FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Kandhai, D Soll, W Chen, S Hoekstra, A Sloot, P AF Kandhai, D Soll, W Chen, S Hoekstra, A Sloot, P TI Finite-Difference Lattice-BGK methods on nested grids SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT 8th International Symposium on the Discrete Simulation of Fluid Dynamics (LGA99) CY JUL 28-30, 1999 CL UNIV TOKYO, TOKYO, JAPAN HO UNIV TOKYO ID BOLTZMANN-EQUATION; SCHEME AB From a computational point of view non uniform grids can be efficient for computing fluid flows because the grid resolution can be adapted to the spatial complexity of the flow problem. In this contribution an extension of the Finite-Difference Lattice-BGK method on nested grids is presented. This approach is based on multiple nested lattices with increasing resolution. Basically, the discrete velocity Boltzmann equation is solved numerically on each sub-lattice and interpolation between the interfaces is carried out in order to couple the sub-grids consistently. Preliminary results of the method applied on the Taylor vortex benchmark are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Amsterdam, Sect Computat Sci, NL-1098 SJ Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM USA. RP Kandhai, D (reprint author), Univ Amsterdam, Sect Computat Sci, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. RI Chen, Shiyi/A-3234-2010 NR 13 TC 21 Z9 22 U1 0 U2 3 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 JUL PY 2000 VL 129 IS 1-3 BP 100 EP 109 DI 10.1016/S0010-4655(00)00097-7 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 336XH UT WOS:000088327900012 ER PT J AU Zhang, RY He, XY Chen, SY AF Zhang, RY He, XY Chen, SY TI Interface and surface tension in incompressible lattice Boltzmann multiphase model SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT 8th International Symposium on the Discrete Simulation of Fluid Dynamics (LGA99) CY JUL 28-30, 1999 CL UNIV TOKYO, TOKYO, JAPAN HO UNIV TOKYO ID RAYLEIGH-TAYLOR INSTABILITY; FLUID-FLOWS; LIQUID-GAS; SIMULATION; EQUATION AB This paper studies the interfacial dynamics and surface tension in an incompressible lattice Boltzmann multiphase model proposed recently by He et al. [J. Comput. Phys. 152 (1999) 642]. The model tracks different phases and the interface between them using an index fluid with molecular interaction. When the molecular interaction is strong enough, the index fluid automatically segregates into two different phases. The surface tension is implemented in the model using a term as a function of the gradient of the index fluid density. The strength of the surface tension depends on the molecular interaction, and can be adjusted conveniently by a free parameter. Numerical simulations for a variety of flow conditions with surface tension are carried out to demonstrate the capability of the model. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM 87545 USA. RP Zhang, RY (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. RI Chen, Shiyi/A-3234-2010 NR 23 TC 45 Z9 46 U1 0 U2 8 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 JUL PY 2000 VL 129 IS 1-3 BP 121 EP 130 DI 10.1016/S0010-4655(00)00099-0 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 336XH UT WOS:000088327900014 ER PT J AU He, XY Li, N AF He, XY Li, N TI Lattice Boltzmann simulation of electrochemical systems SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article; Proceedings Paper CT 8th International Symposium on the Discrete Simulation of Fluid Dynamics (LGA99) CY JUL 28-30, 1999 CL UNIV TOKYO, TOKYO, JAPAN HO UNIV TOKYO DE electrochemistry; lattice Boltzmann method; boundary condition ID RAYLEIGH-TAYLOR INSTABILITY; BGK MODELS; FLOW; DIFFUSION; EQUATIONS; FLUIDS AB We propose a lattice Boltzmann model for studying electrochemical processes. A new lattice Boltzmann equation is introduced to simulate ion transports, including migration in an electric field, diffusion in a concentration gradient, and convection with fluid flow. The electrode reaction is incorporated via special boundary conditions for electric potential and ion flux. Benchmark studies on a variety of electrochemical problems, including the convective diffusion, the primary and secondary current distributions, and a general case, yield satisfactory results. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP He, XY (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 24 TC 83 Z9 85 U1 1 U2 16 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 JUL PY 2000 VL 129 IS 1-3 BP 158 EP 166 DI 10.1016/S0010-4655(00)00103-X PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 336XH UT WOS:000088327900018 ER PT J AU Garcia, HE AF Garcia, HE TI Operational analysis and improvement of a spent nuclear fuel handling and treatment facility using discrete event simulation SO COMPUTERS & INDUSTRIAL ENGINEERING LA English DT Article DE discrete event simulation; operational analysis; nuclear waste management AB Spent nuclear fuel handling and treatment often require facilities with a high level of operational complexity. Simulation models can reveal undesirable characteristics and production problems before they become readily apparent during system operations. The value of this approach is illustrated here through an operational study; using discrete event modeling techniques, to analyze the Fuel Conditioning Facility at Argonne National Laboratory and to identify enhanced nuclear waste treatment configurations. The modeling approach and results of what-if studies are discussed. An example on how to improve productivity is presented. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Garcia, HE (reprint author), Argonne Natl Lab, POB 2528,Bldg 713, Idaho Falls, ID 83403 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-8352 J9 COMPUT IND ENG JI Comput. Ind. Eng. PD JUL PY 2000 VL 38 IS 2 BP 235 EP 249 DI 10.1016/S0360-8352(00)00039-5 PG 15 WC Computer Science, Interdisciplinary Applications; Engineering, Industrial SC Computer Science; Engineering GA 366NW UT WOS:000090012300002 ER PT J AU Burnett, T Chaput, C Arrighi, H Norris, J Suson, DJ AF Burnett, T Chaput, C Arrighi, H Norris, J Suson, DJ TI Simulating the Glast satellite with Gismo SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article AB A Monte Carlo simulation package plays a significant role in the design of the Gamma Ray Large Area Space Telescope, The successor to the Compton Gamma Ray Observatory. C1 Univ Washington, Seattle, WA 98195 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. NASA, Goddard Space Flight Ctr, Compton Observ Sci Support Ctr, Greenbelt, MD USA. Texas A&M Univ, Kingsville, TX USA. RP Burnett, T (reprint author), Univ Washington, Seattle, WA 98195 USA. NR 7 TC 8 Z9 9 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD JUL-AUG PY 2000 VL 2 IS 4 BP 9 EP 18 DI 10.1109/5992.852387 PG 10 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 329UK UT WOS:000087926500004 ER PT J AU Heikoop, JM Dunn, JJ Risk, MJ Tomascik, T Schwarcz, HP Sandeman, IM Sammarco, PW AF Heikoop, JM Dunn, JJ Risk, MJ Tomascik, T Schwarcz, HP Sandeman, IM Sammarco, PW TI delta(15) N and delta C-13 of coral tissue show significant inter-reef variation SO CORAL REEFS LA English DT Article DE corals; isotopes; nitrogen; carbon ID CONTINENTAL SHELF TRENDS; NITROGEN ISOTOPE RATIOS; GREAT-BARRIER-REEF; PRIMARY PRODUCERS; DELTA-N-15; CARBON; ZOOXANTHELLAE; CALIFORNIA; ECOSYSTEM; MANGROVE C1 McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4M1, Canada. Dalhousie Univ, Sch Resource & Environm Sci, Halifax, NS, Canada. Trent Univ, Dept Biol, Peterborough, ON K9J 7B8, Canada. Louisiana Univ Marine Consortium, Chauvin, LA 70344 USA. RP Heikoop, JM (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Geol & Geochem Grp EES1, MS-D462, Los Alamos, NM 87545 USA. RI Heikoop, Jeffrey/C-1163-2011 NR 33 TC 34 Z9 34 U1 0 U2 13 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD JUL PY 2000 VL 19 IS 2 BP 189 EP 193 DI 10.1007/s003380000092 PG 5 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 341WM UT WOS:000088614000013 ER PT J AU Zou, F Isaacs, HS Thierry, D AF Zou, F Isaacs, HS Thierry, D TI Interpretation of AC surface current density by deconvolution of potential differences in solution SO CORROSION SCIENCE LA English DT Article DE AC surface current; current density; deconvolution; solution potential difference ID ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY; CORROSION; PROBE AB In localized electrochemical impedance techniques, the measurable AC potential difference in solution is related to the AC surface current distribution simply by using Ohm's law. However, this relationship is not true for the cases in which current distribution is non-uniform. In order to correctly obtain the surface current density, deconvolutions of the solution potential difference using the base line stripping procedure and the Fast Fourier Transform method have been simulated and discussed. A more accurate spatial estimate of the surface current density distribution can be obtained by deconvoluting the measured potential difference distribution in the solution than by simply using Ohm's law. The accuracy of the deconvolution using the base line stripping procedure is greatly dependent on the errors of measurement, and experimental data with a very low noise level are therefore required. Deconvolution by a Fast Fourier Transform is also very sensitive to noise and discontinuity in the potential difference distribution, but the sensitivity can be dramatically reduced to an acceptable level by using a low pass filter. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Swedish Corros Inst, S-10405 Stockholm, Sweden. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. RP Thierry, D (reprint author), Swedish Corros Inst, Roslagsvagen 101 Hus 25, S-10405 Stockholm, Sweden. NR 15 TC 5 Z9 5 U1 0 U2 2 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 JUL PY 2000 VL 42 IS 7 BP 1149 EP 1167 DI 10.1016/S0010-938X(99)00133-X PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 314MD UT WOS:000087059100002 ER PT J AU Turteltaub, KW Vogel, JS AF Turteltaub, KW Vogel, JS TI Bioanalytical applications of accelerator mass spectrometry for pharmaceutical research SO CURRENT PHARMACEUTICAL DESIGN LA English DT Review ID HETEROCYCLIC AMINE CARCINOGENS; BIOMEDICAL APPLICATIONS; COVALENT BINDING; ADDUCT FORMATION; HUMAN METABOLISM; AMS-FACILITY; ION SOURCES; FOLIC-ACID; DNA-ADDUCT; ALUMINUM AB Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying isotopes. It has had great impact in the geosciences and is now being applied in the biomedical fields. AMS measures radioisotopes such as C-14, H-3, C-41, and Cl-36, and others, with attomole sensitivity and high precision. Its use is allowing absorption, distribution, metabolism and elimination studies, as well as detailed pharmacokinetics, to be carried out directly in humans with very low chemical or radiological hazard. It is used in combination with standard separation methodologies, such as chromatography, in identification of metabolites and molecular targets for both toxicants and pharmacologic agents. AMS allows the use of very low specific activity chemicals (less than or equal to 1 mCi/mmol), creating opportunities to use compounds not available in a high specific activity form, such as those that must be biosynthesized, produced in combinatorial libraries, or made through inefficient synthesis. AMS is allowing studies to be carried out with agents having low bioavailability, low systemic distributions, or high toxicity where administered doses must be kept low (less than or equal to 1 mu g/kg). It may have uses in tests for idiosyncratic metabolism, drug interaction, or individual susceptibility, among others. The ability to use very low chemical doses, low radiological doses, small samples and conduct multiple dose studies may help move drug candidates into humans faster and safer than before. The uses of AMS are growing and its potential for drug development is only now beginning to be realized. C1 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry & Biol, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Biol Res Program, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry & Biol, 7000 East Ave, Livermore, CA 94551 USA. EM turteltaub2@llnl.gov FU NCI NIH HHS [CA55861]; NIDDK NIH HHS [DK45939]; NIEHS NIH HHS [ES09690] NR 75 TC 56 Z9 56 U1 0 U2 4 PU BENTHAM SCIENCE PUBL LTD PI SHARJAH PA EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES SN 1381-6128 EI 1873-4286 J9 CURR PHARM DESIGN JI Curr. Pharm. Design PD JUL PY 2000 VL 6 IS 10 BP 991 EP 1007 DI 10.2174/1381612003400047 PG 17 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 329UH UT WOS:000087926300003 PM 10828298 ER PT J AU Saljoughian, M Williams, PG AF Saljoughian, M Williams, PG TI Recent developments in tritium incorporation for radiotracer studies SO CURRENT PHARMACEUTICAL DESIGN LA English DT Review ID ACCELERATOR MASS-SPECTROMETRY; HOMOGENEOUS RHODIUM TRICHLORIDE; METHYLOCOCCUS-CAPSULATUS BATH; HIGH SPECIFIC RADIOACTIVITY; HYDROGEN ISOTOPE-EXCHANGE; ACID RELATED-COMPOUNDS; METHANE MONOOXYGENASE; NMR CHARACTERIZATION; CATALYTIC EXCHANGE; ORGANOIRIDIUM CATALYSIS AB The essential nature of rapid radiotracer synthesis very early in drug discovery programs has driven the need for better and more varied tritium incorporation methods. This review presents a summary of recent advances for tritium introduction via tritiated water, tritium gas, complex tritides, and a range of recently improved tritiation reagents. Access to a wider range of tritiated reagents (for tritioacetylation, tritioformylation, methylation, etc.) and commercial manifolds for the transfer and use of tritium gas is also discussed. C1 Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Williams, PG (reprint author), Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Phys Biosci Div, Natl Tritium Labelling Facil,Mailstop 75-123,1 Cy, Berkeley, CA 94720 USA. FU NCRR NIH HHS [P41RR01237] NR 144 TC 34 Z9 34 U1 2 U2 5 PU BENTHAM SCIENCE PUBL LTD PI HILVERSUM PA PO BOX 1673, 1200 BR HILVERSUM, NETHERLANDS SN 1381-6128 J9 CURR PHARM DESIGN JI Curr. Pharm. Design PD JUL PY 2000 VL 6 IS 10 BP 1029 EP 1056 DI 10.2174/1381612003399969 PG 28 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 329UH UT WOS:000087926300005 PM 10828300 ER PT J AU Xu, D Xu, Y Uberbacher, EC AF Xu, Dong Xu, Ying Uberbacher, Edward C. TI Computational Tools For Protein Modeling SO CURRENT PROTEIN & PEPTIDE SCIENCE LA English DT Review AB Protein modeling is playing a more and more important role in protein and peptide sciences due to improvements in modeling methods, advances in computer technology, and the huge amount of biological data becoming available. Modeling tools can often predict the structure and shed some light on the function and its underlying mechanism. They can also provide insight to design experiments and suggest possible leads for drug design. This review attempts to provide a comprehensive introduction to major computer programs, especially on-line servers, for protein modeling. The review covers the following aspects: (1) protein sequence comparison, including sequence alignment/search, sequence-based protein family classification, domain parsing, and phylogenetic classification; (2) sequence annotation, including annotation/prediction of hydrophobic profiles, transmembrane regions, active sites, signaling sites, and secondary structures; (3) protein structure analysis, including visualization, geometry analysis, structure comparison/classification, dynamics, and electrostatics; (4) three-dimensional structure prediction, including homology modeling, fold recognition using threading, ab initio prediction, and docking. We will address what a user can expect from the computer tools in terms of their strengths and limitations. We will also discuss the major challenges and the future trends in the field. A collection of the links of tools can be found at http://compbio.ornl.gov/structure/resource/. C1 [Xu, Dong; Xu, Ying; Uberbacher, Edward C.] Oak Ridge Natl Lab, Computat Biosci Sect, Div Life Sci, Oak Ridge, TN 37831 USA. RP Xu, D (reprint author), Oak Ridge Natl Lab, Computat Biosci Sect, 1060 Commerce Pk Dr, Oak Ridge, TN 37830 USA. EM xud@ornl.gov FU Office of Health and Environmental Research, U.S. Department of Energy, with Lockheed Martin Energy Research Corporation [DE-AC05-96OR22464] FX We thank Dr. Michael A. Unseren for a critical reading of this manuscript. We also thank Drs. Oakley H. Crawford and J. Ralph Einstein for helpful discussions. This research was sponsored by the Office of Health and Environmental Research, U.S. Department of Energy, under Contract No. DE-AC05-96OR22464 with Lockheed Martin Energy Research Corporation. NR 178 TC 38 Z9 40 U1 0 U2 11 PU BENTHAM SCIENCE PUBL LTD PI SHARJAH PA EXECUTIVE STE Y26, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES SN 1389-2037 J9 CURR PROTEIN PEPT SC JI Curr. Protein Pept. Sci. PD JUL PY 2000 VL 1 IS 1 BP 1 EP 21 DI 10.2174/1389203003381469 PG 21 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA V13FY UT WOS:000207653900002 PM 12369918 ER PT J AU Steinzig, M Harlow, F AF Steinzig, M Harlow, F TI Determination of final average grain size in alloy solidification SO DIE CASTING ENGINEER LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Steinzig, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU DIE CASTING ENGINEER PI ROSEMONT PA 9701 W HIGGINS RD, SUITE 880, ROSEMONT, IL 60018-4721 USA SN 0012-253X J9 DIE CAST ENG JI Die Cast. Eng. PD JUL-AUG PY 2000 VL 44 IS 4 BP 48 EP 50 PG 3 WC Engineering, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Metallurgy & Metallurgical Engineering GA 341NE UT WOS:000088595800015 ER PT J AU Thom, RM AF Thom, RM TI Adaptive management of coastal ecosystem restoration projects SO ECOLOGICAL ENGINEERING LA English DT Article; Proceedings Paper CT Symposium on Goal Setting and Success Criteria for Coastal Habitat Restoration CY JAN 13-15, 1998 CL CHARLESTON, SOUTH CAROLINA DE adaptive management; coastal ecosystem restoration; salt marsh; seagrass AB There is a clear need to apply better and more affective management schemes to coastal ecosystem restoration projects. It is very common for aquatic ecosystem restoration projects not to meet their goals. Poor performance has led to a high degree of uncertainty about the potential success of any restoration effort. Under adaptive management, the knowledge gained through monitoring of the project and social policies is translated into restoration policy and program redesign. Planners and managers can utilize the information from the monitoring programs in an effective way to assure that project goals are met or that informed and objective decisions are made to address both ecological and societal needs. The three main ingredients of an effective adaptive management plan in a restoration project are: 1. a clear goal statement; 2. a conceptual model; and 3. a decision framework. The goal 'drives' the design of the project and helps guide the development of performance criteria. The goal statement and performance criteria provide the means by which the system can be judged. With the conceptual model, the knowledge base from the field of ecological science plays an active and critical role in designing the project to meet the goal. A system-development matrix provides a simple decision framework to view the alternative states for the system during development, incorporate knowledge gained through the monitoring program, and formulate a decision on actions to take if the system is not meeting its goal. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Battelle Marine Sci Lab, Sequim, WA 98382 USA. RP Thom, RM (reprint author), Battelle Marine Sci Lab, 1529 W Sequim Bay Rd, Sequim, WA 98382 USA. NR 14 TC 46 Z9 49 U1 6 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-8574 J9 ECOL ENG JI Ecol. Eng. PD JUL PY 2000 VL 15 IS 3-4 BP 365 EP 372 DI 10.1016/S0925-8574(00)00086-0 PG 8 WC Ecology; Engineering, Environmental; Environmental Sciences SC Environmental Sciences & Ecology; Engineering GA 340RW UT WOS:000088549600015 ER PT J AU Martin, MJ Stirling, CM Humphries, SW Long, SP AF Martin, MJ Stirling, CM Humphries, SW Long, SP TI A process-based model to predict the effects of climatic change on leaf isoprene emission rates SO ECOLOGICAL MODELLING LA English DT Article DE isoprene emissions; climate change; elevated carbon dioxide; temperature ID NATURAL HYDROCARBONS; SYNTHASE ACTIVITY; PHOTOSYNTHESIS; LEAVES; CO2; PLANTS; PHOTORESPIRATION; DIPHOSPHATE; TEMPERATURE; OZONE AB A process-based model was constructed around the current knowledge of the biochemical pathway of isoprene synthesis, with the objective of producing a new model of high mechanistic content to simulate the effects of environmental change on rates of isoprene emission, and thus enable the prediction of emission rates under future climates. The model was based on the three potentially limiting processes underlying isoprene synthesis: pyruvate supply to provide the substrate of isoprene carbon, supply of adenosine triphosphate (ATP) for phosphorylation to dimethylallyl pyrophosphate (DMAPP), and the rate of isoprene synthesis from DMAPP, which was controlled by the temperature dependency of the enzyme isoprene synthase. Using mechanistic methods wherever possible, model simulations predicted the relative effects of changing photon flux density, carbon dioxide concentrations and temperature on leaf isoprene emission rates. The model was used to predict the interactive effects of elevated concentrations of carbon dioxide and temperature on rates of isoprene emission. Simulations indicated that the effects of carbon dioxide and temperature on isoprene emission rates were complicated by the interactive effects of two of the controlling rate-limiting processes in the synthesis of isoprene, namely phosphorylation rates and isoprene synthase activity. Under present concentrations of carbon dioxide and at photon flux density levels above ca. 500 mu mol m(-2) s(-1) the controlling rate process is the temperature dependency of isoprene synthase. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Essex, Dept Biol Sci, John Tabor Labs, Colchester CO4 3SQ, Essex, England. Univ Wales, Sch Agr & Forest Sci, Bangor LL57 2UW, Gwynedd, Wales. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Illinois, Dept Crop Sci, Urbana, IL 61801 USA. Univ Illinois, Dept Plant Biol, Edward R Madigan Lab 190, Urbana, IL 61801 USA. RP Martin, MJ (reprint author), Univ Essex, Dept Biol Sci, John Tabor Labs, Colchester CO4 3SQ, Essex, England. RI Long, Stephen/A-2488-2008 OI Long, Stephen/0000-0002-8501-7164 NR 44 TC 40 Z9 40 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD JUL 1 PY 2000 VL 131 IS 2-3 BP 161 EP 174 DI 10.1016/S0304-3800(00)00258-1 PG 14 WC Ecology SC Environmental Sciences & Ecology GA 342UT UT WOS:000088664100005 ER PT J AU Jager, HI Hargrove, WW Brandt, CC King, AW Olson, RJ Scurlock, JMO Rose, KW AF Jager, HI Hargrove, WW Brandt, CC King, AW Olson, RJ Scurlock, JMO Rose, KW TI Constructive contrasts between modeled and measured climate responses over a regional scale SO ECOSYSTEMS LA English DT Article DE constructive model validation; residual analysis; regional analysis; regression; net primary productivity ID NET PRIMARY PRODUCTION; GLOBAL-MODEL; GRASSLANDS; REGRESSION; QUALITY; SAMPLE AB Reducing uncertainty in predictions of regional-scale models depends on meaningful contrasts with field measurements. This paper introduces a two-stage process that works from the premise that an appropriate goal for regional models is to produce reasonable behavior over dominant environmental gradients. We demonstrate two techniques for contrasting models with data, one based on the shape of modeled relationships (functional contrasts) and the other based on an examination of the residuals (residual contrasts) between the model and an empirically derived surface fit to field data. Functional contrasts evaluated the differences between the response of simulated net primary production (NPP) to climate variables and the response observed in field measurements of NPP. Residual contrasts compared deviations of NPP from the empirical surface to identify groupings (for example, vegetation classes, geographic regions) with model deviations different from those of the field data. In all model-data contrasts, we assigned sample weights to field measurements to ensure unbiased representation of the region, and we included both constructive comparisons and formal statistical tests. In general, we learned more from constructive methods designed to reveal structure or pattern in discrepancy than we did from statistical tests designed to falsify models. Although our constructive methods were more subjective and less concise, they succeeded in revealing gaps in our understanding of regional-scale processes that can guide future efforts to reduce scientific uncertainty. This was best illustrated by NPP predictions from the Biome-BGC model, which showed a stronger response to precipitation than apparently operates in the field. In another case, differences revealed in savanna and dry woodlands had insufficient field-data support, suggesting a need for future field studies to improve understanding in this, and other, poorly studied ecosystems. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Louisiana State Univ, Baton Rouge, LA 70808 USA. RP Jager, HI (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 36 TC 10 Z9 11 U1 0 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-9840 J9 ECOSYSTEMS JI Ecosystems PD JUL-AUG PY 2000 VL 3 IS 4 BP 396 EP 411 DI 10.1007/s100210000035 PG 16 WC Ecology SC Environmental Sciences & Ecology GA 348KP UT WOS:000088984300007 ER PT J AU Walls, HJ Zawodzinski, TA AF Walls, HJ Zawodzinski, TA TI Anion and cation transference numbers determined by electrophoretic NMR of polymer electrolytes sum to unity SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID TRANSPORT-PROPERTIES; COMPOSITE ELECTROLYTES; ION-TRANSPORT; FUMED SILICA; LITHIUM; RHEOLOGY; CELLS; GEL AB The lithium ion transference number (T-Li) and anion transference number (T-F) were determined for composite polymer electrolytes based on ethylene oxide (250 M-n) and hydrophobic fumed silica. These transference numbers were measured using electrophoretic nuclear magnetic resonance (ENMR), which essentially is a rapid Hittorf method. We demonstrated the validity and power of the ENMR technique by independently measuring both T+ and T- for a single sample and showed that T+ + T- = 1 (within experimental error). Measurement of T-F is typically easier and more accurate than measurement of T-Li. ENMR is a powerful technique for characterizing polymer electrolytes without the need for assumptions, such as treatment of the electrolyte as an ideal solution, or for multiple measurements and regressions, as required by methods based on concentrated solution theory. (C) 2000 The Electrochemical Society. S1099-0062(00)02-105-2. All rights reserved. C1 N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Elect Mat & Device Grp, Los Alamos, NM 87545 USA. RP Walls, HJ (reprint author), N Carolina State Univ, Dept Chem Engn, Raleigh, NC 27695 USA. NR 22 TC 13 Z9 13 U1 1 U2 13 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 JUL PY 2000 VL 3 IS 7 BP 321 EP 324 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 319CX UT WOS:000087323300007 ER PT J AU Feldberg, SW AF Feldberg, SW TI On the dilemma of the use of the electroneutrality constraint in electrochemical calculations SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE electroneutrality; Nernst-Planck; Poisson; Gouy-Chapman; charge density; electric field AB A simple treatment is developed to demonstrate that invoking the electroneutrality assumption to solve electrochemical transport problems is equivalent to invoking the limit of the exact (Nernst-Planck-Poisson) treatment when certain charge-density-related terms become negligibly small. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Brookhaven Natl Lab, Energy Sci & Technol Dept, Upton, NY 11973 USA. RP Feldberg, SW (reprint author), Brookhaven Natl Lab, Energy Sci & Technol Dept, Upton, NY 11973 USA. NR 9 TC 21 Z9 21 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1388-2481 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD JUL PY 2000 VL 2 IS 7 BP 453 EP 456 DI 10.1016/S1388-2481(00)00055-2 PG 4 WC Electrochemistry SC Electrochemistry GA 330RY UT WOS:000087976000001 ER PT J AU Martinovic, S Pasa-Tolic, L Masselon, C Jensen, PK Stone, CL Smith, RD AF Martinovic, S Pasa-Tolic, L Masselon, C Jensen, PK Stone, CL Smith, RD TI Characterization of human alcohol dehydrogenase isoenzymes by capillary isoelectric focusing-mass spectrometry SO ELECTROPHORESIS LA English DT Article DE human alcohol dehydrogenase; noncovalent complexes; capillary isoelectric focusing; mass spectrometry ID POLYACRYLAMIDE GELS; INHIBITOR COMPLEXES; PROTEIN COMPLEXES; BINDING; DISSOCIATION; BIOMOLECULES; ACCURACY; SEQUENCE; VARIANTS AB The human liver alcohol dehydrogenase (ADH) isoenzymes are currently believed to play a major role in ethanol metabolism, accounting for most of the ethanol oxidized in the liver. They have similar molecular masses and similar isoelectric point (pi) values (the 13 possible isoenzymes having pls in the range of 8.26-8.87), making their characterization a significant analytical challenge. Capillary isoelectric focusing (CIEF) coupled on-line with electrospray ionization - Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry was applied to separate and characterize mixtures of alpha alpha, beta(1)beta(1) and beta(3)beta(3) ADH isoenzymes. Seven different species were resolved by the separation in the p/ 8.26-8.67 range. ESI-FTICR analysis of native ADHs revealed that each noncovalent ADH complex contains two monomeric protein units and four zinc atoms. The combination of CIEF separations with mass spectrometry appears well-suited for detailed characterization of ADH isozymes, and the attomole level sensitivity of FTICR should allow very small samples to be addressed. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. Stevens Inst Technol, Dept Chem & Biol Chem, Hoboken, NJ 07030 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm & Mol Sci Lab, POB 999,MSIN K8-98, Richland, WA 99352 USA. RI Masselon, Christophe/A-2340-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NIAAA NIH HHS [AA 11633] NR 40 TC 20 Z9 22 U1 0 U2 7 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD JUL PY 2000 VL 21 IS 12 BP 2368 EP 2375 DI 10.1002/1522-2683(20000701)21:12<2368::AID-ELPS2368>3.0.CO;2-F PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 335UG UT WOS:000088262700011 PM 10939447 ER PT J AU Unander, F Karbuz, S Schipper, L Khrushch, M Ting, M AF Unander, F Karbuz, S Schipper, L Khrushch, M Ting, M TI Manufacturing energy use in OECD countries: decomposition of long-term trends (vol 27, pg 769, 1999) SO ENERGY POLICY LA English DT Correction C1 Int Energy Agcy, F-75739 Paris 15, France. Lawrence Berkeley Lab, Berkeley, CA USA. RP Unander, F (reprint author), Int Energy Agcy, 9 Rue Federat, F-75739 Paris 15, France. NR 2 TC 0 Z9 0 U1 0 U2 0 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 JUL PY 2000 VL 28 IS 8 BP 567 EP 567 DI 10.1016/S0301-4215(00)00047-1 PG 1 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 315MK UT WOS:000087117400007 ER PT J AU Rubin, J Leiby, P AF Rubin, J Leiby, P TI An analysis of alternative fuel credit provisions of US automotive fuel economy standards SO ENERGY POLICY LA English DT Article DE alternative fuels; energy policy; CAFE standards AB In the United States, alternative fuel vehicles are treated favorably in the calculations that are used to determine compliance with automotive fuel efficiency standards. We estimate that this favorable treatment is worth approximately $550-$1100 per alternative fuel vehicle in terms of avoided penalties. We use a dynamic simulation model to examine the implications of this favorable treatment of alternative fuel vehicles for the goals of oil displacement contained in the United States Energy Policy Act. Welfare analysis shows that the favorable treatment of alternative fuel vehicles costs $66 million or about 84 cents per gallon of gasoline displaced in the base case. Policy scenarios show greater costs. Whether this money is well spent depends on one's views of the need to build alternative fuel and vehicle infrastructure anti the goal of oil displacement. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Maine, Margaret Chase Smith Ctr Publ Policy, Dept Resource Econ & Policy, Orono, ME 04469 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Rubin, J (reprint author), Univ Maine, Margaret Chase Smith Ctr Publ Policy, Dept Resource Econ & Policy, 5715 Coburn Hall, Orono, ME 04469 USA. NR 29 TC 11 Z9 11 U1 0 U2 0 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 JUL PY 2000 VL 28 IS 9 BP 589 EP 601 DI 10.1016/S0301-4215(00)00046-X PG 13 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 327XC UT WOS:000087818900003 ER PT J AU Reddy, CM Heraty, LJ Holt, BD Sturchio, NC Eglinton, TI Drenzek, NJ Xu, L Lake, JL Maruya, KA AF Reddy, CM Heraty, LJ Holt, BD Sturchio, NC Eglinton, TI Drenzek, NJ Xu, L Lake, JL Maruya, KA TI Stable chlorine isotopic compositions of aroclors and aroclor-contaminated sediments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ORGANIC-COMPOUNDS; CARBON; DECHLORINATION AB An exploratory investigation was conducted to evaluate if stable chlorine isotopic ratios of polychlorinated biphenyls (PCBs) could be useful in studying the processes that determine their transport and fate in the environment First, we determined the variability of delta(37)Cl in the source materials for PCBs. Second, we determined if the delta(37)Cl values of contaminated environmental samples fell outside the range in source variability. The isotopic variability among the source materials (Aroclors) was rather small; delta(37)- Cl values ranged from -3.37 to -2.11% (mean and standard deviation, -2.78 +/- 0.39%, n = 12). There was no correlation between the delta(37)Cl values and percentages of chlorine in the mixtures. We also found very similar values in several Clophen mixtures and one Phenoclor. The delta(37)Cl values in the total PCBs isolated from Aroclor-contaminated sediments from the Hudson River, New Bedford Harbor, and Turtle River Estuary ranged from -4.54 to -2.25% (n = 19). While most of the delta(37)Cl values were within 2 standard deviations of the mean Aroclor value (our assumed estimate for overall source variability), two of the PCB contaminated sediment samples from New Bedford Harbor did appear to be isotopically distinct. The PCBs in these sediments had lower amounts of less chlorinated congeners (when compared to the source material) and were likely isotopically affected by alteration processes that preferentially removed these congeners. Compound specific measurements of two congeners in Aroclor 1268 suggest that there are no large congener-specific differences in the stable chlorine isotope ratios in Aroclors. This study shows that the delta(37)Cl Values of PCBs may be a potentially useful diagnostic tool in studying the transport and fate of PCBs and indicates that additional research is warranted. C1 Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. US EPA, Atlantic Ecol Div, Natl Hlth & Effects Res Lab, Narragansett, RI 02882 USA. Skidaway Inst Oceanog, Savannah, GA 31411 USA. RP Reddy, CM (reprint author), Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA. NR 16 TC 39 Z9 40 U1 2 U2 15 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 JUL 1 PY 2000 VL 34 IS 13 BP 2866 EP 2870 DI 10.1021/es9908220 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 330RC UT WOS:000087974200046 ER PT J AU Neff, JM Ostazeski, S Gardiner, W Stejskal, I AF Neff, JM Ostazeski, S Gardiner, W Stejskal, I TI Effects of weathering on the toxicity of three offshore Australian crude oils and a diesel fuel to marine animals SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE polycyclic aromatic hydrocarbons; monocyclic aromatic hydrocarbons; phenols ID RESIDUE-BASED INTERPRETATION; BIOCONCENTRATION QSARS; AQUATIC BIOASSAYS; NARCOTIC ORGANICS; PETROLEUM; HYDROCARBONS; CRUSTACEANS; FISH AB The evaporative weathering properties, chemical composition, and toxicity of three Australian Northwest Shelf crude oils and an Australian diesel fuel were evaluated. The crude oils include one each of a condensate, a light, and a medium crude oil. Between 23 and 100% of the mass of the oils is lost during evaporative weathering equivalent to about 1 week on the sea surface. During weathering, the oils lose most of their monocyclic aromatic hydrocarbons (MAHs) and phenols; concentrations increase of less volatile phenols and polycyclic aromatic hydrocarbons (PAHs). The acute toxicity of water-accommodated fractions (WAFs) of the fresh and weathered oils to six species of temperate and tropical marine animals ranges from > 100% to about 11% WAF The MAHs are the most important contributors to the acute toxicity of the WAFs of the fresh oils. The contribution of PAHs to WAF toxicity increases with weathering. About 58% of the hazard indices (HI: exposure concentration/acutely toxic concentration) for the WAFs of the two light oils weathered for the equivalent of 1 d are attributable to PAHs. The toxicity of the WAFs of the condensate and light crude oil can be accounted for by MAHs, PAHs, and phenols; WAFs of the middle-weight crude oil and diesel fuel are higher than predicted based on their concentrations of total MAHs, PAHs, and phenols, indicating that othercomponents of the WAFs are contributing to their toxicity. These components may include the unresolved complex mixture and polar compounds (resins). C1 Battelle Ocean Sci Lab, Duxbury, MA 02332 USA. Battelle Marine Res Lab, Sequim, WA 98382 USA. Apache Energy, Perth, WA 6000, Australia. RP Neff, JM (reprint author), Battelle Ocean Sci Lab, 397 Washington St, Duxbury, MA 02332 USA. NR 33 TC 37 Z9 38 U1 4 U2 35 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUL PY 2000 VL 19 IS 7 BP 1809 EP 1821 PG 13 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 325KK UT WOS:000087674600015 ER PT J AU Peles, JD Philippi, T Smith, MH Brisbin, IL Gibbons, JW AF Peles, JD Philippi, T Smith, MH Brisbin, IL Gibbons, JW TI Seasonal variation in radiocesium levels of largemouth bass (Micropterus salmoides): Implications for humans and sensitive wildlife species SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE bioaccumulation; largemouth bass; radiocesium; seasonal variation ID REACTOR COOLING RESERVOIR; GAMBUSIA-HOLBROOKI GIRARD; CS-137; FISH; ELIMINATION; BIOACCUMULATION; MOSQUITOFISH; CESIUM-137 AB To examine seasonal variation in levels of radiocesium (Cs-137) within largemouth bass (Micropterus salmoides; N = 589), fish were collected monthly over a one-year period from an abandoned reactor cooling reservoir. Month of collection, sex, age, and body mass (log transformed) were all significant factors influencing Cs-137 concentrations. Levels of Cs-137 reached a peak in late winter/early spring (February/March), and minimum values occurred in the fall (October). An asymmetric sawtooth model with a four-month period of increase and an eight-month period of decrease fit the data for monthly 137Cs values significantly better than symmetric sinusoidal and sawtooth models. The mean concentration of Cs-137 for bass collected during all months was 7.09 Bq/g wet mass.-All individuals examined, regardless of month, sex, age, or body mass, had Cs-137 levels (2.95-12.60 Bq/g) that were much higher than the maximum level (0.60 Bq/g wet mass) generally considered safe for human consumption. Radiocesium is relatively long-lived within this reservoir and will continue to remain an important issue in risk assessments for both humans and wildlife species. C1 Penn State Univ, McKeesport, PA 15132 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Peles, JD (reprint author), Penn State Univ, McKeesport, PA 15132 USA. EM jdp12@psu.edu NR 32 TC 9 Z9 9 U1 1 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUL PY 2000 VL 19 IS 7 BP 1830 EP 1836 DI 10.1897/1551-5028(2000)019<1830:SVIRLO>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 325KK UT WOS:000087674600017 ER PT J AU Groom, DE Aguilar-Benitez, M Amsler, C Barnett, RM Burchat, PR Carone, CD Caso, C Conforto, G Dahl, O Doser, M Eidelman, S Feng, JL Gibbons, L Goodman, M Grab, C Gurtu, A Hagiwara, K Hayes, KG Hernandez, JJ Hikasa, K Honscheid, K Kolda, C Mangano, ML Manohar, AV Masoni, A Monig, K Murayama, H Nakamura, K Navas, S Olive, KA Pape, L Piepke, A Roos, M Tanabashi, M Tornqvist, NA Trippe, TG Vogel, P Wohl, CG Workman, RL Yao, WM Armstrong, B Casas Serradilla, JL Filimonov, BB Gee, PS Lugovsky, SB Nicholson, F Babu, KS Besson, D Biebel, O Bloch, P Cahn, RN Cattai, A Chivukula, RS Cousins, RD Damour, T Desler, K Donahue, RJ Edwards, DA Erler, J Ezhela, VV Fasso, A Fetscher, W Froidevaux, D Fukugita, M Gaisser, TK Garren, L Geer, S Gerber, HJ Gilman, FJ Haber, HE Hagmann, C Hinchliffe, I Hogan, CJ Hohler, G Igo-Kemenes, P Jackson, JD Johnson, KF Karlen, D Kayser, B Klein, SR Kleinknecht, K Knowles, IG Kolb, EW Kreitz, P Landua, R Langacker, P Littenberg, L Manley, DM March-Russell, J Nakada, T Quinn, HR Raffelt, G Renk, B Rolandi, L Ronan, MT Rosenberg, LJ Sadrozinski, HFW Sanda, AI Schmitt, M Schneider, O Scott, D Seligman, WG Shaevitz, MH Sjostrand, T Smoot, GF Spanier, S Spieler, H Srednicki, M Stahl, A Stanev, T Suzuki, M Tkachenko, NP Turner, MS Valencia, G VanBibber, K Voss, R Ward, D Wolfenstein, L Womersley, J AF Groom, DE Aguilar-Benitez, M Amsler, C Barnett, RM Burchat, PR Carone, CD Caso, C Conforto, G Dahl, O Doser, M Eidelman, S Feng, JL Gibbons, L Goodman, M Grab, C Gurtu, A Hagiwara, K Hayes, KG Hernandez, JJ Hikasa, K Honscheid, K Kolda, C Mangano, ML Manohar, AV Masoni, A Monig, K Murayama, H Nakamura, K Navas, S Olive, KA Pape, L Piepke, A Roos, M Tanabashi, M Tornqvist, NA Trippe, TG Vogel, P Wohl, CG Workman, RL Yao, WM Armstrong, B Casas Serradilla, JL Filimonov, BB Gee, PS Lugovsky, SB Nicholson, F Babu, KS Besson, D Biebel, O Bloch, P Cahn, RN Cattai, A Chivukula, RS Cousins, RD Damour, T Desler, K Donahue, RJ Edwards, DA Erler, J Ezhela, VV Fasso, A Fetscher, W Froidevaux, D Fukugita, M Gaisser, TK Garren, L Geer, S Gerber, HJ Gilman, FJ Haber, HE Hagmann, C Hinchliffe, I Hogan, CJ Hohler, G Igo-Kemenes, P Jackson, JD Johnson, KF Karlen, D Kayser, B Klein, SR Kleinknecht, K Knowles, IG Kolb, EW Kreitz, P Landua, R Langacker, P Littenberg, L Manley, DM March-Russell, J Nakada, T Quinn, HR Raffelt, G Renk, B Rolandi, L Ronan, MT Rosenberg, LJ Sadrozinski, HFW Sanda, AI Schmitt, M Schneider, O Scott, D Seligman, WG Shaevitz, MH Sjostrand, T Smoot, GF Spanier, S Spieler, H Srednicki, M Stahl, A Stanev, T Suzuki, M Tkachenko, NP Turner, MS Valencia, G VanBibber, K Voss, R Ward, D Wolfenstein, L Womersley, J CA Particle Data Grp TI Review of Particle Physics SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article AB This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2000 new measurements from 610 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 9808578, Japan. CIEMAT, E-28040 Madrid, Spain. Univ Zurich, Inst Phys, CH-8057 Zurich, Switzerland. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Coll William & Mary, Dept Phys, Nucl & Particle Theory Grp, Williamsburg, VA 23187 USA. Univ Genoa, Dipartimento Fis, I-16146 Genoa, Italy. Univ Genoa, Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Univ Urbino, I-61029 Urbino, Italy. Ist Nazl Fis Nucl, Sez Firenze, I-50125 Florence, Italy. Budker Inst Nucl Phys, SU-630090 Novosibirsk, Russia. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Cornell Univ, Newman Lab Nucl Studies, Ithaca, NY 14853 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Swiss Fed Inst Technol, Inst Particle Phys, CH-8093 Zurich, Switzerland. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Hillsdale Coll, Dept Phys, Hillsdale, MI 49242 USA. Univ de Valencia, CSIC, Inst Fis Corpuscular, IFIC, E-46071 Valencia, Spain. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Cittadella Univ Monserrato, Ist Nazl Fis Nucl, Sez Cagliari, I-09042 Monserrato, CA, Italy. DESY, D-15735 Zeuthen, Germany. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Ctr Phys Particules Marseille, F-13288 Marseille, France. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. CALTECH, Dept Phys, Pasadena, CA 91125 USA. George Washington Univ, Dept Phys, Ashburn, VA 20147 USA. Inst High Energy Phys, COMPAS Grp, RU-142284 Protvino, Russia. Univ Kansas, Dept Phys, Lawrence, KS 66045 USA. Rhein Westfal TH Aachen, Inst Phys, Phys Zentrum, D-52074 Aachen, Germany. Boston Univ, Dept Phys, Boston, MA 02215 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Inst Hautes Etud Sci, F-91440 Bures Sur Yvette, France. DESY, D-22603 Hamburg, Germany. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Stanford Linear Accelerator Ctr, Dept Radiat Phys, Stanford, CA 94309 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Karlsruhe, Inst Theoret Teilchenphys, D-76128 Karlsruhe, Germany. Univ Heidelberg, Inst Phys, D-69120 Heidelberg, Germany. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Carleton Univ, Dept Phys, Ottawa, ON K1S 5B6, Canada. Natl Sci Fdn, Div Phys, Arlington, VA 22230 USA. Univ Mainz, Inst Phys, D-55099 Mainz, Germany. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Kent State Univ, Dept Phys, Kent, OH 44242 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Max Planck Inst Phys & Astrophys, Werner Heisenberg Inst Phys, D-80805 Munich, Germany. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Univ Lausanne, Inst Phys Hautes Energies, CH-1015 Lausanne, Switzerland. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Columbia Univ, Nevis Labs, Irvington, NY 10533 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Lund Univ, Dept Theoret Phys, S-22362 Lund, Sweden. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Inst Phys, DE-53115 Bonn, Germany. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. Stan Lin Accel Center, Stanford 94309, CA USA. RP Groom, DE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Stahl, Achim/E-8846-2011; Chivukula, R. Sekhar/C-3367-2012; Murayama, Hitoshi/A-4286-2011; Rolandi, Luigi (Gigi)/E-8563-2013; Navas, Sergio/N-4649-2014 OI Stahl, Achim/0000-0002-8369-7506; Chivukula, R. Sekhar/0000-0002-4142-1077; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Navas, Sergio/0000-0003-1688-5758 NR 0 TC 3007 Z9 3012 U1 4 U2 57 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD JUL PY 2000 VL 15 IS 1-4 BP 1 EP 878 PG 878 WC Physics, Particles & Fields SC Physics GA 342UE UT WOS:000088662900001 ER PT J AU Blaum, K Bushaw, BA Diel, S Geppert, C Kuschnick, A Muller, P Nortershauser, W Schmitt, A Wendt, K AF Blaum, K Bushaw, BA Diel, S Geppert, C Kuschnick, A Muller, P Nortershauser, W Schmitt, A Wendt, K TI Isotope shifts and hyperfine structure in the [Xe]4f(7)5d 6s(2) D-2(J) -> [Xe]4f(7)5d 6s 6p F-9(J+1) transitions of gadolinium SO EUROPEAN PHYSICAL JOURNAL D LA English DT Article ID IONIZATION MASS-SPECTROMETRY; S-PROCESS NUCLEOSYNTHESIS; CALCIUM ISOTOPES; DOUBLE-RESONANCE; LASER; GD; ENRICHMENT; POISON AB High-resolution resonance ionization mass spectrometry has been used to measure isotope shifts and hyperfine structure in all [Xe]4f(7)5d(6)s(2) D-9(J) --> [Xe]4f(7)5d6s6p F-9(J+1) (J = 2-6) and the [Xe]4f(7)5d6s(2) D-9(6) --> [Xe]4f(7)5d6s6p, D-9(5) transitions of gadolinium (Gd I). Gadolinium atoms in an atomic beam were excited with a tunable single-frequency laser in the wavelength range of 422-429 am. Resonant excitation was followed by photoionization with the 363.8 nm line of an argon ion laser and resulting ions were mass separated and detected with a quadrupole mass spectrometer. Isotope shifts for all stable gadolinium isotopes in these transitions have been measured for the first time. Additionally, the hyperfine structure constants of the upper states have been derived for the isotopes Gd-155,Gd-157. and are compared with previous work. Using prior experimental values for the mean nuclear charge radii, derived from the combination of muonic atoms and electron scattering data, field shift and specific mass shift; coefficients for the investigated transitions have been determined and nuclear charge parameters lambda for the minor isotopes Gd-152,Gd-154 have been calculated. C1 Univ Mainz, Inst Phys, D-55099 Mainz, Germany. Pacific NW Lab, Richland, WA 99352 USA. RP Blaum, K (reprint author), Univ Mainz, Inst Phys, D-55099 Mainz, Germany. RI Mueller, Peter/E-4408-2011; Wendt, Klaus/D-7306-2011; Nortershauser, Wilfried/A-6671-2013 OI Mueller, Peter/0000-0002-8544-8191; Wendt, Klaus/0000-0002-9033-9336; Nortershauser, Wilfried/0000-0001-7432-3687 NR 37 TC 22 Z9 22 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6060 J9 EUR PHYS J D JI Eur. Phys. J. D PD JUL PY 2000 VL 11 IS 1 BP 37 EP 44 DI 10.1007/s100530070103 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 334KX UT WOS:000088186600005 ER PT J AU Feldman, DE Lyuksyutov, IF Pokrovsky, VL Vinokur, VM AF Feldman, DE Lyuksyutov, IF Pokrovsky, VL Vinokur, VM TI Vortex plasma and transport in superconducting films with magnetic dots SO EUROPHYSICS LETTERS LA English DT Article AB We consider a superconducting film supplied with a magnetic dot array. The dot magnetization is random and oriented, perpendicular to the film. The concentration of the superconducting vortices bound to the dots is a step-like function of the dot magnetic flux. The concentration of the unbound vortices is an oscillating function of the same variable. The resistivity is determined by the thermal drift of the vortices through the corner points of a checker-board formed by positive and negative unbound vortices. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. LD Landau Theoret Phys Inst, Chernogolovka 142432, Moscow Region, Russia. Weizmann Inst Sci, Dept Condensed Matter Phys, IL-76100 Rehovot, Israel. Ukrainian Acad Sci, Inst Phys, UA-252028 Kiev, Ukraine. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Feldman, DE (reprint author), Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. NR 6 TC 9 Z9 9 U1 0 U2 3 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 JUL PY 2000 VL 51 IS 1 BP 110 EP 115 DI 10.1209/epl/i2000-00500-3 PG 6 WC Physics, Multidisciplinary SC Physics GA 333ZF UT WOS:000088160100017 ER PT J AU Bankiewicz, KS Eberling, JL Kohutnicka, M Jagust, W Pivirotto, P Bringas, J Cunningham, J Budinger, TF Harvey-White, J AF Bankiewicz, KS Eberling, JL Kohutnicka, M Jagust, W Pivirotto, P Bringas, J Cunningham, J Budinger, TF Harvey-White, J TI Convection-enhanced delivery of AAV vector in parkinsonian monkeys; In vivo detection of gene expression and restoration of dopaminergic function using pro-drug approach SO EXPERIMENTAL NEUROLOGY LA English DT Article; Proceedings Paper CT 7th Intenational Symposium on Neural Transplantation and Repair (INT-7) CY AUG 26-30, 1999 CL ODENSE, DENMARK ID ADENOASSOCIATED VIRUS VECTORS; IN-VIVO; TYROSINE-HYDROXYLASE; BEHAVIORAL RECOVERY; STRIATAL NEURONS; CLINICAL CHANGES; VIRAL VECTOR; DISEASE; MPTP; PRIMATES AB Using an approach that combines gene therapy with aromatic L-amino acid decarboxylase (AADC) gene and a pro-drug (L-dopa), dopamine, the neurotransmitter involved in Parkinson's disease, can be synthesized and regulated. Striatal neurons infected with the AADC gene by an adeno-associated viral vector can convert peripheral L-dopa to dopamine and may therefore provide a buffer for unmetabolized L-dopa, This approach to treating Parkinson's disease may reduce the need for L-dopa/carbidopa, thus providing a better clinical response with fewer side effects. In addition, the imbalance in dopamine production between the nigrostriatal and mesolimbic dopaminergic systems can be corrected by using AADC gene delivery to the striatum, We have also demonstrated that a fundamental obstacle in the gene therapy approach to the central nervous system, i.e., the ability to deliver viral vectors in sufficient quantities to the whole brain, can be overcome by using convection-enhanced delivery, Finally, this study demonstrates that positron emission tomography and the AADC tracer, 6-[F-18]fluoro-L-m-tyrosine, can be used to monitor gene therapy in vine, Our therapeutic approach has the potential to restore dopamine production, even late in the disease process, at levels that can be maintained during continued nigrostriatal degeneration. (C) 2000 Academic Press. C1 NINDS, Mol Therapeut Sect, LMMN, Bethesda, MD 20892 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Avigen Inc, Alameda, CA USA. Univ Calif Davis, Dept Neurol, Davis, CA 95616 USA. Med Acad Warsaw, Dept Expt & Clin Pharmacol, Warsaw, Poland. RP Bankiewicz, KS (reprint author), NINDS, Mol Therapeut Sect, LMMN, Bldg 36,Rm 4D04, Bethesda, MD 20892 USA. NR 39 TC 241 Z9 251 U1 4 U2 14 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0014-4886 J9 EXP NEUROL JI Exp. Neurol. PD JUL PY 2000 VL 164 IS 1 BP 2 EP 14 DI 10.1006/exnr.2000.7408 PG 13 WC Neurosciences SC Neurosciences & Neurology GA 336XM UT WOS:000088328300002 PM 10877910 ER PT J AU Hoffer, JK AF Hoffer, JK TI Alternative fuels for ICF targets SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID NATIONAL IGNITION FACILITY; BERYLLIUM AB The first observation of the beta-layering phenomenon showed that it was possible to fabricate inertial confinement fusion (ICF) targets having an outer ablating shell surrounding a symmetric solid layer of DT fusion fuel. The sensitivity of fusion yield to the internal DT ice roughness is a function of many factors, one of which is the relatively low density of solid DT (0.25 g/cm(3)), leading to a high Atwood number for the ablator/fuel interface. This is one of the issues that has led us to consider other DT-based fuels having higher densities than pure DT but still capable of being automatically redistributed into a uniform layer by beta-layering. The two principle conditions for beta-layering redistribution, self-heating and a moderately high vapor pressure, can be found in only a few other systems. But by concentrating on hydrides of elements in the second row of the periodic chart, we can find materials which should beta-layer and which might be good candidates for fusion fuel. We exclude lithium hydride and beryllium hydride, because these materials are solids at room temperature where an automatic redistribution technique such as beta-layering would not be necessary. Therefore we begin with boron and consider the following materials: diborane: B-2(DT)(3) (or B2D3T3), methane: C(DT)(2) (or CD2T2), ammonia: N(DT)(3/2) (i.e., 0.5 . NDT2 + 0.5 . ND2T), water: DT0, and hydrofluoric acid: (DT)(1/2)F (i.e., 0.5 . DF + 0.5 . TF). C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hoffer, JK (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 3 Z9 3 U1 1 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 1 EP 5 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300003 ER PT J AU Olson, RE AF Olson, RE TI Shock timing and yield sensitivity studies for NIF ignition capsules SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID FACILITY; DRIVE; DESIGN AB A cryogenic, beta-layered NIF ignition capsule with a beryllium ablator that employs a BeO dopant (2% O) for opacity control is described. The design has an optimized yield of 12 MJ and uses a "reduced drive" hohlraum temperature pulse shape that peaks at similar to 250 eV. Shock timing sensitivity calculations have been performed for this capsule design. Individual uncertainties of: 1) similar to 200 ps in the timing of the foot pulse; 2) similar to 5% in the x-ray flux of the foot pulse and first step; 3) similar to 10% in the ablator EOS; or 4) similar to 5 mu m in the DT ice layer thickness each have a significant impact on thermonuclear yield. Combined uncertainties have greater impact than isolated, individual issues. For example, a combination of uncertainties of: 200 ps in the foot, 2 eV in the foot, and 5 mu m in the DT thickness results in a calculation that produces only similar to 1% of the original design yield. A second, more speculative, capsule concept utilizing a liquid DT ablator is also discussed. This design produces a 2 MJ yield in a 250 eV peak drive calculation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Olson, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 8 Z9 8 U1 0 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 6 EP 10 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300004 ER PT J AU Sanford, TWL Olson, RE Vesey, RA Chandler, GA Hebron, DE Mock, RC Leeper, RJ Nash, TJ Ruiz, CL Ruggles, LE Simpson, WW Bowers, RL Matuska, W Peterson, DL Peterson, RR AF Sanford, TWL Olson, RE Vesey, RA Chandler, GA Hebron, DE Mock, RC Leeper, RJ Nash, TJ Ruiz, CL Ruggles, LE Simpson, WW Bowers, RL Matuska, W Peterson, DL Peterson, RR TI Characteristics of ICF relevant hohlraums driven by x-rays from a z-pinch SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID NATIONAL-IGNITION-FACILITY; DESIGN; INSIGHTS; POWER AB Radiation environments characteristic of those encountered during the low-temperature foot pulse and subsequent higher-temperature early-step pulses (without the foot pulse) required for indirect-drive ICF ignition on the National Ignition Facility have been produced in hohlraums driven by x-rays from a z-pinch. These environments provide a platform to better understand the dynamics of full-scale NIF hohlraums, ablator material, and capsules prior to NIF completion. Radiation temperature, plasma fill, and wall motion of these hohlraums are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Sanford, TWL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 8 Z9 8 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 11 EP 15 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300005 ER PT J AU Wilson, DC Bradley, PA Goldman, SR Hoffman, NM Margevicius, RW Stephens, RB Olson, RE AF Wilson, DC Bradley, PA Goldman, SR Hoffman, NM Margevicius, RW Stephens, RB Olson, RE TI Developments in nif beryllium capsule design SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID NATIONAL-IGNITION-FACILITY; FABRICATION; PHYSICS; TARGET AB Recent beryllium capsule designs have focussed on the lower temperatures and laser powers expected before the NIF laser reaches its full capability, 192 beams, 500TW, and 1.8MJ. First, several new designs are given with peak radiation temperatures for 250 to 280 eV. A 250eV design uses 2% oxygen dopant instead of 0.9% copper. Second, a radiography study of planar joints in S200D beryllium using a Cu, Au, Ag, Al, or Au/Cu braze quantified the diffusion away from the joint. LASNEX calculations show that Cu joint perturbations grow to large enough amplitude to preclude ignition. However by allowing the copper to diffuse twice as far as in these experiments (e.g. by holding at brats temperature longer), the joint calculates to be acceptable, and the capsule gives full yield. Aluminum diffuses extremely far from the joint, almost uniformly in the sample. Third, a capsule with a high Z shell and beryllium ablator calculates to ignite. As expected its ignition threshold is lower, about 70% of the implosion velocity for a capsule like the Be330, The extra tamping of DT burn by a 6 mu m tungsten shell increases the yield from 17 to 32 MJ. The capsule radiates 3 MJ of this yield as X-rays. Unfortunately the capsule is more sensitive to DT ice roughness than the Be330 design, failing at 0.6 mu m roughness. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Gen Atom Co, San Diego, CA 92186 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wilson, DC (reprint author), Univ Calif Los Alamos Natl Lab, X-2,MS B220, Los Alamos, NM 87545 USA. OI Stephens, Richard/0000-0002-7034-6141 NR 15 TC 15 Z9 16 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 16 EP 21 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300006 ER PT J AU Takagi, M Cook, R Stephens, R Gibson, J Paguio, S AF Takagi, M Cook, R Stephens, R Gibson, J Paguio, S TI Decreasing out-of-round in poly(alpha-methylstyrene) mandrels by increasing interfacial tension SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA AB Currently, poly(alpha-methylstyrene) mandrel precursors are suspended in a salt-containing water bath during curing. Matching the density of the precursors to their bath almost, but not quite, eliminates shell sagging caused by gravity. This sagging is opposed by the interfacial tension between the plastic containing oil solution and the water bath, but the tension is barely adequate to give satisfactory sphericity. We found that adding a small amount (<0.1 wt%) of high-molecular-weight poly(acrylic acid) to the water bath substantially increased the interfacial tension. Combining that change with a gentler shell curing process enabled consistent production of more spherical mandrels. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gen Atom Co, Inertial Fus Div, San Diego, CA 92186 USA. RP Takagi, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 5 TC 13 Z9 18 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 46 EP 49 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300011 ER PT J AU Takagi, M Cook, R Stephens, R Gibson, J Paguio, S AF Takagi, M Cook, R Stephens, R Gibson, J Paguio, S TI Stiffening of P alpha MS mandrels during curing SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID TARGETS AB Poly(alpha-methylstyrene) (P alpha MS) mandrel precursors (a fluorobenzene solution of P alpha MS surrounding a water core) must be agitated to center the core. The initially fluid P alpha MS solution stiffens as the organic solvent is extracted, and it eventually becomes brittle; a collision with a stirring propeller will either dent or crack the surface. Dried mandrels often exhibit dents on the surface or cracks in the wall that may result from such collisions. We have studied the deformation relaxation rate of mandrel precursors as a function of curing time. We have found a point in the cure at which the core centering process has stopped but permanent denting has not started, and have found a simple test for this condition. We can use this information to produce highly spherical plastic mandrels by controlling propeller speed as a function of time. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gen Atom Co, Inertial Fus Div, San Diego, CA 92186 USA. RP Takagi, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 4 TC 5 Z9 10 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 50 EP 53 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300012 ER PT J AU Takagi, M Cook, R Stephens, R Gibson, J Paguio, S AF Takagi, M Cook, R Stephens, R Gibson, J Paguio, S TI The effects of controlling osmotic pressure on a P alpha MS microencapsulated mandrel during curing SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID TARGETS; SHELLS AB Poly(alpha-methylstyrene) (P alpha MS) mandrel precursors (a P alpha MS containing fluorobenzene solution surrounding a water core) are suspended in a salt-containing water solution during curing. The salt is necessary to suppress the growth of water drops in the curing oil phase (resulting in vacuoles in the dried mandrel). However the use of salts in this manner results in a chemical potential difference between the inner pure water droplets and the outer bath. This results in a loss of water from the inner water phase, shrinking the mandrel as it cures and potentially wrinkling its surface. We have quantified the degree of mandrel shrinkage and expansion as a function of the difference in salt concentration. Expansion is not proportional to concentration difference. It does not appear that osmotically driven expansion removes wrinkles; the large wrinkle amplitudes were seen with all salt concentrations. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gen Atom Co, Inertial Fus Div, San Diego, CA 92186 USA. RP Takagi, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 6 TC 1 Z9 3 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 54 EP 57 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300013 ER PT J AU Salazar, KV Pattillo, SG Trkula, M AF Salazar, KV Pattillo, SG Trkula, M TI Progress update on CVD of beryllium SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA AB Capsules with beryllium ablators are very important targets for the DOE National Ignition Facility (NIF) laser in the Inertial Confinement Fusion Program. Two leading candidates for fabricating beryllium capsules are the machining and bonding of hemispheres, and physical vapor deposition of beryllium onto plastic or other shells. An attractive possibility would be to coat a spherical mandrel with a thin layer of beryllium by a non-line-of-sight process. This coating could be applied via the chemical vapor deposition (CVD) of beryllium. Our first attempt at coating beryllium via CVD was done by using bis(cyclopentadienyl)beryllium, (C2H5)(2)Be, as the precursor material. Results obtained by use of (C5H5)(2)Be as the precursor material is discussed. However, difficulties we encountered with use of the (C5H5)(2)Be precursor material led us to examine a relatively unexplored area of beryllium chemistry, namely that of its amines. This redirection also led us to change surrogate material for use in the developmental work. C1 Univ Calif Los Alamos Natl Lab, MST Div, Los Alamos, NM 87545 USA. RP Salazar, KV (reprint author), Univ Calif Los Alamos Natl Lab, MST Div, POB 1663, Los Alamos, NM 87545 USA. NR 7 TC 5 Z9 5 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 69 EP 73 PG 5 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300016 ER PT J AU Cook, R AF Cook, R TI Models of polyimide spray coatings SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CA ID INERTIAL CONFINEMENT FUSION; NATIONAL IGNITION FACILITY; VAPOR-PHASE DEPOSITION; TARGET CAPSULES; NIF TARGET; DESIGN; FABRICATION; MANDRELS; SHELLS; GAIN AB Model calculations have been performed to provide guidance for the development of solution spray techniques for coating NIF scale mandrels with 150 mu m thick polyimide abIator layers. The deposition models considered assume independent random placement of the spray droplets on the mandrel surface followed by their spreading to form thin disk-like additions. The dependence on the final surface roughness of the effective thickness of the addition, the size (diameter) of the addition, and the cross-sectional profile of the addition have been explored. In addition, a model that assumes randomly placed, independent additions that cover 50% of the mandrel surface per addition is considered For each model and parameter set the rms surface finish is calculated as well as the surface power spectra. The primary result is that individual, randomly placed coating additions must be very thin, on the order of a few nm at most, if NIF surface specifications are to be met. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Cook, R (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM bobcook@llnl.gov NR 16 TC 3 Z9 3 U1 0 U2 2 PU AMER NUCLEAR SOC PI LA GRANGE PK PA 555 N KENSINGTON AVE, LA GRANGE PK, IL 60526 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 74 EP 82 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300017 ER PT J AU Roberts, CC Orthion, PJ Hassel, AE Parrish, BK Buckley, SR Fearon, E Letts, SA Cook, RC AF Roberts, CC Orthion, PJ Hassel, AE Parrish, BK Buckley, SR Fearon, E Letts, SA Cook, RC TI Development of polyimide ablators for NIF: Analysis of defects on shells, a novel smoothing technique and Upilex coatings SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID VAPOR-DEPOSITION POLYMERIZATION; FILMS; CAPSULES AB Over the last three years, LLNL has developed polyimide vapor deposition technology suitable for mandrel overcoating and fabrication of polyimide capsules. Agitated mandrels were overcoated with 4,4'-oxydianiline and pyromellitic dianhydride, and the PMDA/ODA coating was thermally converted to polyimide by heating to 300 degrees C. Shells from this process did not meet smoothness requirements specified by the target designs for the National Ignition Facility (NIF). The defects and the possible mechanism(s) for defect generation were analyzed, and it was determined that surface roughness was the result of shell-pan interaction(s). A post-processing, shell smoothing technique was also developed which simultaneously levitates the shell while exposing it to solvent vapor. Efforts to form Upilex(TM), a high strength polyimide, using vapor deposition will also be discussed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Roberts, CC (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,M-S L-474, Livermore, CA 94550 USA. NR 19 TC 17 Z9 17 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 94 EP 107 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300020 ER PT J AU Koch, JA Bernat, TP Collins, GW Hammel, BA Kozioziemski, BJ MacKinnon, AJ Sater, JD Bittner, DN Lee, Y AF Koch, JA Bernat, TP Collins, GW Hammel, BA Kozioziemski, BJ MacKinnon, AJ Sater, JD Bittner, DN Lee, Y TI Quantitative analysis of backlit shadowgraphy as a diagnostic of hydrogen ice surface quality in ICF capsules SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA ID NATIONAL-IGNITION-FACILITY; DEUTERIUM-TRITIUM; DESIGN AB We have developed a numerical raytrace model, SHELL3D, which simulates the backlit imaging of cryogenic inertial-confinement fusion (ICF) ignition capsules in three dimensions. We have used this model to investigate the limitations of backlit shadowgraphy as a diagnostic of hydrogen ice surface quality inside the capsules. We impose known modal perturbations upon the simulated inner ice surface, and produce simulated shadowgraphs which are then analyzed as if they were real experimental data. We find that power spectra derived from backlit shadowgraphs appear to be reliable indicators of ice surface power spectra out to Fourier mode numbers as high as 80. We also suggest that some advantages may be obtained by using a collimated backlight, and possibly by utilizing backlit transmission interferometry. These results support the conclusion that backlit shadowgraphy is a valid quantitative diagnostic of lower-mode ice surface imperfections inside transparent spherical ICF shells. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Schafer Corp, Livermore, CA 94550 USA. RP Koch, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-481, Livermore, CA 94551 USA. RI MacKinnon, Andrew/P-7239-2014 OI MacKinnon, Andrew/0000-0002-4380-2906 NR 11 TC 24 Z9 27 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 123 EP 131 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300025 ER PT J AU Salazar, MA Gobby, P Watt, R AF Salazar, MA Gobby, P Watt, R TI Pressure testing of micro balloons by bursting SO FUSION TECHNOLOGY LA English DT Article; Proceedings Paper CT 13th Target Fabrication Specialists Meeting (TFSM) CY NOV 08-12, 1999 CL CATALINA ISL, CALIFORNIA AB A reliable easy to use, transportable pressure measurement device (Fig.l) for assessing the gas fill in spherical ICF targets is needed for LANL experiments at OMEGA. This paper describes the burst system design and the method used to calibrate and operate the system. It also presents the first test results. C1 Univ Calif Los Alamos Natl Lab, DOE, Los Alamos, NM 87545 USA. RP Salazar, MA (reprint author), Univ Calif Los Alamos Natl Lab, DOE, POB 1663, Los Alamos, NM 87545 USA. NR 2 TC 2 Z9 5 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD JUL PY 2000 VL 38 IS 1 BP 136 EP 138 PG 3 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 329DF UT WOS:000087890300027 ER PT J AU Teng, HH Dove, PM De Yoreo, JJ AF Teng, HH Dove, PM De Yoreo, JJ TI Kinetics of calcite growth: Surface processes and relationships to macroscopic rate laws SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID 101 ADP FACE; CRYSTAL-GROWTH; PRECIPITATION KINETICS; FORCE MICROSCOPY; SPIRAL GROWTH; DISSOLUTION; CARBONATE; CRYSTALLIZATION; MECHANISMS; INHIBITION AB This study links classical crystal growth theory with observations of microscopic surface processes to quantify the dependence of calcite growth on supersaturation, sigma, and show relationships to the same dependencies often approximated by affinity based expressions. In situ Atomic Force Microscopy was used to quantify calcite growth rates and observe transitions in growth processes on {10 (1) over bar4} faces in characterized solutions with variable sigma. When sigma < 0.8, growth occurs by step flow at, surface defects, including screw dislocations. As exceeds 0.8, two-dimensional surface nucleation becomes increasingly important. The single sourced, single spirals that are produced at lower sigma were examined to measure rates of step flow and the slopes of growth hillocks. These data were used to obtain the surface-normal growth rate, R-m, by the pure spiral mechanism. The dependence of overall growth rate upon dislocation source structure was analyzed using the fundamentals of crystal growth theory. The resulting surface process based rate expressions for spiral growth show the relationships between R-m and the distribution and structures of dislocation sources. These theoretical relations are upheld by the process-based experimental rate data reported in this study. The analysis further shows that the dependence of growth rate on dislocation source structures is essential for properly representing growth. This is because most growth sources exhibit complex structures with multiple dislocations. The expressions resulting from this analysis were compared to affinity-based rate equations to show when popular affinity-based rare laws hold or break down. Results of this study demonstrate that the widely used second order chemical affinity-based rate laws are physically meaningful only under special conditions. The exponent in affinity-based expressions is dependent upon the supersaturation range used to fit data. An apparent second order dependence is achieved when solution supersaturations are very near equilibrium and growth occurs only by simple, single sourced dislocation spirals. These findings indicate the need to apply caution when deducing growth mechanisms and rate laws from temporal changes in bulk solution chemistry. Observations of various types of surface defects that give rise to step formation suggest that popular 'rate laws are sample-dependent composites of rate contributions from each dislocation structure. Copyright (C) 2000 Elsevier Science Ltd. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Dove, PM (reprint author), Virginia Polytech Inst & State Univ, Dept Geol Sci, Blacksburg, VA 24061 USA. RI Dove, Patricia/A-7911-2010 NR 54 TC 227 Z9 227 U1 18 U2 106 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 JUL PY 2000 VL 64 IS 13 BP 2255 EP 2266 DI 10.1016/S0016-7037(00)00341-0 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 409TJ UT WOS:000167401500007 ER PT J AU Sylwester, ER Hudson, EA Allen, PG AF Sylwester, ER Hudson, EA Allen, PG TI The structure of uranium (VI) sorption complexes on silica, alumina, and montmorillonite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; AQUEOUS-SOLUTION; URANYL SILICATE; FINE-STRUCTURE; EXAFS; ADSORPTION; FERRIHYDRITE; SPECIATION; CLAY; IONS AB We have investigated the adsorption of the uranyl ion (UO22+) in contact with amorphous silica (SiO2) gamma-alumina (Al2O3), and montmorillonite surfaces in the pH range of 3.1-6.5, using X-ray absorption fine structure (XAFS) spectroscopy to observe the local structure around the uranium atom. Analysis shows that in all samples the uranyl ion structure is preserved, with two axial oxygen atoms detected at ca. 1.8 Angstrom. For the montmorillonite samples at low pH a single equatorial oxygen shell is observed at ca. 2.4 Angstrom, with a coordination number of 6 +/- 1. At near-neutral pH (6.41) and high ion concentration (0.1 M NaCl), two separate equatorial shells are observed with bond lengths of ca. 2.30 and 2.48 Angstrom. The samples of uranyl on silica and gamma-alumina are all observed to have two separate equatorial shells with bond lengths of ca. 2.30 Angstrom and 2.49 Angstrom. A uranium shell at ca. 4.0 Angstrom is observed in the near-neutral pH (similar to 6.5) samples of uranyl on silica and on gamma-alumina. A silicon shell at ca. 3.10 Angstrom is observed in the sample of uranyl on silica at pH 6.5. These results suggest that adsorption of the uranyl ion onto montmorillonite at low pH occurs via ion exchange, leaving the inner-sphere uranyl aquo-ion structure intact. At near-neutral pH and in the presence of a competing cation, inner-sphere complexation with the surface predominates. Adsorption of the uranyl onto the silica and gamma-alumina surfaces appears to occur via an inner-sphere, bidentate complexation with the surface, with the formation of polynuclear surface complexes occurring at near-neutral pH. Copyright (C) 2000 Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Livermore, CA 94551 USA. RP Sylwester, ER (reprint author), Univ Calif Lawrence Livermore Natl Lab, Glenn T Seaborg Inst Transactinium Sci, POB 808, Livermore, CA 94551 USA. NR 41 TC 244 Z9 249 U1 17 U2 94 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 JUL PY 2000 VL 64 IS 14 BP 2431 EP 2438 DI 10.1016/S0016-7037(00)00376-8 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 331LR UT WOS:000088021000006 ER PT J AU Kelley, MC Gardner, C Drummond, J Armstrong, T Liu, A Chu, X Papen, G Kruschwitz, C Loughmiller, P Grime, B Engelman, J AF Kelley, MC Gardner, C Drummond, J Armstrong, T Liu, A Chu, X Papen, G Kruschwitz, C Loughmiller, P Grime, B Engelman, J TI First observations of long-lived meteor trains with resonance lidar and other optical instruments SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB In November 1998 the earth passed through a maximum in the cometary material responsible for the yearly Leonids meteor shower. The meteor storm event produced numerous examples of long-lived chemiluminescent trails-visible to the naked eye-over New Mexico, where a major observation campaign was centered. One trail was detected for over an hour with a CCD camera employing a narrow sodium filter, and many others were observed for over ten minutes each. For the first time, sodium densities in such trails were measured while also being imaged in sodium light. We have verified one source of long-lived light emissions-a sodium-catalyzed reaction involving ozone-but it is far too weak to explain the visibility of such trails. In addition, we present a new explanation for the cylindrical shell appearance long reported for chemiluminescent trails and show that ozone depletion by chemical processes is a possible explanation for this phenomenon. C1 Cornell Univ, Dept Elect Engn, Ithaca, NY 14853 USA. Univ Illinois, CSRL, Dept Elect & Comp Engn, Urbana, IL 61801 USA. USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kelley, MC (reprint author), Cornell Univ, Dept Elect Engn, Ithaca, NY 14853 USA. RI Chu, Xinzhao/I-5670-2015; Liu, Alan/C-3738-2008 OI Chu, Xinzhao/0000-0001-6147-1963; Liu, Alan/0000-0002-1834-7120 NR 15 TC 19 Z9 20 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 2000 VL 27 IS 13 BP 1811 EP 1814 DI 10.1029/1999GL011175 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 331LY UT WOS:000088021600002 ER PT J AU Liu, YG Daum, PH AF Liu, YG Daum, PH TI Spectral dispersion of cloud droplet size distributions and the parameterization of cloud droplet effective radius SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION MODEL; LIQUID-WATER-CONTENT; STRATOCUMULUS CLOUDS; WARM CLOUDS; GCM; SENSITIVITY; PREDICTION; NUMBER AB Parameterization of effective radius (r(e)) as proportional to the cube root of the ratio of cloud liquid water content (L) to droplet concentration (N), i.e., r(e) = alpha(L/N)(1/3), is becoming widely accepted. The principal distinction between different parameterization schemes lies in the specification of the prefactor alpha. This work focuses on the dependence of alpha on the spectral dispersion of the cloud droplet size distribution. Relationships by Pontikis and Hicks [1992] and by Liu and Hallet [1997] that account for the dependence of a on the spectral dispersion are compared to each other and to cloud microphysical data collected during two recent field studies. The expression of Liu and Wallet describes the spectral dependence of alpha (or r(e)) more accurately than the Pontikis and Hicks relation over the observed range of spectral dispersions. The comparison shows that the different treatments of alpha as a function of spectral dispersion alone can result in substantial differences in r(e) estimated from different parameterization schemes, suggesting that accurately representing r(e) in climate models requires predicting alpha in addition to L and N. C1 Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. RP Liu, YG (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Div Atmospher Sci, Upton, NY 11973 USA. RI Liu, Yangang/H-6154-2011 NR 26 TC 45 Z9 45 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 2000 VL 27 IS 13 BP 1903 EP 1906 DI 10.1029/1999GL011011 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 331LY UT WOS:000088021600026 ER PT J AU Smith, E TenCate, JA AF Smith, E TenCate, JA TI Sensitive determination of nonlinear properties of Berea sandstone at low strains SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STICK-SLIP MOTION; PROPAGATION AB Resonant response functions of a sandstone bar, measured at strain magnitudes between 10(-8) and 10(-6) at several temperatures, are used to extract Young's modulus and loss tangent as functions of frequency and driving force. Expressing the distorted shape of nonlinear resonances in terms of shifts in the resonant frequency and Q enables correlation analysis of these functions against components of the strain response function. Resonance shies are found to be strongly correlated with somewhat complicated functions of strain, but only weakly with frequency or phase of the response. Decomposing the data along contours of constant strain magnitude yields the quantitative scaling of resonance shifts with strain, which shows a superposition of both conventional and necessarily hysteretic nonlinear sources. No statistically significant temperature dependence is found in the coefficients of the fits. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smith, E (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 16 TC 11 Z9 12 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUL 1 PY 2000 VL 27 IS 13 BP 1985 EP 1988 DI 10.1029/1999GL008424 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 331LY UT WOS:000088021600047 ER PT J AU Costigan, KR Bossert, JE Langley, DL AF Costigan, KR Bossert, JE Langley, DL TI Atmospheric/hydrologic models for the Rio Grande Basin: simulations of precipitation variability SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE regional climate; precipitation; grid resolution; interannual variations; spatial variations ID WESTERN UNITED-STATES; NORTH-AMERICAN MONSOON; REGIONAL CLIMATE-CHANGE; NEW-MEXICO; INTERANNUAL VARIABILITY; EL-NINO; PATTERNS; REGIME; CONVECTION; STREAMFLOW AB The headwaters of the Rio Grande are located in the San Juan Mountains of southwestern Colorado and the upper portions of the river are fed primarily by snowmelt from winter storms. In contrast, the lower portions of the river accumulate runoff from thunderstorms of the summer monsoon season. Thus, the waters of the Rio Grande are strongly influenced by regional climate and could be vulnerable to climate change. In order to study water resources in the Rio Grande Basin and how they may be affected by changes in regional climate, a modeling system, which relies on the use of coupled atmospheric, runoff, and ground water models, is being developed. Preliminary work on the project has focused on winter precipitation simulations of the upper Rio Grande Basin and evaluation of the suitability of the atmospheric model for simulating regional climate. This paper describes the spatial and temporal precipitation variability predicted by this model. To examine the temporal variability, results of simulations carried out with the Regional Atmospheric Modeling System (RAMS), at 20 km resolution, are presented for the month of January 1996, representing a dry extreme far the region, and January 1993, representing a recent wet extreme. Results are also presented of a case study with higher resolution (5 km) over the upper Rio Grande Basin to examine spatial variability of the snowpack within complex terrain. The simulation results are compared to observations of daily-accumulated precipitation in the region. The comparisons of model predicted precipitation indicate that the RAMS model can reproduce the interannual changes in precipitation patterns found in the western US. In the month of January 1996, both RAMS and observed precipitation are highest in the northern mountain ranges of the domain. Likewise, in the month of January 1993, both predicted and observed precipitation in the southern tier of states are dramatically higher. Results of the simulations with increased model grid resolution indicate a modest improvement of precipitation estimates with the finer grid resolution over the Rio Grande Basin. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Atmospher & Climate Sci Grp, Los Alamos, NM 87545 USA. RP Costigan, KR (reprint author), Univ Calif Los Alamos Natl Lab, Atmospher & Climate Sci Grp, EES-8,Mail Stop D401, Los Alamos, NM 87545 USA. NR 42 TC 8 Z9 9 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD JUL PY 2000 VL 25 IS 1-2 BP 83 EP 110 DI 10.1016/S0921-8181(00)00023-0 PG 28 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 336ZU UT WOS:000088333500007 ER PT J AU Streets, DG Glantz, MH AF Streets, DG Glantz, MH TI Exploring the concept of climate surprise SO GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS LA English DT Article DE climate change; surprise; environmental policy; emergency planning AB This paper examines the concept of climate surprise and its implications for environmental policymaking. Although long-term, incremental changes in climate can have serious consequences, it is usually the extreme, surprising events that cause the most damage to human health and property. Different taxonomies of surprise are explored, drawing from literature concerning diverse aspects of human society. Surprise is revealed to be a subjective concept in many respects, triggered by such factors as prior experience, belief systems, and media exposure. How policymakers have reacted to climate surprises in the past is considered, particularly with regard to choices made between pro-active and reactive measures. It is concluded that, while some kinds of surprise are truly unpredictable, there are other types that could be anticipated and their adverse effects forestalled. (C) 2000 Published by Elsevier Science Ltd. C1 Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. Natl Ctr Atmospher Res, Environm & Societal Impacts Grp, Boulder, CO 80307 USA. RP Streets, DG (reprint author), Argonne Natl Lab, Decis & Informat Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Streets, David/0000-0002-0223-1350 NR 45 TC 22 Z9 22 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0959-3780 J9 GLOBAL ENVIRON CHANG JI Glob. Environ. Change-Human Policy Dimens. PD JUL PY 2000 VL 10 IS 2 BP 97 EP 107 DI 10.1016/S0959-3780(00)00015-7 PG 11 WC Environmental Sciences; Environmental Studies; Geography SC Environmental Sciences & Ecology; Geography GA 353TW UT WOS:000089292400002 ER PT J AU Seligman, PJ AF Seligman, PJ TI The US-Russian Radiation Health Effects Research Program in the Southern Urals SO HEALTH PHYSICS LA English DT Article DE radiation, low-level; health effects; exposure, population; exposure, occupational ID WORKERS; EXPOSURE AB The Joint Coordinating Committee for Radiation Effects Research (JCCRER) was established through a bilateral U.S.-Russian agreement to support research and exchange information on radiation health effects. The U.S. member agencies include the Department of Energy (DOE), Nuclear Regulatory Commission (NRC), Department of Health and Human Services (DHHS), Department of Defense (DoD), National Aeronautics and Space Administration (NASA), and Environmental Protection Agency (EPA), The Russians are represented by the Ministries of Emergencies (EMERCOM), Atomic Energy (MINATOM) and Health (MINZDRAV), and the Russian Academy of Sciences (IBRAE). The focus of this research is on the workers from the Mayak Production Association (MAYAK) in the Southern Urals and on the neighboring populations along the Techa River exposed to contamination from the plant. The goal of the program is to better define the relationship between the health effects and the chronic low dose and dose-rate exposure, these data being essential to validate current radiation protection standards and practices. The current primary areas of JCCRER research include dose reconstruction, epidemiologic health studies, molecular epidemiology/biodosimetry, and the creation of tissue banks. The organization of the ongoing research conducted under the aegis of the JCCRER and the rationale for this work are described. C1 US Dept Energy, Germantown, MD 20874 USA. EM Paul.Seligman@eh.doe.gov RI huang, hongqi/N-1473-2014 NR 14 TC 8 Z9 8 U1 0 U2 1 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 JUL PY 2000 VL 79 IS 1 BP 3 EP 8 DI 10.1097/00004032-200007000-00003 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 323ND UT WOS:000087570700003 PM 10855771 ER PT J AU Melamed, E AF Melamed, E TI Radiological medical data preservation in the Southern Urals SO HEALTH PHYSICS LA English DT Article DE radiation, low-level; health effects; exposure, population; exposure, occupational AB Information is being microfilmed and scanned in the Southern Urals to ensure the archival preservation of the unique, important and irreplaceable records documenting chronic low-level radiation exposure to workers and neighboring populations of the Mayak Production Association (MAYAK), as well as health effects. The records include dosimetric and epidemiologic information maintained on workers and neighboring populations located at facilities in Ozyorsk and Chelyabinsk. Microfilming is being done in Ozyorsk, and on a more limited basis in Chelyabinsk, where a scanning project has also recently been initiated. Over 1,800 rolls of film have been produced as of the fall of 1999. This article describes the background and results of this data preservation effort and includes brief summary tables describing the types of records being preserved. Researchers interested in access to these records should contact Paul Seligman, Deputy Assistant Secretary for the Office of Health Studies at the Department of Energy (DOE) for more information. C1 US Dept Energy, Germantown, MD 20874 USA. EM elly.melamed@eh.doe.gov NR 0 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD JUL PY 2000 VL 79 IS 1 BP 11 EP 14 DI 10.1097/00004032-200007000-00005 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 323ND UT WOS:000087570700005 PM 10855773 ER PT J AU Mokrov, Y Glagolenko, Y Napier, B AF Mokrov, Y Glagolenko, Y Napier, B TI Reconstruction of radionuclide contamination of the Techa River caused by liquid waste discharge from radiochemical production at the Mayak Production Association SO HEALTH PHYSICS LA English DT Article DE contamination, environmental; accidents, nuclear; radiation, environmental; dose assessment AB Because of its importance to reconstructing radiation doses for ongoing epidemiological studies, a feasibility study was undertaken to determine if the source term of radioactive materials released to the Techa River from the Mayak Production Association, the first facility in the former Soviet Union for the production of plutonium, could be reconstructed from historical measurements made at a limited number of downriver locations. The feasibility study used historically measured water flow rates and total-beta radioactivity measurements, and considered the processes of radioactive decay and of sorption/desorption. A simple radionuclide mass balance approach was used. To determine the rate of input of radionuclides to the Techa River system, the Techa River was depicted as a series of segments for which measurements are available. For each segment of the river, a system of recurrent (with time) equations was compiled for radioactivity balance accounting for the radioactivity inflow at the inflowing end, activity discharge with water at the outflowing end, and the reduction of activity because of radioactive decay. The equations change with time to account for the changing nature of the river regime. Effective sorption constants for Sr-90 and Cs-137, which characterize the transport of radionuclides among the river system components (water and bottom sediments), were defined based on the inventory of these radionuclides deposited at each of the studied river segments and data on water concentration and radioactive removal. All the information an radioactive contamination of the river system components during the period 1949-1996 was used. Solution of the series of equations provided information on the rate of input of these radionuclides into the upper end of the river. The pilot study indicated that it is possible to determine the historical releases of a wider suite of radionuclides using the historical monitoring data from numerous locations along the river, rather than relying on a more uncertain reconstruction of quantities released at the point of discharge. Radionuclides considered include Sr-90, Ru-106, (CS)-C-137, and Ce-144. Estimated concentrations of selected radionuclides at various times are presented. C1 Mayak Cent Lab, Ozersk, Chelyabinsk Obl, Russia. Pacific NW Nat Lab, Richland, WA 99352 USA. EM Bruce.Napier@pnl.gov NR 10 TC 11 Z9 13 U1 0 U2 1 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 JUL PY 2000 VL 79 IS 1 BP 15 EP 23 DI 10.1097/00004032-200007000-00006 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 323ND UT WOS:000087570700006 PM 10855774 ER PT J AU Degteva, MO Kozheurov, VP Tolstykh, EI Vorobiova, MI Anspaugh, LR Napier, BA Kovtun, AN AF Degteva, MO Kozheurov, VP Tolstykh, EI Vorobiova, MI Anspaugh, LR Napier, BA Kovtun, AN TI The Techa River Dosimetry System: Methods for the reconstruction of internal dose SO HEALTH PHYSICS LA English DT Article DE biokinetics; contamination, environmental; dose assessment; Sr-90 ID HUMAN BONE; POPULATION; MODEL AB The Mayak Production Association (MPA) was the first facility in the former Soviet Union for the production of plutonium. Significant worker and population exposures occurred as a result of failures in the technological processes in the late 1940's and early 1950's. Residents of many villages downstream on the Techa River were exposed via a variety of pathways; the more significant included drinking of water from the river and external gamma exposure due to proximity to contaminated bottom sediment and shoreline. After the extent of the major contamination of the Techa River became known, several villages on the upper part of the Techa River were evacuated. Organ doses are being reconstructed on the basis of derivation of an historical source term and a simple river model used to simulate the transport of radionuclides downstream and their retention on sediments; measurements of Sr-90 content in teeth and the whole body of half of the members of the cohort; and development of the "Techa River Dosimetry System" for computation of the doses. C1 Urals Res Ctr Radiat Med, Chelyabinsk, Russia. Univ Utah, Div Radiobiol, Salt Lake City, UT 84117 USA. Batelle Pacific NW Lab, Richland, WA USA. Res Inst Ind & Marine Med, St Petersburg, Russia. EM LAnspaugh@aol.com NR 32 TC 47 Z9 54 U1 1 U2 3 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 JUL PY 2000 VL 79 IS 1 BP 24 EP 35 DI 10.1097/00004032-200007000-00007 PG 12 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 323ND UT WOS:000087570700007 PM 10855775 ER PT J AU Neta, R AF Neta, R TI The promise of molecular epidemiology in defining the association between radiation and cancer SO HEALTH PHYSICS LA English DT Article DE epidemiology; cancer; exposure, radiation; risk analysis ID TUMOR-SUPPRESSOR GENES; MISMATCH REPAIR; HYPERSENSITIVITY; INSTABILITY; BRCA1; MICE; ATM; P53 AB Molecular epidemiology involves the inclusion in epidemiologic studies of biologic measurements made at a genetic and molecular level and aims to improve the current knowledge of disease etiology and risk. One of the goats of molecular epidemiology studies of cancer is to determine the role of environmental and genetic factors in initiation and progression of malignancies and to use this knowledge to develop preventive strategies. This approach promises extraordinary opportunities for revolutionizing the practice of medicine and reducing risk. However, this will be accompanied by the need to address and resolve many challenges, such as ensuring the appropriate interpretation of molecular testing and resolving associated ethical, legal, and social issues. Traditional epidemiologic approaches determined that exposure to ionizing radiation poses significantly increased risk of leukemia and several other types of cancer. Such studies provided the basis for setting exposure standards to protect the public and the workforce from potentially adverse effects of ionizing radiation. These standards were set by using modeling approaches to extrapolate from the biological effects observed in high-dose radiation studies to predicted, but mostly unmeasurable, effects at low radiation doses. It is anticipated that the addition of the molecular parameters to the population-based studies will help identify the genes and pathways characteristic of cancers due to radiation exposure of individuals, as well as identify susceptible or resistant subpopulations. In turn, the information about the molecular mechanisms should aid to improve risk assessment. While studies on radiogenic cancers are currently limited to only a few candidate genes, the exponential growth of scientific knowledge and technology promises expansion of knowledge about identity of participating genes and pathways in the future. This article is meant to provide an introductory overview of recent advances in understanding of carcinogenesis at the molecular level, with an emphasis of the aspects that may be of use in establishing the association between radiation and cancer. C1 US Dept Energy, Int Hlth Program Off, Germantown, MD 20874 USA. EM ruth.neta@eh.doe.gov RI huang, hongqi/N-1473-2014 NR 30 TC 11 Z9 11 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD JUL PY 2000 VL 79 IS 1 BP 77 EP 84 DI 10.1097/00004032-200007000-00013 PG 8 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 323ND UT WOS:000087570700013 PM 10855781 ER PT J AU Stohr, J Anders, S AF Stohr, J Anders, S TI X-ray spectro-microscopy of complex materials and surfaces SO IBM JOURNAL OF RESEARCH AND DEVELOPMENT LA English DT Article ID MAGNETIC CIRCULAR-DICHROISM; PHOTOEMISSION ELECTRON-MICROSCOPY; THIN-FILMS; ANTIFERROMAGNETIC DOMAINS; UNIDIRECTIONAL ANISOTROPY; HEAD/DISK INTERFACE; FERROMAGNETIC-FILMS; TITANIUM SILICIDE; TUNNEL-JUNCTIONS; NARROW LINES AB The detailed understanding of complex materials used in information technology requires the use of state-of-the-art experimental techniques that provide information on the electronic and magnetic properties of the materials. The increasing miniaturization of components furthermore demands the use of techniques with spatial resolution down to the nanometer range. A means to satisfy both requirements is to combine the capabilities of conventional X-ray absorption spectroscopy with those of electron microscopy in a new technique designated as X-ray photoemission electron microscopy. This paper reviews the principles of this new spectro-microscopy approach and presents selected applications to the study of materials of interest in information technology. C1 Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Stohr, J (reprint author), Stanford Synchrotron Radiat Lab, POB 20450,MS 69, Stanford, CA 94309 USA. RI Raoux, Simone/G-3920-2016 NR 62 TC 44 Z9 45 U1 0 U2 9 PU IBM CORP PI ARMONK PA OLD ORCHARD RD, ARMONK, NY 10504 USA SN 0018-8646 J9 IBM J RES DEV JI IBM J. Res. Dev. PD JUL PY 2000 VL 44 IS 4 BP 535 EP 551 PG 17 WC Computer Science, Hardware & Architecture; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA 336RK UT WOS:000088316600007 ER PT J AU Hereld, M Judson, IR Stevens, RL AF Hereld, M Judson, IR Stevens, RL TI Introduction to building projection-based tiled display systems SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. RP Hereld, M (reprint author), Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. OI Hereld, Mark/0000-0002-0268-2880 NR 22 TC 52 Z9 56 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD JUL-AUG PY 2000 VL 20 IS 4 BP 22 EP 28 DI 10.1109/38.851746 PG 7 WC Computer Science, Software Engineering SC Computer Science GA 327KR UT WOS:000087793500007 ER PT J AU Schikore, DR Fischer, RA Frank, R Gaunt, R Hobson, J Whitlock, B AF Schikore, DR Fischer, RA Frank, R Gaunt, R Hobson, J Whitlock, B TI High-resolution multiprojector display walls SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Univ Calif Lawrence Livermore Natl Lab, Visual Environm Weap Simulat Visualizat Project, Livermore, CA 94550 USA. RP Schikore, DR (reprint author), Computat Engn Int, 600 Airport Blvd,Suite 500, Morrisville, NC 27560 USA. NR 8 TC 25 Z9 26 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 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD JUL-AUG PY 2000 VL 20 IS 4 BP 38 EP 44 DI 10.1109/38.851748 PG 7 WC Computer Science, Software Engineering SC Computer Science GA 327KR UT WOS:000087793500009 ER PT J AU Friesen, JA Tarman, TD AF Friesen, JA Tarman, TD TI Remote high-performance visualization and collaboration SO IEEE COMPUTER GRAPHICS AND APPLICATIONS LA English DT Article C1 Sandia Natl Labs, Livermore, CA 94551 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Friesen, JA (reprint author), Sandia Natl Labs, Dept 8990 MS 9012,Box 969, Livermore, CA 94551 USA. NR 9 TC 7 Z9 7 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0272-1716 J9 IEEE COMPUT GRAPH JI IEEE Comput. Graph. Appl. PD JUL-AUG PY 2000 VL 20 IS 4 BP 45 EP 49 DI 10.1109/38.851749 PG 5 WC Computer Science, Software Engineering SC Computer Science GA 327KR UT WOS:000087793500010 ER PT J AU Williams, C Reynolds, PF de Supinski, BR AF Williams, C Reynolds, PF de Supinski, BR TI Delta coherence protocols SO IEEE CONCURRENCY LA English DT Article ID MEMORY CONSISTENCY MODELS; MULTIPROCESSORS C1 Univ Virginia, Dept Comp Sci, Charlottesville, VA 22904 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Williams, C (reprint author), Univ Virginia, Dept Comp Sci, 151 Engineers Way, Charlottesville, VA 22904 USA. NR 16 TC 8 Z9 8 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 1092-3063 J9 IEEE CONCURR JI IEEE Concurr. PD JUL-SEP PY 2000 VL 8 IS 3 BP 23 EP 29 DI 10.1109/4434.865889 PG 7 WC Computer Science, Theory & Methods SC Computer Science GA 346XM UT WOS:000088896400008 ER PT J AU Lang, RJ Carlson, NW Beyer, E AF Lang, RJ Carlson, NW Beyer, E TI Introduction to the issue on high-power and high-brightness lasers SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Editorial Material C1 SDL Inc, San Jose, CA 95134 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Fraunhofer Inst Werkstoff Strahtech, D-01277 Dresden, Germany. Keio Univ, Dept Elect & Elect Engn, Yokohama, Kanagawa 223, Japan. RP Lang, RJ (reprint author), SDL Inc, San Jose, CA 95134 USA. RI Beyer, Eckhard/B-4426-2010 NR 0 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD JUL-AUG PY 2000 VL 6 IS 4 BP 561 EP 563 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 376TL UT WOS:000165472800001 ER PT J AU Carlson, NW AF Carlson, NW TI Failure statistics for diode laser array modules and replacement model in large-scale laser systems SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE diode laser arrays; lifetime arrays; reliability; semiconductor laser ID RELIABILITY AB This paper presents a methodology for synthesizing diode-laser array module failure statistics from the failure statistics of constituent diode laser arrays. In addition, a model is elucidated for analyzing replacement strategies of systems containing large numbers of diode laser array modules. Simulations reveal the dependence of synthsized module failure statistics and replacement characteristics on module size and failure statistics of the constituent diode laser arrays. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Carlson, NW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 20 TC 2 Z9 2 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 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD JUL-AUG PY 2000 VL 6 IS 4 BP 615 EP 622 DI 10.1109/2944.883375 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 376TL UT WOS:000165472800008 ER PT J AU Pennington, DM Brown, CG Cowan, TE Hatchett, SP Henry, E Herman, S Kartz, M Key, M Koch, J MacKinnon, AJ Perry, MD Phillips, TW Roth, M Sangster, TC Singh, M Snavely, RA Stoyer, M Stuart, BC Wilks, SC AF Pennington, DM Brown, CG Cowan, TE Hatchett, SP Henry, E Herman, S Kartz, M Key, M Koch, J MacKinnon, AJ Perry, MD Phillips, TW Roth, M Sangster, TC Singh, M Snavely, RA Stoyer, M Stuart, BC Wilks, SC TI Petawatt laser system and experiments SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE adaptive optics; Bremsstrahlung; chirped pulse amplification; electron emission; nuclear physics; optical pulse compression; plasmas; proton beams; pulsed lasers; relativistic effects; ultrafast optics ID CHIRPED-PULSE AMPLIFICATION; TI-SAPPHIRE LASER; HOT-ELECTRON PRODUCTION; FAST-IGNITER; GLASS-LASER; FEMTOSECOND PULSES; INTENSITY LASERS; OPTICAL PULSES; GENERATION; TERAWATT AB We have developed a hybrid Ti:sapphire-Nd: glass laser system that produces more than 1.5 PW of peak power. The system has produced up to 680 J of energy on target at 1054 nm in a compressed 440 +/- 20-fs pulse by use of 94-cm diffraction gratings. A focused irradiance of up to 6 x 10(20) W/cm(2) was achieved using an on-axis parabolic mirror and adaptive optic wavefront control. Experiments with the petawatt laser system focused the beam on solid targets and produced a strongly relativistic interaction. Energy content, spectra, and angular pattern of the photon, electron, and ion radiations were diagnosed in a number of ways, including several nuclear activation techniques. Approximately 40-50% of the laser energy was converted to broadly beamed hot electrons, with an associated bremsstrahlung beam. High luminosity ion beams were observed normal to the rear surface of various targets with energies up to greater than or equal to 55 MeV, representing similar to7% of the laser energy. These and other results are presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Gesell Schwerionenforsch, Darmstadt, Germany. RP Pennington, DM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI MacKinnon, Andrew/P-7239-2014; Stuart, Brent/K-4988-2015; Cowan, Thomas/A-8713-2011 OI MacKinnon, Andrew/0000-0002-4380-2906; Cowan, Thomas/0000-0002-5845-000X NR 69 TC 29 Z9 30 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD JUL-AUG PY 2000 VL 6 IS 4 BP 676 EP 688 PG 13 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 376TL UT WOS:000165472800015 ER PT J AU Blum, O Klem, JF AF Blum, O Klem, JF TI Characteristics of GaAsSb single-quantum-well-lasers emitting near 1.3 mu m SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID PERFORMANCE AB We report data on GaAsSb single-quantum-well lasers grown on GaAs substrates. Room temperature pulsed emission at 1.275 mu m in a 1250-mu m-long device has been observed, Minimum threshold current densities of 535 A/cm(2) were measured in 2000-mu m-long lasers, We also measured internal losses of 25 cm(-1), internal quantum efficiencies of 30%-38% and characteristic temperatures To of 67 degrees C-77 degrees C. From these parameters, a gain constant G(o) of 1660 cm(-1) and a transparency current density J(tr) of 134 A/cm(2) were calculated. The results indicate the potential for fabricating 1.3-mu m vertical-cavity surface-emitting lasers from these materials. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Blum, O (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 36 Z9 37 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 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD JUL PY 2000 VL 12 IS 7 BP 771 EP 773 DI 10.1109/68.853495 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 339YQ UT WOS:000088505800005 ER PT J AU Schulte, MJ Balzola, PI Akkas, A Brocato, RW AF Schulte, MJ Balzola, PI Akkas, A Brocato, RW TI Integer multiplication with overflow detection or saturation SO IEEE TRANSACTIONS ON COMPUTERS LA English DT Article DE overflow; saturation; two's complement; unsigned; integer; array multipliers; tree multipliers; computer arithmetic ID MULTIPLIERS; DESIGN AB High-speed multiplication is frequently used in general-purpose and application-specific computer systems. These systems often support integer multiplication, where two n-bit integers are multiplied to produce a 2n-bit product. To prevent growth in word length, processors typically return the n least significant bits of the product and a flag that indicates whether or not overflow has occurred. Alternatively, some processors saturate results that overflow to the most positive or most negative representable number. This paper presents efficient methods for performing unsigned or two's complement integer multiplication with overflow detection or saturation. These methods have significantly less area and delay than conventional methods for integer multiplication with overflow detection or saturation. C1 Lehigh Univ, Dept Comp Sci & Elect Engn, Bethlehem, PA 18015 USA. Sandia Natl Labs, Digital Microelect Dept, Albuquerque, NM 87185 USA. RP Schulte, MJ (reprint author), Lehigh Univ, Dept Comp Sci & Elect Engn, Bethlehem, PA 18015 USA. NR 28 TC 6 Z9 6 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 0018-9340 J9 IEEE T COMPUT JI IEEE Trans. Comput. PD JUL PY 2000 VL 49 IS 7 BP 681 EP 691 DI 10.1109/12.863038 PG 11 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 345YW UT WOS:000088843800007 ER PT J AU Barnum, H Knill, E Nielsen, MA AF Barnum, H Knill, E Nielsen, MA TI On quantum fidelities and channel capacities SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Article DE channel capacity; entanglement; quantum channels; quantum coding; quantum fidelity; quantum information ID ERROR-CORRECTION; CLASSICAL INFORMATION; OPTIMAL CLONING; CODING THEOREM; PURE STATES; ENTANGLEMENT; CANNOT AB For the discrete memoryless quantum channel, me show the equivalence of two different notions of quantum channel capacity: that which uses the entanglement fidelity as its criterion for success in transmission, and that which uses the minimum fidelity of pure states in a subspace of the input Hilbert space as its criterion. As a corollary, arty source with entropy rate less than the capacity may be transmitted with high entanglement fidelity. We also show that a restricted class of encodings is sufficient to transmit any quantum source which may be transmitted on a given channel. This enables us to simplify a known upper bound for the channel capacity It also enables us to show that the availability of an auxiliary classical channel from encoder to decoder does not increase the quantum capacity. C1 Univ Bristol, Dept Comp Sci, Bristol BS8 1UB, Avon, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Queensland, Dept Phys, Brisbane, Qld 4072, Australia. RP Barnum, H (reprint author), Univ Bristol, Dept Comp Sci, Merchant Venturers Bldg, Bristol BS8 1UB, Avon, England. NR 49 TC 122 Z9 123 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD JUL PY 2000 VL 46 IS 4 BP 1317 EP 1329 DI 10.1109/18.850671 PG 13 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 334VK UT WOS:000088206200010 ER PT J AU D'yachkov, AG Torney, DC AF D'yachkov, AG Torney, DC TI On similarity codes SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Letter DE complementary pairs; DNA hybridization; energy of duplex; quaternary DNA sequences; similarity code AB We introduce a biologically motivated measure of sequence similarity for quaternary N-sequences, extending Humming similarity. This measure is the sum over the length of the sequences of "alphabetic" similarities at all positions. Alphabetic similarities are defined, symmetrically on the Cartesian square of the alphabet. These similarities equal zero whenever the two elements differ. In distinction to Hamming similarity, however, our alphabetic similarities Lake individual values whenever the two elements are identical. In this correspondence,ve derive lower and upper bounds on the rate of the corresponding quaternary nonlinear and linear codes called similarity codes and applied for DNA sequences. C1 Moscow State Univ, Fac Mech & Math, Dept Probabil Theory, Moscow 119899, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP D'yachkov, AG (reprint author), Moscow State Univ, Fac Mech & Math, Dept Probabil Theory, Moscow 119899, Russia. NR 7 TC 6 Z9 7 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 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD JUL PY 2000 VL 46 IS 4 BP 1558 EP 1564 DI 10.1109/18.850695 PG 7 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 334VK UT WOS:000088206200034 ER PT J AU Braunstein, SL Fuchs, CA Gottesman, D Lo, HK AF Braunstein, SL Fuchs, CA Gottesman, D Lo, HK TI A quantum analog of Huffman coding SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Letter DE data compression; Huffman coding; instantaneous codes; quantum coding; quantum information; variable-length codes ID COMPRESSION; FIDELITY AB We analyze a generalization of Huffman coding to the quantum ease. In particular, Re notice various difficulties in using instantaneous codes for quantum communication. Nevertheless, for the storage of quantum information, we have succeeded in constructing a Huffman-coding-inspired quantum scheme. The number of computational steps in the encoding and decoding processes of N quantum signals can be made to be of polylogarithmic depth by a massively parallel implementation of a quantum gate array. This is to be compared with the O(N-8) computational steps required in the sequential implementation by Cleve and DiVincenzo of the well-known quantum noiseless block-coding scheme of Schumacher. We also show that O(N-2(log N)(a)) sequential computational steps are needed for the communication of quantum information using another Huffman-coding-inspired scheme where the sender must disentangle her encoding device before the receiver can perform any measurements on his signals. C1 Univ Wales, SEECS, Bangor LL57 1UT, Gwynedd, Wales. Hewlett Packard Labs, Bristol BS34 8QZ, Avon, England. CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. MagiQ Technol Inc, New York, NY 10001 USA. RP Braunstein, SL (reprint author), Univ Wales, SEECS, Bangor LL57 1UT, Gwynedd, Wales. RI Braunstein, Samuel/A-5501-2009 NR 12 TC 14 Z9 16 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 0018-9448 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD JUL PY 2000 VL 46 IS 4 BP 1644 EP 1649 DI 10.1109/18.850709 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 334VK UT WOS:000088206200048 ER PT J AU Hull, JR Turner, LR AF Hull, JR Turner, LR TI Magnetomechanics of internal-dipole, Halbach-array motor/generators SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 12th Conference on the Computation of Electromagnetic Fields (COMPUMAG 99) CY OCT 25-28, 1999 CL SAPPORO, JAPAN SP Int Compumag Soc, Hokkaido Univ, IEE Japan, Japan Soc Appl Electromagnet & Mech, Hokkaido Univ, Ctr Adv Sci & Technol DE flywheel energy storage; magnetic levitation; permanent magnet motors ID PERMANENT; BEARINGS; MACHINES; MAGNETS; DESIGN AB The magnetomechanical behavior of internal-dipole, Halbach-type magnet arrays is analyzed for application as a motor/generator (M/G) with an energy-storage flywheel that is suspended by low-stiffness bearings. Scaling laws for the maximization of torque are derived as a function of geometry, The optimal geometry is relatively insensitive to gap and stator design and occurs approximately at a ratio of inner to outer diameter of the array of 0.8. Values are found for the angular extent of each phase of the stator coil that minimize the stiffness. The negative stiffness of the internal-dipole array is calculated for several manufacturable configurations and is shown to provide an upper limit on the available torque of the M/G according to the positive stiffness of the bearings. Experimental results are reported for an internal-dipole array used as a M/G for a flywheel suspended by a bearing consisting of a permanent-magnet assembly levitated over an array of high-temperature superconductors. Results show that the system is stable and that idling losses are low. C1 Argonne Natl Lab, Energy Technol Div, Argonne, IL 60439 USA. RP Hull, JR (reprint author), Argonne Natl Lab, Energy Technol Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 11 Z9 12 U1 2 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD JUL PY 2000 VL 36 IS 4 BP 2004 EP 2011 DI 10.1109/20.875294 PN 2 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 367UH UT WOS:000090079500007 ER PT J AU Tuominen, MW Olsen, RG AF Tuominen, MW Olsen, RG TI Electrical design parameters of all-dielectric-self-supporting fiber optic cable SO IEEE TRANSACTIONS ON POWER DELIVERY LA English DT Article DE dry band arcing; fiber optic cables; high electric field AB A lumped circuit model for calculating voltages and currents on all-dielectric self-supporting (ADSS) fiber optic cable near high voltage transmission lines has been developed. The model has been used to show that contamination levels, tower attachment points, relative ADSS and conductor sag and electrical phasing of the conductors are important parameters and must be considered in calculations, especially when determining the possibility: of dry band arcs which could lead to cable damage. C1 US DOE, Bonneville Power Adm, Portland, OR 97208 USA. Washington State Univ, Sch EECS, Pullman, WA 99164 USA. RP Tuominen, MW (reprint author), US DOE, Bonneville Power Adm, Portland, OR 97208 USA. NR 16 TC 21 Z9 21 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 0885-8977 J9 IEEE T POWER DELIVER JI IEEE Trans. Power Deliv. PD JUL PY 2000 VL 15 IS 3 BP 940 EP 947 DI 10.1109/61.871356 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 359UF UT WOS:000089629900014 ER PT J AU Tolbert, LM Peng, FZ Habetler, TG AF Tolbert, LM Peng, FZ Habetler, TG TI Multilevel PWM methods at low modulation indices SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article DE cascade inverter; diode-clamped inverter; low modulation index; multilevel inverter; multilevel PWM ID CONVERTERS; INVERTERS; DRIVES AB When utilized at low amplitude modulation indices, existing multilevel carrier-based PWM strategies have no special provisions for this operating region, and several levels of the inverter go unused. This paper proposes some novel multilevel PWM strategies to take advantage of the multiple levels in both a diode-clamped inverter and a cascaded II-bridges inverter by utilizing all of the levels in the inverter even at low modulation indices. Simulation results show what effects the different strategies have on the active device utilization. A prototype 6-level diode-clamped inverter and an 11-level cascaded H-bridges inverter have been built and controlled with the novel PWM strategies proposed in this paper. C1 Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. RP Tolbert, LM (reprint author), Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. OI Tolbert, Leon/0000-0002-7285-609X NR 12 TC 114 Z9 129 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8993 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD JUL PY 2000 VL 15 IS 4 BP 719 EP 725 DI 10.1109/63.849042 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 332RF UT WOS:000088086700015 ER PT J AU Graves, TL Karr, AF Marron, JS Siy, H AF Graves, TL Karr, AF Marron, JS Siy, H TI Predicting fault incidence using software change history SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article DE fault potential; code decay; change management data; metrics; statistical analysis; generalized linear models ID PRONE SOFTWARE AB This paper is an attempt to understand the processes by which software ages. We define code to be aged or decayed if its structure makes it unnecessarily difficult to understand or change and we measure the extent of decay by counting the number of faults in code in a period of time. Using change management data from a very large, long-lived software system, we explore the extent to which measurements from the change history are successful in predicting the distribution over modules of these incidences of faults. In general, process measures based on the change history are more useful in predicting fault rates than product metrics of the code: For instance, the number of times code has been changed is a better indication of how many faults it will contain than is its length. We also compare the fault Fates of code of Various ages, finding that if a module is, on the average, a year older than an otherwise similar module, the older module will have roughly a third fewer faults. Our most successful model measures the fault potential of a module as the sum of contributions from all of the times the module has been changed, with large, recent changes receiving the most weight. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lucent Technol, Naperville, IL 60566 USA. Natl Inst Stat Sci, Res Triangle Pk, NC 27709 USA. Univ N Carolina, Chapel Hill, NC 27599 USA. RP Graves, TL (reprint author), Univ Calif Los Alamos Natl Lab, MS F600, Los Alamos, NM 87545 USA. NR 21 TC 236 Z9 243 U1 1 U2 8 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD JUL PY 2000 VL 26 IS 7 BP 653 EP 661 DI 10.1109/32.859533 PG 9 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 341PB UT WOS:000088597800006 ER PT J AU Friessnegg, T Aggarwal, S Nielsen, B Ramesh, R Keeble, DJ Poindexter, EH AF Friessnegg, T Aggarwal, S Nielsen, B Ramesh, R Keeble, DJ Poindexter, EH TI A study of vacancy-related defects in (Pb,La)(Zr,Ti)O-3 thin films using positron annihilation SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID HETEROSTRUCTURES; CAPACITORS; GROWTH; PAIRS AB The formation of vacancy-type defects in La-doped lead zirconate titanate (PLZT) thin films (Zr/Ti=20/80) was studied as a function of lanthanum doping and after cooling in an oxygen-reduced ambient. The changes in the Doppler-broadening S parameter are consistent with the progressive introduction of Ph-vacancies upon La-doping. Cooling of PLZT thin films with 0 and 10% La doping in 10(-5) Torr oxygen partial pressure after growth exhibits an increase in the density of vacancy-type defects compared to films cooled in 760 Torr. It is proposed that the defects formed are likely cation-oxygen vacancy complexes. C1 Univ Maryland, College Pk, MD 20742 USA. Brookhaven Natl Lab, Upton, NY 11793 USA. Univ Dundee, Dundee DD1 4HN, Scotland. USA, Res Lab, Adelphi, MD 20783 USA. RP Friessnegg, T (reprint author), Univ Maryland, College Pk, MD 20742 USA. RI Nielsen, Bent/B-7353-2009; Keeble, David /C-6633-2012 OI Nielsen, Bent/0000-0001-7016-0040; Keeble, David /0000-0002-5378-799X NR 16 TC 5 Z9 5 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD JUL PY 2000 VL 47 IS 4 BP 916 EP 920 DI 10.1109/58.852074 PG 5 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 334FK UT WOS:000088175800019 PM 18238625 ER PT J AU Liu, WR Kim, J Nwankwo, C Ashworth, LK Arm, JP AF Liu, WR Kim, J Nwankwo, C Ashworth, LK Arm, JP TI Genomic organization of the human leukocyte immunoglobulin-like receptors within the leukocyte receptor complex on Chromosome 19q13.4 SO IMMUNOGENETICS LA English DT Article DE leukocyte Ig-like receptors; ILT; human Chromosome 19; immunoglobulin superfamily; gene structure ID CELL INHIBITORY RECEPTOR; RNA SECONDARY STRUCTURE; FC RECEPTOR; TRANSLATIONAL CONTROL; INITIATOR CONSENSUS; MOLECULAR-CLONING; MESSENGER-RNAS; MYELOID CELLS; PIR-B; GENE AB The leukocyte immunoglobulin (Ig)-like receptors (LIRs) comprise a family of eel surface receptors that couple to either activating or inhibitory signals depending on the nature of their transmembrane and cytoplasmic domains. We describe the organization and fine localization of the genes for LIR-1 and LIR-5, which are inhibitory receptors, and LIR-6, which is an activating receptor. The genomic organization of all three genes is highly conserved from the signal peptide through the membrane-proximal Ig domain but diverges thereafter depending on the inhibitory or activating nature of the gene product. The 3' untranslated region of the gene for LIR-6 contains a 37-base pair repeat not present in the LIR-1 or LIR-5 genes. 5' rapid amplification of cDNA ends defined the putative transcription initiation site of the LIR-5 gene, which is TATA-less. A nucleotide substitution in the LIR-5 gene led to loss of an intron present in the 5' untranslated region of the LIR-1 and LIR-6 genes. Differences in the genomic structure of these three LIR genes suggests possible mechanisms for their differential expression in cells of hematopoietic lineage. The three genes are in a region of Chromosome 19q13.4 that is immediately centromeric of the killer cell Ig-like receptor genes and are separated from one another by similar to 20 to 30 kb, suggesting that they arose by gene duplication from a common ancestor. C1 Brigham & Womens Hosp, Dept Med, Div Rheumatol Allergy & Immunol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Boston, MA 02115 USA. Brigham & Womens Hosp, Partners Asthma Ctr, Boston, MA 02115 USA. Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Arm, JP (reprint author), Brigham & Womens Hosp, Dept Med, Div Rheumatol Allergy & Immunol, 1 Jimmy Fund Way, Boston, MA 02115 USA. EM jarm@rics.bwh.harvard.edu FU NIAID NIH HHS [AI31599, AI07306] NR 54 TC 22 Z9 24 U1 1 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0093-7711 J9 IMMUNOGENETICS JI Immunogenetics PD JUL PY 2000 VL 51 IS 8-9 BP 659 EP 669 DI 10.1007/s002510000183 PG 11 WC Genetics & Heredity; Immunology SC Genetics & Heredity; Immunology GA 339ZH UT WOS:000088507400006 PM 10941837 ER PT J AU Dang, A Ooi, L Fales, J Stroeve, P AF Dang, A Ooi, L Fales, J Stroeve, P TI Yield stress measurements of magnetorheological fluids in tubes SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID MAGNETIC-FIELD; FLOW AB A pressure-driven apparatus was used to measure the yield stress of magnetorheological (MR) fluids as a function of the applied magnetic field, the carbonyl iron particle content, and the amount of surfactant used to stabilize the MR fluid. The yield stress was measured from the pressure difference necessary to initiate flow of a MR fluid in a straight tube present in a magnetic field. Yield stress measurements were made on MR fluids that contained up to 30 vol % carbonyl iron particles, up to 14 vol % surfactant oleic acid, and the remainder 100 cS silicone oil. In the absence of an applied magnetic field, the MR fluids did not have a yield stress and behaved as Newtonian fluids. In the presence of magnetic fields up to 2.2 kG, the MR fluids had yield stresses up to 1.9 kPa. An effect of the tube size on the yield stress was observed-for MR fluids above 15 vol % carbonyl iron and magnetic fields above 1.0 kG. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Stroeve, P (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. NR 19 TC 35 Z9 37 U1 1 U2 9 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 JUL PY 2000 VL 39 IS 7 BP 2269 EP 2274 DI 10.1021/ie9908276 PG 6 WC Engineering, Chemical SC Engineering GA 331UJ UT WOS:000088036800019 ER PT J AU Wang, JG Nieh, TG AF Wang, JG Nieh, TG TI Creep of a beta phase-containing TiAl alloy SO INTERMETALLICS LA English DT Article DE titanium aluminides, based on TiAl; creep; microstructure; electron microscopy, transmission ID GAMMA-TITANIUM ALUMINIDES; HIGH-TEMPERATURE DEFORMATION; SELF-DIFFUSION; METASTABLE MICROSTRUCTURE; MECHANICAL-PROPERTIES; INTERMETALLIC ALLOYS; CHEMICAL DIFFUSION; AL ALLOY; BEHAVIOR; VANADIUM AB The creep properties of a powder-metallurgy Ti-46.5Al-2Cr-2Nb-0.8Mo-0.2W-0.2Si (at%) alloy containing beta phase were investigated. Tensile creep experiments were performed in air at 705, 760 and 815 degrees C at stresses ranging from 35 to 414 MPa. Stress exponent and activation energy were both measured. Data indicated that the creep of the alloy can be divided into two regimes, depending upon the applied stress. Microstructures before and after deformation were examined using X-ray diffraction, scanning and transmission electron microscopy techniques. Efforts were made to correlate creep properties with microstructures. Possible deformation mechanisms in the two creep regimes were discussed. The creep resistance of the present alloy was also compared with other alloys without beta phase. It is concluded that the presence of beta phase reduces the creep resistance of TiAl. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wang, JG (reprint author), Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. EM wangjg@uci.edu RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 41 TC 53 Z9 55 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD JUL PY 2000 VL 8 IS 7 BP 737 EP 748 DI 10.1016/S0966-9795(00)00009-1 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 323MA UT WOS:000087568100006 ER PT J AU Horstemeyer, MF AF Horstemeyer, MF TI A numerical parametric investigation of localization and forming limits SO INTERNATIONAL JOURNAL OF DAMAGE MECHANICS LA English DT Article ID DEFORMATION AB The ability of a theoretical model to accurately predict localization and failure strains, which characterize the formability of materials, has been a controversial subject as researchers have tried various analytical methods over the years to predict forming limit diagrams. In this work, we analyze various aspects of finite element modeling in which large deformation plasticity is coupled with continuum damage evolution. In the context of the Bammann-Chiesa-Johnson (BCJ) internal state variable model, we examine different finite element codes (DYNA3D, PRONTO3D, and JAC3D), sheet thicknesses (1.0 cm and 0.1 cm), types of instabilities (geometric perturbation and various initial void volume fraction mismatches), element types [solid continuum, Hughes and Liu (1980), and Belytschko and Tsay (1983)], mesh refinement, and two-stage nonproportional straining conditions. By varying these parameters in finite element calculations for determining forming limits, we ascertain not only the forming limit diagrams in a short time but an understanding of parametric effects that have been issues of concern for the auto, steel, and aircraft industries. C1 Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94551 USA. RP Horstemeyer, MF (reprint author), Sandia Natl Labs, Ctr Mat Sci & Engn, MS 9405, Livermore, CA 94551 USA. OI Horstemeyer, Mark/0000-0003-4230-0063 NR 45 TC 8 Z9 8 U1 0 U2 4 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1056-7895 J9 INT J DAMAGE MECH JI Int. J. Damage Mech. PD JUL PY 2000 VL 9 IS 3 BP 255 EP 285 DI 10.1177/105678950000900304 PG 31 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 335LT UT WOS:000088245500003 ER PT J AU Taylor, R Takasaki AF Taylor, R Takasaki TI Status of KEKB accelerator and detector, BELLE - Discussion SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Editorial Material C1 SLAC, Stanford, CA USA. RP Taylor, R (reprint author), SLAC, Stanford, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 21 EP 21 PG 1 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200004 ER PT J AU Dorfan, J AF Dorfan, J TI Status of PEP-II and BaBar SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 19th International Symposium on Lepton and Photon Interactions CY AUG 09-14, 1999 CL STANFORD UNIV, STANFORD, CALIFORNIA SP Stanford Univ HO STANFORD UNIV C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Dorfan, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 22 EP 34 DI 10.1142/S0217751X0000505X PG 13 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200005 ER PT J AU Paulini, M AF Paulini, M TI Brief report from the Tevatron SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 19th International Symposium on Lepton and Photon Interactions CY AUG 09-14, 1999 CL STANFORD UNIV, STANFORD, CALIFORNIA SP Stanford Univ HO STANFORD UNIV ID P(P)OVER-BAR COLLISIONS; ROOT-S=1.8 TEV; CHARGE C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Paulini, M (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Paulini, Manfred/N-7794-2014 OI Paulini, Manfred/0000-0002-6714-5787 NR 4 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 43 EP 50 DI 10.1142/S0217751X00005073 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200007 ER PT J AU Peskin, M Thaler, J Blaylock AF Peskin, M Thaler, J Blaylock TI Heavy quark lifetimes, mixing, and CP violation - Discussion SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Editorial Material C1 SLAC, Stanford, CA USA. Univ Illinois, Chicago, IL 60680 USA. RP Peskin, M (reprint author), SLAC, Stanford, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 103 EP 103 PG 1 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200011 ER PT J AU Peskin, M AF Peskin, M TI Results on direct CP violation from NA48 - Discussion SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Editorial Material C1 SLAC, Stanford, CA USA. RP Peskin, M (reprint author), SLAC, Stanford, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 131 EP 131 PG 1 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200015 ER PT J AU Haber, H Ferbel, T Peskin, M AF Haber, H Ferbel, T Peskin, M TI Precise electroweak results from LEP2 - Discussion SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Editorial Material C1 Univ Rochester, Rochester, NY 14627 USA. SLAC, Stanford, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUL PY 2000 VL 15 SU 1A BP 366 EP 367 PG 2 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 350VE UT WOS:000089121200031 ER PT J AU Massoudi, M Phuoc, TX AF Massoudi, M Phuoc, TX TI The effect of slip boundary condition on the flow of granular materials: a continuum approach SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article DE granular materials; slip boundary condition; continuum approach; inclined flow ID FULLY-DEVELOPED FLOW; STEADY COMPRESSIBLE FLOW; WEDGE-SHAPED HOPPER; ANTIGRANULOCYTES MATERIALS; CONSTITUTIVE RELATIONS; STRESS CALCULATIONS; INCLINED PLANE; SHEAR; PARTICLES; GRAVITY AB In the previous studies we have looked at a fully developed flow under the assumption that the granular materials adhere to the boundary. Whether one uses the continuum approach or the kinetic theory approach in modeling of the granular materials, slip may occur at the wall, especially when the interstitial fluid is a gas, and therefore the classical assumption of adherence boundary condition at the wall no longer applies. The steady, fully developed flow of granular materials down an inclined plane subject to slip at the wall is studied numerically. This is a non-linear boundary value problem. The results for the velocity profiles are presented in terms of appropriate dimensionless numbers. Published by Elsevier Science Ltd. C1 US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Massoudi, M (reprint author), US DOE, Fed Energy Technol Ctr, POB 10940, Pittsburgh, PA 15236 USA. NR 52 TC 10 Z9 10 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7462 J9 INT J NONLINEAR MECH JI Int. J. Non-Linear Mech. PD JUL PY 2000 VL 35 IS 4 BP 745 EP 761 DI 10.1016/S0020-7462(99)00057-8 PG 17 WC Mechanics SC Mechanics GA 297FF UT WOS:000086070700015 ER PT J AU Aboudi, J Williams, TO AF Aboudi, J Williams, TO TI A coupled micro-macromechanical analysis of hygrothermoelastic composites SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE hygrothermoelasticity; diffusion; micromechanics; composite materials ID HIGHER-ORDER THEORY AB A micro-macromechanical procedure is developed to establish the response of multiphase composites whose constituents behave, in general, as hygrothermoelastic materials. The response of the single phase is governed by the fully coupled theory of heat, moisture and deformation, and the micromechanical theory provides the hygrothermoelastic behavior of the composite. Results are presented to illustrate the effects of coupling between temperature, moisture and stress, and the interaction between the phases on the overall temporal and spatial response of a composite slab. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Tel Aviv Univ, Fac Engn, IL-69978 Tel Aviv, Israel. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Aboudi, J (reprint author), Tel Aviv Univ, Fac Engn, IL-69978 Tel Aviv, Israel. NR 11 TC 9 Z9 10 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD JUL PY 2000 VL 37 IS 30 BP 4149 EP 4179 DI 10.1016/S0020-7683(99)00145-6 PG 31 WC Mechanics SC Mechanics GA 312ZN UT WOS:000086974000006 ER PT J AU Sinnott, SB Wood, RF Cho, JH Zhang, ZY AF Sinnott, SB Wood, RF Cho, JH Zhang, ZY TI Quantum size effects in metallic overlayer epitaxy SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS LA English DT Article; Proceedings Paper CT 3rd International Symposium on Surface Science for Micro- and Nano-device Fabrication (ISSS-3) CY NOV 29-DEC 01, 1999 CL WASEDA UNIV, TOKYO, JAPAN SP Minist Educ, Sci, Sport, & Culture HO WASEDA UNIV DE first principles calculations; metal thin films; semiconductors ID SCANNING TUNNELING MICROSCOPY; GAAS(110) SURFACE; SB OVERLAYERS; GROWTH; FILMS; DENSITY; ULTRATHIN; MONOLAYER; SUBSTRATE; GEOMETRY AB Ab-initio total energy calculations have been performed to study the stability and electronic structure of epitaxial Sb and close-packed Ag films on GaAs(110) surfaces. These are model metal-semiconductor systems that have been studied extensively experimentally. The method used is density functional theory within the pseudopotential approximation. These calculations provide information on the relaxation and structure of the Sb and Ag surface layers and the stability of the metal films as a function of the number of metal layers. C1 Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Sinnott, SB (reprint author), Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. EM zlz@ornl.gov RI Sinnott, Susan/P-8523-2014; Cho, Jun-Hyung/R-7256-2016 OI Sinnott, Susan/0000-0002-3598-0403; Cho, Jun-Hyung/0000-0002-1785-1835 NR 29 TC 3 Z9 3 U1 2 U2 4 PU JAPAN SOC APPLIED PHYSICS PI TOKYO PA KUDAN-KITA BUILDING 5TH FLOOR, 1-12-3 KUDAN-KITA, CHIYODA-KU, TOKYO, 102-0073, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Brief Commun. Rev. Pap. PD JUL PY 2000 VL 39 IS 7B BP 4302 EP 4306 DI 10.1143/JJAP.39.4302 PG 5 WC Physics, Applied SC Physics GA 347CN UT WOS:000088910000013 ER PT J AU Muralidharan, G AF Muralidharan, G TI Strains in InAs quantum dots embedded in GaAs: A finite element study SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE InAs; GaAs; axi-symmetric model; quantum dots; finite element method; strains ID SCANNING-TUNNELING-MICROSCOPY; ISLANDS AB Strains in InAs quantum dots embedded in GaAs have been examined using a 2-D axi-symmetric finite element method within a thermo-mechanical framework. The initial shape of the dot was assumed to be conical in 3-D. Results show that the shape and the width/height ratio are critical in determining the strains within the quantum dots. Results of the calculation are compared with the results of other calculations and experimental measurements of strains using the scanning tunneling microscope (STM). C1 Inst Microelect, Singapore 117685, Singapore. RP Muralidharan, G (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Muralidharan, Govindarajan/J-6155-2015 NR 12 TC 17 Z9 17 U1 0 U2 3 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO, 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD JUL 1 PY 2000 VL 39 IS 7A BP L658 EP L660 DI 10.1143/JJAP.39.L658 PG 3 WC Physics, Applied SC Physics GA 337ZG UT WOS:000088393200006 ER PT J AU Meike, A Rajan, K AF Meike, A Rajan, K TI The multidisciplinary character of alloy science SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Editorial Material C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Rensselaer Polytech Inst, Troy, NY 12181 USA. RP Meike, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JUL PY 2000 VL 52 IS 7 BP 13 EP 13 DI 10.1007/s11837-000-0153-6 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 335GF UT WOS:000088235200001 ER PT J AU Yoo, CS Holmes, NC Souers, PC Wu, CJ Ree, FH Dick, JJ AF Yoo, CS Holmes, NC Souers, PC Wu, CJ Ree, FH Dick, JJ TI Anisotropic shock sensitivity and detonation temperature of pentaerythritol tetranitrate single crystal SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INITIATION; ORIENTATION AB Shock temperatures of pentaerythritol tetranitrate (PETN) single crystals have been measured by using a nanosecond time-resolved spectropyrometric system operated at six discrete wavelengths between 350 and 700 nm. The results show that the shock sensitivity of PETN is strongly dependent on the crystal orientation: Sensitive along the shock propagation normal to the (110) plane, but highly insensitive normal to the (100) plane. The detonation temperature of PETN is, however, independent from the crystal orientation and is determined to be 4140 (+/- 70) K. The time-resolved data yielding the detonation velocity 8.28 (+/- 0.10) mm/mu s can be interpreted in the context of a modified thermal explosion model. (C) 2000 American Institute of Physics. [S0021-8979(00)05413-X]. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM yoo1@llnl.gov NR 31 TC 57 Z9 60 U1 2 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2000 VL 88 IS 1 BP 70 EP 75 AR PII [S0021-8979(00)05413-X] DI 10.1063/1.373626 PG 6 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000012 ER PT J AU Sewell, TD Bennett, CM AF Sewell, TD Bennett, CM TI Monte Carlo calculations of the elastic moduli and pressure-volume-temperature equation of state for hexahydro-1,3,5-trinitro-1,3,5-triazine SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; CRYSTALS; SIMULATIONS; PACKING; HMX; RDX AB Isothermal-isobaric Monte Carlo calculations were used to obtain predictions of the elastic coefficients and derived engineering moduli and Poisson ratios for crystalline hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The elastic coefficients were computed using the strain fluctuation formula due to Rahman and Parrinello [J. Chem. Phys. 76, 2662 (1982)]. Calculations were performed as a function of temperature (218 K less than or equal to T less than or equal to 333 K) and hydrostatic pressure (0 GPa less than or equal to p less than or equal to 4 GPa). The predicted values of the moduli and Poisson ratios under ambient conditions are in accord with general expectations for molecular crystals and with a very recent, unpublished determination for RDX. The moduli exhibit a sensitive pressure dependence whereas the Poisson ratios are relatively independent of pressure. The temperature dependence of the moduli is comparable to the precision of the results. However, the crystal does exhibit thermal softening for most pressures. An additional product of the calculations is information about the pressure-volume-temperature (pVT) equation of state. We obtain near-quantitative agreement with experiment for the case of hydrostatic compression and reasonable, but not quantitative, correspondence for thermal expansion. The results indicate a significant dependence of the thermal expansion coefficients on hydrostatic pressure. (C) 2000 American Institute of Physics. [S0021-8979(00)03010-3]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM sewell@lanl.gov NR 30 TC 42 Z9 42 U1 1 U2 16 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 JUL 1 PY 2000 VL 88 IS 1 BP 88 EP 95 AR PII [S0021-8979(00)03010-3] DI 10.1063/1.373628 PG 8 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000014 ER PT J AU Ryu, YR Zhu, S Budai, JD Chandrasekhar, HR Miceli, PF White, HW AF Ryu, YR Zhu, S Budai, JD Chandrasekhar, HR Miceli, PF White, HW TI Optical and structural properties of ZnO films deposited on GaAs by pulsed laser deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB ZnO films were synthesized on GaAs substrates at different growth conditions by pulse laser deposition. High-purity (99.999%) oxygen was used as the ambient gas. The pressure of the ambient oxygen gas for ZnO film growth was varied from 20 to 50 mTorr, and the growth temperature from 300 to 450 degrees C. ZnO films showed very strong bound exciton peaks located between 3.37 and 3.35 eV. The full width at half maximum of the bound exciton peak is less than 5 meV. These results indicate ZnO films on GaAs substrates can be used for optical devices such as light-emitting diodes. The other significant properties of textured ZnO films on GaAs substrates are described. (C) 2000 American Institute of Physics. [S0021-8979(00)02013-2]. C1 Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Ryu, YR (reprint author), Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 13 TC 226 Z9 238 U1 1 U2 12 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2000 VL 88 IS 1 BP 201 EP 204 DI 10.1063/1.373643 PG 4 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000030 ER PT J AU Lozykowski, HJ Jadwisienczak, WM Brown, I AF Lozykowski, HJ Jadwisienczak, WM Brown, I TI Photoluminescence and cathodoluminescence of GaN doped with Pr SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ERBIUM-IMPLANTED GAN; VISIBLE CATHODOLUMINESCENCE; ENERGY-LEVELS; ER; LUMINESCENCE; ELECTROLUMINESCENCE; SEMICONDUCTORS; EXCITATION; EMISSION; NITRIDE AB We report on our observation of visible photoluminescence and cathodoluminescence of Pr-implanted GaN. The implanted samples were subjected to isochronal thermal annealing treatments at a temperature of 1100 degrees C in N-2 at atmospheric pressure to recover from implantation damage and activate the rare earth ions. The sharp characteristic emission lines corresponding to Pr3+ intra-4f(n)-shell transitions are resolved in the spectral range from 400 to 1000 nm and observed over the temperature range from 12 to 335 K. We have developed an energy level diagram for Pr3+ ions in GaN using recorded spectra. The photoluminescence decay kinetics measurements of P-3(1), P-3(0), and D-1(2) levels and quenching mechanism analysis allow us to conclude that the dominant de-excitation process is of electric dipole-electric quadrupole type. We found also that the D-1(2) level separated from the upper P-3(0) level by 3755 cm(-1) energy gap can be populated in several ways, by direct energy transfer processes, cross relaxation \P-3(0),H-3(4)]-->\D-1(2),H-3(6)] and cascade processes from the P-3(0) or higher levels. The full width at half maximum of the strongest photoluminescence line at 653 nm, the P-3(0) level, is 2.9 meV at 13 K, with a 1.86 meV blue peak shift in going from 13 to 330 K temperature, while the line at 670 nm, P-3(1) level, has a full width at half maximum of 4 meV at 13 K and a 1.6 meV red peak shift. The thermal stability of GaN:Pr3+ epilayers indicates the suitability of this material for visible optoelectronic devices. (C) 2000 American Institute of Physics. [S0021-8979(00)01613- 3]. C1 Ohio Univ, Sch Elect Engn & Comp Sci, Stocker Ctr, Athens, OH 45701 USA. Ohio Univ, Condensed Matter & Surface Sci Program, Stocker Ctr, Athens, OH 45701 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Lozykowski, HJ (reprint author), Ohio Univ, Sch Elect Engn & Comp Sci, Stocker Ctr, Athens, OH 45701 USA. NR 54 TC 84 Z9 85 U1 3 U2 16 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2000 VL 88 IS 1 BP 210 EP 222 AR PII [S0021-8979(00)01613-3] DI 10.1063/1.373645 PG 13 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000032 ER PT J AU Windt, DL Christensen, FE Craig, WW Hailey, C Harrison, FA Jimenez-Garate, M Kalyanaraman, R Mao, PH AF Windt, DL Christensen, FE Craig, WW Hailey, C Harrison, FA Jimenez-Garate, M Kalyanaraman, R Mao, PH TI Growth, structure, and performance of depth-graded W/Si multilayers for hard x-ray optics SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERNAL-STRESSES; INTRINSIC STRESS; ELECTRON-MICROSCOPY; ROUGH SURFACES; FILMS; SCATTERING; MAGNETRON; REFLECTION; DEPOSITION; THIN AB We describe the development of depth-graded W/Si multilayer films prepared by magnetron sputtering for use as broad-band reflective coatings for hard x-ray optics. We have used specular and nonspecular x-ray reflectance analysis to characterize the interface imperfections in both periodic and depth-graded W/Si multilayer structures, and high-resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAED) to characterize the interface structure and layer morphology as a function of depth in an optimized depth-graded multilayer. From x-ray analysis we find interface widths in the range sigma=0.275-0.35 nm for films deposited at low argon pressure (with a slight increase in interface width for multilayers having periods greater than similar to 20 nm, possibly due to the transition from amorphous to polycrystalline metal layers identified by TEM and SAED), and somewhat larger interface widths (i.e., sigma=0.35-0.4 nm) for structures grown at higher Ar pressures, higher background pressures, or with larger target-to-substrate distances. We find no variation in interface widths with magnetron power. Nonspecular x-ray reflectance analysis and TEM suggest that the dominant interface imperfection in these films is interfacial diffuseness; interfacial roughness is minimal (sigma(r)similar to 0.175 nm) in structures prepared under optimal conditions, but can increase under conditions in which the beneficial effects of energetic bombardment during growth are compromised. X-ray reflectance analysis was also used to measure the variation in the W and Si deposition rates with bilayer thickness: we find that the W and Si layer thicknesses are nonlinear with the deposition times, and we discuss possible mechanisms responsible for this nonlinearity. Finally, hard x-ray reflectance measurements made with synchrotron radiation were used to quantify the performance of optimized depth-graded W/Si structures over the photon energy range from 18 to 212 keV. We find good agreement between the synchrotron measurements and calculations made using either 0.3 nm interface widths, or with a depth-graded distribution of interface widths in the range sigma=0.275-0.35 nm (as suggested by 8 keV x-ray and TEM analyses) for a structure containing 150 bilayers, and designed for high reflectance over the range 20 keV < E < 70 keV. We also find for this structure good agreement between reflectance measurements and calculations made for energies up to 170 keV, as well as for another graded W/Si structure containing 800 bilayers, designed for use above 100 keV, where the peak reflectance was measured at E=212 keV to be R=76.5+/-4% at a graze angle of theta=0.08 degrees. (C) 2000 American Institute of Physics. [S0021-8979(00)04013-5]. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Danish Space Res Inst, Copenhagen, Denmark. CALTECH, Pasadena, CA 91125 USA. Oak Ridge Natl Labs, Oak Ridge, TN 37831 USA. RP Windt, DL (reprint author), Columbia Univ, Columbia Astrophys Lab, 550 W 120th St, New York, NY 10027 USA. NR 49 TC 63 Z9 65 U1 1 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2000 VL 88 IS 1 BP 460 EP 470 DI 10.1063/1.373681 PG 11 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000071 ER PT J AU Murty, MVR Couture, AJ Cooper, BH Woll, AR Brock, JD Headrick, RL AF Murty, MVR Couture, AJ Cooper, BH Woll, AR Brock, JD Headrick, RL TI Persistent layer-by-layer sputtering of Au(111) SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID X-RAY-SCATTERING; MOLECULAR-BEAM EPITAXY; SURFACE-MORPHOLOGY; GROWTH; INSTABILITY; PT(111) AB Persistent layer-by-layer removal of Au(111) during Ar+ ion irradiation was observed in a real-time x-ray scattering study. Over 100 specular beam intensity oscillations were measured. For a given ion energy, a smoother surface morphology is obtained when the ion flux is reduced. For a fixed erosion rate, ion energy in the range of 70-500 eV does not have a strong influence on the evolution of surface morphology. Diffuse scattering measurements show the development of features with a characteristic lateral length scale on the surface during ion irradiation. (C) 2000 American Institute of Physics. [S0021-8979(00)06213-7]. C1 Cornell Univ, Dept Phys, Ithaca, NY 14853 USA. Cornell Univ, Cornell Ctr Mat Res, Ithaca, NY 14853 USA. Cornell Univ, Sch Appl & Engn Phys, Ithaca, NY 14853 USA. Cornell Univ, Cornell High Energy Synchrotron Source, Wilson Lab, Ithaca, NY 14853 USA. RP Murty, MVR (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 21 TC 8 Z9 8 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 2000 VL 88 IS 1 BP 597 EP 599 AR PII [S0021-8979(00)06213-7] DI 10.1063/1.373703 PG 3 WC Physics, Applied SC Physics GA 325YE UT WOS:000087704000094 ER PT J AU deLaubenfels, R Emamirad, H Protopopescu, V AF deLaubenfels, R Emamirad, H Protopopescu, V TI Linear chaos and approximation SO JOURNAL OF APPROXIMATION THEORY LA English DT Article DE hypercyclic and chaotic semigroups; approximation in the sense of Kato; convection-diffusion equation ID DEFINITION; OPERATORS AB Let {T-n(t)}(n = 1)(infinity) be a sequence of strongly continuous linear semigroups on Banach spaces X-n converging in the sense of Kato to a semigroup T(t) on the Banach space X. We discuss under what conditions the chaoticity of T-n(t) is inherited by T(t). We apply our results to a discrete parabolic equation. (C) 2000 Academic Press. C1 Sci Res Inst, Athens, OH 45701 USA. SP2MI, Lab Modelisat Mecan & Math, F-86950 Futuroscope, France. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP deLaubenfels, R (reprint author), Sci Res Inst, POB 988, Athens, OH 45701 USA. NR 12 TC 12 Z9 12 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9045 J9 J APPROX THEORY JI J. Approx. Theory PD JUL PY 2000 VL 105 IS 1 BP 176 EP 187 DI 10.1006/jath.2000.3465 PG 12 WC Mathematics SC Mathematics GA 333GX UT WOS:000088123500009 ER PT J AU Youngren, B Radnedge, L Hu, P Garcia, E Austin, S AF Youngren, B Radnedge, L Hu, P Garcia, E Austin, S TI A plasmid partition system of the P1-P7par family from the pMT1 virulence plasmid of Yersinia pestis SO JOURNAL OF BACTERIOLOGY LA English DT Article ID P1 PLASMID; PARB PROTEIN; CLONING VEHICLES; HOST FACTOR; F-PLASMID; SPECIFICITY; SITE; DNA; SEGREGATION; CENTROMERE AB The complete sequence of the virulence plasmid pMT1 of Yersinia pestis KIM5 revealed a region homologous to the plasmid partition (par) region of the P7 plasmid prophage of Escherichia coli. The essential genes parA and parB and the downstream partition site gene, parS, are highly conserved in sequence and organization. The pMT1parS site and the parA-parB operon were separately inserted into vectors that could be maintained in E. coli. A mini-P1 vector containing pMT1parS was stably maintained when the pMT1 ParA and ParB proteins were supplied in trans, showing that the pMT1par system is fully functional for plasmid partition in E. coli. The pMT1par system exerted a plasmid silencing activity similar to, but weaker than those of P7par and P1par. In spite of the high degree of similarity, especially to P7par, it showed unique specificities with respect to the interactions of key components. Neither the P7 nor P1 Par proteins could support partition via the pMT1parS site, and the pMT1 Par proteins failed to support partition with P1parS or P7parS. Typical of other partition sites. supernumerary copies of pMT1parS exerted incompatibility toward plasmids supported by pMT1par. However, no interspecies incompatibility effect was observed between pMT1par, P7par, and P1par. C1 NCI, Gene Regulat & Chromosome Biol Lab, DBS, NCI FCRDC, Frederick, MD 21702 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Austin, S (reprint author), NCI, Gene Regulat & Chromosome Biol Lab, DBS, NCI FCRDC, Frederick, MD 21702 USA. NR 31 TC 16 Z9 18 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 JUL PY 2000 VL 182 IS 14 BP 3924 EP 3928 DI 10.1128/JB.182.14.3924-3928.2000 PG 5 WC Microbiology SC Microbiology GA 329ZN UT WOS:000087938500006 PM 10869068 ER PT J AU Moreno-Bondi, MC Mobley, J Alarie, JP Vo-Dinh, T AF Moreno-Bondi, MC Mobley, J Alarie, JP Vo-Dinh, T TI Antibody-based biosensor for breast cancer with ultrasonic regeneration SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE immunosensor; antibody; regenerable biosensor; ultrasound; fiberoptic ID FLUOROIMMUNOSENSOR; DISSOCIATION AB We describe a novel method and instrumental setup for regenerating antibodies immobilized on a fiberoptic probe of an immunosensor using ultrasonic irradiation with broadband imaging transducers. The instrumental setup and irradiation conditions for antibody regeneration using ultrasound are described. The results of the measurements with antibody against breast cancer antigen illustrate the effectiveness and potential of the regenerable immunosensor. A 65% removal of the antigens bound to the Mab immobilized on the fiber surface is attained after ultrasound regeneration. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S1083-3668(00)00703-6]. C1 Oak Ridge Natl Lab, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. Univ Complutense Madrid, Fac Chem, Dept Analyt Chem, E-28040 Madrid, Spain. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Adv Monitoring Dev Grp, POB 2008, Oak Ridge, TN 37831 USA. RI Moreno-Bondi, Maria/H-3138-2011 OI Moreno-Bondi, Maria/0000-0002-3612-0675 NR 21 TC 7 Z9 8 U1 0 U2 4 PU SPIE-INT SOCIETY OPTICAL ENGINEERING 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 JUL PY 2000 VL 5 IS 3 BP 350 EP 354 DI 10.1117/1.430006 PG 5 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA 343NE UT WOS:000088707800014 PM 10958622 ER PT J AU Miller, JT Reagan, WJ Kaduk, JA Marshall, CL Kropf, AJ AF Miller, JT Reagan, WJ Kaduk, JA Marshall, CL Kropf, AJ TI Selective hydrodesulfurization of FCC naphtha with supported MoS2 catalysts: The role of cobalt SO JOURNAL OF CATALYSIS LA English DT Article DE hydrodesulfurization; olefin hydrogenation; hydrotreating of FCC naphtha; MoS2 catalysts; CoMo sulfide catalysts; Mo EXAFS; Co EXAFS ID ABSORPTION FINE-STRUCTURE; SIZE DETERMINATION; SULFIDE CATALYSTS; ACTIVE PHASE; EXAFS; CO; DISPERSION; SPECTROSCOPY; ALUMINA; NI AB The catalytic activity and selectivity for hydrodesulfurization (HDS) and olefin hydrogenation of FCC naphtha have been determined for MoS2 (no Co) catalysts on different supports and for a commercial CoMo/alumina HDS catalyst both with and without the addition of alkali. For MoS2 catalysts, the specific HDS activity is higher on silica than alumina, while addition of Cs resulted in no change in the activity. The differences in activity, however, are relatively small, a factor of less than two. EXAFS and XRD structural analysis indicate that small MoS2 particles are present on all catalysts. The differences in rate are not due to differences in particle size, dispersion, or support physical properties, but are likely due to the modification of catalytic properties by an interaction with the support. While there is a small influence on the rate, the composition of the support, or modification by Cs, has no effect on the HDS/olefin hydrogenation selectivity. The olefin hydrogenation conversion increases linearly with HDS conversion, and at high HDS conversion, few olefins remain in the FCC naphtha, Similar to the effect for Cs promotion of MoS2 on alumina, the addition of K to sulfided CoMo/alumina had little affect on the activity or selectivity for HDS and olefin hydrogenation. Unlike MoS2 catalysts, however, with sulfided CoMo at less than about 85% HDS conversion, the rate of olefin hydrogenation is low, but it increases rapidly as the sulfur in the naphtha drops below about 300 ppm. Selective HDS of FCC naphtha appears to correlate primarily to the formation of the CoMoS phase, rather than to the basic nature of the support. It is proposed that the enhanced olefin hydrogenation selectivity of CoMo catalysts is due to the competitive adsorption of sulfur compounds, which inhibit adsorption and saturation of olefins in the naphtha. (C) 2000 Academic Press. C1 BP Amoco Res Ctr, Naperville, IL 60563 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Miller, JT (reprint author), BP Amoco Res Ctr, E-1F,150 W Warrenville Rd, Naperville, IL 60563 USA. RI ID, MRCAT/G-7586-2011; Kropf, Arthur/B-8665-2015; Marshall, Christopher/D-1493-2015 OI Marshall, Christopher/0000-0002-1285-7648 NR 45 TC 49 Z9 50 U1 2 U2 27 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD JUL 1 PY 2000 VL 193 IS 1 BP 123 EP 131 DI 10.1006/jcat.2000.2873 PG 9 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 332CC UT WOS:000088055000015 ER PT J AU Nakamura, H Wu, CF Kuang, J Larabell, C Etkin, LD AF Nakamura, H Wu, CF Kuang, J Larabell, C Etkin, LD TI XCS-1, a maternally expressed gene product involved in regulating mitosis in Xenopus SO JOURNAL OF CELL SCIENCE LA English DT Article DE XNF7; embryogenesis; cleavage signal-1 (CS-1); centrosome; cell cycle; mitosis; Xenopus laevis; development ID MAMMALIAN CELL FUSION; MITOTIC SPINDLE; GAMMA-TUBULIN; COILED COILS; PROTEIN; CENTROSOME; KINASE; DROSOPHILA; HOMOLOG; POLO AB The regulation of the cell cycle during early development is an important and complex biological process. We have cloned a cDNA, XCS-1, that may play an important role in regulating mitosis during early embryogenesis in Xenopus laevis. XCS-1 is a maternally expressed gene product that is the Xenopus homologue of the human cleavage signal protein (CS-1), XCS-1 transcripts were detected in oocytes with the titer decreasing just prior to the MET. During development the XCS-1 protein was detected on the membrane and in the nucleus of blastomeres, It was also detected on the mitotic spindle In mitotic cells and on the centrosomes In interphase cells. Overexpression of myc-XCS-1 in Xenopus embryos resulted in abnormal mitoses with increased numbers of centrosomes, multipolar spindles, and abnormal distribution of chromosomes. Also, we observed incomplete cytokinesis resulting in multiple nuclei residing in the same cytoplasm with the daughter nuclei in different phases of the cell cycle. The phenotype depended on the presence of the N terminus of XCS-1 (aa 1-73) and a consensus NIMA kinase phosphorylation site (aa159-167). Mutations in this site affected the ability of the overexpressed XCS-1 protein to produce the phenotype. These results suggest that XCS-1 is a maternal factor playing an important role in the regulation of the cell cycle during early embryogenesis and that its function depends on its state of phosphorylation. C1 Univ Texas, MD Anderson Canc Ctr, Dept Mol Genet, Houston, TX 77030 USA. Univ Texas, MD Anderson Canc Ctr, Dept Clin Invest, Houston, TX 77030 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Etkin, LD (reprint author), Univ Texas, MD Anderson Canc Ctr, Dept Mol Genet, 1515 Holcombe Blvd, Houston, TX 77030 USA. FU NCI NIH HHS [CA16672] NR 40 TC 4 Z9 4 U1 0 U2 1 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE CB4 4DL, CAMBS, ENGLAND SN 0021-9533 J9 J CELL SCI JI J. Cell Sci. PD JUL PY 2000 VL 113 IS 13 BP 2497 EP 2505 PG 9 WC Cell Biology SC Cell Biology GA 336TU UT WOS:000088319700016 PM 10852828 ER PT J AU Chernyak, V Schulz, MF Mukamel, S Tretiak, S Tsiper, EV AF Chernyak, V Schulz, MF Mukamel, S Tretiak, S Tsiper, EV TI Krylov-space algorithms for time-dependent Hartree-Fock and density functional computations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIFFERENTIAL-OVERLAP TECHNIQUE; STATE ADIABATIC SURFACES; NONLINEAR POLARIZABILITIES; ELECTRONIC EXCITATIONS; INTERMEDIATE NEGLECT; OPTICAL-EXCITATIONS; RESPONSE THEORY; SPECTROSCOPY; IMPLEMENTATION; MOLECULES AB A fast, low memory cost, Krylov-space-based algorithm is proposed for the diagonalization of large Hamiltonian matrices required in time-dependent Hartree-Fock (TDHF) and adiabatic time-dependent density-functional theory (TDDFT) computations of electronic excitations. A deflection procedure based on the symplectic structure of the TDHF equations is introduced and its capability to find higher eigenmodes of the linearized TDHF operator for a given numerical accuracy is demonstrated. The algorithm may be immediately applied to the formally-identical adiabatic TDDFT equations. (C) 2000 American Institute of Physics. [S0021-9606(00)30425-1]. C1 Univ Rochester, Dept Chem, Rochester, NY 14627 USA. Univ Rochester, Rochester Theory Ctr Opt Sci & Engn, Rochester, NY 14627 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. RP Univ Rochester, Dept Chem, POB 270216, Rochester, NY 14627 USA. RI Tretiak, Sergei/B-5556-2009; Kahnert, Michael/A-3275-2009; Chernyak, Vladimir/F-5842-2016 OI Tretiak, Sergei/0000-0001-5547-3647; Kahnert, Michael/0000-0001-5695-1356; Chernyak, Vladimir/0000-0003-4389-4238 NR 34 TC 52 Z9 52 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 36 EP 43 AR PII [S0021-9606(00)30425-1] DI 10.1063/1.481770 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800005 ER PT J AU Feller, D Dupuis, M Garrett, BC AF Feller, D Dupuis, M Garrett, BC TI Barrier for the H2CO -> H-2+CO reaction: A discrepancy between high-level electronic structure calculations and experiment SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; CORRELATED MOLECULAR CALCULATIONS; TRANSITION-STATE THEORY; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; SYSTEMATIC SEQUENCES; BENCHMARK CALCULATIONS; ATOMIZATION ENERGIES; PHOTO-DISSOCIATION; MOLLER-PLESSET AB The unimolecular dissociation of formaldehyde to H-2+CO was studied using extended basis set calculations and a variety of medium-to-high accuracy correlation recovery techniques. These included second and fourth order perturbation theory, multireference configuration interaction wave functions, coupled cluster theory with perturbative triples and full iterative triples, and estimated full configuration interaction wave functions. The intrinsic error of the electronic structure methods was assessed by extrapolating total energies to the complete basis set limit. Our best estimate of the barrier height, including zero point vibrational effects, is 81.9 +/- 0.3 kcal/mol, almost 3 kcal/mol larger than the experimental value of 79.2 +/- 0.8 kcal/mol. This estimate includes corrections for the effects of finite basis set truncation (which is negligible at the quintuple zeta level), higher order correlation recovery, core/valence correlation, and scalar relativistic effects. Using the same theoretical approach, we estimate the exothermicity of the dissociation reaction to be -1.6 kcal/mol, compared to experimental values in the -0.4 to -2.2 kcal/mol range. New calculations of the unimolecular dissociation rate constants using a variety of techniques failed to reconcile theory and experiment. (C) 2000 American Institute of Physics. [S0021-9606(00)30917-5]. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Lab, Environm Mol Sci Lab, MS K8-91,POB 999, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011 NR 52 TC 45 Z9 45 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 218 EP 226 AR PII [S0021-9606(00)30917-5] DI 10.1063/1.481788 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800027 ER PT J AU Skokov, S Tsuchida, T Nanbu, S Bowman, JM Gray, SK AF Skokov, S Tsuchida, T Nanbu, S Bowman, JM Gray, SK TI A comparative study of the quantum dynamics and rate constants of the O(P-3)+HCl reaction described by two potential surfaces SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; REAL WAVE-PACKETS; CHEMICAL-REACTIONS; ENERGY SURFACE; SCATTERING; HCL; APPROXIMATION; O(D-1)+H-2->OH+H; REPRESENTATION; COLLISIONS AB Wave packet calculations, using direct and damped-L-2 real propagation methods, of initial state-resolved and cumulative reaction probabilities for the O(P-3)+HCl((1)Sigma(+))--> OH((2)Pi)+Cl(P-2) reaction are reported. Results are obtained using the recently developed "S4" potential surface of Ramachandran and co-workers and, for comparison, the earlier Koizumi, Schatz, and Gordon (KSG) potential energy surface. Most calculations are for total angular momentum J=0, although some J > 0 centrifugal sudden results are also obtained. The thermal rate constant and the rate constant for HCl(v=1) are obtained from the J=0 cumulative reaction probability and J-K-shifting, using standard transition-state rotation constants. This type of shifting is justified by examining limited centrifugal sudden calculations. The S4 surface is shown to yield some surprising results. For example, despite a significantly higher ground state adiabatic barrier than the KSG surface, the thermal rate constant is not significantly different from one obtained with the KSG surface, although the one for the vibrationally excited HCl is. (C) 2000 American Institute of Physics. [S0021- 9606(00)30824-8]. C1 Emory Univ, Dept Chem, Atlanta, GA 30322 USA. Emory Univ, Cherry L Emerson Ctr Sci Computat, Atlanta, GA 30322 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Inst Mol Sci, Ctr Comp, Okazaki, Aichi 444, Japan. RP Skokov, S (reprint author), Emory Univ, Dept Chem, 1515 Pierce Dr, Atlanta, GA 30322 USA. NR 48 TC 29 Z9 30 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 227 EP 236 AR PII [S0021-9606(00)30824-8] DI 10.1063/1.481789 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800028 ER PT J AU Dang, LX AF Dang, LX TI Molecular dynamics study of benzene-benzene and benzene-potassium ion interactions using polarizable potential models SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIQUID BENZENE; GAS-PHASE; DIMER; CLUSTERS; CATION; ENERGY; WATER AB We have constructed a polarizable potential model for benzene using molecular dynamics techniques. The atomic site polarizabilities for carbon and hydrogen were taken from the recent work of Applequist [J. Phys. Chem. 97, 6016 (1993)], which reproduced the experimental molecular polarizability of the benzene molecule very accurately. Our model describes well the available experimental data such as the structure and thermodynamic properties of liquid benzene and the equilibrium properties of the liquid/vapor interface of benzene. The lowest minimum-energy structure of the benzene dimer predicted by our model has a T-shape with a potential energy of -2.5 kcal/mol. This value agrees with the experimentally obtained value (-2.4 +/- 0.4 kcal/mol), which was determined from a high-precision ionization measurement. The cyclic minimum-energy structures are found for both the benzene trimer and tetramer clusters. The computed density profile shows that the interface is not sharp at a microscopic level and has a thickness about 5 Angstrom at 300 K. The calculated surface tension is 25 +/- 2 dyn/cm, which is in excellent agreement with the experimentally obtained value of 28 dyn/cm. The results of our model also compare well with the corresponding results for benzene obtained by Jorgensen and Severance [J. Am. Chem. Soc. 112, 4768 (1990)], who used nonpolarizable potential parameters. We also report the details of our study of K+(C6H6)(n=1-6) clusters. We found that the polarization effects were quite significant in these systems. (C) 2000 American Institute of Physics. [S0021-9606(00)50525-X]. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Dang, LX (reprint author), Pacific NW Lab, POB 999,Mail Stop K8-91, Richland, WA 99352 USA. NR 31 TC 25 Z9 25 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 266 EP 273 AR PII [S0021-9606(00)50525-X] DI 10.1063/1.481814 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800032 ER PT J AU Keblinski, P Eggebrecht, J Wolf, D Phillpot, SR AF Keblinski, P Eggebrecht, J Wolf, D Phillpot, SR TI Molecular dynamics study of screening in ionic fluids SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COMPUTER-SIMULATION; PRIMITIVE MODEL; ALKALI-HALIDES AB Molecular-dynamics simulations of molten and gaseous NaCl are used to probe the entire range of screening behaviors including weakly and strongly-coupled regimes as well as the transition between them. Our simulations confirm that, in accordance with the Debye-Huckel theory, in the weakly-coupled regime (corresponding to the ionic gas) the spatial correlations between the ions decay monotonically, with a screening length, lambda(Q), given by the Debye length, lambda(D), which decreases with increasing ionic coupling strength. By contrast, in the strongly-coupled regime (corresponding to the melt) the spatial correlations between the ions decay in an oscillatory manner, lambda(Q) then being given by the envelope of the damped oscillations. In accordance with theoretical predictions, in the strongly-coupled lambda(Q) increases with increasing coupling strength. Also in agreement with existing theories our simulations show that the transition from monotonic to oscillatory screening occurs at the shortest possible screening length, which is on the order of the average ion diameter, sigma; also, the simulated values of lambda(Q) across the entire range can be represented by a universal function of the ionic-strength parameter, sigma/lambda(D). (C) 2000 American Institute of Physics. [S0021-9606(00)51225-2]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. RP Keblinski, P (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 39 TC 54 Z9 55 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 282 EP 291 AR PII [S0021-9606(00)51225-2] DI 10.1063/1.481819 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800034 ER PT J AU Kwei, GH Trouw, F Morosin, B King, HF AF Kwei, GH Trouw, F Morosin, B King, HF TI Dynamics of methane trapped in C-60 interstices SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NEUTRON INELASTIC-SCATTERING; NE-INTERCALATED C-60; RARE-GAS SOLIDS; MOLECULAR-DYNAMICS; HINDERED ROTATION; PHASE-TRANSITION; FULLERENE C-60; SITE STRUCTURE; C60; TEMPERATURE AB We have carried out inelastic neutron scattering studies of the methane/C-60 system in order to understand the hindered rotational and vibrational dynamics of methane trapped in C-60 interstices and to determine the structure around the interstitial site. At temperatures of 20 K and below, we observe inelastic peaks from rotational transitions of the CH4. These transitions allow unambiguous assignment of the hindered rotational energy levels and a determination of the interaction potential. The appearance of two peaks for one of the J=0 --> 3 transitions implies the existence of two distinct kinds of interstitial sites and the measured transition energies suggest rotational barriers of about 26 and 16 meV for these sites. Time-dependent changes in peak heights indicate slow (t(1/2)approximate to 2.6 h) triplet --> quintet nuclear spin conversion that necessarily accompanies the J=1 --> 0 rotational relaxation. We also have observed an inelastic peak at 10.9 meV in a region where there is a gap in the calculated, and otherwise dense, rotational spectrum. We believe that this must correspond to a local vibrational mode of CH4 rattling in its cage at similar to 2.6 THz. Other peaks involving higher-energy vibrational excitations in CD4/C-60 correspond in energy to assigned peaks in the inelastic neutron scattering spectra of C-60, albeit sometimes with different intensities. Taken together, these findings suggest the rotation of CH4 is hindered by the C-60 cage and that the vibrations of CH4 and C-60 are loosely coupled. (C) 2000 American Institute of Physics. [S0021-9606(00)00325-1]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60636 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. RP Kwei, GH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Lujan Center, LANL/G-4896-2012 NR 48 TC 15 Z9 15 U1 2 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 2000 VL 113 IS 1 BP 320 EP 328 AR PII [S0021-9606(00)00325-1] DI 10.1063/1.481797 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 326TE UT WOS:000087750800039 ER PT J AU Putnam, RL Navrotsky, A Cordfunke, EHP Huntelaar, ME AF Putnam, RL Navrotsky, A Cordfunke, EHP Huntelaar, ME TI Thermodynamics of formation of two cerium aluminum oxides, CeAlO3(s) and CeAl12O19.918(S), and cerium sesquioxide, Ce2O3(s) at T=298.15 K SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE enthalpy of formation; nuclear waste; lamp materials; thermodynamic properties; calorimetry; CeAlO3; Ce2O3; CeAl12O19.918 ID HIGH-TEMPERATURE CALORIMETRY; ENERGETICS; DIRECTIONS; PROGRESS AB Oxides containing cerium are of great interest in the chemistry of modem lamp materials as well as being surrogates for materials containing plutonium in the development of ceramic nuclear waste materials. Using high temperature oxide-melt solution calorimetry, the molar enthalpies of drop solution Delta(298.15 K)(T) H-m(sol) of CeO2(s), CeAlO3(s), and CeAl12O19.918 (s) in molten lead berate solvent (2PbO . B2O3) have been measured at T = 973 K and are (122.9 +/- 2.6) kJ . mol(-1), (62.31 +/- 0.80) kJ . mol(-1), and (631.7 +/- 2.8) kJ . mol(-1), respectively. The standard molar enthalpies of formation from the elements Delta(f)H(m)(o) for CeAlO3 (s) and CeAl12O19.918 (s) are -(1806.6 +/- 3.1) kJ . mol(-1) and - (11001.8 +/- 9.5) kJ . mol(-1), respectively, at T = 298.15 K. The Delta(f)H(m)(o), of Ce2O3 (s) is -(1805.8 +/- 5.8) kJ . mol(-1) at T = 298.15 K. It is suggested that CeAl12O19.918 (s) is an entropy-stabilized material. (C) 2000 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Davis, Thermochem Facil, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Univ Amsterdam, Inst Mol Chem, NL-1018 WV Amsterdam, Netherlands. NRG, NL-1755 ZG Petten, Netherlands. RP Putnam, RL (reprint author), Univ Calif Los Alamos Natl Lab, MS-G721, Los Alamos, NM 87545 USA. NR 18 TC 20 Z9 20 U1 2 U2 9 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JUL PY 2000 VL 32 IS 7 BP 911 EP 921 DI 10.1006/jcht.2000.0665 PG 11 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 344MY UT WOS:000088764500007 ER PT J AU Gomes-Solecki, MJC Dunn, JJ Luft, BJ Castillo, J Dykhuizen, DE Yang, XH Glass, JD Dattwyler, RJ AF Gomes-Solecki, MJC Dunn, JJ Luft, BJ Castillo, J Dykhuizen, DE Yang, XH Glass, JD Dattwyler, RJ TI Recombinant chimeric Borrelia proteins for diagnosis of Lyme disease SO JOURNAL OF CLINICAL MICROBIOLOGY LA English DT Article ID OUTER SURFACE PROTEIN; LINKED-IMMUNOSORBENT-ASSAY; BURGDORFERI SENSU-STRICTO; SERODIAGNOSIS; OSPC; ANTIGEN; FLAGELLIN; DOMAINS; ELISA; GENES AB Current serologic Lyme disease tests use whole borrelia cells as the source of antigen, These assays are difficult to standardize and to optimize for sensitivity and specificity. To help solve these problems, we constructed a library of recombinant chimeric proteins composed of portions of key antigens of Borrelia burgdorferi, These proteins were then used to develop an enzyme-linked immunosorbent assay. We compared our assay with the most sensitive of three whole-cell borrelia assays. We found that the recombinant assay could detect antibodies significantly better from early Lyme disease sera (P < 0.05), and had the same sensitivity for late Lyme disease sera, as the most sensitive whole-cell borrelia assay. On potentially cross-reactive sera, the recombinant assay was more specific, but not significantly so, than the best whole-cell borrelia assay. Optimization of the recombinant assay offers the potential for a significant improvement in both sensitivity and specificity. C1 SUNY Stony Brook, Dept Med, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Ecol & Evolut, Stony Brook, NY 11794 USA. Brook Biotechnol Inc, Long Isl High Technol Incubator, Stony Brook, NY 11790 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11793 USA. RP Dattwyler, RJ (reprint author), SUNY Stony Brook, Dept Med, Stony Brook, NY 11794 USA. OI Luft, Benjamin/0000-0001-9008-7004; Dattwyler, Raymond/0000-0002-1983-1301 FU NIAID NIH HHS [AI38724-03, AI43786-01]; NIAMS NIH HHS [ALAR 37256-01] NR 30 TC 23 Z9 24 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0095-1137 J9 J CLIN MICROBIOL JI J. Clin. Microbiol. PD JUL PY 2000 VL 38 IS 7 BP 2530 EP 2535 PG 6 WC Microbiology SC Microbiology GA 331WR UT WOS:000088042100013 PM 10878038 ER PT J AU Chen, WYC Louck, JD Wang, J AF Chen, WYC Louck, JD Wang, J TI Adjacency and parity relations of words in discrete dynamical systems SO JOURNAL OF COMBINATORIAL THEORY SERIES A LA English DT Article ID DNA-SEQUENCES; MSS SEQUENCES; ITERATION; NUMBERS; NECKLACES AB Words on two letters, or their equivalent representation by a sequences, label the branches of the inverse graph of the nth iterate of the parabolic map p(zeta)(x) = zeta x(2-x) of the real line. The abstract properties of words control the evolution of this graph in the content parameter zeta. In particular, properties of words (alpha sequences) control the process of creation and bifurcation of fixed points. The subset of lexical words of length n - 1 or the corresponding set of lexical alpha sequences of degree D = n - 1 are key entities in this description, as are the divisor set of lexical words of degree D such that 1 + D divides n. The parity, even or odd, of the length of the lexical sequences in the divisor set controls the motion, from left to right or right to left, of the central point (1, x(zeta)) of the inverse graph through the midpoint (1, 1), as the content parameter zeta increase. It is proved in this paper that adjucent sequences in the ordered divisor set alternate in the parity of their lengths, this then corresponding to an oscillatory motion of the central point back and forth through the central point. The abstract parity property of words thus corresponds to an important property of the inverse graph in its evolution in the content parameter. (C) 2000 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Nankai Univ, Ctr Combinator, Tianjin 300071, Peoples R China. Dalian Univ Technol, Dept Appl Math, Dalian 116024, Liaoning, Peoples R China. RP Chen, WYC (reprint author), Univ Calif Los Alamos Natl Lab, T-7,Mail Stop B284, Los Alamos, NM 87545 USA. NR 15 TC 4 Z9 4 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0097-3165 J9 J COMB THEORY A JI J. Comb. Theory Ser. A PD JUL-AUG PY 2000 VL 91 IS 1-2 BP 476 EP 508 DI 10.1006/jcta.2000.3112 PG 33 WC Mathematics SC Mathematics GA 353EK UT WOS:000089261700024 ER PT J AU Sanchez, R Hirshman, SP Whitson, JC Ware, AS AF Sanchez, R Hirshman, SP Whitson, JC Ware, AS TI COBRA: An optimized code for fast analysis of ideal ballooning stability of three-dimensional magnetic equilibria SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE stellarators; magnetohydrodynamics; ballooning instabilities; growth rate; spectrum of Sturm-Liouville operators; Richardson's extrapolation ID DEVICES; MODES AB A new, fast, and accurate numerical algorithm to assess stability against ideal ballooning modes in general three-dimensional magnetic configurations of interest to controlled thermonuclear fusion is described. The code for ballooning rapid analysis (COBRA) performs this assessment by solving an eigenvalue problem in the form of a linear second-order ordinary differential equation along magnetic field lines in the configuration. An initial approximation for the eigenvalue is obtained from a fast second order matrix method. In COBRA, this approximate eigenvalue is further refined using a variational principle to obtain fourth-order convergence with the mesh size. Richardson's extrapolation is then applied to a sequence of eigenvalues to estimate the exact eigenvalue using the coarsest possible mesh, thus minimizing the computational time. (C) 2000 Academic Press. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59801 USA. RP Sanchez, R (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37831 USA. RI Sanchez, Raul/C-2328-2008 NR 20 TC 32 Z9 32 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUL 1 PY 2000 VL 161 IS 2 BP 576 EP 588 DI 10.1006/jcph.2000.6514 PG 13 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 329JD UT WOS:000087903100009 ER PT J AU Bourret-Courchesne, E Ye, Q Peters, DW Arnold, J Ahmed, M Irvine, SJC Kanjolia, R Smith, LM Rushworth, SA AF Bourret-Courchesne, E Ye, Q Peters, DW Arnold, J Ahmed, M Irvine, SJC Kanjolia, R Smith, LM Rushworth, SA TI Pyrolysis of dimethylhydrazine and its co-pyrolysis with triethylgallium SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE GaN; dimethylhydrazine; pyrolysis; triethylgallium; mass spectroscopy; vapor pressure; organometallic ID VAPOR-PHASE EPITAXY; CUBIC GAN; OMVPE GROWTH; LASER-DIODES; TEMPERATURE; TRIMETHYLGALLIUM; GAAS; MONOMETHYLHYDRAZINE; DEPOSITION; MOVPE AB Dimethylhydrazine is a potential nitrogen precursor for organometallic vapor-phase epitaxy of GaN-based ternaries and quaternaries at relatively low temperatures. We have measured the vapor pressure of dimethylhydrazine and studied the pyrolysis characteristics of dimethylhydrazine in H-2 ambient. Results of co-pyrolysis with triethylgallium in H-2 ambient are also reported. The vapor pressure of dimethylhydrazine is given by Log P = 8.19-1780/T. Pyrolysis of the dimethylhydrazine is found to proceed by cleavage of the N-N bond followed by elimination of the methyl groups. Co-pyrolysis studies showed that an adduct and an intermediate dimer form at low temperatures then further decomposed at higher temperatures to the final product GaN. (C) 2000 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NE Wales Inst, Wrexham, Wales. Epichem Inc, Haverhill, MA 01835 USA. Epichem Ltd, Wirral CH62 3QF, Merseyside, England. RP Bourret-Courchesne, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd,Mailstop 2-200, Berkeley, CA 94720 USA. RI Arnold, John/F-3963-2012 OI Arnold, John/0000-0001-9671-227X NR 30 TC 32 Z9 32 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JUL PY 2000 VL 217 IS 1-2 BP 47 EP 54 DI 10.1016/S0022-0248(00)00398-5 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 337CT UT WOS:000088340400006 ER PT J AU Graupner, R Ye, Q Warwick, T Bourret-Courchesne, E AF Graupner, R Ye, Q Warwick, T Bourret-Courchesne, E TI Study of interface reactions between Si and GaN at high temperatures using scanning photoelectron microscopy and X-ray absorption spectroscopy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE GaN; silicon; scanning photoelectron microscopy; X-ray absorption spectroscopy ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; INTERMEDIATE LAYER; CUBIC GAN; SUBSTRATE; GROWTH; SI(111); SILICON AB Scanning photoelectron microscopy (SPEM) and X-ray absorption spectroscopy have been used to study interface reactions between Si and GaN when GaN is deposited on nitridated silicon substrates at high temperatures. The results show that the interface reactions between silicon and GaN are strongly dependent on the reaction temperature with the more severe reactions occurring at higher temperatures. In addition to the observation of the direct reaction of nitrogen with the Si to form silicon nitride at the interface, the chemical maps obtained with SPEM indicate that Si migrates to the top surface of the GaN layers. The migration of Si to the surface results in formation of SiNx on the top surface and in severe roughening of the GaN layers deposited at 950 and 1010 degrees C, X-ray absorption data indicate that the hexagonal structure forms at higher temperature while the cubic form of GaN is the dominant structure at low temperature. The three-dimensional growth of the hexagonal structure appears to be responsible for enhancement of the Si migration. (C) 2000 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Bourret-Courchesne, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Mailstop 2-200, Berkeley, CA 94720 USA. NR 36 TC 14 Z9 16 U1 2 U2 13 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 JUL PY 2000 VL 217 IS 1-2 BP 55 EP 64 DI 10.1016/S0022-0248(00)00413-9 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 337CT UT WOS:000088340400007 ER PT J AU Theodoropoulos, C Mountziaris, TJ Moffat, HK Han, J AF Theodoropoulos, C Mountziaris, TJ Moffat, HK Han, J TI Design of gas inlets for the growth of gallium nitride by metalorganic vapor phase epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE axisymmetric gas inlets; gallium nitride; kinetic mechanism; rotating disk; vertical stagnation flow reactor; massively parallel computations; MPSalsa; parametric study ID FLOW MOVPE REACTORS; ORGANOMETALLIC PRECURSORS; TRANSPORT PHENOMENA; HEAT-TRANSFER; DEPOSITION; FILMS; TRIMETHYLGALLIUM; DIFFRACTION; KINETICS; AMMONIA AB The problem of gas inlet design for metalorganic Vapor phase epitaxy (MOVPE) of group III nitrides from metal alkyls and ammonia is addressed. The focus is on GaN growth from trimethyl-gallium and ammonia. In traditional reactors with well-mixed inlet streams, parasitic gas-phase reactions between the two precursors may lead to the formation of stable adducts that can condense on cool inlet walls, thus reducing the him growth efficiency. Such reactions may also lead to the formation of particulates through gas-phase condensation reactions (e.g. during AlN growth). A fundamentally-based model was developed to describe the MOVPE of GaN and was used to study the effect of inlet design and reactor operating conditions on film thickness uniformity in vertical stagnation-flow and rotating-disk reactors. The model includes a description of gas-phase kinetics and a simple gas-surface reaction mechanism. The kinetic model was coupled to a two-dimensional transport model describing flow, heat and mass transfer in a vertical MOVPE reactor. Predictions of growth rate compare well to experimental observations from a vertical rotating-disk reactor, without any adjustable parameters. The model was also used to study the distribution of gaseous species in the reactor and their role in film growth. Finite element simulations using a massively parallel computer code (MPSalsa) indicate that the species responsible for film growth are Ga-alkyls and not their adducts with ammonia. Sensitivity analysis was also performed to assess the relative importance of each reaction in determining the growth rate. The model was subsequently employed in the design of axisymmetric, multi-aperture gas inlets feeding precursors into the reactor in an alternating (not well-mixed) fashion. Simulations were performed to study the effect of key design parameters, such as inlet velocities, susceptor rotating speed, inlet to susceptor distance as well as the number and distribution of inlets, on GaN film growth rate and uniformity in industrial scale reactors. Optimal cases are presented that lead to uniform films over large-area substrates. An alternating precursor feed scheme based on concentric rings was found to lead to more uniform films as the number of inlets increased. The other important reactor parameters were inlet velocity, relative size of inlet "rings" and susceptor distance from the inlet. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 SUNY Buffalo, Dept Chem Engn, Buffalo, NY 14260 USA. Sandia Natl Labs, Chem Proc Sci Div, Albuquerque, NM 87185 USA. RP Mountziaris, TJ (reprint author), SUNY Buffalo, Dept Chem Engn, Buffalo, NY 14260 USA. EM tjm@eng.buffalo.edu OI Theodoropoulos, Constantinos/0000-0003-3249-0422 NR 42 TC 52 Z9 63 U1 0 U2 18 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 JUL PY 2000 VL 217 IS 1-2 BP 65 EP 81 DI 10.1016/S0022-0248(00)00402-4 PG 17 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 337CT UT WOS:000088340400008 ER PT J AU Bartram, ME Breiland, WG Bruskas, LA Killeen, KP AF Bartram, ME Breiland, WG Bruskas, LA Killeen, KP TI Gas chromatography-mass spectroscopy study of tert-butylarsine stability and purification SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID TERTIARYBUTYLARSINE; DECOMPOSITION; MECHANISMS AB We have used gas chromatography-mass spectroscopy (GCMS) to study the decomposition of TEA (tert-butylarsine, H2AsC(CH3)(3)) in storage containers at room temperature. Over a four-week period, as much as 1% of the TEA decomposed to arsine and isobutane in a stainless-steel bottle, Several freeze-thaw purification schemes were tested. Use of a liquid-nitrogen bath left a substantial amount of arsine and isobutane in the bottle, while an ice water bath removed all of the arsine but left residual isobutane, Evacuation of the storage container at room temperature removed both arsine and isobutane: to below the GCMS detection limits. However, this approach did lead to significant TEA loss. Storing TEA in a Teflon-lined bottle and in a high-surface-to-volume stainless-steel container did not change the decomposition rate measurably, suggesting that stainless-steel surfaces do not promote TEA decomposition. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Chem Proc Sci Dept, Albuquerque, NM 87185 USA. Hewlett Packard, Palo Alto, CA USA. RP Bartram, ME (reprint author), Sandia Natl Labs, Chem Proc Sci Dept, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 1 Z9 1 U1 0 U2 1 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 JUL PY 2000 VL 216 IS 1-4 BP 33 EP 36 DI 10.1016/S0022-0248(00)00381-X PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 336DE UT WOS:000088286000006 ER PT J AU Ng, CY AF Ng, CY TI Advances in photoionization and photoelectron studies using third generation synchrotron radiation SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT Beijing International Conference on Photoelectron Spectroscopy: Molecules, Ions and CLusters (BICPES 99) CY SEP 12-17, 1999 CL BEIJING, PEOPLES R CHINA SP Chinese Acad Sci, Natl Nat Sci Fdn China DE photoionization; third generation synchrotron radiation ID PULSED-FIELD-IONIZATION; HIGH-RESOLUTION; ENERGY-RANGE; RESOLVED PHOTOELECTRON; DISSOCIATION THRESHOLD; CORRELATION SATELLITES; SPECTROSCOPY; COINCIDENCE; BANDS; XENON AB In the past few years, we have established a unique high-resolution photoionization-photoelectron facility at the Chemical Dynamics Beamline of the Advanced Light Source. By combining a 6.65-m off-plane Eagle mounted scanning monochromator with the undulator synchrotron radiation source, we have demonstrated photon energy resolving powers up to E/Delta E = 72,000-100,000 in the photon energy range of 6-27 eV. We have also developed novel synchrotron-based pulsed field ionization photoelectron (PFI-PE) detection schemes, achieving resolutions of 1-6 cm(-1) (FWHM). Using the specially designed photoelectron-photoion apparatus, which features a supersonic molecular beam source and opposing electron and ion time-of-flight spectrometers, we have recently succeeded in performing synchrotron-based PFI-PE photoion coincidence experiments, attaining resolutions limited only by the PFI-PE measurements. Most recently, we have demonstrated a generally applicable synchrotron-based scheme for PF1-photoion measurements. The PFI-PEPICO and PFI-PI methods are expected to have a significant impact in future reaction dynamics studies involving the preparation of rovibronically state-selected reactant ions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Ng, CY (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 27 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUL PY 2000 VL 108 IS 1-3 BP 41 EP 45 DI 10.1016/S0368-2048(00)00144-4 PG 5 WC Spectroscopy SC Spectroscopy GA 343MA UT WOS:000088705100006 ER PT J AU Davis, AV Zanni, MT Frischkorn, C Neumark, DM AF Davis, AV Zanni, MT Frischkorn, C Neumark, DM TI Time-resolved dynamics of charge transfer to solvent states in solvated iodide clusters SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT Beijing International Conference on Photoelectron Spectroscopy: Molecules, Ions and CLusters (BICPES 99) CY SEP 12-17, 1999 CL BEIJING, PEOPLES R CHINA SP Chinese Acad Sci, Natl Nat Sci Fdn China DE clusters; photoelectron spectroscopy; time-resolved dynamics; solvated electrons ID I-XEN CLUSTERS; FEMTOSECOND DYNAMICS; EXCITED-STATES; PHOTODETACHMENT; EXCITATION; ANION AB The dynamics of the cluster precursors to charge-transfer-to-solvent (CTI'S) states have been studied in clusters of iodide with xenon, water, D2O, ammonia and methanol using femtosecond photoelectron spectroscopy. The dynamics of these states differ dramatically according to solvent type and number. Excitation of the lower CTTS state in I-(Xe)(n) clusters yields a state that is stable over the time scale of the experiment (similar to 200 ps), whereas the upper spin-orbit state decays by spin-orbit autodetachment within 500 to 1000 fs, depending on the number of Xe atoms. The hydrogen-bonded clusters show evidence for partial solvation of the excess electron following CTTS excitation. In general they exhibit more complicated dynamics which correspond to internal rearrangement in one or more electronic states. A description including isomerization and electron solvation is given for the I-(D2O)(n) clusters, and compared to the dynamics observed in I-(NH3)(n) and I-(CH3OH)(n) clusters. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Zanni, Martin/K-2707-2013; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 14 TC 31 Z9 31 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUL PY 2000 VL 108 IS 1-3 BP 203 EP 211 DI 10.1016/S0368-2048(00)00129-8 PG 9 WC Spectroscopy SC Spectroscopy GA 343MA UT WOS:000088705100021 ER PT J AU Zheng, Y Moran, PD Guan, ZF Lau, SS Hansen, DM Kuech, TF Haynes, TE Hoechbauer, T Nastasi, M AF Zheng, Y Moran, PD Guan, ZF Lau, SS Hansen, DM Kuech, TF Haynes, TE Hoechbauer, T Nastasi, M TI Transfer of n-type GaSb onto GaAs substrate by hydrogen implantation and wafer bonding SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Compliant and Alternative Substrate Technology CY SEP 19-23, 1999 CL LAKE BUENA VISTA, FLORIDA SP USAF, Off Sci Res, USN, Off Naval Res, DARPA, Boeing, HRL Labs, Minerals Met & Mat Soc DE GaSb; GaSb on insulator; ion-cut; smart cut; hydrogen; implantation; wafer bonding; blistering; layer transfer; layer splitting ID SEPARATION; SILICON; EPITAXY AB Many GaSb devices would greatly benefit from the availability of a semiinsulating substrate. Since semi-insulating GaSb is not currently available, the formation of thin GaSb layers through wafer bonding and transfer onto a semiinsulating GaAs substrate was investigated. GaSb-on-insulator structures, formed on GaAs substrates. were realized by the ion-cut process using H+ ions. Blistering, bonding and layer splitting phenomena were studied to optimize the ion dose and the process window. Bonded structures of thin layers of GaSb bonded to GaAs wafers were formed using a borosilicate glass (BSG) layer. The transferred GaSb layers were characterized by atomic force microscopy, MeV helium ion channeling and high-resolution x-ray diffractometry. The transferred film possessed a narrow x-ray linewidth of about 140 arcsec indicating improved crystalline quality over the direct growth of GaSb on GaAs. C1 Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. Univ Wisconsin, Dept Chem Engn, Madison, WI 53706 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zheng, Y (reprint author), Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. RI Schaff, William/B-5839-2009; Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 14 TC 13 Z9 14 U1 1 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JUL PY 2000 VL 29 IS 7 BP 916 EP 920 DI 10.1007/s11664-000-0181-6 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 349QQ UT WOS:000089057500007 ER PT J AU Bhargava, A Colket, M Sowa, W Casleton, K Maloney, D AF Bhargava, A Colket, M Sowa, W Casleton, K Maloney, D TI An experimental and modeling study of humid air premixed flames SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 07-10, 1999 CL INDIANAPOLIS, INDIANA AB An experimental and modeling study has been performed jointly by UTRC and DOE-FETC to determine the effect of humidity in the combustion air on emissions and stability limits of gels turbine premixed flames. This study focuses on developing gas turbine combustor design criteria for the Humid Air Turbine (HAT) cycle. The experiments,were conducted at different moisture levels (0 percent, 5 percent. 10 percent, and 15 percent by mass in the air), at a total pressure of 200 psi, pilot levels (0 percent, I percent. 3 percent. and 5 percent total fuel). and equivalence ratio (0.4 to 0.8 depending on the moisture levels). The moisture levels were achieved by injecting steam into dry air well upstream of the fuel-dir premixing nozzle. Computations were made for comparison to the experiments using GRI Mech 2.11 kinetics and thermodynamic database for modeling the flame chemistry. A Perfectly Stirred Reactor (PSR) network code was used to create a network of PSRs It, simulate the flame. Excellent agreement between the measured and modeled NOx (5-10 percent) was obtained Trends of added moisture reducing NOx and the effects of equivalence ratio and piloting level were well predicted. The CO predictions rt ere higher by about 30-50 percent. The CO discrepancies are attributed to in-probe oxidation. The agreement between the data and model predictions over a IL ide range of conditions indicate the consistency and reliability of the measured data and usefulness of the modeling approach. An analysis of NOx formation revealed that at constant equilibrium temperature, T-eq, the presence of steam lends to lower O-atom concentration which reduces "Zeldovich and N2O" NOx while higher OH-atom concentration reduces ''Fenimore'' NOx. C1 United Technol Res Ctr, E Hartford, CT 06108 USA. US Dept Energy, Fed Energy Technol Ctr, Morgantown, WV 26507 USA. RP Bhargava, A (reprint author), United Technol Res Ctr, E Hartford, CT 06108 USA. NR 18 TC 46 Z9 49 U1 1 U2 12 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 2000 VL 122 IS 3 BP 405 EP 411 DI 10.1115/1.1286921 PG 7 WC Engineering, Mechanical SC Engineering GA 404QG UT WOS:000167111600006 ER PT J AU Gall, K Horstemeyer, MF AF Gall, K Horstemeyer, MF TI Integration of basic materials research into the design of cast components by a multi-scale methodology SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Symposium on Integration and Engineering Aspects of Structural Materials in High Temperature Applications held at the International Mechanical Congress and Exposition CY NOV 14-19, 1999 CL NASHVILLE, TENNESSEE SP Amer Soc Mech Engineers, Mat Div, Amer Soc Mech Engineers, Pressure Vessels and Piping Div ID FRACTURE; IMPURITIES; ALLOY AB We present a formal methodology to integrate basic materials research results into a design procedure for engineering components. Although the methodology is generic, we demonstrate its development and application in designing a cast automotive control arm. Specifically, we propose a multi-scale analysis whereby the local mechanisms of deformation are accounted for by an internal state variable constitutive model embedded within a non-linear elastic-plastic finite element analysis. Multiple fundamental materials research approaches at different length scales are utilized to quantify the pertinent deformation mechanisms, such as atomistic stimulations, microscopy, micromechanical finite element simulations, and mechanical testing. The current methodology is a step toward a larger goal of interactively integrating basic materials science research into engineering system design. [S0094-4289(00)01903-4]. C1 Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94550 USA. RP Gall, K (reprint author), Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. OI Horstemeyer, Mark/0000-0003-4230-0063 NR 29 TC 10 Z9 10 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JUL PY 2000 VL 122 IS 3 BP 355 EP 362 DI 10.1115/1.482809 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 404PE UT WOS:000167108700020 ER PT J AU Masri, SF Smyth, AW Chassiakos, AG Caughey, TK Hunter, NF AF Masri, SF Smyth, AW Chassiakos, AG Caughey, TK Hunter, NF TI Application of neural networks for detection of changes in nonlinear systems SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID ADAPTIVE RANDOM SEARCH; IDENTIFICATION AB A nonparametric structural damage detection methodology based on nonlinear system identification approaches is presented for the health monitoring of structure-unknown systems. In its general form, the method requires no information about the topology or the nature of the physical system being monitored. The approach relies on the use of vibration measurements from a "healthy" system to train a neural network for identification purposes. Subsequently, the trained network is fed comparable vibration measurements from the same structure under different episodes of response in order to monitor the health of the structure and thereby provide a relatively sensitive indicator of changes (damage) in the underlying structure. For systems with certain topologies, the method can also furnish information about the region within which structural changes have occurred. The approach is applied to an intricate mechanical system that incorporates significant nonlinear behavior typically encountered in the applied mechanics field. The system was tested in its "virgin" state as well as in "damaged" states corresponding to different degrees of parameter changes. It is shown that the proposed method is a robust procedure and a practical tool for the detection and overall quantification of changes in nonlinear structures whose constitutive properties and topologies are not known. C1 Univ So Calif, Sch Engn, Dept Civil Engn, Los Angeles, CA 90089 USA. Columbia Univ, Sch Engn & Appl Sci, New York, NY 10027 USA. Calif State Univ Long Beach, Sch Engn, Long Beach, CA 90840 USA. CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Masri, SF (reprint author), Univ So Calif, Sch Engn, Dept Civil Engn, 3620 S Vermont Ave,KAP 210,MC 2531, Los Angeles, CA 90089 USA. OI Smyth, Andrew/0000-0001-9037-306X NR 16 TC 125 Z9 129 U1 1 U2 11 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD JUL PY 2000 VL 126 IS 7 BP 666 EP 676 DI 10.1061/(ASCE)0733-9399(2000)126:7(666) PG 11 WC Engineering, Mechanical SC Engineering GA 324GU UT WOS:000087614100002 ER PT J AU De Keyser, J Roth, M Forsyth, R Reisenfeld, D AF De Keyser, J Roth, M Forsyth, R Reisenfeld, D TI Ulysses observations of sector boundaries at aphelion SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Ulysses Aphelion Workshop CY OCT 27-30, 1998 CL OXNARD, CALIFORNIA ID HELIOSPHERIC CURRENT SHEET; MASS EJECTIONS CMES; TANGENTIAL DISCONTINUITIES; 3-DIMENSIONAL PROPAGATION; PLASMA SHEETS; STREAMER BELT; CONNECTION; DYNAMICS; AU AB We study a sample of sector boundaries observed by Ulysses near its early 1998 aphelion at 5.4 AU. We relate these sector boundaries to solar wind structure seen by Wind at 1 AU, guided by a hydrodynamic simulation. For each Ulysses sector boundary we are able to identify a corresponding 1 AU sector boundary, except when strong transients are present. Sector boundaries appear embedded in complex plasma structures that generally are in a state of pressure balance. Minimum variance analysis confirms the tangential discontinuity nature of the heliospheric current sheet (HCS) and indicates that the current sheet tends to be inclined more steeply than at 1 AU (HCS normal closer to the equatorial plane and nearly radially outward). We discuss evidence for the nonplanarity of the current sheet. Magnetic field depressions are characteristic features of the sector boundaries. We attribute them to particles that are magnetically confined inside the current sheet and that carry the diamagnetic current responsible far the large magnetic field rotation. C1 Belgian Inst Space Aeron, B-1180 Brussels, Belgium. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP De Keyser, J (reprint author), Belgian Inst Space Aeron, Ringlaan 3, B-1180 Brussels, Belgium. RI Reisenfeld, Daniel/F-7614-2015 NR 28 TC 4 Z9 4 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 2000 VL 105 IS A7 BP 15689 EP 15698 DI 10.1029/2000JA900040 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330KW UT WOS:000087962100001 ER PT J AU Anderson, PC McKenzie, DL Brittnacher, MJ Chen, MW Hairston, M Thomsen, MF AF Anderson, PC McKenzie, DL Brittnacher, MJ Chen, MW Hairston, M Thomsen, MF TI Global storm time auroral X-ray morphology and timing and comparison with UV measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ELECTRON-PRECIPITATION; MORNING SECTOR; PLASMA SHEET; MAGNETOSPHERE; IONIZATION; SUBSTORM; ORBIT AB The Polar Ionospheric X-ray Imaging Experiment (PIXIE) on. NASA's Polar spacecraft provides the first global images of the auroral oval in X-rays and allows very accurate measurements of the timing of geomagnetic disturbances to a degree of temporal resolution not available from previous imagers due to its photon counting characteristics. On October 19, 1998, a magnetic cloud associated with a CME encountered the Earth's magnetopause near 0500 UT, generating a magnetic storm that reached a minimum value in Dst of -139 nT. The z component of the interplanetary magnetic field (IMF) (B-z) remained remarkably steady for the first 10 hours of the storm as did the solar wind particle pressure. The PIXIE and UVI instruments on the Polar spacecraft were both imaging the auroral oval from 0800 to 1800 UT; six distinct impulsive auroral enhancements were observed by the imagers during this time period. Global imaging combined with geosynchronous particle observations allowed classification of the geomagnetic disturbances associated with the events. Only two of the events were classified as substorms;one was classified as a poleward boundary intensification, one was a convection bay, and one was a pseudobreakup. A sixth event occurred after a dramatic northward turning of the IMF at the end of the 10-hour B-z south period but was very weak and transient. The effects of the northward turning were counteracted by a simultaneous increase in the B-y component of the IMF. The first sign of significant substorm activity occurred over 8 hours after the cloud encountered the Earth and was not associated with any change in the solar wind magnetic field or particle pressure. The cross polar cap potential remained large (> 100 kV), and most of the X-ray emissions observed were associated with enhanced earthward convection caused by large cross-tail electric fields; 50% were collected from the 0000 - 0600 magnetic local time (MLT) sector. C1 Aerospace Corp, Space & Environm Technol Ctr, Los Angeles, CA 90009 USA. Univ Washington, Geophys Program, Seattle, WA 98195 USA. Univ Texas, WB Hanson Ctr Space Sci, Richardson, TX 75083 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Anderson, PC (reprint author), Aerospace Corp, Space & Environm Technol Ctr, POB 92957, Los Angeles, CA 90009 USA. RI Chen, Margaret/C-9658-2013; OI Chen, Margaret/0000-0001-7771-4771; Hairston, Marc/0000-0003-4524-4837 NR 35 TC 19 Z9 19 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 2000 VL 105 IS A7 BP 15757 EP 15777 DI 10.1029/1999JA000355 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330KW UT WOS:000087962100006 ER PT J AU Seki, K Elphic, RC Thomsen, MF Bonnell, J Lund, EJ Hirahara, M Terasawa, T Mukai, T AF Seki, K Elphic, RC Thomsen, MF Bonnell, J Lund, EJ Hirahara, M Terasawa, T Mukai, T TI Cold flowing O+ beams in the lobe/mantle at Geotail: Does FAST observe the source? SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; LATITUDE ELECTRIC POTENTIALS; DENSE ION FLOWS; PARTICLE-PRECIPITATION; DISTANT MAGNETOTAIL; DAYSIDE IONOSPHERE; BOUNDARY-LAYER; SOLAR-ACTIVITY; PLASMA; CUSP AB The Geotail spacecraft observed high-energy (similar to 3-10 keV) cold O+ beams (COBs) streaming tailward together with protons entering from the magnetosheath in the northern dusk lobe/mantle when the IMF (interplanetary magnetic field) B-y and B-z are steadily negative. He+ beams were also observed intermittently. During the same period the FAST satellite passed across the dayside northern polar regions from dawn to dusk at low altitudes (1200-3400 km) and observed O+ precipitation on both closed and open field lines. There are regions where the magnetosheath and dayside plasma sheet/ring current components coexist and are precipitating together. In the open field line regions the precipitating O+ seem continuous with the precipitation in the closed regions, while the H+ and He++ precipitations are denser and typically have lower energy than O+. The phase space density (PSD) of the precipitating ions is highly isotropic except for the loss cone in the upward direction. Utilizing Liouville's theorem, we have compared the PSD of locally mirroring Of at FAST with the PSD of COBs observed at Geotail. This comparison shows that the PSD in the high-energy precipitation region on closed field lines is comparable to that of the COBs. In regions where the magnetosheath and dayside magnetosphere ions coexist, the O+ PSD is typically smaller than that of the COBs, but at low latitudes it sometimes reaches values comparable to that of the COBs. These results suggest that the high-energy O+ ions in the dayside magnetosphere are a promising candidate for the source of COBs in the lobe/mantle. The ion dynamics on reconnected flux tubes needs to be examined further to clarify the possible energization mechanisms and their effect on the O+ ions. C1 Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Rikkyo Univ, Coll Sci, Dept Phys, Tokyo 1718501, Japan. Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp NIS I, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Seki, K (reprint author), Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, 7-3-1 Hongo, Tokyo 1130033, Japan. NR 32 TC 15 Z9 15 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 2000 VL 105 IS A7 BP 15931 EP 15944 DI 10.1029/1999JA900470 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330KW UT WOS:000087962100018 ER PT J AU Rudd, LV Pines, DJ Carter, PH AF Rudd, LV Pines, DJ Carter, PH TI Long-range performance of suboptimal periodic hypersonic cruise trajectories SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID VEHICLE; FLIGHT C1 Univ Maryland, Dept Aerosp Engn, College Pk, MD 20742 USA. Univ Calif Lawrence Livermore Natl Lab, Div Mech Engn, Livermore, CA 94550 USA. NR 7 TC 1 Z9 2 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JUL-AUG PY 2000 VL 23 IS 4 BP 756 EP 758 DI 10.2514/2.4598 PG 3 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 335TH UT WOS:000088260500026 ER PT J AU Liu, S Saha, S Stelly, D Burr, B Cantrell, RG AF Liu, S Saha, S Stelly, D Burr, B Cantrell, RG TI Chromosomal assignment of microsatellite loci in cotton SO JOURNAL OF HEREDITY LA English DT Article ID COMPREHENSIVE GENETIC-MAP; GOSSYPIUM-HIRSUTUM; SIZE HOMOPLASY; GENOME; MARKERS; ORGANIZATION; WHEAT; PCR AB Microsatellite markers or simple sequence repeats (SSRs) represent a new class of genetic markers for cotton (Gossypium sp,), Sixty-five SSR primer pairs were used to amplify 71 marker loci and genotype 13 monosomic and 27 monotelodisomic cotton cytogenetic stocks, Forty-two SSR loci were assigned to cotton chromosomes or chromosome arms. Thirty SSRs were not located to specific chromosomes in this study, Nineteen marker loci were shown to occur on the A subgenome and 11 on the D subgenome by screening accessions of G. herbaceum (2n = 2x = 26 = 2A(1)) and G. raimondii(2n = 2x = 26 = 2D(5)). The aneuploid stocks proved to be very powerful tools for localizing SSR markers to individual cotton chromosomes. Multiplex PCR bins of the SSR primers and semiautomated detection of the amplified products were optimized in this experiment, Thirteen multiplex PCR bins were optimized to contain an average of 4 SSR primer pairs per bin. This provides a protocol for high-throughput genotyping of cotton SSRs that improves the efficiency of genetic mapping and marker-assisted programs utilizing SSR markers. C1 New Mexico State Univ, Dept Agron & Hort, Las Cruces, NM 88003 USA. ARS, Crop Sci Res Lab, USDA, Mississippi State, MS USA. Texas A&M Univ, Dept Soil & Crop Sci, College Stn, TX 77843 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Cantrell, RG (reprint author), New Mexico State Univ, Dept Agron & Hort, Las Cruces, NM 88003 USA. OI Stelly, David/0000-0002-3468-4119 NR 27 TC 71 Z9 85 U1 1 U2 5 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD JUL-AUG PY 2000 VL 91 IS 4 BP 326 EP 332 PG 7 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 333UK UT WOS:000088149000010 PM 10912681 ER PT J AU Kolda, C Murayama, H AF Kolda, C Murayama, H TI The Higgs mass and new physics scales in the minimal standard model SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE beyond standard model; Higgs physics ID OBLIQUE ELECTROWEAK CORRECTIONS; GRAND UNIFIED THEORIES; LARGE EXTRA DIMENSIONS; TECHNICOLOR THEORIES; SYMMETRY-BREAKING; BOSON; BOUNDS; TRIVIALITY; PARAMETERS; STABILITY AB We study the theoretical correlation between the Higgs mass of the minimal standard model and the scale at which new physics is expected to occur. In addition to the classic constraints of unitarity, triviality and vacuum stability, we reexamine the constraints imposed by the precision electroweak data. We then pay particular attention to the constraint imposed by the absence of fine-tuning in the Higgs mass parameter (the Veltman condition). We find that the fine-tuning condition places a significant constraint on the new physics scale for the Higgs mass range 100 GeV less than or similar to m(h) less than or similar to 200 GeV mostly unconstrained by the classic constraints. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theory Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM cfkolda@lbl.gov; murayama@lbl.gov RI Murayama, Hitoshi/A-4286-2011 NR 50 TC 62 Z9 62 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD JUL PY 2000 IS 7 AR 035 DI 10.1088/1126-6708/2000/07/035 PG 21 WC Physics, Particles & Fields SC Physics GA 423AU UT WOS:000168153900035 ER PT J AU Moroi, T Murayama, H AF Moroi, T Murayama, H TI The minimal supersymmetric leptogenesis SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE supersymmetric effective theories; baryogenesis; neutrino physics ID NUMBER NON-CONSERVATION; GRAND UNIFICATION; FLAT DIRECTIONS; STANDARD MODEL; EARLY UNIVERSE; BARYOGENESIS; NEUTRINO; MECHANISM; HIERARCHIES; BREAKING AB We reanalyze the supersymmetric leptogenesis model by one of the authors (H.M.) and Yanagida based on (L) over tilde = H-u flat direction in detail. We point out that the appropriate amount of baryon asymmetry can be generated in this model with the neutrino mass matrix consistent with the atmospheric neutrino oscillation and solutions to the solar neutrino problem, preferably the small angle MSW solution. The reheating temperature can be low enough to avoid the cosmological gravitino problem. This model is the minimal one because it does not rely on any new physics beyond supersymmetry and Majorana neutrino masses. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Inst Adv Study, Sch Nat Sci, Olden Lane, Princeton, NJ 08540 USA. EM moroi@ias.edu; murayama@thsrv.lbl.gov RI Murayama, Hitoshi/A-4286-2011 NR 32 TC 16 Z9 16 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD JUL PY 2000 IS 7 AR 009 PG 14 WC Physics, Particles & Fields SC Physics GA 423AU UT WOS:000168153900009 ER PT J AU Neumann, AU Lam, NP Dahari, H Davidian, M Wiley, TE Mika, BP Perelson, AS Layden, TJ AF Neumann, AU Lam, NP Dahari, H Davidian, M Wiley, TE Mika, BP Perelson, AS Layden, TJ TI Differences in viral dynamics between genotypes 1 and 2 of hepatitis C virus SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article; Proceedings Paper CT 50th Annual Meeting of the American-Association-for-the-Study-of-Liver-Diseases CY NOV 05-09, 1999 CL DALLAS, TEXAS SP Amer Assoc Study Liver Diseases ID NONSTRUCTURAL 5A GENE; HYPERVARIABLE REGION-1; INTERFERON-ALFA; PROTEIN-KINASE; IN-VIVO; MUTATIONS; INFECTION; RIBAVIRIN; THERAPY; SEQUENCE AB Many studies have shown that patients infected with hepatitis C virus (HCV) of genotype 2 have better response to interferon (IFN)-alpha treatment than genotype 1 patients; however, the mechanisms responsible for this difference are not understood. In this study, viral dynamics during high-dose IFN induction treatment were compared between the genotypes, Patients in each group received 10 MU of IFN-alpha 2b for 14 days, and HCV RNA levels were frequently determined. Nonlinear fitting, both individually for each patient and using a mixed-effects approach, of the viral kinetic data to a mathematical model of the IFN effect on HCV infection was performed, The antiviral effectiveness of IFN in blocking virus production, the free virion clearance rate, and the HCV-infected cell death rate were all significantly higher for genotype 2 patients than for genotype 1 patients. Thus, the better response rate of patients infected with HCV genotype 2 is multifactorial, This is the first finding of a difference in viral dynamics between subtypes of the same virus and demonstrates the importance of subtype-specific virus-host-drug interactions. C1 Univ Illinois, Sect Digest & Liver Dis, Dept Med, Chicago, IL 60612 USA. Bar Ilan Univ, Fac Life Sci, Ramat Gan, Israel. Santa Fe Inst, Santa Fe, NM 87501 USA. N Carolina State Univ, Dept Stat, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Layden, TJ (reprint author), Univ Illinois, Sect Digest & Liver Dis, Dept Med, 840 S Wood St,Rm 718E, Chicago, IL 60612 USA. FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI39049-2]; NIDDK NIH HHS [A1/DK41320-2] NR 39 TC 175 Z9 179 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0022-1899 J9 J INFECT DIS JI J. Infect. Dis. PD JUL PY 2000 VL 182 IS 1 BP 28 EP 35 DI 10.1086/315661 PG 8 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 340FK UT WOS:000088522300005 PM 10882578 ER PT J AU Jerschow, A AF Jerschow, A TI Thermal convection currents in NMR: Flow profiles and implications for coherence pathway selection SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE Rayleigh-Benard convection; free convection; flow; magnetic resonance imaging; coherence pathway selection ID NUCLEAR-MAGNETIC-RESONANCE; CYLINDRICAL FLUID LAYER; PULSED-FIELD GRADIENTS; THERMOCONVECTIVE INSTABILITY; SUPPRESSION AB Rayleigh-Benard convection currents are visualized in a vertical cylindrical tube by means of magnetic resonance imaging. Axially antisymmetric flow, multiple vertical rolls, and twisted node planes are observed. The how can also be induced by strong RF irradiation. Its effects on the coherence pathways in NMR experiments employing field gradients are discussed, (C) 2000 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Lausanne, Chim Sect, CH-1015 Lausanne, Switzerland. RP Jerschow, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Hildebrand D62, Berkeley, CA 94720 USA. OI Jerschow, Alexej/0000-0003-1521-9219 NR 26 TC 39 Z9 39 U1 1 U2 11 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD JUL PY 2000 VL 145 IS 1 BP 125 EP 131 DI 10.1006/jmre.2000.2083 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 332CD UT WOS:000088055100013 ER PT J AU Van Berkel, GJ AF Van Berkel, GJ TI Electrolytic deposition of metals on to the high-voltage contact in an electrospray emitter: implications for gas-phase ion formation SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE electrospray mass spectrometry; metals; deposition; reduction; oxidation ID IONIZATION MASS-SPECTROMETRY; ELECTROCHEMICAL OXIDATION; ORGANOMETALLIC CHEMISTRY; CELL; METALLOCENES; DERIVATIVES; INHERENT; SYSTEM AB The electrospray ion source is an electrolytic flow cell. Electrolytic reactions in the electrospray emitter maintain the production of charged droplets by this ion source that contain an excess of ions of one polarity, These redox reactions necessarily change the composition of the solution that initially enters the emitter. As a result, the ions ultimately observed in the gas phase by electrospray mass spectrometry (ESMS) may be substantially influenced by both the nature and extent of these electrochemical reactions. It is demonstrated in this paper that Ag+, Cu2+ and Hg2+ ions in solution can be electrolytically reduced and deposited as the respective metals on to the surface of the high-voltage contact in the electrospray emitter in negative ion mode electrospray, The deposited metals are shown to be liberated from the surface by switching the electrospray high-voltage polarity to operate in the positive ion mode. The deposited metals are oxidized in positive ion mode, releasing the metal ions back into solution where they are detected in the electrospray mass spectrum. in a semi-quantitative analysis, it was found that up to 50% of the Ag+ in a 2.5 mu M solution was deposited on the high-voltage contact of the emitter as the solution flowed through the emitter. Deposition of Cu2+ and Hg2+ was less efficient. These data illustrate that in the analysis of metals by ESMS, one must be aware that both the concentration and form of the metals may be altered by electrochemical processes in the emitter. Hence reduction or oxidation of metals in the electrospray emitter, which may remove ions from solution, or change metal valence, would be expected to impact both quantitative metal determinations and metal speciation attempts using ESMS, Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 40 TC 53 Z9 54 U1 0 U2 16 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD JUL PY 2000 VL 35 IS 7 BP 773 EP 783 DI 10.1002/1096-9888(200007)35:7<773::AID-JMS4>3.3.CO;2-Y PG 11 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 340QB UT WOS:000088544900003 PM 10934431 ER PT J AU Shukla, A Nicol, G Futrell, J AF Shukla, A Nicol, G Futrell, J TI Tandem mass spectrometric study of 1,3,5-trinitrobenzene molecular ion: an unusual ortho effect involving a hydrogen atom from the aromatic ring SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE collision-induced dissociation; metastable dissociation; ortho effect; linked scans; 1,3,5-trinitrobenzene ID SPECTRAL FRAGMENTATION PATHWAYS; COLLISION-INDUCED DISSOCIATION; ELECTRON-IMPACT; DECOMPOSITION AB Unimolecular (metastable) and collision-induced dissociation of 1,3,5-trinitrobenzene molecular ion was studied using linked scans and mass-analyzed ion kinetic energy spectrometry on a hybrid instrument of EBEqQ geometry, An unusual ortho effect leading to the loss of OH radical from the parent molecular ion is observed as a unimolecular dissociation process only in the first-field free region between the ion source and the electric sector, although corresponding dissociation in the ion source is of negligible abundance (<0.1%). This unimolecular process is taken over by other dissociation pathways when the parent ion is collisionally activated, suggesting that this dissociation process occurs only in a very narrow energy window with a rate constant of the order of 2 x 10(5) s(-1). Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. RP Shukla, A (reprint author), Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 20 TC 4 Z9 4 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD JUL PY 2000 VL 35 IS 7 BP 885 EP 890 DI 10.1002/1096-9888(200007)35:7<885::AID-JMS13>3.0.CO;2-# PG 6 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 340QB UT WOS:000088544900014 ER PT J AU Guyer, RA Johnson, PA AF Guyer, RA Johnson, PA TI Hysteresis, energy landscapes and slow dynamics: A survey of the elastic properties of rocks SO JOURNAL OF MATERIALS PROCESSING & MANUFACTURING SCIENCE LA English DT Article; Proceedings Paper CT International Workshop on Hysteresis, Metastabilitiy and Aftereffect CY AUG 28-30, 2000 CL CHICAGO, ILLINOIS AB Rocks are prototypical of a class of materials that exhibit unusual elastic properties. They are (1) strikingly nonlinear at modest stress, (2) exhibit hysteresis and discrete memory in quasi-static exploration of their equation of state, (3) have frequency shift, attenuation, and harmonic generation properties in dynamic measurements that are beyond explanation using the classical model of nonlinear elasticity, and (4) recover from transient disturbances with log(t). This collection of elastic properties of rocks is explained using phenomenologies which employ mesoscopic or microscopic hysteretic elastic elements. The experimental properties (1)-(4) that are signatures of the unusual elastic properties of rocks will be described as well as the rudiments of the phenomenologies that are used to understand these properties. C1 Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1062-0656 J9 J MATER PROCESS MANU JI J. Mater. Process. Manuf. Sci. PD JUL PY 2000 VL 9 IS 1 BP 14 EP 26 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 443JR UT WOS:000169338500003 ER PT J AU Chou, YS Stevenson, JW Armstrong, TR Hardy, JS Hasinska, K Pederson, LR AF Chou, YS Stevenson, JW Armstrong, TR Hardy, JS Hasinska, K Pederson, LR TI Microstructure and mechanical properties of Sm1-xSrxCo0.2Fe0.8O3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PEROVSKITE-TYPE OXIDES; DOPED LANTHANUM CHROMITE; FRACTURE-TOUGHNESS; METHANE; CONDUCTIVITY; CERAMICS; CELLS AB The room temperature mechanical properties of a mixed conducting perovskite Sm1-xSrxCo0.2Fe0.8O3 (x = 0.2 to 0.8) were examined. Density, crystal phase, and microstructure were characterized. It was found that the grain size increased abruptly with increasing Sr content. Mechanical properties of elastic modulus, microhardness, indentation fracture toughness, and biaxial flexure strength were measured. Young's modulus of 180-193 GPa and shear modulus of 70-75 Cpa were determined. The biaxial flexure strength was found to decrease with increasing Sr content from similar to 70 to similar to 20 MPa. The drop in strength was due to the occurrence of extensive cracking. Indentation toughness showed a similar trend to the strength in that it decreased with increasing Sr content from similar to 1.1 to similar to 0.7 MPa m(1/2). In addition, fractography was used to characterize the fracture behavior in these materials. C1 Pacific NW Natl Lab, Dept Mat Sci, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Natl Lab, Dept Mat Sci, Richland, WA 99352 USA. RI Hardy, John/E-1938-2016 OI Hardy, John/0000-0002-1699-3196 NR 39 TC 5 Z9 5 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 2000 VL 15 IS 7 BP 1505 EP 1513 DI 10.1557/JMR.2000.0216 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 330NK UT WOS:000087968000011 ER PT J AU Branagan, DJ Kramer, MJ Tang, YL McCallum, RW Crew, DC Lewis, LH AF Branagan, DJ Kramer, MJ Tang, YL McCallum, RW Crew, DC Lewis, LH TI Engineering magnetic nanocomposite microstructures SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ND2FE14B; SYSTEM AB The realization of high energy densities in permanent magnetic materials requires careful control of both the composition and the processing conditions to develop appropriate microstructures. In this paper, we will show that manipulation of multiple alloying additions leads to the synthesis of magnetically optimum nanoscale metal matrix composite microstructures in a 9-element modified Nd-Fe-B alloy. The development of composite microstructures in hard magnetic materials is a novel concept resulting in many beneficial effects on the resulting structure/processing/property relationships. (C) 2000 Kluwer Academic Publishers. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Branagan, DJ (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 19 TC 6 Z9 6 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL PY 2000 VL 35 IS 14 BP 3459 EP 3466 DI 10.1023/A:1004836807586 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA 328UZ UT WOS:000087869600004 ER PT J AU Boyd, JK AF Boyd, JK TI Probability amplitude dynamics for a two-level system SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID ROTATING-WAVE APPROXIMATION; ORDER HARMONIC-GENERATION; JAYNES-CUMMINGS MODEL; 2-LEVEL ATOM; TRANSITION-PROBABILITY; SPECTROSCOPY; RADIATION; FIELDS; BAND AB The time-dependent probability amplitudes are determined for a two-level system without invoking the rotating wave approximation. A new analytic solution is obtained in the limit of small ratio of Rabi frequency to driver frequency. An analytic solution is also obtained in the limit of large ratio of Rabi frequency to driver frequency for a restricted range of parameters. The form of this solution guides the selection of parameters that cause substantial changes in the character of the solution. The dependence on parameter values is studied numerically for the transition probability and the coherent spectrum. (C) 2000 American Institute of Physics. [S0022-2488(00)01107-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Boyd, JK (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 56 TC 8 Z9 8 U1 4 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JUL PY 2000 VL 41 IS 7 BP 4330 EP 4364 AR PII [S0022-2488(00)01107-5] DI 10.1063/1.533345 PG 35 WC Physics, Mathematical SC Physics GA 326EW UT WOS:000087720600007 ER PT J AU Zachos, C AF Zachos, C TI Geometrical evaluation of star products SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID INFINITE-DIMENSIONAL ALGEBRAS; QUANTIZATION; DEFORMATION; UNIQUENESS AB The geometric picture of the star product based on its Fourier representation kernel is utilized in the evaluation of chains of star products and the intuitive appreciation of their associativity and symmetries. Such constructions appear even simpler for a variant asymmetric product, and carry through for the standard star-product supersymmetrization. (C) 2000 American Institute of Physics. [S0022-2488(00)01407-9]. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Zachos, C (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RI zachos, cosmas/C-4366-2014 OI zachos, cosmas/0000-0003-4379-3875 NR 22 TC 42 Z9 42 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD JUL PY 2000 VL 41 IS 7 BP 5129 EP 5134 AR PII [S0022-2488(00)01407-9] DI 10.1063/1.533395 PG 6 WC Physics, Mathematical SC Physics GA 326EW UT WOS:000087720600058 ER PT J AU Chang, BC Costen, ML Marr, AJ Ritchie, G Hall, GE Sears, TJ AF Chang, BC Costen, ML Marr, AJ Ritchie, G Hall, GE Sears, TJ TI Near-infrared spectroscopy of bromomethylene in a slit-jet expansion SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ORBITAL ANGULAR-MOMENTUM; ABSORPTION-SPECTROSCOPY; MOLECULAR-STRUCTURES; LASER SPECTROSCOPY; HIGH-RESOLUTION; GAS-PHASE; SPECTRA; STATE; CH2; RADICALS AB Several rotational subbands of the bromomethylene (HCBr) and deuterated bromomethylene (DCBr) (A) over tilde(1)A " <-- (X) over tilde(1)A' origin band in the region of 830-840 nm have been recorded under slit-jet cooled conditions that result in rotational and translational temperatures of approximately 20 K. The radical was formed by 193-nm laser photolysis of bromoform in the early stages of the expansion and detected by absorption of a single-frequency Ti:sapphire ring laser. The spectral simplification achieved compared to earlier measurements at ambient temperature allowed a nearly complete rotational analysis. The data were combined with additional measurements at room temperature in order to determine rotational constants and estimate a structure for the radical in its ground state. With the exception of K' = 0, the excited state levels were found to suffer multiple perturbations due to interactions with the manifold of excited (X) over tilde state levels caused by Renner-Teller and anharmonic coupling. Atomic bromine transitions from the P-4(5/2) level at 63 400 cm(-1) were also observed in the source following absorption of at least two 193-nm photons by the precursor. (C) 2000 Academic Press. C1 Natl Cent Univ, Dept Chem, Chungli 32054, Taiwan. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. DERA, Ft Halstead TN14 7BP, Kent, England. Univ Oxford, Phys Chem Lab, Oxford OX1 3QZ, England. RP Chang, BC (reprint author), Natl Cent Univ, Dept Chem, Chungli 32054, Taiwan. RI Sears, Trevor/B-5990-2013; Hall, Gregory/D-4883-2013; Costen, Matthew/K-5178-2012 OI Sears, Trevor/0000-0002-5559-0154; Hall, Gregory/0000-0002-8534-9783; Costen, Matthew/0000-0002-6491-9812 NR 37 TC 38 Z9 38 U1 0 U2 4 PU ACADEMIC PRESS INC 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 JUL PY 2000 VL 202 IS 1 BP 131 EP 143 DI 10.1006/jmsp.2000.8116 PG 13 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 327JN UT WOS:000087790900014 ER PT J AU Chervenak, A Foster, I Kesselman, C Salisbury, C Tuecke, S AF Chervenak, A Foster, I Kesselman, C Salisbury, C Tuecke, S TI The data grid: Towards an architecture for the distributed management and analysis of large scientific datasets SO JOURNAL OF NETWORK AND COMPUTER APPLICATIONS LA English DT Article ID INFRASTRUCTURE AB In an increasing number of scientific disciplines, large data collections are emerging as important community resources. In this paper, we introduce design principles for a data management architecture called the data grid. We describe two basic services that we believe are fundamental to the design of a data grid, namely, storage systems and metadata management. Next, we explain how these services can be used to develop higher-level services for replica management and replica selection. We conclude by describing our initial implementation of data grid functionality. (C) 2000 Academic Press. C1 Univ So Calif, Inst Informat Sci, Los Angeles, CA 90089 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. RP Chervenak, A (reprint author), Univ So Calif, Inst Informat Sci, Los Angeles, CA 90089 USA. OI Kesselman, Carl/0000-0003-0917-1562; Tuecke, Steven/0000-0003-2038-2512 NR 24 TC 269 Z9 292 U1 8 U2 18 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1084-8045 J9 J NETW COMPUT APPL JI J. Netw. Comput. Appl. PD JUL PY 2000 VL 23 IS 3 BP 187 EP 200 DI 10.1006/jnca.2000.0110 PG 14 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 368LA UT WOS:000090117400005 ER PT J AU Yang, W Barth, RF Rotaru, JH Boesel, CP Wilkie, DA Bresnahan, JC Hadjiconstantinou, M Goettl, VM Joel, DD Nawrocky, MM AF Yang, W Barth, RF Rotaru, JH Boesel, CP Wilkie, DA Bresnahan, JC Hadjiconstantinou, M Goettl, VM Joel, DD Nawrocky, MM TI Boron neutron capture therapy of brain tumors: Functional and neuropathologic effects of blood-brain barrier disruption and intracarotid injection of sodium borocaptate and boronophenylalanine SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE blood-brain barrier disruption; boron neutron capture therapy; boronophenylalanine; sodium borocaptate; intracarotid injection; neuropathologic effects ID MORRIS WATER MAZE; RAT-BRAIN; SPINAL-CORD; IRRADIATION; MEMORY; INTRAARTERIAL; GLIOSARCOMAS; TOXICITY; GLIOMA; SKIN AB Sodium borocaptate (BSH) and boronophenylalanine (BPA) are two drugs that have been used clinically for boron neutron capture therapy (BNCT) of brain tumors. We previously have reported that hyperosmotic mannitol-induced disruption of the blood-brain barrier (BBB-D), followed by intracarotid (i.c.) administration of BPA or BSH, either individually or in combination, significantly enhanced tumor boron delivery and the efficacy of BNCT in F98 glioma bearing rats. The purpose of the present study was to determine the short-term neuropathologic consequences of this treatment and the long-term effects on motor and cognitive function, as well as the neuropathologic sequelae 1 year following neutron capture irradiation. BBB-D was carried out in non-tumor bearing Fischer rats by infusing a 25% solution of mannitol i.c. followed by i.c. injection of BPA or BSH, either individually or in combination, immediately thereafter. Animals were euthanized 2 days after compound administration, and their brains were processed for neuropathologic examination, which revealed sporadic, mild, focal neuronal degeneration, hemorrhage, and necrosis. To assess the long-term effects of such treatment followed by neutron capture irradiation, non-tumor bearing rats were subjected to BBB-D after which they were injected i.c. with BPA (25 mg B/kg body weight (b.w)) or BSH (30 mg B/kg b.w.) either individually or in combination (BPA 12.5 mg and BSH 14 mg B/kg b.w.). Two and a half hours later they were irradiated at the Medical Research Reactor, Brookhaven National Laboratory, Upton, NY, with the same physical radiation doses (5.79, 8.10 or 10.06 Gy), delivered to the brain, as those that previously had been used for our therapy experiments. The animals tolerated this procedure well, after which they were returned to Columbus, Ohio where their clinical status was monitored weekly. After 1 year, motor function was assessed using a sensitive and reliable locomotor rating scale for open field testing in rats and cognitive function was evaluated by their performance in the Morris water maze, the results of which were similar to those obtained with age matched controls. After functional evaluation, the rats were euthanized, their brains were removed, and then processed for neuropathologic examination. Subtle histopathologic changes were seen in the choroid plexuses of irradiated animals that had received BPA, BSH or saline. Radiation related ocular changes consisting of keratitis, blepharitis, conjunctivitis and cataract formation were seen with similar frequency in most rats in each treatment group. Based on these observations, and the previously reported significant therapeutic gain associated with BBB-D and i.c. injection of BSH and BPA, the present observations establish its safety in rats and suggest that further studies in large animals and humans are warranted. C1 Ohio State Univ, Dept Pathol, Columbus, OH 43210 USA. Ohio State Univ, Dept Vet Clin Sci, Columbus, OH 43210 USA. Ohio State Univ, Dept Cell Biol Neurobiol & Anat, Columbus, OH 43210 USA. Ohio State Univ, Dept Pharmacol, Columbus, OH 43210 USA. Ohio State Univ, Ctr Comprehens Canc, Columbus, OH 43210 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Barth, RF (reprint author), Ohio State Univ, Dept Pathol, 165 Hamilton Hall,1645 Neil Ave, Columbus, OH 43210 USA. EM barth.1@osu.edu FU NIA NIH HHS [AG-105330, AG/OD 10530]; NINDS NIH HHS [T32-NS07291] NR 53 TC 15 Z9 16 U1 1 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD JUL PY 2000 VL 48 IS 3 BP 179 EP 190 DI 10.1023/A:1006410611067 PG 12 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA 366BQ UT WOS:000089985300001 PM 11100816 ER PT J AU Li, SX Sofu, T Johnson, TA Wigeland, RA Laug, DV AF Li, SX Sofu, T Johnson, TA Wigeland, RA Laug, DV TI Experimental observations on electrorefining spent nuclear fuel in molten LiCl-KCl/liquid cadmium system SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE uranium electrorefining; molten salt; liquid cadmium; pulsating current effect ID METALLIC FUEL AB Argonne National Laboratory (ANL) has developed and demonstrated an electrometallurgical process for the Department of Energy (DOE) which processes spent nuclear fuel from the Experimental Breeder Reactor (EBR-II). One of the key steps in this demonstration was electrorefining of the spent fuel in a molten LiCl-KCl/liquid cadmium system using a pilot scale electrorefiner (Mk-IV ER). This article summarizes experimental observations and engineering aspects for electrorefining spent fuel in the molten LiCl-KCl/liquid cadmium system. It was found that the liquid cadmium pool acted as an intermediate electrode during the electrorefining process in the ER. The cadmium level was gradually decreased due to its high vapor pressure and vaporization rate at the ER operational temperature. The low cadmium level caused the anode assembly momentarily to touch the ER vessel hardware, which generated a periodic current change at the salt/cathode interface and improved uranium recovery efficiency for the process. The primary current distributions calculated by numerical simulations were used in interpreting the experimental results. C1 Argonne Natl Lab W, Idaho Falls, ID 83404 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Li, SX (reprint author), Argonne Natl Lab W, POB 2528, Idaho Falls, ID 83404 USA. EM sli@anl.gov NR 21 TC 6 Z9 7 U1 0 U2 1 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 JUL PY 2000 VL 3 IS 3 BP 259 EP 268 PG 10 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 334GE UT WOS:000088178000011 ER PT J AU Strachan, DM Croak, TL AF Strachan, DM Croak, TL TI Compositional effects on long-term dissolution of borosilicate glass SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID SURFACE AB Calculations have been performed to determine why, in static dissolution tests, the experimentally observed formation of a zeolite, such as analcime, causes a rapid increase in the dissolution rate for some glasses but not for others. The results of these calculations with a series of simple glasses show that there is a strong dependence on the Al content of the glass. For ratios of Si/(Si + Al) < 0.7, the amount of glass that has to dissolve for analcime to cause the dissolution rate to increase is 100-1000 times less than for glasses with higher ratios of Si/(Si + Al). Other glass components such as Na, Ca, B and Li are less effective at changing the rate of dissolution, although a minimum amount of Na needs to be present in the glass for analcime to form. These effects may be calculated for multi-component glasses by use of a simple six-component glass, although experimental verification is necessary to show that a six-component glass can be used. We also discuss the reasons why the effect of analcime precipitation on the silicon concentration in solution may be experimentally difficult to determine. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. Univ Illinois, Urbana, IL 61801 USA. RP Strachan, DM (reprint author), Pacific NW Lab, POB 999,902 Battelle Blvd, Richland, WA 99352 USA. NR 28 TC 33 Z9 33 U1 1 U2 8 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 JUL PY 2000 VL 272 IS 1 BP 22 EP 33 DI 10.1016/S0022-3093(00)00154-X PG 12 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 334GB UT WOS:000088177600003 ER PT J AU Li, LY Strachan, DM Li, H Davis, LL Qian, MX AF Li, LY Strachan, DM Li, H Davis, LL Qian, MX TI Crystallization of gadolinium- and lanthanum-containing phases from sodium alumino-borosilicate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID DISPOSITION; SOLUBILITY AB Lanthanide-containing glasses, commonly used for optical and laser applications, are also important in the vitrification of actinide-bearing radioactive wastes. In previous studies, we measured the glass forming regions of La2O3 and Gd2O3 in some sodium alumino-borosilicate glasses. Above their highest concentrations in these glasses, lanthanide silicate crystals with an apatite structure were found. In this paper, we characterize these crystals using powder X-ray diffraction (XRD), electron microscopy, energy dispersive spectroscopy (EDS), and selective area diffraction (SAD) to evaluate baseline glass composition effect and mixed La/Gd effect on the structure and chemistry of these crystals. When different lanthanide elements (lanthanum and gadolinium) co-exist in the glasses, complete lanthanide silicate solid solution is observed. Small amounts of boron can enter the gadolinium silicate structure if aluminum is present in the melt. The boron is probably substituting for the silicon in the crystal lattice. This substitution will cause a decrease in the unit cell parameters a(0) and c(0). A small amount of Na can also enter the crystal lattice, causing a decrease in the cell parameter a(0), but an increase in c(0). These results may help us to develop better understanding on the solution mechanism of lanthanide oxides in these glasses. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Li, LY (reprint author), Pacific NW Lab, POB 999 K6-24, Richland, WA 99352 USA. NR 15 TC 28 Z9 28 U1 2 U2 18 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 JUL PY 2000 VL 272 IS 1 BP 46 EP 56 DI 10.1016/S0022-3093(00)00117-4 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 334GB UT WOS:000088177600006 ER PT J AU Kupferman, R Kawaguchi, MN Denn, MM AF Kupferman, R Kawaguchi, MN Denn, MM TI Emergence of structure in a model of liquid crystalline polymers with elastic coupling SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE liquid crystalline polymers; elastic coupling ID MOLECULAR KINETIC-EQUATION; CONSTITUTIVE EQUATION; RODLIKE POLYMERS; FLOW AB We have solved the equations of transient shear flow for a model of a liquid crystalline polymer that contains a long-range interaction term in the nematic potential. The model exhibits a rich set of dynamics when the structure and momentum equations are coupled, including a periodic vorticity 'burst' near the shearing surface and very large gradients in velocity at discrete planes. Textures that are independent of the macroscopic scale were not observed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Hebrew Univ Jerusalem, Inst Math, IL-91904 Jerusalem, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Denn, MM (reprint author), CUNY City Coll, Levich Inst, 1-M Steinman Hall,140th St & Convent Ave, New York, NY 10031 USA. NR 17 TC 39 Z9 39 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD JUL 1 PY 2000 VL 91 IS 2-3 BP 255 EP 271 DI 10.1016/S0377-0257(99)00098-1 PG 17 WC Mechanics SC Mechanics GA 323TA UT WOS:000087580000008 ER PT J AU Lee, EH Hunn, JD Byun, TS Mansur, LK AF Lee, EH Hunn, JD Byun, TS Mansur, LK TI Effects of helium on radiation-induced defect microstructure in austenitic stainless steel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID IRRADIATION AB In the construction materials surrounding the spallation neutron source (SNS) mercury target, considerable quantities of transmutation products, particularly hydrogen and helium, will be generated due to the exposure to a high flux of 1 GeV protons and associated neutrons. In an effort to investigate the effects of high helium, therefore, bubble formation and defect clustering processes in AISI 316 LN austenitic steel were studied as a function of helium concentration and displacement damage dose with 360 keV He+ and 3500 keV Fe+ ion beams at 200 degrees C. Helium irradiation was less effective in producing defects such as black dots and dislocation loops than Fe+ ion irradiation at equivalent displacement dose. On the other hand, the formation of helium bubbles produced a strong depressive effect on the growth of loops and the evolution of line dislocations. The results indicated that the effect of helium bubbles was augmented as the bubble number density and size increased with increasing helium beyond 1 atomic percent (at.%). Tn such a case, the effect of helium bubbles can be more important than that of radiation-induced defects on the evolution of microstructure and the change in mechanical properties. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Lee, EH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 19 TC 46 Z9 50 U1 1 U2 19 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 JUL PY 2000 VL 280 IS 1 BP 18 EP 24 DI 10.1016/S0022-3115(00)00038-6 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 330ER UT WOS:000087950300002 ER PT J AU Guhlke, S Beets, AL Oetjen, K Mirzadeh, S Biersack, HJ Knapp, FF AF Guhlke, S Beets, AL Oetjen, K Mirzadeh, S Biersack, HJ Knapp, FF TI Simple new method for effective concentration of Re-188 solutions from alumina-based W-188-Re-188 generator SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article; Proceedings Paper CT 44th Annual Meeting of the Society-of-Nuclear-Medicine CY JUN 01-06, 1997 CL SAN ANTONIO, TEXAS SP Soc Nucl Med DE Re-188; W-188-Re-188 generator; bolus concentration ID MONOCLONAL-ANTIBODIES; SOMATOSTATIN ANALOG; RE-188-RC-160; RADIOTHERAPY; RHENIUM AB Re-188 is a useful generator-produced radioisotope currently under evaluation for a variety of therapeutic applications, including bone pain palliation and intravascular radiation therapy. Because the W-188 parent is available only in a relatively low specific activity (<0.15-0.19 GBq/mg) from reactor irradiation of enriched W-186, relatively large volumes of 0.9% saline (>15 mL) are required for elution of the 188Re daughter from traditional alumina-based W-188-Re-188 generators. Because these large bolus volumes result in solutions with a relatively low specific volume activity of Re-188 (<1 GBq/mL for the 18.5-GBq generator), the availability of effective methods for eluent concentration is important, Our new approach is based on the use of 0.3 mol/L ammonium acetate as a representative salt of a weak acid instead of saline for generator elution. Methods: After generator elution, the ammonium acetate generator eluent (15-20 mt) is passed through a tandem IC-H Plus cation (Dowex-H)-anion (QMA Light) column system. Exchange of ammonium cations with hydrogen ions on the cation column forms an acetic acid solution containing perrhenate anions from which the macroscopic levels of the acetate anion of the eluent have been effectively removed. Because perrhenic acid is fully dissociated at this pH, the QMA Light column specifically traps the Re-188-perrhenate, which is subsequently eluted with a low volume (<1 mt) of saline. Concentration ratios greater than 20:1 are readily achieved with this method. Results: A typical clinical-scale generator loaded with 19.2 GBq W-188 was used to validate the approach. Saline elution provided 188Re in a 75%-80% yield. Although elution with 0.15 mol/L NH4OAc gave lower yields (55%-60%), use of 0.3 mol/L NH4OAc provided yields comparable with those of saline (70%-75%). W-188 parent breakthrough was not detected after passage of the bolus through the tandem concentration system. Bolus volumes of 15-20 mt, which initially contained as much as 11.1-14.8 GBq Re-188, were readily concentrated to less than 1 mt saline using QMA Light cartridges. The generator was evaluated for more than 3 mo with no decrease in performance. Conclusion: This approach represents a simple, rapid, and effective method using inexpensive disposable components of concentrating solutions of Re-188 for preparation of therapeutic agents. C1 Oak Ridge Natl Lab, Nucl Med Program, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Bonn, Clin Nucl Med, D-5300 Bonn, Germany. RP Knapp, FF (reprint author), Oak Ridge Natl Lab, Nucl Med Program, Div Life Sci, Bldg 4501,Mail Stop 6229,POB 2008, Oak Ridge, TN 37831 USA. NR 38 TC 59 Z9 60 U1 0 U2 2 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD JUL PY 2000 VL 41 IS 7 BP 1271 EP 1278 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 364JF UT WOS:000089888700035 PM 10914921 ER PT J AU Nishimura, M Fujii, S Shehata, AM Kunugi, T McEligot, DM AF Nishimura, M Fujii, S Shehata, AM Kunugi, T McEligot, DM TI Prediction of forced gas flows in circular tubes at high heat fluxes accompanied by laminarization SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE turbulent gas flow; forced convection; heat transfer; laminarization; numerical analysis; turbulence model; Reynolds stress equation model; turbulence heat flux equation model; gas cooled reactor; circular tube ID CLOSURE; MODEL AB The application of high heat fluxes to turbulent gas flows causes significant variation of the gas properties due to the large temperature increase, invalidating the use of design relations such as the popular Dittus-Boelter correlation and of conventional turbulence models. To develop turbulence models for such flows, the predictive capabilities of a Reynolds stress equation model (RSM) with turbulence heat flux equations and of a k-kL-<(u'v')over bar> model were examined. We have employed the turbulence stress-thermal energy gradient production, in the pressure-temperature fluctuatio gradient correlation, for the turbulence heat flux equations, in order to improve the accuracy of predictions for heat transfer accompanied by laminarization. The k-kL-<(u'v')over bar> model has already been validated for gas flows in annular tubes; in this study its applicability to a circular tube was examined. Validations were performed by comparison of predictions with constant fluid properties at fully-established conditions and to experimental measurements extending to laminarization conditions. The turbulence models both predict laminar and turbulent results and the approximate transition Reynolds number for the fully established flow at low heat fluxes. The results predicted with both models also agreed well with data on laminarizing flows. Thus, the models presented here are capable of predicting the flow reasonably from low to high heat fluxes. C1 Kawasaki Heavy Ind Co Ltd, Power Plant Syst Div, Kohto Ku, Tokyo 1368588, Japan. Kawasaki Heavy Ind Co Ltd, Kanto Tech Inst, Noda, Chiba 2788585, Japan. Xerox Corp, Webster, NY 14580 USA. Kyoto Univ, Dept Nucl Engn, Sakyo Ku, Kyoto 6068501, Japan. Idaho Natl Lab, Idaho Falls, ID 83415 USA. Univ Arizona, Tucson, AZ 85721 USA. RP Kawasaki Heavy Ind Co Ltd, Power Plant Syst Div, Kohto Ku, Tokyo 1368588, Japan. EM nishimura-mo@khi.co.jp NR 40 TC 5 Z9 5 U1 0 U2 2 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 JUL PY 2000 VL 37 IS 7 BP 581 EP 594 DI 10.1080/18811248.2000.9714934 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 353XM UT WOS:000089300800004 ER PT J AU Charlton, WS Stanbro, WD Perry, RT AF Charlton, WS Stanbro, WD Perry, RT TI Comparisons of HELIOS, ORIGEN2, and Monteburns calculated Am-241 and Am-243 concentrations to measured values for PWR, BWR, and VVER spent fuel SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE spent fuels; BWR type reactors; PWR type reactors; americium 241; VVER-type pressurized water reactor; americium 243; calculation methods; monte carlo method; concentration ratio; computer code; evaluations; accuracy ID ONLY BURNUP CREDIT; NUCLEAR-FUEL; VALIDATION AB A study was performed at Los Alamos National Laboratory to explore the accuracy of several reactor analysis codes in calculating Am-241 and Am-243 concentrations in light water reactor spent fuel. Calculated higher-actinide concentrations were compared to measured values from the literature for three reactor fuels. The fuel samples were taken from the Mihama Unit 3 pressurized water reactor, the Garigliano boiling water reactor, and a VVER-440. The Am-241 and Am-243 concentrations were calculated using the HELIOS-1.4 lattice-physics code, the ORIGEN2 burnup code, and a linked MCNP/ORIGEN2 code named Monteburns 3.01. Comparisons were made between the calculated and measured values. It was determined that all codes performed consistently well for the Mihama Unit 3 measurements (within +/- 5% for Am-241 and +/- 20% for Am-243) and the Garigliano measurements (within +/- 12% for Am-241 and +/- 12% for Am-243). It was determined that the ORIGEN2 pressurized water reactor libraries are insufficient for the VVER-440 measurements, The HELIOS and MONTEBURNS codes both demonstrated good ability to calculate these isotopes for VVER-440 fuel (+/- 10% for Am-241 and +/- 12% for Am-243). The accuracies of these codes and the associated radiochemical measurements of these higher-actinide isotopes may be insufficient for safeguards and fuel management purposes; thus, development, of new methods and modification to existing data libraries may be necessary in order to enable cost-effective safeguarding of these higher-actinide materials. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM charlton@lanl.gov NR 32 TC 0 Z9 0 U1 0 U2 5 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 JUL PY 2000 VL 37 IS 7 BP 615 EP 623 DI 10.1080/18811248.2000.9714938 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 353XM UT WOS:000089300800008 ER PT J AU Smith, RD Maltrud, ME Bryan, FO Hecht, MW AF Smith, RD Maltrud, ME Bryan, FO Hecht, MW TI Numerical simulation of the North Atlantic Ocean at 1/10 degrees SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID BRAZIL CURRENT RETROFLECTION; HIGH-RESOLUTION MODEL; GULF-STREAM; MESOSCALE VARIABILITY; CIRCULATION MODEL; THERMOHALINE CIRCULATION; TOPEX/POSEIDON ALTIMETRY; SATELLITE ALTIMETRY; KINETIC-ENERGY; TRANSPORT AB In this paper an initial analysis of an 0.1 degrees simulation of the North Atlantic Ocean using a level-coordinate ocean general circulation model forced with realistic winds covering the period 1985-96 is presented. Results are compared to the North Atlantic sector of a global 0.28 degrees simulation with similar surface forcing and to a variety of satellite and in situ observations. The simulation shows substantial improvements in both the eddy variability and the time-mean circulation compared to previous eddy-permitting simulations with resolutions in the range of 1/2-1/6 degrees. The resolution is finer than the zonal-mean first baroclinic mode Rossby radius at all latitudes, and the model appears to be capturing the bulk of the spectrum of mesoscale energy. The eddy kinetic energy constitutes 70% of the total basin-averaged kinetic energy. Model results agree well with observations of the magnitude and geographical distribution of eddy kinetic energy and sea-surface height variability, with the wavenumber-frequency spectrum of surface height anomalies in the Gulf Stream, with estimates of the eddy length scale as a function of latitude, and with measurements of eddy kinetic energy as a function of depth in the eastern basin. The mean circulation also shows significant improvements compared to previous models, although there are notable remaining discrepancies with observations in some areas. The Gulf Stream separates at Cape Hatteras, and its speed and cross-stream structure are in good agreement with current meter data; however, its path is somewhat too far south and its meander envelope too broad to the west of the New England Seamounts. The North Atlantic Current is remarkably well simulated in the model: it exhibits meanders and troughs in its rime-mean path that agree with similar structures seen in float data, although the separation of this current in the region of the "Northwest Corner" is displaced somewhat too far to the northwest. The Azores Current appears in the simulation, perhaps for the first rime in a basin-scale model, and its position, total transport, and eddy variability are consistent with observational estimates. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Smith, RD (reprint author), Univ Calif Los Alamos Natl Lab, T-3,Mail Stop B216, Los Alamos, NM 87545 USA. RI Bryan, Frank/I-1309-2016 OI Bryan, Frank/0000-0003-1672-8330 NR 66 TC 288 Z9 292 U1 0 U2 22 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUL PY 2000 VL 30 IS 7 BP 1532 EP 1561 DI 10.1175/1520-0485(2000)030<1532:NSOTNA>2.0.CO;2 PG 30 WC Oceanography SC Oceanography GA 341GY UT WOS:000088583700003 ER PT J AU Fukui, K Sumpter, BG Noid, DW Yang, C Tuzun, RE AF Fukui, K Sumpter, BG Noid, DW Yang, C Tuzun, RE TI Spectra analysis for macromolecular systems: Chain-length effects in polymer particles SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE polymer particle; normal mode analysis; density of state; heat capacity; Gibbs free energy ID MOLECULAR-DYNAMICS; CRYSTALLINE POLYETHYLENE; REFRACTIVE-INDEX AB A complete set of frequencies for the density of states spectrum g(omega) is obtained for 6000-atom polymer particles involving all 18,000 degrees of freedom. We efficiently generate the particle using molecular dynamics and molecular mechanics, and systematically analyze the spectra and thermal properties as a function of chain lengths: from one to 100 monomers. The density of states spectrum g(omega) shows a higher number of low-frequency modes for the polymer particle with a smaller chain length, which results in a higher heat capacity at low temperature. Gibbs free energy was also calculated for the formation of a particle from a crystal as a function of temperature to evaluate thermal stability of those systems. (C) 2000 John Wiley & Sons, Inc. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Computat Sci Program, Brockport, NY 14420 USA. RP Noid, DW (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 36 TC 12 Z9 12 U1 1 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD JUL 1 PY 2000 VL 38 IS 13 BP 1812 EP 1823 PG 12 WC Polymer Science SC Polymer Science GA 322MM UT WOS:000087513400014 ER PT J AU Ameel, TA Papautsky, I Warrington, RO Wegeng, RS Drost, MK AF Ameel, TA Papautsky, I Warrington, RO Wegeng, RS Drost, MK TI Miniaturization technologies for advanced energy conversion and transfer systems SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 2nd International Conference on Advanced Energy Conversion Systems and Related Technologies (RAN98) CY DEC 01-03, 1998 CL NAGOYA UNIV, NAGOYA, JAPAN HO NAGOYA UNIV AB Microfabrication technologies have made possible the development of meso-scale energy conversion and chemical processing systems with microscale features, Scaling effects, such as the linear increase in surface-area-to-volume ratio that affects surface processes such as convection heat transfer, adsorption, and catalytic chemical conversion processes, provide some of the motivation for the miniaturization efforts. Other mechanical, thermal, and fluid scaling effects are presented. Fabrication and material limitations, as well as scaling effects, must be considered in the design process and may result in miniaturized systems that are considerably different than their full-scale prototypes, System and component development efforts at Battelle Pacific Northwest National Laboratories are highlighted. A fuel atomizer for gas turbine engines and a multicomponent fuel processor for the production of on-demand hydrogen are microscale components that show potential for improving current large-scale systems. Complete miniaturized systems such as a gas turbine, a vapor-absorption heat pump, and a Joule-Thompson cryocooler could be used for mobile power production and cooling of electronics and individuals. Components for miniaturized systems include microbatteries with multiple definable voltage levels and a high degree of integratability and a combustor/evaporator for methane combustion with low levels of harmful emissions. C1 Univ Utah, Dept Mech Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Bioengn, Salt Lake City, UT 84112 USA. Michigan Technol Univ, Coll Engn, Houghton, MI 49931 USA. Pacific NW Lab, Elect & Chem Proc Grp, Richland, WA 99352 USA. Pacific NW Lab, Dept Energy Sci, Richland, WA 99352 USA. RP Ameel, TA (reprint author), Univ Utah, Dept Mech Engn, 50 S Campus Ctr Dr,Room 2202, Salt Lake City, UT 84112 USA. NR 15 TC 8 Z9 8 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 2000 VL 16 IS 4 BP 577 EP 582 DI 10.2514/2.5642 PG 6 WC Engineering, Aerospace SC Engineering GA 336NJ UT WOS:000088308900009 ER PT J AU Hamada, M Weerahandi, S AF Hamada, M Weerahandi, S TI Measurement system assessment via generalized inference SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article DE confidence intervals; gauge R & R study; repeatability; reproductibility ID CONFIDENCE-INTERVALS; VARIANCE-COMPONENTS; P-VALUES; TESTS AB Good measurement systems are an important requirement for a successful quality improvement or statistical process control program. A measurement system is assessed by performing a designed experiment known as a gauge repeatability acid reproducibility (R & R) study. Confidence intervals for the parameters which describe measurement system quality are an important part of analyzing the data from a gauge R & R study In this paper, we show how confidence intervals can easily be obtained using the recently developed generalized inference methodology, which can be calculated by exact numerical integration or can be approximated to any desired accuracy using simulation. The methodology is demonstrated on data from two gauge R & R studies based on two-way layouts. The approach is simple and general enough to extend the results to higher-way layouts. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Telcordia Technol, Morristown, NJ 07960 USA. RP Hamada, M (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 32 Z9 35 U1 0 U2 1 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA ASQC MEMBERSHIP MANAGER 611 E. WISCONSIN AVENUE, MILWAUKEE, WI 53202 USA SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD JUL PY 2000 VL 32 IS 3 BP 241 EP 253 PG 13 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA 333HZ UT WOS:000088126000005 ER PT J AU Chen, YL Lewis, JWL Parigger, C AF Chen, YL Lewis, JWL Parigger, C TI Probability distribution of laser-induced breakdown and ignition of ammonia SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID PREMIXED GASES; FLAME; NITROGEN; NH AB Laser-induced breakdown and ignition of atmospheric pressure ammonia and ammonia/oxygen mixtures were studied using a nominal 7-ns pulsed Nd : YAG laser source. The probability distribution functions (pdf) for the breakdown and ignition events were determined. For the pdf measurements, the NH-radical ground electronic state was observed using resonant laser-induced fluorescence (LIF), and comparison of the LIF and spontaneous emission of the NH A-state emission is shown. The NH X-state concentration is shown to give a reliable indicator of ignition at 5 mu s following breakdown. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Tennessee, Inst Space, Ctr Laser Applicat, Tullahoma, TN 37388 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Parigger, C (reprint author), Univ Tennessee, Inst Space, Ctr Laser Applicat, Tullahoma, TN 37388 USA. RI Parigger, Christian/M-4925-2013 OI Parigger, Christian/0000-0003-1286-7405 NR 26 TC 13 Z9 13 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL 1 PY 2000 VL 66 IS 1 BP 41 EP 53 DI 10.1016/S0022-4073(99)00166-1 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 298RR UT WOS:000086153400004 ER PT J AU Rice, SF Wickham, JJ AF Rice, SF Wickham, JJ TI Hydrogen Raman linewidths in supercritical water and carbon dioxide SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article ID Q-BRANCH; ROOM-TEMPERATURE; LINE-PROFILES; FOREIGN GASES; H-2; TRANSITIONS; SPECTRA; N-2; PARAMETERS; WIDTHS AB H-2 Raman linewidths provide a probe of intermolecular potentials and have been examined in the past to explore collisional dynamic characteristics in high-pressure gas mixtures. We report the measurement of H-2 Delta v = 1 Q-branch lines, Q(0)-Q(5), and pure rotational lines, S(0)-S(5), in supercritical water and high-pressure carbon dioxide at 450 degrees C and pressures up to 50 MPa, The data are analyzed by separating the contributions to the line broadening due to different collisional processes characterized as vibrational dephasing, inelastic J-changing and rotational reorientation, The linear broadening coefficients for these different processes are determined. Both water and carbon dioxide are shown to be much more effective at disturbing H-2 rotation than other less polar molecules that have been examined in the past, Water is shown to be much more effective at causing inelastic J-changing relaxation than carbon dioxide, Elastic rotational reorientation rates are comparable for both colliders, Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Rice, SF (reprint author), Sandia Natl Labs, Combust Res Facil, MS-9052,POB 969, Livermore, CA 94551 USA. NR 29 TC 5 Z9 5 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD JUL PY 2000 VL 31 IS 7 BP 619 EP 624 DI 10.1002/1097-4555(200007)31:7<619::AID-JRS586>3.0.CO;2-R PG 6 WC Spectroscopy SC Spectroscopy GA 345CA UT WOS:000088796800012 ER PT J AU Gist, DH Turner, TW Congdon, JD AF Gist, DH Turner, TW Congdon, JD TI Chemical and thermal effects on the viability and motility of spermatozoa from the turtle epididymis SO JOURNAL OF REPRODUCTION AND FERTILITY LA English DT Article ID SPERM MOTILITY; STORAGE; SEMEN; INITIATION; FISH AB The viability and motility of spermatozoa harvested from the epididymides of turtles were estimated to elucidate properties that might enable them to be stored over long periods of time. Spermatozoa from the painted turtle, Chrysemys picta, were analysed and compared with spermatozoa from two other turtles, Trachemys scripta and Sternotherus odoratus using the Cellsoft analysis system for videotaped images. Spermatozoa from C. picta and T. scripta, suspended in F-10 medium, showed low motility (3-6% motile) and motion velocities, whereas the motility of spermatozoa from S. odoratus was higher (40% motile). Spermatozoa from C. picta and S, odoratus, but not T. scripta, had higher motilities and motion velocities when incubated at 2 degrees C before analyses. C. picta spermatozoa were unresponsive to calcium concentrations ranging from 10(-8) to 10(-1) mol l(-1), potassium concentrations ranging from 0.1 to 10 mmol l(-1), and to pH values in the range 5.9-8.4. Spermatozoa from C. picta were sensitive to hypoosmotic media, and showed reduced motility at 25% of normal osmolarity and no motility at 10% of normal osmolarity. Distorted cells and missing flagellae were noted at 50% of normal osmolarity. C. picta spermatozoa were viable up to 40 days after harvest when incubated at 4 degrees C; during this time, both motility and motion velocity were increased in response to 0.5 mmol 3-isobutyl-1-methylxanthine l(-1). Spermatozoa from turtles have osmotic properties and resistance to changing chemical environments similar to spermatozoa from other vertebrates that have internal fertilization, and appear to be stable over long periods of time compared with spermatozoa from other vertebrate species. C1 Univ Cincinnati, Dept Biol Sci, Cincinnati, OH 45221 USA. NIOSH, Div Biomed & Behav Sci, Expt Toxicol Branch, Cincinnati, OH 45226 USA. Savannah River Ecol Lab, Aiken, SC 29801 USA. RP Gist, DH (reprint author), Univ Cincinnati, Dept Biol Sci, Cincinnati, OH 45221 USA. NR 28 TC 22 Z9 24 U1 0 U2 4 PU JOURNALS OF REPRODUCTION FERTILITY LTD PI CAMBRIDGE PA 22 NEWMARKET RD, CAMBRIDGE CB5 8DT, ENGLAND SN 0022-4251 J9 J REPROD FERTIL JI J. Reprod. Fertil. PD JUL PY 2000 VL 119 IS 2 BP 271 EP 277 DI 10.1530/reprod/119.2.271 PG 7 WC Reproductive Biology SC Reproductive Biology GA 335BZ UT WOS:000088223300012 PM 10864839 ER PT J AU Ganguli, AK Guloy, AM Corbett, JD AF Ganguli, AK Guloy, AM Corbett, JD TI Concerning the Ca(2-x)Mg(x)Tt systems, Tt = Sn, Pb SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID PHASE; TIN AB The Ca(2)Tt-Mg(2)Tt systems for tetrel Tt = Sn, Pb each contain a single Ca(2-x)Mg(x)Tt phase with the Co2Si structure (Pnma) over 0 less than or equal to x less than or equal to 1, beyond which Mg(2)Tt (inverse CaF2-type, x = 2) appear. At x = 1, Mg occupies the unique position in the tricapped trigonal prisms (TCTP) of cations about tin that is not involved in the formation of chains of edge-shared prisms, but rather it participates in interchain bonding via face-capping functions on adjoining trigonal prisms. This substitution produces notably less distortion in the TCTP units than in Ca(2)Tt. Resistivity data for the tin system show changes from a semiconductor for Ca2Sn to a poor metal at CaMgSn, rho similar to 180 mu Omega cm at 240 K. Only very small and approximately temperature-independent magnetic susceptibilities are found over the same range, values that are only fractions of the standard diamagnetic core corrections. The systems behave as typical Zintl phases containing Ca2+, Mg2+ and Tt(4-) oxidation states. (C) 2000 Academic Press. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 16 TC 13 Z9 14 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 2000 VL 152 IS 2 BP 474 EP 477 DI 10.1006/jssc.2000.8715 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 332CT UT WOS:000088056400022 ER PT J AU Mozharivskyj, Y Franzen, HF AF Mozharivskyj, Y Franzen, HF TI Crystal structure and bonding in the rare-earth rich ternary pnictides RE5M2X (RE = Y, Gd, Tb, Dy, Ho, Er, Tm, Lu; M = Ni, Pd; X = Sb, Bi) SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MAGNETIC-PROPERTIES; ELECTRONIC-STRUCTURE; LN=LA-ND; ANTIMONIDES; NICKEL; SUBSTITUTION; SM; CU AB Eleven new rare-earth antimonides and bismuthides RE5M2X (see Table 1) have been synthesized and characterized by X-ray powder methods. The compounds are isostructural to the previously reported pnictides RE5M2X and adopt the Mo5B2Si structure (space group 14/mcm, an ordered version of Cr5B3). Atomic and thermal parameters have been refined for Ho,Ni,Sb and Ho,Ni,Bi. Extended Huckel tight-binding calculations performed on Y5Ni2Sb show strong Y-Ni, Y-Sb, and Y-Y interactions. (C) 2000 Academic Press. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Franzen, HF (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 37 TC 19 Z9 19 U1 0 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 2000 VL 152 IS 2 BP 478 EP 485 DI 10.1006/jssc.2000.8716 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 332CT UT WOS:000088056400023 ER PT J AU Ling, CD Argyriou, DN Wu, GQ Neumeier, JJ AF Ling, CD Argyriou, DN Wu, GQ Neumeier, JJ TI Neutron diffraction study of La2Ni2O7: Structural relationships among n=1, 2, and 3 phases Lan+1NinO3n+1 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID ELECTRONIC-PROPERTIES; BEHAVIOR; VALENCE; PR; ND AB Structural relationships among the n = 1, 2, and 3 members of the Ruddlesden-Popper series Lan+1NinO3n+1 are used to predict a lowering of symmetry in the n = 2 phase, subsequently observed and refined against neutron powder diffraction data. Resistivity and magnetic susceptibility measurements are presented for n = 2 and 3 that suggest the possibility of a further symmetry lowering at low temperature, such as occurs for n = 1; however, no evidence for this is found in low-temperature neutron data. Re-refinement of the n = 3 phase reveals significant strain within the perovskite-type layers that appears to increase with n, This strain is used to explain the absence of low temperature phase transformations for n > 1, In the absence of a phase transformation, possible origins for the resistivity and susceptibility anomalies are considered, (C) 2000 Academic Press. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RP Ling, CD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ling, Chris D/B-2228-2009 OI Ling, Chris D/0000-0003-2205-3106 NR 17 TC 24 Z9 24 U1 2 U2 15 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 2000 VL 152 IS 2 BP 517 EP 525 DI 10.1006/jssc.2000.8721 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 332CT UT WOS:000088056400028 ER PT J AU Early, JT London, RA AF Early, JT London, RA TI Dust grain damage to interstellar laser-pushed lightsail SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID EXPANSION; PLASMA; VACUUM AB Lightsails pushed by laser beams to velocities around 0.1c have been proposed as propulsion systems for interstellar travel. These lightsails will undergo high-energy collisions with small (similar to 1-mu m) dust grains in the interstellar environment. For a very thin beryllium sail, the grains pass through the sail with only 10(-4) of the energy coupled into the sail. The resulting damaged area is not significantly larger than the cross section of the dust grain. Only a small fraction (10(-6)-10(-4)) of the sail will be destroyed by these 1-mu m-sized grains during the sail acceleration. For thick sails or larger grains, the damage can be more significant. C1 Univ Calif Lawrence Livermore Natl Lab, Laser Directorate, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Div 10, Livermore, CA 94550 USA. RP Early, JT (reprint author), Univ Calif Lawrence Livermore Natl Lab, Laser Directorate, POB 808, Livermore, CA 94550 USA. NR 13 TC 0 Z9 0 U1 2 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2000 VL 37 IS 4 BP 526 EP 531 DI 10.2514/2.3595 PG 6 WC Engineering, Aerospace SC Engineering GA 341HD UT WOS:000088584200017 ER PT J AU Whitehead, JC Brewster, GT AF Whitehead, JC Brewster, GT TI High-pressure-pumped hydrazine for Mars sample return SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB A monopropellant single stage can lift geological samples from Mars to orbit. The proposed propulsion system uses previously demonstrated miniature pump-fed hydrazine technology. Loading the propellant just prior to operation avoids the prohibitive structural, thermal, and safety constraints that existed during earlier mission phases. A 100-kg Mars liftoff mass is 86% hydrazine, < 6% propulsion hardware, and > 6% payload and guidance. The useful mass delivered to Mars can be increased by also using pump-fed hydrazine for landing. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Primex Aerosp Co, Redmond, WA 98073 USA. RP Whitehead, JC (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 97009, Livermore, CA 94550 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JUL-AUG PY 2000 VL 37 IS 4 BP 532 EP 538 DI 10.2514/2.3596 PG 7 WC Engineering, Aerospace SC Engineering GA 341HD UT WOS:000088584200018 ER PT J AU Chialvo, AA Kusalik, PG Kalyuzhnyi, YV Cummings, PT AF Chialvo, AA Kusalik, PG Kalyuzhnyi, YV Cummings, PT TI Applications of integral equation calculations to high-temperature solvation phenomena SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE high-temperature solvation thermodynamic; molecular asymmetry; supercritical fluids; solvation formalism; aqueous electrolyte solutions; solvation effects on kinetic rate constants; solute-induced effects; compressibility-driven phenomena ID PARTIAL MOLAR VOLUMES; AQUEOUS-ELECTROLYTE SOLUTIONS; MEAN SPHERICAL APPROXIMATION; ORNSTEIN-ZERNIKE EQUATION; NEAR-CRITICAL CONDITIONS; LASER FLASH-PHOTOLYSIS; INFINITE DILUTION; GAS SOLUBILITY; SUPERCRITICAL CONDITIONS; COMPUTER-SIMULATION AB The solvation of infinitely dilute solutes in supercritical solvents is illustrated by integral equation calculations, according to a recently proposed molecular-based formalism that characterizes the solvent environment around individual species and connects ii to the resulting macroscopic solvation behavior. The formalism is applied to the analysis of the solubility enhancement of nonelectrolyte species, the solvent effect in kinetic rate constants, and the solvation of ionic species. Finally, some relevant theoretical implications are discussed regarding the modeling of high-temperature solutions. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. 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. Dalhousie Univ, Dept Chem, Halifax, NS B3H 4J3, Canada. Inst Condensed Matter Phys, UA-290011 Lviv, Ukraine. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Chialvo, AA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Cummings, Peter/B-8762-2013; OI Cummings, Peter/0000-0002-9766-2216; Chialvo, Ariel/0000-0002-6091-4563 NR 60 TC 9 Z9 9 U1 0 U2 0 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 JUL PY 2000 VL 100 IS 1-2 BP 167 EP 199 DI 10.1023/A:1018639728431 PG 33 WC Physics, Mathematical SC Physics GA 361TF UT WOS:000089739400012 ER PT J AU Baker, GA Johnson, JD AF Baker, GA Johnson, JD TI The Pauli principle and the restricted primitive model SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE equations of state; primitive model; quantum perturbation theory; classical perturbation theory; hydrogen ID DEBYE-HUCKEL THEORY; COULOMBIC CRITICALITY; IONIC FLUIDS; MONTE-CARLO; ELECTROLYTE; DIMENSIONS; SPHERES AB The restricted primitive model is an electrically neutral, classical model consisting of hard spheres charged either +q or -q. We show that, by appropriately selecting the diameter of the hard spheres, the pressure when q = 0 can be made equal to that for a fluid of Maxwell-Boltzmann point ions and an ideal Fermi gas of electrons. We compare the series expansion of these classical and quantum systems and find that, except for intermediate de Broglie density and moderate to strong electrical interaction strength, the restricted primitive model gives a reasonable representation of the pressure of the corresponding quantum system, Much of the current interest, however, has been focused on the above, excepted region. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Baker, GA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 31 TC 0 Z9 0 U1 0 U2 0 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 JUL PY 2000 VL 100 IS 1-2 BP 233 EP 242 PG 10 WC Physics, Mathematical SC Physics GA 361TF UT WOS:000089739400016 ER PT J AU Hoover, WG Posch, HA Castillo, VM Hoover, CG AF Hoover, WG Posch, HA Castillo, VM Hoover, CG TI Computer simulation of irreversible expansions via molecular dynamics, smooth particle applied mechanics, Eulerian, and Lagrangian continuum mechanics SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE irreversible expansion; smooth particles; Eulerian continuum mechanics; Lagrangian continuum mechanics ID ENTROPY AB We simulate the far-from-equilibrium irreversible expansion or a compressed ideal gas in two space dimensions. For this problem the particle trajectories from conventional smooth particle applied mechanics are isomorphic to those from a corresponding molecular dynamics simulation. The smooth-particle "weight function" used to describe the expanding gas is identical to the pair potential governing the molecular dynamics simulation. These many-body particle simulations are compared with those using a modified smooth-particle algorithm invented by Monaghan, as well as with those based on conventional grid-bused Eulerian and Lagrangian methods. C1 Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Methods Dev Grp, Dept Mech Engn, Livermore, CA 94551 USA. Univ Vienna, Inst Expt Phys, A-1090 Vienna, Austria. RP Hoover, WG (reprint author), Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. NR 9 TC 6 Z9 6 U1 0 U2 2 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 JUL PY 2000 VL 100 IS 1-2 BP 313 EP 326 DI 10.1023/A:1018656132065 PG 14 WC Physics, Mathematical SC Physics GA 361TF UT WOS:000089739400020 ER PT J AU Watkins, JP Eisele, GR Matthews, KO AF Watkins, JP Eisele, GR Matthews, KO TI Occupational medical program alcohol screening - Utility of the CAGE and BMAST SO JOURNAL OF SUBSTANCE ABUSE TREATMENT LA English DT Article DE CAGE; BMAST; alcohol screening; occupational medicine; assessment ID IDENTIFICATION TEST AUDIT; BRIEF MAST; QUESTIONNAIRE; DISORDERS; VALIDATION; VALIDITY; CONSUMPTION; INSTRUMENT; DEPENDENCE; SCORES AB Alcohol consumption is a primary or secondary factor in many work-related accidents, suicides, homicides, violent crimes, and motor vehicle accidents. The absentee rate in alcoholics is 3.8 to 8.3 times greater than that for nonalcoholic workers. The purpose of this research was to evaluate the effectiveness of two interview questionnaires-the Brief Michigan Alcoholism Screening Test (BMAST) and the CAGE (cut down, annoyed by criticism, guilty about drinking, and eye-opener drinks). The validity of the BMAST and the CAGE as screening tools for alcohol problems has been verified in a number of nonworkplace settings. If they prove to be as effective for screening workers in an occupational medical setting, follow-up definitive diagnoses could result in earlier detection of alcohol problems and allow prompt intervention. Positive outcomes could include a safer workplace, less absenteeism, improved worker productivity, and a reduction in personal and family problems caused by drinking. (C) 2000 Elsevier Science Inc. All rights reserved. C1 Oak Ridge Inst Sci & Educ, Ctr Human Reliabil Studes, Oak Ridge, TN 37831 USA. US DOE, Off Occupat Med & Med Surveillance, Washington, DC 20585 USA. RP Eisele, GR (reprint author), Oak Ridge Inst Sci & Educ, Ctr Human Reliabil Studes, POB 117,Mail Stop 50, Oak Ridge, TN 37831 USA. NR 23 TC 5 Z9 6 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0740-5472 J9 J SUBST ABUSE TREAT JI J. Subst. Abus. Treat. PD JUL PY 2000 VL 19 IS 1 BP 51 EP 57 DI 10.1016/S0740-5472(99)00099-9 PG 7 WC Psychology, Clinical; Substance Abuse SC Psychology; Substance Abuse GA 328HG UT WOS:000087844200008 PM 10867301 ER PT J AU George, MJ AF George, MJ TI XAS-Collect: a computer program for X-ray absorption spectroscopic data acquisition SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray absorption spectroscopy; XAS; EXAFS; data acquisition AB A computer program for X-ray absorption spectroscopy (XAS) data acquisition, called XAS-Collect, is described. The software employs the X Windows system to provide a pull-down menu, dialog-box style of graphical user interface. The software provides state-of-the-art features while still being sufficiently simple for novice users. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP George, MJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, POB 4349,MS 69, Stanford, CA 94309 USA. NR 4 TC 32 Z9 32 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JUL PY 2000 VL 7 BP 283 EP 286 DI 10.1107/S090904950000683X PN 4 PG 4 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 329DT UT WOS:000087891400014 PM 16609209 ER PT J AU Chen, D Gilbert, CJ Ritchie, RO AF Chen, D Gilbert, CJ Ritchie, RO TI In situ measurement of fatigue crack growth rates in a silicon carbide ceramic at elevated temperatures using a DC potential system SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE crack monitoring; electrical-potential method; ceramics; fatigue crack propagation; elevated temperatures ID B-C ADDITIONS; CYCLIC FATIGUE; BEHAVIOR; PROPAGATION AB The understanding of the mechanisms of fatigue-crack propagation in advanced ceramics at elevated temperatures (>800 degrees C) has in part been hampered by the experimental difficulty in directly measuring crack lengths, and hence crack growth rates, at such high temperatures. In this study, we show how the direct-current (DC) electrical-potential technique, which has been used for such measurements in metallic materials for over 30 years, can be successfully utilized to monitor fatigue crack growth rates in situ in a silicon carbide ceramic at temperatures between 850 and 1300 degrees C, because of the electrical conductivity in SiC at these temperatures. In addition to providing a highly efficient means of collecting such data, this approach offers several significant advantages over the techniques that have been used to date for advanced ceramics, particularly in avoiding artifacts due to thermal fatigue and oxidation from repeated exposure to air and/or lower temperatures while making measurements. Effects of parameters such as load ratio and loading frequency are examined, both on crack growth behavior and the accuracy of measurement. With appropriate considerations, electrical-potential calibrations determined at ambient temperatures in metallic materials can be applied readily to elevated temperature measurements in silicon carbide. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Chen, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 24 TC 11 Z9 11 U1 1 U2 5 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JUL PY 2000 VL 28 IS 4 BP 236 EP 241 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 338MD UT WOS:000088423000002 ER PT J AU Sigmund, WM Bell, NS Bergstrom, L AF Sigmund, WM Bell, NS Bergstrom, L TI Novel powder-processing methods for advanced ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Review ID ATOMIC-FORCE MICROSCOPY; HAMAKER CONSTANTS; LINEAR VISCOELASTICITY; POLYMER-SOLUTIONS; ADSORBED POLYMER; HYDRATION FORCES; SURFACE FORCES; GEL POINT; INTERFACE; SUSPENSIONS AB Novel approaches for optimized powder processing of advanced ceramics are reviewed with an emphasis on direct-casting methods and solid freeform fabrication techniques. The fundamental principles for green body formation are discussed; a distinction is made between physical and chemical gels based on the nature of the induced gelation. An overview of the properties of dense suspensions is presented, with a focus on the factors controlling the maximum solids loading. Recent work on direct measurements of interparticle forces in ceramic systems is presented and related to rheological properties. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87123 USA. Inst Surface Chem, S-11486 Stockholm, Sweden. RP Sigmund, WM (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RI Sigmund, Wolfgang/B-2856-2008; Bergstrom, Lennart/F-2938-2011 OI Bergstrom, Lennart/0000-0002-5702-0681 NR 128 TC 321 Z9 337 U1 11 U2 93 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 2000 VL 83 IS 7 BP 1557 EP 1574 PG 18 WC Materials Science, Ceramics SC Materials Science GA 333HF UT WOS:000088124300001 ER PT J AU Summers, EM Akinc, M AF Summers, EM Akinc, M TI Wick debinding of molybdenum-silicon-boron extrudates SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Wick debinding was investigated as possible means of binder removal for the Mo-Si-B extrudates. With increased temperature the amount of hinder wicked out of the extrudate increased because of a decrease in viscosity, 2513 mPa.s at 75 degrees C down to 7 mPa.s at 250 degrees C. The permeability of the binder in the 1 mu m wicking powder was higher than that in the 0.05 mu m powder, 3.1 x 10(-13) m(2) compared to 6.024 x 10(-15) m(2). The amount of hinder removed at a given temperature was considerably lower, which could be attributed to the larger capillary pressure difference between the 0.05 pm nick and the extrudate (1.55 x 10(5) Pa compared to 1.46 x 10(4) Pa for the 1 mu m powder), Wicking removed approximately 80% of the binder in <10 h at 250 degrees C with no defect formation. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Summers, EM (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 9 TC 5 Z9 5 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 2000 VL 83 IS 7 BP 1670 EP 1674 PG 5 WC Materials Science, Ceramics SC Materials Science GA 333HF UT WOS:000088124300016 ER PT J AU Zheng, J Unal, O Akinc, M AF Zheng, J Unal, O Akinc, M TI Green state joining of silicon carbide using polycarbosilane SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMICS AB Green state joining of SIC was investigated using a paste consisting of polycarbosilane polymer and SIC powder. The joining process and densification were described, Initial experiments resulted in the formation of symmetrical black bands and cracks on both sides of the joint. However, with modifications in processing conditions, the cracks were eliminated and the resulting joints were indistinguishable from the matrix. The flexural strength of joined samples was measured to be 233 MPa, which was comparable to that of the control sample with similar density. As the applied pressure during joining was increased from 33 to 138 MPa, the strength of the joined samples increased from 180 to 250 MPa. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Zheng, J (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 15 TC 25 Z9 28 U1 0 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 2000 VL 83 IS 7 BP 1687 EP 1692 PG 6 WC Materials Science, Ceramics SC Materials Science GA 333HF UT WOS:000088124300019 ER PT J AU Schmidt, TJ Paulus, UA Gasteiger, HA Alonso-Vante, N Behm, RJ AF Schmidt, TJ Paulus, UA Gasteiger, HA Alonso-Vante, N Behm, RJ TI Oxygen reduction on Ru1.92Mo0.08SeO4, Ru/carbon, and Pt/carbon in pure and methanol-containing electrolytes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PT-RU ALLOYS; FUEL-CELL; DISK ELECTRODE; POLYMER-ELECTROLYTE; SURFACE; ELECTROOXIDATION; ELECTROCATALYST AB The oxygen reduction reaction (ORR) activity of a Ru1.92Mo0.08SeO4 catalyst, a Vulcan XC72-supDortcd Ru catalyst and, for comparison, a Vulcan XC72-supported Pt catalyst was studied with a rotating ring-disk electrode. The very similar reaction characteristics of the two Ru catalysts in pure and CH3OH-containing H2SO4 electrolyte, which differ markedly from those of the Pt catalyst, indicate that the reactive centers in both Ru catalysts must be identical. They are highly selective (>95%) toward reduction to H2O (four electron pathway), independent of the presence of methanol. In the latter case, they are 100% selective toward the ORR, i.e., completely methanol tolerant, while the ORR on Pt catalysts is accompanied by significant CH3OH oxidation. Based on mass specific current densities, however, the Ru catalysts are significantly less active than the standard Pt catalysts. Only at methanol concentrations above 10-30 mM does their methanol tolerance make them more active than Pt/Vulcan. Implications for their use as cathode catalysts in a direct methanol fuel cell are discussed. (C) 2000 The Electrochemical Society. C1 Univ Ulm, Abt Oberflachenchem & Katalyse, D-89069 Ulm, Germany. Univ Poitiers, CNRS, UMR 6503, Lab Electrocatalysis, F-86022 Poitiers, France. RP Schmidt, TJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Schmidt, Thomas/A-2586-2010; OI Schmidt, Thomas/0000-0002-1636-367X; Alonso-Vante, Nicolas/0000-0002-6311-9258 NR 27 TC 174 Z9 178 U1 6 U2 34 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 JUL PY 2000 VL 147 IS 7 BP 2620 EP 2624 DI 10.1149/1.1393579 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 333HX UT WOS:000088125800033 ER PT J AU Richman, BA Aniolek, KW Kulp, TJ Bisson, SE AF Richman, BA Aniolek, KW Kulp, TJ Bisson, SE TI Continuously tunable, single-longitudinal-mode, pulsed mid-infrared optical parametric oscillator based on periodically poled lithium niobate SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID LASER-ABSORPTION SPECTROSCOPY; RING-DOWN SPECTROSCOPY; CAVITY RING; AMPLIFIER; LINBO3; GENERATION AB We present theoretical predictions and experimental results of a mid-infrared optical parametric oscillator (OPO) leased on periodically poled lithium niobate. An air-space intracavity etalon causes our OPO to oscillate on a single longitudinal mode. Continuous frequency tuning of this mode is achieved by simultaneous adjustment of the etalon mirror spacing and the OPO resonator length with piezoelectric translators. We achieved 10 cm(-1) of continuous frequency tuning and more than 10 cm(-1) of mode-hop tuning. The OPO is pumped with 200 mu J/pulse by a seeded, 1-kHz, Q-switched Nd:YAG laser and provides as much as 10 mu J of energy in both the idler near the 3-mu m wavelength and in the signal near the 1.6-mu m wavelength. We obtained a resolution of 0.01 cm(-1) with the idler when measuring the spectrum of the Q branch of the methane C-I-I stretch under Doppler-limited conditions. (C) 2000 Optical Society of America [S0740-3224(00)01207-8]. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Richman, BA (reprint author), Informed Diagnost, 1050 E Duane Ave,Suite I, Sunnyvale, CA 94086 USA. NR 25 TC 14 Z9 14 U1 0 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 JUL PY 2000 VL 17 IS 7 BP 1233 EP 1239 DI 10.1364/JOSAB.17.001233 PG 7 WC Optics SC Optics GA 331WN UT WOS:000088041800018 ER PT J AU Ruffner, JA Sault, AG Rodriguez, MA Tissot, RG AF Ruffner, JA Sault, AG Rodriguez, MA Tissot, RG TI Deposition and characterization of highly oriented Mg-3(VO4)(2) thin film catalysts SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WA SP Amer Vacuum Soc ID MG-O CATALYSTS; OXIDATIVE DEHYDROGENATION; PROPANE AB Magnesium vanadates are potentially important catalytic materials for the conversion of alkanes to alkenes via oxidative dehydrogenation. However, little is known about the active sites at which the catalytic reactions take place. It may be possible to obtain a significant increase in the catalytic efficiency if the effects of certain material properties on the surface reactions could be quantified and optimized through the use of appropriate preparation techniques. Given that surface reactivity is often dependent upon surface structure and that the atomic level structure of the active sites in these catalysts is virtually unknown, we desire thin film samples consisting of a single magnesium vanadate phase and a well defined crystallographic orientation in order to reduce the complexity and simplify the study of active sites. We report on the use of reactive rf sputter deposition to fabricate very highly oriented, stoichiometric Mg-3(VO4)(2) thin films for use in these surface analysis studies. Deposition of samples onto amorphous substrates resulted in very poor crystallinity. However, deposition of Mg-3(VO4)(2) Onto well-oriented, lattice-matched thin film "seed" layers such as Ti(0001), Au(lll), or Pt(lll) resulted in very strong preferential (042) crystallographic orientation (pseudohexagonal oxygen planes parallel to the substrate). This strong preferential growth of the Mg-3(VO4)(2) suggests epitaxial (single-crystal) growth of this mixed metal oxide on the underlying metal seed layer. The effects of the seed layer material, deposition temperature, and postdeposition reactive treatments on thin film properties such as stoichiometry, crystallographic orientation, and chemical interactions will be discussed. (C) 2000 American Vacuum Society. [S0734-2101(00)00504-2]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jaruffn@sandia.gov NR 12 TC 4 Z9 4 U1 0 U2 6 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD JUL-AUG PY 2000 VL 18 IS 4 BP 1928 EP 1932 DI 10.1116/1.582448 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000072 ER PT J AU Nelson, AJ Reynolds, JG Roos, JW AF Nelson, AJ Reynolds, JG Roos, JW TI Core-level satellites and outer core-level multiplet splitting in Mn model compounds SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID RAY PHOTOELECTRON-SPECTROSCOPY; FE INSULATING COMPOUNDS; PHOTOEMISSION SPECTRA; DIHALIDES; ORIGIN AB We report a systematic study of the Mn 2p. 3s, and 3p core-level photoemission and satellite structures for Mn model compounds. Charge transfer from the ligand state to the 3d metal state is observed and is distinguished by prominent shake-up satellites. We also observe that the Mn 3s multiplet splitting becomes smaller as the Mn oxidation state increases, and that 3s-3d electron correlation reduces the branching ratio of the S-7:S-5 states in the Mn 3s spectra. In addition, as the ligand electronegativity decreases, the spin-state purity is lost in the 3s spectra, as evidenced by peak broadening. Our results are best understood in terms of the configuration-interaction model including intrashell electron correlation, charge transfer, and final-state screening. (C) 2000 American Vacuum Society. [S0734-2101(00)07304-8]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Ethyl Corp, Richmond, VA 23217 USA. RP Nelson, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 16 TC 51 Z9 51 U1 1 U2 14 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1072 EP 1076 DI 10.1116/1.582302 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800006 ER PT J AU Dang, GT Zhang, AP Mshewa, MM Ren, F Chyi, JI Lee, CM Chuo, CC Chi, GC Han, J Chu, SNG Wilson, RG Cao, XA Pearton, SJ AF Dang, GT Zhang, AP Mshewa, MM Ren, F Chyi, JI Lee, CM Chuo, CC Chi, GC Han, J Chu, SNG Wilson, RG Cao, XA Pearton, SJ TI High breakdown voltage Au/Pt/GaN Schottky diodes SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID RECTIFIERS; DEVICES; GAN AB Au/Pt/GaN Schottky diode rectifiers were fabricated with reverse breakdown voltage (V-RB) UP to 550 V on vertically depleting structures and >2000 V on lateral devices. The figure-of-merit (V-RB)(2)/R-ON, where R-ON is the on-state resistance, had values between 4.2 and 4.8 MW cm(-2). The reverse leakage currents and forward on-voltages were still somewhat higher than the theoretical minimum values, but were comparable to SiC Schottky rectifiers reported in the literature. These devices show promise for use in ultrahigh-power switches. (C) 2000 American Vacuum Society. [S0734-2101(00)00804-6]. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Bell Labs, Murray Hill, NJ 07974 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Dang, GT (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Chyi, Jen-Inn/A-1799-2016 NR 11 TC 14 Z9 14 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1135 EP 1138 DI 10.1116/1.582312 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800018 ER PT J AU Shul, RJ Zhang, L Baca, AG Willison, CG Han, J Pearton, SJ Ren, F AF Shul, RJ Zhang, L Baca, AG Willison, CG Han, J Pearton, SJ Ren, F TI Inductively coupled plasma-induced etch damage of GaN p-n junctions SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID SURFACE-INDUCED DAMAGE; SCHOTTKY DIODES; GALLIUM NITRIDE; DC PLASMA; LOW-NOISE; SEMICONDUCTORS; PHOTODIODES; SIDEWALL; ALGAN; INP AB Plasma-induced etch damage can degrade the electrical and optical performance of III-V nitride electronic and photonic devices. We have investigated the etch-induced damage of an inductively coupled plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN positive-insulating-negative mesa diodes were formed by Cl-2/BCl3/Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions (less than or equal to 500 W), pressures greater than or equal to 2 mTorr, and at ion energies below approximately -275 V. (C) 2000 American Vacuum Society. [S0734-2101(00)00304-3]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 32 TC 43 Z9 45 U1 4 U2 29 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1139 EP 1143 DI 10.1116/1.582313 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800019 ER PT J AU Cao, XA Zhang, AP Dang, GT Ren, F Pearton, SJ Shul, RJ Zhang, L AF Cao, XA Zhang, AP Dang, GT Ren, F Pearton, SJ Shul, RJ Zhang, L TI Schottky diode measurements of dry etch damage in n- and p-type GaN SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID GALLIUM NITRIDE; ELECTRONICS AB n- and p-type GaN was exposed to inductively coupled plasma of N-2, H-2, Ar, or Cl-2/Ar, as a function of source power (0-1000 W) and rf chuck power (20-250 W). For n-GaN, there was a strong reduction in diode reverse breakdown voltage and an increase in forward and reverse currents, while for p-GaN the reverse breakdown voltage increased. These results are consistent with creation of point defects with shallow donor nature that increase the conductivity of initially n-type GaN or decrease the conductivity of p-type GaN. Annealing at 750 degrees C under N-2 produced significant recovery of the electrical properties, while wet etch removal of 500-600 Angstrom, of the surface produced a full recovery. For completed n-type mesa diodes exposed to Ar or Cl-2/Ar discharges, the low bias forward currents increased by several orders of magnitude. The exposed surfaces became N-2 deficient in all cases. (C) 2000 American Vacuum Society. [S0734-2101(00)00104-4]. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cao, XA (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 15 TC 40 Z9 43 U1 6 U2 15 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1144 EP 1148 DI 10.1116/1.582314 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800020 ER PT J AU Berger, A Mitchell, JF Miller, DJ Jiang, JS Bader, SD AF Berger, A Mitchell, JF Miller, DJ Jiang, JS Bader, SD TI Intrinsic and extrinsic magnetic properties of the naturally layered manganites SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID T-C; GIANT MAGNETORESISTANCE; MANGANESE OXIDES; SINGLE-CRYSTALS; LA1.2SR1.8MN2O7; INTERGROWTHS; EXCHANGE; ORDER AB Structural and magnetic properties of the two-layered Ruddlesden-Popper phase SrO(La1-xSrxMnO3)(2) with x=0.3-0.5 are highlighted. Intrinsic properties of these naturally layered manganites include a "colossal" magnetoresistance, a composition-dependent magnetic anisotropy, and almost no remanence. Above the Curie temperature there is a nonvanishing extrinsic magnetization attributed to intergrowths (stacking faults in the layered structure). These lattice imperfections consist of additional or missing manganite lagers, as observed in transmission electron microscopy. Their role in influencing the properties of the host material is highlighted. (C) 2000 American Vacuum Society, [S0734-2101(00)01404-4]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bader, SD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 26 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1239 EP 1246 DI 10.1116/1.582333 PN 1 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800040 ER PT J AU Schumann, FO Willis, RF Tobin, JG AF Schumann, FO Willis, RF Tobin, JG TI Surface-sensitive, element-specific magnetometry with x-ray linear dichroism SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID MAGNETIC DICHROISM; ULTRATHIN FILMS; CU(100); ALLOY; FE; PHOTOEMISSION; INSTABILITY; TRANSITION; GROWTH; IRON AB It is shown that the x-ray magnetic linear dichroism (XMLD) in x-ray photoemission signal can be used to monitor the element specific magnetic moments in ultra thin alloy films. Comparison with recent superconducting quantum interference device data provides a quantitative check that demonstrates that the total magnetization derived from summing the constituent elemental moments changes with the composition of the alloy. This is illustrated by the contrasting behavior of FeNi and CoNi alloys. (C) 2000 American Vacuum Society. [S0734-2101(00)14704-9]. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. RP Tobin, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RI Schumann, Frank /K-9364-2014; Tobin, James/O-6953-2015 NR 21 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1259 EP 1263 DI 10.1116/1.582336 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800043 ER PT J AU Jiang, JS Felcher, GP Inomata, A Goyette, R Nelson, CS Bader, SD AF Jiang, JS Felcher, GP Inomata, A Goyette, R Nelson, CS Bader, SD TI Exchange bias in Fe/Cr double superlattices SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID POLARIZED-NEUTRON-REFLECTION; GIANT MAGNETORESISTANCE; 100 SUPERLATTICES; ANISOTROPY; BILAYERS; MODEL; FILMS; FERROMAGNET; INTERFACES; PERMALLOY AB Utilizing the oscillatory interlayer exchange coupling in Fe/Cr superlattices, we have constructed "double superlattice" structures where a ferromagnetic (F) and an antiferromagnetic (BF) Fe/Cr superlattice are coupled through a Cr spacer. The minor hysteresis loops in the magnetization are shifted from zero field, i.e., the F superlattice is exchange biased by the AF one. The double superlattices are sputter deposited with (211) epitaxy and possess uniaxial in-plane magnetic anisotropy. The magnitude of the bias field is satisfactorily described by the classic formula for collinear spin structures. The coherent structure and insensitivity to atomic-scale roughness makes it possible to determine the spin distribution by polarized neutron reflectivity, which confirms that the spin structure is collinear. The magnetic reversal behavior of the double superlattices suggests that a realistic model of exchange bias needs to address the process of nucleating local reverse domains. (C) 2000 American Vacuum Society. [S0734-2101(00)02204-1]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Jiang, JS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 27 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1264 EP 1268 DI 10.1116/1.582337 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800044 ER PT J AU Inomata, A Jiang, JS You, CY Pearson, JE Bader, SD AF Inomata, A Jiang, JS You, CY Pearson, JE Bader, SD TI Magnetic stability of novel exchange coupled systems SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID GIANT MAGNETORESISTANCE; ANISOTROPY; COERCIVITY; BILAYERS; FILMS AB The magnetic stability of two different interfacial exchange coupled systems is investigated using the magneto-optic Kerr effect during repeated reversal of the soft layer magnetization by field cycling up to 10(7) times, For uniaxial Fe/Cr(211) exchange biased "double-superlattice" systems, small but rapid initial decay of exchange bias field HE and the remanent magnetization is observed. Also the Sm-Co/Fe bilayers grown epitaxially with uniaxial in-plane anisotropy show similar decay, However, the HE Of biaxial and random in-plane bilayers shows gradual decay without large reduction of the magnetization. These different decay behaviors are explained by their different microstructure and interfacial spin configurations. (C) 2000 American Vacuum Society. [S0734-2101(00)02104-7]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Fujitsu Ltd, Atsugi, Kanagawa, Japan. RP Inomata, A (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Chun-Yeol/B-1734-2010; Bader, Samuel/A-2995-2013 OI You, Chun-Yeol/0000-0001-9549-8611; NR 11 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1269 EP 1272 DI 10.1116/1.582338 PN 1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZH UT WOS:000088276800045 ER PT J AU Moutinho, HR Dhere, RG Ballif, C Al-Jassim, MM Kazmerski, LL AF Moutinho, HR Dhere, RG Ballif, C Al-Jassim, MM Kazmerski, LL TI Alternative procedure for the fabrication of close-spaced sublimated CdTe solar cells SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID THIN-FILMS; RECRYSTALLIZATION; EFFICIENCY AB We deposited CdTe thin films by close-spaced sublimtation using an alternative procedure, with temperatures about 170 degrees C lower than the ones used in the standard procedure. These films were used in the fabrication of all thin-film CdTe/CdS solar cells. We treated the cells using the well-established CdCl2 dipping process as well as a new vapor treatment. The vapor process was more reproducible and easier to control, and it produced the best devices. This process was also much more effective in the recrystallization of the CdTe films. The best device that we produced had an efficiently of 11.6%, close to the 12.3% efficiency of the best device fabricated using the standard process. These results show that the new process has good potential, and besides being an alternative for lower-cost solar cell prouction, it can also produce high-efficiency devices. (C) 2000 American Vacuum Society. [S0734-2101(00)12604-1]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Moutinho, HR (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Ballif, Christophe/G-4621-2012 NR 10 TC 20 Z9 20 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1599 EP 1603 DI 10.1116/1.582392 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000013 ER PT J AU Dhere, RG Al-Jassim, MM Yan, Y Jones, KM Moutinho, HR Gessert, TA Sheldon, P Kazmerski, LL AF Dhere, RG Al-Jassim, MM Yan, Y Jones, KM Moutinho, HR Gessert, TA Sheldon, P Kazmerski, LL TI CdS/CdTe interface analysis by transmission electron microscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc AB CdTe-based polycrystalline solar cells are leading candidates for terrestrial photovoltaic applications. High efficiency devices have been obtained despite large lattice mismatch between hexagonal CdS and cubic CdTe. In the present work, CdS was deposited by chemical bath deposition on Si substrates, and CdTe was deposited by close spaced sublimation. The chemical nature of the CdS/CdTe interface, structural properties, and their dependence on the fabrication parameters, e.g., substrate temperature (475-600 degrees C) and postdeposition CdCl2 heat treatment, were analyzed. In addition, the effects of crystallinity of CdS on the interface structural defects were examined. Small spot energy dispersive spectroscopy of the interface revealed a considerable amount of sulfur in CdTe. The concentration of sulfur, in general, was higher ill the grains with higher density of structural defects and at the grain boundaries. The planar defect density in CdTe films increased with substrate temperature, whereas the threading dislocation density decreased. Interface analysis showed that the majority of the crystalline defects in the CdTe films deposited on CdS were generated at the interface. The crystallinity of CdS did not have a major influence on the interface defect generation. (C) 2000 American Vacuum Society. [S0734-2101(00)17101-0]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dhere, RG (reprint author), Natl Renewable Energy Lab, 1617 Cole BLvd, Golden, CO 80401 USA. NR 11 TC 10 Z9 11 U1 2 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1604 EP 1608 DI 10.1116/1.582393 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000014 ER PT J AU Windisch, CF Exarhos, GJ AF Windisch, CF Exarhos, GJ TI Mott-Schottky analysis of thin ZnO films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc AB Thin ZnO films, both native and doped with secondary metal ions, have been prepared by sputter deposition and also by casting from solutions containing a range of precursor salts. The conductivity and infrared reflectivity of these films are subsequently enhanced chemically following treatment in H-2 gas at 400 degrees C Or by cathodic electrochemical treatment in a neutral (pH=7) phosphate buffer solution. While Hall-type measurements usually are used to evaluate the electrical properties of such films, the present study investigated whether a conventional Mott-Schottky analysis could be used to monitor the change in concentration of free carriers in these films before and after chemical and electrochemical reduction. The Mott-Schottky approach would be particularly appropriate for electrochemically modified films since the measurements could be made in the same electrolyte used for the post-deposition electrochemical processing. Results of studies on sputtered pure ZnO films in ferricyanide solution were promising. Mott-Schottky plots were linear and gave free carrier concentrations typical for undoped semiconductors. Film thicknesses estimated from the Mott-Schottky data were also reasonably close to thicknesses calculated from reflectance measurements. Studies on solution-deposited films were less successful. Mott-Schottky plots were nonlinear, apparently due to film porosity. A combination of de polarization and atomic force microscopy measurements confirmed this conclusion. The results suggest that Mott-Schottky analysis would be suitable for characterizing solution-deposited ZnO films only after extensive modeling was performed to incorporate the effects of film porosity on the characteristics of the space-charge region of the semiconductor. (C) 2000 American Vacuum Society. [S0734-2101(00)00204-9]. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Windisch, CF (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 6 TC 27 Z9 27 U1 1 U2 34 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1677 EP 1680 DI 10.1116/1.582406 PN 2 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000027 ER PT J AU Biscardi, C Hseuh, H Mapes, M AF Biscardi, C Hseuh, H Mapes, M TI Application of porcelain enamel as an ultra-high-vacuum-compatible electrical insulator SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc AB Many accelerator vacuum system components require electrical insulation internal to the vacuum system. Some accelerator components at Brookhaven National Laboratory are installed in ultra-high-vacuum systems which require the insulation to have excellent vacuum characteristics, be radiation resistant, and he able to withstand high temperatures when used on baked systems. Porcelain enamel satisfies all these requirements. This article describes the process and application of coating metal parts with porcelain enamel to provide electrical insulation. The mechanical and vacuum testing of Marman flanges coated with porcelain and using metal Helicoflex seals to form a zero-length electrical break are detailed. The use of porcelain enameled parts is attractive since it can be done quickly, is inexpensive and environmentally safe, and most of all satisfies stringent vacuum system requirements. (C) 2000 American Vacuum Society. [S0734-2101(00)06504-0]. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Biscardi, C (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 2 TC 0 Z9 0 U1 3 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1751 EP 1754 DI 10.1116/1.582418 PN 2 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000040 ER PT J AU Mammana, VP Degasperi, FT Monteiro, OR Vuolo, JH Salvadori, MC Brown, IG AF Mammana, VP Degasperi, FT Monteiro, OR Vuolo, JH Salvadori, MC Brown, IG TI New field-emission device with improved vacuum features SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID DIAMOND-LIKE-CARBON; ELECTRON-EMISSION; EMITTERS; FABRICATION; DEPOSITION; ARRAYS; ENHANCEMENT; MEMBRANES; FILMS AB We introduce in this article a novel geometry that can be used in the manufacturing of field-emission displays. The geometry proposed combines superior vacuum conductance and a good field-enhancement factor. A theoretical model is developed for the calculation of the upper limit to the electrostatic field at the emitting regions, and these values are compared to those calculated for the actual geometry. The vacuum conductance of the proposed geometry is also calculated, and we show that conductances up to an order of magnitude higher than other schemes are readily achievable. Finally, we present field-emission results obtained from a prototype, and compare them with other emission schemes. (C) 2000 American Vacuum Society. [S0734-2101(00)16203-9]. C1 Univ Sao Paulo, Inst Fis, BR-01498 Sao Paulo, Brazil. CEETEPS, FATEC SP, Fac Tecnol, Sao Paulo, Brazil. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Mammana, VP (reprint author), Univ Sao Paulo, Inst Fis, CP 20516, BR-01498 Sao Paulo, Brazil. RI Salvadori, Maria Cecilia/A-9379-2013 NR 28 TC 5 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1818 EP 1822 DI 10.1116/1.582430 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000052 ER PT J AU Tober, ED Witte, G Poppa, H AF Tober, ED Witte, G Poppa, H TI Variable temperature and ex situ spin-polarized low-energy electron microscope SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID FILMS AB The spin-polarized low-energy electron microscope (SPLEEM) at NCEM has been utilized to examine the magnetic domain formation in thin films of Co grown on Au(lll) single-crystal surfaces. A new, low-temperature liquid nitrogen cooling system has been added to this instrument, achieving sample temperatures over a wide range (115-2300 K) and enabling the first SPLEEM images to be obtained at below room temperature. Furthermore, the deposition of protective, nonmagnetic capping layers on top of the Co/Au(111) surface is observed to have little effect on the domain shape except for decreasing magnetic contrast due to the attenuation of the diffracted electrons from the Co layer. The magnetic domain contrast is nearly completely restored upon thinning the capping layers by ion bombardment enabling the examination of ex situ prepared samples. (C) 2000 American Vacuum Society. [S0734-2101(00)01204-5]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Tober, ED (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. NR 6 TC 6 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1845 EP 1847 DI 10.1116/1.582433 PN 2 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000057 ER PT J AU Wang, LQ Ferris, KF Herman, GS Engelhard, MH AF Wang, LQ Ferris, KF Herman, GS Engelhard, MH TI Interaction of HCOOH with stoichiometric and reduced SrTiO3(100) surfaces SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID FORMIC-ACID DECOMPOSITION; CATALYTIC DECOMPOSITION; TIO2(110) SURFACE; REACTION PATHS; TIO2; FORMALDEHYDE; SRTIO3(001); ADSORPTION; SWITCHOVER; OXIDE AB interaction of formic acid with stoichiometric (TiO2-terminated) and reduced SrTiO3(100) surfaces has been investigated using temperature programmed desorption (TPD), and x-ray photoelectron spectroscopy (XPS). Formic acid was dissociated to form formate and a surface proton below 250 K on both stoichiometric and reduced SrTiO3(100) surfaces. Formate was decomposed primarily through dehydration to produce CO and H2O, instead of through dehydrogenation to produce CO2 and H-2, on both surfaces. Formaldehyde produced from decomposition of formate was also observed on both surfaces. On stoichiometric surfaces, formaldehyde was produced through bimolecular coupling of two formates on low-coordination Ti cation sites: However, on the reduced surface, formaldehyde formation involves the reduction of surface formates through the oxidation of reduced Ti cations. XPS results show that surface defects on reduced SrTiO3(100) surfaces were reoxidized significantly upon exposure to 30 L HCOOH at 300 K, in contrast to defects on reduced TiO2(110) surfaces where no reduction in defect intensity was observed under identical conditions. The TPD peak of formaldehyde on a reduced SrTiO3(100) surface is shifted to lower temperature and is significantly broader (down to below 300 K) compared to on the stoichiometric surface. The adsorption and decomposition of HCOOH on SrTiO3(100) surfaces are compared with those on TiO2 sur faces. (C) 2000 American Vacuum Society. [S0734-2101(00)10204-0]. C1 Pacific NW Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. RP Wang, LQ (reprint author), Pacific NW Lab, Environm & Hlth Sci Div, POB 999, Richland, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; OI Engelhard, Mark/0000-0002-5543-0812 NR 21 TC 9 Z9 9 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1893 EP 1899 DI 10.1116/1.582442 PN 2 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000066 ER PT J AU Hite, DA Kizilkaya, O Sprunger, PT Howard, MM Ventrice, CA Geisler, H Zehner, DM AF Hite, DA Kizilkaya, O Sprunger, PT Howard, MM Ventrice, CA Geisler, H Zehner, DM TI Surface morphology and electronic structure of Ni/Ag(100) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID NI FILMS; GROWTH; MONOLAYER; AG(100); AG(001); CU(001) AB The growth morphology and electronic structure of Ni on Ag(100) has been studied with scanning tunneling microscopy (STM) and synchrotron based angle resolved photoemission spectroscopy. At deposition temperatures at or below 300 K, STM reveals Ni cluster growth on the surface along with some subsurface growth. Upon annealing to 420 K, virtually all Ni segregates into the subsurface region forming embedded nanoclusters. The electronic structure of Ni d bands in the unannealed surface shows dispersion only perpendicular to the surface whereas the annealed surface has Ni d bands that exhibit a three-dimensional-like structure. This is a result of the increased Ni d-Ag sp hybridization bonding and increased coordination of the embedded Ni nanoclusters. (C) 2000 America Vacuum Society. [S0734-2101(00)07004-4]. C1 Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Louisiana State Univ, Ctr Adv Microstruct & Devices, Baton Rouge, LA 70806 USA. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. Xavier Univ, Dept Chem, New Orleans, LA 70125 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Hite, DA (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. NR 16 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1950 EP 1954 DI 10.1116/1.582452 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000077 ER PT J AU Coulthard, I Antel, WJ Frigo, SP Freeland, JW Moore, J Calaway, WS Pellin, MJ Mendelsohn, M Sham, TK Naftel, SJ Stampfl, APJ AF Coulthard, I Antel, WJ Frigo, SP Freeland, JW Moore, J Calaway, WS Pellin, MJ Mendelsohn, M Sham, TK Naftel, SJ Stampfl, APJ TI Resonant Auger studies of metallic systems SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID PHOTOEMISSION SPECTROSCOPY; OXIDATION-STATES; HIGH-RESOLUTION; THRESHOLD; PHOTOELECTRON; SPECTRA; DECAY; TRANSITIONS; SCATTERING; RADIATION AB Results of resonant Auger spectroscopy experimental are presented for Cu, Co, and oxidized Al. Sublifetime narrowing of Auger spectra and generation of sublifetime narrowed absorption spectra constructed from Auger yield measurements were observed. Resonant Auger yields are used to identify three chemical states of oxidized Al. Partial absorption yield spectra were derived giving detailed electronic information and thickness information for the various chemical states of the bulk metal, the passivating aluminum oxide layer, and the metal-oxide interface region. In addition, the total absorption yield spectrum for the oxidized Al sample was constructed from the partial yield data, supporting the consistency of our method. (C) 2000 American Vacuum Society. [S0734-2101(00)12304-8]. C1 Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. Australian Nucl Sci & Technol Org, Div Phys, Lucas Hts, NSW, Australia. RP Coulthard, I (reprint author), Argonne Natl Lab, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 22 TC 7 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1955 EP 1958 DI 10.1116/1.582453 PN 2 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000078 ER PT J AU Erdemir, A Eryilmaz, OL Fenske, G AF Erdemir, A Eryilmaz, OL Fenske, G TI Synthesis of diamondlike carbon films with superlow friction and wear properties SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc ID TRIBOLOGICAL PERFORMANCE; COATINGS; BEHAVIOR; SURFACE AB In this study, we introduce a new diamondlike carbon (DLC) film providing a friction coefficient of 0.001 and wear rates of 10(-9)-10(-10) mm(3)/N m in inert-gas environments (e.g., dry nitrogen and argon). The him was grown on steel and sapphire substrates in a plasma enhanced chemical vapor deposition system that uses a hydrogen-rich plasma. Employing a combination of surface and structure analytical techniques, we explored the structural chemistry of the resultant DLC films and correlated these findings with the friction and wear mechanisms of the films. The results of tribological tests under a 10 N load (creating initial peak Hertz pressures of 1 and 2.2 GPa on steel and sapphire test pairs, respectively) and at 0.2 to 0.5 m/s sliding velocities indicated that a close correlation exists between the friction and wear coefficients of DLC films and the source gas chemistry. Specifically, films grown in source gases with higher hydrogen-to-carbon ratios had the lowest friction coefficients and the highest wear resistance. The lowest friction coefficient (0.001) was achieved with a film on sapphire substrates produced in a gas discharge plasma consisting of 25% methane and 75% hydrogen. (C) 2000 American Vacuum Society. [S0734-2101(00)14204-6]. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Istanbul Tech Univ, Fac Met & Chem Engn, TR-80626 Istanbul, Turkey. RP Erdemir, A (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 37 TC 179 Z9 184 U1 5 U2 41 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1987 EP 1992 DI 10.1116/1.582459 PN 2 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000084 ER PT J AU Matson, DW Martin, PM Bennett, WD Johnston, JW Stewart, DC Bonham, CC AF Matson, DW Martin, PM Bennett, WD Johnston, JW Stewart, DC Bonham, CC TI Sputtered coatings for microfluidic applications SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc AB Magnetron sputter-deposited features and coatings are finding a broad range of uses in microfluidic devices being developed at the Pacific Northwest National Laboratory. Such features are routinely incorporated into multilayer laminated microfluidic components when specific functionality is required, and where other methods for producing these features have been deemed unacceptable. Applications include electrochemical sensors, heaters and temperature probes, electrical leads and insulation layers, piezoelectric actuators and transducers, and chemical modification of surfaces. Small features, such as those required for the production of microsensor electrodes or miniature resistive heaters on microfluidic chips, were patterned using standard lithographic methods, or with masks produced by laser micromachining processes. Thin-film piezoelectric materials such as aluminum nitride have been deposited at low temperatures for use with temperature sensitive materials. Use of the coating technology and its application in the fabrication of specific microfluidic devices, including a groundwater sensor, miniature piezoelectric ultrasonic transducers and actuators, a polymerase chain reaction thermal cycler, and a microchannel flow diagnostic device, are discussed. Technical issues associated with these coatings, such as adhesion, chemical resistance, and surface defects are also addressed. (C) 2000 American Vacuum Society. [S0734-2101(00)07104-9]. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Matson, DW (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 12 TC 3 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 1998 EP 2002 DI 10.1116/1.582461 PN 2 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000086 ER PT J AU Morse, JD Jankowski, AF Graff, RT Hayes, JP AF Morse, JD Jankowski, AF Graff, RT Hayes, JP TI Novel proton exchange membrane thin-film fuel cell for microscale energy conversion SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 46th National Symposium of the American-Vacuum-Society CY OCT 25-29, 1999 CL SEATTLE, WASHINGTON SP Amer Vacuum Soc AB Thin-film, proton exchange membrane fuel cells are developed using photolithographic patterning, physical vapor deposition, and spin-cast deposition techniques. In this study, micrometer-thick layers of nickel (Ni) and platinum (Pt) electrodes, as well as the proton conducting electrolyte layer of perfluoronated sulfonic acid, are synthesized. The anode layer is conductive to pass the electric current and provides mechanical support to the electrolyte and cathode layer that enables combination of the reactive gases. The morphology desired for both the anode and cathode layers facilitates generation of maximum current density from the fuel cell. For these purposes, the parameters of the deposition process and post-deposition patterning are optimized for continuous porosity across both electrode layers. The power output generated through current-voltage measurement is characterized at various temperatures in the range of 60-90 degrees C using dilute (4%) hydrogen fuel. (C) 2000 American Vacuum Society. [S0734-2101(00)05304-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Morse, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 3 TC 53 Z9 54 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 2000 VL 18 IS 4 BP 2003 EP 2005 DI 10.1116/1.582462 PN 2 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 335ZK UT WOS:000088277000087 ER PT J AU Tiszauer, DH AF Tiszauer, DH TI Statistical considerations of the overlay error in laser driven point source x-ray lithography SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article AB A statistical measure of the point source divergence-induced overlay error over the print field is derived. The assumptions of a wide-sense stationary distribution of gap error and the assumption of a symmetric distribution of overlay sites on the chip field give rise to simple expressions for the overlay error variance. The computations for overlay error are also expressed in the Fourier domain. From this formulation, it is found that these simple results hold for the zero frequency and high frequency limit of gap error in the Fourier domain, even without the assumptions of stationarity. (C) 2000 American Vacuum Society. [S0734-211X(00)01104-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Laser Sci & Technol Dept, Livermore, CA 94550 USA. RP Tiszauer, DH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Laser Sci & Technol Dept, POB 5508, Livermore, CA 94550 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 2000 VL 18 IS 4 BP 1886 EP 1889 DI 10.1116/1.1303754 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 345UW UT WOS:000088834400011 ER PT J AU Smith, PM Bailey, G Hu, YZ Tay, SP AF Smith, PM Bailey, G Hu, YZ Tay, SP TI Effect of ramp rate on the C49 to C54 titanium disilicide phase transformation from Ti and Ti(Ta) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID TEMPERATURE; NUCLEATION; TISI2 AB The C49 to C54 TiSi2 transformation temperature is shown to be reduced by increasing the ramp rate during rapid thermal processing and this effect is more pronounced for thinner initial Ti and Ti(Ta) films. Experiments were performed on blanket wafers and on wafers that had patterned polycrystalline Si lines with Si3N4 sidewall spacers. Changing the ramp rate caused no change in the transformation temperature for 60 nm blanket Ti films. For blanket Ti films of 25 or 40 nm, however, increasing the ramp rate from 7 to 180 degrees C/s decreased the transformation temperature by 15 degrees C. Studies of patterned lines indicate that sheet resistance of narrow lines is reduced by increased ramp rates for both Ti and Ti(Ta) films, especially as the linewidths decrease below 0.4 mu m. This improvement is particularly pronounced for the thinnest Ti(Ta) films, which exhibited almost no linewidth effect after being annealed with a ramp rate of 75 degrees C/s. (C) 2000 American Vacuum Society. [S0734-211X(00)05104-0]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Steag RTP Syst Inc, San Jose, CA 95134 USA. RP Smith, PM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 2000 VL 18 IS 4 BP 1949 EP 1952 DI 10.1116/1.1305808 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 345UW UT WOS:000088834400023 ER PT J AU Voight, B Davis, MJ AF Voight, B Davis, MJ TI Emplacement temperatures of the November 22, 1994 nuee ardente deposits, Merapi Volcano, Java SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE emplacement temperature; Merapi volcano; nuee ardente AB A study of emplacement temperatures was carried out fur the largest of the 22 November 1993 nuee ardente deposits at Merapi Volcano. based mainly on the response of plastic and woody materials subjected to the hot pyroclastic current and the deposits, and to some extent on eyewitness observations. The study emphasizes the Turgo-Kaliurang area in the distal part of the area affected by the nuee ardente, where nearly 100 casualties occurred. The term nuee ardente as used here includes channeled block-and-ash Rows, and associated ash-clouds of surge and fallout origins. The emplacement temperature of the 8 m thick channeled block-and-ash deposit was relatively high, similar to 550 degrees C, based mainly on eyewitness reports of visual thermal radiance. Emplacement temperatures for ash-cloud deposits a few cm thick were deduced from polymer objects collected at Turgo and Kaliurang. Most polymers do not display a sharp melting range, but polyethylene terephthalate used in water bottles melts between 245 and 265 degrees C, and parts of the bottles that had been deformed during fabrication molding turn a milky color at 200 degrees C. The experimental evidence suggests that deposits in the Turgo area briefly achieved a maximum temperature near 300 degrees C, whereas those near Kaliurang were <200 degrees C. Maximum ash deposit temperatures occurred in fallout with a local source in the channeled block-and-ash Row of the Boyong river valley; the surge deposit was cooler (similar to 180 degrees C) due to entrainment of cool air and soils, and tree singe-zone temperatures were around 100 degrees C. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Sandia Corp, Albuquerque, NM USA. US Geol Survey, Cascades Volvano Observ, Vancouver, WA 98661 USA. RP Voight, B (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. NR 27 TC 17 Z9 17 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD JUL PY 2000 VL 100 IS 1-4 BP 371 EP 377 DI 10.1016/S0377-0273(00)00146-3 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 336QY UT WOS:000088315500020 ER PT J AU Clark, BM Mangelson, NF St Clair, LL Rees, LB Bench, GS Southon, JR AF Clark, BM Mangelson, NF St Clair, LL Rees, LB Bench, GS Southon, JR TI Measurement of age and growth rate in the crustose saxicolous lichen Caloplaca trachyphylla using C-14 accelerator mass spectrometry SO LICHENOLOGIST LA English DT Article AB Sections of the crustose saxicolous lichen, Caloplaca trachyphylla, were dared using C-14 accelerator mass spectrometry (AMS). The data show a strong linear dependence of radial position on time (r=0.993), suggesting a constant radial growth rate. This specimen had averaged a marginal growth rare of 1.48 mm/year. Extrapolation of the growth curve yields a thallus age of 20 years. These data demonstrate the feasibility of using AMS technology to precisely date lichen tissues and determine growth races of lichen thalli. (C) 2000 The British Lichen society. C1 Brigham Young Univ, Dept Biochem & Chem, Provo, UT 84602 USA. Brigham Young Univ, Dept Bot & Range Sci, Provo, UT 84602 USA. Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Clark, BM (reprint author), Brigham Young Univ, Dept Biochem & Chem, Provo, UT 84602 USA. NR 14 TC 12 Z9 12 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-2829 J9 LICHENOLOGIST JI Lichenologist PD JUL PY 2000 VL 32 BP 399 EP 403 DI 10.1006/lich.2000.0279 PN 4 PG 5 WC Plant Sciences; Mycology SC Plant Sciences; Mycology GA 330FT UT WOS:000087952700007 ER PT J AU Tank, JL Meyer, JL Sanzone, DM Mulholland, PJ Webster, JR Peterson, BJ Wollheim, WM Leonard, NE AF Tank, JL Meyer, JL Sanzone, DM Mulholland, PJ Webster, JR Peterson, BJ Wollheim, WM Leonard, NE TI Analysis of nitrogen cycling in a forest stream during autumn using a N-15-tracer addition SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID OXYGEN CHANGE TECHNIQUE; AMMONIA DIFFUSION METHOD; TRANSIENT STORAGE MODEL; N-15 TRACER; CHLOROFORM FUMIGATION; PHOSPHORUS UPTAKE; SOLUTE TRANSPORT; HYPORHEIC ZONE; SOIL-NITROGEN; METABOLISM AB We added (NH4Cl)-N-15 over 6 weeks to Upper Ball Creek, a second-order deciduous forest stream in the Appalachian Mountains, to follow the uptake, spiraling, and fate of nitrogen in a stream food web during autumn. A priori predictions of N flow and retention were made using a simple food web mass balance model. Values of delta(15)N were determined for stream water ammonium, nitrate, dissolved organic nitrogen, and various compartments of the food web over time and distance and then compared to model predictions. Ammonium uptake lengths were shortest at the beginning of the tracer addition (28 m) and increased through time (day 20 = 82 m; day 41 = 94 m), and ammonium residence time in stream water ranged from 4 min on day 0 to 15 min on day 41. Whole-stream ammonium uptake rates, determined from the decline in (NH4)-N-15 in water over the stream reach, decreased from 191 mg N m(-2) d(-1) on day 0 to 83.2 mg N m(-2) d(-2) on day 41. Temporal trends in the NH4 mass transfer coefficient (v(f)) were similar to uptake rates; v(f) was highest on day 0 (7.4 x 10(-4) m s(-1)) and lower on days 20 and 41 (2.7 and 2.8 x 10(-4) m s(-1), respectively). Rates of nitrification were estimated to be very low throughout the tracer addition and accounted for <3% of (NH)-N-15, uptake on day 0. It appears that most of the N in epilithon was actively cycling based on comparisons of N-15 in stream water and biomass at the end of the experiment. In contrast, for allochthonous organic matter, we found that microbial N-15 represented 69% of the label in wood, 20% in leaves, and 31% in fine benthic organic matter (FBOM). Despite higher delta(15)N values in primary producers, (NH4)-N-15 uptake rates per unit stream bottom area were generally lower in epilithon compared to the detrital compartments, a result of the lower biomass of epilithon. Turnover times were similar for epilithon (47 d), leaves (38 d), and FBOM (53 d) based on the decline in N-15 tracer over the first 28 d after the addition stopped. Incorporation of N-15 varied among biomass compartments involved in ammonium uptake from water. Primary producers were more highly labeled than allochthonous organic matter. Epilithon delta(15)N values were higher than leaves or FBOM, appeared to reach isotopic equilibrium by day 42, and followed model-predicted trends. The grazing mayfly Stenonema was more highly labeled than the epilithon, which suggests selective feeding or assimilation of the more highly labeled algal-bacterial portion of the epilithon. Leaves had very low delta(15)N values, and delta(15)N values for the shredding stonefly Tallaperla were close to model predictions and followed labeling in leaves. Total retention of N-15 at the end of the experiment by the nine largest biomass compartments within the study reach accounted for only 12.3% of added N-15(4) With leaves and FBOM representing the largest portions. Export of N-15 by suspended particulate and dissolved N accounted for an additional 11% and 30% of added N-15(4) respectively. Results from the N-15-tracer addition in Upper Ball Creek demonstrate the high ammonium demand associated with microbes colonizing leaf detritus and the resultant linkage to invertebrate shredders. In Upper Ball Creek in autumn, spiraling of NH4 is very tight, NH4 residence time in water is short, and uptake rates are very high. Analyses of N spiraling in unimpacted streams provide an ecological foundation for assessment of spiraling in high-N streams. C1 Univ Illinois, Dept Nat Resources & Environm Sci, Urbana, IL 61801 USA. Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Virginia Tech, Dept Biol, Blacksburg, VA 24061 USA. Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA. RP Tank, JL (reprint author), Univ Illinois, Dept Nat Resources & Environm Sci, Urbana, IL 61801 USA. RI Mulholland, Patrick/C-3142-2012 NR 56 TC 106 Z9 108 U1 4 U2 38 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0024-3590 EI 1939-5590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 2000 VL 45 IS 5 BP 1013 EP 1029 PG 17 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 341CD UT WOS:000088572700001 ER PT J AU Bolvig, S Hansen, PE Morimoto, H Wemmer, D Williams, P AF Bolvig, S Hansen, PE Morimoto, H Wemmer, D Williams, P TI Primary tritium and deuterium isotope effects on chemical shifts of compounds having an intramolecular hydrogen bond SO MAGNETIC RESONANCE IN CHEMISTRY LA English DT Article DE NMR; primary tritium and deuterium isotope effects; chemical shifts; intramolecular hydrogen bonding; variable-temperature NMR; tautomerism ID NUCLEAR MAGNETIC-RESONANCE; C-13 NMR SHIFTS; TAUTOMERIC EQUILIBRIUM; COUPLING-CONSTANTS; ACYL AROMATICS; BETA-DIKETONES; SYSTEMS; PROTON; ENOL; MODEL AB The primary deuterium and tritium isotope effects, delta(XH) - delta(XD/T), were measured for 55 compounds having one or more intramolecular hydrogen bonds. The primary isotope effects were measured at various temperatures. For compounds displaying tautomerism the primary isotope effects are found to have contributions from both intrinsic and equilibrium isotope effects. The primary tritium isotope effect, (P)Delta(H-1, H-3), and the primary deuterium isotope effect, (P)Delta(H-1, H-2), shown to be related by (P)Delta(H-1, H-3) = 1.4(P)Delta(H-1, H-2) This finding is valid for both tautomeric compounds and compounds with localized hydrogen bonds. Large negative primary tritium and deuterium isotope effects were observed for compounds displaying tautomerism and having sulfur as donor or acceptor. These isotope effects show a strong temperature dependence, which is related to the change in equilibrium due to isotope substitution. For the compounds with localized hydrogen bonds, the primary deuterium and tritium isotope effects correlated with the two bond deuterium isotope effect on C-13 chemical shifts. The primary deuterium and tritium isotope effects are therefore a measure of the hydrogen bond strength for compounds with localized hydrogen bonds. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Roskilde Univ, Dept Chem & Life Sci, DK-4000 Roskilde, Denmark. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Tritium Labelling Facil, Berkeley, CA 94720 USA. RP Roskilde Univ, Dept Chem & Life Sci, POB 260, DK-4000 Roskilde, Denmark. EM poulerik@virgil.ruk.dk NR 52 TC 17 Z9 17 U1 4 U2 11 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0749-1581 EI 1097-458X J9 MAGN RESON CHEM JI Magn. Reson. Chem. PD JUL PY 2000 VL 38 IS 7 BP 525 EP 535 DI 10.1002/1097-458X(200007)38:7<525::AID-MRC663>3.3.CO;2-J PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 330UW UT WOS:000087980400009 ER PT J AU Gakh, YG Gakh, AA Gronenborn, AM AF Gakh, YG Gakh, AA Gronenborn, AM TI Fluorine as an NMR probe for structural studies of chemical and biological systems SO MAGNETIC RESONANCE IN CHEMISTRY LA English DT Article DE NMR; fluorine NMR; probe; chemical structure; biological systems ID SPIN-COUPLING-CONSTANTS; F-19 NMR; ESCHERICHIA-COLI; CONFORMATIONAL HETEROGENEITY; DIHYDROFOLATE-REDUCTASE; CARBON-FLUORINE; CUBYL CATION; C-13; H-1; PROTEINS AB Applications of fluorine NMR to probe long-range interactions in rigid organic molecules, namely cubanes, and to study structures and dynamics of proteins and other biological systems, are presented. F-19 NMR parameters, especially long-range coupling constants are shown to reveal intrinsic features of the molecules. Correlations between long-range (more than three-bond) couplings involving fluorine and other chemical and physicochemical properties of the compounds are demonstrated, and examples of unusual couplings which cannot be explained by existing theories of 'through-bond' and 'through-space' mechanisms are discussed. Recent applications of fluorine labeling of aromatic and aliphatic amino acids in investigating protein structures and dynamics are highlighted. The potential of using F-19 NMR parameters, such as large spin-spin coupling constants observed for organic compounds, for structural analysis of biological macromolecules is outlined. Copyright (C) 2000 John Wiley & Sons. C1 NIDDKD, Chem Phys Lab, NIH, Bethesda, MD 20892 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gronenborn, AM (reprint author), NIDDKD, Chem Phys Lab, NIH, Bldg 2, Bethesda, MD 20892 USA. NR 70 TC 78 Z9 78 U1 2 U2 17 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0749-1581 J9 MAGN RESON CHEM JI Magn. Reson. Chem. PD JUL PY 2000 VL 38 IS 7 BP 551 EP 558 DI 10.1002/1097-458X(200007)38:7<551::AID-MRC686>3.0.CO;2-Q PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 330UW UT WOS:000087980400012 ER PT J AU Sammi, MK Pan, JW Telang, FW Schuhlein, D Molina, PE Volkow, ND Springer, CS Hetherigton, HP AF Sammi, MK Pan, JW Telang, FW Schuhlein, D Molina, PE Volkow, ND Springer, CS Hetherigton, HP TI Measurements of human brain ethanol T-2 by spectroscopic imaging at 4 T SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article DE spectroscopy; brain; ethanol; T-2 ID MAGNETIC-RESONANCE SPECTROSCOPY; ALCOHOL; RELAXATION; INVIVO AB Previous MRS measurements of ethanol in human brain have yielded a range of transverse relaxation times for ethanol methyl resonance at 1.5 T (200-380 ms). To determine the T,of the methyl proton resonance of ethanol in human brain, 8 x 8 spectroscopic images were acquired at 16 different TE values. A frequency-selective refocusing pulse was used to suppress J-modulation of the ethanol triplet, permitting nonintegral multiples of 1/J to be used for TE values. The measured T,values for the methyl resonances of ethanol, creatine, and N-acetyl aspartate in mixed tissues were 82 +/- 12, 148 +/- 20, and 227 +/- 25 ms, respectively. Regression analysis of the measured T,as a function of gray matter content indicates a shorter T,value for ethanol in pure white matter compared to that in pure gray matter. (C) 2000 Wiley-Liss, Inc. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. N Shore Univ Hosp, Dept Surg, Manhasset, NY USA. RP Sammi, MK (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. OI Springer, Charles/0000-0002-5966-2135 FU NIGMS NIH HHS [R01-GM32125] NR 25 TC 12 Z9 12 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0740-3194 J9 MAGNET RESON MED JI Magn. Reson. Med. PD JUL PY 2000 VL 44 IS 1 BP 35 EP 40 DI 10.1002/1522-2594(200007)44:1<35::AID-MRM7>3.0.CO;2-G PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 329PW UT WOS:000087917000007 PM 10893519 ER PT J AU Justice, MJ Carpenter, DA Favor, J Neuhauser-Klaus, A de Angelis, MH Soewarto, D Moser, A Cordes, S Miller, D Chapman, V Weber, JS Rinchik, EM Hunsicker, PR Russell, WL Bode, VC AF Justice, MJ Carpenter, DA Favor, J Neuhauser-Klaus, A de Angelis, MH Soewarto, D Moser, A Cordes, S Miller, D Chapman, V Weber, JS Rinchik, EM Hunsicker, PR Russell, WL Bode, VC TI Effects of ENU dosage on mouse strains SO MAMMALIAN GENOME LA English DT Article ID DOMINANT CATARACT MUTATIONS; ETHYL-N-NITROSOUREA; LOCUS MUTATIONS; ETHYLNITROSOUREA MUTAGENESIS; DOSE FRACTIONATION; LETHAL MUTATIONS; T-REGION; SPERMATOGONIA; INDUCTION; MICE AB The germline supermutagen, N-ethyl-N-nitrosourea (ENU), has a variety of effects on mice. ENU is a toxin and carcinogen as well as a mutagen, and strains differ in their susceptibility to its effects. Therefore, it is necessary to determine an appropriate mutagenic, non-toxic dose of ENU for strains that are to be used in experiments. In order to provide some guidance, we have compiled data from a number of laboratories that have exposed male mice from inbred and non-inbred strains or their F-1 hybrids to ENU. The results show that most F-1 hybrid animals tolerate ENU well, but that inbred strains of mice vary in their longevity and in their ability to recover fertility after treatment with ENU. C1 Baylor Coll Med, Dept Mol & Human Genet, Houston, TX 77030 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. GSF, Natl Res Ctr Environm & Hlth, Neuherberg, Germany. Univ Wisconsin, Dept Human Oncol, Madison, WI 53792 USA. Mt Sinai Hosp, Samuel Lunenfeld Res Inst, Toronto, ON M5G 1X5, Canada. Roswell Pk Canc Inst, Buffalo, NY 14263 USA. Kansas State Univ, Div Biol, Manhattan, KS 66706 USA. RP Justice, MJ (reprint author), Baylor Coll Med, Dept Mol & Human Genet, Houston, TX 77030 USA. RI Cordes, Sabine/A-5423-2012; Hrabe de Angelis, Martin/F-5531-2012 OI Hrabe de Angelis, Martin/0000-0002-7898-2353 NR 24 TC 105 Z9 114 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD JUL PY 2000 VL 11 IS 7 BP 484 EP 488 DI 10.1007/s003350010094 PG 5 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 331HN UT WOS:000088013000004 PM 10886010 ER PT J AU Rinchik, EM AF Rinchik, EM TI Developing genetic reagents to facilitate recovery, analysis, and maintenance of mouse mutations SO MAMMALIAN GENOME LA English DT Article ID EMBRYONIC STEM-CELLS; DILUTION P LOCUS; STRUCTURE FUNCTIONAL-ANALYSIS; N-NITROSOUREA MUTAGENESIS; BROWN (B)-LOCUS REGION; MOLECULAR CHARACTERIZATION; LETHAL MUTATIONS; COMPLEMENTATION ANALYSIS; CHROMOSOMAL INVERSION; DELETION COMPLEXES AB Because the mouse has become the pre-eminent model system for functional genomics and analysis of complex-systems/pathways in mammals, there has been an escalation of interest in the generation and analysis of mouse mutations to use as tools in these analyses. I argue here for a parallel investment in continuing the development of appropriately marked chromosomal rearrangements to use as genetic reagents in mutation recovery, analysis, and maintenance crosses. Specifically, visibly marked interstitial chromosomal deletions can be valuable for regional mutagenesis screens for recessives based on hemizygosity, and they can also be used to simplify genetic fine-mapping as a prelude to gene identification based on positional cloning/candidacy strategies. Dominantly marked chromosomal inversions that also manifest some kind of recessive phenotype can be exploited in more extensive regional mutagenesis screens based on homozygosity, and are invaluable for simplified, low-cost and error-reduced mutant-stock maintenance. Also discussed are several issues concerning genetic background, particularly from the point of view of genetic-reagent resource development. C1 Oak Ridge Natl Lab, Div Life Sci, Holmes, NY 12531 USA. Univ Tennessee, Dept Biochem & Cellular & Mol Biol, Knoxville, TN 37996 USA. RP Rinchik, EM (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 713, Holmes, NY 12531 USA. NR 65 TC 27 Z9 27 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD JUL PY 2000 VL 11 IS 7 BP 489 EP 499 DI 10.1007/s003350010095 PG 11 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 331HN UT WOS:000088013000005 PM 10886011 ER PT J AU Heikoop, JM Risk, MJ Lazier, AV Edinger, EN Jompa, J Limmon, GV Dunn, JJ Browne, DR Schwarcz, HP AF Heikoop, JM Risk, MJ Lazier, AV Edinger, EN Jompa, J Limmon, GV Dunn, JJ Browne, DR Schwarcz, HP TI Nitrogen-15 signals of anthropogenic nutrient loading in reef corals SO MARINE POLLUTION BULLETIN LA English DT Article DE sewage; wastewater; nitrogen; carbon; isotopes; corals ID GREAT-BARRIER-REEF; CONTINENTAL SHELF TRENDS; STABLE ISOTOPES; MARINE-ENVIRONMENT; FOOD-CHAINS; SEWAGE; DELTA-N-15; POLLUTION; EUTROPHICATION; NITRATE AB The N-15 content of tissue from the coral Porites lobata mas enriched, relative to corals from reference sites, at 5 of 7 Indo-Pacific sewage-affected reefs. Enrichment Nas as high as 3.7. The delta(13)C of sewage-affected corals suggests they maintained a high degree of autotrophic nutrition. N-15-enriched wastewater dissolved inorganic nitrogen (DIN), derived from untreated sewage, is the most likely cause for enrichment in coral tissue N-15, though changes in coral nutrition, metabolism and zooxanthellae population dynamics are possible additional factors. Isotopic measurements of coral tissue can provide a simple means of detecting wastewater uptake by corals. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Geol & Geochem Grp, EES 1, Los Alamos, NM 87545 USA. McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4M1, Canada. St Francis Xavier Univ, Dept Geol, Antigonish, NS B2G 1C0, Canada. McMaster Univ, Dept Biol, Hamilton, ON L8S 4M1, Canada. Hasanuddin Univ, Fac Fisheries & Marine Sci, Ujung Pandang, Indonesia. James Cook Univ N Queensland, Dept Marine Biol, Townsville, Qld 4812, Australia. Pattimura Univ, Fac Fisheries & Marine Sci, Ambon, Indonesia. Hans Knoell Inst Nat Prod Res, Dept Cell & Mol Biol, D-07745 Jena, Germany. RP Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Geol & Geochem Grp, EES 1, Mail Stop D462, Los Alamos, NM 87545 USA. EM jheikoop@lanl.gov RI Heikoop, Jeffrey/C-1163-2011; OI Jompa, Jamaluddin/0000-0001-9740-333X NR 58 TC 68 Z9 74 U1 2 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD JUL PY 2000 VL 40 IS 7 BP 628 EP 636 DI 10.1016/S0025-326X(00)00006-0 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 341XT UT WOS:000088616800016 ER PT J AU Han, SH Trivedi, R AF Han, SH Trivedi, R TI Banded microstructure formation in off-eutectic alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PERITECTIC SYSTEMS; DIRECTIONAL-SOLIDIFICATION; RAPID SOLIDIFICATION; SPACINGS; GROWTH AB The transition from a eutectic to a single phase has been examined through critical experimental studies in the vicinity of the transition conditions. The actual transition is shown to depend on the dynamics of the two competing phases. Close to the transition, an oscillating mode was found in which the system oscillated between the two steady-state morphologies. The transition from a eutectic to a single phase was observed not to be sharp, but to occur over a finite range of velocities in which an oscillating or a banded structure was formed, in which bands of primary phase and eutectic grew alternately in the growth direction. The effects of the imposed velocity and composition on this oscillatory mode were examined. It was found that, when the conditions were farther from the transition paint, the oscillations damped out and the system selected one of the stable morphologies. The alloy composition had a significant influence on the oscillation behavior, and the oscillations were found to increase as the compositions deviated from the eutectic composition. The regime of banded structures was established for the carbon tetrabromide-hexachloroethane system, and a conceptual model is presented for the formation of bands. The results are generalized to show that the transition from one phase to the other is accompanied by a transition zone, in which the dynamic processes give rise to an oscillating microstructure between the two phases. Such a transition zone occurs in eutectic, peritectic, and monotectic systems and also during the cellular-to-planar transition of single-phase microstructures. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Samsung Elect, Seoul, South Korea. NR 28 TC 10 Z9 12 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 2000 VL 31 IS 7 BP 1819 EP 1832 DI 10.1007/s11661-006-0246-0 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 333UP UT WOS:000088149400011 ER PT J AU Yang, N Li, B Robinson, S Lavernia, EJ AF Yang, N Li, B Robinson, S Lavernia, EJ TI Solute segregation behavior in spray-atomized Pd-Rh-V(Co) powders SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID RAPIDLY SOLIDIFIED POWDERS; DYNAMIC COMPACTION PROCESS; HOMOGENEOUS STRUCTURES; MATHEMATICAL-MODEL; HEAT-FLOW; PD-RH; ATOMIZATION; DEPOSITION; MICROSTRUCTURE; NUCLEATION AB In the present study, two palladium-based ternary alloys, with nominal compositions of Pd-4.9 wt pet Rh-0.72 wt pet V and Pd-5 wt pet Rh-1 wt pet Co, were spray atomized into micron-sized powders using a high-energy gas atomization technique. Solute segregation in the spray-atomized powders was systematically investigated. It was found that, as the powder size decreases, the solute segregation level decreases, either in terms of standard deviation of solute content from the average value, or in terms of the percentage of segregation-free regions in the powder, or in terms of the maximum (Rh)/ minimum (Co, V) solute content in the powder. Moreover, theoretical analyses were carried out to evaluate the percentage of segregation-free regions, as well as the maximum/minimum solute content, in each powder. The theoretical analysis indicated that, among the different mechanisms governing the solute segregation behavior, undercooling levels experienced by the droplets, both prior to and after nucleation, played the most important role in decreasing the solute segregation level as the powder size decreased. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Univ Calif Irvine, Dept Chem & Biochem Engn & Mat Sci, Irvine, CA 92697 USA. RP Yang, N (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 40 TC 2 Z9 2 U1 1 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 2000 VL 31 IS 7 BP 1843 EP 1855 DI 10.1007/s11661-006-0244-2 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 333UP UT WOS:000088149400013 ER PT J AU Sawyer, DJ McGehee, MD Canepa, J Moore, CB AF Sawyer, DJ McGehee, MD Canepa, J Moore, CB TI Water soluble ions in the Nakhla martian meteorite SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID LOW-TEMPERATURE; SNC METEORITES; AQUEOUS ALTERATION; NOBLE-GASES; ALH84001; MARS; ORIGIN; CARBONATES; SOIL; ALLAN-HILLS-84001 AB Water-soluble ion concentrations from the martian achondrite Nakhla and three asteroidal achondrites are reported. The Nakhla sample contains significant concentrations of chloride, sulfate, Mg, Na, Ca, and K ions. The results are interpreted to indicate that this rock has been in contact with a seawater-like brine on the martian surface. C1 Arizona State Univ, Ctr Meteorite Studies, Tempe, AZ 85287 USA. Scottsdale Community Coll, Scottsdale, AZ 85256 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Arizona State Univ, Ctr Meteorite Studies, Tempe, AZ 85287 USA. EM cmoore@asu.edu NR 36 TC 34 Z9 35 U1 0 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 2000 VL 35 IS 4 BP 743 EP 747 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 341YC UT WOS:000088617700013 ER PT J AU Burchiel, SW Edwards, BS Kuckuck, FW Lauer, FT Prossnitz, ER Ransom, JT Sklar, LA AF Burchiel, SW Edwards, BS Kuckuck, FW Lauer, FT Prossnitz, ER Ransom, JT Sklar, LA TI Analysis of free intracellular calcium by flow cytometry: Multiparameter and pharmacologic applications SO METHODS-A COMPANION TO METHODS IN ENZYMOLOGY LA English DT Article DE flow cytometry; calcium; multiparameter; surface markers ID POLYCYCLIC AROMATIC-HYDROCARBONS; IONIZED CALCIUM; CELLS; IMMUNOTOXICITY; INHIBITION; INDICATORS; PROTEIN; FLUO-3; CA2+ AB Flow cytometry offers numerous advantages over traditional techniques for measuring intracellular Ca2+ in lymphoid and nonlymphoid cells. In particular, the heterogeneity of cell responses can be defined by flow cytometry, and multiparameter analyses permit the determination of intracellular Ca2+ in surface-marker-defined target cells as well as correlation of changes in Ca2+ with other biochemical markers, including ligand binding. This article presents several established methods for measuring intracellular Ca2+ by flow cytometry in lymphoid and nonlymphoid cells. Examples are provided for determination of Ca2+ in human peripheral blood leukocytes and two human epithelial cell lines grown in monolayer. In addition, applications are reviewed or presented for correlating changes In intracellular Ca2+ with other cell parameters, including cell cycle analysis, changes in cell membrane integrity, and the induction of apoptosis markers. Finally, a number of novel sample handling capabilities useful for performing kinetic analyses of Ca2+ changes by flow cytometry are now available and one application is presented which is finding utility in pharmacologic studies, (C) 2000 Academic Press. C1 Univ New Mexico, Coll Pharm, Toxicol Program, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Pathol, Sch Med, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Cell Biol & Physiol, Sch Med, Albuquerque, NM 87131 USA. Univ New Mexico, UNM Canc Ctr Flow Cytometry Core Lab, Albuquerque, NM 87131 USA. Axiom Biotechnol Inc, San Diego, CA 95055 USA. Univ Calif Los Alamos Natl Lab, Natl Flow Cytometry Resource Ctr, Los Alamos, NM 87545 USA. RP Burchiel, SW (reprint author), Univ New Mexico, Coll Pharm, Toxicol Program, Albuquerque, NM 87131 USA. RI Prossnitz, Eric/B-4543-2008; OI Prossnitz, Eric/0000-0001-9190-8302 FU NIEHS NIH HHS [ES05495, ES07259] NR 24 TC 37 Z9 38 U1 0 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1046-2023 J9 METHODS JI Methods PD JUL PY 2000 VL 21 IS 3 BP 221 EP 230 DI 10.1006/meth.2000.1002 PG 10 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 332RC UT WOS:000088086400003 PM 10873476 ER PT J AU Fredrickson, JK AF Fredrickson, JK TI Microbial Ecology update SO MICROBIAL ECOLOGY LA English DT Editorial Material C1 Pacific NW Natl Lab, Biogeochem Dept, Richland, WA 99352 USA. RP Fredrickson, JK (reprint author), Pacific NW Natl Lab, Biogeochem Dept, POB 999,P7-50,902 Battelle Blvd, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD JUL PY 2000 VL 40 IS 1 BP 1 EP 1 PG 1 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA 350XL UT WOS:000089126900001 PM 10977870 ER PT J AU Pennycook, SJ Rafferty, B Nellist, PD AF Pennycook, SJ Rafferty, B Nellist, PD TI Z-contrast imaging in an aberration-corrected scanning transmission electron microscope SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE scanning transmission electron microscopy; aberration correction; Z-contrast; high angle annular dark field; channeling; Bloch states ID ENERGY-LOSS SPECTROSCOPY; SCATTERED ELECTRONS; RESOLUTION; CRYSTALS; STEM; ATOMS AB We show that in the limit of a large objective (probe-forming) aperture, relevant to a spherical aberration corrected microscope, the Z-contrast image of a zone-axis crystal becomes an image of the Bloch states. The limiting resolution is therefore the width of the Bloch states, which may be greater than that of the free probe. Nevertheless, enormous gains in image quality are expected from the improved contrast and signal-to-noise ratio. We present an analytical channeling model for the thickness dependence of the Z-contrast image in a zone-axis crystal, and show that, at large thicknesses, columnar intensities become proportional to the mean square atomic number, Z(2). C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. RP Pennycook, SJ (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 38 TC 78 Z9 79 U1 2 U2 24 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JUL-AUG PY 2000 VL 6 IS 4 BP 343 EP 352 PG 10 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 335QK UT WOS:000088255600010 ER PT J AU Raabe, D Becker, RC AF Raabe, D Becker, RC TI Coupling of a crystal plasticity finite-element model with a probabilistic cellular automaton for simulating primary static recrystallization in aluminium SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article; Proceedings Paper CT Symposium on the Modelling of Texture and Anisotropic Properties in Steel and Aluminium Industries for Optimum Materials Performance CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc ID CHANNEL DIE COMPRESSION; GRAIN; MICROSTRUCTURES; POLYCRYSTALS; ORIENTATION; DEFORMATION; TEXTURE AB The paper presents a two-dimensional approach for simulating primary static recrystallization, which is based on coupling a viscoplastic crystal plasticity finite-element model with a probabilistic kinetic cellular automaton. The crystal plasticity finite-element model accounts for crystallographic slip and for the rotation of the crystal lattice during plastic deformation. The model uses space and time as independent variables and the crystal orientation and the accumulated slip as dependent variables. The ambiguity in the selection of the active slip systems is avoided by using a viscoplastic formulation that assumes that the slip rate on a slip system is related to the resolved shear stress through a power-law relation. The equations are cast in an updated Lagrangian framework. The model has been implemented as a user subroutine in the commercial finite-element code Abaqus. The cellular automaton uses a switching rule that is formulated as a probabilistic analogue of the Linearized symmetric Turnbull kinetic equation for the motion of sharp grain boundaries. The actual decision about a switching event is made using a simple sampling nonMetropolis Monte Carlo step. The automaton uses space and rime as independent variables and the crystal orientation and a stored energy measure as dependent variables. The kinetics produced by the switching algorithm are scaled through the mesh size, the grain boundary mobility, and the driving force data. The coupling of the two models is realized by: translating the state variables used in the finite-element plasticity model into state variables used in the cellular automaton; mapping the finite-element integration point locations on the quadratic cellular automaton mesh; using the resulting cell size, maximum driving force, and maximum grain boundary mobility occurring in the region for determining the length scale, time step, and local switching probabilities in the automaton; and identifying an appropriate nucleation criterion. The coupling method is applied to the two-dimensional simulation of texture and microstructure evolution in a heterogeneously deformed, high-purity aluminium polycrystal during static primary recrystallization, considering local grain boundary mobilities and driving forces. C1 Max Planck Inst Eisenforsch GmbH, D-40237 Dusseldorf, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Raabe, D (reprint author), Max Planck Inst Eisenforsch GmbH, Max Planck Str 1, D-40237 Dusseldorf, Germany. RI Becker, Richard/I-1196-2013; Raabe, Dierk/A-6470-2009 OI Raabe, Dierk/0000-0003-0194-6124 NR 33 TC 118 Z9 125 U1 3 U2 24 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 2000 VL 8 IS 4 BP 445 EP 462 DI 10.1088/0965-0393/8/4/304 PG 18 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 343VG UT WOS:000088722700005 ER PT J AU Engler, O Padmanabhan, KA Lucke, K AF Engler, O Padmanabhan, KA Lucke, K TI A model for superplastic flow induced texture annihilation SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article; Proceedings Paper CT Symposium on the Modelling of Texture and Anisotropic Properties in Steel and Aluminium Industries for Optimum Materials Performance CY OCT 11-15, 1998 CL ROSEMONT, ILLINOIS SP Minerals Met & Mat Soc ID OPTIMAL STRUCTURAL SUPERPLASTICITY; RELEVANCE; ALLOY; BEHAVIOR; CREEP AB A phenomenological model that simulates the frequently observed texture annihilation during superplastic deformation is presented using the random walk process as an analogy. This phenomenon has been described as 'orientation diffusion'. The model has bean validated by considering the texture changes accompanying superplastic deformation in the alloy SUPRAL LOO (Al-6.5%Cu-0.4%Zr). The resulting 'orientation diffusion coefficient' is given physical significance in terms of two processes present during superplastic flow, namely grain boundary sliding and grain rotation. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Indian Inst Technol, Kanpur 208016, Uttar Pradesh, India. Rhein Westfal TH Aachen, Inst Met & Met Phys, D-52056 Aachen, Germany. RP Padmanabhan, KA (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K765, Los Alamos, NM 87545 USA. NR 29 TC 21 Z9 21 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 2000 VL 8 IS 4 BP 477 EP 490 DI 10.1088/0965-0393/8/4/306 PG 14 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 343VG UT WOS:000088722700007 ER PT J AU Xia, JQ Peng, Y Mian, IS Lue, NF AF Xia, JQ Peng, Y Mian, IS Lue, NF TI Identification of functionally important domains in the N-terminal region of telomerase reverse transcriptase SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID SACCHAROMYCES-CEREVISIAE TELOMERASE; CATALYTIC SUBUNIT GENE; TEMPLATE RNA COMPONENT; TETRAHYMENA TELOMERASE; YEAST TELOMERASE; ATAXIA-TELANGIECTASIA; EUPLOTES AEDICULATUS; MAMMALIAN TELOMERASE; BINDING PROTEIN; EST GENES AB Telomerase is a ribonucleoprotein reverse transcriptase responsible for the maintenance of one strand of telomere terminal repeats. The key protein subunit of the telomerase complex, known as TERT, possesses reverse transcriptase-like motifs that presumably mediate catalysis. These motifs are located in the C-terminal region of the polypeptide. Hidden Markov model-based sequence analysis revealed in the N-terminal region of all TERTs the presence of four conserved motifs, named GQ, CP, QFP, and T. Paint mutation analysis of conserved residues confirmed the functional importance of the GQ motif. In addition, the distinct phenotypes of the GQ mutants suggest that this motif may play at least two distinct functions in telomere maintenance. Deletion analysis indicates that even the most N-terminal nonconserved region of yeast TERT (N region) is required for telomerase function. This N region exhibits a nonspecific nucleic acid binding activity that probably reflects an important physiologic function. Expression studies of various portions of the yeast TERT in Escherichia coli suggest that the N region and the GQ motif together may constitute a stable domain. We propose that all TERTs may have a bipartite organization, with an N-GQ domain connected to the other motifs through a flexible linker. C1 Cornell Univ, Weill Med Coll, WR Hearst Microbiol Res Ctr, Dept Microbiol & Immunol, New York, NY 10021 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Lue, NF (reprint author), Cornell Univ, Weill Med Coll, WR Hearst Microbiol Res Ctr, Dept Microbiol & Immunol, 1300 York Ave, New York, NY 10021 USA. NR 50 TC 110 Z9 115 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 JUL PY 2000 VL 20 IS 14 BP 5196 EP 5207 DI 10.1128/MCB.20.14.5196-5207.2000 PG 12 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 327XP UT WOS:000087820000023 PM 10866675 ER PT J AU Keenan, FP O'Shea, E Thomas, RJ Brosius, JW Katsiyannis, A Ryans, RSI Reid, RHG Pradhan, AK Zhang, HL AF Keenan, FP O'Shea, E Thomas, RJ Brosius, JW Katsiyannis, A Ryans, RSI Reid, RHG Pradhan, AK Zhang, HL TI Si x emission lines in spectra obtained with the Solar EUV Rocket Telescope and Spectrograph (SERTS) SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic data; Sun : activity; Sun : flares; ultraviolet : general ID B-LIKE IONS; HIGH-RESOLUTION OBSERVATIONS; ELECTRON-IMPACT EXCITATION; BORON-LIKE IONS; ATOMIC DATA; IRON PROJECT; ISOELECTRONIC SEQUENCE; RATE COEFFICIENTS; CROSS-SECTIONS; DIAGNOSTICS AB New R-matrix calculations of electron impact excitation rates for transitions among the 2s(2)2p, 2s2p(2) and 2p(3) levels of SI X are presented. These data are subsequently used, in conjunction with recent estimates for proton excitation rates, to derive theoretical electron density sensitive emission-line ratios involving transitions in the similar to 253-356 Angstrom wavelength range. A comparision of these with observations of a solar active region and subflare, obtained during the 1989 flight of the Solar EUV Rocket Telescope and Spectrograph (SERTS), reveals that the electron densities determined from most of the SI X line ratios are consistent with one another for both solar features. In addition, the derived densities are also in good agreement with the values of N-e estimated from diagnostic lines in other species formed at similar electron temperatures to SI X, such as Fe XII and Fe XIII. These results provide observational support for the general accuracy of the adopted atomic data, and hence line ratio calculations, employed in the present analysis. However, we find that the SI X 256.32-Angstrom line is blended with the He ii transition at the same wavelength, while the feature at 292.25 Angstrom is not due to SI X, but currently remains unidentified. The intensity of the 253.81-Angstrom line in the SERTS active region spectrum is about a factor of 3 larger than expected from theory, but the reason for this is unclear, and requires additional observations to explain the discrepancy. C1 Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Raytheon ITSS, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Queens Univ Belfast, Dept Appl Math & Theoret Phys, Belfast BT7 1NN, Antrim, North Ireland. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Keenan, FP (reprint author), Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. RI Katsiyannis, Thanassis/L-8496-2013 NR 31 TC 16 Z9 16 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUL 1 PY 2000 VL 315 IS 3 BP 450 EP 456 DI 10.1046/j.1365-8711.2000.03599.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331JR UT WOS:000088016100006 ER PT J AU Chin, HNS Rodriguez, DJ Cederwall, RT Chuang, CC Grossman, AS Yio, JJ Fu, Q Miller, MA AF Chin, HNS Rodriguez, DJ Cederwall, RT Chuang, CC Grossman, AS Yio, JJ Fu, Q Miller, MA TI A microphysical retrieval scheme for continental low-level stratiform clouds: Impacts of the subadiabatic character on microphysical properties and radiation budgets SO MONTHLY WEATHER REVIEW LA English DT Article ID LIQUID WATER; MIXED-LAYER; AIRCRAFT OBSERVATIONS; STRATOCUMULUS CLOUDS; MARINE STRATOCUMULUS; CUMULUS CLOUDS; STRATUS CLOUD; SQUALL LINE; PARAMETERIZATION; CLIMATE AB Using measurements from the Department of Energy's Atmospheric Radiation Measurement Program, a modified ground-based remote sensing technique is developed and evaluated to study the impacts of the subadiabatic character of continental low-level stratiform clouds on microphysical properties and radiation budgets. Airborne measurements and millimeter-wavelength cloud radar data are used to validate retrieved microphysical properties of three stratus cloud systems occurring in the April 1994 and 1997 intensive observation periods at the Southern Great Plains site. The addition of the observed cloud-top height into the Han and Westwater retrieval scheme eliminates the need to invoke the adiabatic assumption. Thus, the retrieved liquid water content (LWC) profile is represented as the product of an adiabatic LWC profile and a weighting function. Based on in situ measurements, two types of weighting functions are considered in this study: one is associated with a subadiabatic condition involving cloud-top entrainment mixing alone (type I) and the other accounts for both cloud-top entrainment mixing and drizzle effects (type II). The adiabatic cloud depth ratio (ACDR), defined as the ratio of the actual cloud depth to the one derived from the adiabatic assumption, is found to be a useful parameter for classifying the subadiabatic character of low-level stratiform clouds. The type I weighting function only exists in the lower ACDR regime, while the type II profile can appear for any adiabatic cloud depth ratio. Results indicate that the subadiabatic character of low-level stratiform clouds has substantial impacts on radiative energy budgets, especially those in the shortwave, via the retrieved LWC distribution and its related effective radius profile of liquid water Results also show that this subadiabatic character can act to stabilize the cloud deck by reducing the in-cloud radiative heating/cooling contrast. As a whole, these impacts strengthen as the subadiabatic character of low-level stratiform clouds increases. C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94551 USA. Dalhousie Univ, Atmospher Sci Program, Halifax, NS, Canada. Brookhaven Natl Lab, Div Appl Sci, Upton, NY 11973 USA. RP Chin, HNS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, POB 808,L-103, Livermore, CA 94551 USA. RI chuang, cathy/H-4814-2012 NR 40 TC 13 Z9 14 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUL PY 2000 VL 128 IS 7 BP 2511 EP 2527 DI 10.1175/1520-0493(2000)128<2511:AMRSFC>2.0.CO;2 PN 2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386JV UT WOS:000166058500008 ER PT J AU Vo-Dinh, T Alarie, JP Cullum, BM Griffin, GD AF Vo-Dinh, T Alarie, JP Cullum, BM Griffin, GD TI Antibody-based nanoprobe for measurement of a fluorescent analyte in a single cell SO NATURE BIOTECHNOLOGY LA English DT Article DE nanoprobe; nanotechnology; bioprobe; antibody; benzo[a]pyrene; benzopyrene tetrol; DNA damage; DNA adduct; carcinogen; intracellular measurement ID DNA; BIOSENSOR; SENSORS AB We report here the application of an antibody-based nanoprobe for in situ measurements of a single cell. The nanoprobe employs antibody-based receptors targeted to a fluorescent analyte, benzopyrene tetrol (BPT), a metabolite of the carcinogen benzo[a]pyrene (BaP) and of the BaP-DNA adduct. Detection of BPT is of great biomedical interest, since this species can serve as a biomarker for monitoring DNA damage due to BaP exposure and for possible precancer diagnosis. The measurements were performed on the rat liver epithelial clone 9 cell line, which was used as the model cell system. Before making measurements, the cells were treated with BPT. Nanoprobes were inserted into individual cells, incubated 5 min to allow antigen-antibody binding, and then removed for fluorescence detection. We determined a concentration of 9.6 +/- 0.2 x 10(-11) M for BPT in the individual cells investigated. The results demonstrate the possibility of in situ measurements inside a single cell using an antibody-based nanoprobe. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 15 TC 84 Z9 87 U1 2 U2 30 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD JUL PY 2000 VL 18 IS 7 BP 764 EP 767 DI 10.1038/77337 PG 4 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 331YN UT WOS:000088046400027 PM 10888846 ER PT J AU Li, J Derewenda, U Dauter, Z Smith, S Derewenda, ZS AF Li, J Derewenda, U Dauter, Z Smith, S Derewenda, ZS TI Crystal structure of the Escherichia coli thioesterase II, a homolog of the human Nef binding enzyme SO NATURE STRUCTURAL BIOLOGY LA English DT Letter ID CATALYTIC TRIADS; ACYL; IDENTIFICATION; PURIFICATION; MECHANISM; CLONING; SYSTEM; HIV-1; GENE AB Here we report the solution and refinement at 1.9 Angstrom resolution of the crystal structure of the Escherichia coli medium chain length acyl-CoA thioesterase II. This enzyme is a close homolog of the human protein that interacts with the product of the HIV-1 Nef gene, sharing 45% amino acid sequence identity with it. The structure of the a coli thioesterase II reveals a new tertiary fold, a 'double hot dog: showing an internal repeat with a basic unit that is structurally similar to the recently described beta-hydroxydecanoyl thiol ester dehydrase, The catalytic site, inferred from the crystal structure and verified by site directed mutagenesis, involves novel chemistry and includes Asp 204, Gin 278 and Thr 228, which synergistically activate a nucleophilic water molecule. C1 Univ Virginia, Dept Mol Physiol & Biol Phys, Charlottesville, VA 22908 USA. NCI, Frederick, MD 21701 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Childrens Hosp Oakland, Res Inst, Oakland, CA 94609 USA. RP Derewenda, ZS (reprint author), Univ Virginia, Dept Mol Physiol & Biol Phys, POB 800736, Charlottesville, VA 22908 USA. NR 34 TC 105 Z9 108 U1 0 U2 4 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUL PY 2000 VL 7 IS 7 BP 555 EP 559 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 330MR UT WOS:000087966300011 PM 10876240 ER PT J AU Yang, WL Barth, RF Bartus, RT Rotaru, JH Moeschberger, ML Ferketich, AK Nawrocky, MM Coderre, EA Goodman, JH AF Yang, WL Barth, RF Bartus, RT Rotaru, JH Moeschberger, ML Ferketich, AK Nawrocky, MM Coderre, EA Goodman, JH TI Improved survival after boron neutron capture therapy of brain tumors by cereport-mediated blood-brain barrier modulation to enhance delivery of boronophenylalanine SO NEUROSURGERY LA English DT Article; Proceedings Paper CT 8th International Symposium on Neutron Capture Therapy for Cancer CY SEP 13-24, 1998 CL LA JOLLA, CA SP US DOE, Natl Canc Inst, Univ Calif Los Angeles DE boron neutron capture therapy; boronophenylalanine; cereport ID INTRACAROTID INFUSION; BRADYKININ ANALOG; DRUG-DELIVERY; SODIUM BOROCAPTATE; RMP-7; CARBOPLATIN; GLIOMAS; RATS; DISRUPTION; INJECTION AB OBJECTIVE: Cereport (Alkermes, Inc., Cambridge, MA), or, as it has been previously called, RMP-7 (receptor-mediated permeabilizer-7), is a bradykinin analog that has been shown to produce a transient, pharmacologically mediated opening of the blood-brain barrier. The purpose of the present study was to determine whether the efficacy of boron neutron capture therapy (BNCT) could be enhanced by means of intracarotid (i.c.) infusion of Cereport, in combination with intravenous (i.v.) injection or i.c. infusion of boronophenylalanine (BPA) in the F98 rat glioma model. METHODS: For biodistribution studies, Fischer rats bearing intracerebral implants of the F98 glioma received i.v. or i.c. injections of 300 or 500 mg/kg body weight (b.w.) of BPA with or without i.c. infusion of 1.5 mu g/kg b.w. of Cereport. For therapy studies, BNCT was initiated 14 days after intracerebral implantation of 10(3) F98 cells. The i.v. or i.c. injection of BPA (500 mg/kg b.w.) was given with or without Cereport, and the animals were irradiated 2.5 hours later at the Brookhaven Medical Research Reactor with a collimated beam of thermal neutrons delivered to the head. RESULTS: At a BPA dose of 500 mg/kg b.w., tumor boron concentrations (mean +/- standard deviation) were 55.7 +/- 9.6 mu g/g with Cereport versus 33.6 +/- 3.9 mu g/g without Cereport at 2.5 hours after i.c. infusion of BPA, and concentrations were 29.4 +/- 9.9 mu g/g with Cereport versus 15.4 +/- 3.5 mu g/g without Cereport (P < 0.05) after i.v. injection of BPA. After i.c. administration of BPA and Cereport, the tumor-to-blood ratio was 5.4 +/- 0.6, and the tumor-to-brain ratio was 5.2 +/- 2.4. After BNCT with BPA at a dose of 500 mg/kg, the survival time was 50 +/- 16 days for i.c. administration of BPA with Cereport versus 40 +/- 6 days without Cereport (P = 0.05), 38 +/- 4 days for i.v. administration of BPA with Cereport versus 34 +/- 3 days without Cereport (P = 0.02), 28 +/- 5 days for irradiated controls, and 23 +/- 3 days for untreated controls. Compared with untreated controls, there was a 117% increase in lifespan in rats that received an i.c. infusion of Cereport and then BPA, and an 86% increase in lifespan in rats that received i.c. administration of BPA without Cereport. CONCLUSION: These studies have established that i.c. administration of Cereport can not only increase tumor uptake of BRA, but also enhance the efficacy of BNCT. C1 Ohio State Univ, Dept Pathol, Sch Publ Hlth, Columbus, OH 43210 USA. Ohio State Univ, Sch Publ Hlth, Div Epidemiol & Biometr, Columbus, OH 43210 USA. Ohio State Univ, Div Neurosurg, Columbus, OH 43210 USA. Alkermes Inc, Cambridge, MA USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Barth, RF (reprint author), Ohio State Univ, Dept Pathol, Sch Publ Hlth, 165 Hamilton Hall,1645 Neil Ave, Columbus, OH 43210 USA. EM barth.1@osu.edu NR 54 TC 13 Z9 15 U1 1 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0148-396X J9 NEUROSURGERY JI Neurosurgery PD JUL PY 2000 VL 47 IS 1 BP 189 EP 197 DI 10.1097/00006123-200007000-00039 PG 9 WC Clinical Neurology; Surgery SC Neurosciences & Neurology; Surgery GA 333ML UT WOS:000088133800101 PM 10917362 ER PT J AU Norby, R Fitter, A Jackson, R AF Norby, R Fitter, A Jackson, R TI Root dynamics and global change: An ecosystem perspective SO NEW PHYTOLOGIST LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ York, York YO1 5DD, N Yorkshire, England. Duke Univ, Durham, NC 27706 USA. RP Norby, R (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 2 TC 11 Z9 14 U1 2 U2 11 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD JUL PY 2000 VL 147 IS 1 BP 1 EP 2 DI 10.1046/j.1469-8137.2000.00674.x PG 2 WC Plant Sciences SC Plant Sciences GA 341EK UT WOS:000088577900001 ER PT J AU Norby, RJ Jackson, RB AF Norby, RJ Jackson, RB TI Root dynamics and global change: seeking an ecosystem perspective SO NEW PHYTOLOGIST LA English DT Review DE fine roots; root dynamics; turnover; climatic change; global change; elevated CO2; nitrogen deposition; mycorrhizas ID ATMOSPHERIC CARBON-DIOXIDE; NORTHERN HARDWOOD FOREST; CO2; TURNOVER; RESPONSES; GROWTH AB Changes in the production and turnover of roots in forests and grasslands in response to rising atmospheric CO2 concentrations, elevated temperatures, altered precipitation, or nitrogen deposition could be a key link between plant responses and longer-term changes in soil organic matter and ecosystem carbon balance. Here we summarize the experimental observations, ideas, and new hypotheses developed in this area in the rest of this volume. Three central questions are posed. Do elevated atmospheric CO2, nitrogen deposition, and climatic change alter the dynamics of root production and mortality! What are the consequences of root responses to plant physiological processes ? What are the implications of root dynamics to soil microbial communities and the fate of carbon in soil, Ecosystem-level observations of root production and mortality in response to global change parameters are just starting to emerge. The challenge to root biologists is to overcome the profound methodological and analytical problems and assemble a more comprehensive data set with sufficient ancillary data that differences between ecosystems can be explained. The assemblage of information reported herein on global patterns of root turnover, basic root biology that controls responses to environmental variables, and new observations of root and associated microbial responses to atmospheric and climatic change helps to sharpen our questions and stimulate new research approaches. New hypotheses have been developed to explain why responses of root turnover might differ in contrasting systems, how carbon allocation to roots is controlled, and how species differences in root chemistry might explain the ultimate fate of carbon in soil. These hypotheses and the enthusiasm for pursuing them are based on the firm belief that a deeper understanding of root dynamics is critical to describing the integrated response of ecosystems to global change. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Duke Univ, Dept Bot, Durham, NC 27708 USA. Duke Univ, Nicholas Sch Environm, Durham, NC 27708 USA. RP Norby, RJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Norby, Richard/C-1773-2012 OI Norby, Richard/0000-0002-0238-9828 NR 48 TC 210 Z9 279 U1 14 U2 114 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD JUL PY 2000 VL 147 IS 1 BP 3 EP 12 DI 10.1046/j.1469-8137.2000.00676.x PG 10 WC Plant Sciences SC Plant Sciences GA 341EK UT WOS:000088577900002 ER PT J AU Joslin, JD Wolfe, MH Hanson, PJ AF Joslin, JD Wolfe, MH Hanson, PJ TI Effects of altered water regimes on forest root systems SO NEW PHYTOLOGIST LA English DT Review DE global climate; drought; root growth; fine-root turnover (FRT); root mortality; upland oaks; carbon allocation ID CO2-INDUCED CLIMATE CHANGE; EASTERN NORTH-AMERICA; FINE ROOTS; HARDWOOD FOREST; ORGANIC-MATTER; DOUGLAS-FIR; NITROGEN; DYNAMICS; GROWTH; PINE AB How ecosystems adapt to climate changes depends in part on how individual trees allocate resources to their components. A review of research using tree seedlings provides some support for the hypothesis that some tree species respond to exposure to drought with increases in root:shoot ratios but little change in total root biomass. Limited research on mature trees over moderately long time periods (2-10 yr), has given mixed results with some studies also providing evidence for increases in root:shoot ratios. The Throughfall Displacement Experiment (TDE) was designed to simulate both an increase and a decrease of 33% in water inputs to a mature deciduous forest over a number of years. Belowground research on TDE was designed to examine four hypothesized responses to long-term decreases in water availability; (1) increases in fine-root biomass, (2) increases in fine root:foliage ratio, (3) altered rates of fine-root turnover (FRT), and (4) depth of rooting. Minirhizotron root elongation data from 1994 to 1998 were examined to evaluate the first three hypotheses. Differences across treatments in net fine-root production (using minirhizotron root elongation observations as indices of biomass production) were small and not significant. Periods of lower root production in the dry treatment were compensated for by higher growth during favorable periods. Although not statistically significant, both the highest production (20 to 60% higher) and mortality (18 to 34 % higher) rates were found in the wet treatment, resulting in the highest index of FRT. After 5 yr, a clear picture of stand fine-root-system response to drought exposure has yet to emerge in this forest ecosystem. Our results provide little support for either an increase in net fine-root production or a shift towards an increasing root:shoot ratio with long-term drought exposure. One possible explanation for higher FRT rates in the wet treatment could be a positive relationship between FRT and nitrogen and other nutrient availability, as treatments hare apparently resulted in increased immobilization of nutrients in the forest floor litter under drier conditions. Such hypotheses point to the continued need to study the interactions of water stress, nutrient availability and carbon-fixation efficiency in future long-term studies. C1 Belowground Forest Res, Oak Ridge, TN 37830 USA. Tennessee Valley Author, Norris, TN 37828 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Joslin, JD (reprint author), Belowground Forest Res, 112 Newcrest Lane, Oak Ridge, TN 37830 USA. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 59 TC 109 Z9 124 U1 8 U2 62 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD JUL PY 2000 VL 147 IS 1 BP 117 EP 129 DI 10.1046/j.1469-8137.2000.00692.x PG 13 WC Plant Sciences SC Plant Sciences GA 341EK UT WOS:000088577900010 ER PT J AU Gorelenkov, NN Bernabei, S Cheng, CZ Hill, KW Nazikian, R Kaye, S Kusama, Y Kramer, GJ Shinohara, K Ozeki, T Gorelenkova, MV AF Gorelenkov, NN Bernabei, S Cheng, CZ Hill, KW Nazikian, R Kaye, S Kusama, Y Kramer, GJ Shinohara, K Ozeki, T Gorelenkova, MV TI Stability properties of toroidal Alfven modes driven by fast particles SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems CY OCT 12-14, 1999 CL NAKA, JAPAN SP IAEA ID ENERGETIC PARTICLES; EIGENMODES; PLASMAS; TOKAMAKS; INSTABILITIES; REACTOR; CODE AB Issues of Alfven mode stability in advanced tokamak regimes are addressed on the basis of recent developments in theory, computational methods and progress in experiments. The instability of toroidal Alfven eigenmodes (TAEs) is analysed for spherical tokamaks, such as the NSTX using the NOVA-K code. Modes in the Alfven frequency range observed in JT-60U during negative ion based NBI heating at energies epsilon(b0) = 360 keV, and in TFTR during ICRH experiments with chirping frequency, on various timescales, are analysed using the kinetic non-perturbative code HINST, which is able to resolve new resonant branches of the toroidal Alfven modes called resonant TAEs (RTAEs). However, as is shown the mechanisms for frequency chirping may be different in different experiments. In TFTR, frequency chirping results from the slow variation of q profile between sawteeth. In JT-60U experiments some frequency chirping modes have very short timescales, which suggests the cause is the change in fast particle distribution. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Japan Atom Energy Res Inst, Ibaraki, Osaka, Japan. TRINITI, Troitsk, Moscow Region, Russia. RP Gorelenkov, NN (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Cheng, Chio/K-1005-2014 NR 27 TC 24 Z9 24 U1 0 U2 0 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 JUL PY 2000 VL 40 IS 7 BP 1311 EP 1323 DI 10.1088/0029-5515/40/7/303 PG 13 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700003 ER PT J AU Kolesnichenko, YI Lutsenko, VV White, RB Yakovenko, YV AF Kolesnichenko, YI Lutsenko, VV White, RB Yakovenko, YV TI Effect of sawtooth oscillations on energetic ions SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems CY OCT 12-14, 1999 CL NAKA, JAPAN SP IAEA ID EMISSION PROFILE MEASUREMENTS; FUSION TEST REACTOR; NEUTRON EMISSION; ALPHA-PARTICLES; REDISTRIBUTION; CRASHES; TFTR; JET; TRANSPORT; PLASMAS AB The results are summarized of studies on energetic ion transport induced by sawtooth oscillations in tokamaks. The main attention is paid to a description of the physical mechanisms responsible for this transport. In addition to an overview, new material is also presented. The new results concern the resonant interaction of the particles and the electromagnetic field of sawtooth crashes. In particular, it is discovered that the dominant harmonic of the crashes (m = n = 1) can lead to stochastic motion of particles with large. orbit widths ('potato' orbits). The regular motion of potato orbits and quasi-stagnation particles in the presence of an n = 1 mode is studied, and their characteristic displacements associated with quick switching on and off of the mode are found. C1 Ukrainian Acad Sci, Inst Nucl Res, Ctr Sci, UA-252028 Kiev, Ukraine. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kolesnichenko, YI (reprint author), Ukrainian Acad Sci, Inst Nucl Res, Ctr Sci, UA-252028 Kiev, Ukraine. RI White, Roscoe/D-1773-2013; OI White, Roscoe/0000-0002-4239-2685; Yakovenko, Yuriy/0000-0002-3499-5275 NR 36 TC 26 Z9 26 U1 0 U2 3 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 JUL PY 2000 VL 40 IS 7 BP 1325 EP 1341 DI 10.1088/0029-5515/40/7/304 PG 17 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700004 ER PT J AU Toi, K Takechi, M Isobe, M Nakijima, N Osakabe, M Takagi, S Kondo, T Matsunaga, G Ohkuni, K Sasao, M Yamamoto, S Ohdachi, S Sakakibara, S Yamada, H Watanabe, KY Darrow, DS Fujisawa, A Goto, M Ida, K Idei, H Iguchi, H Lee, S Kado, S Kubo, S Kaneko, O Kawahata, K Matsuoka, K Minami, T Morita, S Motojima, O Narihara, K Nishimura, S Ohyabu, N Oka, Y Okamura, S Ozaki, T Sato, K Sato, M Shimizu, A Shimozuma, T Takeiri, Y Tanaka, K Tokuzawa, T Tsumori, K Yamada, I Yoshimura, Y AF Toi, K Takechi, M Isobe, M Nakijima, N Osakabe, M Takagi, S Kondo, T Matsunaga, G Ohkuni, K Sasao, M Yamamoto, S Ohdachi, S Sakakibara, S Yamada, H Watanabe, KY Darrow, DS Fujisawa, A Goto, M Ida, K Idei, H Iguchi, H Lee, S Kado, S Kubo, S Kaneko, O Kawahata, K Matsuoka, K Minami, T Morita, S Motojima, O Narihara, K Nishimura, S Ohyabu, N Oka, Y Okamura, S Ozaki, T Sato, K Sato, M Shimizu, A Shimozuma, T Takeiri, Y Tanaka, K Tokuzawa, T Tsumori, K Yamada, I Yoshimura, Y CA CHS LHD Expt Grp TI Energetic ion driven MHD instabilities observed in the heliotron/torsatron devices Compact Helical System and Large Helical Device SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems CY OCT 12-14, 1999 CL NAKA, JAPAN SP IAEA ID TOROIDAL ALFVEN EIGENMODES; DIII-D TOKAMAK; FISHBONE INSTABILITY; NEAR-THRESHOLD; MODES; TFTR; STELLARATOR; STABILITY; PLASMA; EXCITATION AB Recent results of energetic ion driven MHD instabilities observed in the heliotron/torsatron devices Compact Helical System (CHS) and Large Helical Device (LHD) are presented. Alfven eigenmodes (AEs) and fishbone-like burst modes (FBs) destabilized by energetic ions were observed in NBI heated plasmas of CHS. The AEs are toroidicity induced Alfven eigenmodes (TAEs) and global Alfven eigenmodes (GAEs), where the identified toroidal mode numbers are n = 1 and 2 for TAEs and n = 0 for GAEs. The frequencies of the FBs are less than, at most, half of the minimum TAE gap frequency and do not exhibit the obvious density dependence related to Alfven velocity. The modes have characteristic features of the energetic particle modes or the resonant TAEs excited by circulating energetic beam ions produced by NBI. Bursting amplitude modulation is observed in TAEs as well as in FBs. Rapid frequency chirping is observed in each burst, by a factor of 2-6 in FBs and about 25% in TAEs. In several shots, the power spectrum of the TAEs is split into multiple peaks having the same toroidal mode number through non-linear evolution of TAEs. A pulsed increase in energetic ion loss towards the wall is induced by m = 3/n = 2 FBs, but so far not by m = 2/n = 1 FBs, TAEs and GAEs, where m is the poloidal mode number. This research has been extended to LHD plasmas heated by neutral hydrogen beams with about 130 keV energy. Similar to CHS, TAEs and FBs were observed in relatively low density plasmas at low toroidal magnetic field (Bt = 1.5 T). C1 Nagoya Univ, Dept Energy Engn Sci, Nagoya, Aichi, Japan. Grad Univ Adv Studies, Tokishi, Japan. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Japan Atom Energy Res Inst, Naka, Ibaraki 31101, Japan. RP Toi, K (reprint author), Nagoya Univ, Dept Energy Engn Sci, Nagoya, Aichi, Japan. RI Ida, Katsumi/E-4731-2016 OI Ida, Katsumi/0000-0002-0585-4561 NR 46 TC 59 Z9 60 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 2000 VL 40 IS 7 BP 1349 EP 1362 DI 10.1088/0029-5515/40/7/306 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700006 ER PT J AU Sharapov, SE Alper, B Borba, D Eriksson, LG Fasoli, A Gill, RD Gondhalekar, A Gormezano, C Heeter, RF Huysmans, GTA Jacquinot, J Korotkov, AA Lamalle, P Mantsinen, MJ McDonald, DC Rimini, FG Start, DFH Testa, D Thomas, PR AF Sharapov, SE Alper, B Borba, D Eriksson, LG Fasoli, A Gill, RD Gondhalekar, A Gormezano, C Heeter, RF Huysmans, GTA Jacquinot, J Korotkov, AA Lamalle, P Mantsinen, MJ McDonald, DC Rimini, FG Start, DFH Testa, D Thomas, PR CA JET Team TI Energetic particle physics in JET SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems CY OCT 12-14, 1999 CL NAKA, JAPAN SP IAEA ID DEUTERIUM-TRITIUM PLASMAS; ION-CYCLOTRON EMISSION; ALFVEN EIGENMODE EXPERIMENTS; FUSION ALPHA-PARTICLES; DT PLASMAS; RUNAWAY ELECTRONS; TEST REACTOR; ICRF WAVES; TOKAMAK; TFTR AB Results achieved on JET during the 1997-1999 experimental campaigns in the physics of energetic ions and runaway electrons are reviewed. Heating of deuterium-tritium (DT) plasmas by fusion born alpha particles is found to be similar to that achieved by comparable ICRF heating of deuterium plasmas. The stability of alpha particle driven Alfven eigenmodes (AEs) in the highest fusion power ELM-free H mode discharges is shown to be consistent with the existing theoretical analysis for AEs. Direct measurements of the trapped alpha particle and knock-on deuteron distribution functions by a neutral particle analyser (NPA) are described, New ICRF heating scenarios tested in JET DT plasmas are presented in view of the possible use of the ICRF heating of ITER-like DT plasmas on route to ignition. The energetic ion pinch in the presence of toroidally asymmetric ICRF waves is studied experimentally on JET. Recent experimentally observed effects of ICRF accelerated ions on sawteeth in JET are reviewed. Detailed time and space resolved X ray images of the electron runaway beam in flight spontaneously generated by disruptions on JET are described. C1 Jet Joint Undertaking, JET Team, Abingdon OX14 3EA, Oxon, England. IST, EURATOM Assoc, Lisbon, Portugal. CEA, EURATOM Assoc, St Paul Durance, France. MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Tekes, EURATOM Assoc, Helsinki, Finland. RP Sharapov, SE (reprint author), Jet Joint Undertaking, JET Team, Abingdon OX14 3EA, Oxon, England. RI Borba, Duarte/K-6148-2015; Mantsinen, Mervi/B-8023-2016 OI Borba, Duarte/0000-0001-5305-2857; Mantsinen, Mervi/0000-0001-9927-835X NR 57 TC 7 Z9 7 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 2000 VL 40 IS 7 BP 1363 EP 1381 DI 10.1088/0029-5515/40/7/307 PG 19 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700007 ER PT J AU Kramer, GJ Iwase, M Kusama, Y Morioka, A Nemoto, M Nishitani, T Shinohara, K Takeji, S Tobita, K Ozeki, T Cheng, CZ Fu, GY Nazikian, R AF Kramer, GJ Iwase, M Kusama, Y Morioka, A Nemoto, M Nishitani, T Shinohara, K Takeji, S Tobita, K Ozeki, T Cheng, CZ Fu, GY Nazikian, R TI Fast particle experiments in JT-60U SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 6th IAEA Technical Committee Meeting on Energetic Particles in Magnetic Confinement Systems CY OCT 12-14, 1999 CL NAKA, JAPAN SP IAEA ID INDUCED ALFVEN EIGENMODES; FUSION TEST REACTOR; FAST-ION TRANSPORT; TOROIDAL PLASMAS; SAWTOOTH STABILIZATION; SAFETY-FACTOR; Q-PROFILE; TOKAMAK; JET; MODES AB Results of fast particle experiments in JT-60U are presented. The fast particles were created with ICRF heating and negative ion based neutral beam injection (N-NBI) heating. With both heating systems Alfven eigenmodes (AEs) were excited. The AEs that were excited with ICRF during sawtooth stabilization experiments are used to extract information about the magnetic safety profile in the plasma centre. These measurements are compared with motional Stark effect measurements and with sawtooth models. The first results on the radial mode structure of TAEs as measured with an X mode reflectometer system are also given. When the N-NBI beam was injected into a sawtoothing plasma, a significant increase in sawtooth period was observed. A survey is given of the bursting, chirping and stationary frequency modes that have been found in the Alfven range of frequencies when N-NBI was injected. Most, but not all, of these modes scale with the Alfven velocity. One group of modes that starts in the continuum and chirps up to the toroidicity induced Alfven eigenmode (TAE) gap in typically 200 ms can be identified as resonant TAEs, whereas another group of modes appears as short bursts (up to 20 ms) in the Alfven continuum. C1 Japan Atom Energy Res Inst, Naka Fus Res Estab, Naka, Ibaraki 31101, Japan. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kramer, GJ (reprint author), Japan Atom Energy Res Inst, Naka Fus Res Estab, Naka, Ibaraki 31101, Japan. RI Cheng, Chio/K-1005-2014 NR 56 TC 41 Z9 41 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 JUL PY 2000 VL 40 IS 7 BP 1383 EP 1396 DI 10.1088/0029-5515/40/7/308 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700008 ER PT J AU Ferron, JR Lao, LL Luce, TC Miller, RL Osborne, TH Rice, BW Strait, EJ Taylor, TS AF Ferron, JR Lao, LL Luce, TC Miller, RL Osborne, TH Rice, BW Strait, EJ Taylor, TS TI Modification of tokamak edge instability character through control of ballooning mode second stability regime accessibility SO NUCLEAR FUSION LA English DT Article ID DIII-D; MAGNETOHYDRODYNAMIC STABILITY; CURRENT PROFILES; LOCALIZED MODES; PLASMAS AB The frequency and amplitude of edge localized instabilities in DIII-D tokamak H mode discharges are shown to depend on the discharge shape squareness. An abrupt increase in instability frequency and decreases in instability amplitude and edge pressure gradient are observed when the squareness is changed to a sufficiently large or a sufficiently small value. The observed changes in the instability frequency and amplitude correlate with a predicted loss, at high and low; values of discharge shape squareness, of access in the H mode edge region to thr ideal infinite toroidal mode number ballooning mode second regime of stability. When no edge region second stability regime access is predicted, the measured pressure gradient is in agreement with the predicted ballooning mode first stability regime threshold. When the second stability regime is predicted to be locally accessible, the edge region pressure gradient increases to values well above the first stability regime limit. C1 Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Ferron, JR (reprint author), Gen Atom Co, San Diego, CA 92186 USA. NR 20 TC 11 Z9 11 U1 0 U2 3 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 JUL PY 2000 VL 40 IS 7 BP 1411 EP 1418 DI 10.1088/0029-5515/40/7/310 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 332NQ UT WOS:000088080700010 ER PT J AU Burger, A Chattopadhyay, K Chen, H Ma, X Ndap, JO Schieber, M Schlesinger, TE Yao, HW Erickson, J James, RB AF Burger, A Chattopadhyay, K Chen, H Ma, X Ndap, JO Schieber, M Schlesinger, TE Yao, HW Erickson, J James, RB TI Defects in CZT crystals and their relationship to gamma-ray detector performance SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International-Union-of-Materials-Research-Societies International Conference on Advanced Materials (IUMRS-ICAM 99) CY JUN 13-18, 1999 CL BEIJING, PEOPLES R CHINA SP Int Union Mat Res Soc ID CDZNTE RADIATION DETECTORS; HIGH-PRESSURE BRIDGMAN; CDTE SURFACES; SPECTROSCOPY; PASSIVATION; OXIDATION AB This gaper reviews some of the progress obtained in the understanding of defects in detector grade cadmium zinc telluride material (CZT). Several techniques have been utilized to elucidate some of the issues related to compositional uniformity. effects of precipitates, grain boundaries, and surface defects related to mechanical and chemical treatments. In few cases, special mapping capabilities had to be developed to allow correlations with detector performance. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. Hebrew Univ Jerusalem, IL-91904 Jerusalem, Israel. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Burger, A (reprint author), Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. NR 20 TC 20 Z9 20 U1 1 U2 7 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 JUL 1 PY 2000 VL 448 IS 3 BP 586 EP 590 DI 10.1016/S0168-9002(00)00294-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336CU UT WOS:000088285000013 ER PT J AU Ditroi, F Tarkanyi, F Ali, MA Ando, L Heselius, SJ Yu, SB Zhuang, YX Mustafa, MG AF Ditroi, F Tarkanyi, F Ali, MA Ando, L Heselius, SJ Yu, SB Zhuang, YX Mustafa, MG TI Investigation of He-3-induced reactions on natural Ti for nuclear analytical and radionuclide production purposes SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE cross-section; charged particle; excitation function; natural titanium; He-3; stacked-foil; TLA; wear measurements ID EXCITATION-FUNCTIONS; BEAM ENERGY; ACTIVATION; IMPLANTATION; INTENSITY; NICKEL AB Excitation Russian Federation functions of He-3-induced nuclear reactions producing Sc-43.44m,Sc-46.47.48, V-48, Cr-48,Cr-49,Cr-51 were measured up to 36 MeV bombarding energy by using the stacked-foil technique on different medium-energy accelerators, The results were compared with the data (cross-section, thick-target yield, activity-distribution functions,...) from the literature, model calculations and other measurements. Earlier measurements at higher energies up to 135 MeV are also plotted to complete the database for He-3-reactions on natural Ti. The new experimental and literature data were compared with the predictions of different model calculations for the V-48 producing reactions. The selected experimental data sets were fitted using different methods to obtain recommended values. The measurements and compilation proved, that the He-3 induced reactions on natural titanium, especially those leading to V-48 and Cr-48 are especially useful for monitoring, for activation analysis and for Thin Layer Activation (TLA) purposes. Production of V-48 as a radiotracer is also recommended. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Hungarian Acad Sci, Inst Nucl Res, H-4001 Debrecen, Hungary. AEA Nucl Res Ctr, Cairo, Egypt. Abo Akad Univ, Turku PET Ctr, Turku, Finland. Obninsk Phys & Power Engn Inst, Obninsk 249020, Russia. Inst Atom Energy, China Nucl Data Ctr, Beijing 102413, Peoples R China. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ditroi, F (reprint author), Hungarian Acad Sci, Inst Nucl Res, POB 51, H-4001 Debrecen, Hungary. RI Ditroi, Ferenc/N-7444-2016 OI Ditroi, Ferenc/0000-0002-3520-157X NR 26 TC 9 Z9 9 U1 1 U2 2 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 JUL PY 2000 VL 168 IS 3 BP 337 EP 346 DI 10.1016/S0168-583X(99)01200-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 329TN UT WOS:000087924500006 ER PT J AU Brantley, PS Larsen, EW AF Brantley, PS Larsen, EW TI Spatial and angular moment analysis of continuous and discretized transport problems SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID EQUATIONS AB A new theoretical tool for analyzing continuous and discretized transport equations is presented. This technique is based on a spatial and angular moment analysis of the analytic transport equation, which yields exact expressions for the "center of mass" and "squared radius of gyration" of the particle distribution. Essentially the same moment analysis is applied to discretized particle transport problems to determine numerical expressions for the center of mass and squared radius of gyration. Because this technique makes no assumption about the optical thickness of the spatial cells or about the amount of absorption in the system, it is applicable to problems that cannot be analyzed by a truncation analysis or an asymptotic diffusion limit analysis. The spatial differencing schemes examined (weighted-diamond, lumped linear discontinuous, and multiple balance) yield a numerically consistent expression for computing the squared radius of gyration plus an error term that depends on the mesh spacing, quadrature constants, and material properties of the system. The numerical results presented suggest that the relative accuracy of spatial differencing schemes for different types of problems can be assessed by comparing the magnitudes of these error terms. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RP Brantley, PS (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-23, Livermore, CA 94551 USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUL PY 2000 VL 135 IS 3 BP 199 EP 226 PG 28 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 328TX UT WOS:000087867200001 ER PT J AU Fu, CY AF Fu, CY TI Effects of differing energy dependences in three level-density models on calculated cross sections SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID ISOTOPES; NICKEL AB Three level-density formalisms commonly used for cross-section calculations are examined. Residual nuclides in neutron interaction with Ni-58 are chosen to quantify the well-known differences in the energy dependences of the three formalisms. Level-density parameters for the Gilbert and Cameron model are determined from experimental information. Parameters for the back-shifted Fermi-gas and generalized superfluid models are obtained by fitting their level densities at two selected energies for each nuclide to those of the Gilbert and Cameron model, forcing the level densities of the three models to be as close as physically allowed. The remaining differences are in their energy dependences that, it is shown, cart change the calculated cross sections and particle emission spectra significantly, in some cases or energy ranges by a factor of 2. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Fu, CY (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 29 TC 6 Z9 6 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUL PY 2000 VL 135 IS 3 BP 246 EP 259 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 328TX UT WOS:000087867200003 ER PT J AU Grimes, SM Anderson, JD Bauer, RW AF Grimes, SM Anderson, JD Bauer, RW TI Application of a simple Ramsauer model for neutron total cross sections for nuclear mass numbers A < 40 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB A recent paper discussed fits of the nuclear Ramsauer model to total neutron cross sections for mass numbers A > 40 and for neutron energies between 6 and 60 MeV; These results are extended to nuclei of mass < 40 A reasonably simple parameterization is found that gives a good representation of a recent set of precision data in this mass range, Particular emphasis is placed on the elements of biological importance: carbon, nitrogen, and oxygen. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Ohio Univ, Dept Phys, Athens, OH 45701 USA. RP Grimes, SM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUL PY 2000 VL 135 IS 3 BP 296 EP 303 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 328TX UT WOS:000087867200008 ER PT J AU Minato, K Sawa, K Koya, T Tomita, T Ishikawa, A Baldwin, CA Gabbard, WA Malone, CM AF Minato, K Sawa, K Koya, T Tomita, T Ishikawa, A Baldwin, CA Gabbard, WA Malone, CM TI Fission product release behavior of individual coated fuel particles for high-temperature gas-cooled reactors SO NUCLEAR TECHNOLOGY LA English DT Article ID PERFORMANCE AB Postirradiation heating tests of TRISO-coated UO2 particles at 1700 and 1800 degrees C were performed to understand fission product release behavior at accident temperatures. The inventory measurements of the individual particles were carried out before and after the heating rests with gamma-ray spectrometry to study the behavior of the individual particles. The time-dependent release behavior of Kr-85, Ag-110m, Cs-134, Cs-137, and Eu-154 were obtained with on-line measurements of fission gas release and intermittent measurements of metallic fission product release during the heating tests. The inventory measurements of the individual particles revealed that fission product release behavior of the individual particles was not uniform, and large particle-to-particle variations in the release behavior of Ag-110, Cs-134, Cs-137, and Eu-154 were found X-my microradiography and ceramography showed that the variations could not be explained by only the presence or absence of cracks in the SiC coating layer The SiC degradation may have been related to the variations. C1 Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Minato, K (reprint author), Japan Atom Energy Res Inst, Tokai, Ibaraki 3191195, Japan. NR 18 TC 47 Z9 47 U1 0 U2 7 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 2000 VL 131 IS 1 BP 36 EP 47 PG 12 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 325BT UT WOS:000087657000004 ER PT J AU Lee, SY Sindelar, RL Losey, DC AF Lee, SY Sindelar, RL Losey, DC TI Thermal modeling and performance analysis of interim dry storage and geologic disposal facilities for spent nuclear fuel SO NUCLEAR TECHNOLOGY LA English DT Article AB Thermal models are constructed and analyses are performed of aluminum-based spent nuclear fuel (Al-SNF) in interim dry storage and geologic disposal configurations. Two models are developed referred to as the interim storage model and the codisposal waste package (WP) model. Time-dependent source terms of Al-SNF forms and the defense high-level waste (DHLW) canisters are also developed for thermal performance analysis of the geologic codisposal WP. The interim storage model is a three-dimensional conduction-convection conjugate model to investigate the natural convection cooling of a sealed dry storage canister with vertical orientation in a dry storage vault. The analysis is made for various decay heat sources (Equivalent to 25 to 35 kW/m(3)) using various boundary conditions around the canister wall and,with backfilled nitrogen or helium gas. Based on the data obtained from the Savannah River Site experimental work and available from the literature, an improved dimensionless correlation for the external heat transfer of the canister by the airflow crossing normal to the staggered tubes is developed. The codisposal WP model considers heat transfer driven by conduction and convection processes combined with radiation for the thermal performance study of an enclosed WP containing one Al-SNF canister and five DHLW glass canisters. Two-dimensional analysis for a representative cross-sectional area of the codisposal WP is performed because each component has a lar ge aspect ratio of package length to diameter and the package is laid down horizontally in a drift tunnel repository. The results showed that the codisposal disposition options for the helium- and air-filled WPs satisfied the present waste acceptance criteria for the WP design under the reference conditions. C1 Westinghouse Savannah River Co, River Technol Ctr, Aiken, SC 29808 USA. Westinghouse Safety Management Solut, Critical Technol Serv, Aiken, SC 29803 USA. RP Lee, SY (reprint author), Westinghouse Savannah River Co, River Technol Ctr, Savannah River Site, Aiken, SC 29808 USA. NR 19 TC 4 Z9 4 U1 1 U2 4 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 2000 VL 131 IS 1 BP 124 EP 151 PG 28 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 325BT UT WOS:000087657000009 ER PT J AU Venclovas, C Thelen, MP AF Venclovas, C Thelen, MP TI Structure-based predictions of Rad1, Rad9, Hus1 and Rad17 participation in sliding clamp and clamp-loading complexes SO NUCLEIC ACIDS RESEARCH LA English DT Article ID DNA-DAMAGE CHECKPOINT; CELL NUCLEAR ANTIGEN; REPLICATION-FACTOR-C; SCHIZOSACCHAROMYCES-POMBE; SACCHAROMYCES-CEREVISIAE; BUDDING YEAST; MUTATIONAL ANALYSIS; CRYSTAL-STRUCTURE; POLYMERASE-III; FISSION YEAST AB The repair of damaged DNA is coupled to the completion of DNA replication by several cell cycle checkpoint proteins, including, for example, in fission yeast Rad1(Sp), HUs1S(p), Rad9(Sp) and Rad17(Sp), We have found that these four proteins are conserved with protein sequences throughout eukaryotic evolution, Using computational techniques, including fold recognition, comparative modeling and generalized sequence profiles, we have made high confidence structure predictions for the each of the Rad1, Hus1 and Rad9 protein families (Rad17(Sc), Mec3(Sc) and Ddc1(Sc) in budding yeast, respectively). Each of these families was found to share a common protein fold with that of PCNA, the sliding damp protein that tethers DNA polymerase to its template. We used previously reported genetic and biochemical data for these proteins from yeast and human cells to predict a heterotrimeric PCNA-like ring structure for the functional Rad1/Rad9/Hus1 complex and to determine their exact order within it. In addition, for each individual protein family, contact regions with neighbors within the PCNA-like ring were identified, Based on a molecular model for Rad17(Sp), we concluded that members of this family, similar to the subunits of the RFC clamp-loading complex, are capable of coupling ATP binding with conformational changes required to load a sliding clamp onto DNA, This model substantiates previous findings regarding the behavior of Rad17 family proteins upon DNA damage and within the RFC complex of clamp-loading proteins. C1 Univ Calif Lawrence Livermore Natl Lab, Mol & Struct Biol Div, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Inst Biotechnol, LT-2028 Vilnius, Lithuania. RP Venclovas, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mol & Struct Biol Div, Biol & Biotechnol Res Program, L-448,POB 808, Livermore, CA 94550 USA. RI Thelen, Michael/C-6834-2008; Thelen, Michael/G-2032-2014 OI Thelen, Michael/0000-0002-2479-5480; Thelen, Michael/0000-0002-2479-5480 NR 54 TC 210 Z9 217 U1 1 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUL 1 PY 2000 VL 28 IS 13 BP 2481 EP 2493 DI 10.1093/nar/28.13.2481 PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 332JN UT WOS:000088070700005 PM 10871397 ER PT J AU Barsky, D Foloppe, N Ahmadia, S Wilson, DM MacKerell, AD AF Barsky, D Foloppe, N Ahmadia, S Wilson, DM MacKerell, AD TI New insights into the structure of abasic DNA from molecular dynamics simulations SO NUCLEIC ACIDS RESEARCH LA English DT Article ID HUMAN APURINIC ENDONUCLEASE; NUCLEAR-MAGNETIC-RESONANCE; REFINED SOLUTION STRUCTURE; DUPLEX DNA; BASE SEQUENCE; SITE ANALOGS; MAJOR HUMAN; HELIX; ACIDS; CONFORMATION AB Abasic (AP) sites constitute a common form of DNA damage, arising from the spontaneous or enzymatic breakage of the N-glycosyl bond and the loss of a nucleotide base, To examine the effects of such damage on DNA structure, especially in the vicinity of the abasic sugar, four 1.5 ns molecular dynamics simulations of double-helical DNA dodecamers with and without a single abasic (tetrahydrofuran, X) lesion in a 5'-d(CXT) context have been performed and analyzed, The results indicate that the abasic site does not maintain a hole or gap in the DNA, but instead perturbs the canonical structure and induces additional flexibility close to the abasic site, In the apurinic simulations (i.e., when a pyrimidine is opposite the AP site), the abasic sugar flipped in and out of the minor groove, and the gap was water filled, except during the occurrence of a novel non-Watson-Crick C-T base pair across the abasic site. The apyrimidinic gap was not penetrated by water until the abasic sugar flipped out and remained extrahelical. Both AP helices showed kinks of 20-30 degrees at the abasic site, The Watson-Crick hydrogen bonds are more transient throughout the DNA double helices containing an abasic site. The abasic sugar displayed an unusually broad range of sugar puckers centered around the northern pucker. The increased motion of the bases and backbone near the abasic site appear to correlate with sequence-dependent helical stability, The data indicate that abasic DNA contorts more easily and in specific ways relative to unmodified DNA, an aspect likely to be important in abasic site recognition and hydrolysis. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Maryland, Sch Pharm, Baltimore, MD 21201 USA. RP Barsky, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, 7000 East Ave,L-448, Livermore, CA 94550 USA. OI MacKerell, Alex/0000-0001-8287-6804 FU NCI NIH HHS [CA79056]; NIGMS NIH HHS [R29 GM051501, GM51501, R01 GM051501] NR 55 TC 46 Z9 47 U1 0 U2 12 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUL 1 PY 2000 VL 28 IS 13 BP 2613 EP 2626 DI 10.1093/nar/28.13.2613 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 332JN UT WOS:000088070700021 PM 10871413 ER PT J AU Howse, JW Hansen, GA Cagliostro, DJ Muske, KR AF Howse, JW Hansen, GA Cagliostro, DJ Muske, KR TI Solving a thermal regenerator model using implicit Newton-Krylov methods SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article ID GMRES AB In this article we discuss the use of an implicit Newton-Krylov method to solve a set of partial differential equations (PDEs) representing a physical model of a blast furnace stove. Blast furnace stoves ave thermal regenerators used to heat the air injected into the blast furnace, providing the heat to chemically reduce iron oxides to iron. The stoves are modeled using a set of PDEs that describe the heatflow in the system. The model is used as a part of a predictive controller that minimizes the fuel gas consumption during the heating cycle while maintaining a high enough output air temperature in the cooling cycle to drive the chemical reaction in the blast furnace. The discrete representation of this model is solved with a preconditioned implicit Newton-Krylov technique. This algorithm uses Newton's method, in which the update to the current solution at each stage is computed by solving a linear system. This linear system is obtained by linearizing the discrete approximation to the PDEs, using a numerical approximation for the Jacobian of the discretized system. This linear system is then solved for the needed update using a preconditioned Krylov subspace projection method. C1 Univ Calif Los Alamos Natl Lab, Div Appl Phys, Computat Sci Methods Grp, Los Alamos, NM 87545 USA. Villanova Univ, Dept Chem Engn, Villanova, PA 19085 USA. RP Howse, JW (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Phys, Computat Sci Methods Grp, X-8,Mail Stop F645, Los Alamos, NM 87545 USA. NR 25 TC 11 Z9 11 U1 0 U2 0 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 USA SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD JUL PY 2000 VL 38 IS 1 BP 23 EP 44 PG 22 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 345DV UT WOS:000088800900002 ER PT J AU Holmgren, M AF Holmgren, M TI Combined effects of shade and drought on tulip poplar seedlings: trade-off in tolerance or facilitation? SO OIKOS LA English DT Article ID RELATIVE GROWTH-RATE; ALLOCATION PATTERNS; PLANT INTERACTIONS; CARBON ALLOCATION; TREE SEEDLINGS; QUERCUS-ALBA; WATER STATUS; COMPETITION; PHOTOSYNTHESIS; COMMUNITIES AB It has been hypothesised that many natural plant distribution patterns can be explained by a trade-off between shade and drought tolerance which would make plants more sensitive to shade under dry conditions. On the other hand, shading by nurse plants is often observed to enhance growth and survival of smaller plants in dry areas. This paper describes an experiment designed to address the interactive effects of drought and shade on growth and physiology of tulip poplar seedlings (Liriodendron tulipifera) grown in shade houses under different combinations of irradiance (1%, 5%, 12%, 17%, and 27% of ambient PAR) and soil water content (5-9%, 11-15%, and >20%). The results show no evidence that higher PAR levels compensate for the negative effects of drought on photosynthesis and growth. Rather, rates of estimated daily shoot carbon gain decreased with PAR under dry conditions. Daily xylem sapflow patterns indicated that this was associated with a strong reduction in stomatal conductance in plants growing in dry soil and high PAR conditions. Whole-shoot light compensation points were higher for plants raised under higher PAR conditions, but were not significantly influenced by the water treatments. Shoot dark respiration rates decreased under drier conditions. These results do not support the hypothesis of a trade-off between shade and drought tolerance. Instead, they indicate mechanisms that can lead to positive effects of shading by neighbouring plants under dry conditions. Indeed, such facilitation is thought to be important in many plant communities. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Holmgren, M (reprint author), Wageningen Univ Agr, Dept Environm Sci, Subdept Forestry, NL-6700 AH Wageningen, Netherlands. NR 63 TC 76 Z9 99 U1 5 U2 37 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0030-1299 J9 OIKOS JI Oikos PD JUL PY 2000 VL 90 IS 1 BP 67 EP 78 DI 10.1034/j.1600-0706.2000.900107.x PG 12 WC Ecology SC Environmental Sciences & Ecology GA 341ML UT WOS:000088594100007 ER PT J AU Wang, DY Aikens, DM English, RE AF Wang, DY Aikens, DM English, RE TI Design of optical systems with both near-field and far-field system requirements SO OPTICAL ENGINEERING LA English DT Article DE lens design; optimization ID PUPIL ABERRATIONS AB The authors describe a simple technique for the generation of well-corrected optical designs with both far-field and near-field requirements. Several design examples illustrate the use of this technique and its range of applicability. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)00207-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wang, DY (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-495, Livermore, CA 94551 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD JUL PY 2000 VL 39 IS 7 BP 1788 EP 1795 DI 10.1117/1.602558 PG 8 WC Optics SC Optics GA 334YJ UT WOS:000088213800007 ER PT J AU Ziober, BL Turner, MA Palefsky, JM Banda, MJ Kramer, RH AF Ziober, BL Turner, MA Palefsky, JM Banda, MJ Kramer, RH TI Type I collagen degradation by invasive oral squamous cell carcinoma SO ORAL ONCOLOGY LA English DT Article DE invasion; matrix metalloproteinases; squamous cell carcinoma; collagen; epidermal growth factor ID EPIDERMAL-GROWTH-FACTOR; MATRIX METALLOPROTEINASES; INTERSTITIAL COLLAGENASE; TUMOR PROGRESSION; TISSUE INHIBITOR; EXPRESSION; METASTASIS; KERATINOCYTES; LOCALIZATION; MIGRATION AB Expression of extracellular matrix-degrading proteases is required for tumor cell invasion. In the present study we examined the production of type I collagen-degrading matrix metalloproteinases (MMPs) in the invasive oral squamous cell carcinoma-derived cell line HSC-3. In the absence of serum or exogenous growth factors, HSC-3 cells displayed no collagen degradation activity. Addition of serum slightly increased collagen proteolysis. However, addition of epidermal growth factor (EGF) resulted in nearly complete degradation of the collagen matrix. Zymography showed that MMP-2 and -9 are secreted by HSC-3 cells. EGF stimulated secretion of an additional gelatinase with a molecular weight similar to that of MMP-1. Immunoblotting of conditioned medium confirmed that EGF and, to a lesser degree type I collagen, increased production of MMP-1. Finally, in situ hybridization revealed intense expression of MMP-1 in oral squamous cell carcinoma specimens. Together, these results indicate that MMP-1 is expressed, induced by EGF, and required for type I collagen degradation in oral squamous cell carcinoma. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif San Francisco, Dept Stomatol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Lab Med, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. RP Ziober, BL (reprint author), Univ Penn, Dept Otorhinolaryngol Head & Neck Surg, 5 Ravdin,3400 Spruce St, Philadelphia, PA 19104 USA. FU NIDCR NIH HHS [P50 DE 11912] NR 36 TC 35 Z9 37 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0964-1955 J9 ORAL ONCOL JI Oral Oncol. PD JUL PY 2000 VL 36 IS 4 BP 365 EP 372 DI 10.1016/S1368-8375(00)00019-1 PG 8 WC Oncology; Dentistry, Oral Surgery & Medicine SC Oncology; Dentistry, Oral Surgery & Medicine GA 333WN UT WOS:000088153900008 PM 10899676 ER PT J AU Nobes, RH Rendell, AP Nieplocha, J AF Nobes, RH Rendell, AP Nieplocha, J TI Computational chemistry on Fujitsu vector-parallel processors: Hardware and programming environment SO PARALLEL COMPUTING LA English DT Article DE Fujitsu supercomputers; architecture; vectorisation; parallelisation; bandwidth; latency ID VX/VPP300/VPP700 SERIES; SUPERCOMPUTER SYSTEMS; OPERATING SYSTEM AB In this and the following paper, we provide an introduction to the Fujitsu VPP range of vector-parallel supercomputers and to some of the computational chemistry software available for the VPP, Here, we consider the hardware and the design of software to exploit its capabilities. The VPP employs proprietary vector processors connected via a crossbar switch in a distributed-memory architecture. High single-node performance requires consideration of vector operand lengths, arithmetic pipe utilisation and memory-to-CPU bandwidth. Most parallel chemistry applications use either explicit 'message-passing' or a 'global-memory' paradigm, and benchmark results are presented for the communications performance of MPI, Linda and the Global Arrays. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fujitsu European Ctr Informat Technol, Uxbridge UB11 1AB, Middx, England. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Nobes, RH (reprint author), Fujitsu European Ctr Informat Technol, 2 Longwalk Rd,Stockley Pk, Uxbridge UB11 1AB, Middx, England. EM nobes@fecit.co.uk RI Rendell, Alistair/A-4883-2008 OI Rendell, Alistair/0000-0002-9445-0146 NR 14 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 EI 1872-7336 J9 PARALLEL COMPUT JI Parallel Comput. PD JUL PY 2000 VL 26 IS 7-8 BP 869 EP 886 DI 10.1016/S0167-8191(00)00018-1 PG 18 WC Computer Science, Theory & Methods SC Computer Science GA 332EG UT WOS:000088060700005 ER PT J AU Schaaf, GD Roth, J Trebin, HR AF Schaaf, GD Roth, J Trebin, HR TI Numerical simulation of dislocation motion in three-dimensional icosahedral quasicrystals SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID DECAGONAL QUASI-CRYSTALS; MOLECULAR-DYNAMICS; SHEAR-STRESS AB In a large number of experiments it has been shown that plastic deformation of quasicrystals can occur by a dislocation mechanism. By molecular dynamics simulations close to zero temperature we have investigated the application of shear stress to a three-dimensional model quasicrystal consisting of Lennard-Jones particles and containing an edge dislocation of the Peierls-Nabarro type. Various visualization methods have been used to trace the dislocation line. To determine suitable Burgers vectors we have calculated the gamma surface, that is the misfit energy obtained by a rigid shift of two probe halves along a glide plane. Glide motion of the dislocation on different glide planes was observed. In its wake a plane of phasonic defects was detected. C1 Univ Stuttgart, Inst Theoret & Angew Phys, D-70550 Stuttgart, Germany. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Schaaf, GD (reprint author), Univ Stuttgart, Inst Theoret & Angew Phys, Pfaffenwaldring 57, D-70550 Stuttgart, Germany. NR 24 TC 9 Z9 9 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUL PY 2000 VL 80 IS 7 BP 1657 EP 1668 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 336AJ UT WOS:000088279500013 ER PT J AU Dobson, JE Bright, EA Coleman, PR Durfee, RC Worley, BA AF Dobson, JE Bright, EA Coleman, PR Durfee, RC Worley, BA TI LandScan: A global population database for estimating populations at risk SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID UNITED-STATES; NIGHTTIME AB The LandScan Global Population Project produced a world-wide 1998 population database at a 30- by 30-second resolution for estimating ambient populations at risk. Best available census counts were distributed to cells based on probability coefficients which, in turn, were based on road proximity, slope, land cover, and nighttime lights. LandScan 1998 has been completed for the entire world. Verification and validation (V&V) studies were conducted routinely for all regions and more extensively for Israel, Germany, and the southwestern United States. Geographic information systems (GIS) were essential for conflation of diverse input variables, computation of probability coefficients, allocation of population to cells, and reconciliation of cell totals with aggregate (usually province) control totals. Remote sensing was an essential source of two input variables-land cover and nightime lights-and one ancillary database-high -resolution panchromatic imagery-used in V&V of the population model and resulting LandScan database. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Dobson, JE (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6237, Oak Ridge, TN 37831 USA. NR 7 TC 308 Z9 344 U1 4 U2 43 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JUL PY 2000 VL 66 IS 7 BP 849 EP 857 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 327ZH UT WOS:000087824000005 ER PT J AU Bill, A Morawitz, H Kresin, VZ AF Bill, A Morawitz, H Kresin, VZ TI Plasmons in layered superconductors SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE acoustic plasmons; collective modes ID ELECTRON-GAS AB Collective modes of a layered electron gas are characterized by the presence of "acoustic" branches in addition to the usual optical plasmon branch. The influence of such acoustic modes on superconducting properties is studied within the strong-coupling phonon-plasmon scheme. Only the lowest acoustic branch at q(z) = pi and the optical branch at q(z) = 0 (where q(z) is the wave-vector perpendicular to the planes), for which the density-of-states (DOS) is peaked, are considered here. The effective plasmon-induced pairing interaction is given as a function of Matsubara frequency and T-c is calculated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Max Planck Inst Phys Complex Syst, D-01187 Dresden, Germany. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bill, A (reprint author), Paul Scherrer Inst, WHGA-127, CH-5232 Villigen, Switzerland. NR 7 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 433 EP 434 DI 10.1016/S0921-4526(99)02000-1 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700216 ER PT J AU Dumont, E Mota, AC Smith, JL AF Dumont, E Mota, AC Smith, JL TI Unconventional strong pinning in the low-temperature phase of U0.9725Th0.0275Be13 SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE heavy fermions; vortex creep AB We investigated low-held vortex dynamics in a single crystal of U-0.9725 Th-0.0275 Be-13.We found a sharp transition in the vortex creep rate at the lower transition temperature T-c2, coincident with the second jump in the specific heat. In the high-temperature phase, rather strong creep rates are observed. In the low-temperature phase, the rates drop to undetectably low levels. This behaviour indicates that a very strong pinning mechanism is present in the low-temperature phase of U0.9725Th0.0275Be13, Which could be explained by the existence of domain walls, separating discreetly degenerate states of a superconductor, that can sustain fractional vortices and thus act as very strong pinning centers. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dumont, E (reprint author), ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 525 EP 526 DI 10.1016/S0921-4526(99)02124-9 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700262 ER PT J AU Walti, C Felder, E Ott, HR Fisk, Z Smith, JL AF Walti, C Felder, E Ott, HR Fisk, Z Smith, JL TI Low-temperature specific heat of the heavy electron superconductor U1-xThxBe13(x=0, 0.033) in external magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE heavy fermions; specific heat in magnetic fields; UBe13 ID UBE13 AB We report on results of low-temperature specific-heat measurements of the unconventional superconductors UBe13 and U0.9669Th0.0331Be13 in external magnetic fields up to 7 T. For T << T-c or, respectively, T-c2 for the thoriated sample, the magnetic field-induced contribution to C-p(T,B) varies linearly with temperature, which is consistent with the temperature dependence of the specific heat due to the flow of supercurrent around the vortices. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Walti, C (reprint author), ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. NR 4 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 529 EP 530 DI 10.1016/S0921-4526(99)02132-8 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700264 ER PT J AU Kimura, K Koshida, R Okayasu, S Sataka, M Kazumata, Y Kwok, WK Crabtree, GW Kadowski, K AF Kimura, K Koshida, R Okayasu, S Sataka, M Kazumata, Y Kwok, WK Crabtree, GW Kadowski, K TI Magnetization anomalies above the vortex lattice melting transition SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE columnar defects; disorder-induced pinning-driven phase; irreversible behavior; Bi-2212; magnetization; vortex states AB A weak irreversible behavior was found in magnetization hysteresis curves in pristine as well as heavy-ion-irradiated Bi2Sr2CaCu2O8+delta Single crystals measured by a SQUID magnetometer both above the vortex lattice melting transition in lower fields and the vortex-glass transition in higher fields. The onset of this anomaly on magnetic field H-F strongly depends on sample disorder level, and begins to appear in the middle of the first-order phase transition. H-F systematically shifts to higher temperature and field region with increasing the number of columnar defects. The results are interpreted by a disorder-induced pinning, which is effective below H-F and becomes ineffective above H-F (C) 2000 Published by Elsevier Science B.V, All rights reserved. C1 Univ Tsukuba, Inst Mat Sci, Tsukuba, Ibaraki 3058573, Japan. Japan Atom Energy Res Inst, Naka, Ibaraki 3191106, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60435 USA. RP Kimura, K (reprint author), Univ Tsukuba, Inst Mat Sci, 1-1-1 Tennodai, Tsukuba, Ibaraki 3058573, Japan. NR 4 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 717 EP 718 DI 10.1016/S0921-4526(99)02413-8 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700357 ER PT J AU Kopnin, NB Vinokur, VM AF Kopnin, NB Vinokur, VM TI Effect of pinning on the vortex Hall resistivity SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Hall effect; pinning; scaling relations; vortex dynamics ID SUPERCONDUCTORS; STATE AB We demonstrate that pinning strongly renormalizes both longitudinal and Hall resistivity. Using a simple model for the pinning potential we show that the magnitude of the vortex contribution to the Hall voltage decreases with an increase in the pinning strength or with a decrease in transport current. The Hall resistivity rho(perpendicular to) does not scale generally as rho(parallel to)(-2). A strong enough pinning can even result in the sign reversal of rho(perpendicular to). (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 LD Landau Theoret Phys Inst, Moscow 117940, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kopnin, NB (reprint author), LD Landau Theoret Phys Inst, Kosygina 2, Moscow 117940, Russia. NR 5 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 737 EP 738 DI 10.1016/S0921-4526(99)02434-5 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700367 ER PT J AU Song, KJ Thompson, JR Yethiraj, M Christen, DK Mandrus, D Tomy, CV Paul, DM AF Song, KJ Thompson, JR Yethiraj, M Christen, DK Mandrus, D Tomy, CV Paul, DM TI Non-local superconductivity and the vortex-state properties of YNi2B2C SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE borocarbides; magnetization; non-local electrodynamics; specific heat ID LATTICE TRANSITIONS; MAGNETIZATION AB The magnetization M and heat capacity of clean, single crystal YNi2B2C superconductor have been studied with magnetic field H parallel to c-axis. The magnetization M(H) deviates from conventional predictions, but is accurately described by recent non-local London theory, with well-behaved parameters. We show that the Ginzburg-Landau parameters kappa(1) and kappa(2) increase considerably as T decreases, similar to niobium, but with kappa(T-c) approximate to 7. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RP Thompson, JR (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Mandrus, David/H-3090-2014 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 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 777 EP 778 DI 10.1016/S0921-4526(99)02078-5 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700387 ER PT J AU Vinnikov, LY Barkov, TL Cheon, KO Canfield, PC Kogan, VG AF Vinnikov, LY Barkov, TL Cheon, KO Canfield, PC Kogan, VG TI The vortex lattices in LuNi2B2C single crystals SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE borocarbides; decoration method AB Vortex lattices in LuNi2B2 C have been investigated by the decoration method at fields 20-1000 Oe at liquid helium temperatures and in a field cooling regime. At small fields of 20-200 Oe we have observed vortex lattice domains with different lattices orientations. Domains size increased with magnetic field increase. At low fields vortex lattices closepacked directions in small domains do not correlate with crystal directions and the correlations become stronger at greater fields. One of the closepacked vortex arrays directions within a domain becomes parallel to [110] or [100] directions. The vortex lattices themselves evolve at larger fields. The vortex lattice is aligned with the [100] direction and its rhombic cell apex angle beta increases from 64 degrees at 180 Oe to 75-90 degrees at 1000 Oe. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Vinnikov, LY (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. RI Canfield, Paul/H-2698-2014 NR 4 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 813 EP 814 DI 10.1016/S0921-4526(99)02113-4 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700405 ER PT J AU Pan, VM Komashko, VA Flis, VS Kasatkin, AL Svetchnikov, VL Karasevskaja, OP Popov, AG Pronin, AV Snead, CL Suenaga, M Zandbergen, HW AF Pan, VM Komashko, VA Flis, VS Kasatkin, AL Svetchnikov, VL Karasevskaja, OP Popov, AG Pronin, AV Snead, CL Suenaga, M Zandbergen, HW TI Vortex pinning anisotropy in perfect YBCO films studied by transport current measurements SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE angular dependence; critical current; linear pins; YBaCuO films; vortex pinning AB Critical current densities J(c) are studied for YBa2Cu3O7-delta films With J(c)(77 K) > 3MA/cm(2) in a range of applied fields, temperatures, angles between the field vector and the C-axis of YBCO films. Two-peaked angular J(c)(H, T) dependencies are detected. Opposite temperature behavior of J(c)(theta)-peaks for H \\ C and H \\ ab is found. The J(c)(H \\ C)-peak first rises with T and then diminishes while T approaches T-irr(H). In contrast, the J(c)(H \\ ab)-peak becomes more remarkable with temperature increase. J(c)(H, T)-curves for H \\ C-orientation exhibit two distinct crossovers, corresponding to transitions from J(c)(H) similar to const at low fields to J(c) proportional to H-0.5 at intermediate fields and to J(c) proportional to H-q(q similar to 1-1.5) at higher fields. Vortex interaction with linear pin arrays is assumed to be the reason for the phenomena. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. Brookhaven Natl Lab, Upton, NY 11973 USA. Delft Univ Technol, Natl Ctr HREM, NL-2628 AL Delft, Netherlands. RP Pan, VM (reprint author), Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 831 EP 832 DI 10.1016/S0921-4526(99)02137-7 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700414 ER PT J AU Thompson, JR Ossandon, JG Krusin-Elbaum, L Song, KJ Christen, DK Ullmann, JL AF Thompson, JR Ossandon, JG Krusin-Elbaum, L Song, KJ Christen, DK Ullmann, JL TI Quantum tunneling of vortices in Bi-2212 with randomly oriented columnar defects SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE columnar defects; flux creep; irradiation; Bi-2212; quantum vortex tunneling AB Vortex pinning in textured Bi-2212/Ag superconducting tapes was enhanced by randomly oriented columnar defects, formed by GeV proton-induced fission of Bi-nuclei. Studies of J versus time in the range 2-40 K shows that thermally activated current decay decreased greatly. However, temperature-independent quantum tunneling of vortices considerably limits J and its temporal stability for a significant fraction of the finite-J(c) region. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Univ Talca, Curico, Chile. IBM Corp, Watson Res Ctr, Yorktown Heights, NY USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Thompson, JR (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 877 EP 878 DI 10.1016/S0921-4526(99)02196-1 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700437 ER PT J AU Rogacki, K Dabrowski, B Chmaissem, O Jorgensen, JD AF Rogacki, K Dabrowski, B Chmaissem, O Jorgensen, JD TI Improved pinning properties in Y123 materials by chemical substitutions SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE critical current; irreversibility line; pinning; YBaCuO AB We have investigated how T-c, J(c) and B-irr of compounds with double CuO2 planes depend on the physical properties and structural features of the blocking layer. By comparing J(c) and B-irr for several families of HTSC we have concluded that the intrinsic flux pinning is controlled to a large extent by the conductivity of the blocking layer. The width of the intermediate region between the blocks of the double CuO2 planes is less significant. To modify the conductivity of the CuO chains and decrease the anisotropy of the YBa2Cu3Oy compound, substitutions of transition elements for Cu and Sr for Ba were done resulting in enhanced pinning properties and increased T-c of YBaSrCu3-xMoxOy from 81 K for x = 0 to 86 K for x = 0.05-0.1. The pinning characteristics of substituted material were significantly modified most likely by a formation of dimers of corner shared MoO6 octahedra. The same structural modification was used to improve the pinning properties of the YBa2Cu3Oy compound. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Polish Acad Sci, Inst Low Temp & Struct Res, PL-50950 Wroclaw, Poland. No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Rogacki, K (reprint author), Polish Acad Sci, Inst Low Temp & Struct Res, POB 937, PL-50950 Wroclaw, Poland. NR 5 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 889 EP 890 DI 10.1016/S0921-4526(99)02205-X PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700443 ER PT J AU Gasparov, VA Batov, IE Li, Q Kwon, C AF Gasparov, VA Batov, IE Li, Q Kwon, C TI Frequency and temperature dependence of complex conductance of ultrathin YBa2Cu3O7-x films: a study of vortex-antivortex pair unbinding SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE AC susceptibility; Kosterlitz-Thouless-Berezinski transition; microwave surface impedance; YBaCuO films ID KOSTERLITZ-THOULESS TRANSITION; COULOMB-GAS AB We have studied frequency and temperature dependences of complex sheet conductance of ultrathin (1-3 unit cell (UC) thick) YBa2Cu3O7-x films using a radio frequency (1-20, 100-1000 MHz) sheet impedance and a microwave (30 GHz) loss measurements. We found the activated temperature dependence of the vortex diffusion constant and scaling behaviour of the universal ratio T-KTB(DC)/L-k(-1)(T-KTB) for 1UC, 2UC and 3UC YBCO films, in close agreement with theoretical prediction for vortex-antivortex unbinding transition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Gasparov, VA (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow District, Russia. RI Kwon, Chuhee/A-8687-2008 NR 8 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1021 EP 1022 DI 10.1016/S0921-4526(99)02364-9 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700509 ER PT J AU Jaime, M Movshovich, R Balatsky, AV Yoshizaki, R AF Jaime, M Movshovich, R Balatsky, AV Yoshizaki, R TI Heat capacity of Ni-doped Bi2Sr2CaCu2O8 single crystals SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Bi-2212 substituted; magnetic impurities; specific heat ID THERMAL-CONDUCTIVITY; BI2SR2CA(CU1-XNIX)(2)O-8; PHASE AB The specific heat of Ni-doped Bi2Sr2CaCu2O8 crystals has been measured between 0.035 and 2 K in magnetic fields up to 9 T. Both pure and doped samples display identical low-temperature nuclear Schottky anomaly tails at T < 200 mK. The difference between the specific heat of the Ni-doped sample and that of the pure one is a broad peak centered at about 1 K. Applied magnetic fields move the peak to higher temperatures, which is consistent with spin glass-like behavior of the impurity atoms. Freezing of magnetic impurities may be related to the observation of a second low-temperature transition in several of the Ni-doped samples. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 305, Japan. RP Jaime, M (reprint author), Univ Calif Los Alamos Natl Lab, MS K764, Los Alamos, NM 87545 USA. RI Jaime, Marcelo/F-3791-2015 OI Jaime, Marcelo/0000-0001-5360-5220 NR 6 TC 1 Z9 1 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1069 EP 1070 DI 10.1016/S0921-4526(99)02417-5 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700533 ER PT J AU Song, KJ Khan, HR Kim, HJ Thompson, JR AF Song, KJ Khan, HR Kim, HJ Thompson, JR TI Properties of polycrystalline Hg1-xBixBa2Ca2Cu3Oy superconductors SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE magnetization; penetration depth ID FIELDS AB Polycrystalline Hg1-xBixBa2Ca2Cu3Oy materials, with Bi-content x = 0.1, 0.2 and 0.3, were prepared by a direct, one-step synthesis. Characterization methods included X-ray diffraction, SEM, and studies of the magnetization M. The T-c's were 133.5, 133 and 128 K, respectively. The persistent current density J(p) falls off roughly exponentially with held H and temperature T. The irreversibility fields H-irr(T) similar to (1 - T/T-c)(n), with n approximate to 3, were similar for the three materials. Analysis of the equilibrium M with London theory provided the London penetration depth lambda(T). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. FEM, Dept Phys Mat, D-73525 Schwabisch Gmund, Germany. RP Thompson, JR (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1089 EP 1090 DI 10.1016/S0921-4526(99)02440-0 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700543 ER PT J AU Chun, SH Salamon, MB Jaime, M Suryanarayanan, R Dhalenne, G Revcolevschi, A AF Chun, SH Salamon, MB Jaime, M Suryanarayanan, R Dhalenne, G Revcolevschi, A TI Hall effect of a layered manganite La1.2Sr1.8Mn2O7 single crystal SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Hall effect; La1.2Sr1.8Mn2O7; layered manganite AB We report the first Hall effect measurements on the layered manganite La1.2Sr1.8Mn2O7 single crystal, a colossal magnetoresistance material with T-c = 121 K. At low temperatures, the Hall resistivity is a mixture of a positive ordinary Hall effect and a negative anomalous Hall effect, similar to that of the pseudo-cubic counterpart La(1-x)A(x)MnO(3). However, the carrier concentration from the high-field slope turns out to be 0.36 +/- 0.02 holes/Mn, very close to the nominal doping concentration (0.4 holes/Mn), in contrast to the large deviation in La(1-x)A(x)MnO(3). We also find that the anomalous Hall effect becomes larger for T < 40 K, where the longitudinal resistivity shows a minimum. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Paris 11, Lab Chim Solides, F-91405 Orsay, France. RP Chun, SH (reprint author), Penn State Univ, Dept Phys, Davey Lab 104, University Pk, PA 16802 USA. RI Jaime, Marcelo/F-3791-2015; OI Jaime, Marcelo/0000-0001-5360-5220; Chun, Seung-Hyun/0000-0001-8397-4481 NR 2 TC 3 Z9 3 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1442 EP 1443 DI 10.1016/S0921-4526(99)02663-0 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100160 ER PT J AU Pashkevich, YG Blinkin, VA Gnezdilov, VP Kurnosov, VS Tsapenko, VV Eremenko, VV Lemmens, P Fischer, M Grove, M Guntherodt, G Degiorgi, L Wachter, P Tranquada, JM Buttrey, DJ AF Pashkevich, YG Blinkin, VA Gnezdilov, VP Kurnosov, VS Tsapenko, VV Eremenko, VV Lemmens, P Fischer, M Grove, M Guntherodt, G Degiorgi, L Wachter, P Tranquada, JM Buttrey, DJ TI Optical studies of the incommensurate charge ordered phase in La1.775Sr0.225NiO4 SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE charge ordering; light absorption; light scattering; phonon spectrum; stripe phase ID SPECTROSCOPY; DYNAMICS AB Raman light-scattering and optical conductivity measurements of a single crystal of La1.775Sr0.225NiO4 which shows incommensurate charge ordering in a stripe phase have been carried out. The analysis of the positions, shifts and splitting of the phonon lines that are induced by charge ordering and the comparison with inelastic neutron scattering data lead to the conclusion that the charges are located on Ni-sites. The lines which appear from the (epsilon, epsilon, 0) point of Brillouin zone give unambiguous evidence of the pinning of stripes to the lattice. The magnitude of a charge gap 840 cm(-1) opening below T-c = 150 K is the same for both far-infrared absorption and Raman light scattering measurements. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Acad Sci Ukraine, AA Galkin Donetsk Phystech, UA-340114 Donetsk, Ukraine. Natl Acad Sci Ukraine, Inst Single Crystals, UA-310001 Kharkov, Ukraine. Natl Acad Sci Ukraine, BI Verkin Inst Low Temp Phys, UA-310164 Kharkov, Ukraine. Rhein Westfal TH Aachen, Inst Phys 2, D-52056 Aachen, Germany. ETH Zurich, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Delaware, Newark, DE 19716 USA. RP Pashkevich, YG (reprint author), Natl Acad Sci Ukraine, AA Galkin Donetsk Phystech, UA-340114 Donetsk, Ukraine. RI Tranquada, John/A-9832-2009; Lemmens, Peter/C-8398-2009 OI Tranquada, John/0000-0003-4984-8857; Lemmens, Peter/0000-0002-0894-3412 NR 4 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1473 EP 1474 DI 10.1016/S0921-4526(99)02717-9 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100175 ER PT J AU Masuda, T Ina, K Hadama, K Tsukada, I Uchinokura, K Nakao, H Nishi, M Fujii, Y Hirota, K Shirane, G Wang, YJ Kiryukhin, V Birgeneau, RJ AF Masuda, T Ina, K Hadama, K Tsukada, I Uchinokura, K Nakao, H Nishi, M Fujii, Y Hirota, K Shirane, G Wang, YJ Kiryukhin, V Birgeneau, RJ TI Temperature versus concentration phase diagram of Mg- and Si-doped CuGeO3 SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE CuGeO3; first-order phase transition; spin-Peierls transition ID SPIN-PEIERLS TRANSITION; CUPRATE AB We studied the temperature versus concentration(T-x) phase diagram in Cu1 - xMgxGeO3 by susceptibility measurements, synchrotron X-ray diffraction and neutron diffraction and the first-order phase transition between dimerized-antiferromagnetic and uniform-antiferromagnetic phases reported by Masuda et al. [Phys. Rev. Lett, 80 (1998) 4566] was established. We found that the T-x phase diagram of Cu1 - xMxGeO3(M = Zn,Ni) is similar to that of Cu1 - xMgxGeO3, while that of CuGe1 - xSixO3 is qualitatively different. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1138656, Japan. Cent Res Inst Elect Power Ind, Tokyo 2018511, Japan. Univ Tokyo, Inst Solid State Phys, Minato Ku, Tokyo 1068666, Japan. Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 9808578, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Masuda, T (reprint author), Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, 6th Eng Bld, Tokyo 1138656, Japan. RI Hirota, Kazuma/C-6797-2008; wang, yujie/C-2582-2015 NR 7 TC 9 Z9 9 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1637 EP 1638 DI 10.1016/S0921-4526(99)02764-7 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100257 ER PT J AU Uchinokura, K Uchiyama, Y Masuda, T Sasago, Y Tsukada, I Zheludev, A Hayashi, T Miura, N Boni, P AF Uchinokura, K Uchiyama, Y Masuda, T Sasago, Y Tsukada, I Zheludev, A Hayashi, T Miura, N Boni, P TI Phase diagram of spin-vacancy-induced antiferromagnetism in a new Haldane compound PbNi2V2O8 SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Haldane-gap state; new material; spin-vacancy-induced antiferromagnetism ID PEIERLS TRANSITION; CUGEO3; STATE; CUPRATE; GAP AB Recent discoveries of a new Haldane compound PbNi2V2O8 and the spin-vacancy-induced antiferromagnetism (Uchiyama et al., Phys. Rev. Lett, 83 (1999) 632) were studied in more detail by heat capacity measurements. The existence of the antiferromagnetic transition was more firmly proved by these measurements. We also obtained temperature versus Mg-concentration phase diagram. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1138656, Japan. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Inst Solid State Phys, Minato Ku, Tokyo 1068666, Japan. ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. PSI, CH-5232 Villigen, Switzerland. RP Uchinokura, K (reprint author), Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, 6th Eng Bld, Tokyo 1138656, Japan. NR 10 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1641 EP 1642 DI 10.1016/S0921-4526(99)02772-6 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100259 ER PT J AU Watanabe, M Itoh, KM Ootuka, Y Haller, EE AF Watanabe, M Itoh, KM Ootuka, Y Haller, EE TI Metal-insulator transition of NTD Ge-70 : Ga in magnetic fields SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE critical exponent; metal-insulator transition; neutron-transmutation doping; semiconductor ID TRANSMUTATION-DOPED GE-70-GA AB We have determined the temperature dependence of the electrical conductivity sigma(N, B, T) of nominally uncompensated, neutron-transmutation-doped (NTD)Ge-70:Ca samples in magnetic fields up to B = 8 T at low temperatures (T = 0.05-0.5 K) to investigate both the doping-induced metal-insulator transition (MIT), sigma(N, B, 0) proportional to (N - N-c)(mu), and the magnetic-field-induced MIT, sigma(N,B,0) proportional to (B-c - B)(mu)'. Our experimental results show that mu = mu' = 1.1 + 0.1 in sufficiently large magnetic fields. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Keio Univ, Dept Appl Phys & Physicoinformat, Kohoku Ku, Yokohama, Kanagawa 2238522, Japan. Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 3058571, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Watanabe, M (reprint author), Keio Univ, Dept Appl Phys & Physicoinformat, Kohoku Ku, 3-14-1 Hiyoshi, Yokohama, Kanagawa 2238522, Japan. RI Itoh, Kohei/C-5738-2014 NR 3 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1677 EP 1678 DI 10.1016/S0921-4526(99)02879-3 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100277 ER PT J AU Haviland, DB Chow, E Delsing, P AF Haviland, DB Chow, E Delsing, P TI Quantum-phase transition in 1D Josephson junction arrays SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Coulomb blockade; Josephson junction arrays; superconductor-insulator transition AB One-dimensional arrays of small capacitance SQUIDs have been studied experimentally. The effective Josephson coupling between neighboring electrodes is tunable in situ. The arrays can be tuned from a Josephson-like state, with low resistance and sharp critical current, to a Coulomb blockade state, with infinite resistance and sharp threshold voltage. A quantum phase transition occurs at the crossover between these two types of behavior, which is evident from an analysis of the temperature dependence of the zero bias resistance. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Royal Inst Technol, S-10044 Stockholm, Sweden. Sandia Natl Labs, Albuquerque, NM 87185 USA. Chalmers Univ Technol, MINA, S-41296 Gothenburg, Sweden. RP Haviland, DB (reprint author), Royal Inst Technol, S-10044 Stockholm, Sweden. RI Delsing, Per/F-7288-2010 OI Delsing, Per/0000-0002-1222-3506 NR 2 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 1808 EP 1809 DI 10.1016/S0921-4526(99)03022-7 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100342 ER PT J AU Ullom, JN Fisher, PA AF Ullom, JN Fisher, PA TI Quasiparticle behavior in tunnel junction refrigerators SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE microrefrigeration; quasiparticles; tunnel junctions AB We present simulations of quasiparticle creation, propagation, and loss in the superconducting electrode of a normal-insulator-superconductor tunnel junction refrigerator. We calculate the electronic temperature in the superconducting electrode from self-consistent solutions to the diffusion equation. We then calculate the power load on the normal electrode due to recombination phonons and the reduction in cooling power due to the elevated temperature of the superconductor. Our calculations explain the degraded cooling performance observed in 20 mu m sized Ag/AlOx/Al junctions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Analog Devices Corp, Wilmington, MA 01887 USA. RP Ullom, JN (reprint author), Univ Calif Lawrence Livermore Natl Lab, 700 East Ave, Livermore, CA 94550 USA. NR 3 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 2036 EP 2038 DI 10.1016/S0921-4526(99)02828-8 PN 2 PG 3 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100456 ER PT J AU Wei, X Honig, A Lewis, A Lowry, M Sandorfi, A Whisnant, S Didelez, JP AF Wei, X Honig, A Lewis, A Lowry, M Sandorfi, A Whisnant, S Didelez, JP TI Large, mobile frozen-spin polarized solid HD SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE nuclear spin polarization; hydrogen; deuterium AB A completed system for producing large quantities of highly spin-polarized H and D in solid HD is described. It is of the relaxation-switched frozen-spin type, in which relaxation is turned off after polarization at high B (17 T) and low T(15 mK), and the polarization is retained at high T (4 K) and low B (fractional Tesla). The first application is as targets for polarized gammas at BNL, presently, three targets of 1.3 mol each are produced in a single run at Syracuse, cold transferred to a mobile storage cryostat with high field, transported to BNL, and cold-transferred there into an in-beam cryostat. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Syracuse Univ, Dept Phys, Syracuse, NY 13244 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ S Carolina, Columbia, SC 29208 USA. Univ Paris, Orsay, France. RP Honig, A (reprint author), Syracuse Univ, Dept Phys, 201 Phys Bldg, Syracuse, NY 13244 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 2051 EP 2052 DI 10.1016/S0921-4526(99)02855-0 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100463 ER PT J AU Karapetrov, G Cambel, V Kwok, WK Crabtree, GW Zheng, H Veal, BW AF Karapetrov, G Cambel, V Kwok, WK Crabtree, GW Zheng, H Veal, BW TI Contactless characterization of melt-textured superconducting junctions using micro-Hall sensor arrays SO PHYSICA B LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE Hall probe array; magneto-optical imaging; melt-textured superconductor; YBa2Cu3O7 AB We use spatially resolved Hall probe magnetometry and magneto-optical imaging to study current-carrying properties of melt-textured high-temperature superconducting welds at high magnetic fields. The study of the vortex dynamics near the junction using high-resolution Hall probe magnetometry revealed enhanced relaxation of the magnetization at the junction at high temperatures. We attribute this behavior to an increased local concentration of defects near the weld which, depending on the temperature range, either facilitate enhanced relaxation or strengthen the local pinning properties. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Slovak Acad Sci, Inst Elect Engn, SK-84239 Bratislava, Slovakia. RP Karapetrov, G (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Karapetrov, Goran/C-2840-2008 OI Karapetrov, Goran/0000-0003-1113-0137 NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 2065 EP 2066 DI 10.1016/S0921-4526(99)02893-8 PN 2 PG 2 WC Physics, Condensed Matter SC Physics GA 320WD UT WOS:000087423100470 ER PT J AU Mints, RG Kogan, VG AF Mints, RG Kogan, VG TI Josephson torque on junctions between anisotropic superconductors SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Low Temperature Physics CY AUG 04-11, 1999 CL HELSINKI UNIV TECHNOL, HELSINKI, FINLAND SP Commiss C5 low Temp Phys, Int Union Pure & Appl Phys, Acad Finland, Helsinki Univ Technol, Int Assoc Promot Sci, Oxford Instruments Ltd, FortumCorp, Nokia Grp, Finnair Ltd, Datex Engstrom Ltd, Finnish Phys Soc, Picker Nordstar Ltd, Neuromag ltd, SAP Finland Ltd, Espoo Elect Ltd, Outokumpu Ltd, City Espoo, Finnish Acad Sci & Letters, DCA-Instruments Ltd, Vaisala Ltd HO HELSINKI UNIV TECHNOL DE anisotropic superconductors; Josephson vortices; torque measurement AB Properties of Josephson junctions between anisotropic superconductors are reviewed briefly. We focus on the mechanical torque experienced by a tunnel junction and estimate the torque as a small but measurable quantity. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Iowa State Univ, Ames Lab, DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. EM mints@ccsg.tau.ac.il RI Mints, Roman/A-5091-2008 NR 4 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD JUL PY 2000 VL 284 BP 555 EP 556 DI 10.1016/S0921-4526(99)02173-0 PN 1 PG 2 WC Physics, Condensed Matter SC Physics GA 318YF UT WOS:000087311700277 ER PT J AU Chirayil, TG Paranthaman, M Beach, DB Lee, DF Goyal, A Williams, RK Cui, X Kroeger, DM Feenstra, R Verebelyi, DT Christen, DK AF Chirayil, TG Paranthaman, M Beach, DB Lee, DF Goyal, A Williams, RK Cui, X Kroeger, DM Feenstra, R Verebelyi, DT Christen, DK TI Epitaxial growth of La2Zr2O7 thin films on rolled Ni-substrates by sol-gel process for high T-c superconducting tapes SO PHYSICA C LA English DT Article DE La2Zr2O7; buffer layers; epitaxial thin films; sol-gel; textured Ni substrates; YBCO ID CRITICAL-CURRENT DENSITY; BUFFER LAYERS; LANTHANUM ZIRCONATE; COATED CONDUCTORS; GRAIN-BOUNDARIES; ALUMINATE FILMS; YBCO; CATALYSTS AB A solution process was used to grow epitaxial La2Zr2O7 (LZO) buffer layers on roll-textured Ni (100) substrates to produce YBa2Cu3O7-delta (YBCO)-coated conductors. The LZO precursor solution was prepared by an all alkoxide sol-gel route using mixed metal methoxyethoxides in 2-methoxyethanol. The partially hydrolyzed solution was either spin-coated or dip-coated onto the textured Ni substrates. The amorphous thin film was then heat treated at 1150 degrees C under (96%)Ar/(4%)H-2 atmosphere for 1 h. X-ray diffraction (XRD) of the buffer layer indicated a strong c-axis orientation on the Ni (100) substrate. The LZO (222) pole figure revealed a single cube-on-cube texture. SEM images of the LZO buffer layer showed a dense microstructure without cracks. The YBCO deposited on the sol-gel LZO-buffered Ni substrates with sputtered YSZ and CeO2 top layers had a critical current density of 480,000 A/cm(2) at 77 K and self-field. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Paranthaman, M (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 34 TC 67 Z9 70 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUL 1 PY 2000 VL 336 IS 1-2 BP 63 EP 69 DI 10.1016/S0921-4534(00)00089-7 PG 7 WC Physics, Applied SC Physics GA 331ZA UT WOS:000088047500008 ER PT J AU De Leon, JM Perez, VA Espinosa, FJ Jimenez-Sandoval, S Lopez-Lopez, S Montano, PA AF De Leon, JM Perez, VA Espinosa, FJ Jimenez-Sandoval, S Lopez-Lopez, S Montano, PA TI Atomic local structure around Cu in CuxCd1-xTe thin films SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT XVth Latin American Symposium on Solid State Physics (SLAFES XV) CY NOV 01-05, 1999 CL CARTAGENA DE INDIAS, COLOMBIA AB X-ray absorption spectroscopy (XAS) was used to investigate the local atomic structure around Cu atoms in CuxCd1-xTe thin films, for x = 10 and 15 at.% nominal Cu concentrations. X-ray absorption near edge spectra (XANES) reveal a Cu local electronic structure different from that encountered in Cu metal. X-ray diffraction measurements have shown the presence of a single zincblende phase even for 15 at.% nominal Cu concentration. However, X-ray absorption fine structure (XAFS) spectra show Cu-Cu distances characteristic of Cu metal clusters, and Cu-Te distances significantly shorter than the CdTe nearest neighbor distance. These results imply the occurrence of microscopic phase separation in this material, and significant lattice distortions around the Cu incorporated in the CdTe matrix. C1 Cinvestav Merida, Dept Fis Aplicada, Merida 97133, Yuc, Mexico. Cinvestav Queretaro, Lab Invest Mat, Queretaro 76001, Mexico. Cinvestav Mexico, Dept Fis, Mexico City 07000, DF, Mexico. Argonne Natl Lab, Adv Photon Source, BESSRC CAT, Argonne, IL 60439 USA. RP De Leon, JM (reprint author), Cinvestav Merida, Dept Fis Aplicada, AP 73, Merida 97133, Yuc, Mexico. RI Jimenez-Sandoval, Sergio/A-9627-2015 OI Jimenez-Sandoval, Sergio/0000-0002-2143-3759 NR 4 TC 3 Z9 3 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD JUL PY 2000 VL 220 IS 1 BP 227 EP 231 DI 10.1002/1521-3951(200007)220:1<227::AID-PSSB227>3.0.CO;2-X PG 5 WC Physics, Condensed Matter SC Physics GA 344PV UT WOS:000088768800040 ER PT J AU Moreno, NO Pagliuso, PG Campoy, JCP Granado, E Rettori, C Cheong, SW Oseroff, SB AF Moreno, NO Pagliuso, PG Campoy, JCP Granado, E Rettori, C Cheong, SW Oseroff, SB TI Microwave absorption study in the ferromagnetic superconductor Gd1.4Ce0.6RuSr2Cu2O10-delta SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT XVth Latin American Symposium on Solid State Physics (SLAFES XV) CY NOV 01-05, 1999 CL CARTAGENA DE INDIAS, COLOMBIA AB We have performed microwave absorption (MWA) and ferromagnetic resonance measurements (FMR) in Gd1.4Ce0.6RuSr2Cu2O10-delta polycrystalline samples between 300 and 8 K. Below the magnetic ordering temperature (T-m approximate to 89 K) a MWA is observed due to the appearance of weak ferromagnetism (WFMWA). The intensity of the WFMWA decreases as T approaches the superconducting (SC) state at T-c approximate to 45 K. For T less than or equal to T-c, a new and much stronger MWA (SCMWA) is found. This SCMWA may be associated to Josephson intergrain and to viscose dynamic dissipation of intragrain Abrikosov vortex in the SC state. C1 Univ Estadual Campinas, Inst Fis, BR-13087970 Campinas, SP, Brazil. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. RP Moreno, NO (reprint author), Univ Estadual Campinas, Inst Fis, CP6165, BR-13087970 Campinas, SP, Brazil. RI Rettori, Carlos/C-3966-2012; Pagliuso, Pascoal/C-9169-2012; Granado, Eduardo/F-5389-2012; Moreno, Nelson/H-1708-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rettori, Carlos/0000-0001-6692-7915; Moreno, Nelson/0000-0002-1672-4340; NR 5 TC 2 Z9 2 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD JUL PY 2000 VL 220 IS 1 BP 541 EP 543 DI 10.1002/1521-3951(200007)220:1<541::AID-PSSB541>3.0.CO;2-0 PG 3 WC Physics, Condensed Matter SC Physics GA 344PV UT WOS:000088768800098 ER PT J AU Ortiz, G Aligia, AA AF Ortiz, G Aligia, AA TI How localized is an extended quantum system? SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT XVth Latin American Symposium on Solid State Physics (SLAFES XV) CY NOV 01-05, 1999 CL CARTAGENA DE INDIAS, COLOMBIA ID POLARIZATION AB We elaborate on a geometric characterization of the electromagnetic properties of matter. A fundamental complex quantity, z(L), is introduced to study the localization properties of extended quantum systems. z(L), which allows us to discriminate between conducting and non-conducting thermodynamic phases, has an illuminating physical (and geometric) interpretation. Its phase can be related to the expectation value of the position operator (and a Berry phase), while its modulus is associated with quantum electric polarization fluctuations (and a quantum metric). We also study the scaling behavior of z(L) in the one-dimensional repulsive Hubbard model. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 Bariloche, Rio Negro, Argentina. Inst Balseiro, RA-8400 Bariloche, Rio Negro, Argentina. RP Ortiz, G (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 11 TC 9 Z9 9 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD JUL PY 2000 VL 220 IS 1 BP 737 EP 743 DI 10.1002/1521-3951(200007)220:1<737::AID-PSSB737>3.0.CO;2-9 PG 7 WC Physics, Condensed Matter SC Physics GA 344PV UT WOS:000088768800132 ER PT J AU De Leon, JM De Coss, R Rubio-Ponce, A Pali, R Bishop, AR Trugman, SA AF De Leon, JM De Coss, R Rubio-Ponce, A Pali, R Bishop, AR Trugman, SA TI Polaronic signatures in phonon isotopic shifts SO PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS LA English DT Article; Proceedings Paper CT XVth Latin American Symposium on Solid State Physics (SLAFES XV) CY NOV 01-05, 1999 CL CARTAGENA DE INDIAS, COLOMBIA ID CUO2 PLANE; SUPERCONDUCTORS; LATTICE; OXYGEN; SCATTERING; LA1.85SR0.15CUO4; YBA2CU3O7-DELTA; ANHARMONICITY; SUBSTITUTION; SPECTROSCOPY AB The isotopic shift of c-axis O(4)-related phonon frequencies in YBa2Cu3O7 is calculated using a model electron-phonon Hamiltonian. This Hamiltonian was previously used to describe the dynamics of the O(4)-Cu(1)-O(4) cluster. The model includes electronic correlations and electron-phonon interactions, exhibiting polaron tunneling. The calculated isotopic shifts of phonon excitations differ from these found using harmonic or anharmonic potentials, and are consistent with results of optical measurements. The isotopic substitution also changes the dynamics of polaron tunneling and produces a change in the local structure of the cluster. C1 IPN, Ctr Invest & Estudios Avanzados, Merida 97310, Yucatan, Mexico. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP IPN, Ctr Invest & Estudios Avanzados, Merida 97310, Yucatan, Mexico. NR 26 TC 2 Z9 2 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0370-1972 EI 1521-3951 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Solid State Phys. PD JUL PY 2000 VL 220 IS 1 BP 499 EP 502 DI 10.1002/1521-3951(200007)220:1<499::AID-PSSB499>3.0.CO;2-Q PG 4 WC Physics, Condensed Matter SC Physics GA 344PV UT WOS:000088768800089 ER PT J AU Crane, SG Zhao, X Taylor, W Vieira, DJ AF Crane, SG Zhao, X Taylor, W Vieira, DJ TI Trapping an isotopic mixture of fermionic Rb-84 and bosonic Rb-87 atoms SO PHYSICAL REVIEW A LA English DT Article ID BOSE-EINSTEIN CONDENSATION; MAGNETIC TRAP; NEUTRAL ATOMS; GAS; SCATTERING; HYDROGEN AB We have simultaneously confined fermionic Rb-84 and bosonic Rb-87 atoms in overlapping magneto-optical traps in which radioactive Rb-84 atoms (t(1/2) = 33 d) have been trapped. We investigated Rb-84 trap loss when overlapped with a cloud of Rb-87 atoms trapped from a background rubidium vapor. Collision loss measurements were taken with similar to 5 x 10(5) and similar to 4 x 10(7) atoms of trapped Rb-84 and Rb-87, respectively. We have found a trapping solution for which there is negligible additional trap loss for Rb-84 due to the presence of Rb-87, showing that the mixture can be readily prepared for a sympathetic cooling experiment. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Utah State Univ, Dept Phys, Logan, UT 84322 USA. RP Crane, SG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 20 TC 21 Z9 21 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2000 VL 62 IS 1 BP art. no. EP 011402 DI 10.1103/PhysRevA.62.011402 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800006 ER PT J AU Guo, CL Jones, RT Gibson, GN AF Guo, CL Jones, RT Gibson, GN TI Influence of spatial symmetry on the dynamics of strong-field ionization SO PHYSICAL REVIEW A LA English DT Article ID NONSEQUENTIAL DOUBLE-IONIZATION; MULTIPHOTON IONIZATION; THRESHOLD IONIZATION; LASER FIELDS; HELIUM; MODEL; HE; SINGLE; ATOM AB The effect of spatial symmetry on strong-field ionization is investigated with one-dimensional two-electron ab initio quantum-mechanical calculations. Numerical results clearly show that the nonsequential double-ionizatiom rate in atoms with spatially symmetric wave functions is higher than in atoms with antisymmetric wave functions. Moreover, single ionization is demonstrated to be correlated with double ionization, indicating that strong-field ionization is in fact a highly dynamic process. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Guo, CL (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. NR 19 TC 13 Z9 13 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2000 VL 62 IS 1 BP art. no. EP 015402 DI 10.1103/PhysRevA.62.015402 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800121 ER PT J AU Lower, J Elliott, A Weigold, E Mazevet, S Berakdar, J AF Lower, J Elliott, A Weigold, E Mazevet, S Berakdar, J TI Dichroism in the electron-impact ionization of excited and oriented sodium atoms SO PHYSICAL REVIEW A LA English DT Article ID SPIN-POLARIZED ELECTRONS; DISTORTED-WAVE BORN; E,2E COLLISIONS; ORIENTATIONAL DICHROISM; SCATTERING; ALIGNMENT; XENON AB Measurements are reported for kinematically complete electron-impact ionization collisions with oriented 3 P sodium atoms excited from the ground state by right- and left-hand circularly polarized light. The measurements reveal a strong dependence of the ionization cross section on the helicity inversion of the exciting photon. This dichroic effect and the magnetic state resolved cross sections are described using the distorted-wave Born approximation and the dynamically screened Coulomb wave method. Within the context of these methods we investigate the role of different short- and long-range interactions involved in the process. For moderate values of incident energy we conclude that the shape and magnitude of the dichroism is predominantly determined by the Coulomb interactions of the outgoing electrons with the residual ion. For slow escaping electrons the dichroism is also influenced by the interelectronic correlations. C1 Australian Natl Univ, Res Sch Phys Sci & Engn, Inst Adv Studies, Atom & Mol Phys Labs, Canberra, ACT 0200, Australia. Max Planck Inst Microstruct Phys, D-06120 Halle, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Lower, J (reprint author), Australian Natl Univ, Res Sch Phys Sci & Engn, Inst Adv Studies, Atom & Mol Phys Labs, Canberra, ACT 0200, Australia. NR 42 TC 6 Z9 6 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 JUL PY 2000 VL 62 IS 1 BP art. no. EP 012706 DI 10.1103/PhysRevA.62.012706 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800055 ER PT J AU Abdallah, MA Wolff, W Wolf, HE Coelho, LFS Cocke, CL Stockli, M AF Abdallah, MA Wolff, W Wolf, HE Coelho, LFS Cocke, CL Stockli, M TI Observation of a quasimolecular ionization window in low-to-intermediate impact velocity collisions of He(+) ions with H(2) and He SO PHYSICAL REVIEW A LA English DT Article ID SADDLE-POINT ELECTRONS; PROJECTILE-CHARGE DEPENDENCE; ATOM COLLISIONS; IONIZING COLLISIONS; ANGULAR-DISTRIBUTION; CONTINUUM ELECTRONS; HELIUM COLLISIONS; SINGLE IONIZATION; CROSS-SECTIONS; LOW-ENERGY AB The ionization of H(2), leading to H(2)(+) recoil ions in nondissociative stales, and the ionization of He by incident He(+) ions were investigated in the 0.25-1.23-a.u. impact velocity range employing electron and target recoil-ion momentum-imaging techniques. Similarities as well as differences were observed in the electron velocity distributions from H(2) and He targets. In both cases the data strongly suggest of the promotion of molecular orbitals formed between target and projectile within a rather well-defined projectile velocity window. In particular, the data support the promotion of the 2p pi molecular orbital populated via rotational coupling. Outside this molecular promotion window, in particular at lower velocities, mechanisms of a different kind appear to dominate the ionization process, and electron momentum distributions are very dissimilar for He and H(2). Reduced projectile scattering cross sections, derived from measured target recoil-ion transverse momentum distributions, support these conclusions and paint to the coexistence, at certain impact velocities, of different ionization mechanisms. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Fed Rio de Janeiro, Inst Fis, Rio De Janeiro, Brazil. Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. RP Abdallah, MA (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM abdallah@mail.phy.ornl.gov; wania@if.ufrj.br; cocke@phys.ksu.edu RI Wolff, Wania/O-5556-2015 NR 56 TC 10 Z9 10 U1 0 U2 0 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 JUL PY 2000 VL 62 IS 1 AR 012711 DI 10.1103/PhysRevA.62.012711 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800060 ER PT J AU Dalvit, DAR Dziarmaga, J Zurek, WH AF Dalvit, DAR Dziarmaga, J Zurek, WH TI Decoherence in Bose-Einstein condensates: Towards bigger and better Schrodinger cats SO PHYSICAL REVIEW A LA English DT Article ID OPEN QUANTUM SYSTEM; SUPERPOSITION; MIXTURE; STATES AB We consider a quantum superposition of Bose-Einstein condensates (BEC's) in two immiscible internal states. A decoherence rate for the resulting Schrodinger cat is calculated and shown to be a significant threat to this macroscopic quantum superposition of BEC's. An experimental scenario is outlined where the decoherence rate due to the thermal cloud is dramatically reduced thanks to trap engineering and "symmetrization" of the environment, which allow the Schrodinger cat to be an approximate painter state. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Jagiellonian Univ, Inst Phys, Krakow, Poland. RP Dalvit, DAR (reprint author), Los Alamos Natl Lab, Div Theoret, T-6,MS-B288, Los Alamos, NM 87545 USA. EM dalvit@lanl.gov; dziarmaga@t6-serv.lanl.gov; whz@lanl.gov NR 29 TC 62 Z9 62 U1 0 U2 5 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 JUL PY 2000 VL 62 IS 1 AR 013607 DI 10.1103/PhysRevA.62.013607 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800088 ER PT J AU Doherty, AC Habib, S Jacobs, K Mabuchi, H Tan, SM AF Doherty, AC Habib, S Jacobs, K Mabuchi, H Tan, SM TI Quantum feedback control and classical control theory SO PHYSICAL REVIEW A LA English DT Article ID OPTICAL FEEDBACK; HOMODYNE DETECTION; STATE DIFFUSION; SINGLE-ATOM; SYSTEMS; COHERENCE; WAVE; CONTROLLABILITY; COMPUTATION; DECOHERENCE AB We introduce and discuss the problem of quantum feedback control in the context of established formulations of classical control theory, examining conceptual analogies and essential differences. We describe the application of state-observer-based control laws, familiar in classical control theory, to quantum systems and apply our. methods to the particular case of switching the state of a particle in a double-well potential. C1 Univ Auckland, Dept Phys, Auckland, New Zealand. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. RP Doherty, AC (reprint author), CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. RI Jacobs, Kurt/E-7049-2011; Doherty, Andrew/D-1816-2010 OI Jacobs, Kurt/0000-0003-0828-6421; Doherty, Andrew/0000-0002-8069-7754 NR 66 TC 211 Z9 219 U1 2 U2 16 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 JUL PY 2000 VL 62 IS 1 AR 012105 DI 10.1103/PhysRevA.62.012105 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800018 ER PT J AU McGuire, JH Itza-Ortiz, S Godunov, AL Ederer, DL Wang, J Burgdorfer, J AF McGuire, JH Itza-Ortiz, S Godunov, AL Ederer, DL Wang, J Burgdorfer, J TI Exclusive and inclusive cross sections for Compton scattering from H- and He SO PHYSICAL REVIEW A LA English DT Article ID DOUBLE-IONIZATION; X-RAYS; EXCITATION-IONIZATION; CHARGED-PARTICLES; SINGLE IONIZATION; HELIUM; PHOTONS; PHOTOIONIZATION; RATIO AB Absolute inclusive and exclusive cross sections for ionization of H- and He by Compton scattering are presented and analyzed. The exclusive cross section for ionization of one electron, leaving the second electron in the ground state, is 20% smaller for H- than for He. Furthermore, the exclusive cross section for ionization with excitation to the first excited state is seven times larger for H- than for He. However, at high energies the inclusive Compton cross sections for both H- and He are within 1% of two times the Thomson cross section for elastic scattering of a free electron, even when ground-state correlation is accurately included. A general analysis based on quasielastic scattering is applied to both shake and correlated calculations. C1 Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Massachusetts, Dept Phys, N Dartmouth, MA 02747 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. RP McGuire, JH (reprint author), Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. RI Godunov, Alexander/G-4266-2011 NR 32 TC 2 Z9 2 U1 2 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2000 VL 62 IS 1 AR 012702 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800051 ER PT J AU Smith, AJ Beiersdorfer, P Reed, KJ Osterheld, AL Decaux, V Widmann, K Chen, MH AF Smith, AJ Beiersdorfer, P Reed, KJ Osterheld, AL Decaux, V Widmann, K Chen, MH TI Ratios of n=3 -> 1 intercombination to resonance line intensities for heliumlike ions with intermediate Z values SO PHYSICAL REVIEW A LA English DT Article ID HIGHLY CHARGED IONS; HIGH-RESOLUTION MEASUREMENT; X-RAY SPECTROSCOPY; K-BETA SPECTRUM; ELECTRON-BEAM; CROSS-SECTIONS; LITHIUM-LIKE; FE-XXV; EMISSION; IDENTIFICATION AB We have measured the ratio of the intensity of the n = 3 --> 1 intercombination line (1s3p P-3(1) --> 1s(2) S-1(0)) to that of the resonance line (1s3p P-1(1) --> 1s(2) S-1(0)) for the heliumlike ions Mg10+, Al11+, Ar16+, Ti20+, V21+, Cr22+, and Fe24+. The measurements were carried out on the Lawrence Livermore National Laboratory electron-beam ion trap using electron-beam energies mostly near the threshold for the direct excitation of the resonance line, or near the threshold for excitation of the n = 4 levels, to avoid populating the n = 3 levels by cascades from levels with n greater than or equal to 5. High-resolution Bragg crystal spectrometers in curved as well as flat geometry were used to record the x rays. The measured ratios have been compared to predicted values, which were found to underestimate the measured values. C1 Morehouse Coll, Dept Phys, Atlanta, GA 30314 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Smith, AJ (reprint author), Morehouse Coll, Dept Phys, Atlanta, GA 30314 USA. NR 29 TC 13 Z9 13 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 JUL PY 2000 VL 62 IS 1 AR 012704 DI 10.1103/PhysRevA.62.012704 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800053 ER PT J AU Vane, CR Krause, HF Datz, S Grafstrom, P Knudsen, H Scheidenberger, C Schuch, RH AF Vane, CR Krause, HF Datz, S Grafstrom, P Knudsen, H Scheidenberger, C Schuch, RH TI Radiative electron capture at ultrarelativistic energies: 33-TeV Pb(82+) ions SO PHYSICAL REVIEW A LA English DT Article ID RELATIVISTIC ATOMIC-COLLISIONS; POSITRON PAIR PRODUCTION; BOUND-ELECTRON; IONIZATION AB Cross sections for radiative electron capture (REC) by 33-TeV Pb(82+) ions in Be and C targets have been extracted from an analysis of measurements of total electron capture by these ions in Be, C, Al, Cu, Sn, and Au targets. The REC cross sections in the Be and C targets, when REC is significant, were obtained by subtracting cross sections for electron capture from pair production (ECPP), the only other significant capture process at these energies. The ECPP contributions in Be and C were determined from extrapolations of measured cross sections in the heavier targets where the ECPP process dominates, with suitable accounting for slightly decreased screening effects for the light targets. We obtain an experimental K-REC cross section (0.010 +/- 0.002b per electron per Pb K vacancy), which agrees with a calculation of REC made by applying detailed balance to the corresponding process of radiative recombination and using tabulated photoelectric effect cross sections. A comparison is also presented of the present experimental result with other heavy-ion measurements made at lower energies, and with nonrelativistic and relativistic calculations, which differ considerably in this energy regime. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. CERN, SPS SL Div, CH-1211 Geneva 23, Switzerland. Aarhus Univ, Inst Phys, DK-8000 Aarhus C, Denmark. Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. Stockholm Univ, Dept Atom Phys, S-10405 Stockholm, Sweden. RP Vane, CR (reprint author), Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. NR 25 TC 5 Z9 5 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 2000 VL 62 IS 1 AR 010701 DI 10.1103/PhysRevA.62.010701 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 333QB UT WOS:000088139800003 ER PT J AU Knigavko, A Kogan, VG Rosenstein, B Yang, TJ AF Knigavko, A Kogan, VG Rosenstein, B Yang, TJ TI Nature of the 45 degrees vortex lattice reorientation in tetragonal superconductors SO PHYSICAL REVIEW B LA English DT Article ID FLUX-LINE-LATTICE; NEUTRON-SCATTERING; YNI2B2C; LU(NI1-XCOX)(2)B2C; TRANSITION AB The transformation of the vortex lattice in a tetragonal superconductor which consists of the 45 degrees reorientation relative to the crystal axes is studied using the nonlocal London model. It is shown that the reorientation occurs as two successive second order (continuous) phase transitions. The transition magnetic fields are calculated for a range of parameters relevant for borocarbide superconductors in which the reorientation has been observed. C1 Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 30050, Taiwan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 30050, Taiwan. RP Knigavko, A (reprint author), Natl Chiao Tung Univ, Dept Electrophys, Hsinchu 30050, Taiwan. NR 17 TC 6 Z9 6 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 111 EP 114 DI 10.1103/PhysRevB.62.111 PG 4 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000029 ER PT J AU Chernikov, MA Paschen, S Felder, E Vorburger, P Ruzicka, B Degiorgi, L Ott, HR Fisher, IR Canfield, PC AF Chernikov, MA Paschen, S Felder, E Vorburger, P Ruzicka, B Degiorgi, L Ott, HR Fisher, IR Canfield, PC TI Low-temperature transport, thermal, and optical properties of single-grain quasicrystals of icosahedral phases in the Y-Mg-Zn and Tb-Mg-Zn alloy systems SO PHYSICAL REVIEW B LA English DT Article ID AL-RE-PD; QUASI-CRYSTALS; WEAK LOCALIZATION; SPIN-GLASSES; CU-FE; = Y; CONDUCTIVITY; AL70MN9PD21; MAGNETORESISTANCE; BEHAVIOR AB We present a comprehensive series of results of electrical transport (electrical conductivity, magnetoconductivity, Hall effect), thermal (specific heat), and optical (reflectivity) measurements in varying temperature ranges between 1.5 and 300 K on high-quality single-grain quasicrystals of icosahedral Y-Mg-Zn. This data set is augmented by the specific-heat and optical-reflectivity data obtained from a single-grain quasicrystal of icosahedral Tb-Mg-Zn. For Y-Mg-Zn, both the electrical conductivity sigma(T) and magnetoconductivity delta sigma(H) may be described by calculations considering quantum interference effects. A detailed comparison of the weak-localization contributions to sigma(T) and delta sigma(H) with our experimental data provides estimates of the inelastic and spin-orbit relaxation rates. The inelastic relaxation rate is found to be proportional to T-3. The dominant contributions to the optical conductivity sigma(1)(omega) spectrum, obtained from the reflectivity R(omega) data in the frequency range between 16 and 9.7 X 10(4) cm(-1), are a strong Drude feature at low frequencies and a prominent absorption signal centered at approximately 6 X 10(3) cm(-1). A comparison of the spectral weight of the Drude contribution to sigma(1)(omega) with the magnitude of the linear-in-ir term gamma T of the low-temperature specific heat C-p(T) yields the itinerant charge-carrier density n(i) = 7.62 X 10(21) cm(-3) or 0.13 charge carriers per atom. The low ni value is corroborated by the results of the Hall effect measurements. For Tb-Mg-Zn, the optical conductivity sigma(1)(omega) spectrum reveals features similar to those of Y-Mg-Zn. The low-temperature specific heat C-P(T) of Tb-Mg-Zn is strongly influenced by a spin-glass-type freezing of Tb moments and by crystal-electric-field effects. C1 ETH Zurich, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Chernikov, MA (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RI Paschen, Silke/C-3841-2014; Canfield, Paul/H-2698-2014; Ruzicka, Barbara/P-1702-2014 OI Paschen, Silke/0000-0002-3796-0713; Ruzicka, Barbara/0000-0003-2019-620X NR 41 TC 17 Z9 17 U1 1 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 262 EP 272 DI 10.1103/PhysRevB.62.262 PG 11 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000053 ER PT J AU Gianno, K Sologubenko, AV Chernikov, MA Ott, HR Fisher, IR Canfield, PC AF Gianno, K Sologubenko, AV Chernikov, MA Ott, HR Fisher, IR Canfield, PC TI Low-temperature thermal conductivity of a single-grain Y-Mg-Zn icosahedral quasicrystal SO PHYSICAL REVIEW B LA English DT Article ID R = Y; QUASI-CRYSTALS; TB; TRANSPORT; PHASE; HO; EXCITATIONS; GLASSES; GROWTH; ALLOYS AB We report measurements of the thermal conductivity kappa(T) of a single-grain icosahedral Y8.6Me34.6Zn56.8 in the temperature range between 0.1 and 300 K. The quasilattice thermal conductivity kappa(ph) increases monotonically with T by three orders of magnitude between 0.1 and 23 K. Above 23 K, kappa(ph)(T) decreases substantially with increasing temperature, typical for high-quality single grain quasicrystals. The decrease ends in a minimum at approximately 140 K. The interpretation of our data is based on a Debye-type relaxation time approximation. At very low temperatures, the corresponding fit reveals that the phonon mean free path is of the order of the smallest sample dimension, while at high temperatures, a power-law decrease of the phonon scattering time with increasing temperature evidences the effect of structural scattering on the mean free path of itinerant quasilattice excitations. The behavior of kappa(ph)(T) at intermediate temperatures may best be fit by assuming the existence of stacking-fault-like phonon scatterers. No clear evidence for a scattering of phonons by tunneling states has been observed. If compared to previously reported measurements of the thermal conductivity of quasicrystals, these data indicate the very high structural perfection of this quasiperiodic material. C1 ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Gianno, K (reprint author), ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. RI Canfield, Paul/H-2698-2014 NR 43 TC 39 Z9 39 U1 1 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 292 EP 300 DI 10.1103/PhysRevB.62.292 PG 9 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000056 ER PT J AU Guerrero, M Ortiz, G Gubernatis, JE AF Guerrero, M Ortiz, G Gubernatis, JE TI Pairing correlations in the attractive Hubbard model on chains, ladders, and squares SO PHYSICAL REVIEW B LA English DT Article ID MONTE-CARLO METHOD; FERMION GROUND-STATES; LONG-RANGE ORDER; ELECTRON-SYSTEMS; ONE-DIMENSION; SUPERCONDUCTIVITY; THERMODYNAMICS AB We report the results of zero-temperature quantum Monte Carlo simulations and zero-temperature mean-field calculations of the attractive Hubbard model on chains, ladders, and square lattices. We investigated the predictability of the BCS approximation, the dimensional crossover of the pairing correlation function from one to two dimensions as a function of the ladder width, and the scaling of these correlations to the thermodynamic limit of the two-dimensional model. We found that the BCS wave function is quantitatively correct only for small values of U/t. For the system sizes, electron fillings, and interaction strengths studied, we never saw the dimensional crossover. In general, our ability to achieve the dimensional crossover and accurate scaling to the thermodynamic limit was limited by the size of the systems we could simulate. For these sizes, although we saw the necessary signature of off-diagonal long-range order, the properties of the model did not vary monotonically with increasing system size because of shell effects. We contrast this situation with the dimensional crossover and scaling to the thermodynamic limit of the Ising model. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87444 USA. RP Guerrero, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87444 USA. NR 48 TC 13 Z9 13 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 600 EP 614 DI 10.1103/PhysRevB.62.600 PG 15 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000096 ER PT J AU Arnold, GB Klemm, RA AF Arnold, GB Klemm, RA TI Theory of coherent c-axis Josephson tunneling between layered superconductors SO PHYSICAL REVIEW B LA English DT Article ID JUNCTIONS AB We calculate exactly the Josephson current for c-axis coherent tunneling between two layered superconductors, each with internal coherent tight-binding intra- and interlayer quasiparticle dispersions. Our results also apply when one or both of the superconductors is a bulk material, and include the usually neglected effects of surface states. For weak tunneling, our results reduce to our previous results derived using the tunneling Hamiltonian. Our results are also correct for strong tunneling. However, the c-axis tunneling expressions of Tanaka and Kashiwaya are shown to be incorrect in any limit. In addition, we consider the c-axis coherent critical current between two identical layered superconductors twisted an angle phi(0) about the c axis with respect to each other. Regardless of the order-parameter symmetry, our coherent tunneling results using a tight-binding intralayer quasiparticle dispersion are inconsistent with the recent c-axis twist bicrystal Bi2Sr2CaCu2O8+delta twist junction experiments of Li et al. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Arnold, GB (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 14 TC 26 Z9 26 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 661 EP 670 DI 10.1103/PhysRevB.62.661 PG 10 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000104 ER PT J AU Breitwisch, M Finnemore, DK AF Breitwisch, M Finnemore, DK TI Pinning of a single Abrikosov vortex in superconducting Nb thin films using artificially induced pinning sites SO PHYSICAL REVIEW B LA English DT Article ID FORCE AB Artificial structures were intentionally introduced into Nb films in order to study the interaction of a single Abrikosov vortex with pinning sites caused by these known defects. A vortex trapped on one of these structures or defects can be induced to move either by thermal depinning or by pushing on the vortex with a transport current in one of the films. The resulting motion, in turn, can be followed by observing the changes in the Fraunhofer-like interference pattern of a cross-strip Josephson junction having the thin film as one leg of the junction. Artificial pinning sites were successfully created by depositing Fe bans on the surface of a previously characterized thin film. Attempts to create artificial pinning sites by depressing the order parameter with a thin strip of Au on the surface of the Nb were not successful. There was no correlation between the location of trapped vortices and the location of the Au line. In a separate measurement, Lorentz-force-depinning studies for several intrinsic pinning sites in the thin film show that a transport current in the top film will depin a vortex in the top film with about one-tenth the current needed in the bottom film to depin the same vortex. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Breitwisch, M (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 11 TC 8 Z9 8 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 1 BP 671 EP 677 DI 10.1103/PhysRevB.62.671 PG 7 WC Physics, Condensed Matter SC Physics GA 331UL UT WOS:000088037000105 ER PT J AU Woodward, PM Cox, DE Moshopoulou, E Sleight, AW Morimoto, S AF Woodward, PM Cox, DE Moshopoulou, E Sleight, AW Morimoto, S TI Structural studies of charge disproportionation and magnetic order in CaFeO3 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-DIFFRACTION; POWDER DIFFRACTION; PEROVSKITE OXIDES; IRON-OXIDES; VALENCE; TEMPERATURE; TRANSITIONS; STATE AB The crystal and magnetic structures of CaFeO3 have been determined at 300 and 15 K using synchrotron x-ray and neutron powder-diffraction techniques. At 300 K, CaFeO3 adopts: the GdFeO3 struture, space group P-bnm with unit-cell dimensions a = 5.326 30(4), b = 5.352 70(4), and c = 7.539 86(6) Angstrom. This structure is distorted from the ideal perovskite structure by tilting of the FeO6 octahedra about [110] and [001]. The average Fe-O distance is 1.922(2) Angstrom, and the Fe-O-Fe angles are 158.4(2)degrees and 158.1(1)degrees. At 15 K the crystal structure belongs to space group P2(1)/n with a = 5.311 82(3), b = 5.347 75(4), c = 7.520 58(5) Angstrom and beta = 90.065(1)degrees, and contains two distinct Fe sites. The average Fe-O bond length is 1.872(6) Angstrom about the one iron site, and 1.974(6) Angstrom about the second site. with bond valence sums of 4.58 and 3.48, respectively. This provides quantitative evidence for charge disproportionation. 2Fe(4+) --> Fe3+ + Fe5+, at low temperature. The temperature evolution of the lattice parameters indicates a second- (or higher-) order phase transition from the orthorhombic charge-delocalized state to the monoclinic charge-disproportionated state, beginning just below room temperature. The magnetic structure at 15 K is incommensurate, having a modulation vector [delta,0,delta] with delta similar to 0.322, corresponding to one of the < 111 > directions in the pseudocubic cell. A reasonable fit to the magnetic intensities is obtained with the recently proposed screw spiral structure [S. Kawasaki et al., J. Phys. Sec. Jpn. 67, 1529 (1998)], with Fe moments of 3.5 and 2.5 mu(B), respectively. However, a comparable lit is given by a sinusoidal amplitude-modulated model in which the Fe moments are directed along [010], which leaves open the possibility that the true magnetic structure may be intermediate between the spiral and sinusoidal models (a fan structure). C1 Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. Oregon State Univ, Ctr Adv Mat Res, Corvallis, OR 97331 USA. Osaka Univ, Grad Sch Engn Sci, Toyonaka, Osaka 5608531, Japan. RP Woodward, PM (reprint author), Ohio State Univ, Dept Chem, 120 W 18Th Ave, Columbus, OH 43210 USA. EM woodward@chemistry.ohio-state.edu NR 46 TC 160 Z9 163 U1 6 U2 65 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP 844 EP 855 DI 10.1103/PhysRevB.62.844 PG 12 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500025 ER PT J AU Billinge, SJL Proffen, T Petkov, V Sarrao, JL Kycia, S AF Billinge, SJL Proffen, T Petkov, V Sarrao, JL Kycia, S TI Evidence for charge localization in the ferromagnetic phase of La1-xCaxMnO3 from high real-space-resolution x-ray diffraction SO PHYSICAL REVIEW B LA English DT Article ID JAHN-TELLER DISTORTION; COLOSSAL-MAGNETORESISTANCE; NEUTRON-DIFFRACTION; POLARON FORMATION; LOCAL-STRUCTURE; MANGANITES; LA1-XSRXMNO3; PEROVSKITE; SCATTERING; SEPARATION AB High real-space-resolution atomic pair distribution functions of La1-xCaxMnO3 (x = 0.12, 0.25, and 0.33) have been measured using high-energy x-ray powder diffraction to study the size and shape of the MnO6 octahedron as a function of temperature and doping. In the paramagnetic insulating phase we find evidence for three distinct bond lengths which we: ascribe to Mn4+-O, Mn3+-O-short, and Mn3+-O-long bonds, respectively. In the ferromagnetic metallic (FM) phase, for x = 0.33 and T = 20 K, we find a single Mn-O bond length; however, as the metal-insulator transition is approached either by increasing Tor decreasing x, intensity progressively appears around r = 2.15 and in the region 1.85-1.9 Angstrom suggesting the appearance of Mn3+-O-long bonds and short Mn4+-O bonds. This is strong evidence that charge localized and delocalized phases coexist close to the metal-insulator transition in the FM phase. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, Ctr Fundamental Mat Res, E Lansing, MI 48824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Cornell High Energy Synchrotron Source, Ithaca, NY 14853 USA. RP Billinge, SJL (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RI Lujan Center, LANL/G-4896-2012; Proffen, Thomas/B-3585-2009 OI Proffen, Thomas/0000-0002-1408-6031 NR 47 TC 73 Z9 74 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP 1203 EP 1211 DI 10.1103/PhysRevB.62.1203 PG 9 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500072 ER PT J AU Sasik, R Bettencourt, LMA Habib, S AF Sasik, R Bettencourt, LMA Habib, S TI Thermal vortex dynamics in a two-dimensional condensate SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTORS; MOTION; VORTICES; SUPERFLUID; FIELD; FLOW AB We carry out an analytical and numerical study of the motion of an isolated vortex in thermal equilibrium, the vortex being defined as the point singularity of a complex scaler field psi(r,t) obeying a nonlinear stochastic Schrodinger equation. Because hydrodynamic fluctuations are included in this description, the dynamical picture of the vortex emerges as that of both a massive particle in contact with a heat bath, and as a passive scalar advected to a background random flow. We show that the vortex does not execute a simple random walk and that the probability distribution of vortex flights has non-Gaussian (exponential) tails. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sasik, R (reprint author), Univ Calif San Diego, Inst Pure & Appl Phys Sci, 9500 Gilman Dr, La Jolla, CA 92093 USA. NR 32 TC 9 Z9 9 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP 1238 EP 1243 DI 10.1103/PhysRevB.62.1238 PG 6 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500076 ER PT J AU Yang, IS Klein, MV Cooper, SL Canfield, PC Cho, BK Lee, SI AF Yang, IS Klein, MV Cooper, SL Canfield, PC Cho, BK Lee, SI TI Study of the superconducting gap in RNi2B2C (R = Y, Lu) single crystals by inelastic light scattering SO PHYSICAL REVIEW B LA English DT Article ID FLUX-LINE-LATTICE; RAMAN-SCATTERING; ENERGY-GAP; ELECTRONIC-STRUCTURE; SOFT PHONONS; T-C; LUNI2B2C; YNI2B2C; RNI(2)B(2)C; EXCITATIONS AB Superconductivity-induced changes in thr electronic Raman-scattering response were observed for the RNi2B2C (R =Y, Lu) system in different scattering geometries. In the superconducting state, 2 Delta-like peaks were observed in A(1g), B-1g, and B-2g spectra from single crystals. The peaks, in A,, and Bz, symmetries are significantly sharper and stronger than the peak in B-1g symmetry. The temperature dependence of the frequencies of the 2 Delta-like peaks shows typical BCS-type behavior, but the apparent values of the 2 Delta gap are strongly anisotropic for both systems. In addition, for both YNi2B2C and LuNi2B2C systems, there exists reproducible scattering strength below the 2 Delta gap which is roughly linear to the frequency in B-1g and B-2g symmetries. This discovery of scattering below the gap in nonmagnetic borocarbide superconductors, which are thought to be conventional BCS-type superconductors. is a challenge for current understanding of superconductivity in this system. C1 Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea. Univ Illinois, Dept Phys, Mat Res Lab, Urbana, IL 61801 USA. Iowa State Univ, Dept Phys & Astron, Ames Lab, Ames, IA 50011 USA. Pohang Univ Sci & Technol, Natl Creat Res Initiat, Dept Phys, Ctr Superconduct, Pohang 790390, South Korea. RP Yang, IS (reprint author), Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea. RI Canfield, Paul/H-2698-2014 NR 35 TC 46 Z9 46 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP 1291 EP 1295 DI 10.1103/PhysRevB.62.1291 PG 5 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500080 ER PT J AU Booth, CH Gardner, JS Kwei, GH Heffner, RH Bridges, F Subramanian, MA AF Booth, CH Gardner, JS Kwei, GH Heffner, RH Bridges, F Subramanian, MA TI Local lattice disorder in the geometrically frustrated spin-glass pyrochlore Y2Mo2O7 SO PHYSICAL REVIEW B LA English DT Article ID FERROMAGNET; DYNAMICS; TL2MN2O7 AB The geometrically frustrated spin-glass Y2Mo2O7 has been widely considered to be crystallographically ordered with a unique nearest-neighbor magnetic exchange interaction, J. To test this assertion, we present x-ray-absorption fine-structure results for the Mo and Y K edges as a function of temperature and compare them to results from a well-ordered pyrochlore, Tl2Mn2O7. We find that the Mo-Mo pair distances are significantly disordered at approximately right angles to the Y-Mo pairs. These results strongly suggest that lattice disorder nucleates thr spin-glass phase in this material. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Dupont Co, Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. RP Booth, CH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Gardner, Jason/A-1532-2013; Booth, Corwin/A-7877-2008 NR 23 TC 52 Z9 52 U1 3 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP R755 EP R758 DI 10.1103/PhysRevB.62.R755 PG 4 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500007 ER PT J AU Hamalainen, K Huotari, S Laukkanen, J Soininen, A Manninen, S Kao, CC Buslaps, T Mezouar, M AF Hamalainen, K Huotari, S Laukkanen, J Soininen, A Manninen, S Kao, CC Buslaps, T Mezouar, M TI Free electron gas under high pressure SO PHYSICAL REVIEW B LA English DT Article ID RESOLUTION COMPTON-SCATTERING; X-RAY SPECTROMETER; FERMI-SURFACE; LI; TEMPERATURE; DENSITIES; PROFILE; SYSTEM AB We have carried out Compton scattering studies on metallic sodium under various pressures up to 42 kbar utilizing high-energy x rays from a third generation synchrotron source. The high pressure was applied using a large volume cell with a boron gasket. The induced change of free electron density (Delta V/V = 27%) is clearly detectable in the measured Compton profiles. The observed pressure effects are due to the change of the Fermi momentum, electron-ion, and electron-electron correlations as the average distance between electrons is reduced. The observed differences in the Compton profiles are well explained by a RPA calculation. C1 Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Hamalainen, K (reprint author), Univ Helsinki, Dept Phys, POB 9, FIN-00014 Helsinki, Finland. RI Hamalainen, Keijo/A-3986-2010 OI Hamalainen, Keijo/0000-0002-9234-9810 NR 29 TC 12 Z9 12 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP R735 EP R738 DI 10.1103/PhysRevB.62.R735 PG 4 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500002 ER PT J AU Weisse, A Fehske, H Wellein, G Bishop, AR AF Weisse, A Fehske, H Wellein, G Bishop, AR TI Optimized phonon approach for the diagonalization of electron-phonon problems SO PHYSICAL REVIEW B LA English DT Article ID DIMENSIONAL HOLSTEIN MODEL; T-J MODEL; SPINLESS FERMIONS; PHASE-DIAGRAM; SYSTEMS; BIPOLARONS AB We propose an optimized phonon approach for the numerical diagonalization of interacting electron-phonon systems combining density-matrix and Lanczos algorithms. We demonstrate the reliablity of this approach by calculating the phase diagram for bipolaron formation in the one-dimensional Holstein-Hubbard model, and the Luttinger parameters for the metallic phase of the half-filled one-dimensional Holstein model of spinless fermions. C1 Univ Bayreuth, Inst Phys, D-95440 Bayreuth, Germany. Univ Erlangen Nurnberg, Reg Rech Zentrum Erlangen, D-91058 Erlangen, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Weisse, A (reprint author), Univ Bayreuth, Inst Phys, POB 101251, D-95440 Bayreuth, Germany. NR 16 TC 41 Z9 41 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 2000 VL 62 IS 2 BP R747 EP R750 DI 10.1103/PhysRevB.62.R747 PG 4 WC Physics, Condensed Matter SC Physics GA 334MP UT WOS:000088190500005 ER PT J AU Bedaque, PF Savage, MJ AF Bedaque, PF Savage, MJ TI Parity violation in gamma(p)over-right-arrow Compton scattering SO PHYSICAL REVIEW C LA English DT Article ID EFFECTIVE-FIELD-THEORY; CHIRAL PERTURBATION-THEORY; NUCLEON COUPLINGS; FORCES; MODEL; F-18 AB A measurement of parity-violating spin-dependent gamma p Compton scattering will provide a theoretically clean determination of the parity-violating pion-nucleon coupling constant h(pi NN)((1)). We calculate the leading parity-violating amplitude arising from one-loop pion graphs in chiral perturbation theory. An asymmetry of similar to 5 x 10(-8) is estimated for Compton scattering of 100 MeV photons. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Bedaque, PF (reprint author), Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. EM bedaque@phys.washington.edu; savage@phys.washington.edu NR 40 TC 26 Z9 26 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 018501 DI 10.1103/PhysRevC.62.018501 PG 4 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200060 ER PT J AU Carlton, RF Harvey, JA Larson, DC Hill, NW AF Carlton, RF Harvey, JA Larson, DC Hill, NW TI Neutron resonance spectroscopy for n+Cr-52: Total and differential elastic scattering cross sections SO PHYSICAL REVIEW C LA English DT Article ID LEVEL AB Neutron total and elastic scattering cross sections have been measured over the neutron energy range 0.040-1.55 MeV. Spins and parities have been deduced for 90% of the resonances observed in the n + Cr-52 reaction up to 1.05 MeV. This work brings into doubt a previously claimed parity dependence of the level spacing in Cr-53. We have used an R-matrix analysis to obtain resonance parameters for 194 resonances up to 1.05 MeV and strengths and level spacings for partial waves up to and including d(5/2). The conventional s-, p-, and d-wave strength functions have been determined to be 3.5+/-1.0, 0.44+/-0.08, and 2.9+/-0.4, respectively (in units of 10(-4)). This is the first work to report d-wave strength in this nuclide, identifying 87 additional resonances in this group. This, in turn, has resulted in a significant increase in the p-wave level spacing compared to that of two other similar works. Evidence is presented to explain differences among evaluated nuclear data files for this nuclide in terms of the influence of the strength outside the region upon the background cross section. C1 Middle Tennessee State Univ, Dept Phys & Astron, Murfreesboro, TN 37132 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Carlton, RF (reprint author), Middle Tennessee State Univ, Dept Phys & Astron, Murfreesboro, TN 37132 USA. NR 21 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014608 PG 11 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200031 ER PT J AU Garrett, PE Bernstein, LA Becker, JA Hauschild, K McGrath, CA McNabb, DP Younes, W Tavukcu, E Johns, GD Nelson, RO Wilburn, WS Yates, SW AF Garrett, PE Bernstein, LA Becker, JA Hauschild, K McGrath, CA McNabb, DP Younes, W Tavukcu, E Johns, GD Nelson, RO Wilburn, WS Yates, SW TI States in Mo-92 observed with the (n,n ' gamma) reaction with spallation neutrons SO PHYSICAL REVIEW C LA English DT Article AB States in Mo-92 have been observed with the (n,n' gamma) reaction with spallation neutrons produced at the LANSCE-WNR facility. Gamma rays were detected with the GEANIE spectrometer, and the neutron energies were determined by the time-of-flight method. Combining excitation function and gamma gamma coincidence analysis, 13 new levels have been deduced. The level scheme has been extended considerably for low- to medium-spin levels below 5 MeV in excitation energy. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Kentucky, Lexington, KY 40506 USA. RP Garrett, PE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Hauschild, Karl/A-6726-2009; McGrath, Christopher/E-8995-2013 NR 16 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014307 DI 10.1103/PhysRevC.62.014307 PG 5 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200014 ER PT J AU LaFosse, DR Chiara, CJ Fossan, DB Lane, GJ Sears, JM Smith, JF Starosta, K Boston, AJ Paul, ES Semple, AT Devlin, M Sarantites, DG Lee, IY Macchiavelli, AO Afanasjev, AV Ragnarsson, I AF LaFosse, DR Chiara, CJ Fossan, DB Lane, GJ Sears, JM Smith, JF Starosta, K Boston, AJ Paul, ES Semple, AT Devlin, M Sarantites, DG Lee, IY Macchiavelli, AO Afanasjev, AV Ragnarsson, I TI Collective structures and band termination in Sb-107 SO PHYSICAL REVIEW C LA English DT Article ID HIGH-SPIN STATES; ROTATIONAL BANDS; INTRUDER BANDS; SMOOTH TERMINATION; MAGNETIC ROTATION; EXCITED-STATES; CLOSED-SHELL; NUCLEI; ISOTOPES; SN-106 AB High-spin states in the near proton-dripline nucleus Sb-107 have been identified, and collectivity in this nucleus has been observed for the first time in the form of two rotational bands. One of the observed rotational structures is a Delta I = 1 band, and is interpreted as based on a pi(g(9/2))(-1) x pi(g(7/2)d(5/2))(2) proton configuration. A second structure has Delta I = 2 character, and is explained as being based on pi h(11/2) x [pi(g(9/2))(-2) x pi(g(7/2)d(5/2))(2)] proton configuration through comparison with cranked Nilsson-Strutinsky model calculations. The calculations predict that this band terminates at a spin of 79/2 (h) over bar. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Lund Inst Technol, Dept Math Phys, S-22100 Lund, Sweden. Univ Latvia, Inst Solid State Phys, Lab Radiat Phys, LV-2169 Salaspils, Latvia. RP LaFosse, DR (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RI Lane, Gregory/A-7570-2011; Devlin, Matthew/B-5089-2013 OI Lane, Gregory/0000-0003-2244-182X; Devlin, Matthew/0000-0002-6948-2154 NR 43 TC 9 Z9 9 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014305 DI 10.1103/PhysRevC.62.014305 PG 10 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200012 ER PT J AU Talou, P Carjan, N Negrevergne, C Strottman, D AF Talou, P Carjan, N Negrevergne, C Strottman, D TI Exact dynamical approach to spherical ground-state proton emitters SO PHYSICAL REVIEW C LA English DT Article ID TIME-DEPENDENT APPROACH; DEFORMED-NUCLEI; DECAY AB The proton emission from ground-state spherical nuclei is investigated exactly through the numerical solution of the time-dependent Schrodinger equation for initial single-proton quasistationary states. Contrary to common belief, it is shown that such calculations can be performed for any proton half-life ranging from 10(-22)-20 s, the longest proton lifetime observed at present. The important and careful choice of the initial metastable state is clarified. Applied to the calculation of the decay width of several ground-state spherical emitters, this method gives comparable results with the distorted wave-Born approximation and therefore justifies its use. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. CEN Bordeaux Gradignan, F-33175 Gradignan, France. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. RP Talou, P (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM talou@lanl.gov NR 20 TC 14 Z9 15 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014609 DI 10.1103/PhysRevC.62.014609 PG 4 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200032 ER PT J AU von Neumann-Cosel, P Ginocchio, JN AF von Neumann-Cosel, P Ginocchio, JN TI l-forbidden M1 transitions and pseudospin symmetry SO PHYSICAL REVIEW C LA English DT Article ID GAMOW-TELLER TRANSITIONS; MAGNETIC-PROPERTIES; MATRIX-ELEMENTS; DECAY; NUCLEI; OPERATOR; BRANCH; CA-39 AB Pseudospin symmetry relates the l-forbidden magnetic dipole transition strengths between pseudospin partners to the magnetic moments of the involved states. These relations are tested against experimental data after correction for the fragmentation of the single particle strengths. Within typical uncertainties of the experimental spectroscopic factors good agreement is found for a wide, range of shell closures Z = 20-82, N = 20 - 126, and pseudo-orbital angular momenta. Systematic deviations are observed for particle states above N = 28 and Z = 50 where the predicted B(M1) values are about an order of magnitude too large. C1 Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. RP von Neumann-Cosel, P (reprint author), Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany. NR 28 TC 24 Z9 24 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014308 DI 10.1103/PhysRevC.62.014308 PG 5 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200015 ER PT J AU Wiringa, RB Pieper, SC Carlson, J Pandharipande, VR AF Wiringa, RB Pieper, SC Carlson, J Pandharipande, VR TI Quantum Monte Carlo calculations of A=8 nuclei SO PHYSICAL REVIEW C LA English DT Article ID FERMION GROUND-STATES; FEW-BODY NUCLEI; LIGHT-NUCLEI; VARIATIONAL CALCULATIONS; FORM-FACTORS; 4 NUCLEI; SYSTEMS; ENERGY; SCATTERING; DISTRIBUTIONS AB We report quantum Monte Carlo calculations of ground and low-lying excited states for A = 8 nuclei using a realistic Hamiltonian containing the Argonne v(18) two-nucleon and Urbana IX three-nucleon potentials. The calculations begin with correlated eight-body wave functions that have a filled alpha-like core and four p-shell nucleons LS coupled to the appropriate (J(pi); T) quantum numbers for the state of interest. After optimization, these variational wave functions are used as input to a Green's function Monte Carlo calculation made with a new constrained path algorithm. We find that the Hamiltonian produces a Be-8 ground state that is within 2 MeV of the experimental resonance, but the other eight-body energies are progressively worse as the neutron-proton asymmetry increases. The Li-8 ground state is stable against breakup into subclusters, but the He-8 ground state is not. The excited state spectra are in fair agreement with experiment, with both the single-particle behavior of He-8 and Li-8 and the collective rotational behavior of Be-8 being reproduced. We also examine energy differences in the T = 1,2 isomultiplets and isospin-mixing matrix elements in the excited states of Be-8. Finally, we present densities, momentum distributions, and studies of the intrinsic shapes of these nuclei, with Be-8 exhibiting a definite 2 alpha cluster structure. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. EM wiringa@anl.gov; spieper@anl.gov; carlson@lanl.gov; vrp@uiuc.edu RI Wiringa, Robert/M-4970-2015 NR 43 TC 317 Z9 321 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 2000 VL 62 IS 1 AR 014001 DI 10.1103/PhysRevC.62.014001 PG 23 WC Physics, Nuclear SC Physics GA 333PV UT WOS:000088139200007 ER PT J AU Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlson, J Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Cihangir, S Ciobanu, CI Clark, AG Connolly, A Conway, J Cooper, J Cordelli, M Costanzo, D Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Geer, S Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauer, J Heinrich, J Heiss, A Herndon, M Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nicolaidi, P Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Plunkett, R Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Riegler, W Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Theriot, D Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Xu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Zanetti, A Zetti, F Zucchelli, S AF Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlson, J Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Cihangir, S Ciobanu, CI Clark, AG Connolly, A Conway, J Cooper, J Cordelli, M Costanzo, D Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Geer, S Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauer, J Heinrich, J Heiss, A Herndon, M Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nicolaidi, P Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Plunkett, R Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Riegler, W Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Theriot, D Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Xu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Search for the charged Higgs boson in the decays of top quark pairs in the e tau and mu tau channels at root s=1.8 TeV SO PHYSICAL REVIEW D LA English DT Article ID DOUBLET MODEL PREDICTIONS; P(P)OVER-BAR COLLISIONS; (P)OVER-BAR-P COLLISIONS; NLO QCD; COLLIDER; FERMILAB AB Top quark production offers the unique opportunity to search for a charged Higgs;boson (H+/-), as the contribution from t-->H+ b-->tau(+) nu b can be large in extensions of the standard model. We use results from a search for top quark pair production by the Collider Detector at Fermilab (CDF) in the e tau + E-T + jets and mu tau + E-T + jets signatures to set an upper limit on the branching ratio of B(t-->H+ b) in 106 pb(-1) of data. The upper limit is in the range 0.5 to 0.6 at 95% C.L. for H+ masses in the range 60 to 160 GeV, assuming the branching ratio for H+-->tau nu is 100%. The tau lepton is detected through its 1-prong and 3-prong hadronic decays. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Cantabria, Inst Fis Cantabria, E-39005 Santander, Spain. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Joint Nucl Res Inst, RU-141980 Dubna, Russia. Duke Univ, Dept Geol, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Kyungpook Natl Univ, Jorean Hadron Collider Lab, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Dept Chem, Suwon 440746, South Korea. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. MIT, Cambridge, MA 02139 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Affolder, T (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; vilar, rocio/P-8480-2014; Prokoshin, Fedor/E-2795-2012; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Prokoshin, Fedor/0000-0001-6389-5399; Introzzi, Gianluca/0000-0002-1314-2580 NR 28 TC 37 Z9 37 U1 0 U2 2 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 JUL 1 PY 2000 VL 62 IS 1 AR 012004 DI 10.1103/PhysRevD.62.012004 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100006 ER PT J AU Aranda, A Carone, CD Lebed, RF AF Aranda, A Carone, CD Lebed, RF TI Maximal neutrino mixing from a minimal flavor symmetry SO PHYSICAL REVIEW D LA English DT Article ID DYNAMICAL SUPERSYMMETRY BREAKING; DISCRETE GAUGE-SYMMETRY; STANDARD MODEL; UNIFIED THEORIES; FERMION MASSES; U(2); ANOMALIES; OSCILLATIONS; UNIFICATION; MATRICES AB We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U(2) theories of flavor. These models allow for solutions to the solar and atmospheric neutrino problems that do not require altering successful predictions for the charged fermions or introducing sterile neutrinos. Although Yukawa matrices are hierarchical in the models we consider, the mixing between second- and third-generation neutrinos is naturally large. We first present a quantitative analysis of a minimal model proposed in earlier work, consisting of a global fit to fermion masses and mixing angles, including the most important renormalization group effects. We then propose two new variant models: The first reproduces all important features of the SU(5) x U(2) unified theory with neither SU(5) nor U(2). The second demonstrates that discrete subgroups of SU(2) can be used in constructing viable supersymmetric theories of flavor without scalar universality even though SU(2) by itself cannot. C1 Coll William & Mary, Dept Phys, Nucl & Particle Theory Grp, Williamsburg, VA 23187 USA. Jefferson Lab, Newport News, VA 23606 USA. RP Coll William & Mary, Dept Phys, Nucl & Particle Theory Grp, Williamsburg, VA 23187 USA. EM fefo@physics.wm.edu; carone@physics.wm.edu; lebed@jlab.org OI Aranda, Alfredo/0000-0002-8639-5167 NR 55 TC 80 Z9 80 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 JUL 1 PY 2000 VL 62 IS 1 AR 016009 DI 10.1103/PhysRevD.62.016009 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100083 ER PT J AU Bachacou, H Hinchliffe, I Paige, FE AF Bachacou, H Hinchliffe, I Paige, FE TI Measurements of masses in supergravity models at CERN LHC SO PHYSICAL REVIEW D LA English DT Article ID DYNAMICAL SUPERSYMMETRY BREAKING; W-BOSON MASS; GRAND UNIFICATION AB This paper presents new measurements in a case study of the minimal supergravity (SUGRA) model with m(0) = 100 GeV, m(1/2) = 300 GeV, A(0) = 0, tan beta = 2, and sgn mu = + based on four-body distributions from three-step decays and on minimum masses in such decays. These measurements allow masses of supersymmetric particles to be determined without relying on a model. The feasibility of testing slepton universality at the similar to 0.1% level at high luminosity is discussed. In addition, the effect of enlarging the parameter space of the minimal SUGRA model is discussed. The direct production of left-handed sleptons and the nonobservation of additional structure in the dilepton invariant mass distributions are shown to provide additional constraints. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Kungliga Tekn Hgsk, Stockholm, Sweden. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bachacou, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 38 TC 171 Z9 171 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 JUL 1 PY 2000 VL 62 IS 1 AR 015009 DI 10.1103/PhysRevD.62.015009 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100069 ER PT J AU Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Guo, ZJ Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Huang, GS Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mandelkern, M Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Schmid, B Schultz, J Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Stoker, D Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wang, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, N Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, HX Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA AF Bai, JZ Ban, Y Bian, JG Blum, I Chen, GP Chen, HF Chen, J Chen, JC Chen, Y Chen, YB Chen, YQ Cheng, BS Cui, XZ Ding, HL Dong, LY Du, ZZ Dunwoodie, W Gao, CS Gao, ML Gao, SQ Gratton, P Gu, JH Gu, SD Gu, WX Gu, YF Guo, YN Guo, ZJ Han, SW Han, Y Harris, FA He, J He, JT He, KL He, M Heng, YK Hitlin, DG Hu, GY Hu, HM Hu, JL Hu, QH Hu, T Hu, XQ Huang, YZ Huang, GS Izen, JM Jiang, CH Jin, Y Jones, BD Ju, X Ke, ZJ Kelsey, MH Kim, BK Kong, D Lai, YF Lang, PF Lankford, A Li, CG Li, D Li, HB Li, J Li, JC Li, PQ Li, RB Li, W Li, WG Li, XH Li, XN Liu, HM Liu, J Liu, RG Liu, Y Lou, XC Lowery, B Lu, F Lu, JG Luo, XL Ma, EC Ma, JM Malchow, R Mandelkern, M Mao, HS Mao, ZP Meng, XC Nie, J Olsen, SL Oyang, J Paluselli, D Pan, LJ Panetta, J Porter, F Qi, ND Qi, XR Qian, CD Qiu, JF Qu, YH Que, YK Rong, G Schernau, M Schmid, B Schultz, J Shao, YY Shen, BW Shen, DL Shen, H Shen, XY Sheng, HY Shi, HZ Song, XF Standifird, J Stoker, D Sun, F Sun, HS Sun, Y Sun, YZ Tang, SQ Toki, W Tong, GL Varner, GS Wang, F Wang, LS Wang, LZ Wang, M Wang, P Wang, PL Wang, SM Wang, TJ Wang, YY Weaver, M Wei, CL Wu, N Wu, YG Xi, DM Xia, XM Xie, PP Xie, Y Xie, YH Xu, GF Xue, ST Yan, J Yan, WG Yang, CM Yang, CY Yang, HX Yang, J Yang, W Yang, XF Ye, MH Ye, SW Ye, YX Yu, CS Yu, CX Yu, GW Yu, YH Yu, ZQ Yuan, CZ Yuan, Y Zhang, BY Zhang, C Zhang, CC Zhang, DH Zhang, DH Zhang, HL Zhang, J Zhang, JW Zhang, L Zhang, LS Zhang, P Zhang, QJ Zhang, SQ Zhang, XY Zhang, YY Zhao, DX Zhao, HW Zhao, JW Zhao, M Zhao, WR Zhao, ZG Zheng, JP Zheng, LS Zheng, ZP Zheng, LS Zheng, ZP Zhou, BQ Zhou, GP Zhou, HS Zhou, L Zhu, KJ Zhu, QM Zhu, YC Zhu, YS Zhuang, BA CA BES Collaboration TI Measurement of the inclusive charm cross section at 4.03 GeV and 4.14 GeV SO PHYSICAL REVIEW D LA English DT Article ID E+E ANNIHILATION AB The cross section for charmed meson production at root s = 4.03 and 4.14 GeV has been measured with the Beijing Spectrometer. The measurement was made using 22.3 pb(-1) of e(+) e(-) data collected at 4.03 GeV and 1.5 pb(-1) of e(+) e(-) data collected at 4.14 GeV. Inclusive observed cross sections for the production of charged and neutral D mesons and momentum spectra are presented. Observed cross sections were radiatively corrected to obtain tree level cross sections. Measurements of the total hadronic cross section rue obtained from the charmed meson cross section and an extrapolation of results from below the charm threshold. C1 Inst High Energy Phys, Beijing 100039, Peoples R China. CALTECH, Pasadena, CA 91125 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Hangzhou Univ, Hangzhou 310028, Peoples R China. Peking Univ, Beijing 100871, Peoples R China. Shandong Univ, Jinan 250100, Peoples R China. Shanghai Jiao Tong Univ, Shanghai 200030, Peoples R China. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Calif Irvine, Irvine, CA 92717 USA. Univ Sci & Technol China, Hefei 230026, Peoples R China. Univ Texas, Richardson, TX 75083 USA. RP Bai, JZ (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China. RI Chen, Yu/E-3788-2012 NR 18 TC 11 Z9 11 U1 0 U2 3 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 JUL 1 PY 2000 VL 62 IS 1 AR 012002 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100004 ER PT J AU Barger, V Geer, S Raja, R Whisnant, K AF Barger, V Geer, S Raja, R Whisnant, K TI Long-baseline study of the leading neutrino oscillation at a neutrino factory SO PHYSICAL REVIEW D LA English DT Article ID MUON STORAGE-RINGS; GEV ENERGY-RANGE; ATMOSPHERIC NEUTRINOS; SUPER-KAMIOKANDE; CP VIOLATION; PARAMETRIC-RESONANCE; LSND EXPERIMENT; MATTER; FLUX; PHYSICS AB Within the framework of three-flavor neutrino oscillations, we consider the physics potential of nu(e)-->nu(mu) appearance and nu(mu)-->nu(mu) survival measurements at a neutrino factory for a leading oscillation scale delta m(2) similar to 3.5 x 10(-3) eV(2). Event rates are evaluated versus baseline and stored muon energy, and optimal values discussed. Over a sizable region of oscillation parameter space, matter effects would enable the sign of delta m(2) to be determined from a comparison of nu(e)-->nu(mu) with <(nu)over bar>(e)--><(nu)over bar>(mu) event rates and energy distributions. Ii is important, therefore, that both positive and negative muons can be stored in the ring. Measurements of the nu(mu)-->nu(mu) survival spectrum could determine the magnitude of delta m(2) and the leading oscillation amplitude with a precision of O (1%-2%). C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Barger, V (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 83 TC 105 Z9 105 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 JUL 1 PY 2000 VL 62 IS 1 AR 013004 DI 10.1103/PhysRevD.62.013004 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100010 ER PT J AU Berger, EL Gordon, LE Klasen, M AF Berger, EL Gordon, LE Klasen, M TI Spin dependence of massive lepton pair production in proton-proton collisions SO PHYSICAL REVIEW D LA English DT Article ID PROMPT-PHOTON PRODUCTION; TO-LEADING-ORDER; SMALL TRANSVERSE-MOMENTUM; VECTOR BOSON PRODUCTION; DRELL-YAN; PARTON DISTRIBUTIONS; HADRON-COLLISIONS; CROSS-SECTIONS; HIGH ENERGIES; BACK JETS AB We calculate the transverse momentum distribution for the production of massive lepton pairs in longitudinally polarized proton-proton reactions at collider energies within the context of perturbative quantum chromodynamics. For values of the transverse momentum Q(T) greater than roughly half the pair mass Q, Q(T) >Q/2, we show that the differential cross section is dominated by subprocesses initiated by incident gluons, provided that the polarized gluon density is not too small. Massive lepton-pair differential cross sections should be a good source of independent constraints on the polarized gluon density, free from the experimental and theoretical complications of photon isolation that beset studies of prompt photon production. We provide predictions for the spin-averaged and spin-dependent differential cross sections as a function of Q(T) at energies relevant for the Relativistic Heavy Ion Collider at Brookhaven, and we compare these with predictions for real prompt photon production. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Jefferson Lab, Newport News, VA 23606 USA. Hampton Univ, Hampton, VA 23668 USA. RP Berger, EL (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 34 TC 16 Z9 16 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 JUL 1 PY 2000 VL 62 IS 1 AR 014014 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100032 ER PT J AU Burakovsky, L Page, PR AF Burakovsky, L Page, PR TI Filtering overpopulated isoscalar tensor states with mass relations SO PHYSICAL REVIEW D LA English DT Article ID PARTIAL-WAVE ANALYSIS; PP INTERACTIONS; 450 GEV/C AB Schwinger-type mass formulas are used to analyze glueball-meson mixing for isoscalar tensor mesons. In one solution, the f(J)(2220) is the physical glueball, and in the other the glueball is distributed over various states, with f(2)( 1810) having the largest glueball component. Neither the f(2)(1565) nor the f(J)(1710) are among the physical states without assuming significant coupling to decay channels. The decay f(2)(1525)-->pi pi is consistent with experiment, and f(J)(2220) is neither narrow nor decays flavor democratically. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Burakovsky, L (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM burakov@t5.lanl.gov; prp@lanl.gov RI Page, Philip/L-1885-2015 OI Page, Philip/0000-0002-2201-6703 NR 14 TC 11 Z9 12 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 JUL 1 PY 2000 VL 62 IS 1 AR 014011 DI 10.1103/PhysRevD.62.014011 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100029 ER PT J AU Gelb, JM Rosen, SP AF Gelb, JM Rosen, SP TI Mass matrix for atmospheric, solar, and LSND neutrino oscillations SO PHYSICAL REVIEW D LA English DT Article ID RECONCILING DARK-MATTER; VACUUM OSCILLATION; NUCLEOSYNTHESIS; LIGHT; PREDICTIONS; SPECTRA AB We construct a mass matrix for the four neutrino flavors, three active and one sterile, needed to fit oscillations in all three neutrino experiments: atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into two doublets whose central values are about 1 eV apart, and whose splittings are of the order of 10(-3) eV. Atmospheric neutrino oscillations are described as maximal mixing within the upper doublet, and solar as the same within the lower doubler. Then LSND is a weak transition from one doublet to the other. We comment on the Majorana versus Dirac nature of the active neutrinos and show that our mass matrix can he derived from an S-2 x S-2 permutation symmetry plus an equal splitting rule. C1 Univ Texas, Dept Phys, Arlington, TX 76019 USA. US DOE, Germantown, MD 20874 USA. RP Gelb, JM (reprint author), Univ Texas, Dept Phys, POB 19059, Arlington, TX 76019 USA. EM gelb@alum.mit.edu; Peter.Rosen@oer.doe.gov NR 47 TC 3 Z9 3 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 JUL 1 PY 2000 VL 62 IS 1 AR 013003 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100009 ER PT J AU Gribushin, A Abramov, V Antipov, Y Baldin, B Crittenden, R Davis, C Dauwe, L Denisov, S Dyshkant, A Dzierba, A Glebov, V Goldberg, H Jesik, R Koreshev, V Krider, J Krinitsyn, A Li, R Margulies, S Marshall, T Martin, J Mendez, H Petrukhin, A Solomon, J Sirotenko, V Smith, P Sulanke, T Sulyaev, R Vaca, F Zieminski, A Apanasevich, L Bacigalupi, J Begel, M Blusk, S Bromberg, C Chang, P Choudhary, B Chung, WH de Barbaro, L Dlugosz, W Dunlea, J Engels, E Fanourakis, G Ginther, G Hartman, K Huston, J Kapoor, V Lirakis, C Mani, S Mansour, J Maul, A Miller, R Osborne, G Pellett, D Pothier, E Roser, R Shepard, P Skow, D Slattery, P Sorrell, L Striley, D Varelas, N Weerasundara, D Yosef, C Zielinski, M Zutshi, V AF Gribushin, A Abramov, V Antipov, Y Baldin, B Crittenden, R Davis, C Dauwe, L Denisov, S Dyshkant, A Dzierba, A Glebov, V Goldberg, H Jesik, R Koreshev, V Krider, J Krinitsyn, A Li, R Margulies, S Marshall, T Martin, J Mendez, H Petrukhin, A Solomon, J Sirotenko, V Smith, P Sulanke, T Sulyaev, R Vaca, F Zieminski, A Apanasevich, L Bacigalupi, J Begel, M Blusk, S Bromberg, C Chang, P Choudhary, B Chung, WH de Barbaro, L Dlugosz, W Dunlea, J Engels, E Fanourakis, G Ginther, G Hartman, K Huston, J Kapoor, V Lirakis, C Mani, S Mansour, J Maul, A Miller, R Osborne, G Pellett, D Pothier, E Roser, R Shepard, P Skow, D Slattery, P Sorrell, L Striley, D Varelas, N Weerasundara, D Yosef, C Zielinski, M Zutshi, V CA E672 Collaboration E706 Collaboration TI Production of J/psi mesons in pBe collisions at 530 and 800 GeV/c SO PHYSICAL REVIEW D LA English DT Article ID OCTET QUARKONIA PRODUCTION; FIXED TARGET ENERGIES; PSI' PRODUCTION; 515 GEV/C; P(P)OVER-BAR COLLISIONS; CHARMONIUM PRODUCTION; ROOT-S=1.8 TEV; CROSS-SECTIONS; HADROPRODUCTION; PROTON AB We report on the production of J/psi mesons in 530 and 800 GeV/c pBe collisions in the Feynman-x range 0.0C TRANSITIONS; MASSIVE FERMIONS; FORM-FACTORS; RENORMALIZATION; OPERATORS AB Heavy-quark effective theory (HQET) is applied to lattice QCD with Wilson fermions at fixed lattice spacing a. This description is possible because heavy-quark symmetries are respected. It is desirable because the ultraviolet cutoff 1/a in current numerical work and the heavy-quark mass m(Q) are comparable. Effects of both short distances a and 1/m(Q) are captured fully into coefficient functions, which multiply the operators of the usual HQET. Standard tools of HQET are used to develop heavy-quark expansions of lattice observables and, thus, to propagate heavy-quark discretization errors. Three explicit examples are given: namely, the mass, decay constant, and semileptonic form factors of heavy-light mesons. C1 Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Kronfeld, AS (reprint author), Fermilab Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. OI Kronfeld, Andreas/0000-0003-2716-1149 NR 56 TC 54 Z9 54 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 EI 1550-2368 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 2000 VL 62 IS 1 AR 014505 DI 10.1103/PhysRevD.62.014505 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100057 ER PT J AU Lane, K Rador, T Eichten, E AF Lane, K Rador, T Eichten, E TI Vacuum alignment in technicolor theories: The technifermion sector SO PHYSICAL REVIEW D LA English DT Article ID TOPCOLOR-ASSISTED TECHNICOLOR; SYMMETRY-BREAKING; EXTENDED TECHNICOLOR; CHIRAL HIERARCHIES; ISOSPIN-SYMMETRY; HYPERCOLOR; VIOLATION; VERTEX; SCALE; MODEL AB We have carried out numerical studies of vacuum alignment in technicolor models of electroweak and flavor symmetry breaking. The goal is to understand alignment implications for strong and weak CP nonconservation in quark interactions. In this first part, we restrict our attention to the technifermion sector of simple models. We find several interesting phenomena, including (1) the possibility that all observable phases in the technifermions' unitary vacuum-alignment matrix are integer multiples of pi/N' where N'less than or equal to N, the number of technifermion doublets, and (2) the possibility of exceptionally light pseudo Goldstone technipions. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Lane, K (reprint author), Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. EM lane@buphyc.bu.edu; rador@budoe.bu.edu; eichten@fnal.gov NR 27 TC 10 Z9 10 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 JUL 1 PY 2000 VL 62 IS 1 AR 015005 DI 10.1103/PhysRevD.62.015005 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100065 ER PT J AU Manak, JJ Adams, T Bishop, JM Cason, NM Ivanov, EI LoSecco, JM Sanjari, AH Shephard, WD Stienike, DL Taegar, SA Thompson, DR Chung, SU Danyo, K Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Denisov, SP Dorofeev, VA Kachaev, IA 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 Sinev, NB Vardanyan, IN Yershov, AA Brown, DS Pedlar, TK Seth, KK Wise, J Zhao, D Adams, GS Cummings, JP Kuhn, J Napolitano, J Nozar, M Smith, JA White, DB Witkowski, M AF Manak, JJ Adams, T Bishop, JM Cason, NM Ivanov, EI LoSecco, JM Sanjari, AH Shephard, WD Stienike, DL Taegar, SA Thompson, DR Chung, SU Danyo, K Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Denisov, SP Dorofeev, VA Kachaev, IA 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 Sinev, NB Vardanyan, IN Yershov, AA Brown, DS Pedlar, TK Seth, KK Wise, J Zhao, D Adams, GS Cummings, JP Kuhn, J Napolitano, J Nozar, M Smith, JA White, DB Witkowski, M CA E852 Collaboration TI Partial-wave analysis of the eta pi(+) pi(-) system produced in the reaction pi(-)p ->eta pi(+) pi(-)n at 18 GeV/c SO PHYSICAL REVIEW D LA English DT Article ID ETA-PI+PI SYSTEM; PSEUDOSCALAR RESONANCES AB A partial-wave analysis of 9082 eta pi(+) pi(-) n events produced in the reaction pi(-) p--> eta pi(+) pi(-) n at 18.3 GeV/c has been carried out using data from experiment 852 at Brookhaven National Laboratory. The data are dominated by J(PC) = 0(-+) partial waves consistent with observation of the eta(1295) and the eta(1440). The mass and width of the eta(1295) were determined to be 1282 +/- 5 MeV and 66 +/- 13 MeV, respectively, while the eta(1440) was observed with a mass of 1404 +/- MeV and a width of 80 +/- 21 MeV. Other partial waves of importance include the 1(++) and the 1(+-) waves. Results of the partial wave analysis are combined with results of other experiments to estimate f(1)(1285) branching fractions. These values are considerably different from current values determined without the aid of amplitude analyses. C1 RAFAEL, IL-31021 Haifa, Israel. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. Inst High Energy Phys, Protvino, Russia. Univ Massachusetts, Dept Phys, N Dartmouth, MA 02747 USA. Moscow State Univ, Inst Phys Nucl, Moscow, Russia. Northwestern Univ, Dept Phys, Evanston, IL 60208 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. RP Cummings, JP (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RI Vardanyan, Irina/K-7981-2012 NR 22 TC 17 Z9 17 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 JUL 1 PY 2000 VL 62 IS 1 AR 012003 DI 10.1103/PhysRevD.62.012003 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100005 ER PT J AU Silva, JP Wolfenstein, L AF Silva, JP Wolfenstein, L TI Qualitative signals of new physics in B-B mixing SO PHYSICAL REVIEW D LA English DT Article ID CP VIOLATION; FACTORIZATION; PHASES; DECAYS AB It is expected that, within the next three years, the determination of the CKM matrix elements with the least theoretical uncertainty will arise from the measurements of CP violation in B-d-->J/psi K-S decays and from B-s-(B) over bar(s) mixing. If there is significant new physics in B-B mixing, then those experiments will not yield the correct values for the CKM matrix elements. As a result, a qualitative signal of new physics may appear in the CP violation of decays such as B-d-->pi(+) pi(-). C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Inst Super Engn Lisboa, P-1900 Lisbon, Portugal. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Silva, Joao/A-2896-2009; Physics Department, ISEL/F-6664-2010 OI Silva, Joao/0000-0002-6455-9618; NR 18 TC 5 Z9 5 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 2000 VL 62 IS 1 AR 014018 DI 10.1103/PhysRevD.62.014018 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330GH UT WOS:000087954100036 ER PT J AU Rintoul, MD AF Rintoul, MD TI Precise determination of the void percolation threshold for two distributions of overlapping spheres SO PHYSICAL REVIEW E LA English DT Article ID CONTINUUM PERCOLATION; VORONOI POLYHEDRA; SERIES EXPANSIONS; EXPONENTS; SYSTEMS; CONSTRUCTION; UNIVERSALITY; DIAGRAMS AB The void percolation threshold is calculated for a distribution of overlapping spheres with equal radii, and for a binary-sized distribution of overlapping spheres, where half of the spheres have radii twice as large as the other half Using systems much larger than previous work, we determine a much more precise value for the percolation thresholds and correlation length exponent. The value of the percolation threshold for the monodisperse case is shown to be 0.0301+/-0.0003, whereas the value for the bidisperse case is shown to be p(c) = 0.0287+/-0.0005. The fact that these are significantly different is in contrast with previous, less precise works that speculated that the threshold might be universal with respect to sphere size distribution. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rintoul, MD (reprint author), Sandia Natl Labs, POB 5800,MS 1111, Albuquerque, NM 87185 USA. NR 29 TC 30 Z9 30 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2000 VL 62 IS 1 BP 68 EP 72 DI 10.1103/PhysRevE.62.68 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YG UT WOS:000088274100018 ER PT J AU Toroczkai, Z Korniss, G Das Sarma, S Zia, RKP AF Toroczkai, Z Korniss, G Das Sarma, S Zia, RKP TI Extremal-point densities of interface fluctuations SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-BEAM EPITAXY; SURFACE-GROWTH; RANDOM NETWORKS; KINETIC GROWTH; MODELS; DIFFUSION; EQUATIONS; UNIVERSALITY; INVARIANCE; EXPONENTS AB We introduce and investigate the stochastic dynamics of the density of local extrema (minima and maxima) of nonequilibrium surface fluctuations. We give a number of analytic results for interface fluctuations described by linear Langevin equations, and for an-lattice, solid-on-solid surface-growth models. We show that, in spite of the nonuniversal character of the quantities studied, their behavior against the variation of the microscopic length scales can present generic features, characteristic of the macroscopic observables of the system. The quantities investigated here provide us with tools that give an unorthodox approach to the dynamics of surface morphologies: a statistical analysis from the short-wavelength end of the Fourier decomposition spectrum. In addition to surface-growth applications, our results can be used to solve the asymptotic scalability problem of massively parallel algorithms for discrete-event simulations, which are extensively used in Monte Carlo simulations on parallel architectures. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM 87544 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RP Toroczkai, Z (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RI Toroczkai, Zoltan/A-3421-2008; Korniss, Gyorgy/A-7360-2011; Das Sarma, Sankar/B-2400-2009 OI Toroczkai, Zoltan/0000-0002-6602-2849; Das Sarma, Sankar/0000-0002-0439-986X NR 49 TC 23 Z9 23 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2000 VL 62 IS 1 BP 276 EP 294 DI 10.1103/PhysRevE.62.276 PN A PG 19 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YG UT WOS:000088274100044 ER PT J AU Bar, M Hagberg, A Meron, E Thiele, U AF Bar, M Hagberg, A Meron, E Thiele, U TI Front propagation and pattern formation in anisotropic bistable media SO PHYSICAL REVIEW E LA English DT Article ID REACTION-DIFFUSION-SYSTEMS; ORDER-PARAMETER EQUATIONS; NEMATIC LIQUID-CRYSTALS; CHEMICAL WAVE PATTERNS; EXCITABLE MEDIA; SURFACE-REACTION; NO+H-2 REACTION; CURVED FRONTS; SPIRAL WAVES; TRANSITIONS AB The effects of diffusion anisotropy on pattern formation in bistable media are studied using a FitzHugh-Nagumo reaction-diffusion model. A relation between the normal velocity of a front and its curvature is derived and used to identify distinct spatiotemporal patterns induced by the diffusion anisotropy. In a wide parameter range anisotropy is found to have an ordering effect: initial patterns evolve into stationary or breathing periodic stripes parallel to one of the principal axes. In a different parameter range, anisotropy is found to induce spatiotemporal chaos confined to one space dimension, a state we term "stratified chaos." C1 Max Planck Phys Komplexer Syst, D-01187 Dresden, Germany. Ben Gurion Univ Negev, Jacob Blaustein Inst Desert Res, IL-84990 Sede Boqer, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84990 Sede Boqer, Israel. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Complutense Madrid, Inst Pluridisciplinar, E-28040 Madrid, Spain. RP Bar, M (reprint author), Max Planck Phys Komplexer Syst, Nothnitzer Str 38, D-01187 Dresden, Germany. RI MERON, EHUD/F-1810-2012; Bar, Markus/B-8396-2011; thiele, uwe/B-6236-2008 OI Bar, Markus/0000-0002-6935-7759; thiele, uwe/0000-0001-7989-9271 NR 54 TC 19 Z9 19 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2000 VL 62 IS 1 BP 366 EP 374 DI 10.1103/PhysRevE.62.366 PN A PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YG UT WOS:000088274100053 ER PT J AU Vahala, L Wah, D Vahala, G Carter, J Pavlo, P AF Vahala, L Wah, D Vahala, G Carter, J Pavlo, P TI Thermal lattice Boltzmann simulation for multispecies fluid equilibration SO PHYSICAL REVIEW E LA English DT Article ID STABILITY ANALYSIS; MODELS; FLOWS AB The equilibration rate for multispecies fluids is examined using thermal lattice Boltzmann simulations. Two-dimensional free-decay simulations are performed for effects of velocity shear layer turbulence on sharp temperature profiles. In particular, parameters are so chosen that the lighter species is turbulent while the heavier species is laminar-and so its vorticity layers would simply decay and diffuse in time. With species coupling, however, there is velocity equilibration followed by the final relaxation to one large co- and one large counter-rotating vortex. The temperature equilibration proceeds on a slower time scale and is in good agreement with the theoretical order of magnitude estimate of Morse [Phys. Fluids 6, 1420 (1963)]. C1 Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Lawrence Berkeley Natl Lab, NERSE, Berkeley, CA USA. Acad Sci Czech Republ, Inst Plasma Phys, Prague 8, Czech Republic. RP Vahala, L (reprint author), Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. RI Pavlo, Pavol/G-4214-2014 OI Pavlo, Pavol/0000-0003-1400-1074 NR 21 TC 14 Z9 17 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2000 VL 62 IS 1 BP 507 EP 516 DI 10.1103/PhysRevE.62.507 PN A PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YG UT WOS:000088274100069 ER PT J AU Gleiser, M Sornborger, A AF Gleiser, M Sornborger, A TI Long-lived localized field configurations in small lattices: Application to oscillons SO PHYSICAL REVIEW E LA English DT Article ID OSCILLATED GRANULAR LAYERS; VIBRATED SAND; PATTERNS AB Long-lived localized field configurations such as breathers, oscillons, or more complex objects naturally arise in the context of a wide range of nonlinear models in different numbers of spatial dimensions. We present a numerical method, which we call the adiabatic damping method, designed to study such configurations in small lattices. Using three-dimensional oscillons in phi(4) models as an example, we show that the method accurately (to one part in 10(5) or better) reproduces results obtained with static or dynamically expanding lattices, dramatically cutting down in integration time. We further present results for two-dimensional oscillons, whose lifetimes would be prohibitively long to study with conventional methods. C1 Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Gleiser, M (reprint author), Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. EM gleiser@dartmouth.edu; ats@camelot.mssm.edu NR 29 TC 34 Z9 34 U1 0 U2 0 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 JUL PY 2000 VL 62 IS 1 BP 1368 EP 1374 DI 10.1103/PhysRevE.62.1368 PN B PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YH UT WOS:000088274200070 ER PT J AU Aranson, IS Malomed, BA Pismen, LM Tsimring, LS AF Aranson, IS Malomed, BA Pismen, LM Tsimring, LS TI Crystallization kinetics and self-induced pinning in cellular patterns SO PHYSICAL REVIEW E LA English DT Article ID SWIFT-HOHENBERG EQUATION; STABILITY; SYSTEMS AB Within the framework of the Swift-Hohenberg model it is shown numerically and analytically that the front propagation between cellular and uniform states is determined by periodic nucleation events triggered by the explosive growth of the localized zero-eigenvalue mode of the corresponding linear problem. We derive an evolution equation for this mode using asymptotic analysis, and evaluate the time interval between nucleation events, and hence the front speed. In the presence of noise, we find the velocity exponent of "thermally activated" front propagation (creep) beyond the pinning threshold. [SI063-651X(00)50407-3]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Tel Aviv Univ, Fac Engn, Dept Interdisciplinary Studies, IL-69978 Tel Aviv, Israel. Technion Israel Inst Technol, Dept Chem Engn, IL-32000 Haifa, Israel. Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Pismen, Len/B-3500-2008; Aranson, Igor/I-4060-2013 NR 12 TC 19 Z9 19 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 2000 VL 62 IS 1 BP R5 EP R8 DI 10.1103/PhysRevE.62.R5 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 335YG UT WOS:000088274100002 ER PT J AU Majaron, B Verkruysse, W Tanenbaum, BS Milner, TE Telenkov, SA Goodman, DM Nelson, JS AF Majaron, B Verkruysse, W Tanenbaum, BS Milner, TE Telenkov, SA Goodman, DM Nelson, JS TI Combining two excitation wavelengths for pulsed photothermal profiling of hypervascular lesions in human skin SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID PORT WINE STAINS; LIGHT DISTRIBUTIONS; BIOLOGICAL TISSUES; RADIOMETRY; CHROMOPHORES; TEMPERATURE; MEDIA AB When pulsed photothermal radiometry (PPTR) is used for depth profiling of hypervascular lesions in human skin, melanin absorption also heats the most superficial skin layer (epidermis). Determination of lesion depth may be difficult when it lies close to the epidermaldermal junction, due to PPTR's limited spatial resolution. To overcome this problem, we have developed an approximation technique, which uses two excitation wavelengths (585 and 600 nm) to separate the vascular and epidermal components of the PPTR signal. This technique permits a noninvasive determination of lesion depth and epidermal thickness in vivo, even when the two layers are in close physical proximity to each other. Such information provides the physician with guidance in selecting the optimal parameters for laser therapy on an individual patient basis. C1 Univ Calif Irvine, Beckman Laser Inst & Med Clin, Irvine, CA 92612 USA. Jozef Stefan Inst, SI-1000 Ljubljana, Slovenia. Harvey Mudd Coll, Dept Engn, Claremont, CA 91711 USA. Univ Texas, Dept Elect & Comp Engn, Austin, TX 78712 USA. Univ Texas, Biomed Engn Program, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Majaron, B (reprint author), Univ Calif Irvine, Beckman Laser Inst & Med Clin, 1002 Hlth Sci Rd E, Irvine, CA 92612 USA. RI Majaron, Boris/A-1025-2008; OI Majaron, Boris/0000-0003-2841-8276; verkruysse, wim/0000-0002-1381-2740 FU NIAMS NIH HHS [AR43419] NR 24 TC 26 Z9 26 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD JUL PY 2000 VL 45 IS 7 BP 1913 EP 1922 DI 10.1088/0031-9155/45/7/315 PG 10 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA 333PN UT WOS:000088138600016 PM 10943928 ER PT J AU Brunner, S Valeo, E Krommes, JA AF Brunner, S Valeo, E Krommes, JA TI Linear delta-f simulations of nonlocal electron heat transport SO PHYSICS OF PLASMAS LA English DT Article ID STEEP TEMPERATURE-GRADIENTS; PARTICLE-SIMULATION; PLASMAS; DISTRIBUTIONS; SCHEME AB Nonlocal electron heat transport calculations are carried out by making use of some of the techniques developed previously for extending the delta f method to transport time scale simulations [S. Brunner, E. Valeo, and J. Krommes, Phys. Plasmas 6, 4504 (1999)]. By considering the relaxation of small amplitude temperature perturbations of an homogeneous Maxwellian background, only the linearized Fokker-Planck equation has to be solved, and direct comparisons can be made with the equivalent, nonlocal hydrodynamic approach [V. Yu. Bychenkov , Phys. Rev. Lett. 75, 4405 (1995)]. A quasineutrality-conserving algorithm is derived for computing the self-consistent electric fields driving the return currents. In the low-collisionality regime, results illustrate the importance of taking account of nonlocality in both space and time. (C) 2000 American Institute of Physics. [S1070-664X(00)01707-9]. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Brunner, S (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Brunner, Stephan/B-6200-2009 OI Brunner, Stephan/0000-0001-7588-7476 NR 25 TC 18 Z9 20 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 2000 VL 7 IS 7 BP 2810 EP 2823 DI 10.1063/1.874131 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 326TG UT WOS:000087751200008 ER PT J AU Sanbonmatsu, KY Vu, HX DuBois, DF Bezzerides, B AF Sanbonmatsu, KY Vu, HX DuBois, DF Bezzerides, B TI Quantitative comparison of reduced-description particle-in-cell and quasilinear-Zakharov models for parametrically excited Langmuir turbulence SO PHYSICS OF PLASMAS LA English DT Article ID AURORAL IONOSPHERE; PLASMA; INSTABILITY; SIMULATIONS; SCATTERING; COLLAPSE; WAVES AB The effect of kinetic processes on the saturation of parametric instabilities in an electromagnetically driven plasma is investigated. A reduced-description particle-in-cell technique is used as a benchmark to test a new quasilinear-Zakharov model which accounts for electron heating due to Landau damping by coupling the quasilinear diffusion equation to the Zakharov equations. The reduced-description particle-in-cell method utilizes a two-time-scale approximation which significantly reduces the numerical dissipation and ion noise levels. This approach allows accurate modeling of Langmuir and ion acoustic waves in regimes typically studied with Zakharov simulations. The comparison of the two models is performed for the test case of a one-dimensional homogeneous plasma driven by a spatially uniform pump in both the Langmuir decay instability cascade and collapse regimes. Good agreement is found in both weakly and strongly driven regimes for the total Langmuir wave energy and evolved electron velocity distributions. Electron heating significantly decreases saturation levels in strongly driven regimes by increasing the Landau damping rate, bringing the quasilinear-Zakharov simulations in much closer agreement with the reduced-description particle-in-cell simulations than standard Zakharov simulations, which do not account for the evolution of the electron distribution. (C) 2000 American Institute of Physics. [S1070-664X(00)01907-8]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sanbonmatsu, KY (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 19 Z9 20 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 2000 VL 7 IS 7 BP 2824 EP 2841 AR PII [S1070-664X(00)01907-8] DI 10.1063/1.874132 PG 18 WC Physics, Fluids & Plasmas SC Physics GA 326TG UT WOS:000087751200009 ER PT J AU Clark, DS Fisch, NJ AF Clark, DS Fisch, NJ TI The possibility of high amplitude driven contained modes during ion Bernstein wave experiments in the tokamak fusion test reactor SO PHYSICS OF PLASMAS LA English DT Article ID DEUTERIUM-TRITIUM PLASMAS; ENERGETIC ALPHA-PARTICLES; CYCLOTRON EMISSION; TFTR; INSTABILITY; EXCITATION; RANGE AB Extremely high quasilinear diffusion rates for energetic beam ions can be deduced from mode conversion experiments in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire, H. Adler, P. Alling , Phys. Plasmas 2(6), 2176 (1995)]. A comparison of the experimental loss rates with the theoretical prediction for the interaction of energetic ions with mode converted ion Bernstein waves showed the theory to underpredict the diffusion coefficient by a factor of 30-70. An anomalously high diffusion coefficient might enhance the advantageous channeling of energetic alpha particle energy in a tokamak reactor. Resolving this discrepancy is thus of importance from the standpoint of practical interest in an improved tokamak reactor as well as from the standpoint of academic interest in basic wave-particle theory. A mechanism is proposed for this accelerated diffusion involving the excitation of a contained mode, possibly similar to that used in explaining the ICE (ion cyclotron emission) phenomenon, near the edge of a tokamak. (C) 2000 American Institute of Physics. [S1070-664X(00)03107-4]. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Clark, DS (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 23 TC 18 Z9 18 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 2000 VL 7 IS 7 BP 2923 EP 2932 DI 10.1063/1.874143 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 326TG UT WOS:000087751200020 ER PT J AU Douglas, MR Deeney, C Spielman, RB Coverdale, CA Roderick, NF Haines, MG AF Douglas, MR Deeney, C Spielman, RB Coverdale, CA Roderick, NF Haines, MG TI Long implosion time tungsten wire array Z pinches on the Saturn generator SO PHYSICS OF PLASMAS LA English DT Article ID X-RAY POWER; PLASMA FORMATION; Z-ACCELERATOR; INSTABILITIES; ENHANCEMENT; ALUMINUM; RADIUS; NUMBER AB Recent success on the Saturn [C. Deeney , Phys. Rev. E 56, 5945 (1997)] and Z [R. B. Spielman , Phys. Plasmas 5, 2105 (1998)] accelerators at Sandia National Laboratories have demonstrated the ability to scale Z-pinch parameters to increasingly larger current pulsed power facilities. Next generation machines will require even larger currents (> 20 MA), placing further demands on pulsed power technology. To this end, experiments have been carried out on Saturn operating in a long pulse mode, investigating the potential of lower voltages and longer implosion times while still maintaining pinch fidelity. High wire number, 25 mm diam tungsten arrays were imploded with implosion times ranging from 130 to 240 ns. The results were comparable to those observed in the Saturn short pulse mode, with rise times on the order of 4.5-6.5 ns. Experimental data will be presented, along with two-dimensional radiation magnetohydrodynamic simulations used to explain and reproduce the experiment. (C) 2000 American Institute of Physics. [S1070- 664X(00)04307-X]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Albuquerque, NM 87102 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. RP Douglas, MR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 36 TC 12 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 2000 VL 7 IS 7 BP 2945 EP 2958 DI 10.1063/1.874146 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 326TG UT WOS:000087751200023 ER PT J AU Li, K Littenberg, L Rubinstein, R AF Li, K Littenberg, L Rubinstein, R TI Thaddeus Francis Kycia - Obituary SO PHYSICS TODAY LA English DT Biographical-Item C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Li, K (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUL PY 2000 VL 53 IS 7 BP 71 EP 72 DI 10.1063/1.1292492 PG 2 WC Physics, Multidisciplinary SC Physics GA 331BP UT WOS:000087997700018 ER PT J AU Weinberg, AM AF Weinberg, AM TI Copenhagen - Roles in quantum mechanics SO PHYSICS TODAY LA English DT Letter C1 Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. RP Weinberg, AM (reprint author), Oak Ridge Associated Univ, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUL PY 2000 VL 53 IS 7 BP 74 EP 75 PG 2 WC Physics, Multidisciplinary SC Physics GA 331BP UT WOS:000087997700021 ER PT J AU Taylor, GJ McDonald-Stephens, JL Hunter, DB Bertsch, PM Elmore, D Rengel, Z Reid, RJ AF Taylor, GJ McDonald-Stephens, JL Hunter, DB Bertsch, PM Elmore, D Rengel, Z Reid, RJ TI Direct measurement of aluminum uptake and distribution in single cells of Chara corallina SO PLANT PHYSIOLOGY LA English DT Article ID TRITICUM-AESTIVUM L; ION MASS-SPECTROMETRY; SENSITIVE CULTIVARS; EXCISED ROOTS; SOIL SOLUTION; WHEAT; AL; TOLERANCE; KINETICS; CALCIUM AB Quantitative information on the uptake and distribution of Al at the cellular level is required to understand mechanisms of Al toxicity, but direct measurement of uptake across the plasma membrane has remained elusive. We measured rates of Al transport across membranes in single cells of Chara corallina using the rare Al-26 isotope, an emerging technology (accelerator mass spectrometry), and a surgical technique for isolating subcellular compartments. Accumulation of Al in the cell wall dominated total uptake (71-318 mu g m(-2) min(-1)), although transport across the plasma membrane was detectable (71-540 ng m(-2) min(-1)) within 30 min of exposure. Transport across the tonoplast was initially negligible, but accelerated to rates approximating uptake across the plasma membrane. The avacuolate protoplasm showed signs of saturation after 60 min, but continued movement across the plasma membrane was supported by sequestration in the vacuole. Saturation of all compartments was observed after 12 to 24 h. Accumulation of Al in the cell wall reflected variation in (Al3+) induced by changes in Al supply or complexing ligands, but was unaffected by pH. In contrast, transport across the plasma membrane peaked at pH 4.3 and increased when (Al3+) was reduced by complexing ligands. Cold temperature (4 degrees C) reduced accumulation in the cell wall and protoplasm, whereas 2,4-dinitrophenol and m-chlorocarbonylcyanidephenyl hydrazone increased membrane transport by 12- to 13-fold. Our data suggest that the cell wall is the major site of Al accumulation. Nonetheless, membrane transport occurs within minutes of exposure and is supported by subsequent sequestration in the vacuole, The rapid delivery of Al to the protoplasm suggests that intracellular lesions may be possible. C1 Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2E9, Canada. Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Studies, Aiken, SC 29801 USA. Purdue Univ, Purdue Rare Isotope Measurement Lab, W Lafayette, IN 47907 USA. Univ Western Australia, Fac Agr, Perth, WA 6907, Australia. Univ Adelaide, Dept Bot, Adelaide, SA 5005, Australia. RP Taylor, GJ (reprint author), Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2E9, Canada. RI Rengel, Zed (Zdenko)/A-2496-2008; Taylor, Gregory/A-3764-2014 NR 51 TC 107 Z9 125 U1 2 U2 20 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 2000 VL 123 IS 3 BP 987 EP 996 DI 10.1104/pp.123.3.987 PG 10 WC Plant Sciences SC Plant Sciences GA 334YD UT WOS:000088213300021 PM 10889247 ER PT J AU Danis, JA Hawkins, HT Scott, BL Runde, WH Scheetz, BE Eichhorn, BW AF Danis, JA Hawkins, HT Scott, BL Runde, WH Scheetz, BE Eichhorn, BW TI X-ray structure determination of two related uranyl phosphate crown ether compounds SO POLYHEDRON LA English DT Article DE uranium; uranyl; phosphate; crown; crystal structures ID COMPLEXES; URANIUM(VI); NZP AB Two new uranyl phosphate compounds have been prepared and their structures determined. [UO2(H2PO4)(2)(H2O)](2).(18-crown-6) . 5H(2)O (1) and UO2(H2PO4)(2)(H2O).(18-crown-6). 3H(2)O (2) contain neutral one-dimensional [UO2(H2PO4)(2)(H2O)](infinity) chains that are nearly identical to those of a previously reported binary phosphate, UO2(H2PO4)(2)(H2O). 2H(2)O (3). The new compounds, however, crystallized with either one-half or one 18-crown-6 molecule per uranium atom for 1 and 2, respectively. The seven-coordinate uranium(VI) assumes a pentagonal bipyramidal configuration, which is common for uranyl compounds. Empty 18-crown-6 molecules are hydrogen bonded to the uranyl phosphate chains as well as to lattice water molecules and function as 'packing-directing' agents. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Chem Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Technol, Los Alamos, NM 87545 USA. RP Eichhorn, BW (reprint author), Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 27 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 0277-5387 J9 POLYHEDRON JI Polyhedron PD JUL 1 PY 2000 VL 19 IS 13 BP 1551 EP 1557 DI 10.1016/S0277-5387(00)00408-3 PG 7 WC Chemistry, Inorganic & Nuclear; Crystallography SC Chemistry; Crystallography GA 347HW UT WOS:000088923700003 ER PT J AU Dair, BJ Avgeropoulos, A Hadjichristidis, N Capel, M Thomas, EL AF Dair, BJ Avgeropoulos, A Hadjichristidis, N Capel, M Thomas, EL TI Oriented double gyroid films via roll casting SO POLYMER LA English DT Article DE double gyroid; block copolymers; roll casting ID SEGREGATED AMORPHOUS PHASES; X-RAY-DIFFRACTION; 3 BLOCK COPOLYMER; MECHANICAL-PROPERTIES; NONIONIC SURFACTANT; DIBLOCK COPOLYMERS; SINGLE-CRYSTALS; MACRO-LATTICE; CUBIC PHASE; TRANSITION AB Films of an isoprene-rich poly (styrene-b-isoprene-b-styrene) (SIS) triblock copolymer thermoplastic elastomer having a highly textured double gyroid (DG) morphology were produced via roll casting and annealing. The symmetries of the extensional and shear flows involved in the roll casting process are not commensurate with those of the cubic Ia (3) over bar d symmetry of the tricontinuous, triply periodic cubic DC phase. Upon roll casting the microdomain morphology produced is predominantly that of cylinders, oriented with the axes along the roll cast direction. Upon annealing, the DG phase nucleates and grows with the [111] direction oriented along the roll cast direction. The resultant textured films are suitable for investigating the directional dependence of physical properties. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Athens, Dept Chem, Athens 15771, Greece. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Thomas, EL (reprint author), MIT, Dept Mat Sci & Engn, Room 13-5094,77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Avgeropoulos, Apostolos/I-5772-2012 NR 38 TC 23 Z9 23 U1 0 U2 10 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 JUL PY 2000 VL 41 IS 16 BP 6231 EP 6236 DI 10.1016/S0032-3861(99)00847-2 PG 6 WC Polymer Science SC Polymer Science GA 315QF UT WOS:000087123900024 ER PT J AU Kwon, YK Boller, A Pyda, M Wunderlich, B AF Kwon, YK Boller, A Pyda, M Wunderlich, B TI Melting and heat capacity of gel-spun, ultra-high molar mass polyethylene fibers SO POLYMER LA English DT Article DE ultra-high molar mass polyethylene; melting; orthorhombic-hexagonal transition ID DIFFERENTIAL SCANNING CALORIMETRY; POLYMER CRYSTALS; TEMPERATURE; BEHAVIOR; GROWTH; PHASE; DSC AB The melting behaviors of gel-spun, ultra-high molar mass polyethylene fibers have been investigated using standard differential scanning calorimetry and wide-angle X-ray diffraction. For laterally constrained fibers the standard DSC exhibits the usually reported two melting peaks (one at about 415 K and one at about 423 K), a glass transition (at about 275 K) and an unusually large and reversible heat capacity as one approaches the melting peaks (starting at about 350-370 K). Earlier observations that sometimes only the lower melting endotherm is retained, are proven to be of fibers free of longitudinal and lateral constraints. Up to the beginning of major melting, all fibers are mainly orthorhombic. The orthorhombic-hexagonal transition is proven to occur only for the constrained fibers, implying that the hexagonal phase is a non-equilibrium phase, usually not present in the initial fibers. An oriented, intermediate phase, discovered by solid state NMR and full-pattern X-ray analysis, gives rise to a substantially broadened glass transition that reaches to about 300 K, compared to the glass transition of the amorphous polyethylene with a midpoint at 237 K and end at 250 K. Published by Elsevier Science Ltd. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 46 TC 51 Z9 53 U1 2 U2 16 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 JUL PY 2000 VL 41 IS 16 BP 6237 EP 6249 DI 10.1016/S0032-3861(99)00839-3 PG 13 WC Polymer Science SC Polymer Science GA 315QF UT WOS:000087123900025 ER PT J AU Venugopalan, R AF Venugopalan, R TI What's new at small x? SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 6th Workshop on High Energy Physics Phenomentology (WHEPP-6) CY JAN 03-15, 2000 CL INST MATH SCI, CHENNAI, INDIA SP SN Bose Natl Ctr Basic Sci, Tata Inst Fundamental Res, Board Res Nuclear Sci, Int Ctr theoret Phys, Dept Sci & Technol HO INST MATH SCI DE small x physics; classical fields; diffraction; heavy ion collisions ID DEEP-INELASTIC-SCATTERING; ULTRARELATIVISTIC NUCLEAR COLLISIONS; WILSON RENORMALIZATION-GROUP; DIFFRACTIVE HARD SCATTERING; GLUON MINIJET PRODUCTION; BFKL EQUATION; HIGH-ENERGIES; SMALL VALUES; POMERON; BEHAVIOR AB We discuss some recent developments in small a: physics. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Venugopalan, R (reprint author), Brookhaven Natl Lab, Dept Phys, Bldg 510A, Upton, NY 11973 USA. NR 81 TC 3 Z9 3 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JUL-AUG PY 2000 VL 55 IS 1-2 SI SI BP 73 EP 84 DI 10.1007/s12043-000-0085-2 PG 12 WC Physics, Multidisciplinary SC Physics GA 349ZH UT WOS:000089075200008 ER PT J AU Gelis, F AF Gelis, F TI Two problems in thermal field theory SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 6th Workshop on High Energy Physics Phenomentology (WHEPP-6) CY JAN 03-15, 2000 CL INST MATH SCI, CHENNAI, INDIA SP SN Bose Natl Ctr Basic Sci, Tata Inst Fundamental Res, Board Res Nuclear Sci, Int Ctr theoret Phys, Dept Sci & Technol HO INST MATH SCI DE thermal field theory; quark-gluon plasma ID PHOTON PRODUCTION-RATE; HOT GAUGE-THEORIES; FINITE-TEMPERATURE; GLUON PLASMA; PERTURBATION-THEORY; FEYNMAN-RULES; FREE-ENERGY; QCD; THERMODYNAMICS; FERMIONS AB In this talk, I review recent progress made in two areas of thermal field theory. In particular, I discuss various approaches for the calculation of the quark gluon plasma thermodynamical properties, and the problem of its photon production rate. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Gelis, F (reprint author), Brookhaven Natl Lab, Bldg 510A, Upton, NY 11973 USA. NR 34 TC 0 Z9 0 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JUL-AUG PY 2000 VL 55 IS 1-2 SI SI BP 113 EP 124 DI 10.1007/s12043-000-0088-z PG 12 WC Physics, Multidisciplinary SC Physics GA 349ZH UT WOS:000089075200011 ER PT J AU Gupta, S Indumathi, D Banerjee, S Basu, R Dittmar, M Gavai, RV Gelis, F Ghosh, D Gupta, S Indumathi, D Mukherjee, A AF Gupta, S Indumathi, D Banerjee, S Basu, R Dittmar, M Gavai, RV Gelis, F Ghosh, D Gupta, S Indumathi, D Mukherjee, A TI Quantum chromodynamics: Working group report SO PRAMANA-JOURNAL OF PHYSICS LA English DT Editorial Material DE QCD; polarized scattering; light front held theory; heavy ion physics; non-equilibrium field theory; parton distributions at LHC; fragmentation functions; event shapes ID FIELD-THEORY; PERTURBATION-SERIES; CERN LHC; QCD; SCATTERING; COHERENCE AB This is the report of the QCD working group at WHEPP-6. Discussions and work on heavy ion collisions, polarized scattering, and collider phenomenology are reported. C1 Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Inst Math Sci, Madras 600113, Tamil Nadu, India. ETH Zurich, CH-8093 Zurich, Switzerland. Brookhaven Natl Lab, Upton, NY 11973 USA. Saha Inst Nucl Phys, Calcutta 700064, W Bengal, India. RP Gupta, S (reprint author), Tata Inst Fundamental Res, Homi Bhabha Rd, Bombay 400005, Maharashtra, India. OI Gavai, Rajiv V./0000-0002-4539-2584 NR 39 TC 0 Z9 0 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JUL-AUG PY 2000 VL 55 IS 1-2 SI SI BP 327 EP 333 DI 10.1007/s12043-000-0112-3 PG 7 WC Physics, Multidisciplinary SC Physics GA 349ZH UT WOS:000089075200041 ER PT J AU Green, MA Emery, K King, DL Igari, S Warta, W AF Green, MA Emery, K King, DL Igari, S Warta, W TI Short communication: Solar cell efficiency tables (version 16) SO PROGRESS IN PHOTOVOLTAICS LA English DT Article ID SILICON; MULTICRYSTALLINE; PROGRESS AB Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented, Guidlines for inclusion of results into these tables are outlined and new entries since January 2000 are reviewed Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Univ New S Wales, Ctr Photovolta Engn, Sydney, NSW 2052, Australia. Natl Renewable Energy Lab, Golden, CO 80401 USA. Sandia Natl Labs, Div 6224, Albuquerque, NM 87185 USA. Japan Qual Assurance Org, Solar Technol Ctr, Solar Cell Test Res Div, Hamamatsu, Shizuoka 4311207, Japan. Fraunhofer Inst Solar Energy Syst, D-79100 Freiburg, Germany. RP Green, MA (reprint author), Univ New S Wales, Ctr Photovolta Engn, Sydney, NSW 2052, Australia. NR 46 TC 6 Z9 6 U1 1 U2 14 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JUL-AUG PY 2000 VL 8 IS 4 BP 377 EP 383 PG 7 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 352WB UT WOS:000089241400002 ER PT J AU Tung, CS Wall, ME Gallagher, SC Trewhella, J AF Tung, CS Wall, ME Gallagher, SC Trewhella, J TI A model of troponin-I in complex with troponin-C using hybrid experimental data: The inhibitory region is a beta-hairpin SO PROTEIN SCIENCE LA English DT Article DE actin-binding protein; calcium-binding protein; cross-linking; fast skeletal muscle contraction; FRET; profilin; small-angle neutron scattering; troponin; regulatory complex ID SKELETAL-MUSCLE TROPONIN; PROTEIN SECONDARY STRUCTURE; RESONANCE ENERGY-TRANSFER; SMALL-ANGLE SCATTERING; PHOTO-CROSS-LINKING; N-TERMINAL DOMAIN; REGULATORY DOMAIN; PHOSPHORYLASE-KINASE; CENTRAL HELIX; X-RAY AB We present a model for the skeletal muscle troponin-C (TnC)/troponin-I (TnI) interaction, a critical molecular switch that is responsible for calcium-dependent regulation of the contractile mechanism. Despite concerted efforts by multiple groups for more than a decade, attempts to crystallize troponin-C in complex with troponin-I, or in the ternary troponin complex, have not yet delivered a high-resolution structure. Many groups have pursued different experimental strategies, such as X-ray crystallography NMR, small-angle scattering chemical cross-linking and fluorescent resonance energy transfer (FRET) to gain insights into the nature of the TnC/TnI interaction. We have integrated the results of these experiments to develop a model of the TnC/TnI interaction, using an atomic model of TnC as a scaffold. The TnI sequence was fit to each of two alternate neutron scattering envelopes: one that winds about TnC in a left-handed sense (Model L), and another that winds about TnC in a right-handed sense (Model R). Information from crystallography and NMR experiments was used to define segments of the models. Tests show that both models are consistent with available cross-linking and FRET data. The inhibitory region TnI(95-114) is modeled as a flexible beta-hairpin, and in both models it is localized to the same region on the central helix of TnC. The sequence of the inhibitory region is similar to that of a beta-hairpin region of the actin-binding protein profilin. This similarity supports our model and suggests the possibility of using an available profilin/actin crystal structure to model TnI/actin interaction. We propose that the beta-hairpin is an important structural motif that communicates the Ca2+-activated troponin regulatory signal to actin. C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Wall, ME (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, B-1,MS G758, Los Alamos, NM 87545 USA. OI Trewhella, Jill/0000-0002-8555-6766 FU NIGMS NIH HHS [GM40528] NR 88 TC 42 Z9 42 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD JUL PY 2000 VL 9 IS 7 BP 1312 EP 1326 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 337RU UT WOS:000088376100006 PM 10933496 ER PT J AU Rajpal, A Kirsch, JF AF Rajpal, A Kirsch, JF TI Role of the minor energetic determinants of chicken egg white lysozyme (HEWL) to the stability of the HEWL center dot antibody scFv-10 complex SO PROTEINS-STRUCTURE FUNCTION AND GENETICS LA English DT Article DE hen egg white lysozyme; monoclonal antibody HyHEL-10; association dissociation kinetics; multiple alanine mutations ID DOUBLE MUTANT CYCLES; MUTATIONAL ANALYSIS; FAB COMPLEX; PROTEINS; HYHEL-10; MUTAGENESIS; INTERFACE; BINDING; EPITOPE; AFFINITY AB Seven of the 13 non-glycine contact amino acids in the hen (chicken) egg white lysozyme (HEWL) epitope for antibody Fab-10 each contribute less than or equal to 0.3 kcal/mol to the change in free energy (Delta Delta G(D)) from wild type (WT) when replaced by alanine (nullspots), and three others each give (0.7 < Delta Delta G(D) less than or equal to 1.0) kcal/mol (warm spots) (Rajpal et al. Protein Sci 1908;7:1868-1874). The low Delta Delta G(D) values introduced by alanine mutations present an opportunity to explore accurately their cumulative effects, as the sum of the combined Delta Delta G(D) values is not so large as to destabilize the complex beyond the range of accurate measurement. Substitution of six of the seven null spot residues by alanine leads to a cumulative Delta Delta G(D) = 2.25 +/- 0.04 kcal/mol, whereas the sum of the six individual changes is only -0.36 +/- 0.32 kcal/mol, The triple warm spot mutation generates a Delta Delta G(D) = 5.11 +/- 0.06 kcal/mol versus Delta Delta G(D) = 2.52 +/- 0.22 kcal/mol for the sum of the three individuals. The non-additivity in the individual Delta Delta G(D) values for the alanine mutations may indicate that these residues provide a conformationally stabilizing effect on the hot spot residues, each of which exhibits Delta Delta G(D) > 4.0 kcal/mol on alanine substitution. (C) 2000 Wiley-Liss, Inc. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Kirsch, JF (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 25 TC 6 Z9 6 U1 1 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-3585 J9 PROTEINS JI Proteins PD JUL 1 PY 2000 VL 40 IS 1 BP 49 EP 57 DI 10.1002/(SICI)1097-0134(20000701)40:1<49::AID-PROT70>3.0.CO;2-L PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 320QN UT WOS:000087412000007 PM 10813830 ER PT J AU Tundo, P Anastas, P Black, DS Breen, J Collins, T Memoli, S Miyamoto, J Polyakoff, M Tumas, W AF Tundo, P Anastas, P Black, DS Breen, J Collins, T Memoli, S Miyamoto, J Polyakoff, M Tumas, W TI Synthetic pathways and processes in green chemistry. Introductory overview SO PURE AND APPLIED CHEMISTRY LA English DT Editorial Material C1 Univ Ca Foscari Venezia, Dipartimento Sci Ambientali, Venice, Italy. White House Off Sci & Technol Policy, Washington, DC 20502 USA. Univ New S Wales, Sch Chem, Sydney, NSW, Australia. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Evaluat & Res Inst, Tokyo, Japan. Univ Nottingham, Nottingham NG7 2RD, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tundo, P (reprint author), Univ Ca Foscari Venezia, Dipartimento Sci Ambientali, Dorsoduro 2137, Venice, Italy. RI Anastas, Paul/L-3258-2013 OI Anastas, Paul/0000-0003-4777-5172 NR 13 TC 313 Z9 317 U1 6 U2 41 PU INT UNION PURE APPLIED CHEMISTRY PI RES TRIANGLE PK PA 104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD JUL PY 2000 VL 72 IS 7 BP 1207 EP 1228 DI 10.1351/pac200072071207 PG 22 WC Chemistry, Multidisciplinary SC Chemistry GA 372RE UT WOS:000165247200004 ER PT J AU Sperber, KR Slingo, JM Annamalai, H AF Sperber, KR Slingo, JM Annamalai, H TI Predictability and the relationship between subseasonal and interannual variability during the Asian summer monsoon SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE Asian monsoon; dynamical seasonal predictability; interannual variability ID OBSERVATIONAL ASPECTS; ATMOSPHERIC MOISTURE; GAUGE OBSERVATIONS; RAINFALL; MODEL; OSCILLATIONS; REANALYSES; NCEP/NCAR; ENSO; PRECIPITATION AB The relationship between subseasonal and interannual variability of the Asian summer monsoon has been investigated through analysis of the dominant modes of variability in the 40-year NCEP/NCAR Re-analysis, with complementary satellite and surface-based precipitation data. The hypothesis that the characteristics of monsoon subseasonal variability (i.e. weather regimes) are modulated on interannual time-scales in a systematic and therefore predictable manner has been tested. The null hypothesis is that predictability of the seasonal mean monsoon behaviour requires that the effects of the slowly varying components of the climate system be correctly simulated. An interannual mode of monsoon variability has been identified which is closely related to the observed seasonal mean all-India Rainfall (AIR). A counterpart of this mode has also been identified at subseasonal timescales which projects strongly on to the daily AIR, confirming that a common mode of monsoon variability exists on sub-seasonal and interannual time-scales. It has been shown that the temporal behaviour of this subseasonal mode, as described by the probability distribution function (PDF) of the principal component time series, does not show any evidence of bimodality, the shape of the PDF being Gaussian. Further, it has been shown that the mean of the PDF is systematically and significantly perturbed towards negative (positive) values in weak (strong) monsoon years as categorized in terms of the seasonal mean AIR. This translation in the mean of the PDF, rather than a change in shape of the PDF, suggests that anomalous monsoons are not associated with changes in weather regimes. Further analysis has confirmed that low-frequency modulation of the basic state is primarily responsible for these shifts in the subseasonal PDFs, supporting the null hypothesis that predictability of the seasonal mean monsoon requires that the effects of the slowly varying components of the climate system be correctly simulated. Thus, model improvements to reduce systematic errors in the mean simulation and the response to low-frequency boundary forcing may improve the prospects for dynamical seasonal prediction. However, the results indicate that only a subset of the subseasonal modes are systematically perturbed either by the El Nino Southern Oscillation or in weak vs. strong monsoon years, suggesting that predictability is likely to be limited by the chaotic, internal variability of the monsoon system. C1 Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, POB 808,L-264, Livermore, CA 94550 USA. Univ Reading, Reading RG6 2AH, Berks, England. RP Lawrence Livermore Natl Lab, Program Climate Model Diag & Intercomparison, POB 808,L-264, Livermore, CA 94550 USA. EM sperber@space.llnl.gov RI Sperber, Kenneth/H-2333-2012 NR 50 TC 137 Z9 140 U1 1 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9009 EI 1477-870X J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JUL PY 2000 VL 126 IS 568 BP 2545 EP 2574 DI 10.1002/qj.49712656810 PN C PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 351YH UT WOS:000089187300009 ER PT J AU Dauble, DD Geist, DR AF Dauble, DD Geist, DR TI Comparison of mainstem spawning habitats for two populations of fall chinook salmon in the Columbia River basin SO REGULATED RIVERS-RESEARCH & MANAGEMENT LA English DT Article DE salmon; spawning habitat ID ECOSYSTEM PERSPECTIVE; ANADROMOUS SALMONIDS; PACIFIC-NORTHWEST; RESTORATION; CALIFORNIA; TROUT AB Extensive hydroelectric development in the Columbia River system has eliminated most mainstem riverine habitat available for spawning by fall chinook salmon (Oncorhynchus tshawytscha). The two remaining populations, Hanford Reach, Columbia River and Hells Canyon Reach, Snake River, are separated geographically and their status is markedly different. Annual escapements to Hanford Reach have averaged approximately 80000 adults, while the Snake River run size has declined to < 1500 adults over the past 10 years. We compared their spawning habitat characteristics over a range of measurement scales, as a means to identify strategies for rebuilding the weak Snake River population. Physical habitat characteristics of redds were similar for both study areas. Redd locations were correlated with channel characteristics, such as braiding and sinuosity. Several differences between the two spawning areas were identified at the watershed scale: the Hells Canyon Reach had a much steeper longitudinal gradient, was largely confined by bedrock, and had a more variable flow regime. These features are controlling variables that operate at the reach-scale to limit the availability and size of substrate and other conditions that influence egg deposition and incubation survival. Geomorphological characteristics of the two study sites are sufficiently different to indicate that the production potential of the Hells Canyon Reach population is markedly lower than that of the Hanford Reach population. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Dauble, DD (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 55 TC 34 Z9 34 U1 2 U2 10 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0886-9375 J9 REGUL RIVER JI Regul. Rivers-Res. Manage. PD JUL-AUG PY 2000 VL 16 IS 4 BP 345 EP 361 DI 10.1002/1099-1646(200007/08)16:4<345::AID-RRR577>3.3.CO;2-I PG 17 WC Environmental Sciences; Water Resources SC Environmental Sciences & Ecology; Water Resources GA 340AU UT WOS:000088511600003 ER PT J AU Helton, JC Marietta, MG AF Helton, JC Marietta, MG TI The 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Editorial Material ID NUCLEAR WASTE; RADIOACTIVE-WASTE; SUBJECTIVE UNCERTAINTY; SENSITIVITY ANALYSIS; DISPOSAL C1 Sandia Natl Labs, Carlsbad, NM 88220 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 38 TC 36 Z9 36 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 1 EP 3 DI 10.1016/S0951-8320(00)00022-3 PG 3 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600001 ER PT J AU Rechard, RP AF Rechard, RP TI Historical background on performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Review DE performance assessment; probabilistic risk assessment; risk assessment; radioactive waste disposal; Waste Isolation Pilot Plant; history ID SENSITIVITY ANALYSIS TECHNIQUES; EPA RELEASE LIMITS; CUMULATIVE DISTRIBUTION-FUNCTIONS; PROBABILISTIC RISK ASSESSMENTS; SUBJECTIVE UNCERTAINTY; COMPUTER-MODELS; DISPOSAL; CONSTRUCTION; SYSTEMS AB In 1979, six years after selecting the Delaware Basin as a potential disposal area, Congress authorized the US Department of Energy to build the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, as a research and development facility for the safe management, storage, and disposal of waste contaminated with transuranic radioisotopes. In 1998, 19 years after authorization and 25 years after site selection, the US Environmental protection Agency (EPA) certified that the WIPP disposal system complied with its regulations. The EPA's decision was primarily based on the results from a performance assessment conducted in 1996, which is summarized in this special issue of Reliability, Engineering and System Safety. This performance assessment was the culmination of four preliminary performance assessments conducted between 1989 and 1992. This paper provides a historical setting and context for how the performance of the deep geologic repository at the WIPP was analyzed. Also included is background on political forces acting on the project. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Performance Assessment Dept 6849, Albuquerque, NM 87185 USA. RP Rechard, RP (reprint author), Sandia Natl Labs, Performance Assessment Dept 6849, POB 5800, Albuquerque, NM 87185 USA. NR 181 TC 36 Z9 37 U1 3 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 5 EP 46 DI 10.1016/S0951-8320(00)00023-5 PG 42 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600002 ER PT J AU Swift, PN Corbet, TF AF Swift, PN Corbet, TF TI The geologic and hydrogeologic setting of the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE Waste Isolation Pilot Plant (WIPP); geologic disposal of radioactive waste; bedded salt; Salado Formation; Culebra Dolomite; geologic and hydrogeologic site characterization ID SOUTHEASTERN NEW-MEXICO; WEST TEXAS; BASIN AB The Waste isolation Pilot Plant (WIPP) is a mined repository for the permanent disposal of transuranic wastes. It has been constructed by the United States Department of Energy (DOE) in semiarid, sparsely inhabited rangeland in southeastern New Mexico. The disposal area is 655 m below the land surface, in bedded salt of the Late Permian (approximately 255 million-years-old) Salado Formation. The extremely low permeability of the halite and other evaporite rocks provide the primary geologic barrier assuring long-term (10,000-year-plus) isolation of the radioactive waste from the accessible environment. Extensive geologic investigations during site characterization have provided information on the stratigraphy, structure, and natural resources of the region (including hydrocarbons, potash, and groundwater), and have investigated the potential fur disruption by processes such as dissolution, salt deformation, tectonic activity, and climate change. Hydrogeologic investigations have documented the physical properties of the evaporite rocks, and have identified the Culebra Dolomite Member of the overlying Rustler Formation as the most transmissive water-bearing unit in the region. Lf the evaporite barriers are breached by accidental drilling intrusion, the Culebra would provide the most likely pathway fur radionuclide transport away from the site. Although water in the Culebra is of poor quality and none is currently used for human consumption, groundwater flow and potential radionuclide transport in the unit have been studied in detail. Results of geologic and hydrogeologic studies of the WIPP region indicate that the geologic and hydro- geologic features of the site will provide effective long-term containment of radionuclides. Geologic and hydrogeologic information is used in the performance assessment that supported the DOE's compliance certification application to the United States Environmental Protection Agency. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Swift, PN (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 49 TC 11 Z9 11 U1 2 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 47 EP 58 DI 10.1016/S0951-8320(00)00024-7 PG 12 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600003 ER PT J AU Larson, KW AF Larson, KW TI Development of the conceptual models for chemical conditions and hydrology used in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Review DE probabilistic performance assessment; transuranic isotopes; sensitivity studies; Waste Isolation Pilot Plant; conceptual model development; chemistry; hydrology; Salado Formation; Culebra dolomite; peer review; MgO backfill; gas generation; radionuclide transport and retardation ID GROUNDWATER-FLOW; NATURAL-WATERS; SOLUBILITY; SYSTEM; ION; THERMODYNAMICS; 25-DEGREES-C; PREDICTION; OXIDE AB The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) facility for the permanent disposal of defense-related transuranic (TRU) waste. US Environmental Protection Agency (EPA) regulations specify that the DOE must demonstrate on a sound basis that the WIPP disposal system will effectively contain long-lived alpha-emitting radionuclides within its boundaries for 10,000 years following closure. In 1996, the DOE submitted the 40 CFR Part 191 Compliance Certification Application for the Waste Isolation Pilot Plant (CCA) to the EPA. The CCA proposed that the WIPP site complies with EPA's regulatory requirements. Contained within the CCA are descriptions of the scientific research conducted to characterize the properties of the WIPP site and the probabilistic performance assessment (PA) conducted to predict the containment properties of the WIPP disposal system. In May 1998, the EPA certified that the TRU waste disposal at the WIPP complies with its regulations. Waste disposal operations at WIPP commenced on 28 March 1999. The 1996 WIPP PA model of the disposal system included conceptual and mathematical representations of key hydrologic and geochemical processes. These key processes were identified over a 22-year period involving data collection, data interpretation, computer models, and sensitivity studies to evaluate the importance of uncertainty and of processes that were difficult to evaluate by other means. Key developments in the area of geochemistry were the evaluation of gas generation mechanisms in the repository; development of a model of chemical conditions in the repository and actinide concentrations in brine; selecting MgO backfill and demonstrating its effects experimentally; and, determining the chemical retardation capability of the Culebra. Key developments in the area of hydrology were evaluating the potential For groundwater to dissolve the Salado Formation (the repository host formation); development of a regional model for hydrologic conditions; development of a stochastic, probabilistic representation of hydraulic properties in the Culebra Member of the Rustler Formation; characterization of physical transport in the Culebra; and, the evaluation of brine and gas flow in the Salado. Additional confidence in the conceptual models used in the 1996 WIPP PA was grained through independent peer review in many stages of their development. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, WIPP Tech Integrat Dept 6848, Albuquerque, NM 87185 USA. RP Larson, KW (reprint author), Sandia Natl Labs, WIPP Tech Integrat Dept 6848, POB 5800, Albuquerque, NM 87185 USA. EM kwlarso@sandia.gov NR 205 TC 7 Z9 7 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 59 EP 86 DI 10.1016/S0951-8320(00)00025-9 PG 28 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600004 ER PT J AU Hansen, FD Knowles, MK AF Hansen, FD Knowles, MK TI Design and analysis of a shaft seal system for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE disturbed rock zone; design; fluid migration; performance; repository seals; rock mechanics; seal system materials; structural analysis; Waste Isolation Pilot Plant AB The Waste Isolation Pilot Plan requires a dependable shaft seal system to isolate the waste from the biosphere. This paper describes the shaft sealing system, which is designed to limit fluid transport through the four existing shafts. The design approach applies redundancy to functional elements and specifies multiple, common, low-permeability materials to ensure reliable performance. The system comprises 13 elements that completely fill the shafts with engineered materials possessing high density and low permeability. Laboratory and field measurements of component properties and performance provide the basis for the design and related evaluations. Hydrologic, mechanical, thermal, and physical features of the system are evaluated in a series of calculations. These calculations indicate that the design limits transport of fluids within the shafts, thereby limiting transport of hazardous material to regulatory boundaries. Additionally, the use or adaptation of existing technologies for seal construction combined with the use of available common materials assure that the design can he constructed. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Carlsbad, NM 88220 USA. RP Hansen, FD (reprint author), Sandia Natl Labs, MS 1395,4100 Natl Pk Highway, Carlsbad, NM 88220 USA. NR 25 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 87 EP 98 DI 10.1016/S0951-8320(00)00026-0 PG 12 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600005 ER PT J AU Sanchez, LC Drez, PE Rath, JS Trellue, HR AF Sanchez, LC Drez, PE Rath, JS Trellue, HR TI Radioactive and nonradioactive waste intended for disposal at the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE Compliance Certification Application (CCA) contact-handled (CH-) transuranic (TRU) waste; containment requirements; performance assessment; radioactive waste; radionuclide inventory; release limits; remote-handled (RH-) TRU; source term; Waste Isolation Pilot Plant (WIPP) AB Transuranic (TRU) waste generated by the handling of plutonium during research on or production of U.S. nuclear weapons will be disposed of in the Waste Isolation Pilot Plant (WIPP). This paper describes the physical and radiological properties of the TRU waste that will be deposited in the WIPP. This geologic repository will accommodate up to 175,564 m(3) of TRU waste, corresponding to 168,385 m(3) of contact-handled (CH-) TRU waste and 7079 m(3) of remote-handled (RH-) TRU waste. Approximately 35% of the TRU waste is currently packaged and stored (i.e. legacy) waste, with the remainder of the waste to be packaged or generated and packaged in activities before the year 2033, which is the closure time for the repository. These wastes were produced at 27 U.S. Department of Energy (DOE) sites in the course of generating defense nuclear materials. The radionuclide and nonradionuclide inventories for the TRU wastes described in this paper were used in the 1996 WIPP Compliance Certification Application (CCA) performance assessment calculations by the Sandia National Laboratories/New Mexico (SNL/NM). Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Drez Environm Associates, Albuquerque, NM 87111 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sanchez, LC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 10 Z9 10 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 99 EP 107 DI 10.1016/S0951-8320(00)00027-2 PG 9 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600006 ER PT J AU Howard, BA Crawford, MB Galson, DA Marietta, MG AF Howard, BA Crawford, MB Galson, DA Marietta, MG TI Regulatory basis for the Waste Isolation Pilot Plant performance assessment SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE compliance certification application; features, events and processes; performance assessment; transuranic waste; uncertainty; Waste Isolation Pilot Plant AB The Waste Isolation Pilot Plant (WIPP) is the first operational repository designed for the safe disposal of transuranic (TRU) radioactive waste from the defense programs of the US Department of Energy (DOE). The US Environmental Protection Agency (EPA) is responsible for certifications and regulation of the WIPP facility for the radioactive components of the waste. The EPA has promulgated general radioactive waste disposal standards at 40 CFR Part 191,and WIPP-specific criteria to implement and interpret the generic disposal standards at 40 CFR Part 194. In October 1996, the DOE submitted its Compliance Certification Application (CCA) to the EPA to demonstrate compliance with the disposal standards at Subparts B and C of 40 CFR Part 191. This paper summarizes the development of the overall legal framework fur radioactive waste disposal at the WIPP, the parallel development of the WIPP performance assessment (PA), and how the EPA disposal standards and implementing criteria formed the basis fur the CCA WIPP PA. The CCA resulted in a certification in May 1998 by the EPA of the WIPP's: compliance with the EPA's disposal standard, thus enabling the WIPP to begin radioactive waste disposal. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Galson Sci Ltd, Rutland LE15 6AX, England. RP Howard, BA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 44 TC 14 Z9 14 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 109 EP 127 DI 10.1016/S0951-8320(00)00028-4 PG 19 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600007 ER PT J AU Galson, DA Swift, PN Anderson, DR Bennett, DG Crawford, MB Hicks, TW Wilmot, RD Basabilvazo, G AF Galson, DA Swift, PN Anderson, DR Bennett, DG Crawford, MB Hicks, TW Wilmot, RD Basabilvazo, G TI Scenario development for the Waste Isolation Pilot Plant Compliance Certification Application SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE Waste Isolation Pilot Plant; undisturbed performance; disturbed performance AB Demonstrating compliance with the applicable regulations for the Waste Isolation Pilot Plant (WIPP) requires an assessment of the longterm performance of the disposal system. Scenario development is one starting point of this assessment, and generates inquiry about the present state and future evolution of the disposal system. Scenario development consists of four tasks: (i) identifying and classifying features, events and processes (FEPs); (ii) screening FEPs according to well-defined criteria; (iii) forming scenarios (combinations of FEPs) in the context of regulatory performance criteria, and (iv) specifying of scenarios for consequence analysis. The development and screening of a comprehensive FEP list provides assurance that the identification of significant processes and events is complete, that potential interactions between FEPs are not overlooked, and that responses to possible questions are available and well documented. Two basic scenarios have been identified for the WIPP: undisturbed performance (UP) and disturbed performance (DP). The UP scenario is used to evaluate compliance with the Environmental Protection Agency's (EPA's) Individual Dose (40 CFR 191.15) and Groundwater Protection (40 CFR 191.24) standards and accounts for all natural and waste- and repository-induced FEPs that survive the screening process. The DP scenario is required fur assessment calculations for the EPA's cumulative release standard (Containment Requirements, 40 CFR 191.13) and accounts for disruptive future human events, which have an uncertain probability of occurrence, in addition to the UP FEPs. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Galson Sci Ltd, Rutland LE15 6AX, England. Sandia Natl Labs, Albuquerque, NM 87185 USA. US DOE, Carlsbad, NM 88221 USA. RP Galson, DA (reprint author), Galson Sci Ltd, 5 Grosvenor House,Melton Rd, Rutland LE15 6AX, England. NR 20 TC 14 Z9 14 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 129 EP 149 DI 10.1016/S0951-8320(00)00029-6 PG 21 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600008 ER PT J AU Helton, JC Anderson, DR Basabilvazo, G Jow, HN Marietta, MG AF Helton, JC Anderson, DR Basabilvazo, G Jow, HN Marietta, MG TI Conceptual structure of the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Review DE aleatory uncertainty; complementary cumulative distribution function; compliance certification application; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; radioactive waste; risk; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID SYSTEMS PRIORITIZATION METHODOLOGY; CUMULATIVE DISTRIBUTION-FUNCTIONS; EPA RELEASE LIMITS; RISK ASSESSMENT; SENSITIVITY ANALYSIS; INTERINDIVIDUAL VARIABILITY; SUBJECTIVE UNCERTAINTY; COMPLEX-SYSTEMS; PROBABILITY; DISPOSAL AB The conceptual structure of the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) is described. This structure involves three basic entities (EN1, EN2, EN3): (i) EN1, a probabilistic characterization of the likelihood of different futures occurring at the WIPP site over the next 10,000 years; (ii) EN2, a procedure for estimating the radionuclide releases to the accessible environment associated with each of the possible futures that could occur at the WIPP site over the next 10.000 years; and (iii) EN3, a probabilistic characterization of the uncertainty in the parameters used in the definition of EN1 and EN2. In the formal development of the 1996 WIPP PA, EN1 is characterized by a probability space (f(st,) G(st), p(st)) for stochastic (i.e. aleatory) uncertainty; EN2 is characterized by a function f that corresponds to the models and associated computer programs used to estimate radionuclide releases; and EN3 is characterized by a probability space (f(su), G(su), p(su)) for subjective (i.e. epistemic) uncertainty. A high-level overview of the 1996 WIPP PA and references to additional sources of information are given in the context of (f(su), G(su), p(su)), f and (f(st), G(su), p(su)), Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. US DOE, Carlsbad, NM 88221 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 108 TC 29 Z9 29 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 151 EP 165 DI 10.1016/S0951-8320(00)00030-2 PG 15 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600009 ER PT J AU Helton, JC Davis, FJ Johnson, JD AF Helton, JC Davis, FJ Johnson, JD TI Characterization of stochastic uncertainty in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; complementary cumulative distribution function; compliance certification application; epistemic uncertainty; Latin hypercube sampling; performance assessment; radioactive waste; random sampling; scenario; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID CUMULATIVE DISTRIBUTION-FUNCTIONS; EPA RELEASE LIMITS; SENSITIVITY ANALYSIS; DISPOSAL; CONSTRUCTION AB The 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) maintains a separation between stochastic (i.e. aleatory) and subjective (i.e. epistemic) uncertainty, with stochastic uncertainty arising from the possible disruptions that could occur at the WIPP over the 10,000-yr regulatory period specified by the US Environmental Protection Agency (40 CFR 191, 40 CFR 194) and subjective uncertainty arising from an inability to uniquely characterize many of the inputs required in the 1996 WIPP PA. The characterization of stochastic uncertainty is discussed, including drilling intrusion time, drilling location, penetration of excavated/nonexcavated areas of the repository, penetration of pressurized brine beneath the repository, borehole plugging patterns, activity level of waste, and occurrence of potash mining. Additional topics discussed include sampling procedures, generation of individual 10,000-yr futures for the WIPP, construction of complementary cumulative distribution functions (CCDFs), mechanistic calculations carried out to support CCDF construction, the Kaplan/Ganick ordered triple representation fur risk, and determination of scenarios and scenario probabilities. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. GRAM Inc, Albuquerque, NM 87112 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS0779, Albuquerque, NM 87185 USA. NR 47 TC 21 Z9 21 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 167 EP 189 DI 10.1016/S0951-8320(00)00031-4 PG 23 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600010 ER PT J AU Helton, JC Martell, MA Tierney, MS AF Helton, JC Martell, MA Tierney, MS TI Characterization of subjective uncertainty in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; complementary cumulative distribution function; compliance certification application; epistemic uncertainty; Latin hypercube sampling; performance assessment; radioactive waste; scenario; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID SENSITIVITY ANALYSIS; BRINE MIGRATION; PERMEABLE SHAFT; PANEL SEALS; GAS AB The 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) maintains a separation between stochastic (i.e. aleatory) and subjective (i.e. epistemic) uncertainty, with stochastic uncertainty arising from the possible disruptions that could occur at the WIPP over the 10,000 yr regulatory period specified by the US Environmental Protection Agency (40 CFR 191, 40 CFR 194) and subjective uncertainty arising from an inability to uniquely characterize many of the inputs required in the 1996 WIPP PA. The characterization of subjective uncertainty is discussed, including assignment of distributions, uncertain variables selected for inclusion in analysis, correlation control, sample size, statistical confidence on mean complementary cumulative distribution functions, generation of Latin hypercube samples, sensitivity analysis techniques, and scenarios involving stochastic and subjective uncertainty. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 90 TC 24 Z9 24 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 191 EP 204 DI 10.1016/S0951-8320(00)00032-6 PG 14 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600011 ER PT J AU Vaughn, P Bean, JE Helton, JC Lord, ME MacKinnon, RJ Schreiber, JD AF Vaughn, P Bean, JE Helton, JC Lord, ME MacKinnon, RJ Schreiber, JD TI Representation of two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE BRAGFLO; compliance certification application; performance assessment; radioactive waste; repository; transuranic waste; two-phase flow; Waste Isolation Pilot Plant AB The following topics related to the representation of two-phase (i.e. gas and brine) flow in the vicinity of the repository in the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) are discussed: (i) system of nonlinear partial differential equations used to model two-phase flow: (ii) incorporation of repository shafts into model; (iii) creep closure of repository; (iv) interbed fracturing; (v) gas generation; (vi) capillary action in waste; (vii) borehole model; (viii) numerical solution; and (ix) gas and brine Row across specified boundaries, Two-phase flow calculations are a central part of the 1996 WIPP PA and supply results that are subsequently used in the calculation of releases to the surface at the time of a drilling intrusion (i.e. spallings, direct brine releases) and long-term releases due to radionuclide transport by flowing groundwater. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6821, Carlsbad, NM 87185 USA. New Mexico Engn Res Inst, Albuquerque, NM 87106 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. RP Vaughn, P (reprint author), Sandia Natl Labs, Dept 6821, MS 1395,4100 Natl Pk Highway, Carlsbad, NM 87185 USA. NR 54 TC 28 Z9 28 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 205 EP 226 DI 10.1016/S0951-8320(00)00033-8 PG 22 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600012 ER PT J AU Helton, JC Bean, JE Economy, K Garner, JW MacKinnon, RJ Miller, J Schreiber, JD Vaughn, P AF Helton, JC Bean, JE Economy, K Garner, JW MacKinnon, RJ Miller, J Schreiber, JD Vaughn, P TI Uncertainty and sensitivity analysis for two-phase flow in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant: undisturbed conditions SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE BRAGFLO; compliance certification application; epistemic uncertainty; Latin hypercube sampling; performance assessment; radioactive waste; sensitivity analysis; subjective uncertainty; transuranic waste; two-phase flow; uncertainty analysis; undisturbed conditions; Waste Isolation Pilot Plant ID BRINE MIGRATION; PERMEABLE SHAFT; PANEL SEALS; GAS AB Uncertainty and sensitivity analysis results obtained in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented for two-phase how in the vicinity of the repository under undisturbed conditions. Techniques based on Latin hypercube sampling, examination of scatterplots, stepwise regression analysis, partial correlation analysis and rank transformations are used to investigate brine inflow, gas generation, repository pressure, brine saturation, and brine and gas outflow. Of the variables under study, repository pressure is potentially the most important due to its influence on spallings and direct brine releases, with the uncertainty in its value being dominated by the extent to which the microbial degradation of cellulose takes place, the rate at which the corrosion of steel takes place, and the amount of brine that drains from the surrounding disturbed rock zone into the repository. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Piru Associates, Albuquerque, NM 87106 USA. GRAM Inc, Albuquerque, NM 87112 USA. New Mexico Engn Res Inst, Albuquerque, NM 87106 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 28 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 227 EP 261 DI 10.1016/S0951-8320(00)00034-X PG 35 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600013 ER PT J AU Berglund, JW Garner, JW Helton, JC Johnson, JD Smith, LN AF Berglund, JW Garner, JW Helton, JC Johnson, JD Smith, LN TI Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: cuttings, cavings and spallings SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; cavings; compliance certification application; cuttings; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; radioactive waste; risk; spallings; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID SENSITIVITY ANALYSIS; UNCERTAINTY; DISPOSAL AB The following topics related to the treatment of cuttings, cavings and spallings releases to the surface environment in thr 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e, aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results fur CCDFs. The presented results indicate that direct releases due to cuttings, cavings and spallings do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for cuttings, cavings and spellings releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194). Published by Elsevier Science Ltd. C1 New Mexico Engn Res Inst, Albuquerque, NM 87106 USA. Piru Associates, Albuquerque, NM 87106 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. GRAM Inc, Albuquerque, NM 87112 USA. Comforce, Albuquerque, NM 87110 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 58 TC 19 Z9 19 U1 2 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 305 EP 330 DI 10.1016/S0951-8320(00)00036-3 PG 26 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600015 ER PT J AU Knowles, MK Hansen, FD Thompson, TW Schatz, JF Gross, M AF Knowles, MK Hansen, FD Thompson, TW Schatz, JF Gross, M TI Review and perspectives on spallings release models in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Review DE compliance certification application; drilling intrusion; performance assessment; radioactive waste; release mechanism; repository science; risk assessment; spallings; transuranic waste; Waste Isolation Pilot Plant AB The Waste Isolation Pilot Plant was licensed for disposal of transuranic wastes generated by the US Department of Energy. The facility consists of a repository mined in a bedded salt formation, approximately 650 m below the surface. Regulations promulgated by the US Environmental Protection Agency require that performance assessment calculations for the repository include the possibility that an exploratory drilling operation could penetrate the waste disposal areas at some time in the future. Release of contaminated solids could reach the surface during a drilling intrusion. One of the mechanisms for release, known as spallings, can occur if gas pressures in the repository exceed the hydrostatic pressure of a column of drilling mud. Calculation of solids releases for spallings depends critically on the conceptual models for the waste, for the spallings process, and assumptions regarding driller parameters and practices. This paper presents a review of the evolution of these models during the regulatory review of the Compliance Certification Application for the repository. A summary and perspectives on the implementation of conservative assumptions in model development are also provided. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Carlsbad, NM 88220 USA. Golder Associates Inc, Lakewood, CO 80228 USA. John F Schatz Res & Consulting, Del Mar, CA 90214 USA. RP Knowles, MK (reprint author), Sandia Natl Labs, 4100 Natl Pk Hwy, Carlsbad, NM 88220 USA. NR 24 TC 8 Z9 8 U1 2 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 331 EP 341 DI 10.1016/S0951-8320(00)00037-5 PG 11 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600016 ER PT J AU Stoelzel, DM O'Brien, DG Garner, JW Helton, JC Johnson, JD Smith, LN AF Stoelzel, DM O'Brien, DG Garner, JW Helton, JC Johnson, JD Smith, LN TI Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: direct brine release SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; compliance certification application; direct brine release; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; radioactive waste; risk; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant AB The following topics related to the treatment of direct brine releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e, aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented analyses indicate that direct brine releases do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility fur transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for direct brine releases fall substantially to the ten of the boundary line specified in the US Environmental Protection Agencys standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194). Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Solut Engn, Lakewood, CO 80232 USA. Piru Associates, Albuquerque, NM 87106 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. GRAM Inc, Albuquerque, NM 87112 USA. Comforce, Albuquerque, NM 87110 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 34 TC 14 Z9 14 U1 2 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 343 EP 367 DI 10.1016/S0951-8320(00)00038-7 PG 25 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600017 ER PT J AU Stockman, CT Garner, JW Helton, JC Johnson, JD Shinta, A Smith, LN AF Stockman, CT Garner, JW Helton, JC Johnson, JD Shinta, A Smith, LN TI Radionuclide transport in the vicinity of the repository and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; compliance certification application; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; radioactive waste; risk; radionuclide transport; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID UNCERTAINTY AB The following topics related to radionuclide transport in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e, epistemic) uncertainty fur individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e. aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that no releases to the accessible environment take place due to radionuclide movement through the anhydrite marker beds, through the Dewey Lake Red Beds or directly to the surface, and also that the releases to the Culebra Dolomite are small. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for release to the Culebra Dolomite fall to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194). Published by Elsevier Science Ltd. C1 Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Piru Associates, Albuquerque, NM 87106 USA. GRAM Inc, Albuquerque, NM 87112 USA. Comforce, Albuquerque, NM 87110 USA. RP Helton, JC (reprint author), Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. NR 36 TC 18 Z9 18 U1 2 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 369 EP 396 DI 10.1016/S0951-8320(00)00039-9 PG 28 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600018 ER PT J AU Ramsey, JL Blaine, R Garner, JW Helton, JC Johnson, JD Smith, LN Wallace, M AF Ramsey, JL Blaine, R Garner, JW Helton, JC Johnson, JD Smith, LN Wallace, M TI Radionuclide and colloid transport in the Culebra Dolomite and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE aleatory uncertainty; compliance certification application; Culebra Dolomite; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; risk; radioactive waste; radionuclide transport; stochastic uncertainty; subjective uncertainty; transuranic waste; Waste Isolation Pilot Plant ID UNCERTAINTY AB The following topics related to radionuclide and colloid transport in the Culebra Dolomite in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; and (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e, aleatory) uncertainty. The presented results indicate that radionuclide and colloid transport in the Culebra Dolomite does not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, no radionuclide transport to the boundary with the accessible environment was observed; thus, the associated CCDFs for comparison with the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194) are degenerate in the sense of having a probability of zero of exceeding a release of zero. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Ecodynam Res Associates, Albuquerque, NM 87106 USA. Piru Associates, Albuquerque, NM 87106 USA. GRAM Inc, Albuquerque, NM 87112 USA. Comforce, Albuquerque, NM 87110 USA. Plus Grp, Albuquerque, NM 87112 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS0779, Albuquerque, NM 87185 USA. NR 57 TC 17 Z9 17 U1 2 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 397 EP 420 DI 10.1016/S0951-8320(00)00040-5 PG 24 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600019 ER PT J AU Froehlich, GK Ogden, HC Byle, KA AF Froehlich, GK Ogden, HC Byle, KA TI Software quality assurance in the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE software quality assurance; software QA; software testing; software verification; software validation; software lift-cycle; quality assurance; performance assessment; Waste Isolation Pilot Plant; transuranic waste; radioactive waste AB The US Dc Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP), located in southeast New Mexico, is a deep geologic repository for the permanent disposal of transuranic waste generated by DOE defense-related activities. Sandia National Laboratories (SNL), in its role as scientific advisor to the DOE, is responsible for evaluating the long-term performance of the WIPP. This risk-based Performance Assessment (PA) is accomplished in part through the use of numerous scientific modeling codes, which rely for some of their inputs on data gathered during characterization of the site. The PA is subject to formal requirements set forth in federal regulations. In particular, the components of the calculation fall under the configuration management and software quality assurance aegis of the American Society of Mechanical Engineers (ASME) Nuclear Quality Assurance (NQA) requirements. This paper describes SNL's implementation of the NQA requirements regarding software quality assurance (SQA). The description of the implementation of SQA for a PA calculation addresses not only the interpretation of the NQA requirements, it also discusses roles, deliverables, and the resources necessary for effective implementation. Finally, examples are given which illustrate the effectiveness of SNL's SQA program, followed by a detailed discussion of lessons learned. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Regulatory Compliance Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Tech Integrat Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Qual Assurance Dept, Albuquerque, NM 87185 USA. RP Froehlich, GK (reprint author), Sandia Natl Labs, Regulatory Compliance Dept, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 421 EP 427 DI 10.1016/S0951-8320(00)00041-7 PG 7 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600020 ER PT J AU Froehlich, GK Williamson, CM Ogden, HC AF Froehlich, GK Williamson, CM Ogden, HC TI Computational environment and software configuration management of the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE configuration management; run control; run management; traceability; reproducibility; quality assurance; performance assessment; Waste Isolation Pilot Plant; transuranic waste; radioactive waste AB The US Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP), located in southeast New Mexico, is a deep geologic repository for the permanent disposal of transuranic waste generated by DOE defense-related activities. Sandia National Laboratories (SNL), in its role as scientific advisor to the DOE, is responsible for evaluating the long-term performance of the WIPP. This risk-based Performance Assessment (PR) is accomplished in part through the use of numerous scientific modeling codes, which rely for some of their inputs on data gathered during characterization of the site. The PA is subject to formal requirements set forth in federal regulations. In particular, the components of the calculation fail under the configuration management and software quality assurance aegis of the American Society of Mechanical Engineers (ASME) Nuclear Quality Assurance (NQA) requirements. This paper describes SNL's implementation of the NQA requirements regarding configuration management. The complexity of the PA calculation is described, and the rationale for developing a flexible, robust run-control process is discussed. The run-control implementation is described, and its integration with the configuration-management system is then explained, to show how a calculation requiring 37,000 CPU-hours, and involving 225,000 output files totaling 95 GB, was accomplished in 5 months by two individuals, with full traceability and reproducibility. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Regulatory Compliance Dept, Albuquerque, NM 87185 USA. Compaq Comp Corp, Networks & Syst Integrat Serv, Albuquerque, NM 87109 USA. Sandia Natl Labs, Tech Integrat Dept, Albuquerque, NM 87185 USA. RP Froehlich, GK (reprint author), Sandia Natl Labs, Regulatory Compliance Dept, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 429 EP 436 DI 10.1016/S0951-8320(00)00018-1 PG 8 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600021 ER PT J AU Helton, JC Anderson, DR Basabilvazo, G Jow, HN Marietta, MG AF Helton, JC Anderson, DR Basabilvazo, G Jow, HN Marietta, MG TI Summary discussion of the 1996 performance assessment for the Waste Isolation Pilot Plant SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Review DE aleatory uncertainty; complementary cumulative distribution function; compliance certification application; epistemic uncertainty; Latin hypercube sampling; Monte Carlo; performance assessment; radioactive waste; risk assessment; sensitivity analysis; stochastic uncertainty; subjective uncertainty; transuranic waste; uncertainty analysis; Waste Isolation Pilot Plant ID SENSITIVITY ANALYSIS; RADIOACTIVE-WASTE; NUCLEAR WASTE; BRINE MIGRATION; SUBJECTIVE UNCERTAINTY; CONCEPTUAL MODELS; EXPERT JUDGMENTS; RISK ASSESSMENTS; PERMEABLE SHAFT; PANEL SEALS AB The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic waste. The construction of complementary cumulative distribution functions (CCDFs) for total radionuclide release from the WIPP to the accessible environment is described. The resultant CCDFs (i) combine releases due to cuttings and cavings, spallings, direct brine release, and long-term transport in Rowing groundwater; (ii) fall substantially to the left of the boundary line specified by the US Environmental Protection Agency's (EPA's) standard 40 CFR 191 for the geologic disposal of radioactive waste; and (iii) constitute an important component of the DOE's successful Compliance Certification Application to the EPA for the WIPP. Insights and perspectives gained in the performance assessment (PA) that led to these CCDFs are described, including the importance of: (i) an iterative approach to PA; (ii) uncertainty and sensitivity analysis; (iii) a clear conceptual model for the analysis; (iv) the separation of stochastic (i.e. aleatory) and subjective (i.e, epistemic) uncertainty; (v) quality assurance procedures: (vi) early involvement of peer reviewers, regulators, and stakeholders; (vii) avoidance of conservative assumptions; and (viii) adequate documentation. Published by Elsevier Science Ltd. C1 Sandia Natl Labs, Dept 6849, Albuquerque, NM 87185 USA. Arizona State Univ, Dept Math, Tempe, AZ 85287 USA. US DOE, Carlsbad, NM 88221 USA. RP Helton, JC (reprint author), Sandia Natl Labs, Dept 6849, MS 0779, Albuquerque, NM 87185 USA. NR 138 TC 12 Z9 12 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD JUL-SEP PY 2000 VL 69 IS 1-3 BP 437 EP 451 DI 10.1016/S0951-8320(00)00019-3 PG 15 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 353VF UT WOS:000089295600022 ER PT J AU Ice, GE Chung, JS Tischler, JZ Lunt, A Assoufid, L AF Ice, GE Chung, JS Tischler, JZ Lunt, A Assoufid, L TI Elliptical x-ray microprobe mirrors by differential deposition SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SYNCHROTRON-RADIATION; ACCURACY AB A differential coating method is described for fabricating high-performance x-ray microfocusing mirrors. With this method, the figure of ultrasmooth spherical mirrors can be modified to produce elliptical surfaces with low roughness and low figure errors. Submicron focusing is demonstrated with prototype mirrors. The differential deposition method creates stiff monolithic mirrors which are compact, robust, and easy to cool and align. Prototype mirrors have demonstrated gains of more than 10(4) in beam intensity while maintaining submilliradian divergence on the sample. This method of producing elliptical mirrors is well matched to the requirements of an x-ray microdiffraction Kirkpatrick-Baez focusing system. (C) 2000 American Institute of Physics. [S0034-6748(00)01607-5]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Beamline Technol, Tucson, AZ 85745 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Ice, GE (reprint author), Oak Ridge Natl Lab, Bethel Valley Rd, Oak Ridge, TN 37831 USA. NR 13 TC 102 Z9 102 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUL PY 2000 VL 71 IS 7 BP 2635 EP 2639 DI 10.1063/1.1150668 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 329KU UT WOS:000087906800002 ER PT J AU Kouznetsov, KA Borgmann, J Clarke, J AF Kouznetsov, KA Borgmann, J Clarke, J TI High T-c superconducting asymmetric gradiometer for biomagnetic applications SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID UNSHIELDED ENVIRONMENT; SQUID MAGNETOMETER; FLUX TRANSFORMERS; SINGLE-LAYER; DC-SQUIDS; NOISE; SYSTEM; JUNCTIONS AB We describe a high transition temperature superconducting, first-order gradiometer intended for biomagnetic measurements in an unshielded environment. The gradiometer involves a single-layer, planar flux transformer with two loops of unequal size, the smaller of which is inductively coupled to the pickup loop of a directly coupled magnetometer. In this configuration, the presence of the flux transformer reduces the sensitivity of the magnetometer by only about 5%. The flux transformer is patterned in a thin film of YBa2Cu3O7-delta deposited on a 100 mm diam wafer, and has a baseline of 48 mm. The flux transformer and magnetometer substrates are permanently bonded together in a flipchip arrangement. The common mode rejection of uniform magnetic field fluctuations in any direction is better than 1 part per 100. The outputs of two such gradiometers are subtracted to form a second-order gradiometer, which rejects first-order gradient fluctuations to about 1 part in 100. With the aid of three orthogonally mounted magnetometers, one can reduce the response of the gradiometers to uniform field fluctuations to below 100 ppm. This system is used to detect magnetic signals from the human heart in an unshielded environment. (C) 2000 American Institute of Physics. [S0034-6748(00)00407-X]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Clarke, J (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 34 TC 16 Z9 16 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUL PY 2000 VL 71 IS 7 BP 2873 EP 2881 AR PII [S0034-6748(00)00407-X] DI 10.1063/1.1150706 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 329KU UT WOS:000087906800042 ER PT J AU Rehr, JJ Albers, RC AF Rehr, JJ Albers, RC TI Theoretical approaches to x-ray absorption fine structure SO REVIEWS OF MODERN PHYSICS LA English DT Review ID MULTIPLE-SCATTERING THEORY; NEAR-EDGE STRUCTURE; DEBYE-WALLER FACTORS; EXCHANGE-CORRELATION POTENTIALS; OVERLAPPING-SPHERE RADII; 3D TRANSITION-METALS; CURVED-WAVE THEORY; PHOTOELECTRON DIFFRACTION; DISORDERED-SYSTEMS; STRUCTURE EXAFS AB Dramatic advances in the understanding of x-ray absorption fine structure (XAFS) have been made over the past few decades, which have led ultimately to a highly quantitative theory. This review covers these developments from a unified multiple-scattering viewpoint;The authors focus on extended x-ray absorption fine structure (EXAFS) well above an x-ray edge,and, to a lesser extent, on x-ray absorption near-edge structure (XANES) closer to an edge. The discussion includes both formal considerations, derived from a many-electron formulation, and practical computational methods based on independent-electron models, with many-body effects lumped into various inelastic losses and energy shifts. The main conceptual issues in XAFS theory are identified and their relative importance is assessed; these include the convergence of the multiple-scattering expansion, curved-wave effects, the scattering potential, inelastic losses, self-energy shifts, and vibrations and structural disorder. The advantages and limitations of current computational approaches are addressed. with particular regard to quantitative experimental comparisons. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Washington, Dept Phys, Seattle, WA 98195 USA. NR 179 TC 1650 Z9 1668 U1 48 U2 377 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 2000 VL 72 IS 3 BP 621 EP 654 DI 10.1103/RevModPhys.72.621 PG 34 WC Physics, Multidisciplinary SC Physics GA 343ER UT WOS:000088689200001 ER PT J AU Sonier, JE Brewer, JH Kiefl, RF AF Sonier, JE Brewer, JH Kiefl, RF TI mu SR studies of the vortex state in type-II superconductors SO REVIEWS OF MODERN PHYSICS LA English DT Review ID HIGH-T-C; FLUX-LINE-LATTICE; MAGNETIC PENETRATION DEPTH; D-WAVE SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; SPIN-ROTATION MEASUREMENTS; SINGLE-CRYSTAL YBA2CU3O7-DELTA; GINZBURG-LANDAU THEORY; CONSISTENT ELECTRONIC-STRUCTURE; SCANNING-TUNNELING-MICROSCOPY AB The authors present a review of recent muon spin rotation (mu SR) studies of the vortex state in type-IT superconductors. There are significant gaps in our understanding of this unusual phase of matter, especially in unconventional superconductors, for which the description of the vortex structure is a subject of great controversy. The mu SR technique provides a sensitive local probe of the spatially inhomogeneous magnetic field associated with the vortex state. For the case of a regular vortex lattice, the magnetic penetration depth lambda and the coherence length Scan he simultaneously extracted from the measured internal field distribution. The penetration depth is directly related to the density of superconducting carriers in the material, and measurements of its variation with temperature, magnetic field, and impurities can provide essential information on the symmetry of the order parameter. The coherence length measured with mu SR is the length scale for spatial variations of the order parameter within a vortex core. A primary goal of this review article is to show that measurements of these fundamental length scales are fairly robust with respect to the details of how the field distribution is modeled. The reliability of the results is demonstrated by a comparison of the mu SR experiments with relevant theories and with other experimental techniques. The authors also review mu SR measurements that have focused on the study of pinning-induced spatial disorder and vortex fluctuation phenomena. The mu SR technique has proven to be a powerful tool for investigating exotic vortex phases, where vortex transitions are directly observable from changes in the mu SR line shape. Particular emphasis is given to mu SR experiments performed on high-temperature superconductors since high-quality single crystals have become available. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Canadian Inst Adv Res, Toronto, ON M5G 1ZB, Canada. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 282 TC 225 Z9 227 U1 4 U2 39 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 2000 VL 72 IS 3 BP 769 EP 811 DI 10.1103/RevModPhys.72.769 PG 43 WC Physics, Multidisciplinary SC Physics GA 343ER UT WOS:000088689200005 ER PT J AU Kharazhanov, SZ AF Kharazhanov, SZ TI Temperature and doping level dependence of solar cell performance including excitons SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE excitons; solar cells; silicon; short-circuit current; open-circuit voltage; fill factor; efficiency; sensitivity ID DEEP IMPURITY LEVELS; NONRADIATIVE RECOMBINATION; AUGER RECOMBINATION; SILICON; SEMICONDUCTORS; COEFFICIENTS AB Recent papers have indicated that the excitonic population in silicon can approach that of minority carriers and make their presence felt even at room and higher temperatures in generation-recombination processes and solar energy conversion. This paper presents an investigation of temperature and doping-level dependence of silicon solar cell perfomance for doping levels from 10(16) to 10(18) cm(-3) and temperature interval 100-500 K. Our investigation was been performed using the three-particle theory developed by R. Corkish, D.S.-P. Chan, and M.A. Green (J. Appl. Phys. 79 (1996) 195). We have found that dissociation lifetime and diffusion length of excitons are 3-6 orders of magnitude less than that of free carriers. Inclusion of excitons results in a significant increase of dark current, decrease of short-circuit current, open-circuit voltage, fill factor, and efficiency. The results obtained, taking into account the effect of excitons, are in good agreement with experimental data. We have found accurate and simplified expressions for the dark saturation current and short-circuit current. Approximate value of the upper limit of photogeneration intensity of excitons phi(ex) is found that is at least eight times less than that of free carriers phi, i.e., phi(ex) less than or equal to phi. An optimal doping-level range of silicon solar cell base region was found that is less than 10(17) cm(-3), and agrees with experimental data. The work includes a suggestion for experimental methods to confirm exciton involvement in photocurrent transport in silicon solar cells. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kharazhanov, SZ (reprint author), Phys Tech Inst, Mavlyanov Str 2 B, Tashkent 700084, Uzbekistan. NR 24 TC 4 Z9 4 U1 0 U2 8 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 JUL 1 PY 2000 VL 63 IS 2 BP 149 EP 163 DI 10.1016/S0927-0248(99)00173-7 PG 15 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 336VG UT WOS:000088323200005 ER PT J AU Zhang, AP Dang, G Ren, F Han, J Cho, H Pearton, SJ Chyi, JI Nee, TE Lee, CM Chuo, CC Chu, SNG AF Zhang, AP Dang, G Ren, F Han, J Cho, H Pearton, SJ Chyi, JI Nee, TE Lee, CM Chuo, CC Chu, SNG TI Forward turn-on and reverse blocking characteristics of GaN Schottky and p-i-n rectifiers SO SOLID-STATE ELECTRONICS LA English DT Article ID DEVICES AB High voltage GaN Schottky and p-i-n rectifiers have been fabricated on heteroepitaxial layers. The Schottky diodes have reverse blocking voltages around 500 V for vertical devices employing undoped, conducting GaN, whereas these voltages are >3000 V for lateral devices employing resistive GaN, The forward turn-on voltages are greater than or equal to 3.5 V for the Schottky rectifiers, with ideality factors of 1.5-2. The dominant current transport mechanism is Shockley-Read-Hall recombination. The p-i-n rectifiers fabricated with conducting i layers also have reverse blocking voltages of similar to 500 V, but the forward turn-on voltages are typically similar to 5 V. A comparison with the state-of-the-art SiC Schottky and p-i-n rectifiers is also given. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Natl Cent Univ, Dept Elect Engn, Chungli 32054, Taiwan. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Chyi, Jen-Inn/A-1799-2016 NR 10 TC 10 Z9 12 U1 0 U2 1 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 JUL PY 2000 VL 44 IS 7 BP 1157 EP 1161 DI 10.1016/S0038-1101(00)00059-9 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 318RF UT WOS:000087297100004 ER PT J AU French, NB Haas, W Priebe, S AF French, NB Haas, W Priebe, S TI Status of multimetal continuous emission monitoring technologies SO SPECTROSCOPY LA English DT Article ID METALS C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83401 USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU ADVANSTAR COMMUNICATIONS PI DULUTH PA 131 W FIRST ST, DULUTH, MN 55802 USA SN 0887-6703 J9 SPECTROSCOPY JI Spectroscopy PD JUL PY 2000 VL 15 IS 7 BP 24 EP + PG 8 WC Spectroscopy SC Spectroscopy GA 337JG UT WOS:000088353300003 ER PT J AU Ynzunza, RX Denecke, R Palomares, FJ Morais, J Tober, ED Wang, Z de Abajo, FJG Liesegang, J Hussain, Z Van Hove, MA Fadley, CS AF Ynzunza, RX Denecke, R Palomares, FJ Morais, J Tober, ED Wang, Z de Abajo, FJG Liesegang, J Hussain, Z Van Hove, MA Fadley, CS TI Kinetics and atomic structure of O adsorption on W(110) from time- and state-resolved photoelectron spectroscopy and full-solid-angle photoelectron diffraction SO SURFACE SCIENCE LA English DT Article DE adsorption kinetics; electron-solid interactions, scattering, diffraction; low index single crystal surfaces; models of surface kinetics; oxygen; photoelectron diffraction; surface structure, morphology, roughness, and topography; synchrotron radiation photoelectron spectroscopy; tungsten ID ENERGY-ELECTRON-DIFFRACTION; CORE-LEVEL SHIFTS; METAL-SURFACES; OXYGEN; RESOLUTION; CHEMISORPTION; DIFFUSION; TUNGSTEN AB We have studied the kinetics of the low-pressure adsorption of oxygen on W(110) via time- and chemical-state-resolved photoelectron spectroscopy (PS) and diffraction (PD). Using high-brightness third-generation synchrotron radiation from the Advanced Light Source, together with a new photoelectron spectrometer/diffractometer system, we are able to resolve four distinct chemical states in W 4f spectra (clean surface, bulk, W bound to two O atoms = O2, and W bound to three O atoms = O3) and to measure such spectra in about 20 s each so as to follow the kinetics of oxygen adsorption at 3 x 10(-9) Torr from the clean surface to near saturation. The time-dependent transformations from one state of the surface W atoms to another have been determined at three temperatures of 298, 360, and 593 K. We also find that, for this adsorption pressure on our surface, no long-range-ordered structures are observable in LEED, even though the previously observed ordered structures of p(2 x 1), p(2 x 2), and (1 x 1) x 12 are formed at higher pressures of approximately 10(-6) Torr. The room-temperature state-resolved PS data are modelled using a simple Monte Carlo approach which assumes no mobility after molecular dissociation, and these calculations are found to describe the experimental data very well. Combining experiment and theory also permits deriving the sticking coefficient as a function of time, yielding results which agree with prior work. Full-solid-angle PD patterns have also been determined at the end of 298 K oxygen exposure for the O2 and O3 W atoms, and these have been analyzed using multiple scattering theory and R-factor analysis. The final local pseudo-threefold hollow geometries for oxygen are found to be very similar to those for a saturated one-monolayer structure of O on W(110) (the (1 x 1) x 12 structure), including a lateral shift of O away from the position corresponding to three equal bond distances, but with some contraction of the O-W vertical separation in going from O2 to O3 suggested. This study indicates considerable potential of such time- and state-resolved PS and diffraction for investigating surface reaction kinetics and structure, particularly for the large number of systems that do not exhibit long-range order and in view of future instrumentation improvements that should lead to much shorter data accumulation times and/or higher ambient pressures of measurement. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. EHU, UPV, Dept CCIA, Fac Informat, San Sebastian 20080, Spain. EHU, UPV, CSIC, Ctr Mixto, San Sebastian 20080, Spain. La Trobe Univ, Dept Phys, Bundoora, Vic 3083, Australia. RP Ynzunza, RX (reprint author), Lawrence Berkeley Lab, Div Mat Sci, Mailstop 2-100, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008; Palomares, Francisco Javier/C-4605-2011; Garcia de Abajo, Javier/A-6095-2009; CSIC-UPV/EHU, CFM/F-4867-2012; Morais, Jonder/E-5022-2013; Register, CMSS/G-7191-2015; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014 OI Van Hove, Michel/0000-0002-8898-6921; Palomares, Francisco Javier/0000-0002-4768-2219; Garcia de Abajo, Javier/0000-0002-4970-4565; Morais, Jonder/0000-0002-4143-1208; NR 40 TC 25 Z9 25 U1 0 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUL 1 PY 2000 VL 459 IS 1-2 BP 69 EP 92 DI 10.1016/S0039-6028(00)00450-7 PG 24 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 333QU UT WOS:000088141400014 ER PT J AU Sagie, E Polak, M AF Sagie, E Polak, M TI Surface segregation in Ni(W) solid solution SO SURFACE SCIENCE LA English DT Article DE alloys; Auger electron spectroscopy; chemisorption; equilibrium thermodynamics and statistical mechanics; metallic surfaces; nickel; surface segregation; tungsten ID TRANSITION-METAL ALLOYS; SHORT-RANGE ORDER; TRENDS AB The surface composition of Ni-7%W solid solution equilibrated under UHV in the range 750-1100 K was determined by means of quantitative Auger electron spectroscopy. Only part of the excess tungsten accumulated at the sputter-cleaned surface dissolved upon subsequent annealing, and from the temperature dependence of the residual W equilibrium concentration, quantified for two different in-depth distribution models, segregation enthalpies and excess entropies are derived. The observed tungsten surface segregation tendency indicates dominance of elastic strain release over weakened interatomic bonding driving forces in this solid solution. Tungsten segregation levels are relatively low because of the small net energetic driving force, and due to a suppressing excess entropy effect. Adsorption of oxygen on the alloy surfaces enhances W segregation at elevated temperatures due to preferential W-O interactions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Ben Gurion Univ Negev, Dept Mat Engn, IL-84105 Beer Sheva, Israel. RP Polak, M (reprint author), Lawrence Berkeley Natl Lab 2 100, Berkeley, CA 94720 USA. NR 23 TC 14 Z9 14 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUL 1 PY 2000 VL 459 IS 1-2 BP 223 EP 229 DI 10.1016/S0039-6028(00)00485-4 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 333QU UT WOS:000088141400027 ER PT J AU Wei, JJ Erdemir, A Fenske, GR AF Wei, JJ Erdemir, A Fenske, GR TI Dry lubricant films for aluminum forming SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT STLE/ASME Tribology Conference CY OCT 11-13, 1999 CL ORLANDO, FLORIDA SP Soc Tribologists & Lubricat Engineers, ASME DE boric acid dry films; clean lubrication; aluminum forming; lubrication mechanisms ID BORIC-ACID AB During metal forming, lubricants are necessary to prevent direct contact, adhesion, transfer, and scuffing of workpiece materials and tools. Boric acid films, which can be firmly adhered to clean aluminum surfaces by spraying their methanol solutions, provide extremely low friction coefficients (approximate to 0.04). The adhesion strengths of the bonded films vary with the type of aluminum alloy (6061, 6111, and 5754). Sheet metal forming tests indicate that boric acid films and combined films of boric acid and mineral oil can enable larger strains than commercial liquid and solid lubricants, showing that their lubricities are excellent for aluminum forming. Scanning electron microscopy analyses indicate that the dry boric acid films effectively separate the workpiece and die materials and, thus, prevent direct contact and preserve the sur face qualities. Because boric acid is nontoxic and easily removed by water, the authors can expect these films to be environmentally friendly, cost-effective, and very efficient lubricants for sheet aluminum cold forming. C1 Argonne Natl Lab, Div Energy Technol, Tribol Sect, Argonne, IL 60439 USA. RP Wei, JJ (reprint author), Argonne Natl Lab, Div Energy Technol, Tribol Sect, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 9 Z9 11 U1 1 U2 6 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 JUL PY 2000 VL 43 IS 3 BP 535 EP 541 DI 10.1080/10402000008982374 PG 7 WC Engineering, Mechanical SC Engineering GA 328CJ UT WOS:000087831000025 ER PT J AU Afanasyev-Charkin, IV Cooke, DW Gritsyna, VT Ishimaru, M Sickafus, KE AF Afanasyev-Charkin, IV Cooke, DW Gritsyna, VT Ishimaru, M Sickafus, KE TI Effects of He+ ion implantation on optical and structural properties of MgAl2O4 SO VACUUM LA English DT Article; Proceedings Paper CT 3rd International Conference on the Modification of Properities of Surface Layer of Non-Semiconducting Materials Using Particle Beams (MPSL 99) CY MAY 24-29, 1999 CL SUMY, UKRAINE SP Sumy Inst Surface Modification, Minist Sci & Technol ID CRYSTALS; SPINEL; RADIATION; DAMAGE; AL2O3 AB Single crystals of magnesium-aluminate spinel were implanted with 170 keV Het ions to fluences ranging from 1 x 10(16) to I x 10(21) ions/m(2) at 120 K. The effects of ion implantation were studied using Optical Absorption Spectroscopy, Rutherford Backscattering Spectroscopy and Ion Channeling (RBS/C) and Transmission Electron Microscopy (TEM). In absorption spectra obtained from the implanted samples, growth of an F-center band at 5.3 eV was observed. At the fluence of 3 x 10(20) ions/m(2), the growth of this band not only ceases but the intensity suddenly decreases. This may be due to formation of a new phase at this fluence. This is partially confirmed by the fact that at this and higher ion doses, a modulated absorbance becomes apparent in the absorption spectrum of spinel. This effect is caused by formation of a buried layer with refraction index lower than that of an unimplanted sample. RBS/C and TEM measurements show that spinel is not amorphized over the fluence range examined in this study. TEM microdiffraction observations show that in the damaged region the intensities of superlattice spots decrease significantly, suggesting that ion beam irradiation induces either an order-disorder phase transition or a transformation into the so-called "metastable" phase of spinel. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Kharkov State Univ, Dept Phys & Technol, UA-310077 Kharkov, Ukraine. Kyushu Univ, Dept Mat Sci & Engn, Fukuoka 8128581, Japan. RP Afanasyev-Charkin, IV (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS-K762, Los Alamos, NM 87545 USA. NR 14 TC 9 Z9 9 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-207X J9 VACUUM JI Vacuum PD JUL PY 2000 VL 58 IS 1 BP 2 EP 9 DI 10.1016/S0042-207X(99)00206-7 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 343FM UT WOS:000088691100002 ER PT J AU Kishimoto, N Umeda, N Takeda, Y Gritsyna, VT Renk, TJ Thompson, MO AF Kishimoto, N Umeda, N Takeda, Y Gritsyna, VT Renk, TJ Thompson, MO TI In-beam growth and rearrangement of nanoparticles in insulators induced by high-current negative copper ions SO VACUUM LA English DT Article; Proceedings Paper CT 3rd International Conference on the Modification of Properities of Surface Layer of Non-Semiconducting Materials Using Particle Beams (MPSL 99) CY MAY 24-29, 1999 CL SUMY, UKRAINE SP Sumy Inst Surface Modification, Minist Sci & Technol ID IMPLANTED SIO2 GLASS; DOSE-RATE DEPENDENCE; OPTICAL-ABSORPTION; SILICA GLASSES; FUSED-SILICA; NANOCLUSTERS; COLLOIDS AB In fabricating metal nanoparticles in insulators, high-current negative ions have been shown to cause efficient and spontaneous growth of nanospheres. The in-beam growth is inevitably subjected to rearrangement of implanted atoms, departing from initially deposited positions. For high-current techniques for insulators, we discuss important experimental factors and explore possible mechanisms of the in-beam growth and atomic rearrangement of nanoparticles, Experimental data of interest are for negative Cu ion implantation at 60 keV into insulators, amorphous(a-), crystalline (c-) SiO2 and a spinel oxide, MgAl2O4. Dose rates ranged up to 260 mu A/cm(2), with a total dose of 3.0 x 10(16) ions/cm(2). Nanoparticle morphology and surface morphology by AFM were significantly dependent not only on dose rate but also on the boundary conditions. With increasing close ratel the in-beam growth of nanoparticles became pronounced and the atomic profile shifted toward the surface. Since beam heating, especially in vacuum, is of concern, thermal analysis was carried out with a one-dimensional simulation code. Candidate mechanisms are depth-oriented gradients of deposited nuclear/electronic energy, chemical/elastic potentials and thermal effects. The relevant mechanisms are explored among these candidates. (C) 2000 Elsevier Science Ltd, All rights reserved. C1 Natl Res Inst Met, High Resolut Beam Res Stn, Tsukuba, Ibaraki 3050047, Japan. Univ Tsukuba, Tsukuba, Ibaraki 3050006, Japan. Kharkov State Univ, UA-310077 Kharkov, Ukraine. Sandia Natl Labs, Albuquerque, NM 87185 USA. Cornell Univ, Dept Mat Sci, Ithaca, NY 14853 USA. RP Kishimoto, N (reprint author), Natl Res Inst Met, High Resolut Beam Res Stn, 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan. RI Gritsyna, Vasyl/J-9021-2016; OI Gritsyna, Vasyl/0000-0002-6734-3812; Thompson, Michael/0000-0002-4933-009X NR 20 TC 28 Z9 29 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-207X J9 VACUUM JI Vacuum PD JUL PY 2000 VL 58 IS 1 BP 60 EP 78 DI 10.1016/S0042-207X(00)00111-1 PG 19 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 343FM UT WOS:000088691100008 ER PT J AU Knowles, MK Economy, KM AF Knowles, MK Economy, KM TI Evaluation of brine inflow at a Waste Isolation Pilot Plant SO WATER ENVIRONMENT RESEARCH LA English DT Article DE brine inflow; nuclear repository; transuranic; waste disposal; waste isolation pilot plant AB The Waste Isolation Pilot Plant (WIPP) is a mined, geologic repository operated for the U.S. Department of Energy in New Mexico. Ongoing technical programs at the facility support requirements regarding continued demonstration of compliance with regulations and improvements to operational efficiency. One factor that can be important to performance measurements at WIPP is the volume of fluid flowing into the repository. The objective of the analysis presented in this paper is to address those processes that influence liquid inflow to the waste disposal areas. Simulations focus on the coupling between brine inflow and properties of the proximal damaged zone in the host rock. Calculations show that significant reduction in predicted brine inflow results when two-phase flow properties of the damaged zone are modified relative to baseline values. Results warrant further investigation regarding these properties. The study also indicates that only nominal improvement to predictive capabilities would result from using a fully coupled transient approach to simulate development of damage in the host rock. C1 Sandia Natl Labs, Carlsbad, NM 88220 USA. Appl Phys Inc, Albuquerque, NM USA. RP Knowles, MK (reprint author), Sandia Natl Labs, 4100 Natl Pk Hwy, Carlsbad, NM 88220 USA. NR 26 TC 0 Z9 0 U1 0 U2 1 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 USA SN 1061-4303 J9 WATER ENVIRON RES JI Water Environ. Res. PD JUL-AUG PY 2000 VL 72 IS 4 BP 397 EP 404 DI 10.2175/106143000X137923 PG 8 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 487FK UT WOS:000171862800003 ER PT J AU Smith, CA Phiefer, CB MacNaughton, SJ Peacock, A Burkhalter, RS Kirkegaard, R White, DC AF Smith, CA Phiefer, CB MacNaughton, SJ Peacock, A Burkhalter, RS Kirkegaard, R White, DC TI Quantitative lipid biomarker detection of unculturable microbes and chlorine exposure in water distribution system biofilms SO WATER RESEARCH LA English DT Article DE biofilms; biomarkers; oxiranes; epoxides; mass spectrometry; chlorine ID FATTY-ACIDS; OXYLIPINS AB Biofilms in the drinking water distribution system can protect pathogens from disinfection and provide the inocula for periodic infestations. Assessing these biofilms can be difficult, as the plate counts of pelagic bacteria may bear little relationship to the biofilm load. Culturing the water at the outlet most often does not reflect the biofilm composition. Herein we show that analysis of polar lipid fatty acids recovered from biofilms on devices possessing a large surface area provides quantitative analysis of the Viable biomass, community composition, and nutritional status that is independent of the recovery and culturability. Analysis of the polar lipid fatty acids indicated the biofilm contained a stressed and predominantly Gram-negative bacterial community. The composition was not significantly different whether collected in the summer or winter. Oxirane (epoxide) fatty acids were detected in the polar lipids of the biofilm, indicating exposure to chlorine and loss of viability within the biofilm. Tests with monocultures of Escherichia coli and Sphingomonas paucimobilis exposed to chlorine resulted in oxirane fatty acid generation and rendered them nonculturable. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP White, DC (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 10515 Res Dr,Suite 300, Knoxville, TN 37932 USA. NR 32 TC 29 Z9 32 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0043-1354 J9 WATER RES JI Water Res. PD JUL PY 2000 VL 34 IS 10 BP 2683 EP 2688 DI 10.1016/S0043-1354(00)00028-2 PG 6 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA 321CD UT WOS:000087436600007 ER PT J AU Detwiler, RL Rajaram, H Glass, RJ AF Detwiler, RL Rajaram, H Glass, RJ TI Solute transport in variable-aperture fractures: An investigation of the relative importance of Taylor dispersion and macrodispersion SO WATER RESOURCES RESEARCH LA English DT Article ID SINGLE FRACTURE; TRACER DISPERSION; ROCK FRACTURE; LATTICE-GAS; FLOW; MODEL; ROUGHNESS; FIELDS; ERRORS; CRACKS AB Dispersion of solutes in a variable aperture fracture results from a combination of molecular diffusion and velocity variations in both the plane of the fracture (macrodispersion) and across the fracture aperture (Taylor dispersion). We use a combination of physical experiments and computational simulations to test a theoretical model in which the effective longitudinal dispersion coefficient D-L is expressed as a sum of the contributions of these three dispersive mechanisms. The combined influence of Taylor dispersion and macrodispersion results in a nonlinear dependence of D-L on the Peclet number (Pe = Y(b)/D-m, where V is the mean solute velocity, (b) is the mean aperture, and D-m is the molecular diffusion coefficient). Three distinct dispersion regimes become evident: For small Pe (Pe much less than 1), molecular diffusion dominates resulting in D-L proportional to Pe(0); for intermediate Pe, macrodispersion dominates (D-L proportional to Pe) and for large Pe, Taylor dispersion dominates (D-L proportional to Pe(2)). The Pe range corresponding to these different regimes is controlled by the statistics of the aperture field. In particular, the upper limit of Pe corresponding to the macrodispersion regime increases as the macrodispersivity increases. Physical experiments in an analog, rough-walled fracture confirm the nonlinear Pe dependence of D-L predicted by the theoretical model. However, the theoretical model underestimates the magnitude of D-L. Computational simulations, using a particle-tracking algorithm that incorporates all three dispersive mechanisms, agree very closely with the theoretical model predictions. The close agreement between the theoretical model and computational simulations is largely because, in both cases, the Reynolds equation describes the flow field in the fracture. The discrepancy between theoretical model predictions and D-L estimated from the physical experiments appears to be largely due to deviations from the local cubic law assumed by the Reynolds equation. C1 Univ Colorado, Dept Civil Environm & Architectural Engn, Boulder, CO 80309 USA. Sandia Natl Labs, Flow Visualizat & Proc Lab, Albuquerque, NM 87123 USA. RP Detwiler, RL (reprint author), Univ Colorado, Dept Civil Environm & Architectural Engn, Boulder, CO 80309 USA. RI Detwiler, Russell/C-3228-2008 OI Detwiler, Russell/0000-0002-7693-9271 NR 44 TC 86 Z9 86 U1 2 U2 16 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 JUL PY 2000 VL 36 IS 7 BP 1611 EP 1625 DI 10.1029/2000WR900036 PG 15 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 329VH UT WOS:000087928800001 ER PT J AU Tokunaga, TK Wan, JM Sutton, SR AF Tokunaga, TK Wan, JM Sutton, SR TI Transient film flow on rough fracture surfaces SO WATER RESOURCES RESEARCH LA English DT Article ID SOIL-WATER PROPERTIES; CAPILLARY HYPERDIFFUSION; POROUS-MEDIUM; LIQUID; RETENTION; MODELS; ROCK; FRAGMENTATION; POROSITY; FRONT AB Transient film flow in unsaturated fractures was investigated conceptually and experimentally. By considering films on fracture surfaces as analogs to water in partially saturated porous media, the film hydraulic diffusivity and equation for transient film flow are obtained from their porous medium counterparts, the hydraulic diffusivity and the Richards equation. Experiments on roughened glass show that the average film thickness dependence on matric potential can be approximated as a power function. It is also shown that: the film hydraulic diffusivity increases with increased film thickness (and with increased matric potential). Fast film flow (average velocities greater than 3 x 10(-7) m s(-1) under unit gradient conditions) was observed for average film thicknesses greater than 2 mu m and matric potentials greater than -1 kPa. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. RP Tokunaga, TK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-116, Berkeley, CA 94720 USA. RI Tokunaga, Tetsu/H-2790-2014; Wan, Jiamin/H-6656-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128; NR 47 TC 45 Z9 47 U1 3 U2 10 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 JUL PY 2000 VL 36 IS 7 BP 1737 EP 1746 DI 10.1029/2000WR900079 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 329VH UT WOS:000087928800011 ER PT J AU Liao, TW Li, K McSpadden, SB AF Liao, TW Li, K McSpadden, SB TI Wear mechanisms of diamond abrasives during transition and steady stages in creep-feed grinding of structural ceramics SO WEAR LA English DT Article DE diamond abrasives; wear; fracture; structural ceramics ID STRENGTH; WHEELS AB A study was performed to quantify the wear mechanisms of diamond abrasives of a resin bonded diamond wheel (320 US mesh and 100 concentration) in creep-feed grinding of a silicon nitride material. This was achieved with a combined use of a lead-tape imprint technique and SEM. The wear mechanisms observed include attritious wear, fracture (or chipping), mixed mode of wear and fracture, and dislodgment (or pullout). The percentage of each wear mechanism was quantified for different points of the grinding process: five during the transition stage and six during the steady stage. The results indicate that: (1) the percentage of grits not involved in removing the first 10 cm(3)/cm volume of material per unit width was high (similar to 70%) and decreased as more material was removed (from - 50% to 20% during the steady stage). (2) Attritious wear dominated the wear mechanism and the percentage increased as more material was removed (from similar to 15% to 30% during the transition stage and from similar to 50% to 75% during the steady stage). Correspondingly, the percentage of wear-flat area also increased. (3) The percentages of grit dislodgment and grit fracture were relatively higher during the transition stage than during the steady stage. (4) The number of active grits per unit area increased with cumulative volume of material removed. (5) Specific forces increase nonlinearly with wear-nat percentage and the percentage of worn grits. (C) 2000 Published by Elsevier Science S.A. C1 Louisiana State Univ, Dept Ind & Mfg Syst Engn, Baton Rouge, LA 70803 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Liao, TW (reprint author), Louisiana State Univ, Dept Ind & Mfg Syst Engn, Baton Rouge, LA 70803 USA. RI Liao, Thunshun/B-2724-2009 NR 18 TC 15 Z9 20 U1 0 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUL PY 2000 VL 242 IS 1-2 BP 28 EP 37 DI 10.1016/S0043-1648(00)00366-5 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 349EF UT WOS:000089030100003 ER PT J AU Bandoni, SM Mulvey, M Loker, ES AF Bandoni, SM Mulvey, M Loker, ES TI Population structure and taxonomic discrimination among three species of Biomphalaria Preston, 1910 (Gastropoda : Planorbidae) from Kenya SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article ID SUBDIVIDED POPULATIONS; ALLOZYME VARIATION; GENE DIVERSITY; SCHISTOSOMIASIS; GLABRATA; TRANSMISSION; PATTERNS; MOLLUSCA; CAMEROON; MANSONI AB The genetic basis for species designations for African species of Biomphalaria has received Little attention. Populations of B. choanomphala, B. sudanica and B. pfeifferi from Kenya were examined using starch gel electrophoresis. Analysis of population structure as measured using Wright's F-statistics for B. sudanica and B. choanomphala revealed that both species show substantial departures from expectations under random mating. Populations of B. choanomphala show the least evidence of inbreeding, and populations of B, sudanica are intermediate between B. choanomphala and previously reported levels of inbreeding for B. pfeifferi. Syntopic populations of B. Pfeifferi and B. sudanica were genetically distinct. Syntopic populations of B. choanomphala and B. sudanica also showed evidence of separate gene pools, although the evidence is not as conclusive as for B. pfeifferi and B. sudanica. Possible explanations for the failure to find clear differences between B. sudanica and B. choanomphala are considered. (C) 2000 The Linnean Society of London. C1 SUNY Geneseo, Dept Biol, Geneseo, NY 14454 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. RP Bandoni, SM (reprint author), SUNY Geneseo, Dept Biol, 1 Coll Circle, Geneseo, NY 14454 USA. NR 42 TC 4 Z9 4 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD JUL PY 2000 VL 129 IS 3 BP 387 EP 401 DI 10.1111/j.1096-3642.2000.tb00017.x PG 15 WC Zoology SC Zoology GA 331BH UT WOS:000087997100003 ER PT J AU Carter, DH Bourke, MAM AF Carter, DH Bourke, MAM TI Neutron diffraction study of the deformation behavior of beryllium-aluminum composites SO ACTA MATERIALIA LA English DT Article DE beryllium; aluminum; composites; neutron scattering; mechanical properties ID AL-BE ALLOYS; RIETVELD REFINEMENT; MATRIX COMPOSITE; STRESSES; STRAINS AB Neutron diffraction measurements of the mean phase elastic strains during loading were performed on two different beryllium-aluminum composites. The first was Be-47.5Al-2.5Ag produced from hot isostatically pressed powder fabricated by rapid solidification using a centrifugal atomization process; the second was a commercially available Be-38Al extruded powder product. Under rapid solidification, Be-Al undergoes liquid phase separation, resulting in a three-dimensional interpenetrating morphology in which both phases are continuous. Elastic strains in the individual phases were measured as a function of tensile and compressive load at the Los Alamos Neutron Scattering Center using a pulsed neutron source. The deformation behavior was unusual due to the unique composite microstructure and elastic properties of beryllium. Notably, the aluminum developed compressive elastic strains in the direction perpendicular to the compressive loading axis. These strains were compared with predictions from finite element analyses to clarify the stress state in each phase during deformation. Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Carter, DH (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 40 TC 21 Z9 22 U1 2 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN 30 PY 2000 VL 48 IS 11 BP 2885 EP 2900 DI 10.1016/S1359-6454(00)00087-2 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CJ UT WOS:000089196700012 ER PT J AU Hughes, DA Hansen, N AF Hughes, DA Hansen, N TI Microstructure and strength of nickel at large strains SO ACTA MATERIALIA LA English DT Article DE nickel; cold working; dislocations; microstructure; mechanical properties (plastic) ID RANGE INTERNAL-STRESSES; COPPER SINGLE-CRYSTALS; PLASTIC-DEFORMATION; FCC METALS; CELL STRUCTURES; FLOW-STRESS; BOUNDARIES; EVOLUTION; MISORIENTATION; INTERMEDIATE AB A quantitative microstructural analysis is presented for pure polycrystalline nickel (99.99%) cold rolled to reductions from 70 to 98% (epsilon(vM) 1.4-4.5). Applying transmission electron microscopy (TEM) techniques, key structural parameters, such as spacing between dislocation boundaries and high angle boundaries, as well as the misorientations across their boundaries, have been measured and analyzed. Application of scaling and similitude hypotheses to these microstructural parameters and their distributions revealed that the structures maintain a similar character with increasing strain. This similarity indicates that the measured parameters capture the important features of the structure. Scaring and similitude provide governing principles for structure formation. Based on this structural information and a detailed description of the morphology, structural parameters are identified, strength determining parameters chosen, and strength-structural relationships discussed. The suggestion is then made that two strengthening contributions should be considered: (i) dislocation strengthening due to the presence of low angle boundaries and (ii) grain boundary strengthening due to medium to high angle boundaries. The calculated individual strength contributions evolve differently with the strain and their addition leads to flow stress values and hardening rates in good agreement with those observed experimentally. No saturation of the calculated or experimental flow stress was observed. Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94550 USA. Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. RP Hughes, DA (reprint author), Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94550 USA. NR 47 TC 408 Z9 422 U1 19 U2 117 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN 30 PY 2000 VL 48 IS 11 BP 2985 EP 3004 DI 10.1016/S1359-6454(00)00082-3 PG 20 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CJ UT WOS:000089196700021 ER PT J AU Xiao, CB King, DW Palmer, DA Wesolowski, DJ AF Xiao, CB King, DW Palmer, DA Wesolowski, DJ TI Study of enhancement effects in the chemiluminescence method for Cr(III) in the ng 1(-1) range SO ANALYTICA CHIMICA ACTA LA English DT Article DE chemiluminescence; luminol; Cr(III) determination ID LUMINOL CHEMI-LUMINESCENCE; HYDROGEN-PEROXIDE; AQUEOUS-SOLUTION; ION CHROMATOGRAPHY; HYDROXYL RADICALS; CYCLIC HYDRAZIDES; METAL-COMPLEXES; RATE CONSTANTS; MECHANISM; OXIDATION AB A procedure is developed for the determination of Cr(III) to 1 ng l(-1) (2 x 10(-11) mol l(-1)) in alkali samples by means of H2O2-luminol based chemiluminescence (CL). The significant improvement in sensitivity from the previous CL methods for this metal is achieved by a modified design of the flow cell, utilizing the carbonate and bromide enhancement effect, and adapting the experimental parameters that have not been explored previously, such as metal impurities and the initiation time after mixing carbonate and hydrogen peroxide. The importance of these experimental parameters and the carbonate enhancement effect are discussed based on knowledge of the mechanism of oxidation of luminol and decomposition of H2O2 in the presence of metal ions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37830 USA. Colby Coll, Dept Chem, Waterville, ME 04901 USA. RP Xiao, CB (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37830 USA. NR 34 TC 35 Z9 37 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD JUN 30 PY 2000 VL 415 IS 1-2 BP 209 EP 219 DI 10.1016/S0003-2670(00)00860-6 PG 11 WC Chemistry, Analytical SC Chemistry GA 318KV UT WOS:000087283900023 ER PT J AU Bedrov, D Smith, GD Sewell, TD AF Bedrov, D Smith, GD Sewell, TD TI Thermal conductivity of liquid octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) from molecular dynamics simulations SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FORCE-FIELD AB The thermal conductivity of liquid octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) has been determined from imposed heat flux non-equilibrium molecular dynamics (NEMD) simulations using a previously published quantum chemistry-based atomistic potential. The thermal conductivity was determined in the temperature domain 550 less than or equal to T less than or equal to 800 K, which corresponds approximately to the existence limits of the liquid phase of HMX at atmospheric pressure. The NEMD predictions, which comprise the first reported values for thermal conductivity of HMX liquid, were found to be consistent with measured values for crystalline HMX. The thermal conductivity of liquid HMX was found to exhibit a much weaker temperature dependence than the shear viscosity and self-diffusion coefficients. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem & Fuels Engn, Salt Lake City, UT 84112 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bedrov, D (reprint author), Univ Utah, Dept Mat Sci & Engn, 122 S Cent Campus Dr,Room 304, Salt Lake City, UT 84112 USA. NR 17 TC 39 Z9 44 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 30 PY 2000 VL 324 IS 1-3 BP 64 EP 68 DI 10.1016/S0009-2614(00)00559-5 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 330PF UT WOS:000087969900011 ER PT J AU Czarnecki, A Marciano, WJ AF Czarnecki, A Marciano, WJ TI Polarized Moller scattering asymmetries SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID ELECTROWEAK RADIATIVE-CORRECTIONS; HIGH-ENERGIES; COLLISIONS; PRECISION AB The utility of polarized electron beams for precision electroweak studies is described. Parity violating Mailer scattering asymmetries in e(-)e(-) --> e(-)e(-) are discussed. Effects of electroweak radiative corrections and the running sin(2) theta(W)(Q(2)) are reviewed. The sensitivity of E158 (a fixed target e(-)e(-) experiment at SLAG) and future e(-)e(-) collider studies to "new physics" is briefly outlined. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Czarnecki, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 16 TC 67 Z9 67 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2365 EP 2375 DI 10.1142/S0217751X00002430 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700004 ER PT J AU Rizzo, TG AF Rizzo, TG TI TeV gravity and Kaluza-Klein excitations in e(+)e(-) and e(-)e(-) collisions SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID LARGE EXTRA DIMENSIONS; COLLIDER SIGNATURES; CONSTRAINTS; HIERARCHY AB We review the capability of e(+)e(-) and e(-)e(-) colliders to detect the virtual exchange of Kaluza-Klein towers of gravitons within the large extra dimension scenario of Arkani-Hamed, Dimopoulos and Dvali and in the localized gravity model of Randall and Sundrum with non-factorisable geometry. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Rizzo, TG (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 20 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2405 EP 2414 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700008 ER PT J AU Grossman, Y AF Grossman, Y TI Experimental signatures of split fermions in extra dimensions SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB The smallness and hierarchy of the fermion parameters could be explained in theories with extra dimensions where doublets and singlets are localized at slightly separated points. Scattering cross sections for collisions of such fermions vanish exponentially at energies high enough to probe the separation distance. This is because the separation puts a lower bound on the attainable impact parameter in the collision. The NLC, and in particular the combination of the e(+)e(-) and e(-)e(-) modes, can probe this scenario, even if the inverse fermion separation is of order tens of TeVs. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Grossman, Y (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 12 TC 12 Z9 12 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2419 EP 2427 DI 10.1142/S0217751X00002492 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700010 ER PT J AU Tenenbaum, P AF Tenenbaum, P TI Next Linear Collider: Overview and e(-)e(-) option SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB A lepton collider capable of generating a luminosity of 5 x 10(33) to 1 x 10(34) at center-of-mass energies from 0.5 to 1.5 TeV would permit studies of fundamental interactions complementary to those planned at the Large Hadron Collider. Such energies would be more easily achieved for electrons at a linear collider than a conventional storage ring. We describe the Next Linear Collider (NLC), a proposed linear collider which utilizes room-temperature RF systems operating at 11.4 GHz to achieve the desired energies and room-temperature electromagnets and permanent magnets to achive the extremely small beam sizes required to meet the specified luminosity goal. The NLC design has been optimized to permit electron-electron collisions as well as electron-positron collisions. We discuss a few of the detailed technical challenges which are posed by electron-electron collisions in the NLC parameter regime. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Tenenbaum, P (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2461 EP 2468 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700014 ER PT J AU Gronberg, J AF Gronberg, J TI Charged particle and neutron backgrounds in an e(-)e(-) interaction region at the NLC SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB We compare the detector background situation in an e(-)e(-) interaction region at the NLC with previous studies done of the NLC e(+)e(-) interaction region. We note from previous studies that the dominant source of detector backgrounds are the beamstrahlung pairs. Since these scale with luminosity, the reduction in luminosity in e(-)e(-) collisions leads to a reduction in detector backgrounds compared to the e(+)e(-) situation. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gronberg, J (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2469 EP 2475 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700015 ER PT J AU Larsen, RS AF Larsen, RS TI e(-)e(-) switchover in the NLC linac SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB This paper discusses various options for reconfiguring magnets and power sources to convert the NLC to e(-)e(-) operation. Operational practicality of various scenarios and likely cost impacts lead to a conclusion that potential e(-)e(-) options must be planned into the initial engineering design. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Larsen, RS (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2477 EP 2483 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700016 ER PT J AU Thompson, KA AF Thompson, KA TI Optimization of NLC luminosity for e(-)e(-) running SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB We examine the optimization of the NLC for e(-)e(-) running. The dependence of luminosity on the interaction point beta functions beta(x), beta(y) emittances epsilon(x), epsilon(y), bunch charge N, and bunch length a, are very different for e(+)e(-) and e(-)e(-) because disruption reduces the luminosity in e(-)e(-) rather than increasing it as in e(+)e(-). We examine how much luminosity may be regained in e(-)e(-) by varying these parameters away from optimized Aat beam e(+)e(-) values. The results are compared with round beam e(-)e(-) designs considered in an earlier paper.(1) C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Thompson, KA (reprint author), Stanford Linear Accelerator Ctr, POB 4349, Stanford, CA 94309 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2485 EP 2493 DI 10.1142/S0217751X00002561 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700017 ER PT J AU Subashiev, AV Clendenin, JE AF Subashiev, AV Clendenin, JE TI Polarized electron beams with P >= 90%, will it be possible? SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID SPIN POLARIZATION; GAAS LAYER; PHOTOELECTRONS; PHOTOEMISSION; SCATTERING AB Recent results of electron spin depolarization studies in electron emission from the photocathode semiconductor structures are reviewed. The main mechanisms of electronic depolarization being well understood, a considerable improvement of polarization is expected to be achieved in new superlattice structures, which can be designed to have less depolarization at excitation and in extraction to the surface. Additional polarization growth is expected to be obtained by lowering the operating temperature of the source. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Subashiev, AV (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 25 TC 8 Z9 8 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 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2519 EP 2527 DI 10.1142/S0217751X00002595 PG 9 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700020 ER PT J AU Woods, M AF Woods, M TI Polarimetry at a future linear collider - How precise? SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB At a future linear collider, a polarized electron beam will play an important role in interpreting new physics signals. Backgrounds to a new physics reaction can be reduced by choice of the electron polarization state. The origin of a new physics reaction can be clarified by measuring its polarization-dependence. This paper examines some options for polarimetry with an emphasis on physics issues that motivate how precise the polarization determination needs to be. In addition to Compton polarimetry, the possibility of using Standard Model asymmetries, such as the asymmetry in forward W-pairs, is considered as a possible polarimeter. Both e(+)e(-) and e(-)e(-) collider modes are considered. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Woods, M (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2529 EP 2536 DI 10.1142/S0217751X00002600 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700021 ER PT J AU Weideman, AW AF Weideman, AW TI Depolarization in e(+)e(-) and e(-)e(-) collisions SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA AB I make some comments on the depolarization in beam-beam interactions at electron-electron and electron-positron colliders and present some results from a CAIN study of this effect. C1 Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Weideman, AW (reprint author), SLAC, MS 94,POB 4349, Stanford, CA 94309 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2537 EP 2542 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700022 ER PT J AU Spencer, JE AF Spencer, JE TI Limitations imposed by beam-beam effects and their remedies - II SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID BEAMSTRAHLUNG; LUMINOSITY; COLLIDER AB Effects that limit the luminosities of a general purpose linear collider (GLC) capable of (e) over bar(+/-)(e) over bar(+/-), <(gamma)over bar>(e) over bar(+/-) and <(gamma)over bar><(gamma)over bar> channels are discussed together with mitigations. Previous results are extended to understand the differences between channels to maximize the generalized luminosity. A standard NLC configuration at root s(ee) = 0.5 TeV is used for comparison. Without charge compensation or bunch shaping, such hat beam configurations (aspect ratios R*much greater than 1) imply major disadvantages for e(-)e(-) due to the strong disruption (D) and small, longitudinal f-numbers (f(l)#=beta(y)*/sigma(z)) that are imposed. Previous round and hat beam configurations are studied as functions of D(or f(b)#), f(l)# and the constraints Delta(B), N-gamma and Y. Round beams with decreased disruptions and larger f(l)-stops are preferred with tensor beams, charge compensation or other bunch manipulation schemes. A low energy, high luminosity prototype is again proposed based on the possible physics. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Spencer, JE (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2543 EP 2554 PG 12 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700023 ER PT J AU Cheshkov, S Tajima, T AF Cheshkov, S Tajima, T TI Depolarization and luminosity issues in a high energy linear collider SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID LASER AB In the next energy frontier of an electron-positron (electron-electron) linear collider its demand of both extreme high energy and high luminosity leads to a high production of W+ W- (W- particles). In order to delineate processes of interest, it is advantageous to polarize the electron and positron beams, as this tends to suppress the above known processes and thus heightens the sensitivity to the sought-after processes. We investigate the possible depolarization of the electron (positron) beams in the acceleration stages as well as in the collision point. We take the example of the laser wakefield accelerator design at 5 TeV center of mass energy of colliding beams. We find that in this design the spin depolarization due to the stage jitter noise is certainly negligible, and the depolarization due to the self-generated fields at the collision point is still tolerable. We also consider several lower energy scenarios as they might be possible to achieve in a single beam driven acceleration stage. C1 Univ Texas, Austin, TX 78712 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Cheshkov, S (reprint author), Univ Texas, Austin, TX 78712 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2555 EP 2564 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700024 ER PT J AU Parsa, Z AF Parsa, Z TI Future lepton colliders and laser acceleration SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CA ID ELECTRONS; FIELD AB Future high energy colliders along with their physics potential, and relationship to new laser technology are discussed. Experimental approaches and requirements for "New Physics" exploration are also described. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Parsa, Z (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 36 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2565 EP 2575 DI 10.1142/S0217751X00002649 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700025 ER PT J AU Ohgaki, T AF Ohgaki, T TI Simulation of laser-Compton cooling of electron beams SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID LINEAR COLLIDERS AB We study a method of laser-Compton cooling of electron beams. Using a Monte Carlo code, we evaluate the effects of the laser-electron interaction for transverse cooling. The optics with and without chromatic correction for the cooling are examined. The laser-Compton cooling for JLC/NLC at E-0 = 2 GeV is considered. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ohgaki, T (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 14 TC 3 Z9 3 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 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2587 EP 2597 DI 10.1142/S0217751X00002662 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700027 ER PT J AU Ohgaki, T AF Ohgaki, T TI Precision mass determination of the Higgs boson at photon-photon colliders SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID GAMMA-GAMMA COLLISIONS; HEAVY-QUARK PRODUCTION; LINEAR COLLIDER; PHYSICS; WIDTH AB We demonstrate a measurement of the Higgs boson mass by the method of energy scanning at photon-photon colliders, using the high energy edge of the photon spectrum. With an integrated luminosity of 50 fb(-1) it is possible to measure the standard model Higgs mass to within 110 MeV in photon-photon collisions for m(h) = 100 GeV. As for the total width of the Higgs boson, the statistical error Delta Gamma(h)/Gamma(h) SM = 0.06 is expected for m(h) = 100 GeV, if both Gamma(h --> gamma gamma) and Gamma(h --> b (b) over bar) are fixed at the predicted standard model value. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ohgaki, T (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 20 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2605 EP 2611 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700029 ER PT J AU Davoudiasl, H AF Davoudiasl, H TI Signatures of extra dimensions at e gamma and gamma gamma colliders SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article; Proceedings Paper CT 3rd Electron-Electron Linear Collider Workshop CY DEC 10-12, 1999 CL SANTA CRUZ, CALIFORNIA ID SCALE QUANTUM-GRAVITY; ART. AB We study the processes gamma e --> gamma e and gamma gamma --> gamma gamma, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M-S similar to 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e gamma an gamma gamma options, deviate from the predictions of the Standard Model significantly. Our results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV less than or similar to M-S less than or similar to 10 TeV, making e gamma an gamma gamma colliders important tools for probing WSQG. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Davoudiasl, H (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 2000 VL 15 IS 16 BP 2613 EP 2622 DI 10.1142/S0217751X00002698 PG 10 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 335LV UT WOS:000088245700030 ER PT J AU Caffrey, M Braddock, DT Louis, JM Abu-Asab, MA Kingma, D Liotta, L Tsokos, M Tresser, N Pannell, LK Watts, N Steven, AC Simon, MN Stahl, SJ Wingfield, PT Clore, GM AF Caffrey, M Braddock, DT Louis, JM Abu-Asab, MA Kingma, D Liotta, L Tsokos, M Tresser, N Pannell, LK Watts, N Steven, AC Simon, MN Stahl, SJ Wingfield, PT Clore, GM TI Biophysical characterization of gp41 aggregates suggests a model for the molecular mechanism of HIV-associated neurological damage and dementia SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; IMMUNE-DEFICIENCY SYNDROME; NITRIC-OXIDE SYNTHASE; NECROSIS-FACTOR-ALPHA; AIDS DEMENTIA; NERVOUS-SYSTEM; SIV GP41; SPONGIFORM ENCEPHALOPATHY; CLINICAL-FEATURES; CRYSTAL-STRUCTURE AB In human immunodeficiency virus (HIV)-infected individuals, the level of the HIV envelope protein gp41 in brain tissue is correlated with neurological damage and dementia, In this paper we show by biochemical methods and electron microscopy that the extracellular ectodomain of purified HIV and simian immunodeficiency virus gp41 (e-gp41) forms a mixture of soluble high molecular weight aggregate and native trimer at physiological pH. The e-gp41 aggregate is shown to be largely alpha-helical and relatively stable to denaturants, The high molecular weight form of e-gp41 is variable in size ranging from 7 to 70 trimers, which associate by interactions at the interior of the aggregate involving the loop that connects the N- and C-terminal helices of the e-gp41 core. The trimers are predominantly arranged with their long axes oriented radially, and the width of the high molecular weight aggregate corresponds to the length of two e-gp41 trimers (similar to 200 Angstrom). Using both light and electron microscopy combined with immunohistochemistry we show that HIV gp41 accumulates as an extracellular aggregate in the brains of HIV-infected patients diagnosed with dementia, We postulate that the high molecular weight aggregates of e-gp41 are responsible for HIV-associated neurological damage and dementia, consistent with known mechanisms of encephalopathy. C1 NIDDK, Chem Phys Lab, NIH, Bethesda, MD 20892 USA. NCI, Pathol Lab, NIH, Bethesda, MD 20892 USA. NINDS, Neuroimmunol Branch, NIH, Bethesda, MD 20892 USA. NIDDK, Bioorgan Chem Lab, NIH, Bethesda, MD 20892 USA. NIAMS, Struct Biol Res Lab, NIH, Bethesda, MD 20892 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NIAMS, Prot Express Lab, NIH, Bethesda, MD 20892 USA. RP Clore, GM (reprint author), NIDDK, Chem Phys Lab, NIH, Bldg 5,Rm B1-301, Bethesda, MD 20892 USA. RI Clore, G. Marius/A-3511-2008; OI Clore, G. Marius/0000-0003-3809-1027; Abu-Asab, Mones/0000-0002-4047-1232 NR 52 TC 24 Z9 24 U1 0 U2 7 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JUN 30 PY 2000 VL 275 IS 26 BP 19877 EP 19882 DI 10.1074/jbc.M001036200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 330AU UT WOS:000087941300061 PM 10747981 ER PT J AU Hall, BL Lachmar, TE Dupont, RR AF Hall, BL Lachmar, TE Dupont, RR TI Field monitoring and performance evaluation of an in situ air sparging system at a gasoline-contaminated site SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE groundwater; contamination; monitoring; remediation ID INJECTED HELIUM; SOIL; FLOW; BIODEGRADATION; HYDROCARBONS; TOMOGRAPHY; OREGON; RATES AB In situ air sparging (IAS) has been used since the mid-1980s, but few carefully designed field studies have been performed to evaluate its effectiveness. In this study, 27 discrete monitoring points (MPs) were installed at a gasoline-contaminated site to investigate the efficacy of IAS. Each MP was instrumented with a pressure transducer and a Technalithics dissolved oxygen (DO) probe, and located so they could be used to characterize subsurface changes in total head and DO with depth, distance and orientation around a central injection well. Because the blower over-heated and automatically shut down after approximately 30 min and short-circuiting of air into two MPs occurred within 2 min, the study was designed as three sets of three 30-min trials. Longer trials would not have yielded different nor more insightful results. A volume of soil was not oxygenated during any injection. Instead, air traveled directly to at least four of seven different MPs during eight of the nine trials, probably as a result of an air bubble forming beneath a confining layer. The order of air arrival at the MPs varied during the first few trials, but once a preferential pathway was established, it did not collapse between trials and provided the shortest distance to the vadose zone during subsequent trials. Oxygen uptake rates estimated for MPs that received air during any trial exceeded the consumption rates of the Technalithics DO probes, and indicate that the probes could be used for estimating oxygen transfer during system operation or for oxygen uptake measurements during shut-down tests. The data from the monitoring system indicate that IAS is infeasible for remediation of soil and,groundwater at this site due to its low horizontal hydraulic conductivity. Similar behavior is anticipated when IAS is applied at other sites with low hydraulic conductivity materials. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Battelle Pacific NW Natl Lab, Richland, WA 99352 USA. Utah State Univ, Dept Geol, Logan, UT 84322 USA. Utah State Univ, Utah Water Res Lab, Logan, UT 84322 USA. RP Hall, BL (reprint author), Battelle Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 36 TC 10 Z9 12 U1 2 U2 5 PU ASPEN LAW & BUSINESS DIV ASPEN PUBLISHERS INC PI NEW YORK PA 1185 AVENUE OF THE AMERICAS, NEW YORK, NY 10036 USA SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD JUN 30 PY 2000 VL 74 IS 3 BP 165 EP 186 DI 10.1016/S0304-3894(99)00189-2 PG 22 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 319KN UT WOS:000087340200003 PM 10794912 ER PT J AU Ogunsola, OM AF Ogunsola, OM TI Decomposition of isoquinoline and quinoline by supercritical water SO JOURNAL OF HAZARDOUS MATERIALS LA English DT Article DE supercritcal water; quinoline; isoquinoline; heterocyclic compounds ID EXTRACTION AB The ability of supercritical water (SCW) to decompose heterocyclic compounds (quinoline and isoquinoline) has been explored in this study. The results obtained suggest that water acts as a chemical reagent above its critical point (374 degrees C and 22.1 MPa). Significant proportions of isoquinoline and quinoline were removed during the reaction with SCW. The response of these compounds to pyrolysis was also compared with their reaction with SCW. Both compounds were relatively more reactive in the presence of SCW than during pyrolysis. Because of the different positions of N atom in the two compounds, they reacted with SCW differently. Breaking of C-N bonds during SCW reaction was by hydrogenation and hydrocracking, while pyrolysis was due to thermocracking mainly. (C) 2000 Elsevier Science B.V. All rights reserved. C1 US DOE, Natl Energy TEchnol Lab, MLSTP A04, Morgantown, WV 26507 USA. RP Ogunsola, OM (reprint author), POB 4010, Morgantown, WV 26504 USA. NR 10 TC 24 Z9 30 U1 1 U2 16 PU ASPEN LAW & BUSINESS DIV ASPEN PUBLISHERS INC PI NEW YORK PA 1185 AVENUE OF THE AMERICAS, NEW YORK, NY 10036 USA SN 0304-3894 J9 J HAZARD MATER JI J. Hazard. Mater. PD JUN 30 PY 2000 VL 74 IS 3 BP 187 EP 195 DI 10.1016/S0304-3894(00)00162-X PG 9 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 319KN UT WOS:000087340200004 PM 10794913 ER PT J AU Reinsch, VE Greenberg, AR Kelley, SS Peterson, R Bond, LJ AF Reinsch, VE Greenberg, AR Kelley, SS Peterson, R Bond, LJ TI A new technique for the simultaneous, real-time measurement of membrane compaction and performance during exposure to high-pressure gas SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE gas separations; microporous and porous membranes; compaction; ultrasonic measurement ID DOMAIN REFLECTOMETRY; CELLULOSE-ACETATE; BEHAVIOR; TRANSPORT AB Membrane compaction accounts for a major source of the flux decline that occurs during gas separation using polymeric membranes. Previous membrane compaction studies have been limited by the inability to simultaneously measure membrane performance. In this study, we report the development of a technique based on ultrasonic time-domain reflectometry (TDR) that enables the simultaneous, real-time, noninvasive measurement of membrane compaction and performance during gas separation. In order to demonstrate the utility of the technique, representative data are presented for membrane compaction and pressure-normalized flux of a commercial asymmetric cellulose acetate (CA) gas separation membrane. Data obtained during the recovery cycle, i.e., after the pressure difference across the membrane is removed, are also described. These preliminary results indicate that the ultrasonic TDR technique can be successfully applied to quantify the effect of high-pressure gases on polymeric films and asymmetric membranes. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO USA. Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. RP Greenberg, AR (reprint author), Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. NR 24 TC 41 Z9 44 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD JUN 30 PY 2000 VL 171 IS 2 BP 217 EP 228 DI 10.1016/S0376-7388(00)00307-0 PG 12 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 317JT UT WOS:000087222800006 ER PT J AU Wang, LM Wang, SX Ewing, RC Meldrum, A Birtcher, RC Provencio, PN Weber, WJ Matzke, H AF Wang, LM Wang, SX Ewing, RC Meldrum, A Birtcher, RC Provencio, PN Weber, WJ Matzke, H TI Irradiation-induced nanostructures SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT International-Union-of-Materials-Research-Societies International Conference on Advanced Materials (IUMRS-ICAM 99) CY JUN 13-18, 1999 CL BEIJING, PEOPLES R CHINA SP Int Union Mat Res Soc DE nanocrystalline structures; irradiation-induced; recrystallisation ID BEAM-INDUCED AMORPHIZATION; TRANSMISSION ELECTRON-MICROSCOPY; MECHANICAL-PROPERTIES; CERAMIC MATERIALS; ION; CRYSTALLINE; NANOCRYSTALS; TEMPERATURE; PHASE; IMPLANTATION AB This paper summarizes the results of our studies on the irradiation-induced formation of nanostructures, where the injected interstitials from the source of irradiation are not major components of the nanophase. This phenomena has been observed by in situ transmission electron microscopy (TEM) in a number of intermetallic compounds and ceramics during high-energy electron or ion irradiations when the ions completely penetrate through the specimen. Beginning with single crystals, electron or ion irradiation in a certain temperature range may result in nanostructures composed of amorphous domains and nanocrystals with either the original composition and crystal structure or new nanophases formed by decomposition of the target material. The phenomenon has also been observed in natural materials that have suffered irradiation from the decay of constituent radioactive elements and in nuclear reactor fuels that have been irradiated by fission neutrons and other fission products. The mechanisms involved in the process of this nanophase formation are discussed in terms of the evolution of displacement cascades, radiation-induced defect accumulation, radiation-induced segregation and phase decomposition, as well as the competition between irradiation-induced amorphization and recrystallization. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Pacific NW Natl Lab, Dept Mat Sci, Richland, WA 99352 USA. European Commiss Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. RP Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. EM lmwang@umich.edu RI Weber, William/A-4177-2008 OI Weber, William/0000-0002-9017-7365 NR 36 TC 45 Z9 48 U1 1 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 30 PY 2000 VL 286 IS 1 BP 72 EP 80 DI 10.1016/S0921-5093(00)00677-8 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 347EP UT WOS:000088914700011 ER PT J AU Rasmussen, LJ Rasmussen, M Lee, BI Rasmussen, AK Wilson, DM Nielsen, FC Bisgaard, HC AF Rasmussen, LJ Rasmussen, M Lee, BI Rasmussen, AK Wilson, DM Nielsen, FC Bisgaard, HC TI Identification of factors interacting with hMSH2 in the fetal liver utilizing the yeast two-hybrid system - In vivo interaction through the C-terminal domains of hEXO1 and hMSH2 and comparative expression analysis SO MUTATION RESEARCH-DNA REPAIR LA English DT Article DE mismatch repair; hMSH2; hEXO1; two-hybrid; cancer ID DNA MISMATCH REPAIR; SACCHAROMYCES-CEREVISIAE EXO1; NUCLEOTIDE EXCISION-REPAIR; EXONUCLEASE-I; GENE; MICE; PROTEIN; RECOMBINATION; MSH2; REPLICATION AB Mutations in DNA mismatch repair (MMR) genes have been shown to segregate with Hereditary Nonpolyposis Colorectal Cancer (HNPCC), However, because many HNPCC families fail to display mutations in known MMR genes, we argued that changes in other components of the MMR pathway may be responsible. The increasing number of proteins reported to interact in the MMR pathway suggests that larger complexes are formed, the composition of which may differ among cell types and tissues. In an attempt to identify tissue-specific MMR-associated factors, we employed the yeast two-hybrid system, using the human hMSH2 as bait and a human fetal liver library as prey. We demonstrate that hMSH2 interacts with a human 5'-3' exonuclease 1 (hEXO1/HEX1) and that this interaction is mediated through their C-terminal domains. The hMSH6 protein does not interact with hEXO1 in the two-hybrid system. Dot-blot analysis of multiple tissue RNA revealed that hMSH2 and hEXO1 are coexpressed at high levels in fetal liver as well as in adult testis and thymus. Northern blot analysis also revealed that hEXO1/HEX1 is highly expressed in several liver cancer cell lines as well as in colon and pancreas adenocarcinomas, but not in the corresponding non-neoplastic tissue. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Roskilde Univ Ctr, Dept Chem & Life Sci, DK-4000 Roskilde, Denmark. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. Rigshosp, Dept Clin Biochem, DK-2100 Copenhagen, Denmark. RP Rasmussen, LJ (reprint author), Roskilde Univ Ctr, Dept Chem & Life Sci, DK-4000 Roskilde, Denmark. NR 36 TC 40 Z9 41 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8777 J9 MUTAT RES-DNA REPAIR JI Mutat. Res.-DNA Repair PD JUN 30 PY 2000 VL 460 IS 1 BP 41 EP 52 DI 10.1016/S0921-8777(00)00012-4 PG 12 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 330DN UT WOS:000087947700004 PM 10856833 ER PT J AU Game, JC AF Game, JC TI The Saccharomyces repair genes at the end of the century SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Review ID DOUBLE-STRAND BREAKS; NUCLEOTIDE EXCISION-REPAIR; ESCHERICHIA-COLI DINB; GAMMA-RAY MUTAGENESIS; DNA MISMATCH REPAIR; MEIOTIC RECOMBINATION; MITOTIC RECOMBINATION; HOMOLOGOUS RECOMBINATION; XERODERMA-PIGMENTOSUM; YEAST HOMOLOG C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Game, JC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI huang, hongqi/N-1473-2014 NR 126 TC 55 Z9 55 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD JUN 30 PY 2000 VL 451 IS 1-2 SI SI BP 277 EP 293 DI 10.1016/S0027-5107(00)00055-5 PG 17 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 343FR UT WOS:000088691500018 PM 10915878 ER PT J AU Frazer, KA Loots, G Rubin, EM AF Frazer, KA Loots, G Rubin, EM TI Database searches for binding sites - Response SO SCIENCE LA English DT Letter C1 Affymetrix, Santa Clara, CA 95051 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Frazer, KA (reprint author), Affymetrix, Santa Clara, CA 95051 USA. OI Loots, Gabriela/0000-0001-9546-5561 NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 30 PY 2000 VL 288 IS 5475 BP 2319 EP 2319 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 329NP UT WOS:000087913400018 ER PT J AU Labouriau, A Ott, KC Rau, J Earl, WL AF Labouriau, A Ott, KC Rau, J Earl, WL TI Titanium-substituted zeolites and molecular sieves investigated by NMR SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PARAMAGNETIC SHIFT PROBES; TI-BETA CATALYST; P-31 NMR; SOLID-STATE; MAS NMR; ISOMORPHOUS SUBSTITUTION; PHOSPHORUS; OXIDATION; COBALT; ALKENES AB Si-29 MAS NMR spectra for TS-1, TiMCM-41, and Ti-beta, and P-31 MAS NMR spectrum for TiAlPO4-11 have been obtained before and after CO treatment that reduces Ti4+ to Ti3+. We have used the large paramagnetic influence of Ti3+ on the NMR spectrum to obtain information about the location of titanium in metal-substituted molecular sieves. The unpaired electrons were found to cause a large reduction in the intensity of the NMR signal of the paramagnetic samples when compared to their diamagnetic counterparts. The intensity loss seems to be proportional to the number of paramagnetic titanium ions present in the sample. The data suggest that the Fermi contact interaction is the main mechanism responsible for the large reduction of the NMR signal, whereas dipolar interactions were found to be negligible. Our results strongly indicate that most of the titanium atoms are sitting at a framework site for the materials investigated in the present contribution. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Labouriau, A (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Mail Stop J514, Los Alamos, NM 87545 USA. NR 33 TC 7 Z9 7 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 29 PY 2000 VL 104 IS 25 BP 5890 EP 5896 DI 10.1021/jp9936695 PG 7 WC Chemistry, Physical SC Chemistry GA 330LH UT WOS:000087963200006 ER PT J AU Van Patten, PG Shreve, AP Donohoe, RJ AF Van Patten, PG Shreve, AP Donohoe, RJ TI Structural and photophysical properties of a water-soluble porphyrin associated with polycations in solution and electrostatically-assembled ultrathin films SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID EXCITATION-ENERGY TRANSPORT; BY-LAYER ADSORPTION; THIN-FILMS; MOLECULAR FILMS; GLUCOSE-OXIDASE; MULTILAYER HETEROSTRUCTURES; POLY(PHENYLENE VINYLENE); METAL-COMPLEXES; FLUORESCENCE; LUMINESCENCE AB A water-soluble porphyrin, meso-tetra(4-sulfonatophenyl)porphyrin (TSPP), has been associated with two different polycations, poly(diallyldimethylammonium chloride) (PDDA) and poly(ethyleneimine) (PEI), to investigate the effects of polymer binding upon the TSPP structure and excited-state dynamics both in solution and in ultrathin (similar to 10-30 Angstrom) films deposited on glass slides by electrostatic assembly. Association of the porphyrin with PEI intrinsically quenches the singlet state dynamics of TSPP, both in solution and in films, while quenching is observed upon association with PDDA only for high concentrations of porphyrins or in films where TSPP aggregates are observed. For PDDA:TSPP films without significant aggregate content, the fluorescence decay time (tau(1/e) similar to 5-6 ns) approaches that observed for monomeric or polymer-bound porphyrins in dilute solution (tau(1/e) = 10.2 and 11.3 ns, respectively). However, rapid (< 1 ns) deactivation of the singlet states can be observed whenever appreciable aggregates are present, indicating that efficient energy transfer between the porphyrins leads to quenching at aggregate sites. A number of phenomenological observations regarding the presence of aggregates are presented. In particular, the extent of aggregation in the films depends on the concentration, pH, and temperature of the deposition solutions and also the age of the films, with older samples exhibiting reduced effects due to aggregation. C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Michelson Resource, Los Alamos, NM 87545 USA. RP Donohoe, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, Michelson Resource, MS J586, Los Alamos, NM 87545 USA. NR 39 TC 42 Z9 43 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 29 PY 2000 VL 104 IS 25 BP 5986 EP 5992 DI 10.1021/jp000692d PG 7 WC Chemistry, Physical SC Chemistry GA 330LH UT WOS:000087963200017 ER PT J AU Woodward, J Orr, M Cordray, K Greenbaum, E AF Woodward, J Orr, M Cordray, K Greenbaum, E TI Biotechnology - Enzymatic production of biohydrogen SO NATURE LA English DT Article ID HYDROGEN-PRODUCTION C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Woodward, J (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. EM woodwardj@ornl.gov NR 13 TC 162 Z9 174 U1 5 U2 39 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD JUN 29 PY 2000 VL 405 IS 6790 BP 1014 EP 1015 DI 10.1038/35016633 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 328VN UT WOS:000087871700032 PM 10890432 ER PT J AU Chekanov, SV AF Chekanov, SV TI Soft-gluon angular screening in heavy-quark fragmentation SO PHYSICS LETTERS B LA English DT Article ID MONTE-CARLO GENERATOR; COLLISIONS; SIMULATION AB A method to measure the suppression of soft-gluon radiation by a heavy quark ('dead cone') is discussed. We analyse this QCD phenomenon in the framework of the HERA experiment using Monte Carlo simulations. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, HEP Div, Argonne, IL 60439 USA. RP Chekanov, SV (reprint author), Argonne Natl Lab, HEP Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 17 TC 1 Z9 1 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 JUN 29 PY 2000 VL 484 IS 1-2 BP 51 EP 57 DI 10.1016/S0370-2693(00)00619-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 330KB UT WOS:000087960300007 ER PT J AU Annunziata, O Paduano, L Pearlstein, AJ Miller, DG Albright, JG AF Annunziata, O Paduano, L Pearlstein, AJ Miller, DG Albright, JG TI Extraction of thermodynamic data from ternary diffusion coefficients. Use of precision diffusion measurements for aqueous lysozyme chloride-NaCl at 25 degrees C to determine the change of lysozyme chloride chemical potential with increasing NaCl concentration well into the supersaturated region SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT Annual Meeting of the American-Crystallographic-Association CY MAY 22-27, 1999 CL BUFFALO, NEW YORK SP Amer Crystallograph Assoc ID MULTICOMPONENT DIFFUSION; INCLUSION-COMPOUNDS; PROTEIN SOLUTIONS; CRYSTAL-GROWTH; RAYLEIGH; SYSTEMS; WATER; SALTS; GOUY AB For ternary systems, we present a method for using measured values of the four ternary diffusion coefficients and the Onsager reciprocal relations to extract derivatives of solute chemical potentials with respect to solute molar concentrations. The method is applicable to systems in which the molar concentration of one solute is very small compared to that of the other, and also small enough that an inverse concentration dependence dominates certain activity coefficient derivatives. These conditions apply to a large number of aqueous systems involving macromolecules of biological interest. Unlike other techniques, the present method can be used to study undersaturated and supersaturated solutions. The approach is illustrated for the lysozyme chloride NaCl-H2O system at 25 degrees C, using data reported here for pH 6.0 at 0.60 mM (8.6 mg/mL) lysozyme chloride and 0.25, 0.50, 0.65, 0.90, and 1.30 M (1.4, 2.8, 3.7, 5.1, and 7.2 wt %) NaCl concentrations, and our earlier data for pH 4.5 at the same concentrations. We use these solute chemical potential derivatives to compute the protein cation charge approximately, and to construct a function approximating the derivative of the lysozyme chloride chemical potential with respect to NaCl concentration, which we integrate over a range of NaCl concentrations. This provides the change of the lysozyme chloride chemical potential with NaCl concentration well into the supersaturated region, and hence provides the driving force for nucleation and crystal growth of lysozyme chloride as a function of the extent of supersaturation. We also compute the diffusion Onsager coefficients (L-ij)(0) for each composition at pH 4.5 and 6.0. Binary diffusion coefficients of aqueous lysozyme chloride at 0.89 mM (12.7 mg/mL) for pH values from 4.0 to 6.0, and at pH 6.0 for concentrations from 0.25 to 1.95 mM (3.6-27.9 mg/mL) are also reported. C1 Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. Univ Naples, Dipartimento Chim, I-80134 Naples, Italy. RP Albright, JG (reprint author), Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. EM albright@gamma.is.tcu.edu NR 51 TC 54 Z9 54 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 28 PY 2000 VL 122 IS 25 BP 5916 EP 5928 DI 10.1021/ja993871l PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 332CB UT WOS:000088054900002 ER PT J AU Stultz, LK Huynh, MHV Binstead, RA Curry, M Meyer, TJ AF Stultz, LK Huynh, MHV Binstead, RA Curry, M Meyer, TJ TI Allylic oxidation of cyclohexene and indene by cis-[Ru-IV(bpy)(2)(py)(O)](2+) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COUPLED ELECTRON-TRANSFER; ACETONITRILE SOLUTION; MOLECULAR-OXYGEN; OXO COMPLEX; EPOXIDATION; ALKENES; CYTOCHROME-P-450; RUTHENIUM(IV); ACTIVATION; ALCOHOLS AB The kinetics of oxidation of cyclohexene, cyclohexen-1-ol, and indene by cis-[Ru-IV(bpy)(2)(py)(O)](2+) (bpy = 2,2'-bipyridine and py = pyridine) have been studied in CH3CN. The reactions are first-order in both Ru-IV=O2+ and substrate in an initial, rapid stage in which Ru(IV) is reduced to Ru(III). The rate constants are 0.16 +/- 0.01, 1.10 +/- 0.02, and 5.74 +/- 0.74 M-1 s(-1) for cyclohexene, cyclohexen-1-ol, and indene, respectively. A k(alpha,alpha'-H-4)/k(alpha,alpha'-D-4) kinetic isotope effect of 21 +/- 1 is observed for the oxidation of cyclohexene. At a 2:1 ratio of Ru-IV=O2+ to olefin, the reactions of Ru-IV=O2+ with either cyclohexene or indene give Ru-II-NCCH32+ and the 4-electron ketone products, 2-cyclohexen-1-one and indenone, respectively, as identified by GC-MS. As the ratio of cyclohexene to Ru-IV=O2+ is increased, cyclohexen-1-ol becomes an increasingly competitive product. The mechanisms of these reactions are highly complex. They involve two distinct stages and the formation and subsequent reactions of Ru-III-substrate bound intermediates. C1 Univ N Carolina, Venable & Kenan Labs, Dept Chem, Chapel Hill, NC 27599 USA. RP Meyer, TJ (reprint author), Univ Calif Los Alamos Natl Lab, ALDSSR MS A127, Los Alamos, NM 87545 USA. NR 47 TC 56 Z9 56 U1 4 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 28 PY 2000 VL 122 IS 25 BP 5984 EP 5996 DI 10.1021/ja991722x PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 332CB UT WOS:000088054900009 ER PT J AU Long, CN Ackerman, TP AF Long, CN Ackerman, TP TI Identification of clear skies from broadband pyranometer measurements and calculation of downwelling shortwave cloud effects SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIATION AB We present an automated method to identify periods of clear skies for a 160 degrees field of view using only 1-min measurements of surface downwelling total and diffuse shortwave irradiance. The clear-sky detection method is verified using Whole Sky Imager and lidar data, observer reports, and model comparisons. Identified clear-ski irradiance measurements are then used to empirically fit clear-sky irradiance functions using the cosine of the solar zenith angle as the independent variable. These fitted functions produce continuous estimates of clear-sky total, diffuse, and direct component shortwave irradiances. While this method ignores diurnal changes in such variables as column water vapor and aerosol amounts and changes between clear-sky days, it is shown that the resultant clear-sky irradiance estimates have RMS uncertainty comparable to the uncertainty of the measuring instruments themselves. The estimated clear-sky irradiances are used to estimate the effect of clouds on the downwelling shortwave irradiance as a difference between the measured and clear-shy amounts. We show that the cloud effect calculations from this method appear to decrease the uncertainty due to systematic pyranometer offsets and cosine response errors. Thus any data set that includes downwelling diffuse and total shortwave measurements can be processed to identify clearsky periods and produce estimates of clear-sky irradiance and cloud effects. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Pacific NW Natl Lab, Environm & Hlth Sci Div, Atmospheric Radiat Measurement Program, POB 999,902 Battelle Blvd, Richland, WA 99352 USA. EM chuck.long@pnl.gov NR 17 TC 249 Z9 253 U1 2 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 2000 VL 105 IS D12 BP 15609 EP 15626 DI 10.1029/2000JD900077 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 328HP UT WOS:000087844900034 ER PT J AU Jacobson, AR Cummins, KL Carter, M Klingner, P Roussel-Dupre, D Knox, SO AF Jacobson, AR Cummins, KL Carter, M Klingner, P Roussel-Dupre, D Knox, SO TI FORTE radio-frequency observations of lightning strokes detected hy the National Lightning Detection Network SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TRANSIONOSPHERIC PULSE PAIRS; EASTERN NEW-YORK; PERFORMANCE EVALUATION; INTERFEROMETRY; PHENOMENOLOGY; RADIATION; PICTURES; FLASHES AB This work compares simultaneous observations of lightning from two complementary systems. FORTE is a low-Earth-orbit satellite carrying radiowave and optical instruments for the study of lightning. The radio receivers aboard FORTE observe very high frequency (VHF) emissions from the air-breakdown process preceding (and sometimes accompanying) a lightning current. The National Lightning Detection Network (NLDN) is a ground-based array of sensors in the contiguous United States observing the low-frequency (LF) and very low frequency (VLF) radiation from vertical currents. Prior to the launch of FORTE in 1997, essentially no work had been done on the statistical correlations between (1) ground-based LF/VLF and (2) spaced-based VHF remote sensing of lightning. During a 6-month campaign in April-September 1998, FORTE took most of its triggered VHF data over and near the contiguous United States, and NLDN data were specially postprocessed in a loosened-criterion mode providing enhanced detection range beyond the coastline and borders of the array itself. The time history of reported events from the two systems was compared, and event pairs (each pair containing one event from FORTE, the other from NLDN) which were candidate correlations (closer than 200 ms from each other) were scrutinized to determine whether the members of a pair actually came from the same discharge process. We have found that there is a statistically significant correlation, for a subset of FORTE events, This correlation is most likely to occur for intracloud and less likely to occur for cloud-to-ground discharges. The correlated VHF and NLDN events tend to occur within +/-30 mu s of each other, after correction for the propagation of the VHF signal to FORTE from the NLDN-geolocated stroke location. Most correlations outside of +/-30 mu s turn out to be merely a statistical accident. The NLDN-furnished geolocation allows the correlated FORTE-detected VHF pulses to be better interpreted, In particular, we can deduce, from the lag of the VHF ground-reflection echo, the height of the VHF emission region in the storm. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Global Atmospher Inc, Tucson, AZ USA. RP Los Alamos Natl Lab, Mail Stop D466, Los Alamos, NM 87545 USA. EM ajacobson@lanl.gov OI Cummins, Kenneth/0000-0001-9871-691X NR 23 TC 44 Z9 45 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 2000 VL 105 IS D12 BP 15653 EP 15662 DI 10.1029/2000JD900103 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 328HP UT WOS:000087844900036 ER PT J AU Pichot, F Pitts, JR Gregg, BA AF Pichot, F Pitts, JR Gregg, BA TI Low-temperature sintering of TiO2 colloids: Application to flexible dye-sensitized solar cells SO LANGMUIR LA English DT Article ID PHOTOELECTROCHROMIC WINDOWS; ELECTRODES AB Colloidal TiO2 films have been prepared in a manner suitable for use with flexible substrates. Sol-gel particles were sintered under various conditions of temperature and initial presence/absence of organic surfactants. The physicochemical properties of the resulting films are reported. Independent of the sintering temperature, films that did not initially contain organic surfactants adhered more strongly to the underlying F:SnO2 substrate. The amount of sensitizing dyes adsorbed by a film is also sensitive to the initial presence or absence of organic surfactants and to the sintering temperature. Used as a dye-sensitized anode in photoelectrochemical cells, an open-circuit photovoltage of 647 mV and a short-circuit photocurrent density of 2 mA/cm(2) were obtained for 1 mu m thick TiO2 films sintered at 100 degrees C; normalized to the same thickness, similar results were obtained with films initially containing surfactant and sintered at 450 degrees C. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Gregg, BA (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 13 TC 192 Z9 203 U1 9 U2 57 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 27 PY 2000 VL 16 IS 13 BP 5626 EP 5630 DI 10.1021/la000095i PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 327NQ UT WOS:000087800300022 ER PT J AU Boeckl, MS Bramblett, AL Hauch, KD Sasaki, T Ratner, BD Rogers, JW AF Boeckl, MS Bramblett, AL Hauch, KD Sasaki, T Ratner, BD Rogers, JW TI Self-assembly of tetraphenylporphyrin monolayers on gold substrates SO LANGMUIR LA English DT Article ID IODINE-MODIFIED AU(111); SURFACE-PLASMON EXCITATION; IN-SITU STM; X-RAY; ELECTRON-TRANSFER; THIN-FILMS; PORPHYRINS; MOLECULES; ADSORPTION; PHOSPHORUS AB Two tetraphenylporphyrins, TPP-P-disulfide and TPP-P-thiol, were synthesized and used to form self-assembled monolayers (SAMs) on gold surfaces. The monolayers were characterized using X-ray photoelectron spectroscopy (XPS), ultraviolet/visible absorption spectroscopy (UV/vis), and scanning tunneling microscopy (STM). XPS binding energy shifts revealed that the porphyrins were chemisorbed to the surface through a sulfur-gold bond. A red shift without a significant blue-shifted component of the Soret band in the absorption spectra demonstrated that the porphyrin molecules are aligned on the gold surface in a side-by-side orientation. Round STM features, approximately 2 nm in diameter, correspond closely to the diameter of tetraphenylporphyrin (1.8 nm). Taken together, these data indicated the formation of monolayers of uniformly spaced TPP-P-disulfide and TPP-P-thiol molecules, with the porphyrin ring oriented parallel to the gold surface. Furthermore, porphyrin monolayers were stable for at least a week at ambient conditions. These monolayers have the potential to anchor biorecognition molecules in an ideal spacing for protein and cell attachment, making them appropriate models for the development of new biorecognition surfaces. C1 Univ Washington, Dept Chem, Seattle, WA 98195 USA. Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA. Univ Washington, Dept Bioengn, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sasaki, T (reprint author), Univ Washington, Dept Chem, Box 351700, Seattle, WA 98195 USA. NR 65 TC 67 Z9 69 U1 5 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 27 PY 2000 VL 16 IS 13 BP 5644 EP 5653 DI 10.1021/la991513q PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 327NQ UT WOS:000087800300025 ER PT J AU Chen, HL Liu, HH Lin, JS AF Chen, HL Liu, HH Lin, JS TI Microstructure of semicrystalline poly(L-lactide)/poly(4-vinylphenol) blends evaluated from SAXS absolute intensity measurement SO MACROMOLECULES LA English DT Article ID ANGLE X-RAY; SOLUTION-GROWN CRYSTALS; SOLUTION-CAST BLENDS; POLY(ETHYLENE OXIDE); POLY(L-LACTIC ACID); MOLECULAR-WEIGHT; POLYMER BLENDS; ALIPHATIC POLYESTERS; BINARY MIXTURE; CRYSTALLIZATION AB The semicrystalline morphology of melt-miscible poly(L-lactide) (PLLA)/poly(4-vinylphenol) (PVPh) blends was probed by small-angle X-ray scattering (SAXS) with the measurement of absolute intensity. Blending with PVPh enhanced the SAXS intensity associated with the lamellar stacks. This was attributed to the presence of PVPh in the interlamellar regions that enhanced the electron density contrast (Delta eta) between the crystalline and amorphous layers. The interlamellar morphology was quantitatively characterized by the magnitude of Delta eta deduced from Strobl-Schneider's one-dimensional correlation function assuming the corresponding two-phase model. Good agreement between the measured Delta eta and the values calculated by assuming a complete interlamellar incorporation indicated that nearly all PVPh was expelled into the interlamellar regions upon the crystallization of PLLA. C1 Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, HL (reprint author), Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. NR 34 TC 27 Z9 27 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 27 PY 2000 VL 33 IS 13 BP 4856 EP 4860 DI 10.1021/ma991504o PG 5 WC Polymer Science SC Polymer Science GA 329HD UT WOS:000087900800037 ER PT J AU Young, JA Hinkley, JA Farmer, BL AF Young, JA Hinkley, JA Farmer, BL TI Molecular simulations of the imidization of adsorbed polyamic acid SO MACROMOLECULES LA English DT Article ID ULTRATHIN POLYMER-FILMS; DYNAMICS SIMULATIONS; AB-INITIO; COMPUTER-SIMULATION; SOLID-SURFACES; POLYIMIDE; SILICA; MELTS; SITES; HYDROCARBONS AB Computer simulations have been developed to investigate the intramolecular cyclization of polyimides (i.e., imidization, the conversion of the precursor polyamic acid into polyimide). Imidization was examined as a function of time, temperature, and presence or absence of a silica substrate. To do this, the essential results of quantum mechanical studies were incorporated into a molecular dynamics simulation. Molecular dynamics simulations were used to determine the conformational properties of the polymer chain and to simulate the imidization reaction when the conformational criteria established by quantum mechanical methods were met. In agreement with experiments, imidization occurred in two distinct stages, and increased temperatures were shown to produce higher extents of imidization. Finally, the interfacial chains exhibited more complete imidization than the isolated chains. These results not only support the proposed molecular rationale behind the kinetic models of imidization but also demonstrate that only local chain motions are necessary for imidization to occur. C1 Univ Virginia, Dept Mat Sci & Engn, Charlottesville, VA 22903 USA. NASA, Langley Res Ctr, Div Mat, Hampton, VA 23681 USA. RP Young, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, L 474, Livermore, CA 94550 USA. NR 41 TC 3 Z9 3 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 27 PY 2000 VL 33 IS 13 BP 4936 EP 4944 DI 10.1021/ma991639u PG 9 WC Polymer Science SC Polymer Science GA 329HD UT WOS:000087900800048 ER PT J AU Miller, JE Sault, AG Trudell, DE Nenoff, TM Thoma, SG Jackson, NB AF Miller, JE Sault, AG Trudell, DE Nenoff, TM Thoma, SG Jackson, NB TI Oxidation reactions of ethane over Ba-Ce-O based perovskites SO APPLIED CATALYSIS A-GENERAL LA English DT Article DE ethane; oxidation; perovskites; ethylene; oxidative dehydrogenation ID MIXED OXIDES; METHANE; DEHYDROGENATION; CATALYSTS; METAL AB Ethane oxidation reactions were studied over pure and Ca-, Mg-, Sr-, La-, Nd-, and Y-substituted BaCeO3 perovskites under oxygen limited conditions. Several of the materials, notably the Ca- and Y-substituted materials, show activity for complete oxidation of the hydrocarbon to CO2 at temperatures below 650 degrees C. At higher temperatures, the oxidative dehydrogenation (ODH) to ethylene becomes significant. Conversions and ethylene yields are enhanced by the perovskites above the thermal reaction in our system in some cases. The perovskite structure is not retained in the high temperature reaction environment. Rather, a mixture of carbonates and oxides is formed. Loss of the perovskite structure correlates with a loss of activity and selectivity to ethylene. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Miller, JE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Miller, James/C-1128-2011 OI Miller, James/0000-0001-6811-6948 NR 21 TC 7 Z9 7 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-860X J9 APPL CATAL A-GEN JI Appl. Catal. A-Gen. PD JUN 26 PY 2000 VL 201 IS 1 BP 45 EP 54 DI 10.1016/S0926-860X(00)00429-4 PG 10 WC Chemistry, Physical; Environmental Sciences SC Chemistry; Environmental Sciences & Ecology GA 326NG UT WOS:000087741200006 ER PT J AU Fini, P Munkholm, A Thompson, C Stephenson, GB Eastman, JA Murty, MVR Auciello, O Zhao, L DenBaars, SP Speck, JS AF Fini, P Munkholm, A Thompson, C Stephenson, GB Eastman, JA Murty, MVR Auciello, O Zhao, L DenBaars, SP Speck, JS TI In situ, real-time measurement of wing tilt during lateral epitaxial overgrowth of GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; LIGHT-EMITTING DIODES; LAYERS AB By performing in situ, real-time x-ray diffraction measurements in the metalorganic chemical-vapor deposition environment, we have directly observed the emergence and evolution of wing tilt that occurs during the lateral overgrowth of GaN from stripes patterned in a SiO2 mask. This was done by repeatedly performing line scans through the 10 (1) over bar 3 peak in the direction perpendicular to the [10 (1) over bar 0](GaN) stripe direction. The wing tilt developed as soon as the wings started forming, and increased slightly thereafter to reach a value of similar to 1.19 degrees after 3600 s of growth. Upon cooldown to room temperature, the tilt increased to similar to 1.36 degrees, indicating that thermally induced stresses during cooldown have only a small effect on wing tilt. However, changes in mask density, composition, and stress state during early lateral overgrowth must be considered as possible origins of wing tilt. (C) 2000 American Institute of Physics. [S0003-6951(00)02926-0]. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Fini, P (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RI Eastman, Jeffrey/E-4380-2011; Speck, James/H-5646-2011; OI Eastman, Jeff/0000-0002-0847-4265; Thompson, Carol/0000-0003-3832-4855 NR 18 TC 56 Z9 56 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 26 PY 2000 VL 76 IS 26 BP 3893 EP 3895 DI 10.1063/1.126812 PG 3 WC Physics, Applied SC Physics GA 326EM UT WOS:000087719800016 ER PT J AU Lee, SH Cheong, HM Tracy, CE Mascarenhas, A Pitts, JR Jorgensen, G Deb, SK AF Lee, SH Cheong, HM Tracy, CE Mascarenhas, A Pitts, JR Jorgensen, G Deb, SK TI Alternating current impedance and Raman spectroscopic study on electrochromic a-WO3 films SO APPLIED PHYSICS LETTERS LA English DT Article ID TUNGSTEN-OXIDE FILMS; TRIOXIDE THIN-FILMS; DIFFUSION AB The chemical diffusion of lithium ions in a-LixWO3 films is investigated using alternating current impedance spectroscopy and Raman scattering measurements. The diffusion coefficients increase with increasing x in a-LixWO3 up to x=0.072 and then decrease. Raman measurements show that the W6+=O/O-W6+-O ratio also increases at the early stage of lithium insertion and then decreases with further lithium insertion. We conclude that the diffusion kinetics of lithium ions in a-LixWO3 films is very closely related to the W6+=O/O-W6+-O ratio. (C) 2000 American Institute of Physics. [S0003-6951(00)04626-X]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Sogang Univ, Dept Phys, Seoul 121742, South Korea. RP Lee, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Lee, Sehee/A-5989-2011; Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 18 TC 97 Z9 99 U1 6 U2 26 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 26 PY 2000 VL 76 IS 26 BP 3908 EP 3910 AR PII [S0003-6951(00)04626-X] DI 10.1063/1.126817 PG 3 WC Physics, Applied SC Physics GA 326EM UT WOS:000087719800021 ER PT J AU Sepliarsky, M Phillpot, SR Wolf, D Stachiotti, MG Migoni, RL AF Sepliarsky, M Phillpot, SR Wolf, D Stachiotti, MG Migoni, RL TI Atomic-level simulation of ferroelectricity in perovskite solid solutions SO APPLIED PHYSICS LETTERS LA English DT Article ID KNBO3; DYNAMICS; OXIDES; MODEL; POLYMORPHS; ORIGIN; BATIO3 AB Building on the insights gained from electronic-structure calculations and from experience obtained with an earlier atomic-level method, we developed an atomic-level simulation approach based on the traditional Buckingham potential with shell model which correctly reproduces the ferroelectric phase behavior and dielectric and piezoelectric properties of KNbO3. This approach now enables the simulation of solid solutions and defected systems; we illustrate this capability by elucidating the ferroelectric properties of a KTa0.5Nb0.5O3 random solid solution. (C) 2000 American Institute of Physics. [S0003-6951(00)04526-5]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. UNR, CONICET, Inst Fis Rosario, Rosario, Santa Fe, Argentina. RP Sepliarsky, M (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 19 TC 42 Z9 42 U1 3 U2 14 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 26 PY 2000 VL 76 IS 26 BP 3986 EP 3988 DI 10.1063/1.126843 PG 3 WC Physics, Applied SC Physics GA 326EM UT WOS:000087719800046 ER PT J AU Kim, BM Feit, MD Rubenchik, AM Joslin, EJ Eichler, J Stoller, PC Da Silva, LB AF Kim, BM Feit, MD Rubenchik, AM Joslin, EJ Eichler, J Stoller, PC Da Silva, LB TI Effects of high repetition rate and beam size on hard tissue damage due to subpicosecond laser pulses SO APPLIED PHYSICS LETTERS LA English DT Article ID ABLATION; DIELECTRICS; NANOSECOND; ABSORPTION; THRESHOLD; BREAKDOWN AB We report the effects of the repetition rate and the beam size on the threshold for ultrashort laser pulse induced damage in dentin. The observed results are explained as cumulative thermal effects. Our model is consistent with the experimental results and explains the dependence of the threshold on repetition rate, beam size, and exposure time. (C) 2000 American Institute of Physics. [S0003-6951(00)05226-8]. C1 Univ Calif Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94550 USA. Univ Appl Sci, Tech Fachhsch Berlin, D-13347 Berlin, Germany. RP Kim, BM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94550 USA. RI Feit, Michael/A-4480-2009; OI Stoller, Patrick/0000-0002-6620-1249 NR 13 TC 35 Z9 35 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 26 PY 2000 VL 76 IS 26 BP 4001 EP 4003 DI 10.1063/1.126847 PG 3 WC Physics, Applied SC Physics GA 326EM UT WOS:000087719800051 ER PT J AU Graudejus, O Wilkinson, AP Chacon, LC Bartlett, N AF Graudejus, O Wilkinson, AP Chacon, LC Bartlett, N TI M-F interatomic distances and effective volumes of second and third transition series MF6- and MF62- anions SO INORGANIC CHEMISTRY LA English DT Article ID ABSORPTION FINE-STRUCTURE; ELECTRON-DIFFRACTION; METAL HEXAFLUORIDES; FLUOROANIONS; OXIDATION; SALTS; PTF6 AB Synchrotron X-ray powder diffraction data (SPDD) for representative LiMF6 and Li2MF6 salts of the second and third transition series have provided unit-cell parameters and, from Rietveld analysis, M-F interatomic distances. M-F distances have also been obtained from X-ray single-crystal structural analyses of LiOsF6, Li2PtF6, and KRhF6. The LiMF6 all have the LiSbF6 structure type (space group R (3) over bar). For M = Ta to Au the primitive unit cell volume decreases with increasing nuclear charge (Z), the volumes (sigma = 0.01 Angstrom(3)) being as follows: Ta, 111.26; Os, 102.42; Ir, 100.77; Pt, 99.62; and Au, 99.12 Angstrom(3). A similar contraction, with increase in Z, occurs from Nh to Rh, the primitive cell volume (sigma = 0.01 Angstrom(3)) being: Nb, 110.92; Ru, 100.51; and Rh, 98.63 Angstrom(3). For the TaF6- to AuF6- the M-F distances are not significantly different across the series, at similar to 1.87(1) Angstrom; also, Nb-F, Ru-F, and Rh-F = 1.86(1) Angstrom. In each series, the a and c values of the hexagonal-cell representation for the LiMF6 structure (separate layers of MF6- and Li+ stacked along c) change smoothly. As Z increases, a decreases and c increases. The variation in a, like the volume change, indicates that the size of MF6- is decreasing with Z. The variation in c suggests that the charge on the F-ligand is decreasing with Z. In the trirutile Li2MF6 series, M = Mo to Pd, the formula-unit volume decreases with Z (Mo, 100.92(6); Ru, 98.21(1); Ph, 97.43(1); Pd, 96.83(1) Angstrom(3)) and a shortening in M-F occurs (Mo-F = 1.936(4); Ru-F = 1.921(7); Rh-F = 1.910(7); Pd-F = 1.899(4) Angstrom). The less abundant data for MF62- salts of the third transition series indicate similar trends. For both series, M-F distances of MF62- are longer by 0.03-0.09 Angstrom than in MF6-. C1 Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. RP Bartlett, N (reprint author), Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Wilkinson, Angus/C-3408-2008 OI Wilkinson, Angus/0000-0003-2904-400X NR 46 TC 28 Z9 29 U1 1 U2 10 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 JUN 26 PY 2000 VL 39 IS 13 BP 2794 EP 2800 DI 10.1021/ic000041w PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 329JZ UT WOS:000087905000015 PM 11232815 ER PT J AU Gerken, M Kolb, P Wegner, A Mercier, HPA Borrmann, H Dixon, DA Schrobilgen, GJ AF Gerken, M Kolb, P Wegner, A Mercier, HPA Borrmann, H Dixon, DA Schrobilgen, GJ TI Tetrachloro- and tetrabromoarsonium(V) cations: Raman and As-75, F-19 NMR spectroscopic characterization and X-ray crystal structures of [AsCl4][As(OTeF5)(6)] and [AsBr4][AsF(OTeF5)(5)] SO INORGANIC CHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; VIBRATIONAL-SPECTRA; ANIONS; COMPLEXES; OTEF5; ENERGIES; SALTS; ION AB The salts [AsX4][As(OTeFs)(6)] and [AsBr4] [AsF(OTeF5)(5)] (X = Cl, Br) have been prepared by oxidation of AsX3 with XOTeF5 in the presence of the OTeF5 accepters As(OTeF5)(5) and AsF(OTeF5)(4). The mixed salts [AsCl4]Sb(OTeF5)(6-n)Cln-2 and [AsCl4][Sb(OTeF5)(6-n)Cl-n] (n greater than or equal to 2) have also been prepared. The AsBr4+ cation has been fully structurally characterized for the first time in SO2ClF solution by As-75 NMR spectroscopy and in the solid state by a single-crystal X-ray diffraction study of [AsBr4][AsF(OTeF5)(5)]: P (1) over tilde, a = 9.778(4) Angstrom, b = 17.731(7) Angstrom, c = 18.870(8) Angstrom, alpha = 103.53(4)degrees beta = 103.53(4)degrees gamma = 105.10(4)degrees, V= 2915(2) Angstrom(3), Z = 4, and R-1 = 0.0368 at -183 degrees C. The crystal structure determination and solution As-75 NMR study of the related [AsCl4][As(OTeF5)(6)] salt have also been carried out: [AsCl4][As(OTeF5)(6)], R (3) over bar, a = 9.8741(14) Angstrom, c = 55.301(11) Angstrom, V = 4669(1) Angstrom(3), Z = 6, and R-1 = 0.0438 at -123 degrees C; and R (3) over bar, a = 19.688(3) Angstrom, c = 55.264(11) Angstrom, V = 18552(5) Angstrom(3), z = 24, and R-1 = 0.1341 at -183 degrees C. The crystal structure of the As(OTeF5)(6)(-) salt reveals weaker interactions between the anion and cation than in the previously known AsF6- salt. The AsF(OTeF5)(5)(-) anion is reported for the first time and is also weakly coordinating with respect to the AsBr4+ cation. Both cations are undistorted tetrahedra with bond lengths of 2.041(5)-2.056(3) Angstrom fur AsCl4+ and 2.225(2)-2.236(2) Angstrom for AsBr4+. The Raman spectra are consistent with undistorted AsX4+ tetrahedra and have been assigned under T-d point symmetry. The Cl-35/Cl-37 isotope shifts have been observed and assigned for AsCl4+, and the geometrical parameters and vibrational frequencies of all known and presently unknown PnX(4)(+) (Pn = P, As, Sb, Bi; X = F, Cl, Br, I) cations have been calculated using density functional theory methods. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. NR 82 TC 22 Z9 22 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD JUN 26 PY 2000 VL 39 IS 13 BP 2813 EP 2824 DI 10.1021/ic000118g PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 329JZ UT WOS:000087905000018 PM 11232818 ER PT J AU Huynh, MHV White, PS Meyer, TJ AF Huynh, MHV White, PS Meyer, TJ TI Mechanistic control of product selectivity. Reactions between cis-/trans-[Os-VI(tpy)(Cl)(2)(N)](+) and triphenylphosphine sulfide SO INORGANIC CHEMISTRY LA English DT Article ID NITROGEN ATOM-TRANSFER; PHOSPHORANEIMINATO COMPLEXES; CRYSTAL-STRUCTURE; PHOSPHORANIMINATO COMPLEXES; OSMIUM(VI) NITRIDES; AZIDE ION; REACTIVITY; THIONITROSYL; CHEMISTRY; REDUCTION AB Reactions between the Os(VI)-nitrido complexes cis- and trans-[Os-VI(tpy)(Cl)(2)(N)](+) (tpy is 2,2':6',2"-terpyridine) and triphenylphosphine sulfide, SPPh3, give the corresponding Os(IV)-phosphoraniminato, [Os-IV(tpy)(Cl)(2)(NPPh3)](+), and Os(II)-thionitrosyl, [Os-II(tpy)(Cl)(2)(NS)](+), complexes as products. The Os-N bond length and Os-N-P angle in cis-[Os-IV(tpy)(Cl)(2)(NPPh3)](PF6) are 2.077(6) Angstrom and 138.3(4)degrees. The rate law for formation of cis- and trans-[Os-IV(tpy)(Cl)(2)(NPPh3)](+) is first order in both [Os-VI(tpy)(Cl)(2)(N)](+) and SPPh3 with k(trans)(25 degrees C, CH3CN) = 24.6 +/- 0.6 M-1 s(-1) and k(cis)(25 degrees C, CH3CN) = 0.84 +/- 0.09 M-1 s(-1). As found earlier for [Os-II- (tpm)(Cl)(2)(NS)](+), both cis- and trans-[Os-II(tpy)(Cl)(2)(NS)](+) react with PPh3 to give [Os-IV(tpy)(Cl)(2)(NPPh3)](+) and SPPh3, For both complexes, the reaction is first order in each reagent with k(trans)(25 degrees C, CH3CN) = (6.79 +/- 0.08) x 10(2) M-1 s(-1) and k(cis)(25 degrees C, CH3CN) = (2.30 +/- 0.07) x 10(2) M-1 s(-1). The fact that both reactions occur rules out mechanisms involving S atom transfer. These results can be explained by invoking a common intermediate, [OsIV(tpy)(Cl)(2)(NSPPh3)](+), which undergoes further reaction with PPh3 to give [Os-IV(tpy)(Cl)(2)(NPPh3)](+) and SPPh3 or with [Os-VI(tpy)(Cl)(2)(N)](+) to give [Os-IV(tpy)(Cl)(2)(NPPh3)](+) and [Os-II(tpy)(Cl)(2)(NS)](+). C1 Univ N Carolina, Dept Chem, Venable & Kenan Labs, Chapel Hill, NC 27599 USA. RP Meyer, TJ (reprint author), Univ Calif Los Alamos Natl Lab, MS A127, Los Alamos, NM 87545 USA. NR 26 TC 22 Z9 22 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUN 26 PY 2000 VL 39 IS 13 BP 2825 EP 2830 DI 10.1021/ic991425t PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 329JZ UT WOS:000087905000019 PM 11232819 ER PT J AU Du, CH Lin, WJ Su, Y Tanner, BK Hatton, PD Casa, D Keimer, B Hill, JP Oglesby, CS Hohl, H AF Du, CH Lin, WJ Su, Y Tanner, BK Hatton, PD Casa, D Keimer, B Hill, JP Oglesby, CS Hohl, H TI X-ray scattering studies of 2H-NbSe2, a superconductor and charge density wave material, under high external magnetic fields SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID SPIN-DENSITY; NBSE3; PHASE; TEMPERATURE; CONVERSION; MECHANISM AB Using x-ray scattering we have measured the response of the incommensurate charge-density wave (CDW) modulation in the quasi-low-dimensional material 2H-NbSe2 to applied magnetic fields at low temperatures. The application of a magnetic field, either perpendicular or parallel to the layers of a single crystal of 2H-NbSe2, caused no significant change to either the correlation length or the intensity of the CDW satellites for magnetic fields up to 10 T. These results suggest that the enhancement of the resistance observed in low-dimensional CDW materials exposed to the applied magnetic field does not result from an appreciable conversion of carriers from the normal state to the CDW state. In addition 2H-NbSe2 is a superconductor at low temperatures (T-c = 7.2 K), whilst still within the incommensurate CDW state. This material therefore affords an opportunity to study any interaction between the CDW and superconducting condensates. High magnetic fields can suppress the superconducting stale yet no change in the incommensurate CDW satellite correlation length or intensity was observed at high applied magnetic fields. These results conflict with spectroscopic measurements, which suggest a coupling between the superconducting gap excitations and the CDW. C1 Univ Durham, Dept Phys, Durham DH1 3LE, England. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. AT&T Bel Labs, Murray Hill, NJ 07974 USA. SRRC, Hsinchu, Taiwan. RP Du, CH (reprint author), Univ Durham, Dept Phys, Durham DH1 3LE, England. RI Su, Yixi/K-9119-2013; Hatton, Peter/J-8445-2014; Casa, Diego/F-9060-2016 OI Su, Yixi/0000-0001-8434-1758; NR 34 TC 26 Z9 26 U1 0 U2 11 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 JUN 26 PY 2000 VL 12 IS 25 BP 5361 EP 5370 DI 10.1088/0953-8984/12/25/302 PG 10 WC Physics, Condensed Matter SC Physics GA 335FB UT WOS:000088232200009 ER PT J AU Tellers, DM Skoog, SJ Bergman, RG Gunnoe, TB Harman, WD AF Tellers, DM Skoog, SJ Bergman, RG Gunnoe, TB Harman, WD TI Comparison of the relative electron-donating abilities of hydridotris(pyrazolyl)borate and cyclopentadienyl ligands: Different interactions with different transition metals SO ORGANOMETALLICS LA English DT Letter ID H BOND ACTIVATION; RAY CRYSTAL-STRUCTURE; MAIN-GROUP ELEMENTS; X = H; C-H; QUANTITATIVE-ANALYSIS; MOLECULAR-STRUCTURE; MATRIX-ISOLATION; MULTIPLE BONDS; COMPLEXES C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. N Carolina State Univ, Dept Chem, Raleigh, NC 27695 USA. Univ Virginia, Dept Chem, Charlottesville, VA 22901 USA. RP Bergman, RG (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 67 TC 109 Z9 110 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JUN 26 PY 2000 VL 19 IS 13 BP 2428 EP 2432 DI 10.1021/om000043o PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 327QL UT WOS:000087804200010 ER PT J AU Csaki, C Erlich, J Hollowood, TJ AF Csaki, C Erlich, J Hollowood, TJ TI Quasilocalization of gravity on a brane by resonant modes SO PHYSICAL REVIEW LETTERS LA English DT Article ID DIMENSIONS; MILLIMETER; HIERARCHY AB We examine the behavior of gravity in brane theories with extra dimensions in a nonfactorizable background geometry. We find that for metrics which are asymptotically flat: far from the brane there is a resonant graviton mode at zero energy. The presence of this resonance ensures quasilocalization of gravity, whereby at intermediate scales the gravitational laws on the brane are approximately four dimensional. However, for scales larger than the lifetime of the graviton resonance the five-dimensional laws of gravity will be reproduced due to the decay of the four-dimensional graviton. We also give a simple classification of effective gravity theories for general background geometries. C1 Univ Calif Los Alamos Natl Lab, Theory Div T8, Los Alamos, NM 87545 USA. Univ Wales, Dept Phys, Swansea SA2 8PP, W Glam, Wales. RP Csaki, C (reprint author), Univ Calif Los Alamos Natl Lab, Theory Div T8, POB 1663, Los Alamos, NM 87545 USA. NR 8 TC 94 Z9 94 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 JUN 26 PY 2000 VL 84 IS 26 BP 5932 EP 5935 DI 10.1103/PhysRevLett.84.5932 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500004 PM 10991092 ER PT J AU Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, S Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadof, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S AF Bonvicini, G Cinabro, D McGee, S Perera, LP Zhou, GJ Lipeles, E Pappas, S Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Sharma, V Asner, DM Eppich, A Hill, TS Morrison, RJ Nelson, HN Briere, RA Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Dickson, M Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Thayer, JG Thies, PG Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Yelton, J Zheng, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R Browder, TE Li, Y Rodriguez, JL Yamamoto, H Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadof, AJ Ammar, R Bean, A Besson, D Davis, R Kwak, N Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Mahmood, AH Saleem, M Timm, S Wappler, F Anastassov, A Duboscq, JE Gan, KK Gwon, C Hart, T Honscheid, K Hufnagel, D Kagan, H Kass, R Pedlar, TK Schwarthoff, H Thayer, JB von Toerne, E Zoeller, MM Richichi, SJ Severini, H Skubic, P Undrus, A Chen, S Fast, J Hinson, JW Lee, J Menon, N Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Kwon, Y Lyon, AL Thorndike, EH Jessop, CP Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S CA CLEO Collaboration TI Search for CP violation in B-+/--> J/psi K-+/- and B-+/-->psi(2S)K-+/- decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID DETECTOR AB We present a search for direct CP violation in B+/- --> J/psi K+/- and B+/- --> psi(2S)K+/- decays. In a sample of 9.7 X 10(6) B (B) over bar meson pairs collected with the CLEO detector, we have fully reconstructed 534 B+/- --> J/psi K+/- and 120 B+/- --> psi(2S)K+/- decays with very low background. We have measured the CP-violating charge asymmetry to be [+1.8 +/- 4.3(stat) +/- 0.4(syst)]% for B+/- --> J/psi K+/- and [+2.0 +/- 9.1(stat) +/- 1.0(syst)]% for B+/- --> psi(2S)K+/-. C1 Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. MIT, Cambridge, MA 02139 USA. Univ Texas Pan Amer, Edinburg, TX 78539 USA. Yonsei Univ, Seoul 120749, South Korea. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Bonvicini, G (reprint author), Wayne State Univ, Detroit, MI 48202 USA. RI Warburton, Andreas/N-8028-2013; Briere, Roy/N-7819-2014 OI Warburton, Andreas/0000-0002-2298-7315; Briere, Roy/0000-0001-5229-1039 NR 12 TC 23 Z9 23 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 JUN 26 PY 2000 VL 84 IS 26 BP 5940 EP 5944 DI 10.1103/PhysRevLett.84.5940 PG 5 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500006 PM 10991094 ER PT J AU Abe, K Abe, K Abe, T Adam, I Akimoto, H Aston, D Baird, KG Baltay, C Band, HR Barklow, TL Bauer, JM Bellodi, G Berger, R Blaylock, G Bogart, JR Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Calcaterra, A Cassell, R Chou, A Cohn, HO Coller, JA Convery, MR Cook, V Cowan, RF Crawford, G Damerell, CJS Daoudi, M Dasu, S de Groot, N de Sangro, R Dong, DN Doser, M Dubois, R Erofeeva, I Eschenburg, V Etzion, E Fahey, S Faiciai, D Fernandez, JP Fero, MJ Flood, K Frey, R Hart, EL Hasuko, K Hertzbach, SS Huffer, ME Huynh, X Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Kajikawa, R Kang, HJ Kalelkar, M Kofler, RR Kroeger, RS Langston, M Leith, DWG Lia, V Lin, C Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T McKemey, AK Messner, R Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Narita, S Nauenberg, U Neal, H Nesom, G Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, CH Peruzzi, I Piccolo, M Piemontese, L Plano, RJ Prepost, R Prescott, CY Ratcliff, BN Reidy, J Reinertsen, PL Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schumm, BA Schwiening, J Serbo, VV Shapiro, G Sinev, NB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, H Su, D Suekane, F Sugiyama, A Swartz, M Taylor, FE Thom, J Torrence, E Usher, T Va'vra, J Verdier, R Wagner, DL Waite, AP Walston, S Wang, J Weidemann, AW Weiss, ER Whitaker, JS Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Wright, TR Yamamoto, RK Yashima, J Yellin, SJ Young, CC Yuta, H AF Abe, K Abe, K Abe, T Adam, I Akimoto, H Aston, D Baird, KG Baltay, C Band, HR Barklow, TL Bauer, JM Bellodi, G Berger, R Blaylock, G Bogart, JR Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Calcaterra, A Cassell, R Chou, A Cohn, HO Coller, JA Convery, MR Cook, V Cowan, RF Crawford, G Damerell, CJS Daoudi, M Dasu, S de Groot, N de Sangro, R Dong, DN Doser, M Dubois, R Erofeeva, I Eschenburg, V Etzion, E Fahey, S Faiciai, D Fernandez, JP Fero, MJ Flood, K Frey, R Hart, EL Hasuko, K Hertzbach, SS Huffer, ME Huynh, X Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Kajikawa, R Kang, HJ Kalelkar, M Kofler, RR Kroeger, RS Langston, M Leith, DWG Lia, V Lin, C Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T McKemey, AK Messner, R Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Narita, S Nauenberg, U Neal, H Nesom, G Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, CH Peruzzi, I Piccolo, M Piemontese, L Plano, RJ Prepost, R Prescott, CY Ratcliff, BN Reidy, J Reinertsen, PL Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schumm, BA Schwiening, J Serbo, VV Shapiro, G Sinev, NB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, H Su, D Suekane, F Sugiyama, A Swartz, M Taylor, FE Thom, J Torrence, E Usher, T Va'vra, J Verdier, R Wagner, DL Waite, AP Walston, S Wang, J Weidemann, AW Weiss, ER Whitaker, JS Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Wright, TR Yamamoto, RK Yashima, J Yellin, SJ Young, CC Yuta, H CA SLD Collaboration TI High-precision measurement of the left-right Z boson cross-section asymmetry SO PHYSICAL REVIEW LETTERS LA English DT Article ID E+E COLLISIONS AB We present a measurement of the left-right cross-section asymmetry (A(LR)) for Z boson production by e(+) e(-) collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider during the period 1996-1998. Using a sample of 383 487 Z decays collected during the 1996-1998 runs-we measure the pole value of the asymmetry, A(LR)(0), to be 0.150 56 +/- 0.002 39 which is equivalent to an effective weak mixing angle of sin(2)theta(W)(eff) = 0.231 07 +/- 0.000 30. Our result for the complete 1992-1998 data set comprising approximately 537 000 Z decays is sin(2)theta(W)(eff) = 0.230 97 +/- 0.000 27. C1 Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. Univ Bristol, Bristol, Avon, England. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Boston Univ, Boston, MA 02215 USA. Univ Colorado, Boulder, CO 80309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Nazl Frascati Lab, I-00044 Frascati, Italy. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Mississippi, University, MS 38677 USA. MIT, Cambridge, MA 02139 USA. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Univ Oregon, Eugene, OR 97403 USA. Univ Oxford, Oxford OX1 3RH, England. Ist Nazl Fis Nucl, Sez Perugia, I-06100 Perugia, Italy. Univ Perugia, I-06100 Perugia, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Rutgers State Univ, Piscataway, NJ 08855 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Soongsil Univ, Seoul 156743, South Korea. Univ Tennessee, Knoxville, TN 37996 USA. Tohoku Univ, Sendai, Miyagi 980, Japan. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Univ Washington, Seattle, WA 98105 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Abe, K (reprint author), Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. RI de Groot, Nicolo/A-2675-2009; Stahl, Achim/E-8846-2011; de Sangro, Riccardo/J-2901-2012; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016 OI Stahl, Achim/0000-0002-8369-7506; de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636 NR 24 TC 68 Z9 68 U1 0 U2 2 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 JUN 26 PY 2000 VL 84 IS 26 BP 5945 EP 5949 DI 10.1103/PhysRevLett.84.5945 PG 5 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500007 PM 10991095 ER PT J AU Marcucci, LE Schiavilla, R Viviani, M Kievsky, A Rosati, S AF Marcucci, LE Schiavilla, R Viviani, M Kievsky, A Rosati, S TI Realistic calculation of the He-3+p (hep) astrophysical factor SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRINO ENERGY-SPECTRUM; MONTE-CARLO CALCULATIONS; CROSS-SECTION; HEP-NEUTRINOS; CAPTURE; SCATTERING; NUCLEI; 3-NUCLEON; TRITIUM AB The astrophysical factor for the proton weak capture on He-3 is calculated with correlated hyperspherical harmonic wave functions corresponding to a realistic Hamiltonian consisting of the Argonne upsilon(18) two-nucleon and Urbana-IX three-nucleon interactions. The nuclear weak current has Vector and axial vector components with one- and many-body terms. All possible transitions connecting any of the p He-3 S- and P-wave channels to He-4 are considered. The S factor at a p He-3 center-of-mass energy of 10 keV is predicted to be 10.1 x 10(-20) keVb, a factor of similar or equal to 4.5 larger than the value adopted in the standard solar model. The P-wave transitions are found to contribute about 40% of the calculated S factor. C1 Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Jefferson Lab, Newport News, VA 23606 USA. Ist Nazl Fis Nucl, Sez Pisa, I-56100 Pisa, Italy. Univ Pisa, Dept Phys, I-56100 Pisa, Italy. RP Marcucci, LE (reprint author), Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RI kievsky, alejandro/A-7123-2011 NR 34 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 JUN 26 PY 2000 VL 84 IS 26 BP 5959 EP 5962 DI 10.1103/PhysRevLett.84.5959 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500010 PM 10991098 ER PT J AU Ma, WC Martin, V Khoo, TL Lauritsen, T Egido, JL Ahmad, I Bhattacharyya, P Carpenter, MP Daly, PJ Grabowski, ZW Hamilton, JH Janssens, RVF Nisius, D Ramayya, AV Varmette, PG Zhang, CT AF Ma, WC Martin, V Khoo, TL Lauritsen, T Egido, JL Ahmad, I Bhattacharyya, P Carpenter, MP Daly, PJ Grabowski, ZW Hamilton, JH Janssens, RVF Nisius, D Ramayya, AV Varmette, PG Zhang, CT TI Phase transitions above the yrast line in Dy-154 SO PHYSICAL REVIEW LETTERS LA English DT Article ID GIANT-DIPOLE RESONANCES; HOT ROTATING NUCLEI; STRENGTH FUNCTIONS; EXCITATION-ENERGY; ANGULAR-MOMENTUM; GAMMA-RAY; DY-152,DY-154,DY-156; FLUCTUATIONS AB Spectra of the E2 quasicontinuum gamma rays feeding different spin regions of the Dy-154 yrast line have been extracted. These are compared with corresponding theoretical spectra obtained by numerical simulations based on temperature-dependent Hartree-Fock theory, with thermal shape fluctuations. In this manner, different regions of the spin-energy plane can be examined. The results support the predictions of a smeared-out phase transition at high spin above the yrast line. C1 Mississippi State Univ, Mississippi State, MS 39762 USA. Univ Politecn Madrid, Fac Informat, E-28660 Madrid, Spain. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Autonoma Madrid, Dept Fis Teor C XI, E-28049 Madrid, Spain. Purdue Univ, W Lafayette, IN 47907 USA. Vanderbilt Univ, Nashville, TN 37235 USA. RP Ma, WC (reprint author), Mississippi State Univ, Mississippi State, MS 39762 USA. RI Carpenter, Michael/E-4287-2015; Egido, J. Luis/F-4921-2017 OI Carpenter, Michael/0000-0002-3237-5734; Egido, J. Luis/0000-0002-8292-6127 NR 20 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 26 PY 2000 VL 84 IS 26 BP 5967 EP 5970 DI 10.1103/PhysRevLett.84.5967 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500012 PM 10991100 ER PT J AU Beaulieu, L Lefort, T Kwiatkowski, K de Souza, RT Hsi, WC Pienkowski, L Back, B Bracken, DS Breuer, H Cornell, E Gimeno-Nogues, F Ginger, DS Gushue, S Korteling, RG Laforest, R Martin, E Morley, KB Ramakrishnan, E Remsberg, LP Rowland, D Ruangma, A Viola, VE Wang, G Winchester, E Yennello, SJ AF Beaulieu, L Lefort, T Kwiatkowski, K de Souza, RT Hsi, WC Pienkowski, L Back, B Bracken, DS Breuer, H Cornell, E Gimeno-Nogues, F Ginger, DS Gushue, S Korteling, RG Laforest, R Martin, E Morley, KB Ramakrishnan, E Remsberg, LP Rowland, D Ruangma, A Viola, VE Wang, G Winchester, E Yennello, SJ TI Signals for a transition from surface to bulk emission in thermal multifragmentation SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-FRAGMENT CORRELATION-FUNCTIONS; TIME-SCALE; AR-36+AU-197 COLLISIONS; GEV/C ANTIPROTON; NUCLEI; EXCITATION; ENERGY; BEAMS; FRAGMENTS; PHYSICS AB Excitation-energy-gated two-fragment correlation functions have been studied between E*/A = (2-9)A MeV for equilibriumlike sources formed in 8-10 GeV/c pi(-) and p + Au-197 reactions. Comparison with an N-body Coulomb-trajectory code shows an order of magnitude decrease in the fragment emission time in the interval E*/A = (2-5)A MeV, followed by a nearly constant breakup time at higher excitation energy. The decrease in emission time is strongly correlated with the onset of multifragmentation and thermally induced radial expansion, consistent with a transition from surface-dominated to bulk emission expected for spinodal decomposition. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, IUCF, Bloomington, IN 47405 USA. Warsaw Univ, Heavy Ion Lab, Warsaw, Poland. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Maryland, Dept Phys, College Pk, MD 20740 USA. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Cyclotron Lab, College Stn, TX 77843 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. RP Beaulieu, L (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RI Ginger, David/C-4866-2011; Yennello, Sherry/B-5803-2015; deSouza, Romualdo/P-5862-2015; Beaulieu, Luc/A-6803-2009; Rowland, Douglas/F-3104-2014 OI Ginger, David/0000-0002-9759-5447; Yennello, Sherry/0000-0003-3963-5217; deSouza, Romualdo/0000-0001-5835-677X; Beaulieu, Luc/0000-0003-0429-6366; Rowland, Douglas/0000-0001-8059-6905 NR 30 TC 84 Z9 85 U1 2 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 JUN 26 PY 2000 VL 84 IS 26 BP 5971 EP 5974 DI 10.1103/PhysRevLett.84.5971 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500013 PM 10991101 ER PT J AU Davies, JA Continetti, RE Chandler, DW Hayden, CC AF Davies, JA Continetti, RE Chandler, DW Hayden, CC TI Femtosecond time-resolved photoelectron angular distributions probed during photodissociation of NO2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHAPE RESONANCE; CO MOLECULES; PHOTOIONIZATION; IONIZATION; CONTINUUM; DYNAMICS AB Femtosecond time-resolved photoelectron angular distributions (PADs) are measured for the first time in the molecular frame of a dissociating molecule. Various stages of the dissociation process, NO2 --> NO((CII)-I-2) + O(P-3), are probed using ionization of the NO((CII)-I-2) fragment to NO+(X(1)Sigma(+)). The PADs evolve from forward-backward asymmetric with respect to the dissociation axis at short time delays (less than or equal to 500 fs) to symmetric at long time delays (greater than or equal to 1 ps). Changes in the PADs directly reflect the time dependent separation and reorientation of the dissociating photofragments. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Hayden, CC (reprint author), Sandia Natl Labs, Combust Res Facil, POB 969, Livermore, CA 94551 USA. OI Continetti, Robert/0000-0002-0685-4459 NR 24 TC 125 Z9 125 U1 3 U2 27 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 26 PY 2000 VL 84 IS 26 BP 5983 EP 5986 DI 10.1103/PhysRevLett.84.5983 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500016 PM 10991104 ER PT J AU Mattor, N AF Mattor, N TI Spatiotemporal signal analysis via the phase velocity transform SO PHYSICAL REVIEW LETTERS LA English DT Article AB The phase velocity transform (PVT) is an integral transform that divides a function of space and time into components that propagate at uniform phase velocities without distortion. This paper examines the PVT as a method to analyze spatiotemporal fluctuation data. The transform is extended to systems with discretely sampled data on a periodic domain, and applied to data from eight azimuthally distributed probes on the Sustained Spheromak Physics Experiment (SSPX). This reveals features not shown by Fourier analysis, particularly regarding nonsinusoidal mode structure. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mattor, N (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 6 TC 2 Z9 2 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 26 PY 2000 VL 84 IS 26 BP 6022 EP 6025 DI 10.1103/PhysRevLett.84.6022 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500026 PM 10991114 ER PT J AU Kalman, G Rosenberg, M DeWitt, HE AF Kalman, G Rosenberg, M DeWitt, HE TI Collective modes in strongly correlated Yukawa liquids: Waves in dusty plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID ONE-COMPONENT-PLASMA; COUPLED COULOMB LIQUIDS; DIELECTRIC TENSOR; SYSTEMS; DISPERSION; LIMIT; THERMODYNAMICS; CRYSTAL AB We determine the collective mode structure of a strongly correlated Yukawa fluid, with the purpose of analyzing wave propagation in a strongly coupled dusty plasma. We identify a longitudinal plasmon and a transverse shear mode. The dispersion is characterized by a low-k acoustic behavior, a frequency maximum well below the plasma frequency, and a high-k merging of the two modes around the Einstein frequency of localized oscillations. The damping effect of collisions between neutrals and dust grains is estimated. C1 Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kalman, G (reprint author), Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA. NR 26 TC 112 Z9 112 U1 2 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 26 PY 2000 VL 84 IS 26 BP 6030 EP 6033 DI 10.1103/PhysRevLett.84.6030 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500028 PM 10991116 ER PT J AU Bachtold, A Fuhrer, MS Plyasunov, S Forero, M Anderson, EH Zettl, A McEuen, PL AF Bachtold, A Fuhrer, MS Plyasunov, S Forero, M Anderson, EH Zettl, A McEuen, PL TI Scanned probe microscopy of electronic transport in carbon nanotubes SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORCE MICROSCOPY; SINGLE-WALL; CONDUCTANCE; DISORDER; CHARGE; PHASE; ROPES AB We use electrostatic force microscopy and scanned gate microscopy to probe the conducting properties of carbon nanotubes at room temperature. Multiwalled carbon nanotubes are shown to be diffusive conductors, while metallic single-walled carbon nanotubes are ballistic conductors over micron lengths. Semiconducting single-walled carbon nanotubes are shown to have a series of large barriers to conduction along their length. These measurements are also used to probe the contact resistance and locate breaks in carbon nanotube circuits. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Bachtold, A (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Fuhrer, Michael/E-7634-2010; Bachtold, Adrian/C-1389-2014; Zettl, Alex/O-4925-2016 OI Fuhrer, Michael/0000-0001-6183-2773; Bachtold, Adrian/0000-0002-6145-2479; Zettl, Alex/0000-0001-6330-136X NR 28 TC 471 Z9 475 U1 15 U2 119 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 JUN 26 PY 2000 VL 84 IS 26 BP 6082 EP 6085 DI 10.1103/PhysRevLett.84.6082 PG 4 WC Physics, Multidisciplinary SC Physics GA 329LY UT WOS:000087909500041 PM 10991129 ER PT J AU Bell, CE Frescura, P Hochschild, A Lewis, M AF Bell, CE Frescura, P Hochschild, A Lewis, M TI Crystal structure of the lambda repressor C-terminal domain provides a model for cooperative operator binding SO CELL LA English DT Article ID RECA-MEDIATED CLEAVAGE; TRANSCRIPTIONAL ACTIVATION FUNCTION; SINGLE-SITE MUTATIONS; BACTERIOPHAGE-LAMBDA; PHAGE REPRESSOR; GENE-REGULATION; UMUD' PROTEIN; MOLECULAR REPLACEMENT; POSITIVE CONTROL; P22 REPRESSORS AB Interactions between transcription factors bound to separate operator sites commonly play an important role in gene regulation by mediating cooperative binding to the DNA. However, few detailed structural models for understanding the molecular basis of such cooperativity are available. The cl repressor of bacteriophage lambda is a classic example of a protein that binds to its operator sites cooperatively. The C-terminal domain of the repressor mediates dimerization as well as a dimer-dimer interaction that results in the cooperative binding of two repressor dimers to adjacent operator sites. Here, we present the x-ray crystal structure of the lambda repressor C-terminal domain determined by multiwavelength anomalous diffraction. Remarkably, the interactions that mediate cooperativity are captured in the crystal, where two dimers associate about a 2-fold axis of symmetry. Based on the structure and previous genetic and biochemical data, we present a model for the cooperative binding of two lambda repressor dimers at adjacent operator sites. C1 Johnson Fdn, Philadelphia, PA 19104 USA. Univ Penn, Sch Med, Dept Biochem & Biophys, Philadelphia, PA 19104 USA. Harvard Univ, Sch Med, Dept Microbiol & Mol Genet, Boston, MA 02115 USA. Brookhaven Natl Lab, NSLS Beamline X25, Upton, NY 11973 USA. Brookhaven Natl Lab, NSLS Beamline X12B, Upton, NY 11973 USA. RP Lewis, M (reprint author), Johnson Fdn, Philadelphia, PA 19104 USA. FU NIGMS NIH HHS [R01 GM044025] NR 54 TC 91 Z9 92 U1 0 U2 7 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD JUN 23 PY 2000 VL 101 IS 7 BP 801 EP 811 DI 10.1016/S0092-8674(00)80891-0 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 327YE UT WOS:000087821400013 PM 10892750 ER PT J AU Gingl, F Vogt, T Akiba, E AF Gingl, F Vogt, T Akiba, E TI Trigonal SrAl2H2: the first Zintl phase hydride SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Zintl phases; gas-solid reaction; crystal structure; neutron diffraction; X-ray diffraction ID CRYSTAL-STRUCTURE AB The title compound and its deuteride were synthesized by hydrogenating/deuterating SrAl2 at 50 bar H-2/D-2 pressure and temperatures below 200 degrees C. As found by in situ X-ray powder diffraction, the hydrogenation of SrAl2 proceeds in three steps, with SrAl2H2 as the first product. SrAl2H2 and SrAl2D2 were characterized by X-ray and neutron powder diffraction. They crystallize with a new trigonal structure in space group P (3) over bar m1 (164), cell parameters: a=4.5283(1) Angstrom, c=4.7215(2) Angstrom (hydride), a=4.5253(1) Angstrom, c=4.7214(2) Angstrom (deuteride), Z=1. The main feature of this structure is a two-dimensional polymer Zintl anion, (2)(infinity)[AlH-](2n), in which one H atom is covalently bonded to each Al atom. SrAl2H2 is the first example of a Zintl phase hydride, i.e., the first Zintl phase in which hydrogen atoms are a part of the Zintl anion. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Natl Inst Mat & Chem Res, Dept Inorgan Mat, Tsukuba, Ibaraki 3058565, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Akiba, E (reprint author), Natl Inst Mat & Chem Res, Dept Inorgan Mat, 1-1 Higashi, Tsukuba, Ibaraki 3058565, Japan. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 19 TC 53 Z9 55 U1 0 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 23 PY 2000 VL 306 IS 1-2 BP 127 EP 132 DI 10.1016/S0925-8388(00)00755-6 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 328XL UT WOS:000087877000020 ER PT J AU Gross, KJ Chartouni, D Fauth, F AF Gross, KJ Chartouni, D Fauth, F TI A new hexagonal Laves phase deuteride CeMn1.5Al0.5Dx (0 < x < 4) - Investigated by in situ neutron diffraction SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE metal hydride; deuteride; neutron powder diffraction; Laves phase; Rietveld refinement ID HYDROGEN ABSORPTION; ZRMN2D3; ORDER; ATOMS AB The crystal structure of the C14 (P6(3)/mmc) hexagonal Laves phase compound CeMn1.5Al0.5Dx (x<4) was investigated using in situ neutron powder diffraction during deuteriding. First, real-time neutron scattering measurements were performed during the deuteriding of the compound from 0 to 170 ncm(3) D-2/g-sample (3.9 D/fu). From these measurements we determined the critical concentrations at which phase transitions occurred. In this compound, the deuterium initially dissolved into the host-metal lattice forming a solid solution (alpha-phase). This phase exhibited an isotropic lattice expansion with increasing deuterium concentration. The nucleation of a deuteride (the beta phase) occurred at a total deuterium content of 20 ncm(3) D-2/g-sample. The transformation into the deuteride was complete at 145 ncm(3) D-2/g-sample, giving a stoichiometry of CeMn1.5Al0.5D3.0 for the beta phase. With increasing pressure, this phase continued to absorb deuterium forming a beta' deuteride solid solution. The growth of the beta phase is accompanied by the occurrence of a broad peak in the background. The position and diffuse character of this peak clearly indicates the presence of short-range deuterium ordering in the otherwise disordered occupation of interstitial sites. Finally, the crystal structures of all CeMn1.5Al0.5Dx (x<4) phases were precisely determined using high resolution neutron powder diffraction. The host metal compound, CeMn1.5Al0.5, is a pseudo-binary AB(2)-type compound showing a statistical distribution of Mn and Al on two different B sites. In the CeMn1.5Al0.5Dx phases, deuterium was located only on A2B2-type tetrahedral interstitial sites. The occupation of these specific interstitial sites can be explained in terms of diffusion paths, maximized D-D distances, as well as, the preference of deuterium for interstitial sites coordinated by the largest number of Ce second-nearest-neighbors atoms. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Sandia Natl Labs, Analyt Mat Sci Dept, Livermore, CA 94551 USA. Univ Fribourg, Solid State Phys Grp, CH-1700 Fribourg, Switzerland. Paul Scherrer Inst, SLS, CH-5232 Villigen, Switzerland. RP Gross, KJ (reprint author), Sandia Natl Labs, Analyt Mat Sci Dept, POB 969 MS 9403, Livermore, CA 94551 USA. RI Fauth, Francois/K-9643-2014 OI Fauth, Francois/0000-0001-9465-3106 NR 23 TC 11 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 23 PY 2000 VL 306 IS 1-2 BP 203 EP 218 DI 10.1016/S0925-8388(00)00745-3 PG 16 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 328XL UT WOS:000087877000032 ER PT J AU Garguilo, MG Thomas, DH Anex, DS Rakestraw, DJ AF Garguilo, MG Thomas, DH Anex, DS Rakestraw, DJ TI Laser-induced dispersed fluorescence detection of polycyclic aromatic compounds in soil extracts separated by capillary electrochromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE laser-induced dispersed fluorescence; deconvolution; soil extracts; polynuclear aromatic compounds ID TRANSFER DEVICE DETECTORS; CHARGE-TRANSFER DEVICES; LIQUID-CHROMATOGRAPHY; PSEUDOSTATIONARY PHASES; ZONE ELECTROPHORESIS; CHEMICAL-ANALYSIS; COUPLED-DEVICE; PERFORMANCE; SPECTROSCOPY; FLUORIMETRY AB Polycyclic aromatic hydrocarbons (PAHs) and nitrogen containing aromatic compounds (NCACs) are characterized in soil extracts and laboratory standards by capillary electrochromatography (CEC) with laser-induced dispersed fluorescence (LIDF) detection using a liquid-nitrogen cooled charge-coupled device detector. The LIDF detection technique provides information on compound identity and, when coupled with the high separation efficiencies of the CEC technique, proves useful in the analysis of complex mixtures. Differences in fluorescence spectra also provide a means of identifying co-eluting compounds by using deconvolution algorithms. Detection limits range from 0.5 to 96x10(-10) M for selected PAHs and 0.9-3.7x10(-10) M for selected NCACs. Soil extracts are also injected onto the CEC column to evaluate chromatographic method performance with respect to complex samples and the ability to withstand exposure to environmental samples. (C) 2000 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Garguilo, MG (reprint author), PE Biosyst, 850 Lincoln Ctr Dr, Foster City, CA 94404 USA. NR 36 TC 8 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUN 23 PY 2000 VL 883 IS 1-2 BP 231 EP 248 DI 10.1016/S0021-9673(00)00409-X PG 18 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 330GN UT WOS:000087954600022 PM 10910217 ER PT J AU Raikhel, NV AF Raikhel, NV TI Plant cell vacuoles - An introduction SO SCIENCE LA English DT Book Review C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. RP Raikhel, NV (reprint author), Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. NR 1 TC 0 Z9 0 U1 2 U2 5 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 JUN 23 PY 2000 VL 288 IS 5474 BP 2138 EP 2138 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 327FH UT WOS:000087782900023 ER PT J AU deMenocal, P Ortiz, J Guilderson, T Sarnthein, M AF deMenocal, P Ortiz, J Guilderson, T Sarnthein, M TI Coherent high- and low-latitude climate variability during the holocene warm period SO SCIENCE LA English DT Article ID GREENLAND ICE; SEA; TEMPERATURES; INSTABILITY; MIDHOLOCENE; AFRICA; EVENT; CORE; AGE; BP AB A faunal record of sea-surface temperature (SST) variations off West Africa documents a series of abrupt, millennial-scale cooling events, which punctuated the Holocene warm period. These events evidently resulted from increased southward advection of cooler temperate or subpolar waters to this subtropical location or from enhanced regional upwelling. The most recent of these events was the Little Ice Age, which occurred between 1300 to 1850 A.D., when subtropical SSTs were reduced by 3 degrees to 4 degrees C. These events were synchronous with Holocene changes in subpolar North Atlantic SSTs, documenting a strong, in-phase link between millennial-scale variations in high- and Low-latitude climate during the Holocene. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ Kiel, Inst Geowissensch, Kiel, Germany. RP deMenocal, P (reprint author), Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RI demenocal, peter/B-1386-2013; Ortiz, Joseph/E-1144-2011 OI demenocal, peter/0000-0002-7191-717X; Ortiz, Joseph/0000-0002-6583-3850 NR 34 TC 418 Z9 441 U1 7 U2 62 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 JUN 23 PY 2000 VL 288 IS 5474 BP 2198 EP 2202 DI 10.1126/science.288.5474.2198 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 327FH UT WOS:000087782900054 ER PT J AU D'Azevedo, EF AF D'Azevedo, EF TI Are bilinear quadrilaterals better than linear triangles? SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE mesh generation; interpolation; quadrilateral patch; triangulation; bilinear approximation ID TRIANGULAR MESH GENERATION; METRIC SPECIFICATIONS; ERROR AB This paper compares the theoretical effectiveness of bilinear approximation over quadrilaterals with linear approximation over triangles. Anisotropic mesh transformation is used to generate asymptotically optimally efficient meshes for piecewise linear interpolation over triangles and bilinear interpolation over quadrilaterals. For approximating a convex function, although bilinear quadrilaterals are more efficient, linear triangles are more accurate and may be preferred in finite element computations; whereas for saddle-shaped functions, quadrilaterals may over a higher-order approximation on a well-designed mesh. A surprising finding is different grid orientations may yield an order of magnitude improvement in approximation accuracy. C1 Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. RP D'Azevedo, EF (reprint author), Oak Ridge Natl Lab, Math Sci Sect, POB 2008,Bldg 6012, Oak Ridge, TN 37831 USA. NR 19 TC 18 Z9 19 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUN 23 PY 2000 VL 22 IS 1 BP 198 EP 217 DI 10.1137/S106482759630406X PG 20 WC Mathematics, Applied SC Mathematics GA 334BP UT WOS:000088165500010 ER PT J AU de Almeida, VF Derby, JJ AF de Almeida, VF Derby, JJ TI Construction of solution curves for large two-dimensional problems of steady-state flows of incompressible fluids SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE incompressible and viscous fluids; Navier-Stokes equations; parameter continuation; path following; factorization of large unsymmetric sparse matrices; lid driven cavity ID MATERIALS PROCESSING SYSTEMS; ALGORITHMS; EQUATIONS; REDUCTION; PROFILE AB This work represents a step toward advancing classical methods of bifurcation analysis in conjunction with very large-scale scientific computing needed to model realistically processes which involve laminar and steady flows of incompressible fluids. A robust method of analysis based on pseudoarclength continuation, Newton's method, and direct solution of linear systems is proposed and applied to the analysis of a representative system of fluid mechanics, namely the tilted lid driven cavity. Accurate solution curves, possessing simple singular points, were computed for Reynolds numbers varying from 0 to 10,000 and for different angles of tilt. The results demonstrate that two-dimensional models with up to 1,000,000 algebraic equations can be studied feasibly using the methods described here with state-of-the-art vector supercomputers. C1 USA, Dept Chem Engn & Mat Sci, High Performance Comp Res Ctr, Minneapolis, MN 55455 USA. Univ Minnesota, Minnesota Supercomp Inst, Minneapolis, MN 55455 USA. RP de Almeida, VF (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Derby, Jeffrey/B-9706-2009; de Almeida, Valmor/P-5498-2016; OI de Almeida, Valmor/0000-0003-0899-695X; Derby, Jeffrey/0000-0001-6418-2155 NR 27 TC 4 Z9 4 U1 1 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUN 23 PY 2000 VL 22 IS 1 BP 285 EP 311 DI 10.1137/S1064827598334514 PG 27 WC Mathematics, Applied SC Mathematics GA 334BP UT WOS:000088165500014 ER PT J AU Garbey, M Kaper, HG AF Garbey, M Kaper, HG TI Asymptotic-numerical study of supersensitivity for generalized Burgers' equations SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE asymptotic analysis; domain decomposition; Burgers' equation; viscous conservation laws; transition layers; supersensitivity ID NAVIER-STOKES EQUATIONS; DOMAIN DECOMPOSITION; VISCOUS SHOCK; MOTION AB This article addresses some asymptotic and numerical issues related to the solution of Burgers' equation, -epsilon u(xx) + u(t) + uu(x) = 0 on (-1, 1), subject to the boundary conditions u(-1) = 1+delta, u(1) = -1, and its generalization to two dimensions, -epsilon Delta u + u(t) + uu(x) + uu(y) = 0 on (-1, 1) x (-pi, pi), subject to the boundary conditions u\(x=1) = 1 + delta, u \(x=-1) = 1, with 2 pi periodicity in y. The perturbation parameters and are arbitrarily small positive and independent; when they approach 0, they satisfy the asymptotic order relation delta = O(s)(e(-a/epsilon)) for some constant a is an element of (0, 1). The solutions of these convection-dominated viscous conservation laws exhibit a transition layer in the interior of the domain, whose position as t --> infinity is supersensitive to the boundary perturbation. Algorithms are presented for the computation of the position of the transition layer at steady state. The algorithms generalize to viscous conservation laws with a convex nonlinearity and are scalable in a parallel computing environment. C1 Univ Lyon 1, ISTIL, CDCSP, F-69622 Villeurbanne, France. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Garbey, M (reprint author), Univ Lyon 1, ISTIL, CDCSP, F-69622 Villeurbanne, France. EM garbey@cdcsp.univ-lyon1.fr; kaper@mcs.anl.gov NR 36 TC 12 Z9 12 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUN 23 PY 2000 VL 22 IS 1 BP 368 EP 385 DI 10.1137/S1064827598342201 PG 18 WC Mathematics, Applied SC Mathematics GA 334BP UT WOS:000088165500018 ER PT J AU Qi, F Sorkhabi, O Suits, AG AF Qi, F Sorkhabi, O Suits, AG TI Evidence of triplet ethylene produced from photodissociation of ethylene sulfide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ADVANCED LIGHT-SOURCE; CHEMICAL-DYNAMICS; ELECTRON-IMPACT; 193 NM; SINGLET; EXCITATION; RESOLUTION; THIIRANE; BEAMLINE; STATE AB Tunable synchrotron radiation has been used to probe the dissociation dynamics of ethylene sulfide, providing selective determination of the translational energy distributions of both excited (D-1) and ground-state (P-3) sulfur atoms, with momentum-matching to the ethylene cofragments. The results suggest the presence of a channel giving S(P-3) in conjunction with triplet ethylene C2H4 (B-3(1u)), and allow for the first experimental measure of the energy of the latter species near the equilibrium geometry, in which the two methylene groups occupy perpendicular planes. (C) 2000 American Institute of Physics. [S0021-9606(00)02524-1]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Qi, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RI Qi, Fei/A-3722-2012 NR 25 TC 24 Z9 24 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 2000 VL 112 IS 24 BP 10707 EP 10710 DI 10.1063/1.481713 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 324HY UT WOS:000087617300004 ER PT J AU Wyatt, RE Kouri, DJ Hoffman, DK AF Wyatt, RE Kouri, DJ Hoffman, DK TI Quantum wave packet dynamics with trajectories: Implementation with distributed approximating functionals SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TIME-DEPENDENT SCHRODINGER; STATE REACTIVE SCATTERING; FOKKER-PLANCK EQUATION; BURGERS-EQUATION; PROPAGATOR AB The quantum trajectory method (QTM) was recently developed to solve the hydrodynamic equations of motion in the Lagrangian, moving-with-the-fluid, picture. In this approach, trajectories are integrated for N fluid elements (particles) moving under the influence of both the force from the potential surface and from the quantum potential. In this study, distributed approximating functionals (DAFs) are used on a uniform grid to compute the necessary derivatives in the equations of motion. Transformations between the physical grid where the particle coordinates are defined and the uniform grid are handled through a Jacobian, which is also computed using DAFs. A difficult problem associated with computing derivatives on finite grids is the edge problem. This is handled effectively by using DAFs within a least squares approach to extrapolate from the known function region into the neighboring regions. The QTM-DAF is then applied to wave packet transmission through a one-dimensional Eckart potential. Emphasis is placed upon computation of the transmitted density and wave function. A problem that develops when part of the wave packet reflects back into the reactant region is avoided in this study by introducing a potential ramp to sweep the reflected particles away from the barrier region. (C) 2000 American Institute of Physics. [S0021-9606(00)00224-5]. C1 Univ Texas, Inst Theoret Chem, Dept Chem & Biochem, Austin, TX 78712 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Wyatt, RE (reprint author), Univ Texas, Inst Theoret Chem, Dept Chem & Biochem, Austin, TX 78712 USA. NR 47 TC 39 Z9 39 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 2000 VL 112 IS 24 BP 10730 EP 10737 AR PII [S0021-9606(00)00224-5] DI 10.1063/1.481717 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 324HY UT WOS:000087617300008 ER PT J AU Glaesemann, KR Gordon, MS AF Glaesemann, KR Gordon, MS TI Auxiliary basis sets for grid-free density functional theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-ORBITAL METHODS; GAUSSIAN-TYPE BASIS; PERTURBATION-THEORY; ORGANIC-MOLECULES; EXACT-EXCHANGE; ENERGY; ATOMS; DFT; APPROXIMATIONS; PERFORMANCE AB Density functional theory (DFT) has gained popularity because it can frequently give accurate energies and geometries. The evaluation of DFT integrals in a fully analytical manner is generally impossible; thus, most implementations use numerical quadrature over grid points. The grid-free approaches were developed as a viable alternative based upon the resolution of the identity (RI). Of particular concern is the convergence of the RI with respect to basis set in the grid-free approach. Conventional atomic basis sets are inadequate for fitting the RI, particularly for gradient corrected functionals [J. Chem. Phys. 108, 9959 (1998)]. The focus of this work is on implementation of and selection of auxiliary basis sets. Auxiliary basis sets of varying sizes are studied and those with sufficient flexibility are found to adequately represent the RI. (C) 2000 American Institute of Physics. [S0021-9606(00)30424-X]. C1 Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. RP Glaesemann, KR (reprint author), Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. RI Glaesemann, Kurt/B-4841-2010; OI Glaesemann, Kurt/0000-0002-9512-1395 NR 52 TC 8 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 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 2000 VL 112 IS 24 BP 10738 EP 10745 AR PII [S0021-9606(00)30424-X] DI 10.1063/1.481763 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 324HY UT WOS:000087617300009 ER PT J AU Liu, JB Chen, WW Hsu, CW Hochlaf, M Evans, M Stimson, S Ng, CY AF Liu, JB Chen, WW Hsu, CW Hochlaf, M Evans, M Stimson, S Ng, CY TI High resolution pulsed field ionization-photoelectron study of CO2+(X (2)Pi(g)) in the energy range of 13.6-14.7 eV SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLUORESCENCE QUANTUM YIELDS; SYNCHROTRON-RADIATION; THRESHOLD PHOTOELECTRON; EMISSION-SPECTRUM; RESOLVED PHOTOELECTRON; ELECTRONIC STATES; CARBON-DIOXIDE; BAND SYSTEM; SPECTROSCOPY; PHOTOIONIZATION AB The vacuum ultraviolet pulsed field ionization-photoelectron (PFI-PE) spectra for CO2 have been measured in the energy range of 13.6-14.7 eV, revealing complex vibronic structures for the ground CO2+(X (2)Pi(g)) state. Many vibronic bands for CO2+(X (2)Pi(g)), which were not resolved in previous photoelectron studies, are identified in the present measurement based on comparison with available optical data and theoretical predictions. As observed in the HeI photoelectron spectrum of CO2, the PFI-PE spectrum is dominated by the symmetry allowed nu(1)(+) (symmetric stretch) vibrational progression for CO2+(X (2)Pi(g)). However, PFI-PE vibronic bands due to excitation of the symmetry disallowed nu(2)(+) (bending) and nu(3)(+) (asymmetric stretch) modes with both odd quanta, together with the symmetry allowed even quanta excitations, are clearly discernible. The simulation of rotational contours resolved in PFI-PE vibronic bands associated with excitation to the (nu(1)(+) = 0-1, nu(2)(+) = 0-2, nu(3)(+) = 0) vibrational levels has yielded accurate ionization energies for the formation of these vibronic states from CO2(X (1)Sigma(g)(+)). (C) 2000 American Institute of Physics. [S0021-9606(00)00124-0]. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Marne La Vallee, Theoret Chem Grp, F-77454 Champs Sur Marne, Marne La Vallee, France. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Ng, CY (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 55 TC 32 Z9 33 U1 2 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 2000 VL 112 IS 24 BP 10767 EP 10777 AR PII [S0021-9606(00)00124-0] DI 10.1063/1.481721 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 324HY UT WOS:000087617300013 ER PT J AU Gutzow, I Ilieva, D Babalievski, F Yamakov, V AF Gutzow, I Ilieva, D Babalievski, F Yamakov, V TI Thermodynamics and kinetics of the glass transition: A generic geometric approach SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COOLING RATE; ANALYTIC APPROACH; VITRIFICATION; TEMPERATURE; RELAXATION; DEPENDENCE; PARAMETER; PRESSURE AB A generic phenomenological theory of the glass transition is developed in the framework of a quasilinear formulation of the thermodynamics of irreversible processes. Starting from one of the basic principles of this science in its approximate form given by de Donder's equation, after a change of variables the temperature dependence of the structural parameter xi(T), the thermodynamic potentials Delta (G) over tilde(T), the thermodynamic functions and the time of molecular relaxation tau of vitrifying systems is constructed. In doing so, a new effect in the Delta (G) over tilde(T) course is observed. The analysis of the higher derivatives of the thermodynamic potential, and especially the nullification of the second derivative of the configurational specific heats Delta (C) over tilde(p)(T) of the vitrifying liquid defines glass transition temperature (T) over tilde(g) and leads directly to the basic dependence of glass transition kinetics: the Frenkel-Kobeko-Reiner equation. The conditions guaranteeing the fulfillment of this equation specify the temperature dependence of the activation energy U(T,<(xi)over tilde>) for viscous flow and give a natural differentiation of glass formers into fragile and strong liquids. The effect of thermal prehistory on the temperature dependence of both thermodynamic functions and kinetic coefficients is established by an appropriate separation of de Donder's equation. (C) 2000 American Institute of Physics. [S0021-9606(00)51024-1]. C1 Bulgarian Acad Sci, Inst Phys Chem, BU-1113 Sofia, Bulgaria. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Gutzow, I (reprint author), Bulgarian Acad Sci, Inst Phys Chem, BU-1113 Sofia, Bulgaria. NR 50 TC 33 Z9 33 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 2000 VL 112 IS 24 BP 10941 EP 10948 AR PII [S0021-9606(00)51024-1] DI 10.1063/1.481733 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 324HY UT WOS:000087617300032 ER PT J AU Redfern, PC Zapol, P Curtiss, LA Raghavachari, K AF Redfern, PC Zapol, P Curtiss, LA Raghavachari, K TI Assessment of Gaussian-3 and density functional theories for enthalpies of formation of C-1-C-16 alkanes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ELECTRONIC-STRUCTURE; LARGER MOLECULES; BOND SEPARATION; ENERGIES; THERMOCHEMISTRY; SET; COMPUTATION; GEOMETRIES; AFFINITIES; SPECTRA AB We have examined the performance of Gaussian-3 (G3) theory and six related methods for the calculation of enthalpies of formation of n-alkanes of up to 16 carbons and isoalkanes of up to 10 carbons. We have also examined the accuracy of the B3LYP density functional theory for the n-alkanes. The G3 enthalpies of formation of the n-alkanes have errors of less than 2 kcal/mol compared to experiment. There is a small accumulation of error (0.04 kcal/mol per bond) that increases the deviation with chain length. The effects of conformational averaging on the G3 enthalpies of the n-alkanes are estimated to be small, but are in the direction td reduce the error. The branched alkanes have errors of less than 1 kcal/mol. Four of the variations of G3 theory [G3(MP3), G3(MP2), G3(MP2)//B3LYP, and G3(MP2,CCSD)//B3LYP] also have errors similar to or smaller than G3 theory while two of the variations [G3(CCSD) and G3(MP2,CCSD)] have maximum errors for the n-alkanes of about 2.5 kcal/mol. The B3LYP method does very poorly for the calculation of enthalpies of formation of the larger n-alkanes with an error of over 30 kcal/mol for hexadecane. This suggests that B3LYP has a significant problem with accumulation of errors as the molecular size increases. Several schemes for correcting systematic errors in B3LYP calculations for large molecules are also explored. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zapol, Peter/G-1810-2012 OI Zapol, Peter/0000-0003-0570-9169 NR 30 TC 194 Z9 197 U1 0 U2 20 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 JUN 22 PY 2000 VL 104 IS 24 BP 5850 EP 5854 DI 10.1021/jp994429s PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 327FG UT WOS:000087782800022 ER PT J AU Gakh, AA Tuinman, AA AF Gakh, AA Tuinman, AA TI Chemical fragmentation of C60F48 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID IONIZATION MASS-SPECTROMETRY; HYPERFLUORINATION AB Complex mixtures of fused alicyclic fluorocarbons CnFm (n = 16-30, m = 30-50) were obtained during extensive fluorination of C-60 beyond C60F48 using elemental fluorine at elevated temperatures (275-325 degrees C), Analysis of these fluorocarbon mixtures (performed by GC-MS and NMR) demonstrated that the distribution of individual fluorocarbons in these mixtures is not random. A plausible computational model of the chemical fragmentation process was developed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Gakh, AA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 11 TC 11 Z9 11 U1 0 U2 3 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 JUN 22 PY 2000 VL 104 IS 24 BP 5888 EP 5891 DI 10.1021/jp994467b PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 327FG UT WOS:000087782800028 ER PT J AU Dutta, A Kmetko, J Yu, CJ Richter, AG Chung, KS Bai, JM Dutta, P AF Dutta, A Kmetko, J Yu, CJ Richter, AG Chung, KS Bai, JM Dutta, P TI pH-dependent appearance of chiral structure in a Langmuir monolayer SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID FATTY-ACID MONOLAYERS; X-RAY-DIFFRACTION; AIR-WATER-INTERFACE; BLODGETT-FILMS; PHASE; TRANSITIONS; ORDER; IONS AB Grazing incidence X-ray diffraction studies on a heneicosanoic (C-21) acid monolayer with cadmium ions in the subphase, at near-zero surface pressure and similar to 9 degrees C, show that there exists a pH "window" within which the monolayer takes on a chiral structure and an ordered superlattice is also observed. Below this pH window, the monolayer has a tilted structure like that of a pure fatty acid monolayer at low pressures, indicating negligible headgroup-ion interaction. Above the window, the monolayer goes to a structure very similar to the high-pressure untilted S phase seen in pure fatty acid monolayers. The chiral structure is never seen when cadmium is replaced by zinc, another divalent metal with only slightly lower electronegativity, or (as reported earlier) with calcium. Raising temperature within the cadmium pH window destroys the superlattice and takes the monolayer to the backbone-disordered Rotator-I structure. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. RP Kmetko, J (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RI Datta, Alokmay/C-1252-2008; Bai, Jianming/O-5005-2015 NR 19 TC 24 Z9 24 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 22 PY 2000 VL 104 IS 24 BP 5797 EP 5802 DI 10.1021/jp0006375 PG 6 WC Chemistry, Physical SC Chemistry GA 327FF UT WOS:000087782700020 ER PT J AU Lamport, DTA AF Lamport, DTA TI Showman barely blinked at a dose of nerve gas SO NATURE LA English DT Letter C1 Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. RP Lamport, DTA (reprint author), Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 22 PY 2000 VL 405 IS 6789 BP 882 EP 882 DI 10.1038/35016253 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 326JT UT WOS:000087732700018 PM 10879510 ER PT J AU Ritchie, B Minner, LD AF Ritchie, B Minner, LD TI Use of the continuity equation for electromagnetic energy flow to describe radiation transport SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID COLLISIONS AB In the geometric-optics limit the electromagnetic (EM) continuity equation, which describes EM energy flow, reduces to the radiation transport equation, in which energy flow is described generically as the motion of light (or particle) rays along straight-line trajectories in the direction of a unit vector (k) over cap. In practical applications (k) over cap is discretized, making the transport equation extremely difficult to implement computationally and giving rise to 'ray effect' distortions owing to the non-continuous distribution of the energy over (k) over cap. In this paper we solve the EM continuity equation directly in the transport regime, obtaining an energy which is continuously distributed in (k) over cap and free of ray distortion. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ritchie, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD JUN 21 PY 2000 VL 33 IS 12 BP 1470 EP 1477 DI 10.1088/0022-3727/33/12/307 PG 8 WC Physics, Applied SC Physics GA 331TQ UT WOS:000088035100008 ER PT J AU Wang, SJ Oldham, WJ Hudack, RA Bazan, GC AF Wang, SJ Oldham, WJ Hudack, RA Bazan, GC TI Synthesis, morphology, and optical properties of tetrahedral oligo(phenylenevinylene) materials SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID LIGHT-EMITTING DEVICES; AMORPHOUS MOLECULAR MATERIALS; GLASS-TRANSITION TEMPERATURES; FIELD-EFFECT TRANSISTORS; ORGANIC ELECTROLUMINESCENT DEVICES; HOLE-TRANSPORTING MATERIALS; THIN-FILM TRANSISTORS; CONJUGATED POLYMERS; THERMAL-STABILITY; THERMODYNAMIC PARAMETERS AB A novel topological strategy is described for designing amorphous molecular solids suitable for optoelectronic applications. In this approach, chromophores are attached to a tetrahdral point of convergence. Stilbenoid units were covalently linked to tetraphenylmethane, tetraphenyladamantane, or tetraphenylsilane cores using palladium catalyzed coupling methodology, Thus, reaction of E(C6H5X)(4) (E = C and adamantane, X = I; E = Si, X = Br) with styrene or 4,3'-tert-butylvinylstilbene under Heck coupling conditions yields the corresponding tetrakis(stillbenyl) (E(STB)(4)) and tetrakis(4-tert-butyIstyrylstilbenyl) (E((BuSSB)-Bu-t)(4)) compounds. Similarly, reaction of 1,1-diphenyl-2-(4-dihydroxyboronphenyl)ethene or 2-(4-pinacolatoboronphenyl)-3,3-diphenylacrylonitrile with tetrakis(4-bromophenyl)methane using Suzuki coupling methodology gives tetrakis(4,4'-(2,2-diphenyl-vinyl)-1,1'-biphenyl (C(DPVBi)(4)) or tetrakis(4,4'-(3,3-diphenylacrylonitrile biphenyl)methane (C(DPAB)(4)), respectively, in good yields. Compounds with more extended conjugation can also be prepared. Thus, reaction of excess 1-(4'-tert-butylstyryl)-4-(4'-vinylstyryl)benzene with C(C6H4I)(4) provides tetrakis(4-(4'-(4"-tert-butylstyryl)styryl)stilbenyl)methane (C(4R-Bu-t)(4)) in low yield (similar to 20%). The more soluble analogue, tetrakis(4-(4'-(3",5"-di-tert-butylstyryl)stilbenyl)methane (C(4R-2(t)Bu)(4)) is prepared similarly using 1-(3',5'-di-tert-butylstyryl)-4-(4'-vinylstyryl)benzene and in better yield (similar to 80%). Alkoxy substituents can also be used to increase solubility. Tetrakis((4-(2',5'-dioctyloxy-4'-styryl)styryl)stilbenyl)methane methane, C(4R-(OC8H17)(2))(4), was prepared by treatment of C(C6H4I)(4) with excess 2,5-dioctyloxy-1-styryl-4(4'-vinylstyryl)benzene (yield similar to 73%). The simple stilbenyl-derivatives were found by DSC measurements and powder diffraction experiments to be crystalline compounds. Comparison of single-crystal X-ray diffraction data shows that C(STB)(4) and Si(STB)(4) form isomorphous crystals. The larger E((BuSSB)-Bu-t)4, C(DPVBi)(4), and C(DPAB)(4) compounds readily form amorphous glasses with elevated glass transition temperatures (T-g = 142-190 degrees C) in the absence of solvent. Extending the conjugation length of the arm leads to more stable glasses. For example, the glass transition temperature of C(4R-Bu-t)(4) was measured at 230 degrees C. Solution phase optical spectroscopic data of E((BuSSB)-Bu-t)(4) (E = C, adamantane, and Si) are characteristic of the parent distyrylbenzene chromophore. Films, however, show broad and significantly red-shifted emission spectra. In contrast, C(DPVBi)(4) gives absorption and emission spectra which are nearly identical between dilute solution phase samples and neat solid films. The emission of C(DPAB)(4) is broad and structureless, reminiscent of exciplex or excimer emission. Films of the tetramers with longer arms (C(4R-Bu-t)(4), C(4R-2(t)Bu)(4), and C(4R-(OC8H17)(2))(4)) show emission properties which are dependent on sample history. Annealing the sample at elevated temperature leads to red-shifted emission as a result of better interdigitation between the optically active fragments. C1 Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bazan, GC (reprint author), Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RI Bazan, Guillermo/B-7625-2014 NR 105 TC 257 Z9 263 U1 9 U2 107 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 JUN 21 PY 2000 VL 122 IS 24 BP 5695 EP 5709 DI 10.1021/ja992924w PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA 328HX UT WOS:000087845700003 ER PT J AU DuBois, JL Mukherjee, P Stack, TDP Hedman, B Solomon, EI Hodgson, KO AF DuBois, JL Mukherjee, P Stack, TDP Hedman, B Solomon, EI Hodgson, KO TI A systematic K-edge X-ray absorption spectroscopic study of Cu(III) sites SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID HIGH-TC SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; GALACTOSE-OXIDASE; MOLECULAR-STRUCTURE; ACTIVE-SITE; CRYSTAL-STRUCTURE; COPPER-COMPLEXES; OXIDATION-STATE; CU; CORE AB Highly oxidized metals are constituents of oxidants, reactive intermediates, and materials with interesting conductive and magnetic properties. High-energy spectroscopies have played an important role in identifying and describing the bonding character of highly oxidized metals in these materials. A systematic study of Cu(III) K-edge X-ray absorption spectra was carried out to identify analytically useful signatures of Cu(III) in the K-edge, and to elucidate bonding descriptions for Cu(III)-containing complexes. K-edges for six Cu(III) complexes and their same-ligand Cu(II) counterparts are compared. Edges for the Cu(III) species generally appear at higher energies than their Cu(II) counterparts, though energy shifts between most individual edge features vary. However, for all Cu(III) compounds studied, the 1s --> 3d transition in the preedge energy range exhibits a distinct, 2 eV shift to higher energy, relative to the known and relatively unvarying energy of the 1s --> 3d transition in Cu(II) species. This energy shift provides a direct means of distinguishing Cu(III) from Cu(II). The K-edge for a complex containing Cu(II) coordinated to a 1e(-)-oxidized ligand (phenoxyl) does not show such a change in the 1s --> 3d transition energy. The analytical, potential of the Cu K-edge was tested with good success using a mixed-valent trinuclear species. Cu(III) is detectable using the K-edge. The limitations of the K-edge as a Cu(III) analytical probe are discussed. An analysis applied to the 1s --> 4p and 1s --> 4p + shakedown transitions in the edge for a {Cu-2(II)(mu-OH)(2)}(2)(+) dimer, using a configurational interaction (CI) model, predicted similar to 75% d-character in the ground state. A similar analysis of the K-edge for (Cu-2(III)(mu-O)(2)}(2+) indicates that the Cu in this complex has far more covalent bonds with the oxo bridging ligands (d-character similar to 60%). C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Stack, TDP (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. NR 76 TC 121 Z9 121 U1 1 U2 25 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 JUN 21 PY 2000 VL 122 IS 24 BP 5775 EP 5787 DI 10.1021/ja993134p PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 328HX UT WOS:000087845700012 ER PT J AU Gabuzda, DC Kochenov, PY Kollgaard, RI Cawthorne, TV AF Gabuzda, DC Kochenov, PY Kollgaard, RI Cawthorne, TV TI VLBI and VLA observations of intraday polarization variability in 0917+624 and 0954+658 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE polarization; BL Lacertae objects : individual : 0954+658; galaxies : jets; quasars : individual : 0917+624; radio continuum : galaxies ID BL-LACERTAE OBJECTS; EXTRAGALACTIC RADIO-SOURCES; INTERSTELLAR SCINTILLATION; MILLIARCSECOND RESOLUTION; RAPID VARIABILITY; QUASAR 0917+624; MODEL; SCATTERING; SPECTRUM; SAMPLE AB Total intensity and polarization lambda = 6 cm Very Large Array (VLA) and global very long baseline interferometry (VLBI) images of the quasar 0917+624 and the BL Lacertae object 0954+658 (both at epoch 1991.43) are analysed. Integrated measurements using the VLA during the VLBI observations indicated that, although there were no substantial total intensity variations, there were significant polarization variations for both sources during the 24-h VLBI experiment. The VLBI data were divided into 2-3 h segments in order to try to identify corresponding rapid variability in the VLBI structure. This analysis revealed intraday variability (IDV) in the VLBI core of 0917+624: both the polarized flux and the polarization position angle varied substantially on time-scales of similar to 5-10 h. There is evidence that the VLA polarization variations for 0954+658 occurred in an inner VLBI jet component, where the polarized flux varied by similar to 30-40 per cent on time-scales of similar to 2 h. 0917+624 and 0954+658 were observed together with 0716+714, an object that also displayed IDV in the polarized flux density measured during our experiment (analysed in a separate paper). These three sources were targeted for the VLBI observations since they had been previously identified as intraday variables, but we had no way of knowing whether they would vary during our observations. The fact that all three exhibited IDV in polarization (but not in total intensity) during our experiment suggests that polarization IDV occurs frequently in at least some IDV sources. C1 VLBI Europe, Joint Inst, NL-7990 AA Dwingeloo, Netherlands. PN Lebedev Phys Inst, Astro Space Ctr, Moscow 117924, Russia. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Cent Lancashire, Dept Phys & Astron, Preston PR1 2HE, Lancs, England. RP Gabuzda, DC (reprint author), VLBI Europe, Joint Inst, Postbus 2, NL-7990 AA Dwingeloo, Netherlands. NR 33 TC 13 Z9 13 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 21 PY 2000 VL 315 IS 2 BP 229 EP 240 DI 10.1046/j.1365-8711.2000.03400.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330AY UT WOS:000087941700006 ER PT J AU Chernov, VA Kim, SK Kovalenko, NV Zolotarev, KV AF Chernov, VA Kim, SK Kovalenko, NV Zolotarev, KV TI Enhanced reflectance X-ray absorption fine structure sensitivity using a whispering-gallery waveguide SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 12th National Synchrotron Radiation Conference (SR'98) CY JUL 14-18, 1998 CL NOVOSIBIRSK, RUSSIA SP Minist Sci & Technol, Siberian Branch Russian Acad Sci, Russian Fund Basic Res DE XAFS; X-ray waveguides; surface; total reflection ID REGIONS AB A new technique of reflectance X-ray absorption fine structure (REFL-XAFS) utilizing waveguides where X-rays are reflected many times along the waveguide surface is discussed. The multiple total reflection (MTR) phenomenon highly increases X-ray interaction with the waveguide surface and hence offers higher sensitivity compared to conventional (single reflection) REFL-XAFS. On the one hand, this technique is a direct structural method for characterizing waveguides (e.g. capillaries) where the application of other methods is very difficult. On the other hand, the conventional thin wafer can be transformed to a whispering-gallery (WG) waveguide by bending to a curved mirror. Ray tracing calculations demonstrate that the WG waveguide is very suitable for REFL-XAFS measurements. This method was experimentally realized for a cylindrically bent silica wafer with the surface covered with a GeO2 monolayer. The Ge K-edge REFL-XAFS measurements were performed using both MTR and conventional techniques. The MTR technique allows us to achieve about 20-fold gain in the signal-to-background ratio compared with the conventional technique. The MTR phenomenon discussed in this paper can provide new possibilities to study clean surfaces, ultrathin films and adsorbed molecules. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Inst Phys Nucl, Siberian SR Ctr, Budker INP, Novosibirsk 630090, Russia. Boreskov Inst Catalysis, Novosibirsk 630090, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. New Ind Res Org, Chuo Ku, Kobe, Hyogo 6500047, Japan. RP Chernov, VA (reprint author), Inst Phys Nucl, Siberian SR Ctr, Budker INP, 11 Lavrentyev Ave, Novosibirsk 630090, Russia. RI Kim, Sang-Koog/J-4638-2014 NR 11 TC 1 Z9 2 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 JUN 21 PY 2000 VL 448 IS 1-2 BP 173 EP 178 DI 10.1016/S0168-9002(00)00216-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336BR UT WOS:000088282500037 ER PT J AU Irving, TC Fischetti, R Rosenbaum, G Bunker, GB AF Irving, TC Fischetti, R Rosenbaum, G Bunker, GB CA Biophysics Collaborative Acess Tea TI Fiber diffraction using the BioCAT undulator beamline at the Advanced Photon Source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 12th National Synchrotron Radiation Conference (SR'98) CY JUL 14-18, 1998 CL NOVOSIBIRSK, RUSSIA SP Minist Sci & Technol, Siberian Branch Russian Acad Sci, Russian Fund Basic Res DE synchrotron; undulator; fiber diffraction; biology; muscle AB The BioCAT undulator-based beamline at the Advanced Photon Source, Argonne IL, USA is designed to be a state-of-the-art instrument for biological non-crystalline diffraction and X-ray absorption spectroscopy. The optics consist of double crystal monochromators with sagitally focussing second crystals followed by a vertically focussing mirror which allow independent focussing of the beam in the vertical and horizontal directions virtually anywhere along the length of the 12 m experimental enclosure. When configured for a 2 m fiber diffraction camera, a focal spot of less than 40 x 200 mu m (FWHM) has been observed which contained essentially all of the 1.5-2.5 x 10(13) ph/s delivered by the cryogenically-cooled Si(1 1 1) double crystal monochromator. This combination of highly demagnifying optics and the very low divergence of the very small source have yielded excellent quality patterns from various muscle specimens and collagen-containing tissues. Detectors available include a Fuji BAS2500 image plate scanner and a 1kx1k CCD detector optimized for small-angle applications. Future developments will include, in vacuum beam monitoring, longer camera lengths (6-8 m), and optimizations to improve first-order resolution in small-angle applications. (C) 2000 Elsevier Science B.V. All rights reserved. C1 IIT, Dept Biol Chem & Phys Sci, Chicago, IL 60616 USA. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP Irving, TC (reprint author), IIT, Dept Biol Chem & Phys Sci, 3101 S Dearborn St, Chicago, IL 60616 USA. RI ID, BioCAT/D-2459-2012 NR 6 TC 19 Z9 19 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 JUN 21 PY 2000 VL 448 IS 1-2 BP 250 EP 254 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 336BR UT WOS:000088282500052 ER PT J AU Li, H Kusunose, M AF Li, H Kusunose, M TI Temporal and spectral variabilities of high-energy emission from blazars using synchrotron self-compton models SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; gamma rays : theory; radiation mechanisms : nonthermal ID GAMMA-RAY EMISSION; LACERTAE OBJECT MARKARIAN-421; MULTIWAVELENGTH OBSERVATIONS; PAIR PLASMAS; X-RAY; FLARE; JETS; ACCELERATION AB Multiwavelength observations of blazars such as Mrk 421 and Mrk 501 show that they exhibit strong short time variabilities in flarelike phenomena. Working from the homogeneous synchrotron self-Compton (SSC) model and assuming that time variability of the emission is initiated by changes in the injection of nonthermal electrons, we perform detailed temporal and spectral studies of a purely cooling plasma system using parameters appropriate to blazars. One Important parameter is the total injected energy E, and we show how the synchrotron and Compton components respond as E varies. When the synchrotron and SSC components have comparable peak fluxes, we find that the SSC process contributes strongly to the electron cooling and that the whole system is nonlinear; thus, simultaneously solving electron and photon kinetic equations is necessary. In the limit of the injection-dominated situation when the cooling timescale is long, we find a unique set of model parameters that are fully constrained by observable quantities. In the limit of the cooling-dominated situation, TeV emissions arise mostly from a cooled electron distribution and the Compton scattering process is always in the Klein-Nishina regime, which gives the TeV spectrum a large curvature. Furthermore, even in a single-injection event, the multiwavelength light curves do not necessarily track each other because the electrons that are responsible for those emissions might have quite different lifetimes. We discuss in detail how one could infer important physical parameters using the observed spectra. In particular, we could infer the size of the emission region by looking for exponential decay in the light curves. We could also test the basic assumption of the SSC model by measuring the difference in the rate of peak energy changes of synchrotron and SSC peaks. We also show that the trajectory in the photon index-flux plane evolves clockwise or counterclockwise depending on the value of E and the observed energy bands. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kwansei Gakuin Univ, Sch Sci, Dept Phys, Nishinomiya, Hyogo 6628501, Japan. RP Li, H (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Astrophys T-6,MS B288, Los Alamos, NM 87545 USA. NR 31 TC 64 Z9 64 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 729 EP 741 DI 10.1086/308960 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900018 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Geha, M Griest, R Lehner, MJ Marshall, SL McNamara, BJ Minniti, D Nelson, C Peterson, BA Popowski, P Pratt, MR Quinn, PJ Rodgers, AW Sutherland, W Templeton, MR Vandehei, T Welch, DL AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Geha, M Griest, R Lehner, MJ Marshall, SL McNamara, BJ Minniti, D Nelson, C Peterson, BA Popowski, P Pratt, MR Quinn, PJ Rodgers, AW Sutherland, W Templeton, MR Vandehei, T Welch, DL TI The MACHO project sample of galactic bulge high-amplitude delta Scuti stars: Pulsation behavior and stellar properties SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxy : center; stars : blue stragglers; stars : fundamental parameters; stars : oscillations; stars : variables : delta Scuti ID BLUE STRAGGLERS; VARIABLE-STARS; LIGHT CURVES; BAADE-WINDOW; DATABASE AB We have detected 90 objects with periods and light-curve structures similar to those of held delta Scuti stars using the Massive Compact Halo Object (MACHO) Project database of Galactic bulge photometry. If we assume similar extinction values for all candidates and absolute magnitudes similar to those of other field high-amplitude delta Scuti stars (HADS), the majority of these objects lie in or near the Galactic bulge. At least two of these objects are likely foreground delta Scuti stars, one of which may be an evolved nonradial pulsator, similar to other evolved, disk-population delta Scuti stars. We have analyzed the light curves of these objects and find that they are similar to the light curves of held delta Scuti stars and the delta Scuti stars found by the Optical Gravitational Lens Experiment (OGLE). However, the amplitude distribution of these sources lies between those of low- and high-amplitude delta Scuti stars, which suggests that they may be an intermediate population. We have found nine double-mode HADS with frequency ratios ranging from 0.75 to 0.79, four probable double- and multiple-mode objects, and another four Objects with marginal detections of secondary modes. The low frequencies (5-14 cycles day(-1)) and the observed period ratios of similar to 0.77 suggest that the majority of these objects are evolved stars pulsating in fundamental or first overtone radial modes. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. European So Observ, D-85748 Garching, Germany. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Univ Calif Los Alamos Natl Lab, Thermonucl Applicat Grp, X Div, Los Alamos, NM 87545 USA. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Quinn, Peter/B-3638-2013 NR 40 TC 17 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 798 EP 815 DI 10.1086/308979 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900024 ER PT J AU Brachwitz, F Dean, DJ Hix, WR Iwamoto, K Langanke, K Martinez-Pinedo, G Nomoto, K Strayer, MR Thielemann, FK Umeda, H AF Brachwitz, F Dean, DJ Hix, WR Iwamoto, K Langanke, K Martinez-Pinedo, G Nomoto, K Strayer, MR Thielemann, FK Umeda, H TI The role of electron captures in Chandrasekhar-mass models for Type Ia supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE nuclear reactions, nucleosynthesis, abundances; supernovae : general; white dwarfs ID WEAK-INTERACTION RATES; GAMOW-TELLER STRENGTH; ACCRETION-INDUCED COLLAPSE; NUCLEAR SHELL-MODEL; WHITE-DWARFS; MONTE-CARLO; LIGHT CURVES; NUCLEOSYNTHESIS; FE-54; DISTRIBUTIONS AB The Chandrasekhar-mass model for Type Ia supernovae (SNe Ia) has received increasing support from recent comparisons of observations with light-curve predictions and modeling of synthetic spectra. It explains SN Ia events via thermonuclear explosions of accreting white dwarfs in binary stellar systems, being caused by central carbon ignition when the white dwarf approaches the Chandrasekhar mass. As the electron gas in white dwarfs is degenerate, characterized by high Fermi energies for the high-density regions in the center, electron capture on intermediate-mass and Fe group nuclei plays an important role in explosive burning. Electron capture affects the central electron fraction Y-e, which determines the composition of the ejecta from such explosions. Up to the present, astrophysical tabulations based on shell model matrix elements were available only for light nuclei in the sd-shell. Recently, new shell model Monte Carlo and large-scale shell model diagonalization calculations have also been performed for pf-shell nuclei. These lead in general to a reduction of electron capture rates in comparison with previous, more phenomenological, approaches. Making use of these new shell model-based rates, we present the first results for the composition of Fe group nuclei produced in the central regions of SNe Ia and possible changes in the constraints on model parameters like ignition densities pi,, and burning front speeds v(def). C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Nihon Univ, Dept Phys, Tokyo 1018308, Japan. Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Tokyo 1130033, Japan. Univ Tokyo, Dept Astron, Tokyo 1130033, Japan. RP Univ Basel, Dept Phys & Astron, Klingelbergstr B2, CH-4056 Basel, Switzerland. RI Hix, William/E-7896-2011; Nomoto, Ken'ichi/A-4393-2011; Martinez-Pinedo, Gabriel/A-1915-2013 OI Hix, William/0000-0002-9481-9126; Martinez-Pinedo, Gabriel/0000-0002-3825-0131 NR 61 TC 96 Z9 98 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 934 EP 947 DI 10.1086/308968 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900037 ER PT J AU Mauskopf, PD Ade, PAR de Bernardis, P Bock, JJ Borrill, J Boscaleri, A Crill, BP DeGasperis, G De Troia, G Farese, P Ferreira, PG Ganga, K Giacometti, M Hanany, S Hristov, VV Iacoangeli, A Jaffe, AH Lange, AE Lee, AT Masi, S Melchiorri, A Melchiorri, F Miglio, L Montroy, T Netterfield, CB Pascale, E Piacentini, F Richards, PL Romeo, G Ruhl, JE Scannapieco, E Scaramuzzi, F Stompor, R Vittorio, N AF Mauskopf, PD Ade, PAR de Bernardis, P Bock, JJ Borrill, J Boscaleri, A Crill, BP DeGasperis, G De Troia, G Farese, P Ferreira, PG Ganga, K Giacometti, M Hanany, S Hristov, VV Iacoangeli, A Jaffe, AH Lange, AE Lee, AT Masi, S Melchiorri, A Melchiorri, F Miglio, L Montroy, T Netterfield, CB Pascale, E Piacentini, F Richards, PL Romeo, G Ruhl, JE Scannapieco, E Scaramuzzi, F Stompor, R Vittorio, N TI Measurement of a peak in the cosmic microwave background power spectrum from the North American test flight of Boomerang SO ASTROPHYSICAL JOURNAL LA English DT Article DE balloons; cosmic microwave background; cosmology : observations; instrumentation : photometers; methods : data analysis; telescopes ID LOSING INFORMATION; ANISOTROPY; MAPS; SUBMILLIMETER; JUPITER AB We describe a measurement of the angular power spectrum of anisotropies in the cosmic microwave background (CMB) at scales of 0 degrees.3 to 5 degrees from the North American test flight of the Boomerang experiment. Boomerang is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a long-duration balloon flight. During a 6 hr test flight of a prototype system 1997, we mapped more than 200 deg(2) at high Galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26' and 16.'5 FWHM, respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of 1 degrees with an amplitude 70 K-mu(CMB). C1 Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. Univ Wales, Dept Phys & Astron, Cardiff CF1 3NS, S Glam, Wales. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. Univ La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. LBNL, Natl Energy Res Sci Comp Ctr, Berkeley, CA USA. CNR, Ist Ric Onde Elettromagneitche, Florence, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Inst Super Tecn, Ctr Multidisciplinar Astrofis, Lisbon, Portugal. CERN, Div Theory, CH-1211 Geneva, Switzerland. Coll France, F-75231 Paris 05, France. Ctr Infrared Proc & Anal, Pasadena, CA USA. Univ Minnesota, Dept Phys, Minneapolis, MN 55455 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Geneva, Dept Phys Theor, CH-1211 Geneva, Switzerland. Univ Toronto, Dept Phys, Toronto, ON, Canada. Univ Toronto, Dept Astron, Toronto, ON, Canada. Ist Nazl Geofis, I-00161 Rome, Italy. RP Mauskopf, PD (reprint author), Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA. RI Jaffe, Andrew/D-3526-2009; de Gasperis, Giancarlo/C-8534-2012 OI de Gasperis, Giancarlo/0000-0003-2899-2171 NR 29 TC 115 Z9 116 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP L59 EP L62 DI 10.1086/312743 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ER UT WOS:000088231000001 ER PT J AU Melchiorri, A Ade, PAR de Bernardis, P Bock, JJ Borrill, J Boscaleri, A Crill, BP De Troia, G Farese, P Ferreira, PG Ganga, K de Gasperis, G Giacometti, M Hristov, VV Jaffe, AH Lange, AE Masi, S Mauskopf, PD Miglio, L Netterfield, CB Pascale, E Piacentini, F Romeo, G Ruhl, JE Vittorio, N AF Melchiorri, A Ade, PAR de Bernardis, P Bock, JJ Borrill, J Boscaleri, A Crill, BP De Troia, G Farese, P Ferreira, PG Ganga, K de Gasperis, G Giacometti, M Hristov, VV Jaffe, AH Lange, AE Masi, S Mauskopf, PD Miglio, L Netterfield, CB Pascale, E Piacentini, F Romeo, G Ruhl, JE Vittorio, N TI A measurement of Omega from the North American test flight of Boomerang SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; dark matter; methods : data analysis ID MICROWAVE BACKGROUND ANISOTROPIES; ANGULAR POWER SPECTRUM; OPEN UNIVERSE; CONSTRAINTS; INFLATION; LAMBDA AB We use the angular power spectrum of the cosmic microwave background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe. Within the class of cold dark matter models, we find that the overall fractional energy density of the universe Omega is constrained to be 0.85 less than or equal to Omega less than or equal to 1.25 at the 68% confidence level. Combined with the COBE measurement, the data on degree scales from the Microwave Anisotropy Telescope in Chile, and the high-redshift supernovae data, we obtain new constraints on the fractional matter density and the cosmological constant. C1 Univ Rome La Sapienza, Dipartimento Fis, Rome, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy. Univ Geneva, Dept Phys Theor, CH-1211 Geneva, Switzerland. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. CALTECH, Pasadena, CA 91125 USA. Jet Prop Lab, Pasadena, CA USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA USA. CNR, Ist Ric Onde Elettromagneitche, Florence, Italy. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Inst Super Tecn, Ctr Multidisciplinar Astrofis, Lisbon, Portugal. CERN, Div Theory, European Lab Particle Phys, CH-1211 Geneva, Switzerland. Coll France, F-75231 Paris 05, France. Univ Massachusetts, Dept Phys & Astron, Amherst, MA USA. Univ Toronto, Dept Phys, Toronto, ON, Canada. Univ Toronto, Dept Astron, Toronto, ON, Canada. Ist Nazl Geofis, I-00161 Rome, Italy. RP Melchiorri, A (reprint author), Univ Rome La Sapienza, Dipartimento Fis, Rome, Italy. RI Jaffe, Andrew/D-3526-2009; de Gasperis, Giancarlo/C-8534-2012; Piacentini, Francesco/E-7234-2010; OI de Gasperis, Giancarlo/0000-0003-2899-2171; Piacentini, Francesco/0000-0002-5444-9327; Melchiorri, Alessandro/0000-0001-5326-6003 NR 30 TC 142 Z9 142 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP L63 EP L66 DI 10.1086/312744 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ER UT WOS:000088231000002 ER PT J AU Leveque, VJP Stroupe, ME Lepock, JR Cabelli, DE Tainer, JA Nick, HS Silverman, DN AF Leveque, VJP Stroupe, ME Lepock, JR Cabelli, DE Tainer, JA Nick, HS Silverman, DN TI Multiple replacements of glutamine 143 in human manganese superoxide dismutase: Effects on structure, stability, and catalysis SO BIOCHEMISTRY LA English DT Article ID ESCHERICHIA-COLI; ACTIVE-SITE; TETRAMERIC INTERFACE; THERMUS-THERMOPHILUS; IRON; TYROSINE-34; RADIOLYSIS; PROTEIN; COMPLEX; ENZYME AB Glutamine 143 in human manganese superoxide dismutase (MnSOD) forms a hydrogen bond with the manganese-bound solvent molecule and is investigated by replacement using site-specific mutagenesis. Crystal structures showed that the replacement of Gin 143 with Ala made no significant change in the overall structure of the mutant enzyme. Two new water molecules in Q143A MnSOD were situated in positions nearly identical with the O epsilon 1 and N epsilon 2 of the replaced Gin 143 side chain and maintained a hydrogen-bonded network connecting the manganese-bound solvent molecule to other residues in the active site. However, their presence could not sustain the stability and activity of the enzyme; the main unfolding transition of Q143A was decreased 16 degrees C and its catalysis decreased 250-fold to k(cat)/K-m = 3 x 10(6) M-1 s(-1), as determined by stopped-flow spectrophotometry and pulse radiolysis. The mutant Q143A MnSOD and other mutants at position 143 showed very low levels of product inhibition and favored Mn(II)SOD in the resting state, whereas the wild type showed strong product inhibition and favored Mn(III)SOD. However, these differences did not affect the rate constant for dissociation of the product-inhibited complex in Q143A MnSOD which was determined from a characteristic absorbance at 420 nm and was comparable in magnitude (similar to 100 s(-1)) to that of the wild-type enzyme. Hence, Gin 143, which is necessary for maximal activity in superoxide dismutation, appears to have no role in stabilization and dissociation of the product-inhibited complex. C1 Univ Florida, Ctr Hlth, Dept Pharmacol, Gainesville, FL 32610 USA. Univ Florida, Dept Biochem, Gainesville, FL 32610 USA. Univ Florida, Dept Neurosci, Gainesville, FL 32610 USA. Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Silverman, DN (reprint author), Univ Florida, Ctr Hlth, Dept Pharmacol, Box 100267, Gainesville, FL 32610 USA. FU NHLBI NIH HHS [HL39593]; NIGMS NIH HHS [GM48495, GM54903] NR 26 TC 49 Z9 50 U1 3 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUN 20 PY 2000 VL 39 IS 24 BP 7131 EP 7137 DI 10.1021/bi9929958 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 327DQ UT WOS:000087778300011 PM 10852710 ER PT J AU Dohrmann, CR Key, SW Heinstein, MW AF Dohrmann, CR Key, SW Heinstein, MW TI A method for connecting dissimilar finite element meshes in two dimensions SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE finite elements; dissimilar meshes; uniform strain; contact ID SHAPE FUNCTIONS AB A method is presented for connecting dissimilar finite element meshes in two dimensions. The method combines standard master-slave concepts with the uniform strain approach for finite elements. By modifying the definition of the slave boundary, corrections ape made to element formulations such that first-order patch tests are passed. The method can be used to connect meshes which use different element types. In addition, master and slave boundaries can be designated independently of relative mesh resolutions. Example problems in two-dimensional linear elasticity are presented. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Struct Dynam Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Engn & Mfg Mech Dept, Albuquerque, NM 87185 USA. RP Dohrmann, CR (reprint author), Sandia Natl Labs, Struct Dynam Dept, MS 0847, Albuquerque, NM 87185 USA. NR 14 TC 31 Z9 31 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JUN 20 PY 2000 VL 48 IS 5 BP 655 EP 678 DI 10.1002/(SICI)1097-0207(20000620)48:5<655::AID-NME893>3.0.CO;2-D PG 24 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 316PC UT WOS:000087175600002 ER PT J AU Khan, KA Camillone, N Yarmoff, JA Osgood, RM AF Khan, KA Camillone, N Yarmoff, JA Osgood, RM TI Modification of the surface termination of GaAs(001) using photon-activated electron-transfer reactions SO SURFACE SCIENCE LA English DT Article DE desorption induced by electronic transition; gallium arsenide; molecule-solid reactions; surface chemical reaction; surface relaxation and reconstruction; thermal desorption spectroscopy ID SCANNING-TUNNELING-MICROSCOPY; SELF-ASSEMBLED MONOLAYERS; SEMICONDUCTOR SURFACES; ALKYL BROMIDES; METHYL HALIDES; CHAIN-LENGTH; GAAS(110); GAAS; PHOTOCHEMISTRY; FRAGMENTATION AB We report the use of a photon-activated electron-transfer chemical reaction to modify the surface termination of the (001) face of single-crystal GaAs. The technique involves the extraction of surface Ga atoms as a result of reaction with bromine. The bromine is produced at the surface by photoinitiated dissociative electron attachment to methyl bromide molecules in a single monolayer physisorbed at similar to 80 K. Subsequent to the photoinduced surface reaction, the gallium is removed by annealing to desorb a gallium halide product. We have demonstrated that variation in photon exposure and thermal treatment allows the surface reconstruction to be controllably adjusted from the Ga-rich c(8 x 2) to the (4 x 6), (3 x 1) and As-rich c(2 x 8) terminations. A comparison of the results obtained with several surface diagnostics, including low energy electron diffraction, temperature programmed desorption and energy-resolved photofragment angular distribution measurements, indicates that the most As-rich surface obtained by our technique is identical in structure to that of a control surface prepared using the standard thermal reaction technique. In principle, the use of this photon-activated reaction, and others like it, allows precise adjustment and patterning of the surface structure based on control of photon or electron exposure, molecular coverage, thermal treatment and lateral patterning of the incident photon or electron beam. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Columbia Radiat Lab, New York, NY 10027 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Camillone, N (reprint author), Columbia Univ, Columbia Radiat Lab, New York, NY 10027 USA. NR 30 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 20 PY 2000 VL 458 IS 1-3 BP 53 EP 62 DI 10.1016/S0039-6028(00)00388-5 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 329UP UT WOS:000087927100005 ER PT J AU Baer, BJ Yoo, CS Cynn, H AF Baer, BJ Yoo, CS Cynn, H TI X-ray induced luminescence of solid argon at high pressures: A pressure probe SO APPLIED PHYSICS LETTERS LA English DT Article AB Above 7 GPa, visible luminescence is observed when argon in a diamond anvil cell is irradiated by high energy x rays from a synchrotron source. The spectrum consists of two peaks which shift by -43.6 +/- 0.7 cm(-1)/GPa and -47.5 +/- 2.4 cm(-1)/GPa from ambient pressure emission energies of 17 900 +/- 40 and 17 300 +/- 140 cm(-1), respectively. These shifts are linear up to 60 GPa and reversible on decompression. Extrapolation of the shifts to ambient pressure suggests that this is a 4p-5d atomic transition. (C) 2000 American Institute of Physics. [S0003-6951(00)03225-3]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Baer, BJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 6 TC 0 Z9 1 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 19 PY 2000 VL 76 IS 25 BP 3721 EP 3722 DI 10.1063/1.126761 PG 2 WC Physics, Applied SC Physics GA 323LW UT WOS:000087567700017 ER PT J AU Soo, YL Huang, S Kim, S Kioseoglou, G Kao, YH Compaan, AD Grecu, D Albin, D AF Soo, YL Huang, S Kim, S Kioseoglou, G Kao, YH Compaan, AD Grecu, D Albin, D TI Effects of heat treatment on diffusion of Cu atoms into CdTe single crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION FINE-STRUCTURE; X-RAY-FLUORESCENCE; INTERFACE MORPHOLOGY; HETEROJUNCTION AB Angular dependence of x-ray fluorescence and x-ray absorption fine structure techniques have been used to study the diffusion of Cu atoms into the photovoltaic material CdTe. Depth profile, effective valency, and local structure of Cu atoms in a Cu-doped single crystal of CdTe were investigated before and after a second heat treatment. Enhanced Cu diffusion into the CdTe single crystal was observed as a result of heating at a moderate temperature around 200 degrees C, resulting in a redistribution of the Cu impurities through a broader depth profile. Some of the Cu atoms are believed either to form small complexes with Te or occupy interstitial sites in the host but accompanied by a large local lattice distortion while others substitute for Cd on the cation sites. The results thus demonstrate that these nondestructive x-ray characterization methods are useful for probing microstructural changes in CdTe photovoltaic materials/devices in which some Cu-containing compounds are used as back contacts. (C) 2000 American Institute of Physics. [S0003-6951(00)03625-1]. C1 SUNY Buffalo, Dept Phys, Amherst, NY 14260 USA. Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP SUNY Buffalo, Dept Phys, Amherst, NY 14260 USA. EM yhk@acsu.buffalo.edu NR 17 TC 4 Z9 4 U1 0 U2 2 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 JUN 19 PY 2000 VL 76 IS 25 BP 3729 EP 3731 AR PII [S0003-6951(00)03625-1] DI 10.1063/1.126764 PG 3 WC Physics, Applied SC Physics GA 323LW UT WOS:000087567700020 ER PT J AU Wei, YY Eres, G AF Wei, YY Eres, G TI Directed assembly of carbon nanotube electronic circuits SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; SINGLE-WALL; GROWTH AB We report on a method for directed assembly of integrated carbon nanotube circuits using selective area chemical vapor deposition on prepatterned catalyst electrodes. The circuits consist of a multiwall carbon nanotube bridging a pair of electrodes, forming a metal/carbon nanotube/metal structure. Electron-beam lithography was used to define electrode sets separated by a desired distance on a SiO2/Si substrate. Following metal evaporation and lift-off, molecular jet chemical vapor deposition was used for selective growth of carbon nanotubes on the catalyst electrodes. The carbon nanotubes eventually form a bridge between nearby electrodes consisting of one, or in some cases more than one multiwall nanotubes. The room temperature resistance of the carbon nanotube circuits measured at the electrode leads is typically less than 100 k Omega. The carbon nanotube circuits were characterized by electronic transport measurements in the temperature range from room temperature to 2 K. (C) 2000 American Institute of Physics. [S0003-6951(00)00125-X]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Wei, YY (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Eres, Gyula/C-4656-2017 OI Eres, Gyula/0000-0003-2690-5214 NR 17 TC 72 Z9 74 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 19 PY 2000 VL 76 IS 25 BP 3759 EP 3761 DI 10.1063/1.126772 PG 3 WC Physics, Applied SC Physics GA 323LW UT WOS:000087567700030 ER PT J AU Zhang, AP Dang, G Ren, F Han, J Polyakov, AY Smirnov, NB Govorkov, AV Redwing, JM Cho, H Pearton, SJ AF Zhang, AP Dang, G Ren, F Han, J Polyakov, AY Smirnov, NB Govorkov, AV Redwing, JM Cho, H Pearton, SJ TI Temperature dependence and current transport mechanisms in AlxGa1-xN Schottky rectifiers SO APPLIED PHYSICS LETTERS LA English DT Article ID FIELD-EFFECT TRANSISTORS; GAN; DEVICES AB GaN and Al0.25Ga0.75N lateral Schottky rectifiers were fabricated either with (GaN) or without (AlGaN) edge termination. The reverse breakdown voltage V-B (3.1 kV for GaN; 4.3 kV for AlGaN) displayed a negative temperature coefficient of -6.0 +/- 0.4 V K-1 for both types of rectifiers. The reverse current originated from contact periphery leakage at moderate bias, while the forward turn-on voltage at a current density of 100 A cm(-2) was similar to 5 V for GaN and similar to 7.5 V for AlGaN. The on-state resistances, R-ON, were 50 m Omega cm(2) for GaN and 75 m Omega cm(2) for AlGaN, producing figures-of-merit (V-RB)(2)/R-ON of 192 and 246 MW cm(-2), respectively. The activation energy of the reverse leakage was 0.13 eV at moderate bias. (C) 2000 American Institute of Physics. [S0003-6951(00)04725-2]. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87195 USA. Inst Rare Met, Moscow 109017, Russia. Epitron, Phoenix, AZ 85027 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Zhang, AP (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RI Smirnov, Nickolai/K-8935-2015 OI Smirnov, Nickolai/0000-0002-4993-0175 NR 17 TC 35 Z9 35 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 19 PY 2000 VL 76 IS 25 BP 3816 EP 3818 DI 10.1063/1.126791 PG 3 WC Physics, Applied SC Physics GA 323LW UT WOS:000087567700049 ER PT J AU Cullen, DM Reed, AT Appelbe, DE Wilson, AN Paul, ES Bergstrom, MH Sharpey-Schafer, JF Baktash, C Frosch, I Lee, IY Macchiavelli, AO MacLeod, RW Prevost, D Theisen, C Curien, D AF Cullen, DM Reed, AT Appelbe, DE Wilson, AN Paul, ES Bergstrom, MH Sharpey-Schafer, JF Baktash, C Frosch, I Lee, IY Macchiavelli, AO MacLeod, RW Prevost, D Theisen, C Curien, D TI High-spin states and lifetime measurements in Hf-171 SO NUCLEAR PHYSICS A LA English DT Article DE Gd-160(O-18,7n), E=106 MeV; measured E gamma, I gamma, I gamma gamma(theta); Hf-171 deduced high-spin levels, J, pi, band structure; comparison with Woods-Saxon cranking calculations, B(M1)/B(E2) ratios; enriched targets; EUROGAM II spectrometer; Te-128(Ca-48,5n), E=200 MeV; Hf-171 Doppler Shift Attenuation measurement of mean lifetimes of collective states, transition quadrupole ID ROTATIONAL BANDS; TRANSITION RATES; SPECTROSCOPY; NUCLEI; DECAY AB This paper describes the results of two complementary experiments which studied the properties of the well-deformed nucleus Hf-171. The first experiment, with a thin self-supporting target, extended the rotational bands built upon the [633]7/2, [512]5/2 and [521]1/2 configurations up to spins of 73/2-85/2h. The configurations of these bands and observed band crossings are discussed within the framework of the cranked-shell model. The second experiment employed a backed target in order to measure the lifetimes, by the Doppler Shift Attenuation method, and thereby establish deformations for some of the states in the collective rotational bands. The extracted deformations are found to be consistent with those predicted from theoretical Total Routhian Surface calculations, These deformations provide strong evidence that the high-spin states in 171Hf, and perhaps more importantly, in the region where the high-K (K-pi = 19/2(+) and K-pi = 23/2(-)) isomeric states decay, retain their well-deformed axial symmetry. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Inst Rech Subatom, F-67037 Strasbourg, France. RP Cullen, DM (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RI CURIEN, Dominique/B-6718-2013; THEISEN, Christophe/A-9343-2015; OI THEISEN, Christophe/0000-0002-8509-1022; Wilson, Anna/0000-0001-6928-1689 NR 33 TC 8 Z9 9 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 JUN 19 PY 2000 VL 673 IS 1-4 BP 3 EP 30 DI 10.1016/S0375-9474(00)00061-0 PG 28 WC Physics, Nuclear SC Physics GA 322TU UT WOS:000087525600001 ER PT J AU Ogawa, Y Arai, K Suzuki, Y Varga, K AF Ogawa, Y Arai, K Suzuki, Y Varga, K TI Microscopic four-cluster description of Be-10 and C-10 with the stochastic variational method SO NUCLEAR PHYSICS A LA English DT Article DE the second 0(+) state at 6.179 MeV in Be-10; microscopic alpha plus alpha plus n plus n four-cluster model; stochastic optimization; spectroscopic amplitudes for cluster decays ID INTERACTION CROSS-SECTIONS; MULTICLUSTER DESCRIPTION; LIGHT-NUCLEI; NEUTRON-HALO; MODEL SPACE; STATES; B-9; ISOTOPES; RADII AB The structure of the Be-10 nucleus has been studied by using fully antisymmetrized 10-nucleon wave functions built in a microscopic alpha + alpha + n + n four-cluster model. The effective two-nucleon interaction employed contains central and spin-orbit components as well as the Coulomb potential. Stochastic optimization of basis functions has been applied to obtain not only the ground-state hut also other bound excited-states which lie below the Be-9 + n threshold. Calculated energy spectra and electromagnetic transition rates are in reasonable agreement with experiment. The calculation has reasonably well reproduced the second 0(+) state at 6.18 MeV as well as the tightly bound ground state, The second 0(+) state has been found to have spatially very extended structure in which two alpha-particles are separated like in Be-8. The change of neutron and proton density distributions is analyzed for Be-8 to Be-10 as a function of the number of valence neutrons outside two cu-particles. The basis functions obtained for Be-10 are used to calculate some of the properties of its mirror nucleus C-10. (C) 2000 Elsevier Science B.V. All rights reserved. C1 RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Niigata Univ, Dept Phys, Niigata 9502181, Japan. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Hungarian Acad Sci, Inst Nucl Res, H-4001 Debrecen, Hungary. RP Ogawa, Y (reprint author), Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan. RI Varga, Kalman/A-7102-2013 NR 30 TC 65 Z9 66 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 19 PY 2000 VL 673 IS 1-4 BP 122 EP 142 DI 10.1016/S0375-9474(00)00133-0 PG 21 WC Physics, Nuclear SC Physics GA 322TU UT WOS:000087525600006 ER PT J AU Ellis, J Karliner, M Kharzeev, DE Sapozhnikov, MG AF Ellis, J Karliner, M Kharzeev, DE Sapozhnikov, MG TI Hadronic probes of the polarized intrinsic strangeness of the nucleon SO NUCLEAR PHYSICS A LA English DT Article ID ZWEIG-IIZUKA RULE; PHI-MESON PRODUCTION; OZI-RULE; ANTIPROTON ANNIHILATION; (P)OVER-BAR-P ANNIHILATION; PBARP ANNIHILATION; NEAR-THRESHOLD; HYDROGEN GAS; SIGMA-TERM; PROTON AB We have previously interpreted the Various large apparent violations of the naive Okubo-Zweig-Iizuka (OZI) rule found in many channels in (p) over bar p annihilation at LEAR as evidence for an intrinsic polarized Ss component of the nucleon wave function. The model is further supported by new data from LEAR and elsewhere. Here we discuss in more detail the possible form of the (s) over bar s component of the nucleon wave function, interpret the new data and clarify the relative roles of strangeness shake-out and rearrangement, discuss whether alternative interpretations are still allowed by the new data, and propose more tests of the model. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, Div Theory, CH-1211 Geneva, Switzerland. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Brookhaven Natl Lab, RIKEN, Res Ctr, Upton, NY 11973 USA. Joint Inst Nucl Res, Dubna, Russia. RP CERN, Div Theory, CH-1211 Geneva, Switzerland. NR 73 TC 64 Z9 64 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 JUN 19 PY 2000 VL 673 IS 1-4 BP 256 EP 278 DI 10.1016/S0375-9474(00)00128-7 PG 23 WC Physics, Nuclear SC Physics GA 322TU UT WOS:000087525600014 ER PT J AU Wu, GH Ping, JL Teng, LJ Wang, F Goldman, T AF Wu, GH Ping, JL Teng, LJ Wang, F Goldman, T TI Quark delocalization, color screening model and nucleon-baryon scattering SO NUCLEAR PHYSICS A LA English DT Article DE hyperon-nucleon; phase shift; scattering amplitude; potential; dibaryons ID INTERMEDIATE RANGE ATTRACTION; PARTIAL-WAVE ANALYSIS; HYPERON NUCLEON; CLUSTER MODEL; SUBSTRUCTURE; POTENTIALS; DIBARYONS; STATES; SYSTEM; QCD AB We apply the quark delocalization and color screening model to nucleon-baryon scattering. A semi-quantitative fit to N-N, N-Lambda and N-Sigma phase shifts and scattering cross sections is obtained without invoking meson exchange. Quarks delocalize reasonably in all of the different flavor channels to induce effective nucleon-baryon interactions with both a repulsive core and with an intermediate range attraction in the cases expected. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Nanjing Univ, Ctr Theoret Phys, Nanjing 210008, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Sichuan Univ, Inst Nucl Sci & Technol, Ctr Radiat, Natl Key Lab Radiat Phys & Technol, Chengdu 610064, Peoples R China. Nanjing Normal Univ, Dept Phys, Nanjing 210097, Peoples R China. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Wu, GH (reprint author), Nanjing Univ, Ctr Theoret Phys, Nanjing 210008, Peoples R China. NR 41 TC 53 Z9 58 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 19 PY 2000 VL 673 IS 1-4 BP 279 EP 297 DI 10.1016/S0375-9474(00)00141-X PG 19 WC Physics, Nuclear SC Physics GA 322TU UT WOS:000087525600015 ER PT J AU Carena, M Garcia, D Nierste, U Wagner, CEM AF Carena, M Garcia, D Nierste, U Wagner, CEM TI Effective Lagrangian for the (t)over-bar-bH+ interaction in the MSSM and charged Higgs phenomenology SO NUCLEAR PHYSICS B LA English DT Article DE supersymmetry; charged Higgs phenomenology; higher-order radiative corrections ID SUPERSYMMETRIC STANDARD MODEL; LARGE HADRON COLLIDER; TOP-QUARK DECAY; QCD-CORRECTIONS; BOSON DECAY; PHYSICS; SEARCH; MASS; SUPERGRAVITY; BREAKING AB In the framework of a 2HDM effective Lagrangian for the MSSM, we analyse important phenomenological aspects associated with quantum soft SUSY-breaking effects that modify the relation between the bottom mass and the bottom Yukawa coupling. We derive a resummation of the dominant supersymmetric corrections for large values of tan beta to all orders in perturbation theory. With the help of the operator product expansion we also perform the resummation of the leading and next-to-leading logarithms of the standard QCD corrections. We use these resummation procedures to compute the radiative corrections to the t --> bH(+), H+ --> t (b) over bar decay rates. In the large tan beta regime, we derive simple formulae embodying all the dominant contributions to these decay rates and we compute the corresponding branching ratios. We show, as an example, the effect of these new results on determining the region of the MH+-tan beta plane excluded by the Tevatron searches for a supersymmetric charged Higgs boson in top quark decays, as a function of the MSSM parameter space. (C) 2000 Elsevier Science B.V. All rights reserved. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Carena, M (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. NR 63 TC 383 Z9 383 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 JUN 19 PY 2000 VL 577 IS 1-2 BP 88 EP 120 DI 10.1016/S0550-3213(00)00146-2 PG 33 WC Physics, Particles & Fields SC Physics GA 326GK UT WOS:000087724300005 ER PT J AU Kovchegov, YV Levin, E AF Kovchegov, YV Levin, E TI Diffractive dissociation including multiple pomeron exchanges in high parton density QCD SO NUCLEAR PHYSICS B LA English DT Article DE diffractive dissociation; BFKL pomeron; rapidity gaps ID DEEP-INELASTIC SCATTERING; QUASI-CLASSICAL APPROXIMATION; HIGH-ENERGY SCATTERING; SMALL-X; PERTURBATIVE QCD; DIPOLE PICTURE; MODEL; NUCLEUS AB We derive an evolution equation describing the high energy behavior of the cross section for the single diffractive dissociation in deep inelastic scattering on a hadron or a nucleus. The evolution equation resums multiple BFKL pomeron exchanges contributing to the cross section of the events with large rapidity gaps. Analyzing the properties of an approximate solution of the proposed equation we point out that at very high energies there is a possibility that for a fixed center of mass energy the cross section will reach a local maximum at a certain intermediate size of the rapidity gap, or, equivalently, at some non-zero value of the invariant mass of the produced particles. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. RP Kovchegov, YV (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 31 TC 66 Z9 66 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 JUN 19 PY 2000 VL 577 IS 1-2 BP 221 EP 239 DI 10.1016/S0550-3213(00)00125-5 PG 19 WC Physics, Particles & Fields SC Physics GA 326GK UT WOS:000087724300013 ER PT J AU Abusaidi, R Akerib, DS Barnes, PD Bauer, DA Bolozdynya, A Brink, PL Bunker, R Cabrera, B Caldwell, DO Castle, JP Clarke, RM Colling, P Crisler, MB Cummings, A Silva, AD Davies, AK Dixon, R Dougherty, BL Driscoll, D Eichblatt, S Emes, J Gaitskell, RJ Golwala, SR Hale, D Haller, EE Hellmig, J Huber, ME Irwin, KD Jochum, J Lipschultz, FP Lu, A Mandic, V Martinis, JM Nam, SW Nelson, H Neuhauser, B Penn, MJ Perera, TA Isaac, MCP Pritychenko, B Ross, RR Saab, T Sadoulet, B Schnee, RW Seitz, DN Shestople, P Shutt, T Smith, A Smith, GW Sonnenschein, AH Spadafora, AL Stockwell, W Taylor, JD White, S AF Abusaidi, R Akerib, DS Barnes, PD Bauer, DA Bolozdynya, A Brink, PL Bunker, R Cabrera, B Caldwell, DO Castle, JP Clarke, RM Colling, P Crisler, MB Cummings, A Silva, AD Davies, AK Dixon, R Dougherty, BL Driscoll, D Eichblatt, S Emes, J Gaitskell, RJ Golwala, SR Hale, D Haller, EE Hellmig, J Huber, ME Irwin, KD Jochum, J Lipschultz, FP Lu, A Mandic, V Martinis, JM Nam, SW Nelson, H Neuhauser, B Penn, MJ Perera, TA Isaac, MCP Pritychenko, B Ross, RR Saab, T Sadoulet, B Schnee, RW Seitz, DN Shestople, P Shutt, T Smith, A Smith, GW Sonnenschein, AH Spadafora, AL Stockwell, W Taylor, JD White, S CA CDMS Collaboration TI Exclusion limits on the WIMP-nucleon cross section from the Cryogenic Dark Matter Search SO PHYSICAL REVIEW LETTERS LA English DT Article ID 25 MK; IONIZATION; GERMANIUM; CRYSTAL AB Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c(2) WIMP mass and, at >75% C.L., the entire 3 sigma allowed region for the WIMP signal reported by the DAMA experiment. C1 Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Santa Clara Univ, Dept Phys, Santa Clara, CA 95053 USA. San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94132 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Colorado, Dept Phys, Denver, CO 80217 USA. RP Golwala, SR (reprint author), Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. RI Huber, Martin/B-3354-2011 NR 33 TC 214 Z9 214 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5699 EP 5703 DI 10.1103/PhysRevLett.84.5699 PG 5 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300005 PM 10991035 ER PT J AU Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, FE Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, BS Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlson, J Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Cihangir, S Ciobanu, CI Clark, AG Cobal, M Cocca, E Connolly, A Conway, J Cooper, J Cordelli, M Costanzo, D Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Geer, S Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Goshaw, AT Gorta, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A 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Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, MJ Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Mezione, A Meschi, E Mesropian, C Miao, C Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Moggi, N Moore, E Moore, R Morita, Y Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nicolaidi, P Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Parri, A Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Perazzo, A Pescara, L Phillips, TJ Piacentino, G Pitts, KT Plunkett, R Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Punzi, G Pagan, K Rakitine, A Reher, D Reichold, A Riegler, W Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Sakumoto, WK Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PE Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FP Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, S Suzuki, T Takashima, R Takikawa, K Tanaka, M Takano, T Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Theriot, D Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Ukegawa, F Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Vologouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Zanetti, A Zetti, E Zucchelli, S CA CDF Collaboration TI Search for scalar top and scalar bottom quarks in (p)over-barp collisions at j root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID JET CROSS-SECTIONS; P(P)OVER-BAR COLLISIONS; ROOT-S=1.8 TEV; HADRON COLLIDERS; FERMILAB TEVATRON; SQUARKS; PHYSICS; SUPERSYMMETRY; PYTHIA-5.7 AB We have searched for direct pair production of scalar top and scalar bottom quarks in 88 pb(-1) of p (p) over bar collisions at root s = 1.8 TeV with the CDF detector. We looked fur events with a pair of heavy flavor jets and missing energy, consistent with scalar top (bottom) quark decays to a charm (bottom) quark and a neutralino. The numbers of events that pass our selections show no significant deviation From standard model expectations. We compare our results to the next-to-leading order scaler quark production cross sections to exclude regions in scalar quality-neutralino mass parameter space. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. KEK, Tsukuba, Ibaraki 305, Japan. Sungkyunkwan Univ, Suwon 440746, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Kyungpook Natl Univ, Korean Hadeon Collider Lab, Taegu 702701, South Korea. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Illinois, Urbana, IL 61801 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Harvard Univ, Cambridge, MA 02138 USA. Univ Geneva, CH-1211 Geneva 4, Switzerland. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Florida, Gainesville, FL 32611 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Duke Univ, Durham, NC 27708 USA. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Cantabria, Inst Fis Cantabria, E-39005 Santander, Spain. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. MIT, Cambridge, MA 02139 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Texas A&M Univ, College Stn, TX 77843 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Affolder, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; vilar, rocio/P-8480-2014; Prokoshin, Fedor/E-2795-2012; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Prokoshin, Fedor/0000-0001-6389-5399; Introzzi, Gianluca/0000-0002-1314-2580 NR 27 TC 55 Z9 55 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5704 EP 5709 DI 10.1103/PhysRevLett.84.5704 PG 6 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300006 PM 10991036 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Ahn, S Akimov, V Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Bassier, U Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buescher, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del 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Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, S Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, H Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R Mcdonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Owen, D Padley, P Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B 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DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Y Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA DO Collaboration TI Measurement of the W ->tau nu production cross section in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID E(+)E(-) INTERACTIONS; BRANCHING FRACTIONS; PAIR PRODUCTION; COLLIDER; DECAY AB of data collected with the DO detector during 1993-1995. We find that a(p (p) over bar --> W + X)B(W --> tau nu) = 2.22 +/- 0.09 (stat) +/- 0.10 (syst) +/- 0.10 (lum) nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, g(T)(W)/g(e)(W), be unity. We find g(T)(W)/g(e)(W) = 0.980 +/- 0.031, in agreement with lepton universality. C1 NYU, New York, NY 10003 USA. Columbia Univ, New York, NY 10027 USA. Univ Nebraska, Lincoln, NE 68588 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Northeastern Univ, Boston, MA 02115 USA. Boston Univ, Boston, MA 02215 USA. Univ Maryland, College Pk, MD 20742 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Kansas, Lawrence, KS 66045 USA. Iowa State Univ Sci & Technol, Ames, IA 50011 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Indiana Univ, Bloomington, IN 47405 USA. Northwestern Univ, Evanston, IL 60208 USA. 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RI Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015 OI Sznajder, Andre/0000-0001-6998-1108; Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775 NR 15 TC 8 Z9 8 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 JUN 19 PY 2000 VL 84 IS 25 BP 5710 EP 5715 DI 10.1103/PhysRevLett.84.5710 PG 6 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300007 PM 10991037 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Dennino, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G Martin, A Matthews, JAJ Mazzanti, P McFarland, K McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Partos, D Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vologouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, S Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Bloom, K Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Dennino, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Green, C Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Heiss, A Hinrichsen, B Hoffman, KD Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kirk, M Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Lee, AM Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G Martin, A Matthews, JAJ Mazzanti, P McFarland, K McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Musy, M Nakada, H Nakaya, T Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Partos, D Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vologouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, S Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Search for a W ' boson via the decay mode W '->mu nu(mu) in 1.8 TeV p(p)over-bar collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID SILICON VERTEX DETECTOR; RIGHT-HANDED CURRENTS; ROOT-S=1.8 TEV; PHYSICS AB report the results of a search for a W' boson produced in p (p) over bar collisions at a center-of-mass energy of 1.8 TeV using a 107 pb(-1) data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W' --> mu nu(mu), and search for anomalous production of high transverse mass py, lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using abt of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c(2) at 95% confidence level. C1 Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Toronto, Toronto, ON M5S 1A7, Canada. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Illinois, Urbana, IL 61801 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Harvard Univ, Cambridge, MA 02138 USA. Univ Geneva, CH-1211 Geneva 4, Switzerland. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Florida, Gainesville, FL 32611 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Duke Univ, Durham, NC 27708 USA. Univ Chicago, Chicago, IL 60637 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Brandeis Univ, Waltham, MA 02254 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Abe, F (reprint author), Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Peters, Michael/B-4973-2009; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 20 TC 14 Z9 14 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 JUN 19 PY 2000 VL 84 IS 25 BP 5716 EP 5721 DI 10.1103/PhysRevLett.84.5716 PG 6 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300008 PM 10991038 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buescher, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Abramov, V Acharya, BS Adams, DL Adams, M Akimov, V Alves, GA Amos, N Anderson, EW Baarmand, MM Babintsev, VV Babukhadia, L Baden, A Baldin, B Banerjee, S Bantly, J Barberis, E Baringer, P Bartlett, JF Bassler, U Bean, A Belyaev, A Beri, SB Bernardi, G Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Boehnlein, A Bojko, NI Borcherding, F Brandt, A Breedon, R Briskin, G Brock, R Brooijmans, G Bross, A Buchholz, D Buescher, V Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chan, KM Chekulaev, SV Chen, W Cho, DK Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Connolly, B Cooper, WE Coppage, D Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Dyshkant, A Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Estrada, J Evans, H Evdokimov, VN Fahland, T Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Fleuret, F Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Gilmartin, R Ginther, G Gobbi, B Gomez, B Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, JA Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hays, C Hebert, C Hedin, D Heinson, AP Heintz, U Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Juste, A Kahn, S Kajfasz, E Karmanov, D Karmgard, D Kehoe, R Kim, SK Klima, B Klopfenstein, C Knuteson, B Ko, W Kohli, JM Kostritskiy, AV Kotcher, J Kotwal, AV Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kubantsev, M Kuleshov, S Kulik, Y Kunori, S Landsberg, G Leflat, A Lehner, F Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Lundstedt, C Maciel, AKA Madaras, RJ Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Martin, RD Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McMahon, T Melanson, HL Merkin, M Merritt, KW Miao, C Miettinen, H Mihalcea, D Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mostafa, M da Motta, H Nagy, E Nang, F Narain, M Narasimham, VS Neal, HA Negret, JP Negroni, S Norman, D Oesch, L Oguri, V Olivier, B Oshima, N Padley, P Pan, LJ Para, A Parashar, N Partridge, R Parua, N Paterno, M Patwa, A Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pope, BG Popkov, E Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Santoro, A Sawyer, L Schamberger, RD Schellman, H Schwartzman, A Sculli, J Sen, N Shabalina, E Shankar, HC Shivpuri, RK Shpakov, D Shupe, M Sidwell, RA Singh, H Singh, JB Sirotenko, V Slattery, P Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Song, XF Sorin, V Sosebee, M Sotnikova, N Souza, M Stanton, NR Steinbruck, G Stephens, RW Stevenson, ML Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Stutte, L Sznajder, A Tarazi, J Taylor, W Tentindo-Repond, S Thomas, TLT Thompson, J Toback, D Trippe, TG Turcot, AS Tuts, PM van Gemmeren, P Vaniev, V Varelas, N Volkov, AA Vorobiev, AP Wahl, HD Wang, H Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Whiteson, D Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yip, K Youssef, S Yu, J Yu, Z Zanabria, M Zheng, H Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A CA D0 Collaboration TI Probing Balitsky-Fadin-Kuraev-Lipatov dynamics in the dijet cross section at large rapidity intervals in p(p)over-bar collisions at root s=1800 and 630 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEEP-INELASTIC SCATTERING; JET PRODUCTION; HERA; ENERGY; SINGULARITY; POMERON; MESON AB Inclusive dijet production at large pseudorapidity intervals (Delta eta) between the two jets has been suggested as a regime for observing Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. We have measured the dijet cross section for large Delta eta in p (p) over bar collisions at root s = 1800 and 630 GeV using the D0 detector. The partonic cross section increases strongly with the size of Delta eta; The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alpha(BFKL)(20 GeV) = 1.65 +/- 0.07. C1 NYU, New York, NY 10003 USA. Columbia Univ, New York, NY 10027 USA. Univ Nebraska, Lincoln, NE 68588 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Northeastern Univ, Boston, MA 02115 USA. Boston Univ, Boston, MA 02215 USA. Univ Maryland, College Pk, MD 20742 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Kansas, Lawrence, KS 66045 USA. Iowa State Univ Sci & Technol, Ames, IA 50011 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Indiana Univ, Bloomington, IN 47405 USA. Northwestern Univ, Evanston, IL 60208 USA. No Illinois Univ, De Kalb, IL 60115 USA. Univ Illinois, Chicago, IL 60607 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Hawaii, Honolulu, HI 96822 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Calif State Univ Fresno, Fresno, CA 93740 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Arizona, Tucson, AZ 85721 USA. Univ Lancaster, Lancaster, England. Inst High Energy Phys, Protvino, Russia. Moscow MV Lomonosov State Univ, Moscow, Russia. Inst Theoret & Expt Phys, Moscow 117259, Russia. Inst Nucl Phys, Krakow, Poland. CINVESTAV, Mexico City 14000, DF, Mexico. Seoul Natl Univ, Seoul, South Korea. Tata Inst Fundamental Res, Mumbai, India. Univ Delhi, Delhi 110007, India. Panjab Univ, Chandigarh 160014, India. CEA, DAPNIA, Serv Phys Particules, Saclay, France. Univ Paris 06, CNRS, IN2P3, LPNHE, Paris, France. Univ Paris 07, CNRS, IN2P3, LPNHE, Paris, France. Univ Mediterranee, CNRS, IN2P3, CPPM, Marseille, France. Univ Grenoble 1, CNRS, IN2P3, Inst Sci Nucl, Grenoble, France. Univ San Francisco, Quito, Ecuador. Univ Los Andes, Bogota, Colombia. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Estado Rio Janeiro, Rio De Janeiro, Brazil. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Rochester, Rochester, NY 14627 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Langston Univ, Langston, OK 73050 USA. Univ Oklahoma, Norman, OK 73019 USA. Brown Univ, Providence, RI 02912 USA. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. Rice Univ, Houston, TX 77005 USA. Univ Washington, Seattle, WA 98195 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Chekulaev, Sergey/O-1145-2015; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Yip, Kin/D-6860-2013; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Sznajder, Andre/L-1621-2016 OI Dudko, Lev/0000-0002-4462-3192; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Sznajder, Andre/0000-0001-6998-1108 NR 24 TC 31 Z9 31 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5722 EP 5727 DI 10.1103/PhysRevLett.84.5722 PG 6 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300009 PM 10991039 ER PT J AU Brizard, AJ AF Brizard, AJ TI New variational principle for the Vlasov-Maxwell equations SO PHYSICAL REVIEW LETTERS LA English DT Article ID PLASMA AB A new Eulerian variational principle is presented for the Vlasov-Maxwell equations, This principle uses constrained variations for the Vlasov distribution in eight-dimensional extended phase space. The standard energy-momentum conservation law is then derived explicitly by the Noether method. This new variational principle can be applied to various reduced Vlasov-Maxwell equations in which fast time scales have been asymptotically eliminated (e.g., low-frequency gyrokinetic theory). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Brizard, AJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. OI Brizard, Alain/0000-0002-0192-6273 NR 10 TC 35 Z9 35 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 JUN 19 PY 2000 VL 84 IS 25 BP 5768 EP 5771 DI 10.1103/PhysRevLett.84.5768 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300020 PM 10991050 ER PT J AU Blase, X Lin, KR Canning, A Louie, SG Chrzan, DC AF Blase, X Lin, KR Canning, A Louie, SG Chrzan, DC TI Structure and energy of the 90 degrees partial dislocation in diamond: A combined ab initio and elasticity theory analysis SO PHYSICAL REVIEW LETTERS LA English DT Article ID CORE RECONSTRUCTION; ATOMIC-STRUCTURE; SILICON; PSEUDOPOTENTIALS; SEMICONDUCTORS; GERMANIUM; KINKS AB The core structure and stability of the 90 degrees partial dislocation in diamond is studied within isotropic elasticity theory and nb initio total energy calculations. The double-period reconstruction is found to be more stable than the single-period reconstruction for a broad range of stress states. The analysis of the ab initio results shows further that elasticity theory is valid for dislocation spacings as small as 10-20 Angstrom, thus allowing ab initio calculations to provide reliable parameters for continuum theory analysis. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. UMR 5586, Dept Mat Phys, F-69622 Villeurbanne, France. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 25 TC 58 Z9 58 U1 0 U2 8 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 JUN 19 PY 2000 VL 84 IS 25 BP 5780 EP 5783 DI 10.1103/PhysRevLett.84.5780 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300023 PM 10991053 ER PT J AU Mugele, F Salmeron, M AF Mugele, F Salmeron, M TI Dynamics of layering transitions in confined liquids SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE FORCES APPARATUS; THIN-FILMS; SOLVATION FORCES; FLUID; MICA AB Multiple beam interferometry and video microscopy were used to investigate the layering transition of thin liquid films of 1-undecanol confined between atomically smooth mica surfaces. The expulsion of a molecularly thin lubricant layer was followed directly in two dimensions. Overall, the dynamics of the transition follows theoretical predictions based on two-dimensional hydrodynamics. Frequently, pockets of liquid remain trapped inside the contact area at the end of the transition. The trapped pockets undergo shape transformations to minimize elastic and interfacial energy. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Mugele, F (reprint author), Univ Ulm, Abt Angewandte Phys, Albert Einstein Allee 11, D-89069 Ulm, Germany. RI Mugele, Frieder/A-5225-2017 OI Mugele, Frieder/0000-0003-3824-3617 NR 23 TC 49 Z9 49 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5796 EP 5799 DI 10.1103/PhysRevLett.84.5796 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300027 PM 10991057 ER PT J AU Erlebacher, J Aziz, MJ Chason, E Sinclair, MB Floro, JA AF Erlebacher, J Aziz, MJ Chason, E Sinclair, MB Floro, JA TI Nonclassical smoothening of nanoscale surface corrugations SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTAL-SURFACES; MORPHOLOGICAL EQUILIBRATION; ROUGHENING TRANSITION; SI(001); DIFFUSION; DYNAMICS; SI; TEMPERATURE; EVOLUTION; PROFILES AB We report the first experimental observation of nonclassical morphological equilibration of a corrugated crystalline surface. Periodic rippled structures with wavelengths of 290-550 nm were made on Si(001) by sputter rippling and then annealed at 650-750 degrees C. Tn contrast to the classical exponential decay with time, the ripple amplitude A(lambda)(t) followed an inverse linear decay, Al(t) = A(lambda)(0)/(1 + k(lambda)t), agreeing with a prediction of Ozdemir and Zangwill. We measure the activation energy for surface relaxation to be 1.6 +/- 0.2 eV, consistent with the fundamental energies of creation and migration on Si(001). C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Brown Univ, Providence, RI 02912 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Erlebacher, J (reprint author), Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RI Erlebacher, Jonah/A-3231-2010 NR 32 TC 60 Z9 61 U1 1 U2 8 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 JUN 19 PY 2000 VL 84 IS 25 BP 5800 EP 5803 DI 10.1103/PhysRevLett.84.5800 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300028 PM 10991058 ER PT J AU Fogler, MM Vinokur, VM AF Fogler, MM Vinokur, VM TI Hydrodynamics of the quantum Hall smectics SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH LANDAU-LEVELS; CHARGE-DENSITY-WAVE; 2-DIMENSIONAL ELECTRON LIQUID; WEAK MAGNETIC-FIELD; SYSTEMS; TRANSITION; DYNAMICS; CRYSTALS; PHASES; STATE AB We propose a dynamical theory of the stripe phase arising in a two-dimensional electron liquid near half-integral fillings of high Landau levels. The system is modeled as a novel type of a smectic liquid crystal with Lorentz force dominated dynamics. We calculate the structure factor, the dispersion relation of the collective modes, and their intrinsic attenuation rate. We show that thermal fluctuations cause a strong power-law renormalization of the elastic and dissipative parameters familiar from the conventional smectics but with different dynamical scaling exponents. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Fogler, MM (reprint author), Inst Adv Study, Sch Nat Sci, Olden Lane, Princeton, NJ 08540 USA. NR 24 TC 21 Z9 21 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5828 EP 5831 DI 10.1103/PhysRevLett.84.5828 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300035 PM 10991065 ER PT J AU Petrean, AM Paulius, LM Kwok, WK Fendrich, JA Crabtree, GW AF Petrean, AM Paulius, LM Kwok, WK Fendrich, JA Crabtree, GW TI Experimental evidence for the vortex glass phase in untwinned, proton irradiated YBa2Cu3O7-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID BA-CU-O; HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTALS; TRANSPORT-PROPERTIES; IRREVERSIBILITY LINE; MELTING TRANSITION; BOSON LOCALIZATION; MONTE-CARLO; DEFECTS; DISORDER AB We report on magnetoresistance measurements of the effects of 9 MeV proton irradiation on a dean, untwinned single crystal of YBa2Cu3O7-(delta). For the first time, evidence for a vortex glass transition is detected in an untwinned single crystal of YBa2CU3O7-(delta) With induced pointlike disorder. in which the first order vortex melting transition is completely suppressed after proton irradiation. Our results suggest that a sufficiently high pinning disorder is required in order fur the vortex glass phase to be observed. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Superconduct, Argonne, IL 60439 USA. RP Petrean, AM (reprint author), Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. NR 36 TC 66 Z9 67 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 19 PY 2000 VL 84 IS 25 BP 5852 EP 5855 DI 10.1103/PhysRevLett.84.5852 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300041 PM 10991071 ER PT J AU Bozin, ES Kwei, GH Takagi, H Billinge, SJL AF Bozin, ES Kwei, GH Takagi, H Billinge, SJL TI Neutron diffraction evidence of microscopic charge inhomogeneities in the CuO(2) plane of superconducting La(2-x)Sr(x)CuO(4) (0 <= x <= 0.30) SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; C SUPERCONDUCTIVITY AB High-resolution atomic pair distribution functions have been obtained using neutron powder diffraction data from La(2-x)Sr(x)CuO(4) over the range of doping 0 less than or equal to x less than or equal to 0.30 at 10 K. Despite the average structure getting less orthorhombic, we see a broadening of thr in-plane Cu-O bond distribution as a function of doping up to optimal doping. Thereafter the peak abruptly sharpens. The peak broadening can be well explained by a local microscopic coexistence of doped and undoped material. This suggests a crossover from a charge inhomogeneous state at and below optimal doping to a homogeneous charge stale above optimal doping. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, Ctr Fundamental Mat Res, E Lansing, MI 48824 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Tokyo, Dept Adv Mat Sci, Bunkyo Ku, Tokyo 1138656, Japan. RP Bozin, ES (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RI Takagi, Hidenori/B-2935-2010; Bozin, Emil/E-4679-2011 NR 21 TC 140 Z9 141 U1 0 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 JUN 19 PY 2000 VL 84 IS 25 BP 5856 EP 5859 DI 10.1103/PhysRevLett.84.5856 PG 4 WC Physics, Multidisciplinary SC Physics GA 325AC UT WOS:000087653300042 PM 10991072 ER PT J AU Li, YA Promislow, K AF Li, YA Promislow, K TI The mechanism of the polarizational mode instability in birefringent fiber optics SO SIAM JOURNAL ON MATHEMATICAL ANALYSIS LA English DT Article DE traveling waves; Evans function; polarization mode instability; Dirichlet expansion ID NONLINEAR SCHRODINGER-EQUATIONS; SOLITARY WAVES; TRAVELING WAVES; VECTOR SOLITONS; GROUND-STATES; STABILITY; PULSES; PROPAGATION; DISPERSION; COLLISIONS AB We show that the soliton solutions of the integrable Manakov equation exhibit an instability under arbitrarily small Hamiltonian perturbations. The instability arises from eigenvalues embedded in the essential spectrum of the associated linearized operators; these eigenvalues are dislodged by smooth perturbations. Specifically we consider perturbations which arise in ber optics as a result of birefringence, including the so-called four-wave mixing term. Employing the Evans function and a Dirichlet expansion on the stable manifold of the linearized system, we obtain rigorous perturbation results and compute the stability diagram of the fast wave for all physical values of the birefringent parameters, using a novel numerical scheme derived from the Dirichlet expansion. C1 Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Simon Fraser Univ, Dept Math & Stat, Burnaby, BC V5A 1S6, Canada. RP Los Alamos Natl Lab, CNLS, POB 1663, Los Alamos, NM 87545 USA. EM yili@cs.stevens-tech.edu; kpromisl@sfu.ca NR 38 TC 18 Z9 18 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1410 EI 1095-7154 J9 SIAM J MATH ANAL JI SIAM J. Math. Anal. PD JUN 17 PY 2000 VL 31 IS 6 BP 1351 EP 1373 DI 10.1137/S0036141099349966 PG 23 WC Mathematics, Applied SC Mathematics GA 326PT UT WOS:000087744500009 ER PT J AU Gomez-Vega, JM Saiz, E Tomsia, AP Oku, T Suganuma, K Marshall, GW Marshall, SJ AF Gomez-Vega, JM Saiz, E Tomsia, AP Oku, T Suganuma, K Marshall, GW Marshall, SJ TI Novel bioactive functionally graded coatings on Ti6Al4V SO ADVANCED MATERIALS LA English DT Article ID METAL-CERAMIC COMPOSITES; PHOSPHATE; BEHAVIOR C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Osaka Univ, Inst Sci & Ind Res, Ibaraki, Osaka 5670047, Japan. Univ Calif San Francisco, Dept Restorat Dent, San Francisco, CA 94143 USA. RP Gomez-Vega, JM (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 22 TC 50 Z9 50 U1 1 U2 14 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD JUN 16 PY 2000 VL 12 IS 12 BP 894 EP 898 DI 10.1002/1521-4095(200006)12:12<894::AID-ADMA894>3.0.CO;2-4 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 328LB UT WOS:000087851400008 ER PT J AU Geck, MK Hartman, FC AF Geck, MK Hartman, FC TI Kinetic and mutational analyses of the regulation of phosphoribulokinase by thioredoxins SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID DISULFIDE INTERCHANGE REACTIONS; OXIDATION-REDUCTION PROPERTIES; ESCHERICHIA-COLI THIOREDOXIN; CALVIN CYCLE ACTIVITY; SPINACH PHOSPHORIBULOKINASE; MULTIENZYME COMPLEX; GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE; CHLOROPLAST PHOSPHORIBULOKINASE; RIBULOSE-5-PHOSPHATE KINASE; EQUILIBRIUM-CONSTANTS AB Despite little supportive data, differential target protein susceptibility to redox regulation by thioredoxin (Trx) fend Trx in has been invoked to account for two distinct Trxs in chloroplasts. However, this postulate has not been rigorously tested with phosphoribulokinase (PRK), a fulcrum for redox regulation of the Calvin cycle. Prerequisite to Trx studies, the activation of spinach PRK by dithiothreitol, 2-mercaptoethanol, and glutathione was examined. Contrary to prior reports, each activated PRK, but only dithiothreitol supported Trx-dependent activation. Comparative kinetics of activation of PRK showed Trx m to be more efficient than Trx f because of its 40% higher V-max but similar S-0.5. Activations were insensitive to ribulosebisphosphate carboxylase, which may complex with PRK in vivo. To probe the basis for superiority of Trx m, we characterized site-directed mutants of Trx f, in which unique residues in conserved regions were replaced with Trx m counterparts or deleted. These changes generally resulted in V-max enhancements, the largest (6-fold) of which occurred with T105I, reflective of substitution in a hydrophobic region that opposes the active site. inclusive of the present study activation kinetics of several different Trx-regulated enzymes indicate redundancy in the functions of the chloroplastic Trxs. C1 Univ Tennessee, Oak Ridge Grad Sch Biomed Sci, Oak Ridge, TN 37830 USA. Oak Ridge Natl Lab, Div Life Sci, Prot Engn Program, Oak Ridge, TN 37831 USA. RP Hartman, FC (reprint author), Univ Tennessee, Dept Biochem & Cellular & Mol Biol, Knoxville, TN 37996 USA. NR 62 TC 21 Z9 23 U1 1 U2 9 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JUN 16 PY 2000 VL 275 IS 24 BP 18034 EP 18039 DI 10.1074/jbc.M001936200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 325CU UT WOS:000087659400019 PM 10751409 ER PT J AU Kleinman, LI Daum, PH Imre, DG Lee, JH Lee, YN Nunnermacker, LJ Springston, SR Weinstein-Lloyd, J Newman, L AF Kleinman, LI Daum, PH Imre, DG Lee, JH Lee, YN Nunnermacker, LJ Springston, SR Weinstein-Lloyd, J Newman, L TI Ozone production in the New York City urban plume SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; SOUTHERN NOVA-SCOTIA; POWER-PLANT PLUMES; CONTROL STRATEGIES; BIOGENIC HYDROCARBONS; NITROGEN-OXIDES; AIRSHED MODEL; RURAL SITE; SENSITIVITY; TRANSPORT AB In the summer of 1996 the Department of Energy G-1 aircraft was deployed in the New York City metropolitan area as part of the North American Research Strategy for Tropospheric Ozone-Northeast effort to determine the causes of elevated O-3 levels in the northeastern United States. Measurements of O-3, O-3 precursors, and other photochemically active trace gases were made upwind and downwind of New York City with the objective of characterizing the O-3 formation process and its dependence on ambient levels of NOx and volatile organic compounds (VOCs). Four flights are discussed in detail. On two of these flights, winds were from the W-SW, which is the typical direction for an O-3 episode. On the other two flights, winds were from the NW, which puts a cleaner area upwind of the city. The data presented include plume and background values of O-3, CO, NOx, and NOy concentration and VOC reactivity. On the W-SW flow days 0, reached 110 ppb. According to surface observations the G-1 intercepted the plume close to the region where maximum 0, occurred. At this point the ratio NOx/NOy was 20-30%, indicating an aged plume. Plume values of CO/NOy agree to within 20% with emission estimates from the core of the New York City metropolitan area. Steady state photochemical calculations were performed using observed or estimated trace gas concentrations as constraints. According to these calculations the local rate of 0, production P(O-3) in all four plumes is VOC sensitive, sometimes strongly so. The local sensitivity calculations show that a specified fractional decrease in VOC concentration yields a similar magnitude fractional decrease in P(O-3). Imposing a decrease in NOx, however, causes P(O-3) to increase. The question of primary interest from a regulatory point of view is the sensitivity of O-3 concentration to changes in emissions of NOx and VOCs. A qualitative argument is given that suggests that the total O-3 formed in the plume, which depends on the entire time evolution of the plume, is also VOC sensitive. Indicator ratios O-3/NOz and H2O2/NOz mainly support the conclusion that plume O-3 is VOC sensitive. C1 Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. RP Kleinman, LI (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, POB 5000, Upton, NY 11973 USA. EM kleinman@bnl.gov; phdaum@bnl.gov; imre@bnl.gov; ynlee@bnl.gov; srs@bnl.gov; jlloyd@bnl.gov; newman@bnl.gov NR 48 TC 54 Z9 57 U1 2 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 16 PY 2000 VL 105 IS D11 BP 14495 EP 14511 DI 10.1029/2000JD900011 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 326LB UT WOS:000087736000012 ER PT J AU Kato, S Bergin, MH Ackerman, TP Charlock, TP Clothiaux, EE Ferrare, RA Halthore, RN Laulainen, N Mace, GG Michalsky, J Turner, DD AF Kato, S Bergin, MH Ackerman, TP Charlock, TP Clothiaux, EE Ferrare, RA Halthore, RN Laulainen, N Mace, GG Michalsky, J Turner, DD TI A comparison of the aerosol thickness derived from ground-based and airborne measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LOWER GREAT-PLAINS; LIGHT-SCATTERING; UNITED-STATES; INTEGRATING NEPHELOMETER; TROPOSPHERIC CHEMISTRY; OPTICAL-PROPERTIES; APPORTIONMENT; PROFILES; GROWTH AB The extinction optical thickness of particles obtained from scattering and absorption coefficients measured by an airborne integrating nephelometer and particle soot absorption photometer, respectively, is compared with the aerosol optical thickness derived from a ground-based multifilter rotating shadowband radiometer, a Sun photometer, and a Raman lidar for 9 days. These 9 days are selected from intensive operation periods of the Atmospheric Radiation Measurement in April 1997, September 1997, and August 1998 at the southern Great Plains. For April 1997 and September 1997 cases the difference between the extinction optical thickness of particles estimated from vertical profiles and the extinction optical thickness of aerosol derived from the multifilter rotating shadowband radiometer is not significant. For August 1998 cases when the boundary layer relative humidity is higher than April 1997 and September 1997 cases, the extinction optical thickness of particles is 0.03 to 0.07 less than the extinction optical thickness of aerosol. The difference corresponds to 25% to 31% of the extinction optical thickness of aerosol. Based on these comparisons, the upper and lower limits of the single-scattering albedo of particles present in the lower part of troposphere are 0.97 and 0.84, respectively. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12205 USA. Pacific NW Lab, Richland, WA 99352 USA. Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30332 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Kato, S (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM s.katol@larc.nasa.gov NR 37 TC 30 Z9 30 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 16 PY 2000 VL 105 IS D11 BP 14701 EP 14717 DI 10.1029/2000JD900013 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 326LB UT WOS:000087736000027 ER PT J AU Berkowitz, CM Fast, JD Easter, RC AF Berkowitz, CM Fast, JD Easter, RC TI Boundary layer vertical exchange processes and the mass budget of ozone: Observations and model results SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NORTHEAST UNITED-STATES; AIR-QUALITY MODELS; ACID DEPOSITION; CLOSURE-MODEL; TURBULENCE; TRANSPORT; EPISODE; DESIGN; CLOUD AB An Eulerian chemical model is used to assess the relative importance of a variety of processes associated with producing high surface ozone episodes during selected periods of the North American Research Strategy for Tropospheric Ozone (NARSTO) 1995 field campaign over the northeastern United States. A comparison of the observed and predicted hourly surface ozone mixing ratios showed that the model qualitatively reproduced the observed ozone trends over the northeastern United States. The model had a mean hourly bias of similar to 15 ppb with a wide range of skill compared to individual observing stations clustered around one node. The simulated mass budget tendency terms are compared for days with low ozone values immediately followed by days with high values. The later days showed observed and simulated ozone mixing ratios aloft to be of order twice that found on preceding days, although the associated chemical mix appeared to have relatively little potential for the subsequent generation of "new" ozone. Under conditions of shallow mixing over urban regions, simulated surface ozone production rates were negative (a net loss) throughout much of the day with convective mixing bringing newly produced ozone from aloft to the surface. It is noted that surface ozone levels appeared to be relatively insensitive to mixing layer growth rates. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Berkowitz, CM (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. EM carl.berkowitz@pnl.gov; jerome.fast@pnl.gov; richard.easter@pnl.gov NR 41 TC 19 Z9 20 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 16 PY 2000 VL 105 IS D11 BP 14789 EP 14805 DI 10.1029/2000JD900026 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 326LB UT WOS:000087736000033 ER PT J AU Xie, SC Zhang, MH AF Xie, SC Zhang, MH TI Impact of the convection triggering function on single-column model simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SCHUBERT CUMULUS PARAMETERIZATION; LARGE-SCALE ENVIRONMENT; SEMIPROGNOSTIC TESTS; CLOUD ENSEMBLE; MOISTURE; SCHEMES; BUDGETS; ENERGY; WAVE; MASS AB We analyze the causes of the large thermal biases in the simulation of the National Center for Atmospheric Research's Community Climate Model Version 3 (CCM3) single-column model (SCM) when it is forced with the Atmospheric Radiation Measurement Program's (ARM) summer 1995 Intensive Observing Period (IOP) data. We have found that deficiencies of the convection triggering function used in the model can explain a significant part of the biases. In the model, convection is triggered whenever there is positive convective available potential energy (CAPE), which happens to occur during daytime due to solar heating of the land surface. In observations, however, convection takes place only when the large-scale dynamic condition is favorable to the release of CAFE. On the basis of observations we propose a new triggering function for the CCM3 deep convection scheme. We assume that model convection occurs only when the large-scale dynamic forcing makes positive contributions to the existing positive CAFE. Improved simulation results are obtained when the new triggering function is implemented in the model. We further test the new triggering function using the ARM Southern Great Plains summer 1997 TOP data and the Global Atmospheric Research Program's Atlantic Tropical Experiment phase III observations. These tests confirm the results obtained from the ARM 1995 experiments. C1 SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. RP Lawrence Livermore Natl Lab, ASD, L-103, Livermore, CA 94550 USA. EM xie2@llnl.gov RI Xie, Shaocheng/D-2207-2013 OI Xie, Shaocheng/0000-0001-8931-5145 NR 30 TC 52 Z9 55 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 16 PY 2000 VL 105 IS D11 BP 14983 EP 14996 DI 10.1029/2000JD900170 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 326LB UT WOS:000087736000045 ER PT J AU Kleiger, G Beamer, LJ Grothe, R Mallick, P Eisenberg, D AF Kleiger, G Beamer, LJ Grothe, R Mallick, P Eisenberg, D TI The 1.7 angstrom crystal structure of BPI: A study of how two dissimilar amino acid sequences can adopt the same fold SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE BPI; X-ray crystallography; 3D-1D environment; domain; fold ID BACTERICIDAL/PERMEABILITY-INCREASING PROTEIN; BOVINE LIVER RHODANESE; 3-DIMENSIONAL STRUCTURE; SECONDARY STRUCTURE; TERMINAL FRAGMENT; ESCHERICHIA-COLI; BINDING-SITE; RESOLUTION; SUBSTITUTION; RECOGNITION AB We have extended the resolution of the crystal structure of human bactericidal/permeability-increasing protein (BPI) to 1.7 Angstrom. BPI has two domains with the same fold, but with little sequence similarity. To under stand the similarity in structure of the two domains, we compare the corresponding residue positions in the two domains by the method of 3D-1D profiles. A 3D-1D profile is a string formed by assigning each position in the 3D structure to one of 18 environment classes. The environment classes are defined by the local secondary structure, the area of the residue which is buried from solvent, and the fraction of the area buried by polar atoms. A structural alignment between the two BPI domains was used to compare the 3D-1D environments of structurally equivalent positions. Greater than 31% of the aligned positions have conserved 3D-1D environments, but only 13% have conserved residue identities. Analysis of the 3D-1D environmentally conserved positions helps to identify pairs of residues likely to be important in conserving the fold, regardless of the residue similarity. We find examples of 3D-1D environmentally conserved positions with dissimilar residues which nevertheless play similar structural roles. To generalize our findings, we analyzed four other proteins with similar structures yet dissimilar sequences. Together, these examples show that aligned pairs of dissimilar residues often share similar structural roles, stabilizing dissimilar sequences in the same fold. (C) 2000 Academic Press. C1 Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Missouri, Dept Biochem, Columbia, MO 65211 USA. RP Eisenberg, D (reprint author), Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Inst Mol Biol, Box 951570, Los Angeles, CA 90095 USA. FU NIGMS NIH HHS [GM07185, GM08375] NR 34 TC 36 Z9 39 U1 1 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUN 16 PY 2000 VL 299 IS 4 BP 1019 EP 1034 DI 10.1006/jmbi.2000.3805 PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 325MV UT WOS:000087680400016 PM 10843855 ER PT J AU Zhang, C Kim, SH AF Zhang, C Kim, SH TI The anatomy of protein beta-sheet topology SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE protein fold anatomy and taxonomy; topological preference; common beta-sheet motifs; kinetics of protein folding; structural genomics ID STRUCTURAL GENOMICS; GLOBULAR-PROTEINS; PLEATED SHEETS; CLASSIFICATION; FOLDS; PRINCIPLES; HANDEDNESS; PATHWAYS; PATTERNS; FUNNELS AB Here, we present a systematic analysis of the open-faced beta-sheet topologies in a set of non-redundant protein domain structures; in particular, we focus on the topological diversity of four-stranded beta-sheet motifs. Of the 96 topologies that are possible for a four-stranded beta-sheet, 42 were identified in known protein structures. Of these, four account for 50 % of the structures that we have studied. Two sets of the topologies that were not observed may represent the section of the topological space that is not readily accessible to proteins on either thermodynamic or kinetic grounds. The first set contains topologies with alternating parallel and antiparallel beta-ladders. Their rare occurrence reflects the expectation that it is energetically unfavorable to match different hydrogen bonding patterns. The polypeptide chains in the second set of topologies go through convoluted paths and are expected to experience great kinetic frustrations during the folding processes. A knowledge of the potential causes for the topological preference of small beta-sheets also helps us to understand the topological properties of larger beta-sheet structures which frequently contain four-stranded motifs. The notion that protein topologies can only be taken from a confined and discrete space has important implications for structural genomics. (C) 2000 Academic Press. 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. FU NCI NIH HHS [CA78406] NR 42 TC 40 Z9 40 U1 1 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUN 16 PY 2000 VL 299 IS 4 BP 1075 EP 1089 DI 10.1006/jmbi.2000.3678 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 325MV UT WOS:000087680400020 PM 10843859 ER PT J AU Reddmann, H Schultze, H Amberger, HD Edelstein, NM AF Reddmann, H Schultze, H Amberger, HD Edelstein, NM TI Electronic structures of organometallic complexes of f-elements L. Experimental elucidation and simulation of the electronic structure of the first organometallic pi-complex of a lanthamide in the yttrium subgroup, erbium: (eta(5)-Cp)(3)Er center dot CNC6H11 SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA German DT Article AB The absorption spectrum of (eta(5)-Cp)(3)Er . CNC6H11 (1) has been measured at room and low temperatures. From the spectra obtained, a truncated crystal field (CF) splitting pattern is derived, and simulated by fitting the-parameters of an empirical Hamiltonian. For 46 assignments, a reduced r.m.s. deviation of 31 cm(-1) is achieved. On the basis of the wavefunction of the CF ground state obtained from these calculations, the 2.5 K EPR spectrum of magnetically diluted 1 could be explained. Making use of the calculated wavefunctions and eigenvalues the experimentally determined temperature dependence of mu(eff)(2) of powdered 1 could be reproduced by adopting an orbital reduction factor k = 0.985. C1 Univ Hamburg, Inst Anorgan & Angew Chem, D-20146 Hamburg, Germany. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Amberger, HD (reprint author), Univ Hamburg, Inst Anorgan & Angew Chem, Martin Luther King Pl 6, D-20146 Hamburg, Germany. NR 12 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD JUN 16 PY 2000 VL 604 IS 2 BP 296 EP 299 DI 10.1016/S0022-328X(00)00241-2 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 341KY UT WOS:000088590600024 ER PT J AU Kim, R Yokota, H Kim, SH AF Kim, R Yokota, H Kim, SH TI Electrophoresis of proteins and protein-protein complexes in a native agarose gel SO ANALYTICAL BIOCHEMISTRY LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys Biocsci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Kim, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys Biocsci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 6 TC 12 Z9 13 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD JUN 15 PY 2000 VL 282 IS 1 BP 147 EP 149 DI 10.1006/abio.2000.4598 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 327DE UT WOS:000087777300021 PM 10860512 ER PT J AU Bagan, E Lavelle, M McMullan, D AF Bagan, E Lavelle, M McMullan, D TI Charges from dressed matter: Construction SO ANNALS OF PHYSICS LA English DT Article ID QUANTUM ELECTRODYNAMICS; LARGE DISTANCES; CORRESPONDENCE-PRINCIPLE; DIRACS OBSERVABLES; SCATTERING THEORY; HADRON SPECTRA; GAUGE-THEORIES; HIGGS-MODEL; QUARKS; QCD AB There is a widespread belief in particle physics that there is no relativistic description of a charged particle. This is claimed to be due to persistent, long range interactions which distort the incoming and outgoing plane waves and generate infrared divergences. In this paper we will show that this is not the case in QED. We construct locally gauge invariant charged fields which do create in and out Fock slates. In a companion paper we demonstrate that the Green's functions of these fields have a good pole structure describing particle propagation. (C) 2000 Academic Press. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Plymouth, Sch Math & Stat, Plymouth PL4 8AA, Devon, England. Univ Autonoma Barcelona, IFAE, E-08193 Barcelona, Spain. RP Bagan, E (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 62 TC 37 Z9 37 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD JUN 15 PY 2000 VL 282 IS 2 BP 471 EP 502 DI 10.1006/aphy.2000.6048 PG 32 WC Physics, Multidisciplinary SC Physics GA 327DL UT WOS:000087777900012 ER PT J AU Bagan, E Lavelle, M McMullan, D AF Bagan, E Lavelle, M McMullan, D TI Charges from dressed matter: Physics and renormalisation SO ANNALS OF PHYSICS LA English DT Article ID HEAVY MESONS AB Gauge theories are characterised by long range interactions. Neglecting these interactions at large limes and identifying the Lagrangian matter fields with the asymptotic physical fields leads to the infrared problem. In this paper we study the perturbative applications of a construction of physical charges in QED, where the matter fields are combined with the associated electromagnetic clouds. This has been formally shown, in a companion paper, to include these asymptotic interactions. It is explicitly demonstrated that the on-shell Green's functions and S-matrix elements describing these charged fields have, to all orders in the coupling, the pole structure associated with particle propagation and scattering. We show in derail that the renormalisation procedure may be carried out straightforwardly. II is shown that standard infrared finite predictions of QED are not altered and it is speculated that the good infrared properties of our construction may open the way to the calculation of previously uncalculable properties. Finally extensions of this approach to QCD are briefly discussed. (C) 2000 Academic Press. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Plymouth, Sch Math & Stat, Plymouth PL4 8AA, Devon, England. Univ Autonoma Barcelona, IFAE, E-08193 Barcelona, Spain. RP Bagan, E (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 23 TC 30 Z9 30 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD JUN 15 PY 2000 VL 282 IS 2 BP 503 EP 540 DI 10.1006/aphy.2000.6049 PG 38 WC Physics, Multidisciplinary SC Physics GA 327DL UT WOS:000087777900013 ER PT J AU Wasserman, E Felmy, AR Chilakapati, A AF Wasserman, E Felmy, AR Chilakapati, A TI Non-equilibrium thermodynamic simulation of metal uptake in the bacterial electrical double-layer SO COLLOIDS AND SURFACES B-BIOINTERFACES LA English DT Article DE electrical double layer; diffusion; metal uptake; simulation; bacterial surface; Poisson-Boltzmann equation ID ION CHANNELS; MEMBRANES AB A non-equilibrium thermodynamic (Onsager) formalism is presented for modeling transport processes in the bacterial electrical double-layer. This formalism is then applied to model the time-dependent metal uptake within the bacteria electrical double-layer that occurs in response to gradients in concentration and electrostatic potential. The formal development of the equations is presented along with an efficient numerical procedure to solve the system of equations for spherical geometry. Numerical results are given for two values of ionic strength, I=0.1 and 0.001 M and a bulk trivalent tracer concentration of 1 x 10(-6) M. Equilibrium distribution of the trivalent tracer cations was shown to be reached very rapidly, in about 2 ms at I=0.1 M and 0.2 s at I=0.001 M. Therefore diffusion-conduction was demonstrated to be a highly efficient mechanism of ionic transport on the nanoscale for the conditions at which electrostatic metal uptake is significant. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. NR 19 TC 8 Z9 8 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7765 J9 COLLOID SURFACE B JI Colloid Surf. B-Biointerfaces PD JUN 15 PY 2000 VL 18 IS 1 BP 19 EP 29 DI 10.1016/S0927-7765(99)00122-8 PG 11 WC Biophysics; Chemistry, Physical; Materials Science, Biomaterials SC Biophysics; Chemistry; Materials Science GA 312WJ UT WOS:000086966700003 ER EF