3)+alkane reactions by direct imaging SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID H ABSTRACTION DYNAMICS; SATURATED-HYDROCARBONS; CHEMICAL-DYNAMICS; MOLECULAR-BEAMS; 193 NM; PHOTODISSOCIATION; O(P-3) AB We report a crossed molecular beam study of the reaction of O(P-3) with cyclohexane with velocity map imaging of the cyclohexyl radical product using single photon ionization. The results represent the first direct measurement of the differential cross sections for ground state oxygen atom reactions with alkanes. The experimental approach has the advantage that the collision energy is not only well defined but also continuously tunable in a reasonable range. The results show that at 5.8 kcal/mol collision energy the products are mainly backward scattered, clearly confirming the anticipated rebound reaction mechanism. More surprising is the large fraction, nearly 60%, of the available energy partitioned into the internal degrees of freedom of the products. (C) 2002 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RP Liu, XH (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 24 TC 27 Z9 27 U1 3 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 2002 VL 116 IS 13 BP 5341 EP 5344 DI 10.1063/1.1464830 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700003 ER PT J AU Naleway, C Seth, M Shepard, R Wagner, AF Tilson, JL Ermler, WC Brozell, SR AF Naleway, C Seth, M Shepard, R Wagner, AF Tilson, JL Ermler, WC Brozell, SR TI An ab initio study of the ionization potentials and f-f spectroscopy of europium atoms and ions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPIN-ORBIT OPERATORS; CONFIGURATION-INTERACTION; ENERGY-LEVELS; ELECTRONIC-STRUCTURE; LANTHANIDE; SPECTRA; PSEUDOPOTENTIALS; STATES; EU3; CI AB The first three ionization potentials of europium and the f-f spectroscopy of the two lowest multiplets of Eu+3 have been calculated using ab initio spin-orbit configuration interaction techniques. To accomplish this, a new averaged relativistic effective core potential has been developed which leaves only the 5s, 5p, and 4f in the valence space. A series of configuration interaction calculations were carried out up through single and partial double excitations with a double-zeta quality basis set. The computed ionization values have an absolute error of about 0.1 eV from the experimental values. The computed f-f spectroscopy for the lowest F-7 multiplet of Eu+3 has a RMS error with experiment of about 100 cm(-1). The computed f-f spectroscopy for the first excited D-5 multiplet has a higher RMS error of about 350 cm(-1). The computed center of gravity separation between the D-5-F-7 multiplet is underestimated by 750 cm(-1). Comparisons between non-spin-orbit and spin-orbit configuration interaction calculations for the separations of the centers of gravity of multiplets are very favorable up through single and double excitations with differences of a tenth of an eV or less. The spin-orbit configuration interaction calculations are among the largest ever performed for lanthanides, with expansion lengths in excess of 1.9 million double-group-adapted functions. The calculations were achieved by application of a new parallel spin-orbit configuration interaction component in the COLUMBUS Program System. (C) 2002 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Stevens Inst Technol, Dept Chem & Biol Chem, Hoboken, NJ 07030 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Naleway, C (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wagner@tcg.anl.gov RI Ermler, Walter/B-6876-2011 NR 39 TC 6 Z9 6 U1 2 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 APR 1 PY 2002 VL 116 IS 13 BP 5481 EP 5493 DI 10.1063/1.1455619 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700020 ER PT J AU Tilson, JL Naleway, C Seth, M Shepard, R Wagner, AF Ermler, WC AF Tilson, JL Naleway, C Seth, M Shepard, R Wagner, AF Ermler, WC TI An ab initio study of the f-f spectroscopy of americium+3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION; IONIZATION-POTENTIALS; ELECTRONIC-STRUCTURE; ABSORPTION; STATES; ATOMS; AM AB The levels associated with the lowest F-7 and D-5 terms of Am+3 have been calculated using ab initio spin-orbit configuration interaction techniques. A series of configuration interaction calculations were carried out that include significant amounts of single and double excitations and with two different pseudopotentials available in the literature. Double and single excitations from the 6s, 6p, and 5f subshells are all important in the determination of the level energies. A comparison of the two examined pseudopotentials with increasing amounts of electron correlation indicates that both yield results in qualitative agreement with experiment. More importantly, though, it is estimated that both are in significant quantitative error relative to experimental results, even for very large configuration interaction calculations. The calculations were performed using the new parallel spin-orbit configuration interaction component to the COLUMBUS Program System. (C) 2002 American Institute of Physics. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Stevens Inst Technol, Dept Chem & Biol Chem, Hoboken, NJ 07030 USA. RP Tilson, JL (reprint author), SUNY Buffalo, Ctr Computat Res, Buffalo, NY 14260 USA. RI Ermler, Walter/B-6876-2011 NR 31 TC 5 Z9 5 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 2002 VL 116 IS 13 BP 5494 EP 5502 DI 10.1063/1.1455620 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700021 ER PT J AU Chen, WW Hochlaf, M Rosmus, P He, GZ Ng, CY AF Chen, WW Hochlaf, M Rosmus, P He, GZ Ng, CY TI Vacuum ultraviolet pulsed field ionization-photoelectron study of OCS in the energy range of 15-19 eV SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HIGH-RESOLUTION; SYNCHROTRON-RADIATION; ROVIBRONIC SPECTRUM; SUPEREXCITED STATES; VARIATIONAL METHOD; PHOTO-IONIZATION; VIBRONIC LEVELS; MOLECULAR-IONS; SPECTROSCOPY; COS+ AB Vacuum ultraviolet pulsed field ionization-photoelectron (PFI-PE) spectra for OCS have been obtained in the energy range 15.0-19.0 eV, covering the vibronic bands of OCS+ (A (2)Pi, B (2)Sigma(+), and C (2)Sigma(+)). The ionization energies for the formation of the ground vibrational levels of OCS+ (A (2)Pi(3/2), A (2)Pi(1/2), B (2)Sigma(+), and C (2)Sigma(+)) from the ground OCS(X (1)Sigma(+)) state have been determined as 15.0759+/-0.0005 eV, 15.0901+/-0.0005 eV, 16.0403+/-0.0005 eV, and 17.9552+/-0.0005 eV, respectively. We have also generated the theoretical adiabatic three dimensional potential energy functions (PEFs) for OCS+(A (2)Pi) by employing the complete active space self-consistent field and internally contracted multireference configuration interaction methods. Using these PEFs, the spectroscopic constants and low-lying rovibronic energy levels for OCS+(A (2)Pi) are calculated variationally. These calculations have made possible the identification of many PFI-PE vibronic bands for OCS+(A (2)Pi), which are originated from vibronic and Fermi resonance interactions. Owing to the different equilibrium geometries between the OCS+(A (2)Pi) and OCS(X (1)Sigma(+)) states, the PFI-PE spectrum for OCS+(A (2)Pi) exhibits a long vibronic progression extending well above the OCS+(B (2)Sigma(+)) state. On the contrary, the PFI-PE spectra for OCS+ (B (2)Sigma(+) and C (2)Sigma(+)) are overwhelmingly dominated by the ground (0,0,0) bands, exhibiting only weak vibrational progressions. (C) 2002 American Institute of Physics. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Univ Marne La Vallee, Theoret Chem Grp, F-77454 Marne La Vallee 2, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ng, CY (reprint author), Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. NR 52 TC 17 Z9 17 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD APR 1 PY 2002 VL 116 IS 13 BP 5612 EP 5621 DI 10.1063/1.1455622 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700034 ER PT J AU Harper, WW Nizkorodov, SA Nesbitt, DJ AF Harper, WW Nizkorodov, SA Nesbitt, DJ TI Reactive scattering of F+HD -> HF(v,J)+D: HF(v,J) nascent product state distributions and evidence for quantum transition state resonances SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; MOLECULAR-BEAM EXPERIMENTS; POTENTIAL-ENERGY SURFACE; F+H-2->HF+H REACTION; F+H-2 REACTION; ANGULAR-DISTRIBUTIONS; SUPERSONIC JETS; REACTION F+D-2; ABSORPTION; DYNAMICS AB Single collision reactive scattering dynamics of F+HD-->HF(v,J)+D have been investigated exploiting high-resolution (Deltanuapproximate to0.0001 cm-1) infrared laser absorption for quantum state resolved detection of nascent HF(v,J) product states. State resolved Doppler profiles are recorded for a series of HF rovibrational transitions and converted into state resolved fluxes via density-to-flux analysis, yielding cross-section data for relative formation of HF(v,J) at E(com)approximate to0.6(2), 1.0(3), 1.5(3), and 1.9(4) kcal/mol. State resolved HF(v,J) products at all but the lowest collision energy exhibit Boltzmann-type populations, characteristic of direct reactive scattering dynamics. At the lowest collision energy [E(com)approximate to0.6(2) kcal/mol], however, the HF(v=2,J) populations behave quite anomalously, exhibiting a nearly "flat" distribution out to Japproximate to11 before dropping rapidly to zero at the energetic limit. These results provide strong experimental support for quantum transition state resonance dynamics near E(com)approximate to0.6 kcal/mol corresponding classically to H atom chattering between the F and D atoms, and prove to be in remarkably quantitative agreement with theoretical wave packet predictions by Skodje [J. Chem. Phys. 112, 4536 (2000)]. These fully quantum state resolved studies therefore nicely complement the recent crossed beam studies of Dong [J. Chem. Phys. 113, 3633 (2000)], which confirm the presence of this resonance via angle resolved differential cross-section measurements. The observed quantum state distributions near threshold also indicate several rotational states in the HF(v=3) vibrational manifold energetically inaccessible to F(P-2(3/2)) reagent, but which are consistent with a minor (less than or similar to5%) nonadiabatic contribution from spin-orbit excited F-*(P-2(1/2)). (C) 2002 American Institute of Physics. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. RP Harper, WW (reprint author), Pacific NW Natl Lab, POB 999 MS K5-25, Richland, WA 99352 USA. RI Nizkorodov, Sergey/I-4120-2014 OI Nizkorodov, Sergey/0000-0003-0891-0052 NR 37 TC 44 Z9 44 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 APR 1 PY 2002 VL 116 IS 13 BP 5622 EP 5632 DI 10.1063/1.1456507 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700035 ER PT J AU Radziszewski, JG Gil, M Gorski, A Spanget-Larsen, J Waluk, J Mroz, BJ AF Radziszewski, JG Gil, M Gorski, A Spanget-Larsen, J Waluk, J Mroz, BJ TI Electronic states of the phenoxyl radical (vol 115, pg 9733, 2001) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Polish Acad Sci, Inst Phys Chem, PL-01224 Warsaw, Poland. Roskilde Univ Ctr, RUC, Dept Chem, DK-4000 Roskilde, Denmark. RP Radziszewski, JG (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Waluk, Jacek/C-8250-2011 NR 1 TC 5 Z9 5 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 APR 1 PY 2002 VL 116 IS 13 BP 5912 EP 5912 DI 10.1063/1.1458539 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 532JH UT WOS:000174470700070 ER PT J AU Kim, J Choi, H AF Kim, J Choi, H TI Modeling in situ ozonation for the remediation of nonvolatile PAH-contaminated unsaturated soils SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE modeling; in situ oxidation; ozonation; unsaturated soil; soil organic matter; phenanthrene ID HYDROGEN-PEROXIDE; KINETICS AB Mathematical models were developed to investigate the characteristics of gaseous ozone transport under various soil conditions and the feasibility of in situ ozone venting for the remediation of unsaturated soils contaminated with phenanthrene. On the basis of assumptions for the mass transfer and reactions of ozone, three approaches were considered: equilibrium, kinetic, and lump models. Water-saturation-dependent reactions of gaseous ozone with soil organic matter (SOM) and phenanthrene were employed. The models were solved numerically by using the finite-difference method, and the model parameters were determined by using the experimental data of Hsu [The use of gaseous ozone to remediate the organic contaminants in the unsaturated soils, PhD Thesis, Michigan State Univ., East Lansing, MI, 1995]. The transport of gas-phase ozone is significantly retarded by ozone consumption due to reactions with SOM and phenanthrene, in addition to dissolution. An operation time of 156 h was required to completely remove phenanthrene in a 5-m natural soil column. In actual situations, however, the operation time is likely to be longer than the ideal time because of unknown factors including heterogeneity of the porous medium and the distribution of SOM and contaminant. The ozone transport front length was found to be very limited (< 1 m). The sensitivity analysis indicated that SOM is the single most important factor affecting in situ ozonation for the remediation of unsaturated soil contaminated with phenanthrene. Models were found to be insensitive to the reaction mechanisms of phenathrene with either gas-phase ozone or dissolved ozone. More study is required to quantify the effect of OHcircle formation on the removal of contaminant and on ozone transport in the subsurface. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Environm Res Div, Argonne, IL 60439 USA. Kwang Ju Inst Sci & Technol, Dept Environm Sci & Engn, Buk Gu, Kwangju 500712, South Korea. RP Kim, J (reprint author), Lawrence Berkeley Natl Lab, Earth Sci Div, 1 Cyclotron Rd MS 90-1116, Berkeley, CA 94720 USA. NR 17 TC 39 Z9 41 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD APR PY 2002 VL 55 IS 3-4 BP 261 EP 285 AR PII S0169-7722(01)00196-6 DI 10.1016/S0169-7722(01)00196-6 PG 25 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 540TK UT WOS:000174945000004 PM 11999632 ER PT J AU Ciszek, TF Wang, TH AF Ciszek, TF Wang, TH TI Silicon defect and impurity studies using float-zone crystal growth as a tool SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 13th International Conference on Crystal Growth held in conjunction with the 11th International Conference on Vapor Growth and Epitaxy CY JUL 30-AUG 04, 2001 CL KYOTO, JAPAN SP Sci Council Japan, Japan Soc Appl Phys, Japanese Assoc Crystal Growth, Fdn Promot Mat Sci & Technol Japan, Izumi Fdn Promot Sci & Engn, Kansai Res Fdn Technol Program, Murata Fdn Promot Sci & Engn, Doshisha Univ, Japan Soc Micrograv Applicat, Anritsu Corp, ASEC Inc, Canon Inc, Chichibu Fuji Co Ltd, Dai Ichi Kiden Co Ltd DE defects; impurities; point defects; floating zone technique; scmiconducting silicon ID HIGH-PURITY; DISLOCATION AB The float-zone (FZ) method for silicon crystal growth produces very high purities and low defect levels because no crucibles or other heated components are used, and the melt is only in contact with solid silicon. FZ growth is thus a useful tool for the study of defect and impurity effects on material properties such as minority charge carrier lifetime T or photovoltaic efficiency eta using controlled samples in which specific defects or impurities are deliberately introduced into the high-purity, low-defect baseline material, as desired. We have used this tool for defect studies on grain size, dislocations, silicon self interstitial clusters, and fast-cooling defects, as well as for impurity studies on H, N, Fe, p-type dopants, and interactions between Fe and Ga. Float zoning was conducted in vacuum or pure argon using induction heating at 2 MHz. The ASTM F28-91 photoconductive decay method was used to measure tau after growth. Arrays of isolated diagnostic solar cell devices were used to characterize defect and impurity effects on photovoltaic parameters. Published by Elsevier Science B.V. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ciszek, TF (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 14 TC 16 Z9 16 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD APR PY 2002 VL 237 BP 1685 EP 1691 AR PII S0022-0248(01)02325-9 DI 10.1016/S0022-0248(01)02325-9 PN 3 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 569CA UT WOS:000176581400011 ER PT J AU Schieber, M Schlesinger, TE James, RB Hermon, H Yoon, H Goorsky, M AF Schieber, M Schlesinger, TE James, RB Hermon, H Yoon, H Goorsky, M TI Study of impurity segregation, crystallinity, and detector performance of melt-grown cadmium zinc telluride crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 13th International Conference on Crystal Growth held in conjunction with the 11th International Conference on Vapor Growth and Epitaxy CY JUL 30-AUG 04, 2001 CL KYOTO, JAPAN SP Sci Council Japan, Japan Soc Appl Phys, Japanese Assoc Crystal Growth, Fdn Promot Mat Sci & Technol Japan, Izumi Fdn Promot Sci & Engn, Kansai Res Fdn Technol Program, Murata Fdn Promot Sci & Engn, Doshisha Univ, Japan Soc Micrograv Applicat, Anritsu Corp, ASEC Inc, Canon Inc, Chichibu Fuji Co Ltd, Dai Ichi Kiden Co Ltd DE X-ray topography; growth from melt; zinc compounds; semiconducting II-VI materials ID BRIDGMAN METHOD; CDZNTE AB A review of growth methods used to produce Cd1-xZnxTe (CZT) (0.0Rac1-->PAK1-->mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase-->ERK cascade that we earlier described. Tumor cell ligation stimulated DAP12 tyrosine phosphorylation and its association with Syk in NK92 cells; Syk tyrosine phosphorylation and activation were also observed. Inhibition of Syk function by kinase-deficient Syk or piceatannol blocked target cell-induced PI3K, Rac1, PAK1, mitogen-activated protein/ERK kinase, and ERK activation, perforin movement, as well as NK cytotoxicity, indicating that Syk is upstream of all these signaling events. Confirming that Syk does not act downstream of PI3K, constitutively active PI3K reactivated all the downstream effectors as well as NK cytotoxicity suppressed in Syk-impaired NK cells. Our results are the first report documenting the instrumental role of Syk in control of PI3K-dependent natural cytotoxicity. C1 Univ S Florida, Coll Med, Program Immunol, H Lee Moffitt Canc Ctr,Dept Interdisciplinary Onc, Tampa, FL 33612 USA. CNRS Marseille Luminy, Ctr Immunol, INSERM, Marseille, France. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Djeu, JY (reprint author), Univ S Florida, Coll Med, Program Immunol, H Lee Moffitt Canc Ctr,Dept Interdisciplinary Onc, MRC 4072,12902 Magnolai Dr, Tampa, FL 33612 USA. FU NCI NIH HHS [CA83146] NR 55 TC 80 Z9 82 U1 2 U2 5 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD APR 1 PY 2002 VL 168 IS 7 BP 3155 EP 3164 PG 10 WC Immunology SC Immunology GA 534CE UT WOS:000174566400007 PM 11907067 ER PT J AU Davenport, MP Fazou, C McMichael, AJ Callan, MFC AF Davenport, MP Fazou, C McMichael, AJ Callan, MFC TI Clonal selection, clonal senescence, and clonal succession: The evolution of the T cell response to infection with a persistent virus SO JOURNAL OF IMMUNOLOGY LA English DT Article ID EPSTEIN-BARR-VIRUS; PRIMARY IMMUNE-RESPONSE; IN-VIVO; RECEPTOR REPERTOIRE; VIRAL-INFECTION; MEMORY; LYMPHOCYTES; REEVALUATION; MATURATION; EXHAUSTION AB We have analyzed the CD8(+) T cell response to EBV and find that a larger primary burst size is associated with proportionally greater decay during the development of memory. Consequently, immunodominance and clonal dominance are less marked in memory than primary responses. An intuitive interpretation of this finding is that there is a limit to the number of cell divisions a T cell clone can undergo, and that the progeny of clones that have expanded massively during a primary immune response are more prone to die as a result of senescence. To test this hypothesis, we have derived a mathematical model of the response of different T cell clones of varying avidity for Ag in the primary and persistent phases of viral infection. When cellular survival and replication are linked to T cell avidity for Ag and Ag dose, then high-avidity T cells dominate both the primary and secondary responses. We then incorporated a limit in the number of cell divisions of individual T cell clones to test whether such a constraint could reproduce the observed association between cell division number and alterations in the contribution of clones to the response to persistent infection. Comparison of the model output with the experimental results obtained from primary and persistent EBV infection suggests that there is indeed a role for cellular senescence in shaping the immune response to persistent infection. C1 John Radcliffe Hosp, Inst Mol Med, Oxford OX4 1DQ, England. Univ New S Wales, Kensington, NSW 2033, Australia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Callan, MFC (reprint author), John Radcliffe Hosp, Inst Mol Med, Oxford OX4 1DQ, England. FU Medical Research Council [G116/121] NR 34 TC 64 Z9 65 U1 0 U2 1 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD APR 1 PY 2002 VL 168 IS 7 BP 3309 EP 3317 PG 9 WC Immunology SC Immunology GA 534CE UT WOS:000174566400027 PM 11907087 ER PT J AU Bryan, JC Chen, TN Levitskaia, TG Haverlock, TJ Barnes, CE Moyer, BA AF Bryan, JC Chen, TN Levitskaia, TG Haverlock, TJ Barnes, CE Moyer, BA TI Solvation of calix[4]arene-bis-crown-6 molecules SO JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY LA English DT Article DE crown ether; solvation; calixarene; crystal structure ID CRYSTAL-STRUCTURES; ALKALI CATIONS; CESIUM NITRATE; EXTRACTION; COMPLEXATION; 1,2-DICHLOROETHANE; SELECTIVITY; DYNAMICS; SOLVENT; CONFORMATION AB Single crystal X-ray diffraction analyses of calix[4]arene-bis-crown-6 (1) and calix[4]arene-bis-benzocrown-6.1,2-dichloroethane ( 2) are reported. These structures offer an opportunity to study the conformation of calix[4]arene-bis-crown-6 molecules in the absence of solvent, and when very weakly solvated. These structures exhibit different conformations of the crown ring, and limited flexibility of the calix[4]arene, but do not show solvent or crown inclusion in the calix[4]arene cavity. Comparisons to similar structures are made, and the implications for cesium binding are discussed. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Bryan, JC (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 29 TC 5 Z9 6 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0923-0750 EI 1573-1111 J9 J INCL PHENOM MACRO JI J. Incl. Phenom. Macrocycl. Chem. PD APR PY 2002 VL 42 IS 3-4 BP 241 EP 245 DI 10.1023/A:1016096203791 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 565UA UT WOS:000176386800012 ER PT J AU Gibbs, AR Morimoto, H VanBrocklin, HF Williams, PG Biegon, A AF Gibbs, AR Morimoto, H VanBrocklin, HF Williams, PG Biegon, A TI Synthesis of N-(2-chloro-5-methylthiophenyl)-N '-(3-methyl-thiophenyl)-N '-[H-3(3)]methylguanidine, {[H-3(3)]CNS-5161} SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE CNS-5161; tritium; NMDA ID D-ASPARTATE RECEPTOR; EXCITATORY AMINO-ACIDS; NMDA RECEPTOR; BRAIN; NEUROTOXICITY; DISEASE; MK-801; F-18 AB The preparation of the title compound, [H-3(3)]CNS-5161, was accomplished in three steps starting with the production of [H-3(3)]iodomethane (CT3I). The intermediate N-[H-3(3)]methyl-3-(thiomethylphenyl)cyanamide was prepared in 77% yield by the addition of CT3I to 3-(thiomethylphenyl)cyanamide, previously treated with sodium hydride. Reaction of this tritiated intermediate with 2-chloro-5-thiomethylaniline hydrochloride formed the guanidine compound [H-3(3)]CNS-5161. Purification by HPLC gave the desired labeled product in an overall yield of 9% with > 96% radiochemical purity and a final specific activity of 66 Ci mmol(-1). Copyright (C) 2002 John Wiley Sons, Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Tritium Labeling Facil, Berkeley, CA 94720 USA. RP Gibbs, AR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Funct Imaging, 1 Cyclotron Rd MS 55-121, Berkeley, CA 94720 USA. NR 16 TC 3 Z9 3 U1 2 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD APR PY 2002 VL 45 IS 5 BP 395 EP 400 DI 10.1002/jlcr.561 PG 6 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA 548ML UT WOS:000175391700004 ER PT J AU Goodson, BM AF Goodson, BM TI Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials, and organisms SO JOURNAL OF MAGNETIC RESONANCE LA English DT Review ID HYPERPOLARIZED XE-129 NMR; SPATIALLY-RESOLVED MEASUREMENTS; SUPERCRITICAL CARBON-DIOXIDE; OPTICALLY PUMPED XENON; HIGH-RESOLUTION NMR; SOLID-STATE NMR; LUNG AIR SPACES; IN-VIVO; HE-3 GAS; CROSS-POLARIZATION AB The sensitivity of conventional nuclear magnetic resonance (NMR) techniques is fundamentally limited by the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This review describes the principles and magnetic resonance applications of laser-polarized noble gases. The enormous sensitivity enhancement afforded by optical pumping can be exploited to permit a variety of novel NMR experiments across numerous disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, NMR sensitivity enhancement via polarization transfer, and low-field NMR and MRI. (C) 2002 Elsevier Science (USA). C1 Univ Calif Berkeley, Div Mat Sci, Lawrence Berkley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, AA Noyes Lab, Berkeley, CA 94720 USA. RP CALTECH, NSF Lab Mol Sci, Pasadena, CA 91125 USA. OI Goodson, Boyd/0000-0001-6079-5077 NR 327 TC 250 Z9 252 U1 10 U2 72 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 EI 1096-0856 J9 J MAGN RESON JI J. Magn. Reson. PD APR PY 2002 VL 155 IS 2 BP 157 EP 216 DI 10.1006/jmre.2001.2341 PG 60 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 560GE UT WOS:000176073700001 PM 12036331 ER PT J AU Shield, JE Kappes, BB Branagan, DJ Bentley, J AF Shield, JE Kappes, BB Branagan, DJ Bentley, J TI Chemical partitioning during crystallization and its effect on the microstructure and magnetic behavior of modified Nd-Fe-B permanent magnets SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE permanent magnets; microstructural evolution; alloying; exchange interactions; segregation ID PHASE-FORMATION; SM-FE; REVERSIBLE MAGNETIZATION; THIN-FILMS; ALLOYS; NDFEB; SEGREGATION; ND2FE14B; TI AB In this paper, the effect of alloy composition on the microstructural development of devitrified Nd-Fe-B-based alloys is investigated. While crystallization of simple ternary Nd2Fe14B resulted in a highly variable microstructure and relatively poor demagnetization behavior, alloying additions, notably Ti and C, were found to significantly refine and homogenize the crystallized microstructure. High spatial resolution energy dispersive X-ray spectroscopy revealed that partitioning to the grain boundaries led to the grain refinement by slowing interface kinetics. The more homogeneous grain structure resulted in improved demagnetization behavior, but segregating elements isolated grains and limited intergranular exchange coupling. (C) 2002 Published by Elsevier Science B.V. C1 Univ Nebraska, Dept Mech Engn, Lincoln, NE 68588 USA. Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Shield, JE (reprint author), Univ Nebraska, Dept Mech Engn, Lincoln, NE 68588 USA. NR 19 TC 10 Z9 10 U1 1 U2 5 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 APR PY 2002 VL 246 IS 1-2 BP 73 EP 79 AR PII S0304-8853(02)00028-8 DI 10.1016/S0304-8853(02)00028-8 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 561QQ UT WOS:000176154000012 ER PT J AU Gornakov, VS Nikitenko, VI Shapiro, AJ Shull, RD Jiang, JS Bader, SD AF Gornakov, VS Nikitenko, VI Shapiro, AJ Shull, RD Jiang, JS Bader, SD TI Direct experimental study of the exchange spring formation process SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE ferromagnetism; exchange spring; domain walls ID MAGNETIC-STRUCTURES; MAGNETORESISTANCE; BILAYERS; ASYMMETRY; BIAS AB The remagnetization of a soft ferromagnetic film exchange coupled with a high-coercivity ferromagnetic film is studied by a magneto-optic imaging technique. If the magnetic field is antiparallel to the macroscopic unidirectional inplane anisotropy, the soft layer reverses via the formation of exchange springs consisting of subdomains with opposite spin twistings. However, if the field is instead rotated in-plane, remagnetization initially proceeds via formation of a single uniform exchange spring. Then, at a critical angle, the spring incoherently untwists, leading again to subdomains with opposite chirality. These phenomena are attributed to the influence of inhomogeneity in the unidirectional magnetic anisotropy. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NIST, Gaithersburg, MD 20899 USA. Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Russia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Shull, RD (reprint author), NIST, 100 Bur Dr,Stop 8525, Gaithersburg, MD 20899 USA. RI Bader, Samuel/A-2995-2013; Shull, Robert/F-5971-2013 NR 20 TC 20 Z9 20 U1 0 U2 6 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 APR PY 2002 VL 246 IS 1-2 BP 80 EP 85 AR PII S0304-8853(02)00029-X DI 10.1016/S0304-8853(02)00029-X PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 561QQ UT WOS:000176154000013 ER PT J AU Chambers, SA Farrow, RFC Maat, S Toney, MF Folks, L Catalano, JG Trainor, TP Brown, GE AF Chambers, SA Farrow, RFC Maat, S Toney, MF Folks, L Catalano, JG Trainor, TP Brown, GE TI Molecular beam epitaxial growth and properties of CoFe2O4 on MgO(001) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE cobalt ferrite; molecular beam epitaxy; magnetic and structural properties ID FERRITE THIN-FILMS; RAY-ABSORPTION-SPECTRA; MAGNETIC-PROPERTIES; FE3O4 FILMS; BEHAVIOR; GAMMA-FE2O3; ANISOTROPY; BILAYERS AB We have grown single-crystal Co ferrite (CoFe2O4) on MgO(001) by oxygen-plasma-assisted molecular beam epitaxy (OPA-MBE), and have characterized the composition, structure, surface morphology, and magnetic properties by a number of methods. The as-grown OPA-MBE material forms a perfect inverse spinel, in which all Co is in the 2+ formal oxidation state, and occupies octahedral sites within the cation sublattice. The OPA-MBE film surfaces are very flat, with mean roughnesses of only a few Angstrom, and exhibit large, stable magnetic domains. The measured moment per unit volume is 250 emu/cm(3), and the saturation magnetization for films in the 1000Angstrom film thickness range is similar to60% of that of bulk Co ferrite. The material also exhibits strain-dependent magnetic anisotropy that can be understood by considering the various contributions to the total magnetic energy. The overall quality of epitaxial Co ferrite grown on MgO by OPA-MBE is superior in every respect to that obtained using pulsed laser deposition as the growth method. (C) 2002 Published by Elsevier Science B.V. C1 Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. IBM Corp, Almaden Res Ctr, San Jose, CA USA. Stanford Univ, Dept Environm & Geol Sci, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Chambers, SA (reprint author), Pacific NW Natl Lab, Fundamental Sci Div, Mail Stop K2-12,POB 999,Batelle Blvd, Richland, WA 99352 USA. RI Catalano, Jeffrey/A-8322-2013; Folks, Liesl/C-7611-2016 OI Catalano, Jeffrey/0000-0001-9311-977X; Folks, Liesl/0000-0003-0161-957X NR 29 TC 90 Z9 90 U1 9 U2 58 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 APR PY 2002 VL 246 IS 1-2 BP 124 EP 139 AR PII S0304-8853(02)00039-2 DI 10.1016/S0304-8853(02)00039-2 PG 16 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 561QQ UT WOS:000176154000019 ER PT J AU Yu, MH Zhao, T Zhang, ZD AF Yu, MH Zhao, T Zhang, ZD TI Second-order spin reorientation reform in the two-sublattice ferrimagnetic system SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE mean-field model; two-sublattice systems; ferrimagnetism spin reorientation transitions second-order transition; ferrimagnetism ID 2-SUBLATTICE AB Temperature dependence of the spontaneous magnetization and its derivatives reveal the existence of second-order spin reorientation reform (SOSRR) in the two-sublattice ferrimagnetic system. The variation of the competition between two sublattice moments and that between two sublattice anisotropies gives rise to eight types of temperature dependences of the spontaneous magnetization. An example of the phase diagram for the conditions for different types of thermal curves was delineated by means of numerical calculation. Phase diagrams related to SOSRR transitions were depicted by analyzing the exchange-anisotropy flow in the exchange-anisotropy space. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci & Int Ctr Mat Phys, Shenyang 110016, Peoples R China. Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. RP Yu, MH (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Bldg 480, Upton, NY 11973 USA. RI Zhang, Zhidong/G-6049-2011 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 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD APR PY 2002 VL 246 IS 1-2 BP 310 EP 316 AR PII S0304-8853(02)00099-9 DI 10.1016/S0304-8853(02)00099-9 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 561QQ UT WOS:000176154000044 ER PT J AU Lander, GH AF Lander, GH TI Magnetic scattering with synchrotrons: new developments SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Joint European Magnetic Symposia (JEMS 01) CY AUG 28-SEP 01, 2001 CL GRENOBLE, FRANCE SP CNRS, CEA, MENRT, DGA, Inst Natl Polytechn Grenoble, Univ Joseph Fourier, Soc Francaise Phys, European Phys Soc, IEEE Magnet Soc, Mairie Grenoble, Grenoble Alpes Metropole, Reg Rhone Alpes, Conseil Gen Isere DE synchrotron radiation; magnetic structure; scattering theory ID X-RAY-SCATTERING; RESONANCE EXCHANGE SCATTERING; RARE-EARTH COMPOUNDS; ABSORPTION-SPECTRA; POLARIZATION DEPENDENCE; DIFFRACTION; ORDER; SURFACE; SPIN; DICHROISM AB The magnetic scattering of X-rays was first performed 30 years ago and was considered a curiosity. Huge increases in the available photon flux have made these experiments possible, although still by no means routine. However, what has made the technique popular has been the discovery of resonant effects when the photon energy is tuned near the absorption edges. Experiments at the K, L, and M edges will be referenced and some new possibilities mentioned. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Lander, GH (reprint author), Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, Postfach 2340, D-76125 Karlsruhe, Germany. NR 59 TC 5 Z9 5 U1 1 U2 5 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 APR PY 2002 VL 242 BP 3 EP 8 AR PII S0304-8853(01)01175-1 DI 10.1016/S0304-8853(01)01175-1 PN 1 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 567WU UT WOS:000176509600003 ER PT J AU Jiles, DC AF Jiles, DC TI Hysteresis models: non-linear magnetism on length scales from the atomistic to the macroscopic SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Joint European Magnetic Symposia (JEMS 01) CY AUG 28-SEP 01, 2001 CL GRENOBLE, FRANCE SP CNRS, CEA, MENRT, DGA, Inst Natl Polytechn Grenoble, Univ Joseph Fourier, Soc Francaise Phys, European Phys Soc, IEEE Magnet Soc, Mairie Grenoble, Grenoble Alpes Metropole, Reg Rhone Alpes, Conseil Gen Isere DE hysteresis ID FERROMAGNETIC MATERIALS; MAGNETIZATION; DYNAMICS; EQUATION; MOTION; LOOP AB When materials are exposed to high levels of external magnetic field, the response of materials eventually extends beyond the simple linear regime. Under these conditions it is found that the change in response of the materials is no longer reversible. These phenomena are well documented in the experimental literature. However, the theoretical non-linear description of the response of materials is only at a very early stage of development compared to with the low amplitude linear/reversible model theories. High performance computing is enabling researchers to model magnetic devices at smaller and smaller length scales, while at the same time accurate first principles calculations of magnetic properties now extend to systems involving thousands of atoms. The two different approaches, continuum versus discrete, are approaching each other at the mesoscopic length scales. The lecture will discuss some of the model theories that have been developed to describe the properties of magnetic materials. Beginning with first principles theories, the lecture will then trace the development of model theories at increasing length scales through micromagnetics, macroscopic Preisach, domain rotational models and phenomenological models of domain wall motion such as the stochastic process model. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. RP Jiles, DC (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RI Jiles, David/H-9548-2012 NR 43 TC 17 Z9 18 U1 1 U2 7 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 APR PY 2002 VL 242 BP 116 EP 124 AR PII S0304-8853(01)01213-6 DI 10.1016/S0304-8853(01)01213-6 PN 1 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 567WU UT WOS:000176509600021 ER PT J AU Frontera, C Garcia-Munoz, JL Llobet, A Aranda, MAG Rodriguez-Carvajal, J Respaud, M Broto, JM Raquet, B Rakoto, H Goiran, M AF Frontera, C Garcia-Munoz, JL Llobet, A Aranda, MAG Rodriguez-Carvajal, J Respaud, M Broto, JM Raquet, B Rakoto, H Goiran, M TI Spin state transition: the origin of structural, magnetic and metal-insulator transitions in GdBaCo2O5+delta (delta approximate to 0.5) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT Joint European Magnetic Symposia (JEMS 01) CY AUG 28-SEP 01, 2001 CL GRENOBLE, FRANCE SP CNRS, CEA, MENRT, DGA, Inst Natl Polytechn Grenoble, Univ Joseph Fourier, Soc Francaise Phys, European Phys Soc, IEEE Magnet Soc, Mairie Grenoble, Grenoble Alpes Metropole, Reg Rhone Alpes, Conseil Gen Isere DE correlated electron system; phase transitions-metal-insulator; perovskite structure ID PEROVSKITE; MAGNETORESISTANCE; GD AB The metal-insulator transition in GdBaCo2O5.5 at T-MI approximate to 360 K has been investigated by synchrotron X-ray powder diffraction and magnetic measurements, We have found that, at T-MI remarkable structural distortions and magnetic changes take place. These changes evidence a spin state transition of Co ions at this temperature that is the origin of the metal-insulator transition. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CSIC, Inst Ciencia Mat Barcelona, E-08193 Bellaterra, Spain. Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. Univ Malaga, Dept Quim Inorgan Cristalog & Mineral, E-29071 Malaga, Spain. CEA, CNRS, Lab Leon Brillouin, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. SNCMP, F-31077 Toulouse, France. LPMC, INSA, Complexe Sci Rangueil, F-31077 Toulouse, France. RP Frontera, C (reprint author), CEA, MDN, SPSMS, DRFMC, Grenoble, France. RI Rodriguez-Carvajal, Juan/C-4362-2008; Aranda, Miguel A.G./D-4614-2009; Frontera, Carlos/B-4910-2008; Llobet, Anna/B-1672-2010; Lujan Center, LANL/G-4896-2012; Garcia-Munoz, Jose Luis /A-7983-2015 OI Rodriguez-Carvajal, Juan/0000-0001-5582-2632; Aranda, Miguel A.G./0000-0001-7708-3578; Frontera, Carlos/0000-0002-0091-4756; Garcia-Munoz, Jose Luis /0000-0002-4174-2794 NR 17 TC 12 Z9 12 U1 0 U2 3 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 APR PY 2002 VL 242 BP 751 EP 753 AR PII S0304-8853(01)01018-6 DI 10.1016/S0304-8853(01)01018-6 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 574BQ UT WOS:000176868900035 ER PT J AU Boyle, TJ Clem, PG Tuttle, BA Brennecka, GL Dawley, JT Rodriguez, MA Dunbar, TD Hammetter, WF AF Boyle, TJ Clem, PG Tuttle, BA Brennecka, GL Dawley, JT Rodriguez, MA Dunbar, TD Hammetter, WF TI Lanthanide series doping effects in lead zirconate titanate (PLnZT) thin films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID RARE-EARTH IONS; FERROELECTRIC-FILMS; CERAMICS; EVOLUTION; BATIO3; SITE; SPECTRA; SYSTEMS; ND3+; EPR AB Lanthanide (Ln) doping of lead zirconate titanate (PLnZT 4/30/70) thin films was conducted to investigate effects on structural and electrical properties. Films were spin-coat deposited from precursor solutions made using a previously reported "basic route to PZT" chemistry. The remanent polarization (P-r), dielectric constant (is an element of), dielectric loss (tan 8), and lattice parameter values were obtained for each of the doped PLnZT films. Films doped with amphoteric cations (Tb, Dy, Y, and Ho) displayed high P, values, square hysteresis loops, and enhanced fatigue resistance. Smaller radius Ln-doped films display an increased tendency toward (100) orientation in otherwise (111)-oriented films. C1 Adv Mat Lab, Sandia Natl Labs, Albuquerque, NM 87105 USA. Sandia Natl Labs, Integrated Mats Res Lab, Albuquerque, NM 87185 USA. Univ Missouri, Ceram Engn Dept, Rolla, MO 65409 USA. RP Boyle, TJ (reprint author), Adv Mat Lab, Sandia Natl Labs, MS 1349 1001 Univ Blvd SE, Albuquerque, NM 87105 USA. RI Brennecka, Geoff/J-9367-2012 OI Brennecka, Geoff/0000-0002-4476-7655 NR 36 TC 23 Z9 23 U1 2 U2 10 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD APR PY 2002 VL 17 IS 4 BP 871 EP 878 DI 10.1557/JMR.2002.0126 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 538FZ UT WOS:000174805700024 ER PT J AU Gibbons, BJ Eom, CB Rao, RA Trolier-McKinstry, S Schlom, DG AF Gibbons, BJ Eom, CB Rao, RA Trolier-McKinstry, S Schlom, DG TI Oxidation of c-axis-oriented epitaxial YBa2Cu3O7-delta thin films in ozone-containing atmospheres SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID OXYGEN SELF-DIFFUSION; SPECTROSCOPIC ELLIPSOMETRY; CHEMICAL DIFFUSION; TRACER DIFFUSION; INSITU; OXIDES; YBA2CU3O6+X; TEMPERATURE; TRANSPORT; Y1BA2CU3O7-X AB Oxygen diffusion into c-axis-oriented YBa2Cu3O7-delta epitaxial thin films was observed using real-time spectroscopic ellipsometry. The experiments were conducted under controlled atmospheres of 10% O-3/90% O-2 and 80% O-3/20% O-2. At 2 x 10(-5) torr, oxidation of the films began at temperatures as low as 100-125 degreesC for heating rates less than or equal to3 degreesC/min. Full oxidation was seen by 190 degreesC at these rates. Based on these data, the activation energy of oxygen diffusion into YBa2Cu3O7-delta from an ozone/oxygen atmosphere was found to be between 0.43 and 0.52 eV. This was appreciably smaller than for in-diffusion in a molecular oxygen atmosphere. Higher ozone content atmospheres did not improve the oxidation kinetics. These atmospheres did, however, delay the onset of reduction in the films by 60-70 degreesC at higher temperatures. C1 Los Alamos Natl Lab, Supercond Technol Ctr, Los Alamos, NM 87545 USA. Univ Wisconsin, Madison, WI 53706 USA. Penn State Univ, University Pk, PA 16802 USA. RP Los Alamos Natl Lab, Supercond Technol Ctr, POB 1663, Los Alamos, NM 87545 USA. EM gibbons@lanl.gov RI Schlom, Darrell/J-2412-2013; Eom, Chang-Beom/I-5567-2014 OI Schlom, Darrell/0000-0003-2493-6113; NR 45 TC 0 Z9 0 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD APR PY 2002 VL 17 IS 4 BP 884 EP 889 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 538FZ UT WOS:000174805700026 ER PT J AU Jagannadham, K Watkins, TR Dinwiddie, RB AF Jagannadham, K Watkins, TR Dinwiddie, RB TI Novel heat spreader coatings for high power electronic devices SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THERMAL MANAGEMENT; DIAMOND; IMPROVEMENT; COMPOSITES AB A new set of heat spreader coatings consisting of multilayers of diamond/AlN/diamond were deposited on high heat capacity substrates of molybdenum and silicon nitride. Bonding of the heat spreaders to the device wafers using gold-tin eutectic solder was carried out after metallization layers of titanium, gold and copper were deposited on diamond. Prior to bonding, backside of the silicon wafers was also metallized with titanium, gold and copper and the gallium arsenide wafers with titanium, copper-germanium alloy and gold. Characterization of the multilayer diamond films was carried out by Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The bonded wafers were tested for adhesion strength, resistance against peeling due to thermal cycling and failure under stress. Further, the bonded regions were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray mapping of different elements. The heat spreader characteristics of the single layer diamond and the multilayer diamond substrates were tested by infrared imaging. The results illustrate that the multilayer diamond heat spreader coatings provide better heat dissipation and also possess better adhesion strength and resistance against peeling under thermal cycling. These novel multilayer diamond/AlN/diamond heat spreaders are expected to considerably improve the life of high frequency power devices. (C) 2002 Kluwer Academic Publishers. C1 N Carolina State Univ, Raleigh, NC 27695 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Jagannadham, K (reprint author), N Carolina State Univ, Raleigh, NC 27695 USA. RI Jagannadham, Kasichainula/A-2953-2008; Watkins, Thomas/D-8750-2016 OI Watkins, Thomas/0000-0002-2646-1329 NR 21 TC 13 Z9 13 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 1 PY 2002 VL 37 IS 7 BP 1363 EP 1376 DI 10.1023/A:1014568512077 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 530MA UT WOS:000174360400012 ER PT J AU Chaudhuri, J George, JT Kolske, DD Wickenden, AE Henry, RL Rek, Z AF Chaudhuri, J George, JT Kolske, DD Wickenden, AE Henry, RL Rek, Z TI Reduction of dislocation density in GaN films on sapphire using AlN interlayers SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID GROWTH AB GaN (00.1) thin films, of thickness 1.25 to 2.25 mum grown on sapphire substrate (11.0) by metallo organic chemical vapor phase deposition (MOCVD) with different number of AlN interlayers, were characterized by triple crystal diffractometry and synchrotron white beam x-ray topography (SWBXT). The full width at half maximum (FWHM) of x-ray rocking curves from symmetric and asymmetric reflections was used to estimate the dislocation density in GaN films. It has been found that the edge dislocation density decreased from 1.63 x 10(10) cm(-2) to 1.23 x 10(10) cm(-2) and the screw dislocation density decreased from 2.0 x 10(8) cm(-2) to 1.1 x 10(8) cm(-2) when one AlN interlayer was inserted between the high temperature GaN layer. The dislocation density decreased further with the increase in number of interlayers. On the other hand the compressive stress in the GaN film increased from -0.29 GPa to -0.86 GPa. The compressive stress further increased as the number of interlayers increased but no cracking in the GaN film was observed. This could be due to better adhesion between the film and substrate due to interlayers. SWBXT in transmission from a GaN(00.1)/Al2O3(11.0) sample confirms the orientation of GaN and indicates that it is a single crystal with high dislocation density. SWBXT from the Al2O3 substrate shows cellular structure of dislocations. (C) 2002 Kluwer Academic Publishers. C1 Wichita State Univ, Dept Engn Mech, Wichita, KS 67260 USA. USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Chaudhuri, J (reprint author), Wichita State Univ, Dept Engn Mech, Wichita, KS 67260 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 13 TC 4 Z9 4 U1 0 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD APR 1 PY 2002 VL 37 IS 7 BP 1449 EP 1453 DI 10.1023/A:1014557604325 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 530MA UT WOS:000174360400023 ER PT J AU Kobayashi, K Hall, GE Muckerman, JT Sears, TJ Merer, AJ AF Kobayashi, K Hall, GE Muckerman, JT Sears, TJ Merer, AJ TI The E (3)Pi-X (3)Delta transition of jet-cooled TiO observed in absorption SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE titanium oxide; electronic absorption spectroscopy; laser spectroscopy ID FOURIER-TRANSFORM SPECTROSCOPY; ROTATIONAL ANALYSIS; TITANIUM MONOXIDE; ELECTRONIC STATES; DOUBLING PARAMETERS; 0,0 BAND; MOLECULES; VO; RESOLUTION; ENERGIES AB The (0,0) and (1,0) bands of the E(3)Pi-X (3)Delta transition of TiO in the near-infrared have been recorded by frequency modulated laser absorption spectroscopy in a laser ablation/free jet expansion source. The observed linewidths (FWHM) varied from 300 to 500 MHz according to the expansion conditions and are dominated by residual Doppler broadening in the unskimmed source. Data for the (0,0) band have been obtained for TiO molecules containing all the naturally occurring Ti isotopes but, for the weaker (1,0) band, only for (TiO)-Ti-48. Rotational constants for the two upper state vibrational levels were derived by fitting the data to an effective Hamiltonian; equilibrium parameters have been calculated. The experimental results are compared to the results of ab initio calculations on the E-X system. Ab initio results for the b-a system and for the lowest (3)Sigma(-) state are also presented. They indicate that the D (3)Sigma(-) state is not a very low-lying state. (C) 2002 Elsevier Science (USA). C1 Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada. RP Merer, AJ (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Muckerman, James/D-8752-2013; Sears, Trevor/B-5990-2013; Hall, Gregory/D-4883-2013; OI Sears, Trevor/0000-0002-5559-0154; Hall, Gregory/0000-0002-8534-9783; Kobayashi, Kaori/0000-0002-4163-9498 NR 43 TC 13 Z9 15 U1 0 U2 6 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 2002 VL 212 IS 2 BP 133 EP 141 DI 10.1006/jmsp.2002.8543 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 561KZ UT WOS:000176140900001 ER PT J AU Dong, JH Hu, MZ Payzant, EA Armstrong, TR Becher, PF AF Dong, JH Hu, MZ Payzant, EA Armstrong, TR Becher, PF TI Grain growth in nanocrystalline yttrium-stabilized zirconia thin films synthesized by spin coating of polymeric precursors SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE nanocrystalline film; grain growth; YSZ thin film; solid electrolyte; fuel cells; sol-gel coating ID OXIDE FUEL-CELL; Y-TZP CERAMICS; ELECTRICAL-CONDUCTIVITY; TETRAGONAL ZIRCONIA; PHASE; TEMPERATURE; BEHAVIOR; CERIA AB This article reports results of experimental studies on the microstructural evolution of nanocrystalline yttrium-stabilized zirconia thin films synthesized on a Si substrate via a polymeric precursor spin-coating approach. Grain growth behavior has been investigated at different annealing temperatures (700-1200 degreesC) for periods of up to 240 h. A similar film thickness (similar to120 nm) was maintained for all of the samples used in this study, to avoid variation in film thickness-dependent grain growth. The effects of the thermal history of the film and the annealing atmosphere on the grain growth were also studied. A simple semiempirical grain growth model has been developed to describe isothermal annealing data and to predict dynamic grain growth behavior during the sintering of polymeric precursor layers to form cubic-phase nanocrystalline yttrium-stabilized zirconia films. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hu, MZ (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RI Payzant, Edward/B-5449-2009; OI Payzant, Edward/0000-0002-3447-2060; Hu, Michael/0000-0001-8461-9684 NR 30 TC 15 Z9 15 U1 1 U2 8 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 APR PY 2002 VL 2 IS 2 BP 161 EP 169 DI 10.1166/jnn.2002.082 PG 9 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 559MC UT WOS:000176029100010 PM 12908304 ER PT J AU Pozhar, LA Kontar, EP Hu, MZC AF Pozhar, LA Kontar, EP Hu, MZC TI Transport properties of nanosystems: Viscosity of nanofluids confined in slit nanopores SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE nanofluids; nanosystems; interfacial fluids; nanopores; transport phenomena; viscosity; transport theory; molecular dynamic simulations ID STRONGLY INHOMOGENEOUS FLUIDS; THIN LIQUID-FILMS; MOLECULAR-DYNAMICS; SELF-DIFFUSION; DENSE; FLOW; MICROPORES; MIXTURES; PORE; MICROCAPILLARIES AB A fundamental nonequilibrium statistical mechanical approach due to Pozhar and Gubbins (PG) is used to study the Poiseuille flow and momentum transport in 20 model nanofluids confined in slit pores several molecular diameters in width. A simplified version of a general expression for the PG theoretical viscosity is applied to calculate the localized viscosity of the nanofluids in terms of the equilibrium structure factors (density and correlation functions) of nanosystems. These structure factors are calculated by means of the equilibrium molecular dynamics simulations. The localized theoretical viscosity so obtained is used further to calculate the theoretical pore-average viscosity of the nanosystems, and the latter is successfully compared with that extracted from nonequilibrium molecular dynamics simulation data. A simple correlation between the pore-average velocity, viscosity, nanofluid density, and the pore width for nanosystems of moderate density has been developed and recommended for applications in engineering. C1 Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. Univ Surrey, Dept Chem & Proc Engn, Guildford GU2 5XH, Surrey, England. Kharkov AM Gorkii State Univ, UA-310108 Kharkov, Ukraine. RP Pozhar, LA (reprint author), Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. RI Kontar, Eduard/B-7897-2008; OI Kontar, Eduard/0000-0002-8078-0902; Hu, Michael/0000-0001-8461-9684 NR 48 TC 17 Z9 17 U1 0 U2 13 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD APR PY 2002 VL 2 IS 2 BP 209 EP 227 DI 10.1166/jnn.2002.088 PG 19 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 559MC UT WOS:000176029100017 PM 12908311 ER PT J AU Mathew, X Bansal, A Turner, JA Dhere, R Mathews, NR Sebastian, PJ AF Mathew, X Bansal, A Turner, JA Dhere, R Mathews, NR Sebastian, PJ TI Photoelectrochemical characterization of surface modified CdTe for hydrogen production SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE CdTe; close spaced sublimation; PEC; water splitting; hydrogen production; flat band potential ID ELECTROLYTE INTERFACE; SOLAR-CELL AB photo electrochemical measurements of a p-CdTe/water PEC system are reported. The CdTe was prepared by close spaced sublimation on flexible metallic substrates. The p-CdTe is more stable in solutions with pH in the range of 7 to 10. Under one sun illumination the hydrogen evolution potential of the p-CdTe/electrolyte system shift significantly. The V(fb) has a linear dependence on the pH of the solution. The hydrogen evolution onset potential is lower in solutions having low pH. It was observed that the open circuit potentials tinder dark and light has a different dependence on the pH of the solution. The modification of the p-CdTe surface with Ru improves both the hydrogen evolution efficiency and the stability of the photocathode. C1 Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. NREL, Golden, CO 80401 USA. RP Mathew, X (reprint author), Univ Nacl Autonoma Mexico, Ctr Invest Energia, Temixco 62580, Morelos, Mexico. EM xm@mazatl.cie.unam.mx NR 14 TC 10 Z9 10 U1 2 U2 22 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 APR PY 2002 VL 5 IS 2 BP 149 EP 154 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 558RT UT WOS:000175980900011 ER PT J AU Mahan, AH Xu, Y Iwaniczko, E Williamson, DL Nelson, BP Wang, Q AF Mahan, AH Xu, Y Iwaniczko, E Williamson, DL Nelson, BP Wang, Q TI Amorphous silicon films and solar cells deposited by HWCVD at ultra-high deposition rates SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphis and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID CHEMICAL-VAPOR-DEPOSITION; A-SI-H; MICROCRYSTALLINE SILICON; HYDROGEN; MICROVOIDS AB The deposition conditions for hydrogenated amorphous silicon. deposited by hot wire chemical vapor deposition, are linked to the film structure as we increase deposition rates (R-d) to >100 Angstrom/s. At low R-d (<20 Angstrom/s). films with optimal properties are deposited under low silane depletion conditions. and all measures of structure (X-ray diffraction. Raman spectroscopy. H evolution. small-angle X-ray scattering (SAXS)) indicate a compact material. At high R-d (>100 Angstrom/s). optimum films are deposited under silane depletion conditions as high as 75-80%. and all structural properties except for the SAXS results once again indicate a compact material, We relate changes in the film electronic structure (Urbach edge) with increasing R-d to the increase in the SAXS signals. and note the invariance of the saturated defect density versus R-d, discussing reasons why these microvoids do not play a role in the Staebler-Wronski effect for these films. Finally, we present device results over the whole range of R-d that we have studied and suggest why. at high R-d, device quality films can be deposited at such high silane depletions. (C) 2002 Published by Elsevier Science B.V. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Colorado Sch Mines, Dept Phys, Golden, CO 80401 USA. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 23 TC 20 Z9 20 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 APR 1 PY 2002 VL 299 BP 2 EP 8 AR PII S0022-3093(02)00927-4 DI 10.1016/S0022-3093(02)00927-4 PN A PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VG UT WOS:000175757400003 ER PT J AU Branz, HM Reedy, R Crandall, RS Mahan, H Xu, YQ Nelson, BP AF Branz, HM Reedy, R Crandall, RS Mahan, H Xu, YQ Nelson, BP TI Fermi-level dependence of the charge state of diffusing hydrogen in amorphous silicon SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphis and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID SOLAR-CELLS; CRYSTALLINE SILICON; A-SI; BOND; PHOSPHORUS; TRANSPORT; MECHANISM; ENERGY AB We observe that the charge state of diffusing hydrogen depends upon the electronic Fermi level (Er) in hydrogenated amorphous silicon (a-Si:H). We incorporate a thin layer of deuterium (H-2) at various positions between the n- and p-layers of i-n-i-p-i structures on crystalline silicon substrates. The electric field (T) is above 6 x 10(4) V/cm at each H-2 layer. After annealing, marked asymmetries in the secondary ion mass spectrometry profiles of diffused deuterium are observed. With the H-2 layer placed near the p-layer (E-f near the valence band), diffusion is into the p-layer. indicating H+ moving with F. With the H-2 layer near the n-layer (E-f near the conduction band), most diffusion is into the n-layer, indicating H- moving against F. Because the Si-H bond is neutral, the charged diffusing species must be emitted mobile H. We estimate an effective correlation energy of 0.4 +/- 0.1 eV for the mobile H. (C) 2002 Published by Elsevier Science B. V. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Branz, HM (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 21 TC 11 Z9 11 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 APR 1 PY 2002 VL 299 BP 191 EP 195 AR PII S0022-3093(01)01161-9 DI 10.1016/S0022-3093(01)01161-9 PN A PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VG UT WOS:000175757400039 ER PT J AU Ishii, H Brennan, S Bienenstock, A AF Ishii, H Brennan, S Bienenstock, A TI Towards the chemically specific structure of amorphous materials: anomalous X-ray scattering from a molybdenum-germanium alloy SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphis and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID PHASE-SEPARATION; DISPERSION; FILMS AB Anomalous X-ray scattering (AXS) has been used to obtain Mo-Ge, Mo-Mo and Ge-Ge partial pair distribution functions (PPDFs) from amorphous MoGe3 which has no crystalline analog. Experimental removal of inelastic scattering over much of the scattering range has yielded considerably improved PPDFs motivating still further optimization of the experimental system. The PPDFs indicate that on average Mo is surrounded by eight Ge atoms as in crystalline beta-MoGe2. The PPDFs do not indicate phase separation, Other aspects of the structure are discussed. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Bienenstock, A (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. NR 13 TC 3 Z9 3 U1 1 U2 4 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 APR 1 PY 2002 VL 299 BP 243 EP 248 AR PII S0022-3093(01)01164-4 DI 10.1016/S0022-3093(01)01164-4 PN A PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VG UT WOS:000175757400049 ER PT J AU Biswas, R Pan, BC AF Biswas, R Pan, BC TI Defect kinetics in new model of metastability in a-Si : H SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphis and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID HYDROGENATED AMORPHOUS-SILICON; COLLISION MODEL AB We recently developed a new atomistic model of metastability of amorphous hydrogen silicon (a-Si:H). involving changes in silicon and H bonding. and driven by the breaking of weak silicon bonds. The kinetics of degradation in this model are simulated with coupled rate equations which show saturation behavior similar to experiment. Dangling bond (DB) defects follow the well-known G(2/3)t(1) (3) kinetics of defect creation. Saturated defect densities of neutral DBs are accompanied by a much smaller density of floating bonds (FBs). (C) 2002 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Phys & Astron, Ctr Microelect Res, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames Lab, USDOE, Ames, IA 50011 USA. Univ Sci & Technol China, Dept Phys, Anhua 230026, Peoples R China. RP Biswas, R (reprint author), Iowa State Univ, Dept Phys & Astron, Ctr Microelect Res, Ames, IA 50011 USA. RI Pan, Bicai/A-1235-2010 NR 9 TC 3 Z9 5 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 APR 1 PY 2002 VL 299 BP 507 EP 510 AR PII S0022-3093(01)00961-9 DI 10.1016/S0022-3093(01)00961-9 PN A PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VG UT WOS:000175757400101 ER PT J AU Desnica, UV Desnica-Frankovic, ID Gamulin, O White, CW Sonder, E Zuhr, RA AF Desnica, UV Desnica-Frankovic, ID Gamulin, O White, CW Sonder, E Zuhr, RA TI Formation of CdS nanocrystals in SiO2 by ion implantation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphous and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID ELECTRON; SIZE AB We present a systematic study of the influence of ion dose and post-implantation annealing on the synthesis and growth of CdS nanocrystals in a SiO2 matrix. Nanocrystals were obtained after implantation of monoenergetic Cd and S ions and subsequent annealing in a very wide range of annealing temperatures. T,. The average size, as deter-mined from the blue shift of band gap E-g, varied from 3.5-4.5 to 10 nm, depending on implantation and annealing parameters. For the highest dose. 10(17) ions/cm(2), the synthesis of CdS phase starts already during implantation. For T, above 700 degreesC, large nanocrystals (9-10 nm) prevail for all doses. High energy optical transitions. identified as the E-1A and E-1B transitions of hexagonal CdS, were also observed after annealings at higher temperature. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Rudjer Boskovic Inst, Dept Phys, HR-10000 Zagreb, Croatia. Univ Zagreb, Sch Med, HR-10000 Zagreb, Croatia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Desnica, UV (reprint author), Rudjer Boskovic Inst, Dept Phys, Bijenicka 54, HR-10000 Zagreb, Croatia. EM desnica@rudjer.irb.hr OI Gamulin, Ozren/0000-0001-6046-9773 NR 11 TC 9 Z9 9 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 APR 1 PY 2002 VL 299 BP 1100 EP 1104 AR PII S0022-3093(02)00941-9 DI 10.1016/S0022-3093(02)00941-9 PN B PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VJ UT WOS:000175757600074 ER PT J AU Fortmann, CM Mahan, AH Hata, N AF Fortmann, CM Mahan, AH Hata, N TI Advances in amorphous silicon-based photonic technology SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 19th International Conference on Amorphis and Microcrystalline Semiconductors (ICAMS 19) CY AUG 27-31, 2001 CL OLD NICE, FRANCE ID POLARIZED ELECTROABSORPTION; PROSPECTS AB Significant advances have occurred in amorphous silicon-based photonic engineering. Previously we showed that amorphous silicon was an ideal matrix for photonic engineering because of the case by which the refractive index can be controlled through in situ or ex situ hydrogen content manipulation. Concurrently we have been investigating the optical properties changes associated with the light-induced degradation of amorphous silicon materials. These investigations have identified a wide range of light-induced effects with far reaching prospects for photonic engineering. These changes include a slow light-induced reversible change related to structural change and a fast reversible light-induced changes thought to be related to electron-photon-phonon interaction. Significant to many potential applications light-induced changes in optical properties do not significantly decrease with increasing measurement temperature (up to the similar to200 degreesC probed by this work). (C) 2002 Published by Elsevier Science B.V. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. AIST Cent 2, Natl Inst Adv Ind Sci & Technol, Adv Semicond Res Ctr, Tsukuba, Ibaraki 3058568, Japan. RP Fortmann, CM (reprint author), SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. RI Hata, Nobuhiro/F-9579-2014 OI Hata, Nobuhiro/0000-0002-8132-0895 NR 15 TC 1 Z9 1 U1 1 U2 4 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 APR 1 PY 2002 VL 299 BP 1267 EP 1271 AR PII S0033-3093(01)01148-6 DI 10.1016/S0022-3093(01)01148-6 PN B PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 554VJ UT WOS:000175757600106 ER PT J AU Busby, JT Was, GS Kenik, EA AF Busby, JT Was, GS Kenik, EA TI Isolating the effect of radiation-induced segregation in irradiation-assisted stress corrosion cracking of austenitic stainless steels SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID GRAIN-BOUNDARY SEGREGATION AB Post-irradiation annealing was used to help identify the role of radiation-induced segregation (RIS) in irradiation-assisted stress corrosion cracking (IASCC) by preferentially removing dislocation loop damage from proton-irradiated austenitic stainless steels while leaving the RIS of major and minor alloying elements largely unchanged. The goal of this study is to better understand the underlying mechanisms of IASCC. Simulations of post-irradiation annealing of RIS and dislocation loop microstructure predicted that dislocation loops would be removed preferentially over RIS due to both thermodynamic and kinetic considerations. To verify the simulation predictions, a series of post-irradiation annealing experiments were performed. Both a high purity 304L (HP-304L) and a commercial purity 304 (CP-304) tainless steel alloy were irradiated with 3.2 MeV protons at 360 degreesC to doses of 1.0 and 2.5 dpa. Following irradiation, post-irradiation anneals were performed at temperatures ranging from 400 to 650 degreesC for times between 45 and 90 min. Grain boundary composition was measured using scanning transmission electron microscopy with energy-dispersive spectrometry in both as-irradiated and annealed samples. The dislocation loop population and radiation-induced hardness were also measured in as-irradiated and annealed specimens. At all annealing temperatures above 500 C, the hardness and dislocation densities decreased with increasing annealing time or temperature much faster than RIS. Annealing at 600 C for 90 min removed virtually all dislocation loops while leaving RIS virtually unchanged. Cracking susceptibility in the CP-304 alloy was mitigated rapidly during post-irradiation annealing, faster than RIS, dislocation loop density or hardening. That the cracking susceptibility changed while the grain boundary chromium composition remained essentially unchanged indicates that Cr depletion is not the primary determinator for IASCC susceptibility. For the same reason, the visible dislocation microstructure and radiation-induced hardening are also not sufficient to cause IASCC alone. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Busby, JT (reprint author), Univ Michigan, 2937 Cooley Bldg,2355 Bonisteel Blvd, Ann Arbor, MI 48109 USA. NR 38 TC 58 Z9 59 U1 3 U2 34 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 APR 1 PY 2002 VL 302 IS 1 BP 20 EP 40 AR PII S0022-3115(02)00719-5 DI 10.1016/S0022-3115(02)00719-5 PG 21 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 539FQ UT WOS:000174860200003 ER PT J AU Hassanein, A AF Hassanein, A TI Modeling hydrogen and helium entrapment in flowing liquid metal surfaces as plasma-facing components in fusion devices SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB In a fusion reactor, the ability to use liquids as plasma-facing components (PFCs) depends on their interaction with the plasma and the magnetic field. One important issue for the moving liquid is the ability to entrain particles that strike the PFC surface (helium and hydrogen isotopes) while accommodating high heat loads. To study this problem, an analytical model and a two-dimensional comprehensive numerical model have been developed and implemented in the HEIGHTS computer simulation package. The models take into account the kinetics of particle injection, motion and interactions with the liquid lattice, and the ultimate release from the surface. The models were used to investigate an important issue, whether He particles can be pumped by the PFC liquid rather than requiring a standard vacuum system. Hydrogen isotope (DT) particles that strike the surface will likely be trapped in the liquid-metal surface (e.g., lithium) due to the high chemical solubility of hydrogen. The impinging He particles in the established low-recycling regime at PFCs could be harder to pump using the standard vacuum pumping techniques. The analysis results indicate a reasonable chance of adequate helium self-trapping in flowing lithium as PFC without active pumping. (C) 2002 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Hassanein, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 13 Z9 14 U1 0 U2 7 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 APR 1 PY 2002 VL 302 IS 1 BP 41 EP 48 AR PII S0022-3115(02)00726-2 DI 10.1016/S0022-3115(02)00726-2 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 539FQ UT WOS:000174860200004 ER PT J AU Iwamoto, A Moller, P Madland, DG Sierk, AJ AF Iwamoto, A Moller, P Madland, DG Sierk, AJ TI Mass division in nuclear fission and isotope effect SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Isotope Effects in Physics, Chemistry, and Engineering CY AUG 22-24, 2001 CL NAGOYA, JAPAN DE potential energy surface; mass division; saddle point method; bimodal fission; nuclear fission; isotope effects; Fermium isotopes AB The theoretical calculations on the most probable mass division in unclear fission process are given. The model is based on the topographical analysis of the five-dimensional potential energy surface of more than 2.5 million mesh points. Special attention is paid to obtain the energies and deformations of the saddle points without using my approximation. The calculation tells us that there exist multiple saddle points in the static potential energy surface. The lowest and the next lowest saddle point play an important role for the fission process. Of these two saddle points, one is mass-symmetrically deformed and the other is mass-asmmetrically deformed and the relative heights of these two saddle points depend on the fissioning nuclei. In case of Fm isotopes, the relative height of two saddle points appears very sensitively, i.e., Fm-256 has asymmetrically deformed lowest saddle point and in Fm-258, the lowest saddle point is symmetrically deformed. This feature explains the phenomenon called bimodal fission. C1 Japan Atom Energy Res Inst, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Japan Atom Energy Res Inst, Dept Mat Sci, Tokai, Ibaraki 3191195, Japan. EM iwamoto@hadron01.tokai.jaeri.go.jp NR 7 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD APR PY 2002 VL 39 IS 4 SI SI BP 332 EP 336 DI 10.1080/18811248.2002.9715198 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 557CK UT WOS:000175889600011 ER PT J AU Haller, EE AF Haller, EE TI Isotopically controlled semiconductors SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Isotope Effects in Physics, Chemistry, and Engineering CY AUG 22-24, 2001 CL NAGOYA, JAPAN DE stable isotopes; semiconductors; diffusion; neutron-transmutation-doping; phonons; isotope-superlattices; metal-insulator-transition; spintronics; nanoparticles; isotopic composition; isotope ratio ID TRANSMUTATION-DOPED GE-70-GA; METAL-INSULATOR-TRANSITION; SELF-DIFFUSION; ISOTOPE HETEROSTRUCTURES; THERMAL-CONDUCTIVITY; RAMAN-SCATTERING; GERMANIUM; SUPERLATTICES; PHONONS; PARAMETER AB Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandpps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping. isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM EEHALLER@LBL.GOV NR 30 TC 4 Z9 4 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD APR PY 2002 VL 39 IS 4 SI SI BP 382 EP 385 DI 10.1080/18811248.2002.9715208 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 557CK UT WOS:000175889600021 ER PT J AU Marshall, SL AF Marshall, SL TI Calculation of coulombic lattice potentials: II. Spherical harmonic expansion of the Green function SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID POISSON EQUATION; MADELUNG CONSTANTS; MOLECULAR-POLARIZATION; ADSORBED MONOLAYERS; DIFFRACTION DATA; FOURIER-SERIES; SYSTEMS; SUMS; SUMMATION; ELECTRODES AB The modified Green function appropriate for calculation of coulombic lattice potentials is developed in a spherical harmonic expansion. This is derived from the corresponding Ewald sum in Cartesian coordinates, by applying Gegenbauer's addition theorem for modified spherical Bessel functions to the screened Coulomb potentials resulting from Laplace transformation with respect to the scalar convergence parameter, and Bauer's expansion to the plane waves. It is useful where the charge-density distribution about each nucleus is represented by a spherical harmonic expansion. Radial coefficients of the spherical harmonics are attenuated exponentially, and orthogonality reduces determination of electrostatic lattice potentials to one-dimensional quadratures. This use of the Green function is contrasted with conventional approaches based on point-multipole representations, in which important information on the diffuseness of electronic charge density around the nuclei may be lost in the calculation of multipole coefficients. Possible applications of this result in electronic structure calculations are briefly discussed. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Marshall, SL (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Marshall, Simon/E-9518-2010 NR 59 TC 4 Z9 4 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD APR 1 PY 2002 VL 14 IS 12 BP 3175 EP 3198 AR PII S0953-8984(02)27281-1 DI 10.1088/0953-8984/14/12/308 PG 24 WC Physics, Condensed Matter SC Physics GA 547LE UT WOS:000175333200018 ER PT J AU Cottenier, S De Vries, B Meersschaut, J Rots, M AF Cottenier, S De Vries, B Meersschaut, J Rots, M TI What density-functional theory can tell us about the spin-density wave in Cr SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID GENERALIZED-GRADIENT-APPROXIMATION; GROUND-STATE; CHROMIUM; MAGNETISM; SURFACES; ALLOYS; BCC AB The energy-versus-volume curve of the spin-density wave (SDW) in body-centred-cubic Cr is calculated with the density functional theory/full-potential linearized augmented plane wave (DFT/FLAPW) method using the generalized gradient approximation (GGA). The predicted ground state is not the SDW, in contrast to an earlier FLAPW calculation. A conjecture is formulated that the widely varying results of the local density approximation (LDA) and GGA- and of different solution methods-can be scaled by the size of the calculated moment. As a consequence, experimentally relevant properties of the SDW can be calculated by tuning the moment. The implications of these results for the ability of DFT to describe Cr are discussed. C1 Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium. Argonne Natl Lab, Argonne, IL 60439 USA. RP Cottenier, S (reprint author), Katholieke Univ Leuven, Inst Kern & Stralingsfys, Celestijnenlaan 200 D, B-3001 Louvain, Belgium. RI Cottenier, Stefaan/D-3616-2011 NR 24 TC 42 Z9 42 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD APR 1 PY 2002 VL 14 IS 12 BP 3275 EP 3283 AR PII S0953-8984(02)28227-2 DI 10.1088/0953-8984/14/12/314 PG 9 WC Physics, Condensed Matter SC Physics GA 547LE UT WOS:000175333200024 ER PT J AU Patel, D Smith, AG Simpson, GS Wall, RM Smith, JF Onakanmi, OJ Ahmad, I Greene, JP Carpenter, MP Lauritsen, T Lister, CJ Janssens, RF Kondev, FG Seweryniak, D Gall, BJP Dorveaux, O Roux, B AF Patel, D Smith, AG Simpson, GS Wall, RM Smith, JF Onakanmi, OJ Ahmad, I Greene, JP Carpenter, MP Lauritsen, T Lister, CJ Janssens, RF Kondev, FG Seweryniak, D Gall, BJP Dorveaux, O Roux, B TI A new technique for measuring g factors of excited states in fission fragments using large arrays of Ge detectors SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID MAGNETIC-MOMENTS; 2(1)+ STATES; ISOTOPES AB The theory behind a new, three-dimensional analysis technique for the measurement of time-integral, perturbed angular correlation (IPAC) functions is presented. The new technique is described in relation to existing methods and in terms of its specific application to a large, Ge-detector array. The effective application of the new technique is demonstrated with results from an experiment where the g factors of excited states in Cf-252, secondary fission fragments were determined. A Cf-252 source, sandwiched between two iron foils and placed in a saturated magnetic field at the centre of the Gammasphere detector array, was used to make IPAC measurements of prompt gamma rays in order to deduce Larmor precession angles of stopped fragments in iron. The g factor of the I-pi = 2(+) state in (MO)-M-104 was thus measured to be g = +0.248(22). This new measurement shows a factor-of-5 improvement to the precision which has previously been attained in more conventional experiments. C1 Univ Manchester, Schuster Lab, Manchester M13 9PL, Lancs, England. Argonne Natl Lab, Phys Div, Argonne, IL 60439 USA. Univ Strasbourg 1, CNRS, IN2P3, Inst Rech Subatom, F-67037 Strasbourg, France. RP Patel, D (reprint author), Univ Manchester, Schuster Lab, Manchester M13 9PL, Lancs, England. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 14 TC 25 Z9 25 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD APR PY 2002 VL 28 IS 4 BP 649 EP 663 AR PII S0954-3899(02)33713-7 DI 10.1088/0954-3899/28/4/306 PG 15 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 548AC UT WOS:000175364600007 ER PT J AU Gilman, R Gross, F AF Gilman, R Gross, F TI Electromagnetic structure of the deuteron SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Review ID ELECTRIC FORM-FACTOR; HIGH MOMENTUM-TRANSFER; LIGHT-FRONT DYNAMICS; MESON-EXCHANGE CURRENTS; NUCLEON-NUCLEON-INTERACTION; LINEARLY POLARIZED PHOTONS; EFFECTIVE-FIELD THEORY; ONE-BOSON-EXCHANGE; FEYNMAN-SCHWINGER REPRESENTATION; DIFFERENTIAL CROSS-SECTION AB Recent measurements of the deuteron electromagnetic structure functions A, B and T-20 extracted from high-energy elastic ed scattering, and the cross sections and asymmetries extracted from high-energy photodisintegration gamma + d --> n + p, are reviewed and compared with the theory. The theoretical calculations range from nonrelativistic and relativistic models using the traditional meson and baryon degrees of freedom, to effective field theories, to models based on the underlying quark and gluon degrees of freedom of QCD, including nonperturbative quark cluster models and perturbative QCD. We review what has been learned from these experiments, and discuss why elastic ed scattering and photodisintegration seem to require very different theoretical approaches, even though they are closely related experimentally. C1 Rutgers State Univ, Piscataway, NJ 08855 USA. Jefferson Lab, Newport News, VA 23606 USA. Coll William & Mary, Williamsburg, VA 23187 USA. RP Rutgers State Univ, 136 Frelinghuysen Rd, Piscataway, NJ 08855 USA. EM gilman@jlab.org; gross@jlab.org NR 313 TC 142 Z9 144 U1 0 U2 3 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 APR PY 2002 VL 28 IS 4 BP R37 EP R116 AR PII S0954-3899(02)13409-8 DI 10.1088/0954-3899/28/4/201 PG 80 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 548AC UT WOS:000175364600001 ER PT J AU Wenzel, WW Brandstetter, A Wutte, H Lombi, E Prohaska, T Stingeder, G Adriano, DC AF Wenzel, WW Brandstetter, A Wutte, H Lombi, E Prohaska, T Stingeder, G Adriano, DC TI Arsenic in field-collected soil solutions and extracts of contaminated soils and its implication to soil standards SO JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE LA English DT Article DE arsenic; soil solution; soil standards; soil contamination ID SOLUBILITY; SORPTION; ADSORPTION; CADMIUM; COPPER; IRON; ZINC AB Large concentrations of arsenic in soils, sediments, and fresh-waters require risk assessment across the Central Alps and other regions, We measured arsenic concentrations in soil samples collected from 38 sites located in the Austrian Central Alps that had been contaminated due to mining and smelter activities and aeogenic mineralization. Medians and ranges of arsenic concentrations (in mg kg(-1)) in the soil solid phase were: 77.1 (1-3000) for the total (As-t), 19.2 (0-726) for (NH4)(2)C2O4-extractable (As-o), 2,35 (0-169) for (NH4)(2)HPO4-extractable (As-p), and 0.143 (0-11.1) for (NB4)(2)SO4-extractable (As-s) arsenic. Arsenic concentrations in soil solutions (As-sol) collected from organic surface layers and mineral horizons at five selected sites using suction cups fitted with nylon membranes ranged from 0 to 171 mug 1(-1). Typically, the prevailing species of As in the soil solution was As(V). As-sol was correlated with As-s (As-sol = 0.279 + 15.6 As-s; r(2) = 0.938; n = 17) and As-t (As-sol = 1.272 + 0.043 As-t; r(2) = 0.833; n = 17). Using these empirical models, As-sol can be predicted quite accurately based on extraction with 0.05 M (NH4)(2)SO4 or total arsenic concentrations in the soil, Linking these models to drinking water standards (DWS) we propose soil standards for freshwater protection that vary for As. (mg kg(-1)) between 0,62 (for DWS = 10 mug 1(-1) WHO) and 3.19 (for DWS = 50 mug 1(-1)). Corresponding standards for As-t (mg kg(-1)) are 203 (DWS = 10 mug 1(-1)) and 1133 (DWS = 50 mug 1(-1)). These considerations demonstrate that changes in legislation on DWS may have dramatic impact on As concentrations in soil that are acceptable for groundwater protection. C1 Univ Agr Sci, BOKU, Inst Soil Sci, A-1180 Vienna, Austria. IACR Rothamsted, Dept Soil Sci, Harpenden AL5 2JQ, Herts, England. Univ Agr Sci, BOKU, Inst Chem, A-1190 Vienna, Austria. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29801 USA. RP Wenzel, WW (reprint author), Univ Agr Sci, BOKU, Inst Soil Sci, Gregor Mendel Str 33, A-1180 Vienna, Austria. RI Lombi, Enzo/F-3860-2013 OI Lombi, Enzo/0000-0003-3384-0375 NR 43 TC 52 Z9 60 U1 1 U2 11 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1436-8730 J9 J PLANT NUTR SOIL SC JI J. Plant Nutr. Soil Sci.-Z. Pflanzenernahr. Bodenkd. PD APR PY 2002 VL 165 IS 2 BP 221 EP 228 DI 10.1002/1522-2624(200204)165:2<221::AID-JPLN221>3.0.CO;2-0 PG 8 WC Agronomy; Plant Sciences; Soil Science SC Agriculture; Plant Sciences GA 548QG UT WOS:000175399600015 ER PT J AU Hess, JR Carman, JG Banowetz, GM AF Hess, JR Carman, JG Banowetz, GM TI Hormones in wheat kernels during embryony SO JOURNAL OF PLANT PHYSIOLOGY LA English DT Article DE development; ELISA; embryology; plant growth regulators; seed fill ID TRITICUM-AESTIVUM L; ABSCISIC-ACID; MONOCLONAL-ANTIBODIES; CYTOKININ ACCUMULATION; SOMATIC EMBRYOGENESIS; ENDOSPERM DEVELOPMENT; GROWTH-REGULATOR; PLANT CYTOKININ; DORMANCY; RADIOIMMUNOASSAY AB Abscisic acid (ABA), indole-3-acetic acid (IAA) and six cytokinins in wheat (Triticum aestivum L.) grain components were extracted, from 0 to 25 d post anthesis (DPA), and quantified by noncompetitive indirect ELISA. At 3 DPA, which coincides with early embryo and endosperm cell divisions, whole kernel hormone levels in mumol kg(-1) dry mass (DM) were: zeatin (Z) 30, IAA 4, zeatin riboside 1.8, ABA 1.0, other cytokinins < 0.6. Endosperm Z content declined from about 13 mumol kg(-1) DM at 6 DPA to 0.1 mumol kg(-1) DIM by 9 DPA and remained low thereafter. Generally by 9 IDPA, embryo differentiation is nearly complete, and the endosperm mitotic index has decreased to near zero. At 13 IDPA, Z content in embryos was 0.9 mumol kg(-1) DIM, and then decreased to 0.3 mumol kg(-1) DM by 25 DPA. Endosperm IAA content remained low through 9 DPA (about 6 mumol kg(-1) DM) and then increased sharply to about 38 mumol kg(-1) DM by 19 and 25 DPA. In contrast, embryo IAA content decreased from about 34 mumol kg(-1) DM at 13 DPA to about 15 mumol kg(-1) DIM at 19 and 25 IDPA. Endosperm ABA content fluctuated between 1.0 and 4.5 mumol kg(-1) DM between 6 and 25 DPA while embryo ABA content fluctuated between 3.4 and 4.8 mumol kg(-1) DM between 13 and 25 IDPA. These hormone changes may be involved in the coordinated development of embryos in ovulo. C1 Utah State Univ, Dept Plants Soils & Biometeorol, Logan, UT 84322 USA. Idaho Natl Lab, Idaho Falls, ID 83415 USA. USDA ARS, Corvallis, OR 97331 USA. RP Carman, JG (reprint author), Utah State Univ, Dept Plants Soils & Biometeorol, Logan, UT 84322 USA. EM jcarm@mendel.usu.edu NR 42 TC 15 Z9 19 U1 0 U2 5 PU ELSEVIER GMBH, URBAN & FISCHER VERLAG PI JENA PA OFFICE JENA, P O BOX 100537, 07705 JENA, GERMANY SN 0176-1617 J9 J PLANT PHYSIOL JI J. Plant Physiol. PD APR PY 2002 VL 159 IS 4 BP 379 EP 386 DI 10.1078/0176-1617-00718 PG 8 WC Plant Sciences SC Plant Sciences GA 553YY UT WOS:000175707000007 ER PT J AU Glimm, J Grove, J Zhang, YM Dutta, S AF Glimm, J Grove, J Zhang, YM Dutta, S TI Numerical study of axisymmetric Richtmyer-Meshkov instability and azimuthal effect on spherical mixing SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT 9th Annual International Conference on Discrete Simulation of Fluid Dynamics CY AUG 21-24, 2000 CL SANTA FE, NEW MEXICO SP Ctr Nonlinear Studies, Los Alamos Natl Lab, Theoret Div, Sandia Natl Labs DE azimuthal asymmetry; axisymmetric instability; spherical mixing; Richtmyer-Meshkov; random interface ID RAYLEIGH-TAYLOR; FRONT TRACKING; SIMULATION; SHOCK; DRIVEN; LAWS AB In this paper, we present a numerical study of the axisymmetric Richtmyer Meshkov instability in converging spherical geometry by the front tracking method for the first time. The front tracking method has been successfully used in solving fluid instability problems in both rectangular and curved geometry.(IS) The central issue for axisymmetric flows is the absence of the rotational symmetry in the (r, z) plane, although the perturbed shape of the initial contact interface appears to have it. The cause of the asymmetry is somewhat obvious. The sinusoidal perturbations appear symmetric only in the cross-sectional view; in actuality they are not symmetric because they represent rings around the z-axis and hence the perturbed mass at the equator, for example, is different from the perturbed mass at the pole. The first purpose of this paper is to quantify the effect of this inherited asymmetry on the growth of the spherical mixing. We Find this asymmetry drives the original structure to some degree so that the mixing radius at the north pole is noticeably larger than at the equator during the evolution of chaotic mixing, We also study quantitatively the azimuthal dependence of the mixing statistics, such as the mixing edges, the growth rate and volume fraction. Richtmyer-Meshkov (RM) instabilities in spherical geometry have been a challenge due to the inherent difficulty of their accurate simulation. Our second purpose is to demonstrate that our Front Tracking method can describe the Richtmyer- Meshkov instability growth in a complex flow involving multiple reshocks. We have successfully displayed the converging geometry, reshock process, asymmetry phenomenon through the density and pressure color plots. The quantitative growth rate analysis is also presented. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Ctr Data Intens Comp, Upton, NY 11793 USA. Los Alamos Natl Lab, Div Appl Phys, Hydrodynam Methods Grp, Los Alamos, NM 87545 USA. RP Glimm, J (reprint author), SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. NR 24 TC 13 Z9 13 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 2002 VL 107 IS 1-2 BP 241 EP 260 DI 10.1023/A:1014518906518 PG 20 WC Physics, Mathematical SC Physics GA 542NW UT WOS:000175051500016 ER PT J AU Nie, XB Doolen, GD Chen, SY AF Nie, XB Doolen, GD Chen, SY TI Lattice-Boltzmann simulations of fluid flows in MEMS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT 9th Annual International Conference on Discrete Simulation of Fluid Dynamics CY AUG 21-24, 2000 CL SANTA FE, NEW MEXICO SP Ctr Nonlinear Studies, Los Alamos Natl Lab, Theoret Div, Sandia Natl Labs DE Lattice-Boltzmann; microfluid; velocity slip AB The lattice Boltzmann model is a simplified kinetic method based on the particle distribution function. We use this method to simulate problems in MEMS, in which the velocity slip near the wall plays an important role. It is demonstrated that the lattice Boltzmann method can capture the fundamental behaviors in micro-channel flow, including velocity slip, nonlinear pressure drop along the channel and mass flow rate variation with Knudsen number, The Knudsen number dependence of the position of the vortex center and the pressure contour in micro-cavity flows is also demonstrated. C1 Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Peking Univ, Natl Key Lab Turbulence Res, Beijing, Peoples R China. RP Chen, SY (reprint author), Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. RI Chen, Shiyi/A-3234-2010; Kipke, Daryl/A-2167-2009 NR 12 TC 229 Z9 240 U1 1 U2 54 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 2002 VL 107 IS 1-2 BP 279 EP 289 DI 10.1023/A:1014523007427 PG 11 WC Physics, Mathematical SC Physics GA 542NW UT WOS:000175051500018 ER PT J AU He, XY Doolen, GD AF He, XY Doolen, GD TI Thermodynamic foundations of kinetic theory and Lattice Boltzmann models for multiphase flows SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT 9th Annual International Conference on Discrete Simulation of Fluid Dynamics CY AUG 21-24, 2000 CL SANTA FE, NEW MEXICO SP Ctr Nonlinear Studies, Los Alamos Natl Lab, Theoret Div, Sandia Natl Labs DE Lattice Boltzmann method; multiphase flow; kinetic theory ID RAYLEIGH-TAYLOR INSTABILITY; NONIDEAL GASES; LIQUID-GAS; EQUATION; FLUIDS; SIMULATION; DERIVATION; SYSTEMS AB This paper demonstrates that thermodynamically consistent lattice Boltzmann models for single-component multiphase flows can be derived from a kinetic equation using both Enskog's theory for dense fluids and mean-field theory for long-range molecular interaction. The lattice Boltzmann models derived this way satisfy the correct mass, momentum, and energy conservation equations. All the thermodynamic variables in these LBM models are consistent. The strengths and weaknesses of previous lattice Boltzmann multiphase models are analyzed. C1 Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. RP He, XY (reprint author), Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, MS-B213, Los Alamos, NM 87545 USA. NR 40 TC 163 Z9 171 U1 5 U2 28 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 2002 VL 107 IS 1-2 BP 309 EP 328 DI 10.1023/A:1014527108336 PG 20 WC Physics, Mathematical SC Physics GA 542NW UT WOS:000175051500020 ER PT J AU Yamamoto, K He, XY Doolen, GD AF Yamamoto, K He, XY Doolen, GD TI Simulation of combustion field with lattice Boltzmann method SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT 9th Annual International Conference on Discrete Simulation of Fluid Dynamics CY AUG 21-24, 2000 CL SANTA FE, NEW MEXICO SP Ctr Nonlinear Studies, Los Alamos Natl Lab, Theoret Div, Sandia Natl Labs DE lattice Boltzmann method; combustion; premixed flame; chemical reaction ID FLAMES; MODEL AB Turbulent combustion is ubiquitously used in practical combustion devices. However, even chemically non-reacting turbulent flows are complex phenomena, and chemical reactions make the problem even more complicated. Due to the limitation of the computational costs, conventional numerical methods are impractical in carrying out direct 3D numerical simulations at high Reynolds numbers with detailed chemistry. Recently, the lattice Boltzmann method has emerged as an efficient alternative for numerical simulation of complex flows. Compared with conventional methods, the lattice Boltzmann scheme is simple and easy for parallel computing, In this study, we present a lattice Boltzmann model for simulation of combustion, which includes reaction, diffusion, and convection. We assume the chemical reaction does not affect the flow field. Flow, temperature, and concentration fields are decoupled and solved separately, As a preliminary simulation, we study the so-called "counter-flow" laminar flame. The particular flow geometry has two opposed uniform combustible jets which form a stagnation flow. The results are compared with those obtained from solving Navier Stokes equations. C1 Toyohashi Univ Technol, Aichi 4418580, Japan. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Yamamoto, K (reprint author), Toyohashi Univ Technol, 1-1 Tempaku,Hibarigaoka, Aichi 4418580, Japan. NR 21 TC 44 Z9 47 U1 3 U2 17 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 2002 VL 107 IS 1-2 BP 367 EP 383 DI 10.1023/A:1014583226083 PG 17 WC Physics, Mathematical SC Physics GA 542NW UT WOS:000175051500023 ER PT J AU Mason, RJ AF Mason, RJ TI A multi-speed compressible lattice-Boltzmann model SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article; Proceedings Paper CT 9th Annual International Conference on Discrete Simulation of Fluid Dynamics CY AUG 21-24, 2000 CL SANTA FE, NM SP Ctr Nonlinear Studies, Los Alamos Natl Lab, Theoret Div, Sandia Natl Labs DE compressible hydrodynamics; Euler equations; lattice gas; BGK equation; particle-in-cell ID DISCRETE-VELOCITY MODELS; FLOW COMPUTATIONS; BGK MODEL; EQUATION; GAS; STABILITY; SCHEMES AB An extension of the lattice Boltzmann BGK method to compressible flows is presented that combines three novel additions (1) particles move density and energy weights in multiple velocity bins (11 for 1-D flow) to nearby cell centers. (2) the equilibrium distribution remains an unexpanded Maxwellian; and (3) transport and relaxation to equilibrium are performed implicitly at each node. These advances allow for the parallel modeling of high Mach number shocks and high Reynolds number flows, while avoiding advective numerical diffusion, the need for Riemann solvers, and non-linear limiters. A ID shock tube application is shown. Generalization to higher dimensions and multi-materials are discussed. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM mason@lanl.gov NR 42 TC 16 Z9 16 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-4715 EI 1572-9613 J9 J STAT PHYS JI J. Stat. Phys. PD APR PY 2002 VL 107 IS 1-2 BP 385 EP 400 DI 10.1023/A:1014535310153 PG 16 WC Physics, Mathematical SC Physics GA 542NW UT WOS:000175051500024 ER PT J AU Geller, DA Swift, GW AF Geller, DA Swift, GW TI Saturation of thermoacoustic mixture separation SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DIFFUSION AB The theory for thermoacoustic mixture separation is extended to include the effects of a nonzero concentration gradient. New data are presented, which are in excellent agreement with this theory. The maximum concentration gradient which may be achieved in a binary mixture of gases through this separation process is intrinsically limited by the fractional pressure amplitude, by the tidal displacement, and by the size of the thermal diffusion ratio. Ordinary diffusion further detracts from the attainable final concentration gradient and can become the dominant remixing process as the cross section of the duct is increased. Rayleigh streaming also works against thermoacoustic separation, and an estimate of the molar flux from streaming is given. (C) 2002 Acoustical Society of America. C1 Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Geller, DA (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 13 Z9 15 U1 0 U2 0 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 APR PY 2002 VL 111 IS 4 BP 1675 EP 1684 DI 10.1121/1.1453449 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 541TQ UT WOS:000175000900015 PM 12002850 ER PT J AU Mukundhan, P Du, HH Withrow, SP AF Mukundhan, P Du, HH Withrow, SP TI Oxidation studies of aluminum-implanted NBD 200 silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID KINETICS; SI3N4; CERAMICS; BEHAVIOR AB The effects of aluminum-ion-implantation on the oxidation behavior of NBD 200 Si3N4 were investigated over an implant concentration range of 0-30 at.%, at 800degrees-1100degreesC, in 1 atm dry O-2. Oxidation of both unimplanted and implanted samples follows a parabolic rate law. The parabolic rate constant decreases and the activation energy increases with aluminum concentration. Smooth and crack-free oxides are formed under the combination of high implant concentrations and low oxidation temperatures. Outward diffusion of Mg2+ from the bulk of NBD 200 to the oxide layer remains the rate-limiting step for aluminum-implanted samples. The enhancement of the oxidation resistance of NBD 200 by aluminum implantation is attributed to the retardation of the outward diffusion of Mg2+. C1 Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Mukundhan, P (reprint author), Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA. NR 20 TC 7 Z9 7 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 2002 VL 85 IS 4 BP 865 EP 872 PG 8 WC Materials Science, Ceramics SC Materials Science GA 540XV UT WOS:000174956900021 ER PT J AU Becher, PF Waters, SB Westmoreland, CG Riester, L AF Becher, PF Waters, SB Westmoreland, CG Riester, L TI Compositional effects on the properties of Si-Al-Re-based oxynitride glasses (RE = La, Nd, Gd, Y, or Lu) SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID EARTH ALUMINOSILICATE GLASSES; CERAMICS; SPECTRA; MODEL; RAMAN AB A series of silicon-aluminum oxynitride-glass compositions containing selected rare-earth (RE) additions were prepared to examine the effects of specific RE, as well as Si:AI:RE and N:0 ratio, on properties. The properties that were characterized included density, thermal expansion coefficient (alpha), glasstransition temperature (T-g), hardness (H), and Young's modulus (E). The compositions (in equivalent percent) selected included: 55 Si-20 RE-25 Al oxide and 80 0-20 N oxynitride, and 45 Si-30 RE-25 Al oxide and 70 0-30 N glasses. The results show that the density increased significantly with an increase in the RE atomic mass and slightly with an increase in N:O ratio. For each of the fixed Si-Al-RE-O-N compositions, the E, H, and Tg values were each increased by substituting smaller RE ions, whereas the alpha value was decreased. For each specific cation composition and RE, increasing the N:O ratio systematically led to a decrease in the a values but an increase in the E, H, and T-g values. The observed response in the glass properties to changes in composition appears to reflect modifications in the bonding within the glass network. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Becher, PF (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 25 TC 89 Z9 92 U1 0 U2 14 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 2002 VL 85 IS 4 BP 897 EP 902 PG 6 WC Materials Science, Ceramics SC Materials Science GA 540XV UT WOS:000174956900025 ER PT J AU Lubis, AH Hecht, NL Watkins, TR More, KL Ruh, R AF Lubis, AH Hecht, NL Watkins, TR More, KL Ruh, R TI Microstructure and mechanical properties of heat-treated silicon carbide-aluminum nitride solid solutions SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PHASE-SEPARATION; STRAIN-ENERGY; CERAMICS; SYSTEM C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Universal Technol Corp, Beavercreek, OH 45432 USA. RP Univ Dayton, Res Inst, Dayton, OH 45469 USA. RI More, Karren/A-8097-2016; Watkins, Thomas/D-8750-2016 OI More, Karren/0000-0001-5223-9097; Watkins, Thomas/0000-0002-2646-1329 NR 22 TC 3 Z9 3 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 2002 VL 85 IS 4 BP 933 EP 940 PG 8 WC Materials Science, Ceramics SC Materials Science GA 540XV UT WOS:000174956900031 ER PT J AU Hirano, Y Guedes, I Grimsditch, M Loong, CK Wakabayashi, N Boatner, LA AF Hirano, Y Guedes, I Grimsditch, M Loong, CK Wakabayashi, N Boatner, LA TI Brillouin-scattering study of the elastic constants of ErVO4 SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE elastic constants; rare earths; zircon; temperature ID ZIRCON-TYPE; RADIATION; PHOSPHATES; VANADATES; MONAZITE; YTTRIUM; RAMAN AB The room-temperature elastic constants of ErVO4 were considerably smaller than those of isostructural silicate and phosphate analogs. The generally "less-rigid" crystalline lattice and weaker metal-oxygen bond-strength in the RVO4 (R = rare earth elements) phases indicates that these materials are of interest for potential applications as an interphase component in toughened oxide ceramic composites. C1 Keio Univ, Dept Phys, Yokohama, Kanagawa 223, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Fed Ceara, Dept Fis, BR-60455760 Fortaleza, Ceara, Brazil. RP Keio Univ, Dept Phys, Yokohama, Kanagawa 223, Japan. RI GUEDES, ILDE/C-3451-2013; Boatner, Lynn/I-6428-2013; UFC, DF/E-1564-2017; Universidade Federal do Ceara, Physics Department/J-4630-2016; OI Boatner, Lynn/0000-0002-0235-7594; Universidade Federal do Ceara, Physics Department/0000-0002-9247-6780; GUEDES, ILDE/0000-0002-1040-5891 NR 31 TC 17 Z9 17 U1 1 U2 5 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 2002 VL 85 IS 4 BP 1001 EP 1003 DI 10.1111/j.1151-2916.2002.tb00209.x PG 3 WC Materials Science, Ceramics SC Materials Science GA 540XV UT WOS:000174956900045 ER PT J AU Tolmachev, AV Masselon, CD Anderson, GA Udseth, HR Smith, RD AF Tolmachev, AV Masselon, CD Anderson, GA Udseth, HR Smith, RD TI Frequency shifts due to the interference of resolved peaks in magnitude-mode Fourier-transform ion cyclotron resonance mass spectra SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID PROTEIN IDENTIFICATION; LINE-SHAPE; PHASE DEPENDENCE; IMAGE CHARGE; SPECTROMETRY; SPECTROSCOPY; ELIMINATION; RESOLUTION; PRECISION; ACCURACY AB We have obtained relationships for frequency shifts resulting from the interference of spectral components for the magnitude mode Fourier transform. The approximation of a weak perturbation of well resolved peaks has been used. Both the low- and high-pressure limits for Fourier-transform ion cyclotron resonance (FTICR) operation have been considered. We have found that the shifts can be either negative or positive, depending on the initial phase and/or the choice of the time-domain interval. The magnitude of shifts generally does not exceed the peak width. In the approximation of small perturbations the shifts produced by multiple peaks are additive. We have compared theoretical results with experimental shifts for isotopic clusters of multiply charged insulin. Up to 1 ppm frequency variations were experimentally observed for the insulin 5+ charge state, consistent with theoretical estimates. The peak interference is of particular significance in the case of bio-molecular mass spectra having a large number of peaks and covering a considerable dynamic range (i.e., relative abundance). We conclude that the common mass measurement procedure based on the location of the magnitude mode maxima of well resolved peaks can result in systematic mass measurement errors. The relationships obtained provide corrections for the frequency shifts and thus improve the mass measurement accuracy. (C) 2002 American Society for Mass Spectrometry. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MSIN K8-98,POB 999, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA86340] NR 47 TC 6 Z9 6 U1 0 U2 4 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 APR PY 2002 VL 13 IS 4 BP 387 EP 401 AR PII S1044-0305(02)00349-5 DI 10.1016/S1044-0305(02)00349-5 PG 15 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 539AY UT WOS:000174848300012 PM 11951977 ER PT J AU Nilson, RH Griffiths, SK AF Nilson, RH Griffiths, SK TI Enhanced transport by acoustic streaming in deep trench-like cavities SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MICROSTRUCTURES; FABRICATION AB High frequency acoustic agitation is known to enhance chemical dissolution rates of patterned photoresists used in semiconductor and LIGA microdevice fabrication. To better understand the physical mechanism of this enhancement, we have developed analytical and numerical models of the acoustically induced steady streaming motion that transports dissolved polymer fragments from the bottom of trench-like features into the developer bath. Analytical solutions describing the time-periodic wave motion are used to evaluate the time-mean Reynolds stresses that drive the steady streaming motion. The resulting steady torroidal flow within the feature is computed by solving the Navier-Stokes equations, including either the acoustic Reynolds stresses or the slip velocity that applies when the acoustic boundary layers are sufficiently thin. The steady velocity field is then used to compute species transport by diffusion and advection. These numerical results are complemented by analytical solutions describing the dependence of enhanced transport on process parameters. The results indicate that acoustic streaming is probably responsible for the observed three to fourfold increase in development rates of LIGA features having widths of a few micrometers or more. To gain the same relative benefit in submicrometer features would, however, require use of frequencies and power levels more than tenfold greater than the conventional levels of 1 MHz and 10 W/cm(2). (C) 2002 The Electrochemical Society. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nilson, RH (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 15 TC 21 Z9 22 U1 0 U2 4 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 APR PY 2002 VL 149 IS 4 BP G286 EP G296 DI 10.1149/1.1459716 PG 11 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 532XE UT WOS:000174499700056 ER PT J AU Swadener, JG George, EP Pharr, GM AF Swadener, JG George, EP Pharr, GM TI The correlation of the indentation size effect measured with indenters of various shapes SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE dislocations; strengthening and mechanisms; mechanical testing; indentation and hardness ID STRAIN GRADIENT PLASTICITY; LOW-LOAD HARDNESS; SPHERICAL INDENTERS; SINGLE-CRYSTALS; COPPER; DEPTH; SCALE AB Experimental results are presented which show that the indentation size effect for pyramidal and spherical indenters can be correlated. For a pyramidal indenter, the hardness measured in crystalline materials usually increases with decreasing depth of penetration, which is known as the indentation size effect. Spherical indentation also shows an indentation size effect. However, for a spherical indenter, hardness is not affected by depth, but increases with decreasing sphere radius. The correlation for pyramidal and spherical indenter shapes is based on geometrically necessary dislocations and work-hardening. The Nix and Gao indentation size effect model (J. Mech. Phys. Solids 46 (1998) 411) for conical indenters is extended to indenters of various shapes and compared to the experimental results. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RP Swadener, JG (reprint author), Los Alamos Natl Lab, MS-G755,POB 1663, Los Alamos, NM 87545 USA. RI zhang, mingjie/C-1507-2012; George, Easo/L-5434-2014; OI Swadener, John G/0000-0001-5493-3461 NR 33 TC 382 Z9 394 U1 7 U2 77 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD APR PY 2002 VL 50 IS 4 BP 681 EP 694 AR PII S0022-5096(01)00103-X DI 10.1016/S0022-5096(01)00103-X PG 14 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 540JW UT WOS:000174926600001 ER PT J AU Alford, WJ Raymond, TD Allerman, AA AF Alford, WJ Raymond, TD Allerman, AA TI High power and good beam quality at 980 nm from a vertical external-cavity surface-emitting laser SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID CIRCULAR TEM00 BEAMS; SEMICONDUCTOR-LASERS; DESIGN AB We demonstrate 1.5-W continuous-wave output power from a vertical external-cavity surface-emitting laser (VECSEL) based on InGaAs quantum wells as the gain medium. The VECSEL is pumped by the output of a single-bar diode-laser array at 814 nm and produces an optical-to-optical efficiency of 19%, The high output power is made possible by the use of a sapphire window optically contacted to the intracavity semiconductor surface for heat removal. We demonstrate the good beam quality of the VECSEL output by obtaining 1-W output from a single-mode fiber for 1.5 W launched with simple lenses. Pulsed operation produces a maximum peak power of similar to4.4 W and maximum average power of similar to2 W. (C) 2002 Optical Society of America. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Alford, WJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 11 TC 93 Z9 103 U1 2 U2 11 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 APR PY 2002 VL 19 IS 4 BP 663 EP 666 DI 10.1364/JOSAB.19.000663 PG 4 WC Optics SC Optics GA 541ZP UT WOS:000175017800006 ER PT J AU Peskin, AM AF Peskin, AM TI The Internet upheaval: Raising questions, seeking answers in communications policy SO JOURNAL OF URBAN TECHNOLOGY LA English DT Book Review C1 Brookhaven Natl Lab, Comp & Commun Div, Upton, NY 11973 USA. RP Peskin, AM (reprint author), Brookhaven Natl Lab, Comp & Commun Div, Upton, NY 11973 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU CARFAX PUBLISHING PI BASINGSTOKE PA RANKINE RD, BASINGSTOKE RG24 8PR, HANTS, ENGLAND SN 1063-0732 J9 J URBAN TECHNOL JI J. Urban Technol. PD APR PY 2002 VL 9 IS 1 BP 126 EP 128 PG 3 WC Urban Studies SC Urban Studies GA 547GE UT WOS:000175324000009 ER PT J AU Glenn, TC Thompson, JE Ballard, BM Roberson, JA French, JO AF Glenn, TC Thompson, JE Ballard, BM Roberson, JA French, JO TI Mitochondrial DNA variation among wintering midcontinent gulf coast sandhill cranes SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE crane; genetics; Grus canadensis; Gulf Coast; mitochondrial DNA; sandhill crane; subspecies; Texas ID CONTROL REGION; CONSERVATION; SEQUENCES; DISCRIMINATION; POPULATION; GRUIFORMES; GRUIDAE; BIRDS; UNITS; GRUS AB Based on morphological characteristics, 3 subspecies of sandhill cranes (Grus canadensis)-the lesser sandhill crane (G. c. canadensis), Canadian sandhill crane (G. c. rowam), and greater, sandhill crane (G. c. tabida)-occur within the midcontinent population (MCP) and winter along the Gulf Coast of Texas, USA. Of these subspecies, the greater sandhill crane is the least abundant and the most restricted in distribution in the midcontinent region, making it a subspecies of special concern. Twenty individuals from each subspecies with the highest posterior probabilities of membership in subspecies associated with their morphological discriminant score (i.e., those individuals that were least likely to be misclassified based on the morphological model currently used to assign wintering individuals to subspecies) were chosen from a total sample of 220 birds. We amplified and sequenced a 437-base-pair segment from domain I of the mitochondrial DNA (mtDNA) control region for these 60 birds. Analyses of the resulting 41 different mtDNA haplotypes indicate that birds classified as Canadian and greater sandhill cranes based on their morphology do not differ genetically, but lesser sandhill cranes are genetically distinct from both Canadian and greater sandhill cranes. When Canadian and greater sandhill cranes are grouped together, 55 of the 60 individuals sequenced are consistently classified using morphology and mtDNA. We then used the DNA sequences to develop a simple restriction enzyme assay of this mtDNA segment to survey an additional 160 specimens. These results indicate that (1) mtDNA assays provide reliable discrimination of migratory sandhill cranes, (2) the current subspecific designations of sandhill cranes may not accurately reflect genetic structure in (his species, (3) concern for preserving the genetic diversity of sandhill cranes in the midcontinent region may not need to focus on management of greater sandhill cranes wintering in the sampled populations, and (4) studies of individuals from the breeding grounds are clearly needed to determine whether Canadian and greater sandhill cranes are indeed distinct subspecies. C1 Univ S Carolina, Dept Biol Sci, Aiken, SC 29208 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Texas A&M Univ, Caesar Kleberg Wildlife Res Inst, Kingsville, TX 78363 USA. Texas Parks & Wildlife Dept, Austin, TX 78744 USA. RP Glenn, TC (reprint author), Univ S Carolina, Dept Biol Sci, Aiken, SC 29208 USA. EM Travis.Glenn@sc.edu RI Glenn, Travis/A-2390-2008 NR 49 TC 12 Z9 12 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0022-541X EI 1937-2817 J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD APR PY 2002 VL 66 IS 2 BP 339 EP 348 DI 10.2307/3803166 PG 10 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA 548XC UT WOS:000175414300009 ER PT J AU Xiang, XD Gao, C AF Xiang, XD Gao, C TI Quantitative complex electrical impedance microscopy by scanning evanescent microwave microscope SO MATERIALS CHARACTERIZATION LA English DT Article; Proceedings Paper CT Symposium on Scanning Probe Microscopy for Materials Characterization CY JUL 23-26, 2000 CL CITY UNIV HONG KONG, KOWLOON, PEOPLES R CHINA HO CITY UNIV HONG KONG DE scanning probe microscopy; evanescent microwave probe; electrical impedance microscopy ID NEAR-FIELD MICROSCOPE; FERROELECTRIC DOMAINS; RESOLUTION; PROBE; FILM AB Quantitative electrical impedance microscopy has been recently achieved using the scanning evanescent microwave microscope with the help of analytical solution of near-field interactions. The historical perspectives and fundamental physics involved in this field are reviewed. The experimental techniques and theoretical approach are discussed in detail. (C) 2002 Published by Elsevier Science Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Xiang, XD (reprint author), SRI Int, 333 Ravenswood Ave, Menlo Pk, CA 94025 USA. RI Xiang, Xiaodong/A-9445-2012; Xiang, Xiaodong/A-5936-2017 NR 37 TC 27 Z9 27 U1 1 U2 14 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 APR PY 2002 VL 48 IS 2-3 BP 117 EP 125 AR PII S1044-5803(02)00277-2 DI 10.1016/S1044-5803(02)00277-2 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA 597RT UT WOS:000178235100002 ER PT J AU Hinoki, T Katoh, Y Kohyama, A AF Hinoki, T Katoh, Y Kohyama, A TI Effect of fiber properties on neutron irradiated SiC/SiC composites SO MATERIALS TRANSACTIONS LA English DT Article DE silicon carbide; neutron irradiation; mechanical property; highly crystalline fiber; fracture behavior ID SYLRAMIC(TM) SIC FIBERS; SILICON-CARBIDE; NICALON FIBERS; FUSION AB The use of SiC/SiC composites for nuclear application has recently been considered because of intrinsic low activation and superior high temperature mechanical properties of SiC, The property of SiC fiber is a key issue in order to improve mechanical properties of SiC/SiC composites following irradiation, SiC/SiC composites with unidirectional fibers were fabricated by chemical vapor infiltration method. Low oxygen and highly crystalline fibers or just low oxygen fibers were used in the composites. The specimens, were it-radiated at Japan Material Testing Reactor and High Flux Isotope Reactor. The effects of neutron irradiation on mechanical properties were examined by three points flexural test. Microstructure and fracture behavior were observed by scanning electron microscopy before and after neutron irradiation, The SiC/SiC composites with a low oxygen content. near-stoichiometric atomic composition and highly crystalline SiC fibers showed the excellent stability to neutron irradiation. The mechanical property of this material did not degrade, even after neutron irradiation up to 10 dpa. while the other materials with non-highly crystalline SiC fibers degraded significantly. C1 Crest, Japan Sci & Technol Corp, Kawaguchi 3320013, Japan. Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. RP Hinoki, T (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. OI Katoh, Yutai/0000-0001-9494-5862 NR 28 TC 16 Z9 16 U1 0 U2 4 PU JAPAN INST METALS PI SENDAI PA 1-14-32, ICHIBANCHO, AOBA-KU, SENDAI, 980-8544, JAPAN SN 1345-9678 EI 1347-5320 J9 MATER TRANS JI Mater. Trans. PD APR PY 2002 VL 43 IS 4 BP 617 EP 621 DI 10.2320/matertrans.43.617 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 558MU UT WOS:000175971900003 ER PT J AU Maloy, SA James, MR Sommer, W Willcutt, GJ Lopez, M Romero, TJ AF Maloy, SA James, MR Sommer, W Willcutt, GJ Lopez, M Romero, TJ TI The effect of 800 MeV proton irradiation on the mechanical properties of tungsten SO MATERIALS TRANSACTIONS LA English DT Article DE tungsten; irradiation; mechanical properties; proton AB For the Accelerator Production of Tritium (APT) and the Accelerator Driven Transmutation Facility (ADTF), tungsten is being proposed as a target material to produce neutrons. Previous work has shown that the mechanical properties of tungsten are degraded from irradiation in a fission neutron flux but little work has been performed on the irradiation of tungsten in a high energy proton beam, In this study, tungsten rods were irradiated at the 800 MeV Los Alamos Neutron Science Center (LANSCE) proton accelerator for six months. To avoid corrosion during irradiation, the rods were slip fit with thin (0.25 mm thick) 304L stainless steel (SS) or (0.125 mm thick) annealed Alloy 718 tubing. After irradiation to a maximum dose in the tungsten of 23.3 dpa at T-irr = 50-270degreesC, the clad rods were opened in the hot cells and the tungsten was removed. The tungsten was then sliced into short compression specimens (similar to3 mm long). Hardness tests and compression tests, were performed on the tungsten rods to assess the effect of irradiation on their mechanical properties. Results show an increase in hardness with dose and irradiation temperature and an increase in yield stress with dose. C1 Los Alamos Natl Lab, AAA, TDO, Los Alamos, NM 87545 USA. RP Maloy, SA (reprint author), Los Alamos Natl Lab, AAA, TDO, MS H809, Los Alamos, NM 87545 USA. RI Maloy, Stuart/A-8672-2009 OI Maloy, Stuart/0000-0001-8037-1319 NR 24 TC 4 Z9 4 U1 0 U2 6 PU JAPAN INST METALS PI SENDAI PA 1-14-32, ICHIBANCHO, AOBA-KU, SENDAI, 980-8544, JAPAN SN 1345-9678 EI 1347-5320 J9 MATER TRANS JI Mater. Trans. PD APR PY 2002 VL 43 IS 4 BP 633 EP 637 DI 10.2320/matertrans.43.633 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 558MU UT WOS:000175971900006 ER PT J AU Hlavacek, WS Percus, JK Percus, OE Perelson, AS Wofsy, C AF Hlavacek, WS Percus, JK Percus, OE Perelson, AS Wofsy, C TI Retention of antigen on follicular dendritic cells and B lymphocytes through complement-mediated multivalent ligand-receptor interactions: theory and application to HIV treatment SO MATHEMATICAL BIOSCIENCES LA English DT Article DE follicular dendritic cell; B lymphocyte; human immunodeficiency virus type 1; immune memory; birth-death Markov chain; multivalent ligand-receptor binding ID IMMUNODEFICIENCY-VIRUS TYPE-1; ACTIVE ANTIRETROVIRAL THERAPY; BLOOD MONONUCLEAR-CELLS; FC-EPSILON-RI; LYMPHOID-TISSUE; PERIPHERAL-BLOOD; ASYMPTOMATIC PATIENTS; IMMUNE-COMPLEXES; T-LYMPHOCYTES; INFECTION AB In HIV-infected patients, large quantities of HIV are associated with follicular dendritic cells (FDCs) in lymphoid tissue. During antiretroviral therapy, most of this virus disappears after six months of treatment, suggesting that FDC-associated virus has little influence on the eventual outcome of long-term therapy. However, a recent theoretical study using a stochastic model for the interaction of HIV with FDCs indicated that some virus may be retained on FDCs for years, where it can potentially reignite infection if treatment is interrupted. In that study, an approximate expression was used to estimate the time an individual virion remains on FDCs during therapy. Here, we determine the conditions under which this approximation is valid, and we develop expressions for the time a virion spends in any bound state and for the effect of rebinding on retention. We find that rebinding, which is influenced by diffusion, may play a major role in retention of HIV on FDCs. We also consider the possibility that HIV is retained on B cells during therapy, which like FDCs also interact with HIV. We find that virus associated with B cells is unlikely to persist during therapy. (C) 2002 Published by Elsevier Science Inc. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NYU, Courant Inst Math Sci, New York, NY 10012 USA. Univ New Mexico, Dept Math & Stat, Albuquerque, NM 87131 USA. RP Hlavacek, WS (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433] NR 60 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0025-5564 J9 MATH BIOSCI JI Math. Biosci. PD APR PY 2002 VL 176 IS 2 BP 185 EP 202 AR PII S0025-5564(02)00091-3 DI 10.1016/S0025-5564(02)00091-3 PG 18 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 542DN UT WOS:000175028400002 PM 11916508 ER PT J AU Dick, AR MacGregor, SJ Pate, RC AF Dick, AR MacGregor, SJ Pate, RC TI Transmission line switch design for the investigation of sub-nanosecond electrical breakdown SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE high voltage pulse measurement; electric field strength; plasma closing switch; conical transmission line; D-dot monitor AB Ultrafast plasma closing switches rely on sub-nanosecond electrical breakdown of the insulating gas. Until recently, little information was available on gas breakdown occurring within this timescale, because of the difficulties in designing an experimental system for such a study. Recently published papers have reported on the results of studies carried out using two devices designed specifically for the investigation of fast (sub-nanosecond) electrical breakdown processes. The devices are essentially modified transmission line plasma closing switches, and in this paper we describe their structure and operation. Because electromagnetic wave behaviour plays a significant role in sub-nanosecond switching, especially reflections from impedance mismatches, the design of the devices is based on transmission line concepts, rather than those of lumped parameters. One of the switches has a conical transmission line topology and is designed for the study of fast switch closure at insulating gas pressures less than 0.6 MPa. The second has a hybrid radial transmission line/conical transmission line topology and is designed for the study of fast switch closure at pressures up to 10 MPa. The paper also includes details of the D-dot monitors used to investigate sub-nanosecond processes in the two transmission line plasma devices. C1 Univ Strathclyde, Dept Elect & Elect Engn, Glasgow G1 1XW, Lanark, Scotland. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Univ Strathclyde, Dept Elect & Elect Engn, Glasgow G1 1XW, Lanark, Scotland. EM s.macgregor@eee.strath.ac.uk NR 11 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD APR PY 2002 VL 13 IS 4 BP 539 EP 546 AR PII S0957-0233(02)28013-3 PG 8 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 547RX UT WOS:000175346500017 ER PT J AU Christodoulou, N Turner, PA Tome, CN Chow, CK Klassen, RJ AF Christodoulou, N Turner, PA Tome, CN Chow, CK Klassen, RJ TI Analysis of steady-state thermal creep of Zr-2.5Nb pressure tube material SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID WT-PERCENT NB; ALPHA-ZR; SELF-DIFFUSION; SINGLE-CRYSTAL; ZIRCONIUM; DEFORMATION; IRRADIATION; ANISOTROPY; ZIRCALOY-4; TEXTURE AB The steady-state thermal creep rate in the axial and transverse directions of Zr-2.5Nb of pressure tubes, used in CANDU nuclear reactors, was determined. The data were obtained both from tensile samples having their tensile axes cut along the axial and transverse directions of the pressure tubes and from small-sized, thin-walled tubes, i.e., "mini" tubes stressed either in torsion or by internally pressurizing capsules manufactured from the mini tubes, or by additionally applying an external, axial load on these internally pressurized capsules. The temperature range of the data was from 373 to 596 K (100 degreesC to 323 degreesC) and the duration of the tests was from about 1500 hours to over 12,000 hours. The tests were carried out over a sufficiently long time for the creep rate to be measurable in the steady-state creep regime. It was found that the steady-state creep rate depends on stress in a nonlinear fashion and the stress exponent over the entire temperature range was about four. This value is consistent with the values measured earlier on other zirconium alloys. The activation energy Q was found to be about 21 and 10 kcal/mol for temperatures above and below 475 K (similar to200degreesC), respectively. These values are lower than those measured by other investigators on the same material at higher temperatures but similar to values found on other Zr alloys at low temperatures. It appears that Q is dependent on temperature and its value is consistent with the presence of dynamic strain aging (DSA). The results of this study were analyzed with a polycrystalline, nonlinear self-consistent model that take into account the crystallographic texture of the material. This model was used to derive the values of critical resolved shear stress (CRSS), which are consistent with prismatic, basal, and pyramidal glide. By using these values and the apparent temperature dependence of Q, it was shown that this model predicts well the steady-state creep rate over the entire temperature range and under very different stress states. C1 Atom Energy Canada Ltd, Deformat Technol Branch, Chalk River, ON K0J 1P0, Canada. Atom Energy Canada Ltd, Fuel Channel Engn Branch, Mississauga, ON L5K 1B2, Canada. Univ Nacl Rosario, Inst Fis Rosario, RA-2000 Rosario, Santa Fe, Argentina. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Western Ontario, Dept Mech & Mat Engn, London, ON N6A 5B9, Canada. RP Christodoulou, N (reprint author), Atom Energy Canada Ltd, Deformat Technol Branch, Chalk River, ON K0J 1P0, Canada. RI Tome, Carlos/D-5058-2013 NR 49 TC 21 Z9 22 U1 1 U2 8 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 APR PY 2002 VL 33 IS 4 BP 1103 EP 1115 DI 10.1007/s11661-002-0212-4 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 564TD UT WOS:000176328900014 ER PT J AU Babu, SS Martukanitz, RP Parks, KD David, SA AF Babu, SS Martukanitz, RP Parks, KD David, SA TI Toward prediction of microstructural evolution during laser surface alloying SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID INCLUSION FORMATION; STEEL WELDS; IRON; GROWTH AB The stability of tungsten carbide particles in iron-rich and nickel-rich liquid during the laser surface alloying (LSA) process was investigated. Kinetic calculations indicate a rapid dissolution of tungsten carbide particles in iron-rich liquid, as compared with the dissolution rate in nickel-rich liquid. Optical microscopy indicated a heterogeneous microstructure around the tungsten particles that is in agreement with concentration gradients predicted by kinetic calculations. The work demonstrates the applicability of computational thermodynamics and kinetic models for the LSA process. C1 Oak Ridge Natl Lab, M&C Div, Oak Ridge, TN 37831 USA. Penn State Univ, Appl Res Lab, Laser Proc Div, University Pk, PA 16802 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 31 TC 22 Z9 28 U1 0 U2 7 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 APR PY 2002 VL 33 IS 4 BP 1189 EP 1200 DI 10.1007/s11661-002-0220-4 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 564TD UT WOS:000176328900022 ER PT J AU Sabau, AS Viswanathan, S AF Sabau, AS Viswanathan, S TI Microporosity prediction in aluminum alloy castings SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID AL-CU ALLOYS; POROSITY FORMATION; INVERSE SEGREGATION; FEEDING-BEHAVIOR; A356 ALLOY; MUSHY ZONE; LIQUID; FLOW; MODEL AB A comprehensive methodology that takes into account solidification, shrinkage-driven interdendritic fluid flow, hydrogen precipitation, and porosity evolution has been developed for the prediction of the microporosity fraction and distribution in aluminum alloy castings. The approach may be used to determine the extent of gas and shrinkage porosity, i.e., the resultant microporosity which occurs due to gas precipitation and that which occurs when solidification shrinkage cannot be compensated for by the interdendritic fluid flow. A solution algorithm in which the local pressure and microporosity are coupled is presented, and details of the implementation methodology are provided. The models are implemented in a computational framework consistent with that of commonly used algorithms for fluid dynamics, allowing a straightforward incorporation into existing commercial software. The results show that the effect of microporosity on the interdendritic fluid flow cannot be neglected. The predictions of porosity profiles are validated by comparison with independent experimental measurements by other researchers on aluminum A356 alloy test castings designed to capture a variety of solidification conditions. The numerical results reproduce the characteristic microporosity profiles observed in the experimental results and also agree quantitatively with the experimentally measured porosity levels. The approach provides an enhanced capability for the design of structural castings. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Sabau, AS (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RI Sabau, Adrian/B-9571-2008 OI Sabau, Adrian/0000-0003-3088-6474 NR 43 TC 51 Z9 51 U1 1 U2 17 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD APR PY 2002 VL 33 IS 2 BP 243 EP 255 DI 10.1007/s11663-002-0009-2 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 538LG UT WOS:000174817000009 ER PT J AU Khraishi, TA Zbib, HM De La Rubia, TD Victoria, M AF Khraishi, TA Zbib, HM De La Rubia, TD Victoria, M TI Localized deformation and hardening in irradiated metals: Three-dimensional discrete dislocation dynamics simulations SO METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE LA English DT Article ID PLASTIC-DEFORMATION; FCC METALS; BCC METALS; ACCUMULATION; MICROSTRUCTURE; DISPLACEMENT; CASCADES; CRYSTALS; GLIDE; LOOPS AB When irradiated, metals undergo significant internal damage accumulation and degradation of mechanical properties. Damage takes the form of a high number density of nanosize defect clusters (stacking-fault tetrahedrons (SFTs) or interstitial loops). The alteration of mechanical properties is manifested in a hardening behavior and localized plastic deformation in defect-free channels. This work uses discrete dislocation dynamics (DD) to capture these effects. It sets the framework for the elastic interaction between gliding dislocations and defect clusters and details a scheme for loop unfaulting and absorption into dislocations. Here, it is shown that SFTs represents weaker pinning points for dislocation motion than parent dislocation loops. It is also shown that appreciable yield drop can be attributed to high density of defects decorating the dislocations. Strong obstacles cause dislocations in Cu to continually double cross slip causing the formation of defect-free channels. Finally, the correlation between yield stress increase and defect number density is in excellent agreement with the experiment. C1 Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. Ecole Polytech Lausanne, CRPP Fus Technol Mat, CH-5232 Villigen, Switzerland. RP Khraishi, TA (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. NR 36 TC 31 Z9 32 U1 2 U2 13 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1073-5615 J9 METALL MATER TRANS B JI Metall. Mater. Trans. B-Proc. Metall. Mater. Proc. Sci. PD APR PY 2002 VL 33 IS 2 BP 285 EP 296 DI 10.1007/s11663-002-0012-7 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 538LG UT WOS:000174817000012 ER PT J AU Bergmann, U Glatzel, P Cramer, SP AF Bergmann, U Glatzel, P Cramer, SP TI Bulk-sensitive XAS characterization of light elements: from X-ray Raman scattering to X-ray Raman spectroscopy SO MICROCHEMICAL JOURNAL LA English DT Article DE bulk-sensitive XAS characterization; light elements; X-ray Raman scattering; X-ray Raman spectroscopy; inelastic X-ray scattering ID LI-K-EDGE; LIQUID WATER; COLLECTIVE DYNAMICS; ENERGY RESOLUTION; ABSORPTION; SPECTRA; EXCITATIONS; DEPENDENCE; CARBON; SOUND AB X-Ray absorption spectroscopy (XAS) is a powerful tool for element-specific characterization of local structure and chemistry Although application of XAS in the hard X-ray region is now routine, the soft X-ray region (containing light-element K-edges) presents a number of experimental problems. Most of the difficulties, including surface sensitivity, restricted sample environments, and radiation damage, stem from the submicron path lengths of soft Xrays and/or electrons. X-Ray Raman scattering (XRS) provides a means for obtaining the information content of soft X-ray spectra while maintaining the experimental benefits of hard X-ray techniques. In the XRS process, an incident photon is inelastically scattered and part of its energy is transferred to excite an inner shell electron into an unoccupied state. Under the dipole approximation, the resulting features are identical to the corresponding XAS spectrum. In the past, the extremely low cross-section of XRS has made this technique impractical, but intense new X-ray facilities and improvements in X-ray optics have helped to put XRS on the brink of becoming a routine spectroscopic tool. At present, high-quality X-ray Raman spectra can be obtained in minutes to hours. X-Ray Raman spectroscopy thus represents a hard X-ray alternative to conventional XAS techniques in the study of systems with light elements, including C, N and O. In this review we describe the technique, present examples of recent work, and discuss the prospects for the future. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Bergmann, U (reprint author), Lawrence Berkeley Lab, MS 6-2100,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Glatzel, Pieter/E-9958-2010; ID, BioCAT/D-2459-2012 OI Glatzel, Pieter/0000-0001-6532-8144; NR 49 TC 79 Z9 79 U1 1 U2 33 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0026-265X J9 MICROCHEM J JI Microchem J. PD APR PY 2002 VL 71 IS 2-3 SI SI BP 221 EP 230 AR PII S0026-265X(02)00014-0 DI 10.1016/S0026-265X(02)00014-0 PG 10 WC Chemistry, Analytical SC Chemistry GA 580KW UT WOS:000177234600013 ER PT J AU Bishop, DB McCool, GD Nelson, AJ Reynolds, JG Baumann, TF Fox, GA DeWitt, JG Andrews, JC AF Bishop, DB McCool, GD Nelson, AJ Reynolds, JG Baumann, TF Fox, GA DeWitt, JG Andrews, JC TI X-ray absorption spectroscopy of thiacrown compounds used in the remediation of mercury contaminated water SO MICROCHEMICAL JOURNAL LA English DT Article DE mercury-contaminated water; thiacrown compounds; X-ray absorption spectroscopy; sequestration; remediation ID CROWN THIOETHER CHEMISTRY; AQUEOUS-SOLUTIONS; POLYMER; PRECIPITATION; COMPLEXATION; EXTRACTION; BINDING; RESINS; LIGAND; SITES AB Effective methods for the removal of mercury from water are in demand due to the high levels of mercury released from industrial and natural processes. Polymer pendant thiacrown compounds used for the sequestration of Hg(II) from aqueous solutions have shown great promise as effective tools for remediation. Three thiacrowns that have been used for mercury chelation, [18]aneS(6) and [17]aneS(5)-polymer (with divinylbenzene) at two Hg(II) loadings, were examined by X-ray absorption spectroscopy in an attempt to determine the bonding configuration between the sulfurs of the thiacrown and the mercury. For Hg[18]aneS(6), it was found that four of the possible six crown sulfur atoms were involved in mercury bonding. For the Hg[17]aneS(5)-polymer, it was found that three of the possible five crown sulfur atoms were involved in mercury bonding. These thiacrown components appear to form stable mercury complexes and should be effective agents for sequestering and potential recycling of mercury from water. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Calif State Univ Hayward, Dept Chem, Hayward, CA 94542 USA. Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. San Francisco State Univ, Dept Chem & Biochem, San Francisco, CA 94132 USA. RP Andrews, JC (reprint author), Calif State Univ Hayward, Dept Chem, Hayward, CA 94542 USA. NR 30 TC 9 Z9 9 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0026-265X J9 MICROCHEM J JI Microchem J. PD APR PY 2002 VL 71 IS 2-3 SI SI BP 247 EP 254 AR PII S0026-265X(02)00016-4 DI 10.1016/S0026-265X(02)00016-4 PG 8 WC Chemistry, Analytical SC Chemistry GA 580KW UT WOS:000177234600015 ER PT J AU Salt, DE Prince, RC Pickering, IJ AF Salt, DE Prince, RC Pickering, IJ TI Chemical speciation of accumulated metals in plants: evidence from X-ray absorption spectroscopy SO MICROCHEMICAL JOURNAL LA English DT Article DE X-ray absorption spectroscopy; heavy metals; hyperaccumulation; toxicity; tolerance ID HYPERACCUMULATOR THLASPI-CAERULESCENS; INDIAN MUSTARD; OAT ROOTS; CADMIUM; PHYTOCHELATINS; TRANSPORT; SELENIUM; DETOXIFICATION; REDUCTION; TONOPLAST AB For centuries, man has been fascinated by the almost magical ability of plants to grow and reproduce on the simplest of materials - sunlight, air, water and minerals. As part of this conjuring act, plants require roots to acquire essential minerals such as iron, copper, nickel, zinc and selenium from the soil. Though these elements are essential, they are also potentially toxic, so plants possess complex biochemistry to control them. For reasons that are not yet clear, plants also have the ability to acquire and detoxify non-essential elements such as arsenic, cadmium, chromium and lead. Using X-ray absorption spectroscopy to probe the oxidation state and chemical speciation of a number of essential and non-essential elements, we have been able to identify certain common themes in the physiology and biochemistry of trace element (hyper)accumulation by plants. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Purdue Univ, Ctr Plant Environm Stress Physiol, Dept Hort & Landscape Architecture, W Lafayette, IN 47907 USA. ExxonMobil Res & Engn, Annandale, NJ 08801 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Salt, DE (reprint author), Purdue Univ, Ctr Plant Environm Stress Physiol, Dept Hort & Landscape Architecture, W Lafayette, IN 47907 USA. RI Salt, David/B-3864-2009; Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 NR 33 TC 62 Z9 71 U1 2 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0026-265X J9 MICROCHEM J JI Microchem J. PD APR PY 2002 VL 71 IS 2-3 SI SI BP 255 EP 259 AR PII S0026-265X(02)00017-6 DI 10.1016/S0026-265X(02)00017-6 PG 5 WC Chemistry, Analytical SC Chemistry GA 580KW UT WOS:000177234600016 ER PT J AU Intano, GW McMahan, CA McCarrey, JR Walter, RB McKenna, AE Matsumoto, Y MacInnes, MA Chen, DJ Walter, CA AF Intano, GW McMahan, CA McCarrey, JR Walter, RB McKenna, AE Matsumoto, Y MacInnes, MA Chen, DJ Walter, CA TI Base excision repair is limited by different proteins in male germ cell nuclear extracts prepared from young and old mice SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID DNA-POLYMERASE-BETA; LIGASE-III; SPERMATOGENIC CELLS; MORPHOLOGICAL CHARACTERIZATION; TRANSLATIONAL REGULATION; MEIOTIC RECOMBINATION; MOUSE SPERMATOGENESIS; SPONTANEOUS MUTATION; MOLECULAR-CLONING; MAMMALIAN TESTIS AB The combined observations of elevated DNA repair gene expression, high uracil-DNA glycosylase-initiated base excision repair, and a low spontaneous mutant frequency for a lacI transgene in spermatogenic cells from young mice suggest that base excision repair activity is high in spermatogenic cell types. Notably, the spontaneous mutant frequency of the lacI transgene is greater in spermatogenic cells obtained from old mice, suggesting that germ line DNA repair activity may decline with age. A paternal age effect in spermatogenic cells is recognized for the human population as well. To determine if male germ cell base excision repair activity changes with age, uracil-DNA glycosylase-initiated base excision repair activity was measured in mixed germ cell (i.e., all spermatogenic cell types in adult testis) nuclear extracts prepared from young, middle-aged, and old mice. Base excision repair activity was also assessed in nuclear extracts from premeiotic, meiotic, and postmeiotic spermatogenic cell types obtained from young mice. Mixed germ cell nuclear extracts exhibited an age-related decrease in base excision repair activity that was restored by addition of apurinic/apyrimidinic (AP) endonuclease. Uracil-DNA glycosylase and DNA ligase were determined to be limiting in mixed germ cell nuclear extracts prepared from young animals. Base excision repair activity was only modestly elevated in pachytene spermatocytes and round spermatids relative to other spermatogenic cells. Thus, germ line short-patch base excision repair activity appears to be relatively constant throughout spermatogenesis in young animals, limited by uracil-DNA glycosylase and DNA ligase in young animals, and limited by AP endonuclease in old animals. C1 Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Audie L Murphy Mem Vet Adm Med Ctr, S Texas Vet Hlth Care Syst, San Antonio, TX 78284 USA. SW Fdn Biomed Res, Dept Genet, San Antonio, TX 78245 USA. SW Texas State Univ, Dept Chem & Biochem, San Marcos, TX 78666 USA. Fox Chase Canc Ctr, Dept Radiat Oncol, Philadelphia, PA 19111 USA. Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Walter, CA (reprint author), Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, Mail Code 7762,7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NCI NIH HHS [CA75137, P01 CA075137, R37 CA050519, CA50519, R01 CA050519]; NIA NIH HHS [AG14674, AG00205, T32 AG000205, AG13560]; NIEHS NIH HHS [ESO9136] NR 66 TC 41 Z9 42 U1 0 U2 3 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD APR PY 2002 VL 22 IS 7 BP 2410 EP 2418 DI 10.1128/MCB.22.7.2410-2418.2002 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 531GK UT WOS:000174407500039 PM 11884623 ER PT J AU Wu, ZQ Earle, J Saito, S Anderson, CW Appella, E Xu, Y AF Wu, ZQ Earle, J Saito, S Anderson, CW Appella, E Xu, Y TI Mutation of mouse p53 Ser23 and the response to DNA damage SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID INDUCED PHOSPHORYLATION; IONIZING-RADIATION; MDM2; APOPTOSIS; ACTIVATION; CHK2; CHECKPOINT; KINASE; SITES; MICE AB Recent studies have suggested that phosphorylation of human p53 at Ser20 is important for stabilizing p53 in response to DNA damage through disruption of the interaction between MDM2 and p53. To examine the requirement for this DNA damage-induced phosphorylation event in a more physiological setting, we introduced a missense mutation into the endogenous p53 gene of mouse embryonic stem (ES) cells that changes serine 23 (S23), the murine equivalent of human serine 20, to alanine (A). Murine embryonic fibroblasts harboring the p53(S23A) mutation accumulate p53 as well as p21 and Mdm2 proteins to normal levels after DNA damage. Furthermore, ES cells and thymocytes harboring the p53(S23A) mutation also accumulate p53 protein to wild-type levels and undergo p53-dependent apoptosis similarly to wild-type cells after DNA damage. Therefore, phosphorylation of murine p53 at Ser23 is not required for p53 responses to DNA damage induced by UV and ionizing radiation treatment. C1 Univ Calif San Diego, Div Biol, Mol Biol Sect, La Jolla, CA 92093 USA. NCI, Cell Biol Lab, NIH, Bethesda, MD 20892 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Xu, Y (reprint author), Univ Calif San Diego, Div Biol, Mol Biol Sect, 9500 Gilman Dr, La Jolla, CA 92093 USA. NR 42 TC 76 Z9 77 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0270-7306 J9 MOL CELL BIOL JI Mol. Cell. Biol. PD APR PY 2002 VL 22 IS 8 BP 2441 EP 2449 DI 10.1128/MCB.22.8.2441-2449.2002 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 535FZ UT WOS:000174635700002 PM 11909939 ER PT J AU Wilson, WJ Strout, CL DeSantis, TZ Stilwell, JL Carrano, AV Andersen, GL AF Wilson, WJ Strout, CL DeSantis, TZ Stilwell, JL Carrano, AV Andersen, GL TI Sequence-specific identification of 18 pathogenic microorganisms using microarray technology SO MOLECULAR AND CELLULAR PROBES LA English DT Article DE pathogen detection; PCR; GeneChip (R); microarray; bioterrorist threat organisms ID POLYMERASE-CHAIN-REACTION; MYCOBACTERIUM-PARATUBERCULOSIS; PCR; BACTERIA; DISEASE; ARRAYS; IS900 AB We have developed a Multi-Pathogen Identification (MPID) microarray for high confidence identification of eighteen pathogenic prokaryotes, eukaryotes and viruses. Analysis of amplified products from pathogen genomic DNA using microarray hybridization allows for highly specific and sensitive detection, and allows the discrimination between true amplification products and false positive amplification products that might be derived from primers annealing to non-target sequences. Species-specific primer sets were used to amplify multiple diagnostic regions unique to each individual pathogen. Amplified products were washed over the surface of the microarray, and labelled with phycoerythrin-streptavidin for fluorescence detection. A series of overlapping 20-mer oligonucleotide probes hybridize to the entire diagnostic region, while parallel hybridizations on the same surface allow simultaneous screening for all organisms. Comparison to probes that differ by a single mismatch at the central position reduced the contribution of non-specific hybridization. Samples containing individual pathogens were analyzed in separate experiments and the corresponding species-specific diagnostic regions were identified by fluorescence among their highly redundant probe sets. On average, 91 % of the 53 660 pathogen probes on the MPID microarray performed as predicted. The limit of detection was found to be as little as 10 fg of B. anthracis DNA in samples that were amplified with six diagnostic primer-pairs. In contrast, PCR products were not observed at this concentration when identical samples were prepared and visualized by agarose gel electrophoresis. (C) 2002 Elsevier Science Ltd. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Andersen, GL (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-441, Livermore, CA 94551 USA. EM andersen2@llnl.gov RI Andersen, Gary/G-2792-2015 OI Andersen, Gary/0000-0002-1618-9827 NR 24 TC 208 Z9 235 U1 0 U2 17 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0890-8508 J9 MOL CELL PROBE JI Mol. Cell. Probes PD APR PY 2002 VL 16 IS 2 BP 119 EP 127 DI 10.1006/mcpr.2001.0397 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Cell Biology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Cell Biology GA 568RH UT WOS:000176556200005 PM 12030762 ER PT J AU King, LM Ma, JX Srettabunjong, S Graves, J Bradbury, JA Li, LP Spiecker, M Liao, JK Mohrenweiser, H Zeldin, DC AF King, LM Ma, JX Srettabunjong, S Graves, J Bradbury, JA Li, LP Spiecker, M Liao, JK Mohrenweiser, H Zeldin, DC TI Cloning of CYP2J2 gene and identification of functional polymorphisms SO MOLECULAR PHARMACOLOGY LA English DT Article ID CYTOSOLIC EPOXIDE HYDROLASE; ARACHIDONIC-ACID EPOXIDES; MOLECULAR-CLONING; EPOXYEICOSATRIENOIC ACIDS; PARKINSONS-DISEASE; LUNG-CANCER; HYPERPOLARIZING FACTORS; CDNA CLONING; CYTOCHROME-P450; EXPRESSION AB CYP2J2 is abundant in cardiovascular tissue and active in the metabolism of arachidonic acid to eicosanoids that possess potent anti-inflammatory, vasodilatory, and fibrinolytic properties. We cloned and sequenced the entire CYP2J2 gene (similar to40.3 kb), which contains nine exons and eight introns. We then sequenced the CYP2J2 exons and intron-exon boundaries in 72 healthy persons representing African, Asian, and European/ white populations as part of the National Institutes of Health/ National Institute of Environmental Health Sciences Environmental Genome Single Nucleotide Polymorphism Program. A variety of polymorphisms were found, four of which resulted in coding changes (Arg158Cys, Ile192Asn, Asp342Asn, and Asn404Tyr). A fifth variant (Thr143Ala) was identified by screening a human heart cDNA library. All five variant cDNAs of CYP2J2 were generated by site-directed mutagenesis and expressed in Sf9 insect cells by using a baculovirus system. The recombinant wild-type and variant CYP2J2 proteins immunoreacted with peptide-based antibodies to CYP2J2 and displayed typical cytochrome P450 (P450) CO-difference spectra; however, the Asn404Tyr and Ile192Asn variants also had prominent spectral peaks at 420 nm. The ability of these variants to metabolize arachidonic acid and linoleic acid was compared with that of wild-type CYP2J2. Three variants (Asn404Tyr, Arg158Cys, and Thr143Ala) showed significantly reduced metabolism of both arachidonic acid and linoleic acid. The Ile192Asn variant showed significantly reduced activity toward arachidonic acid only. The Asp342Asn variant showed similar metabolism to wild-type CYP2J2 for both endogenous substrates. Based on these data, we conclude that allelic variants of the human CYP2J2 gene exist and that some of these variants result in a P450 protein that has reduced catalytic function. Insofar as CYP2J2 products have effects in the cardiovascular system, we speculate that these variants may be functionally relevant. C1 NIEHS, Div Intramural Res, Res Triangle Pk, NC 27709 USA. Univ Mainz, Dept Med 2, D-6500 Mainz, Germany. Brigham & Womens Hosp, Div Cardiovasc, Boston, MA 02115 USA. Harvard Univ, Sch Med, Boston, MA USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Zeldin, DC (reprint author), NIEHS, Div Intramural Res, 111 TW Alexander Dr,Bldg 101,Room D236, Res Triangle Pk, NC 27709 USA. FU NIEHS NIH HHS [Y1-ES8054-05] NR 61 TC 84 Z9 91 U1 0 U2 5 PU AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0026-895X J9 MOL PHARMACOL JI Mol. Pharmacol. PD APR PY 2002 VL 61 IS 4 BP 840 EP 852 AR UNSP 1423/971867 DI 10.1124/mol.61.4.840 PG 13 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 536ZB UT WOS:000174730800017 PM 11901223 ER PT J AU Zangar, RC Kimzey, AL Okita, JR Wunschel, DS Edwards, RJ Kim, H Okita, RT AF Zangar, RC Kimzey, AL Okita, JR Wunschel, DS Edwards, RJ Kim, H Okita, RT TI Cytochrome P450 3A conjugation to ubiquitin in a process distinct from classical ubiquitination pathway SO MOLECULAR PHARMACOLOGY LA English DT Article ID RAT-LIVER; DEGRADATION; PROTEASOME; INDUCTION; ENZYME; PHOSPHORYLATION; NICARDIPINE; HEPATOCYTES; MICROSOMES; SYSTEM AB We characterize a novel microsome system that forms high-molecular-mass (HMM) CYP3A, CYP2E1, and ubiquitin conjugates, but does not alter CYP4A or most other microsomal proteins. The formation of the HMM bands was observed in hepatic microsomes isolated from rats treated 1 week or more with high doses (50 mg/kg/day) of nicardipine, clotrimazole, or pregnenolone 16alpha-carbonitrile, but not microsomes from control, dexamethasone-, nifedipine-, or diltiazem- treated rats. Extensive washing of the microsomes to remove loosely attached proteins or cytosolic contaminants did not prevent the conjugation reaction. In contrast to prototypical ubiquitination pathways, this reaction did not require addition of ubiquitin, ATP, Mg2+, or cytosol. Addition of cytosol did result in the degradation of the HMM CYP3A bands in a process that was not blocked by proteasome inhibitors. Immunoprecipitated CYP3A contained HMM ubiquitin. Even so, mass spectrometric analysis of tryptic peptides indicated that the HMM CYP3A was in molar excess to ubiquitin, suggesting that the formation of the HMM CYP3A may have resulted from conjugation to itself or a diffuse pool of ubiquitinated proteins already present in the microsomes. Addition of CYP3A substrates inhibited the formation of the HMM CYP3A and the cytosol-dependent degradation of HMM CYP3A. These results suggest that after extended periods of elevated CYP3A expression, microsomal factors are induced that catalyze the formation of HMM CYP3A conjugates that contain ubiquitin. This conjugation reaction, however, seems to be distinct from the classical ubiquitination pathway but may be related to the substrate-dependent stabilization of CYP3A observed in vivo. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Washington State Univ, Pullman, WA 99164 USA. Univ London Imperial Coll Sci Technol & Med, Fac Med, London, England. Detroit R&D Inc, Detroit, MI USA. RP Zangar, RC (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 99352 USA. RI Wunschel, David/F-3820-2010 FU NIDDK NIH HHS [DK54812]; NIEHS NIH HHS [ES03771] NR 37 TC 18 Z9 18 U1 0 U2 0 PU AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0026-895X J9 MOL PHARMACOL JI Mol. Pharmacol. PD APR PY 2002 VL 61 IS 4 BP 892 EP 904 AR UNSP 1464/973554 DI 10.1124/mol.61.4.892 PG 13 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 536ZB UT WOS:000174730800023 PM 11901229 ER PT J AU Corzett, M Mazrimas, J Balhorn, R AF Corzett, M Mazrimas, J Balhorn, R TI Protamine 1 : Protamine 2 stoichiometry in the sperm of eutherian mammals SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE sperm chromatin; P1; P2; nuclear proteins ID AMINO-ACID-SEQUENCE; PROTEIN-DNA INTERACTIONS; NUCLEAR BASIC-PROTEINS; MOUSE PROTAMINE-2; GENE-CLUSTER; BULL SPERMATOZOA; TRANSGENIC MICE; P1 GENES; PRECURSOR; CHROMATIN AB We have compared the relative proportion of protamine 1 (P1) and protamine 2 (P2) bound to DNA in the sperm of a variety of eutherian mammals to obtain insight into how these two proteins interact in sperm chromatin. Gel electrophoresis (combined with microdensitometry) and high performance liquid chromatography (HPLC) were used to determine the content of the two protamines, and the identity of each protein was confirmed by amino-terminal sequencing or amino acid analysis. The sperm of all species examined contained P1, but P2 was found to be present only in certain species. Unlike the fixed ratio of core histones that package DNA into nucleosomes in all somatic cells, the proportion of P2 present in mature sperm was found to be continuously variable from 0 to nearly 80%. These results show that P1 and P2 do not interact with each other or DNA to form a discrete complex or subunit structure that is dependent upon particular P1/P2 stoichiometries, Data obtained from a number of closely and distantly related species also indicate that while the P2 content of sperm chromatin is allowed to vary over a wide range during the course of evolution, the relative proportion of P1 and P2 are tightly regulated within a genus. (C) 2002 Wiley-Liss, Inc. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Balhorn, R (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-441, Livermore, CA 94550 USA. NR 72 TC 90 Z9 92 U1 0 U2 11 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 APR PY 2002 VL 61 IS 4 BP 519 EP 527 DI 10.1002/mrd.10105 PG 9 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA 526YT UT WOS:000174157900012 PM 11891924 ER PT J AU Allard, LF Panjabi, GA Salvi, SN Gates, BC AF Allard, LF Panjabi, GA Salvi, SN Gates, BC TI Imaging of nearly uniform Os5C clusters dispersed on MgO powder SO NANO LETTERS LA English DT Article ID 2; SURFACE AB [Os5C(CO)(14)](2--) was synthesized in 65% yield on the surface of MgO by treatment of adsorbed [Os-3(CO)(12)] in CO. High-resolution transmission electron microscopy (HRTEM) indicated that the nanoclusters were nearly monodisperse and in the size range consistent with [Os5C(CO)(14)](2-). The supported [Os5C(CO)(14)](2-) was decarbonylated in helium, giving supported nanoclusters that are well approximated as Os5C, as shown by HRTEM and EXAFS data. Decarbonylation in H-2 gave larger clusters of osmium, as shown by HRTEM. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. RP Gates, BC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 10 TC 17 Z9 17 U1 0 U2 2 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 APR PY 2002 VL 2 IS 4 BP 381 EP 384 DI 10.1021/nl015621k PG 4 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 542KF UT WOS:000175041800026 ER PT J AU Mao, JR Taylor, G Dean, WB Wagner, DR Afzal, V Lotz, JC Rubin, EM Bristow, J AF Mao, JR Taylor, G Dean, WB Wagner, DR Afzal, V Lotz, JC Rubin, EM Bristow, J TI Tenascin-X deficiency mimics Ehlers-Danlos syndrome in mice through alteration of collagen deposition SO NATURE GENETICS LA English DT Article ID OSTEOGENESIS IMPERFECTA; I PROCOLLAGEN; COL5A1 GENE; GRAVIS FORM; PROPEPTIDE; MUTATIONS; FIBRILS; CHAINS AB Tenascin-X is a large extracellular matrix protein of unknown function(1-3). Tenascin-X deficiency in humans is associated with Ehlers-Danlos syndrome(4,5), a generalized connective tissue disorder resulting from altered metabolism of the fibrillar collagens(6). Because TNXB is the first Ehlers-Danlos syndrome gene that does not encode a fibrillar collagen or collagen-modifying enzyme(7-14), we suggested that tenascin-X might regulate collagen synthesis or deposition(15). To test this hypothesis, we inactivated Tnxb in mice. Tnxb(-/-) mice showed progressive skin hyperextensibility, similar to individuals with Ehlers-Danlos syndrome. Biomechanical testing confirmed increased deformability and reduced tensile strength of their skin. The skin of Tnxb(-/-) mice was histologically normal, but its collagen content was significantly reduced. At the ultrastructural level, collagen fibrils of Tnxb(-/-) mice were of normal size and shape, but the density of fibrils in their skin was reduced, commensurate with the reduction in collagen content. Studies of cultured dermal fibroblasts showed that although synthesis of collagen I by Tnxb(-/-) and wildtype cells was similar, Tnxb(-/-) fibroblasts failed to deposit collagen I into cell-associated matrix. This study confirms a causative role for TNXB in human Ehlers-Danlos syndrome and suggests that tenascin-X is an essential regulator of collagen deposition by dermal fibroblasts. C1 Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94118 USA. Univ Calif San Francisco, Dept Orthoped Surg, San Francisco, CA 94118 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bristow, J (reprint author), Univ Calif San Francisco, Dept Pediat, Laurel Hts Campus,3333 Calif St,Box 1245, San Francisco, CA 94118 USA. NR 29 TC 132 Z9 135 U1 0 U2 5 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1061-4036 J9 NAT GENET JI Nature Genet. PD APR PY 2002 VL 30 IS 4 BP 421 EP 425 DI 10.1038/ng850 PG 5 WC Genetics & Heredity SC Genetics & Heredity GA 536BZ UT WOS:000174682000021 PM 11925569 ER PT J AU Davis, CB Kim, D Todreas, NE Kazimi, MS AF Davis, CB Kim, D Todreas, NE Kazimi, MS TI Core power limits for a lead-bismuth natural circulation actinide burner reactor SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB The Idaho National Engineering and Environmental Laboratory and Massachusetts Institute of Technology are investigating the suitability of lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The design being considered here is a pool type reactor that burns actinides and utilizes natural circulation of the primary coolant, a conventional steam power conversion cycle, and a passive decay heat removal system. Thermal-hydraulic evaluations of the actinide burner reactor were performed to determine allowable core power ratings that maintain cladding temperatures below corrosion-established temperature limits during normal operation and following a loss-of-feedwater transient. An economic evaluation was performed to optimize various design parameters by minimizing capital cost. The transient power limit was initially much more restrictive than the steady-state limit. However, enhancements to the reactor vessel auxiliary cooling system for transient decay heat removal resulted in an increased power limit of 1040 MWt, which was close to the steady-state limit, An economic evaluation was performed to estimate the capital cost of the reactor and its sensitivity to the transient power limit. For the 1040 MWt power level, the capital cost estimate was 49 mills per kWhe based on 1999 dollars. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. RP Davis, CB (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 21 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD APR PY 2002 VL 213 IS 2-3 BP 165 EP 182 AR PII S0029-5493(02)00049-3 DI 10.1016/S0029-5493(02)00049-3 PG 18 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 545JJ UT WOS:000175213500007 ER PT J AU Lang, PT Alper, B Baylor, LR Beurskens, M Cordey, JG Dux, R Felton, R Garzotti, L Haas, G Horton, LD Jachmich, S Jones, TTC Lomas, PJ Lorenz, A Maraschek, M Miller, HW Ongena, J Rapp, J Reich, M Renk, KF Sartori, R Schmidt, G Stamp, M Suttrop, W Villedieu, E AF Lang, PT Alper, B Baylor, LR Beurskens, M Cordey, JG Dux, R Felton, R Garzotti, L Haas, G Horton, LD Jachmich, S Jones, TTC Lomas, PJ Lorenz, A Maraschek, M Miller, HW Ongena, J Rapp, J Reich, M Renk, KF Sartori, R Schmidt, G Stamp, M Suttrop, W Villedieu, E CA EFDA-JET Work Programme Collabor TI Optimization of pellet scenarios for long pulse fuelling to high densities at JET SO NUCLEAR FUSION LA English DT Article ID NEOCLASSICAL TEARING MODES; ASDEX UPGRADE; TOKAMAK PLASMAS; DISCHARGES; OPERATION; PHYSICS; PERFORMANCE; INJECTION; LAUNCH; DRIFT AB Pellet injection was investigated for its fuelling capability to high densities in ELMy H mode discharges at JET. Applying the high field side launch system, optimized refuelling scenarios were developed on the basis of conventional discharge configurations with I(p) = 2.5 MA, B(t) = 2.4 T, averaged triangularity (delta) approximate to 0.34 and mainly neutral beam heating at a level of approximately 17 MW. The accessible operational range was extended with respect to gas puff refuelling by the use of pellet injection. For example, H mode conditions could be maintained at densities beyond the Greenwald level. Plasma energy confinement was observed to become density independent at high densities. Deep pellet particle deposition made possible the uncoupling of edge and core density, allowing more peaked density profiles. When confinement deterioration due to pellet triggered MHD activity or parasitic pellet borne gas was avoided in appropriate pulse schedules, an enhanced particle inventory was achieved while maintaining the plasma pressure profile. In a technical assessment it was found that there is still room for further enhancement of the injection scenario by improved adaptation to high density plasma operation. C1 EURATOM, Max Planck Inst Plasmaphys, Garching, Germany. UKAEA Euratom Fus Assoc, Abingdon, Oxon, England. Oak Ridge Natl Lab, Oak Ridge, TN USA. FOM, Inst Plasmafys Rijnhuizen, Nieuwegein, Netherlands. Assoc Euratom ENEA Fus, Consorzio RFX, Padua, Italy. Assoc Euratom Belgian State, ERM KMS, Plasma Phys Lab, Brussels, Belgium. Forschungszentrum Julich, Inst Plasmaphys, Julich, Germany. Univ Regensburg, Inst Expt & Angew Phys, D-8400 Regensburg, Germany. European Fus Dev Agreement Close Support Unit, Garching, Germany. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lang, PT (reprint author), EURATOM, Max Planck Inst Plasmaphys, Garching, Germany. EM ptl@ipp.mpg.de RI Lang, Peter/H-2507-2013; OI Lang, Peter/0000-0003-1586-8518; Rapp, Juergen/0000-0003-2785-9280 NR 35 TC 18 Z9 18 U1 0 U2 10 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 APR PY 2002 VL 42 IS 4 BP 388 EP 402 AR PII S0029-5515(02)35450-4 DI 10.1088/0029-5515/42/4/303 PG 15 WC Physics, Fluids & Plasmas SC Physics GA 554NT UT WOS:000175742700005 ER PT J AU Rewoldt, G Hill, KW Nazikian, R Tang, WM Shirai, H Sakamoto, Y Kishimoto, Y Ide, S Fujita, T AF Rewoldt, G Hill, KW Nazikian, R Tang, WM Shirai, H Sakamoto, Y Kishimoto, Y Ide, S Fujita, T TI Radial patterns of instability and transport in JT-60U internal transport barrier discharges SO NUCLEAR FUSION LA English DT Article ID NEGATIVE MAGNETIC SHEAR; TURBULENCE SIMULATIONS; ASPECT RATIO; PLASMAS; MODES; PERFORMANCE; TOKAMAKS; REGIMES AB One class of internal transport barrier discharge in the JT-60U tokamak is characterized by two relatively flat regions of the pressure separated by a region with very large pressure gradient. Linear growth rates for toroidal drift type modes are calculated for discharges in this class, without and with sheared E x B rotation effects. For cases with fully developed barriers, the results with rotation are consistent with a picture in which the radial electric field generated in part by the steep pressure gradient causes local stabilization, and thus reduction of the local anomalous transport, which allows the steep pressure gradient to persist. If rotation is omitted from the calculation for these cases, or if rotation is included for cases without barriers or with partially developed barriers, the unstable region spreads into the steep pressure gradient region. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Japan Atom Energy Res Inst, Naka, Ibaraki 31101, Japan. RP Rewoldt, G (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 23 TC 8 Z9 8 U1 0 U2 1 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 APR PY 2002 VL 42 IS 4 BP 403 EP 411 AR PII S0029-5515(02)35446-2 DI 10.1088/0029-5515/42/4/304 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 554NT UT WOS:000175742700006 ER PT J AU Paoletti, F Sabbagh, SA Manickam, J Menard, J Akers, RJ Gates, D Kaye, SM Lao, L AF Paoletti, F Sabbagh, SA Manickam, J Menard, J Akers, RJ Gates, D Kaye, SM Lao, L TI Impact of MHD equilibrium input variations on the high beta stability boundaries of NSTX SO NUCLEAR FUSION LA English DT Article ID RESISTIVE WALL MODE; DIII-D TOKAMAK; BALLOONING MODES; PHYSICS; PLASMAS; SHEAR AB Ideal MHD stability limits of anticipated plasma configurations for NSTX [Ono M. et al 2000 Nucl. Fusion 40 557] and the dependence on the parameters defining the MHD equilibrium are evaluated. The study provides a quantitative computational evaluation of the stability limit variations induced by changes to the equilibrium of NSTX high beta plasmas. The analysis is based on a reference free-boundary equilibrium with beta = 41.5%, monotonic safety factor q profile (q(a) = 12.1. q(o) = 2.8) and broad pressure profile p (peaking factor F-p =p(0)/(p) = 1.7). On this reference target local variation of the plasma boundary. and the safety factor q and pressure profiles 1) are imposed. Localized inflection of the outboard plasma boundary, produced by near field effects from poloidal shaping field coils, weaken the stability due to the destabilization of high n ballooning modes. Variation of the q profile at different radial locations can also degrade stability. Both experimental profiles from existing tokamaks and spherical torus machines and profiles generated from transport modelling of anticipated neutral beani heated plasmas are used. Degraded stability is found at increasing pressure peaking factor due to the destabilization of n = 1 kink/ballooning modes. Direct access to the second region of stability is found in certain configurations and. for the entire set of variations considered, the lower calculated beta limit values are still in the range of 20.0% without considering the stabilizing effect of the passive conducting structures. C1 Columbia Univ, New York, NY 10027 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08544 USA. UKAEA Fus, Abingdon, Oxon, England. Gen Atom Co, San Diego, CA USA. RP Paoletti, F (reprint author), Columbia Univ, New York, NY 10027 USA. RI Sabbagh, Steven/C-7142-2011; OI Menard, Jonathan/0000-0003-1292-3286 NR 18 TC 7 Z9 7 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 APR PY 2002 VL 42 IS 4 BP 418 EP 426 AR PII S0029-5515(02)35448-6 DI 10.1088/0029-5515/42/4/306 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 554NT UT WOS:000175742700008 ER PT J AU Takahashi, H Fredrickson, ED Chance, MS AF Takahashi, H Fredrickson, ED Chance, MS TI Unusual low frequency magnetic perturbations in the TFTR tokamak SO NUCLEAR FUSION LA English DT Article ID FUSION TEST REACTOR; COMPASS-C TOKAMAK; DIII-D TOKAMAK; HIGH-BETA; PLASMA ROTATION; TEARING MODE; IMPROVED CONFINEMENT; WALL STABILIZATION; HALO CURRENTS; MHD MODES AB Low frequency magnetic perturbations (less than or equal to30 kHz) observed in the Tokamak Fusion Test Reactor (TFTR) tokamak do not always conform to expectations from magnetohydrodynamic (MHD) modes. The discrepancy between observations and expectations arises from the existence of three classes of magnetic perturbation in TFTR: (1) edge originated magnetic perturbations (EOMPs), (2) kink-like modes (KLMs) and (3) tearing modes (TMs). The EOMP class shows unusual magnetic phenomena including up/down asymmetry in poloidal intensity variation that cannot be generated by MHD modes alone. The contributions of MHD modes in plasma edge regions are too small to explain the magnitude of the observed EOMP perturbations. At least two-thirds. and possibly nearly all, of the magnetic perturbations in a typical EOMP originate from sources other than MHD modes. An EOMP has a unity toroidal harmonic number and a poloidal harmonic number close to the q value of the discharge edge. It produces insignificant temperature fluctuations, except possibly in edge regions. The KLM class produces temperature fluctuations, mostly confined within the q = 1 surface with an ideal-mode-like structure, but generates only insignificant external magnetic perturbations. The TM class generally conforms to expectations from MHD modes. It is proposed that current flowing in the scrape-off layer (SOL) plasma is a possible origin of EOMPs. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Takahashi, H (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 64 TC 4 Z9 4 U1 1 U2 1 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 APR PY 2002 VL 42 IS 4 BP 448 EP 485 AR PII S0029-5515(02)35453-X DI 10.1088/0029-5515/42/4/309 PG 38 WC Physics, Fluids & Plasmas SC Physics GA 554NT UT WOS:000175742700011 ER PT J AU Alderman, J Job, PK Martin, RC Simmons, CM Owen, GD AF Alderman, J Job, PK Martin, RC Simmons, CM Owen, GD TI Measurement of radiation-induced demagnetization of Nd-Fe-B permanent magnets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE permanent magnets; radiation damage; insertion devices; synchrotron radiation sources ID BREMSSTRAHLUNG; IRRADIATION; DOSIMETRY; FLUX AB Nd-Fe-B permanent magnets are highly desirable for use in the insertion devices of synchrotron radiation sources due to their high remanence, or residual magnetic induction, and intrinsic coercivity. However, the radiation environment within high-energy storage rings makes essential the determination of the degree of radiation sensitivity as well as the mechanisms of radiation-induced demagnetization. Sample Nd-Fe-B permanent magnets were irradiated at the Advanced Photon Source with bending magnet X-rays up to an absorbed dose of approximately 280 Mrad (1 Mrad = 10kGy). Sample magnets were also irradiated with Co-60 gamma-rays up to an absorbed dose of 700 Mrad at the National Institute of Standards and Technology's standard gamma irradiation facility. Changes in the residual induction were found to be within the experimental uncertainties for both the X-ray and gamma-ray irradiations. Sample Nd-Fe-B permanent magnets were then irradiated at Oak Ridge National Laboratory's Californium User Facility for Neutron Science with fast neutrons up to a total fast fluence of 1.61 x 10(14) n/cm(2), and with thermal neutrons up to a total thermal fluence of 2.94 x 10(12) n/cm(2). The fast-neutron irradiation revealed changes between residual induction measurements of the sample magnets before and after irradiation of 0.6% and greater for fast-neutron fluence levels of 2 x 10(13) n/cm(2) and above. Thermal-neutron irradiation revealed changes in the residual induction measurements of the sample magnets before and after irradiation that were within the experimental uncertainties for thermal-neutron fluence levels up to 3 x 10(12) n/cm(2). (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, APS Operat Div, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Div Chem Technol, Californium User Facil Neutron Sci, Oak Ridge, TN 37831 USA. RP Job, PK (reprint author), Argonne Natl Lab, Adv Photon Source, APS Operat Div, 9700 S Cass Ave,Bldg 401-B4157, Argonne, IL 60439 USA. NR 37 TC 25 Z9 26 U1 0 U2 3 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 APR 1 PY 2002 VL 481 IS 1-3 BP 9 EP 28 AR PII S0168-9002(01)01329-8 DI 10.1016/S0168-9002(01)01329-8 PG 20 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700002 ER PT J AU Cho, HS Kadyk, J AF Cho, HS Kadyk, J TI Investigation of metallization suitable for gas avalanche microdetectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE microgap chamber; spark damage; gas avalanche detector ID CHAMBER; GAIN; GEM AB Selected metals. such as aluminum, cold. chromium. nickel, titanium, tungsten (10%, 90%) and tungsten, were used for the anode in the fabrication of microgap chambers (MGCs), in order to investigate metallization suitable for gas avalanche microdetectors that will be both highly robust against sparking and et have sufficiently low resistivity to permit larger sizes of detectors without excessive signal loss. In this paper, the results of spark damage tests with these metals are presented. and an interpretation is made regarding the viability of uses of these metals for larger sizes of detectors. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Yonsei Univ, Inst Yonsei Biomed Engn, Coll Hlth Sci, Dept Med Engn, Wonju 220710, South Korea. Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RP Cho, HS (reprint author), Yonsei Univ, Inst Yonsei Biomed Engn, Coll Hlth Sci, Dept Med Engn, 234 Maeji Heungup, Wonju 220710, South Korea. NR 13 TC 5 Z9 5 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 APR 1 PY 2002 VL 481 IS 1-3 BP 174 EP 182 AR PII S0168-9002(01)01350-X DI 10.1016/S0168-9002(01)01350-X PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700019 ER PT J AU Gorelov, I Gorfine, G Hoeferkamp, M Seidel, SC Ciocio, A Einsweiler, K Gilchriese, M Joshi, A Kleinfelder, S Marchesini, R Milgrome, O Palaio, N Pengg, F Richardson, J Zizka, G Ackers, M Fischer, P Keil, M Meuser, S Stockmanns, T Treis, J Wermes, N Gossling, C Hugging, F Wustenfeld, J Wunstorf, R Barberis, D Beccherle, R Cervetto, M Darbo, G Gagliardi, G Gemme, C Morettini, P Netchaeva, P Osculati, B Parodi, F Rossi, L Dao, K Fasching, D Blanquart, L Breugnon, P Calvet, D Clemens, JC Delpierre, P Hallewell, G Laugier, D Mouthuy, T Rozanov, A Trouilleau, C Valin, I Aleppo, M Andreazza, A Caccia, M Lari, T Meroni, C Ragusa, F Troncon, C Vegni, G Rohe, T Boyd, GR Severini, H Skubic, PL Snow, J Sicho, P Tomasek, L Vrba, V Holder, M Lipka, D Ziolkowski, M Cauz, D D'Auria, S del Papa, C Grassman, H Santi, L Becks, KH Gerlach, P Grah, C Gregor, I Harenberg, T Linder, C AF Gorelov, I Gorfine, G Hoeferkamp, M Seidel, SC Ciocio, A Einsweiler, K Gilchriese, M Joshi, A Kleinfelder, S Marchesini, R Milgrome, O Palaio, N Pengg, F Richardson, J Zizka, G Ackers, M Fischer, P Keil, M Meuser, S Stockmanns, T Treis, J Wermes, N Gossling, C Hugging, F Wustenfeld, J Wunstorf, R Barberis, D Beccherle, R Cervetto, M Darbo, G Gagliardi, G Gemme, C Morettini, P Netchaeva, P Osculati, B Parodi, F Rossi, L Dao, K Fasching, D Blanquart, L Breugnon, P Calvet, D Clemens, JC Delpierre, P Hallewell, G Laugier, D Mouthuy, T Rozanov, A Trouilleau, C Valin, I Aleppo, M Andreazza, A Caccia, M Lari, T Meroni, C Ragusa, F Troncon, C Vegni, G Rohe, T Boyd, GR Severini, H Skubic, PL Snow, J Sicho, P Tomasek, L Vrba, V Holder, M Lipka, D Ziolkowski, M Cauz, D D'Auria, S del Papa, C Grassman, H Santi, L Becks, KH Gerlach, P Grah, C Gregor, I Harenberg, T Linder, C TI A measurement of Lorentz angle and spatial resolution of radiation hard silicon pixel sensors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Lorentz angle; spatial resolution; silicon pixel detectors; radiation hardness; depletion depth; LHC ID ATLAS; DETECTOR; DESIGN AB Silicon pixel sensors developed by the ATLAS collaboration to meet LHC requirements and to withstand hadronic irradiation to fluences of up to 10(15) n(eq)/cm(2) have been evaluated using a test beam facility at CERN providing a magnetic field. The Lorentz angle was measured and found to alter from 9.0degrees before irradiation. when the detectors operated at 150 V bias at B = 1.48 T, to 3.1degrees after irradiation and operating at 600 V bias at 1.01 T. In addition to the effect due to magnetic field variation, this change is explained by the variation of the electric field inside the detectors arising from the different bias conditions. The depletion depths of irradiated sensors at various bias voltages were also measured, At 600 V bias 280 mum thick sensors depleted to approximate to200 mum after irradiation at the design fluence of 1 x 10(15) 1 MeV n(eq)/cm(2) and were almost fully depleted at a fluence of 0.5 x 10(15) 1 MeV n(eq)/cm(2). The spatial resolution was measured for angles of incidence between 0degrees and 30degrees. The optimal value was found to be better than 5.3 mum before irradiation and 7.4 mum after irradiation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy. Univ New Mexico, New Mexico Ctr Particle Phys, Albuquerque, NM 87131 USA. EO Lawrence Berkely Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Bonn, Inst Phys, D-53115 Bonn, Germany. Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. CNRS, IN2P3, Ctr Phys Particules Marseille, F-13288 Marseille, France. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Acad Sci Czech Republ, Inst Phys, CZ-18040 Prague, Czech Republic. Univ Siegen, Fachbereich Phys, D-57068 Siegen, Germany. Univ Udine, Dipartimento Fis, I-33100 Udine, Italy. Ist Nazl Fis Nucl, Sez Trieste, I-33100 Udine, Italy. Berg Univ Gesamthsch Wuppertal, Fachbereich Phys, D-42097 Wuppertal, Germany. RP Troncon, C (reprint author), Univ Milan, Dipartimento Fis, Via Celoria 16, I-20133 Milan, Italy. RI Andreazza, Attilio/E-5642-2011; Gorelov, Igor/J-9010-2015; OI Andreazza, Attilio/0000-0001-5161-5759; Gorelov, Igor/0000-0001-5570-0133; Osculati, Bianca Maria/0000-0002-7246-060X NR 22 TC 31 Z9 31 U1 1 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 APR 1 PY 2002 VL 481 IS 1-3 BP 204 EP 221 AR PII S0168-9002(01)01413-9 DI 10.1016/S0168-9002(01)01413-9 PG 18 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700023 ER PT J AU Dragowsky, MR Hamer, A Chan, YD Deal, R Earle, ED Frati, W Gaudette, E Hallin, A Hearns, C Hewett, J Jonkmans, G Kajiyama, Y McDonald, AB Moffat, BA Norman, EB Sur, B Tagg, N AF Dragowsky, MR Hamer, A Chan, YD Deal, R Earle, ED Frati, W Gaudette, E Hallin, A Hearns, C Hewett, J Jonkmans, G Kajiyama, Y McDonald, AB Moffat, BA Norman, EB Sur, B Tagg, N TI The N-16 calibration source for the Sudbury Neutrino Observatory SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Sudbury Neutrino Observatory; solar neutrinos; radioactive sources; energy calibratiom; N-16 beta-decay AB A calibration source using gamma-rays from N-16 (t(1,2) = 7.13 s) beta-decay has been developed for the Sudbury Neutrino Observatory (SNO) for the purpose of energy and other calibrations. The N-16 is produced via the (n,p) reaction on 160 in the form of CO2 gas using 14-MeV neutrons from a commercially available Deuterium-Tritium (DT) generator, The N-16 is produced in a shielding pit in a utility room near the SNO cavity and transferred to the water volumes (D2O or H2O) in a CO2 gas stream via small diameter capillary tubing, The bulk of the activity decays in a decay/trigger chamber designed to block the energetic beta-particles yet permit the primary. branch 6.13 MeV gamma-rays to exit. Detection of the coincident P-particles with plastic scintillator lining the walls of the decay chamber volume provides a tag for the SNO electronics. This paper gives details of the production, transfer, and triggering systems for this source along with a discussion of the source gamma-ray. output and performance. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oregon State Univ, Corvallis, OR 97331 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Queens Univ, Kingston, ON K7L 3N6, Canada. Atomic Enery Canada Limited, Chalk River Lab, Chalk River, ON K0J 1J0, Canada. Univ Penn, Philadelphia, PA 19104 USA. Laurentian Univ, Sudbury, ON P3E 2C6, Canada. Univ Guelph, Guelph, ON N1G 2W1, Canada. RP Dragowsky, MR (reprint author), Oregon State Univ, Corvallis, OR 97331 USA. EM dragowsky@lanl.gov NR 20 TC 33 Z9 33 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 APR 1 PY 2002 VL 481 IS 1-3 BP 284 EP 296 AR PII S0168-9002(01)02062-9 DI 10.1016/S0168-9002(01)02062-9 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700029 ER PT J AU Baglin, CM Browne, E Norman, EB Molnar, GL Belgya, T Revay, Z Szelecsenyi, F AF Baglin, CM Browne, E Norman, EB Molnar, GL Belgya, T Revay, Z Szelecsenyi, F TI Ga-66: a standard for high-energy calibration of Ge detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE efficiency calibration; Ge detector; Ga-66 ID GAMMA-RAY; RELATIVE INTENSITIES; CO-56 AB Two independent measurements of the relative emission probabilities for the strongest transitions in Ga-66 electron capture decay are reported here. The results of these measurements are in excellent agreement with each other and with those from another recent measurement. Consequently, Ga-66 emission probabilities for 18 strong lines, from 834 to 4806 keV, are now known to better than 1% accuracy. Thus, Ga-66 can now be considered a suitable radionuclide for Ge detector efficiency calibration up to an energy of 4806 keV, the highest energy attainable with radioactive calibration sources. We have also provided an empirical function for correcting earlier incorrect emission probability results for E-gamma greater than about 3 MeV which were produced using an inappropriate efficiency curve extrapolation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Inst Isotope & Surface Chem, Chem Res Ctr, H-1525 Budapest, Hungary. Inst Nucl Res, ATOMKI, H-4001 Debrecen, Hungary. RP Baglin, CM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 29 TC 27 Z9 27 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 APR 1 PY 2002 VL 481 IS 1-3 BP 365 EP 377 AR PII S0168-9002(01)01376-6 DI 10.1016/S0168-9002(01)01376-6 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700036 ER PT J AU Baek, I Iverson, EB Carpenter, JM AF Baek, I Iverson, EB Carpenter, JM TI The Monte Carlo simulation of neutron transmitted and scattered by disk choppers of various compositions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE disk choppers; Monte Carlo simulation; MCNP; uncollided neutron fractions; scattered neutron fractions; chopper material AB We consider the transmission of neutrons through disk-type neutron choppers, considering both the uncollided neutron fraction (phi(u)) and scattered neutron fraction (phi(s)) We have computed phi(u), phi(s) and the ratio phi(s)/phi(u) through plates of five different absorber materials of various thicknesses to give information for selecting optimum materials and thicknesses. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Instense Pulsed Neutron Source, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. RP Baek, I (reprint author), Argonne Natl Lab, Instense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 1 Z9 2 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 APR 1 PY 2002 VL 481 IS 1-3 BP 422 EP 430 AR PII S0168-9002(01)01259-1 DI 10.1016/S0168-9002(01)01259-1 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700041 ER PT J AU Rich, DR Bowman, JD Crawford, BE Delheij, PPJ Espy, MA Haseyama, T Jones, G Keith, CD Knudson, J Leuschner, MB Masaike, A Masuda, Y Matsuda, Y Penttila, SI Pomeroy, VR Smith, DA Snow, WM Szymanski, JJ Stephenson, SL Thompson, AK Yuan, V AF Rich, DR Bowman, JD Crawford, BE Delheij, PPJ Espy, MA Haseyama, T Jones, G Keith, CD Knudson, J Leuschner, MB Masaike, A Masuda, Y Matsuda, Y Penttila, SI Pomeroy, VR Smith, DA Snow, WM Szymanski, JJ Stephenson, SL Thompson, AK Yuan, V TI A measurement of the absolute neutron beam polarization produced by an optically pumped He-3 neutron spin filter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE neutron polarization; polarized He-3; neutron decay ID GAS; SCATTERING; RELAXATION; ENERGIES; TARGET; DECAY; TESTS; C-10; RB AB The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized He-3 spin filter and a relative transmission measurement technique. He-3 was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Wabash Coll, Dept Phys, Crawfordsville, IN 47933 USA. Indiana Univ, Bloomington, IN 47405 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, Durham, NC 27708 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. Univ Minnesota, Minneapolis, MN 55455 USA. Kyoto Univ, Kyoto 60601, Japan. NIST, Gaithersburg, MD 20899 USA. Univ New Hampshire, Durham, NH 03824 USA. RP Rich, DR (reprint author), Wabash Coll, Dept Phys, Crawfordsville, IN 47933 USA. RI Matsuda, Yasuyuki/C-3007-2008 OI Matsuda, Yasuyuki/0000-0002-9847-3791 NR 60 TC 24 Z9 24 U1 2 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 APR 1 PY 2002 VL 481 IS 1-3 BP 431 EP 453 AR PII S0168-9002(01)01331-6 DI 10.1016/S0168-9002(01)01331-6 PG 23 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700042 ER PT J AU Wu, Y Nishimura, H Robin, DS Zholents, AA Forest, E AF Wu, Y Nishimura, H Robin, DS Zholents, AA Forest, E TI Mini-beta lattice for the femto-second X-ray source at the Advanced Light Source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE dynamic aperture; storage ring; femtosecond X-ray source AB After generating the first femto-second X-ray pulses at the Advanced Light Source (ALS), it becomes critical to improve the flux of this femto-second source for user experiments. A narrow-gap in-vacuum undulator has been proposed to be installed in one of the ALS straight sections. To realize the optimal performance of this undulator. a straight section lattice with a mini vertical beta function has been designed. Separation of electrons has been achieved by generating a sizable vertical dispersion via a local dispersion bump and a closed orbit bump. Particle tracking study shows that the modified ALS lattice for the femto-second X-ray source has an adequate dynamic aperture. (C) 2002 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050810, Japan. RP Wu, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 2 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD APR 1 PY 2002 VL 481 IS 1-3 BP 675 EP 681 AR PII S0168-9002(01)01353-5 DI 10.1016/S0168-9002(01)01353-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700067 ER PT J AU Peurrung, AJ AF Peurrung, AJ TI On the long-range detection of radioactivity using electromagnetic radiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE radiation; detection; electromagnetic; ionosphere ID ATMOSPHERE; EMISSIONS AB A series of recent publications (Tech. Phys, Lett. 19 (1993) 184; Atom. Ener. 80 (1996) 47; Atom. Ener. 80 (1996) 135; Physics-Uspekhi 168 (1998) 515; Izvestiya 28 (1992) 262; Geomagn. Aeron. 34 (1994) 229; J. Atmos. Solar-Terres. Phys. 59 (1997) 961; Stud. Geophs. Geod. 42 (1998) 197; Adv. Space Res. 20 (1997) 2173) has provided experimental evidence that radiation fields can be detected well beyond the 10-100-m limit that holds for conventional (direct) approaches for detecting radiation. The techniques that are claimed to provide this capability use remote electromagnetic interrogation to record changes atmospheric electrostatic parameters arising from elevated radiation levels. This paper examines the physics that underlies these proposed new approaches for detecting radiation. If found to be viable for applications, the proposed techniques would be highly significant as they directly address a variety of problems in national security and environmental monitoring. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Peurrung, AJ (reprint author), Pacific NW Natl Lab, M-S P8-20,902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 23 TC 9 Z9 9 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 APR 1 PY 2002 VL 481 IS 1-3 BP 731 EP 738 AR PII S0168-9002(01)01372-9 DI 10.1016/S0168-9002(01)01372-9 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700073 ER PT J AU Pozzi, SA Oberer, RB Chiang, LG Mattingly, JK Mihalczo, JT AF Pozzi, SA Oberer, RB Chiang, LG Mattingly, JK Mihalczo, JT TI Higher-order statistics from NMIS to measure neutron and gamma ray cross talk in plastic scintillators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE higher-order statistics; correlation measurements; cross talk; plastic scintillators; neutron detection; nuclear safeguards ID MULTIDETECTOR SYSTEM; INTERFEROMETRY AB Cross talk occurs when a particle that is detected in a detector is subsequently detected in a neighboring detector. In this paper, a method is proposed to infer the degree and type of neutron and gamma ray cross talk between detectors that are placed side by side. To this end, a set of measurements was performed using the Nuclear Materials Identification System to acquire the time-dependent bicovariance functions of the pulses registered by an instrumented Cf-252 source and two fast plastic scintillators. The acquired signatures were then analyzed to infer the degree and type of coincidences due to cross talk in relation to "true" coincidences given by the spontaneous fission process. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. Politecn Milan, Dept Nucl Engn, I-20133 Milan, Italy. RP Pozzi, SA (reprint author), Oak Ridge Natl Lab, Div Instrumentat & Controls, POB 2008,Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 15 TC 1 Z9 1 U1 0 U2 3 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 APR 1 PY 2002 VL 481 IS 1-3 BP 739 EP 748 AR PII S0168-9002(01)01390-0 DI 10.1016/S0168-9002(01)01390-0 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 550KR UT WOS:000175502700074 ER PT J AU Cohen, DD Siegele, R Stelcer, E Garton, D Stampfl, A Cai, Z Ilinski, P Rodrigues, W Legnini, DG Yun, W Lai, B AF Cohen, DD Siegele, R Stelcer, E Garton, D Stampfl, A Cai, Z Ilinski, P Rodrigues, W Legnini, DG Yun, W Lai, B TI The complementarity of PIXE and synchrotron induced X-ray methods for the characterisation of combustion sources contributing to urban air pollution SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on PIXE and its Analytical Applications CY JUN 08-12, 2001 CL GUELPH, CANADA SP Element Anal Corp, Brigham Yourn Univ, Natl Electrostat Inc, Univ Guelph, Univ Missouri Columbia, Oxford Microbeams DE air pollution; PIXE; synchrotron radiatiom; detection limits; arsenic; selenium ID IBA TECHNIQUES; MORTALITY AB Current knowledge of fine-particle airborne pollution concentrations and constituents with diameters below 2,5 mum (PM2.5) is limited. Sources are both natural and man-made. Here we describe two types of experiments performed using the advanced photon source facility at Chicago, and compare the results with PIXE analysis on the same fine particle filters. These are firstly broad beam (2 mm) studies with tuned synchrotron beam energies to help resolve overlapping X-rays, and secondly highly focused X-ray beam studies (0.2 mum) of individual fine particles from airborne pollution combustion sources. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Australian Nucl Sci & Technol Org, Div Phys, Menai, NSW 2234, Australia. Argonne Natl Lab, APS, Expt Facil Div, Argonne, IL 60439 USA. RP Cohen, DD (reprint author), Australian Nucl Sci & Technol Org, Div Phys, PMB 1, Menai, NSW 2234, Australia. OI Cohen, David/0000-0002-1209-9234 NR 9 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 2002 VL 189 BP 100 EP 106 AR PII S0168-583X(01)01014-X DI 10.1016/S0168-583X(01)01014-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 552AE UT WOS:000175595500019 ER PT J AU Shutthanandan, V Thevuthasan, S Disselkamp, R Stroud, A Cavanagh, A Adams, EM Baer, DR Barrie, LA Cliff, SS Jimenez-Cruz, M Cahill, TA AF Shutthanandan, V Thevuthasan, S Disselkamp, R Stroud, A Cavanagh, A Adams, EM Baer, DR Barrie, LA Cliff, SS Jimenez-Cruz, M Cahill, TA TI Development of PIXE, PESA and transmission ion microscopy capability to measure aerosols by size and time SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 9th International Conference on PIXE and its Analytical Applications CY JUN 08-12, 2001 CL GUELPH, CANADA SP Element Anal Corp, Brigham Yourn Univ, Natl Electrostat Inc, Univ Guelph, Univ Missouri Columbia, Oxford Microbeams DE PIXE; PESA; aerosols; transmission ion microscopy AB We describe a new capability that consists of a combination of proton induced X-ray emission (PIXE), proton elastic scattering analysis (PESA) and transmission ion microscopy (all performed at the same location on the sample) techniques to address some of the research needs associated with time series and size-dependent composition of atmospheric aerosols, Simultaneous measurements of PIXE and PESA can be performed on aerosols collected using 3 stage improved rotating DRUM impactor by size (,Stage A: 2.5-1.15 mum: Stage B: 0.34-1.15 mum, Stage C: 0.07-0.34 mum) with time resolution set by the rotation rate from I min every 4 h to I mm every 6 min on a 16.8 cm long impaction strips that can be coated with Mylar. stretched Teflon, or aluminum, depending on the analysis method chosen. Preliminary measurements carried out using a I mm diameter proton beam were made on industrial test samples, yielding promising results at a time resolution of only 6 min. (C) 2002 Published by Elsevier Science B.V. C1 Pacific NW Natl Lab, PNNL, Richland, WA 99352 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Shutthanandan, V (reprint author), Pacific NW Natl Lab, PNNL, MSIN K8-93, Richland, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 8 TC 12 Z9 15 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 2002 VL 189 BP 284 EP 288 AR PII S0168-583X(01)01058-8 DI 10.1016/S0168-583X(01)01058-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 552AE UT WOS:000175595500051 ER PT J AU Breese, MBH Jamieson, DN Doyle, BL AF Breese, MBH Jamieson, DN Doyle, BL TI The use of solenoid lenses in a two-stage nuclear microprobe probe-forming system SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 7th European Conference on Accelerators in Applied Research and Technology CY AUG 21-24, 2001 CL UNIV SURREY, GUILDFORD, ENGLAND HO UNIV SURREY DE solenoid lenses; nuclear microprobes; ion optics; beam transport AB Nuclear microprobes typically achieve a demagnification between 20 and 100 by using a single-stage quadrupole multiplet as the probe-forming system. Whilst quadrupole lenses provide the strong field necessary for focusing MeV ions. they also have higher intrinsic spherical and chromatic aberrations, and also higher parasitic aberrations than found in solenoid lenses, Given the fundamentally superior spatial resolution which is attainable using solenoids, their use in a two-stage microprobe system comprising a magnetic quadruplet and a solenoid lens as the first and second demagnifying stages respectively is studied here. Calculated results are compared with a two-stage system comprising two quadruplets and also with an existing single-stage system. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Surrey, Sch Phys Sci, Dept Phys, Guildford GU2 5XH, Surrey, England. Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Breese, MBH (reprint author), Univ Surrey, Sch Phys Sci, Dept Phys, Guildford GU2 5XH, Surrey, England. RI Jamieson, David/G-3753-2010; Breese, Mark/G-2068-2012; OI Jamieson, David/0000-0001-7733-6715 NR 24 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 2002 VL 188 BP 261 EP 266 AR PII S0168-583X(01)01110-7 DI 10.1016/S0168-583X(01)01110-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 548AA UT WOS:000175364300050 ER PT J AU Tian, XB Fu, RKY Chen, JY Chu, PK Brown, IG AF Tian, XB Fu, RKY Chen, JY Chu, PK Brown, IG TI Charging of dielectric substrate materials during plasma immersion ion implantation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE ion implantation; plasma processing and deposition; charging ID ELECTRON-EMISSION; BOMBARDMENT; SURFACE; SHEATHS AB We have investigated the electrostatic charging effects of dielectric substrate materials during plasma immersion ion implantation. The results demonstrate that the time-dependent surface potential (negative) may be reduced in magnitude due to the charging effect of the dielectric surface, leading in turn to a reduction in the energy of the incident ions and a broadening of the implanted ion energy spectrum. The charging effect is greater during the plasma immersion bias pulse rise-time, and the electrostatic potential charging may be as large as 75% of the total applied (pulse) potential. This is due to abundant charge movement both of ions and secondary electrons, and has been confirmed by computer simulation. The plasma sheath capacitance has a small influence on the surface potential, via the bias pulse rise-time. Processing parameters, for example voltage, pulse duration, plasma density, and pulse rise-time, have a critical influence on the charging effects. Short pulse duration, high pulse frequency and low plasma density are beneficial from the viewpoint of maximizing the implantation ion energy. (C) 2002 Elsevier Science B.V. All rights reserved. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Chu, PK (reprint author), City Univ Hong Kong, Dept Phys & Mat Sci, 83 Tat Chee Ave, Kowloon, Hong Kong, Peoples R China. RI Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 22 TC 25 Z9 25 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD APR PY 2002 VL 187 IS 4 BP 485 EP 491 AR PII S0168-583X(01)01154-5 DI 10.1016/S0168-583X(01)01154-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 544XD UT WOS:000175186400009 ER PT J AU Muller, RD Ferrieri, RA Gerasimov, N Garza, V AF Muller, RD Ferrieri, RA Gerasimov, N Garza, V TI Supercritical CO2 fluid radiochromatography system used to purify [C-11]toluene for PET SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article DE PET; inhalants; substance abuse; supercritical fluid ID ORGANIC-SOLVENTS; TOLUENE LEVELS; EXTRACTION; SEPARATION; EXPOSURE; DRUGS; BLOOD; BRAIN; RATS AB Abuse of inhalants in today's society has become such a widespread problem among today's adolescents that in many parts of the world their use exceeds that of many other illicit drugs or alcohol, Even so, little is known how such inhalants affect brain function to an extent that can lead to an abuse liability. While methodologies exist for radiolabeling certain inhalants of interest with short-lived positron emitting radioisotopes that would allow their investigation in human subjects using positron emission tomography (PET), the purification methodologies necessary to separate these volatile substances from the organic starting materials have not been developed. We've adapted supercritical fluid technology to this specific PET application by building a preparative-scale supercritical CO2 fluid radiochromatograph, and applied it to the purification of [C-11]toluene. We've demonstrated that [C-11]toluene can be separated from the starting materials using a conventional C18HPLC column and pure supercritical CO2 fluid as the mobile phase operating at 2000 psi and 40degreesC. We've also shown that the purified radiotracer can be quantitatively captured on Tenax GR, a solid support material. as it exits the supercritical fluid stream, thus allowing for later desorption into a 1.5% cyclodextrin solution that: is suitable for human injection, or into a breathing tube for direct inhalation. (C) 2002 Elsevier Science Inc. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Coll William & Mary, Williamsburg, VA 23186 USA. RP Ferrieri, RA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NINDS NIH HHS [NS 15380] NR 35 TC 4 Z9 4 U1 2 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0969-8051 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD APR PY 2002 VL 29 IS 3 BP 351 EP 357 AR PII S0969-8051(01)00284-6 DI 10.1016/S0969-8051(02)00284-6 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 539JK UT WOS:000174866600011 PM 11929706 ER PT J AU Bardakci, K Thorn, CB AF Bardakci, K Thorn, CB TI A worldsheet description of large N-c quantum field theory SO NUCLEAR PHYSICS B LA English DT Article ID STRING THEORY; MODEL; QCD; GRAVITY AB The N-c --> infinity limit of a matrix quantum field theory is equivalent to summing only planar Feymnan diagrams. The possibility of interpreting this sum as some kind worldsheet theory has been in the air ever since 't Hooft's original paper. We establish here just such a worldsheet description for a scalar quantum field with interaction term g Trphi(3) / rootN(c), and we indicate how the approach might be extended to more general field theories. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Bardakci, K (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. OI Thorn, Charles/0000-0002-2671-9799 NR 27 TC 43 Z9 43 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD APR 1 PY 2002 VL 626 IS 1-2 BP 287 EP 306 AR PII S0550-3213(02)00034-2 DI 10.1016/S0550-3213(02)00034-2 PG 20 WC Physics, Particles & Fields SC Physics GA 534XK UT WOS:000174614900012 ER PT J AU Weinstein, M AF Weinstein, M TI Moving mirrors, black holes, Hawking radiation and all that ... SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT International Workshop TRENTO 2001 CY SEP 03-11, 2001 CL TRENT, ITALY C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Weinstein, M (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD APR PY 2002 VL 108 BP 68 EP 73 AR PII S0920-5632(02)01306-3 DI 10.1016/S0920-5632(02)01306-3 PG 6 WC Physics, Particles & Fields SC Physics GA 545ZA UT WOS:000175246400010 ER PT J AU Thorn, CB AF Thorn, CB TI Summing planar diagrams for string and gauge theories SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT International Workshop TRENTO 2001 CY SEP 03-11, 2001 CL TRENT, ITALY AB We discuss the problem of summing planar diagrams in both string and field theory using light-cone methods. We advocate the discretization of both x(+) and p(+) as a useful tool for attacking this problem, We then discuss some technical aspects of this discretization procedure in non-abelian gauge theories. We describe one-loop calculations in this formalism and explain how the Mandelstam-Leibbrandt prescription might be adapted to it. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Thorn, CB (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. OI Thorn, Charles/0000-0002-2671-9799 NR 13 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD APR PY 2002 VL 108 BP 123 EP 129 AR PII S0920-5632(02)01315-4 DI 10.1016/S0920-5632(02)01315-4 PG 7 WC Physics, Particles & Fields SC Physics GA 545ZA UT WOS:000175246400019 ER PT J AU Roberts, CD AF Roberts, CD TI Goldstone boson's valence-quark distribution SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT International Workshop TRENTO 2001 CY SEP 03-11, 2001 CL TRENT, ITALY ID DYSON-SCHWINGER EQUATIONS; INFRARED BEHAVIOR; GLUON PROPAGATOR; SYMMETRY-BREAKING; BETHE-SALPETER; LANDAU GAUGE; FORM-FACTORS; PION; QCD; CONFINEMENT AB Dynamical chiral symmetry breaking (DCSB) is one of the keystones of low-energy hadronic phenomena. Dyson-Schwinger equations provide a model-independent quark-level understanding and correlate that with the behaviour of the pion's Bethe-Salpeter amplitude. This amplitude is a core element in the calculation of pion observables and combined with the dressed-quark Schwinger function required by DCSB it yields a valence-quark distribution function for the pion that behaves as (1-x)(2) for xsimilar to1, in accordance with perturbative analyses. This behaviour can be verified at contemporary experimental facilities. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. RP Roberts, CD (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Roberts, Craig/0000-0002-2937-1361 NR 32 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD APR PY 2002 VL 108 BP 227 EP 233 AR PII S0920-5632(02)01333-6 DI 10.1016/S0920-5632(02)01333-6 PG 7 WC Physics, Particles & Fields SC Physics GA 545ZA UT WOS:000175246400037 ER PT J AU Hwang, DS AF Hwang, DS TI Applications of light-cone wavefunctions to QCD phenomena SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT International Workshop TRENTO 2001 CY SEP 03-11, 2001 CL TRENT, ITALY ID WAVE-FUNCTION REPRESENTATION; VIRTUAL COMPTON-SCATTERING; SPIN AB The matrix elements of the local operators such as electromagnetic current, energy momentum tensor, angular momentum, and skewed parton distribution functions have exact representations in terms of light-cone Fock state wavefunctions of bound states such as hadrons. We present formulae which express the form factors of the local operators in terms of the light-cone wavefunctions. C1 Sejong Univ, Dept Phys, Seoul 143747, South Korea. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Hwang, DS (reprint author), Sejong Univ, Dept Phys, Seoul 143747, South Korea. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD APR PY 2002 VL 108 BP 293 EP 297 AR PII S0920-5632(02)01347-6 PG 5 WC Physics, Particles & Fields SC Physics GA 545ZA UT WOS:000175246400051 ER PT J AU Brodsky, SJ AF Brodsky, SJ TI Physics at the light-front SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT International Workshop TRENTO 2001 CY SEP 03-11, 2001 CL TRENT, ITALY ID CONE WAVE-FUNCTION; INFINITE-MOMENTUM FRAME; YANG-MILLS THEORIES; QUANTUM CHROMODYNAMICS; EXCLUSIVE PROCESSES; COLOR-TRANSPARENCY; INTRINSIC CHARM; FORM-FACTORS; FIELD-THEORY; FUNCTION REPRESENTATION AB The light-front representation of quantum chromodynamics provides a frame-independent, quantum-mechanical representation of hadrons at the amplitude level, capable of encoding their multi-quark, hidden-color and gluon momentum, helicity, and flavor correlations in the form of universal process-independent hadron wavefunctions. The universality and frame-independence of the light-cone wavefunctions thus allow a profound connection between diffractive dissociation, hard scattering exclusive processes such as elastic form factors, two-photon reactions, and heavy hadron decays. In this concluding talk of the ECT* International Conference On Light-Cone Physics: Particles And Strings (Trento 2001), 1 review recent calculations and new applications of light-front wavefunctions in QCD and other theories. I also review the distinction between the structure functions measured in deep inelastic lepton scattering and the quark distributions determined from light-front wavefunctions. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM sjbth@slac.stanford.edu NR 105 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD APR PY 2002 VL 108 BP 327 EP 339 AR PII S0920-5632(02)01355-5 DI 10.1016/S0920-5632(02)01355-5 PG 13 WC Physics, Particles & Fields SC Physics GA 545ZA UT WOS:000175246400059 ER PT J AU Blackwood, LG Harker, YD AF Blackwood, LG Harker, YD TI Incorporating plutonium particle size effects in the assessment of active mode measurement uncertainty in passive-active neutron radioassay systems SO NUCLEAR TECHNOLOGY LA English DT Article DE uncertainty analysis; radioassay; particle size AB Assessment of active mode measurement uncertainty in passive-active neutron radioassay systems used to measure Pu content in nuclear waste is severely hampered by lack of knowledge of the waste Pu particle size distribution, which is a major factor in determining bias in active mode measurements. The sensitivity of active mode measurements to particle size precludes using simulations or surrogate waste forms to estimate uncertainty in active mode measurements when the particle size distribution is not precisely known or inadequately reproduced. An alternative approach is based on a statistical comparison of active and passive mode results in the mass range for which both active and passive mode analyses produce useable measurements. Because passive mode measurements are not particularly sensitive to particle size effects, their uncertainty can be more easily assessed. Once bias corrected, passive mode measurements can serve as confirmatory measurements for the estimation of active mode bias. further statistical analysis of the errors in measurements leads to precision estimates for the active mode. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Blackwood, LG (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 8 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 APR PY 2002 VL 138 IS 1 BP 58 EP 68 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 530TW UT WOS:000174375900005 ER PT J AU Moir, RW AF Moir, RW TI Cost of electricity from molten salt reactors SO NUCLEAR TECHNOLOGY LA English DT Article DE cost of electricity analysis; molten salt reactor; fission power plant AB The cost of electricity is estimated for a molten salt reactor based on evaluations at the Oak Ridge National Laboratory (ORNL) and compared to the ORNL pressurized water reactor and coal plant estimates of the same pre-1980 vintage plants. The results were 3.8, 4.1, and 4.2 cent/kWh for the molten salt reactor, pressurized water reactor, and coal. Surprisingly, such cost estimates have never before been published for the molten salt reactor. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Moir, RW (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 3 TC 9 Z9 9 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD APR PY 2002 VL 138 IS 1 BP 93 EP 95 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 530TW UT WOS:000174375900009 ER PT J AU Di Teodoro, F Koplow, JP Moore, SW Kliner, DAV AF Di Teodoro, F Koplow, JP Moore, SW Kliner, DAV TI Diffraction-limited, 300-kW peak-power pulses from a coiled multimode fiber amplifier SO OPTICS LETTERS LA English DT Article ID ERBIUM-DOPED FIBER; SINGLE-TRANSVERSE-MODE; HIGH-ENERGY; LASER; OPERATION; OUTPUT AB We report a multimode, double-clad, Yb-doped fiber amplifier that produces diffraction-limited, 0.8-ns pulses with energies of 255 muJ and peak powers in excess of 300 kW at a repetition rate of similar to8 kHz. Single-transverse-mode operation was obtained by bend-loss-induced mode filtering of the gain fiber. (C) 2002 Optical Society of America. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Di Teodoro, F (reprint author), USN, Res Lab, Div Opt Sci, 4555 Overlook Ave,SW, Washington, DC 20375 USA. NR 15 TC 47 Z9 47 U1 2 U2 9 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 APR 1 PY 2002 VL 27 IS 7 BP 518 EP 520 PG 3 WC Optics SC Optics GA 536HL UT WOS:000174694600018 ER PT J AU Kimmich, BFM Bullock, RM AF Kimmich, BFM Bullock, RM TI Protonation of (PCP)PtH to give a dihydrogen complex SO ORGANOMETALLICS LA English DT Article ID CARBON-CARBON BOND; HYDRIDE TRANSFER-REACTIONS; TRANSITION-METAL HYDRIDES; P PINCER COMPLEX; C-C BOND; 2,6-BIS<(DIMETHYLAMINO)METHYL>PHENYL-N,N',C COMPLEXES; CATALYTIC DEHYDROGENATION; COORDINATED DIHYDROGEN; OXIDATIVE ADDITION; CRYSTAL-STRUCTURE AB Protonation of (PCP)PtH (PCP = eta(3)-2,6-( Bu2PCH2)(2)C6H3 in CD2Cl2 at - 78 degreesC with [H(OEt2)(2)]+BAr'(4)-[Ar' = 3,5-bis(trifluoromethyl)phenyl] gives the Pt-II dihydrogen complex [(PCP)Pt(H-2)](+). The H-2 ligand is expelled when the solution is warmed to room temperature, but the dihydrogen complex is re-formed when H-2 is added. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Bullock, RM (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 51 TC 29 Z9 29 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD APR 1 PY 2002 VL 21 IS 7 BP 1504 EP 1507 DI 10.1021/om0108651 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 534QZ UT WOS:000174599400024 ER PT J AU Hoagland, RG Kurtz, RJ AF Hoagland, RG Kurtz, RJ TI The relation between grain-boundary structure and sliding resistance SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID COMPUTER-SIMULATION; DISLOCATIONS; MULTIPLICITY; DEFECTS; METALS AB During sliding, the grain-boundary (GB) energy depends on the atomic structures produced during relative translation of the two grains. The variation in the GB energy within the two-dimensional boundary unit cell (BUC) constitutes the GB-gamma surface. Maxima in the slope of the gamma surface determines the sliding resistance, that is the stress required to move the system over the lowest saddle points along a particular path within the BUC. In this paper we present the results of an atomistic study of the gamma surfaces for two types of boundaries in a fcc metal. One of the boundaries is a Sigma = 11, (110) {131} which is a low-energy boundary and has a simple gamma surface with a single stable configuration located at the corners and centre of the BUC. The resistance to sliding was determined by chain-of-states methods along four shear vectors connecting equivalent states within the BUC and is found to be very high in all cases. The asymmetric, Sigma = 11, (110) {252}-{414} GB, has a higher GB energy and its gamma surface is much more complex, with distinctly different structures appearing at various locations in the BUC. At certain locations, more than one structure is found for the asymmetric GB. Although complex, a chain-of-states calculation along one path across the BUC suggests that the shear strength of this GB is also quite high. Extrinsic GB dislocations are found to lower the resistance to shear considerably and, therefore, to perform the same role in shear of GBs as do glide dislocations in slip of the lattice. The existence of multiple configurations has significant implications for the interaction of lattice dislocations with GBs, the core structure of GB dislocations, the temperature dependence of GB properties, and the GB sliding resistance, which we discuss. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hoagland, RG (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. RI Hoagland, Richard/G-9821-2012 NR 16 TC 40 Z9 40 U1 1 U2 13 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD APR PY 2002 VL 82 IS 6 BP 1073 EP 1092 DI 10.1080/01418610110096084 PG 20 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 535BC UT WOS:000174623400001 ER PT J AU Singh, BN Eldrup, M Zinkle, SJ Golubov, SI AF Singh, BN Eldrup, M Zinkle, SJ Golubov, SI TI On grain-size-dependent void swelling in pure copper irradiated with fission neutrons SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID CASCADE DAMAGE CONDITIONS; MEV PROTON IRRADIATION; PRODUCTION BIAS; DEFECT ACCUMULATION; POSITRON-ANNIHILATION; DISLOCATION LOOPS; TRANSIENT REGIME; FCC METALS; ALUMINUM; CU AB The effect of grain size on void swelling has its origin in the intrinsic property of grain boundaries as neutral and unsaturable sinks for both vacancies and self-interstitial atoms. The phenomenon had already been investigated in the 1970s and it was demonstrated that the grain-size-dependent void swelling measured under irradiation producing only Frenkel pairs could be satisfactorily explained in terms of the standard rate theory (SRT) and dislocation bias. Experimental results reported in the 1980s demonstrated, on the other hand, that the effect of grain boundaries on void swelling under cascade damage conditions was radically different and could not be explained in terms of the SRT. In an effort to understand the source of this significant difference, the effect of grain size on void swelling under cascade damage conditions has been investigated both experimentally and theoretically in pure copper irradiated with fission neutrons at 623 K to a dose level of about 0.3 displacement per atom. The post-irradiation defect microstructure including voids was investigated using transmission electron microscopy and positron annihilation spectroscopy. The evolution of void swelling was calculated within the framework of the production bias model (PBM) and the SRT. The grain-size-dependent void swelling measured experimentally is in good accord with the theoretical results obtained using the PBM. The implications of these results on the modelling of void swelling under cascade damage conditions are discussed. C1 Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, Denmark. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Obninsk Phys & Power Engn Inst, Sci Ctr Russian Federat, Obninsk 249020, Russia. RP Singh, BN (reprint author), Riso Natl Lab, Dept Mat Res, DK-4000 Roskilde, Denmark. OI Zinkle, Steven/0000-0003-2890-6915 NR 44 TC 34 Z9 34 U1 0 U2 23 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD APR PY 2002 VL 82 IS 6 BP 1137 EP 1158 DI 10.1080/01418610110098785 PG 22 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 535BC UT WOS:000174623400004 ER PT J AU Kawasaki, K AF Kawasaki, K TI Slow, intermediate and fast dynamics in condensed matter SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 21st IUPAP International Conference on Statistical Physics CY JUL 15-21, 2001 CL CANCUN, MEXICO SP IUPAP DE non-equilibrium; gas theory; critical phenomena; phase ordering AB As is well-known, in gas dynamics there are three levels of descriptions: microscopic, mesoscopic and macroscopic. The corresponding equations are: Lionville, Boltzmann, and hydrodynamic equations, respectively. The difficulty of condensed matter such as classical liquids is general absence of well-defined mesoscopic level of description which is a scaffold so to speak enabling us to jump from microscopic to macroscopic descriptions. However, there are certain circumstances in which this is possible as we illustrate for critical dynamics and phase ordering kinetics. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. RP Kawasaki, K (reprint author), Los Alamos Natl Lab, CNLS, POB 1663, Los Alamos, NM 87545 USA. NR 31 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD APR 1 PY 2002 VL 306 IS 1-4 BP 1 EP 14 AR PII S0378-4371(02)00480-6 DI 10.1016/S0378-4371(02)00480-6 PG 14 WC Physics, Multidisciplinary SC Physics GA 555ET UT WOS:000175781700004 ER PT J AU Prorok, BC Goretta, KC Park, JH Balachandran, U McNallan, MJ AF Prorok, BC Goretta, KC Park, JH Balachandran, U McNallan, MJ TI Oxygen diffusion and internal oxidation of Mg in Ag/1.12at.%Mg SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE internal oxidation; kinetics; diffusion; Ag-Mg alloy; sheath ID SILVER ALLOYS; SUPERCONDUCTING PROPERTIES; MECHANICAL-PROPERTIES; SOLID SILVER; TAPES; AG; SOLUBILITY; SHEATHS AB Internal oxidation of Mg in Ag/1.12at.%Mg was studied at 450-825 degreesC in various oxygen partial pressures. Measurements of O weight gain and oxidation-front velocity showed that at 450 degreesC the rate of O penetration into the alloy was approximate to400 times slower than O diffusion in pure Ag. At 825 degreesC, this factor decreased to approximate to60 times slower. A comparison of these results with a calculation based on a model of internal oxidation indicated that O diffusivity in pure Ag was nearly identical to O diffusivity in the alloy. The decreased O penetration rate in the alloy was attributed to O uptake by the Mg species, which are able to capture superstoichiometric amounts of O. O fixation proceeded according to predictions of the model; oxidation rate increased with partial pressure due to an increased O activity gradient. However, below approximate to600 degreesC and at 0.08 atm partial pressure, O fixation progressed at a rate notably faster than that predicted by the model. This result was attributed to a change in Mg-O fixation stoichiometry, such that smaller amounts of O were absorbed, allowing the oxidation front to proceed more rapidly. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Univ Illinois, Engn Res Facil, Chicago, IL 60607 USA. RP Goretta, KC (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Prorok, Barton/A-7404-2010 NR 38 TC 5 Z9 6 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD APR 1 PY 2002 VL 370 IS 1 BP 31 EP 38 AR PII S0921-4534(01)00953-4 DI 10.1016/S0921-4534(01)00953-4 PG 8 WC Physics, Applied SC Physics GA 542ZL UT WOS:000175075800007 ER PT J AU Nozik, AJ AF Nozik, AJ TI Quantum dot solar cells SO PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES LA English DT Article; Proceedings Paper CT 1st International Workshop on Nanostructures in Photovoltaics CY JUL 28-AUG 04, 2001 CL MAX PLANCK INST PHYS KOMPLESER SYST, DRESDEN, GERMANY HO MAX PLANCK INST PHYS KOMPLESER SYST DE hot electrons; quantum dots; (ultra-high photovoltaic) conversion efficiency; impact ionization; efficiency limits ID SEMICONDUCTOR-ELECTROLYTE JUNCTIONS; HOT-CARRIER RELAXATION; LIGHT-EMITTING-DIODES; MOLECULAR PHOTOVOLTAICS; IMPACT IONIZATION; CDSE NANOCRYSTALS; BOX SYSTEMS; BULK GAAS; EFFICIENCY; POLYMER AB Quantum dot (QD) solar cells have the potential to increase the maximum attainable thermodynamic conversion efficiency of solar photon conversion up to about 66% by utilizing hot photogenerated carriers to produce higher photovoltages or higher photocurrents. The former effect is based on miniband transport and collection of hot carriers in QD array photoelectrodes before they relax to the band edges through phonon emission. The latter effect is based on utilizing hot carriers in QD solar cells to generate and collect additional electron-hole pairs through enhanced impact ionization processes. Three QD solar cell configurations are described: (1) photoelectrodes comprising QD arrays, (2) QD-sensitized nanocrystalline TiO(2), and (3) QDs dispersed in a blend of electron- and hole-conducting polymers. These high-efficiency configurations require slow hot carrier cooling times, and we discuss initial results on slowed hot electron cooling in InP QDs. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RP Nozik, AJ (reprint author), Natl Renewable Energy Lab, Ctr Basic Sci, 1617 Cole Blvd, Golden, CO 80401 USA. EM anozik@nrel.urel.gov RI Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 NR 45 TC 1424 Z9 1449 U1 60 U2 742 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD APR PY 2002 VL 14 IS 1-2 BP 115 EP 120 AR PII S1386-9477(02)00374-0 DI 10.1016/S1386-9477(02)00374-0 PG 6 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 576ZD UT WOS:000177036300018 ER PT J AU Davydov, VY Klochikhin, AA Emtsev, VV Ivanov, SV Vekshin, VV Bechstedt, F Furthmuller, J Harima, H Mudryi, AV Hashimoto, A Yamamoto, A Aderhold, J Graul, J Haller, EE AF Davydov, VY Klochikhin, AA Emtsev, VV Ivanov, SV Vekshin, VV Bechstedt, F Furthmuller, J Harima, H Mudryi, AV Hashimoto, A Yamamoto, A Aderhold, J Graul, J Haller, EE TI Band gap of InN and In-rich InxGa1-xN alloys (0.36 < x < 1) SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article ID MOLECULAR-BEAM EPITAXY; FILMS; SAPPHIRE; GROWTH C1 Russian Acad Sci, Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Univ Jena, Inst Festkorpertheorie & Theoret Opt, D-07743 Jena, Germany. Kyoto Inst Technol, Dept Elect & Informat Sci, Sakyo Ku, Kyoto 6068585, Japan. Belarus Acad Sci, Inst Solid State & Semicond Phys, Minsk 220072, Byelarus. Fukui Univ, Dept Elect Engn, Fukui 9108507, Japan. Univ Hannover, D-30167 Hannover, Germany. Univ Calif & Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Davydov, VY (reprint author), Russian Acad Sci, Ioffe Phys Tech Inst, Politekhnicheskaya 26, St Petersburg 194021, Russia. RI Furthmueller, Juergen/B-2346-2008; Davydov, Valery/E-6060-2010; Ivanov, Sergey/C-1177-2014 NR 10 TC 266 Z9 266 U1 2 U2 26 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD APR PY 2002 VL 230 IS 2 BP R4 EP R6 DI 10.1002/1521-3951(200204)230:23.0.CO;2-Z PG 3 WC Physics, Condensed Matter SC Physics GA 546MR UT WOS:000175278300003 ER PT J AU Bell, NF Sawyer, RF Volkas, RR Wong, YYY AF Bell, NF Sawyer, RF Volkas, RR Wong, YYY TI Generation of entangled states and error protection from adiabatic avoided level crossings SO PHYSICAL REVIEW A LA English DT Article ID NEUTRINO OSCILLATIONS; QUANTUM; MATTER; DYNAMICS; PARADOX AB We consider the environment-affected dynamics of N self-interacting particles living in one-dimensional double wells. Two topics are dealt with. First, we consider the production of entangled states of two-level systems. We show that by adiabatically varying the well biases, we may dynamically generate maximally entangled states, starting from initially unentangled product states. Entanglement degradation due to a common type of environmental influence is then computed by solving a master equation. However, we also demonstrate that entanglement production is unaffected if the system-environment coupling is of the type that induces "motional narrowing." As our second but related topic, we construct a different master equation that seamlessly merges error protection/detection dynamics for quantum information with the environmental couplings responsible for producing the errors in the first place. Adiabatic avoided crossing schemes are used in both topics. C1 Univ Melbourne, Sch Phys, High Energy Phys Res Ctr, Parkville, Vic 3010, Australia. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Bell, NF (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. EM n.bell@physics.unimelb.edu.au; sawyer@vulcan.physics.ucsb.edu; r.volkas@physics.unimelb.edu.au; y.wong@physics.unimelb.edu.au NR 25 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 2002 VL 65 IS 4 AR 042328 DI 10.1103/PhysRevB.65.042328 PN A PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HF UT WOS:000174978600054 ER PT J AU Dean, DJ Papenbrock, T AF Dean, DJ Papenbrock, T TI Phases in weakly interacting finite Bose systems SO PHYSICAL REVIEW A LA English DT Article ID EINSTEIN CONDENSATION; VORTICES; BOSONS AB We study precursors of thermal phase transitions in finite systems of interacting Bose gases. For weakly repulsive interactions there is a phase transition to the one-vortex state. The distribution of zeros of the partition function indicates that this transition is first order, and the precursors of the phase transition are already displayed in systems of a few dozen bosons. Systems of this size do not exhibit new phases as more vortices are added to the system. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Dean, DJ (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 2002 VL 65 IS 4 AR 043603 DI 10.1103/PhysRevA.65.043603 PN B PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HL UT WOS:000174979100022 ER PT J AU Kalosakas, G Bishop, AR AF Kalosakas, G Bishop, AR TI Small-tunneling-amplitude boson-Hubbard dimer: Stationary states SO PHYSICAL REVIEW A LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; SELF-TRAPPING EQUATION; EINSTEIN CONDENSATE; OSCILLATIONS; DYNAMICS; SYSTEM; GAS AB Analytical expressions for the energy eigenstates of the boson-Hubbard (or quantum discrete-nonlinear Schrodinger) dimer are obtained by applying perturbation theory in the small-tunneling-amplitude limit. The results are relevant for a Bose-Einstein condensate trapped in a double-well potential. A detailed comparison with the numerical solutions arising from the direct diagonalization of the Hamiltonian (for even or odd numbers of bosons) is presented, and the limits of validity of the perturbative results are determined. For fixed values of the tunneling amplitude, the accuracy of the perturbative calculation varies with the total number of bosons in different ways, depending on the particular energy level. Results for the fluctuations of the boson-number difference in each eigenstate are also presented. 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 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Kalosakas, George/L-6211-2013 OI Kalosakas, George/0000-0001-7763-718X NR 37 TC 29 Z9 29 U1 0 U2 2 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 APR PY 2002 VL 65 IS 4 AR 043616 DI 10.1103/PhysRevA.65.043616 PN B PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HL UT WOS:000174979100035 ER PT J AU Karkuszewski, ZP Zakrzewski, J Zurek, WH AF Karkuszewski, ZP Zakrzewski, J Zurek, WH TI Breakdown of correspondence in chaotic systems: Ehrenfest versus localization times SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM-CLASSICAL CORRESPONDENCE; DYNAMICAL LOCALIZATION; KICKED TOP; 2ND LAW; DECOHERENCE; STOCHASTICITY; DISSIPATION; NOISE; WAVE AB Breakdown of quantum-classical correspondence is studied on an experimentally realizable example of a one-dimensional periodically driven system. Two relevant time scales are identified in this system: the short Ehrenfest time t(h)similar toln(h(-1)) and the typically much longer localization time scale T(L)similar toh(-2). It is shown that surprisingly weak modification of the Hamiltonian may eliminate the more dramatic symptoms of localization without effecting the more subtle but ubiquitous and rapid loss of correspondence at t(h). C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Karkuszewski, ZP (reprint author), Los Alamos Natl Lab, Div Theoret, T6,MS B288, Los Alamos, NM 87545 USA. RI Zakrzewski, Jakub/B-4487-2011 OI Zakrzewski, Jakub/0000-0003-0998-9460 NR 32 TC 20 Z9 20 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 2002 VL 65 IS 4 AR 042113 DI 10.1103/PhysRevB.65.042113 PN A PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HF UT WOS:000174978600025 ER PT J AU Machicoane, GA Schenkel, T Niedermayr, TR Newmann, MW Hamza, AV Barnes, AV McDonald, JW Tanis, JA Schneider, DH AF Machicoane, GA Schenkel, T Niedermayr, TR Newmann, MW Hamza, AV Barnes, AV McDonald, JW Tanis, JA Schneider, DH TI Internal dielectronic excitation in highly charged ions colliding with surfaces SO PHYSICAL REVIEW A LA English DT Article ID HOLLOW ATOMS; ADSORPTION; SLOW; OXYGEN; NEUTRALIZATION; EQUILIBRATION; HYDROGEN; WATER AB Internal dielectronic excitation (IDE) is a correlated atomic physics process that takes place when the deexcitation of a Rydberg electron is accompanied by the excitation of a more tightly bound electron, resulting in a doubly excited inner-shell configuration. Subsequent x-ray emission involving an electron transition to a shell that initially contained no vacancies identifies the IDE process. IDE is mediated by the electron-electron interaction in a manner similar to a time-reversed Auger transition, and can occur during the neutralization of a slow highly charged ion interacting with a solid where there are many Rydberg levels that can give rise to correlated transitions to degenerate energy states. We have investigated IDE for a wide range of projectiles and solid targets by measuring the resulting x-ray emission. The characteristic features of the x-ray spectra suggest that IDE occurs above the surface of the solid. C1 Lawrence Livermore Natl Lab, Phys & space Technol Directorate, Livermore, CA 94550 USA. Univ Paris 06, Equipe Rech Ion Surface, F-75005 Paris, France. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. RP Lawrence Livermore Natl Lab, Phys & space Technol Directorate, Livermore, CA 94550 USA. NR 22 TC 17 Z9 21 U1 1 U2 3 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 APR PY 2002 VL 65 IS 4 AR 042903 DI 10.1103/PhysRevA.65.042903 PN B PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HL UT WOS:000174979100003 ER PT J AU McCurdy, CW Horner, DA Rescigno, TN AF McCurdy, CW Horner, DA Rescigno, TN TI Time-dependent approach to collisional ionization using exterior complex scaling SO PHYSICAL REVIEW A LA English DT Article ID ELECTRON-IMPACT IONIZATION; CLOSE-COUPLING METHOD; SCHRODINGER-EQUATION; HYDROGEN SCATTERING; COORDINATE CONTOURS; ATOMIC-HYDROGEN; ASYMPTOTIC FORM; CROSS-SECTIONS; THRESHOLD; MODEL AB We present a time-dependent formulation of the exterior complex scaling method that has previously been used to treat electron-impact ionization of the hydrogen atom accurately at low energies. The time-dependent approach solves a driven Schrodinger equation, and scales more favorably with the number of electrons than the original formulation. The method is demonstrated in calculations for breakup processes in two dimensions (2D) and three dimensions for systems involving short-range potentials and in 2D for electron-impact ionization in the Temkin-Poet model for electron-hydrogen atom collisions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM cwmccurdy@lbl.gov; dahorner@lbl.gov; tnr@llnl.gov NR 34 TC 35 Z9 35 U1 0 U2 3 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 APR PY 2002 VL 65 IS 4 AR 042714 DI 10.1103/PhysRevB.65.042714 PN A PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HF UT WOS:000174978600081 ER PT J AU Papenbrock, T Salgueiro, AN Weidenmuller, HA AF Papenbrock, T Salgueiro, AN Weidenmuller, HA TI Rate equations for sympathetic cooling of trapped bosons or fermions SO PHYSICAL REVIEW A LA English DT Article ID PHASE-TRANSITION ANALOGY; N-BOSONS; CONDENSATION; GASES AB We derive two different sets of rate equations for sympathetic cooling of harmonically trapped bosons or fermions. The rate equations are obtained from a master equation derived earlier by Lewenstein et al. [Phys. Rev. A 51, 4617 (1995)] by means of decoherence and ergodicity arguments. We show analytically that the thermal equilibrium state is a stationary solution of our rate equation. We present analytical results for the rate coefficients which are needed to solve the rate equations, and we give approximate formulas that permit their computation in practice. We solve the two sets of rate equations numerically and compare the results. The cooling times obtained in both approaches agree very well. The equilibration rates show fair agreement. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. RP Papenbrock, T (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 18 TC 1 Z9 1 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 2002 VL 65 IS 4 AR 043601 DI 10.1103/PhysRevA.65.043601 PN B PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HL UT WOS:000174979100020 ER PT J AU Schippers, S Kieslich, S Muller, A Gwinner, G Schnell, M Wolf, A Covington, A Bannister, ME Zhao, LB AF Schippers, S Kieslich, S Muller, A Gwinner, G Schnell, M Wolf, A Covington, A Bannister, ME Zhao, LB TI Interference effects in the photorecombination of argonlike Sc3+ ions: Storage-ring experiment and theory SO PHYSICAL REVIEW A LA English DT Article ID RECOMBINATION CROSS-SECTIONS; HIGH-RESOLUTION MEASUREMENT; DIELECTRONIC RECOMBINATION; RADIATIVE-RECOMBINATION; OSCILLATOR-STRENGTHS; URANIUM IONS; TRANSITIONS; EXCITATION; ENERGIES; SEARCH AB Absolute total electron-ion recombination rate coefficients of argonlike Sc3+(3s(2)3p(6)) ions have been measured for relative energies between electrons and ions ranging from 0 to 45 eV. This energy range comprises all dielectronic recombination resonances attached to 3p-->3d and 3p-->4s excitations. A broad resonance with an experimental width of 0.89+/-0.07 eV due to the 3p(5)3d(2) F-2 intermediate state is found at 12.31+/-0.03 eV with a small experimental evidence for an asymmetric line shape. From R-matrix and perturbative calculations we infer that the asymmetric line shape may not only be due to quantum-mechanical interference between direct and resonant recombination channels as predicted by Gorczyca [Phys. Rev. A 56, 4742 (1997)], but may be partly also due to the interaction with an adjacent overlapping dielectronic recombination resonance of the same symmetry. The overall agreement between theory and experiment is poor. Differences between our experimental and our theoretical resonance positions are as large as 1.4 eV. This illustrates the difficulty to accurately describe the structure of an atomic system with an open 3d shell with state-of-the-art theoretical methods. Furthermore, we find that a relativistic theoretical treatment of the system under study is mandatory since the existence of experimentally observed strong 3p(5)3d(2) 2D and 3p(5)3d4s D-2 resonances can only be explained when calculations beyond LS coupling are carried out. C1 Univ Giessen, Strahlenzentrum, Inst Kernphys, D-35392 Giessen, Germany. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Univ Nevada, Dept Phys, Reno, NV 89557 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. CCAST, World Lab, Beijing 100080, Peoples R China. Chinese Acad Sci, China Inst Theoret Phys, Beijing 100088, Peoples R China. RP Schippers, S (reprint author), Univ Giessen, Strahlenzentrum, Inst Kernphys, D-35392 Giessen, Germany. EM Stefan.E.Schippers@strz.uni-giessen.de RI Schippers, Stefan/A-7786-2008; Muller, Alfred/A-3548-2009; OI Schippers, Stefan/0000-0002-6166-7138; Muller, Alfred/0000-0002-0030-6929; Bannister, Mark E./0000-0002-9572-8154 NR 36 TC 42 Z9 42 U1 0 U2 2 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 APR PY 2002 VL 65 IS 4 AR 042723 DI 10.1103/PhysRevA.65.042723 PN A PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HF UT WOS:000174978600090 ER PT J AU Somma, R Ortiz, G Gubernatis, JE Knill, E Laflamme, R AF Somma, R Ortiz, G Gubernatis, JE Knill, E Laflamme, R TI Simulating physical phenomena by quantum networks SO PHYSICAL REVIEW A LA English DT Article ID COMPUTATION; GATES; TRANSFORMATION; COMPUTER; SYSTEMS AB Physical systems, characterized by an ensemble of interacting constituents, can be represented and studied by different algebras of operators (observables). For example, a fully polarized electronic system can be studied by means of the algebra generated by the usual fermionic creation and annihilation operators or by the algebra of Pauli (spin-1/2) operators. The Jordan-Wigner isomorphism gives the correspondence between the two algebras. As we previously noted, similar isomorphisms enable one to represent any physical system in a quantum computer. In this paper we evolve and exploit this fundamental observation to simulate generic physical phenomena by quantum networks. We give quantum circuits useful for the efficient evaluation of the physical properties (e.g., the spectrum of observables or relevant correlation functions) of an arbitrary system with Hamiltonian H. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Somma, R (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 29 TC 70 Z9 70 U1 0 U2 3 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 APR PY 2002 VL 65 IS 4 AR 042323 DI 10.1103/PhysRevB.65.042323 PN A PG 17 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 541HF UT WOS:000174978600049 ER PT J AU Cai, T Fournee, V Lograsso, T Ross, A Thiel, PA AF Cai, T Fournee, V Lograsso, T Ross, A Thiel, PA TI STM study of the atomic structure of the icosahedral Al-Cu-Fe fivefold surface SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ENERGY-ELECTRON DIFFRACTION; SINGLE QUASI-CRYSTALS; PD-MN; AL68PD23MN9; ALPDMN; LEED; NEUTRON AB We use scanning tunneling microscopy (STM) to investigate the atomic structure of the icosahedral (i-) Al-Cu-Fe fivefold surface in ultra high vacuum (UHV). Studies show that large, atomically flat terraces feature many ten-petal "flowers" with internal structure. The observed flower patterns can be associated with features on Al rich dense atomic planes generated from two-dimensional cuts of bulk models based on x-ray and neutron diffraction experiments. The results confirm that the fivefold surface of i-Al-Cu-Fe corresponds to a bulk-terminated plane. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Met & Ceram, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Thiel, PA (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 22 TC 29 Z9 29 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 APR 1 PY 2002 VL 65 IS 14 AR 140202 DI 10.1103/PhysRevB.65.140202 PG 4 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300003 ER PT J AU Chartier, A Meis, C Weber, WJ Corrales, LR AF Chartier, A Meis, C Weber, WJ Corrales, LR TI Theoretical study of disorder in Ti-substituted La2Zr2O7 SO PHYSICAL REVIEW B LA English DT Article ID ABINITIO HARTREE-FOCK; GRAIN-BOUNDARY DIFFUSION; IONIC-CONDUCTIVITY; ELASTIC-CONSTANTS; WASTE FORM; PYROCHLORE; ZIRCONIA; OXIDES; PLUTONIUM; OXYGEN AB Pyrochlores have the striking feature that their radiation resistance is highly dependent on their composition. In this work, the propensity of a pyrochlore to transform to a cation-disordered structure and the influence of titanium ions is ascertained from the mechanisms of defect formation. A detailed study of defect formation and migration activation energies in Ti-substituted La2Zr2O7 is carried out by modern theoretical computational methods that include the use of a classical interatomic potential with a modified shell model to capture the effects of local charge transfer. The results show that La2Zr2O7 has a tendency towards cation disorder, whereas, substitution of Zr with Ti makes this tendency energetically less favorable. C1 CEA Saclay, DEN, DPC, SCPA, F-91191 Gif Sur Yvette, France. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Chartier, A (reprint author), CEA Saclay, DEN, DPC, SCPA, Batiment 450, F-91191 Gif Sur Yvette, France. RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 66 TC 54 Z9 55 U1 3 U2 21 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 APR 1 PY 2002 VL 65 IS 13 AR 134116 DI 10.1103/PhysRevB.65.134116 PG 11 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900061 ER PT J AU Chashka, KB Fisher, B Genossar, J Keren, A Patlagan, L Reisner, GM Shimshoni, E Mitchell, JF AF Chashka, KB Fisher, B Genossar, J Keren, A Patlagan, L Reisner, GM Shimshoni, E Mitchell, JF TI Linear and nonlinear electronic transport in weakly insulating double layered manganites SO PHYSICAL REVIEW B LA English DT Article ID COLOSSAL MAGNETORESISTANCE MANGANITES; TEMPERATURE-DEPENDENCE; MAGNETIC-INTERACTIONS; GRAIN-BOUNDARIES; LA1.2SR1.8MN2O7 AB Polycrystalline La1.2Sr1.8Mn2-yCryO7 (0less than or equal toyless than or equal to0.25) is a weakly insulating ferromagnet with low-T thermopower of metalliclike values. This combination of properties indicates electronic transport through percolating paths embedded in an insulating medium. The temperature dependence of the resistivity at low T and the nonlinear conductivity obtained from pulsed I-V measurements over a wide range of currents are consistent with inelastic tunneling through intergrain or intragrain weak links that disrupt the percolating paths. Thermopower and resistivity measurements on two weakly insulating single crystals of La1.4Sr1.6Mn1.85Cr0.15O7-delta and the I-V measurements on the more resistive crystal exhibit features very similar to those found in the polycrystals. In single crystals the nonlinearity of conductivity is pronounced under much lower electric fields than in polycrystals. C1 Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Technion Israel Inst Technol, Crown Ctr Superconduct, IL-32000 Haifa, Israel. Oranim Haifa Univ, Dept Math Phys, IL-36006 Tivon, Israel. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Chashka, KB (reprint author), Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. NR 22 TC 14 Z9 14 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 APR 1 PY 2002 VL 65 IS 13 AR 134441 DI 10.1103/PhysRevB.65.134441 PG 8 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900117 ER PT J AU Cimpoiasu, E Sandu, V Almasan, CC Paulikas, AP Veal, BW AF Cimpoiasu, E Sandu, V Almasan, CC Paulikas, AP Veal, BW TI Effect of spin ordering on the magnetotransport of YBa2Cu3O6.25 SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; ANTIFERROMAGNETIC YBA2CU3O6+X; MAGNETORESISTANCE ANOMALIES; SUPERCONDUCTING TRANSITION; ANISOTROPIC RESISTIVITY; HYDROSTATIC-PRESSURE; CHARGED STRIPES; UNIAXIAL-STRESS; YBA2CU3O7-DELTA; TEMPERATURE AB In-plane and out-of-plane magnetoresistivity (MR) measurements were performed on the same antiferromagnetic (AF)YBa2Cu3O6.25 single crystal using a six-lead configuration, in magnetic fields H applied along the ab plane. We identified three terms contributing to both MRs. The first term is anisotropic with respect to the in-plane field orientation, with a twofold symmetry for the in-plane MR and a fourfold symmetry for the out-of-plane MR. We show that these anisotropic features of the magnetoresistivity tensor can be understood in terms of the coupling between the spin and the elastic degrees of freedom. The second term in both MRs is negative and isotropic upon in-plane H rotation. We ascribe this term to charge-carrier scattering on the AF domain walls. Finally, the third term is positive, quadratic in H and seems to correlate with the AF phase transition. C1 Kent State Univ, Dept Phys, Kent, OH 44242 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Inst Mat Phys, R-76900 Bucharest, Romania. RP Cimpoiasu, E (reprint author), Kent State Univ, Dept Phys, Kent, OH 44242 USA. RI Sandu, Viorel/B-8660-2011 NR 29 TC 9 Z9 9 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 APR 1 PY 2002 VL 65 IS 14 AR 144505 DI 10.1103/PhysRevB.65.144505 PG 8 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300111 ER PT J AU Eisenbach, M Gyorffy, BL Stocks, GM Ujfalussy, B AF Eisenbach, M Gyorffy, BL Stocks, GM Ujfalussy, B TI Magnetic anisotropy of monoatomic iron chains embedded in copper SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-FUNCTIONAL FORMALISM; MAGNETOCRYSTALLINE ANISOTROPY; GIANT MAGNETORESISTANCE; SCATTERING-THEORY; PILLARS; SYSTEMS; MODEL; FE AB We have calculated the anisotropic magnetic properties of monoatomic chains of iron atoms embedded in fcc copper. The calculations are based on a relativistic extension of the locally self-consistent multiple scattering method that is able to treat the large supercells required to model inhomogeneous systems. We have investigated two chain geometries: Fe chains along the 110 and 100 directions. We found that the magnetocrystalline anisotropy energy favored orientations of the magnetic moments perpendicular to the chains, while the magnetostatic energy was lowest when the moments are aligned parallel to the chain. Interestingly, our parameter free qualitative results implies that these competing effects are finely balanced. C1 Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Eisenbach, M (reprint author), Univ Bristol, HH Wills Phys Lab, Tyndall Ave, Bristol BS8 1TL, Avon, England. RI Ujfalussy, Balazs/A-8155-2013; Stocks, George Malcollm/Q-1251-2016; OI Ujfalussy, Balazs/0000-0003-3338-4699; Stocks, George Malcollm/0000-0002-9013-260X; Eisenbach, Markus/0000-0001-8805-8327 NR 29 TC 29 Z9 29 U1 1 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 APR 1 PY 2002 VL 65 IS 14 AR 144424 DI 10.1103/PhysRevB.65.144424 PG 7 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300079 ER PT J AU Fitzsimmons, MR Leighton, C Nogues, J Hoffmann, A Liu, K Majkrzak, CF Dura, JA Groves, JR Springer, RW Arendt, PN Leiner, V Lauter, H Schuller, IK AF Fitzsimmons, MR Leighton, C Nogues, J Hoffmann, A Liu, K Majkrzak, CF Dura, JA Groves, JR Springer, RW Arendt, PN Leiner, V Lauter, H Schuller, IK TI Influence of in-plane crystalline quality of an antiferromagnet on perpendicular exchange coupling and exchange bias SO PHYSICAL REVIEW B LA English DT Article ID UNIDIRECTIONAL ANISOTROPY; MAGNETIZATION REVERSAL; THIN-FILMS; INTERFACES; DEPENDENCE; SYSTEMS; MODEL; MULTILAYERS; COERCIVITY; BILAYERS AB We have undertaken a systematic study of the influence of in-plane crystalline quality of the antiferromagnet on exchange bias. Polarized neutron reflectometry and magnetometry were used to determine the anisotropies of polycrystalline ferromagnetic (F) Fe thin films exchange coupled to antiferromagnetic (AF) untwinned single crystal (110) FeF2, twinned single crystal (110) FeF2 thin films and (110) textured polycrystalline FeF2 thin films. A correlation between the anisotropies of the AF and F thin films with exchange bias was identified. Specifically, when exchange coupling across the F-AF interface introduces an additional anisotropy axis in the F thin film-one perpendicular to the cooling field, the magnetization reversal mechanism is affected (as observed with neutron scattering) and exchange bias is significantly enhanced. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Autonoma Barcelona, Inst Catalana Recerca & Estudis Avancats, Bellaterra, Spain. Univ Autonoma Barcelona, Dept Fis, Bellaterra, Spain. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. RP Fitzsimmons, MR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Dura, Joseph/B-8452-2008; Liu, Kai/B-1163-2008; Nogues, Josep/D-7791-2012; Lujan Center, LANL/G-4896-2012; Hoffmann, Axel/A-8152-2009 OI Dura, Joseph/0000-0001-6877-959X; Liu, Kai/0000-0001-9413-6782; Nogues, Josep/0000-0003-4616-1371; Hoffmann, Axel/0000-0002-1808-2767 NR 36 TC 53 Z9 53 U1 1 U2 10 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 APR 1 PY 2002 VL 65 IS 13 AR 134436 DI 10.1103/PhysRevB.65.134436 PG 8 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900112 ER PT J AU Garcia, DJ Hallberg, K Batista, CD Capponi, S Poilblanc, D Avignon, M Alascio, B AF Garcia, DJ Hallberg, K Batista, CD Capponi, S Poilblanc, D Avignon, M Alascio, B TI Charge and spin inhomogeneous phases in the ferromagnetic Kondo lattice model SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM RENORMALIZATION-GROUPS; METAL-INSULATOR-TRANSITION; JAHN-TELLER PHONONS; NEUTRON-DIFFRACTION; DOUBLE-EXCHANGE; MAGNETIC CORRELATIONS; ORDERING TRANSITION; ELECTRONIC MODELS; SEPARATION; DIAGRAM AB We study numerically the one-dimensional ferromagnetic Kondo lattice. This model is widely used to describe nickel and manganese perovskites. Due to the competition between double and superexchange, we find a region where the formation of magnetic polarons induces a charge-ordered state. This ordering is present even in the absence of any intersite Coulomb repulsion. There is an insulating gap associated to the charge structure formation. We also study the insulator-metal transition induced by a magnetic field, which removes simultaneously both charge and spin ordering. C1 Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Comis Nacl Energia Atom, Inst Balseiro, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Toulouse 3, Lab Phys Quant IRSAMC, F-31062 Toulouse, France. CNRS, Etud Proprietes Elect Solides Lab, F-38042 Grenoble 9, France. RP Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. RI Capponi, Sylvain/A-8851-2010; Batista, Cristian/J-8008-2016; OI Capponi, Sylvain/0000-0001-9172-049X; Garcia, Daniel Julio/0000-0001-6777-9184 NR 40 TC 25 Z9 25 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 APR 1 PY 2002 VL 65 IS 13 AR 134444 DI 10.1103/PhysRevB.65.134444 PG 8 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900120 ER PT J AU Gronbech-Jensen, N Samuelsen, MR AF Gronbech-Jensen, N Samuelsen, MR TI Magnetic interaction between spatially extended superconducting tunnel junctions SO PHYSICAL REVIEW B LA English DT Article ID JOSEPHSON SOLITON OSCILLATORS; SYSTEM AB A general description of magnetic interactions between superconducting tunnel junctions is given. The description covers a wide range of possible experimental systems, and we explicitly explore two experimentally relevant limits of coupled junctions. One is the limit of junctions with tunneling distance much smaller than the London penetration depth of the superconductors, the other is the limit where the tunneling distance is much larger than the London penetration depth. The former case has previously been studied in the context of adjacent conventional Josephson junctions, while the latter has been considered through arrays of superconducting weak links based on semiconductor quantum wells with superconducting electrodes. We use the model to make direct interpretations of the published experiments and thereby propose that long-range magnetic interactions are responsible for the reported experimental signatures of coupling between tunnel junctions. C1 Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. Tech Univ Denmark, Dept Phys, DK-2800 Kgs Lyngby, Denmark. RP Gronbech-Jensen, N (reprint author), Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. NR 13 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 APR 1 PY 2002 VL 65 IS 14 AR 144512 DI 10.1103/PhysRevB.65.144512 PG 6 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300118 ER PT J AU Hellwig, O Maat, S Kortright, JB Fullerton, EE AF Hellwig, O Maat, S Kortright, JB Fullerton, EE TI Magnetic reversal of perpendicularly-biased Co/Pt multilayers SO PHYSICAL REVIEW B LA English DT Article ID RANDOM-FIELD MODEL; EXCHANGE BIAS; ANISOTROPY; BILAYERS; MECHANISMS; ASYMMETRY; DOMAIN AB We have investigated the magnetic reversal behavior of [(Co/Pt)(4)Co/CoO](N) multilayers that are exchange biased perpendicular to the film plane. We find clear differences in the nucleation properties of the reverse domains of the ascending and descending branches of the hysteresis loops. However, the evolution of the reverse domains, once nucleated, is symmetric to positive and negative field sweeps. This behavior is in contrast to many in-plane biased experiments and can be understood from the collinear uniaxial magnetic anisotropy and unidirectional exchange-bias axis. C1 IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Hellwig, O (reprint author), IBM Corp, Almaden Res Ctr, 650 Harry Rd, San Jose, CA 95120 USA. RI Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 22 TC 67 Z9 68 U1 1 U2 20 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 APR 1 PY 2002 VL 65 IS 14 AR 144418 DI 10.1103/PhysRevB.65.144418 PG 4 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300073 ER PT J AU Hill, JM Johnston, DC Miller, LL AF Hill, JM Johnston, DC Miller, LL TI Decomposition of the spin-1/2 Heisenberg chain compound Sr2CuO3 in air and water: An EPR and magnetic susceptibility study of Sr2Cu(OH)(6) SO PHYSICAL REVIEW B LA English DT Article ID INCOMMENSURATE MODULATED STRUCTURE; HIGH-PRESSURE SYNTHESIS; ANTIFERROMAGNETIC CHAIN; ROTATION MEASUREMENTS; TETRAGONAL SR2CUO3+X; CUPRATE SR2CUO3; HEAT-TREATMENT; SUPERCONDUCTIVITY; TEMPERATURE; THERMODYNAMICS AB The reaction of Sr2CuO3 with air and water was studied to address the origin of the reported variable Curie-Weiss impurity contribution to the magnetic susceptibility chi of this compound at low temperatures. Sr2CuO3 was found to decompose upon exposure to either of these environments. The compound Sr2Cu(OH)(6) was identified as the primary reaction product. A pure sample of Sr2Cu(OH)(6) was then prepared separately. Electron paramagnetic resonance, isothermal magnetization versus magnetic field [M(H)], and chi versus temperature T measurements demonstrate that Sr2Cu(OH)(6) contains weakly interacting Cu2+ magnetic moments with spin S=1/2 and average g factor equal to 2.133. From a fit of chi(T) by the Curie-Weiss law and of the M(H) isotherms by modified Brillouin functions, the exchange interaction between adjacent Cu2+ spins was found to be J/k(B)=1.06(4) K, a weakly antiferromagnetic interaction. Our results indicate that the previously reported, strongly sample-dependent, Curie-Weiss contribution to chi(T) of a polycrystalline Sr2CuO3 sample most likely arises from exposing the sample to air, resulting in a variable amount of paramagnetic Sr2Cu(OH)(6) on the surface of the sample. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Hill, JM (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 51 TC 7 Z9 7 U1 2 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 APR 1 PY 2002 VL 65 IS 13 AR 134428 DI 10.1103/PhysRevB.65.134428 PG 9 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900104 ER PT J AU Jung, MH Lacerda, AH Takabatake, T AF Jung, MH Lacerda, AH Takabatake, T TI Magnetic and transport properties of the antiferromagnetic Kondo-lattice compound CeNiBi2 SO PHYSICAL REVIEW B LA English DT Article ID R = LA; CE AB We report results of studies on the magnetic and transport properties of CeNiBi2. The magnetic susceptibility exhibits a sharp peak at T-N=6 K, indicating an antiferromagnetic phase transition. This antiferromagnetic order below T-N is confirmed by magnetization measurement, which displays a metamagneticlike transition at H-m=5 T. Both low-temperature susceptibility and high-field magnetization are suggestive of strong crystalline-electric-field effect in CeNiBi2. The electrical resistivity shows the presence of Kondo and crystal-field effects with a sharp drop below T-N due to the antiferromagnetic ordering. This sharp drop below T-N in the electrical resistivity is suppressed slightly to higher temperatures by an applied magnetic field to 18 T. With increasing magnetic field, the slope of magnetoresistance changes from positive to negative, being indicative of the transition to a field-induced ferromagnetic state. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Hiroshima Univ, Dept Quantum Matter, ADSM, Higashihiroshima 7398526, Japan. RP Jung, MH (reprint author), Los Alamos Natl Lab, Natl High Magnet Field Lab, MS E536, Los Alamos, NM 87545 USA. RI Takabatake, Toshiro/L-2882-2014 OI Takabatake, Toshiro/0000-0002-3293-8592 NR 11 TC 19 Z9 19 U1 0 U2 17 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 APR 1 PY 2002 VL 65 IS 13 AR 132405 DI 10.1103/PhysRevB.65.132405 PG 3 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900013 ER PT J AU Kenzelmann, M Coldea, R Tennant, DA Visser, D Hofmann, M Smeibidl, P Tylczynski, Z AF Kenzelmann, M Coldea, R Tennant, DA Visser, D Hofmann, M Smeibidl, P Tylczynski, Z TI Order-to-disorder transition in the XY-like quantum magnet Cs2CoCl4 induced by noncommuting applied fields SO PHYSICAL REVIEW B LA English DT Article ID MODEL; CHAIN AB We explore the effects of noncommuting applied fields on the ground-state ordering of the quasi-one-dimensional spin-1/2 XY-like antiferromagnet Cs2CoCl4 using single-crystal neutron diffraction. In zero-field, interchain couplings cause long-range order below T-N=217(5) mK with chains ordered antiferromagnetically along their length and moments confined to the (b,c) plane. Magnetic fields applied at an angle to the XY planes are found to initially stabilize the order by promoting a spin-flop phase with an increased perpendicular antiferromagnetic moment. In higher fields the antiferromagnetic order becomes unstable and a transition occurs to a phase with no long-range order in the (b,c) plane, proposed to be a spin-liquid phase that arises when the quantum fluctuations induced by the noncommuting field become strong enough to overcome ordering tendencies. Magnetization measurements confirm that saturation occurs at much higher fields and that the proposed spin-liquid state exists in the region 2.10BR AB We present high-resolution measurements of the coefficient of thermal expansion alpha(T)=partial derivative ln l(T)/partial derivativeT of the quasi-two-dimensional (quasi-2D) salts kappa-(BEDT-TTF)(2)X with X=Cu(NCS)(2), Cu[N(CN)(2)]Br, and Cu[N(CN)(2)]Cl in the temperature range Tless than or equal to150 K. Three distinct kinds of anomalies corresponding to different temperature ranges have been identified. These are (A) phase-transition anomalies into the superconducting (X=Cu(NCS)(2), Cu[N(CN)(2)]Br) and antiferromagnetic (X=Cu[N(CN)(2)]Cl) ground state, (B) phase-transition-like anomalies at intermediate temperatures (30-50) K for the superconducting salts, and (C) kinetic, glasslike transitions at higher temperatures, i.e., (70-80) K for all compounds. By a thermodynamic analysis of the discontinuities at the second-order phase transitions that characterize the ground state of system (A), the uniaxial-pressure coefficients of the respective transition temperatures could be determined. We find that in contrast to what has been frequently assumed, the intraplane-pressure coefficients of T-c for this family of quasi-2D superconductors do not reveal a simple form of systematics. This demonstrates that attempts to model these systems by solely considering in-plane electronic parameters are not appropriate. At intermediate temperatures (B), distinct anomalies reminiscent of second-order phase transitions have been found at T-*=38 K and 45 K for the superconducting X=Cu(NCS)(2) and Cu[N(CN)(2)]Br salts, respectively. Most interestingly, we find that the signs of the uniaxial pressure coefficients of T-*, partial derivativeT(*)/partial derivativep(i) (i=a,b,c), are strictly anticorrelated with those of T-c. Based on comparative studies including the nonsuperconducting X=Cu[N(CN)(2)]Cl salt as well as isotopically labeled compounds, we propose that T-* marks the transition to a density-wave state forming on minor, quasi-1D parts of the Fermi surface. Our results are compatible with two competing order parameters that form on disjunct portions of the Fermi surface. At elevated temperatures (C), all compounds show alpha(T) anomalies that can be identified with a kinetic, glasslike transition where, below a characteristic temperature T-g, disorder in the orientational degrees of freedom of the terminal ethylene groups becomes frozen in. Our results provide a natural explanation for the unusual time- and cooling-rate dependences of the ground-state properties in the hydrogenated and deuterated Cu[N(CN)(2)]Br salts reported in the literature. C1 Max Planck Inst Chem Phys Fester Stoffe, D-01187 Dresden, Germany. Goethe Univ Frankfurt, Inst Phys, FOR 412, D-60054 Frankfurt, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 980, Japan. RP Max Planck Inst Chem Phys Fester Stoffe, D-01187 Dresden, Germany. RI Sasaki, Takahiko/F-1231-2010; Kini, Aravinda/F-4467-2012 OI Sasaki, Takahiko/0000-0002-0767-5428; NR 76 TC 111 Z9 111 U1 2 U2 14 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 APR 1 PY 2002 VL 65 IS 14 AR 144521 DI 10.1103/PhysRevB.65.144521 PG 14 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300127 ER PT J AU Pierce, JP Shen, J Wu, RQ AF Pierce, JP Shen, J Wu, RQ TI Spin reorientation of ultrathin Fe/Cu(100) films driven by the redistribution of Co adatoms SO PHYSICAL REVIEW B LA English DT Article ID IRON AB Two reorientations of the easy axis of magnetization of Co-capped Fe/Cu(100) ultrathin films can be driven simply by changing the spatial arrangement of the Co atoms. This rearrangement is achieved by annealing and cooling the capped films before each magnetic measurement. Scanning tunneling microscopy images and ab initio calculations indicate that the first transition, a spin flop from the perpendicular to the in-plane direction, results from increasing the average Co island size. Further measurements and ab initio studies show that the reemergence of perpendicular magnetization, which occurs at higher annealing temperatures, is likely to be due to alloying at the Fe-Co interface. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Calif State Univ Northridge, Dept Phys & Astron, Northridge, CA 91330 USA. RP Pierce, JP (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Wu, Ruqian/C-1395-2013 OI Wu, Ruqian/0000-0002-6156-7874 NR 9 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 2002 VL 65 IS 13 AR 132408 DI 10.1103/PhysRevB.65.132408 PG 4 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900016 ER PT J AU Rogado, N Huang, Q Lynn, JW Ramirez, AP Huse, D Cava, RJ AF Rogado, N Huang, Q Lynn, JW Ramirez, AP Huse, D Cava, RJ TI BaNi2V2O8: A two-dimensional honeycomb antiferromagnet SO PHYSICAL REVIEW B LA English DT Article ID SPIN-GLASS BEHAVIOR; RARE-EARTH IONS; MAGNETIC ORDER; MNPS3; ER; 2D AB The magnetic properties of BaNi2V2O8 are reported. The magnetic Ni ions are arranged in a two-dimensional (2D) honeycomb net. Susceptibility, specific heat, and neutron diffraction measurements reveal the onset of antiferromagnetic long-range ordering (LRO) close to 50 K. Diffuse scattering that is characteristic of strong 2D magnetic correlations are observed up to 100 K. chi(T) of Ba(Ni1-xMgx)(2)V2O8 (0less than or equal toxless than or equal to0.2) shows the gradual disappearance of LRO with doping. C1 Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08544 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Dept Thermal Phys, Los Alamos, NM 87545 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RP Rogado, N (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. NR 23 TC 35 Z9 35 U1 4 U2 32 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 APR 1 PY 2002 VL 65 IS 14 AR 144443 DI 10.1103/PhysRevB.65.144443 PG 7 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300098 ER PT J AU Schelling, PK Phillpot, SR Keblinski, P AF Schelling, PK Phillpot, SR Keblinski, P TI Comparison of atomic-level simulation methods for computing thermal conductivity SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; CARBON NANOTUBES; GRAIN-BOUNDARIES; HEAT-FLOW; SILICON; DIAMOND; POINT AB We compare the results of equilibrium and nonequilibrium methods to compute thermal conductivity. Using Sillinger-Weber silicon as a model system, we address issues related to nonlinear response, thermal equilibration, and statistical averaging. In addition, we present an analysis of finite-size effects and demonstrate how reliable results can be obtained when using nonequilibrium methods by extrapolation to an infinite system size. For the equilibrium Green-Kubo method, we show that results for the thermal conductivity are insensitive to the choice of the definition of local energy from the many-body part of the potential. Finally, we show that the results obtained by the equilibrium and nonequilibrium methods are consistent with each other and for the case of Si are in reasonable agreement with experimental results. C1 Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. RP Schelling, PK (reprint author), Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany. RI Phillpot, Simon/J-9117-2012 NR 32 TC 657 Z9 671 U1 16 U2 132 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 APR 1 PY 2002 VL 65 IS 14 AR 144306 DI 10.1103/PhysRevB.65.144306 PG 12 WC Physics, Condensed Matter SC Physics GA 541HZ UT WOS:000174980300055 ER PT J AU Schneibel, JH Rawn, CJ Watkins, TR Payzant, EA AF Schneibel, JH Rawn, CJ Watkins, TR Payzant, EA TI Thermal expansion anisotropy of ternary molybdenum silicides based on Mo5Si3 SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-STRUCTURE AB The coefficient of thermal expansion (CTE) of the tetragonal silicide Mo5Si3 is highly anisotropic. The ratio of the CTE's in the c and a directions, CTE(c)/CTE(a), is approximately 2. Partial substitution of the Mo in Mo5Si3 by "larger" Nb or "smaller" V atoms increases or reduces the lattice parameters, respectively. In both cases the CTE anisotropy CTE(c)/CTE(a) decreases significantly and values as small as 1.25 are observed. Similar results have been reported previously for Ti5Si3 alloyed with "large" Zr atoms and for Zr5Si3 alloyed with "small" Ti atoms. These results are interpreted in terms of the site occupation of the ternary alloying additions and the resulting reductions in the anharmonicity along the c axis. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Payzant, Edward/B-5449-2009; Watkins, Thomas/D-8750-2016 OI Payzant, Edward/0000-0002-3447-2060; Watkins, Thomas/0000-0002-2646-1329 NR 12 TC 22 Z9 23 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 APR 1 PY 2002 VL 65 IS 13 AR 134112 DI 10.1103/PhysRevB.65.134112 PG 5 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900057 ER PT J AU Sturhahn, W Toellner, TS AF Sturhahn, W Toellner, TS TI Quantification of contaminants to incoherent nuclear resonant scattering SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-OF-STATES; X-RAY-SCATTERING; SYNCHROTRON-RADIATION; INELASTIC-SCATTERING; THIN-FILMS; ABSORPTION; SN-119; IRON AB We calculate the contribution of inelastic electronic x-ray scattering to inelastic incoherent nuclear resonant scattering measurements. We discuss the propagation of plane waves in a medium with a strong energy-dependent index of refraction and treat the inelastic electronic scattering in the kinematical approximation. In experimentally relevant situations, the electronic admixture proves negligible. We conclude that inelastic incoherent nuclear resonant scattering provides partial, vibrational densities of states for the resonant nuclei. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Sturhahn, W (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 31 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 2002 VL 65 IS 13 AR 134305 DI 10.1103/PhysRevB.65.134305 PG 12 WC Physics, Condensed Matter SC Physics GA 539ZR UT WOS:000174903900075 ER PT J AU Zhang, CL Chen, XJ Almasan, CC Gardner, JS Sarrao, JL AF Zhang, CL Chen, XJ Almasan, CC Gardner, JS Sarrao, JL TI Low-temperature electrical transport in bilayer manganite La1.2Sr1.8Mn2O7 SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; LAYERED LA1.2SR1.8MN2O7; GIANT MAGNETORESISTANCE; INSULATOR-TRANSITION; NEUTRON-SCATTERING; PHASE-DIAGRAM; LA1-XSRXMNO3; Y1-XPRXBA2CU3O7-DELTA; LA1-XCAXMNO3; COLLAPSE AB The temperature T and magnetic-field H dependences of anisotropic in-plane rho(ab) and out-of-plane rho(c) resistivities are investigated in single crystals of the bilayer manganite La1.2Sr1.8Mn2O7. Below the Curie transition temperature T-c=125 K, rho(ab) and rho(c) display almost the same temperature dependence with an up-turn around 50 K. In the metallic regime (50 K less than or equal toTless than or equal to 110 K), both rho(ab)(T) and rho(c)(T) follow a T-9/2 dependence, consistent with the two-magnon scattering. We found that the value of the proportionality coefficient B-ab(fit) and the ratio of the exchange interaction J(ab)/J(c), obtained by fitting the data, are in excellent agreement with the calculated B-ab based on the two-magnon model and J(ab)/J(c) deduced from neutron scattering, respectively. This provides further support for this scattering mechanism. At even lower T, in the nonmetallic regime (T<50 K), both the in-plane σ(ab) and out-of-plane σ(c) conductivities obey a T-1/2 dependence, consistent with weak-localization effects. Hence this demonstrates the three-dimensional metallic nature of the bilayer manganite La1.2Sr1.8Mn2O7 at Ttau(L)(-)nu in models with a singlet neutrino in large extra dimensions. The observation of such a signal would provide distinctive evidence for these models since in the standard two-Higgs-doublet model type II, H--->tau(L)(-)nu is completely suppressed. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Lyon 1, Inst Phys Nucl, F-69622 Villeurbanne, France. RP Assamagan, KA (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 39 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 2002 VL 65 IS 7 AR 076006 DI 10.1103/PhysRevD.65.076006 PN B PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200052 ER PT J AU Atwood, D Soni, A AF Atwood, D Soni, A TI Determining alpha and gamma from direct CP violation in B-u, B-d, and B-s decays to two vector mesons SO PHYSICAL REVIEW D LA English DT Article ID ANGLE-GAMMA; CKM PHASES; INFORMATION; ASYMMETRIES; PENGUINS; PHYSICS; MODES; B->VV; QCD AB A method for the clean determination of the unitarity angles alpha and gamma is proposed that uses only direct CP violation and does not require any time dependent measurements. The method takes advantage of the helicity amplitudes for B-u, B-d, and B-s decay to two vector mesons and can be used, at any B facility, in conjunction with a large number of modes. It also allows for experimental tests of the theoretical approximations involved. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Brookhaven Natl Lab, Theory Grp, Upton, NY 11973 USA. RP Atwood, D (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. NR 29 TC 14 Z9 14 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 APR 1 PY 2002 VL 65 IS 7 AR 073018 DI 10.1103/PhysRevD.65.073018 PN A PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HX UT WOS:000174980100026 ER PT J AU Blokland, I Czarnecki, A Melnikov, K AF Blokland, I Czarnecki, A Melnikov, K TI Expansion of bound-state energies in powers of m/M and (1-m/M) SO PHYSICAL REVIEW D LA English DT Article ID LAMB SHIFT; RECOIL CONTRIBUTIONS; FIELD; RENORMALIZATION; INTEGRATION; MOMENTA AB Elaborating on a previous Letter [A. Czarnecki and K. Melnikov, Phys. Rev. Lett. 87, 013001 (2001)], we use a new approach to compute energy levels of a nonrelativistic bound state of two constituents, with masses m and M, by systematic expansions-one in powers of m/M and another in powers of (1-m/M). Technical aspects of the calculations are described in detail. Theoretical predictions are given for O(alpha(Zalpha)(5)) radiative recoil and O((Zalpha)(6)) pure recoil corrections to the average energy shift and hyperfine splitting relevant for hydrogen, muonic hydrogen, and muonium. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Blokland, I (reprint author), Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. NR 28 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 2002 VL 65 IS 7 AR 073015 DI 10.1103/PhysRevD.65.073015 PN A PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HX UT WOS:000174980100023 ER PT J AU Chiang, CW Rosner, JL AF Chiang, CW Rosner, JL TI Updated analysis of some two-body charmless B decays SO PHYSICAL REVIEW D LA English DT Article ID MESON DECAYS; K-ETA; FACTORIZATION; STATES; GAMMA; MODES; LIGHT AB New data from the BaBar, Belle, and CLEO Collaborations on B decays to two-body charmless final states are analyzed, with the following consequences. (1) The penguin amplitude which dominates the decay B+-->pi(+)K(*0) has a magnitude similar to that dominating B+-->pi(+)K(0). (2) The decay B+-->pi(+)eta, a good candidate for observing direct CP violation, should be detectable at present levels of sensitivity. (3) The decays B+-->eta(')K(+) and B+-->etaK(*+) are sufficiently similar in rate to the corresponding decays B-0-->eta(')K(0) and B-0-->etaK(*0), respectively, that one cannot yet infer the need for "tree" amplitudes t(') contributing to the B+ but not the B-0 decays. Statistical requirements for observing this and other examples of tree-penguin interference are given. (4) Whereas the B+-->eta(')K(+) and B-0-->eta(')K(0) rates cannot be accounted for by the penguin amplitude p(') alone but require an additional flavor-singlet penguin contribution s('), no such flavor-singlet penguin contribution is yet called for in the decays B+-->etaK(*+) or B-0-->etaK(*0). Predictions for the rates for B+-->eta(')K(*+) and B-0-->eta(')K(*0) are given which would allow one to gauge the importance of these flavor-singlet penguin amplitudes. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. RP Argonne Natl Lab, HEP Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM chengwei@hep.uchicago.edu; rosner@hep.uchicago.edu NR 50 TC 45 Z9 45 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 APR 1 PY 2002 VL 65 IS 7 AR 074035 DI 10.1103/PhysRevD.65.074035 PN B PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200008 ER PT J AU Chung, SU Danyo, K Hackenburg, RW Olchanski, C Suh, JS Willutzki, HJ Denisov, SP Dorofeev, V Lipaev, VV Popov, AV Ryabchikov, DI Bar-Yam, Z Dowd, JP Eugenio, P Hayek, M Kern, W King, E Shenhav, N Bodyagin, VA Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Vardanyan, IN Yershov, AA Brown, DS Fan, XL Joffe, D Pedlar, TK Seth, KK Tomaradze, A Adams, T Bishop, JM Cason, NM Ivanov, EI LoSecco, JM Manak, JJ Shephard, WD Stienike, DL Taegar, SA Adams, GS Cummings, JP Hu, J Kuhn, J Lu, M Napolitano, J White, DB Witkowski, M Nozar, M Shen, X Weygand, DP AF Chung, SU Danyo, K Hackenburg, RW Olchanski, C Suh, JS Willutzki, HJ Denisov, SP Dorofeev, V Lipaev, VV Popov, AV Ryabchikov, DI Bar-Yam, Z Dowd, JP Eugenio, P Hayek, M Kern, W King, E Shenhav, N Bodyagin, VA Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Vardanyan, IN Yershov, AA Brown, DS Fan, XL Joffe, D Pedlar, TK Seth, KK Tomaradze, A Adams, T Bishop, JM Cason, NM Ivanov, EI LoSecco, JM Manak, JJ Shephard, WD Stienike, DL Taegar, SA Adams, GS Cummings, JP Hu, J Kuhn, J Lu, M Napolitano, J White, DB Witkowski, M Nozar, M Shen, X Weygand, DP CA E852 Collaboration TI Exotic and q(q)over-bar resonances in the pi(+)pi(-)pi(-) system produced in pi(-)p collisions at 18 GeV/c SO PHYSICAL REVIEW D LA English DT Article ID PARTIAL-WAVE ANALYSIS; FLUX-TUBE MODEL; ETA-PI STATE; HYBRID MESONS; QCD; PI(-)PI(0)ETA; QUARKONIA; MATRIX; DECAY AB A partial-wave analysis of the reaction pi(-)p-->pi(+)pi(-)pi(-)p at 18 GeV/c has been performed on a data sample of 250 000 events obtained in the Brookhaven experiment E852. The well-known a(1)(1260), a(2)(1320) and pi(2)(1670) resonant states are observed. The existence of the pi(1800), a(1)(1700) and a(4)(2040) states is confirmed. The a(3)(1874) state is also observed. The exotic 1(-+) pi(1)(1600) state produced in the natural parity exchange process is found to decay in the rho(770)pi(-) channel. A mass-dependent fit results in a resonance mass of 1593+/-8(-47)(+29) MeV/c(2) and a width of 168+/-20(-12)(+150) MeV/c(2). C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Inst High Energy Phys, Protvino 142284, Russia. Univ Massachusetts, Dept Phys, N Dartmouth, MA 02747 USA. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Northwestern Univ, Dept Phys, Evanston, IL 60208 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RAFAEL, IL-31021 Haifa, Israel. Inst High Energy Phys, Beijing 100039, Peoples R China. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Vardanyan, Irina/K-7981-2012 NR 45 TC 74 Z9 75 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 APR 1 PY 2002 VL 65 IS 7 AR 072001 DI 10.1103/PhysRevD.65.072001 PN A PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HX UT WOS:000174980100004 ER PT J AU Diaz-Cruz, L Murayama, H Pierce, A AF Diaz-Cruz, L Murayama, H Pierce, A TI Can supersymmetric loops correct the fermion mass relations in SU(5)? SO PHYSICAL REVIEW D LA English DT Article ID ANOMALOUS U(1); STANDARD MODEL; BREAKING; SUPERGRAVITY; UNIFICATION; OPERATOR; PHYSICS; FLAVOR; MOMENT; DECAY AB We investigate possibilities for improving the fermion mass relations that arise in grand unified theories (GUTs). Each scenario relies on supersymmetric loop effects alone, without modifying the naive Yukawa unification. We briefly review the case where A terms follow the usual proportionality condition. In this case SUSY effects cannot completely improve the mass relations. Secondly, we employ a new ansatz for the trilinear A terms that satisfies all experimental and vacuum stability bounds, and can successfully modify the mass relations. Finally, we investigate the use of general (nonproportional) A terms, which can contain large off-diagonal entries. In this case, flavor changing neutral current (FCNC) data present an important constraint, but remedying the mass relations appears possible. We do not pretend to present a complete, motivated theory of fermion masses. Rather this paper can be viewed as an existence proof, serving to show that Yukawa coupling unification can occur even within the framework of minimal GUTs. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Theory Grp, Berkeley, CA 94720 USA. BUAP, Inst Fis, Puebla, Mexico. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Theory Grp, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 30 TC 0 Z9 0 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 2002 VL 65 IS 7 AR 075011 DI 10.1103/PhysRevD.65.075011 PN B PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200032 ER PT J AU Hiller, G Kagan, A AF Hiller, G Kagan, A TI Probing for new physics in polarized Lambda(b) decays at the Z pole SO PHYSICAL REVIEW D LA English DT Article ID RADIATIVE B(B-S) DECAYS; CHARMED-BARYON DECAYS; RIGHT-HANDED CURRENTS; LARGE ENERGY LIMIT; EXTRACTING V-TD; FORM-FACTORS; B->X-S-GAMMA DECAYS; LEADING LOGARITHMS; BRANCHING RATIO; CP-ASYMMETRIES AB Polarized Lambda(b)-->Lambdagamma decays at the Z pole are shown to be well suited for probing a large variety of new physics effects. A new observable is proposed, the angular asymmetry between the Lambda(b) spin and photon momentum, which is sensitive to the relative strengths of the opposite chirality and standard model chirality b-->sgamma dipole operators. Comparison with the Lambda decay polarization asymmetry and with the Lambda(b) polarization extracted from semileptonic decays allows important tests of the V-A structure of the standard model. The modifications of the rates and angular asymmetries which arise at next-to-leading order are discussed. The measurements for Lambda(b)-->Lambdagamma and the CP conjugate mode, with branching ratios of a few times 10(-5), are shown to be sensitive to nonstandard sources of CP violation in the Lambda(b)-->Lambdagamma matrix element. Form factor relations for heavy-to-light baryon decays are derived in the large energy limit, which are of general interest. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. RP Hiller, G (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 65 TC 44 Z9 44 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 APR 1 PY 2002 VL 65 IS 7 AR 074038 DI 10.1103/PhysRevD.65.074038 PN B PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200011 ER PT J AU Mihaila, B Dawson, JF AF Mihaila, B Dawson, JF TI Continuum versus periodic lattice Monte Carlo approach to classical field theory SO PHYSICAL REVIEW D LA English DT Article ID EVOLUTION AB We compare the momentum space with the standard periodic lattice approach to Monte Carlo calculations in classical phi(4) field theory. We show that the mismatch in the initial value of phi(cl)(2)(t) results in a shift in the "thermalized" value, at large times. The two approaches converge to the same result in the continuum limit. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. RP Mihaila, B (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Mihaila, Bogdan/D-8795-2013 OI Mihaila, Bogdan/0000-0002-1489-8814 NR 9 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 2002 VL 65 IS 7 AR 071501 DI 10.1103/PhysRevB.65.071501 PN A PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HX UT WOS:000174980100002 ER PT J AU Sasaki, S Blum, T Ohta, S AF Sasaki, S Blum, T Ohta, S TI Lattice study of the nucleon excited states with domain wall fermions SO PHYSICAL REVIEW D LA English DT Article ID LIGHT-HADRON SPECTRUM; WILSON FERMIONS; CHIRAL FERMIONS; STAGGERED QUARKS; QCD; RENORMALIZATION; OPERATORS; NEUTRINOS; BARYONS; ABSENCE AB We present results of our numerical calculation of the mass spectrum for isospin one-half and spin one-half nonstrange baryons, i.e., the ground and excited states of the nucleon, in quenched lattice QCD. We use a new lattice discretization scheme for fermions, domain wall fermions, which possess almost exact chiral symmetry at nonzero lattice spacing. We make a systematic investigation of the negative-parity N-* spectrum by using two distinct interpolating operators at beta=6/g(2)=6.0 on a 16(3)x32x16 lattice. The mass estimates extracted from the two operators are consistent with each other. The observed large mass splitting between this state, N-*(1535), and the positive-parity ground state, the nucleon N(939), is well reproduced by our calculations. We have also calculated the mass of the first positive-parity excited state and find that it is heavier than the negative-parity excited state for the quark masses studied. C1 Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1330033, Japan. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki 3050801, Japan. RP Brookhaven Natl Lab, RIKEN, BNL Res Ctr, Upton, NY 11973 USA. NR 55 TC 124 Z9 124 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD APR 1 PY 2002 VL 65 IS 7 AR 074503 DI 10.1103/PhysRevD.65.074503 PN B PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200014 ER PT J AU Schafer, T AF Schafer, T TI Mass terms in effective theories of high density quark matter SO PHYSICAL REVIEW D LA English DT Article ID COLOR-FLAVOR-LOCKING; SYMMETRY-BREAKING; BARYON DENSITY; MESON MASS; QCD; SUPERCONDUCTIVITY; SUPERFLUIDITY; BOSONS; PHASE AB We study the structure of mass terms in the effective theory for quasiparticles in QCD at high baryon density. To next-to-leading order in the 1/p(F) expansion we find two types of mass terms: chirality conserving two-fermion operators and chirality violating four-fermion operators. In the effective chiral theory for Goldstone modes in the color-flavor-locked (CFL) phase the former terms correspond to effective chemical potentials, while the latter lead to Lorentz invariant mass terms. We compute the masses of Goldstone bosons in the CFL phase, confirming earlier results by Son and Stephanov as well as Bedaque and Schafer. We show that to leading order in the coupling constant g there is no antiparticle gap contribution to the mass of Goldstone modes, and that our results are independent of the choice of gauge. C1 SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Riken BNL Res Ctr, Upton, NY 11973 USA. RP Schafer, T (reprint author), SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. OI Schaefer, Thomas/0000-0002-2297-782X NR 40 TC 45 Z9 46 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 APR 1 PY 2002 VL 65 IS 7 AR 074006 DI 10.1103/PhysRevD.65.074006 PN A PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HX UT WOS:000174980100049 ER PT J AU Zanotti, JM Bilson-Thompson, S Bonnet, FDR Coddington, PD Leinweber, DB Williams, AG Zhang, JB Melnitchouk, W Lee, FX AF Zanotti, JM Bilson-Thompson, S Bonnet, FDR Coddington, PD Leinweber, DB Williams, AG Zhang, JB Melnitchouk, W Lee, FX CA CSSM Lattice Collaboration TI Hadron masses from novel fat-link fermion actions SO PHYSICAL REVIEW D LA English DT Article ID NONPERTURBATIVE O(A) IMPROVEMENT; LATTICE QCD; CONTINUUM-LIMIT AB The hadron mass spectrum is calculated in lattice QCD using a novel fat-link clover fermion action in which only the irrelevant operators in the fermion action are constructed using smeared links. The simulations are performed on a 16(3)x32 lattice with a lattice spacing of a=0.125 fm. We compare actions with n=4 and 12 smearing sweeps with a smearing fraction of 0.7. The n=4 fat-link irrelevant clover (FLIC) action provides scaling which is superior to mean-field improvement, and offers advantages over nonperturbative O(a) improvement, including a reduced exceptional configuration problem. C1 Univ Adelaide, Special Res Ctr Subatom Struct Mat, Adelaide, SA 5005, Australia. Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. Jefferson Lab, Newport News, VA 23606 USA. George Washington Univ, Dept Phys, Ctr Nucl Studies, Washington, DC 20052 USA. RP Zanotti, JM (reprint author), Univ Adelaide, Special Res Ctr Subatom Struct Mat, Adelaide, SA 5005, Australia. RI Zanotti, James/H-8128-2012; Williams, Anthony/I-6698-2012; Leinweber, Derek/J-6705-2013; OI Zanotti, James/0000-0002-3936-1597; Leinweber, Derek/0000-0002-4745-6027; Lee, Frank/0000-0001-8169-3440 NR 29 TC 90 Z9 90 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 APR 1 PY 2002 VL 65 IS 7 AR 074507 DI 10.1103/PhysRevD.65.074507 PN B PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 541HY UT WOS:000174980200018 ER PT J AU Edwards, BF Smith, DH AF Edwards, BF Smith, DH TI River meandering dynamics SO PHYSICAL REVIEW E LA English DT Article ID BEND THEORY; CHANNEL MIGRATION; SIMULATION-MODEL; SECONDARY FLOW; AMPLITUDE; CANADA AB The Ikeda, Parker, and Sawai river meandering model is reexamined using a physical approach employing an explicit equation of motion. For periodic river shapes as seen from above, a cross-stream surface elevation gradient creates a velocity shear that is responsible for the decay of small-wavelength meander bends, whereas secondary currents in the plane perpendicular to the downstream direction are responsible for the growth of large-wavelength bends. A decay length D=H/2C(f) involving the river depth H and the friction coefficient C(f) sets the scale for meandering, giving the downstream distance required for the fluid velocity profile to recover from changes in the channel curvature. Using this length scale and a time scale T, we explicitly trace the observed length scale invariance to the equations of motion, and predict similar time and velocity scale invariances. A general time-dependent nonlinear modal analysis for periodic rivers reveals that modes higher than the third mode are needed to describe upstream migration of bend apexes just before oxbow cutoff, and are important to accurate calculations of the time and sinuosity at cutoff. C1 Natl Energy Technol Lab, Morgantown, WV 26507 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Edwards, BF (reprint author), Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. NR 31 TC 11 Z9 11 U1 3 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 046303 DI 10.1103/PhysRevE.65.046303 PN 2B PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544FB UT WOS:000175146600003 ER PT J AU Hirst, LS Watson, SJ Gleeson, HF Cluzeau, P Barois, P Pindak, R Pitney, J Cady, A Johnson, PM Huang, CC Levelut, AM Srajer, G Pollmann, J Caliebe, W Seed, A Herbert, MR Goodby, JW Hird, M AF Hirst, LS Watson, SJ Gleeson, HF Cluzeau, P Barois, P Pindak, R Pitney, J Cady, A Johnson, PM Huang, CC Levelut, AM Srajer, G Pollmann, J Caliebe, W Seed, A Herbert, MR Goodby, JW Hird, M TI Interlayer structures of the chiral smectic liquid crystal phases revealed by resonant x-ray scattering SO PHYSICAL REVIEW E LA English DT Article ID ALPHA-ASTERISK PHASE; DEVILS STAIRCASE; STAR AB The structures of the liquid crystalline chiral subphases exhibited by several materials containing either a selenium or sulphur atom have been investigated using a resonant x-ray scattering technique. This technique provides a unique structural probe for the ferroelectric, ferrielectric, antiferroelectric, and SmCalpha* phases. An analysis of the scattering features allows the structural models of the different subphases to be distinguished, in addition to providing a measurement of the helical pitch. This paper reports resonant scattering features in the antiferroelectric hexatic phase, the three- and four-layer intermediate phases, the antiferroelectric and ferroelectric phases and the SmCalpha* phase. The helicoidal pitch has been measured from the scattering peaks in the four-layer intermediate phase as well as in the antiferroelectric and ferroelectric phases. In the SmCalpha* phase, an investigation into the helical structure has revealed a pitch ranging from 5 to 54 layers in different materials. Further, a strong resonant scattering signal has been observed in mixtures of a selenium containing material with as much as 90% nonresonant material. C1 Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. Univ Lille 1, F-59655 Villeneuve Dascq, France. Univ Bordeaux 1, Ctr Rech Paul Pascal, CNRS, F-33600 Pessac, France. Lucent Technol, Bell Labs, Murray Hill, NJ 07914 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Paris 11, Phys Solides Lab, F-91405 Orsay, France. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. Kent State Univ, Inst Liquid Crystal, Kent, OH 44240 USA. Univ Hull, Dept Chem, Kingston Upon Hull HU6 7RJ, N Humberside, England. RP Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. RI Hirst, Linda/A-4862-2008 OI Hirst, Linda/0000-0002-8306-9366 NR 29 TC 78 Z9 78 U1 2 U2 15 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 041705 DI 10.1103/PhysRevE.65.041705 PN 1 PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544EZ UT WOS:000175146400052 PM 12005844 ER PT J AU Ibanes, M Sancho, JM Tsironis, GP AF Ibanes, M Sancho, JM Tsironis, GP TI Dynamical properties of discrete breathers in curved chains with first and second neighbor interactions SO PHYSICAL REVIEW E LA English DT Article ID INTRINSIC LOCALIZED MODES; NONLINEAR LATTICES; VIBRATIONAL-MODES; SYSTEMS; OSCILLATORS; RELAXATION; EXISTENCE; PHYSICS AB We present the study of discrete breather dynamics in curved polymerlike chains consisting of masses connected via nonlinear springs. The polymer chains are one dimensional but not rectilinear and their motion takes place on a plane. After constructing breathers following numerically accurate procedures, we launch them in the chains and investigate properties of their propagation dynamics. We find that breather motion is strongly affected by the presence of curved regions of polymers, while the breathers themselves show a very strong resilience and remarkable stability in the presence of geometrical changes. For chains with strong angular rigidity we find that breathers either pass through bent regions or get reflected while retaining their frequency. Their motion is practically lossless and seems to be determined through local energy conservation. For less rigid chains modeled via second neighbor interactions, we find similarly that chain geometry typically does not destroy the localized breather states but, contrary to the angularly rigid chains, it induces some small but constant energy loss. Furthermore, we find that a curved segment acts as an active gate reflecting or refracting the incident breather and transforming its velocity to a value that depends on the discrete breathers frequency. We analyze the physical reasoning behind these seemingly general breather properties. C1 Univ Barcelona, Dept Estructura & Constituents Mat, E-08028 Barcelona, Spain. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece. Fdn Res & Technol Hellas, Iraklion 71003, Crete, Greece. RP Ibanes, M (reprint author), Univ Barcelona, Dept Estructura & Constituents Mat, Diagonal 647, E-08028 Barcelona, Spain. RI Ibanes, Marta/A-7657-2008; Tsironis, George/C-2683-2011 NR 30 TC 19 Z9 19 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 041902 DI 10.1103/PhysRevE.65.041902 PN 1 PG 13 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544EZ UT WOS:000175146400076 ER PT J AU Jarzynski, C AF Jarzynski, C TI Targeted free energy perturbation SO PHYSICAL REVIEW E LA English DT Article ID MONTE-CARLO METHOD; DYNAMICS AB In this paper generalization of the free energy perturbation identity is derived, and a computational strategy based on this result is presented. A simple example illustrates the efficiency gains that can be achieved with this method. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Jarzynski, C (reprint author), Los Alamos Natl Lab, T-13,MS B213, Los Alamos, NM 87545 USA. EM chrisj@lanl.gov RI Jarzynski, Christopher/B-4490-2009 OI Jarzynski, Christopher/0000-0002-3464-2920 NR 20 TC 40 Z9 40 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 046122 DI 10.1103/PhysRevE.65.046122 PN 2A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544FA UT WOS:000175146500041 PM 12005941 ER PT J AU Joshi, RP Hu, Q Schoenbach, KH Hjalmarson, HP AF Joshi, RP Hu, Q Schoenbach, KH Hjalmarson, HP TI Improved energy model for membrane electroporation in biological cells subjected to electrical pulses SO PHYSICAL REVIEW E LA English DT Article ID PLANAR BILAYER-MEMBRANES; LIPID-MEMBRANES; STRETCHED VESICLES; TRANSIENT PORES; BREAKDOWN; ELECTROPERMEABILIZATION; DYNAMICS; LIFETIME; TENSION AB A self-consistent model analysis of electroporation in biological cells has been carried out based on an improved energy model. The simple energy model used in the literature is somewhat incorrect and unphysical for a variety of reasons. Our model for the pore formation energy E(r) includes a dependence on pore population and density. It also allows for variable surface tension, incorporates the effects of finite conductivity on the electrostatic correction term, and is dynamic in nature. Self-consistent calculations, based on a coupled scheme involving the Smoluchowski equation and the improved energy model, are presented. It is shown that E(r) becomes self-adjusting with variations in its magnitude and profile, in response to pore population, and inhibits uncontrolled pore growth and expansion. This theory can be augmented to include pore-pore interactions to move beyond the independent pore picture. C1 Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. Sandia Natl Labs, Computat Biol & Mat Technol Dept, Albuquerque, NM 87185 USA. RP Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. NR 43 TC 51 Z9 53 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 041920 DI 10.1103/PhysRevE.65.041920 PN 1 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544EZ UT WOS:000175146400094 PM 12005886 ER PT J AU Kevrekidis, PG Kevrekidis, IG Bishop, AR Titi, ES AF Kevrekidis, PG Kevrekidis, IG Bishop, AR Titi, ES TI Continuum approach to discreteness SO PHYSICAL REVIEW E LA English DT Article ID NONLINEAR SCHRODINGER-EQUATION; SINE-GORDON SYSTEM; KINK DYNAMICS; PROPAGATION FAILURE; BLOCH OSCILLATIONS; INTERNAL-MODES; SOLITARY WAVES; BREATHERS; STABILITY; LATTICES AB We study analytically and numerically continuum models derived on the basis of Pade approximations and their effectiveness in modeling spatially discrete systems. We not only analyze features of the temporal dynamics that can be captured through these continuum approaches (e.g., shape oscillations, radiation effects, and trapping) but also point out ones that cannot be captured (such as Peierls-Nabarro barriers and Bloch oscillations). We analyze the role of such methods in providing an effective "homogenization" of spatially discrete, as well as of heterogeneous continuum equations. Finally, we develop numerical methods for solving such equations and use them to establish the range of validity of these continuum approximations, as well as to compare them with other semicontinuum approximations. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA. Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Univ Calif Irvine, Dept Math, Irvine, CA 92697 USA. Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92697 USA. RP Kevrekidis, PG (reprint author), Los Alamos Natl Lab, Div Theoret, MS B258, Los Alamos, NM 87545 USA. NR 71 TC 41 Z9 44 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD APR PY 2002 VL 65 IS 4 AR 046613 DI 10.1103/PhysRevE.65.046613 PN 2B PG 13 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 544FB UT WOS:000175146600047 PM 12006053 ER PT J AU Perrot, F Dharma-wardana, MWC Benage, J AF Perrot, F Dharma-wardana, MWC Benage, J TI Possibility of an unequivocal test of different models of the equation of state of aluminum in the coupling regime Gamma similar to 1-50 SO PHYSICAL REVIEW E LA English DT Article ID PLASMAS; ENERGY AB The equation of state (EOS) in regimes of density (rho) and temperature (T) which are inaccessible to experiment has to be determined using theories which may themselves be out of their range of validity. Even for Al, the EOS in the region 0.1 u decays: Lepton invariant mass spectrum SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-LOOP QCD CORRECTIONS; VERTICAL-BAR; RECOIL; MODEL AB We compute O(alpha(s)(2)) QCD corrections to the lepton invariant mass spectrum in the decay b --> ulnu(l), relevant for the determination of the Cabibbo-Kobayashi-Maskawa matrix element \V-ub\. Our method can also be used to evaluate moments of the lepton energy distribution with an O(alpha(s)(2)) accuracy. The Abelian part of our result gives the neutrino invariant mass spectrum in the muon decay and, upon integration, the O(alpha(2)) correction to the muon lifetime. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Czarnecki, A (reprint author), Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. NR 18 TC 19 Z9 19 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 APR 1 PY 2002 VL 88 IS 13 AR 131801 DI 10.1103/PhysRevLett.88.131801 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QR UT WOS:000174542200005 PM 11955088 ER PT J AU Segre, GP Gedik, N Orenstein, J Bonn, DA Liang, RX Hardy, WN AF Segre, GP Gedik, N Orenstein, J Bonn, DA Liang, RX Hardy, WN TI Photoinduced changes of reflectivity in single crystals of YBa2Cu3O6.5 (ortho II) SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; DYNAMICS; PARTICLE; SUPERCONDUCTORS; SPECTROSCOPY; EXCITATIONS; TIME AB We report measurements of the photoinduced change in reflectivity of an untwinned single crystal of YBa2Cu3O6.5 in the ortho II structure. The decay rate of the transient change in reflectivity is found to decrease rapidly with decreasing temperature and, below T-c, with decreasing laser intensity. We interpret the decay as a process of thermalization of antinodal quasiparticles, with a rate determined by inelastic scattering of quasiparticle pairs. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ British Columbia, Vancouver, BC V5Z 1M9, Canada. RP Segre, GP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Orenstein, Joseph/I-3451-2015 NR 22 TC 98 Z9 98 U1 1 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 APR 1 PY 2002 VL 88 IS 13 AR 137001 DI 10.1103/PhysRevLett.88.137001 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QR UT WOS:000174542200032 PM 11955115 ER PT J AU Stephens, GJ Bettencourt, LMA Zurek, WH AF Stephens, GJ Bettencourt, LMA Zurek, WH TI Critical dynamics of gauge systems: Spontaneous vortex formation in 2D superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEFECT FORMATION; LIQUID-CRYSTALS; COSMOLOGICAL EXPERIMENTS; STRING FORMATION; SUPERFLUID HE-3; FLUX; TRANSITION; VORTICES; PHASE; ALGORITHMS AB We examine the formation of vortices during the nonequilibrium relaxation of a high-temperature initial state of an Abelian-Higgs system. We equilibrate the scalar and gauge fields using gauge-invariant Langevin equations and relax the system by instantaneously removing thermal fluctuations. For couplings near critical, kappa(c) = rootlambda/e = 1, we observe the formation of large clusters of like-sign magnetic vortices. Their appearance has implications for the dynamics of the phase transition, for the distribution of topological defects, and for late-time phase ordering kinetics. We offer explanations for both the observed vortex densities and vortex configurations. C1 Los Alamos Natl Lab, Theoret Div T6 MS B288, Los Alamos, NM 87545 USA. MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. RP Stephens, GJ (reprint author), Los Alamos Natl Lab, Theoret Div T6 MS B288, POB 1663, Los Alamos, NM 87545 USA. NR 29 TC 37 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 APR 1 PY 2002 VL 88 IS 13 AR 137004 DI 10.1103/PhysRevLEtt.88.137004 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QR UT WOS:000174542200035 PM 11955118 ER PT J AU Wang, SQ Clayton, CE Blue, BE Dodd, ES Marsh, KA Mori, WB Joshi, C Lee, S Muggli, P Katsouleas, T Decker, FJ Hogan, MJ Iverson, RH Raimondi, P Walz, D Siemann, R Assmann, R AF Wang, SQ Clayton, CE Blue, BE Dodd, ES Marsh, KA Mori, WB Joshi, C Lee, S Muggli, P Katsouleas, T Decker, FJ Hogan, MJ Iverson, RH Raimondi, P Walz, D Siemann, R Assmann, R TI X-ray emission from betatron motion in a plasma wiggler SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION-FOCUSED REGIME; ELECTRON-BEAM AB The successful utilization of an ion channel in a plasma to wiggle a 28.5-GeV electron beam to obtain broadband x-ray radiation is reported. The ion channel is induced by the electron bunch as it propagates through an underdense 1.4-meter-long lithium plasma. The quadratic density dependence of the spontaneously emitted betatron x-ray radiation and the divergence angle of similar to(1-3) x 10(-4) radian of the forward-emitted x-rays as a consequence of betatron motion in the ion channel are in good agreement with theory. The absolute photon yield and the peak spectral brightness at 14.2-keV photon energy are estimated. C1 Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ So Calif, Los Angeles, CA 90089 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, CH-1211 Geneva 23, Switzerland. RP Wang, SQ (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RI Assmann, Ralph/L-8457-2016 NR 18 TC 88 Z9 91 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 APR 1 PY 2002 VL 88 IS 13 AR 135004 DI 10.1103/PhysRevLett.88.135004 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QR UT WOS:000174542200023 PM 11909365 ER PT J AU Carrigan, RA Chen, D Jackson, G Mokhov, N Murphy, CT Baker, S Bogacz, A Cline, D Ramachandran, S Rhoades, J Rosenzweig, J Asseev, A Biryukov, V Taratin, A Ellison, JA Khanzadeev, A Prokofieva, T Samsonov, V Solodov, G Newberger, B Tsyganov, E Shih, HJ Gabella, W Cox, B Golovatyuk, V McManus, A AF Carrigan, RA Chen, D Jackson, G Mokhov, N Murphy, CT Baker, S Bogacz, A Cline, D Ramachandran, S Rhoades, J Rosenzweig, J Asseev, A Biryukov, V Taratin, A Ellison, JA Khanzadeev, A Prokofieva, T Samsonov, V Solodov, G Newberger, B Tsyganov, E Shih, HJ Gabella, W Cox, B Golovatyuk, V McManus, A TI Beam extraction studies at 900 GeV using a channeling crystal SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID BENT CRYSTAL; PROTON EXTRACTION; CERN-SPS; EFFICIENCY; SIMULATION; TEVATRON; ACCELERATOR; DEFLECTION; PARTICLES AB Luminosity-driven channeling extraction has been observed for the first time in a 900 GeV study at the Fermilab Tevatron. This experiment, Fermilab E853, demonstrated that useful TeV level beams can be extracted from a superconducting accelerator during high luminosity collider operations without unduly affecting the background at the collider detectors. Multipass extraction was found to increase the efficiency of the process significantly. The beam extraction efficiency was about 25%. Studies of time dependent effects found that the turn-to-turn structure was governed mainly by accelerator beam dynamics. Based on the results of this experiment, it is feasible to construct a parasitic 5-10 MHz proton beam from the Tevatron collider. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Inst High Energy Phys, Serpukhov, Russia. Joint Nucl Res Inst, Dubna, Russia. Univ New Mexico, Albuquerque, NM 87131 USA. Petersburg Nucl Phys Inst, Gatchina, Russia. Univ Texas, Austin, TX 78712 USA. Univ Texas, SW Med Ctr, Dallas, TX 75235 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Virginia, Charlottesville, VA 22901 USA. RP Carrigan, RA (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Biryukov, Valery/C-8432-2017 OI Biryukov, Valery/0000-0002-3591-7762 NR 35 TC 56 Z9 56 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD APR PY 2002 VL 5 IS 4 AR 043501 DI 10.1103/PhysRevSTAB.5.043501 PG 24 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 581ZD UT WOS:000177324500004 ER PT J AU Li, YL Huang, ZR Borland, MD Milton, S AF Li, YL Huang, ZR Borland, MD Milton, S TI Small-angle Thomson scattering of ultrafast laser pulses for bright, sub-100-fs x-ray radiation SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID RELATIVISTIC ELECTRONS; GENERATION; DYNAMICS AB We propose a scheme for bright sub-100-fs x-ray radiation generation using small-angle Thomson scattering. Coupling high-brightness electron bunches with high-power ultrafast laser pulses, radiation with photon energies between 8 and 40 keV can be generated with pulse duration comparable to that of the incoming laser pulse and with peak spectral brightness close to that of the third-generation synchrotron light sources of similar to20 photons s(-1) mm(-2) mrad(-2) per 10(-3) bandwidth. A preliminary dynamic calculation is performed to understand the property of this novel scattering scheme with relativistic laser intensities. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Li, YL (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 30 TC 25 Z9 25 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD APR PY 2002 VL 5 IS 4 AR 044701 DI 10.1103/PhysRevSTAB.5.044701 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 581ZD UT WOS:000177324500007 ER PT J AU Srinivasan-Rao, T Amin, M Castillo, V Lazarus, DM Nikas, D Ozben, C Semertzidis, YK Stillman, A Tsang, T Kowalski, L AF Srinivasan-Rao, T Amin, M Castillo, V Lazarus, DM Nikas, D Ozben, C Semertzidis, YK Stillman, A Tsang, T Kowalski, L TI Novel single shot scheme to measure submillimeter electron bunch lengths using electro-optic technique SO PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS LA English DT Article ID PULSES; GENERATION AB A novel, single shot, nondestructive scheme to measure the bunch length of submillimeter relativistic electron bunches using the electro-optical method is described. In this scheme, the birefringence induced by the electric field of the electrons converts the temporal characteristics of the bunch to a spatial intensity distribution of an optical pulse. Electric field characteristics, induced birefringence, and retardation are calculated for a few typical electron beam parameters and criteria limiting the resolution are established. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Montclair State Univ, Montclair, NJ 07043 USA. RP Srinivasan-Rao, T (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Semertzidis, Yannis K./N-1002-2013; Francisco, Suely/D-9065-2014 NR 15 TC 12 Z9 12 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-4402 J9 PHYS REV SPEC TOP-AC JI Phys. Rev. Spec. Top.-Accel. Beams PD APR PY 2002 VL 5 IS 4 AR 042801 DI 10.1103/PhysRevSTAB.5.042801 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 581ZD UT WOS:000177324500003 ER PT J AU Hrma, P Izak, P Vienna, JD Thomas, ML Irwin, GM AF Hrma, P Izak, P Vienna, JD Thomas, ML Irwin, GM TI Partial molar liquidus temperatures of multivalent elements in multicomponent borosilicate glass SO PHYSICS AND CHEMISTRY OF GLASSES LA English DT Article AB A multicomponent borosilicate glass containing several multivalent elements (Fe, Ni, Cr, Mn) and precipitating (Fe,Ni,Mn,Cr)(Fe,Cr,Mn)(2)O-4 spinel as its primary phase, was equilibrated with the gas phase over the range of oxygen partial pressures, po(2), from 10(13) Pa to 10(5) Pa and temperatures, T, from 850 to 1300 degreesC The oxidation-reduction equilibrium of Fe in the glass it-as measured with Mossbauer spectroscopy and wet colorimetry. These data were combined with oxidation-reduction equilibria for Fe, Ni and Cr in a borosilicate frit of a similar composition found in the literature to estimate concentrations of Fe(II), Fe(III), Ni(II), Cr(II), Cr(III) and Cr(VI) as functions of po(2) and T. Measured liquidus temperature (T-L) data for the test glasses within the same range here then added to a critically evaluated TL database composed of multicomponent borosilicate glasses within the spinel primary crystalline phase field. The set of partial molar liquidus temperatures for elements other than oxygen determined from this database was then augmented by values for Fe(II), Fe(III), Cr(II), Cr(III) and Cr(VI). A 0.1 mol% change in the metal ion concentration increases T-L as follows: Fe(II) by 4.6degreesC Fe(III) by 2.8 degreesC, Cr(II) by, 185 degreesC Cr(III) by, 66 degreesC and Cr(VI) by -17 C. The cdegreesalculated TL based on partial molar liquidus temperatures agreed with the measured T-L in the range from 10-(13) Pa to 10(5) Pa. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Lamar Univ, Beaumont, TX 77710 USA. RP Hrma, P (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Izak, Pavel/H-3401-2014 NR 23 TC 2 Z9 2 U1 0 U2 0 PU SOC GLASS TECHNOLOGY PI SHEFFIELD PA THORNTON 20 HALLAM GATE ROAD, SHEFFIELD S10 5BT, S YORKSHIRE, ENGLAND SN 0031-9090 J9 PHYS CHEM GLASSES JI Phys. Chem. Glasses PD APR PY 2002 VL 43 IS 2 BP 119 EP 127 PG 9 WC Chemistry, Physical; Materials Science, Ceramics SC Chemistry; Materials Science GA 555ZY UT WOS:000175824000008 ER PT J AU Curtright, TL Polychronakos, AP Zachos, CK AF Curtright, TL Polychronakos, AP Zachos, CK TI Area potentials and deformation quantization SO PHYSICS LETTERS A LA English DT Article ID PHASE-SPACE; QUANTUM-MECHANICS; WIGNER FUNCTIONS; STATES; NAMBU AB Systems built out of N-body interactions, beyond 2-body interactions, are formulated on the plane, and investigated classically and quantum mechanically (in phase space). Their Wigner functions-the density matrices in phase-space quantization-are given and analyzed. (C) 2002 ELSEVIER COMPANY. All rights reserved. C1 Argonne Natl Lab, High Energy Phys Div, Argonne, IL 60439 USA. Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. Rockefeller Univ, Dept Phys, New York, NY 10021 USA. Univ Ioannina, Dept Phys, GR-45110 Ioannina, Greece. RP Zachos, CK (reprint author), Argonne Natl Lab, High Energy Phys Div, 9700 S Cass Ave, Argonne, IL 60439 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 33 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD APR 1 PY 2002 VL 295 IS 5-6 BP 241 EP 246 AR PII S0375-9601(02)00184-6 DI 10.1016/S0375-9601(02)00184-6 PG 6 WC Physics, Multidisciplinary SC Physics GA 551EL UT WOS:000175546500002 ER PT J AU Chacon, L Finn, JM Knoll, DA AF Chacon, L Finn, JM Knoll, DA TI Nonlinear study of the curvature-driven parallel velocity shear-tearing instability SO PHYSICS OF PLASMAS LA English DT Article ID TRANSPORT BARRIER; TOKAMAK; FLOW; EDGE; GENERATION; EQUILIBRIUM; EQUATIONS; VISCOSITY; DYNAMICS; PLASMAS AB The nonlinear regime of the parallel velocity shear-tearing instability is studied numerically using a two-dimensional reduced, resistive magnetohydrodynamics model. In this instability, a sheared parallel velocity profile interacts with the perpendicular dynamics via the magnetic field curvature. Linearly, it has been shown [J. M. Finn, Phys. Plasmas 2, 4400 (1995)] that, in the inviscid limit, such interaction alters the classical behavior of the tearing instability, resulting in increased growth rates for classically tearing-unstable regimes (Delta(')>0), and destabilizing classically tearing-stable regimes, leading to an electrostatic mode as Delta'--> -infinity. These trends are seen to hold with finite viscosity as long as the perpendicular plasma viscosity is of the order or smaller than the plasma resistivity. Nonlinearly, it is found that a self-consistent perpendicular shear flow and a reversed (stabilizing) density gradient develop. For favorable curvature, the latter implies an anomalous pinch effect. The shear flow generation mechanism is found, using quasilinear theory, to be related to asymmetries (tilting) introduced by the magnetic curvature coupling term. In the classically tearing-stable regime, the nonlinear behavior is very rich, including relaxation-oscillation phenomena and chaotic behavior. The potential implications of the nonlinear regime of this instability for the plasma confinement are also discussed. (C) 2002 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chacon, L (reprint author), Los Alamos Natl Lab, MS K717,POB 1663, Los Alamos, NM 87545 USA. NR 30 TC 9 Z9 9 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 2002 VL 9 IS 4 BP 1164 EP 1176 DI 10.1063/1.1460885 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 533FW UT WOS:000174519600015 ER PT J AU Pigarov, AY Krasheninnikov, SI Rognlien, TD Schaffer, MJ West, WP AF Pigarov, AY Krasheninnikov, SI Rognlien, TD Schaffer, MJ West, WP TI Tokamak edge plasma simulation including anomalous cross-field convective transport SO PHYSICS OF PLASMAS LA English DT Article ID ALCATOR-C-MOD; SCRAPE-OFF LAYER; DIII-D TOKAMAK; DIVERTOR PLASMAS; FLUCTUATIONS; TURBULENCE; PARTICLE; PROFILES; ELMS; CODE AB Multi-fluid two-dimensional transport models such as the UEDGE code model [T. D. Rognlien , J. Nucl. Mater. 196-198, 34 (1992)] are widely used in the simulation of tokamak edge plasmas. Usually these models are based on the assumption of anomalous plasma diffusion in the direction perpendicular to magnetic field lines. As will be shown, the pure diffusive cross-field transport model is inadequate and fails to match properly plasma parameters measured both in the scrape-off layer (SOL) and in the divertor of the DIII-D tokamak. Recently it has been suggested that specific nondiffusive transport occurs in the edge plasma [S. I. Krasheninnikov, Phys. Lett. A 283, 368 (2001)]. The nondiffusive transport is incorporated to the UEDGE model by adding the anomalous cross-field convective velocity for plasma species and by prescribing a specific two-dimensional profile to this velocity. A series of highly radiative discharges obtained on the DIII-D tokamak is analyzed using the UEDGE code with the hybrid, convective and diffusive, cross-field transport model. For these discharges, anomalous convective velocity profiles are adjusted until the simulated radial profiles agree with measurements in the SOL and in the divertor. It is found that in order to reproduce most of the extensive experimental data, anomalous plasma convection should play the dominant role in the outboard edge-plasma region. (C) 2002 American Institute of Physics. C1 Univ Calif San Diego, La Jolla, CA 92037 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Gen Atom Co, San Diego, CA 92186 USA. RRC Kurchatov Inst, Moscow 123132, Russia. RP Pigarov, AY (reprint author), Univ Calif San Diego, La Jolla, CA 92037 USA. NR 37 TC 38 Z9 38 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 2002 VL 9 IS 4 BP 1287 EP 1299 DI 10.1063/1.1459059 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 533FW UT WOS:000174519600029 ER PT J AU Krommes, JA AF Krommes, JA TI Fundamental statistical descriptions of plasma turbulence in magnetic fields SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Article DE plasma turbulence; statistical closure; direct-interaction approximation; MSR formalism; quasilinear theory; weak turbulence; resonance broadening; clumps; realizable Markovian closure; eddy viscosity; submarginal turbulence; bounds on transport ID DRIFT-WAVE TURBULENCE; SELF-ORGANIZED CRITICALITY; GRADIENT-DRIVEN TURBULENCE; RENORMALIZATION-GROUP ANALYSIS; NON-GAUSSIAN STATISTICS; DIRECT-INTERACTION-APPROXIMATION; REALIZABLE MARKOVIAN CLOSURE; FULLY-DEVELOPED TURBULENCE; GUIDING-CENTER PLASMA; PROPER ORTHOGONAL DECOMPOSITION AB A pedagogical review of the historical development and current status (as of early 2000) of systematic statistical theories of plasma turbulence is undertaken. Emphasis is on conceptual foundations and methodology, not practical applications. Particular attention is paid to equations and formalism appropriate to strongly magnetized, fully ionized plasmas. Extensive reference to the literature on neutral-fluid turbulence is made, but the unique properties and problems of plasmas are emphasized throughout. Discussions are given of quasilinear theory, weak-turbulence theory, resonance-broadening theory, and the clump algorithm. The direct-interaction approximation (DIA) is developed as a central focus of the article, and its relationship to the earlier plasma theories is explained. Various methods of renormalized perturbation theory are described, then unified with the aid of the generating-functional formalism of Martin, Siggia, and Rose. A general expression for the renormalized dielectric function is deduced and discussed in detail. Modem approaches such as decimation and PDF methods are described. Derivations of DIA-based Markovian closures are discussed. The eddy-damped quasinormal Markovian (EDQNM) closure is shown to be nonrealizable in the presence of waves, and a new realizable Markovian closure is presented. The test-field model and a realizable modification thereof are also summarized. Numerical solutions of various closures for some plasma-physics paradigms are reviewed. The variational approach to bounds on transport is developed. Miscellaneous topics include Onsager symmetries for turbulence, the interpretation of entropy balances for both kinetic and fluid descriptions, self-organized criticality, statistical interactions between disparate scales, and the roles of both mean and random shear. Appendices are provided on Fourier transform conventions, dimensional and scaling analysis, the derivations of nonlinear gyrokinetic and gyrofluid equations, stochasticity criteria for quasilinear theory, formal aspects of resonance-broadening theory, Novikov's theorem, the treatment of weak inhomogencity, the derivation of the Vlasov and gyrokinetic weak-turbulence wave kinetic equation from a fully renormalized description, some features of a code for solving the DIA and related Markovian closures, the details of the solution of the EDQNM closure for a solvable three-wave model, and the notation used in the article. () 2002 Published by Elsevier Science B.V. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM krommes@princeton.edu NR 876 TC 146 Z9 146 U1 3 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD APR PY 2002 VL 360 IS 1-4 BP 1 EP 352 AR PII S0370-1573(01)00066-7 DI 10.1016/S0370-1573(01)00066-7 PG 352 WC Physics, Multidisciplinary SC Physics GA 532PY UT WOS:000174485300001 ER PT J AU Konechny, A Schwarz, A AF Konechny, A Schwarz, A TI Introduction to M(atrix) theory and noncommutative geometry SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review ID INFINITE-DIMENSIONAL ALGEBRAS; YANG-MILLS THEORIES; IIB MATRIX MODEL; TACHYON CONDENSATION; MORITA EQUIVALENCE; GAUGE-THEORIES; FIELD-THEORY; BPS STATES; INSTANTONS; SOLITONS AB Noncommutative geometry is based on an idea that an associative algebra can be regarded as "an algebra of functions on a noncommutative space". The major contribution to noncommutative geometry was made by A. Connes, who, in particular, analyzed Yang-Mills theories on noncommutative spaces, using important notions that were introduced in his papers (connection, Chern character, etc). It was found recently that Yang-Mills theories on noncommutative spaces appear naturally in string/M-theory; the notions and results of noncommutative geometry were applied very successfully to the problems of physics. In this paper we give a mostly self-contained review of some aspects of M(atrix) theory, of Connes' noncommutative geometry and of applications of noncommutative geometry to M(atrix) theory. The topics include introduction to BFSS and IKKT matrix models, compactifications on noncommutative tori, a review of basic notions of noncommutative geometry with a detailed discussion of noncommutative tori, Morita equivalence and SO(d,d\Z)-duality, an elementary discussion of noncommutative orbifolds, noncommutative solitons and instantons. The review is primarily intended for physicists who would like to learn some basic techniques of noncommutative geometry and how they can be applied in string theory and to mathematicians who would like to learn about some new problems arising in theoretical physics. The second part of the review (Sections 10-12) devoted to solitons and instantons on noncommutative Euclidean space is almost independent of the first part. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Math, Davis, CA 95616 USA. RP Konechny, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Mail Stop 50A-5101, Berkeley, CA 94720 USA. NR 238 TC 133 Z9 134 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD APR PY 2002 VL 360 IS 5-6 BP 353 EP 465 AR PII S0370-1573(01)00096-5 DI 10.1016/S0370-1573(01)00096-5 PG 113 WC Physics, Multidisciplinary SC Physics GA 534MX UT WOS:000174591100001 ER PT J AU Foster, I AF Foster, I TI The grid grew from physicists' computing needs - Reply SO PHYSICS TODAY LA English DT Letter C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Foster, I (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 1 Z9 1 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 2002 VL 55 IS 4 BP 10 EP + PG 2 WC Physics, Multidisciplinary SC Physics GA 545VH UT WOS:000175237900002 ER PT J AU Moniz, EJ Kenderdine, MA AF Moniz, EJ Kenderdine, MA TI Meeting energy challenges: Technology and policy SO PHYSICS TODAY LA English DT Article C1 US DOE, Washington, DC USA. RP Moniz, EJ (reprint author), MIT, Cambridge, England. NR 10 TC 4 Z9 4 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 2002 VL 55 IS 4 BP 40 EP 46 DI 10.1063/1.1480781 PG 7 WC Physics, Multidisciplinary SC Physics GA 545VH UT WOS:000175237900022 ER PT J AU Marcus, GH Levin, AE AF Marcus, GH Levin, AE TI New designs for the nuclear renaissance SO PHYSICS TODAY LA English DT Article C1 US DOE, Off Nucl Energy Sci & Technol, Washington, DC USA. Amer Nucl Soc, La Grange Pk, IL 60526 USA. US Nucl Regulatory Commiss, Rockville, MD USA. RP Marcus, GH (reprint author), US DOE, Off Nucl Energy Sci & Technol, Washington, DC USA. NR 7 TC 6 Z9 6 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 2002 VL 55 IS 4 BP 54 EP + DI 10.1063/1.1480783 PG 6 WC Physics, Multidisciplinary SC Physics GA 545VH UT WOS:000175237900024 ER PT J AU Chernyshev, S Kikoin, K L'vov, V AF Chernyshev, S Kikoin, K L'vov, V TI Victor Iosifovich Belinicher - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Ben Gurion Univ Negev, IL-84105 Beer Sheva, Israel. Weizmann Inst Sci, IL-76100 Rehovot, Israel. RP Chernyshev, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD APR PY 2002 VL 55 IS 4 BP 91 EP 92 PG 2 WC Physics, Multidisciplinary SC Physics GA 545VH UT WOS:000175237900027 ER PT J AU Norman, M AF Norman, M TI Return of the magnetic resonance SO PHYSICS WORLD LA English DT Article C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Norman, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Norman, Michael/C-3644-2013 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD APR PY 2002 VL 15 IS 4 BP 24 EP 25 PG 2 WC Physics, Multidisciplinary SC Physics GA 543AM UT WOS:000175078400031 ER PT J AU Wiench, JW Koprowski, M Stefaniak, L Webb, GA AF Wiench, JW Koprowski, M Stefaniak, L Webb, GA TI Composition of tautomeric mixtures studied by nitrogen chemical shifts and ab initio molecular orbital calculations SO POLISH JOURNAL OF CHEMISTRY LA English DT Article DE prototropic equilibrium; NMR; ab initio calculations ID N-SUBSTITUTED BENZOTRIAZOLES; WORKSTATION COMPUTERS; OCCUPATION NUMBERS; NMR; METHODOLOGY; EQUILIBRIA; JET; 2H-BENZOTRIAZOLE; SPECTROSCOPY; 2H-TAUTOMER AB Some nitrogen and carbon chemical shifts and ab initio Gauge Invariant Atomic Orbitals - Coupled-Perturbed Hartree-Fock (GIAO-CPHF) calculations are reported for benzotriazole 1, 5-nitrobenzimidazole 2, 5-nitrobenzotriazole 3, 4-nitrobenzotriazole 4, and N-methyl derivatives of compounds 1-3. A good correlation is found between the calculated and observed C-13 and N-15 chemical shifts. Two methods were employed for calculation of equilibrium constants. The prototropic equilibria exhibited by the system studied are found to be controlled by enthalpy rather than entropy. C1 Polish Acad Sci, Inst Organ Chem, PL-01224 Warsaw 42, Poland. Univ Surrey, Dept Chem, Guildford GU2 5XH, Surrey, England. RP Wiench, JW (reprint author), Iowa State Univ Sci & Technol, Ames Lab, 229 Spedding Hall, Ames, IA 50011 USA. NR 40 TC 6 Z9 6 U1 0 U2 0 PU POLISH CHEMICAL SOCIETY PI WARSAW PA C/O POLISH ACAD SCIENCES, INST PHYSICAL CHEMISTRY, UL KASPRZAKA 44/52, 01-224 WARSAW, POLAND SN 0137-5083 J9 POL J CHEM JI Pol. J. Chem. PD APR PY 2002 VL 76 IS 4 BP 525 EP 536 PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 535DC UT WOS:000174629100007 ER PT J AU Cornelius, CJ Marand, E AF Cornelius, CJ Marand, E TI Hybrid inorganic-organic materials based on a 6FDA-6FpDA-DABA polyimide and silica: physical characterization studies SO POLYMER LA English DT Article DE polyimide; membrane; gas transport ID SOL-GEL PROCESS; INSITU POLYMERIZATION; COUPLING AGENTS; TETRAETHOXYSILANE; EVOLUTION; GLASS; ALKOXIDES; MEMBRANES; COMPOSITE; BEHAVIOR AB A series of hybrid polyimide-silica composites were fabricated from a functionalized fluorinated polyimide and tetramethoxysilane (TMOS), methyltrimethoxysilane (MTMOS), and phenyltrimethoxysilane (PTMOS) via a sol-gel process. Polyimides were solution imidized employing 4,4'-hexafluoroisopropylidenediphthalic anhydride (6FDA), and various amounts of 4,4'-hexafluoroisopropylidene dianiline (6FpDA) and 3,5-diaminobenzoic acid (DABA). The degree of cross-linking between the silica structures and the polyimide matrixes, as well as the morphology of the hybrid systems were highly dependent on the type and content of the alkoxide employed. The higher functionality and reactivity of TMOS alkoxide gave rise to highly cross-linked, homogeneous hybrid systems, while the MTMOS and PTMOS based hybrid systems were phase separated and the silica structures largely uncondensed. Although the thermal stability changed a little, incorporation of the silica structures in the polyimide matrix increased the rigidity and mechanical strength of the hybrid materials, particularly at elevated temperatures. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Chem Engn, Blacksburg, VA 24061 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Marand, E (reprint author), Virginia Polytech Inst & State Univ, Dept Chem Engn, Blacksburg, VA 24061 USA. NR 35 TC 133 Z9 133 U1 4 U2 25 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD APR PY 2002 VL 43 IS 8 BP 2385 EP 2400 AR PII S0032-3861(02)00803-5 DI 10.1016/S0032-3861(01)00803-5 PG 16 WC Polymer Science SC Polymer Science GA 524UA UT WOS:000174030200032 ER PT J AU Oberkampf, WL Trucano, TG AF Oberkampf, WL Trucano, TG TI Verification and validation in computational fluid dynamics SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID NAVIER-STOKES EQUATIONS; BACKWARD-FACING STEP; INFINITE FLAT PLATE; EXPERIMENTAL AERODYNAMICS RESEARCH; SENSITIVITY ANALYSIS TECHNIQUES; ISOLATION PILOT-PLANT; FINITE-ELEMENT METHOD; LID-DRIVEN CAVITY; MODEL VALIDATION; ERROR ESTIMATION AB Verification and validation (V&V) are the primary means to assess accuracy and reliability in computational simulations. This paper presents an extensive review of the literature in V&V in computational fluid dynamics (CFD), discusses methods and procedures for assessing V&V, and develops a number of extensions to existing ideas. The review of the development of V&V terminology and methodology points out the contributions from members of the operations research, statistics, and CFD communities. Fundamental issues in V&V are addressed, such as code verification versus solution verification, model validation versus solution validation, the distinction between error and uncertainty, conceptual sources of error and uncertainty, and the relationship between validation and prediction. The fundamental strategy of verification is the identification and quantification of errors in the computational model and its solution. In verification activities, the accuracy of a computational solution is primarily measured relative to two types of highly accurate solutions: analytical solutions and highly accurate numerical solutions. Methods for determining the accuracy of numerical solutions are presented and the importance of software testing during verification activities is emphasized. The fundamental strategy of validation is to assess how accurately the computational results compare with the experimental data, with quantified error and uncertainty estimates for both. This strategy employs a hierarchical methodology that segregates and simplifies the physical and coupling phenomena involved in the complex engineering system of interest. A hypersonic cruise missile is used as an example of how this hierarchical structure is formulated. The discussion of validation assessment also encompasses a number of other important topics. A set of guidelines is proposed for designing and conducting validation experiments, supported by an explanation of how validation experiments are different from traditional experiments and testing. A description is given of a relatively new procedure for estimating experimental uncertainty that has proven more effective at estimating random and correlated bias errors in wind-tunnel experiments than traditional methods. Consistent with the authors' contention that nondeterministic simulations are needed in many validation comparisons, a three-step statistical approach is offered for incorporating experimental uncertainties into the computational analysis. The discussion of validation assessment ends with the topic of validation metrics, where two sample problems are used to demonstrate how such metrics should be constructed. In the spirit of advancing the state of the art in V&V, the paper concludes with recommendations of topics for future research and with suggestions for needed changes in the implementation of V&V in production and commercial software. (C) 2002 Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Validat & Uncertainty Estimat Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Optimizat & Uncertainty Estimat Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Validat & Uncertainty Estimat Dept, POB 5800,MS 0828, Albuquerque, NM 87185 USA. EM wloberk@sandia.gov RI Namikawa, Laercio/C-5559-2013 OI Namikawa, Laercio/0000-0001-7847-1804 NR 350 TC 288 Z9 304 U1 13 U2 177 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0376-0421 J9 PROG AEROSP SCI JI Prog. Aeosp. Sci. PD APR PY 2002 VL 38 IS 3 BP 209 EP 272 AR PII S0376-0421(02)00005-2 DI 10.1016/S0376-0421(02)00005-2 PG 64 WC Engineering, Aerospace SC Engineering GA 588PP UT WOS:000177710100002 ER PT J AU Souers, PC Garza, R Vitello, P AF Souers, PC Garza, R Vitello, P TI Ignition & growth and JWL++ detonation models in coarse zones SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article ID REACTIVE FLOW AB "Ignition & Growth" (I&G) and JWL++ models are compared for a variety of problems. The detonation velocity becomes nearly constant with zoning at the edge of convergence, which for TATB, is 8 zones/mm for I&G and 4 for JWL++. The use of pressure in the rate for I&G makes the detonation velocity rapidly decrease as the zones are coarsened. Using pressure plus artificial viscosity to some power in the rate for JWL++ allows the correction for coarsening zones. In coarse zones, the pressure and the burn fraction turn on independently and this feature dominates model behavior. If pressure lags burn fraction, then the maximum pressure will be lower than expected. An unexpected phenomenon is saturation, i.e. the slowing down of the detonation velocity as a function of the fast rate constant. This slowing can be weak and produce a plateau. or it can be strong and cause the detonation velocity to approach an asymptote. The saturation effect comes from a combination of the 1 - F term and declining pressures. Failure (critical diameter effect) occurs in reactive flow but optimizing for this undoes the settings for other results. In JWL++, the fast reaction pressure exponent is near -1 for the best fit for the size (diameter) effect, 2 for the Pop plot and near -3 to fit failure. The Pop plot deflagration rate is derived, although it needs not to be the same as the detonation rate. The use of additive pressures is compared with the pressure equilibrator and no difference is found. Increased zoning by a factor of 5 and improved code structure will be needed for future improvement. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RP Souers, PC (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. NR 28 TC 18 Z9 18 U1 3 U2 9 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD APR PY 2002 VL 27 IS 2 BP 62 EP 71 DI 10.1002/1521-4087(200204)27:2<62::AID-PREP62>3.0.CO;2-5 PG 10 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA 545VV UT WOS:000175239000003 ER PT J AU Kesmir, C Nussbaum, AK Schild, H Detours V Brunak, S AF Kesmir, C Nussbaum, AK Schild, H Detours, V Brunak, S TI Prediction of proteasome cleavage motifs by neural networks SO PROTEIN ENGINEERING LA English DT Article DE artificial neural networks; cleavage site prediction; MHC Class I epitopes; proteasome; protein degradation ID MAJOR HISTOCOMPATIBILITY COMPLEX; CLASS-I LIGANDS; DISTINCT PROTEOLYTIC PROCESSES; 20S PROTEASOME; BINDING PEPTIDES; GENE-PRODUCTS; MOLECULAR PATHOGENESIS; STANDARD PROTEASOME; PROTEIN-STRUCTURE; MESSENGER-RNA AB We present a predictive method that can simulate an essential step in the antigen presentation in higher vertebrates, namely the step involving the proteasomal degradation of polypeptides into fragments which have the potential to bind to MHC Class I molecules. Proteasomal cleavage prediction algorithms published so far were trained on data from in vitro digestion experiments with constitutive proteasomes. As a result, they did not take into account the characteristics of the structurally modified proteasomes-often called immunoproteasomes-found in cells stimulated by gamma-interferon under physiological conditions. Our algorithm has been trained not only on in vitro data, but also on MHC Class I ligand data, which reflect a combination of immunoproteasome and constitutive proteasome specificity. This feature, together with the use of neural networks, a non-linear classification technique, make the prediction of MHC Class I ligand boundaries more accurate: 65% of the cleavage sites and 85% of the non-cleavage sites are correctly determined. Moreover, we show that the neural networks trained on the constitutive proteasome data learns a specificity that differs from that of the networks trained on MHC Class I ligands, i.e. the specificity of the immunoproteasome is different than the constitutive proteasome. The tools developed in this study in combination with a predictor of MHC and TAP binding capacity should give a more complete prediction of the generation and presentation of peptides on MHC Class I molecules. Here we demonstrate that such an approach produces an accurate prediction of the CTL the epitopes in HIV Nef. The method is available at www.cbs.dtu.dk/services/NetChop/. C1 Univ Utrecht, NL-3584 CH Utrecht, Netherlands. Tech Univ Denmark, Bioctr DTU, Ctr Biol Sequence Anal, Copenhagen, Denmark. Univ Tubingen, Dept Immunol, Inst Cell Biol, D-72074 Tubingen, Germany. Santa Fe Inst, Santa Fe, NM 87501 USA. Los Alamos Natl Lab, Div Theoret Biol & Biophys, Los Alamos, NM USA. RP Kesmir, C (reprint author), Univ Utrecht, Padualaan 8, NL-3584 CH Utrecht, Netherlands. EM C.Kesmir@bio.uu.nl RI Kesmir, Can/B-9410-2011 NR 56 TC 139 Z9 153 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0269-2139 J9 PROTEIN ENG JI Protein Eng. PD APR PY 2002 VL 15 IS 4 BP 287 EP 296 DI 10.1093/protein/15.4.287 PG 10 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 551YU UT WOS:000175592200004 PM 11983929 ER PT J AU Chance, MR Bresnick, AR Burley, SK Jiang, JS Lima, CD Sali, A Almo, SC Bonanno, JB Buglino, JA Boulton, S Chen, H Eswar, N He, GS Huang, R Ilyin, V McMahan, L Pieper, U Ray, S Vidal, M Wang, LK AF Chance, MR Bresnick, AR Burley, SK Jiang, JS Lima, CD Sali, A Almo, SC Bonanno, JB Buglino, JA Boulton, S Chen, H Eswar, N He, GS Huang, R Ilyin, V McMahan, L Pieper, U Ray, S Vidal, M Wang, LK TI Structural genomics: A pipeline for providing structures for the biologist SO PROTEIN SCIENCE LA English DT Article ID CRYSTAL-STRUCTURE; PSI-BLAST; PROTEIN; SYNTHASE; REFINEMENT; DATABASE; MATRICES C1 Yeshiva Univ Albert Einstein Coll Med, Ctr Synchrotron Biosci, Bronx, NY 10461 USA. Yeshiva Univ Albert Einstein Coll Med, Dept Phys & Biophys, Bronx, NY 10461 USA. Yeshiva Univ Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. Rockefeller Univ, New York, NY 10021 USA. Howard Hughes Med Inst, Coconut Grove, FL 33133 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Cornell Univ, Weill Med Coll, Dept Biochem, New York, NY 10021 USA. Cornell Univ, Weill Med Coll, Struct Biol Program, New York, NY 10021 USA. Harvard Univ, Sch Med, Dept Genet, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dana Farber Canc Inst, Boston, MA 02115 USA. Sloan Kettering Inst, Program Mol Biol, New York, NY 10021 USA. RP Chance, MR (reprint author), Yeshiva Univ Albert Einstein Coll Med, Dept Biochem, 1300 Morris Pk Ave, Bronx, NY 10461 USA. RI Pieper, Ursula/E-4444-2010; OI Huang, Raymond/0000-0001-7661-797X; Lima, Christopher/0000-0002-9163-6092 FU NCI NIH HHS [CA81658]; NCRR NIH HHS [P41-RR12408, P41-RR01633, P41 RR012408]; NIGMS NIH HHS [GM54762, R29 GM054762, GM62529, P50 GM062529, R01 GM054762] NR 53 TC 117 Z9 123 U1 0 U2 3 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD APR PY 2002 VL 11 IS 4 BP 723 EP 738 DI 10.1110/ps.470102 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 534PF UT WOS:000174594200001 PM 11910018 ER PT J AU Jacobs, K AF Jacobs, Kurt TI How Do Two Observers Pool Their Knowledge About a Quantum System? SO QUANTUM INFORMATION PROCESSING LA English DT Article DE quantum mechanics; quantum information; Bayesian inference; state estimation; states of knowledge AB In the theory of classical statistical inference one can derive a simple rule by which two or more observers may combine independently obtained states of knowledge together to form a new state of knowledge, which is the state which would be possessed by someone having the combined information of both observers. Moreover, this combined state of knowledge can be found without reference to the manner in which the respective observers obtained their information. However, we show that in general this is not possible for quantum states of knowledge; in order to combine two quantum states of knowledge to obtain the state resulting from the combined information of both observers, these observers must also possess information about how their respective states of knowledge were obtained. Nevertheless, we emphasize this does not preclude the possibility that a unique, well motivated rule for combining quantum states of knowledge without reference to a measurement history could be found. We examine both the direct quantum analog of the classical problem, and that of quantum state-estimation, which corresponds to a variant in which the observers share a specific kind of prior information. C1 [Jacobs, Kurt] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Jacobs, K (reprint author), Artabel SA, 69 Rue Paris, F-91400 Orsay, France. FU Department of Energy [W-7405-ENG-36] FX We would like to thank Salman Habib for helpful discussions and a thorough reading of the manuscript. This research is supported by the Department of Energy, under contract W-7405-ENG-36. NR 18 TC 14 Z9 14 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1570-0755 J9 QUANTUM INF PROCESS JI Quantum Inf. Process. PD APR PY 2002 VL 1 IS 1-2 BP 73 EP 89 DI 10.1023/A:1019661404380 PG 17 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA V25SZ UT WOS:000208499000008 ER PT J AU Brown, AR Cederwall, RT Chlond, A Duynkerke, PG Golaz, JC Khairoutdinov, M Lewellen, DC Lock, AP MacVean, MK Moeng, CH Neggers, RAJ Siebesma, AP Stevens, B AF Brown, AR Cederwall, RT Chlond, A Duynkerke, PG Golaz, JC Khairoutdinov, M Lewellen, DC Lock, AP MacVean, MK Moeng, CH Neggers, RAJ Siebesma, AP Stevens, B TI Large-eddy simulation of the diurnal cycle of shallow cumulus convection overland SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE ARM; GCSS; intercomparison ID BOUNDARY-LAYER; MODEL; SENSITIVITY; SHEAR; PARAMETRIZATION; RADIATION; BUDGETS; FLUXES AB Large-eddy simulations of the development of shallow cumulus convection over land are presented. Many characteristics of the cumulus layer previously found in simulations of quasi-steady convection over the sea are found to be reproduced in this more strongly forced, unsteady case. Furthermore, the results are shown to be encouragingly robust, with similar results obtained with eight independent models, and also across a range of numerical resolutions. The datasets produced are already being used in the development and evaluation of parametrizations used in numerical weather-prediction and climate models. C1 Meteorol Off, Bracknell RG12 2SZ, Berks, England. Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Utrecht, NL-3508 TC Utrecht, Netherlands. Colorado State Univ, Ft Collins, CO 80523 USA. W Virginia Univ, Morgantown, WV 26506 USA. Natl Ctr Atmospher Res, Boulder, CO USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. RP Brown, AR (reprint author), Meteorol Off, London Rd, Bracknell RG12 2SZ, Berks, England. RI Lewellen, David/B-1453-2008; Stevens, Bjorn/A-1757-2013; Golaz, Jean-Christophe/D-5007-2014 OI Stevens, Bjorn/0000-0003-3795-0475; Golaz, Jean-Christophe/0000-0003-1616-5435 NR 22 TC 126 Z9 129 U1 1 U2 12 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 2002 VL 128 IS 582 BP 1075 EP 1093 DI 10.1256/003590002320373210 PN B PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 564XR UT WOS:000176339300003 ER PT J AU Xie, SC Xu, KM Cederwall, RT Bechtold, P Del Genio, AD Klein, SA Cripe, DG Ghan, SJ Gregory, D Iacobellis, SF Krueger, SK Lohmann, U Petch, JC Randall, DA Rotstayn, LD Somerville, RCJ Sud, YC Von Salzen, K Walker, GK Wolf, A Yio, JJ Zhang, GJ Zhang, MG AF Xie, SC Xu, KM Cederwall, RT Bechtold, P Del Genio, AD Klein, SA Cripe, DG Ghan, SJ Gregory, D Iacobellis, SF Krueger, SK Lohmann, U Petch, JC Randall, DA Rotstayn, LD Somerville, RCJ Sud, YC Von Salzen, K Walker, GK Wolf, A Yio, JJ Zhang, GJ Zhang, MG TI Intercomparison and evaluation of cumulus parametrizations under summertime midlatitude continental conditions SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE Continental cumulus convection; single-column models ID RELAXED ARAKAWA-SCHUBERT; LARGE-SCALE ENVIRONMENT; SINGLE-COLUMN MODELS; GENERAL-CIRCULATION MODEL; TROPICAL CLOUD CLUSTERS; FLUX CONVECTION SCHEME; TOGA-COARE; STRATIFORM CLOUDS; MOISTURE BUDGETS; SQUALL LINE AB This study reports the Single-Column Model (SCM) part of the Atmospheric Radiation Measurement (ARM)/the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) joint SCM and Cloud-Resolving Model (CRM) Case 3 intercomparison study, with a focus on evaluation Of Cumulus parametrizations used in SCMs. Fifteen SCMs are evaluated under summertime midlatitude continental conditions using data collected at the ARM Southern Great Plains site during the summer 1997 Intensive Observing Period. Results from ten CRMs are also used to diagnose problems in the SCMs. It is shown that most SCMs can generally capture well the convective events that were well-developed within the SCM domain, while most of them have difficulties in simulating the occurrence of those convective events that only occurred within a small part of the domain. All models significantly underestimate the surface stratiform precipitation. A third of them produce large errors in surface precipitation and thermodynamic structures. Deficiencies in convective triggering mechanisms are thought to be one of the major reasons. Using a triggering mechanism that is based on the vertical integral of parcel buoyant energy without additional appropriate constraints results in overactive convection, which in turn leads to large systematic warm/dry biases in the troposphere. It is also shown that a non-penetrative convection scheme can underestimate the depth of instability for midlatitude convection, which leads to large systematic cold/moist biases in the troposphere. SCMs agree well quantitatively with CRMs in the updraught mass fluxes, while most models significantly underestimate the downdraught mass fluxes. Neglect of mesoscale updraught and downdraught mass fluxes in the SCMs contributes considerably to the discrepancies between the SCMs and the CRMs. In addition, uncertainties in the diagnosed mass fluxes in the CRMs and deficiencies with cumulus parametrizations are not negligible. Similar results are obtained in the sensitivity tests when different forcing approaches are used. Finally. sensitivity tests from an SCM indicate that its simulations can be greatly improved when its triggering mechanism and closure assumption are improved. C1 Lawrence Livermore Natl Lab, Atmospher Sci Div L103, Livermore, CA 94551 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Observ Midi Pyrenees, Grenoble, France. NASA, Goddard Inst Space Studies, Greenbelt, MD USA. NOAA, Geophys Fluid Dynam Lab, Silver Spring, MD USA. Colorado State Univ, Ft Collins, CO 80523 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Utah, Salt Lake City, UT 84112 USA. Dalhousie Univ, Halifax, NS B3H 3J5, Canada. CSIRO, Canberra, ACT, Australia. Univ Victoria, Canadian Ctr Climate Modeling & Anal, Victoria, BC V8W 2Y2, Canada. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Xie, SC (reprint author), Lawrence Livermore Natl Lab, Atmospher Sci Div L103, POB 808, Livermore, CA 94551 USA. RI Del Genio, Anthony/D-4663-2012; Xu, Kuan-Man/B-7557-2013; Rotstayn, Leon/A-1756-2012; Xie, Shaocheng/D-2207-2013; Randall, David/E-6113-2011; Ghan, Steven/H-4301-2011; Klein, Stephen/H-4337-2016; Lohmann, Ulrike/B-6153-2009 OI Del Genio, Anthony/0000-0001-7450-1359; Xu, Kuan-Man/0000-0001-7851-2629; Rotstayn, Leon/0000-0002-2385-4223; Xie, Shaocheng/0000-0001-8931-5145; Randall, David/0000-0001-6935-4112; Ghan, Steven/0000-0001-8355-8699; Klein, Stephen/0000-0002-5476-858X; Lohmann, Ulrike/0000-0001-8885-3785 NR 65 TC 88 Z9 90 U1 0 U2 11 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD APR PY 2002 VL 128 IS 582 BP 1095 EP 1135 DI 10.1256/003590002320373229 PN B PG 41 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 564XR UT WOS:000176339300004 ER PT J AU Holroyd, RA Nishikawa, M AF Holroyd, RA Nishikawa, M TI Pressure effects on electron reactions and mobility in nonpolar liquids SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID CHEMICAL-REACTION RATES; CONDUCTION-BAND ENERGY; EXCESS ELECTRONS; N-HEXANE; EQUILIBRIUM; SOLVENTS; ATTACHMENT; 2,2-DIMETHYLBUTANE; TOLUENE; HYDROCARBONS AB High pressure studies have elucidated the mechanisms of both electron reactions and electron transport in nonpolar liquids and provided information about the partial molar volumes of ions and electrons. The very large volume changes associated with electron attachment reactions have been explained as due to electrostriction by the ions, calculated with a continuum model, but modified to include the formation of a glassy shell of solvent molecules around the ion. The mobilities of electrons in cases where the electron is trapped can now be understood by comparing the trap cavity volume with the volume of electrostriction of the solvent around the Cavity. In cases where the electron is quasi-free the compressibility dependent potential fluctuations are shown to be important. The isothermal compressibility is concluded to be the single most important parameter determining the behavior of excess electrons in liquids. Published by Elsevier Science Ltd. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Kanagawa Inst Technol, Fac Engn, Atsugi, Kanagawa 2430292, Japan. RP Holroyd, RA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM holroyd@bnl.gov NR 39 TC 12 Z9 12 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD APR PY 2002 VL 64 IS 1 BP 19 EP 28 AR PII S0969-806X(01)00236-5 DI 10.1016/S0969-806X(01)00236-5 PG 10 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 539UE UT WOS:000174889000005 ER PT J AU Burillo, G Clough, RL Czvikovszky, T Guven, O Le Moel, A Liu, WW Singh, A Yang, JT Zaharescu, T AF Burillo, G Clough, RL Czvikovszky, T Guven, O Le Moel, A Liu, WW Singh, A Yang, JT Zaharescu, T TI Polymer recycling: potential application of radiation technology SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID ELECTRON-BEAM IRRADIATION; CROSS-LINKED POLYETHYLENE; LOW-DENSITY POLYETHYLENE; EPDM-PP BLENDS; MECHANICAL-PROPERTIES; GAMMA-IRRADIATION; POLYOLEFIN BLENDS; RUBBER; POLYPROPYLENE; MORPHOLOGY AB Management of solid waste is an important problem, which is becoming progressively worse as a byproduct of continuing economic growth and development. Polymeric materials (plastics and rubbers) comprise a steadily increasing proportion of the municipal and industrial waste going into landfill. Development of technologies for reducing polymeric waste. which are acceptable from the environmental standpoint, and which are cost-effective, has proven to be a difficult challenge due to complexities inherent in the reuse of polymers. Establishing optimal processes for the reuse/recycling of polymeric materials thus remains a worldwide challenge as we enter the new century. Due to the ability of ionizing radiation to alter the structure and properties of bulk polymeric materials, and the fact that it is applicable to essentially all polymer types, irradiation holds promise for impacting the polymer waste problem. The three main possibilities for use of radiation in this application are: (1) enhancing the mechanical properties and performance of recovered materials or material blends, principally through crosslinking, or through surface modification of different phases being combined; (2) treatment causing or enhancing the decomposition of polymers, particularly through chain scission, leading to recovery of either low molecular weight mixtures. or powders, for use as chemical feedstocks or additives; (3) production of advanced polymeric materials designed for environmental compatibility. This paper provides an overview of the polymer recycling problem. describes the major technological obstacles to the implementation of recycling technologies, and outlines some of the approaches being taken. A review of radiation-based recycling research is then provided. followed by a discussion of future directions where irradiation may be relevant to the problems currently inhibiting the widespread recycling of polymeric materials. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Organ Mat Dept, Albuquerque, NM 87185 USA. Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Tech Univ Budapest, Dept Polymer Engn & Text Technol, H-1111 Budapest, Hungary. IAEA, A-1400 Vienna, Austria. CEA, DSM, DRECAM, SRSIM, F-91191 Gif Sur Yvette, France. Tsing Hua Univ, Huaye Inst Innovat Technol, Beijing 100084, Peoples R China. AHA Enterprises, Victoria, BC V8Y 2R6, Canada. R&D Inst Elect Engn, RO-74204 Bucharest, Romania. RP Clough, RL (reprint author), Sandia Natl Labs, Organ Mat Dept, MS 0888, Albuquerque, NM 87185 USA. RI Zaharescu, Traian/C-4778-2011; Czvikovszky, Tibor/H-4252-2012 NR 83 TC 64 Z9 67 U1 1 U2 37 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD APR PY 2002 VL 64 IS 1 BP 41 EP 51 AR PII S0969-806X(01)00443-1 DI 10.1016/S0969-806X(01)00443-1 PG 11 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 539UE UT WOS:000174889000008 ER PT J AU Tsap, LV AF Tsap, LV TI Gesture-tracking in real time with dynamic regional range computation SO REAL-TIME IMAGING LA English DT Article ID RECOGNITION; REPRESENTATION AB This paper presents a new approach to the range data utilization in a gesture-tracking system. The use of three-dimensional data is essential for human motion analysis; however, the speed of complete range estimation prohibits from including it in most real-time systems. This work describes a gesture-tracking system using real-time local range on-demand. The system represents a gesture-controlled interface for interactive visual exploration of large data sets. The paper describes a method performing range processing only when necessary and where necessary. Range data is processed only for non-static regions of interest. This is accomplished by a set of filters on the color, motion, and range data. The speed-up achieved is between 1.70 and 2.15. The algorithm also includes a robust skin-color segmentation insensitive to illumination changes. Selective range processing results in dynamic regional range images that contain only information needed by the system. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Tsap, LV (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-551, Livermore, CA 94551 USA. NR 25 TC 6 Z9 6 U1 0 U2 2 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1077-2014 J9 REAL-TIME IMAGING JI Real-Time Imaging PD APR PY 2002 VL 8 IS 2 BP 115 EP 126 DI 10.1006/rtim.2001.0260 PG 12 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 587EN UT WOS:000177627700004 ER PT J AU Qin, WH Gerstl, SAW Deering, DW Goel, NS AF Qin, WH Gerstl, SAW Deering, DW Goel, NS TI Characterizing leaf geometry for grass and crop canopies from hotspot observations: A simulation study SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID BIDIRECTIONAL REFLECTANCE; VEGETATION CANOPIES; MODEL; DISTRIBUTIONS; FOREST; SHAPE AB The potential of canopy reflectance distributions in the hotspot region for characterizing leaf geometry (leaf size and shape) of grass and crop canopies is explored with computer simulations. In this article, a computer graphics method-Lindenmayer-systems (L-systems) - is used to render a series of leaf (grass) and architecturally realistic row-planted crop (corn-like) canopies that have a variety of geometrical structures. A radiosity-graphics combined model is then employed to calculate the radiation regime in a canopy, including canopy directional reflectance. An effectiveness ratio (E ratio) is proposed, which is able to evaluate the performance of a given measure or index in estimation of the parameter of interest under the influence of a number of "noise" factors (other geometric and optical parameters of the canopy) at various noise levels. This E ratio is then applied to evaluate reflectance and normalized reflectance in the hotspot region for leaf geometry characterization. The result from simulated hotspot reflectance demonstrates that for both canopies, leaf geometry is estimable by using normalized reflectance within +/-4-8degrees (or +/-2-4degrees) around the hotspot direction in the principal cone (or principal plane). However, the center position and angular width of the optimal sampling region are affected by the number of noise factors [such as leaf area index, leaf angle distribution for leaf canopies, plus row structure for row-plant crop canopies] and their variation ranges. In most cases, normalized spectral reflectance in the near-infrared at a high solar zenith angle in the PC produces the most reliable results. The reason for better estimation of leaf geometry for grass and crop canopies than forests from hotspot observations is also discussed in this article. (C) 2002 Elsevier Science Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Raytheon, ITTS, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Wayne State Univ, Dept Comp Sci, Detroit, MI 48202 USA. RP Qin, WH (reprint author), NASA, Goddard Space Flight Ctr, Raytheon, ITTS, Code 916, Greenbelt, MD 20771 USA. RI 黄, 建荣/B-8070-2011 NR 32 TC 9 Z9 11 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD APR PY 2002 VL 80 IS 1 BP 100 EP 113 AR PII S0034-4257(01)00291-7 DI 10.1016/S0034-4257(01)00291-7 PG 14 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 534HN UT WOS:000174579200009 ER PT J AU Allison, SW Cates, MR Gillies, GT AF Allison, SW Cates, MR Gillies, GT TI Excitation of thermographic phosphors using a blue light emitting diode: Spectral characteristics and instrumentation applications SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NANOSECOND AB A blue light emitting diode (LED) has been used as the excitation source in a series of sensor-related characterization studies carried out on thermographic phosphors. The motivation for the described effort is the potential utility of LEDs for fluorescence based thermometry applications. The phosphors that were evaluated included La2O2S:Tb, Gd2O2S:Tb, Y2O2S:Pr, and various other rare-earth activated ceramics. Periodic and pulsed excitation of the phosphors was demonstrated, with LED gate-on times of 10-12 mus at operating levels of approximate to25 V. The spectral response of the phosphors under these conditions is described, and the implications of such devices for the design of electro-optic instrumentation systems (including remote thermometry applications) are discussed. A beneficial finding of this work is that a good match between the LED emission spectrum and the phosphor excitation spectrum is not required in order to produce useful, detectable fluorescence. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37932 USA. Univ Virginia, Dept Mech & Aerosp Engn, Charlottesville, VA 22904 USA. RP Allison, SW (reprint author), Oak Ridge Natl Lab, Engn Technol Div, POB 2008 MS6472, Oak Ridge, TN 37932 USA. OI Allison, Stephen/0000-0002-5887-5403 NR 11 TC 15 Z9 15 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD APR PY 2002 VL 73 IS 4 BP 1832 EP 1834 DI 10.1063/1.1460928 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 535FG UT WOS:000174634100026 ER PT J AU Raber, E Hirabayashi, JM Mancieri, SP Jin, AL Folks, KJ Carlsen, TM Estacio, P AF Raber, E Hirabayashi, JM Mancieri, SP Jin, AL Folks, KJ Carlsen, TM Estacio, P TI Chemical and biological agent incident response and decision process for civilian and public sector facilities SO RISK ANALYSIS LA English DT Article DE chemical warfare agent; biological warfare agent; decontamination; decontamination decision process AB In the event of a terrorist attack or catastrophic release involving potential chemical and/or biological warfare agents, decisionmakers will need to make timely and informed choices about whether, or how, to respond. The objective of this article is to provide a decision framework to specify initial and follow-up actions, including possible decontamination, and to address long-term health and environmental issues. This decision framework consists of four phases, beginning with the identification of an incident and ending with verification that cleanup and remediation criteria have been met. The flowchart takes into account both differences and similarities among potential agents or toxins at key points in the decisionmaking process. Risk evaluation and communication of information to the public must be done throughout the process to ensure a successful effort. C1 Lawrence Livermore Natl Lab, Environm Protect Dept, Livermore, CA 94551 USA. RP Raber, E (reprint author), Lawrence Livermore Natl Lab, Environm Protect Dept, POB 808,L-626, Livermore, CA 94551 USA. NR 4 TC 13 Z9 13 U1 0 U2 5 PU BLACKWELL PUBLISHERS PI MALDEN PA 350 MAIN STREET, STE 6, MALDEN, MA 02148 USA SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD APR PY 2002 VL 22 IS 2 BP 195 EP 202 DI 10.1111/0272-4332.00026 PG 8 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA 552PU UT WOS:000175629400002 PM 12022670 ER PT J AU Partouche-Sebban, D Holtkamp, DB Pelissier, JL Taboury, J Rouyer, A AF Partouche-Sebban, D Holtkamp, DB Pelissier, JL Taboury, J Rouyer, A TI An investigation of shock induced temperature rise and melting of bismuth using high-speed optical pyrometry SO SHOCK WAVES LA English DT Article DE temperature; bismuth; emissivity; pyrometry; shock; melting ID MODEL-POTENTIAL APPROACH AB Temperature is a basic parameter in physics, but in the case of shock-compressed metals its measurement remains difficult and controversial. Improvements in accuracy of a high-speed optical pyrometer enabled us to study interesting features of bismuth: temperatures of shock-loaded samples measured through a lithium-fluoride anvil and (indirectly) part of the fusion curve. An improved method of analyzing optical pyrometry data is also discussed. C1 CEA, F-91680 Bruyeres Le Chatel, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Inst Opt Theor & Appl, F-91403 Orsay, France. RP Partouche-Sebban, D (reprint author), CEA, BP12, F-91680 Bruyeres Le Chatel, France. NR 23 TC 19 Z9 19 U1 3 U2 12 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-1287 J9 SHOCK WAVES JI Shock Waves PD APR PY 2002 VL 11 IS 5 BP 385 EP 392 DI 10.1007/s001930100116 PG 8 WC Mechanics SC Mechanics GA 547JR UT WOS:000175329700007 ER PT J AU Istratov, AA Hieslmair, H Vyvenko, OF Weber, ER Schindler, R AF Istratov, AA Hieslmair, H Vyvenko, OF Weber, ER Schindler, R TI Defect recognition and impurity detection techniques in crystalline silicon for solar cells SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE solar cells; defect clusters; DLTS; EBIC; X-ray fluorescence; XBIC ID EXTENDED DEFECTS; RECOMBINATION PROPERTIES; LOCALIZED STATES; PRECIPITATION; REGION; NICKEL; SI AB The efficiency of multicrystalline solar cells is limited by defects and impurities, which include grain boundaries, dislocations, and transition metals. The density of these defects often varies from grain to grain. "Bad grains" with low minority carrier diffusion length generate low open circuit voltage and shunt the "good grains" with high minority carrier diffusion length, thus reducing the overall cell efficiency. It was found that it is more likely to find transition metal clusters in "bad grains" than in "good grains", and that gettering is not efficient in improving the areas of low diffusion length. The primary objective of materials research in photovoltaics is identification of these lifetime-limiting defects. In this article we summarize the current state of understanding of lifetime-limiting defects in solar cells, summarize the advantages and limitations of traditional analytical tools and discuss novel emerging techniques, including X-ray fluorescence microprobe, X-ray absorption spectromicroscopy, and X-ray beam-induced current (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, LBNL, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Fraunhofer Inst Solar Energy Syst, D-79110 Freiburg, Germany. RP Istratov, AA (reprint author), Univ Calif Berkeley, LBNL, Mailstop 62-203,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM istratov@socrates.berkeley.edu RI Vyvenko, Oleg/I-6539-2013; OI Vyvenko, Oleg/0000-0001-6077-3679; Hieslmair, Henry/0000-0002-5842-1882 NR 31 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD APR PY 2002 VL 72 IS 1-4 BP 441 EP 451 AR PII S0927-0248(01)00192-1 DI 10.1016/S0927-0248(01)00192-1 PG 11 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 543KL UT WOS:000175101100049 ER PT J AU Luo, B Johnson, JW Gila, BP Onstine, A Abernathy, CR Ren, F Pearton, SJ Baca, AG Dabiran, AM Wowchack, AM Chow, PP AF Luo, B Johnson, JW Gila, BP Onstine, A Abernathy, CR Ren, F Pearton, SJ Baca, AG Dabiran, AM Wowchack, AM Chow, PP TI Surface passivation of AlGaN/GaN HEMTs using MBE-grown MgO or Sc2O3 SO SOLID-STATE ELECTRONICS LA English DT Article DE surface passivation; AlGaN/GaN HEMTs; hydrogen-free dielectrics; dc and rf characterizations; MgO; Sc2O3 ID PERFORMANCE; GAN; DEVICES; FABRICATION; TRANSISTORS; DC AB Thin (100 (A) over circle) layers of MgO or Sc2O3 grown by molecular beam epitaxy were investigated for surface passivation of AlGaN/GaN high electron mobility transistors. A variety of pre-treatments such as UV/O-3 or in situ heating were employed prior to the dielectric deposition. Under optimized conditions, the MgO produced an increase in drain-source current, threshold voltage and extrinsic transconductance, which is consistent with passivation of surface states in the AlGaN. The absence of hydrogen in the dielectrics makes them attractive candidates for long-term stable passivation of the HEMTs. (C) 2002 Published by Elsevier Science Ltd. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. SVT Associates, Eden Prairie, MN 55344 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. NR 15 TC 31 Z9 32 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD APR PY 2002 VL 46 IS 4 BP 467 EP 476 AR PII S0038-1101(01)00314-8 DI 10.1016/S0038-1101(01)00314-8 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 551EH UT WOS:000175546200003 ER PT J AU Johnson, JW Han, J Baca, AG Briggs, RD Shul, RJ Wendt, JR Monier, C Ren, F Luo, B Chu, SNG Tsvetkov, D Dmitriev, V Pearton, SJ AF Johnson, JW Han, J Baca, AG Briggs, RD Shul, RJ Wendt, JR Monier, C Ren, F Luo, B Chu, SNG Tsvetkov, D Dmitriev, V Pearton, SJ TI Comparison of AlGaN/GaN high electron mobility transistors grown on AlN/SiC templates or sapphire SO SOLID-STATE ELECTRONICS LA English DT Article DE GaN; AlGaN; AlN; SiC; HEMT; AFM; TEM; mobility ID FIELD-EFFECT TRANSISTORS; GAN; HEMTS; PERFORMANCE; HETEROSTRUCTURES; MODULATION; DEVICES AB The temperature and gate length effects on dc performance of AlGaN/GaN high-electron mobility transistors (HEMTs) grown on AlN/SiC templates or sapphire substrates are reported. The defect density in the structures grown on the AlN/SiC template is significantly lower than those grown on sapphire, as measured by transmission electron microscopy. Reverse breakdown voltages above 40 V were obtained for 0.25 mum gate length devices on both types of substrate. Extrinsic transconductances of similar to200 mS/mm for HEMTs on sapphire and similar to125 mS/mm for devices on AlN/ SiC were achieved, with the latter devices showing significantly lower self-heating effects. Both types of HEMTs showed similar trends of drain current and transconductance with increasing temperature. There was a clear signature of optical phonon scattering as the dominant scattering mechanism from room temperature to 300 degreesC. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Yale Univ, Dept Elect Engn, New Haven, CT 06520 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Agere Syst, Murray Hill, NJ 07974 USA. TDI Inc, Gaithersburg, MD 20877 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. NR 21 TC 20 Z9 20 U1 1 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD APR PY 2002 VL 46 IS 4 BP 513 EP 523 AR PII S0038-1101(01)00284-2 DI 10.1016/S0038-1101(01)00284-2 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 551EH UT WOS:000175546200010 ER PT J AU Chang, PC Monier, C Baca, AG Li, NY Newman, F Armour, E Hou, HQ AF Chang, PC Monier, C Baca, AG Li, NY Newman, F Armour, E Hou, HQ TI High-speed InGaP/InGaAsN/GaAs NpN double heterojunction bipolar transistors with low turn-on voltage SO SOLID-STATE ELECTRONICS LA English DT Article DE heterojunction bipolar devices; InGaAsN material system; turn-on voltage; high-speed characteristics AB A current gain beta of 23 is demonstrated from a small-area NpN GaAs-based double heterojunction bipolar transistor (HBT) using a low band-gap InGaAsN material (lattice matched to GaAs with an energy band gap E-G of 1.2 eV) as the base layer. An improved band-gap engineering design at both emitter-base and base-collector heterojunctions in this GaAs-based HBT structure allows significant turn-on voltage reduction up to 270 mV compared to conventional In-GaP/GaAs HBTs, while attaining high-speed performance. Self-aligned devices with emitter active area of 3 x 5 mum(2) show cutoff frequency f(T) and maximum oscillation frequency f(MAX) values of 32 and 52 GHz, respectively. These results demonstrate the strong potential of this novel HBT technology to reduce power consumption in future wireless handsets using the GaAs manufacturing platform. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87123 USA. EMCORE Corp, Emcore Photovolta, Albuquerque, NM 87123 USA. EMCORE Corp, Somerset, NJ 08873 USA. RP Monier, C (reprint author), Sandia Natl Labs, POB 5800,M-S 0603, Albuquerque, NM 87123 USA. NR 8 TC 5 Z9 5 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD APR PY 2002 VL 46 IS 4 BP 581 EP 584 AR PII S0038-1101(01)00278-7 DI 10.1016/S0038-1101(01)00278-7 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 551EH UT WOS:000175546200020 ER PT J AU Saboungi, ML Price, DL Mao, GM Fernandez-Perea, R Borodin, O Smith, GD Armand, M Howells, WS AF Saboungi, ML Price, DL Mao, GM Fernandez-Perea, R Borodin, O Smith, GD Armand, M Howells, WS TI Coherent neutron scattering from PEO and a PEO-based polymer electrolyte SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT International Symposium on Polymer Electrolytes (PES2001) CY MAY 14-16, 2001 CL NOORDERWIJKERHOUT, NETHERLANDS DE neutron scattering; poly(ethylene oxide) (PEO); polymer electrolyte ID MOLECULAR-DYNAMICS SIMULATIONS; POLY(ETHYLENE OXIDE)/LII MELTS; SPIN-ECHO SPECTROSCOPY; ENVIRONMENT; RELAXATION; MOTION AB Results of quasi-elastic neutron scattering (QENS) experiments on deuterated forms of pure poly(ethylene oxide) (PEO) and a PEO-based electrolyte are presented. Since hydrogen is an especially favorable element for exploiting QENS due to the considerable difference in coherent and incoherent scattering of hydrogen vs. deuterium, the results are compared to our previous data on hydrogenated materials with the same composition. The dynamics of the polymer, shown to be closely coupled to those of the Li ions, can be probed over a time scale ranging from pico- to nanoseconds by combining QENS and neutron spin-echo spectrometry (NSES). Finally, good agreement is found between the measured coherent and incoherent intermediate scattering functions for PEO and those obtained from molecular dynamics (MID) simulations. (C) 2002 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Appl Mat Corp, Sunnyvale, CA 94086 USA. CSIC, E-28006 Madrid, Spain. Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Fuels Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem & Fuels Engn, Salt Lake City, UT 84112 USA. Univ Montreal, Dept Chem, UMR Int, CNRS 2289, Montreal, PQ H3C 3J7, Canada. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. RP Saboungi, ML (reprint author), CNRS, CRMD, 1 Bis Rue de la Ferollerie, F-45071 Orleans, France. RI Mao, Guomin/G-3933-2010; Borodin, Oleg/B-6855-2012; Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013; Fernandez-Perea, Ricardo/E-9118-2016 OI Borodin, Oleg/0000-0002-9428-5291; Saboungi, Marie-Louise/0000-0002-0607-4815; Fernandez-Perea, Ricardo/0000-0002-4011-2344 NR 26 TC 30 Z9 30 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD APR PY 2002 VL 147 IS 3-4 BP 225 EP 236 AR PII S0167-2738(02)00026-7 DI 10.1016/S0167-2738(02)00026-7 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 545LU UT WOS:000175219600004 ER PT J AU Kasemagi, H Klintenberg, M Aabloo, A Thomas, JO AF Kasemagi, H Klintenberg, M Aabloo, A Thomas, JO TI Molecular dynamics simulation of the LiBF4-PEO system containing Al2O3 nanoparticles SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT International Symposium on Polymer Electrolytes (PES2001) CY MAY 14-16, 2001 CL NOORDERWIJKERHOUT, NETHERLANDS DE polymer battery; polymer electrolytes; nanofillers; poly(ethylene oxide); lithium tetrafluorobolate ID NANOCOMPOSITE POLYMER ELECTROLYTES; POLY(ETHYLENE OXIDE); LITHIUM BATTERIES; CONDUCTIVITY AB The amorphous LiBF4(PEO)(20) system has been simulated alone and containing a ca. 14-Angstrom diameter Al2O3 nanoparticle and in juxtaposition with a ca. 65-Angstrom thick alpha-Al2O3 Slab at a nominal temperature of 293 K by Molecular Dynamics (MD) methods. Li-ion mobility in the poly(ethylene oxide) (PEO) host is found to increase on the addition of the nanoparticle; the effect is also noticeable for the alumina slab. This can be seen as theoretical confirmation of the positive influence of nanoparticles on ion mobility in a PEO-salt system, as observed earlier experimentally. Other effects observed are related to this Li-ion mobility enhancement: PEO forms an immobilised coordination sphere around the particle and an immobilised layer at the surface of the a-alumina slab. No Li ions are found near the particle or at the slab surface. Instead, two to three unpaired BF4- anions are found attached to the particle within the region of immobilised PEO and at least one is found immobilised on the slab surface, leaving free Li ions in the regions away from the particle and slab surfaces. No more than 60% of the Li ions form ion pairs and ion clusters in the regions away from the particle surface and up to 87% of the Li ions form ion pairs and ion clusters in the regions away from the slab surface. (C) 2002 Published by Elsevier Science B.V. C1 Uppsala Univ, Angstrom Lab, SE-75121 Uppsala, Sweden. Univ Tartu, Ctr Technol, EE-51010 Tartu, Estonia. Uppsala Univ, Dept Phys, Condensed Matter Theory Grp, SE-75121 Uppsala, Sweden. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Thomas, JO (reprint author), Uppsala Univ, Angstrom Lab, Box 538, SE-75121 Uppsala, Sweden. RI Aabloo, Alvo/C-5639-2011; Aabloo, Alvo/G-9396-2015 OI Aabloo, Alvo/0000-0002-0183-1282; Aabloo, Alvo/0000-0002-0183-1282 NR 17 TC 27 Z9 27 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD APR PY 2002 VL 147 IS 3-4 BP 367 EP 375 AR PII S0167-2738(02)00013-9 DI 10.1016/S0167-2738(02)00013-9 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 545LU UT WOS:000175219600022 ER PT J AU Farrar, CR Cornwell, PJ AF Farrar, CR Cornwell, PJ TI Los Alamos dynamics summer school SO SOUND AND VIBRATION LA English DT Article AB A unique summer educational program focusing on engineering structural dynamics has been developed and implemented at Los Alamos National Laboratory (LANL). The purpose of this summer school is to expose a select group of students to the broad field of engineering dynamics with the hopes that they will be motivated to pursue this area of research in their graduate studies. The summer school activities included: 1) lectures on various engineering topics such as computational structural dynamics, experimental modal analysis, random vibrations, signal processing, etc.; 2) a distinguished lecturer series in which prominent guest lecturers give talks about cutting edge research in structural dynamics; 3) field trips; and 4) an eight week project having both an analytical and an experimental component. LANL is motivated to pursue such an education program because it represents a proactive approach to recruiting new hires that allows time to better assess candidates' technical abilities and their abilities to perform in a team environment. This article will discuss the details of the program and its implementation. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Rose Hulman Inst Technol, Terre Haute, IN 47803 USA. RP Farrar, CR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI Farrar, Charles/C-6954-2012 NR 8 TC 0 Z9 0 U1 0 U2 0 PU ACOUSTICAL PUBL INC PI BAY VILLAGE PA 27101 E OVIATT RD PO BOX 40416, BAY VILLAGE, OH 44140 USA SN 0038-1810 J9 SOUND VIB JI Sound Vib. PD APR PY 2002 VL 36 IS 4 BP 18 EP 22 PG 5 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 549WJ UT WOS:000175469500004 ER PT J AU Kajander, T Merckel, MC Thompson, A Deacon, AM Mazur, P Kozarich, JW Goldman, A AF Kajander, T Merckel, MC Thompson, A Deacon, AM Mazur, P Kozarich, JW Goldman, A TI The structure of Neurospora crassa 3-carboxy-cis,cis-muconate lactonizing enzyme, a beta propeller cycloisomerase SO STRUCTURE LA English DT Article DE addition-elimination reaction; beta propeller convergent evolution; muconate lactonizing enzyme; X-ray structure ID PSEUDOMONAS-PUTIDA; CRYSTAL-STRUCTURE; ANGSTROM RESOLUTION; KETOADIPATE PATHWAY; MANDELATE RACEMASE; ESCHERICHIA-COLI; TERMINAL DOMAIN; CARBON ACIDS; CRYSTALLIZATION; REDUCTASE AB Muconate lactonizing enzymes (MLEs) convert cis,cis-muconates to muconolactones in microbes as part of the beta-ketoadipate pathway; some also dehalogenate muconate derivatives of xenobiotic haloaromatics. There are three different MLE classes unrelated by evolution. We present the X-ray structure of a eukaryotic MILE, Neurospora crassa 3-carboxy-cis,cis-muconate lactonizing enzyme (NcCMLE) at 2.5 Angstrom resolution, with a seven-bladed beta propeller fold. It is related neither to bacterial MLEs nor to other beta propeller enzymes, but is structurally similar to the G protein beta subunit. It reveals a novel metal-independent, cycloisomerase motif unlike the bacterial metal cofactor MLEs. Together, the bacterial MLEs and NcCMLE structures comprise a striking structural example of functional convergence in enzymes for 1,2-addition-elimination of carboxylic acids. NcCMLE and bacterial MLEs may enhance the reaction rate differently: the former by electrophilic catalysis and the latter by electrostatic stabilization of the enolate. C1 Univ Helsinki, Inst Biotechnol, Res Program Struct Biol & Biophys, FIN-00014 Helsinki, Finland. EMBL, Grenoble Outstn, F-38024 Grenoble, France. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Merck & Co Inc, Merck Sharp & Dohme Res Labs, Rahway, NJ 07065 USA. RP Goldman, A (reprint author), Univ Helsinki, Inst Biotechnol, Res Program Struct Biol & Biophys, FIN-00014 Helsinki, Finland. NR 42 TC 17 Z9 19 U1 0 U2 1 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE,, CAMBRIDGE, MA 02138 USA SN 0969-2126 J9 STRUCTURE JI Structure PD APR PY 2002 VL 10 IS 4 BP 483 EP 492 AR PII S0969-2126(02)00744-X DI 10.1016/S0969-2126(02)00744-X PG 10 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 539GX UT WOS:000174863100007 PM 11937053 ER PT J AU Bugoslavsky, Y Miyoshi, Y Perkins, GK Berenov, AV Lockman, Z MacManus-Driscoll, L Cohen, LF Caplin, AD Zhai, HY Paranthaman, MP Christen, HM Blamire, M AF Bugoslavsky, Y Miyoshi, Y Perkins, GK Berenov, AV Lockman, Z MacManus-Driscoll, L Cohen, LF Caplin, AD Zhai, HY Paranthaman, MP Christen, HM Blamire, M TI Structure of the superconducting gap in MgB2 from point-contact spectroscopy SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID GROWTH; FILMS AB We have studied the structure of the superconducting gap in MgB2 thin films by means of point-contact spectroscopy using a gold tip. The films were produced by depositing pure boron on a sapphire substrate, using e-beam evaporation, followed by reaction with magnesium vapour. The films have a T-c of 38.6 +/- 0.3 K and resistivity of about 20 muOmega cm at 40 K. The point-contact spectra prove directly the existence of a multi-valued order parameter in MgB2. with two distinct values of the gap, Delta(1) = 2.3 +/- 0.3 meV and Delta(2) = 6.2 +/- 0.7 meV at 4.2 K. Analysis of the spectra in terms of the Blonder-Tinkham-Klapwijk model reveals that both gaps close simultaneously at the T-c of the film. Possible mechanisms that can explain the intrinsic coexistence of two values of the gap are discussed. C1 Univ London Imperial Coll Sci Technol & Med, Ctr High Temp Superconduct, London SW7 2BZ, England. Russian Acad Sci, Inst Gen Phys, Moscow 117942, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37931 USA. Univ Cambridge, Dept Mat Sci, Cambridge CB2 3QZ, England. RP Univ London Imperial Coll Sci Technol & Med, Ctr High Temp Superconduct, London SW7 2BZ, England. RI Paranthaman, Mariappan/N-3866-2015; Berenov, Andrey/A-3020-2011; Lockman, Zainovia/F-5260-2011; Christen, Hans/H-6551-2013 OI Paranthaman, Mariappan/0000-0003-3009-8531; Christen, Hans/0000-0001-8187-7469 NR 28 TC 32 Z9 32 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 EI 1361-6668 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD APR PY 2002 VL 15 IS 4 BP 526 EP 532 AR PII S0953-2048(02)29673-6 DI 10.1088/0953-2048/15/4/308 PG 7 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 547LF UT WOS:000175333300009 ER PT J AU Spezzani, C Torelli, P Sacchi, M Delaunay, R Hague, CF Mirone, A Salmassi, F Gullikson, EM Underwood, JH AF Spezzani, C Torelli, P Sacchi, M Delaunay, R Hague, CF Mirone, A Salmassi, F Gullikson, EM Underwood, JH TI Magnetic coupling in Co/Cu multilayers: Field-dependent antiferromagnetic ordering investigated by resonant X-ray scattering SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID GIANT MAGNETORESISTANCE; SUPERLATTICES AB By simultaneous measurements of sample resistance and of X-ray resonant scattering, we tried to establish a direct correlation between magnetoresistance (MR) and antiferromagnetic (AF) order in a Co/Cu metallic multilayer. Field-dependent scattered intensity has been measured in a geometrical configuration corresponding to the Bragg peak coming from the AF coupling, at a photon energy close to the Co L-3 absorption edge (hv = 776.5 eV). The comparison between measurements of the scattered intensity and of the resistance clearly shows a direct correlation between AF order and MR. C1 Ist Nazl Fis Mat, Sez Modena, I-41100 Modena, Italy. Lab Utilisat Rayonnement Electromagnet, F-91898 Orsay, France. Lab chim Phys Mat & Rayonnement, F-75005 Paris, France. European Synchrotron Radiat Facil, F-38042 Grenoble, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Spezzani, C (reprint author), Ist Nazl Fis Mat, Sez Modena, Via Campi 213-A, I-41100 Modena, Italy. RI Torelli, Piero /F-8940-2010 NR 9 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 921 EP 924 DI 10.1142/S0218625X02003214 PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900041 ER PT J AU Schafer, J Claessen, R Rotenberg, E Kevan, SD Blaha, P Thorne, RE AF Schafer, J Claessen, R Rotenberg, E Kevan, SD Blaha, P Thorne, RE TI Peierls fluctuations in the electron system of a quasi-one-dimensional solid SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID CHARGE-DENSITY WAVES; X-RAY; NBSE3; TRANSITION; METAL AB The physics of the Peierls compound NbSe3 is elucidated by mapping of the electron bands obtained from angle-resolved photoemission, We present experimental data on the Fermi level crossing responsible for the charge density wave along the one-dimensional axis. The data are consistent with a density functional calculation of the Fermi surfaces. The instability with periodicity q = 0.44 Angstrom(-1) induces a backfolding of the electron bands in the nominally metallic state high above the critical temperature of 145 K. C1 Univ Augsburg, Inst Expt Phys, D-86135 Augsburg, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Tech Univ Vienna, Inst Phys & Theoret Chem, A-1060 Vienna, Austria. Cornell Univ, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. RP Schafer, J (reprint author), Univ Augsburg, Inst Expt Phys, D-86135 Augsburg, Germany. RI Blaha, Peter/F-2847-2010; Rotenberg, Eli/B-3700-2009; Kevan, Stephen/F-6415-2010; Claessen, Ralph/A-2045-2017 OI Rotenberg, Eli/0000-0002-3979-8844; Kevan, Stephen/0000-0002-4621-9142; Claessen, Ralph/0000-0003-3682-6325 NR 16 TC 2 Z9 2 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 1029 EP 1033 DI 10.1142/S0218625X02003299 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900057 ER PT J AU Wells, BO Yusof, Z Valla, T Fedorov, AV Johnson, P Kendziora, C Jian, S Hinks, D AF Wells, BO Yusof, Z Valla, T Fedorov, AV Johnson, P Kendziora, C Jian, S Hinks, D TI ARPES evidence for a quasiparticle liquid in overdoped Bi2Sr2CaCu2O8+delta SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID PHOTOEMISSION; SUPERCONDUCTORS; SURFACE; STATE AB High resolution angle-resolved photoemission spectroscopy of highly overdoped Bi2Sr2CaCu2O8+delta with T-c = 51 K indicates that the basic transport processes in this material are fundamentally different from both the lesser-doped cuprates and model metallic compounds. The overdoped sample has sharp ARPES peaks at the Fermi energy throughout the Brillouin zone even in the normal state, unlike the lesser-doped compounds. In particular, the spectra near the (pi, 0) point show the presence of a sharp peak well above T-c. The ARPES line shapes, and thus the self-energy, at a given energy are almost independent of k. Further, the quasiparticle scattering rate at the Fermi energy seems to be closely tied to direct resistivity measurements. This leads us to the conclusion that overdoped Bi2Sr2CaCu2O8+delta is best described as a quasiparticle liquid. However, the energy dependence of the scattering rates is quite similar to that found in the lesser-doped compounds and quite different from that seen in a typical metal. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. USN, Res Lab, Washington, DC 20375 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Wells, BO (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 20 TC 0 Z9 0 U1 1 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 1091 EP 1096 DI 10.1142/S0218625X02003391 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900067 ER PT J AU Sato, T Kumigashira, H Ionel, D Ito, T Takahashi, T Hase, I Ding, H Campuzano, JC Shamoto, S AF Sato, T Kumigashira, H Ionel, D Ito, T Takahashi, T Hase, I Ding, H Campuzano, JC Shamoto, S TI High-resolution angle-resolved photoemission study of BaCo1-xNixS2 SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID METAL-INSULATOR TRANSITIONS; ELECTRONIC-STRUCTURE; TRANSPORT; BANIS2 AB We have performed angle-resolved photoemission spectroscopy on a layered Mott system BaCo1-x. NixS2 across the phase transition from the antiferromagnetic insulator (x = 0.18) to anomalous metal (x = 0.28). In the anomalous metallic phase, we found a large Fermi surface centered at the M(A) point with a dominant Co (Ni) 3d(3z2-r2) character. Hubbard bands in the insulating phase have a remnant of Fermi surface in the metallic phase and gradually evolve into metallic dispersive bands upon carrier doping. We conclude that the electronic structure of BaCo1-xNixS2 is basically different from that of the high-T-c cuprates although the transport and magnetic properties share some common features between the two layered compounds. C1 Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Electrotech Lab, Tsukuba, Ibaraki 3058568, Japan. Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Tohoku Univ, Dept Appl Phys, Sendai, Miyagi 9808579, Japan. RP Sato, T (reprint author), Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. RI Sato, Takafumi/E-5094-2010; Tohoku, Arpes/A-4890-2010; Takahashi, Takashi/E-5080-2010; OI Ding, Hong/0000-0003-4422-9248 NR 16 TC 0 Z9 0 U1 2 U2 8 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 1127 EP 1132 DI 10.1142/S0218625X02003627 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900074 ER PT J AU Muino, RD Rolles, D de Abajo, FJG Fadley, CS Van Hove, MA AF Muino, RD Rolles, D de Abajo, FJG Fadley, CS Van Hove, MA TI Multiple scattering theory of photoelectron angular distributions from oriented diatomic molecules SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID SHAPE RESONANCE; CO MOLECULES; PHOTOIONIZATION; DIFFRACTION; N-2 AB We use multiple scattering photoelectron diffraction (MSPD) theory to calculate the angular patterns of electrons photoemitted from the K-shell of CO and N-2 gas-phase oriented molecules, as recently measured by several groups. For low (E < 50 eV) kinetic energies of the photoemitted electron, the electron scattering cannot be adequately represented by spherically symmetric potentials. We thus include nonspherical scattering potentials in our formalism through nondiagonal scattering matrices. We show that intramolecular scattering and interference are responsible for the experimentally measured patterns. This MSPD approach represents a more accurate and versatile method for dealing with such angular distributions as compared to prior calculations of these effects. C1 Donostia Int Phys Ctr, San Sebastian 20018, Spain. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. Ctr Mixto CSIC UPV EHU, San Sebastian 20080, Spain. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Muino, RD (reprint author), Donostia Int Phys Ctr, San Sebastian 20018, Spain. RI Rolles, Daniel/C-2384-2008; Van Hove, Michel/A-9862-2008; Diez Muino, Ricardo/C-9203-2009; Garcia de Abajo, Javier/A-6095-2009; CSIC-UPV/EHU, CFM/F-4867-2012; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014 OI Van Hove, Michel/0000-0002-8898-6921; Diez Muino, Ricardo/0000-0001-8593-0327; Garcia de Abajo, Javier/0000-0002-4970-4565; NR 18 TC 4 Z9 4 U1 1 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 1213 EP 1217 DI 10.1142/S0218625X02003548 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900088 ER PT J AU Denlinger, JD Gweon, GH Allen, JW Bianchi, AD Fisk, Z AF Denlinger, JD Gweon, GH Allen, JW Bianchi, AD Fisk, Z TI Bulk band gaps in divalent hexaborides: A soft X-ray emission study SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 13th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-13) CY JUL 23-27, 2001 CL TRIESTE, ITALY ID FERMI-SURFACE; FERROMAGNETISM; CAB6; CA1-XLAXB6; TRANSPORT; ELECTRON; EUB6 AB Boron K-edge soft X-ray emission and absorption are used to address the fundamental question of whether divalent hexaborides are intrinsic semimetals or defect-doped band gap insulators. These bulk-sensitive measurements, complementary and consistent with surface-sensitive angle-resolved photoemission experiments, confirm the existence of a bulk band gap and the location of the chemical potential at the bottom of the conduction band. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. RP Denlinger, JD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RI Bianchi, Andrea/E-9779-2010 OI Bianchi, Andrea/0000-0001-9340-6971 NR 25 TC 1 Z9 1 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD APR PY 2002 VL 9 IS 2 BP 1309 EP 1313 DI 10.1142/S0218625X0200372X PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 595LC UT WOS:000178109900103 ER PT J AU Kaneko, M Isaacs, HS AF Kaneko, M Isaacs, HS TI In situ measurement of dissolved ion concentration inside an artificial crevice by X-ray fluorescence micro-probe technique SO TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN LA Japanese DT Article DE stainless steel; pitting corrosion; pit; chloride; bromide; crevice ID STAINLESS-STEEL; CHLORIDE AB In this study, solution chemistries inside artificial crevices of high purity nickel and Type 316 stainless steel were investigated by in situ energy dispersion X-ray fluorescence microanalysis technique. Concentration of dissolved metal ions inside the artificial crevice was successfully measured by the technique. In case of high purity nickel, diffusion coefficient of nickel ions inside the artificial crevice was estimated as approximately 6x10(-6) cm(2)/s. Super-saturation of nickel ion at steel/solution interface inside the artificial crevice prior to formation of salt films oil the metal surface was detected. The concentration was about 1.4 times higher than the saturated value. In case of Type316 stainless steel. concentration of iron, chromium and nickel ions inside the artificial crevice were decreased similarly when the potential was stepped down to open circuit potential from 0.6 V (vs, SCE). The diffusion coefficient of these ions was estimated as 8.4X10(-6) cm(2)/s. This technique is very useful for analyzing local solution chemistries. C1 Nippon Steel Corp Ltd, Steel Res Labs, Futtsu 2938511, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kaneko, M (reprint author), Nippon Steel Corp Ltd, Steel Res Labs, 20-1 Shintomi, Futtsu 2938511, Japan. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IRON STEEL INST JAPAN KEIDANREN KAIKAN PI TOKYO PA NIIKURA BLDG 2F, 2 KANDA-TSUKASACHO 2-CHOME, TOKYO, CHIYODA-KU 101-0048, JAPAN SN 0021-1575 J9 TETSU TO HAGANE JI Tetsu To Hagane-J. Iron Steel Inst. Jpn. PD APR PY 2002 VL 88 IS 4 BP 210 EP 213 PG 4 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 549PU UT WOS:000175453900006 ER PT J AU Ivanic, J Ruedenberg, K AF Ivanic, J Ruedenberg, K TI Deadwood in configuration spaces. II. Singles plus doubles and singles plus doubles plus triples plus quadruples spaces SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE electron correlation; configuration interaction ID PERTURBATION-THEORY; CI CALCULATIONS; BASIS SET; WAVEFUNCTIONS; ENERGIES; WATER AB The effect of truncating singles+doubles configuration interaction (CISD) and singles + doubles + triples + quadruples (CISDTQ) spaces on the energies of the systems Ne, H2O, CO and C-2 is investigated through the use of a previously described, general, selected CI program. CI expansions generated by Hartree-Fock orbitals as well as by natural orbitals are examined and the latter typically exhibit faster convergence as regards the energy. For the CISD wavefunctions of Ne, H2O, CO and C-2, chemical accuracy is reached by using, respectively, 34, 47, 53 and 55% of the full sets. For the triples + quadruples parts of the wavefunctions on the other hand, chemical accuracy is already reached by using only 1, 4, 6 and 9% of the respective full sets. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Ruedenberg, K (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 21 TC 24 Z9 24 U1 0 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD APR PY 2002 VL 107 IS 4 BP 220 EP 228 DI 10.1007/s00214-002-0326-1 PG 9 WC Chemistry, Physical SC Chemistry GA 552EQ UT WOS:000175606700005 ER PT J AU Mosesson, MW Siebenlist, KR Hernandez, I Wall, JS Hainfeld, JF AF Mosesson, MW Siebenlist, KR Hernandez, I Wall, JS Hainfeld, JF TI Fibrinogen assembly and crosslinking on a fibrin fragment E template SO THROMBOSIS AND HAEMOSTASIS LA English DT Article DE factor XIII; fibrinogen; fibrin; electron microscopy ID TRANSMISSION ELECTRON-MICROSCOPE; PRO-ARG-PRO; GAMMA-CHAIN; FACTOR-XIIIA; POLYMERIZATION SITE; MASS ANALYSIS; D-DOMAINS; MOLECULES; COMPLEMENTARY; LOCALIZATION AB There is an ongoing controversy concerning whether crosslinked gamma chains in fibrin are oriented "transversely" between fibril strands or "end-to-end" along fibril strands. From the latter viewpoint, Veklich et al. [Proc Natl Acad Sci (USA) 95: 1438, 1998] observed that Fibrinogen fibrils that had been assembled on a fibrin fragment E template, crosslinked with factor XIIIa, and then dissociated in acetic acid solution, were aligned end-to-end. This led to the conclusion that crosslinked gamma chains in fibrin under physiological conditions were also aligned end-to-end. To assess its validity we studied the assembly and organization of fibrinogen molecules on a des AB-fibrin fragment E (E-des AB) or a des A-fibrin fragment E (E-des A) template. We evaluated the roles of E polymerization sites E-A and E-B, and D association sites gamma(XL), Da, Db, beta(C), and alpha(C) in this process. E-A:Da interactions caused fibrinogen: E "DED" complexes to form, and markedly enhanced the gamma chain crosslinking rates of fibrinogen or des alpha(C)-fibrinogen. Fibrinogen crosslinking without added fibrin E was slower, and that of des alpha(C)-fibrinogen was still slower. These events showed that although alphaC domains promote fibrinogen fibril assembly and crosslinking, they contribute little to increasing the E-A:Da-dependent crosslinking rate. Electron microscopic (STEM) images of E-des AB and fibrinogen plus factor XIIIa showed single-, double-, and multi-stranded fibrils with interstrand DED complexes aligned side-to-side. This alignment was due to beta(C):beta(C) contacts resulting from D subdomain rearrangements initiated by the E-B:Db interactions, and also occurred in mixtures of des alphaC-fibrinogen with E-des AB. In contrast, a mixture of fibrinogen and E-des A plus XIIIa revealed double-stranded fibrils with interstrand DED complexes in a half-staggered arrangement, an alignment that we attribute to crosslinking of gamma(XL) sites bridging between fibrils strands. These and other features of E-des A-based fibrinogen fibrils, including interstrand gamma chain bridges and early and extensive lateral fibril strand associations concomitant with accelerated gamma chain crosslinking, indicate that crosslinking of fibrin fibril strands takes place preferentially on transversely positioned gamma chains. C1 Blood Ctr SE Wisconsin Inc, Blood Res Inst, Milwaukee, WI 53201 USA. Marquette Univ, Coll Hlth Sci, Dept Biomed Sci, Milwaukee, WI 53233 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Mosesson, MW (reprint author), Blood Ctr SE Wisconsin Inc, Blood Res Inst, POB 2178, Milwaukee, WI 53201 USA. FU NCRR NIH HHS [RR-01777]; NHLBI NIH HHS [HL-59407] NR 41 TC 14 Z9 15 U1 0 U2 1 PU SCHATTAUER GMBH-VERLAG MEDIZIN NATURWISSENSCHAFTEN PI STUTTGART PA HOLDERLINSTRASSE 3, D-70174 STUTTGART, GERMANY SN 0340-6245 J9 THROMB HAEMOSTASIS JI Thromb. Haemost. PD APR PY 2002 VL 87 IS 4 BP 651 EP 658 PG 8 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA 541JK UT WOS:000174981300015 PM 12008948 ER PT J AU Gray, WG Tompson, AFB Soll, WE AF Gray, WG Tompson, AFB Soll, WE TI Closure conditions for two-fluid flow in porous media SO TRANSPORT IN POROUS MEDIA LA English DT Article DE multiphase flow; porous media; closure; unsaturated flow; interfacial area; entropy inequality; thermodynamics ID 2-PHASE FLOW; INTERFACIAL AREA; MULTIPHASE FLOW; EQUATIONS; TRANSPORT; MOTION AB Modeling of multiphase flow in porous media requires that the physics of the phases present be well described. Additionally, the behavior of interfaces between those phases and of the common lines where the interfaces come together must be accounted for. One factor complicating this description is the fact that geometric variables such as the volume fractions, interfacial areas per volume, and common line length per volume enter the conservation equations formulated at the macroscale or core scale. These geometric densities, although important physical quantities, are responsible for a deficit in the number of dynamic equations needed to model the system. Thus, to obtain closure of the multiphase flow equations, one must supplement the conservation equations with additional evolutionary equations that account for the interactions among these geometric variables. Here, the second law of thermodynamics, the constraint that the energy of the system must be at a minimum at equilibrium, is used to motivate and generate linearized evolutionary equations for these geometric variables and interactions. The constitutive forms, along with the analysis of the mass, momentum, and energy conservation equations, provide a necessary complete set of equations for multiphase flow modeling in the subsurface. C1 Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. Lawrence Livermore Natl Lab, GET Div, Livermore, CA 94551 USA. Los Alamos Natl Lab, EES5 Div, Los Alamos, NM 87545 USA. RP Gray, WG (reprint author), Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. NR 28 TC 20 Z9 20 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD APR PY 2002 VL 47 IS 1 BP 29 EP 65 PG 37 WC Engineering, Chemical SC Engineering GA 540PA UT WOS:000174936300002 ER PT J AU Jallad, KN Ben-Amotz, D Erdemir, A AF Jallad, KN Ben-Amotz, D Erdemir, A TI Raman chemical Imaging of tribological surfaces SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 56th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 20-24, 2001 CL ORLANDO, FLORIDA SP Soc Tribologists Lubricat Engineers DE borides; friction; nitrides; SEM/EDS; Raman spectroscopy (imaging) ID MICRO-RAMAN; COMPRESSION; MICROSTRUCTURE; COATINGS; FILMS AB A Near-Infrared Raman Imaging Microscope (NIRIM) is used to map chemical distributions on solid surfaces. This method combines fiber-bundle image compression (FIC) hardware with advanced multi-variate signal processing software to identify and map chemical species on surfaces. This non-invasive chemical mapping technique is used to study tribological materials containing solid lubricants on a substrate, both before and after tribo-testing, The samples studied consist of boron carbide (B4C) and stainless steel substrates, coated with boric acid (H3BO3), and titanium aluminum nitride (TiAIN), respectively. The NIRIM instrument was used to map the distribution of these solid lubricants on tribological surfaces, both inside and outside wear tracks created under different load and lubrication conditions, in order to better characterize the relation between chemical micro-structure and lubricant performance. The NIRIM results are shown to correlate well with the combined SEM/X-ray micro-analysis of the same samples. C1 Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Jallad, KN (reprint author), Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. OI JALLAD, KARIM N./0000-0002-7778-534X NR 20 TC 3 Z9 3 U1 1 U2 10 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD APR PY 2002 VL 45 IS 2 BP 239 EP 245 DI 10.1080/10402000208982546 PG 7 WC Engineering, Mechanical SC Engineering GA 536CC UT WOS:000174682300015 ER PT J AU Lu, ZM Neuman, SP Guadagnini, A Tartakovsky, DM AF Lu, ZM Neuman, SP Guadagnini, A Tartakovsky, DM TI Conditional moment analysis of steady state unsaturated flow in bounded, randomly heterogeneous soils SO WATER RESOURCES RESEARCH LA English DT Article DE unsaturated flow; heterogeneity; randomness; conditioning; uncertainty ID NONSTATIONARY STOCHASTIC-ANALYSIS; LOCALIZED ANALYSES; MEDIA AB [1] We consider steady state unsaturated flow in bounded, randomly heterogeneous soils under the influence of random boundary and source terms. Our aim is to predict pressure heads and fluxes without resorting to Monte Carlo simulation, upscaling, or linearization of the constitutive relationship between unsaturated hydraulic conductivity and pressure head. We represent this relationship through Gardner's exponential model while treating its exponent a as a random constant and saturated hydraulic conductivity K-s as a spatially correlated random field. We linearize the steady state unsaturated flow equations by means of the Kirchhoff transformation and integrate them in probability space to obtain exact integro-differential equations for the conditional mean and variance-covariance of transformed pressure head and flux. After approximating these equations recursively to second order in the standard deviation sigma(Y) of Y = ln K-s, we solve them by finite elements for superimposed mean uniform and divergent flows in the vertical plane, with and without conditioning on measured Y values. Comparison with Monte Carlo solutions demonstrates that whereas our nonlocal solution is nominally restricted to mildly nonuniform media with sigma(Y)(2) much less than 1, it yields remarkably accurate results for strongly nonuniform media with sigma(Y)(2) at least as large as 2. This accords well with a previous theoretical analysis, which shows that the solution may remain asymptotic for values of sigma(Y)(2) as large as 2. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Politecn Milan, Dipartimento Ingn Idraul Ambientale & Rilevamento, I-20133 Milan, Italy. Los Alamos Natl Lab, Grp CIC19, Los Alamos, NM 87545 USA. RP Lu, ZM (reprint author), Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RI Tartakovsky, Daniel/E-7694-2013 NR 13 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 2002 VL 38 IS 4 AR 1038 DI 10.1029/2001WR000278 PG 15 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 609XT UT WOS:000178932200005 ER PT J AU Akbas, N Oztarhan, A Monteiro, OR Brown, IG AF Akbas, N Oztarhan, A Monteiro, OR Brown, IG TI Investigation on the tribology of Zr ion implanted tool steel SO WEAR LA English DT Article DE tribology; metal vapor vacuum arc; implanted steel ID SIMULATIONS; MECHANISMS; OXIDATION; WEAR AB AISI D3 tool steel was ion implanted with zirconium and the improvement in surface tribological properties investigated. The Zr ion implantation was done using a metal vapor vacuum ire (Mevva) broad-beam ion source, with a mean ion energy of 130 keV and at doses of 3.6 x 10(16), 5 x 10(16) and 1 x 10(17) ions/cm(2). Wear, friction and hardness of the implanted samples were measured and compared to the performance of unimplanted steel. The wear resistance was increased by about a factor of two, the friction remained about the same or was possibly increased by a small amount and the near-surface hardness was improved by a factor of live or more by the ion implantation. We also investigated the effect on the Zr implantation profile of the multi-component energy distribution of the ion beam. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Celal Bayar Univ, TR-45010 Manisa, Turkey. RP Monteiro, OR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Mail Stop 53-0004 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 27 TC 8 Z9 9 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR PY 2002 VL 252 IS 7-8 BP 540 EP 545 AR PII S0043-1648(01)00894-8 DI 10.1016/S0043-1648(01)00894-8 PG 6 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 545YK UT WOS:000175245000002 ER PT J AU Rhoney, BK Shih, AJ Scattergood, RO Ott, R McSpadden, SB AF Rhoney, BK Shih, AJ Scattergood, RO Ott, R McSpadden, SB TI Wear mechanism of metal bond diamond wheels trued by wire electrical discharge machining SO WEAR LA English DT Article DE scanning electron microscopy (SEM); diamond wheels; electrical discharge machining (EDM); grinding wheel wear ID GRINDING PERFORMANCE AB The stereographic scanning electron microscopy (SENT) imaging was used to investigate the wear mechanism in wire electrical discharge machining (EDM) truing of metal bond diamond wheels for ceramic grinding. A piece of the grinding wheel was removed after truing and grinding to enable the examination of A heel surface and measurement of diamond protrusion heights using a SEM and stereographic imaging software. The stereographic SEM imaging method was calibrated by comparing with the profilometer measurement results. On the wheel surface after wire EDM truing and before grinding, some diamond grain protruding heights were measured in the 32 mum level. Comparing to the 54 mum average size of the diamond grain, this indicated that over half of the diamond was exposed. During the wire EDM process, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruded in the gap between the wire electrode and wheel. These protruding diamond grains with weak bond to the wheel were fractured under a light grinding condition, After heavy grinding, the diamond protrusion heights were estimated in the 5-15 mum range above the wear flat, A cavity created by grinding debris erosion wear of the wheel bond could be identified around the diamond grain. (C) 2002 Published by Elsevier Science B.V. C1 N Carolina State Univ, Dept Mech & Aerospace Engn, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Shih, AJ (reprint author), N Carolina State Univ, Dept Mech & Aerospace Engn, Raleigh, NC 27695 USA. RI Scattergood, Ronald/D-5204-2009 NR 12 TC 17 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD APR PY 2002 VL 252 IS 7-8 BP 644 EP 653 AR PII S0043-1648(02)00019-4 DI 10.1016/S0043-1648(02)00019-4 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 545YK UT WOS:000175245000013 ER PT J AU Buttler, D Critchlow, T AF Buttler, D Critchlow, T TI Using meta-data to automatically wrap bioinformatics sources SO INFORMATION AND SOFTWARE TECHNOLOGY LA English DT Article; Proceedings Paper CT 16th Annual ACM Conference on Object-Oriented Programming Systems, Languages, and Applications (OOPSLA) CY OCT, 2001 CL TAMPA BAY, FLORIDA SP ACM DE Bioinformatics; DARPA Agent Markup Language-S; wrappers; data extraction AB Currently there are a huge number of bioinformatics sources available over the web. Accessing these sources manually is infeasible for individual biologists. Our goal is to provide a single point of access for scientists that will retrieve data from each applicable source. One fundamental problem is automating the retrieval of data from each site. We propose a meta-data description language to delineate both the steps required to retrieve data, as well as the mechanisms necessary to access the web site that contains the data. This description will enable the automatic generation of wrappers that can extract the appropriate data. Our meta-data language is based on DARPA Agent Mark-up Language-S (DAML-S), extending the description to include a grounding which details the mechanics of data access. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Buttler, D (reprint author), Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0950-5849 J9 INFORM SOFTWARE TECH JI Inf. Softw. Technol. PD MAR 31 PY 2002 VL 44 IS 4 SI SI BP 237 EP 239 AR PII S0950-5849(02)00013-7 DI 10.1016/S0950-5849(02)00013-7 PG 3 WC Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA 550UJ UT WOS:000175521700006 ER PT J AU Zhu, YT Beyerlein, IJ AF Zhu, YT Beyerlein, IJ TI Bone-shaped short fiber composites - an overview SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE bone shaped short fiber composites; load transfer; mechanical interlocking; BSS fibers ID METAL-MATRIX COMPOSITES; REINFORCED COMPOSITES; TENSILE-STRENGTH AB In recent years, a new class of short fiber composites, in which the ends of the short fibers were enlarged, have been studied. Because of their geometry, these short fibers were named bone-shaped short (BSS) fibers. It was found in several composite systems that the BSS fibers can simultaneously improve both the strength and toughness of composites, and the mechanisms for such improvements vary with mechanical properties of the composite constituents. The strength increase resulted from the effective load transfer from the matrix to the fibers through mechanical interlocking at the enlarged fiber ends. The toughness increase resulted from one or several mechanisms, including: reduction in stress concentration in a brittle fiber reinforced composite with weak fiber/matrix interfacial bonding; higher fiber pullout resistance when the BSS fibers bridging a matrix crack are pulled out, with the enlarged ends attached and perhaps deformed; and plastic deformation of ductile fibers. Both experimental and theoretical studies have been conducted on composite mechanical properties and fractography, fiber pullout, and stress analysis. This paper reviews recent developments in BSS-fiber composites as well as discusses current issues and future directions in this emerging field. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MS G755, Los Alamos, NM 87545 USA. EM yzhu@lanl.gov RI Zhu, Yuntian/B-3021-2008; Beyerlein, Irene/A-4676-2011 OI Zhu, Yuntian/0000-0002-5961-7422; NR 45 TC 27 Z9 28 U1 1 U2 7 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 MAR 31 PY 2002 VL 326 IS 2 BP 208 EP 227 AR PII S0921-5093(01)01486-1 DI 10.1016/S0921-5093(01)01486-1 PG 20 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 533NM UT WOS:000174536700003 ER PT J AU Campisi, J AF Campisi, J TI Between Scylla and Charybdis: p53 links tumor suppression and aging SO MECHANISMS OF AGEING AND DEVELOPMENT LA English DT Editorial Material ID CELL-CYCLE; CAENORHABDITIS-ELEGANS; SYNDROME PROTEIN; WERNER-SYNDROME; DNA-DAMAGE; LIFE-SPAN; SACCHAROMYCES-CEREVISIAE; DROSOPHILA-MELANOGASTER; HISTONE DEACETYLASE; GENE FAMILY C1 Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Campisi, J (reprint author), Lawrence Berkeley Natl Lab, Div Life Sci, 1 Cyclotron Rd,Mailstop 84-171, Berkeley, CA 94720 USA. NR 60 TC 19 Z9 19 U1 0 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0047-6374 J9 MECH AGEING DEV JI Mech. Ageing Dev. PD MAR 31 PY 2002 VL 123 IS 6 BP 567 EP 573 AR PII S0047-6374(02)00006-4 DI 10.1016/S0047-6374(02)00006-4 PG 7 WC Cell Biology; Geriatrics & Gerontology SC Cell Biology; Geriatrics & Gerontology GA 580MJ UT WOS:000177238100002 PM 11850020 ER PT J AU Brady, RJ AF Brady, RJ TI Very high slip rates on continental extensional faults: new evidence from (U-Th)/He thermochronometry of the Buckskin Mountains, Arizona SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE extension; thermochronology; seismic risk; Basin and Range Province; helium ID WEST-CENTRAL ARIZONA; METAMORPHIC CORE COMPLEXES; SOUTH VIRGIN MOUNTAINS; THERMAL EVOLUTION; LOWER PLATE; CALIFORNIA; APATITE; NEVADA; HELIUM; PALEOSEISMICITY AB New (U-Th)/He in apatite ages suggest rapid slip rates on the Tertiary Buckskin-Rawhide detachment fault, which crops out in the Buckskin and Rawhide Mountains of western Arizona. Single-crystal (U-Th)/He in apatite ages were determined for a suite of crystalline rock samples from the footwall to this detachment. The samples were collected from a transect parallel to the fault slip direction, and proximal to the fault zone; they show a linear decrease in age with distance, from similar to 14 to similar to 11 Ma over similar to 15 km. The age versus distance relationship is interpreted to show a slip rate of 4.2 (+1.2/-0.8) mm/yr, continuing for a period of > 3 Myr. This rate is more-or-less in agreement with, but more precise than, previously published slip rates from this and other large-offset extensional detachments. Such slip rates are alarmingly high, being roughly 5-10 times faster than rates commonly observed on active structures at the Earth's surface. These rapid slip rates suggest that significant seismic hazard might be posed by some extensional structures, and they raise questions regarding the relationship between such rapidly slipping, large-offset structures and the slower, smaller offset faults that are more commonly observed at the Earth's surface. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Brady, RJ (reprint author), Los Alamos Natl Lab, Mailstop D461, Los Alamos, NM 87544 USA. NR 25 TC 28 Z9 30 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD MAR 30 PY 2002 VL 197 IS 1-2 BP 95 EP 104 AR PII S0012-821X(02)00460-0 DI 10.1016/S0012-821X(02)00460-0 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 547HY UT WOS:000175328000008 ER PT J AU Blanch, HW Prausnitz, JM Curtis, RA Bratko, D AF Blanch, HW Prausnitz, JM Curtis, RA Bratko, D TI Molecular thermodynamics and bioprocessing: from intracellular events to bioseparations SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 9th International Conference on Properties and Phase Equilibria for Product and Process Design CY MAY 20-25, 2001 CL KURASHIKI, JAPAN SP Commemorat Assoc Japan World Exposit (1970), Natl Sci Fdn, Inoue Fdn Sci, Iwatani Naoji Fdn, Asahi Glass Fdn, Kao Fdn Arts & Sci, Electr Technol Res Fdn Chugoku, Res Fdn Electrotechnol Chubu, Nioppon Sheet Glass Fdn Mat Sci & Engn, Mitsubishi Chem Corp, Rigaku Int Corp, KK Ohkuma, Shin Etsu Chem Co Ltd, SIMSCI Japan KK, AKICO Corp, Nisshin Kikai Co Ltd, Okayama Fdn Sci & Technol, Kurashiki Univ Sci & Arts DE protein interactions; protein aggregation; chaperones; protein phase equilibria ID PROTEIN AB Molecular thermodynamics finds application in biological systems in a number of areas, including separation and purification of biological molecules, and drug delivery mediated by hydrogels; and in understanding a variety of intracellular events, including signal transduction, protein-protein interactions, membrane transport and maintenance and regulation of the cytoskeleton. A particular challenge lies in describing and quantifying interactions of biological macromolecules. An important example from bioprocessing is the separation and subsequent purification of proteins. Protein precipitation by salts is the first and most common step in protein isolation from microbial, plant and animal sources. Subsequent purification by chromatographic means relies on protein interactions with charged or hydrophobic solid phases. In order to obtain protein crystals for X-ray diffraction, solution conditions that favor crystallization can often be identified from thermodynamic measurements at high dilution. Protein-protein intermolecular forces are generally short-ranged. Their specific nature is governed by such factors as pH, protein surface charge, charge distribution, surface hydrophobicity and the nature of the intervening electrolyte solution. These effects require quantification to develop useful molecular thermodynamic models for the processes described above. The role of specific salts on protein-protein interactions has been examined using static light scattering with lysozyme, ovalbumin, and a D101F mutant of lysozyme. These experiments provide insight concerning solvation forces that contribute to the interprotein potential. A statistical-mechanical description of protein crystallization is developed, based on the favorable interactions due to the protein-protein contacts in the crystal and the unfavorable entropy loss resulting from constraining the protein in the crystal. The intracellular environment is crowded, and at high rates of recombinant protein synthesis, protein-protein interactions can form inclusion bodies, presenting purification challenges. Protein aggregation can result in misfolding, while molecular chaperones within the cell can assist in protein folding. The competition between desired folding to a native structure and undesired aggregation is examined by Monte Carlo simulations in the presence and absence of chaperone analogs at finite protein concentrations. Aggregates are favored over native, folded proteins when the protein volume fraction exceeds 10%. Presence of a chaperone enhances the formation of native configurations. (C) 2002 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 USA. RP Blanch, HW (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 14 TC 14 Z9 15 U1 3 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD MAR 30 PY 2002 VL 194 SI SI BP 31 EP 41 AR PII S0378-3812(01)00769-5 DI 10.1016/S0378-3812(01)00769-5 PG 11 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 537TL UT WOS:000174775600004 ER PT J AU McCabe, C Kalyuzhnyi, YV Cummings, PT AF McCabe, C Kalyuzhnyi, YV Cummings, PT TI Thermodynamic properties of freely-jointed hard-sphere multi-Yukawa chain fluids: theory and simulation SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 9th International Conference on Properties and Phase Equilibria for Product and Process Design CY MAY 20-25, 2001 CL KURASHIKI, JAPAN SP Commemorat Assoc Japan World Exposit (1970), Natl Sci Fdn, Inoue Fdn Sci, Iwatani Naoji Fdn, Asahi Glass Fdn, Kao Fdn Arts & Sci, Electr Technol Res Fdn Chugoku, Res Fdn Electrotechnol Chubu, Nioppon Sheet Glass Fdn Mat Sci & Engn, Mitsubishi Chem Corp, Rigaku Int Corp, KK Ohkuma, Shin Etsu Chem Co Ltd, SIMSCI Japan KK, AKICO Corp, Nisshin Kikai Co Ltd, Okayama Fdn Sci & Technol, Kurashiki Univ Sci & Arts DE hard-sphere; Yukawa chain fluid; mean spherical approximation; Ornstein-Zemike equation; simulation ID INTEGRAL-EQUATION THEORY; DIRECTIONAL ATTRACTIVE FORCES; ORNSTEIN-ZERNIKE EQUATION; VAPOR-LIQUID-EQUILIBRIA; GREEN-YVON EQUATION; LENNARD-JONES FLUID; CHEMICAL ASSOCIATION; PRIMITIVE MODELS; GIBBS ENSEMBLE; POLYMER MELTS AB The hard-sphere Yukawa chain (HSYC) fluid is a simple model for chain fluids and polymers in which each molecule is composed of freely-jointed tangent spheres. The spheres each have a hard core and an attractive interaction, written as a single Yukawa potential or as a sum of Yukawa potentials, We have calculated the phase equilibria and PVT behaviour of the HSYC fluid both theoretically and by Monte Carlo simulation. The theoretical approach is based on the analytic solution of the polymer mean spherical approximation for the HSYC fluid. By comparing the theory and simulation we are able to evaluate the accuracy of the theory. We find that in general the theory performs very well, thus, it provides an analytic route to an equation of state for a well-defined model of chain fluids. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Inst Condensed Matter Phys, UA-79011 Lvov, Ukraine. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. RP McCabe, C (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013 OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216 NR 49 TC 9 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD MAR 30 PY 2002 VL 194 SI SI BP 185 EP 196 AR PII S0378-3812(01)00661-6 DI 10.1016/S0378-3812(01)00661-6 PG 12 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 537TL UT WOS:000174775600016 ER PT J AU Furukawa, S McCabe, C Nitta, T Cummings, PT AF Furukawa, S McCabe, C Nitta, T Cummings, PT TI Non-equilibrium molecular dynamics simulation study of the behavior of hydrocarbon-isomers in silicalite SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 9th International Conference on Properties and Phase Equilibria for Product and Process Design CY MAY 20-25, 2001 CL KURASHIKI, JAPAN SP Commemorat Assoc Japan World Exposit (1970), Natl Sci Fdn, Inoue Fdn Sci, Iwatani Naoji Fdn, Asahi Glass Fdn, Kao Fdn Arts & Sci, Electr Technol Res Fdn Chugoku, Res Fdn Electrotechnol Chubu, Nioppon Sheet Glass Fdn Mat Sci & Engn, Mitsubishi Chem Corp, Rigaku Int Corp, KK Ohkuma, Shin Etsu Chem Co Ltd, SIMSCI Japan KK, AKICO Corp, Nisshin Kikai Co Ltd, Okayama Fdn Sci & Technol, Kurashiki Univ Sci & Arts DE configurational-bias Monte Carlo; non-equilibrium molecular dynamics; silicalite; butane isomers; inorganic membrane ID NANOPOROUS CARBON MEMBRANES; UNITED-ATOM DESCRIPTION; GAS PERMEATION; TRANSFERABLE POTENTIALS; PHASE-EQUILIBRIA; BRANCHED ALKANES; MIXTURES; ZSM-5 AB Molecular dynamics simulations have been carried out in order to investigate the adsorption and permeation phenomena of butane isomers through ZSM-5 membranes. Using the muVT ensemble configurational-bias Monte Carlo technique, we are able to determine the preferred locations of the butane isomers in the ZSM-5 channels. In permeation simulations, using the muVT ensemble non-equilibrium molecular dynamics method, the permeate fluxes of the butane isomers are obtained. We find that the permeabilities of the n-butane calculated from the permeate fluxes increase with increasing temperature. The density of n-butane in the ZSM-5 decreases in the permeation direction with a similar pressure-density relationship to that measured by the equilibrium adsorption isotherm of the n-butane. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Osaka Univ, Grad Sch Engn Sci, Dept Sci & Chem Engn, Toyonaka, Osaka 5608531, Japan. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Furukawa, S (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI McCabe, Clare/I-8017-2012; Cummings, Peter/B-8762-2013 OI McCabe, Clare/0000-0002-8552-9135; Cummings, Peter/0000-0002-9766-2216 NR 22 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD MAR 30 PY 2002 VL 194 SI SI BP 309 EP 317 AR PII S0378-3812(01)00670-7 DI 10.1016/S0378-3812(01)00670-7 PG 9 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 537TL UT WOS:000174775600028 ER PT J AU Elvassore, N Prausnitz, JM AF Elvassore, N Prausnitz, JM TI Fluid-solid equilibria of chain-like molecules SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 9th International Conference on Properties and Phase Equilibria for Product and Process Design CY MAY 20-25, 2001 CL KURASHIKI, JAPAN SP Commemorat Assoc Japan World Exposit (1970), Natl Sci Fdn, Inoue Fdn Sci, Iwatani Naoji Fdn, Asahi Glass Fdn, Kao Fdn Arts & Sci, Electr Technol Res Fdn Chugoku, Res Fdn Electrotechnol Chubu, Nioppon Sheet Glass Fdn Mat Sci & Engn, Mitsubishi Chem Corp, Rigaku Int Corp, KK Ohkuma, Shin Etsu Chem Co Ltd, SIMSCI Japan KK, AKICO Corp, Nisshin Kikai Co Ltd, Okayama Fdn Sci & Technol, Kurashiki Univ Sci & Arts DE van der Waals theory; solid-fluid equilibria; phase diagram; chain-like molecules ID EQUATION-OF-STATE; DER-WAALS THEORY; LIQUID EQUILIBRIA; HARD-SPHERES; MODELS; MIXTURES; SYSTEMS AB van der Waals perturbation theory is used to calculate fluid-solid phase diagrams for a system of perturbed-hard-sphere chains. In both fluid and solid phases, the free energy is the sum of a hard-sphere-chain term as the reference system, and a van der Waals term as the perturbation. The reference system for both phases follows from the Percus-Yevick integral theory coupled with Chiew's results for hard chains. An analytic model for the solid-phase reference term of a hard-chain system agrees well with computer-simulation data for the solid hard-chain compressibility. Simulation data for fluid-solid coexistence curves for hard spheres, and for 4-mer hard chains, are used to fit the reference Helmholtz free energy of the solid phase. The pressure and solid and fluid densities at the hard-chain melting point, predicted by our model, fairly reproduce the available simulation data at different chain lengths. The attractive perturbation term follows from an inverse-power potential with variable exponent n for both fluid and solid phases. The theory here presented reproduces the simulated phase diagrams of chain-like molecules and gives the correct trend for experimental melting points of normal alkanes. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Padua, DIPIC, Dipartimento Principi & Impianti Ingn Chim, I-35100 Padua, Italy. RP Prausnitz, JM (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. EM nicola.elvassore@unipd.it; prausnit@acchem.berkeley.edu NR 17 TC 12 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD MAR 30 PY 2002 VL 194 SI SI BP 567 EP 577 AR PII S0378-3812(01)00782-8 DI 10.1016/S0378-3812(01)00782-8 PG 11 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 537TL UT WOS:000174775600049 ER PT J AU Wu, JZ Prausnitz, J AF Wu, JZ Prausnitz, J TI Phase equilibria in a system of "breathing" molecules SO FLUID PHASE EQUILIBRIA LA English DT Article; Proceedings Paper CT 9th International Conference on Properties and Phase Equilibria for Product and Process Design CY MAY 20-25, 2001 CL KURASHIKI, JAPAN SP Commemorat Assoc Japan World Exposit (1970), Natl Sci Fdn, Inoue Fdn Sci, Iwatani Naoji Fdn, Asahi Glass Fdn, Kao Fdn Arts & Sci, Electr Technol Res Fdn Chugoku, Res Fdn Electrotechnol Chubu, Nioppon Sheet Glass Fdn Mat Sci & Engn, Mitsubishi Chem Corp, Rigaku Int Corp, KK Ohkuma, Shin Etsu Chem Co Ltd, SIMSCI Japan KK, AKICO Corp, Nisshin Kikai Co Ltd, Okayama Fdn Sci & Technol, Kurashiki Univ Sci & Arts DE breathing molecules; solid-fluid equilibrium; statistical mechanics AB It is now well known that details in the intermolecular potential can significantly affect the qualitative features of a phase diagram where temperature is plotted against density for the coexistence curves among fluid and solid phases. While previous calculations of phase diagrams have assumed a time-invariant potential function, this report concerns the phase diagram for "breathing" molecules, i.e. molecules whose strength of intermolecular attraction fluctuates in time. Such fluctuations can occur in biomacromolecules where an active site can switch between"on" and "off' positions. Phase-equilibrium calculations were performed for molecules that have a periodic (breathing) attractive force in addition to the conventional intermolecular forces. The phase diagram for such molecules is as expected when the "breathing" properties are independent of density. However, when (more realistically), the "breathing" properties are density-dependent, the phase diagram exhibits dramatic changes. These calculations may be useful for interpreting experimental data for protein precipitation, for plaque formation in blood vessels and for scaffold-supported tissue formation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Riverside, Dept Chem Engn, Riverside, CA 92521 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Wu, JZ (reprint author), Univ Calif Riverside, Dept Chem Engn, Riverside, CA 92521 USA. RI Wu, Jianzhong/I-5164-2013; OI Wu, Jianzhong/0000-0002-4582-5941 NR 7 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD MAR 30 PY 2002 VL 194 SI SI BP 689 EP 700 AR PII S0378-3812(01)00679-3 DI 10.1016/S0378-3812(01)00679-3 PG 12 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 537TL UT WOS:000174775600059 ER PT J AU Huynh, WU Dittmer, JJ Alivisatos, AP AF Huynh, WU Dittmer, JJ Alivisatos, AP TI Hybrid nanorod-polymer solar cells SO SCIENCE LA English DT Article ID CONJUGATED POLYMERS; PHOTOVOLTAIC CELLS; CDSE NANOCRYSTALS; ELECTRON-TRANSFER; TRANSPORT; DEVICES AB We demonstrate that semiconductor nanorods can be used to fabricate readily processed and efficient hybrid solar cells together with polymers. By controlling nanorod length, we can change the distance on which electrons are transported directly through the thin film device. Tuning the band gap by altering the nanorod radius enabled us to optimize the overlap between the absorption spectrum of the cell and the solar emission spectrum. A photovoltaic device consisting of 7-nanometer by 60-nanometer CdSe nanorods and the conjugated polymer poly-3(hexylthiophene) was assembled from solution with an external quantum efficiency of over 54% and a monochromatic power conversion efficiency of 6.9% under 0.1 milliwatt per square centimeter illumination at 515 nanometers. Under Air Mass (A.M.) 1.5 Global solar conditions, we obtained a power conversion efficiency of 1.7%. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Alivisatos, AP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI chen, jia/F-8731-2011; Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 16 TC 3773 Z9 3847 U1 147 U2 1285 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 MAR 29 PY 2002 VL 295 IS 5564 BP 2425 EP 2427 DI 10.1126/science.1069156 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 536QD UT WOS:000174712600047 PM 11923531 ER PT J AU Hsu, HL Yannone, SM Chen, DJ AF Hsu, HL Yannone, SM Chen, DJ TI Defining interactions between DNA-PK and ligase IV/XRCC4 SO DNA REPAIR LA English DT Article DE DNA double-strand breaks; non-homologous end joining; DNA-PK, Ku; ligase IV/XRCC4 ID DEPENDENT PROTEIN-KINASE; STRAND BREAK REPAIR; WERNER-SYNDROME PROTEIN; V(D)J RECOMBINATION; CATALYTIC SUBUNIT; KU PROTEIN; MAMMALIAN-CELLS; XRCC4 PROTEIN; GENE-PRODUCT; IV AB Non-homologous end joining (NHEJ) is a major pathway for the repair of DNA double-strand breaks (DSBs) in mammalian cells. DNA-dependent protein kinase (DNA-PK), ligase IV, and XRCC4 are all critical components of the NHEJ repair pathway. DNA-PK is composed of a heterodimeric DNA-binding component, Ku, and a large catalytic subunit, DNA-PKcs. Ligase IV and XRCC4 associate to form a multimeric complex that is also essential for NHEJ. DNA-PK and ligase IV/XRCC4 interact at DNA termini which results in stimulated ligase activity. Here, we define interactions between the components of these two essential complexes, DNA-PK and ligase IV/XRCC4. We find that ligase IV/XRCC4 associates with DNA-PK in a DNA-independent manner. The specific protein-protein interactions that mediate the interaction between these two complexes are further identified. Direct interactions between ligase IV and Ku as well as between XRCC4 and DNA-PKcs are shown. In contrast, binding of ligase IV to DNA-PKcs or XRCC4 to Ku is very weak or non-existent. Our data defines the specific protein pairs involved in the association of DNA-PK and ligase IV/XRCC4, and suggests a molecular mechanism for coordinating the assembly of the DNA repair complex at DNA breaks. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Dept Cell & Mol Biol, Berkeley, CA 94720 USA. RP Chen, DJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Dept Cell & Mol Biol, Berkeley, CA 94720 USA. RI Yannone, Steven/G-1927-2011; Hsu, Hsin-Ling/E-3672-2010 FU NCI NIH HHS [CA50519]; NIA NIH HHS [AG917709] NR 39 TC 71 Z9 75 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1568-7864 J9 DNA REPAIR JI DNA Repair PD MAR 28 PY 2002 VL 1 IS 3 BP 225 EP 235 AR PII S1568-7864(01)00018-0 DI 10.1016/S1568-7864(01)00018-0 PG 11 WC Genetics & Heredity; Toxicology SC Genetics & Heredity; Toxicology GA 597TA UT WOS:000178235800003 PM 12509254 ER PT J AU Bakke, T Sullivan, CT Mukherjee, SD AF Bakke, T Sullivan, CT Mukherjee, SD TI Polymeric buried core adiabatic optical spot-size transformer SO ELECTRONICS LETTERS LA English DT Article ID WAVE-GUIDE; FABRICATION AB Design, fabrication and characterisation of a polymeric optical spot-size transformer formed by a laterally tapered, buried core is described. Only standard photolithography and dry etching have been used to fabricate this transformer, A fibre to waveguide insertion loss of 0.7 dB has been measured. compared to 2.5 dB without the transformer. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Norwegian Univ Sci & Technol, N-7491 Trondheim, Norway. RP Bakke, T (reprint author), Sandia Natl Labs, POB 5800-0603, Albuquerque, NM 87185 USA. NR 5 TC 2 Z9 2 U1 1 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD MAR 28 PY 2002 VL 38 IS 7 BP 319 EP 321 DI 10.1049/el:20020225 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 540QK UT WOS:000174939500014 ER PT J AU Rakov, VS Denisov, EV Laskin, J Futrell, JH AF Rakov, VS Denisov, EV Laskin, J Futrell, JH TI Surface-induced dissociation of the benzene molecular cation in Fourier transform ion cyclotron resonance mass spectrometry SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID INTERNAL ENERGY-DISTRIBUTIONS; ASSEMBLED MONOLAYER FILMS; POLYATOMIC IONS; PROTONATED PEPTIDES; LIQUID SURFACE; RADICAL-CATION; FRAGMENTATION; COLLISIONS; SCATTERING; NEUTRALIZATION AB Energy transfer in collisions of benzene molecular ions with a fluorinated self-assembled monolayer surface at normal incidence was studied over the range of collision energies from 0 to 75 eV in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). Rice-Ramsperger-Kassel-Marcus (RRKM) theory was used to calculate breakdown graphs for a simplified decomposition scheme of benzene on the time scale of ICR MS detection. Statistical partitioning of excess internal energy between the neutral and the ionic products was included in the theoretical model. Internal energy distributions of the predissociating parent ions were iteratively calculated using the recursive internal energy distribution search (RIEDS) method for each collision energy. On the basis of the above measurements, the collision-energy-dependent E-SID --> E-int energy conversion efficiency was found to maximize at about 19.5% under the conditions of 31 eV SID collision energy. C1 William R Wiley Environm Mol Sci Lab, Pacific NW Natl Lab, Richland, WA 99352 USA. RP Rakov, VS (reprint author), William R Wiley Environm Mol Sci Lab, Pacific NW Natl Lab, POB 999,K8-84, Richland, WA 99352 USA. RI Laskin, Julia/H-9974-2012 OI Laskin, Julia/0000-0002-4533-9644 NR 68 TC 12 Z9 12 U1 0 U2 2 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 MAR 28 PY 2002 VL 106 IS 12 BP 2781 EP 2788 DI 10.1021/jp010245d PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 534LU UT WOS:000174588500002 ER PT J AU Wehrmann, F Albrecht, J Gedat, E Kubas, GJ Eckert, J Limbach, HH Buntkowsky, G AF Wehrmann, F Albrecht, J Gedat, E Kubas, GJ Eckert, J Limbach, HH Buntkowsky, G TI Hydrogen deuterium isotope effect on exchange rates in eta(2) bond transition metal dihydrogen complexes revealed by H-2 solid state NMR spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID QUANTUM-MECHANICAL EXCHANGE; H-H BOND; MOLECULAR-HYDROGEN; SINGLE-CRYSTAL; NUCLEAR-DYNAMICS; METHYL-GROUPS; CD3 GROUPS; LIGAND; COHERENT; HYDRIDE AB A selectively eta(2)-D-2 labeled isotopomer of the complex W(PCy3)(2) (CO)(3)) (eta(2)-D-2) has been synthesized and the H-2 NMR spectra and spin lattice relaxation rates of this complex have been measured in the temperature regime of 50 K to 300 K. The spectra have been analyzed employing a model of a combination of homonuclear dipolar D-D interaction and deuterium quadrupolar interaction and a D-D distance of 0.89 +/- 0.1 Angstrom. The line width of the spectra exhibits a weak temperature dependence at temperatures above 150 K. This temperature dependence is interpreted as a slight decrease of the quadrupolar coupling with increasing temperature, which is an indication of a change of the M-D-2 distance with changing temperatures. The spin lattice relaxation data of the complex exhibit pronounced deviations from a simple Arrhenius behavior at lower temperatures, indicating the presence of a quantum mechanical tunneling process. This process is analyzed in terms of a simple one-dimensional Bell tunnel model. A comparison with INS data from the H-2 complex reveals a strong isotope effect of 2 x 10(3) for the exchange rates of the deuterons. C1 Free Univ Berlin, Inst Chem, D-14195 Berlin, Germany. Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. RP Buntkowsky, G (reprint author), Free Univ Berlin, Inst Chem, Takustr 3, D-14195 Berlin, Germany. RI Limbach, Hans-Heinrich/G-8858-2011; Buntkowsky, Gerd/B-3206-2010 OI Limbach, Hans-Heinrich/0000-0002-2084-6359; Buntkowsky, Gerd/0000-0003-1304-9762 NR 70 TC 22 Z9 22 U1 3 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 MAR 28 PY 2002 VL 106 IS 12 BP 2855 EP 2861 DI 10.1021/jp012087w PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 534LU UT WOS:000174588500013 ER PT J AU Fockenberg, C Preses, JM AF Fockenberg, C Preses, JM TI Temperature dependence of the rate constant and product distribution of the reaction of CH3 radicals with O(P-3) atoms SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID METHYL RADICALS; OXYGEN-ATOMS; PHOTOLYSIS; KINETICS; SPECTROMETRY AB The kinetics and product distribution for the reaction of methyl radicals, CH3, with ground-state, O(P-3) oxygen atoms, have been investigated at temperatures up to 925 K and at constant bath gas (He) concentrations of about 3.2 x 10(16) cm(-3). With a photoionization/time-of-flight mass spectrometer (TOFMS) as an analytical tool, precursor species, reactants, and products were observed simultaneously. The radicals were produced by an excimer laser pulse (lambda = 193 nm), in the cophotolysis of acetone, CH3C(O)CH3 and sulfur dioxide, SO2. In addition to the dominant product, formaldehyde (CH2O), carbon monoxide (CO) was detected as the only other main product. The yields for both products were found to be independent of temperature with values of Phi(CH3+O)(CH2O) = 0.84 +/- 0.12 (2sigma) and Phi(CH3+O)(CO) = 0.15 +/- 0.06 (2sigma). However, the overall rate constant for this reaction shows a slight increase with temperature with k(CH3+O) = (2.4 +/- 0.3) x 10(-10) exp(-(202 +/- 60) K/T) cm(3) molecule(-1) s(-1) between T = 354 and 925 K at [He] = 3.2 x 10(16) cm(-3). In an additional experiment the rate constant for the reaction of deuterated methyl radicals, CD3, with oxygen atoms at 308 K in 3 Torr of He was determined to be k(CD3+O) = (1.3 +/- 0.8) x 10(-10) cm(-1) molecule(-1) s(-1). Using tunable diode laser absorption spectroscopy (TDLAS) the product yield of (CO)-O-18 from the reaction CD3 + O-18(P-3) was measured at room temperature in 5 Torr of Ar indicating an H/D-isotope effect lowering the yield to Phi(CD3+O)((CO)-O-18) = 0.12 +/- 0.01 (2sigma). C1 Brookhaven Natl Lab, Dept Chem 555A, Upton, NY 11973 USA. RP Fockenberg, C (reprint author), Brookhaven Natl Lab, Dept Chem 555A, POB 5000, Upton, NY 11973 USA. NR 21 TC 20 Z9 20 U1 3 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 28 PY 2002 VL 106 IS 12 BP 2924 EP 2930 DI 10.1021/jp0141880 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 534LU UT WOS:000174588500022 ER PT J AU Milonni, PW AF Milonni, PW TI Controlling the speed of light pulses SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Review ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; SUPERLUMINAL GROUP VELOCITIES; WAVE-PROPAGATION; DISPERSIVE MEDIA; QUANTUM-NOISE; ATOMIC VAPOR; BEHAVIORS; CAUSALITY; AMPLIFIER; MIRRORS AB Recent experiments have demonstrated that light pulses can be made to propagate 'superluminally' or, at the opposite extreme, to come to a complete stop. Some of the basic physics underlying these studies and their antecedents are reviewed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM pwm@lanl.gov NR 74 TC 91 Z9 91 U1 1 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD MAR 28 PY 2002 VL 35 IS 6 BP R31 EP R56 AR PII S0953-4075(02)26372-5 DI 10.1088/0953-4075/35/6/201 PG 26 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 583NF UT WOS:000177413400003 ER PT J AU Brodsky, SJ Hwang, DS Schmidt, I AF Brodsky, SJ Hwang, DS Schmidt, I TI Final-state interactions and single-spin asymmetries in semi-inclusive deep inelastic scattering SO PHYSICS LETTERS B LA English DT Article ID DISTRIBUTIONS; LEPTONS; QUARKS AB Recent measurements from the HERMES and SMC Collaborations show a remarkably large azimuthal single-spin asymmetries A(UL) and A(UT) of the proton in semi-inclusive pion leptoproduction gamma*(q)p --> piX. We show that final-state interactions from gluon exchange between the outgoing quark and the target spectator system lead to single-spin asymmetries in deep inelastic lepton-proton scattering at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality Q(2) at fixed x(bj). The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J(p) = +/-1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum L of the proton's constituents and is thus distinct for different proton spin amplitudes. The single-spin asymmetry which arises from such final-state interactions does not factorize into a product of distribution function and fragmentation function, and it is not related to the transversity distribution deltaq(x, Q) which correlates transversely polarized quarks with the spin of the transversely polarized target nucleon. (C) 2002 Elsevier Science B. V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Sejong Univ, Dept Phys, Seoul 143747, South Korea. Univ Tecn Federico Santa Maria, Dept Fis, Valparaiso, Chile. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Schmidt, Ivan/J-5920-2012 NR 11 TC 514 Z9 514 U1 1 U2 4 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 MAR 28 PY 2002 VL 530 IS 1-4 BP 99 EP 107 AR PII S0370-2693(02)01320-5 DI 10.1016/S0370-2693(02)01320-5 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 542TB UT WOS:000175059500013 ER PT J AU Diaz-Cruz, JL He, HJ Yuan, CP AF Diaz-Cruz, JL He, HJ Yuan, CP TI Soft supersymmetry breaking, scalar top-charm mixing and Higgs signatures SO PHYSICS LETTERS B LA English DT Article ID COLLIDERS; STANDARD; QUARK; MODEL AB The squark mass-matrix from the soft supersymmetry (SUSY) breaking sector contains a rich flavor-mixing structure that allows O(1) mixings among top- and charm-squarks while being consistent with all the existing theoretical and experimental bounds. We formulate a minimal flavor-changing-neutral current scheme in which the squark mixings arise from the non-diagonal scalar trilinear interactions. This feature can be realized in a class of new models with a horizontal U(1)g symmetry which generates realistic quark-mass matrices and provides a solution to the SUSY mu-problem. Finally, without using the mass-insertion approximation, we analyze SUSY radiative corrections to the H(+/-)bc and h(0)tc couplings, and show that these couplings can reveal exciting new discovery channels for the Higgs boson signals at the Tevatron and the LHC. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 92710 USA. Univ Texas, Austin, TX 78712 USA. Michigan State Univ, E Lansing, MI 48824 USA. RP Diaz-Cruz, JL (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 92710 USA. NR 22 TC 54 Z9 54 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 28 PY 2002 VL 530 IS 1-4 BP 179 EP 187 AR PII S0370-2693(02)01330-8 DI 10.1016/S0370-2693(02)01330-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 542TB UT WOS:000175059500025 ER PT J AU Huang, CS Jiang, J Li, TJ Liao, W AF Huang, CS Jiang, J Li, TJ Liao, W TI N=2 6-dimensional supersymmetric E-6 breaking SO PHYSICS LETTERS B LA English DT Article DE E-6 model; symmetry breaking; extra dimensions ID SUPERSTRING MODELS; SYMMETRY-BREAKING; ORBIFOLDS; REDUCTION; STRINGS AB We study the N = 2 supersymmetric E-6 models on the 6-dimensional space-time where the supersymmetry and gauge symmetry can be broken by the discrete symmetry. On the space-time M-4 x S-1/(Z(2) x Z(2)') x S-1/ (Z(2) x Z(2)'), for the zero modes, we obtain the 4-dimensional N = 1 supersymmetric models with gauge groups SU(3) x SU(2) x SU(2) x U(1)(2), SU(4) x SU(2) x SU(2) x U(1), and SU(3) x SU(2) x U(1)(3) with one extra pair of Higgs doublets from the vector multiplet. In addition, considering that the extra space manifold is the annulus A(2) and disc D-2, we list all the constraints on constructing the 4-dimensional N = 1 supersymmetric SU(3) x SU(2) x U(1)(3) models for the zero modes, and give the simplest model with Z(9) symmetry. We also comment on the extra gauge symmetry breaking and its generalization. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Acad Sinica, Inst Theoret Phys, Beijing 100080, Peoples R China. Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy. RP Huang, CS (reprint author), Acad Sinica, Inst Theoret Phys, POB 2735, Beijing 100080, Peoples R China. EM tli@bokchoy.hep.upenn.edu RI Liao, Wei/A-1126-2012 NR 43 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAR 28 PY 2002 VL 530 IS 1-4 BP 218 EP 226 AR PII S0370-2693(02)01335-7 DI 10.1016/S0370-2693(02)01335-7 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 542TB UT WOS:000175059500030 ER PT J AU Ciancanelli, R Noll, BC DuBois, DL DuBois, MR AF Ciancanelli, R Noll, BC DuBois, DL DuBois, MR TI Comprehensive thermodynamic characterization of the metal-hydrogen bond in a series of cobalt-hydride complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CARBONYL HYDRIDES; DIHYDROGEN COMPLEXES; ELECTRODE-POTENTIALS; HETEROLYTIC CLEAVAGE; RADICAL REACTIONS; ACIDITY; REDUCTION; REACTIVITY; FERROCENE; ALDEHYDES AB A detailed structural and thermodynamic study of a series of cobalt-hydride complexes is reported. This includes structural studies of [H2Co(dppe)(2)](+), HCo(dppe)(2), [HCo(dPPe)(2)(CH3CN)](+), and [Co(dpPe)(2)(CH3CN)](2+), where dppe = bis(diphenylphosphino)ethane. Equilibrium measurements are reported for one hydride- and two proton-transfer reactions. These measurements and the determinations of various electrochemical potentials were used to determine 11 of 12 possible homolytic and heterolytic solution Co-H bond dissociation free energies of [H2Co(dppe)(2)](+) and its monohydride derivatives. These values provide a useful framework for understanding observed and potential reactions of these complexes. These reactions include the disproportionation of [HCo(dppe)(2)](+) to form [Co(dPPe)(2)](+) and [H2Co(dPPe)(2)](+), the reaction of [Co(dppe)(2)](+) with H-2, the protonation and deprotonation reactions of the various hydride species, and the relative ability of the hydride complexes to act as hydride donors. 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, Boulder, CO 80309 USA. NR 64 TC 90 Z9 90 U1 3 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 27 PY 2002 VL 124 IS 12 BP 2984 EP 2992 DI 10.1021/ja0122804 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 533GF UT WOS:000174520500032 PM 11902890 ER PT J AU Musgrave, KB Laplaza, CE Holm, RH Hedman, B Hodgson, KO AF Musgrave, KB Laplaza, CE Holm, RH Hedman, B Hodgson, KO TI Structural characterization of metallopeptides designed as scaffolds for the stabilization of nickel(II)-Fe4S4 bridged assemblies by X-ray absorption spectroscopy SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CARBON-MONOXIDE DEHYDROGENASE; ACETYL-COA SYNTHASE; DE-NOVO DESIGN; CLOSTRIDIUM-THERMOACETICUM; CRYSTAL-STRUCTURES; MODEL COMPOUNDS; IRON COMPLEXES; FE4S4 CLUSTER; NICKEL SITES; FERREDOXIN AB In earlier work, de novo designed peptides with a helix-loop-helix motif and 63 residues have been synthesized as potential scaffolds for stabilization of the [Ni-II-X-Fe4S4] bridged assembly that is the spectroscopically deduced structure of the A-Cluster in clostridial carbon monoxide dehydrogenase. The 63mers contain a consensus tricysteinyl ferredoxin domain in the loop for binding an Fe4S4 cluster and Cys and His residues proximate to the loop for binding Ni(II), with one Cys residue designed as the bridge X. The metallopeptides HC4H2-[Fe4S4]-Ni and HC5H-[Fe4S4]-M, containing three His and one Cys residue for Ni(II) coordination and two His and two Cys residues for binding M = Ni(II) and Co(II), have been examined by Fe-, Ni-, and Co-K edge spectroscopy and EXAFS. All peptides bind an [Fe4S4](2+) cubane-type cluster. Interpretation of the Ni and Co data is complicated by the presence of a minority population of six-coordinate species with low Z ligands, designated for simplicity as [M(OH2)6]2+. Best fits of the data were obtained with ca. 20% [M(OH2)(6)](2+) and ca. 80% M(II) with mixed N/S coordination. The collective XAS results for HC4H2-[Fe4S4]-Ni and HC5H-[Fe4S4]-M demonstrate the presence of an Fe4S4 cluster and support the existence of the distorted square-planar coordination units [Ni-II(S.Cys)(N.HiS)(3)] and [Ni-II(S.Cys)(2).(N.His)(2)] in the HC4H2 and HC5H metallopeptides, respectively. In the HC5H metallopeptide, tetrahedral [Co-II(S-Cys)(2)(N.HiS)(2)] is present. We conclude that the designed scaffolded binding sites, including Ni-(mu(2)-Cys)-Fe bridges, have been achieved. This is the first XAS study of a de novo designed metallopeptide intended to stabilize a bridged biological assembly, and one of a few XAS analyses of metal derivatives of designed peptides. The scaffolding concept should be extendable to other bridged metal assemblies. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. RP Holm, RH (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. FU NCRR NIH HHS [RR 01209]; NIGMS NIH HHS [GM 28856] NR 48 TC 23 Z9 23 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 27 PY 2002 VL 124 IS 12 BP 3083 EP 3092 DI 10.1021/ja011861q PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 533GF UT WOS:000174520500041 PM 11902899 ER PT J AU Doorn, SK Fields, RE Hu, H Hamon, MA Haddon, RC Selegue, JP Majidi, V AF Doorn, SK Fields, RE Hu, H Hamon, MA Haddon, RC Selegue, JP Majidi, V TI High resolution capillary electrophoresis of carbon nanotubes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID VIBRATIONAL-MODES; ORGANIC POLYMER; PURIFICATION; GROWTH; TEMPERATURE; SEPARATION; HYDROGEN; STORAGE AB Purification of single-walled carbon nanotubes by capillary electrophoresis (CE) is demonstrated. Real-time Raman spectroscopy of the separation process and single-wavelength UV/vis detection show the ability of CE to provide high-resolution separations of nanotube fractions with baseline separation. AFM images of collected fractions demonstrate that separations are based on tube length. The separation method is suggested to be based on alignment of the nanotubes along the separation field. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ Kentucky, Dept Chem, Lexington, KY 40506 USA. RP Doorn, SK (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663,C ACS,MS J-964, Los Alamos, NM 87545 USA. RI Haddon, Robert/A-2528-2008 OI Haddon, Robert/0000-0002-7903-5139 NR 32 TC 112 Z9 115 U1 2 U2 30 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 27 PY 2002 VL 124 IS 12 BP 3169 EP 3174 DI 10.1021/ja012364c PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 533GF UT WOS:000174520500048 PM 11902906 ER PT J AU Edgerton, SA Chow, JC Watson, JG AF Edgerton, SA Chow, JC Watson, JG TI Preface - Tropospheric aerosols: Science and policy in an international community SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Editorial Material C1 Pacific NW Natl Lab, Washington, DC 20024 USA. Desert Res Inst, Reno, NV 89512 USA. RP Edgerton, SA (reprint author), Natl Sci Fdn, 4201 Wilson Blvd, Arlington, VA 22230 USA. RI Watson, John/E-6869-2010 OI Watson, John/0000-0002-1752-6899 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAR 27 PY 2002 VL 287 IS 3 BP 165 EP 166 AR PII S0048-9697(01)01032-4 PG 2 WC Environmental Sciences SC Environmental Sciences & Ecology GA 541WC UT WOS:000175007600001 ER PT J AU Vega, E Reyes, E Sanchez, G Ortiz, E Ruiz, M Chow, J Watson, J Edgerton, S AF Vega, E Reyes, E Sanchez, G Ortiz, E Ruiz, M Chow, J Watson, J Edgerton, S TI Basic statistics of PM2.5 and PM10 in the atmosphere of Mexico city SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT NARSTO Symposium on Tropospheric Aerosols CY OCT 24-26, 2000 CL QUERETARO, MEXICO SP US DOE, US EPA, Meteorol Serv Canada, Environm Canada, Calif Air Resources Board, Natl Ocean & Atmospher Adm, EPRI, US Natl Pk Serv, N Amer Commiss Envrionm Cooperat, Mexican Inst Nacl Ecol DE particulate matter; particulate matter measurements; Mexico City; data management AB The high levels of fine particulate matter in Mexico City are of concern since they may induce severe public health effects as well as the attenuation of visible light. Sequential filter samplers were used at six different sites from 23 February to 22 March 1997. The sampling campaign was carried out as part of the project 'Investigacion sobre Materia Particulada y Deterioro Atmosferico-Aerosol and Visibility Evaluation Research'. This research was a cooperative project sponsored by PEMEX and by the US Department of Energy. Sampling sites represent the different land uses along the city, the northwest station, Tlalnepantla, is located in a mixed medium income residential and industrial area. The northeast station, Xalostoc, is located in a highly industrialized area, Netzahualcoyotl is located in a mixed land use area, mainly commercial and residential. Station La Merced is located in the commercial and administrative district downtown. The southwest station is located in the Pedregal de San Angel, in a high-income neighborhood, and the southeast station located in Cerro de la Estrella is a mixed medium income residential and commercial area. Samples were collected four times a day in Cerro de la Estrella (CES), La Merced (MER) and Xalostoc (XAL) with sampling periods of 6 h. In Pedregal (PED), Tlalnepantla (TLA) and Netzahualcoyotl (NEZ) sampling periods were every 24 It. In this paper the basic statistics of PM2.5 and PM10 mass concentrations are presented. The average results showed that 49, 61, 46, 57, 51 and 44% of the PM10 consisted of PM2.5 for CES, MER, XAL, PED, TLA and NEZ, respectively. The 24-h average highest concentrations of PM2.5 and PM10 were registered at NEZ (184 and 267 mug/m(3)) and the lowest at PED (22 and 39 mug/m(3)). The highest PM10 correlations were between XAL-CES (0.79), PED-TLA (0.80). In contrast, the highest PM2.5 correlations were between CES-PED (0.74), MER-CES (0.73) and TLA-PED (0.72), showing a lower correlation than the PM10 one. The results of the PM, from 12.00 to 18.00 h at CES and MER presented the highest variability and also the highest median concentrations, meanwhile XAL showed them from 06.00 to 12.00 h. The highest variability and median concentrations of PM2.5 were from 06.00 to 12.00 h for the three stations. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Inst Mexicano Petr, Mexico City 07730, DF, Mexico. Desert Res Inst, Reno, NV 89512 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Vega, E (reprint author), Inst Mexicano Petr, Eje Cent Lazaro Cardenas Num 152,Col San Bartolo, Mexico City 07730, DF, Mexico. RI Watson, John/E-6869-2010 OI Watson, John/0000-0002-1752-6899 NR 7 TC 27 Z9 28 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAR 27 PY 2002 VL 287 IS 3 BP 167 EP 176 AR PII S0048-9697(01)00980-9 DI 10.1016/S0048-9697(01)00980-9 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA 541WC UT WOS:000175007600002 PM 11993961 ER PT J AU Chow, JC Watson, JG Edgerton, SA Vega, E AF Chow, JC Watson, JG Edgerton, SA Vega, E TI Chemical composition of PM2.5 and PM10 in Mexico City during winter 1997 SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT NARSTO Symposium on Tropospheric Aerosols CY OCT 24-26, 2000 CL QUERETARO, MEXICO SP US DOE, US EPA, Meteorol Serv Canada, Environm Canada, Calif Air Resources Board, Natl Ocean & Atmospher Adm, EPRI, US Natl Pk Serv, N Amer Commiss Envrionm Cooperat, Mexican Inst Nacl Ecol DE PM2.5; PM10; Mexico City; satellite sites ID CALIFORNIA AIR-QUALITY; LOS-ANGELES; DESCRIPTIVE ANALYSIS; SUSPENDED PARTICLES; RESPIRATORY HEALTH; AMMONIUM-NITRATE; CARBON; POLLUTION; AEROSOL; PM(10) AB PM2.5 and PM10 were measured over 24-h intervals at six core sites and at 25 satellite sites in and around Mexico City from 23 February to 22 March 1997. In addition, four 6-h samples were taken each day at three of the core sites. Sampling locations were selected to represent regional, central city, commercial, residential, and industrial portions of the city. Mass and light transmission concentrations were determined on all of the samples, while elements, ions and carbon were measured on approximately two-thirds of the samples. PM10 concentrations were highly variable, with almost three-fold differences between the highest and lowest concentrations. Fugitive dust was the major cause of PM10 differences, although carbon concentrations were also highly variable among the sampling sites. Approximately 50% of PM10 was in the PM2.5 fraction. The majority of PM mass was comprised of carbon, sulfate, nitrate, ammonium and crustal components, but in different proportions on different days and at different sites. The largest fine-particle components were carbonaceous aerosols, constituting similar to 50% Of PM2.5 mass, followed by similar to 30% secondary inorganic aerosols and similar to 15% geological material. Geological material is the largest component of PM10, constituting similar to 50% of PM10 mass, followed by similar to 32% carbonaceous aerosols and similar to 17% secondary inorganic aerosols. Sulfate concentrations were twice as high as nitrate concentrations. Sulfate and nitrate were present as ammonium sulfate and ammonium nitrate. Approximately two-thirds of the ammonium sulfate measured in urban areas appears to have been transported from regions outside of the study domain, rather than formed from emissions in the urban area. Diurnal variations are apparent, with two-fold increases in concentration from night-time to daytime. Morning samples had the highest PM2.5 and PM10 mass, secondary inorganic aerosols and carbon concentrations, probably due to a shallow surface inversion and rush-hour traffic. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Desert Res Inst, Reno, NV 89512 USA. Battelle Pacific NW Natl Lab, Washington, DC USA. Inst Mexicano Petr, Mexico City 07730, DF, Mexico. RP Chow, JC (reprint author), Desert Res Inst, 2215 Raggio Pkwy, Reno, NV 89512 USA. RI Watson, John/E-6869-2010 OI Watson, John/0000-0002-1752-6899 NR 46 TC 94 Z9 103 U1 4 U2 29 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAR 27 PY 2002 VL 287 IS 3 BP 177 EP 201 AR PII S0048-9697(01)00982-2 DI 10.1016/S0048-9697(01)00982-2 PG 25 WC Environmental Sciences SC Environmental Sciences & Ecology GA 541WC UT WOS:000175007600003 PM 11993962 ER PT J AU Roberts, AG Bowman, MK Kramer, DM AF Roberts, AG Bowman, MK Kramer, DM TI Certain metal ions are inhibitors of cytochrome b(6)f complex 'Rieske' iron-sulfur protein domain movements SO BIOCHEMISTRY LA English DT Article ID PROTONMOTIVE Q-CYCLE; NUCLEAR DOUBLE-RESONANCE; LUMEN-SIDE DOMAIN; BC(1) COMPLEX; ELECTRON-TRANSFER; C REDUCTASE; SPINACH-CHLOROPLASTS; UBIQUINOL OXIDATION; PHOTOSYSTEM-I; UBIHYDROQUINONE OXIDATION AB Many current models of the Q cycle for the cytochrome (cyt) b(6)f and the cyt bc(1) complexes incorporate 'Rieske' iron-sulfur protein (ISP) domain movements to gate electron transfer and to ensure high yields of proton shuttling. It was previously proposed that copper ions, which bind at a site distant from the quinol oxidase (Q,,) site, inhibit plastoquinol (PQH(2)) binding by restraining the hydrophilic head domain of the ISP [Rao B. K., S., Tyryshkin, A. M., Roberts, A. G., Bowman, M. K., and Kramer, D. M. (1999) Biochemistry 38, 3285-32961. The present work presents evidence that this is indeed the case for both copper ions and Zn2+, which appear to inhibit by similar mechanisms. Electron paramagnetic resonance (EPR) spectra show that Cu2+ and Zn2+ binding to the cyt b(6)f complex displaces the Q, site inhibitor,5-dibromo-3-methyl-6-isopropylbenzoquinone (DBMIB). At high concentrations, both DBMIB; and Cu2+ or Zn2+ can bind simultaneously, altering the Rieske 2Fe2S cluster and Cu2+ EPR spectra, suggesting perturbations in their respective binding sites. Both Zn2+ and Cu1+ altered the orientations of the Rieske 2Fe2S cluster with respect to the membrane plane, but had no effect on that of the cyt b(6) hemes. Cu2+ was found to change the orientation of the cyt f heme plane, consistent with binding on the cyt f protein. Within conservative constraints, the data suggest that the ISP is shifted into a position intermediate between the ISPc position, when the Q(o) site is unoccupied, and the ISPB position, when the Q(o) site is occupied by inhibitors such as DBMIB or stigmatellin. These results support the role of ISP domain movements in Q(o) site catalysis. C1 Washington State Univ, Inst Biol Chem, Pullman, WA 99164 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci, Richland, WA 99352 USA. RP Kramer, DM (reprint author), Washington State Univ, Inst Biol Chem, 289 Clark Hall, Pullman, WA 99164 USA. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 FU NIGMS NIH HHS [GM61904] NR 98 TC 25 Z9 27 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAR 26 PY 2002 VL 41 IS 12 BP 4070 EP 4079 DI 10.1021/bi015996k PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 534NK UT WOS:000174592300027 PM 11900550 ER PT J AU Kam, SI Gauglitz, PA Rossen, WR AF Kam, SI Gauglitz, PA Rossen, WR TI The yield stress of foamy sands SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE yield stress; foamy sand; proppant; foam; fracturing fluid ID HIGHLY CONCENTRATED EMULSIONS; SIMPLE SHEARING FLOW; RHEOLOGY; MODEL AB The yield stress of a mixture of foam and solids, or foamy sand, was investigated theoretically using a two-dimensional (2-D) periodic model. The range of solid fractions considered ranged from about 40 to 68%. The yield stress of a foamy sand increases with gas fraction at a given solid fraction and increases with solid fraction at a given gas fraction. At a fixed fraction of solid plus gas, yield stress is relatively insensitive to gas or solid fraction alone. There exists a maximum liquid fraction above which the yield stress disappears. These trends agree with those reported for foamy sands encountered in tunneling through soft sediments and proppant-laden fracturing fluids used in the petroleum industry. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Rossen, WR (reprint author), Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. NR 16 TC 7 Z9 7 U1 4 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD MAR 26 PY 2002 VL 202 IS 1 BP 53 EP 62 AR PII S0927-7757(01)01058-5 DI 10.1016/S0927-7757(01)01058-5 PG 10 WC Chemistry, Physical SC Chemistry GA 544JJ UT WOS:000175154200006 ER PT J AU Rahimian, K Loy, DA Wheeler, DR AF Rahimian, K Loy, DA Wheeler, DR TI Soluble, high molecular weight polysilsesquioxanes with carboxylate functionalities SO MACROMOLECULES LA English DT Article ID CHEMISTRY C1 Sandia Natl Labs, Dept Chem Mat, Albuquerque, NM 87185 USA. Sandia Natl Labs, Catalysia & Chem Technol Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Micro Total Analyt Syst Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Dept Chem Mat, POB 5800, Albuquerque, NM 87185 USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 10 TC 2 Z9 2 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD MAR 26 PY 2002 VL 35 IS 7 BP 2452 EP 2454 DI 10.1021/ma0121215 PG 3 WC Polymer Science SC Polymer Science GA 533ZF UT WOS:000174559600010 ER PT J AU Schonherr, H Wiyatno, W Pople, J Frank, CW Fuller, GG Gast, AP Waymouth, RM AF Schonherr, H Wiyatno, W Pople, J Frank, CW Fuller, GG Gast, AP Waymouth, RM TI Morphology of thermoplastic elastomers: Elastomeric polypropylene SO MACROMOLECULES LA English DT Article ID ATOMIC-FORCE MICROSCOPY; GROUP-IVB CATALYSTS; ISOTACTIC POLYPROPYLENE; ZIRCONOCENE CATALYSTS; POLY(ETHYLENE OXIDE); LAMELLAR MORPHOLOGY; POLYMER STRUCTURE; CRYSTALLIZATION; POLY(PROPYLENE); SPHERULITES AB The morphology of low-density (0.86 g/cm(3)), low-crystallinity (10%) elastomeric polypropylene (ePP) derived from a bis(2-arylindenyl)hafnium catalyst was investigated using a combination of polarized optical microscopy (POM), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), Fourier transform infrared (FT-IR) spectroscopy, and tapping mode atomic force microscopy (TM-AFM). This thermoplastic elastomer, when crystallized isothermally from the melt, exhibits morphologies reminiscent of classical semicrystalline polymers. The presence of lamellae, crosshatching, hedrites, and spherulites was revealed by high-resolution TM-AFM. POM confirmed the presence of hedrites and spherulites. The parent ePP can be fractionated into components of different average tacticities ([mmmm]%: 21%-76%) and crystallinities (1%-40% as determined by DSC and WAXS) but more similar molecular mass (M-w: 147-432 kg/mol) and polydispersity (M-w/M-n: 2.1-2.5). The analysis of the morphologies of these fractions revealed large hierarchical structures for all but the lowest crystallinity fraction and crosshatching typical of the a-modification of crystalline isotactic polypropylene for all fractions. The solubility of the corresponding fractions in ether and heptane combined with new evidence for crystals with melting temperatures higher than 100 degreesC in all of the fractions is most consistent with a stereoblock microstructure of atactic and isotactic sequences in ePP. C1 Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, NSF MRSEC CPIMA, Stanford, CA 94309 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Frank, CW (reprint author), Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. RI Schonherr, Holger/D-5878-2014; OI Schonherr, Holger/0000-0002-5836-5569; Waymouth, Robert/0000-0001-9862-9509 NR 75 TC 49 Z9 49 U1 0 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 26 PY 2002 VL 35 IS 7 BP 2654 EP 2666 DI 10.1021/ma010959m PG 13 WC Polymer Science SC Polymer Science GA 533ZF UT WOS:000174559600037 ER PT J AU Siegal, MP Overmyer, DL Provencio, PP AF Siegal, MP Overmyer, DL Provencio, PP TI Precise control of multiwall carbon nanotube diameters using thermal chemical vapor deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH; ARRAYS AB We grow multiwall carbon nanotube (CNT) films using thermal chemical vapor deposition at atmospheric pressure using a mixture of acetylene and nitrogen from a 4-nm-thick Ni film catalyst. CNTs are characterized using electron microscopy and Rutherford backscattering spectrometry. CNTs grown with this method are extremely uniform in diameter, both throughout the sample and within the lengths of individual tubes. Nanotube outer diameters, ranging from 5-350 nm, and the total deposition of carbon material, increase exponentially with growth temperature from 630 degreesC-790 degreesC. (C) 2002 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87122 USA. RP Siegal, MP (reprint author), Sandia Natl Labs, Albuquerque, NM 87122 USA. NR 12 TC 50 Z9 52 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 MAR 25 PY 2002 VL 80 IS 12 BP 2171 EP 2173 DI 10.1063/1.1463204 PG 3 WC Physics, Applied SC Physics GA 532WU UT WOS:000174498700043 ER PT J AU Kim, CH Shinar, J AF Kim, CH Shinar, J TI Bright small molecular white organic light-emitting devices with two emission zones SO APPLIED PHYSICS LETTERS LA English DT Article ID CONJUGATED POLYMERS; ENERGY-TRANSFER; DIODES; ELECTROLUMINESCENCE; PHOTOLUMINESCENCE; FILMS; LAYER AB Bright multilayer organic light-emitting devices (OLEDs) containing both perylene-doped [4,4(')-bis(9-carbazolyl) biphenyl (CBP)] and [4-(dicyano-methylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran (DCM1)-doped tris-(8-hydroxy quinoline) Al (Alq(3))] are described. The electroluminescence spectra consist of blue and green bands at 453, 487, and 524 nm due to perylene and a red band at 600 nm due to DCM1, although these two emitting layers are separated by a layer of [2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (Bu-PBD)]. As the thickness of the hole-injecting [N,N'-diphenyl-N,N'-bis(1-naphthyl-phenyl)-1, 1'-biphenyl-4,4(')-diamine (NPB)] and perylene:CBP layers increases and that of the DCM1:Alq(3) layer decreases the perylene emission intensifies strongly relative to the DCM1 emission. For 350 Angstrom thick NPB, 350 Angstrom thick perylene:CBP, 100 Angstrom Bu-PBD, and 150 Angstrom DCM1:Alq(3), the brightness reaches 3750 Cd/m(2) at 20 V, the efficiency is 2.4 Cd/A at 19 V, and the (x,y) CIE coordinates are well within the white region. However, as the bias is increased the intensity of the perylene emission increases relative to the DCM1 emission. Both the layer thickness and bias dependence are believed to result from changes in the recombination zone and in the field- and cathode-mirror-induced quenching of DCM1 singlet excitons. (C) 2002 American Institute of Physics. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Kim, CH (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 35 TC 158 Z9 165 U1 1 U2 18 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 25 PY 2002 VL 80 IS 12 BP 2201 EP 2203 DI 10.1063/1.1464223 PG 3 WC Physics, Applied SC Physics GA 532WU UT WOS:000174498700053 ER PT J AU Cherian, S Thundat, T AF Cherian, S Thundat, T TI Determination of adsorption-induced variation in the spring constant of a microcantilever SO APPLIED PHYSICS LETTERS LA English DT Article ID CANTILEVERS AB Although resonating microcantilevers are demonstrated to be excellent mass sensors, adsorption-induced changes in the spring constant result in errors in the calculation of adsorbed mass from shifts in resonance frequencies. However, simultaneous measurement of resonance frequency and adsorption-induced cantilever bending can be used to determine the variation in spring constant. Plotting the change in surface stress as a function of analyte concentration, the surface excess of adsorbed molecules and, therefore, the mass adsorbed can be determined. Here, we demonstrate this concept for adsorption of Na+ ions on microcantilevers in NaCl solutions where a change in the spring constant was found to increase from 9.5x10(-4) to 7.5x10(-3) N/m as the NaCl concentration increased from 0.05 to 0.8 M. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Thundat, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 18 TC 71 Z9 72 U1 0 U2 15 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 25 PY 2002 VL 80 IS 12 BP 2219 EP 2221 DI 10.1063/1.1463720 PG 3 WC Physics, Applied SC Physics GA 532WU UT WOS:000174498700059 ER PT J AU Fujita, E Wishart, JF van Eldik, R AF Fujita, E Wishart, JF van Eldik, R TI Mechanistic information from pressure acceleration of hydride formation via proton binding to a cobalt(I) macrocycle SO INORGANIC CHEMISTRY LA English DT Article ID CARBON-DIOXIDE ACTIVATION; CO HYDROGEN-BONDS; OXIDATIVE-ADDITION; AQUEOUS-SOLUTION; PULSE-RADIOLYSIS; COMPLEXES; THERMODYNAMICS; TEMPERATURE; IODOMETHANE; REDUCTION AB The effect of pressure on proton binding to the racemic isomer of the cobalt(l) macrocycle, CoL+ (L = 5,7,7,12,14,14-hexamethyl-1,4,8,1 1-tetraazacyclotetradeca-4,11-diene), has been studied for a series of proton donors using pulse radiolysis techniques. The second-order rate constants for the reaction of CoL+ with proton donors decrease with increasing pK(a) of the donor acid, consistent with a reaction occurring via proton transfer. Whereas the corresponding volumes of activation (DeltaV(double dagger)) are rather small and negative for all acids (proton donors) with pK(a) values below 8.5, significantly larger negative activation volumes are found for weaker acids (pK(a) > 9.5) containing OH groups as proton donors. In the latter case, the observed DeltaV(double dagger) for these protonation reactions show a correlation with the reaction volumes (DeltaVdegrees(ion)) for the ionization of the weak acids with a slope of 0.44, indicating that bond dissociation of the weak acid molecule bound to the metal center proceeds approximately halfway at the transition state along the reaction coordinate in terms of volume changes. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Erlangen Nurnberg, Inst Inorgan Chem, D-91058 Erlangen, Germany. RP Fujita, E (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Fujita, Etsuko/D-8814-2013; Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 28 TC 9 Z9 9 U1 0 U2 9 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 MAR 25 PY 2002 VL 41 IS 6 BP 1579 EP 1583 DI 10.1021/ic011109q PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 532TZ UT WOS:000174492300033 PM 11896727 ER PT J AU Tai, CC Pitts, J Linehan, JC Main, AD Munshi, P Jessop, PG AF Tai, CC Pitts, J Linehan, JC Main, AD Munshi, P Jessop, PG TI In situ formation of ruthenium catalysts for the homogeneous hydrogenation of carbon dioxide SO INORGANIC CHEMISTRY LA English DT Article ID FORMIC-ACID; PHOSPHINE COMPLEXES; ORGANOMETALLIC CHEMISTRY; MOLECULAR-STRUCTURE; CO2 HYDROGENATION; CRYSTAL-STRUCTURE; H BONDS; LIGANDS; ACTIVATION; PROTON AB A total of 44 different phosphines were tested, in combination with [RuCl2(C6H6)](2) and three other Ru(II) precursors, for their ability to form active catalysts for the hydrogenation Of CO2 to formic acid. Half (22) of the ligands formed catalysts of significant activity, and only 6 resulted in very high rates of production of formic acid. These were PMe3, PPhMe2, dppm, dppe, and cis- and trans-Ph2PCH=CHPPh2. The in situ catalysts prepared from [RuCl2(C6H6)](2) and any of these 6 phosphine ligands were found to be at least as efficient as the isolated catalyst RuCl(O2CMe)(PMe3)(4.) There was no correlation between the basicity of monophosphines (PR3) and the activity of the catalysts formed from them. However, weakly basic diphosphines formed highly active catalysts only if their bite angles were small, while more strongly basic diphosphines had the opposite trend. In situ P-31 NMR spectroscopy showed that trans-Ru(H)(2)(dppm)(2), trans-RuCl2(dppm)p, trans-RuHCl(dppm)(2), cis-Ru(H)(O2CH)(dppm)(2), and cis-Ru(O2CH)(2)(dppm)(2) are produced as the major metal-containing species in reactions of dppm with [RuCl2(C6H6)](2) under catalytic conditions at 50 degreesC. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Pacific NW Natl Lab, Fundamental Sci Div, Richland, WA 99352 USA. RP Jessop, PG (reprint author), Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. NR 73 TC 70 Z9 70 U1 4 U2 28 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 MAR 25 PY 2002 VL 41 IS 6 BP 1606 EP 1614 DI 10.1021/ic010866l PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 532TZ UT WOS:000174492300037 PM 11896731 ER PT J AU Cary, DR Zaitseva, NP Gray, K O'Day, KE Darrow, CB Lane, SM Peyser, TA Satcher, JH Van Antwerp, WP Nelson, AJ Reynolds, JG AF Cary, DR Zaitseva, NP Gray, K O'Day, KE Darrow, CB Lane, SM Peyser, TA Satcher, JH Van Antwerp, WP Nelson, AJ Reynolds, JG TI Rhenium bipyridine complexes for the recognition of glucose SO INORGANIC CHEMISTRY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; OPTICAL SENSING PROPERTIES; BORONIC-ACID; ARTIFICIAL PHOTOSYNTHESIS; SACCHARIDE-BIOSENSORS; EPOXY-RESINS; SENSORS; SYSTEMS; DESIGN; LECTIN AB Bipyridine ligands containing pendant methyl, amino, and amino-boronic acid groups were synthesized. Coordination complexes of these ligands with rhenium were prepared straightforwardly and in good yield. The fluorescence behavior of the Re complexes was studied as a function of pH and exposure to various concentrations of glucose. The methyl bipyridine complex showed no change in fluorescence with pH, the amino derivative showed a rapid decrease from low pH to neutral, and the amino-boronate derivative showed little change from pH 4 to 10. Fluorescence quenching was observed at high pH as expected on the basis of a photoinduced electron transfer (PET) signaling mechanism. This behavior can be explained on the basis of the first oxidation and reduction potentials of these complexes. Glucose testing showed a significant dependence on the solvent system used. In pure methanol, the rhenium boronate complex exhibited a 55% fluorescence intensity increase upon increasing glucose concentration from 0 to 400 mg/dL. However, in 50 vol % methanollphosphate buffered saline, none of the complexes showed significant response in the glucose range of physiological interest. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. MiniMed Inc, Sylmar, CA 91342 USA. RP Cary, DR (reprint author), Lawrence Livermore Natl Lab, POB 808,L-092, Livermore, CA 94551 USA. EM dcary@pcpy.com FU NIDDK NIH HHS [DK-98-008] NR 43 TC 26 Z9 26 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 25 PY 2002 VL 41 IS 6 BP 1662 EP 1669 DI 10.1021/ic010202b PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 532TZ UT WOS:000174492300044 PM 11896738 ER PT J AU Hopkins, MM Fauci, LJ AF Hopkins, MM Fauci, LJ TI A computational model of the collective fluid dynamics of motile micro-organisms SO JOURNAL OF FLUID MECHANICS LA English DT Article ID BIOCONVECTION PATTERNS; GYROTACTIC MICROORGANISMS; SWIMMING MICROORGANISMS; SUSPENSION; PLUMES; WAVELENGTHS; GROWTH; FLOW AB A mathematical model and numerical method for studying the collective dynamics of geotactic, gyrotactic and chemotactic micro-organisms immersed in a viscous fluid is presented. The Navier-Stokes equations of fluid dynamics are solved in the presence of a discrete collection of micro-organisms. These microbes act as point sources of gravitational force in the fluid equations, and thus affect the fluid flow. Physical factors, e.g. vorticity and gravity, as well as sensory factors affect swimming speed and direction. In the case of chemotactic microbes, the swimming orientation is a function of a molecular field. In the model considered here, the molecules are a nutrient whose consumption results in an upward gradient of concentration that drives its downward diffusion. The resultant upward chemotactically induced accumulation of cells results in (Rayleigh-Taylor) instability and eventually in steady or chaotic convection that transports molecules and affects the translocation of organisms. Computational results that examine the long-time behaviour of the full nonlinear system are presented. The actual dynamical system consisting of fluid and suspended swimming organisms is obviously three-dimensional, as are the basic modelling equations. While the computations presented in this paper are two-dimensional, they provide results that match remarkably well the spatial patterns and long-time temporal dynamics of actual experiments; various physically applicable assumptions yield steady states, chaotic states, and bottom-standing plumes. The simplified representation of microbes as point particles allows the variation of input parameters and modelling details, while performing calculations with very large numbers of particles (approximate to 10(4)-10(5)), enough so that realistic cell concentrations and macroscopic fluid effects can be modelled with one particle representing one microbe, rather than some collection of microbes. It is demonstrated that this modelling framework can be used to test hypotheses concerning the coupled effects of microbial behaviour, fluid dynamics and molecular mixing. Thus, not only are insights provided into the differing dynamics concerning purely geotactic and gyrotactic microbes, the dynamics of competing strategies for chemotaxis, but it is demonstrated that relatively economical explorations in two dimensions can deliver striking insights and distinguish among hypotheses. C1 Sandia Natl Labs, Plasma Aerosol & Noncontinuum Proc, Albuquerque, NM 87185 USA. Tulane Univ, Dept Math, New Orleans, LA 70118 USA. RP Hopkins, MM (reprint author), Sandia Natl Labs, Plasma Aerosol & Noncontinuum Proc, POB 5800, Albuquerque, NM 87185 USA. OI Fauci, Lisa/0000-0002-4477-8178 NR 29 TC 34 Z9 34 U1 1 U2 7 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 MAR 25 PY 2002 VL 455 BP 149 EP 174 DI 10.1017/S0022112001007339 PG 26 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 540AA UT WOS:000174904700007 ER PT J AU Feldman, WC Gasnault, O Maurice, S Lawrence, DJ Elphic, RC Lucey, PG Binder, AB AF Feldman, WC Gasnault, O Maurice, S Lawrence, DJ Elphic, RC Lucey, PG Binder, AB TI Global distribution of lunar composition: New results from Lunar Prospector SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Moon; composition; impact phenomena; evolution ID PROCELLARUM KREEP TERRANE; THORIUM ABUNDANCES; FAST-NEUTRONS; MOON; SURFACE; EVOLUTION; VOLCANISM; SPECTRA; MANTLE; ORIGIN AB [1] Maps of thorium [Th], [FeO], the ratio of epithermal to thermal neutrons (E/T), and fast neutrons (FN) from Lunar Prospector were studied to determine their global distribution on the Moon. These distributions are compared to that of the 750 nm lunar albedo from Clementine to aid in their interpretation. All distributions were parameterized using a spherical harmonic expansion out to order l = 30. Resultant harmonic coefficients generally decrease with increasing l value as a power law in l for all five variables. The axes of all dipole components (l = 1) cluster closely about a centroid given by +14.1degrees latitude and 16.4degrees west longitude. This location is very close to the symmetry axes of their quadrupole components (l = 2), which cluster about a centroid given by +24.6degrees latitude and 25.1degrees west longitude. Both centroids are near the center of a suggested Procellarum basin, given by Whitaker [1981] at +23degrees latitude and 15degrees west longitude. This suggestion is strengthened by a sharp decrease of the intensities of all three variables at similar to50degrees from the centroids, which is close to the boundary of the putative Procellarum basin. The coincidence of the global concentration of heat-producing elements (through [Th]) and mare deposits on the lunar surface (through [FeO], [T/E], and [FN]) with the circular outline of a putative Procellarum basin suggests that the events that were responsible for producing Oceanus Procellarum (perhaps a single giant impact) must figure importantly in shaping the global distribution of surface composition. A second, apparently older circular structure having its center near -5degrees latitude and 65degrees east longitude and a radius of 50degrees is also hinted at in the data. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Observ Midi Pyrenees, UMR 5572, F-31400 Toulouse, France. Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Lunar Res Inst, Tucson, AZ 85747 USA. RP Feldman, WC (reprint author), Los Alamos Natl Lab, MS D-466, Los Alamos, NM 87545 USA. RI Gasnault, Olivier/F-4327-2010; Lawrence, David/E-7463-2015 OI Gasnault, Olivier/0000-0002-6979-9012; Lawrence, David/0000-0002-7696-6667 NR 46 TC 17 Z9 17 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD MAR 25 PY 2002 VL 107 IS E3 AR 5016 DI 10.1029/2001JE001506 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 609LQ UT WOS:000178905400001 ER PT J AU Moriarty, JA Belak, JF Rudd, RE Soderlind, P Streitz, FH Yang, LH AF Moriarty, JA Belak, JF Rudd, RE Soderlind, P Streitz, FH Yang, LH TI Quantum-based atomistic simulation of materials properties in transition metals SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID 1ST-PRINCIPLES INTERATOMIC POTENTIALS; CENTERED-CUBIC METALS; EMBEDDED-ATOM METHOD; TILT GRAIN-BOUNDARY; SCREW DISLOCATIONS; MOLECULAR-DYNAMICS; AB-INITIO; LENGTH SCALES; MECHANICAL CALCULATION; ANGULAR FORCES AB We present an overview of recent work on quantum-based atomistic simulation of materials properties in transition metals performed in the Metals and Alloys Group at Lawrence Livermore National Laboratory. Central to much of this effort has been the development, from fundamental quantum mechanics, of robust many-body interatomic potentials for bcc transition metals via model generalized pseudopotential theory (MGPT), providing close linkage between ab initio electronic-structure calculations and large-scale static and dynamic atomistic simulations. In the case of tantalum (Ta), accurate MGPT potentials have been so obtained that are applicable to structural, thermodynamic, defect, and mechanical properties over wide ranges of pressure and temperature. Successful application areas discussed include structural phase stability, equation of state, melting, rapid resolidification, high-pressure elastic moduli, ideal shear strength, vacancy and self-interstitial formation and migration, grain-boundary atomic structure, and dislocation core structure and mobility. A number of the simulated properties allow detailed validation of the Ta potentials through comparisons with experiment and/or parallel electronic-structure calculations. Elastic and dislocation properties provide direct input into higher-length-scale multiscale simulations of plasticity and strength. Corresponding effort has also been initiated on the multiscale materials modelling of fracture and failure. Here large-scale atomistic simulations and novel real-time characterization techniques are being used to study void nucleation, growth, interaction, and coalescence in series-end fcc transition metals. We have so investigated the microscopic mechanisms of void nucleation in polycrystalline copper (Cu), and void growth in single-crystal and polycrystalline Cu, undergoing triaxial expansion at a large, constant strain rate-a process central to the initial phase of dynamic fracture. The influence of pre-existing microstructure on the void growth has been characterized both for nucleation and for growth, and these processes are found to be in agreement with the general features of void distributions observed in experiment. We have also examined some of the microscopic mechanisms of plasticity associated with void growth. C1 Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, Livermore, CA 94551 USA. EM moriarty2@llnl.gov OI Rudd, Robert/0000-0002-6632-2681 NR 91 TC 114 Z9 114 U1 3 U2 39 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAR 25 PY 2002 VL 14 IS 11 BP 2825 EP 2857 AR PII S0953-8984(02)32437-8 DI 10.1088/0953-8984/14/11/305 PG 33 WC Physics, Condensed Matter SC Physics GA 540BC UT WOS:000174901100006 ER PT J AU Beane, SR Bedaque, PF Savage, MJ van Kolck, U AF Beane, SR Bedaque, PF Savage, MJ van Kolck, U TI Towards a perturbative theory of nuclear forces SO NUCLEAR PHYSICS A LA English DT Article ID EFFECTIVE-FIELD THEORY; SHORT-RANGE INTERACTIONS; TO-LEADING-ORDER; CHIRAL LAGRANGIANS; DEUTERON SCATTERING; 2-NUCLEON SYSTEM; NN SCATTERING; PIONS; RENORMALIZATION; EXPANSIONS AB We show that an expansion of nuclear forces about the chiral limit is formally consistent and is equivalent to KSW power counting in the S-1(0) channel and Weinberg power counting in the S-3(1)-D-3(1) coupled channels. Numerical evidence suggests that this expansion converges. The feasibility of making contact between nuclear physics and lattice-QCD simulations is discussed. (C) 2002 Published by Elsevier Science B.V. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Jefferson Lab, Newport News, VA 23606 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Beane, SR (reprint author), Univ Washington, Dept Phys, Seattle, WA 98195 USA. NR 63 TC 216 Z9 215 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 25 PY 2002 VL 700 IS 1-2 BP 377 EP 402 AR PII S0375-9474(01)01324-0 DI 10.1016/S0375-9474(01)01324-0 PG 26 WC Physics, Nuclear SC Physics GA 530ZC UT WOS:000174388800016 ER PT J AU Dumitru, A McLeran, L AF Dumitru, A McLeran, L TI How protons shatter colored glass SO NUCLEAR PHYSICS A LA English DT Article DE QCD; saturation in QCD; high-energy scattering; small-x physics; hadron-nucleus collisions; nucleus-nucleus collisions ID ULTRARELATIVISTIC NUCLEAR COLLISIONS; WILSON RENORMALIZATION-GROUP; GLUON MINIJET PRODUCTION; LOW X PHYSICS; HIGH-ENERGIES; DENSITY; RADIATION AB We consider the implications of the Color Glass Condensate for the central region of p + A collisions. We compute the k(perpendicular to) distribution of radiated gluons and their rapidity distribution dN/dy analytically, both in the perturbative regime and in the region between the two saturation momenta. We find an analytic expression for the number of produced gluons which is valid when the saturation momentum of the proton is much less than that of the nucleus. We discuss the scaling of the produced multiplicity with A. We show that the slope of the rapidity density dN/dy provides an experimental measure for the renormalization-group evolution of the color-charge density of the Color Glass Condensate (CGC). We also argue that these results are easily generalized to collisions of nuclei of different A at central rapidity. or with the same A but at a rapidity far from the central region. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Dumitru, A (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. NR 26 TC 122 Z9 122 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 25 PY 2002 VL 700 IS 1-2 BP 492 EP 508 AR PII S0375-9474(01)01301-X DI 10.1016/S0375-9474(01)01301-X PG 17 WC Physics, Nuclear SC Physics GA 530ZC UT WOS:000174388800021 ER PT J AU Jalilian-Marian, J Orginos, K Sarcevic, I AF Jalilian-Marian, J Orginos, K Sarcevic, I TI Nuclear effects in prompt photon production at the Large Hadron Collider SO NUCLEAR PHYSICS A LA English DT Article ID QUARK-GLUON PLASMA; HEAVY-ION COLLISIONS; PARTON DISTRIBUTIONS; LEADING ORDER; ENERGY-LOSS; FRAGMENTATION AB We present a detailed study of prompt photon production cross section in heavy-ion collisions in the central rapidity region at energy of roots = 5.5 TeV, appropriate to LHC experiment. We include the next-to-leading order radiative corrections, O(alpha(em)alpha(s)(2)), nuclear shadowing and the parton energy-loss effects. We find that the nuclear effects can reduce the invariant cross section for prompt photon production by an order of magnitude at p(t) = 3 GeV. We discuss theoretical uncertainties due to parton energy loss and nuclear shadowing parameters. We show that the K-factor, which signifies the importance of next-to-leading order corrections, is large and has a strong p(t) dependence. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Jalilian-Marian, J (reprint author), Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. OI Orginos, Kostas/0000-0002-3535-7865 NR 37 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAR 25 PY 2002 VL 700 IS 1-2 BP 523 EP 538 AR PII S0375-9474(01)01309-4 DI 10.1016/S0375-9474(01)01309-4 PG 16 WC Physics, Nuclear SC Physics GA 530ZC UT WOS:000174388800023 ER PT J AU Vogt, R AF Vogt, R TI Are the J/psi and chi(c) A dependencies the same? SO NUCLEAR PHYSICS A LA English DT Article DE J/psi suppressions; quarkonium production; nuclear dependence ID NUCLEUS-NUCLEUS COLLISIONS; J-PSI SUPPRESSION; QUARKONIUM PRODUCTION; PARTON DISTRIBUTIONS; HADRONIC COLLISIONS; 300-GEV/C PROTON; HEAVY QUARKS; QCD ANALYSIS; CHARMONIUM; HADROPRODUCTION AB It has been empirically observed that the dependence of J/psi and psi' production on nuclear mass number A is very similar. This has been postulated to be due to the predominance of color-octet preresonant states in charmonium production and absorption. Two new experiments, NA60 at CERN and HERA-B at DESY, will measure the chi(c) A dependence for the first thne. These measurements should shed new light on the charmonium production and absorption mechanisms. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. EM vogt@lbl.gov NR 54 TC 42 Z9 44 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 MAR 25 PY 2002 VL 700 IS 1-2 BP 539 EP 554 AR PII S0375-9474(01)01313-6 DI 10.1016/S0375-9474(01)01313-6 PG 16 WC Physics, Nuclear SC Physics GA 530ZC UT WOS:000174388800024 ER PT J AU Berman, GP Smerzi, A Bishop, AR AF Berman, GP Smerzi, A Bishop, AR TI Quantum instability of a Bose-Einstein condensate with attractive interaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID GROUND-STATE; GASES AB We study the quantum and the mean-field Gross-Pitaevskii ( GP) dynamics of a Bose-Einstein condensate gas confined in a toroidal trap. According to GP, if the interatomic interaction is attractive, the rotational states of the system can be dynamically stable or unstable depending on the strength of the mean-field energy. The full quantum analysis, however, reveals that the condensate is always unstable. Quantum fluctuations are particularly important close to the GP stability borderline, even for systems with a relatively large number of condensate atoms. 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 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 27 TC 21 Z9 21 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 MAR 25 PY 2002 VL 88 IS 12 AR 120402 DI 10.1103/PhysRevLett.88.120402 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000002 ER PT J AU Hamilton, JC AF Hamilton, JC TI Overlayer strain relief on surfaces with square symmetry: Phase diagram or a 2D Frenkel-Kontorova model SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL INTERFACES; RECONSTRUCTION; NI(100); GROWTH; AG AB Overlayers on surfaces with square symmetry exhibit a huge variety of strain relief mechanisms. I present a simple 2D Frenkel-Kontorova model and calculate the associated zero temperature phase diagram which shows a transition from overlayers with square symmetry (and possible square dislocation patterns) to hexagonal symmetry. The phase diagram includes the experimentally observed clock-rotated phase. Local density approximation calculations suggested by the model show that a clean Ni(100) surface reconstructs from a bulk-terminated to a clock-rotated structure at biaxial compressive strains above 2.5%. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Hamilton, JC (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 19 TC 12 Z9 12 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 25 PY 2002 VL 88 IS 12 AR 126101 DI 10.1103/PhysRevLett.88.126101 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000052 PM 11909482 ER PT J AU Janotti, A Zhang, SB Wei, SH AF Janotti, A Zhang, SB Wei, SH TI Hydrogen vibration modes in GaP : N: The pivotal role of nitrogen in stabilizing the H-2* complex SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; CRYSTALLINE SILICON; ATOMIC-HYDROGEN; SEMICONDUCTORS; FREQUENCIES; DIFFUSION; MOLECULES; GAAS AB Atomic structures of N-related hydrogen complexes in GaP:N are calculated from first principles. As the more electronegative N bonds H stronger than P, it stabilizes the H-2* complex that is otherwise unstable against the formation of an H-2 molecule. This provides the first theoretical proof that H-2* can be stable in a III-V semiconductor. The previously proposed H-N-H dihydride model is found to be unstable against spontaneously transforming into H-2*, which involves only monohydrides, H-N and H-Ga. The calculated local vibrational frequencies and isotope shifts are in good agreement with experiment. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Schaff, William/B-5839-2009; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013; Janotti, Anderson/F-1773-2011 OI Zhang, Shengbai/0000-0003-0833-5860; Janotti, Anderson/0000-0001-5028-8338 NR 23 TC 33 Z9 33 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAR 25 PY 2002 VL 88 IS 12 AR 125506 DI 10.1103/PhysRevLett.88.125506 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000046 PM 11909476 ER PT J AU Joo, K Smith, LC Burkert, VD Minehart, R Aznauryan, IG Elouadrhiri, L Stepanyan, S Adams, GS Amaryan, MJ Anciant, E Anghinolfi, M Armstrong, DS Asavapibhop, B Audit, G Auger, T Avakian, H Barrow, S Bagdasaryan, H Battaglieri, M Beard, K Bektasoglu, M Bertozzi, W Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Brooks, WK Calarco, JR Capitani, GP Carman, DS Carnahan, B Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J De Sanctis, E De Vita, R Degtyarenko, PV Demirchyan, RA Denizli, H Dennis, LC Deppman, A Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Eckhause, M Efremenko, YV Egiyan, H Egiyan, KS Farhi, L Feuerbach, RJ Ficenec, J Fissum, K Forest, TA Funsten, H Gai, M Gavrilov, VB Gilad, S Gilfoyle, GP Giovanetti, KL Girard, P Griffioen, KA Guidal, M Guillo, M Gyurjyan, V Hancock, D Hardie, J Heddle, D Heisenberg, J Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Jenkins, D Kelley, JH Khandaker, M Kim, KY Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kuang, Y Kuhn, SE Laget, JM Lawrence, D Longhi, A Loukachine, K Lucas, M Major, RW Manak, JJ Marchand, C Matthews, SK McAleer, S McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mirazita, M Miskimen, R Muccifora, V Mueller, J Mutchler, GS Napolitano, J Niculescu, G Niczyporuk, B Niyazov, RA Ohandjanyan, MS Opper, A Patois, Y Peterson, GA Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Salgado, CW Sanzone, M Sapunenko, V Sargsyan, M Schumacher, RA Sharabian, YG Shaw, J Shuvalov, SM Skabelin, A Smith, ES Smith, T Sober, DI Spraker, M Stoler, P Taiuti, M Taylor, S Tedeschi, D Thompson, R Todor, L Tung, TY Vineyard, MF Vlassov, A Weller, H Weinstein, LB Welsh, R Weygand, DP Whisnant, S Witkowski, M Wolin, E Yegneswaran, A Yun, J Zhou, Z Zhao, J AF Joo, K Smith, LC Burkert, VD Minehart, R Aznauryan, IG Elouadrhiri, L Stepanyan, S Adams, GS Amaryan, MJ Anciant, E Anghinolfi, M Armstrong, DS Asavapibhop, B Audit, G Auger, T Avakian, H Barrow, S Bagdasaryan, H Battaglieri, M Beard, K Bektasoglu, M Bertozzi, W Bianchi, N Biselli, AS Boiarinov, S Bonner, BE Brooks, WK Calarco, JR Capitani, GP Carman, DS Carnahan, B Cole, PL Coleman, A Cords, D Corvisiero, P Crabb, D Crannell, H Cummings, J De Sanctis, E De Vita, R Degtyarenko, PV Demirchyan, RA Denizli, H Dennis, LC Deppman, A Dharmawardane, KV Dhuga, KS Djalali, C Dodge, GE Doughty, D Dragovitsch, P Dugger, M Dytman, S Eckhause, M Efremenko, YV Egiyan, H Egiyan, KS Farhi, L Feuerbach, RJ Ficenec, J Fissum, K Forest, TA Funsten, H Gai, M Gavrilov, VB Gilad, S Gilfoyle, GP Giovanetti, KL Girard, P Griffioen, KA Guidal, M Guillo, M Gyurjyan, V Hancock, D Hardie, J Heddle, D Heisenberg, J Hersman, FW Hicks, K Hicks, RS Holtrop, M Hyde-Wright, CE Ito, MM Jenkins, D Kelley, JH Khandaker, M Kim, KY Kim, W Klein, A Klein, FJ Klusman, M Kossov, M Kuang, Y Kuhn, SE Laget, JM Lawrence, D Longhi, A Loukachine, K Lucas, M Major, RW Manak, JJ Marchand, C Matthews, SK McAleer, S McNabb, JWC Mecking, BA Mestayer, MD Meyer, CA Mirazita, M Miskimen, R Muccifora, V Mueller, J Mutchler, GS Napolitano, J Niculescu, G Niczyporuk, B Niyazov, RA Ohandjanyan, MS Opper, A Patois, Y Peterson, GA Philips, S Pivnyuk, N Pocanic, D Pogorelko, O Polli, E Preedom, BM Price, JW Qin, LM Raue, BA Reolon, AR Riccardi, G Ricco, G Ripani, M Ritchie, BG Ronchetti, F Rossi, P Rowntree, D Rubin, PD Salgado, CW Sanzone, M Sapunenko, V Sargsyan, M Schumacher, RA Sharabian, YG Shaw, J Shuvalov, SM Skabelin, A Smith, ES Smith, T Sober, DI Spraker, M Stoler, P Taiuti, M Taylor, S Tedeschi, D Thompson, R Todor, L Tung, TY Vineyard, MF Vlassov, A Weller, H Weinstein, LB Welsh, R Weygand, DP Whisnant, S Witkowski, M Wolin, E Yegneswaran, A Yun, J Zhou, Z Zhao, J CA CLAS Collaboration TI Q(2) dependence of quadrupole strength in the gamma*p ->Delta(+)(1232)-> p pi(0) transition SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORM-FACTORS; ELECTROPRODUCTION; MODEL; DELTA(1232); NUCLEON; AMPLITUDES; RESONANCE; ISOBAR AB Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q(2) dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma* p --> Delta(+) --> ppi(0) transition. We report new experimental values for the ratios E1+/M1+ and S1+/M1+ over the range Q(2) = 0.4-1.8 GeV2, extracted from precision p(e,e'p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role. C1 Univ Virginia, Dept Phys, Charlottesville, VA 22903 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Duke Univ, Durham, NC 27706 USA. Univ Edinburgh, Dept Phys & Astrophys, Edinburgh EH9 3JZ, Midlothian, Scotland. Florida Int Univ, Miami, FL 33199 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. George Washington Univ, Dept Phys, Washington, DC 20052 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Ist Nazl Fis Nucl, Sez Genova, I-16146 Genoa, Italy. Ist Nazl Fis Nucl, Dipartimento Fis, I-16146 Genoa, Italy. Inst Theoret & Expt Phys, Moscow 117259, Russia. Inst Phys Nucl, IN2P3, F-91406 Orsay, France. James Madison Univ, Dept Phys, Harrisonburg, VA 22807 USA. Kyungpook Natl Univ, Dept Phys, Taegu 702701, South Korea. MIT Bates Linear Accelerator, Middleton, MA 01949 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Ohio Univ, Dept Phys, Athens, OH 45701 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12181 USA. Rice Univ, Bonner Lab, Houston, TX 77251 USA. CEA Saclay, DAPNIA, SPhN, F-91191 Gif Sur Yvette, France. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Connecticut, Dept Pharm, Storrs, CT 06269 USA. Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Richmond, Dept Phys, Richmond, VA 23173 USA. Univ S Carolina, Dept Phys, Columbia, SC 29208 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. RP Joo, K (reprint author), Univ Virginia, Dept Phys, Charlottesville, VA 22903 USA. RI Deppman, Airton/F-6332-2010; Bektasoglu, Mehmet/A-2074-2012; riccardi, gabriele/A-9269-2012; Brooks, William/C-8636-2013; Schumacher, Reinhard/K-6455-2013; Auger, Thierry/L-1073-2013; Meyer, Curtis/L-3488-2014; Deppman, Airton/J-5787-2014 OI Deppman, Airton/0000-0001-9179-6363; Brooks, William/0000-0001-6161-3570; Schumacher, Reinhard/0000-0002-3860-1827; Meyer, Curtis/0000-0001-7599-3973; Deppman, Airton/0000-0001-9179-6363 NR 22 TC 179 Z9 181 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 MAR 25 PY 2002 VL 88 IS 12 AR 122001 DI 10.1103/PhysRevLett.88.122001 PG 5 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000016 PM 11909446 ER PT J AU Lee, SH Tranquada, JM Yamada, K Buttrey, DJ Li, Q Cheong, SW AF Lee, SH Tranquada, JM Yamada, K Buttrey, DJ Li, Q Cheong, SW TI Freezing of a stripe liquid SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN FLUCTUATIONS; MAGNETIC ORDER; CUPRATE SUPERCONDUCTORS; INSULATOR TRANSITION; CHARGE STRIPES; DYNAMICS; TEMPERATURE; LA2-XSRXNIO4+DELTA; ANTIFERROMAGNETS; LA5/3SR1/3NIO4 AB The existence of a stripe-liquid phase in a layered nickelate, La1.725Sr0.275NiO4, is demonstrated through neutron scattering measurements. We show that incommensurate magnetic fluctuations evolve continuously through the charge-ordering temperature, although an abrupt decrease in the effective damping energy is observed on cooling through the transition. The energy and momentum dependence of the magnetic scattering are parametrized with a damped-harmonic-oscillator model describing overdamped spin waves in the antiferromagnetic domains defined instantaneously by charge stripes. C1 Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Kyoto Univ, Inst Chem Res, Kyoto 6110011, Japan. Univ Delaware, Dept Chem Engn, Newark, DE 19716 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RI Yamada, Kazuyoshi/C-2728-2009; Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 35 TC 37 Z9 37 U1 0 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 MAR 25 PY 2002 VL 88 IS 12 AR 126401 DI 10.1103/PhysRevLett.88.126401 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000053 ER PT J AU McLaughlin, KW Yenen, O Jaecks, DH Gay, TJ Sant'Anna, MM Calabrese, D Thaden-Jordan, B AF McLaughlin, KW Yenen, O Jaecks, DH Gay, TJ Sant'Anna, MM Calabrese, D Thaden-Jordan, B TI Effect of relativistic many-electron interactions on photoelectron partial wave probabilities SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOIONIZATION PROCESS; SYNCHROTRON RADIATION; PHASE DIFFERENCES; IONIC STATES; XENON ATOMS; FLUORESCENCE; POLARIZATION; SPECTROSCOPY; TRANSITIONS; SATELLITES AB We obtain relative cross sections for the production of photoelectrons with specific angular momentum quantum numbers. These cross sections are obtained from the polarization analysis of the visible fluorescence of ions produced when circularly polarized vacuum ultraviolet radiation photoionizes ground state Ar. The ratio of cross sections for the production of photoelectrons with the same orbital angular momentum but different total angular momenta shows strong deviations from the statistical ratio, demonstrating the importance of relativistic interactions in many-electron photoionization dynamics. C1 Loras Coll, Dept Phys & Engn, Dubuque, IA 52004 USA. Univ Nebraska, Behlen Lab Phys, Lincoln, NE 68588 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Sierra Community Coll, Rocklin, CA 95677 USA. RP McLaughlin, KW (reprint author), Loras Coll, Dept Phys & Engn, Dubuque, IA 52004 USA. RI Sant'Anna, Marcelo/B-9355-2013 OI Sant'Anna, Marcelo/0000-0001-5342-5799 NR 29 TC 14 Z9 15 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 MAR 25 PY 2002 VL 88 IS 12 AR 123003 DI 10.1103/PhysRevLett.88.123003 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000025 PM 11909455 ER PT J AU McLean, HS Woodruff, S Hooper, EB Bulmer, RH Hill, DN Holcomb, C Moller, J Stallard, BW Wood, RD Wang, Z AF McLean, HS Woodruff, S Hooper, EB Bulmer, RH Hill, DN Holcomb, C Moller, J Stallard, BW Wood, RD Wang, Z TI Suppression of MHD fluctuations leading to improved confinement in a gun-driven spheromak SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY CONFINEMENT; CTX SPHEROMAK; TRANSPORT; EQUILIBRIA; PLASMA AB Magnetic fluctuations have been reduced to similar to1% during discharges on the Sustained Spheromak Physics Experiment by shaping the spatial distribution of the bias magnetic flux in the device. In the resulting quiescent regime, the safety factor pro le is nearly at in the plasma and the dominant ideal and resistive MHD modes are greatly reduced. During this period, the temperature pro le is peaked at the magnetic axis and maps onto magnetic flux contours. Energy confinement time is improved over previous reports in a driven spheromak. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McLean, HS (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 21 TC 48 Z9 48 U1 2 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 MAR 25 PY 2002 VL 88 IS 12 AR 125004 DI 10.1103/PhysRevLett.88.125004 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000039 PM 11909469 ER PT J AU Schmidt, H Zasadzinski, JF Gray, KE Hinks, DG AF Schmidt, H Zasadzinski, JF Gray, KE Hinks, DG TI Evidence for two-band superconductivity from break-junction tunneling on MgB2 SO PHYSICAL REVIEW LETTERS LA English DT Article AB Superconductor-insulator-superconductor tunnel junctions have been fabricated on MgB2 that display Josephson and quasiparticle currents. These junctions exhibit a gap magnitude, Delta similar to 2.5 meV, that is considerably smaller than the BCS value, but which clearly and reproducibly closes near the bulk T-c. In conjunction with fits of the conductance spectra, these results are interpreted as direct evidence of two-band superconductivity. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. IIT, Dept Phys, Chicago, IL 60616 USA. RP Schmidt, H (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 130 Z9 134 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 MAR 25 PY 2002 VL 88 IS 12 AR 127002 DI 10.1103/PhysRevLett.88.127002 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000064 PM 11909494 ER PT J AU Steck, DA Oskay, WH Raizen, MG AF Steck, DA Oskay, WH Raizen, MG TI Fluctuations and decoherence in chaos-assisted tunneling SO PHYSICAL REVIEW LETTERS LA English DT Article ID DRIVEN BISTABLE SYSTEM; ENGINEERED RESERVOIRS; QUANTUM; SCATTERING; COHERENT; STATES; ATOMS AB We study quantum dynamical tunneling between two symmetry-related islands of stability in the phase space of a classically chaotic system. The setting for these experiments is the motion of carefully prepared samples of cesium atoms in an amplitude-modulated standing wave of light. We examine the dependence of the tunneling dynamics on the system parameters and indicate how the observed features provide evidence for chaos-assisted (three-state) tunneling. We also observe the influence of a noisy perturbation of the standing-wave intensity, which destroys the tunneling oscillations, and we show that the tunneling is more sensitive to the noise for a smaller value of the effective Planck constant. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Univ Texas, Ctr Nonlinear Dynam, Austin, TX 78712 USA. RP Steck, DA (reprint author), Los Alamos Natl Lab, Div Theoret T8, MS B285, Los Alamos, NM 87544 USA. NR 25 TC 53 Z9 53 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 MAR 25 PY 2002 VL 88 IS 12 AR 120406 DI 10.1103/PhysRevLett.88.120406 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QP UT WOS:000174542000006 PM 11909436 ER PT J AU Ryttersgaard, C Griffith, SC Sawaya, MR MacLaren, DC Clarke, S Yeates, TO AF Ryttersgaard, C Griffith, SC Sawaya, MR MacLaren, DC Clarke, S Yeates, TO TI Crystal structure of human L-isoaspartyl methyltransferase SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROTEIN CARBOXYL METHYLTRANSFERASE; O-METHYLTRANSFERASE; DAMAGED PROTEINS; BOVINE BRAIN; REPAIR; PURIFICATION; EXPRESSION; PROGRAM; RDEL AB The enzyme L-isoaspartyl methyltransferase initiates the repair of damaged proteins by recognizing and methylating isomerized and racemized aspartyl residues in aging proteins. The crystal structure of the human enzyme containing a bound S-adenosyl-L-homocysteine cofactor is reported here at a resolution of 2.1 Angstrom. A comparison of the human enzyme to homologs from two other species reveals several significant differences among otherwise similar structures. In all three structures, we find that three conserved charged residues are buried in the protein interior near the active site. Electrostatics calculations suggest that these buried charges might make significant contributions to the energetics of binding the charged S-adenosyl-L-Methionine cofactor and to catalysis. We suggest a possible structural explanation for the observed differences in reactivity toward the structurally similar L-isoaspartyl and D-aspartyl residues in the human, archael, and eubacterial enzymes. Finally, the human structure reveals that the known genetic polymorphism at residue 119 (Val/Ile) maps to an exposed region away from the active site. C1 Univ Calif Los Angeles, Dept Chem & Biochem, DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Mol Biol, DOE, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. RP Yeates, TO (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, DOE, Lab Struct Biol & Mol Med, Box 951569, Los Angeles, CA 90095 USA. OI Yeates, Todd/0000-0001-5709-9839 FU NIA NIH HHS [AG18000]; NIGMS NIH HHS [GM26020] NR 31 TC 16 Z9 18 U1 0 U2 1 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 MAR 22 PY 2002 VL 277 IS 12 BP 10642 EP 10646 DI 10.1074/jbc.M200229200 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 533UR UT WOS:000174549200136 PM 11792715 ER PT J AU Wade, EA Cline, JI Lorenz, KT Hayden, C Chandler, DW AF Wade, EA Cline, JI Lorenz, KT Hayden, C Chandler, DW TI Direct measurement of the binding energy of the NO dimer SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NITRIC-OXIDE DIMER; PHOTOELECTRON; BAND AB The binding energy of the NO dimer has been measured directly using velocity-mapped ion imaging. NO dimer is photodissociated to produce NO(X) and NO(A), and the NO(A) is then nonresonantly ionized to NO+. The threshold for production of NO+ ions is measured at 44 893+/-2 cm(-1), which corresponds to a binding energy of 696+/-4 cm(-1). (C) 2002 American Institute of Physics. C1 Mills Coll, Dept Chem & Phys, Oakland, CA 94613 USA. Univ Nevada, Dept Chem, Reno, NV 89557 USA. Univ Nevada, Chem Phys Program, Reno, NV 89557 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Wade, EA (reprint author), Mills Coll, Dept Chem & Phys, Oakland, CA 94613 USA. NR 15 TC 38 Z9 38 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 MAR 22 PY 2002 VL 116 IS 12 BP 4755 EP 4757 DI 10.1063/1.1459702 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 530NH UT WOS:000174363700001 ER PT J AU Montalenti, F Voter, AF AF Montalenti, F Voter, AF TI Exploiting past visits or minimum-barrier knowledge to gain further boost in the temperature-accelerated dynamics method SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; INFREQUENT EVENTS; CLUSTER DIFFUSION; SADDLE-POINTS; SURFACES; MECHANISMS; SIMULATION; ADATOM; CHAINS AB We present a more efficient version of the temperature accelerated dynamics (TAD) method. Without introducing any new approximation, we show how it is possible to make the TAD method faster when a system visits a state more than one time. We demonstrate the method for the diffusion of silver tetramers on Ag(100), obtaining an additional boost (relative to standard TAD) of similar to4 at T=400 K and similar to11 at T=200 K. Larger boosts can be obtained at lower temperatures and/or for different systems. This new formalism also offers a way to gain this additional boost in the dynamics on the first visit to a state, provided information is available about the lowest barrier for escape from the state. (C) 2002 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Montalenti, F (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Montalenti, Francesco/A-7738-2010 OI Montalenti, Francesco/0000-0001-7854-8269 NR 30 TC 39 Z9 39 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 2002 VL 116 IS 12 BP 4819 EP 4828 DI 10.1063/1.1449865 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 530NH UT WOS:000174363700012 ER PT J AU Babikov, D Gislason, EA Sizun, M Aguillon, F Sidis, V Barat, M Brenot, JC Fayeton, JA Picard, YJ AF Babikov, D Gislason, EA Sizun, M Aguillon, F Sidis, V Barat, M Brenot, JC Fayeton, JA Picard, YJ TI Dalitz plot analysis of three-body fragmentation of Na-3(+) excited by He impact SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR 3-BODY DECAY; MULTICHANNEL FRAGMENTATION; CLUSTER-ION; COLLISION; DISSOCIATION; SPECTROMETER; MECHANISMS; DYNAMICS AB Three-body fragmentation of Na-3(+) ions to Na++Na(3s)+Na(3s) following excitation by He is studied experimentally and theoretically. The three reduced kinetic energies of the products in the center-of-mass are determined for each fragmentation event, and the results are displayed in a Dalitz plot. The fragmentation involves three adiabatic (1)A' electronic states of Na-3(+) that become degenerate at the detector. It is possible to determine the final electronic state for each event, and here we show that each of the three product states appears in a particular sector of the Dalitz plot. Theoretical and experimental Dalitz plots for the three-body fragmentation of Na-3(+) are presented, and the results are related to various mechanisms for three-body fragmentation of this system. (C) 2002 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Theoret Chem & Mol Phys Grp, Los Alamos, NM 87545 USA. Univ Illinois, Dept Chem, Chicago, IL 60607 USA. Univ Paris 11, Collis Atom & Mol Lab, CNRS, Unite Mixte Rech C8625, F-91405 Orsay, France. RP Babikov, D (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Chem & Mol Phys Grp, POB 1663, Los Alamos, NM 87545 USA. NR 26 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 2002 VL 116 IS 12 BP 4871 EP 4876 DI 10.1063/1.1455623 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 530NH UT WOS:000174363700019 ER PT J AU Kathmann, SM Schenter, GK Garrett, BC AF Kathmann, SM Schenter, GK Garrett, BC TI Understanding the sensitivity of nucleation kinetics: A case study on water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VAPOR-PHASE NUCLEATION; TRANSITION-STATE THEORY; FREE-ENERGY CHANGES; HOMOGENEOUS NUCLEATION; MOLECULAR THEORY; PARTICLE FORMATION; SULFURIC-ACID; THERMODYNAMIC PROPERTIES; CLUSTER DISTRIBUTION; LIQUID NUCLEATION AB Small atomic or molecular clusters provide the bridge between vapor and liquid phases. Nucleation is a rare event process by which clusters of a new phase are produced. This process is inherently dynamic and as such the new phase cannot exist until an activation barrier is surmounted. Dynamical nucleation theory (DNT) utilizes variational transition state theory to provide a framework in which cluster evaporation and condensation rate constants can be determined directly. To date, the fundamental nature regarding the intrinsic instability of the kinetics of the nucleation process has eluded theoretical efforts. In this paper we present a sensitivity analysis of the homogeneous nucleation rate on kinetic parameters used in DNT. Moreover, several classical interaction potentials for water exist, most of which have been parametrized to reproduce some bulk properties of water at ambient conditions. Thus, an analysis was undertaken to explore what effects different water potentials have on the dynamical quantities relevant to nucleation. The implication of these results on future work will be discussed. (C) 2002 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Kathmann, SM (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 94 TC 50 Z9 50 U1 0 U2 18 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 22 PY 2002 VL 116 IS 12 BP 5046 EP 5057 DI 10.1063/1.1451059 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 530NH UT WOS:000174363700037 ER PT J AU Burnham, CJ Xantheas, SS AF Burnham, CJ Xantheas, SS TI Development of transferable interaction models for water. IV. A flexible, all-atom polarizable potential (TTM2-F) based on geometry dependent charges derived from an ab initio monomer dipole moment surface SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; LIQUID WATER; ICE-IH; INTENSITIES; CLUSTERS AB In this work we examine the consequences of incorporating the ab initio derived monomer potential-energy surface and nonlinear dipole surface of Partridge and Schwenke [J. Chem. Phys. 106, 4618 (1997)] into the previously developed TTM2-R model of Burnham [J. Chem. Phys. 116, 1500 (2002)] in order to develop a new, all-atom polarizable, flexible model for water (TTM2-F). We found that the use of the nonlinear dipole surface is essential in modeling the change in the internal geometry of interacting water molecules and, in particular, the increase in the internal H-O-H bend angle with cluster size. This is the first demonstration of a flexible model which shows an increase in the bending angle in clusters. An explanation for this behavior is presented using the concept of geometric polarizabilities. The model furthermore reproduces the n=2-6 cluster binding energies to within an RMS deviation of 0.05 kcal/mol per hydrogen bond with respect to the MP2 complete basis set estimates. Preliminary results for the liquid with the new model are also presented. (C) 2002 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Xantheas, SS (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-91, Richland, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015; OI Xantheas, Sotiris/0000-0002-6303-1037 NR 36 TC 197 Z9 199 U1 1 U2 24 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 MAR 22 PY 2002 VL 116 IS 12 BP 5115 EP 5124 DI 10.1063/1.1447904 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 530NH UT WOS:000174363700045 ER PT J AU Krapivsky, PL Ben-Naim, E AF Krapivsky, PL Ben-Naim, E TI Nontrivial velocity distributions in inelastic gases SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID HYDRODYNAMIC EQUATIONS; COLLAPSE; FLOWS; ORDER AB We study spatially homogeneous inelastic gases using the Boltzmann equation. We consider uniform collision rates and obtain analytical results valid for arbitrary spatial dimension d and arbitrary dissipation coefficient e. In the unforced case, we find that the velocity distribution decays algebraically, P (v, t) similar to v(-sigma), for sufficiently large velocities. The exponent a (d, epsilon) exhibits nontrivial dependence on the spatial dimension and the dissipation coefficient. C1 Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Krapivsky, PL (reprint author), Boston Univ, Ctr Polymer Studies, Boston, MA 02215 USA. RI Ben-Naim, Eli/C-7542-2009; Krapivsky, Pavel/A-4612-2014 OI Ben-Naim, Eli/0000-0002-2444-7304; NR 24 TC 36 Z9 36 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD MAR 22 PY 2002 VL 35 IS 11 BP L147 EP L152 AR PII S0305-4470(02)33044-0 DI 10.1088/0305-4470/35/11/103 PG 6 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 537RA UT WOS:000174771900003 ER PT J AU Li, J Bursten, BE Liang, BY Andrews, L AF Li, J Bursten, BE Liang, BY Andrews, L TI Noble gas-actinide compounds: Complexation of the CUO molecule by Ar, Kr, and Xe atoms in noble gas matrices SO SCIENCE LA English DT Article ID METAL-CARBONYL-COMPLEXES; NG = AR; MICROWAVE-SPECTRA; INFRARED-SPECTRA; SOLID NEON; ARGON; CONSTANTS; XENON; MO AB The CUO molecule, formed from the reaction of laser-ablated U atoms with CO in a noble gas, exhibits very different stretching frequencies in a solid argon matrix [804.3 and 852.5 wave numbers (cm(-1))] than in a solid neon matrix (872.2 and 1047.3 cm(-1)). Related experiments in a matrix consisting of 1% argon in neon suggest that the argon atoms are interacting directly with the CUO molecule. Relativistic density functional calculations predict that CUO can bind directly to one argon atom (U-Ar = 3.16 angstroms; binding energy = 3.2 kilocalories per mole), accompanied by a change in the ground state from a singlet to a triplet. Our experimental and theoretical results also suggest that multiple argon atoms can bind to a single CUO molecule. C1 Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Virginia, Dept Chem, Charlottesville, VA 22904 USA. RP Ohio State Univ, Dept Chem, 120 W 18th Ave, Columbus, OH 43210 USA. EM bursten.1@osu.edu; lsa@unix.mail.virginia.edu RI Li, Jun/E-5334-2011 OI Li, Jun/0000-0002-8456-3980 NR 26 TC 179 Z9 181 U1 5 U2 27 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD MAR 22 PY 2002 VL 295 IS 5563 BP 2242 EP 2245 DI 10.1126/science.1069342 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 534AD UT WOS:000174561700037 PM 11872801 ER PT J AU McDermott, R Trabesinger, AH Muck, M Hahn, EL Pines, A Clarke, J AF McDermott, R Trabesinger, AH Muck, M Hahn, EL Pines, A Clarke, J TI Liquid-state NMR and scalar couplings in microtesla magnetic fields SO SCIENCE LA English DT Article ID NOBLE-GAS; RESONANCE AB We obtained nuclear magnetic resonance (NMR) spectra of liquids in fields of a few microtesla, using prepolarization in fields of a few millitesta and detection with a dc superconducting quantum interference device (SQUID). Because the sensitivity of the SQUID is frequency independent, we enhanced both signal-to-noise ratio and spectral resolution by detecting the NMR signal in extremely tow magnetic fields, where the NMR tines become very narrow even for grossly inhomogeneous measurement fields. In the absence of chemical shifts, proton-phosphorous scalar (J) couplings have been detected, indicating the presence of specific covalent bonds. This observation opens the possibility for "pure J spectroscopy" as a diagnostic tool, for the detection of molecules in low magnetic fields. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Giessen, Inst Appl Phys, D-35392 Giessen, Germany. RP McDermott, R (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Trabesinger, Andreas/J-2008-2016 OI Trabesinger, Andreas/0000-0003-3078-8399 NR 20 TC 192 Z9 194 U1 0 U2 29 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 MAR 22 PY 2002 VL 295 IS 5563 BP 2247 EP 2249 DI 10.1126/science.1069280 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 534AD UT WOS:000174561700039 PM 11910105 ER PT J AU Robertson, S Wagner, AF Wardlaw, DM AF Robertson, S Wagner, AF Wardlaw, DM TI Flexible transition state theory for a variable reaction coordinate: Analytical expressions and an application SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID METHYL RADICAL RECOMBINATION; KINETICS; DISSOCIATIONS; LOOSENESS; NO2 AB Completely general canonical and microcanonical (energy-resolved) flexible transition state theory (FTST) rate constant expressions for an arbitrary choice of reaction coordinate have recently been derived [Robertson et al. J. Chem. Phys. 2000, 113, 2648.] by the present authors. The rate expressions apply to any definition of the separation distance between fragments in a barrierless recombination (or dissociation) that is held fixed during hindered rotations at the transition state, and to any combination of fragment structure (atom, linear top, nonlinear top). The minimization of the rate constant with respect to this definition can be regarded as optimizing the reaction coordinate within a canonical or microcanonical framework. The expressions are analytic, with the exception of a configuration integral whose evaluation generally requires numerical integration over an integrand which depends on internal angles (from one to five depending on the fragment structures). The primary component of the integrand is the determinant of the inverse G-matrix associated with the external rotations and the relative internal rotation of the fragments. In this paper, we derive closed-forth, analytic expressions for the inverse G-matrix determinant for all combinations of fragment top types for an arbitrary reaction coordinate definition entirely in terms of kinetic energy matrix elements for a centers-of-mass reaction coordinate. For a model potential for CFH2 + H, the effect of optimizing the reaction coordinate definition is displayed, and the optimized coordinate is compared to the traditional center-of-mass definition at the canonical level. The associated rate constant is about a factor of 20% to 45% lower than that obtained using a centers-of-mass reaction coordinate. C1 Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada. Accelrys, Cambridge CB5 8RE, England. Argonne Natl Lab, Argonne, IL 60439 USA. RP Wardlaw, DM (reprint author), Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada. NR 22 TC 17 Z9 17 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 MAR 21 PY 2002 VL 106 IS 11 BP 2598 EP 2613 DI 10.1021/jp0116858 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 533VP UT WOS:000174551200027 ER PT J AU Allendorf, MD Melius, CF Cosic, B Fontijn, A AF Allendorf, MD Melius, CF Cosic, B Fontijn, A TI BAC-G2 predictions of thermochemistry for gas-phase aluminum compounds SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MOLECULAR-ORBITAL CALCULATIONS; H SYSTEM; THERMODYNAMIC PROPERTIES; GAUSSIAN-2; CHEMISTRY; VAPOR; COMPUTATION; HYDRIDES; EPITAXY; HALIDES AB A self-consistent set of thermochemical data for 55 molecules in the Al-H-C-O-F-Cl system are obtained from ab initio quantum-chemistry calculations using the BAC-G2 method. Calculations were performed for both stable and radical species. Good agreement is found between the calculations and experimental heats of formation in most cases where data are available for comparison. Electronic energies, molecular geometries, moments of inertia, and vibrational frequencies are provided in the Supporting Information, as are polynomial fits of the thermodynamic data (heat of formation, entropy, and heat capacity) over the 300-4000 K temperature range. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Rensselaer Polytech Inst, Dept Chem Engn, Troy, NY 12180 USA. RP Allendorf, MD (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 42 TC 26 Z9 26 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAR 21 PY 2002 VL 106 IS 11 BP 2629 EP 2640 DI 10.1021/jp013128r PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 533VP UT WOS:000174551200031 ER PT J AU Ruscic, B Wagner, AF Harding, LB Asher, RL Feller, D Dixon, DA Peterson, KA Song, Y Qian, XM Ng, CY Liu, JB Chen, WW AF Ruscic, B Wagner, AF Harding, LB Asher, RL Feller, D Dixon, DA Peterson, KA Song, Y Qian, XM Ng, CY Liu, JB Chen, WW TI On the enthalpy of formation of hydroxyl radical and gas-phase bond dissociation energies of water and hydroxyl SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID MOLECULAR ELECTRONIC-STRUCTURE; PHOTOELECTRON-PHOTOION COINCIDENCE; HIGHER-ORDER CORRELATION; BASIS-SET CONVERGENCE; FULL CCSDT MODEL; HIGH-RESOLUTION; SYNCHROTRON-RADIATION; DIATOMIC-MOLECULES; OD RADICALS; THRESHOLD PHOTODETACHMENT AB In a recent letter (J. Phys. Chem. A, 2001, 105, 1), we argued that, although all major thermochemical tables recommend a value of DeltaHdegrees(f0)(OH) based on a spectroscopic approach, the correct value is 0.5 kcal/mol lower as determined from an ion cycle. In this paper, we expand upon and augment both the experimental and theoretical arguments presented in the letter. In particular, three separate experiments (mass-selected photoionization measurements, pulsed-field-ionization photoelectron spectroscopy measurements, and photoelectron-photoion coincidence measurements) utilizing the positive ion cycle to derive the O-H bond energy are shown to converge to a consensus value of the appearance energy AE(0)(OH+/H2O) = 146117 +/- 24 cm(-1) (18.116(2) +/- 0.003(0) eV). With the most accurate currently available zero kinetic energy photoionization value for the ionization energy IE(OH) = 104989 +/- 2 cm(-1), corroborated by a number of photoelectron measurements, this leads to D-0(H-OH) = 41128 +/- 24 cm(-1) = 117.59 +/- 0.07 kcal/mol. This corresponds to DeltaH(f0)(OH) = 8.85 +/- 0.07 kcal/mol and implies D-0(OH) = 35593 +/- 24 cm(-1) = 101.76 +/- 0.07 kcal/mol. These results are completely supported by the most sophisticated theoretical calculations ever performed on the HxO system, CCSD(T)/aug-cc-pVnZ, n = Q, 5, 6, and 7, extrapolated to the CBS limit and including corrections for core-valence effects, scalar relativistic effects, incomplete correlation recovery, and diagonal Born-Oppenheimer corrections. These calculations have an estimated theoretical error of less than or equal to0.2 kcal/mol based on basis set convergence properties. They reproduce the experimental results for dissociation energies, atomization energies, and ionization energies for the HxO system to within 0.0-0.2 kcal/mol. In contrast, the previously accepted values of the two successive bond dissociation energies of water differ from the current values by 0.5 kcal/mol. These values were derived from the spectroscopic determinations of D-0(OH) using a very short Birge-Sponer extrapolation on OH/OD A(1)Sigma(+). However, on the basis of a calculation of the A state potential energy curve (with a multireference single and double excitation wave function and an aug-cc-pV5Z basis set) and an exhaustive reanalyzis of the original measured data on both the A and B states of OH, the Birge-Sponer extrapolation can be demonstrated to significantly underestimate the bond dissociation energy, although only the last vibrational level was not observed experimentally. The recommended values of this paper affect a large number of other thermochemical quantities which directly or indirectly rely on or refer to D-0(H-OH), D-0(OH), or DeltaHdegrees(f)(OH). This is illustrated by an analysis of several reaction enthalpies, deprotonation enthalpies, and proton affinities. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Washington State Univ, Richland, WA 99352 USA. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ruscic, B (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 138 TC 365 Z9 366 U1 4 U2 75 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 MAR 21 PY 2002 VL 106 IS 11 BP 2727 EP 2747 DI 10.1021/jp013909s PG 21 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 533VP UT WOS:000174551200041 ER PT J AU Hornyak, GL Grigorian, L Dillon, AC Parilla, PA Jones, KM Heben, MJ AF Hornyak, GL Grigorian, L Dillon, AC Parilla, PA Jones, KM Heben, MJ TI A temperature window for chemical vapor decomposition growth of single-wall carbon nanotubes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID FILAMENTOUS CARBON; VIBRATIONAL-MODES; CATALYTIC GROWTH; METAL PARTICLES; DEPOSITION; PURIFICATION; ENERGETICS; DIAMETER; IRON; CO AB Carbon single-wall nanotubes (SWNTs) grow efficiently from methane on alumina-supported metal catalysts within a fairly narrow temperature window from 680 to 850 degreesC. An abrupt onset in SWNT growth occurs at the low temperature side of the window, and SWNTs produced at these lower temperatures appear to be relatively free of amorphous or nanocrystalline carbon impurities. Raman spectroscopy shows that SWNT yield drops dramatically at the high-temperature side of the window where most previous chemical vapor decomposition (CVD) studies have been performed. The turn-on at the low-temperature side appears to be controlled by the thermodynamics of SWNT growth, while the turn-off at high temperatures is associated with competitive deposition of amorphous and nanocrystalline carbon. The existence of a temperature window for SWNT growth has not been reported elsewhere, and has important general consequences for CVD growth of SWNTs. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Honda R&D Amer Inc, Fundamental Res Lab, Columbus, OH 43212 USA. RP Heben, MJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 30 TC 61 Z9 64 U1 3 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAR 21 PY 2002 VL 106 IS 11 BP 2821 EP 2825 DI 10.1021/jp015554i PG 5 WC Chemistry, Physical SC Chemistry GA 533VT UT WOS:000174551500003 ER PT J AU Tewell, CR Malizia, F Ager, JW Somorjai, GA AF Tewell, CR Malizia, F Ager, JW Somorjai, GA TI An ultraviolet-Raman spectroscopic investigation of magnesium chloride-ethanol solids with a 0.47 to 6 molar ratio of C2H5OH to MgCl2 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ZIEGLER-NATTA CATALYST; THIN-FILMS; TITANIUM CHLORIDE; SURFACE SCIENCE; POLYMERIZATION CATALYSTS; GAS-PHASE; THEORETICAL INVESTIGATIONS; HETEROGENEOUS CATALYSIS; TICL4 CATALYST; GOLD AB MgCl2 and C2H5OH form complexes over a wide range of C2H5OH to MgCl2 molar ratios. MgCl2(C2H5OH)(x) adducts prepared over a wide composition range, x = 0.47 to 6, have been studied by ultraviolet Raman spectroscopy. These studies indicate the breaking of the Mg-Cl bonds at x greater than or equal to 2. The Raman shift of the O-H stretch shifts in the 3230-3480 cm(-1) range as the C2H5OH to MgCl2 molar ratio is altered and thus, it can be used to monitor the MgCl2(C2H5OH)(x) composition. It is suggested that the presence of the peak at 683 cm(-1) may be attributed to the totally symmetric breathing mode of Mg-O octahedra, reinforcing the structure analysis of MgCl2(C2H5OH)(6). C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Basell G Natta Res Ctr, I-44100 Ferrara, Italy. Lawrence Berkeley Natl Lab, Mat Sci Div, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Ager, Joel/0000-0001-9334-9751 NR 54 TC 25 Z9 26 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAR 21 PY 2002 VL 106 IS 11 BP 2946 EP 2949 DI 10.1021/jp012840l PG 4 WC Chemistry, Physical SC Chemistry GA 533VT UT WOS:000174551500021 ER PT J AU Asfaw, B Gilbert, WH Beyene, Y Hart, WK Renne, PR WoldeGabriel, G Vrba, ES White, TD AF Asfaw, B Gilbert, WH Beyene, Y Hart, WK Renne, PR WoldeGabriel, G Vrba, ES White, TD TI Remains of Homo erectus from bouri, Middle Awash, Ethiopia SO NATURE LA English DT Article ID PLEISTOCENE; CLADISTICS; SPECIATION; HOMINIDS; CRANIUM; RECORD AB The genesis, evolution and fate of Homo erectus have been explored palaeontologically since the taxon's recognition in the late nineteenth century. Current debate(1) is focused on whether early representatives from Kenya and Georgia should be classified as a separate ancestral species ('H. ergaster')(2-4), and whether H. erectus was an exclusively Asian species lineage that went extinct(5,6). Lack of resolution of these issues has obscured the place of H. erectus in human evolution. A hominid calvaria and postcranial remains recently recovered from the Dakanihylo Member of the Bouri Formation, Middle Awash, Ethiopia, bear directly on these issues. These similar to1.0-million-year (Myr)-old Pleistocene sediments contain abundant early Acheulean stone tools and a diverse vertebrate fauna that indicates a predominantly savannah environment. Here we report that the 'Daka' calvaria's metric and morphological attributes centre it firmly within H. erectus. Daka's resemblance to Asian counterparts indicates that the early African and Eurasian fossil hominids represent demes of a widespread palaeospecies. Daka's anatomical intermediacy between earlier and later African fossils provides evidence of evolutionary change. Its temporal and geographic position indicates that African H. erectus was the ancestor of Homo sapiens. C1 Rift Valley Res Serv, Addis Ababa, Ethiopia. Univ Calif Berkeley, VLSB, Museum Vertebrate Zool, Lab Human Evolutionary Studies, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. Minist Youth Sports & Culture, Dept Anthropol & Archaeol ARCCH, Addis Ababa, Ethiopia. Miami Univ, Dept Geol, Oxford, OH 45056 USA. Berkeley Geochronol Ctr, Berkeley, CA 94709 USA. Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Yale Univ, Dept Geol & Geophys, New Haven, CT 06511 USA. RP Asfaw, B (reprint author), Rift Valley Res Serv, POB 5717, Addis Ababa, Ethiopia. RI Davidson, Iain/A-9216-2011 NR 30 TC 147 Z9 156 U1 4 U2 38 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 21 PY 2002 VL 416 IS 6878 BP 317 EP 320 DI 10.1038/416317a PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 532NP UT WOS:000174482200041 PM 11907576 ER PT J AU Alexahin, Y AF Alexahin, Y TI A study of the coherent beam-beam effect in the framework of the Vlasov perturbation theory SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE hadron colliders; beam=beam effect; coherent instabilities AB A number of factors which can influence coherent beam-beam oscillations are studied on the basis of the Vlasov equation: difference in the intensities and single-particle tunes in the beams; difference in the phase advances between interaction points; long-range interactions; synchro-betatron coupling due to betatron phase advance variation in the vicinity of IP, chromatic tune modulation and crossing angle. The synchro-betatron coupling appears to have a principal stabilizing effect: at synchrotron tune values in the neighborhood of half the beam-beam parameter it provides Landau damping of the discrete spectral lines by overlapping sidebands; the damping rate being higher with negative chromaticity. At smaller synchrotron tune values a specific mode of the head-tail damping sets in which is not sensitive to chromaticity. Application to LHC shows that with the design values of parameters the coherent beam-beam oscillations should be Landau damped, probably with the help of negative chromaticity of a moderate absolute value. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Joint Inst Nucl Res, Dubna 141980, Russia. RP Alexahin, Y (reprint author), Fermilab Natl Accelerator Lab, POB 500,MS 221, Batavia, IL 60510 USA. NR 21 TC 10 Z9 10 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 MAR 21 PY 2002 VL 480 IS 2-3 BP 253 EP 288 AR PII S0168-9002(01)01219-0 DI 10.1016/S0168-9002(01)01219-0 PG 36 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200001 ER PT J AU Akhmadaliev, S Amaral, P Ambrosini, G Amorim, A Anderson, K Andrieux, ML Aubert, B Auge, E Badaud, F Baisin, L Barreiro, F Battistoni, G Bazan, A Bazizi, K Belymam, A Benchckroun, D Berglund, S Berset, JC Blanchot, G Bogush, A Bohm, C Boldea, V Bonivento, W Bosman, M Bouhemaid, N Breton, D Brette, P Bromberg, C Budagov, J Burdin, S Caloba, L Camarena, F Camin, DV Canton, B Caprini, M Carvalho, J Casado, P Castillo, MV Cavalli, D Cavalli-Sforza, M Cavasinni, V Chadelas, R Chalifour, M Chekhtman, L Chevalley, JL Chirikov-Zorin, I Chlachidze, G Citterio, M Cleland, WE Clement, C Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Crouau, M Daudon, F David, J David, M Davidek, T Dawson, J De, K de la Taille, C Del Peso, J Del Prete, T de Saintignon, P Di Girolamo, B Dinkespiller, B Dita, S Dodd, J Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Dzahini, D Efthymiopoulos, I Errede, D Errede, S Evans, H Eynard, G Fassi, F Fassnacht, P Ferrari, A Ferrari, A Ferrer, A Flaminio, V Fournier, D Fumagalli, G Gallas, E Gaspar, MG Giakoumopoulou, V Gianotti, F Gildemeister, O Giokaris, N Glagolev, V Glebov, V Gomes, A Gonzalez, V De la Hoz, SG Grabsky, V Grauges, E Grenier, P Hakopian, H Haney, M Hebrard, C Henriques, A Hervas, L Higon, E Holmgren, S Hostachy, JY Hoummada, A Huston, J Imbault, D Ivanyushenkov, Y Jezequel, S Johansson, E Jon-And, K Jones, R Juste, A Kakurin, S Karyukhin, A Khokhlov, Y Khubua, J Klyukhin, V Kolachev, G Kopikov, S Kostrikov, M Kozlov, V Krivkova, P Kukhtin, V Kulagin, M Kulchitsky, Y Kuzmin, M Labarga, L Laborie, G Lacour, D Laforge, B Lami, S Lapin, V Le Dortz, O Lefebvre, M Le Flour, T Leitner, R Leltchouk, M Li, J Liablin, M Linossier, O Lissauer, D Lobkowicz, F Lokajicek, M Lomakin, Y Amengual, JML Lund-Jensen, B Maio, A Makowiecki, D Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marrocchesi, P Marroquim, F Martin, P Maslennikov, A Massol, N Mataix, L Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Moynot, M Muanza, GS Nayman, P Nemecek, S Nessi, M Nicoleau, S Niculescu, M Noppe, JM Onofre, A Pallin, D Pantea, D Paoletti, R Park, IC Parrour, G Parsons, J Pereira, A Perini, L Perlas, JA Perrodo, P Pilcher, J Pinhao, J Plothow-Besch, H Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Puzo, P Radeka, V Rahm, D Reinmuth, G Renzoni, G Resica, S Resconi, S Richards, R Richer, JP Roda, C Rodier, S Roldan, J Romance, JB Romance, V Romero, P Rossel, F Russakovich, N Sala, P Sanchis, E Sanders, H Santoni, C Santos, J Sauvage, D Sauvage, G Sawyer, L Says, LP Schaffer, AC Schwemling, P Schwindling, J Seguin-Moreau, N Seidl, W Seixas, JM Sellden, B Seman, M Semenov, A Serin, L Shaldaev, E Shochet, M Sidorov, V Silva, J Simaitis, V Simion, S Sissakian, A Snopkov, R Soderqvist, J Solodkov, A Soloviev, A Soloviev, I Sonderegger, P Soustruznik, K Spano, F Spiwoks, R Stanek, R Starchenko, E Stavina, P Stephens, R Suk, M Surkov, A Sykora, I Takai, H Tang, F Tardell, S Tartarelli, F Tas, P Teiger, J Thaler, J Thion, J Tikhonov, Y Tisserant, S Tokar, S Topilin, N Trka, Z Turcotte, M Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S Vuillemin, V White, A Wielers, M Wingerter-Seez, I Wolters, H Yamdagni, N Yosef, C Zaitsev, A Zitoun, R Zolnierowski, YP AF Akhmadaliev, S Amaral, P Ambrosini, G Amorim, A Anderson, K Andrieux, ML Aubert, B Auge, E Badaud, F Baisin, L Barreiro, F Battistoni, G Bazan, A Bazizi, K Belymam, A Benchckroun, D Berglund, S Berset, JC Blanchot, G Bogush, A Bohm, C Boldea, V Bonivento, W Bosman, M Bouhemaid, N Breton, D Brette, P Bromberg, C Budagov, J Burdin, S Caloba, L Camarena, F Camin, DV Canton, B Caprini, M Carvalho, J Casado, P Castillo, MV Cavalli, D Cavalli-Sforza, M Cavasinni, V Chadelas, R Chalifour, M Chekhtman, L Chevalley, JL Chirikov-Zorin, I Chlachidze, G Citterio, M Cleland, WE Clement, C Cobal, M Cogswell, F Colas, J Collot, J Cologna, S Constantinescu, S Costa, G Costanzo, D Crouau, M Daudon, F David, J David, M Davidek, T Dawson, J De, K de la Taille, C Del Peso, J Del Prete, T de Saintignon, P Di Girolamo, B Dinkespiller, B Dita, S Dodd, J Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Dzahini, D Efthymiopoulos, I Errede, D Errede, S Evans, H Eynard, G Fassi, F Fassnacht, P Ferrari, A Ferrari, A Ferrer, A Flaminio, V Fournier, D Fumagalli, G Gallas, E Gaspar, MG Giakoumopoulou, V Gianotti, F Gildemeister, O Giokaris, N Glagolev, V Glebov, V Gomes, A Gonzalez, V De la Hoz, SG Grabsky, V Grauges, E Grenier, P Hakopian, H Haney, M Hebrard, C Henriques, A Hervas, L Higon, E Holmgren, S Hostachy, JY Hoummada, A Huston, J Imbault, D Ivanyushenkov, Y Jezequel, S Johansson, E Jon-And, K Jones, R Juste, A Kakurin, S Karyukhin, A Khokhlov, Y Khubua, J Klyukhin, V Kolachev, G Kopikov, S Kostrikov, M Kozlov, V Krivkova, P Kukhtin, V Kulagin, M Kulchitsky, Y Kuzmin, M Labarga, L Laborie, G Lacour, D Laforge, B Lami, S Lapin, V Le Dortz, O Lefebvre, M Le Flour, T Leitner, R Leltchouk, M Li, J Liablin, M Linossier, O Lissauer, D Lobkowicz, F Lokajicek, M Lomakin, Y Amengual, JML Lund-Jensen, B Maio, A Makowiecki, D Malyukov, S Mandelli, L Mansoulie, B Mapelli, L Marin, CP Marrocchesi, P Marroquim, F Martin, P Maslennikov, A Massol, N Mataix, L Mazzanti, M Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Monnier, E Montarou, G Mornacchi, G Moynot, M Muanza, GS Nayman, P Nemecek, S Nessi, M Nicoleau, S Niculescu, M Noppe, JM Onofre, A Pallin, D Pantea, D Paoletti, R Park, IC Parrour, G Parsons, J Pereira, A Perini, L Perlas, JA Perrodo, P Pilcher, J Pinhao, J Plothow-Besch, H Poggioli, L Poirot, S Price, L Protopopov, Y Proudfoot, J Puzo, P Radeka, V Rahm, D Reinmuth, G Renzoni, G Resica, S Resconi, S Richards, R Richer, JP Roda, C Rodier, S Roldan, J Romance, JB Romance, V Romero, P Rossel, F Russakovich, N Sala, P Sanchis, E Sanders, H Santoni, C Santos, J Sauvage, D Sauvage, G Sawyer, L Says, LP Schaffer, AC Schwemling, P Schwindling, J Seguin-Moreau, N Seidl, W Seixas, JM Sellden, B Seman, M Semenov, A Serin, L Shaldaev, E Shochet, M Sidorov, V Silva, J Simaitis, V Simion, S Sissakian, A Snopkov, R Soderqvist, J Solodkov, A Soloviev, A Soloviev, I Sonderegger, P Soustruznik, K Spano, F Spiwoks, R Stanek, R Starchenko, E Stavina, P Stephens, R Suk, M Surkov, A Sykora, I Takai, H Tang, F Tardell, S Tartarelli, F Tas, P Teiger, J Thaler, J Thion, J Tikhonov, Y Tisserant, S Tokar, S Topilin, N Trka, Z Turcotte, M Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S Vuillemin, V White, A Wielers, M Wingerter-Seez, I Wolters, H Yamdagni, N Yosef, C Zaitsev, A Zitoun, R Zolnierowski, YP TI Hadron energy reconstruction for the ATLAS calorimetry in the framework of the non-parametrical method SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE calorimetry; combined calorimeter; shower counter; compensation; energy measurement; computer data analysis ID SHOWER DEVELOPMENT; RESOLUTION AB This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within +/-1% of the true values and the fractional energy resolution is [(58+/-3)%/rootE+(2.5+/-0.3)%]circle plus(1.7+/-0.2)/E. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74+/-0.04 and agrees with the prediction that e/h > 1.66 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Natl Acad Sci, Inst Phys, Minsk, Byelarus. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. LIP, Lisbon, Portugal. Univ Lisbon, FCUL, P-1699 Lisbon, Portugal. CERN, CH-1211 Geneva, Switzerland. Univ Chicago, Chicago, IL 60637 USA. Univ Grenoble 1, ISN, CNRS, IN2P3, Grenoble, France. LAPP, Annecy, France. LAL, Orsay, France. Univ Clermont Ferrand, CNRS, IN2P3, LPC Clermont Ferrand, Clermont Ferrand, France. Univ Autonoma Madrid, Madrid, Spain. Univ Milan, Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Univ Hassan II, Fac Sci Ain Chock, Casablanca, Morocco. Univ Stockholm, S-10691 Stockholm, Sweden. Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Barcelona, Spain. Natl Acad Sci, Inst Phys, Minsk, Byelarus. Horia Hulubei Natl Inst Phys & Nucl Engn, IFIN HH, Bucharest, Romania. Michigan State Univ, E Lansing, MI 48824 USA. JINR, Dubna, Russia. Univ Pisa, Pisa, Italy. Ist Nazl Fis Nucl, Pisa, Italy. UFRJ, EE, COPPE, Rio De Janeiro, Brazil. IFIC, Valencia, Spain. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, LPNHE, Paris, France. CPPM, Marseille, France. LIP, Lisbon, Portugal. Univ Coimbra, FCTUC, Coimbra, Portugal. CE Saclay, SPP, DAPNIA, DSM,CEA, Gif Sur Yvette, France. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Royal Inst Technol, Stockholm, Sweden. Univ Illinois, Urbana, IL 61801 USA. Charles Univ, Prague, Czech Republic. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, Arlington, TX 76019 USA. Columbia Univ, Nevis Labs, Irvington, NY USA. Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Athens, Athens, Greece. Yerevan Phys Inst, Yerevan 375036, Armenia. Inst High Energy Phys, Protvino, Russia. Univ Victoria, Victoria, BC V8W 2Y2, Canada. Acad Sci Czech Republ, Prague, Czech Republic. LIP, Lisbon, Portugal. Univ Catolica Figueira Foz, Lisbon, Portugal. PNPI, Gatchina, St Petersburg, Russia. Comenius Univ, Bratislava, Slovakia. RP Kulchitsky, Y (reprint author), Natl Acad Sci, Inst Phys, Minsk, Byelarus. RI Ferrer, Antonio/H-2942-2015; Rescia, Sergio/D-8604-2011; David, Mario/C-4664-2012; Takai, Helio/C-3301-2012; Klyukhin, Vyacheslav/D-6850-2012; sala, paola/E-2868-2013; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Camarena, Francisco/L-9349-2014; Cavalli-Sforza, Matteo/H-7102-2015; Marrocchesi, Pier Simone/N-9068-2015; Carvalho, Joao/M-4060-2013; Gonzalez de la Hoz, Santiago/E-2494-2016; SANCHIS, ENRIQUE/J-7348-2016; Gonzalez Millan, Vicente/J-3023-2012; Solodkov, Alexander/B-8623-2017; Zaitsev, Alexandre/B-8989-2017 OI Ferrer, Antonio/0000-0003-0532-711X; Rescia, Sergio/0000-0003-2411-8903; Takai, Helio/0000-0001-9253-8307; Klyukhin, Vyacheslav/0000-0002-8577-6531; sala, paola/0000-0001-9859-5564; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Camarena, Francisco/0000-0002-6713-1414; Marrocchesi, Pier Simone/0000-0003-1966-140X; Carvalho, Joao/0000-0002-3015-7821; Gonzalez de la Hoz, Santiago/0000-0001-5304-5390; SANCHIS, ENRIQUE/0000-0002-9689-9131; Gonzalez Millan, Vicente/0000-0001-6014-2586; Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368 NR 36 TC 4 Z9 4 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 2002 VL 480 IS 2-3 BP 508 EP 523 AR PII S0168-9002(01)01229-3 DI 10.1016/S0168-9002(01)01229-3 PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200025 ER PT J AU Albrow, M Aota, S Apollinari, G Asakawa, T Bailey, M de Barbaro, P Barnes, V Biery, K Bodek, A Breccia, L Brunetti, R Budd, H Cauz, D Demortier, L Fiori, I Frautschi, M Fukui, Y Ganel, O Gotra, Y Hahn, S Handa, T Hatakeyama, K Ikeda, H Introzzi, G Iwai, J Kikuchi, T Kim, SH Kowald, W Laasanen, A Lamoureux, J Lindgren, M Liu, J Lusin, S Melese, P Minato, H Murgia, S Nakada, H Patrick, J Pauletta, G Sakumoto, W Santi, L Seiya, Y Solodsky, A Wigmans, R Zucchelli, S AF Albrow, M Aota, S Apollinari, G Asakawa, T Bailey, M de Barbaro, P Barnes, V Biery, K Bodek, A Breccia, L Brunetti, R Budd, H Cauz, D Demortier, L Fiori, I Frautschi, M Fukui, Y Ganel, O Gotra, Y Hahn, S Handa, T Hatakeyama, K Ikeda, H Introzzi, G Iwai, J Kikuchi, T Kim, SH Kowald, W Laasanen, A Lamoureux, J Lindgren, M Liu, J Lusin, S Melese, P Minato, H Murgia, S Nakada, H Patrick, J Pauletta, G Sakumoto, W Santi, L Seiya, Y Solodsky, A Wigmans, R Zucchelli, S TI The CDF plug upgrade electromagnetic calorimeter: test beam results SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID TILE FIBER SYSTEM; EM CALORIMETER; PRESHOWER DETECTOR; MASS-PRODUCTION; READOUT AB The CDF Plug Upgrade calorimeter, which fully exploits the tile-fiber technique, was tested at the Fermilab meson beamline. The calorimeter was exposed to positron, positively charged pion and positive muon beams with energies in the range of 5-230 GeV. The energy resolution of the electromagnetic calorimeter to the positron beam is consistent with the design value of 16%/rootEcircle plus 1%, where E is the energy in units of GeV and circle plus represents sum in quadrature. The non-linearity for positrons is studied in an energy range of 11-181 GeV. It is important to incorporate the response of the preshower detector, the first layer of the electromagnetic calorimeter which is readout separately, into that of the calorimeter to reduce the non-linearity to 1% or less. The energy scale is about 1.46 pC/GeV with HAMAMATSU R4125 operated typically at a gain of 2.5 x 10(4). The response non-uniformity over the surface of a tower of the electromagnetic calorimeter is found to be about 2% with 57 GeV positrons. Studies of several detailed detector characteristics are also presented. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 305, Japan. Rockefeller Univ, New York, NY 10021 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Univ Rochester, Rochester, NY 14627 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Udine, I-33100 Udine, Italy. Sez INFN, I-33100 Udine, Italy. Texas Tech Univ, Lubbock, TX 79409 USA. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Hiroshima Univ, Hiroshima, Japan. Waseda Univ, Tokyo 169, Japan. Univ Pavia, I-27100 Pavia, Italy. Sez INFN, I-27100 Pavia, Italy. Duke Univ, Durham, NC 27708 USA. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Wisconsin, Madison, WI 53706 USA. Michigan State Univ, E Lansing, MI 48824 USA. RP Seiya, Y (reprint author), Fermilab Natl Accelerator Lab, POB 500,MS-318, Batavia, IL 60510 USA. RI Introzzi, Gianluca/K-2497-2015 OI Introzzi, Gianluca/0000-0002-1314-2580 NR 21 TC 91 Z9 91 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 2002 VL 480 IS 2-3 BP 524 EP 546 AR PII S0168-9002(01)01238-4 DI 10.1016/S0168-9002(01)01238-4 PG 23 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200026 ER PT J AU Reginatto, M AF Reginatto, M TI Resolving power of a multisphere neutron spectrometer SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE resolution; Bonner spheres; multisphere neutron spectrometer AB The resolving power of a multisphere neutron spectrometer is determined using the approach of Backus and Gilbert. (C) 2002 Elsevier Science B.V. All rights reserved. C1 US DOE, Environm Measurements Lab, Div Environm Sci, New York, NY 10014 USA. RP Reginatto, M (reprint author), US DOE, Environm Measurements Lab, Div Environm Sci, 201 Varick St,5th Floor, New York, NY 10014 USA. NR 6 TC 13 Z9 13 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 2002 VL 480 IS 2-3 BP 690 EP 695 AR PII S0168-9002(01)01207-4 DI 10.1016/S0168-9002(01)01207-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200040 ER PT J AU Borzakov, SB Chrien, RE Faikow-Stanczyk, H Grigoriev, YV Panteleev, TT Pospisil, S Smotritsky, LM Telezhnikov, SA AF Borzakov, SB Chrien, RE Faikow-Stanczyk, H Grigoriev, YV Panteleev, TT Pospisil, S Smotritsky, LM Telezhnikov, SA TI An accurate redetermination of the Sn-118 binding energy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE nuclear reactions; Sn-117, Cu-63(n, gamma), E=reactor, measured gamma-spectra; Sn-118, Cu-64 deduced binding energies; HPGe detector; pair spectrometer; enriched targets ID THERMAL-NEUTRON CAPTURE; CALIBRATION PROCEDURE; LEVEL SCHEME; GAMMA; MASS AB The energy of well-known strong gamma line from Au-198, the "gold standard", has been modified in the light of new adjustments in the fundamental constants and the value of 411.80176(12) keV was determined, which is 0.29eV lower than the latest 1999 value. An energy calibration procedure for determining the neutron binding energy, B-n from complicated (n, gamma) spectra has been developed. A mathematically simple minimization function consisting only of terms having as parameters the coefficients of the energy calibration curve (polynomial) is used. A priori information about the relationships among the energies of different peaks on the spectrum is taken into account by a Monte-Carlo simulation. The procedure was used in obtaining B-n for Sn-118. The gamma-ray spectrum from thermal neutron radiative capture by Sn-117 has been measured on the IBR-2 pulsed reactor. gamma-rays were detected by a 72 cm(3) HPGe detector. For a better determination of B-n it was important to determine B-n for (CU)-C-64. This value was obtained from two gamma-spectra. One spectrum was measured on the IBR-2 by the same detector. The other spectrum was measured with a pair spectrometer at the Brookhaven High Flux Beam Reactor. From these two spectra, B-n for (CU)-C-64 was determined to be equal to 7915.52(8) keV. This result essentially differs from the previous value of 7915.96(11) keV. The mean value of the two most precise results of the B-n for Sn-118, was determined to be 9326.35(9) keV. The B-n for Fe-57 was determined to be 7646.08(9) keV. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Joint Inst Nucl Res, Frank Lab Neutron Phys, Dubna 141980, Moscow Region, Russia. Brookhaven Natl Lab, Upton, NY 11973 USA. Inst Phys & Power Engn, Obninsk, Russia. Czech Tech Univ, Fac Nucl Sci & Phys Engn, Dept Phys, Prague 11519 1, Czech Republic. BP Konstantinov Nucl Phys Inst, Gatchina, Russia. RP Telezhnikov, SA (reprint author), Joint Inst Nucl Res, Frank Lab Neutron Phys, Dubna 141980, Moscow Region, Russia. NR 21 TC 5 Z9 5 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 MAR 21 PY 2002 VL 480 IS 2-3 BP 696 EP 705 AR PII S0168-9002(01)01223-2 DI 10.1016/S0168-9002(01)01223-2 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200041 ER PT J AU O'Connor, P De Geronimo, G AF O'Connor, P De Geronimo, G TI Prospects for charge sensitive amplifiers in scaled CMOS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE charge sensitive amplifier; CMOS scaling ID LOW-NOISE; THERMAL NOISE; TECHNOLOGY; MOSFETS; PREAMPLIFIER; DETECTORS; TRANSISTORS; PERFORMANCE AB Due to its low cost and flexibility for custom design, monolithic CMOS technology is being increasingly employed in charge preamplifiers across a broad range of applications, including both scientific research and commercial products. The associated detectors have capacitances ranging from a few tens of fF to several hundred pF. Applications call for pulse shaping from tens of ns to tens of mus, and constrain the available power per channel from tens of LW to tens of mW. At the same time a new technology generation, with changed device parameters, appears every 2 years or so. The optimum design of the front-end circuitry is examined taking into account submicron device characteristics, weak inversion operation, the reset system, and power supply scaling. Experimental results from recent prototypes will be presented. We will also discuss the evolution of preamplifier topologies and anticipated performance limits as CMOS technology scales down to the 0.1 mum/1.0 V generation in 2006. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP O'Connor, P (reprint author), Brookhaven Natl Lab, Instrumentat Div, Bldg 535B, Upton, NY 11973 USA. NR 25 TC 49 Z9 49 U1 4 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 2002 VL 480 IS 2-3 BP 713 EP 725 AR PII S0168-9002(01)01212-8 DI 10.1016/S0168-9002(01)01212-8 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200043 ER PT J AU Orion, I Wielopolski, L AF Orion, I Wielopolski, L TI Limitations in the PHOTON Monte Carlo gamma transport code SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Three Monte Carlo gamma transport codes, MCNP, EGS, PHOTON, differ in the degree of difficulty in implementing them for calculation and in the requirements for the input file. Differences in the results were discovered when evaluating the same case using these three transport codes. These differences that are energy dependent are presented here. (C) 2002 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Columbia Univ, St Lukes Roosevelt Hosp, New York, NY 10025 USA. RP Wielopolski, L (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Bldg 490-D, Upton, NY 11973 USA. RI ORION, ITZHAK/F-2034-2012 NR 7 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 21 PY 2002 VL 480 IS 2-3 BP 729 EP 733 AR PII S0168-9002(01)01226-8 DI 10.1016/S0168-9002(01)01226-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200045 ER PT J AU Wu, SC Donangelo, R Rasmussen, JO Daniel, AV Hwang, JK Ramayya, AV Hamilton, JH AF Wu, SC Donangelo, R Rasmussen, JO Daniel, AV Hwang, JK Ramayya, AV Hamilton, JH TI Resolution of complex gamma spectra from triple-coincidence data: Ba-Mo split in Cf-252 spontaneous fission SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Gamma spectra; spontaneous fission; gammasphere; neutron multiplicity ID FRAGMENT PAIRS; YIELDS AB Using triple-coincidence events of prompt fission gamma rays from spontaneous fission of Cf-252, we made a new analysis of the yield matrix of coincident pairs of barium (Z = 56) and molybdenum (Z = 42) fission Fragments. Branching from gamma-bands (K = 2) and octupole-bands (K = 0) were also measured. From this reanalysis the previously proposed "extra-hot-fission mode" (8-10 neutrons evaporated) is much weaker than first reported. In this paper, we discuss in detail the methodology, including background subtraction for triple-coincidence data. The importance of minimal compression spectra allowing least-squares peak-fitting analysis is emphasized. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Natl Tsing Hua Univ, Dept Phys, Hsinchu, Taiwan. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RP Rasmussen, JO (reprint author), Lawrence Berkeley Lab, Mailstop 50A-1148, Berkeley, CA 94720 USA. NR 5 TC 3 Z9 3 U1 1 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 MAR 21 PY 2002 VL 480 IS 2-3 BP 776 EP 781 AR PII S0168-9002(01)01232-3 DI 10.1016/S0168-9002(01)01232-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 545YM UT WOS:000175245200051 ER PT J AU Stern, D Moran, EC Coil, AL Connolly, A Davis, M Dawson, S Dey, A Eisenhardt, P Elston, R Graham, JR Harrison, F Helfand, DJ Holden, B Mao, P Rosati, P Spinrad, H Stanford, SA Tozzi, P Wu, KL AF Stern, D Moran, EC Coil, AL Connolly, A Davis, M Dawson, S Dey, A Eisenhardt, P Elston, R Graham, JR Harrison, F Helfand, DJ Holden, B Mao, P Rosati, P Spinrad, H Stanford, SA Tozzi, P Wu, KL TI Chandra detection of a type II quasar at z=3. 288 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : active; quasars : individual (CXO J084837.9+445352); X-rays : galaxies ID REDSHIFT RADIO GALAXIES; ACTIVE GALACTIC NUCLEI; HUBBLE DEEP FIELD; LINE SEYFERT-1 GALAXIES; X-RAY; INFRARED-SPECTROSCOPY; DISTANT GALAXIES; UNIFIED SCHEMES; ALPHA EMISSION; SKY SURVEY AB We report on observations of a type II quasar at redshift z = 3.288, identified as a hard X-ray source in a 185 ks observation with the Chandra X-Ray Observatory and as a high-redshift photometric candidate from deep, multiband optical imaging. CXO J084837.9+ 445352 ( hereafter CXO 52) shows an unusually hard X-ray spectrum from which we infer an absorbing column density N-H = (4.8 +/- 2.1) x 10(23) cm(-2) (90% confidence) and an implied unabsorbed 2-10 keV rest-frame luminosity of L2-10 = 3.3 x 10(44) ergs s(-1), well within the quasar regime. Hubble Space Telescope imaging shows CXO 52 to be elongated with slight morphological differences between the WFPC2 F814W and NICMOS F160W bands. Optical and near-infrared spectroscopy of CXO 52 shows high-ionization emission lines with velocity widths similar to1000 km s(-1) and flux ratios similar to a Seyfert 2 galaxy or radio galaxy. The latter are the only class of high-redshift type II luminous active galactic nuclei that have been extensively studied to date. Unlike radio galaxies, however, CXO 52 is radio quiet, remaining undetected at radio wavelengths to fairly deep limits, f(4.8GHz) < 40 μJy. High-redshift type II quasars, expected from unification models of active galaxies and long thought necessary to explain the X-ray background, are poorly constrained observationally, with few such systems known. We discuss recent observations of similar type II quasars and detail search techniques for such systems, namely, (1) X-ray selection, (2) radio selection, (3) multicolor imaging selection, and (4) narrowband imaging selection. Such studies are likely to begin identifying luminous, high-redshift type II systems in large numbers. We discuss the prospects for these studies and their implications for our understanding of the X-ray background. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Kitt Peak Natl Observ, Tucson, AZ 85719 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. European So Observ, D-85748 Garching, Germany. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Osserv Astron Trieste, I-34131 Trieste, Italy. RP Stern, D (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-327, Pasadena, CA 91109 USA. NR 100 TC 130 Z9 130 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2002 VL 568 IS 1 BP 71 EP 81 DI 10.1086/338886 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 531VN UT WOS:000174438100008 ER PT J AU Moon, YJ Choe, GS Yun, HS Park, YD Mickey, DL AF Moon, YJ Choe, GS Yun, HS Park, YD Mickey, DL TI Force-freeness of solar magnetic fields in the photosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : magnetic fields; Sun : photosphere ID VECTOR MAGNETOGRAPH DATA; STOKES PROFILE ANALYSIS; ACTIVE REGIONS; ELECTRIC CURRENTS; FLARE PHENOMENA; BOUNDARY DATA; SUNSPOT; LINES; RECONSTRUCTION; MORPHOLOGY AB It is widely believed that solar magnetic fields are force-free in the solar corona but not in the solar photosphere at all. In order to examine the force-freeness of active region magnetic fields at the photospheric level, we have calculated the integrated magnetic forces for 12 vector magnetograms of three flare-productive active regions. The magnetic field vectors are derived from simultaneous Stokes profiles of the Fe I doublet lambdalambda6301.5 and 6302.5 obtained by the Haleakala Stokes Polarimeter of Mees Solar Observatory, with a nonlinear least-squares method adopted for field calibration. The resulting vertical Lorentz force normalized to the total magnetic pressure force \F(z)/F(p)\ ranges from 0.06 to 0.32 with a median value of 0.13, which is smaller than the values (similar to0.4) obtained by Metcalf et al., who applied a weak field derivative method to the Stokes profiles of Na I lambda5896. Our results indicate that the photospheric magnetic fields are not so far from force-free as conventionally regarded. As a good example of a linear force-free field, NOAA Active Region 5747 is examined. By applying three different methods (a most probable value method, a least-squares fitting method, and comparison with linear force-free solutions), we have derived relatively consistent linear force-free coefficients for NOAA AR 5747. It is found that the scaled downward Lorentz force \F(z)/F(p)\ in the solar photosphere decreases with increasing \alpha\. Our results also show that the force-freeness of photospheric magnetic fields depends not only on the character of the active region but also on its evolutionary status. C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. Korea Astron Observ, Taejon 305348, South Korea. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Seoul Natl Univ, SEES, Astron Program, Seoul 151742, South Korea. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Moon, YJ (reprint author), New Jersey Inst Technol, Big Bear Solar Observ, 40386 N Shore Lane, Big Bear City, CA 92314 USA. EM yjmoon@bbso.njit.edu RI Moon, Yong-Jae/E-1711-2013; Choe, Gwangson/E-2366-2013 NR 46 TC 39 Z9 39 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2002 VL 568 IS 1 BP 422 EP 431 DI 10.1086/338891 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 531VN UT WOS:000174438100043 ER PT J AU Marohnic, CC Davis, CA Bewley, MC Barber, MJ AF Marohnic, CC Davis, CA Bewley, MC Barber, MJ TI Flavin flexibility in cytochrome b(5) reductase. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ S Florida, Tampa, FL 33612 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 20 PY 2002 VL 16 IS 4 BP A147 EP A147 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 533MG UT WOS:000174533600816 ER PT J AU Scherpereel, A Murciano, JC Wiewrodt, R Kennel, S Muzykantov, V Christofidou-Solomidou, M AF Scherpereel, A Murciano, JC Wiewrodt, R Kennel, S Muzykantov, V Christofidou-Solomidou, M TI Glucose oxidase vascular immunotargeting to pulmonary endothelium enhances luminal expression of ICAM-1 and P-selectin in the lung SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ Penn, Philadelphia, PA 19104 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 20 PY 2002 VL 16 IS 4 BP A439 EP A439 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 533MG UT WOS:000174533602433 ER PT J AU Silver, RB Jiang, Y AF Silver, RB Jiang, Y TI New insights on secretion from imaging calcium microdomains and molecular dynamics (MD) modeling SO FASEB JOURNAL LA English DT Meeting Abstract C1 Wayne State Univ, Sch Med, Detroit, MI 48201 USA. Los Alamos Natl Lab, Los Alamos, NM USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 20 PY 2002 VL 16 IS 4 BP A726 EP A726 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 533MG UT WOS:000174533604030 ER PT J AU Fincke, JR Anderson, RP Hyde, TA Detering, BA AF Fincke, JR Anderson, RP Hyde, TA Detering, BA TI Plasma pyrolysis of methane to hydrogen and carbon black SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SOOT FORMATION; KINETIC DATA; SHOCK-TUBE; NATURAL-GAS; ACETYLENE; FLAMES; CHEMISTRY; SPECTROSCOPY; HYDROCARBONS; ATOM AB The plasma-driven gas-phase thermal decomposition of methane yielding hydrogen and solid-phase carbon has been suggested as an environmentally friendly alternative to conventional methods of producing hydrogen from natural gas. The advantage of the process is that hydrogen is obtained directly from methane without producing CO2 as a byproduct. The process was experimentally examined using a modified version of a dc plasma reactor originally developed for the conversion of methane to acetylene. Carbon yields of 30%, a factor of 6 increase, with a corresponding decrease in acetylene yield were obtained by simply increasing the residence or reaction time. A detailed kinetic model that includes the reaction mechanisms resulting in the formation of acetylene and heavier hydrocarbons through benzene is described. A model for solid carbon nucleation and growth is included. The model is compared to experimental results and is used to examine process optimization. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Fincke, JR (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 48 TC 41 Z9 46 U1 3 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD MAR 20 PY 2002 VL 41 IS 6 BP 1425 EP 1435 DI 10.1021/ie010722e PG 11 WC Engineering, Chemical SC Engineering GA 532LE UT WOS:000174475800005 ER PT J AU Davis, WB Hess, S Naydenova, I Haselsberger, R Ogrodnik, A Newton, MD Michel-Beyerle, ME AF Davis, WB Hess, S Naydenova, I Haselsberger, R Ogrodnik, A Newton, MD Michel-Beyerle, ME TI Distance-dependent activation energies for hole injection from protonated 9-amino-6-chloro-2-methoxyacridine into duplex DNA SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON-TRANSFER REACTIONS; REORGANIZATION ENERGY; TRANSFER RATES C1 Tech Univ Munich, Inst Phys & Theoret Chem, D-85748 Garching, Germany. Washington State Univ, Sch Mol Biosci, Pullman, WA 99164 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Newton, MD (reprint author), Tech Univ Munich, Inst Phys & Theoret Chem, Lichtenbergstr 4, D-85748 Garching, Germany. RI Maria Elisabeth, Michel-Beyerle/F-7869-2012 NR 18 TC 54 Z9 54 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 20 PY 2002 VL 124 IS 11 BP 2422 EP 2423 DI 10.1021/ja017304l PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 531UM UT WOS:000174435700015 PM 11890775 ER PT J AU Zhan, CG Dixon, DA Sabri, MI Kim, MS Spencer, PS AF Zhan, CG Dixon, DA Sabri, MI Kim, MS Spencer, PS TI Theoretical determination of chromophores in the chromogenic effects of aromatic neurotoxicants SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DENSITY-FUNCTIONAL THEORY; ELECTRONICALLY EXCITED-STATES; CARBOXYLIC-ACID ESTERS; REACTION FIELD-THEORY; GAS-PHASE ACIDITIES; ENERGY BARRIERS; ALKALINE-HYDROLYSIS; EXCITATION-ENERGIES; REACTION PATHWAYS; AQUEOUS-SOLUTION AB We report the first computational study of the chromophores responsible for the chromogenic effects of aromatic neurotoxicants; containing a 1,2-diacetyl moiety in their oxidation metabolites. A series of ab initio electronic structure calculations was performed on two representative aromatic compounds, 1,2-diacetyl benzene (1,2-DAB) and 1,2-diacetyl tetramethyl tetralin (1,2-DATT), the putative active metabolites of the neurotoxic aromatic hydrocarbon compounds 1,2-diethylbenzene (1,2-DEB) and acetyl ethyl tetramethyl tetralin (AETT), and on the products of their possible reactions with proteins that result in chromogenic effects. The electronic excitation energies determined by three different computational approaches were found to be consistent with each other. The calculated results are consistent with the conclusion/prediction that the chromogenic effects of 1,2-DAB (or 1,2-DEB) and 1,2-DATT (or AETT) could result from ninhydrin-like reactions, rather than the formation of pyrrole-like compounds. Our pK(a) calculations further indicate that the chromophore, i.e., the product of the ninhydrin-like reaction showing the blue color, is deprotonated in neutral aqueous solution. The corresponding protonated structure has a different color as it absorbs in the blue region of the visible spectrum, and its chromogenic contribution would be significant in solution at low pH. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Oregon Hlth & Sci Univ, Ctr Res Occupat & Environm Toxicol, Portland, OR 97201 USA. RP Dixon, DA (reprint author), Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, MS K1-83,POB 999, Richland, WA 99352 USA. FU NIEHS NIH HHS [5P42 ES 10338] NR 59 TC 38 Z9 40 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 20 PY 2002 VL 124 IS 11 BP 2744 EP 2752 DI 10.1021/ja0113394 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 531UM UT WOS:000174435700066 PM 11890826 ER PT J AU Welm, B Mott, J Werb, Z AF Welm, B Mott, J Werb, Z TI Developmental biology: Vasculogenesis is a wreck RECK without SO CURRENT BIOLOGY LA English DT Editorial Material ID TISSUE INHIBITORS; GENE; TIMP-1 AB The unique membrane-associated inhibitor of matrix metalloproteinases, RECK, is required for vascular maturation during embryogenesis. The phenotype of a loss of function mutation of RECK shows the importance of pericellular proteolysis in development. C1 Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Welm, B (reprint author), Univ Calif San Francisco, Dept Anat, Box 0452,513 Parnassus Ave, San Francisco, CA 94143 USA. NR 19 TC 32 Z9 34 U1 0 U2 1 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTS AVE,, CAMBRIDGE, MA 02138 USA SN 0960-9822 J9 CURR BIOL JI Curr. Biol. PD MAR 19 PY 2002 VL 12 IS 6 BP R209 EP R211 AR PII S0960-98822(02)00752-2 DI 10.1016/S0960-9822(02)00752-2 PG 3 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 533NC UT WOS:000174535700009 PM 11909548 ER PT J AU Kelley, SS Jellison, J Goodell, B AF Kelley, SS Jellison, J Goodell, B TI Use of NIR and pyrolysis-MBMS coupled with multivariate analysis for detecting the chemical changes associated with brown-rot biodegradation of spruce wood SO FEMS MICROBIOLOGY LETTERS LA English DT Article DE brown rot; wood decay; near infrared; pyrolysis-molecular beam mass spectrometry; Postia placenta; Gloeophyllum trabeum ID INFRARED REFLECTANCE SPECTROSCOPY; GLOEOPHYLLUM-TRABEUM; LIGNIN; MECHANISM; BIOMASS; FUNGUS AB Near infrared (NIR) spectroscopy and pyrolysis-molecular beam mass spectrometry (py-MBMS) analysis can be used in conjunction with multivariate regression and principal components analysis to differentiate brown-rot-degraded wood from non-degraded spruce and to follow the temporal changes in wood undergoing brown-rot degradation. Regression of NIR test results vs. percent weight loss for Postia placenta- and Glocophyllum trabeum-infected spruce wood blocks yielded a correlation coefficient of 0.96. Regression of MBMS test results for the same samples yielded a correlation coefficient of 0.96. Principle components analysis was used to differentiate noninfected wood and P. placenta- and G. trabeum-infected wood. These techniques may be used to detect different types of biodegradation and to develop a better understanding of the chemical changes that the wood undergoes when it is subjected to brown-rot biodegradation. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Natl Bioenergy Ctr, Golden, CO 80401 USA. Univ Maine, Dept Biol Sci, Orono, ME 04469 USA. RP Kelley, SS (reprint author), Natl Renewable Energy Lab, Natl Bioenergy Ctr, 1617 Cole Blvd, Golden, CO 80401 USA. NR 26 TC 34 Z9 38 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1097 J9 FEMS MICROBIOL LETT JI FEMS Microbiol. Lett. PD MAR 19 PY 2002 VL 209 IS 1 BP 107 EP 111 AR PII S0378-1097(02)00494-9 DI 10.1111/j.1574-6968.2002.tb11117.x PG 5 WC Microbiology SC Microbiology GA 552FV UT WOS:000175609500017 PM 12007662 ER PT J AU Sloutskin, E Kraack, H Ocko, B Ellmann, J Moller, M Lo Nostro, P Deutsch, M AF Sloutskin, E Kraack, H Ocko, B Ellmann, J Moller, M Lo Nostro, P Deutsch, M TI Thermal expansion of surface-frozen monolayers of semifluorinated alkanes SO LANGMUIR LA English DT Article ID LIQUID NORMAL-ALKANES; CHAIN MOLECULES; ROTATOR PHASES; CRYSTALLIZATION AB The linear coefficient of thermal expansion of a quasi-2D surface-frozen crystalline layer is measured, using surface X-ray diffraction, for three different semifluorinated alkane diblocks. The values obtained are in good agreement with those of surface-frozen monolayers of fully protonated alkanes. An unexpected strong dependence on the protonated block's length is found and discussed. C1 Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Ulm, D-89069 Ulm, Germany. Univ Florence, Dipartimento Chim, I-50019 Sesto Fiorentino, Italy. Univ Florence, CSGI, I-50019 Sesto Fiorentino, Italy. RP Deutsch, M (reprint author), Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. RI Lo Nostro, Pierandrea/G-6585-2011; Moller, Martin/F-7860-2015 OI Moller, Martin/0000-0002-5955-4185 NR 29 TC 16 Z9 16 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 19 PY 2002 VL 18 IS 6 BP 1963 EP 1967 DI 10.1021/la0156309 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 531EL UT WOS:000174403000003 ER PT J AU Maya, L AF Maya, L TI Assembly of gold nanoclusters on silicon surfaces SO LANGMUIR LA English DT Article ID MONOLAYERS; MOLECULES; TRANSISTOR; PARTICLES; CLUSTERS; ARRAYS; FILMS; SIZE AB The electrostatic association between mercaptosuccinic acid-coated gold clusters, about 2 nm in diameter, and amine silane derivatized silicon was examined, Relatively good coverage takes place in the pH range between 5 and 6 that coincides with the dissociation of the acid coating on the. gold clusters. The latter was established by IR spectroscopy taking advantage of the typical carboxylate vibrations that differ from the protonated species. The pK(a) value of the gold-bound acid was estimated to be 1.3 units higher than that on the free acid. Such displacements are anticipated for monolayers of bases or acids, but it is smaller in the spherical cluster than on flat surfaces. The microstructure of the films may be manipulated through control of pH, contact time, and the nature of the crystalline substrate. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Maya, L (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 26 TC 9 Z9 9 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 19 PY 2002 VL 18 IS 6 BP 2392 EP 2397 DI 10.1021/la011339h PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 531EL UT WOS:000174403000067 ER PT J AU Wang, K Singh, AK van Zanten, JH AF Wang, K Singh, AK van Zanten, JH TI Aggregation rate measurements by zero-angle time-resolved multiangle laser light scattering SO LANGMUIR LA English DT Article ID PHOTON-CORRELATION SPECTROSCOPY; COAGULATION RATE CONSTANTS; COLLOIDAL PARTICLES; POLYSTYRENE LATEX; HOMOCOAGULATION; SUSPENSIONS; TURBIDITY AB A new method for determining second-order aggregation rate constants via time-resolved multiangle laser light scattering is introduced. A major advantage of this approach is that second-order aggregation rate constants are determined without any assumptions regarding the dimer intraparticle interference or form factor. The second-order aggregation rate constants are calculated from the temporal variation of the zero-angle excess Rayleigh ratio within the context of von Smoluchowski's well-established model of colloidal aggregation. The new method is illustrated with two systems: (1) GM1-bearing liposomes aggregated in the presence of the cholera toxin B subunit and (2) sulfonated polystyrene latex aggregated in the presence of CaCl2. Whereas the method is demonstrated to be particularly well-suited for investigating slow aggregation processes, rapid aggregation processes are also accessible if proper precautions are taken. C1 N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Sandia Natl Labs, Chem & Radiat Detect Lab, Livermore, CA 94550 USA. RP van Zanten, JH (reprint author), N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. NR 29 TC 3 Z9 3 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 19 PY 2002 VL 18 IS 6 BP 2421 EP 2425 DI 10.1021/la011207o PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 531EL UT WOS:000174403000071 ER PT J AU Zhang, C Hou, JT Kim, SH AF Zhang, C Hou, JT Kim, SH TI Fold prediction of helical proteins using torsion angle dynamics and predicted restraints SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MULTIPLE SEQUENCE ALIGNMENTS; QUASI-CHEMICAL APPROXIMATION; NMR STRUCTURE CALCULATION; CORRELATED MUTATIONS; DISTANCE GEOMETRY; SECONDARY STRUCTURE; MOLECULAR-DYNAMICS; CONTACT ENERGIES; INFORMATION; CONSTRAINTS AB We describe a procedure for predicting the tertiary folds of a-helical proteins from their primary sequences. The central component of the procedure is a method for predicting interhelical contacts that is based on a helix-packing model. Instead of predicting the individual contacts, our method attempts to identify the entire patch of contacts that involve residues regularly spaced in the sequences. We use this component to glue together two powerful existing methods: a secondary structure prediction program, whose output serves as the input to the contact prediction algorithm, and the tortion angle dynamics program, which uses the predicted tertiary contacts and secondary structural states to assemble three-dimensional structures. In the final step, the procedure uses the initial set of simulated structures to refine the predicted contacts for a new round of structure calculation. When tested against 24 small to medium-sized proteins representing a wide range of helical folds, the completely automated procedure is able to generate native-like models within a limited number of trials consistently. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 31 TC 26 Z9 26 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 MAR 19 PY 2002 VL 99 IS 6 BP 3581 EP 3585 DI 10.1073/pnas.052003799 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 533CC UT WOS:000174511000042 PM 11904420 ER PT J AU Allen, C Kurimasa, A Brenneman, MA Chen, DJ Nickoloff, JA AF Allen, C Kurimasa, A Brenneman, MA Chen, DJ Nickoloff, JA TI DNA-dependent protein kinase suppresses double-strand break-induced and spontaneous homologous recombination SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MISMATCH REPAIR SYSTEM; HUMAN RAD51 PROTEIN; MAMMALIAN-CELLS; SACCHAROMYCES-CEREVISIAE; NONHOMOLOGOUS RECOMBINATION; HOMEOLOGOUS RECOMBINATION; GENE CONVERSION; ECTOPIC RECOMBINATION; SEQUENCE IDENTITY; CATALYTIC SUBUNIT AB DNA-dependent protein kinase (DNA-PK), composed of Ku70, Ku80, and the catalytic subunit (DNA-PKcs), is involved in repairing double-strand breaks (DSBs) by nonhomologous end-joining (NHEJ). Certain proteins involved in NHEJ are also involved in DSB repair by homologous recombination (HR). To test the effects of DNA-PKcs on DSB-induced HR, we integrated neo direct repeat HR substrates carrying the I-Scel recognition sequence into DNA-PKcs-defective Chinese hamster ovary (V3) cells. The DNA-PKcs defect was complemented with a human DNA-PKcs cDNA. DSB-induced HR frequencies were 1.5- to 3-fold lower with DNA-PKcs complementation. In complemented and uncomplemented strains, all products arose by gene conversion without associated crossover, and average conversion tract lengths were similar. Suppression of DSB-induced HR in complemented cells probably reflects restoration of NHEJ, consistent with competition between HR and NHEJ during DSB repair. Interestingly, spontaneous HR rates were 1.6-to >3.5-fold lower with DNA-PKcs complementation. DNA-PKcs may suppress spontaneous HR through NHEJ of spontaneous DSBs, perhaps at stalled or blocked replication forks. Because replication protein A (RPA) is involved in both replication and HR, and is phosphorylated by DNA-PKcs, it is possible that the suppression of spontaneous HR by DNA-PKcs reflects regulation of replication-dependent HR by DNA-PKcs, perhaps by means of phosphorylation of RPA. C1 Univ New Mexico, Sch Med, Dept Mol Genet & Microbiol, Albuquerque, NM 87131 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Nickoloff, JA (reprint author), Univ New Mexico, Sch Med, Dept Mol Genet & Microbiol, Albuquerque, NM 87131 USA. FU NCI NIH HHS [CA77693, CA74046, R01 CA077693] NR 72 TC 127 Z9 134 U1 2 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAR 19 PY 2002 VL 99 IS 6 BP 3758 EP 3763 DI 10.1073/pnas.052545899 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 533CC UT WOS:000174511000073 PM 11904432 ER PT J AU Wang, J Gosztola, D Ruffle, SV Hemann, C Seibert, M Wasielewski, MR Hille, R Gustafson, TL Sayre, RT AF Wang, J Gosztola, D Ruffle, SV Hemann, C Seibert, M Wasielewski, MR Hille, R Gustafson, TL Sayre, RT TI Functional asymmetry of photosystem II D1 and D2 peripheral chlorophyll mutants of Chlamydomonas reinhardtii SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID REACTION-CENTER COMPLEX; HIGH-FIELD EPR; ENERGY-TRANSFER; BETA-CAROTENE; SPECTROSCOPIC CHARACTERIZATION; EXCITATION-ENERGY; SUBPICOSECOND EQUILIBRATION; 3-DIMENSIONAL STRUCTURE; THYLAKOID MEMBRANES; PIGMENT COMPOSITION AB The peripheral accessory chlorophylls (Chls) of the photosystem 11 (PSII) reaction center (RC) are coordinated by a pair of symmetry-related histidine residues (D1-H118 and D2-H117). These Chls participate in energy transfer from the proximal antennae complexes (CP43 and CP47) to the RC core chromophores. In addition, one or both of the peripheral Chls are redox-active and participate in a low-quantum-yield electron transfer cycle around PSII. We demonstrate that conservative mutations of the D2-H117 residue result in decreased Chl fluorescence quenching efficiency attributed to reduced accumulation of the peripheral accessory Chl cation, Chl(Z)(+). In contrast, identical symmetry-related mutations at residue D1-H118 had no effect on Chl fluorescence yield or quenching kinetics. Mutagenesis of the D2-H117 residue also altered the line width of the Chl(Z)(+) EPR signal, but the line shape of the D1-H118Q mutant remained unchanged. The D1-H118 and D2-H117 mutations also altered energy transfer properties in PSII RCs. Unlike wild type or the D1-H118Q mutant, D2-H117N RCs exhibited a reduced CD doublet in the red region of Chl absorbance band, indicative of reduced energetic coupling between P680 and the peripheral accessory Chl. In addition, transient absorption measurements of D2-H117N RCs, excited on the blue side of the Chl absorbance band, exhibited a (approximate to400 fs) pheophytin Q(X) band bleach lifetime component not seen in wild-type or D1-H118Q RCs. The origin of this component may be related to delayed fast-energy equilibration of the excited state between the core pigments of this mutant. C1 Ohio State Univ, Dept Plant Biol, Columbus, OH 43210 USA. Ohio State Univ, Dept Mol & Cellular Biochem, Columbus, OH 43210 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Sayre, RT (reprint author), Ohio State Univ, Dept Plant Biol, 2021 Coffey Rd, Columbus, OH 43210 USA. RI Gosztola, David/D-9320-2011; Gustafson, Terry/G-3269-2011; OI Gosztola, David/0000-0003-2674-1379; Sayre, Richard/0000-0002-3153-7084; Hemann, Craig/0000-0002-7380-4072 NR 70 TC 33 Z9 34 U1 2 U2 7 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAR 19 PY 2002 VL 99 IS 6 BP 4091 EP 4096 DI 10.1073/pnas.062056899 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 533CC UT WOS:000174511000129 PM 11904453 ER PT J AU Gutowski, M Jaffe, JE Liu, CL Stoker, M Hegde, RI Rai, RS Tobin, PJ AF Gutowski, M Jaffe, JE Liu, CL Stoker, M Hegde, RI Rai, RS Tobin, PJ TI Thermodynamic stability of high-K dielectric metal oxides ZrO2 and HfO2 in contact with Si and SiO2 SO APPLIED PHYSICS LETTERS LA English DT Article ID DIRECT SYNTHESIS CALORIMETRY; STANDARD ENTHALPIES; MOLECULAR-DYNAMICS; PSEUDOPOTENTIALS; SILICIDES AB We present theoretical and experimental results regarding the thermodynamic stability of the high-k dielectrics ZrO2 and HfO2 in contact with Si and SiO2. The HfO2/Si interface is found to be stable with respect to formation of silicides whereas the ZrO2/Si interface is not. The metal-oxide/SiO2 interface is marginally unstable with respect to formation of silicates. Cross-sectional transmission electron micrographs expose formation of nodules, identified as silicides, across the polycrystalline silicon/ZrO2/Si interfaces but not for the interfaces with HfO2. For both ZrO2 and HfO2, the x-ray photoemission spectra illustrate formation of silicate-like compounds in the MO2/SiO2 interface. (C) 2002 American Institute of Physics. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. Motorola Inc, Adv Proc Dev & External Res Lab, Mesa, AZ 85202 USA. RP Gutowski, M (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. OI Stoker, Matthew/0000-0003-0672-0183 NR 25 TC 237 Z9 242 U1 7 U2 46 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 18 PY 2002 VL 80 IS 11 BP 1897 EP 1899 DI 10.1063/1.1458692 PG 3 WC Physics, Applied SC Physics GA 530NF UT WOS:000174363300014 ER PT J AU Zhai, HY Christen, HM Cantoni, C Goyal, A Lowndes, DH AF Zhai, HY Christen, HM Cantoni, C Goyal, A Lowndes, DH TI Epitaxial titanium diboride films grown by pulsed-laser deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID DIFFUSION-BARRIERS; THIN-FILMS; COATINGS AB Epitaxial, smooth, and low-resistivity titanium diboride (TiB2) films have been grown on SiC substrates using pulsed-laser deposition. Combined studies from ex situ x-ray diffraction and in situ reflection high-energy electron diffraction indicate the crystallographic alignment between TiB2 and SiC both parallel and normal to the substrate. Atomic force microscopy and scanning electron microscopy studies show that these epitaxial films have a smooth surface, and the resistivity of these films is comparable to that of single-crystal TiB2. Growth of these films is motivated by this material's structural and chemical similarity and lattice match to the newly discovered superconductor MgB2, both to gain further insight into the physical mechanisms of diborides in general and, more specifically, as a component of MgB2-based thin-film heterostructures. (C) 2002 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Zhai, HY (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Christen, Hans/H-6551-2013; Cantoni, Claudia/G-3031-2013 OI Christen, Hans/0000-0001-8187-7469; Cantoni, Claudia/0000-0002-9731-2021 NR 23 TC 12 Z9 12 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 MAR 18 PY 2002 VL 80 IS 11 BP 1963 EP 1965 DI 10.1063/1.1461869 PG 3 WC Physics, Applied SC Physics GA 530NF UT WOS:000174363300036 ER PT J AU Taylor, TR Hansen, PJ Acikel, B Pervez, N York, RA Streiffer, SK Speck, JS AF Taylor, TR Hansen, PJ Acikel, B Pervez, N York, RA Streiffer, SK Speck, JS TI Impact of thermal strain on the dielectric constant of sputtered barium strontium titanate thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID FERROELASTIC FILMS; FERROELECTRICITY AB Barium strontium titanate thin films were deposited by sputtering on Pt/SiO2 structures using five different host substrates: magnesium oxide, strontium titanate, sapphire, silicon, and vycor glass. These substrates were chosen to provide a systematic change in thermal strain while maintaining the same film microstructure. All films have a weakly textured microstructure. Temperature dependent dielectric measurements from 100-500 K determined that decreasing thermal expansion coefficient of the host substrate (i.e., larger tensile thermal strain) reduced the film dielectric permittivity. The experimentally determined Curie-Weiss temperature decreased with increasing tensile thermal strain and the Curie-Weiss constant increased with tensile strain as predicted by Pertsev [J. Appl. Phys. 85, 1698 (1999)].(C) 2002 American Institute of Physics. C1 Univ Calif Santa Barbara, Coll Engn, Dept Mat, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Coll Engn, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Univ Calif Santa Barbara, Coll Engn, Dept Mat, Santa Barbara, CA 93106 USA. EM speck@mrl.ucsb.edu RI Streiffer, Stephen/A-1756-2009; Speck, James/H-5646-2011 NR 15 TC 120 Z9 121 U1 1 U2 27 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 MAR 18 PY 2002 VL 80 IS 11 BP 1978 EP 1980 DI 10.1063/1.1459482 PG 3 WC Physics, Applied SC Physics GA 530NF UT WOS:000174363300041 ER PT J AU Zatsepin, DA Butorin, SM Mancini, DC Ma, Y Miyano, KE Shuh, DK Nordgren, J AF Zatsepin, DA Butorin, SM Mancini, DC Ma, Y Miyano, KE Shuh, DK Nordgren, J TI Strong anisotropy of resonant inelastic x-ray scattering from charge-transfer excitations in UO3 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID POLARIZATION DEPENDENCE; CORRELATED SYSTEMS; URANIUM-COMPOUNDS; EMISSION SPECTRA; SPECTROSCOPY; OXIDES; EDGE; PROBE AB Resonant x-ray scattering spectra of UO3 were measured at the U M-5 edge using monochromatic photon excitation. Large differences in inelastic scattering profiles were observed between two 90degrees-scattering geometries with the polarization vector of incident synchrotron radiation parallel and perpendicular to the scattering plane, respectively. For the latter case, a similar to9.5 eV energy-loss structure, associated with the O 2p --> U 5f charge-transfer satellite, shows a significant intensity enhancement. The observed resonance behaviour allows an accurate estimation of the energy of this satellite, which is obscured in the other experimental geometry, and indicates the charge-transfer origin of the U M5 absorption structures at the respective excitation energies. C1 Uppsala Univ, Dept Phys, S-75121 Uppsala, Sweden. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Sharp Microelect Technol Inc, Camas, WA 98607 USA. CUNY Brooklyn Coll, Dept Phys, Brooklyn, NY 11210 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Zatsepin, DA (reprint author), Uppsala Univ, Dept Phys, Box 530, S-75121 Uppsala, Sweden. RI Zatsepin, Dmitry/F-5520-2012 NR 21 TC 8 Z9 8 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAR 18 PY 2002 VL 14 IS 10 BP 2541 EP 2546 AR PII S0953-8984(02)21490-3 PG 6 WC Physics, Condensed Matter SC Physics GA 539RB UT WOS:000174883300006 ER PT J AU Fournee, V Anderegg, JW Ross, AR Lograsso, TA Thiel, PA AF Fournee, V Anderegg, JW Ross, AR Lograsso, TA Thiel, PA TI Electronic structure of quasicrystals deduced from Auger and x-ray photoelectron spectroscopies SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID ICOSAHEDRAL QUASI-CRYSTALS; HUME-ROTHERY ALLOYS; PD ALLOYS; SPECTRA; STATES; DENSITY; PHASE; NI AB Specific features in the electronic structure of Al-transition metal quasicrystals are analysed by a combination of Auger and x-ray photoelectron spectroscopies. We first demonstrate that different degrees of asymmetry in the transition metals' 2p core-level lineshape observed across different types of surface structure correspond to variations in the density of states at the Fermi level, DOS(E-F). Using this effect, we explore the controversial issue of whether the quasicrystalline, decagonal AlNiCo system is electronically stabilized. We find strong evidence for the presence of a reduced DOS(EF) in this system, as expected for electronically stabilized compounds, and as observed in the quasicrystalline, icosahedral AlPdMn and AlCuFe alloys. Finally, qualitative information on the nature of the electronic states in quasiperiodic structures extracted from the core-valence-valence Auger lines are presented and discussed. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Fournee, V (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 44 TC 15 Z9 15 U1 0 U2 1 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 MAR 18 PY 2002 VL 14 IS 10 BP 2691 EP 2703 AR PII S0953-8984(02)31863-0 PG 13 WC Physics, Condensed Matter SC Physics GA 539RB UT WOS:000174883300019 ER PT J AU Hebecker, A March-Russell, J AF Hebecker, A March-Russell, J TI The structure of GUT breaking by orbifolding SO NUCLEAR PHYSICS B LA English DT Article ID GRAND UNIFIED THEORIES; SYMMETRY-BREAKING; EXTRA DIMENSIONS; GRAVITATIONAL ANOMALIES; SUPERSYMMETRY BREAKING; COSMIC STRINGS; GAUGE-THEORY; UNIFICATION; ELECTROWEAK; PREDICTIONS AB Recently, an attractive model of GUT breaking has been proposed in which a 5-dimensional supersymmetric SU(5) gauge theory on an S-1/(Z(2) x Z(2)') orbifold is broken down to the 4d MSSM by SU(5)-violating boundary condifions. Motivated by this construction and several related realistic models, we investigate the general structure of orbifolds in the effective field theory context, and of this orbifold symmetry breaking mechanism in particular. An analysis of the group theoretic structure of orbifold breaking is performed. This depends upon the existence of appropriate inner and outer automorphisms of the Lie algebra, and we show that a reduction of the rank of the GUT group is possible. Some aspects of larger GUT theories based on SO(10) and E-6 are discussed. We explore the possibilities of defining the theory directly on a space with boundaries and breaking the gauge symmetry by more general consistently chosen boundary conditions for the fields. Furthermore, we derive the relation of orbifold breaking with the familiar mechanism of Wilson line breaking, finding a one-to-one correspondence, both conceptually and technically. Finally, we analyse the consistency of orbifold models in the effective field theory context, emphasizing the necessity for self-adjoint extensions of the Hamiltonian and other conserved operators, and especially the highly restrictive anomaly cancellation conditions that apply if the bulk theory lives in more than 5 dimensions. (C) 2002 Published by Elsevier Science B.V. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Calif Berkeley, Theory Grp, LBNL, Berkeley, CA 94720 USA. RP Hebecker, A (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 67 TC 152 Z9 153 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 18 PY 2002 VL 625 IS 1-2 BP 128 EP 150 AR PII S0550-3213(02)00016-0 DI 10.1016/S0550-3213(02)00016-0 PG 23 WC Physics, Particles & Fields SC Physics GA 531CY UT WOS:000174399500004 ER PT J AU Carena, M Ellis, J Pilaftsis, A Wagner, CEM AF Carena, M Ellis, J Pilaftsis, A Wagner, CEM TI Higgs-boson pole masses in the MSSM with explicit CP violation SO NUCLEAR PHYSICS B LA English DT Article ID SUPERSYMMETRIC STANDARD MODEL; ELECTRIC-DIPOLE MOMENTS; ELECTROWEAK PHASE-TRANSITION; N=1 SUPERGRAVITY; RADIATIVE-CORRECTIONS; FERMILAB TEVATRON; GAUGE-INVARIANCE; SOFT PHASES; RENORMALIZATION; UNIFICATION AB Extending previous results obtained in the effective-potential approach, we derive analytic expressions for the pole masses of the charged and neutral Higgs bosons in the minimal supersymmetric standard model (MSSM) with explicit CP violation. In such a minimal supersymmetric model, the CP invariance of the Higgs potential is explicitly broken by quantum effects dominated by third generation squarks at the one-loop level and by one-loop gluino- and higgsino-mediated threshold corrections to the top- and bottom-quark Yukawa couplings at the two-loop level. Field-theoretic issues arising in the description of a two-level Higgs-boson system strongly mixed due to CP violation are addressed. Numerical results for the pole masses of the CP-violating Higgs bosons are presented, and comparisons are made with previous results obtained in the effective-potential approach. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM pilaftsi@theory.ph.man.ac.uk RI Ellis, John/J-2222-2012 OI Ellis, John/0000-0002-7399-0813 NR 88 TC 144 Z9 144 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAR 18 PY 2002 VL 625 IS 1-2 BP 345 EP 371 AR PII S0550-3213(02)00014-7 DI 10.1016/S0550-3213(02)00014-7 PG 27 WC Physics, Particles & Fields SC Physics GA 531CY UT WOS:000174399500015 ER PT J AU Cornelius, AL Lawrence, JM Ebihara, T Riseborough, PS Booth, CH Hundley, MF Pagliuso, PG Sarrao, JL Thompson, JD Jung, MH Lacerda, AH Kwei, GH AF Cornelius, AL Lawrence, JM Ebihara, T Riseborough, PS Booth, CH Hundley, MF Pagliuso, PG Sarrao, JL Thompson, JD Jung, MH Lacerda, AH Kwei, GH TI Two energy scales and slow crossover in YbAl3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERIODIC ANDERSON MODEL; INTERMETALLIC COMPOUNDS; NEUTRON-SCATTERING; HEAVY FERMIONS; EXPANSION; COHERENCE; YBINCU4; LATTICE; VALENT AB Experimental results for the susceptibility, magnetization, specific heat, 4f occupation number, Hall effect, and magnetoresistance for single crystals of the intermediate valence (IV) compound YbAl3 show that, in addition to the Kondo temperature scale T-K similar to 670 K, there is a low temperature scale T-coh similar to 30-40 K for the onset of Fermi liquid coherence. Furthermore, the crossover from the low temperature Fermi liquid regime to the high temperature local moment regime is slower than predicted by the Anderson impurity model. We suggest that these effects are generic for IV compounds and we discuss them in terms of the theory of the Anderson lattice. C1 Univ Nevada, Las Vegas, NV 89154 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Shizuoka Univ, Shizuoka 4228529, Japan. Temple Univ, Philadelphia, PA 19122 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Cornelius, AL (reprint author), Univ Nevada, Las Vegas, NV 89154 USA. EM jmlawren@uci.edu RI Cornelius, Andrew/A-9837-2008; Riseborough, Peter/D-4689-2011; Pagliuso, Pascoal/C-9169-2012; Booth, Corwin/A-7877-2008 NR 19 TC 60 Z9 60 U1 4 U2 22 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 MAR 18 PY 2002 VL 88 IS 11 AR 117201 DI 10.1103/PhysRevLett.88.117201 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QL UT WOS:000174541700038 PM 11909426 ER PT J AU Park, HK Burnstein, RA Chakravorty, A Chan, A Chen, YC Choong, WS Clark, K Dukes, EC Durandet, C Felix, J Gidal, G Gu, P Gustafson, HR Ho, C Holmstrom, T Huang, M James, C Jenkins, CM Kaplan, DM Lederman, LM Leros, N Longo, MJ Lopez, F Lu, L Luebke, W Luk, KB Nelson, KS Perroud, JP Rajaram, D Rubin, HA Teng, PK Volk, J White, C White, S Zyla, P AF Park, HK Burnstein, RA Chakravorty, A Chan, A Chen, YC Choong, WS Clark, K Dukes, EC Durandet, C Felix, J Gidal, G Gu, P Gustafson, HR Ho, C Holmstrom, T Huang, M James, C Jenkins, CM Kaplan, DM Lederman, LM Leros, N Longo, MJ Lopez, F Lu, L Luebke, W Luk, KB Nelson, KS Perroud, JP Rajaram, D Rubin, HA Teng, PK Volk, J White, C White, S Zyla, P CA HyperCP Collaboration TI Observation of the decay K-->pi(-)mu(+)mu(-) and measurements of the branching ratios for K-+/-->pi(+/-)mu(+)mu(-) SO PHYSICAL REVIEW LETTERS LA English DT Article AB Using data collected with the HyperCP ( E871) spectrometer during the 1997 fixed-target run at Fermi-lab, we report the first observation of the decay K 2 ! p 2 m 1 m 2 and new measurements of the branching ratios for K+/- --> pi(+/-) mu(+/-) mu(+) mu(-). By combining the branching ratios for the decays K+ --> pi(+) mu(+) mu(-) and K- --> pi(-) mu(+) mu-, we measure Gamma(K+/- --> pi(+/-) mu(+) mu(-))/Gamma(K+/- --> all) = (9.8 +/- 1.0 +/- 0.5) x 10(-8). The CP asymmetry between the rates of the two decay modes is [Gamma(K+ --> pi(+) mu(+) mu(-)) - Gamma(K- --> pi(-) mu(+) mu(-))]/[Gamma(K+ --> pi(+) mu(+) mu(-)) + Gamma(K- --> pi(-) mu(+) mu(-))] = -0,02 +/- 0.11 +/- 0.04. C1 Univ Michigan, Ann Arbor, MI 48109 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Univ Calif Berkeley, Berkeley, CA 94720 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Guanajuato, Leon 37000, Mexico. IIT, Chicago, IL 60616 USA. Univ Lausanne, CH-1015 Lausanne, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ S Alabama, Mobile, AL 36688 USA. Univ Virginia, Charlottesville, VA 22904 USA. RP Park, HK (reprint author), Univ Michigan, Ann Arbor, MI 48109 USA. NR 11 TC 34 Z9 35 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 MAR 18 PY 2002 VL 88 IS 11 AR 111801 DI 10.1103/PhysRevLett.88.111801 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QL UT WOS:000174541700006 PM 11909394 ER PT J AU Pfeifer, P Ehrburger-Dolle, F Rieker, TP Gonzalez, MT Hoffman, WP Molina-Sabio, M Rodriguez-Reinoso, F Schmidt, PW Voss, DJ AF Pfeifer, P Ehrburger-Dolle, F Rieker, TP Gonzalez, MT Hoffman, WP Molina-Sabio, M Rodriguez-Reinoso, F Schmidt, PW Voss, DJ TI Nearly space-filling fractal networks of carbon nanopores SO PHYSICAL REVIEW LETTERS LA English DT Article ID SMALL-ANGLE SCATTERING; SANDSTONE PORES; NEUTRON-SCATTERING; DISORDERED MEDIA; ENERGY-TRANSFER; X-RAY; DIFFUSION; ROCKS; LATTICES; GLASSES AB Small-angle x-ray scattering, nitrogen adsorption, and scanning tunneling microscopy show that a series of activated carbons host an extended fractal network of channels with dimension D-p = 2.8-3.0 (pore fractal), channel width 15 20 Angstrom (lower end of scaling), network diameter 3000-3400 Angstrom (upper end of scaling), and porosity of 0.3-0.6. We interpret the network as a stack of quasiplanar invasion percolation clusters, formed by oxidative removal of walls between closed voids of diameter of similar to10 Angstrom and held in registry by fibrils of the biological precursor, and point out unique applications. C1 Univ Missouri, Dept Phys, Columbia, MO 65211 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. CNRS, Inst Chim Surfaces & Interfaces, F-68057 Mulhouse, France. Univ New Mexico, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. Univ Alicante, Dept Quim Inorgan, E-03080 Alicante, Spain. USAF, Res Lab, Edwards AFB, CA 93524 USA. RP Pfeifer, P (reprint author), Univ Missouri, Dept Phys, Columbia, MO 65211 USA. RI Rodriguez-Reinoso, Francisco/G-7941-2016 OI Rodriguez-Reinoso, Francisco/0000-0002-4212-9860 NR 52 TC 49 Z9 49 U1 0 U2 6 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 MAR 18 PY 2002 VL 88 IS 11 AR 115502 DI 10.1103/PhysRevLett.88.115502 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QL UT WOS:000174541700019 PM 11909407 ER PT J AU Talon, C Bermejo, FJ Cabrillo, C Cuello, GJ Gonzalez, MA Richardson, JW Criado, A Ramos, MA Vieira, S Cumbrera, FL Gonzalez, LM AF Talon, C Bermejo, FJ Cabrillo, C Cuello, GJ Gonzalez, MA Richardson, JW Criado, A Ramos, MA Vieira, S Cumbrera, FL Gonzalez, LM TI Chemical isomerism as a key to explore free-energy landscapes in disordered matter SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIELECTRIC-RELAXATION; LIQUIDS; NUCLEATION; GLASSES; DIFFRACTION; 1-PROPANOL AB The effects of a minor chemical modi cation on the microscopic structure of a material in its glass and crystal phases are investigated by the concurrent use of neutron diffraction and computer simulation. Significant changes in short-, intermediate-, and long-range order are found, resulting from the change in molecular structure. These differences are explainable by a shift in the balance between directional and excluded-volume interactions. C1 Univ Autonoma Madrid, Dept Fis Mat Condensada, E-28049 Madrid, Spain. Univ Basque Country, Fac Ciencias, Dept Elect & Elect, E-48080 Leioa, Spain. CSIC, E-28006 Madrid, Spain. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Fac Ciencias, Dept Fis Mat Condensada, E-41080 Seville, Spain. Univ Extremadura, Fac Ciencias, Dept Fis, E-06071 Badajoz, Spain. RP Talon, C (reprint author), Univ Autonoma Madrid, Dept Fis Mat Condensada, C-3, E-28049 Madrid, Spain. RI Cuello, Gabriel/C-5831-2009; vieira, sebastian/L-5216-2014; Gonzalez, Miguel/R-8330-2016 OI Cuello, Gabriel/0000-0003-3844-0602; vieira, sebastian/0000-0002-3854-1377; Gonzalez, Miguel/0000-0002-3478-0215 NR 27 TC 32 Z9 32 U1 1 U2 6 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 MAR 18 PY 2002 VL 88 IS 11 AR 115506 DI 10.1103/PhysRevLett.88.115506 PG 4 WC Physics, Multidisciplinary SC Physics GA 533QL UT WOS:000174541700023 PM 11909411 ER PT J AU Yamato, K Bartsch, RA Dietz, ML Rogers, RD AF Yamato, K Bartsch, RA Dietz, ML Rogers, RD TI Improved stereospecific synthesis of the trans-isomers of dicyclohexano-18-crown-6 and the solid-state structure of the trans-syn-trans isomer SO TETRAHEDRON LETTERS LA English DT Article ID MACROCYCLE INTERACTION; KINETIC DATA; MAGNETIC-RESONANCE; NEUTRAL MOLECULES; CROWN ETHERS; CATIONS; ANIONS AB The two trans stereoisomers of dicyclohexano-18-crown-6 are synthesized by a two-step method from cyclohexene oxide and the solid-state structure of the trans syn trans isomer is determined. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RP Bartsch, RA (reprint author), Texas Tech Univ, Dept Chem & Biochem, Lubbock, TX 79409 USA. RI Rogers, Robin/C-8265-2013; Yamato, Kazuhiro/G-4213-2013 OI Rogers, Robin/0000-0001-9843-7494; Yamato, Kazuhiro/0000-0001-9592-0739 NR 25 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD MAR 18 PY 2002 VL 43 IS 12 BP 2153 EP 2156 AR PII S0040-4039(02)00221-6 DI 10.1016/S0040-4039(02)00221-6 PG 4 WC Chemistry, Organic SC Chemistry GA 537DK UT WOS:000174742700007 ER PT J AU Visconti, P Huang, D Yun, F Reshchikov, MA King, T Cingolani, R Jasinski, J Liliental-Weber, Z Morkoc, H AF Visconti, P Huang, D Yun, F Reshchikov, MA King, T Cingolani, R Jasinski, J Liliental-Weber, Z Morkoc, H TI Rapid delineation of extended defects in GaN and a novel method for their reduction SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT International Workshop on Physics of Light-Matter Coupling in Nitrides (PLMCN-1) CY SEP 26-29, 2001 CL ROME, ITALY ID VAPOR-PHASE EPITAXY; LIGHT-EMITTING-DIODES; GALLIUM NITRIDE; GROWN GAN; DISLOCATION DENSITY; LATTICE POLARITY; LATERAL EPITAXY; WURTZITE GAN; BUFFER LAYER; FILMS AB Availability of reliable and quick methods to investigate extended defects and polarity in GaN films are of great interest to researchers investigating and exploiting GaN-based structures. The step immediately following the determination of defect density (DD) is to explore ways in which the DD can be reduced. In this paper, we report a systematic investigation of DD determination in GaN which is followed by a novel technique, use of quantum dots, to reduce the DD. We have used photo-electrochemical (PEC) and hot wet etching to determine the DD. We found the density of whiskers formed by the PEC process to be similar to the density of hexagonal pits formed by wet etching and to the dislocation density obtained by transmission electron microscopy (TEM). Hot wet etching was also used to investigate the polarity of M-BE-gown GaN films together with convergent beam electron diffraction (CBED) and atomic force microscopy (AFM). We have found that hot H3PO4 etches N-polarity GaN films very quickly resulting in the complete removal or a drastic change of surface morphology. We also report on the improvement in the GaN crystal quality by using multiple layers of quantum dots (QDs) as part of a strain-relieving buffer layer. Samples with QDs generally showed narrower X-ray diffraction peaks and higher photoluminescence efficiency than the control samples without QDs. Insertion of QDs reduced the dislocation density, as determined by a defect revealing etch, from similar to10(10) cm(-2) to similar to5 x 10(7) cm(-2). Preliminary TEM investigations show that many of the dislocations terminate at QDs. C1 Virginia Commonwealth Univ, Dept Elect Engn, Richmond, VA 23284 USA. Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. Univ Lecce, Dept Innovat Engn, I-73100 Lecce, Italy. INFM, Natl Nanotechnol Lab, Unit Lecce, I-73100 Lecce, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Morkoc, H (reprint author), Virginia Commonwealth Univ, Dept Elect Engn, Med Coll Virginia Campus, Richmond, VA 23284 USA. RI Cingolani, Roberto/B-9191-2011; Liliental-Weber, Zuzanna/H-8006-2012; VISCONTI, PAOLO/L-7214-2015 OI VISCONTI, PAOLO/0000-0002-4058-4042 NR 36 TC 6 Z9 8 U1 1 U2 8 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD MAR 16 PY 2002 VL 190 IS 1 BP 5 EP 14 DI 10.1002/1521-396X(200203)190:1<5::AID-PSSA5>3.0.CO;2-H PG 10 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 539RC UT WOS:000174883400003 ER PT J AU Brodsky, SJ Hiller, JR McCartor, G AF Brodsky, SJ Hiller, JR McCartor, G TI Exact solutions to Pauli-Villars-regulated field theories SO ANNALS OF PHYSICS LA English DT Article ID LIGHT-CONE QUANTIZATION; FRONT; REGULARIZATION AB We present a new class of quantum field theories which are exactly solvable. The theories are generated by introducing Pauli-Villars (PV) fermionic and bosonic fields with masses degenerate with the physical positive metric fields, An algorithm is given to compute the spectrum and corresponding eigensolutions. We also give the operator solution for a particular case and use it to illustrate some of the tenets of light-cone quantization. Since the solutions of the solvable theory contain ghost quanta, these theories are unphysical. However, the existence of an exact solution provides an important check on the implementation of PV-regulated discretized light-cone quantization (DLCQ). In the limit of exact mass degeneracy of the ghost and physical fields, the numerical DLCQ solutions are constrained to reduce to the explicit forms we give here. We also discuss how perturbation theory in the difference between the masses of the physical and PV particles could be developed. thus generating physical theories. The existence of explicit solutions of the solvable theory also allows one to study the relationship between the equal-time and light-cone vacua and eigensolutions. (C) 2002 Elsevier Science (USA). C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Minnesota, Dept Phys, Duluth, MN 55812 USA. So Methodist Univ, Dept Phys, Dallas, TX 75275 USA. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 14 TC 18 Z9 18 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 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD MAR 15 PY 2002 VL 296 IS 2 BP 406 EP 424 DI 10.1006/aphy.2002.6225 PG 19 WC Physics, Multidisciplinary SC Physics GA 542YY UT WOS:000175074400012 ER PT J AU Jang, BWL Reynolds, JG Boutonnet, M Spivey, JJ AF Jang, BWL Reynolds, JG Boutonnet, M Spivey, JJ TI Catalysis and plasma technology - Preface SO CATALYSIS TODAY LA English DT Editorial Material C1 Texas A&M Univ, Dept Chem, Commerce, TX 75429 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Royal Inst Technol, Dept Chem Engn & Technol, S-10044 Stockholm, Sweden. N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. RP Jang, BWL (reprint author), Texas A&M Univ, Dept Chem, POB 3011, Commerce, TX 75429 USA. NR 0 TC 2 Z9 2 U1 3 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD MAR 15 PY 2002 VL 72 IS 3-4 BP 171 EP 171 AR PII S0920-5861(01)00490-4 DI 10.1016/S0920-5861(01)00490-4 PG 1 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 546MN UT WOS:000175278000001 ER PT J AU Yoon, S Panov, AG Tonkyn, RG Ebeling, AC Barlow, SE Balmer, ML AF Yoon, S Panov, AG Tonkyn, RG Ebeling, AC Barlow, SE Balmer, ML TI An examination of the role of plasma treatment for lean NOx reduction over sodium zeolite Y and gamma alumina Part 1. Plasma assisted NOx reduction over NaY and Al2O3 SO CATALYSIS TODAY LA English DT Article; Proceedings Paper CT 220th National Meeting of the American-Chemical-Society CY AUG 19-23, 2000 CL WASHINGTON, D.C. SP Amer Chem Soc DE chemiluminescent; compression ignition; zeolite AB The role of plasma processing on NOx reduction over gamma-alumina and a basic zeolite, NaY was examined. During the plasma treatment NO is oxidized to NO2 and propylene is partially oxidized to CO, CO2, acetaldehyde, and formaldehyde. With plasma treatment, NO as the NOx gas, and a NaY catalyst, the maximum NOx conversion was 70% between 180 and 230 degreesC. The activity decreased at higher and lower temperatures. As high as 80% NOx removal over gamma alumina was measured by a chemiluminescent NOx meter with plasma treatment and NO as the NOx gas. For both catalysts a simultaneous decrease in NOx and aldehydes concentrations was observed, which suggests that aldehyde may be important components for NOx reduction in plasma-treated exhaust. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Balmer, ML (reprint author), Caterpillar Inc, Technol Ctr E854, POB 1875, Peoria, IL 61656 USA. NR 17 TC 56 Z9 64 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD MAR 15 PY 2002 VL 72 IS 3-4 BP 243 EP 250 AR PII S0920-5861(01)00499-0 DI 10.1016/S0920-5861(01)00499-0 PG 8 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 546MN UT WOS:000175278000010 ER PT J AU Yoon, S Panov, AG Tonkyn, RG Ebeling, AC Barlow, SE Balmer, ML AF Yoon, S Panov, AG Tonkyn, RG Ebeling, AC Barlow, SE Balmer, ML TI An examination of the role of plasma treatment for lean NOx reduction over sodium zeolite Y and gamma alumina Part 2. Formation of nitrogen SO CATALYSIS TODAY LA English DT Article; Proceedings Paper CT 220th National Meeting of the American-Chemical-Society CY AUG 19-23, 2000 CL WASHINGTON, D.C. SP Amer Chem Soc DE plasma treatment; gamma-alumina; chemiluminescent AB NOx reduction with NO2 as the NOx gas in the absence of plasma was compared to plasma treated lean NOx exhaust where NO is converted to NO2 in the plasma. Product nitrogen was measured to prove true chemical reduction of NOx to N-2. With plasma treatment, NO as the NOx gas, and a NaY catalyst, the maximum conversion to nitrogen was 50% between 180 and 230degreesC. The activity decreased at higher and lower temperatures. At 130 C a complete nitrogen balance could be obtained, however between 164 and 227 degreesC less than 20% of the NOx is converted to a nitrogen-containing compound or compounds not readily detected by gas chromatograph (GC) or Fourier transform infrared spectrometer (FT-IR) analysis. With plasma treatment, NO2 as the NOx gas, and a NaY catalyst, a complete nitrogen balance is obtained with a maximum conversion to nitrogen of 55% at 225degreesC. For gamma-alumina, with plasma treatment and NO2 as the NOx gas, 59% of the NOx is converted to nitrogen at 340degreesC. A complete nitrogen balance was obtained at these conditions. As high as 80% NOx removal over gamma-alumina was measured by a chemiluminescent NOx meter with plasma treatment and NO as the NOx gas. When NO is replaced with NO2 and the simulated exhaust gases are not plasma treated, the maximum NO, reduction activity of NaY and gamma-alumina decreases to 26 and 10%, respectively. This is a large reduction in activity compared to similar conditions where the simulated exhaust was plasma treated, Therefore, in addition to NO2, other plasma-generated species are required to maximize NOx reduction. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Balmer, ML (reprint author), Caterpillar Inc, Technol Ctr E854, POB 1875, Peoria, IL 61656 USA. NR 11 TC 24 Z9 30 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD MAR 15 PY 2002 VL 72 IS 3-4 BP 251 EP 257 AR PII S0920-5861(01)00501-6 DI 10.1016/S0920-5861(01)00501-6 PG 7 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 546MN UT WOS:000175278000011 ER EF