FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Cochran, JK Moran, SB Fisher, NS Beasley, TM Kelley, JM AF Cochran, JK Moran, SB Fisher, NS Beasley, TM Kelley, JM TI Sources and transport of anthropogenic radionuclides in the Ob River system, Siberia SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Ob River; human activity; radioactive isotopes; fallout ID FUEL-REPROCESSING FACILITIES; ATOM RATIOS; KARA SEA; SEDIMENTS; CS-137; NP-237; RUSSIA; PU; CONTAMINATION; PLUTONIUM AB The potential sources of anthropogenic radionuclides to the Ob River system of western Siberia include global stratospheric fallout, tropospheric fallout from atomic weapons tests and releases from production and reprocessing facilities. Samples of water, suspended and bottom sediments collected in 1994 and 1995 have been used to characterize the sources and transport of Cs-137, PU isotopes, Np-237 and I-129 through the system. For the radionuclides that associate with particles, isotope ratios provide clues to their sources, providing any geochemical fractionation can be taken into account. Activity ratios of Pu-239.240/Cs-137, suspended sediments are lower than the global fallout ratio in the Irtysh River before its confluence with the Ob, comparable to fallout in the central reach of the Ob, and greater than the fallout values in the lower Ob and in the Taz River. This pattern mirrors the downriver decrease in dissolved organic carbon (DOC) concentrations. Laboratory adsorption experiments with Ob River sediment and water show that Kd values for Am (and presumably other actinides) are depressed by two orders of magnitude in the presence of Ob DOC concentrations, relative to values measured in DOG-free Ob water. Iodine and cesium Kd values show little or no (less than a factor of 2) dependence on DOG. Mixing plots using plutonium isotope ratios (atom ratios) show that Pu in suspended sediments of the Ob is a mixture of stratospheric global fallout at northern latitudes, tropospheric fallout from the former Soviet Union test site at Semipalatinsk and reprocessing of spent fuel at Tomsk-7. Plutonium from Semipalatinsk is evident in the Irtysh River above its confluence with the Tobal. Suspended sediment samples taken in the Ob above its confluence with the Irtysh indicate the presence of Pu derived from the Tomsk-7 reprocessing facilities. A mixing plot constructed using Np-237/Pu-239 vs. Pu-240/Pu-239 shows similar mixtures of stratospheric and tropospheric fallout, with the likely addition of inputs from reprocessing facilities and reactor operations. As with Pu/Cs ratios, Np/ Pu ratios could be modified by differential geochemical behaviors of Np and Pu. Dissolved I-129\ only weakly interacts with particles in the Ob; size-fractionated sampling shows that the colloidal I-129 fraction (defined as 1 kDa-0.2 mu m) contains generally < 5% relative to that passing a 0.2 mu m filter. Iodine-129 concentrations decrease from 8.3 x 10(9) to 0.65 x 10(9) atoms l(-1) through the Ob system toward the Kara Sea, with highest values in the Tobal River and lowest in the Taz River. The likely source of the elevated I-129 in the Tobal is release from the production-reprocessing facilities at Mayak, and decreases downriver are predominantly due to dilution as the various tributaries with low I-129 join the system. Fluxes of I-129 to the lower Ob at Salekhard are < 1% of the releases of this radionuclide from the nuclear fuel reprocessing facilities at Sellafield. UK and La Hague. France. (C) 2000 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. US DOE, Environm Measurements Lab, New York, NY 10014 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Cochran, JK (reprint author), SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. NR 27 TC 34 Z9 35 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD JUN 15 PY 2000 VL 179 IS 1 BP 125 EP 137 DI 10.1016/S0012-821X(00)00110-2 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 326PG UT WOS:000087743500011 ER PT J AU Rea, AW Lindberg, SE Keeler, GJ AF Rea, AW Lindberg, SE Keeler, GJ TI Assessment of dry deposition and foliar leaching of mercury and selected trace elements based on washed foliar and surrogate surfaces SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ATMOSPHERIC DEPOSITION; FOREST CANOPY; PRECIPITATION; THROUGHFALL; SPRUCE; PLANTS; VAPOR AB Throughfall and litterfall are the primary deposition pathways of Hg to forested ecosystems, yet the source of this Hg (soil or atmospheric) remains unclear. Leaf samples were harvested from live trees and used in leaf washing experiments to assess whether the recovered Hg originated from surface deposits (wash-off of dry deposition) or internal sources (foliar leaching). The behavior of Hg was compared to eight other elements also found in leaf wash with known external (Cd, La, Ce, Pb) or internal (Mn, Rb, Sr, Ba) sources. These experiments indicated that wash-off of dry deposition occurred rapidly, while foliar leaching occurred continuously during the entire wash period (up to 12 h). To isolate dry deposition, surrogate Teflon surfaces exposed for a 98 h dry period were washed and compared to washed foliar surfaces. Computed dry deposition velocities for both surfaces were within a factor of 2 for Hg, Cd, La, Ce, and Ph, suggesting that dry deposition was the primary source of these elements from the washed foliage. Deposition velocities varied widely (3-18 times higher from the foliar surfaces) for Mn, Rb, Sr, and Ba, most likely due to the leaching behavior exhibited by these elements. These experiments show that dry deposition of atmospheric Hg is likely the largest source of Hg in throughfall. C1 Univ Michigan, Air Qual Lab, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Rea, AW (reprint author), Univ Michigan, Air Qual Lab, Ann Arbor, MI 48109 USA. EM Rea.Anne@epa.gov NR 31 TC 63 Z9 64 U1 5 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 15 PY 2000 VL 34 IS 12 BP 2418 EP 2425 DI 10.1021/es991305k PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 325MA UT WOS:000087678300007 ER PT J AU Veerapaneni, S Wan, JM Tokunaga, TK AF Veerapaneni, S Wan, JM Tokunaga, TK TI Motion of particles in film flow SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID UNSATURATED POROUS-MEDIA; GAS-WATER INTERFACE; SHEAR-FLOW; INERTIAL LIFT; RIGID SPHERE; TRANSPORT; WALL; DRAG; COLLOIDS; MODEL AB The effect of particle size (d(p)) to film thickness (h(o)) ratio on the motion of spherical particles in a stable liquid film flowing down an inclined flat surface is studied experimentally. Previously reported models that are based on force and torque balance are modified to predict the motion of particles that are smaller than film thickness. At low d(p)/h(o) values, particle velocity is observed to increase nearly linearly with particle size, reflecting the increasing influence of hydrodynamic drag as larger particles expose their surface to regions of higher fluid velocity. Good agreement between model predictions and experimental results is observed for small d(p)/h(o) ratios. When d(p)/h(o), is in the range of similar to 0.7-1, particle velocities are observed to decrease rapidly with an increase in size. This may be attributed to the effect of the proximity of the free interface to the particle surface and also the deformation of the free surface induced by the moving particle. When d(p)/h(o) is in the approximate range of 1-1.75, particles ceased to move due to the surface tension acting on the particle along the circumference of the contact radius of the three-phase interface. For particles significantly larger than film thickness (d(p)/h(o) greater than about 1.7), particle velocity is observed to increase with its size as the particle motion is aided by the increased contribution from the gravitational force. For the range of film thicknesses and particle sizes studied, there appears to be a d(p)/h(o) range in which gravity force begins to dominate over surface tension force. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Veerapaneni, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Mail Stop 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 29 TC 23 Z9 23 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 15 PY 2000 VL 34 IS 12 BP 2465 EP 2471 DI 10.1021/es9912731 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 325MA UT WOS:000087678300014 ER PT J AU Holman, HYN Goth-Goldstein, R Martin, MC Russell, ML McKinney, WR AF Holman, HYN Goth-Goldstein, R Martin, MC Russell, ML McKinney, WR TI Low-dose responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin in single living human cells measured by synchrotron infrared spectromicroscopy SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; MULTIPHOTON FLUORESCENCE MICROSCOPY; WHITE BLOOD-CELLS; X-RAY MICROSCOPY; DNA-ADDUCTS; GENE-EXPRESSION; CYP1A1 EXPRESSION; FOUNDRY WORKERS; HUMAN EXPOSURE; INDUCTION AB Synchrotron radiation (SR)-based Fourier transform infrared (FTIR) spectromicroscopy measurements are presented of HepG2 cells exposed to an environmental contaminant that is a known ligand for the aryl hydrocarbon (Ah) receptor. Measurements were made on cells treated with an Ah receptor-binding model compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Compared to untreated control cells, treated cells displayed unique spectral changes with TCDD concentrations of 0.01-10.0 nM. Key spectral changes involved P=O, C-O, and C-H stretching bands. The first changes are related to the environment of the phosphate backbone of nucleic acids. The C-H stretching bands data show a relative increase in the number of methyl to methylene groups. An excellent correlation was found between spectral changes and an increase in CYP1A1 expression measured by the reverse transcriptase polymerase chain reaction (RT-PCR) technique demonstrating that the SR-FTIR method is observing cellular biochemical changes related to this gene expression pathway. Finally, the potential use of SR-FTIR spectromicroscopy is discussed as a diagnostic tool for monitoring cellular exposure and early molecular responses to environmental pollutants. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Environm Biotechnol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Adv Light Source Div, Berkeley, CA 94720 USA. RP Holman, HYN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Environm Biotechnol, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI McKinney, Wayne/F-2027-2014; Holman, Hoi-Ying/N-8451-2014 OI McKinney, Wayne/0000-0003-2586-3139; Holman, Hoi-Ying/0000-0002-7534-2625 NR 65 TC 37 Z9 38 U1 1 U2 4 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 JUN 15 PY 2000 VL 34 IS 12 BP 2513 EP 2517 DI 10.1021/es991430w PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 325MA UT WOS:000087678300022 ER PT J AU Yan, YE Schwartz, FW AF Yan, YE Schwartz, FW TI Kinetics and mechanisms for TCE oxidation by permanganate SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CARBON DOUBLE-BONDS; POTASSIUM-PERMANGANATE; TRICHLOROETHYLENE; HYDROCARBONS AB The oxidation of trichloroethylene (TCE) by permanganate proceeds in three sequential reaction steps. In the initial step, a cyclic hypomanganate ester is formed via an activated organometallic complex. The activation parameters for this step were determined to he E-a = 41.46 kJ/mol, Delta H double dagger = 39 kJ/mol, and Delta S double dagger = -14 J/mol. The initial reaction is a rate-limiting step (second-order rate constant k(1p) = 0.65-0.68 M-1 s(-1) at 21 degrees C) and independent of pH. In the second step, the decomposition of the cyclic ester with complete chlorine liberation proceeds quickly via various reaction pathways to form four carboxylic acids. Approximately 77% of the TCE was transformed to formic acid at pH 4, while 95-97% of the TCE was transformed to oxalic and glyoxylic acids at pH values of 6-8. Kinetic data suggest that the decomposition rate of the cyclic ester is at least 100 times higher than its formation rate. In the final step, all carboxylic acids are oxidized by permanganate to the final product, CO2. Second-order rate constants of k(3ap) = 0.075-0.35 M-1 s(-1), k(3bp) = 0.13-0.37 M-1 s(-1), and k(3cp) = 0.073-0.11 M-1 s(-1) over a pH range of 4-8 at 21 degrees C were estimated for oxidation of formic, glyoxylic, and oxalic acids, respectively. The oxidation rate of carboxylic acids and accumulation rate of CO2 increase with decreasing pH. The kinetic model that was developed, formulated, and solved analytically on the basis of the understanding of various processes is consistent with results obtained in the kinetic experiments. C1 Ohio State Univ, Dept Geol Sci, Columbus, OH 43210 USA. RP Yan, YE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 25 TC 90 Z9 103 U1 3 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 15 PY 2000 VL 34 IS 12 BP 2535 EP 2541 DI 10.1021/es991279q PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 325MA UT WOS:000087678300026 ER PT J AU Ponder, SM Darab, JG Mallouk, TE AF Ponder, SM Darab, JG Mallouk, TE TI Remediation of Cr(VI) and Pb(II) aqueous solutions using supported, nanoscale zero-valent iron SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID REDUCTIVE DEHALOGENATION; SUBSURFACE REMEDIATION; CHROMATE REDUCTION; METAL; DEGRADATION; WATER; PARTICLES; SOIL; TRICHLOROETHYLENE; DECHLORINATION AB Borohydride reduction of an aqueous iron salt in the presence of a support material gives supported zero-valent iron nanoparticles that are 10-30 nm in diameter. The material is stable in air once it has dried and contains 22.6% iron by weight. The supported zero-valent iron nanoparticles ("Ferragels") rapidly separate and immobilize Cr(VI) and Pb(ll) from aqueous solution, reducing the chromium to Cr(lll) and the Pb to Pb(0) while oxidizing the Fe to goethite (alpha-FeOOH). The kinetics of the reduction reactions are complex and include an adsorption phase. About 10% of the iron in the material appears to be located at active surface sites. Once these sites have been saturated, the reduction process continues but at a much lower rate, which is likely limited by mass transfer. Rates of remediation of Cr(VI) and Pb(ll) are up to 30 times higher for Ferragels than for iron filings or iron powder on a (Fe) molar basis. Over 2 months, reduction of Cr(VI) was 4.8 times greater for Ferragels than for an equal weight of commercial iron filings (21 times greater on the basis of moles of iron present). The higher rates of reaction, and greater number of moles of contaminant reduced overall, suggest that Ferragels may be a suitable material for in situ remediation. C1 Penn State Univ, Dept Chem, State Coll, PA 16803 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Mallouk, TE (reprint author), Penn State Univ, Dept Chem, State Coll, PA 16803 USA. RI Mallouk, Thomas/K-7391-2012 OI Mallouk, Thomas/0000-0003-4599-4208 NR 28 TC 620 Z9 696 U1 51 U2 334 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 JUN 15 PY 2000 VL 34 IS 12 BP 2564 EP 2569 DI 10.1021/es9911420 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 325MA UT WOS:000087678300030 ER PT J AU Marshak, A Knyazikhin, Y Davis, AB Wiscombe, WJ Pilewskie, P AF Marshak, A Knyazikhin, Y Davis, AB Wiscombe, WJ Pilewskie, P TI Cloud-vegetation interaction: Use of Normalized Difference Cloud Index for estimation of cloud optical thickness SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RETRIEVAL AB A new technique to retrieve cloud optical depth for broken clouds above green vegetation using ground-based zenith radiance measurements is developed. By analogy with the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Cloud Index(NDCI) is defined as a ratio between the difference and the sum of two zenith radiances measured for two narrow spectral bands in the visible and near-IR regions. The very different spectral behavior of cloud liquid water drops and green vegetation is the key physics behind the NDCI. It provides extra tools to remove the radiative effects of the 3D cloud structure. Numerical calculations based on fractal clouds and real measurements of NDCI and cloud liquid water path confirm the improvements. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci NIS 2, Los Alamos, NM 87545 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, MC 913, Greenbelt, MD 20771 USA. RI Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012 OI Wiscombe, Warren/0000-0001-6844-9849; NR 20 TC 40 Z9 52 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 2000 VL 27 IS 12 BP 1695 EP 1698 DI 10.1029/1999GL010993 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 325CD UT WOS:000087658000004 ER PT J AU Winter, CL Tartakovsky, DM AF Winter, CL Tartakovsky, DM TI Mean flow in composite porous media SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We develop probabilities and statistics for the parameters of Darcy flows through saturated porous media composed of units of different materials. Our probability model has two levels. On the local level, a porous medium is composed of disjoint, statistically homogeneous volumes (or blocks) each of which consists of a single type of material. On a larger scale, a porous medium is an arrangement of blocks whose extent and location are uncertain. Using this two-scaled model, we derive general formulae for the probability distribution of hydraulic conductivity and its mean; then we develop general perturbation expansions for mean head. We express distributions and parameters in terms of mixtures of locally homogeneous block densities weighted by large-scale block membership probabilities. C1 Univ Calif Los Alamos Natl Lab, Comp Res & Applicat Grp CIC3, Los Alamos, NM 87545 USA. RP Winter, CL (reprint author), Univ Calif Los Alamos Natl Lab, Comp Res & Applicat Grp CIC3, MS B256, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013; Winter, C. Larrabee/D-3918-2013 NR 9 TC 46 Z9 46 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 JUN 15 PY 2000 VL 27 IS 12 BP 1759 EP 1762 DI 10.1029/1999GL011030 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 325CD UT WOS:000087658000020 ER PT J AU Morris, JP AF Morris, JP TI Simulating surface tension with smoothed particle hydrodynamics SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE interfacial flow; meshless methods; surface tension ID RAYLEIGH-TAYLOR INSTABILITY; LEVEL SET APPROACH; INCOMPRESSIBLE FLOWS; NUMERICAL-SIMULATION; STABILITY ANALYSIS; INTERFACIAL FLOW; VOLUME; DYNAMICS; MODEL; SPH AB A method for simulating two-phase flows including surface tension is presented. The approach is based upon smoothed particle hydrodynamics (SPH). The fully Lagrangian nature of SPH maintains sharp fluid-fluid interfaces without employing high-order advection schemes or explicit interface reconstruction. Several possible implementations of surface tension force are suggested and compared. The numerical stability of the method is investigated and optimal choices for numerical parameters are identified. Comparisons with a grid-based volume of fluid method for two-dimensional flows are excellent. The methods presented here apply to problems involving interfaces of arbitrary shape undergoing fragmentation and coalescence within a two-phase system and readily extend to three-dimensional problems. Boundary conditions at a solid surface, high viscosity and density ratios, and the simulation of free-surface flows are not addressed. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Purdue Univ, Sch Civil Engn, W Lafayette, IN 47907 USA. RP Morris, JP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, POB 808,L-206, Livermore, CA 94551 USA. NR 50 TC 151 Z9 162 U1 5 U2 40 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JUN 15 PY 2000 VL 33 IS 3 BP 333 EP 353 DI 10.1002/1097-0363(20000615)33:3<333::AID-FLD11>3.0.CO;2-7 PG 21 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 320FV UT WOS:000087391900002 ER PT J AU Cairncross, RA Schunk, PR Baer, TA Rao, RR Sackinger, PA AF Cairncross, RA Schunk, PR Baer, TA Rao, RR Sackinger, PA TI A finite element method for free surface flows of incompressible fluids in three dimensions. Part I. Boundary fitted mesh motion SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE capillarity; extrusion; finite element method; free surface; pseudo-solid mesh motion; three dimensional ID STOKES PROBLEM; SIMULATION; FORMULATION AB Computational fluid mechanics techniques for examining free surface problems in two-dimensional form are now well established. Extending these methods to three dimensions requires a reconsideration of some of the difficult issues from two-dimensional problems as well as developing new formulations to handle added geometric complexity. This paper presents a new finite element formulation for handling three-dimensional free surface problems with a boundary-fitted mesh and full Newton iteration, which solves for velocity, pressure, and mesh variables simultaneously. A boundary-fitted, pseudo-solid approach is used for moving the mesh, which treats the interior of the mesh as a fictitious elastic solid that deforms in response to boundary motion. To minimize mesh distortion near free boundary under large deformations, the mesh motion equations are rotated into normal and tangential components prior to applying boundary conditions. The Navier-Stokes equations are discretized using a Galerkin-least square/pressure stabilization formulation, which provides good convergence properties with iterative solvers. The result is a method that can track large deformations and rotations of free surface boundaries in three dimensions. The method is applied to two sample problems: solid body rotation of a fluid and extrusion from a nozzle with a rectangular cross-section. The extrusion example exhibits a variety of free surface shapes that arise from changing processing conditions. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Drexel Univ, Dept Chem Engn, Philadelphia, PA 19104 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cairncross, RA (reprint author), Drexel Univ, Dept Chem Engn, 32nd & Chestnut St, Philadelphia, PA 19104 USA. NR 36 TC 64 Z9 64 U1 2 U2 17 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JUN 15 PY 2000 VL 33 IS 3 BP 375 EP 403 DI 10.1002/1097-0363(20000615)33:3<375::AID-FLD13>3.0.CO;2-O PG 29 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 320FV UT WOS:000087391900004 ER PT J AU Baer, TA Cairncross, RA Schunk, PR Rao, RR Sackinger, PA AF Baer, TA Cairncross, RA Schunk, PR Rao, RR Sackinger, PA TI A finite element method for free surface flows of incompressible fluids in three dimensions. Part II. Dynamic wetting lines SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE contact lines; finite element method; free surface; pseudo-solid mesh motion; simulation; three-dimensional; wetting lines ID NON-HORIZONTAL SURFACES; CONTACT ANGLES; CAPILLARY-TUBE; DROPS; ABILITY; BUBBLES; SOLIDS; STICK AB To date, few researchers have solved three-dimensional free surface problems with dynamic wetting lines. This paper extends the free surface finite element method (FEM) described in a companion paper [Cairncross RA, Schunk PR, Baer TA, Sackinger PA, Rao RR. A finite element method for free surface flows of incompressible fluid in three dimensions. Part I. Boundary fitted mesh motion. International Journal for Numerical Methods in Fluids 2000; 33: 375-403] to handle dynamic wetting. A generalization of the technique used in two-dimensional modeling to circumvent double-valued velocities at the wetting line, the so-called kinematic paradox, is presented for a wetting line in three dimensions. This approach requires the fluid velocity normal to the contact line to be zero, the fluid velocity tangent to the contact line to be equal to the tangential component of web velocity, and the fluid velocity into the web to be zero. In addition, slip is allowed in a narrow strip along the substrate surface near the dynamic contact line. For realistic wetting line motion, a contact angle that varies with wetting speed is required because contact lines in three dimensions typically advance or recede at different rates depending upon location and/or have both advancing and receding portions. The theory is applied to capillary rise of static fluid in a corner, the initial motion of a Newtonian droplet down an inclined plane, and extrusion of a Newtonian fluid from a nozzle onto a moving substrate. The extrusion results are compared with experimental visualization. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Drexel Univ, Dept Chem Engn, Philadelphia, PA 19104 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cairncross, RA (reprint author), Drexel Univ, Dept Chem Engn, 32nd & Chestnut St, Philadelphia, PA 19104 USA. NR 23 TC 44 Z9 44 U1 1 U2 12 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JUN 15 PY 2000 VL 33 IS 3 BP 405 EP + DI 10.1002/1097-0363(20000615)33:3<405::AID-FLD14>3.0.CO;2-4 PG 24 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 320FV UT WOS:000087391900005 ER PT J AU Hebner, GA Miller, PA AF Hebner, GA Miller, PA TI Behavior of excited argon atoms in inductively driven plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID COUPLED CHLORINE PLASMAS; LOW-ENERGY ELECTRONS; BORON-TRICHLORIDE; STATE DENSITIES; GLOW-DISCHARGE; REFERENCE CELL; ION DENSITIES; FREQUENCY; EXCITATION; GASES AB Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s(5) and 1s(4), in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s(5) level is metastable and the 1s(4) level is radiatively coupled to the ground state but is radiation trapped. The argon data are compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rf power and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rf powers and pressures investigated, the spatial distributions tended to flatten in the center of the discharge while the density at the edge of the discharge was unaffected. The spatially resolved excited state density measurements were combined with previous line integrated measurements in the same discharge geometry to derive spatially resolved, absolute densities of the 1s(5) and 1s(4) argon excited states and gas temperature spatial distributions. Fluorescence lifetime was a strong function of the rf power, pressure, argon fraction and spatial location. Increasing the power or pressure resulted in a factor of 2 decrease in the fluorescence lifetime while adding Cl-2 or BCl3 increased the fluorescence lifetime. Excited state quenching rates are derived from the data. When Cl-2 or BCl3 was added to the plasma, the maximum argon metastable density depended on the gas and ratio. When chlorine was added to the argon plasma, the spatial density profiles were independent of chlorine fraction. While it is energetically possible for argon excited states to dissociate some of the molecular species present in this discharge, it does not appear to be a significant source of dissociation. The major source of interaction between the argon and the molecular species BCl3 and Cl-2 appears to be through modification of the electron density. (C) 2000 American Institute of Physics. [S0021-8979(00)08712-0]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hebner, GA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 42 TC 38 Z9 38 U1 0 U2 9 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 JUN 15 PY 2000 VL 87 IS 12 BP 8304 EP 8315 DI 10.1063/1.373542 PG 12 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400010 ER PT J AU Yushkov, GY Oks, EM Anders, A Brown, IG AF Yushkov, GY Oks, EM Anders, A Brown, IG TI Effect of multiple current spikes on the enhancement of ion charge states of vacuum arc plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIC-FIELD; DISTRIBUTIONS; PARAMETERS; PULSE AB Ion charge state distributions of vacuum arc ion sources are correlated to the arc operating voltage. Recent research has shown that an enhancement of ion charges via an increase of the arc voltage can be achieved utilizing the transient processes that accompany an arc current spike. The idea investigated is to further enhance the ion charge states by multiple current pulses. It is shown that although the ion charge states are enhanced compared to quasi-dc operation, the application of a sequence of pulses does not lead to the desired additional increase in charge states. This can be attributed to the additional plasma production that is caused by higher arc currents: The additional power supplied to the plasma is distributed over a larger number of plasma particles. One can expect that in the limiting case of many current spikes, the ion charges state distribution approaches the one known for arc plasmas at higher discharge current. (C) 2000 American Institute of Physics. [S0021- 8979(00)05612-7]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634050, Russia. State Univ Control Syst, Tomsk 634050, Russia. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM aanders@lbl.gov RI Oks, Efim/A-9409-2014; Anders, Andre/B-8580-2009; Yushkov, Georgy/O-8024-2015 OI Oks, Efim/0000-0002-9323-0686; Anders, Andre/0000-0002-5313-6505; Yushkov, Georgy/0000-0002-7615-6058 NR 22 TC 21 Z9 25 U1 0 U2 0 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 JUN 15 PY 2000 VL 87 IS 12 BP 8345 EP 8350 DI 10.1063/1.373546 PG 6 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400014 ER PT J AU Gebauer, J Borner, F Krause-Rehberg, R Staab, TEM Bauer-Kugelmann, W Kogel, G Triftshauser, W Specht, P Lutz, RC Weber, ER Luysberg, M AF Gebauer, J Borner, F Krause-Rehberg, R Staab, TEM Bauer-Kugelmann, W Kogel, G Triftshauser, W Specht, P Lutz, RC Weber, ER Luysberg, M TI Defect identification in GaAs grown at low temperatures by positron annihilation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SI-DOPED GAAS; SEMIINSULATING GAAS; POINT-DEFECTS; VACANCY; SPECTROSCOPY; LAYERS; SEMICONDUCTORS; LIFETIME; SOLIDS AB We use positron annihilation to study vacancy defects in GaAs grown at low temperatures (LT-GaAs). The vacancies in as-grown LT-GaAs can be identified to be Ga monovacancies, V-Ga, according to their positron lifetime and annihilation momentum distribution. The charge state of the vacancies is neutral. This is ascribed to the presence of positively charged As-Ga(+) antisite defects in vicinity to the vacancies. Theoretical calculations of the annihilation parameters show that this assignment is consistent with the data. The density of V-Ga is related to the growth stoichiometry in LT-GaAs, i.e., it increases with the As/Ga beam equivalent pressure (BEP) and saturates at 2x10(18) cm(-3) for a BEP greater than or equal to 20 and a low growth temperature of 200 degrees C. Annealing at 600 degrees C removes V-Ga. Instead, larger vacancy agglomerates with a size of approximately four vacancies are found. It will be shown that these vacancy clusters are associated with the As precipitates formed during annealing. (C) 2000 American Institute of Physics. [S0021- 8979(00)02812-7]. C1 Univ Halle Wittenberg, Fachbereich Phys, D-06099 Halle, Germany. Aalto Univ, Phys Lab, FIN-02015 Espoo, Finland. Univ Bundeswehr Munchen, Inst Nukl Festkorperphys, D-85577 Neubiberg, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. RP Univ Halle Wittenberg, Fachbereich Phys, D-06099 Halle, Germany. EM gebauer@physik.uni-halle.de RI Luysberg, Martina/B-6448-2014 OI Luysberg, Martina/0000-0002-5613-7570 NR 58 TC 29 Z9 31 U1 0 U2 12 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 JUN 15 PY 2000 VL 87 IS 12 BP 8368 EP 8379 AR PII [S0021-8979(00)02812-7] DI 10.1063/1.373549 PG 12 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400017 ER PT J AU Barsoum, MW Rawn, CJ El-Raghy, T Procopio, AT Porter, WD Wang, H Hubbard, CR AF Barsoum, MW Rawn, CJ El-Raghy, T Procopio, AT Porter, WD Wang, H Hubbard, CR TI Thermal properties of Ti4AlN3 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TI3SIC2 AB In this article we report on the atomic displacement parameters, lattice expansions, heat capacity, and thermal conductivity of samples of Ti4AlN3 in the 298-1370 K temperature range. Rietveld refinement of high temperature neutron diffraction data shows that the nitrogen is substoichiometric and the formula is Ti4AlN2.9. In this structure, the atomic displacement parameters of the Al atoms are higher than those of either the Ti or N atoms. The Ti-N bonds adjacent to the Al planes are about 2.5% shorter than the Ti-N bonds in the inner layers. The thermal expansion coefficients along the a and c axes are, respectively, (9.6 +/- 0.1)x10(-6) and (8.8 +/- 0.1)x10(-6) K-1. The unit cell expansivity, (9.4 +/- 0.1)x10(-6) K-1, is in agreement with the dilatometric bulk thermal expansivity (9.7 +/- 0.2)x10(-6) K-1. The heat capacity, c(p), is 150 J/mol K at ambient temperatures and extrapolates to approximate to 220 J/mol K at 1300 K. At all temperatures c(p) equals four times the molar heat capacity of TiN. The room temperature thermal conductivity is 12 W/m K and increases linearly to approximate to 20 W/m K at 1300 K. (C) 2000 American Institute of Physics. [S0021-8979(00)04212-2]. C1 Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Drexel Univ, Dept Mat Engn, Philadelphia, PA 19104 USA. EM barsoumw@drexel.edu RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 33 TC 44 Z9 45 U1 1 U2 14 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 JUN 15 PY 2000 VL 87 IS 12 BP 8407 EP 8414 AR PII [S0021-8979(00)04212-2] DI 10.1063/1.373555 PG 8 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400023 ER PT J AU Rujkorakarn, R Nelson, AJ AF Rujkorakarn, R Nelson, AJ TI Optical properties of ZnS1-xSex alloys fabricated by plasma-induced isoelectronic substitution SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BAND OFFSETS; ZNSE; DIODES; FILMS AB Nonequilibrium growth of thin-film ternary ZnS1-xSex semiconductor alloys was accomplished using physical vapor deposition with simultaneous electron cyclotron resonance H2S plasma activation. Substrate temperature, gas flow, and plasma power determine the ZnS1-xSex alloy composition and structure. Integrated optical transmission spectra for the ZnS1-xSex semiconductor alloys as a function of H2S plasma power are presented. Using the alpha(2) vs h nu plots for the various ZnS1-xSex films, the optical band gap E-g is extrapolated from each curve. This methodology yields the values of the band gap as a function of stoichiometry. We observe that the plasma induced isoelectronic substitution of S into the ZnSe lattice increases the band gap. This study shows that plasma-induced isoelectronic substitution is technologically feasible and useful for fabricating ternary II-VI alloys under nonequilibrium conditions. (C) 2000 American Institute of Physics. [S0021-8979(00)02412-9]. C1 Khon Kaen Univ, Dept Phys, Khon Kaen 40002, Thailand. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Khon Kaen Univ, Dept Phys, Khon Kaen 40002, Thailand. EM nelson63@llnl.gov NR 22 TC 33 Z9 34 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 2000 VL 87 IS 12 BP 8557 EP 8560 AR PII [S0021-8979(00)02412-9] DI 10.1063/1.373578 PG 4 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400046 ER PT J AU Karazhanov, SZ Zhang, Y Mascarenhas, A Deb, S AF Karazhanov, SZ Zhang, Y Mascarenhas, A Deb, S TI The effect of excitons on CdTe solar cells SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTRINSIC CARRIER CONCENTRATION; CADMIUM TELLURIDE; TRANSPORT; SILICON; PHOTOLUMINESCENCE; MOBILITY; DEFECTS; EDGE AB Temperature and doping-level dependence of CdTe solar cells is investigated, taking into account the involvement of excitons on photocurrent transport. We show that the density of excitons in CdTe is comparable with that of minority carriers at doping levels greater than or equal to 10(15) cm(-3). From the investigation of the dark-saturation current, we show that the product of electron and hole concentrations at equilibrium is several orders of magnitude more than the square of the intrinsic carrier concentration. With this assumption, we have studied the effect of excitons on CdTe solar cells, and the effect is negative. CdTe solar cell performance with excitons included agrees well with existing experimental results. (C) 2000 American Institute of Physics. [S0021- 8979(00)07612-X]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Phys Tech Inst, Tashkent 700084, Uzbekistan. RP Karazhanov, SZ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Karazhanov, Smagul/E-3357-2015 OI Karazhanov, Smagul/0000-0001-6504-2517 NR 45 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 2000 VL 87 IS 12 BP 8786 EP 8792 DI 10.1063/1.373611 PG 7 WC Physics, Applied SC Physics GA 319MU UT WOS:000087346400080 ER PT J AU Thoss, M Miller, WH Stock, G AF Thoss, M Miller, WH Stock, G TI Semiclassical description of nonadiabatic quantum dynamics: Application to the S-1-S-2 conical intersection in pyrazine SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID INITIAL-VALUE REPRESENTATION; SELF-CONSISTENT-FIELD; VIBRONIC LEVEL FLUORESCENCE; ELECTRON-TRANSFER DYNAMICS; POTENTIAL-ENERGY SURFACES; PATH-INTEGRAL TREATMENT; CURVE-CROSSING PROBLEMS; WAVE-PACKET DYNAMICS; ZERO-POINT ENERGY; MOLECULAR-DYNAMICS AB A recently proposed semiclassical approach to the description of nonadiabatic quantum dynamics [G. Stock and M. Thoss, Phys. Rev. Lett. 78, 578 (1997), X. Sun and W. H. Miller, J. Chem. Phys. 106, 916 (1997)] is applied to the S-1-S-2 conical intersection in pyrazine. This semiclassical method is based on a transformation of discrete quantum variables to continuous variables, thereby bypassing the problem of a classical treatment of discrete quantum degrees of freedom such as electronic states. Extending previous work on small systems, we investigate the applicability of the semiclassical method to larger systems with strong vibronic coupling. To this end, we present results for several pyrazine models of increasing dimensionality and complexity. In particular, we discuss the quality and performance of the semiclassical approach when the number of nuclear degrees of freedom is increased. Comparison with quantum-mechanical calculations and experimental results shows that the semiclassical method is able to describe the ultrafast dynamics in this system. (C) 2000 American Institute of Physics. [S0021-9606(00)01323-4]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Freiburg, Fac Phys, D-79104 Freiburg, Germany. RP Thoss, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Thoss, Michael/C-5976-2013 NR 114 TC 113 Z9 113 U1 3 U2 28 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 15 PY 2000 VL 112 IS 23 BP 10282 EP 10292 AR PII [S0021-9606(00)01323-4] DI 10.1063/1.481668 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 321XC UT WOS:000087479100026 ER PT J AU Gbur, G James, DFV AF Gbur, G James, DFV TI Unpolarized sources that generate highly polarized fields outside the source SO JOURNAL OF MODERN OPTICS LA English DT Article ID ELECTROMAGNETIC-FIELDS AB It is demonstrated that an unpolarized primary electromagnetic source may, under special conditions, produce a field outside the source domain that is almost completely polarized in nearly all directions. This result demonstrates that the polarization statistics of a random electromagnetic field may differ significantly from the polarization statistics of the source distribution that generates it, and may in fact be quite different in different directions of observation. An example of such a source is given. C1 Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Univ Rochester, Rochester Theory Ctr Opt Sci & Engn, Rochester, NY 14627 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T4, Los Alamos, NM 87545 USA. RP Gbur, G (reprint author), Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 8 TC 17 Z9 17 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD JUN 15 PY 2000 VL 47 IS 7 BP 1171 EP 1177 DI 10.1080/09500340008232164 PG 7 WC Optics SC Optics GA 319MZ UT WOS:000087346900003 ER PT J AU Laskin, J Futrell, J AF Laskin, J Futrell, J TI Internal energy distributions resulting from sustained off-resonance excitation in Fourier transform ion cyclotron resonance mass spectrometry. II. Fragmentation of the 1-bromonaphthalene radical cation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID COLLISION-INDUCED DISSOCIATION; INFRARED RADIATIVE DISSOCIATION; GAS-PHASE; UNIMOLECULAR DISSOCIATION; ACTIVATED DISSOCIATION; PROTONATED PEPTIDES; IRRADIATION; NAPHTHALENE; ENERGETICS; DEPOSITION AB The collision energy dependence of the fragmentation of the 1-bromonaphthalene radical cation was studied using sustained off-resonance excitation (SORI) in a 7 T Fourier transform ion cyclotron resonance mass spectrometer (FTMS). Fragmentation efficiency curves were obtained as a function of collision energy at four different pressures of Ar bath gas corresponding to collision numbers of 3, 5, 15, and 20. The results were modeled using RRKM/QET formalism. A refined analytical form for the collisional energy deposition function is proposed. The ability to obtain accurate fragmentation energetics of a complex system using the present approach is demonstrated. The "effective temperatures" deduced from the average internal energies for C6H5Br+. and C10H7Br+. were found to be the same for both ions provided the bath gas pressure and the maximum value of center-of-mass collision energy were the same. The range of effective temperatures from 1000 to 3700 K sampled in the present study significantly exceeds the temperature range accessible by blackbody infrared radiative dissociation (BIRD). We anticipate that the present approach can be used to study fragmentation energetics of biomolecules. C1 Pacific NW Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Laskin, J (reprint author), Pacific NW Lab, William R Wiley Environm Mol Sci Lab, POB 999 K8-96, Richland, WA 99352 USA. RI Laskin, Julia/H-9974-2012 OI Laskin, Julia/0000-0002-4533-9644 NR 45 TC 71 Z9 72 U1 0 U2 8 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 15 PY 2000 VL 104 IS 23 BP 5484 EP 5494 DI 10.1021/jp000281x PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 327DW UT WOS:000087778800011 ER PT J AU Bouten, R Baerends, EJ van Lenthe, E Visscher, L Schreckenbach, G Ziegler, T AF Bouten, R Baerends, EJ van Lenthe, E Visscher, L Schreckenbach, G Ziegler, T TI Relativistic effects for NMR shielding constants in transition metal oxides using the zeroth-order regular approximation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; NUCLEAR MAGNETIC SHIELDINGS; CHEMICAL-SHIFTS; PERTURBATION-THEORY; DIRAC-EQUATION; ELECTRONIC-STRUCTURE; ATOMIC ORBITALS; TENSORS; DFT; ENERGY AB Relativistic effects for NMR shielding constants have been calculated using the zero order regular approximation (ZORA) for relativistic effects. Isotropic NMR shielding constants were obtained using density functional theory with gauge including atomic orbitals (GIAO) in a spin-fi ec formalism for the metal nuclei in transition metal oxides MO4n- (M = Cr, Mn, Fe, Mo, Tc, Ru, W, Re, Os) and carbonyl complexes M(CO)(6) (M = Cr, Mo, W). The ZORA isotropic shieldings are compared with results from an extended version of the relativistic method employing the Pauli Hamiltonian developed earlier by Schreckenbach and Ziegler. Comparison between ZORA and Pauli shieldings, employing the restrictions necessary for the Pauli approach-frozen cores, restricted basis sets in the core region-show the ZORA shieldings to be significantly different from Pauli ones, but the chemical shifts of the metal oxides with respect to the carbonyl complexes do not differ much. However, extending the ZORA calculations (no frozen core, extended basis sets) gives significant changes, proving the limitation to frozen cores and restricted basis sets of the Pauli method to be unwarranted. Comparison to experiment shows that the errors of the most precise ZORA chemical shifts are ca. 10% (in the order of a few 100 ppm) for both the light and heavy transition metals. Error sources may be, apart from deficiencies of the density functional, the neglect of spin-orbit coupling and the neglect of solvent effects. C1 Free Univ Amsterdam, Dept Chem, NL-1081 HV Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, Div Theoret MS B268, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Inst Transactinium Sci, Los Alamos, NM 87545 USA. Univ Calgary, Dept Chem, Calgary, AB T2N 1N4, Canada. RP Baerends, EJ (reprint author), Free Univ Amsterdam, Dept Chem, De Boelelaan 1083, NL-1081 HV Amsterdam, Netherlands. RI Visscher, Lucas/A-3523-2010; Baerends, Evert Jan/F-7206-2011; Ziegler, Tom/D-7863-2012 OI Visscher, Lucas/0000-0002-7748-6243; Baerends, Evert Jan/0000-0002-3045-4906; NR 46 TC 53 Z9 53 U1 0 U2 17 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 15 PY 2000 VL 104 IS 23 BP 5600 EP 5611 DI 10.1021/jp994480w PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 327DW UT WOS:000087778800026 ER PT J AU Kim, SH Somorjai, GA AF Kim, SH Somorjai, GA TI Model Ziegler-Natta polymerization catalysts fabricated by reactions of Mg metal and TiCl4: Film structure, composition, and deposition kinetics SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SURFACE SCIENCE; TITANIUM CHLORIDE; THIN-FILMS; MAGNESIUM; SPECTROSCOPY; ACTIVATION; MONOLAYER; HALIDES; GOLD AB The film structure, composition, and deposition kinetics of model Ziegler-Natta polymerization catalysts produced by chemical vapor deposition have been studied using temperature-programmed desorption (TPD), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). Redox reactions of metallic Mg and TiCl4 deposited from the vapor phase on a Au substrate produce the model catalysts composed of titanium chloride and magnesium chloride (TiClx/MgCl2). The low solubility of TiClx in MgCl2 leads to the formation of a TiClx monolayer on top of MgCl2 multilayers characteristic of the supported catalysts. The TiCl4/Mg flux ratio during the deposition controls the oxidation state distribution and surface coverage of TiClx species of the deposited film. The conversion of Mg to MgCl2 is completed in the codeposition process while it is incomplete in the sequential deposition process due to a kinetic barrier for chlorine diffusion. Upon heating the sequentially deposited film, the surface TiClx (Ti4+) species react with metallic Mg atoms in underlayers to complete the redox reaction. In the case of the codeposited film, the surface TiClx species desorb as TiCl4 at temperatures higher than 430 K. After exposure to triethylaluminum (AlEt3) cocatalyst, the model catalyst films are active for propylene polymerization. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 36 TC 28 Z9 29 U1 2 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 15 PY 2000 VL 104 IS 23 BP 5519 EP 5526 DI 10.1021/jp994441k PG 8 WC Chemistry, Physical SC Chemistry GA 327DZ UT WOS:000087779300018 ER PT J AU Hayes, JM Matsuzaki, S Ratsep, M Small, GJ AF Hayes, JM Matsuzaki, S Ratsep, M Small, GJ TI Red chlorophyll a antenna states of photosystem I of the cyanobacterium Synechocystis sp PCC 6803 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; ELECTRON-DONOR STATE; DISPERSIVE KINETICS; CHARGE SEPARATION; ENERGY-TRANSFER; SYNECHOCOCCUS-ELONGATUS; THYLAKOID MEMBRANES; POLYVINYL-ALCOHOL; CRESYL VIOLET; CORE ANTENNA AB The antenna chlorophyll a (Chl a) molecules of photosystem I of green plants and cyanobacteria that absorb further to the red than P700, the special pair of the reaction center, have long been of considerable interest. Recently, the results of nonphotochemical hole burning experiments at liquid helium temperatures, which included use of high pressure and external electric (Stark) fields, led to the conclusion that the cyanobacterium Synechocystis sp. PCC 6803 possesses two "red" antenna states whose S-0 (ground state) --> Q(y)(S-1) origin absorption bands are at 714 and approximate to 708 nm (Ratsep et al. J. Phys. Chem B 2000, 104, 836). The results indicated that the 714 nm state is due to strongly coupled Chi a molecules (C-714), a dimer or, possibly, a trimer. It was concluded that the 714 nm state is responsible for the fluorescence origin band at 720 nm. Presented here are the results of theoretical simulations of the dependence of the hole spectra on burn wavelength and burn fluence that are consistent with the conclusions of Ratsep et al. They lead to a more detailed characterization of the two states, including determination of their site distribution functions (SDF) and the electron-phonon coupling parameters of the S-0 --> Q(y) transitions. The higher energy state is found to lie closer to 706 nm than 708 nm. The electron-phonon coupling of the 714 nm transition is strong with a total Huang-Rhys factor (S-t) of 2.0 due to low-frequency modes at 18 and approximate to 70 cm(-1). The coupling of the 706 nm transition is weaker by a factor of 1.5. It is concluded that both C-714 and C-706 are, at a minimum, dimers that are not in close proximity to each other. The large widths, approximate to 300 cm(-1), of the SDF suggest that the structures of C-706 and C-714 are fragile. The spectroscopic properties of P700, C-706, and C-714 are compared and discussed in terms of excitation energy transfer at low temperatures. A new model that explains why only about half of the PS I complexes undergo irreversible charge separation in the low-temperature limit following excitation of the higher energy bulk antenna states is presented. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Hayes, JM (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 39 TC 41 Z9 43 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 15 PY 2000 VL 104 IS 23 BP 5625 EP 5633 DI 10.1021/jp000447u PG 9 WC Chemistry, Physical SC Chemistry GA 327DZ UT WOS:000087779300031 ER PT J AU Poulos, GS Bossert, JE McKee, TB Pielke, RA AF Poulos, GS Bossert, JE McKee, TB Pielke, RA TI The interaction of katabatic flow and mountain waves. Part I: Observations and idealized simulations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PAST 3-DIMENSIONAL OBSTACLES; NOCTURNAL DRAINAGE FLOWS; COMPLEX TERRAIN; GRAVITY-WAVES; NUMERICAL SIMULATIONS; DOWNSLOPE WINDSTORMS; BOUNDARY-LAYER; VALLEY; SLOPE; SHEAR AB The mutual interaction of katabatic flow in the nocturnal boundary layer (NBL) and topographically forced gravity waves is investigated, Due to the nonlinear nature of these phenomena, analysis focuses on information obtained from the 1993 Atmospheric Studies in Complex Terrain field program held at the mountain-canyon-plains interface near Eldorado Canyon, Colorado, and idealized simulations. Perturbations to katabatic flow by mountain waves, relative to their more steady form in quiescent conditions, are found to be caused by dynamic pressure effects, Based on a local Froude number climatology, case study analysis, and the simulations, the dynamic pressure effect is theorized to occur as gravity wave pressure perturbations are transmitted through the atmospheric column to the surface and, through altered horizontal pressure gradient forcing, to the surface-based katabatic flows, It is proposed that these perturbations are a routine feature in the atmospheric record and represent a significant portion of the variability in complex terrain katabatic flows. The amplitude, wavelength, and vertical structure of mountain waves caused by flow over a barrier are themselves portly determined by the evolving structure of the NBL in which the drainage flows develop. For Froude number Fr > similar to 0.5 the mountain wave flow is found to separate from the surface at higher altitudes with NBL evolution (increasing time exposed to radiational cooling), as is expected from Fr considerations. However, flow with Fr < similar to 0.5 behaves unexpectedly. In this regime, the separation point descends downslope with NBL evolution. Overall, a highly complicated, mutually evolving, system of mountain wave-katabatic flow interaction is found, such that the two flow phenomena are, at times, indistinguishable. The mechanisms described here are expanded upon in a companion paper through realistic numerical simulations and analysis of a nocturnal case study (3-4 September 1993). C1 Colorado State Univ, Ft Collins, CO 80523 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Colorado Res Associates, 3380 Mitchell Lane, Boulder, CO 80301 USA. EM gsp@co-ra.com RI Pielke, Roger/A-5015-2009 NR 73 TC 24 Z9 24 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUN 15 PY 2000 VL 57 IS 12 BP 1919 EP 1936 DI 10.1175/1520-0469(2000)057<1919:TIOKFA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 326CV UT WOS:000087715800006 ER PT J AU Furuya, K Mitsuishi, K Ishikawa, N Allen, CW AF Furuya, K Mitsuishi, K Ishikawa, N Allen, CW TI Imaging and modeling of nanocrystalline Xe in Al containing defects SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT NSF Symposium on Micromechanic Modeling of Industrial Materials CY JUL 20-22, 1998 CL UNIV WASHINGTON, SEATTLE, WASHINGTON SP Natl Sci Fdn, Minerals Met & Mat Soc, AIME, Amer Soc Met, Amer Soc Mech Engineers, Japan Inst Met, Nippon Steel corp, Kobe Steel Ltd, Nissin Steel Co Ltd, Ryobi N Amer, Awaji Sangyo, Japan Steel Works HO UNIV WASHINGTON DE Xe nanocrystal; OB-HRTEM; cuboctahedron; stacking fault; partial dislocation ID IMPLANTED ALUMINUM; INCLUSIONS; BUBBLES AB Morphological and crystallographic structures of a Xe nanocrystal embedded in Al were determined with off-Bragg high-resolution transmission electron microscopy (OB-HRTEM). The nanocrystals have a size in a range from 1 to 10 nm and precipitate with a FCC structure, mesotactically aligned with Al matrix. OB-HRTEM revealed Xe cuboctahedron crystals with faces parallel to eight Al {111} planes truncated by six {100} planes. Atomic resolution microscopy indicates that the nanocrystals often contain lattice defects, which consist of a stacking fault. Simulated images for a nanocrystal containing a stacking fault agreed well with experimental images. The process of a defect introduction into a nanocrystal was successfully recorded on videotape. A frame by frame analysis shows the introduction of a Shockely partial dislocation to form the fault. This introduction requires the motion of atoms in several layers in one side of the fault, to relax the strain caused by the change in stacking sequence. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Natl Res Inst Met, Tsukuba, Ibaraki 3050003, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Furuya, K (reprint author), Natl Res Inst Met, 3-13 Sakura, Tsukuba, Ibaraki 3050003, Japan. NR 12 TC 7 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 15 PY 2000 VL 285 IS 1-2 BP 85 EP 90 DI 10.1016/S0921-5093(00)00673-0 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 328JZ UT WOS:000087848800015 ER PT J AU Sessler, AM AF Sessler, AM TI Setbacks don't dampen the energy of US physics SO NATURE LA English DT Letter C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Neutrino Factory & Muon Collider Collaborat, Berkeley, CA 94720 USA. RP Sessler, AM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Neutrino Factory & Muon Collider Collaborat, Berkeley, CA 94720 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUN 15 PY 2000 VL 405 IS 6788 BP 733 EP 733 DI 10.1038/35015789 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 324KJ UT WOS:000087620600017 ER PT J AU Nolting, F Scholl, A Stohr, J Seo, JW Fompeyrine, J Siegwart, H Locquet, JP Anders, S Luning, J Fullerton, EE Toney, MF Scheinfein, MR Padmore, HA AF Nolting, F Scholl, A Stohr, J Seo, JW Fompeyrine, J Siegwart, H Locquet, JP Anders, S Luning, J Fullerton, EE Toney, MF Scheinfein, MR Padmore, HA TI Direct observation of the alignment of ferromagnetic spins by antiferromagnetic spins SO NATURE LA English DT Article ID ANISOTROPY AB The arrangement of spins at interfaces in a layered magnetic material often has an important effect on the properties of the material. One example of this is the directional coupling between the spins in an antiferromagnet and those in an adjacent ferromagnet, an effect first discovered(1) in 1956 and referred to as exchange bias. Because of its technological importance for the development of advanced devices such as magnetic read heads(2) and magnetic memory cells(3), this phenomenon has received much attention(4,5). Despite extensive studies, however, exchange bias is still poorly understood, largely due to the lack of techniques capable of providing detailed information about the arrangement of magnetic moments near interfaces. Here we present polarization-dependent X-ray magnetic dichroism spectro-microscopy that reveals the micromagnetic structure on both sides of a ferromagnetic-antiferromagnetic interface. Images of thin ferromagnetic Co films grown on antiferromagnetic LaFeO3 show a direct link between the arrangement of spins in each material. Remanent hysteresis loops, recorded for individual ferromagnetic domains, show a local exchange bias. Our results imply that the alignment of the ferromagnetic spins is determined, domain by domain, by the spin directions in the underlying antiferromagnetic layer. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. RP Nolting, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Fullerton, Eric/H-8445-2013; Seo, Jin Won/J-3980-2013; Scholl, Andreas/K-4876-2012; Raoux, Simone/G-3920-2016 OI Fullerton, Eric/0000-0002-4725-9509; Seo, Jin Won/0000-0003-4937-0769; NR 13 TC 295 Z9 300 U1 14 U2 107 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 15 PY 2000 VL 405 IS 6788 BP 767 EP 769 DI 10.1038/35015515 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 324KJ UT WOS:000087620600042 ER PT J AU Tombler, TW Zhou, CW Alexseyev, L Kong, J Dai, HJ Lei, L Jayanthi, CS Tang, MJ Wu, SY AF Tombler, TW Zhou, CW Alexseyev, L Kong, J Dai, HJ Lei, L Jayanthi, CS Tang, MJ Wu, SY TI Reversible electromechanical characteristics of carbon nanotubes under local-probe manipulation SO NATURE LA English DT Article ID ELECTRONIC-STRUCTURE; ROPES AB The effects of mechanical deformation on the electrical properties of carbon nanotubes are of interest given the practical potential of nanotubes in electromechanical devices, and they have been studied using both theoretical(1-4) and experimental(5,6) approaches. One recent experiment 6 used the tip of an atomic force microscope (AFM) to manipulate multi-walled nanotubes, revealing that changes in the sample resistance were small unless the nanotubes fractured or the metal-tube contacts were perturbed. But it remains unclear how mechanical deformation affects the intrinsic electrical properties of nanotubes. Here we report an experimental and theoretical elucidation of the electromechanical characteristics of individual single-walled carbon nanotubes (SWNTs) under local-probe manipulation. We use AFM tips to deflect suspended SWNTs reversibly, without changing the contact resistance; in situ electrical measurements reveal that the conductance of an SWNT sample can be reduced by two orders of magnitude when deformed by an AFM tip. Our tight-binding simulations indicate that this effect is owing to the formation of local sp(3) bonds caused by the mechanical pushing action of the tip. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Louisville, Dept Phys, Louisville, KY 40292 USA. Univ Calif Lawrence Livermore Natl Lab, Phys Directorate, Livermore, CA 94551 USA. RP Dai, HJ (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Zhou, Chongwu/F-7483-2010 NR 19 TC 874 Z9 888 U1 24 U2 169 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 15 PY 2000 VL 405 IS 6788 BP 769 EP 772 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 324KJ UT WOS:000087620600043 ER PT J AU Huang, SR Beresten, S Li, BM Oshima, J Ellis, NA Campisi, J AF Huang, SR Beresten, S Li, BM Oshima, J Ellis, NA Campisi, J TI Characterization of the human and mouse WRN 3 '-> 5 ' exonuclease SO NUCLEIC ACIDS RESEARCH LA English DT Article ID SYNDROME GENE-PRODUCT; WERNER SYNDROME CELLS; DNA HELICASE; SYNDROME PROTEIN; MISMATCH REPAIR; CLONING; LINES; RECQ; MUTATIONS; INVITRO AB Werner's syndrome (WS) is an autosomal recessive disorder in humans characterized by the premature development of a partial array of age-associated pathologies. WRN, the gene defective in WS, encodes a 1432 amino acid protein (hWRN) with intrinsic 3'-->5' DNA helicase activity. We recently showed that hWRN is also a 3'-->5' exonuclease. Here, we further characterize the hWRN exonuclease, hWRN efficiently degraded the 3' recessed strands of double-stranded DNA or a DNA-RNA heteroduplex, It had little or no activity on blunt-ended DNA, DNA with a 3' protruding strand, or single-stranded DNA. The hWRN exonuclease efficiently removed a mismatched nucleotide at a 3' recessed terminus, and was capable of initiating DNA degradation from a 12-nt gap, or a nick. We further show that the mouse WRN (mWRN) is also a 3'-->5' exonuclease, with substrate specificity similar to that of hWRN. Finally, we show that hWRN forms a trimer and interacts with the proliferating cell nuclear antigen in vitro. These findings provide new data on the biochemical activities of WRN that may help elucidate its role(s) in DNA metabolism. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Mem Sloan Kettering Canc Ctr, Lab Canc Susceptibil, Dept Human Genet, New York, NY 10021 USA. Univ Washington, Dept Pathol, Seattle, WA 98195 USA. RP Campisi, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mailstop 84-144,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NIA NIH HHS [R01 AG011658, AG05776, AG11658, F32 AG005776] NR 44 TC 112 Z9 113 U1 0 U2 5 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 JUN 15 PY 2000 VL 28 IS 12 BP 2396 EP 2405 DI 10.1093/nar/28.12.2396 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 325XD UT WOS:000087701000017 PM 10871373 ER PT J AU Sankaran, V Walsh, JT Maitland, DJ AF Sankaran, V Walsh, JT Maitland, DJ TI Polarized light propagation through tissue phantoms containing densely packed scatterers (vol 25, pg 239, 2000) SO OPTICS LETTERS LA English DT Correction C1 Univ Calif Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94551 USA. Northwestern Univ, Dept Biomed Engn, Evanston, IL 60208 USA. RP Sankaran, V (reprint author), Univ Calif Lawrence Livermore Natl Lab, Med Technol Program, Livermore, CA 94551 USA. RI Walsh, Joseph/B-7636-2009 NR 1 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 15 PY 2000 VL 25 IS 12 BP 933 EP 933 DI 10.1364/OL.25.000933 PG 1 WC Optics SC Optics GA 324VQ UT WOS:000087642400023 PM 18064232 ER PT J AU Hadjiconstantinou, NG Garcia, AL Alder, BJ AF Hadjiconstantinou, NG Garcia, AL Alder, BJ TI The surface properties of a van der Waals fluid SO PHYSICA A LA English DT Article; Proceedings Paper CT 50th Taiwan International Symposium on Statistical Physics CY AUG 09-12, 1999 CL INST PHYS , ACAD SIN, TAIPEI, TAIWAN SP Inst Phys, Acad Sin HO INST PHYS , ACAD SIN AB Surface properties are obtained from an extension of the direct simulation Monte Carlo algorithm to a hard sphere system with an infinite range, weak attractive potential that obeys the van der Waals equation of state. Liquid-vapor surface tension measurements both with and without a gravitational field are in agreement with models summarizing experimental values for simple substances. These measurements are also in agreement with the van der Waals predictions using the measured interface density profile provided the square gradient term identification with a divergent fi ee energy expansion is ignored. The divergent term should be replaced by one that takes into account the work required to form the density gradient in the reference hard sphere system. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. RP Hadjiconstantinou, NG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 14 TC 14 Z9 16 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 15 PY 2000 VL 281 IS 1-4 BP 337 EP 347 DI 10.1016/S0378-4371(00)00026-1 PG 11 WC Physics, Multidisciplinary SC Physics GA 326NM UT WOS:000087741700034 ER PT J AU Zhang, Y Mascarenhas, A AF Zhang, Y Mascarenhas, A TI Isoelectronic impurity states in GaAs : N SO PHYSICAL REVIEW B LA English DT Article ID NITROGEN; PHOTOLUMINESCENCE; EXCITONS; MODEL AB Using the one-band one-site Koster-Slater model, we explain the different behavior of isoelectronic impurities in GaAs:N and GaP:N in terms of their band-structure difference. We show that the two lowest nitrogen bound states, NN1 and NN2, are associated with the [220] and [110] nitrogen pairs, respectively, that the optical transition of the former is dipole allowed whilst the latter is forbidden in both systems, and that the order of the [220] and [110] pair levels are reversed in the two systems. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 23 TC 19 Z9 19 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 2000 VL 61 IS 23 BP 15562 EP 15564 DI 10.1103/PhysRevB.61.15562 PG 3 WC Physics, Condensed Matter SC Physics GA 327LV UT WOS:000087796100013 ER PT J AU Sinnott, SB Wood, RF Pennycook, SJ AF Sinnott, SB Wood, RF Pennycook, SJ TI Ab initio calculations of rigid-body displacements at the Sigma 5 (210) tilt grain boundary in TiO2 SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; PARTICLES; DYNAMICS; RUTILE AB Through extensive ab initio total energy calculations of the Sigma 5 (210) grain boundary in TiO2 (rutile), the remarkably large rigid-body contractions found by high resolution electron microscopy and Z-contrast imaging are explored. Unlike previous calculations, this work emphasizes the importance of the displacements of the two halves of the bicrystal towards one another. Previous experimental work suggests that the stochiometry and ionic charges at the boundary are preserved at their bulk values and therefore vacancies and impurities within the grain boundary core were not considered. The calculations predict no significant rigid-body contraction or expansion. The implications of this result for both computational and experimental studies of rigid-body displacements at grain boundaries are discussed. C1 Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Sinnott, SB (reprint author), Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. RI Sinnott, Susan/P-8523-2014 OI Sinnott, Susan/0000-0002-3598-0403 NR 20 TC 18 Z9 18 U1 0 U2 5 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 JUN 15 PY 2000 VL 61 IS 23 BP 15645 EP 15648 DI 10.1103/PhysRevB.61.15645 PG 4 WC Physics, Condensed Matter SC Physics GA 327LV UT WOS:000087796100035 ER PT J AU Martin, RL Kress, JD Campbell, IH Smith, DL AF Martin, RL Kress, JD Campbell, IH Smith, DL TI Molecular and solid-state properties of tris-(8-hydroxyquinolate)-aluminum SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-FUNCTIONAL THEORY; EXCITATION-ENERGIES; ALUMINUM; MODEL; TRANSPORT; ELECTRON; ALQ(3); ABSORPTION; POLYMERS; DYNAMICS AB We use a hybrid density-functional-theory approach to calculate ground-state electronic properties and a time-dependent density-functional-theory approach to investigate the excited state electronic properties of molecular tris-(8-hydroxyquinolate)-aluminum, Alq. The calculated molecular results are compared with measurements on dense solid-state films of Alq. We specifically consider: the optical absorption spectrum near the fundamental absorption threshold, the ionization potential, the single-particle energy gap, the static dielectric constant, and the electric-field dependence of the electron mobility. We find that the molecular calculations can describe the optical absorption spectrum near the fundamental absorption threshold without significant corrections for solid-state effects. The energies of the triplet excited states are computed and the lowest triplet is found to lie 0.64 eV below the lowest excited singlet state. In contrast, large dielectric corrections must be included for the molecular calculations to describe the ionization potential and single-particle energy gap. When these dielectric corrections are made, using the calculated molecular polarizability, which accurately gives the measured static dielectric constant, both the ionization potential and single-particle energy gap are well described. The calculated molecular dipole moment can be used to interpret the electric-field dependence of the electron mobility. The solid-state properties, determined from the molecular calculations, are then used in a device model to describe the measured current-voltage characteristics in Alq diodes. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Martin, RL (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B268, Los Alamos, NM 87545 USA. NR 35 TC 135 Z9 142 U1 1 U2 20 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 JUN 15 PY 2000 VL 61 IS 23 BP 15804 EP 15811 DI 10.1103/PhysRevB.61.15804 PG 8 WC Physics, Condensed Matter SC Physics GA 327LV UT WOS:000087796100058 ER PT J AU Di Ventra, M Pantelides, ST AF Di Ventra, M Pantelides, ST TI Hellmann-Feynman theorem and the definition of forces in quantum time-dependent and transport problems SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; MOLECULAR-DYNAMICS; GRADIENTS; ATOM AB The conventional Hellmann-Feynman theorem for the definition of forces on nuclei is not directly applicable to quantum time-dependent and transport problems. We present a rigorous derivation of a general Hellmann-Feynman-like theorem that applies to all quantum mechanical systems and reduces to well-known results for ground-state problems. It provides a rigorous definition of forces in time-dependent and transport problems. Explicit forms of Pulay-like forces are derived and the conditions for them to be zero are identified. A practical scheme fur nb initio calculations of current-induced forces is described and the study of the transfer of a Si atom between two electrodes is presented as an example. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Vanderbilt Univ, Dept Phys & Astron, 221 Kirkland Hall, Nashville, TN 37235 USA. RI Di Ventra, Massimiliano/E-1667-2011 OI Di Ventra, Massimiliano/0000-0001-9416-189X NR 33 TC 53 Z9 53 U1 0 U2 6 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 JUN 15 PY 2000 VL 61 IS 23 BP 16207 EP 16212 DI 10.1103/PhysRevB.61.16207 PG 6 WC Physics, Condensed Matter SC Physics GA 327LV UT WOS:000087796100111 ER PT J AU Lawniczak-Jablonska, K Suski, T Gorczyca, I Christensen, NE Attenkofer, KE Perera, RCC Gullikson, EM Underwood, JH Ederer, DL Weber, ZL AF Lawniczak-Jablonska, K Suski, T Gorczyca, I Christensen, NE Attenkofer, KE Perera, RCC Gullikson, EM Underwood, JH Ederer, DL Weber, ZL TI Electronic states in valence and conduction bands of group-III nitrides: Experiment and theory SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; BORON-NITRIDE; STRUCTURAL-PROPERTIES; V NITRIDES; GAN; HETEROSTRUCTURE; SPECTROSCOPY; REFLECTIVITY; ANISOTROPY; CONSTANTS AB A comprehensive study of the electronic structure of group-III nitrides (AlN, GaN, InN, and BN) crystallizing in the wurtzite, zinc-blende, and graphitelike hexagonal (BN) structures is presented. A large set of the x-ray emission and absorption spectra was collected at the several synchrotron radiation facilities at installations offering the highest possible energy resolution. By taking advantage of the linear polarization of the synchrotron radiation and making careful crystallographic orientation of the samples, the bonds along c axis (pi) and "in plane'' (sigma) in the wurtzite structure could be separately examined. Particularly for AlN we found pronounced anisotropy of the studied bonds. The experimental spectra are compared directly with ab initio calculations of the partial density of states projected on the cation and anion atomic sites. For the GaN, AlN, and InN the agreement between structures observed in the calculated density of states (DOS) and structures observed in the experimental spectra is very good. In the case of hexagonal BN we have found an important influence of insufficient core screening in the x-ray spectra that influences the DOS distribution. The ionicity of the considered nitrides is also discussed. C1 Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Polish Acad Sci, High Pressure Res Ctr, PL-01142 Warsaw, Poland. Univ Aarhus, Inst Phys & Astron, DK-8000 Aarhus C, Denmark. DESY, HASYLAB, D-22603 Hamburg, Germany. Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Tulane Univ, New Orleans, LA 70118 USA. RP Polish Acad Sci, Inst Phys, Al Lotnikow 32-46, PL-02668 Warsaw, Poland. EM jablo@ifpan.edu.pl RI Liliental-Weber, Zuzanna/H-8006-2012 NR 31 TC 100 Z9 100 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 2000 VL 61 IS 24 BP 16623 EP 16632 DI 10.1103/PhysRevB.61.16623 PG 10 WC Physics, Condensed Matter SC Physics GA 331FV UT WOS:000088008400048 ER PT J AU Sakata, O Lyman, PF Tinkham, BP Walko, DA Marasco, DL Lee, TL Bedzyk, MJ AF Sakata, O Lyman, PF Tinkham, BP Walko, DA Marasco, DL Lee, TL Bedzyk, MJ TI X-ray scattering study of the Ge(001): Te(1X1) surface structure SO PHYSICAL REVIEW B LA English DT Article ID TELLURIUM; GE(001); DIFFRACTOMETER; DIFFRACTION AB The 1 x 1 surface structure of Te adsorbed on Ge(001) was studied by analyzing the x-ray scattered intensity along several surface crystal truncation rods (CTR). The results were compared to simulations corresponding to the bridge, top, antibridge, and hollow site models. Te at the bridge site was in best agreement. More complex surface models based an modifications of Te at the bridge site were then compared to the data with the missing-row model being in better agreement than the zigzag model. Finally, the CTR data were used to refine the structural parameters of the missing row model. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RP Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RI Bedzyk, Michael/B-7503-2009; SAKATA, Osami/H-2621-2011; Bedzyk, Michael/K-6903-2013 NR 17 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 2000 VL 61 IS 24 BP 16692 EP 16696 DI 10.1103/PhysRevB.61.16692 PG 5 WC Physics, Condensed Matter SC Physics GA 331FV UT WOS:000088008400055 ER PT J AU Cvetic, M Wang, J AF Cvetic, M Wang, J TI Vacuum domain walls in D dimensions: Local and global space-time structure SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM CREATION; EXTRA DIMENSION; SUPERGRAVITY; UNIVERSE AB We study local and global gravitational effects of (D-2)-brane configurations (domain walls) in the vacuum of D-dimensional space-time. We focus on infinitely thin vacuum domain walls with arbitrary cosmological constants on either side of the wall. In the comoving frame of the wall we derive a general metric ansatz, consistent with the homogeneity and isotropy of the space-time intrinsic to the wall, and employ Israel's matching conditions at the wall. The space-time, intrinsic to the wall, is that of a (D - 1)-dimensional Freedman-Lemaitre-Robertson-Walker universe (with k = -1,0,1) which has a (local) description as either anti-de Sitter, Minkowski or de Sitter space-time. For each of these geometries, we provide a systematic classification of the local and global space-time structure transverse to the walls, for those with both positive and negative tension; they fall into different classes according to the values of their energy density relative to that of the extreme (supersymmetric) configurations. We find that in any dimension D, both local and global space-time structure for each class of domain walls is universal. We also comment on the phenomenological implications of these walls in the special case of D = 5. C1 Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Fermi Natl Accelerator Lab, Div Theory, Batavia, IL 60510 USA. RP Cvetic, M (reprint author), Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. EM cvetic@cvetic.hep.upenn.edu; jingw@fnal.gov NR 54 TC 38 Z9 38 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 JUN 15 PY 2000 VL 61 IS 12 AR 124020 DI 10.1103/PhysRevD.61.124020 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 325LY UT WOS:000087678100042 ER PT J AU Mathews, GJ Wilson, JR AF Mathews, GJ Wilson, JR TI Revised relativistic hydrodynamical model for neutron-star binaries SO PHYSICAL REVIEW D LA English DT Article ID STABLE CIRCULAR ORBIT; CENTRAL DENSITY; COLLAPSE; CONSTRAINTS; SIMULATIONS; EQUATION AB We report on numerical results from a revised hydrodynamic simulation of binary neutron-star orbits near merger. We find that the correction recently identified by Flanagan significantly reduces but does not eliminate the neutron-star compression effect. Although results of the revised simulations show that the compression is reduced for a given total orbital angular momentum, the inner most stable circular orbit moves to closer separation distances. At these closer orbits significant compression and even collapse are still possible prior to merger for a sufficiently soft EOS. We note, however, that the compression observed in the simulation is within the numeric:al error and also of order of the error expected from the approximation of a conformally flat spatial three metric. The reduced compression in the corrected simulation is consistent with other recent studies of rigid irrotational binaries in quasiequilibrium in which the compression effect is observed to be small. Another significant effect of this correction is that the derived binary orbital frequencies are now in closer agreement with post-Newtonian expectations. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mathews, GJ (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 25 TC 28 Z9 28 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 JUN 15 PY 2000 VL 61 IS 12 AR 127304 DI 10.1103/PhysRevD.61.127304 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 325LY UT WOS:000087678100072 ER PT J AU Molina-Paris, C Anderson, RP Ramsey, SA AF Molina-Paris, C Anderson, RP Ramsey, SA TI One-loop lambda phi(4) field theory in Robertson-Walker spacetimes: Adiabatic regularization and analytic approximations SO PHYSICAL REVIEW D LA English DT Article ID ENERGY-MOMENTUM TENSOR; CURVED SPACETIME; PARTICLE CREATION; UNIVERSES; CURVATURE AB We study a scalar field with quartic self-coupling in a Robertson-Walker spacetime at one-loop order. A variation of the adiabatic regularization method is presented which leads to analytic approximations for the quantum energy-momentum tensor and the quantum contribution to the effective mass of the mean field. Conservation of the energy-momentum tensor for the field is discussed and it is shown that the full renormalized energy-momentum tensor is conserved as expected and required by the semiclassical Einstein's equation. It is also shown that if the analytic approximations are used, then the resulting approximate energy-momentum tensor is conserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret T 8, Los Alamos, NM 87545 USA. Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA. Univ Washington, Genome Ctr, Seattle, WA 98195 USA. RP Molina-Paris, C (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret T 8, Los Alamos, NM 87545 USA. EM carmen@t6-serv.lanl.gov; anderson@wfu.edu; saramsey@u.washington.edu NR 22 TC 10 Z9 11 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 JUN 15 PY 2000 VL 61 IS 12 AR 127501 DI 10.1103/PhysRevD.61.127501 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 325LY UT WOS:000087678100074 ER PT J AU Smith, JF Chiara, CJ Fossan, DB Lane, GJ Sears, JM Thorslund, I Hibbert, IM Wadsworth, R Lee, IY Macchiavelli, AO AF Smith, JF Chiara, CJ Fossan, DB Lane, GJ Sears, JM Thorslund, I Hibbert, IM Wadsworth, R Lee, IY Macchiavelli, AO TI Multiple shape-driving nu(h(11/2))(2) and pi(h(11/2))(2) alignments in Ba-120 SO PHYSICS LETTERS B LA English DT Article ID HIGH-SPIN STATES; BANDS; REGION AB High-spin states have been observed in Ba-120 up to spin 42 (h) over bar. The ground-state band is observed to fork into two aligned two-quasiparticle bands, which are identified with the pi(h(11/2))(2) and nu(h(11/2))(2) quasiparticles. At higher spin in each of the two aligned bands, the other pair of h(11/2) nucleons aligns in each band are observed to align, resulting in the single four-quasiparticle nu(h(11/2))(2) circle times pi(h(11/2))(2) band. This unique and novel phenomenon has allowed interaction strengths and alignment frequencies to be studied and compared. Differences in alignment frequencies, for the same pairs of nucleons are attributed to shape polarization by the aligned or aligning quasiparticles. The interaction strengths have been investigated using a four-band mixing model. The results are discussed with respect to cranked Woods-Saxon calculations, and to alignments in neighboring nuclei. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Manchester, Schuster Lab, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Smith, JF (reprint author), Univ Manchester, Schuster Lab, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. RI Lane, Gregory/A-7570-2011 OI Lane, Gregory/0000-0003-2244-182X NR 21 TC 8 Z9 8 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 15 PY 2000 VL 483 IS 1-3 BP 7 EP 14 DI 10.1016/S0370-2693(00)00557-8 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 328MR UT WOS:000087855100002 ER PT J AU Beane, SR Bedaque, PF Savage, MJ AF Beane, SR Bedaque, PF Savage, MJ TI Meson masses in high density QCD SO PHYSICS LETTERS B LA English DT Article ID FINITE BARYON DENSITY; EFFECTIVE-FIELD-THEORY; COLOR-FLAVOR LOCKING; QUARK MATTER; DIQUARK CONDENSATION; LATTICE APPROACH; HEAVY MESONS; SUPERCONDUCTIVITY; MODEL; TEMPERATURE AB The low-energy effective theories for the two- and three-flavor color-superconductors arising in the high density limit of QCD are discussed. Using an effective field theory to describe quarks near the fermi surface, we compute the masses of the pseudo-Goldstone bosons that dominate the low-momentum dynamics of these systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Jefferson Lab, Newport News, VA 23606 USA. EM sbeane@phys.washington.edu; bedaque@phys.washington.edu; savage@phys.washington.edu NR 83 TC 112 Z9 112 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 15 PY 2000 VL 483 IS 1-3 BP 131 EP 138 DI 10.1016/S0370-2693(00)00606-7 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 328MR UT WOS:000087855100017 ER PT J AU Landa, A Wynblatt, P Johnson, E Dahmen, U AF Landa, A Wynblatt, P Johnson, E Dahmen, U TI Computer simulation of Pb/Al interfaces SO ACTA MATERIALIA LA English DT Article DE interface; computer simulation; metals; alloys ID SOLUTE-ATOM SEGREGATION; MONTE-CARLO SIMULATION; AG-AU ALLOYS; NI-CU ALLOYS; GRAIN-BOUNDARIES; TWIST BOUNDARIES; PB INCLUSIONS; AL; LEAD; SOLIDIFICATION AB Monte Carlo simulation, in conjunction with glue-type empirical many-body potentials, has been used to model the structure of (111) and (100) Pb/Al interfaces as well as calculate their interfacial free energy. Vibrational contributions to the free energy were accounted for within the framework of the local harmonic approximation, and configurational free energy was described on the basis of a point approximation for the entropy of mixing. The calculated free energy ratios for the Pb/Al (100) and {111} interfaces are in good agreement with recent high resolution transmission electron microscopy measurements performed in the range 500 K < T < 600 K. The simulations indicate a strong temperature dependence of the free energy ratios, from 1.10 at T = 500 K to 1.31 at T = 0 K. Comparison of the present results with previous calculations of the anisotropy of surface energy of pure Pb shows that the glue potential correctly reflects the large change in anisotropy which is observed experimentally between isolated Pb crystals and Pb crystals embedded in Al. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Univ Copenhagen, Niels Bohr Inst, Orsted Lab, DK-2100 Copenhagen, Denmark. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Wynblatt, P (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. NR 38 TC 17 Z9 18 U1 2 U2 5 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 14 PY 2000 VL 48 IS 10 BP 2557 EP 2563 DI 10.1016/S1359-6454(00)00059-8 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CH UT WOS:000089196600011 ER PT J AU Shaw, TJ Chan, JW Kang, SH McDermott, R Morris, JW Clarke, J AF Shaw, TJ Chan, JW Kang, SH McDermott, R Morris, JW Clarke, J TI Scanning squid microscope differentiation of ferromagnetic steel phases SO ACTA MATERIALIA LA English DT Article DE non-destructive evaluation; steels; magnetic methods; SQUID; optical microscopy ID DUPLEX STAINLESS-STEEL; NONDESTRUCTIVE EVALUATION; MAGNETIC-PROPERTIES; MAGNETOMETRY; MICROSTRUCTURE; TEMPERATURE; SENSOR; SYSTEM; NDE AB The remanent magnetization of ferromagnetic steel with five different microstructures has been studied using a microscope based on a high-transition-temperature d.c. Superconducting QUantum Interference Device (SQUID). The samples were prepared using different heat treatments, beginning with the same material composition. Each sample was magnetized in turn in a magnetic field of 50 mT, and the remanent magnetization was studied by scanning the sample over the SQUID using a two-dimensional translation stage with a range of 50 x 50 mm(2). With a sample-to-SQUID separation of 400-500 mu m, this procedure yielded a two-dimensional magnetic field image produced by the local remanent magnetization of the sample. In addition, microstructural information has been obtained using optical imaging, allowing the magnetic images to be correlated with the underlying microstructure. (C) 2000 Acta Metallurgica Inc. Published bq Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Morris, JW (reprint author), Univ Calif Berkeley, Dept Mat Sci, Berkeley, CA 94720 USA. NR 21 TC 7 Z9 7 U1 0 U2 1 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 14 PY 2000 VL 48 IS 10 BP 2655 EP 2664 DI 10.1016/S1359-6454(00)00062-8 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CH UT WOS:000089196600021 ER PT J AU El-Danaf, E Kalidindi, SR Doherty, RD Necker, C AF El-Danaf, E Kalidindi, SR Doherty, RD Necker, C TI Deformation texture transition in brass: Critical role of micro-scale shear bands SO ACTA MATERIALIA LA English DT Article DE shear bands; texture; deformation twinning; crystal structure; copper alloys ID POLYCRYSTALLINE FCC METALS; STACKING-FAULT ENERGY; ROLLING TEXTURES; ALLOYS; MECHANISM AB The transition in deformation textures between low stacking Fault energy f.c.c. metals (e.g. brass textures) and the medium to high stacking fault energy f.c.c, metals (e.g. copper textures) is addressed. A detailed microscopy investigation was conducted in parallel with texture measurements on deformed samples of copper and 70/30 brass to different strain levels in three different deformation paths, namely, plane strain compression, simple compression, and simple shear. The objective of the study was to identify the specific trends in the transition between the brass textures and the copper textures that correlated with the onset of deformation twinning and those that correlated with the onset of micro-scale shear banding. It was found that several important transitions in the evolution of the deformation textures, especially in the rolled samples, correlated not with the onset of deformation twinning but with the onset of micro-scale shear banding. These results strongly suggest that the critical feature in texture transition is not twinning directly, but the shear banding promoted by the high strain hardening rates of low stacking fault energy f.c.c, metal. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Drexel Univ, Dept Mat Engn, Philadelphia, PA 19103 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kalidindi, SR (reprint author), Drexel Univ, Dept Mat Engn, Philadelphia, PA 19103 USA. RI Kalidindi, Surya/A-1024-2007; El-Danaf, Ehab/E-3662-2014; OI El-Danaf, Ehab/0000-0003-1730-0790; Kalidindi, Surya/0000-0001-6909-7507 NR 22 TC 74 Z9 75 U1 1 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN 14 PY 2000 VL 48 IS 10 BP 2665 EP 2673 DI 10.1016/S1359-6454(00)00050-1 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CH UT WOS:000089196600022 ER PT J AU Mitchell, TE AF Mitchell, TE TI A dislocation tetrahedron for MoSi2 SO ACTA MATERIALIA LA English DT Article DE intermetallic compounds; dislocation theory; yield phenomena; theory and modeling of defects ID SOLIDIFIED MOSI2-BASED ALLOYS; SINGLE-CRYSTALS; PLASTIC-DEFORMATION; MOLYBDENUM DISILICIDE; TEMPERATURE; SLIP AB A tetrahedron is proposed for describing slip planes and Burgers vectors of dislocations in the tetragonal Glib structure of MoSi2. The faces are the four {013} slip planes; the edges are the four 1/2[331] Burgers Vectors plus the two [300] vectors. A combination of Greek and Roman letters is used to describe vectors and planes as for the Thompson tetrahedron. Included in the tetrahedron are the two [100], two [110] and four 1/2[111] Burgers vectors, plus partial dislocations such as 1/6[331], 1/4[111] and 1/3[001]. Various dislocation reactions are described. In particular, it is shown that the 1/2[331] screw dislocation should dissociate into three 1/6[331] partials in an asymmetric fashion on two {013} planes. Such a configuration should have a different mobility in tension and compression. An alternative pyramid model is described which has some advantages but is less compact than the tetrahedron. Published bf Elsevier Science Ltd on behalf of Acta Metallurgica Inc. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Mitchell, TE (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, MS K765, Los Alamos, NM 87545 USA. NR 20 TC 4 Z9 4 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN 14 PY 2000 VL 48 IS 10 BP 2713 EP 2718 DI 10.1016/S1359-6454(00)00046-X PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 352CH UT WOS:000089196600026 ER PT J AU Biemont, E Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Osterheld, AL Goldstein, WH Flora, F DiLazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Batani, D Mauri, A Scafati, A Reale, L AF Biemont, E Magunov, AI Dyakin, VM Faenov, AY Pikuz, TA Skobelev, IY Osterheld, AL Goldstein, WH Flora, F DiLazzaro, P Bollanti, S Lisi, N Letardi, T Reale, A Palladino, L Batani, D Mauri, A Scafati, A Reale, L TI Measurements of the ground state ionization energy and wavelengths for the 2l-nl ' transitions of Ni XIX (n=4-15) and Ge XXIII (n=7-9) SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID ATOMS; LASER; CONFIGURATIONS; PLASMAS; LINES; SPECTROSCOPY; IONS AB The wavelengths of the 2l-nl' (n = 4-15) spectral lines of Ne-Like Ni XIX and Ge XXIII were measured in laser-produced plasmas. The accuracy of these measurements (0.5-2.5 m Angstrom) is a large improvement over previous results, and a number of transitions (mainly from levels with n = 8-15) were observed for the first time. The 2P(3/2)-nd(5/2) and 2p(1/2)-nd(3/2) Rydberg series were used to determine the first two ionization limits of the ground states of Ni XIX and Ge XXIII. Effects of configuration interaction were observed in the intensities of some spectral lines. C1 Univ Liege, Inst Phys Nucl Expt, B-4000 Liege, Belgium. Univ Mons, B-7000 Mons, Belgium. VNIIFTRI, Multicharged Ions Spectra Data Ctr, Mendeleevo 141570, Moscow Region, Russia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. ENEA, Frascati Ctr, Dept Innovat Technol, Frascati, Italy. Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Ist Nazl Fis Nucl, GC LNGS, Laquila, Italy. Univ Milan, Dipartimento Fis, Milan, Italy. Ist Nazl Fis Nucl, Sezione Milano, I-20133 Milan, Italy. Inst Super Sanita, Fis Lab, Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. RP Biemont, E (reprint author), Univ Liege, Inst Phys Nucl Expt, B-4000 Liege, Belgium. OI PALLADINO, LIBERO/0000-0001-5291-6246 NR 28 TC 10 Z9 10 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JUN 14 PY 2000 VL 33 IS 11 BP 2153 EP 2162 DI 10.1088/0953-4075/33/11/315 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 331ZX UT WOS:000088049500020 ER PT J AU Hayes, RT Wasielewski, MR Gosztola, D AF Hayes, RT Wasielewski, MR Gosztola, D TI Ultrafast photoswitched charge transmission through the bridge molecule in a donor-bridge-acceptor system SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; OPTICAL CONTROL; WIRES; SWITCHES; DEVICE AB A Donor-Bridge-Acceptor molecule, D-B-A, was synthesized to probe the effects of changing the electronic state of the bridge molecule, B, on the rates of electron transfer within D-B-A. Selective photoexcitation of D in a tetrahydrofuran solution of D-B-A with 400 nm, 130 fs laser pulses at t = 0 ps results in photoinduced electron transfer to yield the ion pair D+-H--A with tau = 60 ps, which undergoes a subsequent charge shift with tau = 140 ps to yield the long-lived ion pair D+-B-A(-) (tau = 700 ns). Subsequent selective photoexcitation of B within D+-B-A(-) with a 520 nm, 150 fs laser pulse at t = 500 ps results in about 20% of the D+-B-A(-) population undergoing charge recombination with tau = 100 ps. This charge recombination rate is about 7000 times faster than the normal recombination rate of the ion pair. The results demonstrate that formation of the lowest excited singlet state of the bridge molecule B significantly alters the reaction pathways leading to charge recombination. Thus, D-B-A can be viewed as a molecular switch in which the D+-B-A(-) state can be rapidly turned on and off using 400 and 520 nm laser pulses, respectively. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Wasielewski, MR (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 32 TC 130 Z9 131 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 14 PY 2000 VL 122 IS 23 BP 5563 EP 5567 DI 10.1021/ja000219d PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 327KK UT WOS:000087792900018 ER PT J AU Cobine, PA George, GN Winzor, DJ Harrison, MD Mogahaddas, S Dameron, CT AF Cobine, PA George, GN Winzor, DJ Harrison, MD Mogahaddas, S Dameron, CT TI Stoichiometry of complex formation between copper(I) and the N-terminal domain of the Menkes protein SO BIOCHEMISTRY LA English DT Article ID TRANSPORTING ATPASE; BINDING PROPERTIES; CANDIDATE GENE; TRANSCRIPTION FACTOR; ENTEROCOCCUS-HIRAE; DISEASE; EXPRESSION; CHAPERONE; COORDINATION; SPECTROSCOPY AB The inherent cellular toxicity of copper ions demands that their concentration be carefully controlled. The cellular location of the Menkes ATPase, a key element in the control of intracellular copper, is regulated by the intracellular copper concentration through the N-terminus of the enzyme, comprising 6 homologous subdomains or modules, each approximately 70 residues in length and containing a -Cys-X-X-Cys- motif. Based on the proposal that binding of copper to these modules regulates the Menkes ATPase cellular location by promoting changes in the tertiary structure of the enzyme, we have expressed the entire N-terminal domain (MNKr) and the second metal-binding module (MNKr2) of the Menkes protein in E. coli and purified them to homogeneity. Ultraviolet-visible, luminescence, and X-ray absorption spectroscopy show that copper and silver bind to the single module, MNKr2, with a stoichiometry of one metal ion per module. However, the array of six modules, MNKr, binds Cu(I) to produce a homogeneous conformer with 4 mol equiv of metal ion. The metal ions are bound in an environment that is shielded from solvent molecules. We suggest a model of the Menkes protein in which the Cu(I) binding induces tertiary changes in the organization of the six metal-binding domains. C1 Univ Queensland, Natl Res Ctr Environm Toxicol, Coopers Plains, Qld 4108, Australia. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Queensland, Dept Biochem, Brisbane, Qld 4072, Australia. RP Dameron, CT (reprint author), Univ Queensland, Natl Res Ctr Environm Toxicol, 39 Kessels Rd, Coopers Plains, Qld 4108, Australia. RI George, Graham/E-3290-2013; Cobine, Paul/G-3107-2011; OI Cobine, Paul/0000-0001-6012-0985; Harrison, Mark/0000-0002-0220-1565 NR 44 TC 45 Z9 45 U1 0 U2 5 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 13 PY 2000 VL 39 IS 23 BP 6857 EP 6863 DI 10.1021/bi000015+ PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 324PR UT WOS:000087631000014 PM 10841766 ER PT J AU Takano, H Wong, SS Harnisch, JA Porter, MD AF Takano, H Wong, SS Harnisch, JA Porter, MD TI Mapping the subsurface composition of organic films by electric force microscopy SO LANGMUIR LA English DT Letter ID RESOLUTION; SURFACES; POTENTIOMETRY; MONOLAYERS; CHARGE; GOLD AB This paper describes preliminary results that demonstrate the ability of electric force microscopy to map compositional differences of organic monolayers buried under a thick (similar to 430 nm) polymeric film. The underlying adlayer was patterned onto a gold surface using the microcontact printing of CH3(CH2)(16)SH followed by solution deposition of HO(CH2)(16)SH. This procedure results in alternating domains of different terminal groups. Results show that the imaging mechanism exhibits sufficient contrast to function as a mapping methodology for buried functional groups. C1 Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. RP Porter, MD (reprint author), Iowa State Univ, Dept Chem, US DOE, Ames Lab, Ames, IA 50011 USA. NR 20 TC 16 Z9 17 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 13 PY 2000 VL 16 IS 12 BP 5231 EP 5233 DI 10.1021/la0002334 PG 3 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 322LF UT WOS:000087510500005 ER PT J AU Cheng, Q Yamamoto, M Stevens, RC AF Cheng, Q Yamamoto, M Stevens, RC TI Amino acid terminated polydiacetylene lipid microstructures: Morphology and chromatic transition SO LANGMUIR LA English DT Article ID REFLECTION-ABSORPTION SPECTROSCOPY; INFRARED REFLECTION; SUPRAMOLECULAR ASSEMBLIES; COLORIMETRIC DETECTION; STRUCTURAL CHARACTERIZATION; DIACETYLENIC ALDONAMIDES; MOLECULAR RECOGNITION; CHIRAL DISCRIMINATION; PHASE-TRANSITION; WATER-INTERFACE AB Novel lipid microstructures with various morphologies have been synthesized using a series of amino acid terminated diacetylenic lipids, and the chromatic transitions of the polymerized microstructures have been characterized by W-vis and FTIR spectroscopies. The observed morphologies for the microstructures include tubule, helix, ribbon, sheet, braided fiber, and planar platelet, formation of which has shown strong dependency on the chemical structure of the headgroup. All amino acid lipids studied in this work form microstructures that allow polymerization by UV irradiation to yield a blue appearance. Molecular chirality, electrostatic interactions, and hydrogen-bonding interactions in the headgroup region determine the formation of microstructures with twisted features, while nonchiral molecules do not form curved structures. The polymerized lipid microstructures exhibit similar colorimetric properties as observed for related bilayer vesicles, undergoing a blue-to-red color transition in response to thermal and pH changes. Microstructures with hydrophobic headgroup lipids are more sensitive to pH change than those with hydrophilic headgroups. For hydrophilic headgroup lipids, microstructures are more pH-resistant relative to their vesicle counterparts. FTIR studies suggest that thermal and pH-induced chromism of PDA microstructures proceed by different pathways. A mechanism is proposed that links function and change of hydrogen-bonding interactions to the observed chromatic behaviors of the PDA microstructures. In thermochromism, hydrogen-bonding interactions lock in the lipid headgroups so that the temperature-induced gauche-trans conformational transition of the side chains imposes strain on the assembly. In pH-induced chromism, surface ionization and breakdown of hydrogen-bonding interactions lead to reorganization of the headgroups that affects the electron delocalization along the conjugated backbone. C1 Lawrence Berkeley Natl Lab, Ctr Adv Mat, Div Mat Sci, Berkeley, CA 94720 USA. RP Cheng, Q (reprint author), Lawrence Berkeley Natl Lab, Ctr Adv Mat, Div Mat Sci, Berkeley, CA 94720 USA. RI Cheng, Jason/C-6345-2011; Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 47 TC 84 Z9 86 U1 8 U2 35 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 13 PY 2000 VL 16 IS 12 BP 5333 EP 5342 DI 10.1021/la9916169 PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 322LF UT WOS:000087510500019 ER PT J AU Gopal, M Thomas, G AF Gopal, M Thomas, G TI Spherulites of silicon carbide: A new morphology SO SCRIPTA MATERIALIA LA English DT Article DE transmission electron microscopy (TEM); composite; phase transformations (nucleation/growth); microstructure; silicon carbide (SiC) ID LIQUID SILICON; GROWTH; CARBON; CRYSTALLIZATION; MICROSTRUCTURE; KINETICS C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Gopal, M (reprint author), MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. NR 32 TC 0 Z9 0 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN 13 PY 2000 VL 42 IS 12 BP 1119 EP 1124 DI 10.1016/S1359-6462(00)00346-8 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 352BL UT WOS:000089194600002 ER PT J AU Goto, DM Bingert, JF Reed, WR Garrett, RK AF Goto, DM Bingert, JF Reed, WR Garrett, RK TI Anisotropy-corrected MTS constitutive strength modeling in HY-100 steel SO SCRIPTA MATERIALIA LA English DT Article ID DEFORMATION C1 USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Illinois, Urbana, IL 61801 USA. RP Goto, DM (reprint author), USN, Ctr Surface Warfare, Indian Head Div, Indian Head, MD 20640 USA. NR 11 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN 13 PY 2000 VL 42 IS 12 BP 1125 EP 1131 DI 10.1016/S1359-6462(00)00347-X PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 352BL UT WOS:000089194600003 ER PT J AU Miodownik, M Holm, EA Hassold, GN AF Miodownik, M Holm, EA Hassold, GN TI Highly parallel computer simulations of particle pinning: Zener vindicated SO SCRIPTA MATERIALIA LA English DT Article DE computer simulation; grain growth; microstructure ID GRAIN-GROWTH; 2ND-PHASE PARTICLES; INHIBITION; DISPERSION; DRAG C1 Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, Albuquerque, NM 87185 USA. Univ Coll Dublin, Dept Mech Engn, Dublin, Ireland. Kettering Univ, Dept Sci & Math, Flint, MI 48504 USA. RP Miodownik, M (reprint author), Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, Albuquerque, NM 87185 USA. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 28 TC 76 Z9 79 U1 0 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN 13 PY 2000 VL 42 IS 12 BP 1173 EP 1177 DI 10.1016/S1359-6462(00)00354-7 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 352BL UT WOS:000089194600010 ER PT J AU Merkulov, VI Lowndes, DH Wei, YY Eres, G Voelkl, E AF Merkulov, VI Lowndes, DH Wei, YY Eres, G Voelkl, E TI Patterned growth of individual and multiple vertically aligned carbon nanofibers SO APPLIED PHYSICS LETTERS LA English DT Article ID CATALYTIC GROWTH; NANOTUBES; NUCLEATION AB The results of studies of patterned growth of vertically aligned carbon nanofibers (VACNFs) prepared by plasma-enhanced chemical vapor deposition are reported. Nickel (Ni) dots of various diameters and Ni lines with variable widths and shapes were fabricated using electron beam lithography and evaporation, and served for catalytic growth of VACNFs whose structure was determined by high resolution transmission electron microscopy. It is found that upon plasma pre-etching and heating up to 600-700 degrees C, thin films of Ni break into droplets which initiate the growth of VACNFs. Above a critical dot size multiple droplets are formed, and consequently multiple VACNFs grow from a single evaporated dot. For dot sizes smaller than the critical size only one droplet is formed, resulting in a single VACNF. In the case of a patterned line, the growth mechanism is similar to that from a dot. VACNFs grow along the line, and above a critical linewidth multiple VACNFs are produced across the line. The mechanism of the formation of single and multiple catalyst droplets and subsequently of VACNFs is discussed. (C) 2000 American Institute of Physics. [S0003-6951(00)00824-X]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Merkulov, VI (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 16 TC 329 Z9 338 U1 5 U2 64 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 12 PY 2000 VL 76 IS 24 BP 3555 EP 3557 DI 10.1063/1.126705 PG 3 WC Physics, Applied SC Physics GA 323GE UT WOS:000087557100019 ER PT J AU Metelski, PD Adamian, VA Espenson, JH AF Metelski, PD Adamian, VA Espenson, JH TI Mechanistic role of benzylic bromides in the catalytic autoxidation of methylarenes SO INORGANIC CHEMISTRY LA English DT Article ID OXIDATION; HYDROCARBONS; BR AB Different pathways for benzylic bromide transformations were examined under conditions of cobalt-bromide catalysis in acetic acid. It has been shown that benzylic bromides participate in the catalytic cycle through their catalyzed and noncatalyzed oxidation, through their reaction with Co(III), and through cobalt(II)-catalyzed solvolysis. The rates of the direct reduction of Co(III) by several benzylic bromides were measured under an argon atmosphere; the reaction occurs by a mechanism involving two forms of Co(III). The same reaction under an oxygen atmosphere initiates the cobalt-bromide-catalyzed oxidation of benzyl bromide, thus leading to the regeneration of inorganic bromide and the fast reduction of Co(III). Solvolysis of benzylic bromides plays only a minor role in the regeneration of inorganic bromide in glacial acetic acid. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 30 TC 17 Z9 17 U1 0 U2 7 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 12 PY 2000 VL 39 IS 12 BP 2434 EP 2439 DI 10.1021/ic990653k PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 323XC UT WOS:000087589400003 PM 11196992 ER PT J AU LeBlond, N Dixon, DA Schrobilgen, GJ AF LeBlond, N Dixon, DA Schrobilgen, GJ TI Fluoride ion donor properties of TcO2F3 and ReO2F3: X-ray crystal structures of MO2F3 center dot SbF5 (M = Tc, Re) and TcO2F3 center dot XeO2F2 and Raman and NMR spectroscopic characterization of MO2F3 center dot PnF(5) (Pn = As, Sb), [ReO2F2(CH3CN)(2)][SbF6], and [Re2O4F5][Sb2F11] SO INORGANIC CHEMISTRY LA English DT Article ID FUNCTIONAL THEORY CALCULATIONS; NUCLEAR-MAGNETIC-RESONANCE; EFFECTIVE CORE POTENTIALS; MOLECULAR CALCULATIONS; VIBRATIONAL-SPECTRA; BOND-VALENCE; ENERGIES; F-19; GEOMETRIES; COMPLEXES AB The fluoride ion donor properties of TcO2F3 and ReO2F3 toward AsF5, SbF5, and XeO2F2 have been investigated, leading to the formation of TcO2F3. PnF(5) and ReO2F3. PnF(5) (Pn = As, Sb) and TcO2F3. XeO2F2, which were characterized in the solid state by Raman spectroscopy and X-ray crystallography. TcO2F3. SbF5 crystallizes in the monoclinic system P2(1)/n, with a = 7.366(2) Angstrom, b = 10.441(2) Angstrom, c = 9.398(2) Angstrom, beta = 93.32(3)degrees, V = 721.6(3) Angstrom(3), and Z = 4 at 24 degrees C, R-1 = 0.0649, and wR(2) = 0.1112. ReO2F3. SbF5 crystallizes in the monoclinic system P2(1)/c, with a = 5.479(1) Angstrom, b = 10.040(2) Angstrom, c = 12.426(2) Angstrom, beta = 99.01(3)degrees, V = 675.1(2) Angstrom(3), and Z = 4 at -50 degrees C, R-1 = 0.0533, and wR(2) = 0.1158. TcO2F3. XeO2F2 crystallizes in the orthorhombic system Cmc2(1), with a = 7.895(2) Angstrom, b = 16.204(3) Angstrom, c = 5.198(1) Angstrom, beta = 90 degrees, V = 665.0(2) Angstrom(3), and Z = 4 at 24 degrees C, R-1 = 0.0402, and wR(2) = 0.0822. The structures of TcO2F3. SbF5 and ReO2F3. SbF5 consist of infinite chains of alternating MO2F4 and SbF6 units in which the bridging fluorine atoms on the antimony are trans to each other. The structure of TcO2F3. XeO2F2 comprises two distinct fluorine-bridged chains, one of TcO2F3 and the other of XeO2F2 bridged by long Tc-F ... Xe contacts. The oxygen atoms of the group 7 metals in the three structures are cis to each other and to two terminal fluorine atoms and trans to the bridging fluorine atoms. The F-19 NMR and Raman spectra of TcO2F3. PnF(5) and ReO2F3. PnF(5) in SbF5 and PnF(5)-acidified HF solvents are consistent with dissociation of the adducts into cis-MO2F2(HF)(2)(+) cations and PnF(6)(-) anions. The energy-minimized geometries of the free MO2F2+ cations and their HF adducts, cis-MO2F2(HF)(2)(+), have been calculated by local density functional theory (LDFT), and the calculated vibrational frequencies have been used as an aid in the assignment of the Raman spectra of the solid MO2F3. PnF(5) adducts and their PnF(5)-acidified HF solutions. In contrast ReO2F3. SbF5 ionizes in SO2ClF solvent to give the novel Re2O4F5+ cation and Sb2F11- anion. The F-19 NMR spectrum of the cation is consistent with two ReO2F2 units joined by a fluorine bridge in which the oxygen atoms are assumed to lie in the equatorial plane. The [ReO2F2(CH3CN)(2)][SbF6] salt was formed upon dissolution of ReO2F3. SbF5 in CH3CN and was characterized by H-1,C-13, and F-19 NMR and Raman spectroscopies. The ReO2F2(CH3CN)(2)(+) cation is a pseudooctahedral cis-dioxo arrangement in which the CH3CN ligands are trans to the oxygens and the fluorines are trans to each other. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Pacific NW 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 75 TC 26 Z9 26 U1 0 U2 4 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 12 PY 2000 VL 39 IS 12 BP 2473 EP 2487 DI 10.1021/ic9908221 PG 15 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 323XC UT WOS:000087589400009 PM 11196998 ER PT J AU Kayser, B Eichberg, MJ Vollhardt, KPC AF Kayser, B Eichberg, MJ Vollhardt, KPC TI Synthesis, structure, and fluxionality of (mu-diphenylsilylene)(fulvalene)tetracarbonyldirhenium-double Si-H activation to the first fulvalene silylene complex SO ORGANOMETALLICS LA English DT Article ID TRANSITION-METAL-COMPLEXES; X-RAY STRUCTURE; R = ME; MU-SILYLENE; SECONDARY SILANES; SILICON; REACTIVITY; LIGANDS; BONDS; PHOTOCHEMISTRY AB (Fulvalene)hexacarbonyldirhenium (1) furnishes the first silylene fulvalenedimetal complex 3 by double Si-H activation. The solid-state structure of the molecule was determined by X-ray analysis and its solution dynamics by (1)H NMR spectroscopy. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Vollhardt, KPC (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM vollhard@cchem.berkeley.edu NR 62 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JUN 12 PY 2000 VL 19 IS 12 BP 2389 EP 2392 DI 10.1021/om000022u PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 324UB UT WOS:000087638800022 ER PT J AU Abbott, B Abolins, M Abramov, V Acharya, BS Adam, I 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 Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Breedon, R Briskin, G Brock, R Bross, A Buchholz, D 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 Cooper, WE Coppage, D Cretsinger, C 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 Fatyga, MK Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B 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 Guida, JA Guida, JM 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 Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Kahn, S 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 Landry, F Landsberg, G Leflat, A Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L 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 McKinley, J 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 Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oshima, N Owen, D Padley, P Para, A Parashar, N Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C 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 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 Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Toback, D Trippe, TG Tuts, PM Vaniev, V Varelas, N Varnes, EW Volkov, AA Vorobiev, AP Wahl, HD Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yepes, P Yip, K Yoshikawa, C Youssef, S Yu, J Yu, Y Zanabria, M 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 Adam, I 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 Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Breedon, R Briskin, G Brock, R Bross, A Buchholz, D 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 Cooper, WE Coppage, D Cretsinger, C 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 Fatyga, MK Feher, S Fein, D Ferbel, T Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B 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 Guida, JA Guida, JM 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 Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Ito, AS Jerger, SA Jesik, R Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Kahn, S 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 Landry, F Landsberg, G Leflat, A Li, J Li, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Lu, JG Lucotte, A Lueking, L Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L 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 McKinley, J 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 Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oshima, N Owen, D Padley, P Para, A Parashar, N Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Reay, NW Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C 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 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 Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Toback, D Trippe, TG Tuts, PM Vaniev, V Varelas, N Varnes, EW Volkov, AA Vorobiev, AP Wahl, HD Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Wood, DR Yamada, R Yamin, P Yasuda, T Yepes, P Yip, K Yoshikawa, C Youssef, S Yu, J Yu, Y Zanabria, M Zhou, Z Zhu, ZH Zielinski, M Zieminska, D Zieminski, A Zutshi, V Zverev, EG Zylberstejn, A TI Small-angle muon and bottom-quark production in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID = 1.8 TEV; DIFFERENTIAL CROSS-SECTION; P(P)OVER-BAR COLLISIONS; HADRON-COLLISIONS; D0 DETECTOR; DISTRIBUTIONS AB This Letter describes a measurement of the muon cross section originating from b-quark decay in the forward rapidity range 2.4 < \y(mu)\ < 3.2 in p (p) over bar collisions at root s = 1.8 TeV. The data used in this analysis were collected by the DO experiment at the Fermilab Tevatron. We find that next-to-leading-order QCD calculations underestimate b-quark production by a factor of 4 in the forward rapidity region. C1 NYU, New York, NY 10003 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. Univ Estado Rio De Janeiro, Rio De Janeiro, Brazil. Inst High Energy Phys, Beijing 100039, Peoples R China. Univ Los Andes, Bogota, Colombia. Univ San Francisco, Quito, Ecuador. Univ Grenoble 1, CNRS, IN2P3, Inst Nucl Sci, Grenoble, France. CEA, Serv Phys Particules, DAPNIA, Saclay, France. Panjab Univ, Chandigarh 160014, India. Univ Delhi, Delhi 110007, India. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Kyungsung Univ, Pusan 608736, South Korea. Seoul Natl Univ, Seoul, South Korea. CINVESTAV, Mexico City 14000, DF, Mexico. Inst Nucl Phys, Krakow, Poland. Inst Theoret & Expt Phys, Moscow 117259, Russia. Moscow State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. Univ Lancaster, Lancaster, England. Univ Arizona, Tucson, AZ 85721 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Chicago, IL 60607 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Indiana Univ, Bloomington, IN 47405 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Purdue Univ, W Lafayette, IN 47907 USA. Iowa State Univ, Ames, IA 50011 USA. Univ Kansas, Lawrence, KS 66045 USA. Kansas State Univ, Manhattan, KS 66506 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Nebraska, Lincoln, NE 68588 USA. Columbia Univ, New York, NY 10027 USA. 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. RP Abbott, B (reprint author), NYU, 550 1St Ave, New York, NY 10003 USA. RI Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Leflat, Alexander/D-7284-2012; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Dudko, Lev/D-7127-2012; Kim, Sun Kee/G-2042-2015; 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; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016 OI Belyaev, Alexander/0000-0002-1733-4408; Dudko, Lev/0000-0002-4462-3192; Kim, Sun Kee/0000-0002-0013-0775; Yip, Kin/0000-0002-8576-4311; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Sznajder, Andre/0000-0001-6998-1108 NR 20 TC 39 Z9 39 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 12 PY 2000 VL 84 IS 24 BP 5478 EP 5483 DI 10.1103/PhysRevLett.84.5478 PG 6 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200006 ER PT J AU Liu, H Ajitanand, NN Alexander, J Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, J Cole, B Crowe, K Das, A Draper, J Gilkes, M Gushue, S Heffner, M Hirsch, A Hjort, E Huo, L Justice, M Kaplan, M Keane, D Kintner, J Klay, J Krofcheck, D Lacey, R Lisa, MA Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, D Panitkin, SY Porile, N Rai, G Ritter, HG Romero, J Scharenberg, R Schroeder, LS Srivastava, B Stone, NTB Symons, TJM Wang, S Whitfield, J Wienold, T Witt, R Wood, L Yang, X Zhang, WN Zhang, Y AF Liu, H Ajitanand, NN Alexander, J Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, J Cole, B Crowe, K Das, A Draper, J Gilkes, M Gushue, S Heffner, M Hirsch, A Hjort, E Huo, L Justice, M Kaplan, M Keane, D Kintner, J Klay, J Krofcheck, D Lacey, R Lisa, MA Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, D Panitkin, SY Porile, N Rai, G Ritter, HG Romero, J Scharenberg, R Schroeder, LS Srivastava, B Stone, NTB Symons, TJM Wang, S Whitfield, J Wienold, T Witt, R Wood, L Yang, X Zhang, WN Zhang, Y TI Sideward flow in Au plus Au collisions between 2A and 8A GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; QUARK-GLUON PLASMA; AU+AU COLLISIONS; COLLECTIVE-FLOW; ELLIPTIC FLOW; PHASE-TRANSITION; TRANSVERSE FLOW; HYDRODYNAMICS; EXPANSION AB Using the large acceptance Time Projection Chamber of experiment E895 at Brookhaven, measurements of collective sideward flow in Au + Au collisions at beam energies of 2A, 4A, 6A, and 8A GeV are presented in the form of in-plane transverse momentum [p(x)] and the first Fourier coefficient of azimuthal anisotropy vl. These measurements indicate a smooth variation of sideward now as a function of beam energy. The data are compared with four nuclear transport models which have an orientation towards this energy range. All four exhibit some qualitative trends similar to those found in the data, although none show a consistent pattern of agreement within experimental uncertainties. C1 Kent State Univ, Kent, OH 44242 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Columbia Univ, New York, NY 10027 USA. Univ Calif Davis, Davis, CA 95616 USA. Harbin Inst Technol, Harbin 150001, Peoples R China. St Marys Coll, Moraga, CA 94575 USA. Univ Auckland, Auckland 1, New Zealand. Ohio State Univ, Columbus, OH 43210 USA. Purdue Univ, W Lafayette, IN 47907 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Liu, H (reprint author), Kent State Univ, Kent, OH 44242 USA. RI Witt, Richard/H-3560-2012 NR 34 TC 68 Z9 70 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 12 PY 2000 VL 84 IS 24 BP 5488 EP 5492 DI 10.1103/PhysRevLett.84.5488 PG 5 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200008 ER PT J AU Murphy, JB Kramer, SL AF Murphy, JB Kramer, SL TI First observation of simultaneous alpha buckets in a quasi-isochronous storage ring SO PHYSICAL REVIEW LETTERS LA English DT Article AB We present the first experimental evidence confirming the theoretical predictions of alpha buckets in an electron storage ring. By controlling both the first- and second-order momentum compaction factors. we succeeded in storing electrons simultaneously in a pair of alpha buckets or in either bucket alone. The two electron bunches are separated in energy by slightly less than 1% and thr energy is unable over a narrow range. The energy difference was directly measured using synchrotron light from an undulator. Simultaneous two-color light beams from an undulator were generated. By changing thc rf voltage, we were able to vary the normally fixed longitudinal bunch separation. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Murphy, JB (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Bldg 725C, Upton, NY 11973 USA. NR 10 TC 5 Z9 8 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 12 PY 2000 VL 84 IS 24 BP 5516 EP 5519 DI 10.1103/PhysRevLett.84.5516 PG 4 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200015 ER PT J AU Chen, SY Maksimchuk, A Esarey, E Umstadter, D AF Chen, SY Maksimchuk, A Esarey, E Umstadter, D TI Observation of phase-matched relativistic harmonic generation SO PHYSICAL REVIEW LETTERS LA English DT Article ID NONLINEAR THOMSON SCATTERING; 2ND-HARMONIC GENERATION; UNDERDENSE PLASMAS; LASER-PULSES; ELECTROMAGNETIC-WAVES; NOBLE-GASES; IONIZATION; INTENSITY; EMISSION; BEAMS AB Phase-matched relativistic harmonic generation in plasmas is observed for the first time. Third-harmonic light is detected and discriminated spectrally and angularly from the harmonics generated from competing processes. Its angular pattern is a narrow forward-directed cone, which is consistent with phase matching of a high-order transverse mode in a plasma. The signal level is found to be on the same order of magnitude for a circularly polarized pump pulse as for a linearly polarized pump pulse. C1 Univ Michigan, Ctr Ultrafast Opt Sci, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Ctr Beam Phys, Berkeley, CA 94720 USA. RP Chen, SY (reprint author), Acad Sinica, Inst Atom & Mol Sci, POB 23-166, Taipei 106, Taiwan. RI Chen, Szu-yuan/F-7555-2012; Umstadter, Donald/A-1581-2016 OI Umstadter, Donald/0000-0002-2182-4346 NR 23 TC 70 Z9 70 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 12 PY 2000 VL 84 IS 24 BP 5528 EP 5531 DI 10.1103/PhysRevLett.84.5528 PG 4 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200018 ER PT J AU Mao, GM Saboungi, ML Price, DL Armand, MB Howells, WS AF Mao, GM Saboungi, ML Price, DL Armand, MB Howells, WS TI Structure of liquid PEO-LiTFSI electrolyte SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLY(ETHYLENE OXIDE); POLYMER ELECTROLYTE; NEUTRON-DIFFRACTION; INTERMEDIATE-RANGE; CRYSTAL-STRUCTURE; LITHIUM IODIDE; CONDUCTIVITY; ORDER AB The structure of a polymer electrolyte, P(EO)(7.5)LiN(SO2CF3)(2), has been determined by neutron diffraction with isotropic substitution. The Li ions are bonded on average to five ether oxygens belonging to pairs of PEO coils. These are arranged with a considerable degree of extended-range order providing pathways for the Li ion conduction. The lack of ion pairing in this system below 4.8 Angstrom is reminiscent of that observed in the remarkable structure of P(EO)(6)LiAsF6 and implies that anions and cations are free to migrate independently. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Montreal, Dept Chem, Montreal, PQ H3C 3J7, Canada. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. RP Mao, GM (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Mao, Guomin/G-3933-2010; Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 24 TC 94 Z9 94 U1 6 U2 42 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 12 PY 2000 VL 84 IS 24 BP 5536 EP 5539 DI 10.1103/PhysRevLett.84.5536 PG 4 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200020 ER PT J AU Celliers, PM Collins, GW Da Silva, LB Gold, DM Cauble, R Wallace, RJ Foord, ME Hammel, BA AF Celliers, PM Collins, GW Da Silva, LB Gold, DM Cauble, R Wallace, RJ Foord, ME Hammel, BA TI Shock-induced transformation of liquid deuterium into a metallic fluid SO PHYSICAL REVIEW LETTERS LA English DT Article ID GPA 1.4 MBAR; MOLECULAR-HYDROGEN; GIANT PLANETS; EQUATION; STATE; CONDUCTIVITY; PRESSURES; IGNITION AB Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, and 404 nm of a high pressure shock front propagating through liquid deuterium show a continuous increase in reflectance from below 10% and saturating at similar to(40-60)% in the range of shock velocities from 12 to 20 mu m/ns (pressure range 17-50 GPa). The high optical reflectance is evidence that the shucked deuterium reaches a conducting state characteristic of a metallic fluid. Above 20 mu m/ns shock velocity (50 GPa pressure) reflectance is constant indicating that the transformation is substantially complete. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Celliers, PM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 29 TC 156 Z9 164 U1 1 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 12 PY 2000 VL 84 IS 24 BP 5564 EP 5567 DI 10.1103/PhysRevLett.84.5564 PG 4 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200027 ER PT J AU Buttler, WT Hughes, RJ Lamoreaux, SK Morgan, GL Nordholt, JE Peterson, CG AF Buttler, WT Hughes, RJ Lamoreaux, SK Morgan, GL Nordholt, JE Peterson, CG TI Daylight quantum key distribution over 1.6 km SO PHYSICAL REVIEW LETTERS LA English DT Article ID FREE-SPACE; CRYPTOGRAPHY; CANNOT AB Quantum key distribution (QKD) has been demonstrated over a point-to-point 1.6-km atmospheric optical path in full daylight. This record transmission distance brings QKD a step closer to surface-to-satellite and other long-distance applications. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Buttler, WT (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 33 TC 106 Z9 126 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 12 PY 2000 VL 84 IS 24 BP 5652 EP 5655 DI 10.1103/PhysRevLett.84.5652 PG 4 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200049 ER PT J AU Lamoreaux, SK AF Lamoreaux, SK TI Comment on "Demonstration of the Casimir force in the 0.6 to 6 mu m range" - Lamoreaux replies SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Lamoreaux, SK (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, P-23,MS H803, Los Alamos, NM 87545 USA. NR 5 TC 10 Z9 10 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 12 PY 2000 VL 84 IS 24 BP 5673 EP 5673 DI 10.1103/PhysRevLett.84.5673 PG 1 WC Physics, Multidisciplinary SC Physics GA 322RH UT WOS:000087522200055 ER PT J AU Pham, HN Viergutz, A Gormley, RJ Datye, AK AF Pham, HN Viergutz, A Gormley, RJ Datye, AK TI Improving the attrition resistance of slurry phase heterogeneous catalysts SO POWDER TECHNOLOGY LA English DT Article DE attrition resistance; slurry phase heterogeneous catalysts; Fischer-Tropsch; precipitated Fe-Cu catalyst ID AGGLOMERATE STRENGTH DISTRIBUTIONS; FISCHER-TROPSCH CATALYSTS; ACTIVATION AB Slurry phase heterogeneous catalysts for processes such as Fischer-Tropsch (F-T) synthesis must exhibit a high degree of attrition resistance. The precipitated Fe-Cu catalyst used for F-T synthesis is quite weak in its as-prepared state. Spray-drying yields spherical particles which show some improvement in attrition resistance. However, the formation of fines (< 5 mu m) in this powder shows that it is not suitable as a slurry phase catalyst. In this paper, we report on the use of a silica binder to improve the strength of spray-dried agglomerates. The attrition resistance was measured using ultrasonic fragmentation followed by sedigraph particle size analysis. The attrition strength of the iron oxide catalyst agglomerates was compared to that of a commercial alumina powder, which was used as a reference material. The role of calcination (before or after spray-drying) and the method of silica binder addition (before or after spray-drying) was investigated. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Univ New Mexico, Dept Chem & Nucl Engn, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Datye, AK (reprint author), Univ New Mexico, Dept Chem & Nucl Engn, Ctr Microengineered Mat, Albuquerque, NM 87131 USA. OI Datye, Abhaya/0000-0002-7126-8659 NR 15 TC 22 Z9 23 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD JUN 12 PY 2000 VL 110 IS 3 BP 196 EP 203 DI 10.1016/S0032-5910(99)00256-9 PG 8 WC Engineering, Chemical SC Engineering GA 340NB UT WOS:000088539600004 ER PT J AU Burov, AV MacLachlan, JA AF Burov, AV MacLachlan, JA TI Optimization of electron cooling for a medium energy accumulator ring SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electron cooling; accumulator storage ring AB The binary collision model of electron cooling is used to discuss the principal issues in the use of electron cooling for accumulating ions at medium energies, where "mediurn energy" is defined by a beam velocity > 0.8c. Some new general results are developed which are important in this context. Longitudinal and transverse cooling rates are calculated analytically for a particle executing betatron oscillations in a storage ring. The formulas obtained are compared with numerical results. Particular attention is paid to the case in which the transverse components of the relative velocities substantially exceed the longitudinal components. The exact analytical results for finite electron temperatures are presented. The time for longitudinal cooling of a Gaussian beam is calculated as a function of the acceptable fraction of uncooled particles; the optimum electron beam size is calculated and an optimum electron density distribution is found. The results obtained are applied to an electron cooling system for the Fermilab Recycler (Jackson, FERMILAB-TM-1991. Unpublished Internal Note, November 1999); the cooling time, optimum parameters and tolerances are calculated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP MacLachlan, JA (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 328 EP 344 DI 10.1016/S0168-9002(99)01313-3 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400004 ER PT J AU Harris, DA Yu, J Adams, T Alton, A Avvakumov, S de Barbaro, L de Barbaro, P Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, J Drucker, RB Fleming, BT Frey, R Formaggio, J Goldman, J Goncharov, M Johnson, RA Kim, JH Koutsoliotas, S Krishnaswami, G Lamm, MJ Marsh, W Mason, D McNulty, C McFarland, KS Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, H Shaevitz, MH Spentzouris, P Stern, EG Vaitaitis, A Vakili, M Van Ark, E Wu, V Yang, UK Zeller, GP AF Harris, DA Yu, J Adams, T Alton, A Avvakumov, S de Barbaro, L de Barbaro, P Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, J Drucker, RB Fleming, BT Frey, R Formaggio, J Goldman, J Goncharov, M Johnson, RA Kim, JH Koutsoliotas, S Krishnaswami, G Lamm, MJ Marsh, W Mason, D McNulty, C McFarland, KS Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, H Shaevitz, MH Spentzouris, P Stern, EG Vaitaitis, A Vakili, M Van Ark, E Wu, V Yang, UK Zeller, GP TI Precision calibration of the NuTeV calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ENERGY AB NuTeV is a neutrino-nucleon deep-inelastic scattering experiment at Fermilab. The detector consists of an iron scintillator sampling calorimeter interspersed with drift chambers, followed by a muon toroidal spectrometer. We present determinations of response and resolution functions of the NuTeV calorimeter for electrons, hadrons, and muons over an energy range from 4.8 to 190 GeV. The absolute hadronic energy scale is determined to an accuracy of 0.43%. We compare our measurements to predictions from calorimeter theory and GEANT3 simulations. 2000 Published by Elsevier Science B.V. C1 Univ Rochester, Rochester, NY 14627 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Kansas State Univ, Manhattan, KS 66506 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Oregon, Eugene, OR 97403 USA. Columbia Univ, New York, NY 10027 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Harris, DA (reprint author), Univ Rochester, 601 Elmwood Ave, Rochester, NY 14627 USA. RI Frey, Raymond/E-2830-2016; OI Frey, Raymond/0000-0003-0341-2636; Bernstein, Robert/0000-0002-7610-950X NR 27 TC 32 Z9 32 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 377 EP 415 DI 10.1016/S0168-9002(99)01304-2 PG 39 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400008 ER PT J AU Yen, YF Bowman, JD Bolton, RD Crawford, BE Delheij, PPJ Hart, GW Haseyama, T Frankle, CM Iinuma, M Knudson, JN Masaike, A Masuda, Y Matsuda, Y Mitchell, GE Penttila, SI Roberson, NR Seestrom, SJ Sharapov, E Shimizu, HM Smith, DA Stephenson, SL Szymanski, JJ Yoo, SH Yuan, VW AF Yen, YF Bowman, JD Bolton, RD Crawford, BE Delheij, PPJ Hart, GW Haseyama, T Frankle, CM Iinuma, M Knudson, JN Masaike, A Masuda, Y Matsuda, Y Mitchell, GE Penttila, SI Roberson, NR Seestrom, SJ Sharapov, E Shimizu, HM Smith, DA Stephenson, SL Szymanski, JJ Yoo, SH Yuan, VW TI A high-rate (10)B-loaded liquid scintillation detector for parity-violation studies in neutron resonances SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE (10)B-loaded liquid scintillator; neutron detector; mean capture time; neutron resonance; parity violation ID COMPOUND-NUCLEUS; SCATTERING; APPARATUS; SYSTEM AB Wt have developed a large-area (10)B-loaded liquid scintillation detector for parity-violation studies in neutron resonances with high instantaneous neutron fluxes from the LANSCE short-pulse spallation source. The detector has an efficiency of 95%. 85% and 71% at neutron energies of 10, 100 and 1000 eV, respectively. The neutron mean capture time In the detector is (416 +/- 5) ns. We describe the detector and the current-mode signal processing system, that can handle neutron rates up to 500 MHz. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, Durham, NC 27708 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. Kyoto Univ, Dept Phys, Kyoto 6068502, Japan. Natl Lab High Energy Phys, Tsukuba, Ibaraki 3050801, Japan. N Carolina State Univ, Raleigh, NC 27695 USA. Joint Inst Nucl Res, Dubna 141980, Russia. RP Mitchell, GE (reprint author), N Carolina State Univ, Raleigh, NC 27695 USA. EM mitchell@tunl.duke.edu RI Matsuda, Yasuyuki/C-3007-2008 OI Matsuda, Yasuyuki/0000-0002-9847-3791 NR 27 TC 11 Z9 11 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 476 EP 489 DI 10.1016/S0168-9002(99)01308-X PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400015 ER PT J AU Strellis, DA Gregorich, KE Adams, JA Chung, YH Lane, MR Laue, CA Lee, DM McGrath, CA Shaughnessy, DA Sylwester, ER Hoffman, DC AF Strellis, DA Gregorich, KE Adams, JA Chung, YH Lane, MR Laue, CA Lee, DM McGrath, CA Shaughnessy, DA Sylwester, ER Hoffman, DC TI A rapid sample changer system for studying fission shape isomers through the electron-capture-delayed fission process SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE delayed fission; shape isomer; sample changer; detector array AB A new sample changer system has been designed to rapidly transport activity from a heavy element production target chamber at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron to a fission, alpha-particle, X-ray, and gamma-ray detection site. This changer was specifically designed to help study the nuclear structure of isotopes involved in electron-capture-delayed fission decay with half-lives greater than 30s. The system integrates a rotating wheel and a cycling piston to transport samples from the end of a gas transport capillary line to the detection site. The overall efficiency of the sample changer system was determined by running off-line experiments to determine the activity collection site efficiency and the detector efficiencies. Under the most favorable conditions, we calculated a relative He-E;CI gas transport and collection efficiency of around 70%. Efficiencies were calculated by comparing the yield of Fr-221 (half-life = 4.8 min) at the sample changer collection site to the activity collected directly on a piece of glass filter paper. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Hallym Univ, Dept Chem, Kangwon Do 200702, South Korea. RP Strellis, DA (reprint author), Lawrence Berkeley Natl Lab, Div Nucl Sci, MS 88,1 Cyclotron Rd,MS 70A 3307, Berkeley, CA 94720 USA. RI McGrath, Christopher/E-8995-2013 NR 8 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 548 EP 555 DI 10.1016/S0168-9002(99)01311-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400021 ER PT J AU Ren, B Dilmanian, FA Chapman, LD Wu, XY Zhong, Z Ivanov, I Huang, X AF Ren, B Dilmanian, FA Chapman, LD Wu, XY Zhong, Z Ivanov, I Huang, X TI Interpretation of bent-crystal rocking curves using phase-space diagrams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE bent-crystal monochromator; rocking curve; phase-space diagram; parallel position ID LAUE MONOCHROMATOR; REFLECTIVITY AB In developing a double bent-laue crystal monochromator for synchrotron-based monochromatic computed tomography system, we applied a special projection of the phase-space diagram to interpret the shape of bent-crystal rocking curves. Unlike the rigorous approach of the lay-tracing method. this graphical method provides direct pictures that allow checks of the physical significance of the shapes of the rocking curves, thereby providing quick guidelines for matching two bent crystals. The method's usefulness is demonstrated with our experimental results, and its limitations are discussed. (C) 2000 Published bq Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. IIT, Ctr Synchrotron Radiat Res & Instrumentat, Chicago, IL 60616 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Ren, B (reprint author), GE Corp, R&D, Schenectady, NY USA. NR 19 TC 5 Z9 6 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 556 EP 568 DI 10.1016/S0168-9002(99)01188-2 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400022 ER PT J AU Tremsin, AS Ruvimov, S Siegmund, OHW AF Tremsin, AS Ruvimov, S Siegmund, OHW TI Structural transformation of CsI thin film photocathodes under exposure to air and UV irradiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CsI photocathodes; quantum efficiency; crystalline structure ID QUANTUM AB Transmission electron microscopy has been employed to study the structure of polycrystalline CsI thin films and its transformation under exposure to humid air and UV irradiation. The catastrophic degradation of CsI thin film photocathode performance is shown to be associated with the film dissolving followed by its re-crystallization. This results in the formation of large lumps of CsI crystal on the substrate surface, so that the film becomes discontinuous and Its performance as a photocathode is permanently degraded. No change in the surface morphology and the film crystalline structure was observed after the samples were UV irradiated. (C) 2000 Elsevier Science B.V, All rights reserved. C1 Univ Calif Berkeley, Space Sci Lab, Expt Astrophys Grp, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Tremsin, AS (reprint author), Univ Calif Berkeley, Space Sci Lab, Expt Astrophys Grp, Berkeley, CA 94720 USA. NR 12 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 2000 VL 447 IS 3 BP 614 EP 618 DI 10.1016/S0168-9002(99)01305-4 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 327QN UT WOS:000087804400028 ER PT J AU Naulleau, P Goldberg, KA Gullikson, EM Bokor, J AF Naulleau, P Goldberg, KA Gullikson, EM Bokor, J TI At-wavelength, system-level flare characterization of extreme-ultraviolet optical systems SO APPLIED OPTICS LA English DT Article ID POINT-DIFFRACTION INTERFEROMETER; EUV; SCATTERING; RADIATION AB The extreme-ultraviolet (EUV) phase-shifting point-diffraction interferometer (PS/PDI) has recently been developed to provide high-accuracy wave-front characterization critical to the development of EW Lithography systems. Here we describe an enhanced implementation of the PS/PDI that significantly extends its measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wave front and flare. PS/PDI-based flare characterization of two recently fabricated EUV 10x-reduction Lithographic optical systems is presented. (C) 2000 Optical Society of America. OCIS codes: 090.0090, 110.1650, 110.2970, 120.2650, 120.3180, 120.3940, 120.5820, 260.7200. C1 Lawrence Berkeley Natl Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Naulleau, P (reprint author), Lawrence Berkeley Natl Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. EM pnaulleau@lbl.gov RI Bokor, Jeffrey/A-2683-2011 NR 19 TC 13 Z9 13 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUN 10 PY 2000 VL 39 IS 17 BP 2941 EP 2947 DI 10.1364/AO.39.002941 PG 7 WC Optics SC Optics GA 324DQ UT WOS:000087606900010 PM 18345220 ER PT J AU Ricker, PM Dodelson, S Lamb, DQ AF Ricker, PM Dodelson, S Lamb, DQ TI COSMOS: A hybrid N-body/hydrodynamics code for cosmological problems SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; gravitation; hydrodynamics; intergalactic medium; large-scale structure of universe; methods : numerical ID SMOOTHED PARTICLE HYDRODYNAMICS; PIECEWISE PARABOLIC METHOD; NUMERICAL TECHNIQUES; CONSERVATION-LAWS; GAS-DYNAMICS; SIMULATIONS; SYSTEMS; SCHEME; EVOLUTION; TESTS AB We describe a new hybrid N-body/hydrodynamical code based on the particle-mesh (PM) method and the piecewise-parabolic method (PPM) for use in solving problems related to the evolution of large-scale structure, galaxy clusters, and individual galaxies. The code, named COSMOS, possesses several new features that distinguish it from other PM-PPM codes. In particular, to solve the Poisson equation we have written a new multigrid solver which can determine the gravitational potential of isolated matter distributions and which properly takes into account the finite-volume discretization required by PPM. All components of the code are constructed to work with a nonuniform mesh, preserving second-order spatial differences. The PPM code uses vacuum boundary conditions for isolated problems, preventing inflows when appropriate. The PM code uses a second-order variable-time-step time integration scheme. Radiative cooling and cosmological expansion terms are included. COSMOS has been implemented for parallel computers using the Parallel Virtual Machine (PVM) library, and it features a modular design which simplifies the addition of new physics and the configuration of the code for different types of problems. We discuss the equations solved by COSMOS and describe the algorithms used, with emphasis on these features. We also discuss the results of tests we have performed to establish that COSMOS works and to determine its range of validity. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM ricker@flash.uchicago.edu; dodelson@fnal.gov; lamb@oddjob.uchicago.edu NR 49 TC 16 Z9 16 U1 0 U2 1 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 10 PY 2000 VL 536 IS 1 BP 122 EP 143 DI 10.1086/308908 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300011 ER PT J AU Kusunose, M Takahara, F Li, H AF Kusunose, M Takahara, F Li, H TI Electron acceleration and time variability of high-energy emission from blazars SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; gamma rays : theory; radiation mechanisms : nonthermal ID SELF-COMPTON MODEL; PARTICLE-ACCELERATION; MARKARIAN-501; FLARE; ABSORPTION; RADIATION; PLASMAS; JETS AB Blazars are known to emit a broadband emission from radio to gamma rays with rapid time variations, particularly in X-rays and gamma rays. Synchrotron radiation and inverse Compton scattering are thought to play an important role in emission, and the time variations are likely related to the acceleration of nonthermal electrons. As simultaneous multiwavelength observations with continuous time spans have been recently available, some characteristics of electron acceleration can possibly be inferred from the spectral changes of high-energy emission. In order to make such inferences, we solve the time-dependent kinetic equations of electrons and photons simultaneously, using a simple model for electron acceleration. We then show how the time variations of emission are dependent on electron acceleration. We also present a simple model for a flare in X-rays and TeV gamma rays by temporarily changing the acceleration timescale. Our model can be used to analyze observed data in detail to obtain information on electron acceleration in blazars. C1 Kwansei Gakuin Univ, Sch Sci, Dept Phys, Nishinomiya, Hyogo 6628501, Japan. Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Osaka 5600043, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kusunose, M (reprint author), Kwansei Gakuin Univ, Sch Sci, Dept Phys, Nishinomiya, Hyogo 6628501, Japan. NR 24 TC 47 Z9 47 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 10 PY 2000 VL 536 IS 1 BP 299 EP 307 DI 10.1086/308928 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300024 ER PT J AU Lacy, M AF Lacy, M TI Radio galaxy clustering at z similar to 0.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; large-scale structure of universe; surveys ID LARGE-SCALE STRUCTURE; NORTH-ECLIPTIC-CAP; REDSHIFT SURVEY; COMPLETE SAMPLE; COSMIC EPOCH; BIAS; SKY AB Radio galaxies are uniquely useful as probes of large-scale structure since their uniform identification with giant elliptical galaxies out to high redshift means that the evolution of their bias factor can be predicted. As the initial stage in a project to study large-scale structure with radio galaxies, we have performed a small redshift survey, selecting 29 radio galaxies in the range of 0.19 < z < 0.45 from a contiguous 40 deg(2) area of sky. We detect significant clustering within this sample. The amplitude of the two-point correlation function that we measure is consistent with no evolution from the local (z < 0.1) value. This is as expected in a model in which radio galaxy hosts form at high redshift and thereafter obey a continuity equation, although the signal-to-noise ratio of the detection is too low to rule out other models. Larger surveys out to z similar to 1 should reveal the structures of superclusters at intermediate redshifts and should strongly constrain models for the evolution of large-scale structure. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Lacy, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, POB 808,L-413, Livermore, CA 94550 USA. NR 23 TC 6 Z9 6 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 10 PY 2000 VL 536 IS 1 BP L1 EP L4 DI 10.1086/312721 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LL UT WOS:000087963500001 ER PT J AU Leggett, SK Geballe, TR Fan, XH Schneider, DP Gunn, JE Lupton, RH Knapp, GR Strauss, MA McDaniel, A Golimowski, DA Henry, TJ Peng, E Tsvetanov, ZI Uomoto, A Zheng, W Hill, GJ Ramsey, LW Anderson, SF Annis, JA Bahcall, NA Brinkmann, J Chen, B Csabai, I Fukugita, M Hennessy, GS Hindsley, RB Ivezic, I Lamb, DQ Munn, JA Pier, JR Schlegel, DJ Smith, JA Stoughton, C Thakar, AR York, DG AF Leggett, SK Geballe, TR Fan, XH Schneider, DP Gunn, JE Lupton, RH Knapp, GR Strauss, MA McDaniel, A Golimowski, DA Henry, TJ Peng, E Tsvetanov, ZI Uomoto, A Zheng, W Hill, GJ Ramsey, LW Anderson, SF Annis, JA Bahcall, NA Brinkmann, J Chen, B Csabai, I Fukugita, M Hennessy, GS Hindsley, RB Ivezic, I Lamb, DQ Munn, JA Pier, JR Schlegel, DJ Smith, JA Stoughton, C Thakar, AR York, DG TI The missing link: Early methane ("T") dwarfs in the Sloan Digital Sky Survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : low-mass; brown dwarfs; surveys ID HOBBY-EBERLY TELESCOPE; LOW-RESOLUTION SPECTROGRAPH; BROWN DWARF; DISCOVERY; PLANETS; SYSTEM AB We report the discovery of three cool brown dwarfs that fall in the effective temperature gap between the latest L dwarfs currently known, with no methane absorption bands in the 1-2.5 mu m range, and the previously known methane (T) dwarfs, whose spectra are dominated by methane and water. The newly discovered objects were detected as very red objects in the Sloan Digital Sky Survey imaging data and have JHK colors between the red L dwarfs and the blue Gl 229B-like T dwarfs. They show both CO and CH(4) absorption in their near-infrared spectra in addition to H(2)O(2) with weaker CH(4) absorption features in the H and K bands than those in all other methane dwarfs reported to date. Due to the presence of CH(4) in these bands, we propose that these objects are early T dwarfs. The three form part of the brown dwarf spectral sequence and fill in the large gap in the overall spectral sequence from the hottest main-sequence stars to the coolest methane dwarfs currently known. C1 United Kingdom Infrared Telescope, Joint Astron Ctr, Hilo, HI 96720 USA. Gemini Observ, Hilo, HI 96720 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Texas, McDonald Observ, Dept Astron, Austin, TX 78712 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Apache Point Observ, Sunspot, NM 88349 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. Inst Adv Study, Princeton, NJ 08540 USA. USN Observ, Washington, DC 20392 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. RP Leggett, SK (reprint author), United Kingdom Infrared Telescope, Joint Astron Ctr, 660 N Aohoku Pl,Univ Pk, Hilo, HI 96720 USA. RI Csabai, Istvan/F-2455-2012 NR 22 TC 158 Z9 158 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP L35 EP L38 DI 10.1086/312728 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LL UT WOS:000087963500009 ER PT J AU Ramos, ALD Schmal, M Aranda, DAG Somorjai, GA AF Ramos, ALD Schmal, M Aranda, DAG Somorjai, GA TI Hydrodechlorination of dichlorodifluoromethane over palladium model catalysts and a comparison with the hydrodechlorination of 1,1-dichlorotetrafluoroethane SO JOURNAL OF CATALYSIS LA English DT Article DE palladium model catalysts; Pd(111); hydrogen; CFC-12; dichlorodifluoromethane; CFC-114a; hydrodechlorination; dechlorination; chlorine ID CCL2F2 CFC-12; CH2F2 HFC-32; SELECTIVE HYDROGENOLYSIS; ACTIVATED CARBON; CHLORINE ADSORPTION; PD/AL2O3 CATALYSTS; PD; CONVERSION; SUPPORT; CF2CL2 AB The hydrodechlorination of dichlorodifluoromethane (CFC-12) was performed on small surface area model catalysts, including Pd(111) and Pd(110) single crystals and polycrystalline palladium foil. Reactions were performed in a batch reactor, at atmospheric pressure and in the temperature range of 423-523 K. The main products were CH2F2 and CH4. Ethane could be detected at higher temperatures. Lower deactivation rates and a higher activation energy for CH2F2 formation were found for Pd(111). In a comparison to our previous results with dichlorotetrafluoroethane (CFC-114a), the hydrodechlorination rate of CCl2F2 was 2 orders of magnitude lower, the mono-dechlorinated product (CHCIF2) was not produced, and the bulk palladium hydrogen activity was not detected. An overview of the hydrodechlorination reaction is presented. (C) 2000 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Fed Rio de Janeiro, Escola Quim, BR-21941 Rio De Janeiro, Brazil. Univ Fed Rio de Janeiro, COPPE, NUCAT, BR-21941 Rio De Janeiro, Brazil. RP Somorjai, GA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. RI Aranda, Donato/G-7877-2012 NR 36 TC 26 Z9 26 U1 1 U2 2 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 JUN 10 PY 2000 VL 192 IS 2 BP 423 EP 431 DI 10.1006/jcat.2000.2856 PG 9 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 327JZ UT WOS:000087791900018 ER PT J AU Palmer, BJ Rector, DR AF Palmer, BJ Rector, DR TI Lattice Boltzmann algorithm for simulating thermal flow in compressible fluids SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID RAYLEIGH-BENARD CONVECTION; MODEL AB An algorithm has been developed for incorporating the effects of temperature into lattice Boltzmann simulations. Instead of modeling the internal energy as a moment of the distribution describing the flow of mass and momentum, the internal energy is modeled as a scalar field using a second distribution. The energy is then coupled to the density and momentum via the partition between moving and nonmoving particles in a conventional two-speed model. The algorithm is tested against a number of systems for which analytic results are available. These include nonuniform conductivity between two plates, entry length behavior for flow in a channel between two parallel plates, and critical Rayleigh number behavior in Rayleigh-Benard convection. Quantitative agreement is found in all cases. (C) 2000 Academic Press. C1 Pacific NW Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Palmer, BJ (reprint author), Pacific NW Lab, Environm & Mol Sci Lab, Box 999, Richland, WA 99352 USA. NR 26 TC 50 Z9 50 U1 2 U2 13 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2000 VL 161 IS 1 BP 1 EP 20 DI 10.1006/jcph.2000.6425 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 323HY UT WOS:000087561000001 ER PT J AU Fadlun, EA Verzicco, R Orlandi, P Mohd-Yusof, J AF Fadlun, EA Verzicco, R Orlandi, P Mohd-Yusof, J TI Combined immersed-boundary finite-difference methods for three-dimensional complex flow simulations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE 3D complex flows; immersed boundaries; finite differences ID NUMERICAL-SIMULATION; BLOOD-FLOW; HEART; SPHERE AB A second-order accurate, highly efficient method is developed for simulating unsteady three-dimensional incompressible flows in complex geometries. This is achieved by using boundary body forces that allow the imposition of the boundary conditions on a given surface not coinciding with the computational grid. The governing equations, therefore, can be discretized and solved on a regular mesh thus retaining the advantages and the efficiency of the standard solution procedures. Two different forcings are tested showing that while the quality of the results is essentially the same in both cases, the efficiency of the calculation strongly depends on the particular expression. A major issue is the interpolation of the forcing over the grid that determines the accuracy of the scheme; this ranges from zeroth-order for the most commonly used interpolations up to second-order for an ad hoc velocity interpolation. The present scheme has been used to simulate several hows whose results have been validated by experiments and other results available in the literature. Finally in the last example we show the flow inside an IC piston/cylinder assembly at high Reynolds number; to our knowledge this is the first example in which the immersed boundary technique is applied to a full three-dimensional complex how with moving boundaries and with a Reynolds number high enough to require a subgrid-scale turbulence model. (C) 2000 Academic Press. C1 Univ Rome La Sapienza, Dipartimento Meccan & Aeronaut, I-00184 Rome, Italy. Politecn Bari, Ist Macchine & Energet, I-70125 Bari, Italy. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fadlun, EA (reprint author), Univ Rome La Sapienza, Dipartimento Meccan & Aeronaut, Via Eudossiana 18, I-00184 Rome, Italy. RI VERZICCO, ROBERTO/K-7496-2015 OI VERZICCO, ROBERTO/0000-0002-2690-9998 NR 27 TC 710 Z9 730 U1 9 U2 128 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUN 10 PY 2000 VL 161 IS 1 BP 35 EP 60 DI 10.1006/jcph.2000.6484 PG 26 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 323HY UT WOS:000087561000003 ER PT J AU Ulitsky, M Collins, LR AF Ulitsky, M Collins, LR TI On constructing realizable, conservative mixed scalar equations using the eddy-damped quasi-normal Markovian theory SO JOURNAL OF FLUID MECHANICS LA English DT Article ID HOMOGENEOUS AXISYMMETRIC TURBULENCE; HIGH REYNOLDS-NUMBER; PASSIVE SCALAR; DIFFERENTIAL DIFFUSION; ISOTROPIC TURBULENCE; EVOLUTION AB The eddy-damped quasi-normal Markovian (EDQNM) turbulence theory has been applied to the covariance spectrum of two passive isotropic scalers with different diffusivities in stationary isotropic turbulence A rigorous application of EDQNM, which introduces no new modelling assumptions or constants, is shown to yield a covariance spectrum that violates the Cauchy-Schwartz inequality over some of the wavenumbers. One approach to this problem is to derive a model based on a stochastic differential equation, as its presence guarantees realizability. For an isotropic scalar, it is possible to construct a Langevin equation for the Fourier transform of the scalar concentrations that is consistent with each EDQNM scalar autocorrelation spectrum. The Langevin equations can then be used to construct a model for the covariance spectrum that is realizable. However, the resulting covariance transfer term does not properly conserve the scalar covariance, and so the model is still not satisfactory. The problem can be traced to the Markovianization step, which leads to the presence of the scalar diffusivities in the transfer functions in an unphysical fashion. A simple fix is described which reconciles the two approaches and gives conservative, realizable results for all time. Next, we apply the EDQNM theory to a more general system involving the mixing of anisotropic scalars. Anisotropy in this case results from a uniform mean gradient of the two scalar concentrations in one direction. As with the isotropic scalars, direct application of the EDQNM closure results in a covariance spectrum that violates the Cauchy-Schwartz inequality; however, in this case it is not as simple to construct a Langevin model that reproduces all of the spectral interactions that result from the EDQNM procedure. Nevertheless, we show that the same modification of the inverse time scale as is done for the isotropic scalar results in an anisotropic scalar covariance spectrum that is realizable for all times. C1 Univ Calif Los Alamos Natl Lab, Grp T 3, Los Alamos, NM 87545 USA. Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA. RP Collins, LR (reprint author), Univ Calif Los Alamos Natl Lab, Grp T 3, MS B216, Los Alamos, NM 87545 USA. NR 31 TC 11 Z9 11 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JUN 10 PY 2000 VL 412 BP 303 EP 329 DI 10.1017/S0022112000008363 PG 27 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 329JY UT WOS:000087904900012 ER PT J AU Devaux, JP Fleitout, L Schubert, G Anderson, C AF Devaux, JP Fleitout, L Schubert, G Anderson, C TI Stresses in a subducting slab in the presence of a metastable olivine wedge SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SPINEL TRANSFORMATION; PHASE-TRANSITIONS; OCEANIC LITHOSPHERE; DEEP EARTHQUAKES; DESCENDING SLAB; MANTLE; BUOYANCY; KINETICS; EVOLUTION AB The transformation of olivine to spinel in a subducting slab gives rise to thermal strain, transformation strain, and buoyancy forces inside the slab. We use a finite element method to solve the mechanical equation, and we follow the evolution of the stresses inside the slab during its descent. We use two different rheologies: elastic and viscoelastic with a viscosity that depends on pressure, temperature, and grain size. The stresses due to buoyancy are found to be negligible compared to the internal stresses due to the phase transformation. When the viscoelastic rheology is used, a zone of very high differential stress coincides with the olivine-spinel phase boundary. This zone is associated with large downdip compressive stresses inside the metastable olivine wedge, and large downdip tensile stresses in the spinel region, along the wedge. If we assume that the failure criterion can be related to the differential stress, our model is in agreement with the patterns of deep seismicity. However. patterns of deep seismicity are unlikely to reflect buoyancy stresses, which in the presence of a metastable olivine wedge, are negligible compared to the internal stresses. C1 Ecole Normale Super, CNRS, URA 1316, F-75231 Paris 05, France. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA USA. RP Devaux, JP (reprint author), Ecole Normale Super, CNRS, URA 1316, 24 Rue Lhomond, F-75231 Paris 05, France. EM devaux@jadeite.ens.fr; fleitout@jadeite.ens.fr; schubert@ucla.edu; derson@lanl.gov NR 26 TC 12 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 2000 VL 105 IS B6 BP 13365 EP 13373 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 324NJ UT WOS:000087628000012 ER PT J AU Zasada, I Van Hove, MA AF Zasada, I Van Hove, MA TI Refinement of the Pd(111)+(root 3x root 3)R30 degrees-CO structure using automated tensor LEED SO SURFACE SCIENCE LA English DT Letter DE carbon monoxide; catalysis; chemisorption; low energy electron diffraction (LEED); low index single crystal surfaces; palladium; single crystal surfaces; surface chemical reaction; surface relaxation and reconstruction ID SURFACE-STRUCTURES; PD(111); CO; CO/PD(111); ADSORPTION; PHOTOEMISSION; PD AB The structure of Pd(111) + (root 3 x root 3)R30 degrees-CO has been refined using automated tensor LEED, especially to optimize adsorbate-induced relaxations in the substrate. The re-analysis considerably improves the best fit to experiment, while retaining most of the detailed features, compared with the last structural analysis performed on this system by 'conventional' quantitative low-energy electron diffraction (LEED). In particular, this study confirms that CO occupies face-centered cubic hollow sites. Relative to the ideal bulk structure, it finds an expansion of the top Pd-Pd interlayer spacing by 0.05+/-0.04 Angstrom, a negligible expansion of the second Pd-Pd interlayer spacing by 0.01+/-0.06 Angstrom, and a possible lateral enlargement by 0.1+/-0.1 Angstrom of the triangle of palladium atoms around the adsorption site. A somewhat small C-O interlayer spacing of 1.11+/-0.04 Angstrom is observed, and no unambiguous CO tilt from the surface normal is detected. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Lodz, Dept Solid State Phys, PL-90131 Lodz, Poland. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Mailstop 2-100,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 15 TC 19 Z9 19 U1 0 U2 15 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 10 PY 2000 VL 457 IS 3 BP L421 EP L424 DI 10.1016/S0039-6028(00)00471-4 PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 329UN UT WOS:000087927000001 ER PT J AU Gwaltney, SR Head-Gordon, M AF Gwaltney, SR Head-Gordon, M TI A second-order correction to singles and doubles coupled-cluster methods based on a perturbative expansion of a similarity-transformed Hamiltonian SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FULL CCSDT MODEL; ELECTRON CORRELATION; CONFIGURATION-INTERACTION; TRIPLE EXCITATIONS; ENERGY CORRECTIONS; HARTREE-FOCK; 5TH-ORDER; IMPLEMENTATION; GRADIENTS; ORBITALS AB We present a new ansatz for deriving perturbative corrections to single-reference coupled-cluster based methods. The methods are based on a perturbative expansion of the Hamiltonian formed by a similarity transformation of the normal Hamiltonian. These new methods naturally contain triple and quadruple excitations at second order. However, because of a factorization approximation, the cost of the method only scales as n(7). Results are presented for a second-order correction to the optimized-orbital coupled-cluster doubles method [OD(2)]. For cases where the standard CCSD(T) method performs poorly, OD(2) gives significantly improved results. (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 Head-Gordon, M (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Gwaltney, Steven/0000-0003-3833-5087 NR 32 TC 119 Z9 119 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 9 PY 2000 VL 323 IS 1-2 BP 21 EP 28 DI 10.1016/S0009-2614(00)00423-1 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 322YX UT WOS:000087538200004 ER PT J AU Richard, CA Rector, D Macey, P Harper, RM AF Richard, CA Rector, D Macey, P Harper, RM TI Changes in ventral medullary light reflectance during hypercapnia in awake and sleeping cats SO NEUROSCIENCE LETTERS LA English DT Article DE state; carbon dioxide; optical imaging; neural activity; respiration; rapid eye movement ID ANESTHETIZED GOATS; SURFACE-ACTIVITY; CHEMORECEPTORS; SIGNALS; VOLUME; CO2 AB Activity within rostral and intermediate ventral medullary surface areas, measured as 660 nm scattered light changes, was examined in six cats, (five experimental, one control site) following 5% CO2 challenges during waking,quiet sleep, and rapid eye movement (REM) sleep states. Activity declined to hypercapnia in all states, with a smaller decline in quiet sleep compared to waking, and intermediate values in REM sleep, The decline occurred more rapidly, with a shorter latency, during wakefulness, but with a much slower return to baseline than during quiet sleep. During REM sleep, the latency to nadir and recovery were greater than in other states. Regional patterns of activation emerged which differed in extent of activation between states. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved. C1 Univ Calif Los Angeles, Sch Med, Dept Neurobiol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Brain Res Inst, Los Angeles, CA 90095 USA. Univ Calif Irvine, Irvine Med Ctr, Dept Neurol, Orange, CA 92868 USA. Univ Calif Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. RP Harper, RM (reprint author), Univ Calif Los Angeles, Sch Med, Dept Neurobiol, 10833 Le Conte Ave, Los Angeles, CA 90095 USA. OI Macey, Paul/0000-0003-4093-7458 FU NHLBI NIH HHS [HL-22418] NR 20 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3940 J9 NEUROSCI LETT JI Neurosci. Lett. PD JUN 9 PY 2000 VL 286 IS 3 BP 175 EP 178 DI 10.1016/S0304-3940(00)01123-X PG 4 WC Neurosciences SC Neurosciences & Neurology GA 321RX UT WOS:000087469400006 PM 10832013 ER PT J AU Scholl, A AF Scholl, A TI Antiferromagnetism - Taking a very close look at magnetic structures SO SCIENCE LA English DT Editorial Material ID EXCHANGE C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Scholl, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,Mailstop 4-230, Berkeley, CA 94720 USA. RI Scholl, Andreas/K-4876-2012 NR 9 TC 2 Z9 3 U1 0 U2 6 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 9 PY 2000 VL 288 IS 5472 BP 1762 EP 1763 DI 10.1126/science.288.5472.1762 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322HH UT WOS:000087503800036 PM 17836690 ER PT J AU Korber, B Muldoon, M Theiler, J Gao, F Gupta, R Lapedes, A Hahn, BH Wolinsky, S Bhattacharya, T AF Korber, B Muldoon, M Theiler, J Gao, F Gupta, R Lapedes, A Hahn, BH Wolinsky, S Bhattacharya, T TI Timing the ancestor of the HIV-1 pandemic strains SO SCIENCE LA English DT Article ID IMMUNODEFICIENCY-VIRUS TYPE-1; DEFICIENCY SYNDROME AIDS; MAXIMUM-LIKELIHOOD; DNA-SEQUENCES; TRANSMISSION HISTORY; INTERSPECIES TRANSMISSION; ANTIRETROVIRAL THERAPY; PHYLOGENETIC METHODS; POPULATION-DYNAMICS; GENETIC DIVERSITY AB HIV-1 sequences were analyzed to estimate the timing of the ancestral sequence of the main group of HIV-1, the strains responsible for the AIDS pandemic. Using parallel supercomputers and assuming a constant rate of evolution, we applied maximum-likelihood phylogenetic methods to unprecedented amounts of data for this calculation. We validated our approach by correctly estimating the timing of two historically documented points. Using a comprehensive full-length envelope sequence alignment, we estimated the date of the Last common ancestor of the main group of HIV-1 to be 1931 (1915-41). Analysis of a gag gene alignment, subregions of envelope including additional sequences, and a method that relaxed the assumption of a strict molecular clock also supported these results. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. Univ Manchester, Inst Sci & Technol, Dept Math, Manchester M60 1QD, Lancs, England. Univ Alabama, Dept Med & Microbiol, Birmingham, AL 35294 USA. Northwestern Univ, Dept Med, Div Infect Dis, Chicago, IL 60611 USA. RP Korber, B (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Muldoon, Mark/C-7505-2009; Wolinsky, Steven/B-2893-2012; Bhattacharya, Tanmoy/J-8956-2013; OI Bhattacharya, Tanmoy/0000-0002-1060-652X; Wolinsky, Steven/0000-0002-9625-6697; Korber, Bette/0000-0002-2026-5757 FU NIAID NIH HHS [N01 AI 85338, R01 AI 44596]; NICHD NIH HHS [R01-HD37356] NR 99 TC 563 Z9 588 U1 10 U2 83 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 9 PY 2000 VL 288 IS 5472 BP 1789 EP 1796 DI 10.1126/science.288.5472.1789 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322HH UT WOS:000087503800041 PM 10846155 ER PT J AU Hasan, MZ Isaacs, ED Shen, ZX Miller, LL Tsutsui, K Tohyama, T Maekawa, S AF Hasan, MZ Isaacs, ED Shen, ZX Miller, LL Tsutsui, K Tohyama, T Maekawa, S TI Electronic structure of Mott insulators studied by inelastic X-ray scattering SO SCIENCE LA English DT Article ID CHARGE-TRANSFER EXCITATIONS; TRANSITION; SUPERCONDUCTORS; SR2CUO2CL2; ND2CUO4; SPECTRA; SYSTEMS; OXIDES AB The electronic structure of Mott insulators continues to be a major unsolved problem in physics despite more than 50 years of research. Well-developed momentum-resolved spectroscopies such as photoemission or neutron scattering cannot probe the full Mott gap. High-resolution resonant inelastic x-ray scattering revealed dispersive charge excitations across the Mott gap in a high-critical temperature parent cuprate (Ca2CuO2Cl2), shedding Light on the anisotropy of the Mott gap. These charge excitations across the Mott gap can be described within the framework of the Hubbard model. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. RP Hasan, MZ (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, Dept Appl Phys, Stanford, CA 94305 USA. RI HASAN, M. Zahid/D-8237-2012 NR 27 TC 167 Z9 168 U1 2 U2 21 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 9 PY 2000 VL 288 IS 5472 BP 1811 EP 1814 DI 10.1126/science.288.5472.1811 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322HH UT WOS:000087503800046 ER PT J AU Kanfoush, SL Hodell, DA Charles, CD Guilderson, TP Mortyn, PG Ninnemann, US AF Kanfoush, SL Hodell, DA Charles, CD Guilderson, TP Mortyn, PG Ninnemann, US TI Millennial-scale instability of the antarctic ice sheet during the last glaciation SO SCIENCE LA English DT Article ID YOUNGER DRYAS EVENT; NORTH-ATLANTIC; SEA-LEVEL; HEINRICH EVENTS; ICEBERG DISCHARGES; CLIMATE OSCILLATIONS; GLOBAL CLIMATE; GREENLAND ICE; RECORD; OCEAN AB Records of ice-rafted detritus (IRD) concentration in deep-sea cores from the southeast Atlantic Ocean reveal millennial-scale pulses of IRD delivery between 20,000 and 74,000 years ago. Prominent IRD Layers correlate across the Polar Frontal Zone, suggesting episodes of Antarctic Ice Sheet instability. Carbon isotopes (delta(13)C) of benthic foraminifers, a proxy of deepwater circulation, reveal that South Atlantic IRD events coincided with strong increases in North Atlantic Deep Water (NADW) production and inferred warming (interstadials) in the high-latitude North Atlantic. Sea level rise or increased NADW production associated with strong interstadials may have resulted in destabilization of grounded ice shelves and possible surging in the Weddell Sea region of West Antarctica. C1 Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Kanfoush, SL (reprint author), Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA. RI Mortyn, P. Graham/I-3860-2015 OI Mortyn, P. Graham/0000-0002-9473-4309 NR 49 TC 127 Z9 131 U1 1 U2 16 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 9 PY 2000 VL 288 IS 5472 BP 1815 EP 1818 DI 10.1126/science.288.5472.1815 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322HH UT WOS:000087503800047 ER PT J AU Twine, TE Kustas, WP Norman, JM Cook, DR Houser, PR Meyers, TP Prueger, JH Starks, PJ Wesely, ML AF Twine, TE Kustas, WP Norman, JM Cook, DR Houser, PR Meyers, TP Prueger, JH Starks, PJ Wesely, ML TI Correcting eddy-covariance flux underestimates over a grassland SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE eddy-covariance; friction velocity; evapotranspiration flux ID LATENT-HEAT FLUX; WATER-VAPOR; BOWEN-RATIO; ENERGY-BALANCE; CARBON-DIOXIDE; PINE FOREST; SURFACE; EXCHANGES; SYSTEMS; ERRORS AB Independent measurements of the major energy balance flux components are not often consistent with the principle of conservation of energy. This is referred to as a lack of closure of the surface energy balance. Most results in the literature have shown the sum of sensible and latent heat fluxes measured by eddy covariance to be less than the difference between net radiation and soil heat fluxes. This under-measurement of sensible and latent heat fluxes by eddy-covariance instruments has occurred in numerous field experiments and among many different manufacturers of instruments. Four eddy-covariance systems consisting of the same models of instruments were set up side-by-side during the Southern Great Plains 1997 Hydrology Experiment and all systems under-measured fluxes by similar amounts. One of these eddy-covariance systems was collocated with three other types of eddy-covariance systems at different sites; all of these systems under-measured the sensible and latent-heat fluxes. The net radiometers and soil heat flux plates used in conjunction with the eddy-covariance systems were calibrated independently and measurements of net radiation and soil heat flux showed little scatter for various sites. The 10% absolute uncertainty in available energy measurements was considerably smaller than the systematic closure problem in the surface energy budget, which varied from 10 to 30%. When available-energy measurement errors are known and modest, eddy-covariance measurements of sensible and latent heat fluxes should be adjusted for closure. Although the preferred method of energy balance closure is to maintain the Bowen-ratio, the method for obtaining closure appears to be less important than assuring that eddy-covariance measurements are consistent with conservation of energy. Based on numerous measurements over a sorghum canopy, carbon dioxide fluxes, which are measured by eddy covariance, are underestimated by the same factor as eddy covariance evaporation measurements when energy balance closure is not achieved. Published by Elsevier Science B.V. C1 Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. USDA ARS, Hydrol Lab, Beltsville, MD 20705 USA. Univ Wisconsin, Dept Soil Sci, Madison, WI 53706 USA. Argonne Natl Lab, Argonne, IL 60439 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Oak Ridge Natl Lab, NOAA, Atmospher Turbulence & Diffus, Oak Ridge, TN 37831 USA. USDA ARS, Natl Soil Tilth Lab, Ames, IA 50011 USA. USDA ARS, Grazinglands Res Lab, El Reno, OK 73036 USA. RP Twine, TE (reprint author), Univ Wisconsin, Dept Atmospher & Ocean Sci, 1225 W Dayton St, Madison, WI 53706 USA. RI Twine, Tracy/H-2337-2013; Houser, Paul/J-9515-2013; Meyers, Tilden/C-6633-2016 OI Twine, Tracy/0000-0002-8457-046X; Houser, Paul/0000-0002-2991-0441; NR 40 TC 805 Z9 855 U1 8 U2 125 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD JUN 8 PY 2000 VL 103 IS 3 BP 279 EP 300 DI 10.1016/S0168-1923(00)00123-4 PG 22 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 322VQ UT WOS:000087530300004 ER PT J AU Bickham, SR Kress, JD Collins, LA AF Bickham, SR Kress, JD Collins, LA TI Molecular dynamics simulations of shocked benzene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; TIGHT-BINDING; HIGH-PRESSURE; COSMOCHEMICAL SIGNIFICANCE; IMPACT SHOCK; WAVES AB The behavior of benzene at high temperatures and pressures is studied using nonequilibrium molecular dynamics. The interatomic forces were generated using linear-scaling tight-binding electronic structure theory on systems containing 128 and 576 molecules. The shock Hugoniot, calculated directly from the simulations without predetermining the equation of state, is compared with experiment. Piston velocities of 4 km/s or greater result in a pressure-induced polymerization. This transition is consistent with the bend in the experimental measurements of shock versus piston velocity. (C) 2000 American Institute of Physics. [S0021-9606(00)02320-5]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Corning Inc, Corning, NY 14831 USA. RP Bickham, SR (reprint author), Corning Inc, Corning, NY 14831 USA. NR 20 TC 27 Z9 27 U1 2 U2 15 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 8 PY 2000 VL 112 IS 22 BP 9695 EP 9698 DI 10.1063/1.481605 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 319MV UT WOS:000087346500002 ER PT J AU Rodriguez, JA Jirsak, T Sambasivan, S Fischer, D Maiti, A AF Rodriguez, JA Jirsak, T Sambasivan, S Fischer, D Maiti, A TI Chemistry of NO2 on CeO2 and MgO: Experimental and theoretical studies on the formation of NO3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FIRST-PRINCIPLES DETERMINATION; DENSITY-FUNCTIONAL THEORY; TOTAL-ENERGY CALCULATIONS; AB-INITIO CALCULATIONS; NITROGEN-DIOXIDE; BONDING MECHANISM; ADSORPTION ENERGY; MGO(100) SURFACE; NITRIC-OXIDE; MOLECULAR-DYNAMICS AB In environmental catalysis the destruction or removal of nitrogen oxides (DeNOx process) is receiving a lot of attention. Synchrotron-based x-ray absorption near-edge spectroscopy, high-resolution photoemission, and first-principles density-functional calculations (DFT-GGA) were used to study the interaction of nitrogen dioxide with CeO2 and MgO. The only product of the reaction of NO2 with pure CeO2 at 300 K is adsorbed nitrate. The NO3 is a thermally stable species which mostly decomposes at temperatures between 450 and 600 K. For the adsorption of NO2 on partially reduced ceria (CeO2-x), there is full decomposition of the adsorbate and a mixture of N, NO, and NO3 coexists on the surface of the oxide at room temperature. Ce3+ cations can assist in the transformation of NO and NO2 in DeNOx operations. Adsorbed NO3 (main product) and NO2 are detected after exposing MgO to NO2 gas. A partial NO2,ads-->NO3,ads transformation is observed on MgO(100) from 150 to 300 K. DFT-GGA calculations show strong bonding interactions for NO2 on Mg sites of this surface, and dicoordination via O, O is more favorable energetically than monocoordination via N. The NO2,ads species disappears from magnesium oxide at temperatures below 600 K, whereas part of the NO3,ads is stable up to temperatures near 800 K. MgO can be very useful as a sorbent for trapping NO2. A general trend is found after comparing the chemical behavior of NO2 on different types of oxides (CeO2, MgO, TiO2, Fe2O3, CuO, ZnO). On all these systems, the main product after adsorbing NO2 at 300 K is nitrate with minor amounts of chemisorbed NO2 and no signs of full decomposition of the adsorbate. This trend and the results of DFT-GGA calculations indicate that NO2 is very efficient for the nitration (i.e., formation of NO3 as a ligand) of metal centers that are missing O neighbors in oxide surfaces. (C) 2000 American Institute of Physics. [S0021-9606(00)71222-0]. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Mol Simulat Inc, San Diego, CA 92121 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 93 TC 79 Z9 80 U1 5 U2 51 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 8 PY 2000 VL 112 IS 22 BP 9929 EP 9939 AR PII [S0021-9606(00)71222-0] DI 10.1063/1.481629 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 319MV UT WOS:000087346500030 ER PT J AU Boldyrev, AI Li, X Wang, LS AF Boldyrev, AI Li, X Wang, LS TI "Napoleon hat" structure of tetraatomic molecules. A combined photoelectron spectroscopy and ab initio study of CAISi(2)(-) and its neutral SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID SILICON-CARBON CLUSTERS; TETRACOORDINATED PLANAR CARBON; HYPERVALENT 1ST-ROW MOLECULES; GAUSSIAN-BASIS SETS; ELECTRONIC-STRUCTURE; IONIZATION-POTENTIALS; VIBRATIONAL-SPECTRA; INFRARED-SPECTRUM; OXIDE CLUSTERS; MGO CLUSTERS AB We report a combined experimental and theoretical investigation of nonstoichiometric species, CA1Si(2)(-) and its neutral. Photoelectron spectra of CA1Si2- were measured at two photon energies; three major detachment features were observed with a broad ground-state transition. Ab initio calculations were performed on the CA1Si2- anion, which was found to have two low-lying isomers, a cis-C, and a trans-Ct, species, both with a "Napoleon Hat" type of structure. Electron detachment energies from the anions and spectroscopic properties for both the anions and neutrals were calculated. The cis isomer was found to be the ground state by comparing the theoretical results with the experimental measurements. Evidence of the trans isomer was inferred by comparing the theoretical detachment transitions to the experimental spectra. The neutral ground state, resulting from detaching an electron from the cis isomer, was found to undergo a significant geometry change from the "Napoleon Hat'' structure to an "Eiffel Tower" structure, consistent with the broad photodetachment transition of the ground state, whereas the trans isomer maintained the "Napoleon Hat" structure in both its anion and neutral states. The novel "Napoleon Hat" structure was due to a new three-center bond, which involves the three peripheral ligands, and was a general structural feature of a 16-valence-electron tetraatomic species consisting of elements from the first and second series of the periodic table. C1 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Boldyrev, AI (reprint author), Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. RI Boldyrev, Alexander/C-5940-2009 OI Boldyrev, Alexander/0000-0002-8277-3669 NR 111 TC 5 Z9 5 U1 0 U2 1 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 8 PY 2000 VL 104 IS 22 BP 5358 EP 5365 DI 10.1021/jp000262n PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 347RT UT WOS:000088943500027 ER PT J AU Feng, JL Matchev, KT Wilczek, F AF Feng, JL Matchev, KT Wilczek, F TI Neutralino dark matter in focus point supersymmetry SO PHYSICS LETTERS B LA English DT Article ID STANDARD MODEL; RELIC DENSITY; EVENT RATES; PRECISION CORRECTIONS; MINIMAL SUPERGRAVITY; UNIFICATION; MASS; CONSTRAINTS; PARTICLE; COANNIHILATION AB In recent work, it has been argued that multi-TeV masses for scalar superpartners are not unnatural. Indeed, they appear to have significant phenomenological virtues, Here we explore the implications of such 'focus point' supersymmetry for the dark matter problem. We find that constraints on relic densities do not place upper bounds on neutralino or scaler masses. We demonstrate that, in the specific context of minimal supergravity, a cosmologically stable mixed gaugino-Higgsino state emerges as an excellent, robust dark matter candidate. We estimate that, over a wide range of the unknown parameters, the spin-independent proton-neutralino cross sections fall in the range accessible to planned search experiments. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. Fermi Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Feng, JL (reprint author), Inst Adv Study, Sch Nat Sci, Olden Lane, Princeton, NJ 08540 USA. NR 66 TC 297 Z9 297 U1 0 U2 9 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 8 PY 2000 VL 482 IS 4 BP 388 EP 399 DI 10.1016/S0370-2693(00)00512-8 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 326GA UT WOS:000087723300010 ER PT J AU Garten, CT Hamby, DM Schreckhise, RG AF Garten, CT Hamby, DM Schreckhise, RG TI Radiocesium discharges and subsequent environmental transport at the major US weapons production facilities SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE environmental transport; radiocesium; Hanford; Oak Ridge National Laboratory; Savannah River Site ID SEDIMENTS AB Radiocesium is one of the more prevalent radionuclides in the environment as a result of weapons production-related atomic projects in the USA and the former Soviet Union. Radiocesium discharges during the 1950s account for a large fraction of the historical releases from US weapons production facilities. Releases of radiocesium to terrestrial and aquatic ecosystems during the early years of nuclear weapons production provided the opportunity to conduct multidisciplinary studies on the transport mechanisms of this potentially hazardous radionuclide. The major US Department of Energy facilities (Oak Ridge Reservation in Tennessee, Hanford Site near Richland, Washington, and Savannah River Site near Aiken, South Carolina, USA) are located in regions of the country that have different geographical characteristics. The facility siting provided diverse backgrounds for the development of an understanding of environmental factors contributing to the fate and transport of radiocesium. In this paper, we summarize the significant environmental releases of radiocesium in the early years of weapons production and then discuss the historically significant transport mechanisms for Cs-137 at the three facilities that were part of the US nuclear weapons complex. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oregon State Univ, Dept Nucl Engn & Radiat Hlth Phys, Radiat Ctr 130, Corvallis, OR 97331 USA. Oak Ridge Natl Lab, Div Environm Sci, Ecol & Earth Sci Sect, Oak Ridge, TN 37831 USA. Washington State Univ Tri Cities, Environm Sci Program, Richland, WA USA. RP Hamby, DM (reprint author), Oregon State Univ, Dept Nucl Engn & Radiat Hlth Phys, Radiat Ctr 130, Corvallis, OR 97331 USA. EM hambydm@ne.orst.edu RI huang, hongqi/N-1473-2014 NR 73 TC 9 Z9 9 U1 3 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 EI 1879-1026 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD JUN 8 PY 2000 VL 255 IS 1-3 BP 55 EP 73 DI 10.1016/S0048-9697(00)00449-6 PG 19 WC Environmental Sciences SC Environmental Sciences & Ecology GA 326QK UT WOS:000087746100006 PM 10898395 ER PT J AU Lu, YF Fan, HY Doke, N Loy, DA Assink, RA LaVan, DA Brinker, CJ AF Lu, YF Fan, HY Doke, N Loy, DA Assink, RA LaVan, DA Brinker, CJ TI Evaporation-induced self-assembly of hybrid bridged silsesquioxane film and particulate mesophases with integral organic functionality SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MESOPOROUS MATERIALS; CO-CONDENSATION; SILICA; MCM-41; SIEVES; NANOCOMPOSITE; REACTIVITY; FRAMEWORKS; COMPLEX AB We report an evaporation-induced self-assembly procedure to prepare poly(bridged silsesquioxane) thin-film and particulate mesophases that incorporate organic moieties (1-3) into periodic, mesostructured frameworks as molecularly dispersed bridging ligands. Capacitance-voltage measurements along with a variety of structural characterization procedures were performed to begin to elucidate structure-property relationships of this new class of surfactant-templated mesophases. We observed a consistent trend of increasing modulus and hardness and decreasing dielectric constant with substitution of the bridged silsesquioxane (drop Si-(CH2)-Si drop) for siloxane (drop Si-O-Si drop) in the framework. This preliminary evidence suggests that the introduction of integral organic groups into the frameworks of mesoporous materials can result in synergistic properties, promising an unprecedented ability to tune properties and function. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Univ New Mexico, NSF Ctr Microengineered Mat, Albuquerque, NM 87131 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Loy, Douglas/D-4847-2009; LaVan, David/C-3943-2012 OI Loy, Douglas/0000-0001-7635-9958; LaVan, David/0000-0002-1952-0028 NR 27 TC 433 Z9 440 U1 6 U2 87 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 7 PY 2000 VL 122 IS 22 BP 5258 EP 5261 DI 10.1021/ja9935862 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 322ZU UT WOS:000087540500004 ER PT J AU Kast, AP AF Kast, AP TI Optimal prediction of stiff oscillatory mechanics SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID QUANTUM LANGEVIN EQUATION; DYNAMICS AB We consider many-body problems in classical mechanics where a wide range of time scales limits what can be computed. We apply the method of optimal prediction to obtain equations that are easier to solve numerically. We demonstrate by examples that optimal prediction can reduce the amount of computation needed to obtain a solution by several orders of magnitude. C1 Lawrence Berkeley Natl Lab, Appl Numer Algorithms Grp, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, Appl Numer Algorithms Grp, Berkeley, CA 94720 USA. NR 16 TC 6 Z9 6 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 6 PY 2000 VL 97 IS 12 BP 6253 EP 6257 DI 10.1073/pnas.97.12.6253 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322UA UT WOS:000087526300006 PM 10841530 ER PT J AU Sarti, A Malladi, R Sethian, JA AF Sarti, A Malladi, R Sethian, JA TI Subjective surfaces: A method for completing missing boundaries SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ACTIVE CONTOURS; CURVATURE; FRONTS; VISION; FIELDS; MODEL; SHAPE AB We present a model and algorithm for segmentation of images with missing boundaries. In many situations. the human visual system fills in missing gaps in edges and boundaries, building and completing information that is not present This presents a considerable challenge in computer vision, since most algorithms attempt to exploit existing data. Completion models, which postulate how to construct missing data, are popular but are often trained and specific to particular images. In this paper, we take the following perspective: We consider a reference point within an image as given and then develop an algorithm that tries to build missing information on the basis of the given point of view and the available information as boundary data to the algorithm. We test the algorithm on some standard images, including the classical triangle of Kanizsa and low signal:noise ratio medical images. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. RP Sarti, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 27 TC 40 Z9 40 U1 1 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 6 PY 2000 VL 97 IS 12 BP 6258 EP 6263 DI 10.1073/pnas.110135797 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322UA UT WOS:000087526300007 PM 10823902 ER PT J AU Hayashi, H Watanabe, N Udagawa, Y Kao, CC AF Hayashi, H Watanabe, N Udagawa, Y Kao, CC TI The complete optical spectrum of liquid water measured by inelastic x-ray scattering SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SPECTROSCOPY; SIMULATION; ELECTRONS; ATOMS AB Interaction of light with matter is of paramount importance in nature. The most fundamental property of a material in relation to light is its oscillator strength distribution, i.e., how strongly it absorbs light as a function of wavelength. Once the oscillator strength distribution is determined precisely for a wide enough energy range, the optical constants such as absorbance and reflectance as well as a number of other properties of the material, some of which are seemingly unrelated to photoabsorption, can be deduced. Most important of all is the fact that the interaction of matter with fast charged particles can be described by its complete optical spectra [Inokuti, M. (1986) Photochem, Photobiol. 44, 279-285], Despite their importance, however, the complete optical spectra of volatile liquids including water have never been obtained accurately because of experimental difficulties inherent in vacuum UV spectroscopy. Inelastic x-ray scattering spectroscopy can provide quantitative data equivalent to those from vacuum UV absorption spectra, Herein, we show the complete optical spectrum of liquid water determined by making use of intense monochromatic x-rays supplied by the wiggler line X21 of the National synchrotron Light source. C1 Tohoku Univ, Sci Measurements Res Inst, Aoba Ku, Sendai, Miyagi 9808577, Japan. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Hayashi, H (reprint author), Tohoku Univ, Sci Measurements Res Inst, Aoba Ku, Katahira 2-1-1, Sendai, Miyagi 9808577, Japan. EM hayashi@bnlls1.nls.bnl.gov OI Hayashi, Hisashi/0000-0002-8504-4066 NR 20 TC 114 Z9 116 U1 3 U2 14 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 6 PY 2000 VL 97 IS 12 BP 6264 EP 6266 DI 10.1073/pnas.110572097 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322UA UT WOS:000087526300008 PM 10829074 ER PT J AU Friddle, CJ Koga, T Rubin, EM Bristow, J AF Friddle, CJ Koga, T Rubin, EM Bristow, J TI Expression profiling reveals distinct sets of genes altered during induction and regression of cardiac hypertrophy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID LEFT-VENTRICULAR HYPERTROPHY; ADULT MICE; PATTERNS; MYOCYTES; GROWTH; CARDIOMYOCYTES; ACTIVATION; HEART; RAT; DIFFERENTIATION AB Although cardiac hypertrophy has been the subject of intensive investigation, regression of hypertrophy has been significantly less studied, precluding large-scale analysis of the relationship between these processes. In the present study, using pharmacological models of cardiac hypertrophy in mice, expression profiling was performed with fragments of more than 4,000 genes to characterize and contrast expression changes during induction and regression of hypertrophy. Administration of angiotensin II and isoproterenol by osmotic minipump produced increases in heart weight (15 and 45%, respectively) that returned to preinduction size after drug withdrawal. From multiple expression analyses of left ventricular RNA isolated at daily time-points during cardiac hypertrophy and regression, we identified sets of genes whose expression was altered at specific stages of this process. While confirming the participation of 25 genes or pathways previously shown to be altered by hypertrophy, a larger set of 30 genes was identified whose expression had not previously been associated with cardiac: hypertrophy or regression. Of the 55 genes that showed reproducible changes during the time course of induction and regression. 32 genes were altered only during induction, and 8 were altered only during regression. This study identified both known and novel genes whose expression is affected at different stages of cardiac hypertrophy and regression and demonstrates that cardiac remodeling during regression utilizes a set of genes that are distinct from those used during induction of hypertrophy. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94118 USA. RP Bristow, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, 84-255,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL 63897-01] NR 46 TC 150 Z9 152 U1 0 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JUN 6 PY 2000 VL 97 IS 12 BP 6745 EP 6750 DI 10.1073/pnas.100127897 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 322UA UT WOS:000087526300092 PM 10829065 ER PT J AU Zakeri, G Philpott, AB Ryan, DM AF Zakeri, G Philpott, AB Ryan, DM TI Inexact cuts in benders decomposition SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE stochastic programming; Benders decomposition; inexact cuts ID ALGORITHMS AB Benders decomposition is a well-known technique for solving large linear programs with a special structure. In particular, it is a popular technique for solving multistage stochastic linear programming problems. Early termination in the subproblems generated during Benders decomposition (assuming dual feasibility) produces valid cuts that are inexact in the sense that they are not as constraining as cuts derived from an exact solution. We describe an inexact cut algorithm, prove its convergence under easily verifiable assumptions, and discuss a corresponding Dantzig-Wolfe decomposition algorithm. The paper is concluded with some computational results from applying the algorithm to a class of stochastic programming problems that arise in hydroelectric scheduling. C1 Argonne Natl Lab, Math Sci Div, Argonne, IL 60439 USA. Univ Auckland, Dept Engn Sci, Operat Res Grp, Auckland, New Zealand. RP Zakeri, G (reprint author), Argonne Natl Lab, Math Sci Div, Argonne, IL 60439 USA. NR 19 TC 20 Z9 20 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PD JUN 6 PY 2000 VL 10 IS 3 BP 643 EP 657 DI 10.1137/S1052623497318700 PG 15 WC Mathematics, Applied SC Mathematics GA 321JH UT WOS:000087452000002 ER PT J AU Mao, SS Mao, XL Greif, R Russo, RE AF Mao, SS Mao, XL Greif, R Russo, RE TI Simulation of a picosecond laser ablation plasma SO APPLIED PHYSICS LETTERS LA English DT Article ID HEAT-TRANSFER; DYNAMICS; METALS AB A theoretical model has been developed to simulate plasma formation and evolution during the early stage of picosecond laser ablation of solids. Surface electron emission was implemented as one boundary condition for plasma development above the target. The simulation results indicate that a plasma forms, with electron density on the order of 10(20)cm(-3), during the picosecond laser pulse. Laser induced gas breakdown assisted by electron emission from the target was found to be the origin of the plasma. In agreement with experimental measurements, longitudinal movement of the electrons inside the plasma was suppressed after the laser pulse. The suppression of the plasma can be attributed to the development of a strong electric field above the target. (C) 2000 American Institute of Physics. [S0003-6951(00)03923-1]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Russo, RE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 13 TC 28 Z9 28 U1 0 U2 9 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 5 PY 2000 VL 76 IS 23 BP 3370 EP 3372 DI 10.1063/1.126651 PG 3 WC Physics, Applied SC Physics GA 323FN UT WOS:000087554500012 ER PT J AU Jadwisienczak, WM Lozykowski, HJ Perjeru, F Chen, H Kordesch, M Brown, IG AF Jadwisienczak, WM Lozykowski, HJ Perjeru, F Chen, H Kordesch, M Brown, IG TI Luminescence of Tb ions implanted into amorphous AlN thin films grown by sputtering SO APPLIED PHYSICS LETTERS LA English DT Article ID VISIBLE CATHODOLUMINESCENCE; ER AB We report the observation of visible cathodoluminescence (CL) of Tb ions implanted into amorphous AIN films produced by sputtering. The implanted samples, were subjected to thermal annealing treatment up to 1100 degrees C to optically activate the incorporated ions. The results show that up to 1000 degrees C annealing temperature the films remain amorphous and the Tb3+ emission intensity increases. The amorphous AIN:Tb films were characterized by x-ray diffraction, CL, and CL kinetics measurements. The sharp characteristic emission lines corresponding to intra-4f(n)-shell transitions are resolved in the spectral range from 350 to 750 nm, and observed over the temperature range from 7 to 330 K due to the transitions from D-5(3) and D-5(4) levels reward the F-5(J) (J = 2 to 6) multiplets. Finally, CL kinetics measurements have revealed that decay times of D-3(3) -->F-7(J) and D-5(4)-->F-7(J) transitions are in the range 0.94-0.77 and 0.49-1.61 ms at 300 K, respectively. (C) 2000 American Institute of Physics. [S0003-6951(00)02223-3]. C1 Ohio Univ, Sch Elect Engn & Comp Sci, Stocker Ctr, Athens, OH 45701 USA. Ohio Univ, Dept Phys & Astron, Clippinger Labs, Athens, OH 45701 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Jadwisienczak, WM (reprint author), Ohio Univ, Sch Elect Engn & Comp Sci, Stocker Ctr, Athens, OH 45701 USA. NR 8 TC 47 Z9 51 U1 1 U2 7 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 5 PY 2000 VL 76 IS 23 BP 3376 EP 3378 DI 10.1063/1.126652 PG 3 WC Physics, Applied SC Physics GA 323FN UT WOS:000087554500014 ER PT J AU Kalyanaraman, R Haynes, TE Venezia, VC Jacobson, DC Gossmann, HJ Rafferty, CS AF Kalyanaraman, R Haynes, TE Venezia, VC Jacobson, DC Gossmann, HJ Rafferty, CS TI Quantification of excess vacancy defects from high-energy ion implantation in Si by Au labeling SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON; DIFFUSION; CLUSTERS; DAMAGE; GOLD AB It has been shown recently that Au labeling [V. C. Venezia, D. J. Eaglesham, T. E. Haynes, A. Agarwal, D. C. Jacobson, H.-J. Gossmann, and F. H. Baumann, Appl. Phys. Lett. 73, 2980 (1998)] can be used to profile vacancy-type defects located near half the projected range (1/2R(p)) in MeV-implanted Si. In this letter, we have determined the ratio of vacancies annihilated to Au atoms trapped (calibration factor ''k'') for the Au-labeling technique. The calibration experiment consisted of three steps: (1) a 2 MeV Si+ implant into Si(100) followed by annealing at 815 degrees C to form stable excess vacancy defects; (2) controlled injection of interstitials in the 1/2R(p) region of the above implant via 600 keV Si+ ions followed by annealing to dissolve the {311} defects; and (3) Au labeling. The reduction in An concentration in the near-surface region (0.1-1.6 mu m) with increasing interstitial injection provides the most direct evidence so far that An labeling detects the vacancy-type defects. By correlating this reduction in Au with the known number of interstitials injected, it was determined that k = 1.2+/-0.2 vacancies per trapped Au atom. (C) 2000 American Institute of Physics. [S0003-6951(00)00723-3]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Kalyanaraman, R (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Haynes, Tony/P-8932-2015; OI Haynes, Tony/0000-0003-2871-4745; kalyanaraman, ramki/0000-0002-5340-029X NR 15 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 5 PY 2000 VL 76 IS 23 BP 3379 EP 3381 DI 10.1063/1.126653 PG 3 WC Physics, Applied SC Physics GA 323FN UT WOS:000087554500015 ER PT J AU Heuer, JK Okamoto, PR Lam, NQ Stubbins, JF AF Heuer, JK Okamoto, PR Lam, NQ Stubbins, JF TI Relationship between segregation-induced intergranular fracture and melting in the nickel-sulfur system SO APPLIED PHYSICS LETTERS LA English DT Article ID IMPLANTATION; TRANSITION AB The effect of S segregation to grain boundaries on the intergranular embrittlement of Ni has been studied at room temperature using Auger electron spectroscopy and slow strain rate tensile tests. The grain-boundary S concentration was varied by time-controlled annealing of dilute Ni-S alloy specimens at 625 degrees C. The ductile-to-brittle transition in Ni, as determined from percent integranular fracture and reduction-in-area measurements, occurred over a narrow range of S concentrations centered on 15.5+/-3.4 at. % S. This critical S concentration for 50% intergranular fracture of polycrystalline Ni is similar to the 14.2+/-3.3 at. % S required to induce 50% amorphization of single-crystal Ni by S+-ion implantation. This suggests that segregation-induced intergranular fracture, like implantation-induced amorphization, may be a disorder-induced polymorphous melting process. In agreement with experimental observations, the polymorphous melting curve for the Ni-S solid solution on the phase diagram drops rapidly to zero as the alloy composition approaches -18 at. % S. The critical grain-boundary concentration for intergranular fracture, while slightly less, is within experimental error of the concentration predicted for polymorphous melting as well as that measured for ion-implantation-induced amorphization. (C) 2000 American Institute of Physics. [S0003-6951(00)03223-X]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Illinois, Dept Nucl Engn, Urbana, IL 61801 USA. RP Heuer, JK (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 26 Z9 26 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 5 PY 2000 VL 76 IS 23 BP 3403 EP 3405 DI 10.1063/1.126660 PG 3 WC Physics, Applied SC Physics GA 323FN UT WOS:000087554500023 ER PT J AU Benezeth, P Palmer, DA AF Benezeth, P Palmer, DA TI Potentiometric determination of cadmium-acetate complexation in aqueous solutions to 250 degrees C SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on Direct Observation and Measurement of Hydrothermal Reactions held at the 8th VM Goldschmidt Conference CY AUG 30-SEP 03, 1998 CL TOULOUSE, FRANCE SP Geochem Soc, European Assoc Geochem DE potentiometry; cadmium; acetate; formation quotients; thermodynamic properties ID ALIPHATIC ACID ANIONS; OIL-FIELD WATERS; ALUMINUM-ACETATE; THERMODYNAMIC PROPERTIES; STABILITY-CONSTANTS; MAGNESIUM-ACETATE; ORGANIC-COMPLEXES; CALCIUM-ACETATE; HIGH-PRESSURES; TEMPERATURES AB The molal formation quotients of cadmium-acetate complexes were measured potentiometrically (hydrogen-electrode concentration cell) from 50 to 250 degrees C at ionic strengths of 0.1, 0.3, and 1.0 molal in aqueous sodium trifluoromethanesulfonate (NaTr) media. Two cadmium-acetate species, namely Cd(Ac)(+) and Cd(Ac)(2)degrees, were identified by regressional analysis of the data. Their formation quotients were modeled by empirical equations to describe their temperature and ionic strength dependencies. The thermodynamic quantities, obtained by differentiating these equations with respect to temperature at 25 degrees C and at infinite dilution are for Cd(Ac)(+): log K-1 = 1.96 +/- 0.24, Delta H degrees = -17 +/- 17 kJ . mol(-1), Delta S degrees = -21 +/- 53 J . K-1 mol(-1) and Delta Cp degrees = 660 +/- 370 J . K-1 . mol(-1); and for Cd(Ac)(2)degrees: log K-2 = 3.15 +/- 0.10, Delta H degrees = 4 +/- 14 kJ . mol(-1), Delta S degrees = 75 +/- 47 J . K-1 . mol(-1) and Delta Cp degrees = -400 +/- 260 J . K-1 . mol(-1). (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Benezeth, P (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. RI BENEZETH, Pascale/H-7969-2014 OI BENEZETH, Pascale/0000-0002-1841-2383 NR 51 TC 16 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 5 PY 2000 VL 167 IS 1-2 BP 11 EP 24 DI 10.1016/S0009-2541(99)00197-7 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 311HY UT WOS:000086879700003 ER PT J AU Hoffmann, MM Darab, JG Heald, SM Yonker, CR Fulton, JL AF Hoffmann, MM Darab, JG Heald, SM Yonker, CR Fulton, JL TI New experimental developments for in situ XAFS studies of chemical reactions under hydrothermal conditions SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on Direct Observation and Measurement of Hydrothermal Reactions held at the 8th VM Goldschmidt Conference CY AUG 30-SEP 03, 1998 CL TOULOUSE, FRANCE SP Geochem Soc, European Assoc Geochem DE X-ray absorption fine structure spectroscopy (XAFS); hydrothermal solutions; sodium tungstate; nickel bromide; quartz ID X-RAY-ABSORPTION; AQUEOUS SODIUM-CHLORIDE; SUPERCRITICAL WATER; FINE-STRUCTURE; ELEVATED-TEMPERATURES; MOLECULAR-DYNAMICS; HYDRATION; EXAFS; ION; PRESSURES AB New experimental developments for in situ X-ray absorption fine structure spectroscopy (XAFS) studies of hydrothermal systems are described. Improvements in materials of construction and the design of spectroscopic cells have allowed application of XAFS as a powerful method to derive the molecular structures of reacting species. Two different spectroscopic cells are described that are suitable for in situ XAFS studies of aqueous solutions under hydrothermal conditions. One cell consists of a titanium alloy body with a corrosion-resistant platinum-iridium insert and diamond windows for X-ray transmission. Using this cell, XAFS spectra were acquired on aqueous tungstate solutions up to 400 degrees C. The results demonstrate how XAFS can be used to study the speciation of isopolytungstates and their equilibria at high temperatures. Results from model calculations using the FEFF ab initio code are used to explain the observed spectral changes with changes in pH and temperature. The second XAFS cell consists of a simple fused-silica capillary having a 180 mu m inner diameter. High-quality spectra of a 0.2 molal nickel bromide solution were collected in these small capillaries demonstrating the feasibility of the approach to the study of a wide range of geochemical systems. Further, the XAFS spectra show that the nickel bromide solution irreversibly reacts with the fused-silica capillary at 425 degrees C. Based upon these observations, a potential use of the fused-silica capillary is suggested for in situ studies of silicate formation, or, in general, for studies of chemical interactions of hydrothermal brine solutions with quartz. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. RP Fulton, JL (reprint author), Pacific NW Natl Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. EM jl_fulton@pnl.gov NR 43 TC 22 Z9 24 U1 2 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 5 PY 2000 VL 167 IS 1-2 BP 89 EP 103 DI 10.1016/S0009-2541(99)00202-8 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 311HY UT WOS:000086879700008 ER PT J AU Wesolowski, DJ Machesky, ML Palmer, DA Anovitz, LM AF Wesolowski, DJ Machesky, ML Palmer, DA Anovitz, LM TI Magnetite surface charge studies to 290 degrees C from in situ pH titrations SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on Direct Observation and Measurement of Hydrothermal Reactions held at the 8th VM Goldschmidt Conference CY AUG 30-SEP 03, 1998 CL TOULOUSE, FRANCE SP Geochem Soc, European Assoc Geochem DE magnetite; point of zero charge; surface protonation; potentiometric titration ID RUTILE-WATER INTERFACE; ZERO CHARGE; THERMODYNAMIC PROPERTIES; TEMPERATURE-DEPENDENCE; EQUILIBRIUM-CONSTANTS; METAL-OXIDES; ADSORPTION; CHLORIDE; 300-DEGREES-C; 250-DEGREES-C AB The proton-induced surface charge of magnetite was investigated in 0.03 and 0.30 molal sodium trifluoromethanesulfonate solutions from 25 degrees C to 290 degrees C by potentiometric titrations using a stirred hydrogen electrode concentration cell. Pure magnetite with excellent crystallinity was produced by reaction with the Ni/NiO/H2O hydrogen fugacity buffer at 500 degrees C. Inflection points in the 0.03 molal proton sorption isotherms (pH(infl)) at 6.50, 6.24, 5.65, 5.47, 5.31 and 5.55 at temperatures of 50 degrees C, 100 degrees C, 150 degrees C, 200 degrees C, 250 degrees C and 290 degrees C, respectively, were used as estimates of the pristine point of zero charge (pH(ppzc)) for modeling purposes. These pH(infl) values parallel 1/2 pK(w) and agree within the assigned uncertainty (+/-0.3 pH units) at all temperatures with independent estimates of the pH(ppzc) calculated from an extension of 88the revised MUSIC model. The surface charging can be adequately described by a one-pK model with a surface protonation constant fitted to the pH(infl) values, and giving the standard state thermodynamic properties log K-H,K-298 = 7.00, Delta H(289)degrees = -32.4 +/- 0.8 kJ/mol and constant Delta C-p = 128 +/- 16 J K-1 mol(-1), with Delta S(298)degrees assumed to be equal to that of rutile protonation (25.5 +/- 3.4 J K-1 mol(-1). The 0.03 and 0.30 molal proton sorption isotherms also exhibit pHs of common intersection (pH(cip)) at 6.33, 5.78, 5.37, 4.82, 4.62 and 4.90 at 50 degrees C, 100 degrees C, 150 degrees C, 200 degrees C, 250 degrees C and 290 degrees C, respectively. The difference between the pH(cip) and pH(ppzx) congruent to pH(infl) values can be related to specific binding of Na+ on the negatively charged surface, which increases with increasing temperature, although the pH(infl) values may also be affected by dissolution of the solid. The electrical double layer model includes a basic Stern layer capacitance, with specific cation and anion binding at the Stern layer, and a fixed diffuse layer capacitance computed from Guoy-Chapman theory. To fit the steepness and asymmetry of the charging curves above the pH(ppzc), an additional cation binding constant was invoked, which allows the cation to experience the surface potential. Significant kinetically controlled dissolution of magnetite was observed below the pH(ppzc), which may be a result of leaching of Fe2+ from the surface, to produce a magnetite + hematite assemblage, despite the high hydrogen partial pressures (ca. 10 bars) used in these experiments. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Illinois State Water Survey, Champaign, IL 61820 USA. RP Wesolowski, DJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 60 TC 60 Z9 62 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 5 PY 2000 VL 167 IS 1-2 BP 193 EP 229 DI 10.1016/S0009-2541(99)00209-0 PG 37 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 311HY UT WOS:000086879700016 ER PT J AU Wood, SA Wesolowski, DJ Palmer, DA AF Wood, SA Wesolowski, DJ Palmer, DA TI The aqueous geochemistry of the rare earth elements IX. A potentiometric study of Nd3+ complexation with acetate in 0.1 molal NaCl solution from 25 degrees C to 225 degrees C SO CHEMICAL GEOLOGY LA English DT Article; Proceedings Paper CT Symposium on Direct Observation and Measurement of Hydrothermal Reactions held at the 8th VM Goldschmidt Conference CY AUG 30-SEP 03, 1998 CL TOULOUSE, FRANCE SP Geochem Soc, European Assoc Geochem DE rare earth elements; aqueous geochemistry; potentiometry; acetate ID ALIPHATIC ACID ANIONS; OIL-FIELD WATERS; ALUMINUM-ACETATE; STABILITY-CONSTANTS; THERMAL DECARBOXYLATION; HIGH-PRESSURES; NATURAL-GAS; THEORETICAL PREDICTION; THERMODYNAMIC BEHAVIOR; HYDROTHERMAL SOLUTIONS AB The concentration quotients for the following reactions with acetate have been measured at temperatures from 25 degrees C to 225 degrees C, at saturated water vapor pressure, and in 0.1 molal NaCl medium, using a potentiometric method: Nd3+ + Ac- = NdAc2+ Nd3+ + 2Ac(-) = NdAc2+ The concentration quotients for both of these reactions increase strongly with increasing temperature. The values of these constants obtained at 25 degrees C are in good agreement with those reported in the literature for both NaCl and NaClO4 media, indicating that complexation of Nd3+ by chloride is weak at room temperature. The concentration quotients were corrected for complexation by chloride using experimentally determined stability constants from the literature; these calculations confirmed the lack of a significant effect due to chloride complexation at 25 degrees C, but showed that the effect becomes more important with increasing temperature. Extrapolation of the chloride-corrected concentration quotients to zero ionic strength using an extended Debye-Huckel expression yielded values of the stability constants for the first and second complexation steps that are significantly higher than theoretical estimates reported in the literature. Our data show that Nd-acetate complexes are considerably more stable than Nd-chloride complexes, but that the stability constants for both systems exhibit very similar temperature dependences. In sedimentary basinal brines REE (rare earth elements)-acetate complexes may predominate over REE-chloride complexes, even where chloride is present in greater concentrations than acetate. However, oxalate, fluoride, or carbonate complexes could be more important than either acetate or chloride if the concentrations of the former ligands are relatively high. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Idaho, Dept Geol & Geol Engn, Moscow, ID 83844 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Univ Idaho, Dept Geol & Geol Engn, Moscow, ID 83844 USA. EM swood@iron.mines.uidaho.edu NR 75 TC 40 Z9 41 U1 2 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 EI 1878-5999 J9 CHEM GEOL JI Chem. Geol. PD JUN 5 PY 2000 VL 167 IS 1-2 BP 231 EP 253 DI 10.1016/S0009-2541(99)00210-7 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 311HY UT WOS:000086879700017 ER PT J AU Zamora, PO Osaki, S Som, P Ferretti, JA Choi, JS Hu, CZ Tsang, R Kuan, HM Singletary, S Stern, RA Oster, ZH AF Zamora, PO Osaki, S Som, P Ferretti, JA Choi, JS Hu, CZ Tsang, R Kuan, HM Singletary, S Stern, RA Oster, ZH TI Radiolabeling brachytherapy sources with Re-188 through chelating microfilms: Stents SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE rhenium-188; brachytherapy; stents; radiolabeling; chelate ID PORCINE CORONARY-ARTERIES; ENERGY RESTENOSIS TRIAL; RADIATION-THERAPY; MONOCLONAL-ANTIBODIES; VASCULAR RESTENOSIS; TANTALUM STENTS; BETA-RADIATION; PHARMACOKINETICS; BIODISTRIBUTION; RADIOTHERAPY AB Rhenium-188 (Re-188, T-1/2 = 17 h) emits beta particles (E-max = 2.12 MeV) having an ideal range for intravascular brachytherapy and certain cancer brachytherapies. Re-188 was attached to metal wafers and stents via a chelating microfilm, and these brachytherapy sources characterized in vitro and in vivo. To prepare the sources, a siloxane film containing reactive amines was plasma deposited on the metal, a chelating microfilm conjugated to the amines, and the chelating microfilm used to attach Re-188, Re-188,vas selectively bound to materials coated with the chelating microfilm, Binding correlated with the amount of radionuclide used. Wafers (1 cm(2)) bound up to 62.9 MBq (1.7 mCi) of Re-188 with yields generally near 30%. Stents bound up to 26.6 MBq (720 mu Ci). Typically, stents were labeled to bind 4-12 MBq and deposit 10-30 Gy at 2 mm in the arterial wall. In phantom studies, the longer nitinol stents deposited doses of 2.3 Gy/MBq (0.085 Gy/mu Ci), while shorter stainless steel stents deposited 4.62 Gy/MBq (0.171 Gy/mu Ci). After placement in arteries of pigs, only the Re-188-stents were detected by scintigraphy at times up to 24 h. Scintigraphy did not detect activity in other organs. Blood sampling (0.1-24 h) detected maximum radioactivity (up to 388 cpm/mL/100 mu Ci) at 6 h. We conclude that on-demand radiolabeling of stents and other brachytherapy sources with Re-188 can be performed routinely. (C) 2000 John Wiley & Sons, Inc. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. InnerDyne Inc, Surface Engn Technol Div, Salt Lake City, UT USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Div Lab Anim Resources, Stony Brook, NY 11794 USA. RP Zamora, PO (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490,30 Bell Ave, Upton, NY 11973 USA. NR 36 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD JUN 5 PY 2000 VL 53 IS 3 BP 244 EP 251 DI 10.1002/(SICI)1097-4636(2000)53:3<244::AID-JBM9>3.0.CO;2-F PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 318AF UT WOS:000087260600009 PM 10813764 ER PT J AU Metzner, KJ Jin, X Lee, FV Gettie, A Bauer, DE Di Mascio, M Perelson, AS Marx, PA Ho, DD Kostrikis, LG Connor, RI AF Metzner, KJ Jin, X Lee, FV Gettie, A Bauer, DE Di Mascio, M Perelson, AS Marx, PA Ho, DD Kostrikis, LG Connor, RI TI Effects of in vivo CD8(+) T cell depletion on virus replication in rhesus macaques immunized with a live, attenuated simian immunodeficiency virus vaccine SO JOURNAL OF EXPERIMENTAL MEDICINE LA English DT Article DE simian immunodeficiency virus; live attenuated vaccine; OKT8F; CD8(+) T lymphocytes; differential PCR ID MOLECULAR BEACONS; ANTIBODY-RESPONSES; MUCOSAL INFECTION; DELETION MUTANT; SIV VACCINE; PROTECTION; CHALLENGE; MONKEYS; TYPE-1; LYMPHOCYTES AB The role of CD8(+) T lymphocytes in controlling replication of live, attenuated simian immnunodeficiency virus (SIV) was investigated as part of a vaccine study to examine the correlates of protection in the SIV/rhesus macaque model. Rhesus macaques immunized for >2 yr with nef-deleted SIV (SIVmac239 Delta nef) and protected from challenge with pathogenic SIVmac251 were treated with anti-CD8 antibody (OKT8F) to deplete CD8(+) T cells in vivo. The effects of CD8 depletion on viral load were measured using a novel quantitative assay based on real-time polymerase chain reaction using molecular beacons. This assay allows simultaneous detection of both the vaccine strain and the challenge virus in the same sample, enabling direct quantification of changes in each viral population. Our results show that CD8(+) T cells were depleted within 1 h after administration of OKT8F, and were reduced by as much as 99% in the peripheral blood. CD8(+) T cell depletion was associated with a 1-2 log increase in SIVmac239 Delta nef plasma viremia. Control of SIVmac239 Delta nef replication was temporally associated with the recovery of CD8(+) T cells between days 8 and 10. The challenge virus, SIVmac251, was not detectable in either the plasma or lymph nodes after depletion of CD8(+) T cells. Overall, our results indicate that CD8(+) T cells play an important role in controlling replication of live, attenuated SIV in vivo. C1 Rockefeller Univ, Aaron Diamond AIDS Res Ctr, New York, NY 10016 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Tulane Reg Primate Res Ctr, Covington, LA 70433 USA. RP Connor, RI (reprint author), Rockefeller Univ, Aaron Diamond AIDS Res Ctr, 455 1st Ave,7th Fl, New York, NY 10016 USA. RI Metzner, Karin/G-5319-2011; Kostrikis, Leondios/A-5330-2016 OI Metzner, Karin/0000-0003-4862-1503; Kostrikis, Leondios/0000-0002-5340-7109 FU NCRR NIH HHS [R01 RR006555, RR06555]; NIAID NIH HHS [AI43868] NR 47 TC 113 Z9 113 U1 0 U2 2 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0022-1007 J9 J EXP MED JI J. Exp. Med. PD JUN 5 PY 2000 VL 191 IS 11 BP 1921 EP 1931 PG 11 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA 322UL UT WOS:000087527300010 PM 10839807 ER PT J AU Zweiback, J Ditmire, T Perry, MD AF Zweiback, J Ditmire, T Perry, MD TI Resonance in scattering and absorption from large noble gas clusters SO OPTICS EXPRESS LA English DT Article ID INTENSE LASER-PULSES; ATOMIC CLUSTERS; IONIZATION AB Light scattering in large noble gas clusters irradiated by intense laser pulses was studied and compared to absorption measurements. The scattering signal shows the presence of a peak, when the pulse width was varied, similar to one previously reported in absorption measurements. The peak of the scattering, however, occurs at a longer pulse width than for absorption. This result disagrees with a simple simulation and may be due to propagation or non-linear effects not included in the model. (C) 2000 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Zweiback, J (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808 L-477, Livermore, CA 94550 USA. NR 12 TC 28 Z9 28 U1 2 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD JUN 5 PY 2000 VL 6 IS 12 BP 236 EP 242 PG 7 WC Optics SC Optics GA 320VH UT WOS:000087420900002 PM 19404356 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 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 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 Hauser, J Heinrich, J Heiss, A Herndon, M 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 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 Menzione, A Meschi, E Mesropian, 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 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 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 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 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, 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 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 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 Hauser, J Heinrich, J Heiss, A Herndon, M 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 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 Menzione, A Meschi, E Mesropian, 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 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 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 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 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, F Zucchelli, S CA CDF Collaboration TI Search for scalar top quark production in p)(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID (P)OVER-BAR-P COLLISIONS; ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; NEUTRALINO PRODUCTION; FERMILAB TEVATRON; COLLIDER DETECTOR; HADRON COLLIDERS; CHARGINO; DECAYS; LEP AB We have searched for direct production of scalar top quarks at the Collider Detector at Fermilab in 88 pb(-1) of p (p) over bar collisions at root s = 1.8 TeV. We assume the scalar top quark decays into either a bottom quark and a chargino or a bottom quark, a lepton, and a scalar neutrino. The event signature for both decay scenarios is a lepton, missing transverse energy, and at least two b-quark jets. For a chargino mass of 90 GeV/c(2) and scalar neutrino masses of at least 40 GeV/c(2), we find no evidence for scalar top production and present upper limits on the production cross section in both decay scenarios. 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 Inst Nucl Res, RU-141980 Dubna, Russia. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. 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, Korean Hadron Collider Lab, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. High Energy Accelerator Res Org, KEK, 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; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Prokoshin, Fedor/E-2795-2012; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; vilar, rocio/P-8480-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Prokoshin, Fedor/0000-0001-6389-5399; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 30 TC 28 Z9 28 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 5 PY 2000 VL 84 IS 23 BP 5273 EP 5278 DI 10.1103/PhysRevLett.84.5273 PG 6 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600010 ER PT J AU Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hazumi, M Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hazumi, M Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED TI Search for the decay K-L ->pi(0) mu(+) mu(-) SO PHYSICAL REVIEW LETTERS LA English DT Article ID BRANCHING RATIO AB We report on a search for the decay K-L --> pi(0)mu(+)mu(-) carried out as a part of the KTeV experiment at Fermilab. This decay is expected to have a significant CP violating contribution and a direct measurement will either support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or point to new physics. Two events were observed in the 1997 data with an expected background of 0.87 +/- 0.15 events, and we set an upper limit B (K-L --> pi(0)mu(+)mu(-)) < 3.8 X 10(-10) at the 90% confidence level. C1 Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Toyonaka, Osaka 560, Japan. Rice Univ, Houston, TX 77005 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Bellantoni, L (reprint author), Univ Arizona, Tucson, AZ 85721 USA. RI Albuquerque, Ivone/H-4645-2012 OI Albuquerque, Ivone/0000-0001-7328-0136 NR 21 TC 61 Z9 61 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 5 PY 2000 VL 84 IS 23 BP 5279 EP 5282 DI 10.1103/PhysRevLett.84.5279 PG 4 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600011 ER PT J AU 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 Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E 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 Lange, DJ Morrison, RJ 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 Sadoff, 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 AF 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 Kopp, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Csorna, SE Danko, I McLean, KW Marka, S Xu, Z Godang, R Kinoshita, K Lai, IC Schrenk, S Bonvicini, G Cinabro, D Perera, LP Zhou, GJ Eigen, G Lipeles, E 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 Lange, DJ Morrison, RJ 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 Sadoff, 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 CA CLEO Collaboration TI Study of exclusive radiative B meson decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP VIOLATION; B->S-GAMMA; DETECTOR; PHYSICS; SEARCH; MODEL AB We have studied exclusive, radiative B meson decays to charmless mesons in 9.7 X 10(6) B (B) over bar decays accumulated with the CLEO detector. We measure B(B-0 --> K*(0)(892)gamma) = (4.55(-0.68)(+0.72) +/- 0.34) X 10(-5) and B(B+ --> K*(+)(892)gamma) = (3.76(-0.83)(+0.89) +/- 0.28) X 10(-5). We have searched for CP asymmetry in B --> K*(892)gamma decays and measure A(CP) = + 0.08 +/- 0.13 +/- 0.03. We report the first observation of B --> K-2*(1430)gamma decays with a branching fraction of (1.66(-0.53)(+0.59) +/- 0.13) x 10(-5). No evidence for the decays B --> rho gamma and B-0 --> omega gamma is found and we limit B(B --> (rho/omega)gamma)/B(B --> K*(892)gamma) < 0.32 at 90% C.L. C1 So Methodist Univ, Dallas, TX 75725 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. 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. 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. RP Coan, TE (reprint author), So Methodist Univ, Dallas, TX 75725 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 23 TC 145 Z9 144 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 5 PY 2000 VL 84 IS 23 BP 5283 EP 5287 DI 10.1103/PhysRevLett.84.5283 PG 5 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600012 ER PT J AU Germann, TC Holian, BL Lomdahl, PS Ravelo, R AF Germann, TC Holian, BL Lomdahl, PS Ravelo, R TI Orientation dependence in molecular dynamics simulations of shocked single crystals SO PHYSICAL REVIEW LETTERS LA English DT Article ID WAVE STRUCTURE; FRACTURE AB We use multimillion-atom molecular dynamics simulations to study shock wave propagation in fee crystals. As shown recently, shock waves along the (100) direction form intersecting stacking faults by slippage along (111) close-packed planes at sufficiently high shock strengths. We find even more interesting behavior of shocks propagating in other low-index directions: for the (111) case, an elastic precursor separates the shock front from the slapped (plastic) region. Shock waves along the (110) direction generate a leading solitary wave train, followed (at sufficiently high shock speeds) by an elastic precursor, and then a region of complex plastic deformation. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. RP Germann, TC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 22 TC 125 Z9 127 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 5 PY 2000 VL 84 IS 23 BP 5351 EP 5354 DI 10.1103/PhysRevLett.84.5351 PG 4 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600029 ER PT J AU Bermejo, FJ Kinugawa, K Cabrillo, C Bennington, SM Fak, B Fernandez-Diaz, MT Verkerk, P Dawidowski, J Fernandez-Perea, R AF Bermejo, FJ Kinugawa, K Cabrillo, C Bennington, SM Fak, B Fernandez-Diaz, MT Verkerk, P Dawidowski, J Fernandez-Perea, R TI Quantum effects on liquid dynamics as evidenced by the presence of well-defined collective excitations in liquid para-hydrogen SO PHYSICAL REVIEW LETTERS LA English DT Article ID CENTROID MOLECULAR-DYNAMICS; FORMULATION; TEMPERATURE; PRESSURE; DENSITY; SYSTEMS; PHASE AB The origin of the well-defined collective excitations found in liquid para-H-2 by recent experiments is investigated. The persistence of their relatively long lifetimes down to microscopic scales is well accounted for by calculations carried out by means of path-integral-centroid molecular dynamics. In contrast only overdamped excitations are found in calculations carried within the classical limit. The results provide fully quantitative evidence of quantum effects on the dynamics of a simple liquid. C1 Consejo Super Invest Cient, E-28006 Madrid, Spain. Nara Womens Univ, Dept Chem, Nara 6308506, Japan. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CEA, SPSMS, Dept Rech Fondamentale Matiere Condensee, F-38054 Grenoble, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Interfac Reactor Inst, NL-2629 JB Delft, Netherlands. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bermejo, FJ (reprint author), Consejo Super Invest Cient, Serrano 121-123, E-28006 Madrid, Spain. RI Fernandez-Diaz, Maria Teresa/D-7373-2014; Fernandez-Perea, Ricardo/E-9118-2016 OI Fernandez-Perea, Ricardo/0000-0002-4011-2344 NR 21 TC 75 Z9 75 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 5 PY 2000 VL 84 IS 23 BP 5359 EP 5362 DI 10.1103/PhysRevLett.84.5359 PG 4 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600031 ER PT J AU Homes, CC McConnell, AW Clayman, BP Bonn, DA Liang, RX Hardy, WN Inoue, M Negishi, H Fournier, P Greene, RL AF Homes, CC McConnell, AW Clayman, BP Bonn, DA Liang, RX Hardy, WN Inoue, M Negishi, H Fournier, P Greene, RL TI Phonon screening in high-temperature superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-CRYSTALS; C-AXIS; TRANSPORT-PROPERTIES; OPTICAL-PROPERTIES; ETA-MO4O11; DEPENDENCE; STATE AB In good conductors optical phonons are usually screened, and therefore not observed. However, sharp features due to infrared-active modes in the copper-oxygen planes are observed in the optical conductivity of Pr1.85Ce0.15CuO4 and YBa2Cu3O6.95. Oscillator strengths indicate that the screening of these modes is poor or totally absent. These materials are compared with eta-Mo4O11, in which lattice modes appear suddenly below the charge-density wave transition. It is proposed that poor screening in the cuprates originates from fluctuating charge inhomogeneities in the copper-oxygen planes. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Hiroshima Univ, Grad Sch Adv Sci Matter, Higashihiroshima 7398526, Japan. Univ Maryland, Dept Phys & Astron, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Homes, CC (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 25 TC 30 Z9 30 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 5 PY 2000 VL 84 IS 23 BP 5391 EP 5394 DI 10.1103/PhysRevLett.84.5391 PG 4 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600039 ER PT J AU Guo, R Cross, LE Park, SE Noheda, B Cox, DE Shirane, G AF Guo, R Cross, LE Park, SE Noheda, B Cox, DE Shirane, G TI Origin of the high piezoelectric response in PbZr1-xTixO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTAL ORIENTATION DEPENDENCE; LEAD-ZIRCONATE-TITANATE; FIRST-PRINCIPLES; SINGLE-CRYSTALS; PBTIO3; PHASE; DIFFRACTION AB High resolution x-ray powder diffraction measurements on poled PbZr1-xTixO3 (PZT) ceramic samples close to the rhombohedral-tetragonal phase boundary (the so-called morphotropic phase boundary) have shown that for both rhombohedral and tetragonal compositions the piezoelectric elongation of the unit cell does not occur along the polar directions but along those directions associated with the monoclinic distortion. This work provides the first direct evidence for the origin of the very high piezoelectricity in PZT. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Univ Autonoma Madrid, Dept Fis Mat, E-28049 Madrid, Spain. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Noheda, B (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NR 16 TC 605 Z9 626 U1 48 U2 307 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 5 PY 2000 VL 84 IS 23 BP 5423 EP 5426 DI 10.1103/PhysRevLett.84.5423 PG 4 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600047 ER PT J AU Melnitchouk, W Afnan, IR Bissey, F Thomas, AW AF Melnitchouk, W Afnan, IR Bissey, F Thomas, AW TI Comment on "Parton distributions, d/u, and higher twist effects at high x" SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Adelaide, Special Res Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. Univ Adelaide, Dept Phys & Math Phys, Adelaide, SA 5005, Australia. Jefferson Lab, Newport News, VA 23606 USA. Flinders Univ S Australia, Sch Phys Sci, Bedford Pk, SA 5042, Australia. RP Melnitchouk, W (reprint author), Univ Adelaide, Special Res Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. RI Thomas, Anthony/G-4194-2012 OI Thomas, Anthony/0000-0003-0026-499X NR 4 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 5 PY 2000 VL 84 IS 23 BP 5455 EP 5455 DI 10.1103/PhysRevLett.84.5455 PG 1 WC Physics, Multidisciplinary SC Physics GA 320QJ UT WOS:000087411600055 ER PT J AU Knupp, PM Robidoux, N AF Knupp, PM Robidoux, N TI A framework for variational grid generation: Conditioning the Jacobian matrix with matrix norms SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE variational grid generation; grid generation; Jacobian matrix; metric tensor; matrix norms ID DIRECTIONAL CONTROL AB Functionals for variational grid generation, in which the Jacobian matrix and matrix norms play a central role, are presented. All first-order geometric qualities of a structured grid ( length, area, volume, angle between sides, aspect ratio, grid alignment) are determined by the Jacobian matrix of the induced mapping between the logical and physical regions. Grids with desirable quality can be generated by requiring the Jacobian matrix or the corresponding metric tensor to have certain properties. Functionals can be obtained by integrating over the logical or physical domain a power of the norm of a matrix derived from the Jacobian matrix. A judicious choice of this derived matrix results in a functional whose minima are mappings with desired features. Many well-known grid generators fit in this framework; for example, the harmonic generator arises when one drives the metric tensor toward the identity. The framework provides insight into what grid qualities these functionals describe. Three new directional control functionals are proposed and tested. C1 Sandia Natl Labs, Parallel Comp Sci Dept, Albuquerque, NM 87185 USA. Massey Univ, Math Inst Fundamental Sci, Palmerston North, New Zealand. RP Knupp, PM (reprint author), Sandia Natl Labs, Parallel Comp Sci Dept, M-S 0847,POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 26 Z9 28 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 5 PY 2000 VL 21 IS 6 BP 2029 EP 2047 DI 10.1137/S1064827598341633 PG 19 WC Mathematics, Applied SC Mathematics GA 324UU UT WOS:000087640400006 ER PT J AU Hendrickson, B Kolda, TG AF Hendrickson, B Kolda, TG TI Partitioning rectangular and structurally unsymmetric sparse matrices for parallel processing SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE matrix partitioning; iterative method; parallel computing; rectangular matrix; structurally unsymmetric matrix; bipartite graph ID HERMITIAN LINEAR-SYSTEMS; INFORMATION-RETRIEVAL; ALGORITHM; COMPUTATIONS; GRAPHS AB A common operation in scientific computing is the multiplication of a sparse, rectangular, or structurally unsymmetric matrix and a vector. In many applications the matrix-transpose-vector product is also required. This paper addresses the efficient parallelization of these operations. We show that the problem can be expressed in terms of partitioning bipartite graphs. We then introduce several algorithms for this partitioning problem and compare their performance on a set of test matrices. C1 Sandia Natl Labs, Parallel Comp Sci Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Sandia Natl Labs, Parallel Comp Sci Dept, POB 5800, Albuquerque, NM 87185 USA. EM bah@cs.sandia.gov; tgkolda@sandia.gov RI Kolda, Tamara/B-1628-2009 OI Kolda, Tamara/0000-0003-4176-2493 NR 46 TC 39 Z9 40 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 EI 1095-7197 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUN 5 PY 2000 VL 21 IS 6 BP 2048 EP 2072 DI 10.1137/S1064827598341475 PG 25 WC Mathematics, Applied SC Mathematics GA 324UU UT WOS:000087640400007 ER PT J AU Glimm, J Grove, JW Li, XL Tan, DC AF Glimm, J Grove, JW Li, XL Tan, DC TI Robust computational algorithms for dynamic interface tracking in three dimensions SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE front tracking; FronTier; interface; Rayleigh-Taylor ID RAYLEIGH-TAYLOR INSTABILITY; RICHTMYER-MESHKOV INSTABILITY; FRONT TRACKING; UNSTABLE INTERFACES; SIMULATION; WAVES AB Front tracking provides sharp resolution of wave fronts through the active tracking of interfaces between distinct materials. A major challenge to this method is to handle changes in the interface topology. We describe two algorithms, implemented in the front tracking code FronTier, to model dynamic changes in three-dimensional interfaces. The two methods can be combined to give a hybrid method that is superior to each individual method. The success of these algorithms is shown by simulations of Rayleigh Taylor instability, which is an interfacial instability driven by an acceleration directed across a material interface. Our numerical results are validated by comparing the numerical computation of the velocity of a single rising bubble with an analytic model for the bubble velocity. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Hydrodynam Methods Grp, Los Alamos, NM 87545 USA. RP Glimm, J (reprint author), SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. NR 23 TC 95 Z9 97 U1 0 U2 7 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 5 PY 2000 VL 21 IS 6 BP 2240 EP 2256 DI 10.1137/S1064827598340500 PG 17 WC Mathematics, Applied SC Mathematics GA 324UU UT WOS:000087640400017 ER PT J AU Simon, HD Zha, HY AF Simon, HD Zha, HY TI Low-rank matrix approximation using the Lanczos bidiagonalization process with applications SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE singular value decomposition; space matrices; Lanczos algorithms; low-rank approximation ID SINGULAR-VALUES; ALGORITHM; REORTHOGONALIZATION; VECTORS AB Low-rank approximation of large and/or sparse matrices is important in many applications, and the singular value decomposition (SVD) gives the best low-rank approximations with respect to unitarily-invariant norms. In this paper we show that good low-rank approximations can be directly obtained from the Lanczos bidiagonalization process applied to the given matrix without computing any SVD. We also demonstrate that a so-called one-sided reorthogonalization process can be used to maintain an adequate level of orthogonality among the Lanczos vectors and produce accurate low-rank approximations. This technique reduces the computational cost of the Lanczos bidiagonalization process. We illustrate the efficiency and applicability of our algorithm using numerical examples from several applications areas. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. Penn State Univ, Dept Comp Sci & Engn, University Pk, PA 16802 USA. RP Simon, HD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. NR 20 TC 48 Z9 49 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 5 PY 2000 VL 21 IS 6 BP 2257 EP 2274 DI 10.1137/S1064827597327309 PG 18 WC Mathematics, Applied SC Mathematics GA 324UU UT WOS:000087640400018 ER PT J AU Lubin, MI Bylaska, EJ Weare, JH AF Lubin, MI Bylaska, EJ Weare, JH TI Ab initio molecular dynamics simulations of aluminum ion solvation in water clusters SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CATIONS; SPECTRA; MODEL; AL3+; BE2+ AB The results of ab initio molecular dynamics simulations of the solvation of Al3+ and its hydrolyzation products in water clusters are reported. Al3+ ions in water clusters (6 less than or equal to n less than or equal to 16) form a stable hexa-hydrate Al(H2O)(6)(3+) complex in finite temperature simulations. The deprotonated Al(H2O)(2)(OH)(4)(-) complex evolves into a tetra-coordinated Al(OH)(4)(-) aluminate ion with two water molecules in the second cluster solvation shell. The influence of a strong polarization of the OH bonds in the first solvation shell on the proton transfer mechanism is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Lubin, MI (reprint author), Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. EM mlubin@ucsd.edu NR 30 TC 49 Z9 50 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 2 PY 2000 VL 322 IS 6 BP 447 EP 453 DI 10.1016/S0009-2614(00)00434-6 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 320BK UT WOS:000087381000001 ER PT J AU Feller, D AF Feller, D TI A complete basis set estimate of cation-pi bond strengths: Na+(ethylene) and Na+(benzene) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; ALKALI-METAL CATIONS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; GAS-PHASE; AB-INITIO; SYSTEMATIC SEQUENCES; HYDROGEN-BOND; WATER DIMER; IONS AB Large-scale second-order perturbation theory and couple-cluster theory calculations were performed on the Na+(ethylene) and Naf(benzene) complexes in an effort to estimate binding enthalpies in the complete basis set limit. The resulting best estimates are Delta H-0[Na+(ethylene)] = - 13.6 +/- 0.2 kcal/mol and Delta H-0[Na+ (benzene)] = -24.4 +/- 0.3 kcal/mol, which include small corrections for core/valence correlation effects. The former value can be compared to a measurement of -10.3 +/- 1.0 kcal/mol obtained from collision-induced dissociation, while the latter value is approximately midway between the two existing experimental values which differ by 6.5 kcal/mol. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Feller, D (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-91,POB 999, Richland, WA 99352 USA. NR 31 TC 89 Z9 89 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 2 PY 2000 VL 322 IS 6 BP 543 EP 548 DI 10.1016/S0009-2614(00)00449-8 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 320BK UT WOS:000087381000014 ER PT J AU Schild, D Lio, YC Collins, DW Tsomondo, T Chen, DJ AF Schild, D Lio, YC Collins, DW Tsomondo, T Chen, DJ TI Evidence for simultaneous protein interactions between human Rad51 paralogs SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID DNA-REPAIR GENE; HOMOLOGOUS RECOMBINATION; MAMMALIAN-CELLS; IONIZING-RADIATION; CHROMOSOME STABILITY; STRAND EXCHANGE; BREAK REPAIR; MOUSE GENES; CROSS-LINKS; YEAST AB In yeast, the Rad51-related proteins include Rad55 and Rad57, which form a heterodimer that interacts with Rad51. Five human Rad51 paralogs have been identified (XRCC2, XRCC3, RadS1B/Rad51L1, Rad51C/ Rad51L2, and Rad51D/Rad51L3), and each interacts with one or more of the others. Previously we reported that HsRad51 interacts with XRCC3, and Rad51C interacts with XRCC3, Rad51B, and HsRad51, Here we report that in the yeast two-hybrid system, Rad51D interacts with XRCC2 and Rad51C, No other interactions, including self-interactions, were found, indicating that the observed interactions are specific. The yeast Rad51 interacts with human Rad51 and XRCC3, suggesting Rad51 conservation since the human yeast divergence. Data from yeast three-hybrid experiments indicate that a number of the pairs of interactions between human Rad51 parlogs can occur simultaneously. For example, Rad51B expression enhances the binding of Rad51C to XRCC3 and to HsRad51D, and Rad51C expression allows the indirect interaction of Rad51B with Rad51D, Experiments using 6xHis-tagged proteins in the baculovirus system confirm several of our yeast results, including Rad51B interaction with Rad51D only when Rad51C is simultaneously expressed and Rad51C interaction with XRCC2 only when Rad51D is present. These results suggest that these proteins may participate in one complex or multiple smaller ones. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Schild, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mail Stop 70A-1118,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA74046]; NIGMS NIH HHS [GM30990] NR 44 TC 140 Z9 145 U1 0 U2 2 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 2 PY 2000 VL 275 IS 22 BP 16443 EP 16449 DI 10.1074/jbc.M001473200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 320FY UT WOS:000087392200008 PM 10749867 ER PT J AU Shrock, R Wu, FY AF Shrock, R Wu, FY TI Spanning trees on graphs and lattices in d dimensions SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID MODELS AB The problem of enumerating spanning trees on graphs and lattices is considered. We obtain bounds on the number of spanning trees N-ST and establish inequalities relating the numbers of spanning trees of different graphs or lattices. A general formulation is presented for the enumeration of spanning trees on lattices in d greater than or equal to 2 dimensions, and is applied to the hypercubic, body-centred cubic, face-centred cubic and specific planar lattices including the kagome, diced, 4-8-8 (bathroom-tile), Union Jack and 3-12-12 lattices. This leads to closed-form expressions for N-ST for these lattices of finite sizes. We prove a theorem concerning the classes of graphs and lattices L with the property that N-ST similar to exp(nz(L)) as the number of vertices n --> infinity, where z(L) is a finite non-zero constant. This includes the bulk limit of lattices in any spatial dimension, and also sections of lattices whose lengths in some dimensions go to infinity while others are finite. We evaluate z(L) exactly for the lattices we consider, and discuss the dependence of z(L) on d and the lattice coordination number. Pie also establish a relation connecting z(L) to the free energy of the critical Ising model for planar lattices. C1 SUNY Stony Brook, CN Yang Inst Theoret Phys, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. RP Shrock, R (reprint author), SUNY Stony Brook, CN Yang Inst Theoret Phys, Stony Brook, NY 11794 USA. NR 34 TC 78 Z9 79 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD JUN 2 PY 2000 VL 33 IS 21 BP 3881 EP 3902 DI 10.1088/0305-4470/33/21/303 PG 22 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 333YH UT WOS:000088158000004 ER PT J AU Para, A AF Para, A TI Neutrino oscillations experiments at Fermilab SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT Cracow Epiphany Conference on Neutrinos in Physics and Astrophysics CY JAN 06-09, 2000 CL KRAKOW, POLAND SP H Niewoeniczanski Inst Nuclear Phys, Jagellonian Univ, M Smoluchowski Inst Phys, Polish State Comm Sci Res, Polish Acad Sci, Comm Phys AB Neutrino oscillations provide an unique opportunity to probe physics beyond the Standard Model. Fermilab is constructing two new neutrino beams to provide a decisive test of two of the recent positive indications for neutrino oscillations: MiniBOONE experiment will settle the LSND controversy, MINOS will provide detailed studies of the region indicated by the SuperKamiokande results. C1 Fermilab, Batavia, IL 60510 USA. RP Para, A (reprint author), Fermilab, Pine St, Batavia, IL 60510 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD JUN PY 2000 VL 31 IS 6 BP 1313 EP U14 PG 18 WC Physics, Multidisciplinary SC Physics GA 338TK UT WOS:000088435200009 ER PT J AU Maziasz, PJ AF Maziasz, PJ TI Gas turbine materials technology (GTMT) 2000 SO ADVANCED MATERIALS & PROCESSES LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Maziasz, PJ (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD JUN PY 2000 VL 157 IS 6 BP 6 EP 6 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA 323KA UT WOS:000087563500002 ER PT J AU Rumynin, V Kanivetsky, R Tsang, CF Tompson, AFB AF Rumynin, V Kanivetsky, R Tsang, CF Tompson, AFB TI In memory of Valery Mironenko (1935-2000) SO ADVANCES IN WATER RESOURCES LA English DT Biographical-Item C1 Russian Acad Sci, Inst Environm Geol, St Petersburg 196140, Russia. Univ Minnesota, Minnesota Geol Survey, St Paul, MN 55108 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Rumynin, V (reprint author), Russian Acad Sci, Inst Environm Geol, St Petersburg 196140, Russia. RI Rumynin, Vyacheslav/F-7568-2015 NR 1 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD JUN PY 2000 VL 23 IS 7 BP 673 EP 675 PG 3 WC Water Resources SC Water Resources GA 312LW UT WOS:000086945600001 ER PT J AU Wu, YS Pruess, K AF Wu, YS Pruess, K TI Numerical simulation of non-isothermal multiphase tracer transport in heterogeneous fractured porous media SO ADVANCES IN WATER RESOURCES LA English DT Article DE numerical reservoir simulation; solute transport; tracer and radionuclide transport; multiphase flow and transport; hydrodynamic dispersion; fractured reservoir ID NONAQUEOUS PHASE LIQUIDS; STEAM INJECTION; SUBSURFACE FLOW; YUCCA-MOUNTAIN; HEAT-FLOW; FLUID; MODEL; REMEDIATION; REMOVAL AB We have developed a new numerical method for modeling tracer and radionuclide transport through heterogeneous fractured rocks in a non-isothermal multiphase system. The model formulation incorporates a full hydrodynamic dispersion tensor, based on three-dimensional velocity fields with a regular or irregular grid in a heterogeneous geological medium. Two different weighting schemes are proposed for spatial interpolation of three-dimensional velocity fields and concentration gradients to evaluate the mass flux by dispersion and diffusion of a tracer or radionuclide. The fracture-matrix interactions are handled using a dual-continua approach, such as the double- or multiple-porosity, or dual-permeability. This new method has been implemented into a multi-dimensional numerical code to simulate processes of tracer or radionuclide transport in non-isothermal, three-dimensional, multiphase, porous/fractured subsurface systems. We have verified this new transport-modeling approach by comparing its results to the analytical solution of a parallel-fracture transport problem. In addition, we use published laboratory results and the particle-tracking scheme to further validate the model. Finally, we present two examples of field applications to demonstrate the use of the proposed methodology for modeling tracer and radionuclide transport in unsaturated fractured rocks. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, MS 90-1116,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM yswu@lbl.gov RI Wu, Yu-Shu/A-5800-2011 NR 53 TC 48 Z9 55 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 EI 1872-9657 J9 ADV WATER RESOUR JI Adv. Water Resour. PD JUN PY 2000 VL 23 IS 7 BP 699 EP 723 DI 10.1016/S0309-1708(00)00008-7 PG 25 WC Water Resources SC Water Resources GA 312LW UT WOS:000086945600004 ER PT J AU Tseng, PH Zyvoloski, GA AF Tseng, PH Zyvoloski, GA TI A reduced degree of freedom method for simulating non-isothermal multi-phase flow in a porous medium SO ADVANCES IN WATER RESOURCES LA English DT Article DE multi-phase flow; non-isothermal flow; dual-permeability model; reduced degree of freedom method ID PARTITIONED SOLUTION PROCEDURE; STABLE STAGGERED SOLUTION; FINITE-ELEMENT ANALYSIS; WATER; ALGORITHM; SYSTEMS AB Two solution algorithms, with guaranteed memory savings over fully implicit methods, are presented for solving coupled processes in subsurface hydrology. They are applied to problems of non-isothermal multi-phase flow in porous media using both an equivalent continuum approximation and a dual-permeability approach. One algorithm uses an approximation of the Jacobian matrix during the Newton-Raphson iteration such that the coupled system of equations can be partitioned into a solution of some selected primary variables plus a back substitution procedure for the solution of the other variables. The second algorithm uses a similar procedure, except the operations are performed during the preconditioning phase of the solution of linear equations. Numerical forms were derived and the solution procedures were illustrated to reduce the problem From three unknowns per node to one for the single continuum formulation, and from six unknowns per node to two for the dual-permeability approximation. Simulation examples showed that the proposed method produced nearly identical results compared to the traditional fully implicit method while enjoying large memory savings and competitive CPU times. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. RP Tseng, PH (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp, EES-5,MS-C306, Los Alamos, NM 87545 USA. NR 37 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD JUN PY 2000 VL 23 IS 7 BP 731 EP 745 DI 10.1016/S0309-1708(00)00006-3 PG 15 WC Water Resources SC Water Resources GA 312LW UT WOS:000086945600006 ER PT J AU Fisk, WJ Faulkner, D Sullivan, D Mendell, MJ AF Fisk, WJ Faulkner, D Sullivan, D Mendell, MJ TI Particle concentrations and sizes with normal and high efficiency air filtration in a sealed air-conditioned office building SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID INDOOR AIR; PENETRATION; DEPOSITION AB During parts of 7 consecutive weeks, indoor and outdoor particle number concentrations and particle sizes were measured versus time in a large sealed air-conditioned office building without tobacco smoking, Building ventilation rates were also measured, During some periods, the normal filters in the building's air handling systems were replaced with high efficiency filters, A mass balance model was used to help interpret the study data, For all particle sizes, indoor number concentrations varied considerably between weeks and within a single work day, Even with the normal air filters, which have a low efficiency for submicron-size particles, indoor number concentrations of submicron particles were a factor of 3-6 smaller than outdoor particle number concentrations, For the range of particle sizes measured (> 0.3 mu m), the indoor particle mass concentration was considerably less than outdoor particle mass concentration, The high efficiency filters dramatically reduced the indoor-outdoor particle concentration ratio for submicron particles (i.e., the decrease was 70% to 95%, depending on particle size), For larger particles, the decreases in indoor concentrations were substantially smaller, Comparisons of model predictions with measured data provide evidence of a large rate of removal of submicron indoor particles by some process other than ventilation or air filtration and also provide evidence of significant indoor generation or resuspension of particles larger than 1 mu m. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. NIOSH, Cincinnati, OH 45226 USA. RP Fisk, WJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Dept, MS 90-3058, Berkeley, CA 94720 USA. NR 34 TC 23 Z9 24 U1 1 U2 10 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUN PY 2000 VL 32 IS 6 BP 527 EP 544 DI 10.1080/027868200303452 PG 18 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 318XM UT WOS:000087310000002 ER PT J AU Marley, NA Gaffney, JS Drayton, PJ Cunningham, MM Orlandini, KA Paode, R AF Marley, NA Gaffney, JS Drayton, PJ Cunningham, MM Orlandini, KA Paode, R TI Measurement of Pb-210, Po-210, and Bi-210 in size-fractionated atmospheric aerosols: An estimate of fine-aerosol residence times SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID BOUNDARY-LAYER; SURFACE AIR; MEXICO-CITY; RN-222; RADON; SAMPLES; PLUMES; RATIO; LEAD AB Lead-210 and Po-210 were measured in size-fractionated aerosol samples collected at several sites in North America. Total particulate mass concentrations of the samples were 23-98 mu g/m(3), with 23-67% of the mass in size ranges below 2 mu m. The aerosol mass size distributions below 9 mu m were generally bimodal, with a maximum in the coarse-particle range occurring primarily at 3.1 mu m and a maximum in the accumulation range occurring at approximately 0.6 mu m. Total Pb-210 concentrations were 0.51-1.7 mBq/m(3), with 63-97% occurring in the size ranges below 2 mu m. The Po-210/Pb-210 ratios suggested residence times of 33-66 days for the aerosols below 2 mu m. The Bi-210/Pb-210 ratios of selected samples gave similar results to the Po-210/Pb-210 ratios, leading to residence times of 6-67 days, with the largest differences occurring in the larger size ranges. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Gaffney, JS (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 35 TC 45 Z9 46 U1 5 U2 13 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD JUN PY 2000 VL 32 IS 6 BP 569 EP 583 DI 10.1080/027868200303489 PG 15 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 318XM UT WOS:000087310000005 ER PT J AU Wang, GJ Volkow, ND Franceschi, D Fowler, JS Thanos, PK Scherbaum, N Pappas, N Wong, CT Hitzemann, RJ Felder, CA AF Wang, GJ Volkow, ND Franceschi, D Fowler, JS Thanos, PK Scherbaum, N Pappas, N Wong, CT Hitzemann, RJ Felder, CA TI Regional brain metabolism during alcohol intoxication SO ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH LA English DT Article DE alcohol; benzodiazepines; cerebral glucose metabolism; [F-18] fluorodeoxyglucose; statistical parametric mapping ID POSITRON EMISSION TOMOGRAPHY; CEREBRAL METABOLISM; RAT-BRAIN; GLUCOSE; LORAZEPAM; ETHANOL; REPRODUCIBILITY; BENZODIAZEPINES; PET; DEPRESSION AB Background: Ethanol has a broad range of actions on many neurotransmitter systems. The depressant actions of ethanol in the brain are related in part to facilitation of gamma-aminobutyric acid (GABB) neuro-transmission via its interaction with the benzodiazepine/GABA receptor complex The purpose of this study was to evaluate the effects of ethanol on regional brain metabolism in 10 healthy right-handed men. The results were compared with those we previously published in a different group of 16 normal male subjects who received intravenous lorazepam, a benzodiazepine drug that also enhances GABA neutrotranmission. Methods: The subjects were scanned with positron emission tomography and [F-18] fluorodeoxyglucose twice: 40 min after the end of placebo (diet soda) or ethanol (0.75 g/kg) oral administration, image data sets were analyzed by using both the region of interest and the statistical parametric mapping (SPM) approach. SPM was used to generate a difference image between baseline and ethanol, which we compared to the difference image between baseline and lorazepam (30 mu g/kg). Results: Ethanol significantly increased self-reports of "high" (p less than or equal to 0.0001), dizziness (p less than or equal to 0.003), and intoxication (p less than or equal to 0.0001). Ethanol significantly decreased whole brain (-25 +/- 6%,p less than or equal to 0.0001) and regional metabolism. Normalization of the regional measures by whole brain metabolism (relative measures) showed that ethanol decreased relative metabolic activity in occipital cortex (-4.9 +/- 4.1%,p less than or equal to 0.006), whereas it increased relative metabolic act in left temporal cortex (+3.5 +/- 2.9%,p less than or equal to 0.006) and left basal ganglia (+9 +/- 6.3%,p less than or equal to 0.0009). SPM analyses revealed the same pattern of responses as the relative measures, showing decreases in occipital cortex and increases in left temporal cortex Comparison of the relative measures and the SPM analyses obtained with lorazepam data revealed a similar pattern of effects, with relative decreases in occipital cortex (-7.8 +/- 4.8%) and relative increases in left temporal cortex (+3.8 +/- 5.7%). Lorazepam, but not ethanol, also decreased thalamic metabolism (-11.2 +/- 7.2%). Conclusions: These results support similar though not identical mechanisms for the effects of alcohol and benzodiazepines on brain glucose metabolism. The fact that lorazepam, but not alcohol, reduced thalamic metabolism, an effect associated with sleepiness could explain the higher sedative effects of lorazepam than of alcohol. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Univ Essen, Dept Psychiat & Psychotherapy, Essen, Germany. RP Wang, GJ (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIAAA NIH HHS [1RO1 AA09481-01] NR 47 TC 60 Z9 61 U1 2 U2 5 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0145-6008 J9 ALCOHOL CLIN EXP RES JI Alcoholism (NY) PD JUN PY 2000 VL 24 IS 6 BP 822 EP 829 DI 10.1111/j.1530-0277.2000.tb02061.x PG 8 WC Substance Abuse SC Substance Abuse GA 326VE UT WOS:000087757000011 PM 10888070 ER PT J AU Rooney, WD Lee, JH Li, X Wang, GJ Franceschi, D Springer, CS Volkow, ND AF Rooney, WD Lee, JH Li, X Wang, GJ Franceschi, D Springer, CS Volkow, ND TI 4.0 T water proton T-1 relaxation times in normal human brain and during acute ethanol intoxication SO ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH LA English DT Article DE brain water; T-1 relaxation time; magnetic resonance imaging; acute alcohol intoxication ID IN-VIVO; ALCOHOL; SPECTROSCOPY; VASOPRESSIN; VOLUNTEERS; EXCHANGE; IMAGES; MRI AB Background: It has been reported that acute ethanol intoxication decreases the brain water proton magnetic resonance T-1 values, an effect that has been interpreted to indicate brain dehydration during this condition. Because water macromolecular interactions largely determine tissue water T-1, another possible explanation for reduced brain water proton T-1 values is that the interaction between water and brain macromolecules is altered by ethanol. Methods: A 4.0 T magnetic resonance imaging (MRI) instrument was used to measure brain water proton T-1 relavation times before, during, and after ethanol intoxication (dose, 0.75 mg/kg) in healthy centrols. Results: The T-1 relaxation times as assessed with MRI were highly reproducible. The mean, paired ethanol-induced differences in T-1 were -0.004 +/- 0.007 sec (mean +/- standard deviation) for white matter and 0.010 +/- 0.015 sec for internal gray matter structures, neither of which was significant. Conclusions: This reasonably sensitive measurement does not support the view that tissue water content or water macromolecule interactions are significantly altered in the brain during acute alcohol intoxication in otherwise healthy subjects. C1 Brookhaven Natl Lab, High Field MRI Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Rooney, WD (reprint author), Brookhaven Natl Lab, High Field MRI Lab, Dept Chem, Bldg 560,POB 5000, Upton, NY 11973 USA. RI Lee, Jing-Huei/J-3978-2016; OI Lee, Jing-Huei/0000-0001-9921-7629; Springer, Charles/0000-0002-5966-2135 FU NIAAA NIH HHS [AA 09481] NR 28 TC 10 Z9 10 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0145-6008 J9 ALCOHOL CLIN EXP RES JI Alcoholism (NY) PD JUN PY 2000 VL 24 IS 6 BP 830 EP 836 DI 10.1111/j.1530-0277.2000.tb02062.x PG 7 WC Substance Abuse SC Substance Abuse GA 326VE UT WOS:000087757000012 PM 10888071 ER PT J AU Dreon, DM Fernstrom, HA Williams, PT Krauss, RM AF Dreon, DM Fernstrom, HA Williams, PT Krauss, RM TI Reduced LDL particle size in children consuming a very-low-fat diet is related to parental LDL-subclass patterns SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE lipoproteins; diet; children; low-density-lipoprotein subclasses; genetics; LDL; LDL peak particle diameter; very-low-fat; high-carbohydrate diet ID CORONARY-ARTERY DISEASE; DENSITY-LIPOPROTEIN SUBCLASSES; PLASMA TRIGLYCERIDE CONCENTRATION; INSULIN-RESISTANCE; CHOLESTEROL LEVELS; HEART-DISEASE; RISK-FACTORS; WOMEN; MEN; PHENOTYPES AB Background: A genetically influenced atherogenic lipoprotein phenotype characterized by a predominance of small, dense LDL particles (subclass pattern B) can be induced by low-fat diets in healthy subjects with large LDL particles (pattern A). Objective: The aim of this study was to test whether genetic predisposition to subclass pattern B contributes to susceptibility to induction of this trait by a low-fat diet. Design: The prevalence of pattern B in children is relatively low compared with that in older individuals, but genetic susceptibility to this trait in offspring can be inferred by its presence in their parents. Plasma lipoproteins were analyzed 10 d after a change from a usual diet to a very-low-fat (10% fat), high-carbohydrate diet in offspring (mean age. 14 y; range: 7-28 y) of 22 families according to parental LDL-subclass patterns when consuming a low-fat diet: AXA mating (9 families with 19 children), AXE mating (5 families with 10 children), and BXB mating (8 families with 21 children). Results: The very-low-fat, high-carbohydrate diet produced significantly greater decreases in LDL particle size in offspring of BXB parents ((x) over bar +/- SE: -0.55 +/- 0.16 nm) and AXE parents (-0.48 +/- 0.19 nm) than in offspring of AxA parents (0.14 +/- 0.20 nm). The number of children expressing pattern B with the 10%-fat diet and the proportion of children converting from pattern A to pattern B was significantly greater in offspring of BXB parents than in those with I or 2 pattern A parents. Conclusion: A very-low-fat, high-carbohydrate diet can induce expression of LDL-subclass pattern B in genetically predisposed children with low expression of the trait while consuming their usual diets. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. Childrens Hosp Oakland, Oakland, CA USA. RP Krauss, RM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Room 465,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL18574, HL57344] NR 43 TC 45 Z9 45 U1 0 U2 1 PU AMER SOC CLINICAL NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, SUBSCRIPTIONS, RM L-3300, BETHESDA, MD 20814-3998 USA SN 0002-9165 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD JUN PY 2000 VL 71 IS 6 BP 1611 EP 1616 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 320XN UT WOS:000087426300034 PM 10837306 ER PT J AU Stange, A Furman, J Hilmas, D AF Stange, A Furman, J Hilmas, D TI The utility of the beryllium lymphocyte proliferation test in chronic beryllium disease case finding. SO AMERICAN JOURNAL OF EPIDEMIOLOGY LA English DT Meeting Abstract C1 Oak Ridge Associated Univ, Golden, CO 80403 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0002-9262 J9 AM J EPIDEMIOL JI Am. J. Epidemiol. PD JUN 1 PY 2000 VL 151 IS 11 SU S MA 323 BP S81 EP S81 PG 1 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 321MZ UT WOS:000087460400322 ER PT J AU Month, M AF Month, M TI Education in a rapidly advancing technology: Accelerators and beams SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB The field of accelerators and beams (A&B) is one of today's fast changing technologies. Because university faculties have not been able to keep pace with the associated advancing knowledge, universities have not been able to play their traditional role of educating the scientists and engineers needed to sustain this technology for use in science, industry, commerce, and defense. This problem for A&B is described and addressed. The solution proposed, a type of "distance'' education, is the U.S. Particle Accelerator School (USPAS) created in the early 1980s. USPAS provides the universities with a means of serving the education needs of the institutions using A&B, primarily but not exclusively the national laboratories. The field of A&B is briefly summarized. The need far education outside the university framework, the raison d'(e) over cap tre for USPAS, the USPAS method, program structure, and curriculum, and particular USPAS-university connections are explained. The management of USPAS is analyzed, including its unique administrative structure, its institutional ties, and its operations, finance, marketing, and governmental relations. USPAS performance over the years is documented and a business assessment is made. Finally, there is a brief discussion of the future potential for this type of educational program, including possible extrapolation to new areas and/or different environments, in particular, its extra-government potential and its international possibilities. (C) 2000 American Association of Physics Teachers. C1 Brookhaven Natl Lab, US Particle Accelerator Sch, Upton, NY 11973 USA. RP Month, M (reprint author), Brookhaven Natl Lab, US Particle Accelerator Sch, Bldg 902A, Upton, NY 11973 USA. NR 31 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD JUN PY 2000 VL 68 IS 6 BP 556 EP 570 DI 10.1119/1.19484 PG 15 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 317QJ UT WOS:000087238200016 ER PT J AU Aloia, JF Vaswani, A Feuerman, M Mikhail, M Ma, RM AF Aloia, JF Vaswani, A Feuerman, M Mikhail, M Ma, RM TI Differences in skeletal and muscle mass with aging in black and white women SO AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM LA English DT Article DE body composition; osteoporosis ID TOTAL-BODY POTASSIUM; BONE MASS; PREMENOPAUSAL WOMEN; AGE; SEX; CALIBRATION; HORMONES; DENSITY; FAT AB Previous cross-sectional studies using delayed gamma neutron activation analysis and whole body counting suggested that the relationship of total body calcium (TBCa) to total body potassium (TBK) (muscle mass, body cell mass) remained constant with age. This led to the hypothesis that the muscle mass and skeletal mass compartments are integrated in their response to aging. It had also been hypothesized that loss of skeletal and muscle mass was similar between races. In the current study, delayed gamma neutron activation analysis and whole body counting were performed on 90 black and 143 white women 20-69 yr of age. Black women had higher TBCa and TBK values than white women, even when the data were adjusted for age, height, and weight. TBCa was correlated with height and TBK with weight. The estimated decline of skeletal mass (TBCa) from 20 to 70 yr was 18% in black women and 19% in white women. However, the lifetime decline of TBK was only 8% for black women, compared with 22% for white women. Black women may lose TBK more slowly than TBCa with aging, compared with white women. In particular, correlation of TBCa and age was similar for blacks and whites (r = -0.44 and r = -0.54, respectively). However, for TBK these correlations were r = -0.14 and r = -0.42. These data confirm a higher musculoskeletal mass in black women and suggest that the loss of muscle mass with age may be lower in black than in white women. These ethnic differences do not support the hypothesis of an integrated musculoskeletal system, so that these two components should be considered separately. A prospective study is needed to confirm these findings. C1 Winthrop Univ Hosp, Dept Med, Mineola, NY 11501 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Aloia, JF (reprint author), 259 1st St, Mineola, NY 11501 USA. EM jaloia@winthrop.org NR 29 TC 18 Z9 18 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0193-1849 EI 1522-1555 J9 AM J PHYSIOL-ENDOC M JI Am. J. Physiol.-Endocrinol. Metab. PD JUN PY 2000 VL 278 IS 6 BP E1153 EP E1157 PG 5 WC Endocrinology & Metabolism; Physiology SC Endocrinology & Metabolism; Physiology GA 323NH UT WOS:000087571200023 PM 10827019 ER PT J AU Praphairaksit, N Houk, RS AF Praphairaksit, N Houk, RS TI Attenuation of matrix effects in inductively coupled plasma mass spectrometry with a supplemental electron source inside the skimmer SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYATOMIC ION INTERFERENCES; ICP-MS; CRYOGENIC DESOLVATION; CONCOMITANT ELEMENTS; INTERNAL STANDARDS; TRACE-ELEMENTS; ANALYTE SIGNAL; ARGON PLASMA; REDUCTION; PRECONCENTRATION AB Electrons are added from a heated filament at the base of the skimmer to reduce the space charge repulsion in the ion beam. This technique improves the analyte sensitivity moderately and also minimizes the matrix effects caused by other elements in the sample significantly, The suppression of signal for even the most troublesome combination of light analyte and heavy matrix elements can be attenuated from 90 to 99% to only 2-10% for 2 mM matrix solutions with an ultrasonic nebulizer, The supplemental electron current can be adjusted to "titrate" out the matrix effects as desired. C1 Iowa State Univ, Dept Chem, Ames Lab, US Dept Energy, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ, Dept Chem, Ames Lab, US Dept Energy, Ames, IA 50011 USA. NR 47 TC 14 Z9 15 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2351 EP 2355 DI 10.1021/ac000150s PG 5 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000009 ER PT J AU Praphairaksit, N Houk, RS AF Praphairaksit, N Houk, RS TI Reduction of space charge effects in inductively coupled plasma mass spectrometry using a supplemental electron source inside the skimmer: Ion transmission and mass spectral characteristics SO ANALYTICAL CHEMISTRY LA English DT Article ID ENLARGED SAMPLING ORIFICE; VACUUM INTERFACE; ICP-MS; INTERFERENCES; LENS; GAS; EXTRACTION; DYNAMICS AB An electron source consisting of a heated filament has been added to the skimmer to suppress space charge effects in inductively coupled plasma mass spectrometry (ICPMS). Electrons from this source can reduce the space charge repulsion between the positive ions in the ion beam. As a result, ion transmission efficiency and analyte ion sensitivities are significantly improved across the full mass range. MO+/M+ abundance ratios are not affected, M2+/M+ abundance ratios increase only slightly, and no new background ions are created by this electron injection technique. C1 Iowa State Univ, Ames Lab, Dept Chem, US Dept Energy, Ames, IA 50011 USA. RP Houk, RS (reprint author), Iowa State Univ, Ames Lab, Dept Chem, US Dept Energy, Ames, IA 50011 USA. NR 28 TC 22 Z9 23 U1 3 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2356 EP 2361 DI 10.1021/ac000159u PG 6 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000010 ER PT J AU Su, YX Duan, YX Jin, Z AF Su, YX Duan, YX Jin, Z TI Helium plasma source time-of-flight mass spectrometry: Off-cone sampling for elemental analysis SO ANALYTICAL CHEMISTRY LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; MICROWAVE-INDUCED PLASMA; ATOMIC-EMISSION-SPECTROMETRY; BACKGROUND SPECTRAL FEATURES; ION-SOURCE; ATMOSPHERIC-PRESSURE; TRACE-ELEMENTS; TORCH; PERFORMANCE; SYSTEM AB In this paper, an atmospheric pressure, helium microwave-induced plasma (MIP) ion source coupled with an orthogonal acceleration time-of-flight mass spectrometer (TOFMS) is explored for elemental analysis. Studies of the relationship between ion signals and sampling distance of the MS reveal that background signals can be suppressed dramatically without sacrificing the signal intensities of analytes when the microwave plasma plume is off the tip of the sampler orifice. This "off-cone" ion sampling mode provides a technique to obtain nearly "clean" background spectra and, thus, eliminates the spectral interference from entrainment air and the working-gas species, making it possible to sensitively determine isotopes that suffered from spectral interference in ICPMS and MIPMS (such as Ca-40, Cr-52, Mn-55, and Fe-56). On the other hand, since the high-temperature plasma is kept away from the sampler aperture, off-cone sampling places little demand on the cooling device and the lifetime of the sampler plate can be extended. The instrumental system can provide a fairly good mass resolution of 1100 (fwhm). The detection limits (3 sigma) in the tens of picograms per milliliter level for the elements studied can be achieved with a digital oscilloscope. These detection limits can be easily improved with an advanced detection system, which is currently available in commercial markets. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Duan, YX (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, CST-9,MS K484, Los Alamos, NM 87545 USA. NR 39 TC 22 Z9 23 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2455 EP 2462 DI 10.1021/ac991374h PG 8 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000025 ER PT J AU Xiang, F Anderson, GA Veenstra, TD Lipton, MS Smith, RD AF Xiang, F Anderson, GA Veenstra, TD Lipton, MS Smith, RD TI Characterization of microorganisms and biomarker development from global ESI-MS/MS analyses of cell lysates SO ANALYTICAL CHEMISTRY LA English DT Article ID FLIGHT MASS-SPECTROMETRY; ASSISTED-LASER-DESORPTION/IONIZATION; COMPLEX BIOLOGICAL SAMPLES; FAST-ATOM-BOMBARDMENT; RAPID IDENTIFICATION; ELECTROSPRAY IONIZATION; DUAL MICRODIALYSIS; WHOLE CELLS; BACTERIA; PROTEINS AB The capability for sensitive and accurate identification of microorganisms has potential applications that include the monitoring of industrial bioprocessing operations, food safety analyses, disease diagnosis, and detection of potential biological hazards. Efforts based upon matrix-assisted laser desorption/ionization mass spectrometry to detect and identify specific microorganisms have been actively pursued for several years, We report a new method being developed to select useful biomarkers for the identification of microorganisms based upon electrospray ionization (ESI)-ion trap mass spectrometry, Crude cell lysates are processed using a recently developed dual-microdialysis device and then directly infused into an ion trap MS, The low ESI flow rate and precursor ion accumulation capability of the ion trap MS enables high-sensitivity MS/MS analyses, Precursor ions are automatically selected and analyzed using tandem MS (MS/MS) to produce "global" MS/MS surveys and processed to yield two-dimensional MS/MS spectral displays. Such global MS/MS surveys are demonstrated for Escherichia coli lysates, The distinctive MS/MS spectral patterns can be used to identify mass spectrometric-detected species useful as biomarkers, which then provide a basis for confident microorganism identification. The results presented demonstrate the application of this method for the identification of microorganisms, as well as for detection of bacteriophage MS2 in the presence of a large excess of E. coli. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 48 TC 45 Z9 45 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2475 EP 2481 DI 10.1021/ac991307n PG 7 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000028 PM 10857623 ER PT J AU Gao, QF Yeung, ES AF Gao, QF Yeung, ES TI High-throughput detection of unknown mutations by using multiplexed capillary electrophoresis with poly(vinylpyrrolidone) solution SO ANALYTICAL CHEMISTRY LA English DT Article ID GRADIENT GEL-ELECTROPHORESIS; NUCLEIC-ACIDS; MASS-SPECTROMETRY; POINT MUTATIONS; RAPID DETECTION; DNA FRAGMENTS; SINGLE; IDENTIFICATION; POLYMORPHISMS; ARRAYS AB Single-nucleotide polymorphism detection has been the focus of much attention recently. Although many methods have been reported, low-cost, high-throughput, and high-detection-rate methods are still in demand. We present a fast and reliable mutation detection scheme based on temperature-gradient capillary electrophoresis. A large temperature gradient(10 degrees C) was applied with a precision of 0.02 degrees C and a temperature ramp of 0.7 degrees C/min. Multiple unlabeled samples from PCR were injected and analyzed. Ethidium bromide was used as the intercalating dye for laser-induced fluorescence detection. Mutations can be recognized by comparing the electrophoretic patterns of the heteroduplex with that of a homoduplex reference without prior knowledge of the exact type of mutation present. Mutations in all five test samples were successfully detected with high confidence. This scheme is demonstrated in 96-capillary array electrophoresis for screening single-point polymorphism in large numbers of samples prior to full sequencing of only the positive samples to identify the nature of the mutation. C1 Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ Sci & Technol, Ames Lab, US DOE, Ames, IA 50011 USA. NR 30 TC 68 Z9 71 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2499 EP 2506 DI 10.1021/ac991362w PG 8 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000031 PM 10857626 ER PT J AU Cummings, EB Griffiths, SK Nilson, RH Paul, PH AF Cummings, EB Griffiths, SK Nilson, RH Paul, PH TI Conditions for similitude between the fluid velocity and electric field in electroosmotic flow SO ANALYTICAL CHEMISTRY LA English DT Article ID DISPERSION; TRANSPORT AB Electroosmotic now is fluid motion driven by an electric field acting on the net fluid charge produced by charge separation at a fluid-solid interface. Under many conditions of practical interest, the resulting fluid velocity is proportional to the local electric field, and the constant of proportionality is everywhere the same. Here we show that the main conditions necessary for this similitude are a steady electric field, uniform fluid and electric properties, an electric Debye layer that is thin compared to any physical dimension, and fluid velocities on all inlet and outlet boundaries that satisfy the Helmholtz-Smoluchowski relation normally applicable to fluid-solid boundaries. Under these conditions, the velocity field can be determined directly from the Laplace equation governing the electric potential, without solving either the continuity or momentum equations. Three important consequences of these conditions are that the fluid motion is everywhere irrotational, that fluid velocities in two-dimensional channels bounded by parallel planes are independent of the channel depth, and that such flows exhibit no dependence on the Reynolds number. Similitude is demonstrated by comparing measured and computed fluid streamlines with computed electric flux lines. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Cummings, EB (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 14 TC 161 Z9 162 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2526 EP 2532 DI 10.1021/ac991165x PG 7 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000035 ER PT J AU Bergmann, U Mullins, OC Cramer, SP AF Bergmann, U Mullins, OC Cramer, SP TI X-ray Raman spectroscopy of carbon in asphaltene: Light element characterization with bulk sensitivity SO ANALYTICAL CHEMISTRY LA English DT Article ID ABSORPTION FINE-STRUCTURE; PETROLEUM ASPHALTENES; FLUORESCENCE SPECTROSCOPY; ENERGY RESOLUTION; K-EDGE; XANES SPECTROSCOPY; SCATTERING; EXCITATION; GRAPHITE; NITROGEN AB X-ray Raman spectra of the carbon K-edge have been recorded using 6.461 keV radiation for a petroleum asphaltene, By comparison with coronene, graphite, and paraffin standards, the asphaltene spectrum is seen to be composed of contributions from saturated and aromatic carbon species. The information contained in the carbon K-edge was extracted with bulk (similar to 1 mm) sensitivity, because the Raman method used hard X-rays, This helps alleviate concerns about surface artifacts that frequently occur with soft X-ray spectroscopy of light elements. X-ray Raman spectroscopy shows great potential for characterization of light elements in fuels, catalysts, and other complex materials under chemically relevant conditions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Schlumberger Doll Res Ctr, Ridgefield, CT 06877 USA. RP Cramer, SP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM-48145]; PHS HHS [44891-5] NR 43 TC 52 Z9 56 U1 3 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2609 EP 2612 DI 10.1021/ac990730t PG 4 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000048 PM 10857643 ER PT J AU Deng, HT Van Berkel, OJ AF Deng, HT Van Berkel, OJ TI Electrochemically modulated liquid chromatography coupled on-line with electrospray mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID POROUS GRAPHITIC CARBON; CONDUCTIVE STATIONARY-PHASE; BIOLOGICAL REDOX REACTIONS; SEPARATIONS; ONLINE; COLUMN; POLYANILINE; EMLC; ELECTROSORPTION; POLYPYRROLE AB Electrochemically modulated liquid chromatography (EMLC) has been coupled to an electrospray mass spectrometer. This combination takes advantage of the ability of EMLC to manipulate retention and enhance separation efficiency solely through changes in the potential applied to a conductive stationary phase, thereby minimizing complications because of possible changes in analyte ionization efficiencies when gradient elution techniques are used. Three examples are presented that demonstrate the attributes of this EMLC/electrospray mass spectrometry (ES-MS) coupling. The first two examples involve the separation of mixtures of corticosteroids or of benzodiazepines, showing the general utility of the union for eluent identification and low-level detection. The ability to identify products from on-column redox transformations is also demonstrated using the benzodiazepine mixture. The third example investigates the electrooxidation of aniline by utilizing an EMLC column as an on-line electrochemical reactor and product separator and ES-MS for detection and product identification. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Iowa State Univ Sci & Technol, US DOE, Ames Lab, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. RP Van Berkel, OJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 42 TC 36 Z9 36 U1 3 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JUN 1 PY 2000 VL 72 IS 11 BP 2641 EP 2647 DI 10.1021/ac991461+ PG 7 WC Chemistry, Analytical SC Chemistry GA 320WZ UT WOS:000087425000053 PM 10857648 ER PT J AU Feltus, MA Miller, WS AF Feltus, MA Miller, WS TI Three-dimensional coupled kinetics/thermal-hydraulic benchmark TRIGA experiments SO ANNALS OF NUCLEAR ENERGY LA English DT Article AB This research project provides separate effects tests in order to benchmark neutron kinetics models coupled with thermal-hydraulic (T/H) models used in best-estimate codes such as the Nuclear Regulatory Commission's (NRC) RELAP and TRAC code series and industrial codes such as RETRAN, Before this research project was initiated, no adequate experimental data existed for reactivity initiated transients that could be used to assess coupled three-dimensional (3D) kinetics and 3D T/H codes which have been, or are being developed around the world. Using various Test Reactor Isotope General Atomic (TRIGA) reactor core configurations at the Penn State Breazeale Reactor (PSBR), it is possible to determine the level of neutronics modeling required to describe kinetics and T/H feedback interactions. This research demonstrates that the small compact PSBR TRIGA core does not necessarily behave as a point kinetics reactor, but that this TRIGA can provide actual test results for 3D kinetics code benchmark efforts. This research focused on developing in-reactor tests that exhibited 3D neutronics effects coupled with 3D T/H feedback. A variety of pulses were used to evaluate the level of kinetics modeling needed for prompt temperature feedback in the fuel. Ramps and square waves were used to evaluate the detail of modeling needed for the delayed T/H feedback of the coolant. A stepped ramp was performed to evaluate and verify the derived thermal constants for the specific PSBR TRIGA core loading pattern. As part of the analytical benchmark research, the STAR 3D kinetics code (Weader, 1992, STAR: Space and time analysis of reactors, Version 5, Level 3. Users Guide, Yankee Atomic Electric Company, YEAC 1758, Bolton, MA) was used to model the transient experiments. The STAR models were coupled with the one-dimensional (1D) WIGL and LRA and 3D COBRA (Rowe, 1973, COBRA IIIC: A digital computer program for steady-state and transient thermal-hydraulic analysis of rod bundle nuclear fuel elements, Battelle Institute, Richland, WA). T/H models to determine the level of T/H modeling required to accurately describe the behaviour of the PSBR TRIGA core during these transient conditions. STAR's ID T/H models (WIGL and LRA) were adequate for the rapid pulse events, when accurate temperature-dependent fuel thermal constants were used and the reactor coolant feedback mechanism was small. However, the longer transients (i.e. ramps, square waves) necessitated the use of the COBRA 3D fluid flow analysis coupled with the 3D STAR kinetics model. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Penn State Univ, University Pk, PA 16802 USA. RP Feltus, MA (reprint author), US DOE, Off Nucl Energy Sci & Technol, Headquarters,1000 Independence Ave, Washington, DC 20585 USA. NR 10 TC 7 Z9 7 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD JUN PY 2000 VL 27 IS 9 BP 771 EP 790 DI 10.1016/S0306-4549(99)00087-0 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 306GD UT WOS:000086588200002 ER PT J AU Hosono, MN Hosono, M Mishra, AK Faivre-Chauvet, A Gautherot, E Barbet, J Knapp, FF Chatal, JF AF Hosono, MN Hosono, M Mishra, AK Faivre-Chauvet, A Gautherot, E Barbet, J Knapp, FF Chatal, JF TI Rhenium-188-labeled anti-neural cell adhesion molecule antibodies with 2-iminothiolane modification for targeting small-cell lung cancer SO ANNALS OF NUCLEAR MEDICINE LA English DT Article DE rhenium-188; monoclonal antibody; small-cell lung cancer; neural cell adhesion molecule; 2-iminothiolane ID MONOCLONAL-ANTIBODIES; BIVALENT HAPTEN; BISPECIFIC ANTIBODY; NUDE-MICE; CARCINOMA; RADIOIMMUNOTHERAPY; BIODISTRIBUTION; GENERATOR; RE-188; XENOGRAFTS AB We have evaluated the potential of Re-188-labeled monoclonal antibodies (MAbs) modified with 2-iminothiolane (2IT) for targeting small-cell lung cancer (SCLC). Radiolabeled MAbs NK1NBL1 and C218 recognizing neural cell adhesion molecule were injected i.v. into athymic mice inoculated with human SCLC tumors, and the biodistribution was examined. NK1NBL1 localized in the tumors better than C218. Re-188-labeled MAbs cleared from the blood faster than I-125-labeled counterparts, resulting in higher tumor-to-blood ratios. In conclusion, the Re-188-labeled MAbs are attractive candidates for imaging and therapy of SCLC. C1 Saitama Med Ctr, Dept Radiol, Kawagoe, Saitama 3508550, Japan. Osaka City Univ, Dept Radiol, Osaka 558, Japan. INSERM, Res Unit 463, Nantes, France. Immunotech SA, F-13288 Marseille, France. Oak Ridge Natl Lab, Nucl Med Program, Oak Ridge, TN USA. RP Hosono, MN (reprint author), Saitama Med Ctr, Dept Radiol, 1981 Kamoda, Kawagoe, Saitama 3508550, Japan. RI Barbet, Jacques/L-4866-2015; Faivre-Chauvet, Alain/L-9923-2015 OI Barbet, Jacques/0000-0002-9188-984X; Faivre-Chauvet, Alain/0000-0003-3849-0087 NR 26 TC 11 Z9 11 U1 0 U2 0 PU JAPANESE SOCIETY NUCLEAR MEDICINE PI TOKYO PA C/O JAPAN RADIOISOTOPE ASSOC, 28-45 HON-KOMAGOME 2-CHOME, BUNKYO-KU, TOKYO, 113-0021, JAPAN SN 0914-7187 J9 ANN NUCL MED JI Ann. Nucl. Med. PD JUN PY 2000 VL 14 IS 3 BP 173 EP 179 DI 10.1007/BF02987856 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 330XV UT WOS:000087987500005 PM 10921481 ER PT J AU King, JK Kostka, JE Frischer, ME Saunders, FM AF King, JK Kostka, JE Frischer, ME Saunders, FM TI Sulfate-reducing bacteria methylate mercury at variable rates in pure culture and in marine sediments SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID TARGETED OLIGONUCLEOTIDE PROBES; SALT-MARSH SEDIMENT; RIBOSOMAL-RNA; PORE WATERS; REDUCTION; ESTUARY; BIOAVAILABILITY; HYBRIDIZATION; DEMETHYLATION; SPECIATION AB Differences in methylmercury (CH3Hg) production normalized to the sulfate reduction rate (SRR) in various species of sulfate-reducing bacteria (SRB) were quantified in pure cultures and in marine sediment slurries in order to determine if SRB strains which differ phylogenetically methylate mercury (Hg) at similar rates. Cultures representing five genera of the SRB (Desulfovibrio desulfuricans, Desulfobulbus propionicus, Desulfococcus multivorans, Desulfobacter sp, strain BG-8, and Desulfobacterium sp, strain BG-33) were grown in a strictly anoxic, minimal medium that received a dose of inorganic Bg 120 h after inoculation, The mercury methylation rates (MMR) normalized per cell were up to 3 orders of magnitude higher in pure cultures of members of SRB groups capable of acetate utilization (e.g., the family Desulfobacteriaceae) than in pure cultures of members of groups that are not able to use acetate (e.g., the family Desulfovibrionaceae). Little or no Hg methylation was observed in cultures of Desulfobacterium or Desulfovibrio strains in the absence of sulfate, indicating that Hg methylation was coupled to respiration in these strains, Mercury methylation, sulfate reduction, and the identities of sulfate-reducing bacteria in marine sediment slurries were also studied. Sulfate-reducing consortia were identified by using group-specific oligonucleotide probes that targeted the 16S rRNA molecule. Acetate-amended slurries, which were dominated by members of the Desulfobacterium and Desulfobacter groups, exhibited a pronounced ability to methylate Ng when the MMR were normalized to the SRR, while lactate-amended and control slurries had normalized MMR that were not statistically different. Collectively, the results of pure-culture and amended-sediment experiments suggest that members of the family Desulfobacteriaceae have a greater potential to methylate Ng than members of the family Desulfovibrionaceae have when the MMR are normalized to the SRR Hg methylation potential may be related to genetic composition and/or carbon metabolism in the SRB, Furthermore, we found that in marine sediments that are rich in organic matter and dissolved sulfide rapid CH3Hg accumulation is coupled to rapid sulfate reduction. The observations described above have broad implications for understanding the control of CH3Hg formation and for developing remediation strategies For Hg-contaminated sediments. C1 Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30332 USA. Skidaway Inst Oceanog, Savannah, GA 31411 USA. Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Kostka, JE (reprint author), Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. RI Mason, Robert/A-6829-2011; Frischer, Marc/L-5207-2014 NR 42 TC 184 Z9 203 U1 9 U2 73 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 2000 VL 66 IS 6 BP 2430 EP 2437 DI 10.1128/AEM.66.6.2430-2437.2000 PG 8 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 319TP UT WOS:000087358700022 PM 10831421 ER PT J AU Wildung, RE Gorby, YA Krupka, KM Hess, NJ Li, SW Plymale, AE McKinley, JP Fredrickson, JK AF Wildung, RE Gorby, YA Krupka, KM Hess, NJ Li, SW Plymale, AE McKinley, JP Fredrickson, JK TI Effect of electron donor and solution chemistry on products of dissimilatory reduction of technetium by Shewanella putrefaciens SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MULTIPLE-SCATTERING CALCULATIONS; REDUCING BACTERIA; METAL REDUCTION; MR-1; CYTOCHROME; BEHAVIOR AB To help provide a fundamental basis for use of microbial dissimilatory reduction processes in separating or immobilizing Tc-99 in waste or groundwaters, the effects of electron donor and the presence of the bicarbonate ion on the rate and extent of pertechnetate ion [Tc(VII)O-4(-)] enzymatic reduction by the subsurface metal-reducing bacterium Shewanella putrefaciens CN32 were determined, and the forms of aqueous and solid-phase reduction products were evaluated through a combination of high-resolution transmission electron microscopy, X-ray absorption spectroscopy, and thermodynamic calculations. When H-2 served as the electron donor, dissolved Tc(VII) was rapidly reduced to amorphous Tc(IV) hydrous oxide, which was largely associated with the cell in unbuffered 0.85% NaCl and with extracellular particulates (0.2 to 0.001 mu m) in bicarbonate buffer. Cell-associated Tc was present principally in the periplasm and outside the outer membrane. The reduction rate was much lower when lactate was the electron donor, with extracellular Tc(IV) hydrous oxide the dominant solid-phase reduction product, but in bicarbonate systems much less Tc(IV) was associated directly with the cell and solid-phase Tc(IV) carbonate may have been present. in the presence of carbonate, soluble (<0.001 pm) electronegative, Tc(IV) carbonate complexes were also formed that exceeded Tc(VII)O-4(-) in electrophoretic mobility. Thermodynamic calculations indicate that the dominant reduced Tc species identified in the experiments would be stable over a range of E-h and pH conditions typical of natural waters. Thus, carbonate complexes may represent an important pathway for Tc transport in anaerobic subsurface environments, where it has generally been assumed that Tc mobility is controlled by low-solubility Tc(IV) hydrous oxide and adsorptive, aqueous Tc(IV) hydrolysis products. C1 Pacific NW Natl Lab, Environm Sci Res Ctr, Richland, WA 99352 USA. RP Wildung, RE (reprint author), Pacific NW Natl Lab, Environm Sci Res Ctr, POB 999, Richland, WA 99352 USA. OI Hess, Nancy/0000-0002-8930-9500 NR 36 TC 114 Z9 116 U1 4 U2 31 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JUN PY 2000 VL 66 IS 6 BP 2451 EP 2460 DI 10.1128/AEM.66.6.2451-2460.2000 PG 10 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 319TP UT WOS:000087358700025 PM 10831424 ER PT J AU Berger, AC Bethke, CM Krumhansl, JL AF Berger, AC Bethke, CM Krumhansl, JL TI A process model of natural attenuation in drainage from a historic mining district SO APPLIED GEOCHEMISTRY LA English DT Article ID ACID-MINE DRAINAGE; SULFATE AB A process model was used to better understand the controls on the chemical evolution of drainage in a historic mining district. At the Pecos Mine Operable Unit, New Mexico, drainage near the waste rock pile is acidic (pH varies from 3.0-5.0) and carries high concentrations of Zn, Al, Cu and Pb. As drainage flows toward the Pecos River, pH increases to greater than 7 and heavy metal content decreases. A process model of natural attenuation in this drainage shows the main controls on pH are reaction with a local bedrock that contains limestone, and concurrent mixing with tributary streams. Models that account for both calcite dissolution and mixing reproduce the observed decrease in aqueous metal concentrations with increasing pH. Contaminant concentrations attenuate primarily via two distinct pathways: Al, Cu, Fe and Pb precipitate directly from solution, whereas Zn, Mg, Mn and SO4 concentrations decrease primarily through dilution. Additionally, Pb adsorbs to precipitating hydroxide surfaces. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Geol, Urbana, IL 61801 USA. Sandia Natl Labs, Div Geochem, Albuquerque, NM 87185 USA. RP Berger, AC (reprint author), Heidelberg Coll, Tiffin, OH 44883 USA. NR 21 TC 64 Z9 76 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD JUN PY 2000 VL 15 IS 5 BP 655 EP 666 DI 10.1016/S0883-2927(99)00074-8 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 291TP UT WOS:000085752400008 ER PT J AU Werner, JH Larson, EJ Goodwin, PM Ambrose, WP Keller, RA AF Werner, JH Larson, EJ Goodwin, PM Ambrose, WP Keller, RA TI Effects of fluorescence excitation geometry on the accuracy of DNA fragment sizing by flow cytometry SO APPLIED OPTICS LA English DT Article ID SINGLE-POLYMER DYNAMICS; POLARIZATION; DYE; SPECTROSCOPY; MOLECULES; DEVICE AB We report on various excitation geometries used in ultrasensitive flow cytometry that yield a linear relation between the fluorescence intensity measured from individual stained DNA fragments and the lengths of the fragments (in base pairs). This linearity holds for DNA samples that exhibit a wide range of conformations. The variety of DNA conformations leads to a distribution of dipole moment orientations for the dye molecules intercalated into the DNA. It is consequently important to use an excitation geometry such that all dye molecules are detected with similar efficiency. To estimate the conformation and the extent of elongation of the stained fragments in the flow, fluorescence polarization anisotropy and autocorrelation measurements were performed. Significant extension was observed for DNA fragments under the flow conditions frequently used for DNA fragment sizing. Classical calculations of the fluorescence emission collected over a finite solid angle are in agreement with the experimental measurements and have confirmed the relative insensitivity to DNA conformation of an orthogonal excitation geometry. Furthermore, the calculations suggested a modified excitation geometry that has increased our sizing resolution. (C) 2000 Optical Society of America OCIS codes: 120.0120, 030.5260, 260.2510, 280.2490, 260.5430. C1 Los Alamos Natl Lab, Div Biosci, Los Alamos, NM 87545 USA. RP Werner, JH (reprint author), Los Alamos Natl Lab, Div Biosci, Mail Stop M888, Los Alamos, NM 87545 USA. EM keller@lanl.gov NR 25 TC 8 Z9 8 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JUN 1 PY 2000 VL 39 IS 16 BP 2831 EP 2839 DI 10.1364/AO.39.002831 PG 9 WC Optics SC Optics GA 318XZ UT WOS:000087311100041 PM 18345207 ER PT J AU Bonlie, JD Patterson, F Price, D White, B Springer, P AF Bonlie, JD Patterson, F Price, D White, B Springer, P TI Production of > 10(21) W/cm(2) from a large-aperture Ti : sapphire laser system SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article; Proceedings Paper CT Ultrafast Optics 1999 Meeting CY JUL 12-16, 1999 CL CTR STEFANO FRANSCINI, ASCONA, SWITZERLAND HO CTR STEFANO FRANSCINI ID CHIRPED-PULSE-AMPLIFICATION; PHASE; GENERATION; INTENSITY AB We have successfully developed a laser system to produce pulses with a wavelength centered at 800 nm, energies above 15 J, temporally compressed to 75 fs and focused to power densities beyond 10(21) W/cm(2). Enabling technologies include chirped-pulse amplification (CPA), 10 cm aperture Ti:Al2O3 crystals, large diffraction gratings, and an energetic Nd:glass laser for pumping the final two amplifiers. Measurements of the compressed pulse spectrum, frequency resolved optical gating (FROG) diagnostic, and focal spot are presented. We have also investigated and developed a technique for suppression of transverse parasitic lasing in large-aperture Ti:sapphire crystal amplifiers. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bonlie, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,M-S L-251, Livermore, CA 94550 USA. NR 22 TC 44 Z9 44 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD JUN PY 2000 VL 70 SU S BP S155 EP S160 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA 335NY UT WOS:000088250600022 ER PT J AU Omenetto, FG Nicholson, JW Luce, BP Yarotski, D Taylor, AJ AF Omenetto, FG Nicholson, JW Luce, BP Yarotski, D Taylor, AJ TI Shaping, propagation and characterization of ultrafast pulses in optical fibers SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article; Proceedings Paper CT Ultrafast Optics 1999 Meeting CY JUL 12-16, 1999 CL CTR STEFANO FRANSCINI, ASCONA, SWITZERLAND HO CTR STEFANO FRANSCINI ID LASER-PULSES; FEMTOSECOND PULSES; CHEMICAL-REACTIONS; MU-M; PHASE; COMPRESSION AB The characterization of medium- to low-energy shaped pulses at 1.55 mu m through frequency-resolved optical gating (FROG) is illustrated. This capability enables the study of ultrafast pulse propagation through optical fibers. The phase dynamics detected furnishes insight on pulse evolution, specifically on soliton formation - a subject of great importance for telecommunication applications. The combination of shaping and propagation of ultrafast pulses in fibers is examined theoretically using an adaptive pulse-shaping model, based on genetic algorithms, that furnishes optimized pulse shapes for fiber propagation. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Omenetto, FG (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST-10,MS K764, Los Alamos, NM 87545 USA. RI Yarotski, Dmitry/G-4568-2010 NR 23 TC 4 Z9 4 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD JUN PY 2000 VL 70 SU S BP S143 EP S148 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA 335NY UT WOS:000088250600020 ER PT J AU Wu, M Ray, M Fung, KH Ruckman, MW Harder, D Sedlacek, AJ AF Wu, M Ray, M Fung, KH Ruckman, MW Harder, D Sedlacek, AJ TI Stand-off detection of chemicals by UV Raman spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE Raman; resonant Raman spectroscopy; UV Raman; remote sensing; spectroscopy; lidar ID LIDAR; TEMPERATURE; ENHANCEMENT; PROFILES AB Experimental results are reported on a mobile, stand-alone, solar-blind ultraviolet (UV) Raman lidar system for the stand-off detection and identification of liquid and solid targets at ranges of hundreds of meters. The lidar is a coaxial system capable of performing range-resolved measurements of gases and aerosols, as well as solids and liquids. The transmitter is a flash lamp pumped 30 Hz Nd:YAG laser with quadrupled output at 266 nm. The receiver subsystem is comprised of a 40 cm Cassegrain telescope, a holographic UV edge filter for suppressing the elastic channel, a 0.46 m Czerny-Turner spectrometer, and a time gated intensified charge-coupled device (CCD) detector. The rejection of elastic light scattering by the edge filter is better than one part in 10(5), while the transmittance 500 cm(-1) to the red of the laser line is greater than 50%. Raman data are shown for selected solids, neat liquids, and mixtures down to the level of 1% volume ratio. On the basis of the strength of the Raman returns, a stand-off detection limit of similar to 500 g/m(2) for liquid spills of common solvents at the range of one half of a kilometer is possible. C1 Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. RP Wu, M (reprint author), Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. NR 33 TC 76 Z9 77 U1 3 U2 30 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUN PY 2000 VL 54 IS 6 BP 800 EP 806 DI 10.1366/0003702001950418 PG 7 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 330LE UT WOS:000087962900007 ER PT J AU Berg, JM Veirs, DK Vaughn, RB Cisneros, MR Smith, CA AF Berg, JM Veirs, DK Vaughn, RB Cisneros, MR Smith, CA TI Speciation model selection by Monte Carlo analysis of optical absorption spectra: Plutonium(IV) nitrate complexes SO APPLIED SPECTROSCOPY LA English DT Article DE visible and NIR absorption spectroscopy; plutonium(IV) nitrate complexes; Monte Carlo simulations; principal component analysis ID SPECTROSCOPY; CONSTANTS; ACID AB Standard modeling approaches can produce the most likely values of the formation constants of metal-ligand complexes if a particular set of species containing the metal ion is known or assumed to exist in solution equilibrium with complexing ligands. Identifying the most likely set of species when more than one set is plausible is a more difficult problem to address quantitatively. A Monte Carlo method of data analysis is described that measures the relative abilities of different speciation models to fit optical spectra of open-shell actinide ions. The best model(s) can be identified from among a larger group of models initially judged to be plausible. The method is demonstrated by analyzing the absorption spectra of aqueous Pu(IV) titrated with nitrate ion at constant 2 molal ionic strength in aqueous perchloric acid. The best speciation model supported by the data is shown to include three Pu(IV) species with nitrate coordination numbers 0, 1, and 2. Formation constants are beta(1) = 3.2 +/- 0.5 and beta(2) = 11.2 +/- 1.2, where the uncertainties are 95% confidence limits estimated by propagating raw data uncertainties using Monte Carlo methods. Principal component analysis independently indicates three Pu(IV) complexes in equilibrium. C1 Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Berg, JM (reprint author), Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. NR 32 TC 12 Z9 12 U1 1 U2 9 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD JUN PY 2000 VL 54 IS 6 BP 812 EP 823 DI 10.1366/0003702001950436 PG 12 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 330LE UT WOS:000087962900009 ER PT J AU Cooper, LW Larsen, IL O'Hara, TM Dolvin, S Woshner, V Cota, GF AF Cooper, LW Larsen, IL O'Hara, TM Dolvin, S Woshner, V Cota, GF TI Radionuclide contaminant burdens in Arctic marine mammals harvested during subsistence hunting SO ARCTIC LA English DT Article DE Cs-137; contamination; marine mammals; North Slope Borough; radioactivity; radionuclides; resolute; Ag-108m; subsistence hunting ID SEDIMENTS; CS-137; ENVIRONMENT; YENISEI; CARIBOU; RIVERS; PB-210; METALS; SEA AB We conducted gamma spectrometric analyses on more than 200 arctic marine mammal tissue samples. These samples were primarily provided by subsistence hunters from northern Alaska, with a smaller number of samples from the Resolute region in Canada. The majority of samples (>90%) had detectable levels of the anthropogenic radionuclide Cs-137, With a mean level observed in all samples of 0.67 Bq kg(-1) dry weight +/- 0.81 (SD). Converted to wet weight, the mean was 0.21 Bq kg(-1) +/- 0.19 SD. The median activity observed was 0.45 Bq kg(-1) dry weight (0.18 Bq kg(-1) wet weight) with a range from detection limits to 6.7 Bq kg(-1) dry weight (1.1 Bq kg(-1) wet weight). These findings confirm expectations that current anthropogenic gamma emitter burdens in marine mammals used in the North American Arctic as subsistence food resources are well below activities that would normally merit public health concern (similar to 1000 Bq kg(-1) wet weight). Some differences among species and tissues were observed. Beluga tissues had slightly higher mean burdens of Cs-137 overall, and epidermis and muscle tissues in bowhead and beluga whales typically had higher burdens than other tissues analyzed. Low levels of the neutron activation product Ag-108 (half-life 418 yr.), probably bioaccumulated from bomb fallout sources, were observed in 16 of 17 beluga livers analyzed, but were not found in any other tissues of beluga or in any other species sampled. A subset of 39 samples of various tissues was analyzed for the alpha and beta emitters Pu-239.240 and Sr-90. Plutonium levels were near the threshold of detectability (similar to 0.1 Bq kg(-1)dry weight) in 6 of the 39 samples; all other samples had no detectable plutonium. A detectable level of Sr-90 (10.3 +/- 1.0 Bq kg(-1) dry weight) was observed in only one of the 39 samples analyzed, a bowhead epidermis sample. Although the accumulation of Ag-108m has not been previously reported in any marine mammal livers, all of our analytical measurements indicate that only very low levels of anthropogenic radioactivity are associated with marine mammals harvested and consumed in the North American Arctic. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Dept Wildlife Management, N Slope Borough, Barrow, AK 99723 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN 37996 USA. Univ Illinois, Coll Vet Med, Urbana, IL 61801 USA. Old Dominion Univ, Ctr Coastal Phys Oceanog, Norfolk, VA 23508 USA. RP Cooper, LW (reprint author), Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN 37996 USA. RI Cooper, Lee/E-5251-2012 OI Cooper, Lee/0000-0001-7734-8388 NR 39 TC 11 Z9 12 U1 1 U2 12 PU ARCTIC INST N AMER PI CALGARY PA UNIV OF CALGARY 2500 UNIVERSITY DRIVE NW 11TH FLOOR LIBRARY TOWER, CALGARY, ALBERTA T2N 1N4, CANADA SN 0004-0843 J9 ARCTIC JI Arctic PD JUN PY 2000 VL 53 IS 2 BP 174 EP 182 PG 9 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 329ER UT WOS:000087894200009 ER PT J AU Gregg, MD Wisotzki, L Becker, RH Maza, J Schechter, PL White, RL Brotherton, MS Winn, JN AF Gregg, MD Wisotzki, L Becker, RH Maza, J Schechter, PL White, RL Brotherton, MS Winn, JN TI A close-separation double quasar lensed by a gas-rich galaxy SO ASTRONOMICAL JOURNAL LA English DT Article DE gravitational lensing; quasars : individual (HE 0512; 3329) ID HUBBLE-SPACE-TELESCOPE; HAMBURG ESO SURVEY; GRAVITATIONAL LENS; BRIGHT QSOS; STATISTICS; EXTINCTION; DESIGN; MAPS; DUST AB In the course of a Cycle 8 snapshot imaging survey with the Space Telescope Imaging Spectrograph (STIS), we have discovered that the z = 1.565 quasar HE 0512-3329 is a double with image separation 0 ".644, differing in brightness by only 0.4 mag. This system is almost certainly gravitationally lensed. Although separate spectra for the two images have not yet been obtained, the possibility that either component is a Galactic star is ruled out by a high signal-to-noise composite ground-based spectrum and separate photometry for the two components: the spectrum shows no trace of any zero-redshift stellar absorption features belonging to a star with the temperature indicated by the broadband photometry. The optical spectrum shows strong absorption features of Mg II, Mg I, Fe II, Fe I, and Ca I, all at an identical intervening redshift of z = 0.9313, probably due to the lensing object. The strength of Mg II and the presence of the other low-ionization absorption features is strong evidence for a damped Ly alpha system, likely the disk of a spiral galaxy. Point-spread function fitting to remove the two quasar components from the STIS image leads to a tentative detection of a third object, which may be the nucleus of the lensing galaxy. The brighter component is significantly redder than the fainter, due to either differential, extinction or microlensing. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Hamburger Sternwarte, Hamburg, Germany. MIT, Cambridge, MA 02139 USA. Univ Chile, Santiago, Chile. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Kitt Peak Natl Observ, Tucson, AZ 85726 USA. RP Gregg, MD (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. NR 26 TC 20 Z9 20 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2000 VL 119 IS 6 BP 2535 EP 2539 DI 10.1086/301377 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ET UT WOS:000088231100001 ER PT J AU Vanden Berk, DE Stoughton, C Crotts, APS Tytler, D Kirkman, D AF Vanden Berk, DE Stoughton, C Crotts, APS Tytler, D Kirkman, D TI QSOs and absorption-line systems surrounding the hubble deep field SO ASTRONOMICAL JOURNAL LA English DT Article DE large-scale structure of universe; quasars : absorption lines; quasars : general; surveys ID REDSHIFT Z-SIMILAR-TO-3; MULTICOLOR SURVEY; ALPHA CLOUDS; GALAXIES; SPECTROSCOPY; EXTRACTION; EVOLUTION; SELECTION; CATALOG; QUASARS AB We have imaged a 45' x 45' area centered on the Hubble Deep Field (HDF) in UBVRI passbands, down to the limiting magnitudes of approximately 21.5, 22.5, 22.2, 22.2, and 21.2, respectively. The principal goals of the survey are to identify quasi-stellar objects (QSOs) and to map structure traced by luminous galaxies and QSO absorption line systems in a wide volume containing the HDF. The area surveyed is 400 times as large as that of the HDF, and 40 times as large as that of the HDF Flanking Fields. We have selected QSO candidates from color space and identified four QSOs and two narrow emission line galaxies not yet discovered, bringing the total number of known QSOs in the area to 19. The bright z = 1.305 QSO only 12' away from the HDF raises the northern HDF to nearly the same status as the southern Hubble Deep Field, which was selected to be proximate to a bright QSO. About half of the QSO candidates remain for spectroscopic verification. Absorption-line spectroscopy has been obtained for three bright QSOs in the field, using the 10 m Keck, 3.5 m ARC, and 2.4 m MDM telescopes. Five heavy-element absorption line systems have been identified, four of which overlap the well-explored redshift range covered by deep galaxy redshift surveys toward the HDF. The two absorbers at z = 0.5565 and z = 0.5621 occur at the same redshift as the secondmost populated redshift peak in the galaxy distribution, but each is more than 7 h(-1) Mpc (comoving, Omega(m) = 1, Omega(Lambda), = 0) away from the HDF line of sight in the transverse dimension. This supports more indirect evidence that the galaxy redshift peaks are contained within large sheetlike structures that traverse the HDF and may be precursors to large-scale "pancake" structures seen in the present-day galaxy distribution. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Univ Texas, McDonald Observ, Austin, TX 78712 USA. RP Vanden Berk, DE (reprint author), Fermi Natl Accelerator Lab, POB 500,500 Wilson Rd, Batavia, IL 60510 USA. NR 44 TC 7 Z9 7 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2000 VL 119 IS 6 BP 2571 EP 2582 DI 10.1086/301404 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ET UT WOS:000088231100004 ER PT J AU Sowards-Emmerd, D Smith, JA McKay, TA Sheldon, E Tucker, DL Castander, FJ AF Sowards-Emmerd, D Smith, JA McKay, TA Sheldon, E Tucker, DL Castander, FJ TI A catalog of photometry for Las Campanas Redshift Survey galaxies on the Sloan Digital Sky Survey system SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : photometry ID CELESTIAL EQUATOR; STANDARD STARS AB We present high-quality photometry in the five Sloan Digital Sky Survey filters, u', g', r', i', and z', for 2195 galaxies with spectroscopic redshifts measured by the Las Campanas Redshift Survey. In addition, a polynomial photometric redshift estimator is derived, with an uncertainty of 0.035 out to z = 0.25. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. RP Sowards-Emmerd, D (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI McKay, Timothy/C-1501-2009 OI McKay, Timothy/0000-0001-9036-6150 NR 16 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 2000 VL 119 IS 6 BP 2598 EP 2604 DI 10.1086/301394 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ET UT WOS:000088231100007 ER PT J AU Kurk, JD Rottgering, HJA Pentericci, L Miley, GK van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Moorwood, A AF Kurk, JD Rottgering, HJA Pentericci, L Miley, GK van Breugel, W Carilli, CL Ford, H Heckman, T McCarthy, P Moorwood, A TI A Search for clusters at high redshift I. Candidate Ly alpha emitters near 1138-262 at z=2.2 SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE galaxies : active; galaxies : clusters : general; galaxies : evolution; galaxies : luminosity function, mass function; cosmology : observations; cosmology : early Universe ID GALAXIES; FIELD; OBJECTS; Z=3.4 AB Radio, optical and X-ray observations of the powerful radio galaxy PKS 1138-262 at z = 2.156 have suggested that this galaxy is a massive galaxy in the center of a forming cluster. We have imaged 1138-262 and the surrounding 38 square arcminute field with the Very Large Telescope(a) in a broad band and a narrow band encompassing the redshifted Ly alpha emission. We detect 50 objects with rest equivalent width larger than 20 Angstrom and a luminous, highly extended Ly alpha halo around 1138-262. If the radio galaxy is at the center of a forming cluster, as observations at other wavelengths suggest, these objects are candidate Ly alpha emitting cluster galaxies. C1 Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. European So Observ, D-85748 Garching, Germany. RP Kurk, JD (reprint author), Sterrewacht Leiden, Pob 9513, NL-2300 RA Leiden, Netherlands. EM kurk@strw.leidenuniv.nl NR 21 TC 92 Z9 92 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUN PY 2000 VL 358 IS 1 BP L1 EP L4 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 333VK UT WOS:000088151300001 ER PT J AU Blasi, P Olinto, AV Stebbins, A AF Blasi, P Olinto, AV Stebbins, A TI The effect of a nonthermal tail on the Sunyaev-Zeldovich effect in clusters of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : clusters : general ID COMA-CLUSTER; RELATIVISTIC CORRECTIONS; MAGNETIC-FIELD; COSMIC-RAYS; EMISSION AB We study the spectral distortions of the cosmic microwave background radiation induced by the effect in clusters of galaxies when the target electrons have a modified Maxwell-Boltzmann distribution with a high-energy nonthermal tail. Bremsstrahlung radiation from this type of electron distribution may explain the suprathermal X-ray emission observed in some clusters such as the Coma Cluster and A2199 and serve as an alternative to the classical but problematic inverse Compton scattering interpretation. We show that the Sunyaev-Zeldovich effect can be used as a powerful tool to probe the electron distribution in clusters of galaxies and discriminate among these different interpretations of the X-ray excess. The existence of a nonthermal tail can have important consequences for cluster-based estimators of cosmological parameters. C1 NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Blasi, P (reprint author), NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Blasi, Pasquale/O-9345-2015 OI Blasi, Pasquale/0000-0003-2480-599X NR 21 TC 20 Z9 20 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 1 PY 2000 VL 535 IS 2 BP L71 EP L74 DI 10.1086/312706 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 327JA UT WOS:000087789700001 ER PT J AU Weaver, AJ Duffy, PB Eby, M Wiebe, EC AF Weaver, AJ Duffy, PB Eby, M Wiebe, EC TI Evaluation of ocean and climate models using present-day observations and forcing SO ATMOSPHERE-OCEAN LA English DT Article ID GENERAL-CIRCULATION MODEL; MULTIPLE EQUILIBRIA; ATMOSPHERE MODEL; CARBON-DIOXIDE; ICE; SIMULATIONS; VARIABILITY; GASES; CO2; BP AB The most common method used to evaluate climate models involves spinning them up under perpetual present-day forcing find comparing the model results with present-day observations. This approach clearly ignores any potential long-term memory of the model ocean to past climatic conditions. Here we examine the validity of this approach through the 6000-year integration of a coupled atmosphere-ocen-sea-ice model. The coupled model is initially spun-up, with atmospheric CO2 concentrations and orbital parameters applicable for 6KBP. The model is then integrated forward in time to 2100. Results from this transient coupled model simulation are compared with the results from two additional simulations, in which the model is spun up with perpetual 1850 (preindustrial) and 1998 (present-day) atmospheric CO2 concentrations and orbital parameters. This comparison leads to substantial differences between the equilibrium climatologies and the transient simulation, even at 1850 tin weakly ventilated regions), prior to any significant changes in atmospheric CO2. When compared to the present-day equilibrium climatology, differences fire very large: the global mean surface air and sea surface temperatures are similar to0.5 degreesC and similar to0.4 degreesC colder respectively deep ocean temperatures are substantially cooler Southern Hemisphere sea-ice cover is 38% larger, and the North Atlantic conveyor 16% weaker in the transient case. These differences are due to the long timescale memory of the deep ocean to climatic conditions which prevailed throghout the late Holocene, as well as to its large thermal inertia. It is also demonstrated that a 'cold start' global warming simulation tone that starts from a 1998 equilibrium climatology) underestimates the global temperature increase at 2100 by similar to 10%. Our results question the accuracy of current techniques for climate model evaluation find underline the importance of using using paleoclimatic simulations in parallel with present-day simulations in this evaluation process. C1 Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC V8W 3P6, Canada. Univ Calif Lawrence Livermore Natl Lab, Climate Syst Modeling Grp, Livermore, CA 94550 USA. RP Weaver, AJ (reprint author), Univ Victoria, Sch Earth & Ocean Sci, POB 3055, Victoria, BC V8W 3P6, Canada. RI Weaver, Andrew/E-7590-2011; Eby, Michael/H-5278-2013; Wiebe, Edward/E-5532-2015 OI Wiebe, Edward/0000-0003-1583-6209 NR 38 TC 21 Z9 21 U1 2 U2 3 PU CANADIAN METEOROLOGICAL OCEANOGRAPHIC SOC PI OTTAWA PA 150 LOUIS PASTEUR PVT., STE 112, MCDONALD BUILDING, OTTAWA, ONTARIO K1N 6N5, CANADA SN 0705-5900 J9 ATMOS OCEAN JI Atmos.-Ocean PD JUN PY 2000 VL 38 IS 2 BP 271 EP 301 PG 31 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 392HX UT WOS:000166406600001 ER PT J AU Balch, T Parker, LE AF Balch, T Parker, LE TI Untitled SO AUTONOMOUS ROBOTS LA English DT Editorial Material C1 Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RP Balch, T (reprint author), Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. NR 0 TC 3 Z9 5 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0929-5593 J9 AUTON ROBOT JI Auton. Robot. PD JUN PY 2000 VL 8 IS 3 BP 207 EP 208 DI 10.1023/A:1008923723685 PG 2 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 324DT UT WOS:000087607100001 ER PT J AU Parker, LE AF Parker, LE TI Lifelong adaptation in heterogeneous multi-robot teams: Response to continual variation in individual robot performance SO AUTONOMOUS ROBOTS LA English DT Article DE multi-robot systems; multi-robot learning; heterogeneous robotics; behavior-based systems ID COOPERATION; ARCHITECTURE AB Generating teams of robots that are able to perform their tasks over long periods of time requires the robots to be responsive to continual changes in robot team member capabilities and to changes in the state of the environment and mission. In this article, we describe the L-ALLIANCE architecture, which enables teams of heterogeneous robots to dynamically adapt their actions over time. This architecture, which is an extension of our earlier work on ALLIANCE, is a distributed, behavior-based architecture aimed for use in applications consisting of a collection of independent tasks. The key issue addressed in L-ALLIANCE is the determination of which tasks robots should select to perform during their mission, even when multiple robots with heterogeneous, continually changing capabilities are present on the team. In this approach, robots monitor the performance of their teammates performing common tasks, and evaluate their performance based upon the time of task completion. Robots then use this information throughout the lifetime of their mission to automatically update their control parameters. After describing the L-ALLIANCE architecture, we discuss the results of implementing this approach on a physical team of heterogeneous robots performing proof-of-concept box pushing experiments. The results illustrate the ability of L-ALLIANCE to enable lifelong adaptation of heterogeneous robot teams to continuing changes in the robot team member capabilities and in the environment. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RP Parker, LE (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, POB 2008, Oak Ridge, TN 37831 USA. NR 49 TC 35 Z9 37 U1 6 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0929-5593 J9 AUTON ROBOT JI Auton. Robot. PD JUN PY 2000 VL 8 IS 3 BP 239 EP 267 DI 10.1023/A:1008977508664 PG 29 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 324DT UT WOS:000087607100003 ER PT J AU Jung, D Zelinsky, A AF Jung, D Zelinsky, A TI Grounded symbolic communication between heterogeneous cooperating robots SO AUTONOMOUS ROBOTS LA English DT Article DE cooperative robotics; heterogeneous systems; symbolic communication; symbol grounding; learning; representation; behavior-based; mobile robots AB In this paper, we describe the implementation of a heterogeneous cooperative multi-robot system that was designed with a goal of engineering a grounded symbolic representation in a bottom-up fashion. The system comprises two autonomous mobile robots that perform cooperative cleaning. Experiments demonstrate successful purposive navigation, map building and the symbolic communication of locations in a behavior-based system. We also examine the perceived shortcomings of the system in detail and attempt to understand them in terms of contemporary knowledge of human representation and symbolic communication. From this understanding, we propose the Adaptive Symbol Grounding Hypothesis as a conception for how symbolic systems can be envisioned. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. Australian Natl Univ, Res Sch Informat Sci & Engn, Dept Syst Engn, Robot Syst Lab, Canberra, ACT 0200, Australia. RP Jung, D (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. NR 48 TC 32 Z9 33 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0929-5593 J9 AUTON ROBOT JI Auton. Robot. PD JUN PY 2000 VL 8 IS 3 BP 269 EP 292 DI 10.1023/A:1008929609573 PG 24 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA 324DT UT WOS:000087607100004 ER PT J AU Griffin, GD Khalaf, W Hayden, KE Miller, EJ Dowray, VR Creekmore, AL Carruthers, CW Williams, MW Gailey, PC AF Griffin, GD Khalaf, W Hayden, KE Miller, EJ Dowray, VR Creekmore, AL Carruthers, CW Williams, MW Gailey, PC TI Power frequency magnetic field exposure and gap junctional communication in Clone 9 cells SO BIOELECTROCHEMISTRY LA English DT Article DE gap junction; ELF-EMFs; chloral hydrate; magnetic field; cell culture; Clone 9 ID NORMAL C3H/10T1/2 CELLS; INTERCELLULAR COMMUNICATION; ELECTROMAGNETIC-FIELDS; NEURITE OUTGROWTH; INHIBITION; CANCER; GROWTH; ONCOGENE AB Exposure to a power-frequency magnetic field has been reported to produce a statistically significant inhibition of gap junctional communication (GJC) in Clone 9 cells that have been pre-stressed by treatment with low concentrations of chloral hydrate (CH) [C.F. Blackman, J.P. Blanchard, S.G. Benane, D.E. House, J.A. Elder, Double blind test of magnetic field effects on neurite outgrowth, Bioelectromagnetics, 19 (1998) 204-209]. This observation might provide mechanistic insight into the possible role of electromagnetic fields (EMFs) in the carcinogenic process, since cancer cells frequently show decreased or absent GJC, and tumor promoting chemicals have been observed to inhibit GJC. Magnetic field exposure conditions were 45 Hz, 23.8 muT rms + parallel DC 36.6 muT, for 30 min of exposure. The responses of Clone 9 cells to the GJC-inhibiting effects of the tumor promoter 12-O-tetradecanoylphorbol 13-acetate and the chemical CH were evaluated and compared to reported results [S.G. Benane, C.F. Blackman, D.E. House, Effects of perchloroethylene and its metabolites on intercellular communication in Clone 9 rat liver cells, J. Toxicol. Environ. Health, 48 (1996) 427-437]. Before magnetic field exposure, cells were exposed fur 24 h to either 3 (nine experiments) or 5 mM (11 experiments) CH to produce GJC of 67% or 50%, respectively, relative to unexposed controls. GJC was assessed microscopically using the scrape-loading technique and a blinded protocol. No statistically significant effect was observed due to magnetic field exposure with either CH concentration. Published by Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Energy, Oak Ridge, TN 37831 USA. RP Griffin, GD (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 2008,MS-6101, Oak Ridge, TN 37831 USA. OI Creekmore, Amy/0000-0002-7092-823X FU NIEHS NIH HHS [5 R03 ES08864-02] NR 35 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0302-4598 J9 BIOELECTROCHEMISTRY JI Bioelectrochemistry PD JUN PY 2000 VL 51 IS 2 BP 117 EP 123 DI 10.1016/S0302-4598(99)00085-9 PG 7 WC Biochemistry & Molecular Biology; Biology; Biophysics; Electrochemistry SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Biophysics; Electrochemistry GA 404LK UT WOS:000167099500003 PM 10910159 ER PT J AU Proudnikov, D Kirillov, E Chumakov, K Donlon, J Rezapkin, G Mirzabekov, A AF Proudnikov, D Kirillov, E Chumakov, K Donlon, J Rezapkin, G Mirzabekov, A TI Analysis of mutations in oral poliovirus vaccine by hybridization with generic oligonucleotide microchips SO BIOLOGICALS LA English DT Article DE generic microchip; mutation analysis; hybridization; vaccine quality control ID FLUORESCENCE ANALYSIS; DNA; ARRAYS; VIRUS; IMMOBILIZATION; POLYMORPHISMS; POPULATIONS; DIAGNOSTICS; SEQUENCE AB This paper describes use of a new technology of hybridization with a micro-array of immobilized oligonucleotides for detection and quantification of neurovirulent mutants in Oral Poliovirus Vaccine (OPV). We used a micro-array consisting of three-dimensional gel-elements containing all possible hexamers (total of 4096 probes). Hybridization of fluorescently labelled viral cDNA samples with such microchips resulted in a pattern of spots that was registered and quantified by a computer-linked CCD camera, so that the sequence of the original cDNA could be deduced. The method could reliably identify single point mutations, since each of them affected fluorescence intensity of 12 micro-array elements. Micro-array hybridization of DNA mixtures with varying contents of point mutants demonstrated that the method can detect as little as 10% of revertants in a population of vaccine virus. This new technology should be useful for quality control of live viral vaccines, as well as for other applications requiring identification and quantification of point mutations. C1 Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. VA Engelhardt Mol Biol Inst, Moscow 117984, Russia. Ctr Biol Evaluat & Res, US FDA, Rockville, MD 20852 USA. RP Mirzabekov, A (reprint author), Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 23 TC 27 Z9 27 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1045-1056 J9 BIOLOGICALS JI Biologicals PD JUN PY 2000 VL 28 IS 2 BP 57 EP 66 DI 10.1006/biol.1999.0241 PG 10 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Pharmacology & Pharmacy SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Pharmacology & Pharmacy GA 318GU UT WOS:000087276200001 PM 10885613 ER PT J AU Glaeser, R Facciotti, M Walian, P Rouhani, S Holton, J MacDowell, A Celestre, R Cambie, D Padmore, H AF Glaeser, R Facciotti, M Walian, P Rouhani, S Holton, J MacDowell, A Celestre, R Cambie, D Padmore, H TI Characterization of conditions required for x-ray diffraction experiments with protein microcrystals SO BIOPHYSICAL JOURNAL LA English DT Article ID LIPIDIC CUBIC PHASES; RADIATION-DAMAGE; CRYSTALS; ELECTRON AB The x-ray exposure at which significant radiation damage occurs has been quantified for frozen crystals of bacteriorhodopsin. The maximum exposure to similar to 11-keV x-rays that can be tolerated for high-resolution diffraction experiments is found to be similar to 10(10) photons/mu m(2), very close to the value predicted from limits that were measured earlier for electron diffraction exposures. Sample heating, which would further reduce the x-ray exposure that could be tolerated, is not expected to be significant unless the x-ray flux density is well above 10(9) photons/s-mu m(2). Crystals of bacteriorhodopsin that contain similar to 10(11) unit cells are found to be large enough to give similar to 100 high-resolution diffraction patterns, each covering one degree of rotation. These measurements are used to develop simple rules of thumb for the minimum crystal size that can be used to record x-ray diffraction data from protein microcrystals. For work with very small microcrystals to be realized in practice, however, it is desirable that there be a significant reduction in the level of background scattering. Background reduction can readily be achieved by improved microcollimation of the x-ray beam, and additional gains can be realized by the use of helium rather than nitrogen in the cold gas stream that is used to keep the protein crystals frozen. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Grad Grp Biophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Expt Syst Grp, Berkeley, CA 94720 USA. RP Glaeser, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM51487] NR 9 TC 31 Z9 31 U1 1 U2 8 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JUN PY 2000 VL 78 IS 6 BP 3178 EP 3185 PG 8 WC Biophysics SC Biophysics GA 323TE UT WOS:000087580400037 PM 10827994 ER PT J AU Patterton, HG Graves, S AF Patterton, HG Graves, S TI DNAssist, a C++ program for editing and analysis of nucleic acid and protein sequences on PC-compatible computers running Windows 95, 98, NT4.0 or 2000 SO BIOTECHNIQUES LA English DT Article ID DNA; PREDICTION; ALIGNMENT; CLUSTAL AB The size of sequence databases, the rapid rate of generating sequence data and the need to routinely construct recombinant DNA molecules in molecular biological research necessitate the frequent handling and analysis of nucleotide and protein sequences on a computer Although several console or Web-based utility programs are available, the application of these programs generally requires reformatting the data when proceeding from one such program to the next. The acquisition of elaborate, integrated program suites is financially prohibitive to smaller laboratories. Here, we report the development of DNAssist, a shareware program for editing and analysis of nucleic acid and protein sequences. It was developed as a multiple-document interface program-similar to a word processor-where sequences are entered, edited and analyzed in a single integrated environment. DNAssist can calculate the physicochemical properties of a sequence, convert between nucleic acid and protein sequences, translate DNA in multiple frames, identify open reading frames and locate ambiguous sequence patterns allowing gaps and mismatches. DNAssist also performs restriction enzyme and transcription factor-binding site analyses of DNA sequences, the multiple alignment of nucleic acid and protein sequences and the analysis of DNA sequences for nucleosome positioning sites. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Univ Cape Town, ZA-7700 Rondebosch, South Africa. RP Graves, S (reprint author), POB 1024, Los Alamos, NM 87544 USA. EM steveg@dnassist.com OI Patterton, Hugh-George/0000-0003-2550-0493 NR 22 TC 5 Z9 5 U1 0 U2 0 PU BIOTECHNIQUES OFFICE PI NEW YORK PA 52 VANDERBILT AVE, NEW YORK, NY 10017 USA SN 0736-6205 EI 1940-9818 J9 BIOTECHNIQUES JI Biotechniques PD JUN PY 2000 VL 28 IS 6 BP 1192 EP 1197 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 323KW UT WOS:000087565400018 PM 10868284 ER PT J AU Loong, CK Rey, C Kuhn, LT Combes, C Wu, Y Chen, SH Glimcher, MJ AF Loong, CK Rey, C Kuhn, LT Combes, C Wu, Y Chen, SH Glimcher, MJ TI Evidence of hydroxyl-ion deficiency in bone apatites: An inelastic neutron-scattering study SO BONE LA English DT Article DE hydroxyapatite; bone apatite; hydroxyl ions; acid phosphates ID SYNTHETIC CALCIUM PHOSPHATES; NUCLEAR-MAGNETIC-RESONANCE; X-RAY-DIFFRACTION; LOW-TEMPERATURE; HYDROXYAPATITE; SPECTROSCOPY; CARBONATE; P-31 AB The novelty of very large neutron-scattering intensity from the nuclear-spin incoherence in hydrogen has permitted the determination of atomic motion of hydrogen in synthetic hydroxyapatite and in deproteinated isolated apatite crystals of bovine and rat hone without the interference of vibrational modes from other structural units. From an inelastic neutron-scattering experiment, we found no sharp excitations characteristic of the vibrational mode and stretch vibrations of OH ions around 80 and 450 meV (645 and 3630 cm(-1)), respectively, in the isolated, deproteinated crystals of bone apatites; such salient features were clearly seen in micron- and nanometer-size crystals of pure hydroxyapatite powders. Thus, the data provide additional definitive evidence for the lark of OH- ions in the crystals of hone apatite. Weak features at 160-180 and 376 meV, which are clearly observed in the apatite crystals of rat bone and possibly in adult mature bovine bone, but to a much lesser degree, but not in the synthetic hydroxyapatite, are assigned to the deformation and stretch modes of OH ions belonging to HPO4-like species. (Bone 26:599-602; 2000) (C) 2000 by Elsevier Science Inc. All rights reserved. C1 Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. INP, ENSCT, UPRESA, Lab Interfaces & Mat Physicochim Phosphates, Toulouse, France. Harvard Univ, Childrens Hosp, Sch Med,Dept Orthopaed Surg, Lab Study Skeletal Disorders & Rehabil, Boston, MA 02115 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. RP Loong, CK (reprint author), Argonne Natl Lab, Div Intense Pulsed Neutron Source, Bldg 360,9700 S Cass Ave, Argonne, IL 60439 USA. NR 42 TC 63 Z9 65 U1 3 U2 16 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 8756-3282 J9 BONE JI Bone PD JUN PY 2000 VL 26 IS 6 BP 599 EP 602 DI 10.1016/S8756-3282(00)00273-8 PG 4 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 318GZ UT WOS:000087276700008 PM 10831931 ER PT J AU Morris, GM Smith, DR Patel, H Chandra, S Morrison, GH Hopewell, JW Rezvani, M Micca, PL Coderre, JA AF Morris, GM Smith, DR Patel, H Chandra, S Morrison, GH Hopewell, JW Rezvani, M Micca, PL Coderre, JA TI Boron microlocalization in oval mucosal tissue: implications for boron neutron capture therapy SO BRITISH JOURNAL OF CANCER LA English DT Article DE borocaptate sodium; p-boronophenylalanine; rat ventral tongue mucosa; compound biological effectiveness factor; ion microscopy imaging ID MOUSE TONGUE EPITHELIUM; B-10(N,ALPHA)LI-7 REACTION; FRACTIONATED IRRADIATIONS; P-BORONOPHENYLALANINE; ION MICROSCOPY; CELLS; MODEL; SKIN; REPOPULATION; B-10 AB Clinical studies of the treatment of glioma and cutaneous melanoma using boron neutron capture therapy (BNCT) are currently taking place in the USA, Europe and Japan. New BNCT clinical facilities are under construction in Finland, Sweden, England and California The observation of transient acute effects in the oral mucosa of a number of glioma patients involved in the American clinical trials, suggests that radiation damage of the oral mucosa could be a potential complication in future BNCT clinical protocols, involving higher doses and larger irradiation field sizes. The present investigation is the first to use a high resolution surface analytical technique to relate the microdistribution of boron-10 (B-10) in the oral mucosa to the biological effectiveness of the B-10(n,alpha)Li-7 neutron capture reaction in this tissue. The two boron delivery agents used clinically in Europe/Japan and the USA, borocaptate sodium (BSH) and p-boronophenylalanine (BPA), respectively, were evaluated using a rat ventral tongue model. B-10 concentrations in various regions of the tongue mucosa were estimated using ion microscopy. In the epithelium, levels of B-10 were appreciably tower after the administration of BSH than was the case after BPA. The epithelium:blood B-10 partition ratios were 0.2:1 and 1:1 far BSH and BPA respectively. The B-10 content of the lamina propria was higher than that measured in the epithelium for both BSH and BPA. The difference was most marked for BSH, where B-10 levels were a factor of six higher in the lamina propria than in the epithelium. The concentration of B-10 was also measured in blood vessel walls where relatively low levels of accumulation of BSH, as compared with BPA, was demonstrated in blood vessel endothelial cells and muscle. Vessel wall:blood B-10 partition ratios were 0.3:1 and 0.9:1 for BSH and BPA respectively Evaluation of tongue mucosal response (ulceration) to BNC irradiation indicated a considerably reduced radiation sensitivity using BSH as the boron delivery agent relative to BPA. The compound biological effectiveness (CBE) factor for BSH was estimated at 0.29 +/- 0.02. This compares with a previously published CBE factor for BPA of 4.87 +/- 0.16. It was concluded that variations in the microdistribution profile of B-10, using the two boron delivery agents, had a significant effect on the response of oral mucosa to BNC irradiation. From a clinical perspective, based on the findings of the present study, it is probable that potential radiation-induced oral mucositis will be restricted to BNCT protocols involving BPA. However, a thorough high resolution analysis of B-10 microdistribution in human oral mucosal tissue, using a technique such as ion microscopy, is a prerequisite for the use of experimentally derived CBE factors in clinical BNCT. (C) 2000 Cancer Research Campaign. C1 Univ Oxford, Churchill Hosp, Res Inst, Oxford OX3 7LJ, England. Cornell Univ, Baker Lab, Dept Chem & Biol Chem, Ithaca, NY 14853 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Morris, GM (reprint author), Univ Oxford, Churchill Hosp, Res Inst, S Parks Rd, Oxford OX3 7LJ, England. NR 33 TC 17 Z9 19 U1 0 U2 4 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH EH1 3AF, MIDLOTHIAN, SCOTLAND SN 0007-0920 J9 BRIT J CANCER JI Br. J. Cancer PD JUN PY 2000 VL 82 IS 11 BP 1764 EP 1771 DI 10.1054/bjoc.2000.1148 PG 8 WC Oncology SC Oncology GA 315UY UT WOS:000087132400002 PM 10839288 ER PT J AU Turner, DD Feltz, WF Ferrare, RA AF Turner, DD Feltz, WF Ferrare, RA TI Continuous water vapor profiles from operational ground-based active and passive remote sensors SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID RAMAN LIDAR MEASUREMENTS; ATMOSPHERIC RADIATION; AEROSOL EXTINCTION; TEMPERATURE; RADIANCE; BACKSCATTERING; SYSTEM AB The Atmospheric Radiation Measurement program's Southern Great Plains Cloud and Radiation Testbed site central facility near Lament, Oklahoma, offers unique operational water vapor profiling capabilities, including active and passive remote sensors as well as traditional in situ radiosonde measurements. Remote sensing technologies include an automated Raman lidar and an automated Atmospheric Emitted Radiance Interferometer (AERI), which are able to retrieve water vapor profiles operationally through the lower troposphere throughout the diurnal cycle. Comparisons of these two water vapor remote sensing methods to each other and to radiosondes over an 8-month period are presented and discussed, highlighting the accuracy and limitations of each method. Additionally, the AERI is able to retrieve profiles of temperature while the Raman lidar is able to retrieve aerosol extinction profiles operationally. These data, coupled with hourly wind profiles from a 915-MHz wind profiler, provide complete specification of the state of the atmosphere in noncloudy skies. Several case studies illustrate the utility of these high temporal resolution measurements in the characterization of mesoscale features within a 3-day time period in which passage of a dryline, warm air advection, and cold front occurred. C1 Pacific NW Lab, Climate Dynam Grp, Richland, WA 99352 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Ctr Space Sci & Engn, Madison, WI USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Turner, DD (reprint author), Pacific NW Lab, Climate Dynam Grp, POB 999,MS K9-38, Richland, WA 99352 USA. NR 31 TC 52 Z9 52 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUN PY 2000 VL 81 IS 6 BP 1301 EP 1317 DI 10.1175/1520-0477(2000)081<1301:CWBPFO>2.3.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 319FF UT WOS:000087330300008 ER PT J AU Korneev, VA McEvilly, TV Karageorgi, ED AF Korneev, VA McEvilly, TV Karageorgi, ED TI Seismological studies at Parkfield VIII: Modeling the observed travel-time changes SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID WAVE-PROPAGATION; CALIFORNIA; MICROEARTHQUAKES; FAULT AB For 10 years, as one element of the Parkfield, California, Prediction Experiment, the borehole seismographic network was illuminated routinely by a large shear-wave Vibroseis from several source points to investigate the stability of wave propagation in the fault zone and the possibility of nucleation-related premonitory phenomena. Clear and progressive travel-time changes of up to 50 msec were detected during the study, most prominent in the S-wave coda, and localized to propagation paths through the shallow fault zone (above about 500 m depth) southeast of Middle Mountain, the section of the fault where previous M 6 earthquakes have initiated. We model the observations successfully as interaction (reflection and transmission) of the shallow wavefield with a 200-meter-wide low-velocity fault zone in which the velocity increases by 6%. due, we hypothesize, to hydrological changes accompanying a significant pulse in fault slip rate and seismicity. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Seismol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley Seismol Lab, Berkeley, CA 94720 USA. Enterprise Oil Explorat Ltd, Athens 15125, Greece. RP Korneev, VA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Seismol, Berkeley, CA 94720 USA. NR 14 TC 11 Z9 14 U1 0 U2 1 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 2000 VL 90 IS 3 BP 702 EP 708 DI 10.1785/0119990038 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 334DN UT WOS:000088170600012 ER PT J AU Fehler, M Phillips, WS House, L Jones, RH Aster, R Rowe, C AF Fehler, M Phillips, WS House, L Jones, RH Aster, R Rowe, C TI Improved relative locations of clustered earthquakes using constrained multiple event location SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SOUTHERN CALIFORNIA; AFTERSHOCK SEQUENCE; FAULT; MICROEARTHQUAKES; VELOCITY; PATTERNS; COALINGA; DOUBLETS; PLANES; ANZA AB A new method for improving relative locations of clustered earthquakes is presented and applied to a suite of microearthquakes induced by hydraulic fracturing. The method is based on the assumption that clustering of earthquake hypocenters is obscured by the uncorrelated scatter of individual hypocenters, The method is implemented as an additional constraint in a Joint Hypocenter Determination (JHD) scheme. The method shifts event hypocenters toward the center of mass of the events within some volume surrounding the event location if the RMS misfit between predicted and measured arrival times does not increase significantly. The method uses the same basic assumption of Jones and Stewart (1997), which is that there is greater clustering in actual earthquake locations than there is in locations determined using conventional techniques, Our method differs in that it is implemented as part of the JHD process so it operates on raw travel-time data rather than on derived hypocenters. The method produces hypocenters from a demonstration field dataset that are similar to those obtained by Phillips Et al. (1997), from time-consuming precise manual repicking of relative arrival times of events. The clustering constraint can easily be incorporated as an additional constraint in earthquake location/velocity tomography codes and may lead to improved velocity structure determination and earthquake location pattern identification and interpretation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos Seism Res Ctr, Los Alamos, NM 87545 USA. ABB Offshore Syst, Penryn, Cornwall, England. New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA. New Mexico Inst Min & Technol, Res Ctr, Socorro, NM 87801 USA. RP Fehler, M (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos Seism Res Ctr, POB 1663, Los Alamos, NM 87545 USA. RI Aster, Richard/E-5067-2013 OI Aster, Richard/0000-0002-0821-4906 NR 24 TC 9 Z9 10 U1 0 U2 3 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 2000 VL 90 IS 3 BP 775 EP 780 DI 10.1785/0119990095 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 334DN UT WOS:000088170600018 ER PT J AU Pasyanos, ME AF Pasyanos, ME TI Predicting geophysical measurements: Testing a combined empirical and model-based approach using surface waves SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB There are several approaches commonly used to provide spatial corrections of geophysical data. One end-member approach is to develop model-based corrections in which the variations are based either on a priori knowledge or on geophysical inversions, such as tomography. While this approach would have the advantage of full spatial coverage, in general one would be unable to recover the full station corrections due to the inherent averaging of models. Another end-member approach, common in seismically active regions, would be to develop empirically based corrections based directly on measurements. An example of this approach would be kriging or other interpolation techniques. The advantage of this approach is a true fit to the most applicable measurements, but at the cost of severe spatial limitations. Ideally, one would like to combine the two approaches. This short note demonstrates the value of a combined empirical and model-based approach to generating accurate spatial correction surfaces using surface wave measurements and a tomography model from the Middle East and North Africa. By kriging residual values from a tomographic model, there was a significant reduction in misfit over either approach alone. In principle, kriging measurement residuals from models could improve many geophysical applications from travel times to amplitudes. C1 Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, Livermore, CA 94551 USA. RP Pasyanos, ME (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, POB 808,L-205, Livermore, CA 94551 USA. RI Pasyanos, Michael/C-3125-2013 NR 13 TC 7 Z9 7 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD JUN PY 2000 VL 90 IS 3 BP 790 EP 796 DI 10.1785/0119990144 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 334DN UT WOS:000088170600021 ER PT J AU Guidotti, CV Sassi, FP Comodi, P Zanazzi, PF Blencoe, JG AF Guidotti, CV Sassi, FP Comodi, P Zanazzi, PF Blencoe, JG TI The contrasting responses of muscovite and paragonite to increasing pressure: Petrological implications SO CANADIAN MINERALOGIST LA English DT Article DE muscovite; paragonite; celadonite; mica; crystal structure; compressibility; high pressure ID COMPOSITIONAL CONTROLS; CELL DIMENSIONS; 2M1 MUSCOVITE; PHLOGOPITE; SOLVUS; MICAS; PAIRS AB The incorporation of Fe, Mg, and Si into muscovite in response to increase of pressure (P) has long been recognized. In the context of the appropriate mineral assemblages, the extent of this substitution has been calibrated to serve as a very useful geobarometer for high-P parageneses. In marked contrast, little or no Fm i.e., Sigma(Mg + Fe-total), substitutes into paragonite regardless of P. To date, Fm substitution into muscovite has been considered only in terms of Delta V-r with little consideration of the crystallochemical aspects of this substitution. Moreover, the substitution seems to occur in response to simple exchange-reactions involving little or no dehydration. Such reactions typically have a negligible Delta V-r. Drawing upon the implications of studies combining high-P refinement of the crystal structures and measurement of compressibility, we suggest that high P causes structural changes in low-Fm muscovite that destabilize it. However, implementation of the Fm substitution facilitates structural adjustments, which reduce this instability. In contrast, paragonite is not only intrinsically less compressible than muscovite, but any substantial amount of Fm substitution would destabilize it. C1 Univ Maine, Dept Geol Sci, Orono, ME 04469 USA. Univ Padua, Dipartimento Mineral & Petrol, I-35137 Padua, Italy. Dipartimento Sci Terra, I-06100 Perugia, Italy. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guidotti, CV (reprint author), Univ Maine, Dept Geol Sci, Orono, ME 04469 USA. OI COMODI, Paola/0000-0002-1899-0589 NR 23 TC 7 Z9 7 U1 0 U2 3 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN, ONTARIO K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD JUN PY 2000 VL 38 BP 707 EP 712 DI 10.2113/gscanmin.38.3.707 PN 3 PG 6 WC Mineralogy SC Mineralogy GA 345ZM UT WOS:000088845500015 ER PT J AU Kennel, SJ Chappell, LL Dadachova, K Brechbiel, MW Lankford, TK Davis, IA Stabin, M Mirzadeh, S AF Kennel, SJ Chappell, LL Dadachova, K Brechbiel, MW Lankford, TK Davis, IA Stabin, M Mirzadeh, S TI Evaluation of Ac-225 for vascular targeted radioimmunotherapy of lung tumors SO CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS LA English DT Article DE Ac-225; HEHA; vascular targeting; radiotoxicity ID ALPHA-PARTICLE EMITTER; MONOCLONAL-ANTIBODY; ACETIC ACIDS; BI-213; COMPLEXES; RADIOTOXICITY; ACTINIUM-225 AB Several alpha particle emitting radioisotopes have been studied for use in radioimmunotherapy. Ac-225 has the potential advantages of a relatively long half life of 10 days, and a yield of 4 alpha emissions in its decay chain with a total energy release of similar to 28 MeV. A new, 12 coordination site chelating ligand, HEHA, has been chemically modified for coupling to targeting proteins without loss of chelating ability. HEHA was coupled with MAb 201B which binds to thrombomodulin and accumulates efficiently in murine lung. Ac-225 was bound to the HEHA-MAb 201B conjugate and injected into BALB/c mice bearing lung tumor colonies of EMT-6 mammary carcinoma. Biodistribution data at 1 and 4 h postinjection indicated that, as expected, Ac-225 was delivered to lung efficiently (>300 % ID/g). The Ac-225 was slowly released from the lung with an initial t(1/2) = 49 h, and the released Ac-225 accumulated in the liver. Injection of free HEHA was only partially successful in scavenging free Ac-225. I, addition to the slow release of Ac-225 from the chelate, data indicated that decay daughters of Ac-225 were also released from the lung. Immediately after organ harvest, the level of Bi-213, the third alpha-decay daughter was found to be deficient in the lungs and to be in excess in the kidney, relative to equilibrium values. Injected doses of Ac-225 MAb 201B of 1.0 mu Ci, delivering a minimum calculated absorbed dose of about 6 Gy to the lungs, was effective in killing lung tumors, but also proved acutely radiotoxic. Animals treated with 1.0 mu Ci or move of the Ac-225 radioconjugate died of a wasting syndrome within days with a dose dependent relationship. We conclude that the potential for Ac-225 as a radioimmunotherapeutic agent is compromised not only by the slow release of Ac-225 from the HEHA chelator, but most importantly by the radiotoxicity associated with decay daughter radioisotopes released from the target organ. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NCI, Div Clin Sci, NIH, Bethesda, MD 20892 USA. UFPE, Dept Nucl Energy, Recife, PE, Brazil. RP Kennel, SJ (reprint author), Oak Ridge Natl Lab, Div Life Sci, POB 2008,Bldg 4500S,Rm F150,Bethel Valley Rd, Oak Ridge, TN 37831 USA. RI Dadachova, Ekaterina/I-7838-2013 FU NHLBI NIH HHS [HL09718] NR 29 TC 38 Z9 40 U1 3 U2 9 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1084-9785 J9 CANCER BIOTHER RADIO JI Cancer Biother. Radiopharm. PD JUN PY 2000 VL 15 IS 3 BP 235 EP 244 DI 10.1089/108497800414329 PG 10 WC Oncology; Medicine, Research & Experimental; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Research & Experimental Medicine; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging GA 339HM UT WOS:000088471700003 PM 10941530 ER PT J AU Liepe, K Hliscs, R Kropp, J Gruning, T Runge, R Koch, R Knapp, FF Franke, WG AF Liepe, K Hliscs, R Kropp, J Gruning, T Runge, R Koch, R Knapp, FF Franke, WG TI Rhenium-188-HEDP in the palliative treatment of bone metastases SO CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS LA English DT Article DE Rhenium-188-HEDP; pain palliation; bone metastases ID PROSTATE-CANCER; OSSEOUS METASTASES; SR-89; GENERATOR; RE-188; PAIN AB Introduction: Rhenium-188-HEDP (Re-188-HEDP) is a new and attractive radiopharmaceutical for the treatment of bone pain due to metastases. As a product of a W-188/Re-188 generator it is convenient for clinical use. With a short physical half life of 16.9 hours and a maximal beta-energy of 2.1 MeV, it is suitable for therapy. Methods: We investigated the influence of Re-188 HEDP on pain relief analgesic intake and impairment of bone marrow function in 15 patients. All patients were interviewed using standardized questions before, and 1, 2, 3, 4 8 and 12 weeks after therapy. Blood samples were drawn weekly for 12 weeks, and a blood count was performed Patients underwent gamma camera imaging to determine the radionuclide accumulation 4, 20 and 28 hours after therapy. The patients were treated with 1600 to 3459 MBq of Re-188-HEDP. Results: Patients showed an improvement of the Karnofsky performance index from 74 +/- 8% to 84 +/- 11% 12 weeks after therapy. This improvement was statistically significant (p = 0.001). Eighty percent of the patients described pain relief and reduction of analgesics. Twenty percent of the patients could discontinue their analgesics. Mean platelet count decreased from (284 +/- 84)*10(3)/mu l to (205 +/- 62)*10(3)/mu l, and mean leukocyte count from (7.5 +/- 1.5)*10(3)/mu l to (5.9 +/- 2.1)*10(3)/mu l after therapy. The maximal differences between the values of platelets and leukocytes before and after therapy were not statistically significant (p = 0.021 and p = 0094). Prostate specific antigen decreased from 95 +/- 83 ng/ml to 41 +/- 21 ng/ml, the difference was not statistically significant (p = 0.443). The bone accumulation 4, 20 and 28 hours after therapy was 1.3 +/- 0.5%, 0.6 +/- 0.3%, and 0.45 +/- 0.2% of the injected dose of a single metastasis, and 57 +/- 17%, 15.5 +/- 2% and II +/- 3% in the whole body, respectively. The effective half-life of Re-188-HEDP was 15.3 +/- 3.0 hours in the bone metastases, and 11.4 +/- 2.8 hours in the whole body. This corresponds to a residence time of 0.22 +/- 0.25 hours in the bone metastases, and of 10.54 +/- 2.59 hours in the whole body. Conclusion: In a small patient population, Re-188-HEDP therapy for bone pain palliation was effective and was associated with minimal toxicity. C1 Univ Hosp Dresden, Dept Nucl Med, D-01307 Dresden, Germany. Univ Hosp Dresden, Inst Med Informat & Biometry, D-01307 Dresden, Germany. Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN USA. RP Liepe, K (reprint author), Univ Hosp Dresden, Dept Nucl Med, Fetscherstr 74, D-01307 Dresden, Germany. RI Gruning, Thomas/B-9306-2014 OI Gruning, Thomas/0000-0003-3847-5303 NR 17 TC 21 Z9 26 U1 1 U2 3 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1084-9785 J9 CANCER BIOTHER RADIO JI Cancer Biother. Radiopharm. PD JUN PY 2000 VL 15 IS 3 BP 261 EP 265 DI 10.1089/108497800414356 PG 5 WC Oncology; Medicine, Research & Experimental; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Research & Experimental Medicine; Pharmacology & Pharmacy; Radiology, Nuclear Medicine & Medical Imaging GA 339HM UT WOS:000088471700006 PM 10941533 ER PT J AU Kabuto, M Akiba, S Stevens, RG Neriishi, K Land, CE AF Kabuto, M Akiba, S Stevens, RG Neriishi, K Land, CE TI A prospective study of estradiol and breast cancer in Japanese women SO CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION LA English DT Article ID CASE-CONTROL INTERVIEW; SEX-HORMONE LEVELS; A-BOMB SURVIVORS; POSTMENOPAUSAL WOMEN; SERUM ESTROGEN; RISK; GUERNSEY AB Few studies have prospectively examined endogenous hormone levels as risk factors for breast cancer, The present study compares prediagnostic hormone levels using stored serum from breast cancer cases and controls selected from the Life Span Study population of the Radiation Effects Research Foundation in Hiroshima and Nagasaki, Japan. Stored serum samples collected in 1968-1970 were assayed for 72 women subsequently diagnosed with breast cancer and 150 control subjects in 72 case-control sets matched on age, date of blood collection, exposure, radiation dose, and city, Serum levels were determined for sex hormone binding globulin, total estradiol (E-2), bioavailable E-2, dehydroepiandrosterone sulfate, and prolactin, Matched case-control comparisons of hormone levels were carried out by conditional logistic regression and were adjusted for menopausal status at the time of blood drawing. The odds ratio per unit log change in bioavailable E-2 was 2.2 [95% confidence interval (CI), 1.02-5.3] for all subjects, and 2.3 (95% CI, 0.55-6.8) and 2.1 (95% CI, 0.55-9.7), respectively, based only on premenopausal or postmenopausal serum. The estimated odds ratios in each quintile of bioavailable E2 level, using the lowest quintile as referent, were 1.00, 1.89, 1.43, 3.45, and 3.37 (P for trend = 0.035), For sex hormone binding globulin, the overall odds ratio was 0.58 (95% CI, 0.14-2.26), and 1.00 (95% CI, 0.19-5.45) and 0.21 (95% CI, 0.02-1.88) based on premenopausal and postmenopausal serum, respectively, This study offers further prospective support for the hypothesis that a high level of biologically available E-2 is a risk factor for the subsequent development of breast cancer. C1 Radiat Effects Res Fdn, Dept Clin Studies, Minami Ku, Hiroshima 7320815, Japan. Radiat Effects Res Fdn, Dept Epidemiol, Hiroshima, Japan. Natl Inst Environm Studies, Environm Risk Res Div, Tsukuba, Ibaraki 3050053, Japan. Kagoshima Univ, Fac Med, Dept Publ Hlth, Kagoshima 8900075, Japan. Pacific NW Natl Lab, Richland, WA 99352 USA. NCI, Radiat Epidemiol Branch, Bethesda, MD 20892 USA. RP Neriishi, K (reprint author), Radiat Effects Res Fdn, Dept Clin Studies, Minami Ku, Hiroshima 7320815, Japan. NR 22 TC 118 Z9 121 U1 1 U2 2 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 1055-9965 J9 CANCER EPIDEM BIOMAR JI Cancer Epidemiol. Biomarkers Prev. PD JUN PY 2000 VL 9 IS 6 BP 575 EP 579 PG 5 WC Oncology; Public, Environmental & Occupational Health SC Oncology; Public, Environmental & Occupational Health GA 324RC UT WOS:000087634300007 PM 10868691 ER PT J AU Singer, B Hang, B AF Singer, B Hang, B TI Nucleic acid sequence and repair: role of adduct, neighbor bases and enzyme specificity SO CARCINOGENESIS LA English DT Editorial Material ID THYMINE-DNA GLYCOSYLASE; NUCLEOTIDE EXCISION-REPAIR; CENTER-DOT-C; ESCHERICHIA-COLI; MUTATION SPECTRA; KLENOW FRAGMENT; MISMATCH REPAIR; POLYMERASE INSERTION; N-METHYLPURINES; G/T MISMATCH C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Singer, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA 47723, CA 72079]; NIEHS NIH HHS [ES 07368] NR 91 TC 18 Z9 18 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD JUN PY 2000 VL 21 IS 6 BP 1071 EP 1078 DI 10.1093/carcin/21.6.1071 PG 8 WC Oncology SC Oncology GA 327XE UT WOS:000087819100001 PM 10836993 ER PT J AU Allan, ML AF Allan, ML TI Materials characterization of superplasticized cement-sand grout SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE permeability; bond strength; elastic moduli; mechanical properties; grout AB Selected material properties were determined for a superplasticized cement-sand grout formulation designed for sealing boreholes used with geothermal heat pumps (GHPs). The grout was investigated as an alternative to bentonite and near cements. Hydraulic conductivities (permeability coefficients) of grouts when cast around high density polyethylene (HDPE) pipes to represent a heat exchanger were measured over a range of typical operating temperatures. It was determined that the cement-sand grout had hydraulic conductivity up to two orders of magnitude lower than neat cements depending on test temperature. Infiltration tests performed on grouted tubes containing HDPE pipes also indicated better sealing capability with the cement-sand grout. Mechanical properties measured included bond strength to HDPE, compressive and splitting tensile strength, dynamic and static elastic moduli, shear modulus and Poisson's ratio. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Allan, ML (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RI Chen, Wei/A-5694-2010; Berndt, Marita/D-1901-2014 OI Berndt, Marita/0000-0002-6622-0597 NR 12 TC 20 Z9 22 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD JUN PY 2000 VL 30 IS 6 BP 937 EP 942 DI 10.1016/S0008-8846(00)00275-1 PG 6 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 342JU UT WOS:000088642100012 ER PT J AU Tolle, CR Budzien, JL LaViolette, RA AF Tolle, CR Budzien, JL LaViolette, RA TI Do dynamical systems follow Benford's law? SO CHAOS LA English DT Article ID MOLECULAR-DYNAMICS; DIGIT PHENOMENON; SIMULATIONS AB Data compiled from a variety of sources follow Benford's law, which gives a monotonically decreasing distribution of the first digit (1 through 9). We examine the frequency of the first digit of the coordinates of the trajectories generated by some common dynamical systems. One-dimensional cellular automata fulfill the expectation that the frequency of the first digit is uniform. The molecular dynamics of fluids, on the other hand, provides trajectories that follow Benford's law. Finally, three chaotic systems are considered: Lorenz, Henon, and Rossler. The Lorenz system generates trajectories that follow Benford's law. The Henon system generates trajectories that resemble neither the uniform distribution nor Benford's law. Finally, the Rossler system generates trajectories that follow the uniform distribution for some parameters choices, and Benford's law for others. (C) 2000 American Institute of Physics. [S1054-1500(00)01402-6]. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP LaViolette, RA (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RI Budzien, Joanne/E-8315-2011 NR 23 TC 21 Z9 22 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD JUN PY 2000 VL 10 IS 2 BP 331 EP 336 DI 10.1063/1.166498 PG 6 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 319MT UT WOS:000087346300004 ER PT J AU Berman, GP James, DFV Kamenev, DI AF Berman, GP James, DFV Kamenev, DI TI Quantum chaos of an ion trapped in a linear ion trap SO CHAOS LA English DT Article ID CYCLOTRON-RESONANCE; DEGENERATE SYSTEM; STATE AB We describe the transition to quantum chaos of an ion trapped in a linear ion trap and interacting with two laser fields. Under the conditions of adiabatic illumination of the upper level of the ion, and when the frequencies of the two laser beams are slightly different, the system is reduced to a quantum linear oscillator interacting with a monochromatic wave. The property of localization over the quantum resonance cells is proposed to exploit in order to facilitate the process of measurement of the probability distribution of an ion on the vibrational levels. In the regime of strong chaos the time-averaged values of the energy and dispersion of energy are computed and compared with the corresponding classical quantities for different values of the perturbation amplitude. In the exact resonance case, the classical analog of the system possesses an infinite inhomogeneous stochastic web. We analyze the quantum dynamics inside the inhomogeneous web. It is shown that the quantum system mimics on average the dynamics of the corresponding classical system. Formation of the quantum resonance cells is illustrated in the case of a finite detuning from the exact resonance, and under increasing of the wave amplitude. The parameters of the model and the initial conditions are close to the real physical situation which can be realized in the system of cold trapped ion perturbed by two lasers fields with close frequencies. (C) 2000 American Institute of Physics. [S1054-1500(00)01502-0]. C1 Univ Calif Los Alamos Natl Lab, Theoret Div T13, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T4, Los Alamos, NM 87545 USA. Nizhny Novgorod State Univ, Nizhnii Novgorod 603600, Russia. RP Berman, GP (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Div T13, Los Alamos, NM 87545 USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 21 TC 3 Z9 3 U1 3 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD JUN PY 2000 VL 10 IS 2 BP 371 EP 382 AR PII [S1054-1500(00)01502-0] DI 10.1063/1.166504 PG 12 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 319MT UT WOS:000087346300010 ER PT J AU Wood, BD Whitaker, S AF Wood, BD Whitaker, S TI Diffusion and reaction in biofilms (vol 53, pg 397, 1998) SO CHEMICAL ENGINEERING SCIENCE LA English DT Correction C1 Pacific NW Lab, Richland, WA 99352 USA. Univ Calif Davis, Davis, CA 95616 USA. RP Wood, BD (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. RI Wood, Brian/K-4025-2012; Wood, Brian/J-8362-2013 OI Wood, Brian/0000-0003-3152-7852; Wood, Brian/0000-0003-3152-7852 NR 2 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD JUN PY 2000 VL 55 IS 12 BP 2349 EP 2349 PG 1 WC Engineering, Chemical SC Engineering GA 298VJ UT WOS:000086159600024 ER PT J AU Block, J Dolhert, LE Petrakis, L Webster, RP AF Block, J Dolhert, LE Petrakis, L Webster, RP TI Eliminating asbestos from fireproofing materials SO CHEMICAL INNOVATION LA English DT Article ID PUBLIC-POLICY C1 WR Grace & Co, DMA Business, Columbia, MD 21044 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Brookhaven Natl Lab, Energy Sci & Technol Dept, Asbestos Res Facil, Upton, NY 11973 USA. RP Block, J (reprint author), WR Grace & Co, DMA Business, 7500 Grace Dr, Columbia, MD 21044 USA. NR 32 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1527-4799 J9 CHEM INNOV JI Chem. Innov. PD JUN PY 2000 VL 30 IS 6 BP 21 EP 29 PG 9 WC Chemistry, Applied SC Chemistry GA 323BV UT WOS:000087545700003 ER PT J AU Naguleswaran, S Reid, MF Stedman, GE AF Naguleswaran, S Reid, MF Stedman, GE TI Prediction of pure electric-dipole two-photon absorption circular dichroism in lanthanide compounds SO CHEMICAL PHYSICS LA English DT Article ID 2ND HARMONIC-GENERATION; 2ND-HARMONIC GENERATION; OPTICAL-ACTIVITY; CHIRAL SURFACES; INTENSITY PARAMETERS; 2-PHOTON ABSORPTION; MOLECULES; SPECTROSCOPY; MONOLAYERS; INTERFACES AB Standard theories of chiral linear and nonlinear optical effects, such as circular intensity differentials and optical activity, require interference between electric-dipole and magnetic-dipole (or higher-order) contributions to the transition moments. Recent experimental and theoretical work on second-harmonic generation processes has shown that in the resonant case, pure electric-dipole contributions to such chiral effects are possible. In this paper, we consider the implications of pure electric-dipole contributions to circular dichroism in two-photon absorption transitions within the 4f(N) configuration of lanthanide ions. We show that in some lanthanide compounds, when several intermediate states are near to resonance, the pure electric-dipole mechanism can give larger contributions than the standard electric-dipole magnetic-dipole mechanism. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Canterbury, Dept Phys & Astron, Christchurch 8020, New Zealand. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Stedman, GE (reprint author), Univ Canterbury, Dept Phys & Astron, Private Bag 4800, Christchurch 8020, New Zealand. OI Reid, Michael/0000-0002-2984-9951 NR 34 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JUN 1 PY 2000 VL 256 IS 2 BP 207 EP 212 DI 10.1016/S0301-0104(00)00107-5 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 319ZA UT WOS:000087375300007 ER PT J AU Goldman, R Day, BW Carver, TA Mauthe, RJ Turteltaub, KW Shields, PG AF Goldman, R Day, BW Carver, TA Mauthe, RJ Turteltaub, KW Shields, PG TI Quantitation of benzo[a]pyrene-DNA adducts by postlabeling with C-14-acetic anhydride and accelerator mass spectrometry SO CHEMICO-BIOLOGICAL INTERACTIONS LA English DT Article DE molecular epidemiology; carcinogenesis; C-14-postlabeling; DNA adduct; benzo[a]pyrene ID CANCER-SUSCEPTIBILITY GENES; HYDROCARBON-DNA ADDUCTS; BREAST-CANCER; CIGARETTE-SMOKING; MOLECULAR EPIDEMIOLOGY; HUMAN-LUNG; RISK; POLYMORPHISMS; BIOMARKERS; PREVENTION AB Quantitation of carcinogen-DNA adducts provides an estimate of the biologically effective dose of a chemical carcinogen reaching the target tissue. In order to improve exposure-assessment and cancer risk estimates, we are developing an ultrasensitive procedure for the detection of carcinogen-DNA adducts. The method is based upon postlabeling of carcinogen-DNA adducts by acetylation with C-14-acetic anhydride combined with quantitation of C-14 by accelerator mass spectrometry (AMS). For this purpose, adducts of benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide (BPDE) with DNA and deoxyguanosine (dG) were synthesized. The most promutagenic adduct of BPDE, 7R,8S,9X-trihydroxy-10S-(N-2-deoxyguanosyl)-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG). was HPLC purified and structurally characterized. Postlabeling of the BPdG adduct with acetic anhydride yielded a major product with a greater than 60% yield. The postlabeled adduct was identified by liquid chromatography-mass spectrometry as pentakis(acetyl) BPdG (AcBPdG). Postlabeling of the BPdG adduct with C-14-acetic anhydride yielded a major product coeluting with an AcBPdG standard. Quantitation of the C-14-postlabeled adduct by AMS promises to allow detection of attomolar amounts of adducts. The method is now being optimized and validated for use in human samples. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved. C1 NCI, Human Carcinogenesis Lab, NIH, Bethesda, MD 20892 USA. Univ Pittsburgh, Dept Environm & Occupat Hlth, Pittsburgh, PA 15238 USA. Univ Pittsburgh, Dept Pharmaceut Sci, Pittsburgh, PA 15238 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Pfizer Inc, Groton, CT 06340 USA. RP Shields, PG (reprint author), Georgetown Univ, Med Ctr, Vincent T Lombardi Canc Res Ctr, Canc Genet & Epidemiol Program, Res Bldg W301,3970 Reservoir Rd NW, Washington, DC 20007 USA. RI Shields, Peter/I-1644-2012 NR 34 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0009-2797 J9 CHEM-BIOL INTERACT JI Chem.-Biol. Interact. PD JUN 1 PY 2000 VL 126 IS 3 BP 171 EP 183 DI 10.1016/S0009-2797(00)00160-5 PG 13 WC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Toxicology SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Toxicology GA 326LZ UT WOS:000087738200001 PM 10862816 ER PT J AU Abdelouas, A Gong, WL Lutze, W Shelnutt, JA Franco, R Moura, I AF Abdelouas, A Gong, WL Lutze, W Shelnutt, JA Franco, R Moura, I TI Using cytochrome c(3) to make selenium nanowires SO CHEMISTRY OF MATERIALS LA English DT Article ID ELECTRON-BEAM LITHOGRAPHY; DESULFOVIBRIO-VULGARIS; NANOSTRUCTURES; REDUCTION AB We report on a new method to make nanostructures in aqueous solution at room temperature. We used the protein cytochrome c(3) to catalyze reduction of selenate (SeO42-) to selenium Se-0 by dithionite. Reduction was instantaneous. After a week spherical nanoparticles of red Se-0 (about 50 nm diameter) precipitated, followed by self-assembling into crystalline nanowires, typically 1 mu m long. The nanowires were composed of one strand of spherical particles; thicker strands contained several nanoparticles in parallel. C1 Univ New Mexico, Farris Engn Ctr, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Univ New Mexico, Ctr Radioact Waste Management, Albuquerque, NM 87106 USA. Sandia Natl Labs, Biomol Mat & Interfaces Dept, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Quim, Ctr Quim Fina & Biotecnol, P-2825 Monte De Caparica, Portugal. RP Lutze, W (reprint author), Univ New Mexico, Farris Engn Ctr, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RI Shelnutt, John/A-9987-2009; REQUIMTE, FMN/M-5611-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013; Franco, Ricardo/C-5247-2008 OI Shelnutt, John/0000-0001-7368-582X; Moura, Isabel/0000-0003-0971-4977; Franco, Ricardo/0000-0002-5139-2871 NR 17 TC 75 Z9 78 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2000 VL 12 IS 6 BP 1510 EP + DI 10.1021/cm990763p PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 325ZZ UT WOS:000087708400004 ER PT J AU Larsen, G Lotero, E Marquez, M AF Larsen, G Lotero, E Marquez, M TI Use of polypropyleneimine tetrahexacontaamine (DAB-Am-64) dendrimer as a single-molecule template to produce mesoporous silicas SO CHEMISTRY OF MATERIALS LA English DT Article ID SIZE DISTRIBUTION; MACROMOLECULES; NANOCLUSTERS AB The use of DAB-Am-64 amine dendrimer as a single-molecule template to produce mesoporous cavities in silica sol-gels is reported. The method is meant to afford the synthesis of spheroidal cavities and is likely to enjoy generality, since there are a number of dendritic molecules commercially available today. X-ray diffraction confirms that a coherent distance of similar to 25 Angstrom is obtained upon calcination, and the modeling of nitrogen adsorption data by a modified Horvath-Kawazoe formalism for spherical cavities reveals that voids of similar to 23 Angstrom in diameter had been formed. C1 Univ Nebraska, Dept Chem Engn, Lincoln, NE 68588 USA. Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, CST, DO, Los Alamos, NM 87545 USA. Kraft Gen Foods Inc, Res & Dev, Nanotechnol Lab, Nanotek, Glenview, IL 60025 USA. RP Larsen, G (reprint author), Univ Nebraska, Dept Chem Engn, Lincoln, NE 68588 USA. NR 16 TC 46 Z9 48 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2000 VL 12 IS 6 BP 1513 EP + DI 10.1021/cm990724d PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 325ZZ UT WOS:000087708400005 ER PT J AU Lee, YC Curtiss, LA Ratner, MA Shriver, DF AF Lee, YC Curtiss, LA Ratner, MA Shriver, DF TI Ionic conductivity of new ambient temperature alkali metal glasses AlCl3/NaN(CN)(2) SO CHEMISTRY OF MATERIALS LA English DT Article ID MOLTEN-SALTS AB Ambient temperature alkali glassy salt mixtures, x[AlCl3]/(1 - x)[NaN(CN)(2)] (x = 0.4-0.75), were prepared. A large increase in the C equivalent to N stretching frequencies for these materials indicate complex formation between the anion [N(CN)(2)](-) and AlCl3 molecule. Ab initio calculations confirm the assignments of the vibrational frequencies. The 1:1 adduct has a glass transition at 27 degrees C, and the glassy state persists for 4 weeks at room temperature. The room temperature ionic conductivity of this glass is 6.6 x 10(-6) S/cm, and it increases as the AlCl3 content increases. The temperature dependence of the conductivity follows the Vogel-Tamman-Fulcher equation, suggesting that ion transport is coupled to local motion in the glassy salt mixture system. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat & Chem Sci, Argonne, IL 60439 USA. RP Shriver, DF (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. NR 25 TC 3 Z9 3 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JUN PY 2000 VL 12 IS 6 BP 1634 EP 1637 DI 10.1021/cm990633g PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 325ZZ UT WOS:000087708400024 ER PT J AU Kaplan, DB Schmaltz, M AF Kaplan, DB Schmaltz, M TI Supersymmetric Yang-Mills theories from domain wall fermions SO CHINESE JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Chiral Gauge Theories (Chiral 99) CY SEP 13-18, 1999 CL TAIPEI, TAIWAN SP Natl Taiwan Univ, Dept Phys, Natl Ctr Theoret Sci ID MASSLESS MAJORANA FERMION; LATTICE AB We present work in progress on employing domain wall fermions to simulate N = 1 supersymmetric Yang-Mills theories on the lattice in d = 4 and d = 3 dimensions. The geometrical nature of domain wall fermions gives simple insights into how to construct these theories. We also discuss the obstacles associated with simulating the N = 2 theory in d = 4. C1 Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. EM dbkaplan@phys.washington.edu; schmaltz@slac.stanford.edu NR 18 TC 61 Z9 61 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD JUN PY 2000 VL 38 IS 3 BP 543 EP 550 PN 2 PG 8 WC Physics, Multidisciplinary SC Physics GA 328VF UT WOS:000087871000004 ER PT J AU Edwards, RG Heller, UM Narayanan, R AF Edwards, RG Heller, UM Narayanan, R TI The overlap-Dirac operator: Topology and chiral symmetry breaking SO CHINESE JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT Workshop on Chiral Gauge Theories (Chiral 99) CY SEP 13-18, 1999 CL TAIPEI, TAIWAN SP Natl Taiwan Univ, Dept Phys, Natl Ctr Theoret Sci ID GAUGE-THEORIES; LATTICE QCD; FERMIONS AB We review the spectral flow techniques for computing the index of the overlap Dirac operator including results relevant for SUSY Yang-Mills theories. We describe properties of the overlap Dirac operator, and methods to implement it numerically. We use the results from the spectral flow to illuminate the difficulties in numerical calculations involving domain wall and overlap fermions. C1 Jefferson Lab, Newport News, VA 23606 USA. Florida State Univ, SCRI, Tallahassee, FL 32306 USA. Amer Phys Soc, Ridge, NY 11961 USA. RP Edwards, RG (reprint author), Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 26 TC 6 Z9 6 U1 0 U2 0 PU PHYSICAL SOC REPUBLIC CHINA PI TAIPEI PA CHINESE JOURNAL PHYSICS PO BOX 23-30, TAIPEI 10764, TAIWAN SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD JUN PY 2000 VL 38 IS 3 BP 594 EP 604 PN 2 PG 11 WC Physics, Multidisciplinary SC Physics GA 328VF UT WOS:000087871000009 ER PT J AU Moss, RH AF Moss, RH TI Ready for IPCC-2001: Innovation and change in plans for the IPCC Third Assessment Report - An editorial comment SO CLIMATIC CHANGE LA English DT Editorial Material C1 Pacific NW Natl Lab, Washington, DC USA. RP Moss, RH (reprint author), Pacific NW Natl Lab, Washington, DC USA. NR 9 TC 2 Z9 2 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD JUN PY 2000 VL 45 IS 3-4 BP 459 EP 468 DI 10.1023/A:1005642416493 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 324XH UT WOS:000087646800004 ER PT J AU Ashurst, WT AF Ashurst, WT TI Flow-frequency effect upon Huygens front propagation SO COMBUSTION THEORY AND MODELLING LA English DT Article ID PREMIXED-FLAME PROPAGATION; LARGE-SCALE; TURBULENCE; VELOCITY; FIELDS AB A premixed flame within a turbulent flow exhibits a decreasing enhancement of fuel consumption rate with increasing turbulence intensity, an effect known as the bending effect. Denet has shown that flow time correlations may be one cause of the bending effect. Using a Damkohler-Huygens front propagation model, we illustrate that the removal of flow components with reduced frequencies greater than unity (omega > kS(L)) causes a small reduction in front area but a large reduction in the flow intensity, which is the bending effect (omega is the frequency and k is the wavenumber). To be effective in producing front area, a how mode must have a phase velocity, omega/k, smaller than the laminar burning velocity, S-L. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Ashurst, WT (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 15 TC 16 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD JUN PY 2000 VL 4 IS 2 BP 99 EP 105 DI 10.1088/1364-7830/4/2/301 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 327WA UT WOS:000087816000001 ER PT J AU Ashurst, WT Najm, HN Paul, PH AF Ashurst, WT Najm, HN Paul, PH TI Chemical reaction and diffusion: a comparison of molecular dynamics simulations with continuum solutions SO COMBUSTION THEORY AND MODELLING LA English DT Article AB Molecular dynamics simulations using the Lennard-Jones energy potential are compared with continuum solutions of reaction and diffusion in a dilute gas. The reaction model is a passive one in which high-energy bath atoms create a species, at dilute concentrations, which may have a very fast consumption reaction. This construction is designed based on typical fast reaction pathways involved in the fuel breakup in a hydrocarbon flame. Using reaction rates and diffusivities obtained from the molecular simulations allows the continuum solution to describe the reactive atom density spatial distribution with good accuracy. Based on this agreement, it is possible to estimate which reaction rates will produce negligible diffusive spreading, and hence, which species might be assumed to be in chemical equilibrium in continuum reacting Row calculations. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Ashurst, WT (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1364-7830 J9 COMBUST THEOR MODEL JI Combust. Theory Model. PD JUN PY 2000 VL 4 IS 2 BP 139 EP 157 DI 10.1088/1364-7830/4/2/304 PG 19 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Mathematics, Interdisciplinary Applications SC Thermodynamics; Energy & Fuels; Engineering; Mathematics GA 327WA UT WOS:000087816000004 ER PT J AU Julien, JP Turchi, PEA Mayou, D AF Julien, JP Turchi, PEA Mayou, D TI Real-space tight-binding approach to electronic structure and stability in substitutional alloys SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society CY JUN 01-04, 1999 CL STRASBOURG, FRANCE SP European Mat Res Soc ID APPROXIMATION; ENERGIES AB A real-space approach based on the tight-binding approximation is proposed for studying electronic structure properties, stability and order in substitutional multi-component chemically random alloy based on periodic as well as topological disordered lattices. We show that the coherent potential approximation (CPA) equations including Shiba's off-diagonal disorder can be solved self-consistently in real-space with the same accuracy currently achieved in reciprocal space, An effective one-electron Green function is given by a continued fraction expansion, and the associated effective medium is used to determine the effective cluster interactions which enter the expression of the configurationl part of the total energy for describing order-disorder phenomena in alloys, Some applications will be presented. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Francaise Pacifique, CUPF, Tahiti, Fr Polynesia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CNRS, LEPES, F-38042 Grenoble 9, France. RP Julien, JP (reprint author), Univ Francaise Pacifique, CUPF, BP 6570,Faaa Aeroport, Tahiti, Fr Polynesia. NR 13 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD JUN PY 2000 VL 17 IS 2-4 BP 217 EP 223 DI 10.1016/S0927-0256(00)00027-6 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 337NE UT WOS:000088367300023 ER PT J AU Postnikov, AV Antropov, VP AF Postnikov, AV Antropov, VP TI Magnetic state of delta- and alpha-plutonium SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society CY JUN 01-04, 1999 CL STRASBOURG, FRANCE SP European Mat Res Soc ID GENERALIZED GRADIENT APPROXIMATION; ELECTRONIC-STRUCTURE; PHASE-STABILITY; PU; SYSTEMS; VOLUME; CE AB Total energies of non-magnetic, ferromagnetic and antiferromagnetic phases of Pu in the fee structure (delta phase) have been calculated by the full-potential linear augmented-plane-wave method. The antiferromagnetic solution (of the CuAu type) has been found as the most stable one. The ground-state equilibrium volume per atom agrees well with that of the low-temperature monoclinic alpha phase. The latter includes 8 pairs of atoms per unit cell and resembles a frustrated body-centered tetragonal structure, making it logical to assume the antiferromagnetic ordering related to the CuAu-type in the fee structure for the alpha phase as well. Such magnetic solution has indeed been found, with magnetic moments not much different from those in the fee phase. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Osnabruck, Fachbereich Phys, Dept Phys, D-49069 Osnabruck, Germany. Iowa State Univ, Ames Lab, Dept Phys, Ames, IA 50010 USA. RP Postnikov, AV (reprint author), Univ Osnabruck, Fachbereich Phys, Dept Phys, D-49069 Osnabruck, Germany. NR 15 TC 31 Z9 31 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD JUN PY 2000 VL 17 IS 2-4 BP 438 EP 440 DI 10.1016/S0927-0256(00)00064-1 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 337NE UT WOS:000088367300060 ER PT J AU Bang, YC Radhakrishnan, S Rao, NSV Batsell, SG AF Bang, YC Radhakrishnan, S Rao, NSV Batsell, SG TI On update algorithms for quickest paths SO COMPUTER COMMUNICATIONS LA English DT Article DE quickest path; dynamic algorithm; network; bandwidth; delay AB The quickest path problem deals with the transmission of a message of size cr from a source to a destination with the minimum end-to-end delay over a network with bandwidth and delay constraints on the links. The path-table that maps all intervals for sigma to the corresponding quickest paths can be computed in O(m(2) + mn log n) time, where n and rn are the number of nodes and links of the network, respectively. We propose linear-time algorithms that update the path-table after a increase or decrease bandwidth of a link or a path, respectively. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Oklahoma, Sch Comp Sci, Norman, OK 73019 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Radhakrishnan, S (reprint author), Univ Oklahoma, Sch Comp Sci, Norman, OK 73019 USA. OI Rao, Nageswara/0000-0002-3408-5941 NR 8 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-3664 J9 COMPUT COMMUN JI Comput. Commun. PD JUN 1 PY 2000 VL 23 IS 11 BP 1064 EP 1068 DI 10.1016/S0140-3664(00)00158-4 PG 5 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 314VY UT WOS:000087079300006 ER PT J AU Challacombe, M AF Challacombe, M TI A general parallel sparse-blocked matrix multiply for linear scaling SCF theory SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Review ID ELECTRONIC-STRUCTURE CALCULATIONS; BINDING MOLECULAR-DYNAMICS; DENSITY-FUNCTIONAL CALCULATIONS; GAUSSIAN-BASIS SETS; SYSTEM-SIZE; HARTREE-FOCK; CONVERGENCE ACCELERATION; ALGEBRAIC-APPROXIMATION; VECTOR MULTIPLICATION; DATA DISTRIBUTIONS AB A general approach to the parallel sparse-blocked matrix-matrix multiply is developed in the context of linear scaling self-consistent-field (SCF) theory. The data-parallel message passing method uses non-blocking communication to overlap computation and communication. The space filling curve heuristic is used to achieve data locality for sparse matrix elements that decay with "separation". Load balance is achieved by solving the bin packing problem for blocks with variable size. With this new method as the kernel, parallel performance of the simplified density matrix minimization (SDMM) for solution of the SCF equations is investigated for RHF/6-31G** water clusters and RHF/3-21G estane globules. Sustained rates above 5.7 GFLOPS for the SDMM have been achieved for (H(2)O)(200) with 95 Origin 2000 processors. Scalability is found to be limited by load imbalance, which increases with decreasing granularity, due primarily to the inhomogeneous distribution of variable block sizes. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Div Theoret, Grp T12, Los Alamos, NM 87545 USA. RP Challacombe, M (reprint author), Los Alamos Natl Lab, Div Theoret, Grp T12, MS B268, Los Alamos, NM 87545 USA. EM MChalla@T12.LANL.Gov NR 102 TC 68 Z9 69 U1 1 U2 12 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 JUN PY 2000 VL 128 IS 1-2 BP 93 EP 107 DI 10.1016/S0010-4655(00)00074-6 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100006 ER PT J AU Tilson, JL Ermler, WC Pitzer, RM AF Tilson, JL Ermler, WC Pitzer, RM TI Parallel spin-orbit coupled configuration interaction SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE parallel computing; spin-orbit CI; computational chemistry; actinide chemistry ID RELATIVISTIC EFFECTIVE POTENTIALS; EFFECTIVE CORE POTENTIALS; ELECTRONIC-STRUCTURE; QUANTUM-CHEMISTRY; OPERATORS AB A parallel spin-orbit configuration interaction (SOCI) code has been developed. This code, named P-SOCI, is an extension of an existing sequential SOCI program and permits solution to heavy-element systems requiring both explicit spin-orbit (SO) effects and significant electron correlation. The relativistic procedure adopted here is an ab initio conventional configuration interaction (CI) method that constructs a Hamiltonian matrix in a double-group-adapted basis. P-SOCI enables solutions to problems far Larger than possible with the original code by exploiting the resources of large massively parallel processing computers (MPP). This increase in capability permits not only the continued inclusion of explicit spin-orbit effects but now also a significant amount of non-dynamic and dynamic correlation as is necessary for a good description of heavy-element systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Stevens Inst Technol, Dept Chem & Biol Chem, Hoboken, NJ 07030 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Tilson, JL (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ermler, Walter/B-6876-2011 NR 47 TC 28 Z9 28 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUN PY 2000 VL 128 IS 1-2 BP 128 EP 138 DI 10.1016/S0010-4655(00)00061-8 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100009 ER PT J AU Fletcher, GD Schmidt, MW Bode, BM Gordon, MS AF Fletcher, GD Schmidt, MW Bode, BM Gordon, MS TI The Distributed Data Interface in GAMESS SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID PERFORMANCE COMPUTATIONAL CHEMISTRY; MOLECULAR ELECTRONIC-STRUCTURE; COUPLED-CLUSTER ALGORITHM; PARALLEL DIRECT SCF; MEMORY COMPUTERS; IMPLEMENTATION; TRANSFORMATIONS; GRADIENT; ENERGY AB The Distributed Data Interface to permit storage of large data arrays in the aggregate memory of distributed memory, message passing computer systems is described. The design of this relatively small library is discussed, in regard to its implementation over SHMEM, MPI-1. or socket based message libraries. The good performance of a MP2 program using DDI is demonstrated on both PC and workstation cluster computers, and some details of the resulting message traffic are presented. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. US DOE, Ames Lab, Scalable Comp Lab, Ames, IA 50011 USA. RP Fletcher, GD (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 34 TC 94 Z9 94 U1 2 U2 9 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 JUN PY 2000 VL 128 IS 1-2 BP 190 EP 200 DI 10.1016/S0010-4655(00)00073-4 PG 11 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100013 ER PT J AU Gubernatis, JE Guerrero, M AF Gubernatis, JE Guerrero, M TI Random walk beyond Hartree-Fock SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID MONTE-CARLO METHOD; FERMION GROUND-STATES; HUBBARD-MODEL; PAIRING CORRELATIONS; SYSTEMS AB We give a brief discussion of the recently developed Constrained-Path Monte Carlo method. This method is a quantum Monte Carlo technique that eliminates the fermion sign problem plaguing simulations of systems of interacting electrons. The elimination is accomplished by trading an exact procedure for an approximate one that has been demonstrated to give very accurate estimates of energies and many-body correlation functions. We also give a short review of its applications, a discussion of several strategies for parallelizing it, and some speculation of its future extensions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gubernatis, JE (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 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 JUN PY 2000 VL 128 IS 1-2 BP 201 EP 209 DI 10.1016/S0010-4655(99)00528-7 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100014 ER PT J AU Heffelfinger, GS AF Heffelfinger, GS TI Parallel atomistic simulations SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Review ID MOLECULAR-DYNAMICS SIMULATION; MONTE-CARLO SIMULATIONS; DISTRIBUTED-MEMORY MACHINES; GRADIENT DRIVEN DIFFUSION; GRAND-CANONICAL ENSEMBLE; LENNARD-JONES FLUIDS; MARKOV-CHAIN MODEL; MASSIVELY-PARALLEL; DOMAIN-DECOMPOSITION; LARGE SYSTEMS AB Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed. Published by Elsevier Science B.V. C1 Sandia Natl Labs, Computat Biol & Mat Technol Dept, Albuquerque, NM 87185 USA. RP Heffelfinger, GS (reprint author), Sandia Natl Labs, Computat Biol & Mat Technol Dept, POB 5800, Albuquerque, NM 87185 USA. EM gsheffe@sandia.gov NR 156 TC 61 Z9 67 U1 1 U2 15 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 JUN PY 2000 VL 128 IS 1-2 BP 219 EP 237 DI 10.1016/S0010-4655(00)00050-3 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100016 ER PT J AU Nielsen, IMB Janssen, CL AF Nielsen, IMB Janssen, CL TI Multi-threading: A new dimension to massively parallel scientific computation SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID IMPLEMENTATION AB Multi-threading is becoming widely available for Unix-like operating systems, and the application of multi-threading opens new ways for performing parallel computations with greater efficiency. We hero briefly discuss the principles of multi-threading and illustrate the application of multi-threading for a. massively parallel direct four-index transformation of electron repulsion integrals. Finally, other potential applications of multi-threading in scientific computing are outlined. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Janssen, CL (reprint author), Sandia Natl Labs, MS 9214,POB 969, Livermore, CA 94551 USA. NR 9 TC 15 Z9 15 U1 0 U2 4 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 JUN PY 2000 VL 128 IS 1-2 BP 238 EP 244 DI 10.1016/S0010-4655(00)00062-X PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100017 ER PT J AU Kendall, RA Apra, E Bernholdt, DE Bylaska, EJ Dupuis, M Fann, GI Harrison, RJ Ju, JL Nichols, JA Nieplocha, J Straatsma, TP Windus, TL Wong, AT AF Kendall, RA Apra, E Bernholdt, DE Bylaska, EJ Dupuis, M Fann, GI Harrison, RJ Ju, JL Nichols, JA Nieplocha, J Straatsma, TP Windus, TL Wong, AT TI High performance computational chemistry: An overview of NWChem a distributed parallel application SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE parallel computational chemistry; electronic structure; molecular dynamics; distributed tools; portability ID GENERALIZED GRADIENT APPROXIMATION; DENSITY-FUNCTIONAL THEORY; EXCHANGE-CORRELATION FUNCTIONALS; TOTAL-ENERGY CALCULATIONS; MOLECULAR-DYNAMICS; ELECTRON-GAS; PSEUDOPOTENTIALS; FORMALISM; THERMOCHEMISTRY; ACCURATE AB NWChem is the software package for computational chemistry on massively parallel computing systems developed by the High Performance Computational Chemistry Group For the Environmental Molecular Sciences Laboratory. The software provides a variety of modules for quantum mechanical rind classical mechanical simulation. This article describes the design and sow implementation details of the overall NWChem architecture. The architecture facilitates rapid development and portability of fully distributed application modules. We also delineate some of the functionality within NWChem and show performance of a few of the modules within NWChem. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Ames Lab, Scalable Comp Lab, Ames, IA 50011 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Syracuse Univ, NE Parallel Architectures Ctr, Syracuse, NY 13244 USA. Natl Energy Res Sci Comp Ctr, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ames Lab, Scalable Comp Lab, Ames, IA 50011 USA. EM rickyk@scl.ameslab.gov RI Apra, Edoardo/F-2135-2010; OI Apra, Edoardo/0000-0001-5955-0734; Nichols, Jeffrey/0000-0001-5454-9726 NR 58 TC 598 Z9 601 U1 2 U2 37 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JUN PY 2000 VL 128 IS 1-2 BP 260 EP 283 DI 10.1016/S0010-4655(00)00065-5 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100019 ER PT J AU Straatsma, TP Philippopoulos, M McCammon, JA AF Straatsma, TP Philippopoulos, M McCammon, JA TI NWChem: Exploiting parallelism in molecular simulations SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID DYNAMICS SIMULATION; MEMORY MULTIPROCESSOR; COMPUTERS; IMPLEMENTATION; PVM AB NWChem is the software package for computational chemistry on massively parallel computing systems developed by the High Performance Computational Chemistry group for the Environmental Molecular Sciences Laboratory. The software provides a variety of modules for quantum mechanical and classical mechanical simulation. This article describes the design of the molecular dynamics simulation module, which is based on a domain decomposition, and provides implementation details on the data and communication structure and how the code deals with the complexity of atom redistribution and load balancing. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, High Performance Computat Chem Grp, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Calif San Diego, Dept Chem & Biochem, La Jolla, CA 92093 USA. RP Straatsma, TP (reprint author), Pacific NW Natl Lab, High Performance Computat Chem Grp, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 18 TC 32 Z9 32 U1 1 U2 5 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 JUN PY 2000 VL 128 IS 1-2 BP 377 EP 385 DI 10.1016/S0010-4655(00)00054-0 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327AH UT WOS:000087769100025 ER PT J AU White, DA AF White, DA TI Vector finite element modeling of optical tweezers SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID DIELECTRIC PARTICLES; FORCE; TRAP; MANIPULATION AB It has been established that under certain conditions microscopic dielectric objects can be trapped by a tightly focused laser beam. This phenomena is commonly referred to as an optical tweezer, and it has important applications in biological instrumentation. In this paper we describe how the vector finite element method can be used to compute optical trapping efficiencies for arbitrarily shaped dielectric objects, and we present new results for trapping efficiencies versus dielectric constant. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP White, DA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, L-560,POB 808, Livermore, CA 94551 USA. NR 18 TC 22 Z9 23 U1 0 U2 5 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 JUN PY 2000 VL 128 IS 3 BP 558 EP 564 DI 10.1016/S0010-4655(00)00007-2 PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 327FX UT WOS:000087784400003 ER PT J AU Tilden, SJ Linnenbrink, TE Green, PJ AF Tilden, SJ Linnenbrink, TE Green, PJ TI Standard for terminology and test methods for analog-to-digital converters: a case study of utilization of IEEE-STD-1241 SO COMPUTER STANDARDS & INTERFACES LA English DT Article DE analog-to-digital converters; IEEE-STD-1241; test methods AB This paper is intended to provide an introduction to IEEE-STD-1241 [IEEE 1241, IEEE draft standard for terminology and test methods for analog-to-digital converters], a draft standard for analog-to-digital converters (ADCs). This standard has been generated by the IEEE TC-10 working group and is intended to establish common terms, definitions, and test methods for ADCs. The TC-10 ADC Subcommittee is coordinating with the IEC to insure that these two organizations can support one international standard for ADCs. In this paper, the basic contents of the standard are described followed by examples of applications of the test methods from the standard. Testing procedures and results are included for specific ADCs used in video and in telecommunications. These practical examples are intended to emphasize the value of having an accepted standard for terms and test methods associated with testing and specifying ADCs. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Burr Brown Corp, Tucson, AZ 85706 USA. Q Dot Inc, Colorado Springs, CO 80907 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 6 TC 0 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5489 J9 COMP STAND INTER JI Comput. Stand. Interfaces PD JUN PY 2000 VL 22 IS 2 BP 103 EP 112 DI 10.1016/S0920-5489(00)00039-8 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA 327FV UT WOS:000087784100004 ER PT J AU Leifer, J Mickalonis, JI AF Leifer, J Mickalonis, JI TI Prediction of aluminum pitting in natural waters via artificial neural network analysis SO CORROSION LA English DT Article DE AA1100; aluminum; neural network; pH; pitting corrosion; spent nuclear fuel ID CORROSION AB One mission of the U.S. Department of Energy's Savannah River Site (SRS) is to store spent nuclear fuel (SNF) and other waste products while permanent storage facilities for such materials are prepared. This extended storage increases the probability of pitting corrosion for At-based SNF stored in natural (fresh) waters. Such pitting can be slowed, or even eliminated, through careful regulation of water chemistry. Although no universal predictive models linking water chemistry with pitting rate in At have been developed, empirical models specific to particular alloy and storage environment combinations can be created using previously collected pitting data. Archival pitting data for Al alloy AA1100 (UNS A91 100) was used with the back propagation of error method to train and test a feed-forward artificial neural network model. The trained model was found capable of predicting expected pit depth as a function of water pH; concentrations of carbonate (CO3-2), copper (Cu+2), and chloride (Cl-); and storage time. C1 Univ S Carolina, Dept Math Sci & Engn, Aiken, SC 29801 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Leifer, J (reprint author), Univ Kentucky, Extended Campus Programs, Dept Mech Engn, Paducah, KY 42002 USA. NR 28 TC 13 Z9 17 U1 1 U2 3 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 J9 CORROSION JI Corrosion PD JUN PY 2000 VL 56 IS 6 BP 563 EP 571 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 565DN UT WOS:000176353700001 ER PT J AU Thomas, LE Bruemmer, SM AF Thomas, LE Bruemmer, SM TI High-resolution characterization of intergranular attack and stress corrosion cracking of Alloy 600 in high-temperature primary water SO CORROSION LA English DT Article DE alloy 600; chromium; grain boundaries; high-temperature water; intergranular attack; nickel; stress corrosion cracking ID OXIDATION; MECHANISM; NICKEL AB Intergranulur (IG) attack regions and stress corrosion cracks in Alloy 600 (UNS N06600) U-bend samples tested in 330degreesC pressurized water reactor water were characterized by analytical transmission electron microscopy (ATEM). Obsevations of cross-sectioned samples revealed short, oxidized zones preceding crack tips and narrow (similar to 40 nm wide). deeply penetrated, oxidized zones along grain boundaries exposed along open cracks. High-resolution imaging and fine-probe analysis were used to determine local chemistries and structures in these corrosion-affected zones. Matrix areas surrounding the crack tips appeared highly strained, whereas IG penetrations generally did not. The predominant oxide structure found along crack walls and just ahead of crack tips was NiO with metal-atom ratios similar to the alloy. The attacked grain boundaries off open cracks contained similar,fine-grained. NiO-structure oxide with local areas of Cr-rich oxide and Ni-rich metal. In contrast, Cr-rich oxide identifted as Cr2O3, predominated at the lending edges of the IG attack. Stereoscopic imaging of these tip structures revealed nanometer-scale porosity and tunnels within the oxide and pores along the grain boundary plane ahead of the oxide. The general interpretation of these results was that IG attack and cracking followed local dissolution or oxidation and the formation of pores at grain boundaries. This degradation occurred at the nanometer scale and therefore required high-resolution ATEM methods to reveal detailed characteristics. Experimental support for several possible IG degradation mechanisms was considered. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 26 TC 77 Z9 79 U1 2 U2 17 PU NATL ASSOC CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0010-9312 EI 1938-159X J9 CORROSION-US JI Corrosion PD JUN PY 2000 VL 56 IS 6 BP 572 EP 587 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 565DN UT WOS:000176353700002 ER PT J AU Shanklin, J AF Shanklin, J TI Exploring the possibilities presented by protein engineering SO CURRENT OPINION IN PLANT BIOLOGY LA English DT Review ID CHIMERIC RNA/DNA OLIGONUCLEOTIDES; IN-VITRO EVOLUTION; DIRECTED EVOLUTION; SUBSTRATE-SPECIFICITY; RANDOM MUTAGENESIS; DIIRON PROTEINS; SUBTILISIN-E; DESIGN; DESATURASE; GENES AB A combination of classical and powerful new combinatorial genetic techniques allows the redesign of enzyme activities and creation of proteins that are tailored to have specific properties. These technologies have far-reaching consequences for the future design of crop plants and the storage compounds within them. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11786 USA. RP Shanklin, J (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463,50 Bell Ave, Upton, NY 11786 USA. NR 47 TC 14 Z9 16 U1 0 U2 4 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1369-5266 J9 CURR OPIN PLANT BIOL JI Curr. Opin. Plant Biol. PD JUN PY 2000 VL 3 IS 3 BP 243 EP 248 DI 10.1016/S1369-5266(00)80072-2 PG 6 WC Plant Sciences SC Plant Sciences GA 313ZB UT WOS:000087028700011 PM 10837269 ER PT J AU Bork, P Eisenberg, D AF Bork, P Eisenberg, D TI Genome and proteome informatics - Editorial overview SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Editorial Material C1 European Mol Biol Lab, D-69012 Heidelberg, Germany. Max Delbruck Ctr Mol Med, Berlin, Germany. Univ Calif Los Angeles, US DOE, Lab Struct Biol & Mol Med, Inst Mol Biol, Los Angeles, CA 90095 USA. RP Bork, P (reprint author), European Mol Biol Lab, Meyerhofstr 1, D-69012 Heidelberg, Germany. RI Bork, Peer/F-1813-2013 OI Bork, Peer/0000-0002-2627-833X NR 0 TC 3 Z9 3 U1 0 U2 1 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD JUN PY 2000 VL 10 IS 3 BP 341 EP 342 DI 10.1016/S0959-440X(00)00093-2 PG 2 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 325GC UT WOS:000087667000010 ER PT J AU Marcotte, EM AF Marcotte, EM TI Computational genetics: finding protein function by nonhomology methods SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Article ID ESCHERICHIA-COLI GENOME; EXPRESSION PATTERNS; MASS-SPECTROMETRY; YEAST; GENES; DATABASE; COMPLEX; IDENTIFICATION; MICROARRAYS; SEQUENCES AB During the past year, computational methods have been developed that use the rapidly accumulating genomic data to discover protein function. The methods rely on properties shared by functionally related proteins other than sequence or structural similarity. Instead, these 'nonhomology' methods analyze patterns such as domain fusion, conserved gene position and gene co-inheritance and coexpression to identify protein-protein relationships. The methods can identify functions for proteins that are without characterized homologs and have been applied to genome-wide predictions of protein function. C1 Univ Calif Los Angeles, US DOE, Inst Mol Biol, Lab Struct Biol & Mol Med, Los Angeles, CA 90095 USA. Prot Pathways Inc, Los Angeles, CA 90024 USA. RP Marcotte, EM (reprint author), Univ Calif Los Angeles, US DOE, Inst Mol Biol, Lab Struct Biol & Mol Med, POB 951570, Los Angeles, CA 90095 USA. NR 48 TC 93 Z9 97 U1 0 U2 0 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD JUN PY 2000 VL 10 IS 3 BP 359 EP 365 DI 10.1016/S0959-440X(00)00097-X PG 7 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 325GC UT WOS:000087667000014 PM 10851184 ER PT J AU Beckman, P Wilson, GV AF Beckman, P Wilson, GV TI Open source meets big iron SO DR DOBBS JOURNAL LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MILLER FREEMAN, INC PI SAN FRANCISCO PA 600 HARRISON ST,, SAN FRANCISCO, CA 94107 USA SN 1044-789X J9 DR DOBBS J JI Dr. Dobbs J. PD JUN PY 2000 VL 25 IS 6 BP 30 EP + PG 4 WC Computer Science, Software Engineering SC Computer Science GA 311FL UT WOS:000086874000018 ER PT J AU Dale, VH Brown, S Haeuber, RA Hobbs, NT Huntly, N Naiman, RJ Riebsame, WE Turner, MG Valone, TJ AF Dale, VH Brown, S Haeuber, RA Hobbs, NT Huntly, N Naiman, RJ Riebsame, WE Turner, MG Valone, TJ TI Ecological principles and guidelines for managing the use of land SO ECOLOGICAL APPLICATIONS LA English DT Review DE conservation; disturbance; ecological processes; ecosystem function; environmental policy; keystone species; land management; land use; ecological principles and guidelines; landscape; nonnative species; planning; settlement patterns ID YELLOWSTONE-NATIONAL-PARK; FOREST FRAGMENTATION; ECOSYSTEM MANAGEMENT; LANDSCAPE STRUCTURE; COVER CHANGE; INFREQUENT DISTURBANCES; RIPARIAN ECOSYSTEMS; COMMUNITY STRUCTURE; OLYMPIC PENINSULA; COMPARING LARGE AB The many ways that people have used and managed land throughout history has emerged as a primary cause of land-cover change around the world. Thus, land use and land management increasingly represent a fundamental source of change in the global environment. Despite their global importance, however, many decisions about the management and use of land are made with scant attention to ecological impacts. Thus, ecologists' knowledge of the functioning of Earth's ecosystems is needed to broaden the scientific basis of decisions on land use and management. In response to this need, the Ecological Society of America established a committee to examine the ways that land-use decisions are made and the ways that ecologists could help inform those decisions. This paper reports the scientific findings of that committee. Five principles of ecological science have particular implications for land use and can assure that fundamental processes of Earth's ecosystems are sustained. These ecological principles deal with time, species, place, disturbance, and the landscape. The recognition that ecological processes occur within a temporal setting and change over time is fundamental to analyzing the effects of land use. In addition, individual species and networks of interacting species have strong and far-reaching effects on ecological processes. Furthermore, each sire or region has a unique set of organisms and abiotic conditions influencing and constraining ecological processes. Disturbances are important and ubiquitous ecological events whose effects may strongly influence population, community, and ecosystem dynamics. Finally, the size, shape, and spatial relationships of habitat patches on the landscape affect the structure and function of ecosystems. The responses of the land to changes in use and management by people depend on expressions of these fundamental principles in nature. These principles dictate several guidelines for land use. The guidelines give practical rules of thumb for incorporating ecological principles into land-use decision making. These guidelines suggest that land managers should: (1) examine impacts of local decisions in a regional context, (2) plan for long-term change and unexpected events, (3) preserve rare landscape elements and associated species, (4) avoid land uses that deplete natural resources, (5) retain large contiguous or connected areas that contain critical habitats, (6) minimize the introduction and spread of nonnative species, (7) avoid or compensate for the effects of development on ecological processes, and (8) implement land-use and management practices that are compatible with the natural potential of the area. Decision makers and citizens are encouraged to consider these guidelines and to include ecological perspectives in choices on how land is used and managed. The guidelines suggest actions required to develop the science needed by land managers. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Illinois, Dept Nat Resources & Environm Sci, Champaign, IL 61820 USA. Ecol Soc Amer, Sustainable Biosphere Initiat, Washington, DC 20006 USA. Colorado State Univ, Colorado Div Wildlife, Ft Collins, CO 80523 USA. Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. Idaho State Univ, Dept Biol Sci, Pocatello, ID 83209 USA. Univ Washington, Coll Ocean & Fishery Sci, Seattle, WA 98195 USA. Univ Colorado, Dept Geog, Boulder, CO 80309 USA. Univ Wisconsin, Dept Zool, Madison, WI 53706 USA. Calif State Univ Northridge, Dept Zool, Northridge, CA 91330 USA. RP Dale, VH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM vhd@ornl.gov RI Dale, Virginia/B-6023-2009; Turner, Monica/B-2099-2010; Naiman, Robert /K-3113-2012; Hobbs, Tom/C-5263-2016; OI Valone, Thomas/0000-0002-7657-3126; Huntly, Nancy/0000-0001-6051-6365; Travis, William/0000-0002-9197-1317 NR 222 TC 254 Z9 269 U1 13 U2 145 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD JUN PY 2000 VL 10 IS 3 BP 639 EP 670 PG 32 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 322JN UT WOS:000087506600001 ER PT J AU Dale, VH Haeuber, RA AF Dale, VH Haeuber, RA TI Perspectives on land use SO ECOLOGICAL APPLICATIONS LA English DT Article C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. US EPA, Washington, DC 20460 USA. RP Dale, VH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dale, Virginia/B-6023-2009 NR 0 TC 5 Z9 5 U1 0 U2 1 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD JUN PY 2000 VL 10 IS 3 BP 671 EP 672 DI 10.1890/1051-0761(2000)010[0671:POLU]2.0.CO;2 PG 2 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 322JN UT WOS:000087506600002 ER PT J AU Scoates, JS Mitchell, JN AF Scoates, JS Mitchell, JN TI The evolution of troctolitic and high Al basaltic magmas in Proterozoic anorthosite plutonic suites and implications for the Voisey's Bay massive Ni-Cu sulfide deposit SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID RARE-EARTH ELEMENTS; KIGLAPAIT GEOCHEMISTRY; MAFIC MAGMAS; CO DEPOSIT; LABRADOR; INTRUSION; COMPLEX; OLIVINE; CANADA; SULFUR AB The Voisey's Bay massive Ni-Cu sulfide deposit is contained within troctolitic (plagioclase + olivine) intrusions of the 1.34 to 1.29 Ca Nain Plutonic Suite, coastal Labrador, Canada, and represents a new setting for magmatic sulfide deposits. Proterozoic anorthosite plutonic suites consist of vast quantities las much as 20,000 km(2) of cumulate anorthosite-leucotroctolite-leuconorite, intrusions of troctolite and Fe-enriched dioritic rocks, and large granitic batholiths. Crystallization ages span nearly 1,200 m.y. within the Middle Proterozoic (2.12-0.92 Ga). Many Proterozoic anorthosite plutonic suites were emplaced into relatively young Proterozoic crust and some were intruded along Archean-Proterozoic boundaries (e.g., Nain, Labrador; Laramie, Wyoming; Korosten, Ukraine). Nearly all of the largest plutonic suites contain significant areas (thousands of km(2)) of plagioclase-rich cumulate rocks that are olivine bearing (olivine anorthosite-leucotroctolite). Troctolitic rocks (20-30% modal olivine) occur in Proterozoic anorthosite plutonic suites, principally as cumulates in layered or massive intrusions (e.g., Kiglapait, Hettasch, Jonathon-Nain) intruded into anorthositic rocks. With the notable exception of the Voisey's Bay deposit, nearly all troctolitic rocks crystallized late in the evolution of individual plutonic suites. Many of the troctolitic intrusions have fine-grained olivine-rich marginal rocks that closely represent parental magma compositions. Numerous fine-grained olivine-normative dikes with high Al basaltic compositions also occur within many plutonic suites (Nain, Harp Lake, Laramie, Adirondack) and share compositional characteristics with the troctolitic magmas. These olivine-normative high Al basaltic mag mas record the least evolved compositions in Proterozoic anorthosite plutonic suites (Mg# = 0.43-0.64; An = 45-60), have high Al2O3 (15-19 wt %) and FeOtotal (9-15 wt %) contents, and typically show the least contaminated Sr and Nd isotope compositions in a given plutonic suite. Many dikes and marginal rocks have strong positive Eu anomalies, a feature of the melt composition that is not related to plagioclase accumulation. Except at Laramie, the least evolved troctolitic magmas appear to have about 8 wt percent MgO and corresponding Ni and S concentrations between 100 to 150 ppm and 0.02 to 0.05 wt percent, respectively. Based on closed system fractionation in the Kiglapait intrusion, sulfide saturation occurs late in the crystallization history of troctolitic magmas, after Ni concentrations have been severely depleted by protracted olivine fractionation. The optimal conditions for formation of a Ni-Cu sulfide deposit associated with a Proterozoic anorthosite plutonic suite require a relatively high MgO parental magma that has not crystallized much prior olivine and an external source of S to promote early sulfide saturation, probably through desulfurization reactions as hot troctolitic magmas ascend through the crust. An economically important massive Ni-Cu sulfide deposit on the scale of Voisey's Bay clearly requires large volumes of magma, probably involving continuous replenishment of relatively Ni rich, unfractionated parental magma in staging chambers or mixing between magmas in conduits during ascent. A model for the formation of troctolite-associated massive Ni-Cu sulfide deposits is proposed. Depending on the relative degrees of sulfide saturation and fractionation of the mixed magmas, mixing between troctolitic magmas in a conduit or magma chamber may either poison the system, stopping sulfide segregation, ol enhance sulfide segregation. C1 Free Univ Brussels, Dept Earth & Environm Sci, B-1050 Brussels, Belgium. Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87545 USA. RP Scoates, JS (reprint author), Free Univ Brussels, Dept Earth & Environm Sci, CP 160-02,Ave FD Roosevelt 50, B-1050 Brussels, Belgium. EM jscoates@ulb.ac.be NR 78 TC 46 Z9 47 U1 0 U2 3 PU ECONOMIC GEOLOGY PUBL CO PI LITTLETON PA 5808 SOUTH RAPP ST, STE 209, LITTLETON, CO 80120-1942 USA SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JUN-JUL PY 2000 VL 95 IS 4 BP 677 EP 701 DI 10.2113/95.4.677 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 327KD UT WOS:000087792300003 ER PT J AU Isaacs, HS Jeffcoate, CS Aldykiewicz, AJ Ryan, MP Kaneko, M Shea-Mccarthy, G AF Isaacs, HS Jeffcoate, CS Aldykiewicz, AJ Ryan, MP Kaneko, M Shea-Mccarthy, G TI Scanning volta potentials and polarization measurements of metals in irradiated air SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID FORCE MICROSCOPY; KELVIN PROBE; CORROSION AB A method for direct dc measurement of the Volta potential is presented. A high intensity synchrotron X-ray beam 20 mu m in diam was used to locally irradiate the atmosphere adjacent to the metal surface and produce a conducting path between a sample and a reference probe. The direct measurements of potential compared favorably with traditional Kelvin probe measurements. The direct measurements have a poorer spatial resolution but the measurements could be made at probe heights of around 1 mm compared to less than 0.1 mm for the Kelvin probe. In contrast to the Kelvin probe methods, the approach described allows observation of the current as a function of impressed voltage. Hence, it can be used as an active probe for electrochemical measurements in the gaseous phase. (C) 2000 The Electrochemical Society. S1099-0062(00)01-005-1. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. Nippon Steel Corp Ltd, Steel Res Labs, Chiba, Japan. Brookhaven Natl Lab, Univ Chicago, CARS, Upton, NY 11973 USA. RP Isaacs, HS (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 18 TC 3 Z9 3 U1 0 U2 4 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 JUN PY 2000 VL 3 IS 6 BP 253 EP 255 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 305QV UT WOS:000086552500002 ER PT J AU Giometti, CS Liang, XL Tollaksen, SL Wall, DB Lubman, DM Subbarao, V Rao, MS AF Giometti, CS Liang, XL Tollaksen, SL Wall, DB Lubman, DM Subbarao, V Rao, MS TI Mouse liver selenium-binding protein decreased in abundance by peroxisome proliferators SO ELECTROPHORESIS LA English DT Article DE mouse liver; peroxisome proliferators; selenium-binding protein ID 2-DIMENSIONAL ANALYSIS; GEL-ELECTROPHORESIS; TISSUE PROTEINS; CELL FRACTIONS; RAT-LIVER; HEPATOCARCINOGENESIS; CARCINOGENESIS; CIPROFIBRATE; WY-14,643; SEQUENCE AB Several studies with two-dimensional gel electrophoresis (2-DE) have shown that the abundance of numerous mouse liver proteins is altered in response to treatment with chemicals known to cause peroxisome proliferation. The peptide masses from tryptic digests of two liver proteins showing dramatic decreases in abundance in response to numerous peroxisome proliferators were used to search sequence databases. The selenium-binding protein 2 (SBP2 formerly 56 kDa acetaminophen-binding protein, AP 56) and selenium-binding protein 1 (SBP1 formerly 56 kDa selenium-binding protein, SP 56) in mouse liver, proteins with a high degree of sequence similarity, were the highest ranked identities obtained. Identity with SBP2 was subsequently confirmed by immunodetection with specific antiserum. Treatment of mice with 0.025% ciprofibrate resulted in the more basic of this pair of proteins being decreased to 30% of control abundance while the acidic protein was decreased to 7% of the control amount. Dexamethasone treatment, in contrast, caused increases of 80% and 20% in the abundance of the acidic and basic forms, respectively. Administration of dexamethasone to mice in combination with ciprofibrate produced expression of the acidic SBP2 at 23% of the control level and the basic SBP2 at 36%, a slightly moderated reduction compared with the decrease that occurred with ciprofibrate alone. These data suggest that peroxisome proliferators such as ciprofibrate cause a decrease in the abundance of the SBP2, which leads to increased cell proliferation, even in the presence of an inhibitor such as dexamethasone. Such a decrease in SEP, thought to serve as cell growth regulation factors, could be central to the nongenotoxic carcinogenicity of the peroxisome proliferators observed in rodents. C1 Argonne Natl Lab, Div Biosci, Argonne, IL 60439 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Northwestern Univ, Sch Med, Dept Pathol, Chicago, IL USA. Lakeside Vet Affairs, Med Ctr, Chicago, IL USA. RP Giometti, CS (reprint author), Argonne Natl Lab, Div Biosci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM csgiometti@anl.gov NR 28 TC 33 Z9 33 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD JUN PY 2000 VL 21 IS 11 BP 2162 EP 2169 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 330RN UT WOS:000087975100009 PM 10892727 ER PT J AU Hansen, RK Bissell, MJ AF Hansen, RK Bissell, MJ TI Tissue architecture and breast cancer: the role of extracellular matrix and steroid hormones SO ENDOCRINE-RELATED CANCER LA English DT Review ID EPIDERMAL-GROWTH-FACTOR; MAMMARY EPITHELIAL-CELLS; HUMAN ESTROGEN-RECEPTOR; HUMAN PROGESTERONE-RECEPTOR; FLOATING COLLAGEN MEMBRANES; GENE-EXPRESSION; BASEMENT-MEMBRANE; MALIGNANT BREAST; TRANSCRIPTIONAL ACTIVITY; MONOCLONAL-ANTIBODIES AB The changes in tissue architecture that accompany the development of breast cancer have been the focus of investigations aimed at developing new cancer therapeutics. As we learn more about the normal mammary gland, we have begun to understand the complex signaling pathways underlying the dramatic shifts in the structure and function of breast tissue. Integrin-, growth factor-, and steroid hormone-signaling pathways all play an important part in maintaining tissue architecture; disruption of the delicate balance of signaling results in dramatic changes in the way cells interact with each other and with the extracellular matrix, leading to breast cancer. The extracellular matrix itself plays a central role in coordinating these signaling processes. In this review, we consider the interrelationships between the extracellular matrix, integrins, growth factors, and steroid hormones in mammary gland development and function. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hansen, RK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd Mailstop 83-101, Berkeley, CA 94720 USA. FU NCI NIH HHS [R01 CA064786-05, CA-57621, CA-64786, R01 CA057621, R01 CA057621-07, R01 CA064786, R37 CA064786] NR 214 TC 75 Z9 78 U1 1 U2 8 PU SOC ENDOCRINOLOGY PI BRISTOL PA 17/18 THE COURTYARD, WOODLANDS, BRADLEY STOKE, BRISTOL BS32 4NQ, ENGLAND SN 1351-0088 J9 ENDOCR-RELAT CANCER JI Endocr.-Relat. Cancer PD JUN PY 2000 VL 7 IS 2 BP 95 EP 113 DI 10.1677/erc.0.0070095 PG 19 WC Oncology; Endocrinology & Metabolism SC Oncology; Endocrinology & Metabolism GA 339UT UT WOS:000088496800003 PM 10903527 ER PT J AU Salsbury, T Diamond, R AF Salsbury, T Diamond, R TI Performance validation and energy analysis of HVAC systems using simulation SO ENERGY AND BUILDINGS LA English DT Article DE HVAC; simulation; energy AB This paper describes the concept of using simulation as a tool for performance validation and energy analysis of HVAC systems. Recent advances in control system technology, including the development of open protocols such as BACnet(TM) have made sensor and control signal information from various components and subsystems in a building more accessible. This development has created significant potential for improving the monitoring and supervision of building systems in order to optimize operational performance. The paper describes one way of making use of this new technology by applying simulations, configured to represent optimum operation, to monitored data. The idea is to use simulation predictions as performance targets with which to compare monitored system outputs for performance validation and energy analysis. The paper presents results from applying the concepts to a large dual-duel air-handling unit installed in an office building in San Francisco. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Salsbury, T (reprint author), Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. NR 22 TC 18 Z9 18 U1 3 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD JUN PY 2000 VL 32 IS 1 BP 5 EP 17 DI 10.1016/S0378-7788(99)00020-1 PG 13 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 316VZ UT WOS:000087189900002 ER PT J AU Fisk, WJ Delp, W Diamond, R Dickerhoff, D Levinson, R Modera, M Nematollahi, M Wang, D AF Fisk, WJ Delp, W Diamond, R Dickerhoff, D Levinson, R Modera, M Nematollahi, M Wang, D TI Duct systems in large commercial buildings: physical characterization, air leakage, and heat conduction gains SO ENERGY AND BUILDINGS LA English DT Article DE duct system; commercial building; effective leakage area; air-leakage rate AB Through field studies in large commercial buildings and reviews of building plans, we investigated the effective leakage areas (ELAs), air-leakage rates, and conduction heat gains of duct systems. Different methods for measuring air-leakage rates were also compared. ELAs of supply ducts ranged from 0.4 to 2.0 cm(2) per square meter of floor area served, and from 1.0 to 4.8 cm(2) per square meter of duct surface area. On a per-unit-floor-area basis, these duct ELAs are comparable to the values measured in residences. The corresponding values of duct leakage class were 60 to 270, much higher than the range of 3 to 12 reported by ASHRAE [ASHRAE Standard 111-1988, Practices for Measurement, Testing, Adjusting, and Balancing of Building Heating, Ventilation, Air Conditioning, and Refrigeration Systems, American Society of Heating, Refrigerating, and Air Conditioning Engineers, Atlanta, 1988] as attainable for quality duct construction and sealing practices when leakage at connections to duct-mounted equipment is not considered. The measured air-leakage rates as a percentage of the inlet air flow rate varied from 0% to 30%, with most of the measurements falling between 10% and 20%. Large inconsistencies among the air-leakage rates determined from different measurement procedures exemplify the need for further development and evaluation of measurement methods. Heat gains between the outlet of the cooling coils and the supply registers caused supply air temperatures to increase, on average, by 0.6 degrees C to 2 degrees C. The corresponding values of conduction effectiveness were 0.75 to 0.90; thus, heat conduction decreased the cooling capacity of the supply air exiting registers by 10% to 25%. Because these results are based on studies in only a few buildings, generalizations from these findings are premature. (C) 2000 Elsevier Science S.A. All rights reserved. C1 Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Fisk, WJ (reprint author), Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. NR 13 TC 15 Z9 15 U1 3 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7788 J9 ENERG BUILDINGS JI Energy Build. PD JUN PY 2000 VL 32 IS 1 BP 109 EP 119 DI 10.1016/S0378-7788(99)00046-8 PG 11 WC Construction & Building Technology; Energy & Fuels; Engineering, Civil SC Construction & Building Technology; Energy & Fuels; Engineering GA 316VZ UT WOS:000087189900012 ER PT J AU Greening, LA Greene, DL Difiglio, C AF Greening, LA Greene, DL Difiglio, C TI Energy efficiency and consumption - the rebound effect - a survey SO ENERGY POLICY LA English DT Article DE energy; conservation; rebound; energy demand ID CES PRODUCTION FUNCTION; DEMAND ELASTICITIES; CONSUMER DEMAND; GASOLINE DEMAND; PRICE; SUBSTITUTION; FALLACIES; POLICY AB Technology policies are one of the options available for the reduction of carbon emissions and the usage of energy. However, gains in the efficiency of energy consumption will result in an effective reduction in the per unit price of energy services. As a result, consumption of energy services should increase (i,e., "rebound" or "take-back"), partially offsetting the impact of the efficiency gain in fuel use. Definitions of the "rebound" effect vary in the literature and among researchers. Depending on the boundaries used for the effect, the size or magnitude of this behavioral response may vary. This review of some of the relevant literature from the US offers definitions and identifies sources including direct, secondary, and economy-wide sources. We then offer a summary of the available empirical evidence for the effect for various sources. For the energy end uses for which studies are available, we conclude that the range of estimates for the size of the rebound effect is very low to moderate. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Int Resources Grp, Washington, DC 20036 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Int Energy Agcy, F-75739 Paris 15, France. RP Greening, LA (reprint author), Int Resources Grp, 1211 Connecticut Ave NW, Washington, DC 20036 USA. RI Quezada, George/I-1106-2012 OI Quezada, George/0000-0002-4060-6109 NR 76 TC 513 Z9 525 U1 18 U2 133 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 JUN PY 2000 VL 28 IS 6-7 BP 389 EP 401 PG 13 WC Energy & Fuels; Environmental Sciences; Environmental Studies SC Energy & Fuels; Environmental Sciences & Ecology GA 315BX UT WOS:000087093700004 ER PT J AU Carter, GA Bahadur, R Norby, RJ AF Carter, GA Bahadur, R Norby, RJ TI Effects of elevated atmospheric CO2 and temperature on leaf optical properties in Acer saccharum SO ENVIRONMENTAL AND EXPERIMENTAL BOTANY LA English DT Article DE Acer saccharum; carbon dioxide; air temperature; leaf optics ID CARBON-DIOXIDE ENRICHMENT; BARLEY PRIMARY LEAVES; CHLOROPHYLL CONTENT; REFLECTANCE; GROWTH; FOREST; TREE; RESPONSES; EXPOSURE AB Elevated partial pressures of atmospheric carbon dioxide, similar to numerous causes of plant stress, may alter leaf pigmentation and structure and thus would be expected to alter leaf optical properties. Hypotheses that elevated CO2 pressure and air temperature would alter leaf optical properties were tested for sugar maple (Acer saccharum) in the middle of its fourth growing season under treatment. The saplings had been growing since 1994 in open-top chambers and partial shade at Oak Ridge, Tennessee under the following treatments: (1) ambient CO2 pressure and air temperature (control); (2) CO2 pressure approximately 30 Pa above ambient; (3) air temperatures 3 degrees C above ambient; and (4) elevated CO2 and air temperature. Under elevated CO2 or temperature, spectral reflectance, transmittance and absorptance in the visible spectrum (400-720 nm) tended to change in patterns that generally are associated with chlorosis, with maximum differences from the control near 700 nm. However, these changes were not significant at P = 0.05. Although reflectance, transmittance and absorptance at 700 nm correlated strongly with leaf chlorophyll concentration, variability in chlorophyll concentration was greater within than among treatments. The lack of treatment effects on pigmentation explained the non-significant change in optical properties in the visible spectrum. Optical properties in the near-infrared (721-850 nm) were similarly unresponsive to treatment with the exception of an increased absorptance throughout the 739-850 nm range in leaves that developed under elevated air temperature alone. This response might have resulted from effects of air temperature on leaf internal structure. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NASA, Earth Syst Sci Off, Stennis Space Ctr, MS 39529 USA. Mississippi Valley State Univ, Itta Bena, MS 38941 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Carter, GA (reprint author), NASA, Earth Syst Sci Off, Room 212,Bldg 1100, Stennis Space Ctr, MS 39529 USA. RI Norby, Richard/C-1773-2012 OI Norby, Richard/0000-0002-0238-9828 NR 32 TC 11 Z9 14 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-8472 J9 ENVIRON EXP BOT JI Environ. Exp. Bot. PD JUN PY 2000 VL 43 IS 3 BP 267 EP 273 DI 10.1016/S0098-8472(00)00048-4 PG 7 WC Plant Sciences; Environmental Sciences SC Plant Sciences; Environmental Sciences & Ecology GA 320LJ UT WOS:000087402400008 ER PT J AU Curlee, TR Yuracko, KL AF Curlee, TR Yuracko, KL TI The use of life cycle analysis within the US. Department of Energy SO ENVIRONMENTAL PROGRESS LA English DT Article AB The U.S. Department of Energy's (DOE's) decisions regarding D&D, waste management, and the selection of technologies for R, D&D are extremely complex. Historically, DOE decisions were based primarily on meeting near-term goals. There is evidence that some of those decisions were not optimal in terms of minimizing costs or in terms of minimizing overall environment and health impacts. Fortunately, DOE is currently embracing the principles of life cycle analysis (LCA) in its decision-making. The results indicate that DOE is making better decisions since implementing the principles of LCA. This paper discusses LCA from the perspective of DOE and reviews several specific examples of the use of LCA by DOE. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Curlee, TR (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 21 TC 0 Z9 0 U1 0 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 3 PARK AVE, NEW YORK, NY 10016-5901 USA SN 0278-4491 J9 ENVIRON PROG JI Environ. Prog. PD SUM PY 2000 VL 19 IS 2 BP 117 EP 123 DI 10.1002/ep.670190210 PG 7 WC Engineering, Environmental; Engineering, Chemical; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 337NR UT WOS:000088368600009 ER PT J AU Johnson, TM Bullen, TD Zawislanski, PT AF Johnson, TM Bullen, TD Zawislanski, PT TI Selenium stable isotope ratios as indicators of sources and cycling of selenium: Results from the northern reach of San Francisco Bay SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ACCUMULATION; REDUCTION; SEDIMENTS; AQUIFER; SULFUR; SOILS AB Selenium stable isotope ratios can serve as indicators of Se sources and reduction of Se oxyanions, much as sulfur and nitrogen isotope ratios do in sulfur and nitrogen biogeochemical studies. A new analytical method, which allows precise Se isotope ratio measurements on 500 ng of Se, greatly enhances analysis of environmental samples. This paper presents the first environmental study to use Se stable isotopes. Se-80/Se-76 ratios, relative to a provisional standard, were measured in water, oil refinery wastewater, total sediment digests, and sediment extracts from the Carquinez area in the San Francisco Bay Estuary. Se isotope ratios in total sediment Se and in extracts designed to recover Se-0 are slightly (about 2 parts per thousand) enriched in the lighter isotope relative to local bay water Se. This difference is smaller than the isotopic fractionations expected upon reduction of Se(VI) or Se(IV) to Se(0) and suggests that reduction of soluble selenium from the overlying waters is not the dominant process by which Se is incorporated into the sediments. Consistent isotopic differences between riverine and refinery inputs were not observed, and thus tracing of refinery inputs with Se isotopes is not possible in this system. C1 Univ Illinois, Dept Geol, Urbana, IL 61801 USA. US Geol Survey, Div Water Resources, Menlo Park, CA 94025 USA. EO Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Johnson, TM (reprint author), Univ Illinois, Dept Geol, 245 Nat Hist Bldg MC-102, Urbana, IL 61801 USA. RI Johnson, Thomas/A-2740-2008 OI Johnson, Thomas/0000-0003-1620-1408 NR 29 TC 38 Z9 41 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 1 PY 2000 VL 34 IS 11 BP 2075 EP 2079 DI 10.1021/es990187y PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 320GX UT WOS:000087394400015 ER PT J AU Im, HJ Yang, YH Allain, LR Barnes, CE Dai, S Xue, ZL AF Im, HJ Yang, YH Allain, LR Barnes, CE Dai, S Xue, ZL TI Functionalized sol-gels for selective copper(II) separation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ORGANIC-INORGANIC MATERIALS; SILICA-GEL; MESOPOROUS SUPPORTS; COMPOSITE-MATERIALS; CHEMISTRY; COORDINATION; HEAVY; IMMOBILIZATION; ORGANIZATION; MONOLAYERS AB Inorganic-organic hybrid SiO2 sol-gels anchored with amino (NH2-CH2CH2-NH-, TMSen, and -NH-CH2CH2NH- Bis-TMSen) and mercapto (HS-) ligands have been studied as new sorbents for Cu2+ separation. The TMSen-anchored gels were found to be selective for Cu2+ removal in the presence of Cd2+ and Zn2+. In comparison, mercapto-anchored gels remove both Cu2+ and Cd2+ from a mixture of Cu2+, Cd2+, and Zn2+. These ligand-anchored materials, which were easily prepared from off-the-shelf chemicals in ca. 1 h, were hydrophilic and thus may give potentially fast kinetics of metal upload and removal (from the gels) in aqueous solutions. The ligand-anchored sol gels loaded with Cu2+ ions were regenerated with acid, and the materials could then be used in subsequent metal removal cycles. The effect of the reaction conditions [catalysts, ligand/Si(OMe)(4) ratios, and curing temperatures] on sol-gel properties and performance were investigated. In addition, the kinetics of Cu2+ upload and removal by these ligand-anchored sol-gel materials were studied. The work here shows that these hydrophilic ligand-anchored sol-gels are a good alternative to ligand-anchored organic polymers for toxic metal separation. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Xue, ZL (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 59 TC 52 Z9 53 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 1 PY 2000 VL 34 IS 11 BP 2209 EP 2214 DI 10.1021/es9911014 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 320GX UT WOS:000087394400034 ER PT J AU Sharma, AK Josephson, GB Camaioni, DM Goheen, SC AF Sharma, AK Josephson, GB Camaioni, DM Goheen, SC TI Destruction of pentachlorophenol using glow discharge plasma process SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID STREAMER CORONA DISCHARGE; HIGH-VOLTAGE DISCHARGE; AQUEOUS-SOLUTION; WATER; DEGRADATION; MECHANISM; REMOVAL; PHENOLS; OZONE; AIR AB Pentachlorophenol (PCP), found in wood preservatives and pesticides, is an acutely toxic recalcitrant organochlorine carcinogenic compound. A point-to-plane glow discharge plasma (GDP) process was used to study the destruction of 30-50 ppm (120-188 mu M) sodium salt of pentachlorophenol (PCP) in an aqueous solution. PCP was converted to less than 10% of its initial concentration in 1-3 h, at room temperature and low pressure (50 Torr). Effects of varying the headspace gas chemistry, stirring rate, pH, and current upon rate of PCP conversion were investigated. Organic acids, including formate, acetate, butyrate, and oxalate, were formed as byproducts after 1-3 h of GDP treatment of PCP. The chloride recovery suggests 50-70% dechlorination. The PCP removal rate exhibited mixed order kinetics. A reaction model developed to verify mixed order kinetics compares well with the experimental data. The increase in order may be due to the production and subsequent destruction of several reaction products throughout the process. An increase in current and stirring rate increased the rate of PCP removal in the GDP reactor. However, the rate of PCP removal decreased when the initial pH of the solution is raised to 11.4. Rapid removal of PCP was observed when the headspace gas was argon, air, or oxygen. Bench scale data was used to compare the power efficiency of the GDP process with atmospheric pressure corona discharge, Results suggest that the cost of power for PCP conversion by glow discharge was less than that of atmospheric pressure corona discharge. Additionally, the operating cost for PCP destruction in aqueous solution using UV based advanced oxidation technologies was found to be comparable with power costs for PCP conversion using GDP. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sharma, AK (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 34 TC 60 Z9 61 U1 0 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN 1 PY 2000 VL 34 IS 11 BP 2267 EP 2272 DI 10.1021/es981001i PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 320GX UT WOS:000087394400043 ER PT J AU Block, J Petrakis, L Dolhert, LE Myers, DF Hegedus, LL Webster, RP Kukacka, LE AF Block, J Petrakis, L Dolhert, LE Myers, DF Hegedus, LL Webster, RP Kukacka, LE TI A novel approach for the in-situ chemical elimination of chrysotile from asbestos-containing fireproofing materials SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID PUBLIC-POLICY AB We report here the development of a method for the chemical digestion of chrysotile asbestos in asbestos-containing fireproofing to levels lower than the regulatory threshold. The resulting fireproofing, no longer defined as asbestos-containing, can remain in place with properties intact. In the process, chrysotile fibers are digested without generating excessive gaseous byproducts, and the foam-based delivery system essentially eliminates release of airborne fibers. New X-ray diffraction methods quantified chrysotile levels with far greater precision than standard optical microscopic methods. Full-scale field testing confirmed the laboratory phase of the project. Fire testing of the treated fireproofing showed th at the treated material functions as well as the original fireproofing. C1 WR Grace & Co, Columbia, MD 21044 USA. WR Grace & Co, Cambridge, MA 02140 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Dolhert, LE (reprint author), WR Grace & Co, 7500 Grace Dr, Columbia, MD 21044 USA. NR 31 TC 4 Z9 4 U1 0 U2 2 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 JUN 1 PY 2000 VL 34 IS 11 BP 2293 EP 2298 DI 10.1021/es990432d PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 320GX UT WOS:000087394400048 ER PT J AU Francis, AJ Dodge, CJ Gillow, JB Papenguth, HW AF Francis, AJ Dodge, CJ Gillow, JB Papenguth, HW TI Biotransformation of uranium compounds in high ionic strength brine by a halophilic bacterium under denitrifying conditions SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ABSORPTION FINE-STRUCTURE; X-RAY; SPECTROSCOPY; COMPLEXES; UO22+; NPO2+; EDTA AB We investigated the transformations of uranyl nitrate, uranyl citrate, uranyl ethylenediaminetetraacetate (U-EDTA), and uranyl carbonate by a denitrifying halophilic bacterium, Halomonas sp. (WIPP1A), isolated from the Waste Isolation Pilot Plant (WIPP) repository. The addition of uranyl nitrate, uranyl citrate, or uranyl EDTA to the brine or bacterial growth medium resulted in the precipitation of uranium. Extended X-ray absorption fine structure (EXAFS) analysis of the precipitates formed in the brine and in the growth medium were identified as uranyl hydroxide [UO2-(OH)(2)] and uranyl hydroxophosphato species [K(UO2)(5)(PO4)(3)- (OH)(2). nH(2)O], respectively. Dissolution of the uranium precipitate was concomitant with the growth of the bacteria under anaerobic conditions. The UV-vis spectra of the culture medium during growth showed that a uranyl dicarbonate complex [UO2(CO3)(2)](2-) was formed due to CO2 production from the metabolism of the carbon source succinate. The bacterium completely metabolized the citrate released from the uranyl citrate complex but not the EDTA released from the U-EDTA complex. Adding uranyl carbonate to the growth medium caused no changes in the uranium speciation due to bacterial growth. Uranyl carbonate was not biosorbed by the growing culture nor by washed resting cells suspended in 20% NaCl brine (3.4 M) because the complex was either neutral or anionic. Our results demonstrate that bacterial activity can enhance the dissolution of uranium phosphate by forming uranyl carbonate species. C1 Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. Sandia Natl Labs, Chem Proc Dept, Albuquerque, NM 87185 USA. RP Francis, AJ (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. NR 23 TC 36 Z9 39 U1 1 U2 9 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 JUN 1 PY 2000 VL 34 IS 11 BP 2311 EP 2317 DI 10.1021/es991251e PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 320GX UT WOS:000087394400051 ER PT J AU Dobson, FS Chesser, RK Zinner, B AF Dobson, FS Chesser, RK Zinner, B TI The evolution of infanticide: genetic benefits of extreme nepotism and spite SO ETHOLOGY ECOLOGY & EVOLUTION LA English DT Article DE breeding groups; coancestry; cooperation; inclusive fitness; infanticide; mammals; nepotism; spite ID COLUMBIAN GROUND-SQUIRREL; SPERMOPHILUS-COLUMBIANUS; SUBDIVIDED POPULATIONS; PRAIRIE DOGS; PHILOPATRY; DIVERSITY; DISPERSAL; STRATEGY; MAMMALS; ANIMALS AB Among patterns of naturally occurring infanticide, one of the most interesting is the killing of young by lactating adult females in several mammalian species. In different species, the litters of either distantly related mothers or of close relatives have been documented as victims. We examined possible genetic benefits of infanticide by adult females using models of inclusive fitness and coancestry. Infanticide is viewed as a form of nepotism, in which offspring that are closer relatives of the infanticidal marauder have a greater chance of recruiting into a breeding group following infanticide. In this context, the genetic relationship of marauders and the young they kill is based upon the competitive social environment within breeding groups of adults. Two models were developed, based on linear and curvilinear changes in the fitness of mothers that either protect their litters or leave their litters unprotected while they maraud the litters of other adult females. Forms of these models that describe genetic polymorphisms of infanticide and ESS (evolutionary stable strategy) frequencies of infanticide yield quantitatively similar results. The models suggest that a balance should occur within populations between marauding and protection of young. At equilibrium, infanticide appears to be a spiteful behavior because it lowers the reproductive success of both the marauder (due to leaving their litters unattended and thus subject to other marauders) and mothers that try to protect their litters (because at least some maraudings are successful). Further, high levels of coancestry among females in a social breeding group should not change the frequency of infanticide when the population is at the equilibrium frequencies of marauding and protecting. Thus, in breeding groups made up of matrilines of highly philopatric females, infanticide of young genetically related to the marauder might be expected. Conclusions drawn from the models are supported by patterns of infanticide in ground-dwelling squirrels, where extensive information on infanticide exists and the social structure of breeding groups varies among species. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Auburn Univ, Dept Biol Sci, Auburn, AL 36849 USA. Univ Georgia, Dept Genet, Athens, GA 30602 USA. Auburn Univ, Dept Discrete & Stat Sci, Auburn, AL 36849 USA. RP Dobson, FS (reprint author), Auburn Univ, Dept Biol Sci, Auburn, AL 36849 USA. NR 53 TC 9 Z9 9 U1 4 U2 30 PU UNIVERSITA DEGLI STUDI DI FIRENZE PI FLORENCE PA C/O PROF F DESSI-FULGHERI, VIA ROMANA 17, 50125 FLORENCE, ITALY SN 0394-9370 J9 ETHOL ECOL EVOL JI Ethol. Ecol. Evol. PD JUN PY 2000 VL 12 IS 2 BP 131 EP 148 PG 18 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 329EK UT WOS:000087893600003 ER PT J AU Appelbe, DE Austin, RAE Ball, GC Cameron, JA Djerroud, B Drake, TE Flibotte, S O'Leary, CD Melarangi, A Svensson, CE Waddington, JC Ward, D AF Appelbe, DE Austin, RAE Ball, GC Cameron, JA Djerroud, B Drake, TE Flibotte, S O'Leary, CD Melarangi, A Svensson, CE Waddington, JC Ward, D TI Gamma-ray spectroscopy of Mn-57(25)32 and Mn-58(25)33 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article AB The decays of Mn-57(25)32 and Mn-58(25)33 have been studied with the 8 pi Spectrometer following the reaction Ca-48(C-13,pxn)Mn60-x at a beam energy of 40 MeV. The level schemes of these two nuclei have been extended, and the multipolarities of the observed transitions have been determined. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Univ Toronto, Dept Phys, Toronto, ON, Canada. Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Lawrence Berkeley Natl Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Appelbe, DE (reprint author), McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. EM dea@physics.mcmaster.ca NR 8 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD JUN PY 2000 VL 8 IS 2 BP 153 EP 155 PG 3 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 343QQ UT WOS:000088713400002 ER PT J AU Degtyarenko, PV Kossov, MV Wellisch, HP AF Degtyarenko, PV Kossov, MV Wellisch, HP TI Chiral invariant phase space event generator I. Nucleon-antinucleon annihilation at rest SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID BAG MODEL; FRAGMENTATION; SCATTERING; ELECTRON AB The CHIPS model and its first implementation within the GEANT4 simulation software package are considered. Hadron production in the process of nucleon-antinucleon annihilation is used as the basic example showing the structure of the model and corresponding software modeling algorithms. Model calculations of multiplicities and spectra of secondary hadrons in the annihilation process are compared with experimental data. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. CERN, CH-1211 Geneva, Switzerland. RP Degtyarenko, PV (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. NR 27 TC 43 Z9 43 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD JUN PY 2000 VL 8 IS 2 BP 217 EP 222 DI 10.1007/s100500070108 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 343QQ UT WOS:000088713400010 ER PT J AU Farhi, E Tagantsev, AK Currat, R Hehlen, B Courtens, E Boatner, LA AF Farhi, E Tagantsev, AK Currat, R Hehlen, B Courtens, E Boatner, LA TI Low energy phonon spectrum and its parameterization in pure KTaO3 below 80 K SO EUROPEAN PHYSICAL JOURNAL B LA English DT Article ID INELASTIC-NEUTRON-SCATTERING; SRTIO3; FERROELECTRICS; DISPERSION; 4-K AB High resolution data on low energy phonon branches (acoustic and soft optic) along the three principal symmetry axes in pure KTaO3 were obtained by cold neutron inelastic scattering between 10 and 80 K. Additional off-principal axis measurements were performed to characterize the dispersion anisotropy (away from the < 100 > and < 110 > axes). The parameters of the phenomenological model proposed by Vaks [28] are refined in order to successfully describe the experimental low temperature (10 < T < 100 K) dispersion curves, over an appreciable reciprocal space volume around the none center (\q\| < 0.25 rlu). The refined model, which involves only 4 temperature-independent adjustable parameters. is intended to serve as a basis for quantitative computations of multiphonon processes. C1 Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Univ Montpellier 2, Lab Verres, F-34095 Montpellier, France. Ecole Polytech Fed Lausanne, Lab Ceram, CH-1015 Lausanne, Switzerland. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Inst Max Von Laue Paul Langevin, BP 156X, F-38042 Grenoble 9, France. EM farhi@ill.fr RI Tagantsev, Alexander/E-3707-2010; Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 46 TC 20 Z9 20 U1 0 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6028 EI 1434-6036 J9 EUR PHYS J B JI Eur. Phys. J. B PD JUN PY 2000 VL 15 IS 4 BP 615 EP 623 PG 9 WC Physics, Condensed Matter SC Physics GA 332WZ UT WOS:000088098500003 ER PT J AU Martineau, RL Anderson, CA Smith, FW AF Martineau, RL Anderson, CA Smith, FW TI Expansion of cylindrical shells subjected to internal explosive detonations SO EXPERIMENTAL MECHANICS LA English DT Article DE dynamic testing; fracture mechanics; impact/shock analysis; rate effects; viscoplasticity AB Two explosively loaded cylindrical shell experiments were conducted to provide experimental data for benchmarking numerical codes. Each shell was subjected to internal high-explosive detonations, which caused it to expand outwardly at strain rates on the order of 10(4) s(-1). At approximately 150 percent strain, multiple plastic instabilities appeared on the surface of these shells in a quasi-periodic pattern. These instabilities continued to develop into bands of localized shear and eventually formed cracks before causing the shell to fragment. Diagnostic equipment on these experiments included a Fabry-Perot interferometer and a fast-framing camera. The experiments and the data obtained from the diagnostic equipment are discussed and illustrated. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Martineau, RL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 8 TC 14 Z9 31 U1 1 U2 9 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD JUN PY 2000 VL 40 IS 2 BP 219 EP 225 DI 10.1007/BF02325049 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA 315YA UT WOS:000087139500014 ER PT J AU Benson, SA Brown, TD AF Benson, SA Brown, TD TI Air quality: mercury, trace elements and particulate matter SO FUEL PROCESSING TECHNOLOGY LA English DT Editorial Material C1 Univ N Dakota, Energy & Environm Res Ctr, Ctr Air Tox Met, Grand Forks, ND 58202 USA. US DOE, Natl Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Benson, SA (reprint author), Univ N Dakota, Energy & Environm Res Ctr, Ctr Air Tox Met, 15 N 23rd St,POB 9018, Grand Forks, ND 58202 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 1 EP 3 DI 10.1016/S0378-3820(00)00080-1 PG 3 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000001 ER PT J AU Lindberg, SE Stratton, WJ Pai, P Allan, MA AF Lindberg, SE Stratton, WJ Pai, P Allan, MA TI Measurements and modeling of a water soluble gas-phase mercury species in ambient air SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE mercury; mist chamber; reactive gaseous mercury ID ATMOSPHERIC MERCURY; SPECIATION AB There are few reliable data on the speciation of Hg in ambient air, although this information is critical to understanding the fate of Hg once released from point sources. The water soluble species of Hg that are thought to exist in flue gases would be subject to far greater local removal rates than is elemental Hg vapor, but methods are lacking to quantify this species. We developed a method using refluxing mist chambers (MC) to measure the airborne concentrations of reactive gaseous mercury (RGM) in short-term samples under ambient conditions, and have simulated the atmospheric transport and fate of anthropogenic mercury emissions over the contiguous United States. The MC method exhibits an effective detection limit of 0.02 ng/m(3) and a precision for ambient concentration levels of +/-20-30%. The average RGM concentrations measured with our method at sites in Tennessee (TN) and Indiana (IN) were similar to 0.06 and similar to 0.10 ng/m(3), respectively, These averages represent about 3% of total gaseous mercury (TGM), and RGM generally exceeds regional particulate Hg. The 24-h simulated RGM concentration averages in the modeling grid cells representing TN and IN are 0.05 and 0.098 ng/m(3), respectively, in good agreement with the data. These concentrations are high enough to suggest that RGM can play an important role in both wet and dry deposition on a regional scale. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Earlham Coll, Dept Chem, Richmond, IN USA. Atmospher & Environm Res, San Ramon, CA USA. Elect Power Res Inst, Palo Alto, CA USA. RP Lindberg, SE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Mason, Robert/A-6829-2011 NR 23 TC 9 Z9 11 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 143 EP 156 DI 10.1016/S0378-3820(99)00082-X PG 14 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000012 ER PT J AU Laudal, DL Brown, TD Nott, BR AF Laudal, DL Brown, TD Nott, BR TI Effects of flue gas constituents on mercury speciation SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE mercury; measurement; chemistry AB Beginning with the 1990 Clean Air Act Amendments, there has been considerable interest in mercury emissions from coal-fired power plants. This past year, the U.S. Environmental Protection Agency (EPA) issued both the Mercury Study Report to Congress and the Study of Hazardous Air Pollutant Emissions from Electric Utility Steam-Generating Units, which make clear that EPA views mercury in the environment as a serious issue and that coal-fired utilities are a major source of mercury. For the past 4 years, EPRI and the U.S. Department of Energy (DOE) have funded research on mercury measurement, control, and chemistry at the Energy and Environmental Research Center (EERC). The primary goal of bench-scale work was to determine what flue gas constituents affect mercury speciation, specifically how mercury speciation affects measurement methods and the ability of mercury sorbents to absorb mercury. A bench-scale test rig was designed and built to simulate flue gas conditions, The baseline simulated flue gas consisted of O-2, CO2, H2O, and N-2. Other flue gas constituents tested include SO2, HCl, NO, NO2, HF, Cl-2, and fly ash. The mercury was delivered to system as either elemental mercury (Hg-0) or mercury(II) chloride (HgCl2) via temperature-controlled permeation tubes. EERC bench-scale data clearly show that the type of fly ash is important in determining mercury speciation in flue gas streams. Not surprisingly, there appear to be a number of interactions between various flue gas constituents that affect mercury speciation. Depending on concentration, there is clearly an interaction between NO-NO2 and fly ash, and it is possible that the interaction may be related to the ratio of NO:NO2. However, it has been shown that when NO-NO2 is tested without fly ash, there is no conversion of Hg-0 to Hg2+. Bench-scale tests clearly show that the chemistry of mercury is very complex and that more research is needed to understand what is occurring. However, it is equally clear that the development of effective mercury sorbents and the ability to accurately model mercury speciation are dependent on understanding mercury chemistry, thermodynamics, and kinetics. (C) 2000 Published hy Elsevier Science B.V. All rights reserved. C1 Univ N Dakota, Energy & Environm Res Ctr, Grand Forks, ND 58202 USA. US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. Elect Power Res Inst, Palo Alto, CA 94303 USA. RP Laudal, DL (reprint author), Univ N Dakota, Energy & Environm Res Ctr, 15 N 23rd St, Grand Forks, ND 58202 USA. NR 12 TC 100 Z9 113 U1 0 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 157 EP 165 DI 10.1016/S0378-3820(99)00083-1 PG 9 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000013 ER PT J AU Cheng, MD AF Cheng, MD TI Real-time measurement of trace metals on fine particles by laser-induced plasma techniques SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE real time; trace metals; aerosol; laser-induced plasma spectroscopy ID INDUCED BREAKDOWN SPECTROSCOPY; STEEL; SPECTROMETRY AB Physical and chemical characterization of airborne particles on-line and in real time can provide direct measurement regarding the dynamics, phase partition, and the transformation of aerosols and chemical species associated with the aerosol particles. This information is extremely useful for a wide range of applications such as emission control and process optimization. A compact laser-based instrument has been developed at the Oak Ridge National Laboratory for measurement of elemental composition on aerosol particles. Laser-induced plasma spectroscopy (LIPS) was employed as the principle in the design of the field-portable instrument. It was found that the LIPS technique itself was insufficient to detect trace metals (i.e., mercury and chromium) in aerosols at a level commonly found in source emissions. The LIPS technique could achieve a detection of aerosol mercury at 9.8 ng m(-3), and chromium at 98 ng m(-3) with a precision of +/-1%. We have enhanced the detection sensitivity for the LIPS measurement of these two species by coupling the spectroscopic technique with an aerosol beam-focusing device. The signal enhancement was about two orders of magnitude over traditional nonfocusing approach. The reported elemental detection level of our instrument was for aerosols of a number median diameter of 300 nm and the geometric standard deviation of 1200 nm. Each measurement was accomplished in an interval approximately 1-2 min. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Bldg 1505,MS6038, Oak Ridge, TN 37831 USA. RI Cheng, Meng-Dawn/C-1098-2012; OI Cheng, Meng-Dawn/0000-0003-1407-9576 NR 14 TC 17 Z9 18 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 219 EP 229 DI 10.1016/S0378-3820(99)00099-5 PG 11 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000018 ER PT J AU Brown, TD Smith, DN O'Dowd, WJ Hargis, RA AF Brown, TD Smith, DN O'Dowd, WJ Hargis, RA TI Control of mercury emissions from coal-fired power plants: a preliminary cost assessment and the next steps for accurately assessing control costs SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE mercury emissions; coal-fired power plants; cost assessment AB Mercury emissions from coal-fired power plants have been extensively evaluated for nearly 10 years to determine possible regulation by the Environmental Protection Agency (EPA). Under a court order, a determination will be made on whether it is appropriate and necessary to regulate toxic air pollutant emissions (focusing on mercury) from coal-fired utility boilers by December 15, 2000, If it is determined that regulations are necessary, then the regulatory process will have a fixed timetable. A proposed regulation will be due no later than December 15, 2003, and promulgated no later than December 15, 2004. The utility industry regulatory compliance must be in place by December 2007 since the Clean Air Act requires that sources come into compliance with Maximum Achievable Control Technology (MACT) 3 years after promulgation of the regulations. While it is recognized that the main driver for regulation is the potential risk to human health and that this risk is currently being examined by a number of health-based organizations, the actual form of any regulation would likely be dependent upon the availability of cost-effective control technologies. Furthermore, the diverse nature of the coal-fired utility industry will likely limit the applicability and cost-effectiveness of any given technology for the current boiler population. In light of a potential regulatory determination, this paper examines a few control options that warrant further consideration. A preliminary assessment of mercury capture technologies and associated costs is conducted for sorbent injection technology. Sorbent-based technologies that may be amenable for mercury control include: (1) sorbent injection with and without spray cooling upstream of existing particulate control devices (i.e., electrostatic precipitators and fabric filters): and (2) sorbent injection with and without spray cooling associated with additional control devices designed to augment particulate collection in a primary particulate control device. Important design criteria for each of the control systems are critically assessed for operability, maintainability, and reliability, with the projected impacts of the control system on power plant operations being evaluated. The sorbent-based technology discussed in this paper focuses on the injection of activated carbon associated with the various particulate control devices used in the utility industry. The paper also addresses the next steps and revisions needed to accurately assess possible cost impacts to the utility industry as the mercury control options mature in their development. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Brown, TD (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 29 TC 19 Z9 21 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 311 EP 341 DI 10.1016/S0378-3820(00)00081-3 PG 31 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000023 ER PT J AU Miller, SJ Dunham, GE Olson, ES Brown, TD AF Miller, SJ Dunham, GE Olson, ES Brown, TD TI Flue gas effects on a carbon-based mercury sorbent SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE flue gas; coal; mercury AB Coal is now the primary source of anthropogenic mercury emissions in the United States, accounting for 46%, or 72 tons/year, of the total U.S. Environmental Protection Agency (EPA) estimated 158 tons/year [U.S. Environmental Protection Agency, Mercury Study Report to Congress, EPA/600/P-94/002Aa, External Review Draft, Jan. 1995.]. Development of cost-effective mercury control for coal-fired boilers is a primary research need identified in the EPA Mercury Study Report to Congress [U.S. Environmental Protection Agency, Mercury Study Report to Congress, EPA/600/P-94/002Aa, External Review Draft, Jan. 1995.]. During combustion of mercury-containing fuels such as coal, the mercury is completely volatilized and is not controlled by conventional particulate control devices unless the solid material effectively traps the mercury through sorption mechanisms. Typically, this does not occur naturally to a significant degree by the collected ash material. However, a promising approach for mercury control is the injection of an effective sorbent upstream of the particulate control device. Since the amount of mercury in the gas stream from coal combustion is usually in the range of 5 to 10 mu g/m(3) (about 1 ppbv), only very small amounts of a sorbent may be necessary. A requirement is that the mercury be tightly bound in the sorbent, not desorbing upon exposure to ambient air or leaching under wet disposal conditions. On a worldwide basis, the projected increase in coal usage over the next two decades in China, India, and Indonesia will dwarf the current U.S. coal consumption of 1 billion tons/year [International Energy Outlook, U.S. Department of Energy, Energy Information Administration, Office of Integrated Analysis and Forecasting, Washington, DC, April 1998, DOE/EIA-0484(98).]. Therefore, in the United States, coal will be the dominant source of mercury emissions, and worldwide, coal may be the cause of significantly increased mercury emissions unless an effective control strategy is implemented. However, there is much uncertainty over the most technically sound and cost-effective approach for reducing mercury emissions from coal-fired boilers. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ N Dakota, Energy & Environm Res Ctr, Grand Forks, ND 58202 USA. US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Miller, SJ (reprint author), Univ N Dakota, Energy & Environm Res Ctr, POB 9018, Grand Forks, ND 58202 USA. NR 14 TC 89 Z9 103 U1 4 U2 32 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 343 EP 363 DI 10.1016/S0378-3820(99)00103-4 PG 21 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000024 ER PT J AU Sliger, RN Kramlich, JC Marinov, NM AF Sliger, RN Kramlich, JC Marinov, NM TI Towards the development of a chemical kinetic model for the homogeneous oxidation of mercury by chlorine species SO FUEL PROCESSING TECHNOLOGY LA English DT Article; Proceedings Paper CT Conference on Air Quality - Mercury, Trace Elements, and Particulate Matter CY DEC 01-04, 1998 CL MCLEAN, VIRGINIA SP Univ N Dakota, Energy & Environm Res Ctr, EERC Ctr Air Toxic Metals, US EPA, Natl Ctr Environm Res & Quality Assurance, US DOE, Natl Energy Technol Lab DE chemical kinetic model; oxidation; mercury chlorine; emission ID FLUE-GAS DESULFURIZATION; POWER-PLANTS; EMISSIONS; EXCHANGE; ELEMENTS AB The potential for regulation of mercury emissions from coal-fired boilers is a concern for the electric utility industry. Field data show a wide variation in the fraction of mercury that is emitted as a vapor vs, that retained in the solid products. The reason for this variation is not well-understood. Near the end of the flue gas path, mercury exists as a combination of elemental vapor and HgCl2 vapor. The data show that HgCl2 is more likely to be removed from the flue gas. Thus, the degree of oxidation is considered to be a critical factor that tends to reduce emission. Mercury is certain to exist as elemental vapor in the flame, with the oxidation occurring at some point in the post-flame environment. At present, the mechanism promoting this oxidation is not quantitatively known, particularly under the low chlorine concentrations afforded by many coals. In the present work, we measure mercury oxidation from a furnace operating between 860 degrees C and 1171 degrees C. These data are compared with similar results from the literature. The possible elementary reactions that may lead to oxidation are reviewed and a chemical kinetic model is proposed. This model yields good qualitative agreement with the data and indicates that mercury oxidation occurs during the thermal quench of the combustion gases. The model also suggests that atomic chlorine is the key oxidizing species. The oxidation is limited to a temperature window between 700 degrees C and 400 degrees C that is defined by the overlap of (1) a region of significant superequilibrium Cl concentration, and (2) a region where oxidized mercury is favored by equilibrium. Above 700 degrees C, reverse reactions effectively limit oxidized mercury concentrations. Below 400 degrees C, atomic chlorine concentrations are too low to support further oxidation. The implication of these results are that homogeneous oxidation is governed primarily by (1) HCl concentration, (2) quench rate, and (3) background gas composition. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Washington, Dept Mech Engn, Seattle, WA 98195 USA. Univ Calif Lawrence Livermore Natl Lab, Div Chem Sci, Livermore, CA 94550 USA. RP Kramlich, JC (reprint author), Univ Washington, Dept Mech Engn, Box 352600, Seattle, WA 98195 USA. NR 26 TC 132 Z9 175 U1 5 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD JUN PY 2000 VL 65 BP 423 EP 438 DI 10.1016/S0378-3820(99)00108-3 PG 16 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 326AF UT WOS:000087709000029 ER PT J AU Planchart, A You, Y Schimenti, JC AF Planchart, A You, Y Schimenti, JC TI Physical mapping of male fertility and meiotic drive quantitative trait loci in the mouse t complex using chromosome deficiencies SO GENETICS LA English DT Article ID TRANSMISSION RATIO DISTORTION; EMBRYONIC STEM-CELLS; DYNEIN LIGHT-CHAIN; TERT-HAPLOTYPES; CYTOPLASMIC DYNEIN; DELETION COMPLEXES; MOLECULAR PROBES; MALE-STERILITY; MICE; GENE AB The t complex spans 20 cM of the proximal region of mouse chromosome 17. A variant form, the t haplotype (t), exists at significant frequencies in wild mouse populations and is characterized by the presence of inversions that suppress recombination with Mild-type (+) chromosomes. Transmission ratio distortion and sterility are associated with t and affect males only. It is hypothesized that these phenomena are caused by trans-acting distorter/sterility factors that interact with a responder locus (Tcr(t)) and that the distorter and sterility factors are the same because homozygosity of the distorters causes male sterility. One factor, Tcd1, was previously shown to be amorphic using a chromosome deletion. To overcome limitations imposed by recombination suppression, we used a series of deletions within the t complex in trans to t chromosomes to characterize the Tcd1 region. The find that the distorter activity of Tcd1 is distinct from a linked sterility factor, originally called tcs1. YACs mapped with respect to deletion breakpoints localize tcs1 to a 1.1-Mb interval flanked by D17Aus9 and Tctex1. We present evidence for the existence of multiple proximal t complex regions that exhibit distorter activity. These studies demonstrate the utility of chromosome deletions for complex trait analysis. C1 Jackson Lab, Bar Harbor, ME 04609 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Schimenti, JC (reprint author), Jackson Lab, 600 Main St, Bar Harbor, ME 04609 USA. FU NICHD NIH HHS [F32 HD008375, HD-24374, F32 HD008375-02] NR 40 TC 21 Z9 21 U1 0 U2 4 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 USA SN 0016-6731 J9 GENETICS JI Genetics PD JUN PY 2000 VL 155 IS 2 BP 803 EP 812 PG 10 WC Genetics & Heredity SC Genetics & Heredity GA 321VJ UT WOS:000087475100028 PM 10835401 ER PT J AU Cai, H White, PS Torney, D Deshpande, A Wang, ZL Marrone, B Nolan, JP AF Cai, H White, PS Torney, D Deshpande, A Wang, ZL Marrone, B Nolan, JP TI Flow cytometry-based minisequencing: A new platform for high-throughput single-nucleotide polymorphism scoring SO GENOMICS LA English DT Article ID PRIMER EXTENSION; POINT MUTATIONS; HUMAN GENOME; DNA; SEQUENCE; MULTIPLEX; IDENTIFICATION; FLUORESCENT; DISEASE; PROBES AB Single-nucleotide polymorphisms (SNPs) are the most abundant type of human genetic variation. These variable sites are present at high density in the genome, making them powerful tools for mapping and diagnosing disease-related alleles. We have developed a sensitive and rapid how cytometry-based assay for the multiplexed analysis of SNPs based on polymerase-mediated primer extension, or minisequencing, using microspheres as solid supports. The new method involves subnanomolar concentrations of sample in small volumes (similar to 10 mu l) which can be analyzed at rates of one sample per minute or faster, without a wash step. Further, genomic analysis using multiplexing microsphere arrays (GAMMArrays), enables the simultaneous analysis of dozens, and potentially hundreds of SNPs per sample. We have tested the new method by genotyping the Glu69 variant from the HLA DPB1 locus, a SNP associated with chronic beryllium disease, as well as HLA DPA1 alleles using the multiplexed method. The results demonstrate the sensitivity and accuracy of flow cytometry-based minisequencing, a powerful new tool for genome- and global-scale SNP analysis. 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 Nolan, JP (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, MS M-888, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [R01 RR014101, R01 RR014101-03, RR14101] NR 32 TC 97 Z9 107 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD JUN 1 PY 2000 VL 66 IS 2 BP 135 EP 143 DI 10.1006/geno.2000.6218 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 327PG UT WOS:000087801500002 PM 10860658 ER PT J AU Liang, LY Hofmann, A Gu, BH AF Liang, LY Hofmann, A Gu, BH TI Ligand-induced dissolution and release of ferrihydrite colloids SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID NATURAL ORGANIC-MATTER; COORDINATION CHEMISTRY; IRON-OXIDE; AQUIFER SAND; REACTIVITY; INHIBITION; TRANSPORT; MINERALS; KINETICS; CLAY AB This laboratory study attempted to delineate the processes of iron oxide particle release from a sandy aquifer as influenced by electrostatic repulsion and chemical dissolution. The release of ferrihydrite particles by 5 mM citrate was studied in flow-through columns that contained ferrihydrite-coated quartz. Results indicated two major mechanisms for the release of ferrihydrite colloids by citrate: (1) the repulsive interfacial forces were the primary cause for the peak output of colloids at the beginning of the breakthrough, and (2) the release of colloids at longer run-times was induced mainly by bondbreaking at the Fe oxide-quartz interface that resulted from the dissolution of ferrihydrite. The rate of chemical dissolution was investigated in batch experiments with 0.1 to 5 mM organic ligands (ascorbate and citrate) and 0.4 gL(-1) ferrihydrite in a pH 1, 10 mM NaCl solution at similar to 21 degrees C. The results of the adsorption and dissolution study showed that citrate dissolved ferrihydrite with initial rates positively related to the adsorption density, and an initial rate up to 1.86 mu mol m(-2)h(-1) was derived at similar to 4.5 mM citrate. Ascorbate dissolved ferrihydrite at an initial rate similar to 4 times faster than citrate. At pH 4, a near complete dissolution occurred at similar to 5 h, and the measured Fe(II) to ligand ratio was about 2 at the maximum dissolution, suggesting a two-electron transfer process from ascorbate to Fe(III). However, the initial dissolution rates in the batch experiment may not be the best measure of dissolution occurring in a flow-through system, where the steady dissolution rate was substantially lower than the batch prediction. The study suggests that, in an Fe-chemistry-dominated aquifer, a chemical perturbation (e.g., a plume of organic ligands) is likely to induce colloid release initially via electrostatic repulsion. Over time, dissolution will rake a controlling role, changing the ratio of dissolved to colloidal Fe. Copyright (C) 2000 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Cardiff Univ, Dept Earth Sci, Cardiff CF1 3YE, S Glam, Wales. RP Liang, LY (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Gu, Baohua/B-9511-2012; Liang, Liyuan/O-7213-2014 OI Gu, Baohua/0000-0002-7299-2956; Liang, Liyuan/0000-0003-1338-0324 NR 39 TC 42 Z9 45 U1 0 U2 19 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 JUN PY 2000 VL 64 IS 12 BP 2027 EP 2037 DI 10.1016/S0016-7037(00)00349-5 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 329WH UT WOS:000087931100002 ER PT J AU Wereszczak, A Wang, H Karakus, M Curtis, W Aume, V VerDow, D AF Wereszczak, A Wang, H Karakus, M Curtis, W Aume, V VerDow, D TI Postmortem analyses of salvaged conventional silica bricks from glass production furnaces SO GLASS SCIENCE AND TECHNOLOGY-GLASTECHNISCHE BERICHTE LA English DT Article ID THERMAL-CONDUCTIVITY; DIFFUSIVITY AB The microstructure, phase content, and thermal conductivity of salvaged conventional silica bricks from float glass and TV-panel glass production furnaces were examined as a function of position through the brick, and compared with the original, unaltered brick materials. The silica brick from the float glass furnace was in service for approximately 10 years while that for the TV-panel glass furnace was for approximately 6 1/2 years. The microstructure and phase content in both salvaged bricks showed gradients, from tridymite at the bricks' cold-face ends, to cristobalite at their hot-face end even though both bricks were an initial mixture of tridymite and cristobalite to begin with. The thermal conductivity of both bricks had increased as a consequence of these phase and microstructural changes. A thermal analysis model predicted that such changes would result in an increase in the bricks' cold-face temperature and heat content during service. The initially-produced temperature gradients and environment caused microstructural changes in the silica brick; however, the cause-and-effect relationship between temperature/environment and microstructural changes in the brick likely became mutually reversible once the microstructural changes initiated and the thermal conductivity of the brick started to change as a consequence. C1 USA, Res Lab, Weap & Mat Res Directorate, Aberdeen Proving Ground, MD 21010 USA. Univ Missouri, Dept Ceram Engn, Rolla, MO 65401 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. PPG Ind Inc, Pittsburgh, PA USA. Thomson Consumer Elect, Circleville, OH 43130 USA. RP Wereszczak, A (reprint author), USA, Res Lab, Weap & Mat Res Directorate, ATTN AMSRL-WM-MC, Aberdeen Proving Ground, MD 21010 USA. RI Wang, Hsin/A-1942-2013; Wereszczak, Andrew/I-7310-2016 OI Wang, Hsin/0000-0003-2426-9867; Wereszczak, Andrew/0000-0002-8344-092X NR 16 TC 1 Z9 1 U1 0 U2 0 PU VERLAG DEUTSCHEN GLASTECHNISCHEN PI FRANKFURT PA MENDELSSOHNSTR 75-77, D-60325 FRANKFURT, GERMANY SN 0946-7475 J9 GLASS SCI TECHNOL JI Glass Sci Technol.-Glastech. Ber. PD JUN PY 2000 VL 73 IS 6 BP 165 EP 174 PG 10 WC Materials Science, Ceramics SC Materials Science GA 340LU UT WOS:000088535700001 ER PT J AU Miller, G Inkret, WC Schillaci, ME Martz, HF Little, TT AF Miller, G Inkret, WC Schillaci, ME Martz, HF Little, TT TI Analyzing bioassay data using Bayesian methods - A primer SO HEALTH PHYSICS LA English DT Review DE bioassay; dosimetry, internal; tritium; statistics ID RADIATION EXPOSURE AB The classical statistics approach used in health physics for the interpretation of measurements is deficient in that it does not take into account "needle in a haystack" effects, that is, correct identification of events, that are rare in a population. This is often the case in health physics measurements, and the false positive fraction (the fraction of results measuring positive that are actually zero) is often very large using the prescriptions of classical statistics. Bayesian statistics pro,ides a methodology to minimize the number of incorrect decisions (wrong calls): false positives and false negatives. We present the basic method and a heuristic discussion. Examples are given using numerically generated and real bioassay data for tritium. Various analytical models are used to fit the prior probability distribution in order to test the sensitivity to choice of model, parametric studies show that for typical situations involving rare events the normalized Bayesian decision level k(alpha) = L-c/sigma(0) ilhero sigma(0) a is the measurement uncertainty for zero true amount, is in the range of 3 to 5 depending on the true positive rate. Four times sigma(0) rather than approximately two times a,, as in classical statistics, mould seem a better choice for the decision level in these situations. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM guthrie@lanl.gov NR 15 TC 21 Z9 21 U1 1 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 JUN PY 2000 VL 78 IS 6 BP 598 EP 613 DI 10.1097/00004032-200006000-00002 PG 16 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 317TP UT WOS:000087243300001 PM 10832919 ER PT J AU Schilk, A Kirkpatrick, J Dunker, R Gesell, T AF Schilk, A Kirkpatrick, J Dunker, R Gesell, T TI Implementation of the MARSSIM philosophy to evaluate the remedial status of a radioactive waste disposal site at the Idaho National Engineering and Environmental Laboratory SO HEALTH PHYSICS LA English DT Article DE waste disposal; radionuclide; soil; contamination, environmental AB Implementation of the MARSSIM remedial-verification protocol at a radioactive waste disposal site is described in some detail to provide a record of the utility of this process. The selected site was the Stationary Low-Power Reactor No, 1 burial ground at the Idaho National Engineering and Environmental Laboratory. Evaluation was restricted to Cs-137 in the uppermost 10 cm of potentially contaminated soils. According to the MARSSIM, this site warranted a "Class 1" designation based on previous remedial activities within the burial ground, its status as a radioactive disposal facility, and the anticipated presence of discrete radioactive particles. Nine survey units within the confines of the burial ground were selected, based primarily on the presence of physical boundaries and disparate histories. Surface sums with 100% coverage were performed using a hand-held plastic scintillator and rate meter with audible output. bt situ gamma-ray spectrometry was not used for the individual stationary measurements due to the limited area and proximity of engineered barriers, Instead, individual soil samples were obtained using a standard hand-held coring de,ice. The number of soil samples taken from the background reference area and each survey unit were determined with the MARSSIM protocol which resulted in a total of 160 (including quality-control samples), Two of the nine regions exhibited elevated radiation levels and the null hypothesis could not be rejected in one survey unit, thereby indicating the need for additional remediation, The MARSSIM process proved to be flexible, scientifically rigorous, and cost effective in this held application Several modifications to the procedure are discussed and offered as recommendations for enhancement of the MARSSIM. C1 Idaho State Univ, Phys Hlth Phys Dept, Pocatello, ID 83209 USA. INEEL Oversight Program, Idaho Falls, ID 83402 USA. Idaho Dept Hlth & Welf, Div Environm Qual, Idaho Falls, ID 83402 USA. NR 5 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 JUN PY 2000 VL 78 IS 6 BP 721 EP 726 DI 10.1097/00004032-200006000-00017 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 317TP UT WOS:000087243300016 PM 10832934 ER PT J AU McDonald, JC AF McDonald, JC TI William C. Roesch 1923-1999 - In memoriam SO HEALTH PHYSICS LA English DT Biographical-Item C1 Pacific NW Lab, Environm Technol Div, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 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 JUN PY 2000 VL 78 IS 6 BP 758 EP 759 DI 10.1097/00004032-200006000-00027 PG 2 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 317TP UT WOS:000087243300021 ER PT J AU Corbet, TF AF Corbet, TF TI A groundwater-basin approach to conceptualize and simulate post-Pleistocene subsurface flow in a semi-arid region, southeastern New Mexico and western Texas, USA SO HYDROGEOLOGY JOURNAL LA English DT Article DE paleohydrology; conceptual model; numerical modeling; free surface; USA ID CANADA SEDIMENTARY BASIN; FINITE-ELEMENT METHOD; ISOLATION PILOT-PLANT; HYDROLOGIC CONSTRAINTS; FLUID-FLOW; EVOLUTION; ALBERTA; MODEL; WATER; AQUIFERS AB Numerical simulation was used to enhance conceptual understanding of the post-Pleistocene hydrogeology of a layered sequence of elastic and evaporite sediments. This work is part of an effort to evaluate the suitability of the Waste Isolation Pilot Plant (WIPP), New Mexico, USA, as a repository for transuranic waste. The numerical model is three-dimensional, extends laterally to topographic features that form the actual boundaries of a regional groundwater system, and uses a free surface with seepage face as an upper boundary condition to simulate the effect of change in recharge rate on the position of the water table. Simulation results suggest that the modern-day flow field is still adjusting to the drying of the climate that has occurred since the end of the Pleistocene Epoch. A wetter climate at the end of the Pleistocene resulted in a shallow water table, and patterns of groundwater flow were controlled by the intermediate features of the land-surface topography. As the climate became drier and the water table declined. groundwater flow began to increasingly reflect the land-surface topography at the scale of the entire groundwater basin. The modern-day flow pattern has not equilibrated with either the present recharge rate or the position of the water table. C1 Sandia Natl Labs, Geohydrol Dept 6115, Albuquerque, NM 87185 USA. RP Corbet, TF (reprint author), Sandia Natl Labs, Geohydrol Dept 6115, POB 5800, Albuquerque, NM 87185 USA. EM tfcorbe@sandia.gov NR 59 TC 6 Z9 7 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1431-2174 J9 HYDROGEOL J JI Hydrogeol. J. PD JUN PY 2000 VL 8 IS 3 BP 310 EP 327 DI 10.1007/s100400000067 PG 18 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 334UN UT WOS:000088204200005 ER PT J AU Satoh, S Tosaka, Y Wender, SA AF Satoh, S Tosaka, Y Wender, SA TI Geometric effect of multiple-bit soft errors induced by cosmic ray neutrons on DRAM's SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE cosmic ray neutrons; geometric effect; multiple-bit SE; 16 Mb DRAM; soft error ID MICRON CMOS CIRCUITS; GROUND-LEVEL; MEMORIES AB Although it has been shown that cosmic ray neutrons play an important role in soft error (SE) phenomena, some important issues remain to be clarified in neutron-induced SE phenomena. This letter reports the geometric effect of multiple-hit SE's induced by neutrons. Multiple-hit SE's in 16Mb DRAM's are investigated and their geometric effects on high reliability systems are discussed. C1 Fujitsu Labs Ltd, Atsugi, Kanagawa 2430197, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Satoh, S (reprint author), Fujitsu Labs Ltd, Atsugi, Kanagawa 2430197, Japan. NR 10 TC 43 Z9 43 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 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD JUN PY 2000 VL 21 IS 6 BP 310 EP 312 DI 10.1109/55.843160 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 320GL UT WOS:000087393400017 ER PT J AU Bennett, CV Kolner, BH AF Bennett, CV Kolner, BH TI Principles of parametric temporal imaging - Part II: System performance SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE dispersive propagation; frequency mixing; phase modulation; temporal imaging; time lens; ultrafast measurement; ultrafast pulse propagation ID CONVERSION TIME MICROSCOPE; 2ND HARMONIC-GENERATION; 2ND-HARMONIC GENERATION; PULSE-COMPRESSION; VELOCITY MISMATCH; PHASE; MAGNIFICATION; LENSES; SPACE AB The waveform manipulation technique known as temporal imaging can expand or compress signals in time while maintaining the shape of their envelope profiles. The temporal imaging system is analogous to that of its spatial counterpart, with dispersive propagation performing the role of diffraction and quadratic phase modulation in time acting as a "time lens.'' Recent work has concentrated on time lenses produced by the parametric mixing of the dispersed input signal with a linearly chirped optical pump pulse because of the broad bandwidth, and thus fine temporal resolution, that can be obtained. In a previous paper, we presented the numerous parametric imaging configurations that are possible and drew temporal ray diagrams to illustrate their operation, In this paper, we study the performance of these systems. Resolution, field of view, number of resolvable features, and distortions particular to this approach are discussed. C1 Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90024 USA. Univ Calif Lawrence Livermore Natl Lab, Elect Engn Div, Livermore, CA 94551 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Bennett, CV (reprint author), Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90024 USA. RI Bennett, Corey/C-2403-2009 OI Bennett, Corey/0000-0003-4365-5739 NR 34 TC 30 Z9 30 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD JUN PY 2000 VL 36 IS 6 BP 649 EP 655 DI 10.1109/3.845718 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 322KZ UT WOS:000087509900003 ER PT J AU Sampayan, SE Vitello, PA Krogh, ML Elizondo, JM AF Sampayan, SE Vitello, PA Krogh, ML Elizondo, JM TI Multilayer high gradient insulator technology SO IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL ID VACUUM SURFACE FLASHOVER AB We are investigating a novel insulator concept that involves the use of alternating layers of conductors and insulators with periods on the order of <1 mm. These structures perform many times better (similar to 1.5 to >4x higher breakdown electric field strength) than conventional insulators in long pulse, short pulse, and alternating polarity applications. A previously defined scaling law of d (0:5), where d is the insulator length, appears to apply to these new structures when the scaling parameter d is replaced by the layer period d(1). This observation implies that each layer within the structure behaves independently in the breakdown process. We present our ongoing studies investigating the degradation of the breakdown electric field strength resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial work on scaling and modeling studies. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. FM&T Kansas City, Allied Signal, Kansas City, MO USA. RP Sampayan, SE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 23 TC 20 Z9 28 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 1070-9878 J9 IEEE T DIELECT EL IN JI IEEE Trns. Dielectr. Electr. Insul. PD JUN PY 2000 VL 7 IS 3 BP 334 EP 339 DI 10.1109/94.848910 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 329UQ UT WOS:000087927200005 ER PT J AU Schwank, JR Shaneyfelt, MR Dodd, PE Burns, JA Keast, CL Wyatt, PW AF Schwank, JR Shaneyfelt, MR Dodd, PE Burns, JA Keast, CL Wyatt, PW TI New insights into fully-depleted SOI transistor response after total-dose irradiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 5th European Conference on Radiation and Its Effects on Components and Systems (RADECS 99) CY SEP 13-17, 1999 CL FONTEVRAUD, FRANCE SP Commissariat Energie Atom, IEEE Nucl & Plasma Sci Soc, COGEMA, CNES, TEMIC, CEA DAM, CEA DTA ID DEVICES; MOSFETS; SIMOX AB In this work we explore the effects of total-dose ionizing irradiation on fully-depleted SOI transistors. Closed-geometry and standard transistors fabricated in two fully-depleted processes were irradiated with 10-keV x rays. Our results show that increases in radiation-induced leakage current are caused by positive charge trapping in the buried oxide inverting the back-channel interface. At moderate levels of trapped charge, the back-channel interface is slightly inverted causing a small leakage current to flow. This leakage current may be amplified to considerably higher levels by impact ionization. At high levels of trapped charge, the back-channel interface is fully inverted and the gate bias has little effect on leakage current. Large increases in leakage currents can be obtained with or without impact ionization occurring in the channel region. For these transistors, the worst-case bias configuration was determined to be the "ON" bias configuration for both the cases where radiation-induced transistor response was dominated by charge buildup in the buried oxide and in the trench sidewall isolation. These results have important implications on hardness assurance. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. MIT, Lincoln Lab, Lexington, MA 02173 USA. RP Schwank, JR (reprint author), Sandia Natl Labs, POB 5800,MS-1083, Albuquerque, NM 87185 USA. NR 17 TC 42 Z9 48 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 604 EP 612 DI 10.1109/23.856487 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TR UT WOS:000088378200022 ER PT J AU Li, Z Huang, W Zhao, LJ AF Li, Z Huang, W Zhao, LJ TI Study of the correlation between the cutting edge current breakdown and the simulated lateral electrical field boundary in high resistivity silicon detectors with multi-guard ring structure SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB High resistivity silicon detectors with Multi-Guard Ring Structure (MGRS), after being subjected to laser cutting to various distances (L, from 10 mu m to 1000 mu m) from the outer most guard ring, have been used to investigate the effect of cutting edge current breakdown (CECB). The bias on the outer most guard ring at which CECB starts, or the edge breakdown voltage V-b, increases monotonically with L. This result has been compared to the simulated lateral depletion depth (W-L) from the outer most guard ring as a function of bias voltage V with very good correlation. For a given bias V, CECB occurs if W-L is larger than L, suggesting that current injects as soon as electrical field reaches the cutting edge. These results indicate that damage caused by laser cutting is very much localized to the edge itself (within a few mu ms). The edge breakdown current can be separated from the bulk leakage current by grounding one of the guard rings. The advantage of using MGRS to spread the electrical potential over a large distance to prevent possible high field breakdown was also simulated and discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Li, Z (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 3 TC 7 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 729 EP 736 DI 10.1109/23.856506 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300002 ER PT J AU Basken, O Becks, KH Ehrmann, O Gerlach, P Grah, C Gregor, IM Linder, C Meuser, S Richardson, J Topper, M Wolf, J AF Basken, O Becks, KH Ehrmann, O Gerlach, P Grah, C Gregor, IM Linder, C Meuser, S Richardson, J Topper, M Wolf, J CA ATLAS Pixel Collaboration TI First MCM-D modules for the b-physics layer of the ATLAS pixel detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WA AB The innermost layer (b-physics layer) of the ATLAS Pixel Detector will consist of modules based on MCM-D technology. Such a module consists of a sensor tile with an active area of 16.4 mm x 60.4 mm, 16 read out ICs, each serving 24 x 160 pixel unit cells, a module controller chip (MCC), an optical transceiver and the local signal interconnection and power distribution busses. Figure 1 shows a prototype of such a module with additional test pads on both sides. The outer dimensions of the final module will be 21.4 mm x 67.8 mm. The extremely high wiring density, which is necessary to interconnect the read-out chips, was achieved using a thin film Copper/Photo-SCB process on the pixel array. The bumping of the read out chips was done using electroplating PbSn. All dice are then attached by flip-chip assembly to the sensor diodes and the local busses. This thin film technology has been described in [1] and is under further development at Fraunhofer-IZM in Berlin. Focus of this paper is the description of the first results of such MCM-D-type modules. C1 IZM, Fraunhofer Inst, Berlin, Germany. Univ Bonn, Dept Phys, D-5300 Bonn, Germany. Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Univ Wuppertal, Dept Phys, Wuppertal, Germany. NR 11 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 745 EP 749 DI 10.1109/23.856508 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300004 ER PT J AU Amman, M Luke, PN Lee, JS AF Amman, M Luke, PN Lee, JS TI CdZnTe material uniformity and coplanar-grid gamma-ray detector performance SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID SEMICONDUCTOR AB "Electron-only" detection techniques such as the coplanar-grid method are effective in overcoming some of the charge transport problems of CdZnTe and, consequently, have led to large-volume gamma-ray detectors with good energy resolution while operating at room temperature. A requirement for the success of these techniques is uniformity in electron generation and transport. Once large inhomogeneities in these properties caused by grain boundaries and other large-scale crystal defects are eliminated through simple material screening techniques, small variations remain and limit the gamma-ray energy resolution. In this paper we present the results from our characterization and analysis of these nonuniformities in commercially available CdZnTe, and we establish the relationship between the nonuniformities and the ultimate coplanar-grid gamma-ray detector performance through experimental measurements. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Amman, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 9 TC 20 Z9 20 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 760 EP 767 DI 10.1109/23.856511 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300007 ER PT J AU Cho, HS Xie, XB Chien, CY Liang, GW Huang, W Dezillie, B Eremin, V Li, Z AF Cho, HS Xie, XB Chien, CY Liang, GW Huang, W Dezillie, B Eremin, V Li, Z TI Characterization of silicon pixel detectors with the n(+)/n/p(+) and double-sided multiguard ring structure before and after neutron irradiation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID CHARGES N-EFF AB The lifetime of silicon detectors in a severe radiation environment at CERN LHC depends strongly upon careful detector design and material selection, due to the anticipated radiation-induced damage. We fabricated recently more radiation-tolerant CMS forward pixel sensors' with new designs of silicon pixel detectors with the n(+)/n/p(+) and double-sided multiguard ring structure. Electrical characterization of such devices was performed before and after irradiation to neutron fluences (1 MeV equivalent) up to 6x10(14) n/cm(2) measuring leakage current, potential distribution over the guard rings and full depletion voltage. Studies on the radiation hardness using oxygen-enriched silicon substrates are being presented separately[1]. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Cho, HS (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 7 TC 5 Z9 5 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 772 EP 776 DI 10.1109/23.856513 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300009 ER PT J AU Lau, K Arinyo, I Atiya, M Bastos, J Broemmelsiek, D Carvalho, J Conde, P Dujmic, D Eckmann, R Garrido, L Gorisek, A Ispiryan, M Ivanouchenkov, I Karabekyan, S Korpar, S Krizan, P Miquel, R Peralta, D Pestotnik, R Pyrlik, J Ramachandran, S Reeves, K Rosen, J Schwitters, R Selover, M Skrk, D Stanovnik, A Staric, M Zivko, T AF Lau, K Arinyo, I Atiya, M Bastos, J Broemmelsiek, D Carvalho, J Conde, P Dujmic, D Eckmann, R Garrido, L Gorisek, A Ispiryan, M Ivanouchenkov, I Karabekyan, S Korpar, S Krizan, P Miquel, R Peralta, D Pestotnik, R Pyrlik, J Ramachandran, S Reeves, K Rosen, J Schwitters, R Selover, M Skrk, D Stanovnik, A Staric, M Zivko, T TI The first year of the HERA-B RICH SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB The operational experience of the RICH detector for the first year at HERA-B is described. The design criteria, detector components, and reconstruction software are reviewed. The results show that the main design goals have been achieved. C1 Univ Houston, Houston, TX 77004 USA. Univ Barcelona, E-08007 Barcelona, Spain. BNL, Upton, NY USA. Univ Coimbra, P-3000 Coimbra, Portugal. Northwestern Univ, Evanston, IL USA. Univ Texas, Austin, TX 78712 USA. Univ Ljubljana, Ljubljana 61000, Slovenia. Jozef Stefan Inst, Ljubljana, Slovenia. DESY, D-2000 Hamburg, Germany. RP Lau, K (reprint author), Univ Houston, Houston, TX 77004 USA. RI Conde Muino, Patricia/F-7696-2011; Carvalho, Joao/M-4060-2013; OI Conde Muino, Patricia/0000-0002-9187-7478; Carvalho, Joao/0000-0002-3015-7821; Miquel, Ramon/0000-0002-6610-4836 NR 2 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 789 EP 792 DI 10.1109/23.856517 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300013 ER PT J AU Adam, I Aleksan, R Aston, D Benkebil, M Bernard, D Bonneaud, G Brochard, F Brown, DN Chauveau, J Cohen-Tanugi, J Convery, M David, P de Domenico, G de Lesquen, A Emery, S Ferrag, S Gaidot, A Geld, T de Monchenault, GH Hamon, O Hoecker, A Kadel, RW Kadyk, J Kalelkar, M Le Diberder, F London, GW Lu, A Lutz, AM Lynch, G Mancinelli, G Martinez-Vidal, F Meadows, BT Plano, R Plaszczynski, S Pripstein, M Ratcliff, BN Roos, L Roussot, E Salnikov, A Schune, MH Schwiening, J Shelkov, V Sokoloff, MD Spanier, S Stark, J Telnov, AV Thiebaux, C Valassi, A Vasileiadis, G Vasseur, G Va'vra, J Verderi, M Wilson, RJ Wormser, G Yeche, C Yellin, S Zito, M AF Adam, I Aleksan, R Aston, D Benkebil, M Bernard, D Bonneaud, G Brochard, F Brown, DN Chauveau, J Cohen-Tanugi, J Convery, M David, P de Domenico, G de Lesquen, A Emery, S Ferrag, S Gaidot, A Geld, T de Monchenault, GH Hamon, O Hoecker, A Kadel, RW Kadyk, J Kalelkar, M Le Diberder, F London, GW Lu, A Lutz, AM Lynch, G Mancinelli, G Martinez-Vidal, F Meadows, BT Plano, R Plaszczynski, S Pripstein, M Ratcliff, BN Roos, L Roussot, E Salnikov, A Schune, MH Schwiening, J Shelkov, V Sokoloff, MD Spanier, S Stark, J Telnov, AV Thiebaux, C Valassi, A Vasileiadis, G Vasseur, G Va'vra, J Verderi, M Wilson, RJ Wormser, G Yeche, C Yellin, S Zito, M TI First year operational experience with the Cherenkov detector (DIRC) of BABAR SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID COUNTER AB The DIRC (acronym for Detection of Internally Reflected Cherenkov (light)) is a new type of Cherenkov ring imaging detector based on total internal reflection that is used for the first time in the BABAR detector at PEP-II ring of SLAG. The Cherenkov radiators are long rectangular bars made of synthetic fused silica. The photon detector is a water tank equipped with an array of 10,752 conventional photomultipliers. The first year operational experience in the BABAR detector is presented using cosmic data and collision data in the energy region of the gamma(4S) resonance. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CEA, DAPNIA, CE Saclay, F-91191 Gif Sur Yvette, France. Univ Paris 06, LPNHE, F-75252 Paris, France. Univ Paris 07, LPNHE, F-75252 Paris 05, France. Univ Paris Sud, LAL Orsay, F-91405 Orsay, France. Ecole Polytech, LPNHE, F-91128 Palaiseau, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. Rutgers State Univ, Dept Phys, Piscataway, NJ 08855 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. RP Adam, I (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Valassi, Andrea/K-7506-2012; Martinez Vidal, F*/L-7563-2014; OI Valassi, Andrea/0000-0001-9322-9565; Martinez Vidal, F*/0000-0001-6841-6035; Wilson, Robert/0000-0002-8184-4103 NR 16 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 793 EP 797 DI 10.1109/23.856518 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300014 ER PT J AU Hahn, SF Sullivan, JP van Hecke, HW Simon-Gillo, JE Smith, GD Schlei, BR Sun, A Young, GR Britton, CL Emery, MS Bobrek, M AF Hahn, SF Sullivan, JP van Hecke, HW Simon-Gillo, JE Smith, GD Schlei, BR Sun, A Young, GR Britton, CL Emery, MS Bobrek, M TI High Density Interconnect multi-chip module for the front-end electronics of the PHENIX/MVD SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID MULTIPLICITY VERTEX DETECTOR AB A multi-chip module (MCM) based on High Density Interconnect (HDI) technology was developed for the front-end electronics of a high energy nuclear physics experiment to process charge pulses from silicon detectors. Stringent requirements in performance as well as low radiation length and minimum physical size of the module dictated the use of the most sophisticated MCM technology available. The module handles 256 input channels on an alumina substrate with milled cavities for die placements and four layers of thin-film traces of 42u width. A total of 20 custom integrated circuit chips and 98 passive components are assembled on a substrate of size 43mm x 48mm. Various aspects of development efforts for the design and fabrication as well as the electrical test results of the module are discussed. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lockheed Martin GES, Moorestown, NJ 08057 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hahn, SF (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 802 EP 805 DI 10.1109/23.856520 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300016 ER PT J AU De Geronimo, G O'Connor, P Grosholz, J AF De Geronimo, G O'Connor, P Grosholz, J TI A CMOS baseline holder (BLH) for readout ASICs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID SOLID-STATE DETECTORS; LINE RESTORER; SIGNALS; SYSTEM; CDTE AB As a result of a cooperation between Brookhaven National Laboratory and eV Products a generation of high performance readout ASICs was developed. One of the novel circuit solutions implemented in the ASICs is the baseline holder (BLH), a system which provides setting and stabilization of the output baseline both at low frequency and at high rate operation. The BLH is conceptually different from the baseline restorer (BLR). With a output peaking voltage 2V (10fC), a peaking time 400ns and a rate 500kHz, an asymptotic shift of the baseline < 8mV was measured in the periodic case. A resolution higher than 12 bit was found in the random arrival of pulses case. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. EV Prod, Saxonburg, PA 16056 USA. RP De Geronimo, G (reprint author), Brookhaven Natl Lab, Instrumentat Div, Bldg 535B, Upton, NY 11973 USA. NR 18 TC 48 Z9 48 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 818 EP 822 DI 10.1109/23.856523 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300019 ER PT J AU Hoff, J Drake, G Byon-Wagner, A Foster, G Lindgren, M AF Hoff, J Drake, G Byon-Wagner, A Foster, G Lindgren, M TI SMQIE: A charge integrator and encoder chip for the CDF run II shower max detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB The Technical Design Report for the CDF II Detector calls for the development of an imbedded two-dimensional position sensitive detector sandwiched inside the electromagnetic calorimeter and placed at the shower maximum. The purpose of this detector is to aid in the identification of electrons and photons, to separate photons from pi(0)s, and to help identify electromagnetic showers. This detector is called the Shower Max. In order to achieve CDF's goals for resolution, timing, power and economy, as well as to fit into the available space, a full-custom integrated circuit was required for the project the SMQIE. The SMQIE has been fabricated in a 1.2 mu m CMOS process using vertical NPN transistors in critical areas. It operates without deadtime. Its QIEs have eight ranges and an overall dynamic range of 13 bits. Its FADCs have a 5-bit resolution with a nominal LSB of 31.25 mV. Its Level 1 Trigger delays are 42 beam crossings or approximately 5.5 mu s. Its data buffers hold up to four events, each of which can consist of four time slices. Finally, the chip accepts a maximum input charge up to 150 pC with a minimum resolution of 15 fC. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. RP Hoff, J (reprint author), Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 834 EP 838 DI 10.1109/23.856526 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300022 ER PT J AU Castoldi, A Gatti, E Guazzoni, C Longoni, A Rehak, P Struder, L AF Castoldi, A Gatti, E Guazzoni, C Longoni, A Rehak, P Struder, L TI A new architecture of the controlled-drift detector: Design and characterization SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID X-RAY-DETECTOR; POSITION; ENERGY AB A novel X-ray silicon detector for time-resolved 2D imaging has been recently proposed. The detector, called Controlled-Drift Detector, is operated in integrate-readout mode. Its basic feature is the fast transport of the integrated charge to the output electrode by means of a uniform. drift field. The drift time of the charge packet identifies the pixel of incidence. A new architecture to implement the Controlled-Drift Detector concept will be presented. The potential wells for the integration of the signal charge are obtained by means of a suitable pattern of deep n-implants and deep p-implants. During the readout mode the signal electrons are transferred in the drift channel that flanks each column of potential wells where they drift towards the collecting electrode at constant velocity. The first experimental measurements demonstrate the successful integration, transfer and drift of the signal electrons. First tests of X-ray imaging and spectroscopy are presented and discussed. C1 Politecn Milan, I-20133 Milan, Italy. Brookhaven Natl Lab, Upton, NY 11973 USA. MPI Halbleiterlab, D-81739 Munich, Germany. RP Castoldi, A (reprint author), Politecn Milan, Pza L da Vinci 32, I-20133 Milan, Italy. RI Guazzoni, Chiara/A-5070-2008 OI Guazzoni, Chiara/0000-0001-6399-8670 NR 8 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 844 EP 850 DI 10.1109/23.856528 PN 2 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300024 ER PT J AU Willson, RM Pandey, SU Bellwied, R Beuttenmuller, R Drees, A Kuczewski, P Leonhart, W Lynn, D Soja, R Takahashi, J AF Willson, RM Pandey, SU Bellwied, R Beuttenmuller, R Drees, A Kuczewski, P Leonhart, W Lynn, D Soja, R Takahashi, J TI Novel applications of PIN-photodiodes in relativistic heavy ion collisions SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB The new ultrarelativistic heavy ion collider at Brookhaven National Laboratory, RHIC, has recently ended its commissioning run, and will begin colliding gold nuclei together at center of mass energies of up to 40 TeV. One of the key requirements for silicon drift detectors is that there can be no direct interaction between the detector and the beam. At the STAR experiment, PM-photodiodes will be in place for the first year of beam running in order to detect beam loss before the silicon drift detector is put into place in 2000. The devices trigger on simultaneous interactions of an incoming particle with two PIN-diodes sandwiched together. In this paper we present methods in which to obtain results that are descriptive of the state of the beam, and show data for the latest commissioning run of beam circulation. C1 Ohio State Univ, Columbus, OH 43210 USA. Wayne State Univ, Detroit, MI 48201 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Sao Paulo, Sao Paulo, Brazil. RP Willson, RM (reprint author), Ohio State Univ, Columbus, OH 43210 USA. RI Takahashi, Jun/B-2946-2012 OI Takahashi, Jun/0000-0002-4091-1779 NR 5 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 851 EP 853 DI 10.1109/23.856529 PN 2 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300025 ER PT J AU Derenzo, SE Weber, MJ Moses, WW Dujardin, C AF Derenzo, SE Weber, MJ Moses, WW Dujardin, C TI Measurements of the intrinsic rise times of common inorganic scintillators SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WA ID FLUORESCENT LIFETIME MEASUREMENTS; RAY AB The intrinsic rise times of a number of common inorganic scintillators are determined using ultrafast measurements of luminescence following pulsed x-ray excitation. A Ti-sapphire mode-locked laser and a light-excited x-ray tube are used to produce x-ray pulses with 60 ps fwhm. Fluorescence photons are detected with a microchannel phototube and the response of the phototube and electronics is 45 ps fwhm. Samples are either powders or thin crystals painted black on five sides to reduce delayed scattered photons. The intrinsic scintillators CeF3, CdWO4, Bi4Ge3O12, and CsI have rise times less than or equal to 30 ps, indicating that electrons are promptly captured to form the excited states. The activated scintillators CaFa(2):Eu, ZnO:Ga, and Lu2SiO5:Ce have rise times less than or equal to 40 ps, indicating that the luminescent centers are excited by rapid sequential hole capture- electron capture. The activated scintillators CsI:TI and YAlO3:Ce have slower rise times due to processes that delay the formation of excited states. It is shown that for practical scintillation detectors, internal reflections in the crystal can degrade observed rise times by hundreds of ps depending on size, reflector, and index of refraction. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Lyon 1, CNRS, URA 442, Lab Physico Chim Mat Luminescents, F-69622 Villeurbanne, France. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Dujardin, Christophe/A-7467-2013 OI Dujardin, Christophe/0000-0002-0205-9837 NR 9 TC 66 Z9 68 U1 0 U2 15 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 860 EP 864 DI 10.1109/23.856531 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300027 ER PT J AU Holm, S Dittman, JR Freeman, J Klein, R Lewis, JD Shaw, TM Wesson, T Ciobanu, C Gerstenslager, J Hoftiezer, J Hughes, R Johnson, M Koehn, P Neu, C Sanchez, C Winer, BL Bloom, K Gerdes, D Dawson, JW Haberichter, WN AF Holm, S Dittman, JR Freeman, J Klein, R Lewis, JD Shaw, TM Wesson, T Ciobanu, C Gerstenslager, J Hoftiezer, J Hughes, R Johnson, M Koehn, P Neu, C Sanchez, C Winer, BL Bloom, K Gerdes, D Dawson, JW Haberichter, WN TI System architecture and hardware design of the CDF XFT online track processor SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB A trigger track processor is being designed for CDF Run 2. This processor identifies high momentum (P-T > 1.5 GeV/c) charged tracks in the new central outer tracking chamber for the CDF II detector. The design of the track processor, called the eXtremely Fast Tracker (XFT), is highly parallel and handle an input rate of 183 Gbits/sec and output rate of 44 Gbits/sec. The XFT is pipelined and reports the results for a new event every 132ns. The XFT uses three stages, hit classification, segment finding, and segment linking. The pattern recognition algorithms for the three stages are implemented in Programmable Logic Devices (PLDs) which allow for in-situ modification of the algorithm at any time. The PLDs reside on three different types of modules. Prototypes of each of these modules have been designed and built, and are working. An overview of the hardware design and the system architecture are presented. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Holm, S (reprint author), Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 4 TC 7 Z9 7 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 895 EP 902 DI 10.1109/23.856714 PN 2 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300034 ER PT J AU Takahashi, J Bellwied, R Beuttenmueller, R Chen, W Dezillie, B Eremin, V Elliot, D Hoffmann, GW Huang, W Humanic, T Ilyashenko, I Kotov, IV Kuczewski, P Leonhardt, W Li, Z Lynn, D Pandey, SU Schambach, J Soja, R Sugarbaker, E Zhao, LJ Willson, RM AF Takahashi, J Bellwied, R Beuttenmueller, R Chen, W Dezillie, B Eremin, V Elliot, D Hoffmann, GW Huang, W Humanic, T Ilyashenko, I Kotov, IV Kuczewski, P Leonhardt, W Li, Z Lynn, D Pandey, SU Schambach, J Soja, R Sugarbaker, E Zhao, LJ Willson, RM TI Radiation damage studies with STAR silicon drift detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB Large (6.3 x 6.3cm(2)) linear Silicon Drift Detectors were developed for use in the SVT, the inner tracking detector of the STAR experiment at the RHIC Collider. The concern of this paper is to estimate the effects of neutron and proton radiation damage to these devices and associated electronics. Detectors and their associated electronics were irradiated with 10(11) - 10(12)/cm(2), 1 MeV equivalent neutrons and 10(10) - 10(12)/cm(2), 24 GeV protons. I-V and C-V characteristics of diode test structures were used to determine depletion voltages, lifetimes, and reverse bias values. Measurements of the voltage and drift linearity with laser injection show the effects of irradiation on the detector performance. Measurements of noise levels show the effects of irradiation on the front-end electronics. C1 Univ Sao Paulo, Sao Paulo, Brazil. Wayne State Univ, Detroit, MI 48201 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Texas, Austin, TX 78712 USA. AF Ioffe Physicotech Inst, St Petersburg, Russia. RP Takahashi, J (reprint author), Univ Sao Paulo, Sao Paulo, Brazil. RI Takahashi, Jun/B-2946-2012 OI Takahashi, Jun/0000-0002-4091-1779 NR 14 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 903 EP 907 DI 10.1109/23.856715 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300035 ER PT J AU Russ, WR Stuenkel, DO Valentine, JD Gross, KC AF Russ, WR Stuenkel, DO Valentine, JD Gross, KC TI Improved radioxenon detection techniques for use with fluid-based concentration SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB A portable system that monitors the quantity of radioxenon (Xe-131m, Xe-133, Xe-133m, and Xe-135) in the atmosphere is being developed. The integrated monitoring system consists of a fluid-based concentration sub-system and a detection sub-system. This study evaluates the performance of different high-efficiency geometries that use NaI(TI) photon detectors along with with either gas proportional, plastic scintillator, or PIPS detectors to distinguish radioxenon signature emissions and discriminate against radon background. In addition, a NaI(T1)/CsI(TI) phoswich detector was investigated as an alternative photon detector. Finally, a dual parameter data acquisition system was demonstrated. Minimum detectable activity (MDA) for a six hour count time of Xe-133 was used as the primary measure of performance. The lowest MDAs were 52+/-7 mBq for the gas proportional/NaI(T1) configuration, 48+/-7 mBq for the plastic scintillator/NaI(T1) configuration and 73+/-8 mBq for the PIPS/NaI(T1) configuration Based on these results, the performance of a proposed final detection system is predicted to result in a MDA of 12.2 mBq without shielding. This detection system performance compares well to existing radioxenon detection systems and indicates the requirements of the concentration system. C1 Georgia Inst Technol, Nucl & Radiol Engn Program, Atlanta, GA 30332 USA. Univ Cincinnati, Nucl & Radiol Engn Program, Cincinnati, OH 45221 USA. Argonne Natl Lab, Reactor Anal Div, Argonne, IL 60439 USA. RP Russ, WR (reprint author), Georgia Inst Technol, Nucl & Radiol Engn Program, Atlanta, GA 30332 USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 908 EP 913 DI 10.1109/23.856716 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300036 ER PT J AU Wielopolski, L Orion, I Hendrey, G Roger, H AF Wielopolski, L Orion, I Hendrey, G Roger, H TI Soil carbon measurements using inelastic neutron scattering SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON AB Soil carbon sequestration is a whole new area of energy related research that provides a fundamentally new approach for dealing with climate change resulting from the substantial increase in CO, concentration in the atmosphere. Carbon sequestration in soil is recognized to play a major role in allowing fossil fuels to remain a vital component of the national energy mix. At present soil carbon is measured by taking core samples and involves extensive laboratory work. We propose a novel nondestructive in situ method for carbon analysis using the Inelastic Neutron Scattering (INS) (n,n'gamma) reaction. The feasibility of detecting carbon in soil was demonstrated using a clinical in vivo body composition facility, located in the Medical Department at BNL. A D-T generator, operated at 55 kV, irradiated 12"x12"x14" aluminum boxes filled with 70 Ib. clean sand and mixtures of sand with 2%, 5% and 10% carbon powder by weight. The spectra were acquired for 1 hr and subsequently the carbon peaks were analyzed using the trapezoidal method for peak extraction. The results demonstrate that the proposed method is suitable for carbon analysis in soil, and it should allow sequential sampling of soil carbon within a soil volume of about 0.5 m(3) with an error of about 1% or less. It is expected that, with final optimization, changes of about 1% in the soil carbon content would be observable with sufficient confidence levels. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Columbia Univ, St Lukes Roosevelt Med Ctr, New York, NY 10025 USA. USDA ARS, Natl Soil Dynam Lab, Auburn, AL 36831 USA. RP Wielopolski, L (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RI ORION, ITZHAK/F-2034-2012 NR 4 TC 20 Z9 23 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 914 EP 917 DI 10.1109/23.856717 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300037 ER PT J AU Kim, HK Jackson, K Hong, WS Park', IJ Han, SH Kadyk, J Perez-Mendez, V Wenzel, W Cho, G AF Kim, HK Jackson, K Hong, WS Park', IJ Han, SH Kadyk, J Perez-Mendez, V Wenzel, W Cho, G TI Application of the LIGA process for fabrication of gas avalanche devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID DETECTOR; GEM AB Arrays of holes having steep wall sides have been successfully prepared by using a deep X-ray lithography technique, or LIGA process, on various thicknesses (50 - 1,000 mu m) polymethylmethacrylate (PMMA) plastic sheets. Electrical contact layers onto the top and bottom sides were deposited by metal evaporation in a vacuum. The completed LIGA devices were studied as an alternative design of the gas electron multiplier (GEM). The first measurements of performance were very promising: a lower limit to the avalanche gain of similar to 3,000 was obtained, and the actual gain is probably much larger. Detailed experimental results and field simulations will be described in this study. In addition, an application of a LIGA device to serve as a drift plane electrode, avoiding the angle dependency, will be discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Engn, Berkeley, CA 94720 USA. Korea Adv Inst Sci & Technol, Dept Nucl Engn, Taejon 305701, South Korea. Myongji Univ, Dept Phys, Yongin 449728, South Korea. Kyungpook Natl Univ, Dept Phys, Taegu 702701, South Korea. RP Kim, HK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RI Cho, Gyuseong/C-1527-2011 NR 10 TC 8 Z9 9 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 923 EP 927 DI 10.1109/23.856719 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300039 ER PT J AU Lopes, JAM dos Santos, JMF Morgado, RE Conde, CAN AF Lopes, JAM dos Santos, JMF Morgado, RE Conde, CAN TI Silicon photodiodes as the VUV photosensor in gas proportional scintillation counters SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT Nuclear Science Symposium (NSS) CY OCT 26-28, 1999 CL SEATTLE, WASHINGTON ID CSI-PHOTOCATHODE; XENON; DETECTOR; PERFORMANCE; CHAMBER AB The application of recently developed VUV silicon photodiodes as a replacement for the standard photomultiplier tube (PMT) in a gas proportional scintillation counter (GPSC) is investigated. A photodiode positioned within the gas envelope would result in a GPSC that is more compact, robust, and simpler to operate. At the 170 nm wavelength of the scintillation light from xenon, UV photodiodes achieve an effective quantum efficiency of 72%, better than the typically 20% figure for PMTs. On the other hand, the lack of amplification in the photodiode readout limits the signal-to-noise ratio that can be achieved. A GPSC based on a silicon photodiode with an active area of 100 mm(2) and no additional amplification stage achieved energy resolutions of 20.5, 14.5 and 13.4% for 5.9, 22.1, and 59.6 keV x-rays, respectively. Signal noise in the low energy limit extends up to approximately 3 keV. C1 Inst Super Engn Coimbra, P-3030 Coimbra, Portugal. Univ Coimbra, Dept Fis, P-3004516 Coimbra, Portugal. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lopes, JAM (reprint author), Inst Super Engn Coimbra, Quinta Nora,Ap 4065, P-3030 Coimbra, Portugal. RI matias-lopes, jose/H-6074-2012; dos Santos, Joaquim/B-3058-2015; OI matias-lopes, jose/0000-0002-6366-2963; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 22 TC 6 Z9 6 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 928 EP 932 DI 10.1109/23.856720 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TT UT WOS:000088378300040 ER PT J AU Klein, GJ Huesman, RH AF Klein, GJ Huesman, RH TI Elastic material model mismatch effects in deformable motion estimation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 Medical Imaging Conference (MIC) CY OCT 24-30, 1999 CL SEATTLE, WASHINGTON AB Deformable motion models are useful for analysis of dynamic datasets exhibiting non-rigid motion, as in gated cardiac PET. We employ an algorithm that obtains a vector field to describe the relative motion of each voxel between two data sets. The estimation is based on a two-component cost function: an image matching component, and a motion field smoothness component. An important aspect of obtaining an accurate motion field estimate is properly balancing the weight between the two cost components. We show that by using a material elastic model inspired by continuum mechanics, an intuitive interpretation of the weighting factors for the smoothness constraint may be obtained. Further, we show that mismatches between actual material elastic parameters and those used by the estimation algorithm can lead to greater estimation error. Results are validated using an ellipsoidal phantom simulating compressible and incompressible deformations. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Klein, GJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 10 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 1000 EP 1005 DI 10.1109/23.856538 PN 3 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TW UT WOS:000088378600005 ER PT J AU Maltz, JS AF Maltz, JS TI Region resolvability versus noise level characteristics for joint spatial and kinetic parameter estimation in inconsistent projection dynamic ECT SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 Medical Imaging Conference (MIC) CY OCT 24-30, 1999 CL SEATTLE, WASHINGTON ID MODEL AB For emission computed tomography (ECT) studies of temporally static source distributions, well-known guidelines exist for the number of resolution elements which may be acceptably resolved in a reconstructed image, at a given noise level. Owing to the incomplete angular-temporal sampling in such ECT modalities as rotating camera dynamic single photon ECT(SPECT), the acquired sinogram is not a consistent representation of a Radon transform, and consequently, no analogous bounds on the performance of dynamic reconstruction algorithms may be derived from Radon transform theory. Applying what we believe to be the first spatiokinetic parameter estimation algorithm able to simultaneously estimate both the geometry and kinetics of multiple dynamic regions directly from inconsistent projections, we establish empirical estimates for the number of regions whose boundaries and time-activity curves (TAC's) may be simultaneously estimated to a specified degree of accuracy at a given signal-to-noise ratio (SNR). Surprisingly, we find that regional TAC recovery for a segmented annulus myocardial phantom is relatively insensitive to noise at realistic SNR's and to a twofold increase in the number of resolution elements. We conclude that errors in the recovered regional TAC's are due primarily to the poorly conditioned nature of the spatiokinetic parameter estimation problem. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Maltz, JS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. NR 8 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 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 2000 VL 47 IS 3 BP 1143 EP 1148 DI 10.1109/23.856561 PN 3 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 337TW UT WOS:000088378600028 ER PT J AU Haworth, MD Luginsland, JW Lemke, RW AF Haworth, MD Luginsland, JW Lemke, RW TI Evidence of a new pulse-shortening mechanism in a load-limited MILO SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE high-power microwave; magnetically insulated transmission line oscillator (MILO); pulse shortening ID TRANSMISSION-LINE OSCILLATOR; ENERGY DEPOSITION; PLASMA AB Experimental evidence shows that the electron flow in a load-limited magnetically insulated transmission line oscillator (MILO) is only partially magnetically insulated at the launch point, yet fully insulated along the downstream slow-wave structure (SWS), This results in a microwave pulse duration substantially less than that of the beam. Computer simulations suggest that anode plasma formation is responsible for this pulse shortening and are able to replicate key features of the experimental data. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Haworth, MD (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 16 TC 18 Z9 21 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 511 EP 516 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900008 ER PT J AU Lefevre, T Gardelle, J Rullier, JL Donohue, JT Lidia, SM AF Lefevre, T Gardelle, J Rullier, JL Donohue, JT Lidia, SM TI Microwave production by a free-electron laser bunched beam driving a resonant cavity at 35 GHz SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE cavity resonators; electron beams; free electron lasers; linear accelerators ID KLYSTRON 2-BEAM ACCELERATOR AB In the two-beam accelerator scheme, a high-current electron beam, bunched at the resonant frequency, traverses extraction cavities, where it generates power intended to drive accelerating cavities on the main beam, Here, we report on work performed to test some aspects of this scheme. We used a free-electron-laser (FEL) amplifier at 35 GHz to bunch a beam of electrons, which is then transported and focused into a resonant cavity. The results of earlier bunching experiments had demonstrated the capacity of the FEL supplied by an induction linac to generate an appropriate drive beam, A summary of this earlier work is presented along with measurements of power from the cavity. This constitutes the first observation of high-frequency power extraction using a FEL in this scheme. C1 CEA, CESTA, F-33114 Le Barp, France. CEN Bordeaux Gradignan, F-33175 Gradignan, France. Ctr Beam Phys, EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Lefevre, T (reprint author), CEA, CESTA, F-33114 Le Barp, France. EM smildia@lbl.gov NR 24 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 812 EP 820 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900046 ER PT J AU Saraph, GP Felch, KL Feinstein, J Borchard, P Cauffman, SR Chu, S AF Saraph, GP Felch, KL Feinstein, J Borchard, P Cauffman, SR Chu, S TI A comparative study of three single-stage, depressed-collector designs for a 1-MW, CW gyrotron SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE depressed collector; ECRH; gyrotron; high power microwave source ID BEAM AB 1-MW continuous-wave (CW) gyrotrons operating at 140 GHz are being developed for heating fusion plasmas [1], Energy recovery using a depressed collector is employed to improve total efficiency and reduce power supply voltage and voltage regulation requirements for various electron beam devices. This paper describes and compares three different types of single-stage, depressed-collector designs. The first design is a magnetically shielded, coaxial collector with fixed-current collector coils. The second and third designs use cylindrical collectors with an outer magnetic shield and collector coils with time-varying current values. The time-varying magnetic field produced by the collector coils sweeps the beam trajectories on the collector surface lowering the average power density. The second design employs axial beam sweeping using axisymmetric collector coils, whereas the third design employs transverse beam sweeping, making the instantaneous fields and electron trajectories nonaxisymmetric and three-dimensional (3-D). Relative advantages and disadvantages of these three schemes are discussed. C1 Commun & Power Ind, Palo Alto, CA 94303 USA. Stanford Linear Accelerator Ctr, Menlo Park, CA 94025 USA. RP Saraph, GP (reprint author), Commun & Power Ind, Palo Alto, CA 94303 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 830 EP 840 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900048 ER PT J AU Lemke, RW Genoni, TC Spencer, TA AF Lemke, RW Genoni, TC Spencer, TA TI Effects that limit efficiency in relativistic magnetrons SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE high-power microwaves; particle-in-cell simulation; relativistic magnetron; rising-sun magnetron ID SIMULATION; EMISSION AB This work is an attempt to elucidate effects that may limit efficiency in magnetrons operated at relativistic voltages (V similar to 500 kV), Three-dimensional (3-D) particle-in-cell (PIC) simulation is used to investigate the behavior of 14- and 22-cavity, cylindrical, rising-sun magnetrons, Power is extracted radially through a single iris located at the end of every other cavity, Numerical results show that in general output power and efficiency increase approximately linearly with increasing iris width (decreasing vacuum Q) until the total Q becomes too low for stable oscillation in the pi -made to be maintained. Beyond this point, mode competition or switching occur and efficiency decreases. Results reveal that the minimum value of Q (maximum efficiency) that can be achieved prior to the onset of mode competition is significantly affected by the magnitude of the 0-space-harmonic of the ir-mode, a unique characteristic of rising-suns, and by the magnitude of the electron current density (space-charge effects). When these effects are minimized, numerical simulation predicts that gigawatt-level power production at 55% efficiency may be possible at relativistic voltage. C1 Sandia Natl Labs, Beam Plasma & Electromagnet Theory Dept, Albuquerque, NM 87185 USA. Mission Res Corp, Albuquerque, NM 87110 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Lemke, RW (reprint author), Sandia Natl Labs, Beam Plasma & Electromagnet Theory Dept, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 35 Z9 37 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 887 EP 897 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900051 ER PT J AU Hartemann, FV Landahl, EC Gibson, DJ Troha, AL Van Meter, JR Heritage, JP Baldis, HA Luhmann, NC Ho, CH Yang, TT Horny, MJ Hwang, JY Lau, WK Yeh, MS AF Hartemann, FV Landahl, EC Gibson, DJ Troha, AL Van Meter, JR Heritage, JP Baldis, HA Luhmann, NC Ho, CH Yang, TT Horny, MJ Hwang, JY Lau, WK Yeh, MS TI RF characterization of a tunable, high-gradient, X-band photoinjector SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE free-electron laser; photoinjector ID FREE-ELECTRON LASER; COHERENT SYNCHROTRON-RADIATION; HIGH-BRIGHTNESS; GUN AB Highly accurate measurements of an X-band (8.538 GHz) radio frequency (RF) gun, designed to produce short (<1 ps), relativistic (5 MeV), low-emittance (<1 pi -mm/mrad, at 0.1 nC) electron bunches, have been performed at medium-power levels (1 kW, 6 mus, 30 Hz). Balanced (within 3%), high-Q (4274), pi -mode excitation at critical coupling(S-11 < -80 dB) has been demonstrated by performing in situ phase measurements. A new tuning method to accurately adjust the coupling has been successfully implemented, which complements the independent tuning of the half and full cells, and the precise (-136 kHz/C) temperature tuning of the gun. Finally, preliminary photoelectron results are also outlined. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Synchrotron Radiat Res Ctr, Hsinchu, Taiwan. RP Hartemann, FV (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. RI Landahl, Eric/A-1742-2010; van meter, james/E-7893-2011 NR 15 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 898 EP 904 PG 7 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900052 ER PT J AU Nusinovich, GS Walter, MT Kremer, M Read, ME Boehme, D AF Nusinovich, GS Walter, MT Kremer, M Read, ME Boehme, D TI A submillimeter-wave gyroklystron: Theory and design SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE electron gun; gyroklystron; gyrotron; microwave; millimeter wave; submillimeter wave ID STAGGER-TUNED GYROKLYSTRONS; HIGH-POWER; GYROTRONS; AMPLIFIER; CONVERTER; BANDWIDTH; GAIN AB New elements of the theory and a preliminary design for a pulse/continuous-wave 360-GHz gyroklystron are presented. Issues germane to very high-frequency operation of gyroklystron amplifiers, including drive power and limits on cavity Q, are discussed. A specific two cavity design is described, That device had a gain of 33 dB and a beam extraction power of 1 kW with an electronic efficiency of 8% and a power output of 700 W after taking into account Ohmic losses. To produce fast-rising pulses, the beam velocity ratio was varied via the modulating anode of a magnetron injection gun, A design for an electron gun through which reduction of the output signal by -50 dB was achieved by a 400-V modulation is given. The input coupler, cavities, electron gun, collector, output coupling optics and collector are described. In addition, issues concerning the fabrication of the high precision, similar to2-mm diameter cavities are discussed. C1 Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. Phys Sci Inc, Alexandria, VA USA. Sandia Natl Labs, Washington, DC 20024 USA. RP Nusinovich, GS (reprint author), Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. NR 34 TC 0 Z9 0 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 2000 VL 28 IS 3 BP 936 EP 944 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 380VJ UT WOS:000165723900057 ER PT J AU Wilson, JR Hunt, RC AF Wilson, JR Hunt, RC TI Problems with correlated data SO IEEE TRANSACTIONS ON RELIABILITY LA English DT Article DE correlated data; Monte Carlo; PRA (probabilistic risk assessment) AB A misunderstanding exists in the PRA (probabilistic risk assessment) field over what constitutes correlated data, This report clarifies the applications that fit the initial intent of the definition. In addition, even when used as intended, current theory appears to give an overly conservative answer. A more realistic answer, which is still conservative (e.g,, overestimates the failure frequency of the group being estimated), is obtained by assuming the data are uncorrelated. Definition: "Correlated" data (as used in this paper) are data linked by a common data-distribution; i.e., if two separate components derive their failure rate from this same distribution, they are "correlated". This is not the same as statistically correlated data wherein the data can always be statistically correlated (e.g., race, sex, age, and education of poor people). C1 INEEL, Idaho Falls, ID 83415 USA. RP Wilson, JR (reprint author), INEEL, Box 1625,MS-3850, Idaho Falls, ID 83415 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9529 J9 IEEE T RELIAB JI IEEE Trans. Reliab. PD JUN PY 2000 VL 49 IS 2 BP 127 EP 130 DI 10.1109/24.877326 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 367KP UT WOS:000090060500003 ER PT J AU Mayer, B Rasmussen, S AF Mayer, B Rasmussen, S TI Dynamics and simulation of micellar self-reproduction SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE molecular dynamics; molecular self-assembly; cellular automata; lattice gas ID MONTE-CARLO SIMULATION; CELLULAR-AUTOMATA; SYSTEMS; ORGANIZATION; MODELS AB Molecular self-assembly plays a crucial role as a structural and an organizational principle in supramolecular architecture. The key feature of this process is the generation of higher order molecular structures, and is solely determined by the dynamics of the individual molecular objects, characterized by an overall minimum free energy situation. Equally important as the constructional aspect of the formation process, these macromolecular assemblies carry novel functionalities which can be solely observed at the level of the supramolecular aggregates and not at any of the organizational levels below. This paper discusses the formation and successive self-reproduction of membraneous compartments in a polar environment in 2D using a lattice gas based simulation technique, the Lattice Molecular Automaton. This method describes realistic physico-chemical interactions as well as chemical reactivity between molecular units via discrete force fields propagated on the lattice. We investigate the formation dynamics of micelles, i.e., organized amphiphilic polymers in polar environment, as well as the kinetics of a concomittant micelle self-reproduction based on the formation of catalytic interfaces closely following in vitro experimental results: Micelle self-reproduction is a complex phenomenon based on concerted dynamics of the individual polymers within the many particle aggregate. All observables, i.e., micelle formation and autocatalytic micelle self-reproduction, are solely based on the properties of the individual chemical objects (amphiphilic polymers in polar environment), and are therefore emergent phenomena generated by the implicitly defined system dynamics. We introduce the formal concept of the emergence of novel functions in dynamical hierarchies and finally discuss these issues within the context of self-reproducing dynamical hierarchies. C1 Univ Vienna, Inst Theoret Chem & Mol Struct Biol, A-1090 Vienna, Austria. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Mayer, B (reprint author), Univ Vienna, Inst Theoret Chem & Mol Struct Biol, UZAII Althanstr 14, A-1090 Vienna, Austria. NR 41 TC 18 Z9 18 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD JUN PY 2000 VL 11 IS 4 BP 809 EP 826 DI 10.1142/S0129183100000705 PG 18 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 342WL UT WOS:000088668300014 ER PT J AU Welch, RB AF Welch, RB TI Criteria for testing the visual-perceptual/visual-motor dissociation hypothesis SO INTERNATIONAL JOURNAL OF PSYCHOLOGY LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Ames, IA USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU PSYCHOLOGY PRESS PI HOVE PA 27 CHURCH RD, HOVE BN3 2FA, EAST SUSSEX, ENGLAND SN 0020-7594 J9 INT J PSYCHOL JI Int. J. Psychol. PD JUN-AUG PY 2000 VL 35 IS 3-4 SI SI BP 284 EP 284 PG 1 WC Psychology, Multidisciplinary SC Psychology GA 337XP UT WOS:000088388802775 ER PT J AU Joyce, LA Mitchell, JE Loftin, SR AF Joyce, LA Mitchell, JE Loftin, SR TI Applicability of Montreal Process Criterion 3 - maintenance of ecosystem health - to rangelands SO INTERNATIONAL JOURNAL OF SUSTAINABLE DEVELOPMENT AND WORLD ECOLOGY LA English DT Review DE disturbance; grazing; fire; weeds; air pollution; diminished biological components ID WESTERN UNITED-STATES; TALLGRASS PRAIRIE; NONEQUILIBRIUM RANGELANDS; BIOLOGICAL INVASIONS; VEGETATION DYNAMICS; SPECIES COMPOSITION; PLANT COMMUNITY; SO2 POLLUTION; ALPINE TUNDRA; NORTH-AMERICA AB Criterion 3 - Maintenance of Ecosystem Health - encompasses three indicators: disturbance, air pollution, and biological components. Our objective is to assess how well Criterion 3, developed to monitor temperate and boreal forests, applies to rangelands. We review the applicability of the three indicators, their potential limitations for rangeland ecosystems, the data currently available to quantify these indicators on rangelands, and highlight research needs for monitoring health and vitality of rangeland ecosystems. All indicators are applicable to rangelands. Deficiencies identified for the implementation of these criteria on forests are also present in applying them to rangelands. For Indicator 15, quantifying the spatial extent of disturbances requires a description of the dynamics of each disturbance, a definition of range of historic variation at the ecosystem level, and a baseline inventory of the current disturbance situation at the national level. The national networks currently monitoring air pollutants provide good data for Indicator 16. For Indicator 17, the premise that ecological processes underpin the health and vitality of ecosystems and that monitoring biological components would give advance warning of ecosystem stress is emphasized by numerous scientists. For this indicator, a surrogate such as productivity may be the near-term way to quantify this concept. C1 Rocky Mt Res Stn, Ft Collins, CO 80526 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Joyce, LA (reprint author), Rocky Mt Res Stn, 240 W Prospect Rd, Ft Collins, CO 80526 USA. NR 164 TC 7 Z9 7 U1 0 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1350-4509 J9 INT J SUST DEV WORLD JI Int. J. Sustain. Dev. World Ecol. PD JUN PY 2000 VL 7 IS 2 BP 107 EP 127 PG 21 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Ecology SC Science & Technology - Other Topics; Environmental Sciences & Ecology GA 337UD UT WOS:000088379300004 ER PT J AU Panofsky, WKH AF Panofsky, WKH TI Plutonium politics SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Panofsky, WKH (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SUM PY 2000 VL 16 IS 4 BP 18 EP 18 PG 1 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 397RG UT WOS:000166708900019 ER PT J AU Loffler, JF Thiyagarajan, P Johnson, WL AF Loffler, JF Thiyagarajan, P Johnson, WL TI Concentration and temperature dependence of decomposition in supercooled liquid alloys SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NY SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Source, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID PHASE-SEPARATION; REGION; GLASS; NI AB Small-angle neutron scattering experiments were performed on the bulk amorphous alloy Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vit1(R), subscripts indicate at.%) and on other alloys, where the (Zr, Ti) and (Cu, Be) contents were varied by following the line in composition space connecting Vit1 and Zr46.8Ti8.2Cu7.5Ni10Be27.5 (Vit4(R)). The small-angle neutron scattering data of the samples, annealed at temperatures between 603 K and 663 K, show interference peaks, giving evidence for spatially correlated arrangements of inhomogeneities. The Q values of the interference peaks, Q(max), decrease with increasing annealing temperature T a and, at a given annealing temperature, with composition following the connecting line from Vit1 to Vit4. Down to the glass transition temperature T-g, the data follow a relation 1/L-2 proportional to (T-s - T-a) as predicted by the linearized Cahn theory, with L = 2 pi/ Q(max) the characteristic wavelength of the decomposition and T-s the apparent spinodal temperature. Below T-g, a different behavior is observed, which may be either due to a change in atomic diffusion or due to an insufficient relaxation of the samples. C1 CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. EM loeffler@caltech.edu NR 17 TC 26 Z9 27 U1 1 U2 3 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 1600-5767 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 500 EP 503 DI 10.1107/S0021889899014867 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600020 ER PT J AU Thiyagarajan, P Burkoth, TS Urban, V Seifert, S Benzinger, TLS Morgan, DM Gordon, D Meredith, SC Lynn, DG AF Thiyagarajan, P Burkoth, TS Urban, V Seifert, S Benzinger, TLS Morgan, DM Gordon, D Meredith, SC Lynn, DG TI pH dependent self assembly of beta-amyloid(10-35) and beta-amyloid(10-35)PEG3000 SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID ALZHEIMERS AB Small angle neutron and x-ray scattering (SANS/SAXS) studies were conducted on the structure of the aggregates formed from both the truncated model peptide beta-Amyloid(10-35) (A beta(10-35)) and a block copolymer beta-Amyloid(10-35)-PEG3000 (A beta(10-35)-PEG) in D2O at pHs from 3.0 to 7.0. These studies indicate that A beta(10-35) aggregates into rodlike particles (fibril) and their radii are strongly dependent on the pH of the solution. The fibril-fibril association in A beta(10-35) solutions is less at pH < 5.6, but becomes larger at higher pH. A beta(10-35)-PEG also assembles into rod-like particles whose radius is larger by about 30 Angstrom than that for A beta(10-35) fibril at pH 4.2, while it is about 23 Angstrom larger at higher pH. Contrast matching SAXS/SANS experiments that eliminate the coherent scattering from PEG reveal that PEG moiety is located at the periphery of the fibril. Also the mass per unit length of the peptide portion is similar for both A beta(10-35) and A beta(10-35)-PEG fibrils at pH 5.6. The mass per unit length of the rods from SANS provides key information on the packing of A beta(10-35) peptides in the fibril. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. RP Thiyagarajan, P (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Urban, Volker/N-5361-2015 OI Urban, Volker/0000-0002-7962-3408 NR 9 TC 28 Z9 28 U1 1 U2 10 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 535 EP 539 DI 10.1107/S0021889899014387 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600029 ER PT J AU Tiede, DM Littrell, K Marone, PA Zhang, R Thiyagarajan, P AF Tiede, DM Littrell, K Marone, PA Zhang, R Thiyagarajan, P TI Solution structure of a biological bimolecular electron transfer complex: characterization of the photosynthetic reaction center-cytochrome c(2) protein complex by small angle neutron scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID RHODOBACTER-SPHAEROIDES R-26; X-RAY; BINDING AB The structures of kinetically distinct electron transfer complexes formed between the photosynthetic reaction center from Rhodobacter sphaeroides R-26, and a water-soluble cytochrome c(2) were characterized using small angle neutron scattering, SANS. Reaction center-cytochrome c(2) complexes, RC-C, exhibiting predominately single exponential electron transfer kinetics were found to be 1:1 molar complexes, consistent with a low resolution, co-crystal, x-ray structure (Adir et al., 1996), provided that the cofactor separation was adjusted to 14 +/- 3 Angstrom. Other RC-C configurations are consistent with SANS data, but are distinguishable by cofactor separation. RC-C preparations exhibiting more complex kinetics were found to have a particle volume markedly greater than that of a 1: 1 complex. These results suggest that RC aggregation is associated with the variation in kinetics reported in the literature, and provide evidence that the model for the 1: 1 complex in co-crystals is relevant to the solution environment. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Tiede, DM (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Littrell, Kenneth/D-2106-2013 OI Littrell, Kenneth/0000-0003-2308-8618 NR 16 TC 8 Z9 10 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 560 EP 564 DI 10.1107/S0021889800099891 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600035 ER PT J AU Zhang, RT Thiyagarajan, P Tiede, DM AF Zhang, RT Thiyagarajan, P Tiede, DM TI Probing protein fine structures by wide angle solution X-ray scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID BIOLOGICAL MACROMOLECULES; CYTOCHROME-C; RESOLUTION AB In this report we have investigated the use of wide angle scattering data not only to resolve overall size and shape of protein molecules in solution, but also to resolve details of fine structure. Methods have been developed for calculating protein solution scattering profiles based on atomic coordinates over a wide range of q with high accuracy in order to compare protein atomic models to wide angle scattering data. Calculations based upon these procedures show that X-ray scattering profiles for X-ray crystal and NMR solution structures for cytochrome c are significantly different, and that these differences can be resolved by high-precision wide angle X-ray scattering measurements. It is also shown that wide angle Xray scattering profiles are rather sensitive to atomic fluctuations (Debye-Waller temperature factors), suggesting that wide angle scattering data may provide an opportunity for evaluation of protein dynamics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Zhang, RT (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 43 Z9 45 U1 1 U2 10 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 565 EP 568 DI 10.1107/S0021889800001345 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600036 ER PT J AU Littrell, K Urban, V Tiede, D Thiyagarajan, P AF Littrell, K Urban, V Tiede, D Thiyagarajan, P TI Solution structure of detergent micelles at conditions relevant to membrane protein crystallization SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID PHOTOSYNTHETIC REACTION CENTER; SCATTERING; CRYSTALS; COMPLEX AB In this study small angle neutron scattering was used to characterize the formation of micelles in aqueous solutions of the detergents DMG and SPC as a function of detergent concentration and ionic strength of the solvent. The effects on the micelle structure of the additives glycerol and PEG, alone as well as in combination typical for membrane protein crystallization, were also explored. This study suggests that the micelles are rod-like in form at the concentrations studied. The size of the micelles was observed to increase with increasing ionic strength but decrease with the addition of glycerol or PEG. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Thiyagarajan, P (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Urban, Volker/N-5361-2015; Littrell, Kenneth/D-2106-2013 OI Urban, Volker/0000-0002-7962-3408; Littrell, Kenneth/0000-0003-2308-8618 NR 9 TC 4 Z9 4 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 577 EP 581 DI 10.1107/S002188989901314X PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600039 ER PT J AU Schaefer, DW Rieker, T Agamalian, M Lin, JS Fischer, D Sukumaran, S Chen, CY Beaucage, G Herd, C Ivie, J AF Schaefer, DW Rieker, T Agamalian, M Lin, JS Fischer, D Sukumaran, S Chen, CY Beaucage, G Herd, C Ivie, J TI Multilevel structure of reinforcing silica and carbon SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID SMALL-ANGLE SCATTERING; POWER-LAW APPROACH; X-RAY-SCATTERING; COMBUSTION AEROSOLS; AEROGELS AB Using small-angle x-ray (SAXS), neutron (SANS), x-ray diffraction and light scattering, we study the structure of colloidal silica and carbon on length scales from 4 Angstrom < q(-1) < 10(7) Angstrom where q is the magnitude of the scattering vector. These materials consist of primary particles of the order of 100 Angstrom, aggregated into micron-sized aggregates that in turn are agglomerated into 100 mu agglomerates. The diffraction data show that the primary particles in precipitated silica are composed of highly defective amorphous silica with little intermediate-range order (order on the scale of several bond distances). On the next level of morphology, primary particles arise by a complex nucleation process in which primordial nuclei briefly aggregate into rough particles that subsequently smooth out to become the seeds for the primaries. The primaries aggregate to strongly bonded clusters by a complex process involving kinetic growth, mechanical disintegration and restructuring. Finally, the small-angle scattering (SAS) data lead us to postulate that the aggregates cluster into porous, rough-surfaced, non-mass-fractal agglomerates that can be broken down to the more strongly bonded aggregates by application of shear. We find similar structure in pelletized carbon blacks. In this case we show a linear scaling relation between the primary and aggregate sizes. We attribute the scaling to mechanical processing that deforms the fractal aggregates down to the maximum size able to withstand the compaction stress. Finally, we rationalize the observed structure based on empirical optimization by filler suppliers and some recent theoretical ideas due to Witten, Rubenstein and Colby. C1 Univ Cincinnati, Cincinnati, OH 45221 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Columbian Chem Co, Marietta, GA 30062 USA. RP Schaefer, DW (reprint author), Univ Cincinnati, Cincinnati, OH 45221 USA. RI USAXS, APS/D-4198-2013; OI Agamalian, Michael/0000-0002-9112-2534 NR 18 TC 60 Z9 61 U1 0 U2 18 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 587 EP 591 DI 10.1107/S0021889800001199 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600041 ER PT J AU Bhatia, SR Russel, WB Lal, J AF Bhatia, SR Russel, WB Lal, J TI SANS study of associative triblocks in microemulsion solutions SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID IN-OIL MICROEMULSIONS; ANGLE NEUTRON-SCATTERING; POLYMER; COPOLYMERS; DROPLET; SIZE; CYCLOHEXANE; NETWORKS AB Small-angle neutron scattering was used to study the interactions between AOT/water/decane microemulsions and poly( ethylene oxide)-polyisoprene-poly(ethylene oxide) triblocks. The interdroplet spacing seems to be independent of molecular weight and polymer concentration. Scattering experiments on the polyisoprene layer yield a high q exponent of -1.6 +/- 0.1, indicating that the layer is swollen by decane. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Russel, WB (reprint author), Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. RI Bhatia, Surita/B-4536-2008 NR 16 TC 3 Z9 3 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 614 EP 617 DI 10.1107/S0021889899012236 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600047 ER PT J AU Li, X Loong, CK Thiyagarajan, P Lager, GA Miranda, R AF Li, X Loong, CK Thiyagarajan, P Lager, GA Miranda, R TI Small-angle neutron scattering study of nanophase zirconia in a reverse micelle synthesis SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID ZRO2; NANOPARTICLES; MICROEMULSION; PARTICLES; ACID AB Nanophase zirconia particles are synthesized by mixing two reverse micelle solutions containing the precursor salt ZrOCl2 and the base NH4OH. The primary reverse micelle solution consists of AOT, toluene and water. The reverse micelle structure of four solutions as a function of w (the molar ratio of [water]/[AOT]) is characterized by small-angle neutron scattering at room temperature. With the addition of ZrOCl2 and NH4OH into the water pools, the reverse micelle sizes decrease as compared to those in the D2O/AOT/C6D5CD3 primary system. The mixed microemulsions contain reverse micelle sizes that fall between the values of the premixed solutions. All the reverse micelles exhibit uniform size and spherical shape. The effect of concentration of inorganic salt precursor in the water pools on the reverse micelle structure is also studied. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Univ Louisville, Dept Chem Engn, Louisville, KY 40292 USA. Univ Louisville, Dept Geosci, Louisville, KY 40292 USA. Natl Sci Fdn, Chem & Transport Syst Div, Arlington, VA 22230 USA. RP Li, X (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 628 EP 631 DI 10.1107/S0021889899012777 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600050 ER PT J AU Triolo, F Triolo, A Triolo, R Betts, DE McClain, JB De Simone, JM Steytler, DC Wignall, GD Deme, B Heenan, RK AF Triolo, F Triolo, A Triolo, R Betts, DE McClain, JB De Simone, JM Steytler, DC Wignall, GD Deme, B Heenan, RK TI Critical micellisation density: a SAS structural study of the unimer-aggregate transition of block-copolymers in supercritical CO2 SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID ANGLE NEUTRON-SCATTERING; CARBON-DIOXIDE; INTERACTION PARAMETERS; MICROEMULSIONS; SURFACTANTS; SANS AB In this paper we report a SANS investigation of micelle formation by fluorocarbon-hydrocarbon block copolymers in supercritical CO2 (scCO(2)) at 313K. A sharp unimer-micelle transition is obtained due to the tuning of the solvating ability of scCO(2) by profiling pressure. At high pressure the copolymer is in a monomeric state with a random coil structure. By lowering the pressure aggregates are formed with the hydrocarbon segments forming the core and the fluorocarbon segments forming the corona of spherical aggregates. This aggregate-unimer transition is driven by the gradual penetration of CO2 molecules toward the core of the aggregate and is critically related to the density of the solvent, thus suggesting the definition of a critical micellisation density (CMD). C1 Univ Palermo, Dept Phys Chem, Palermo, Italy. CUNY Mt Sinai Sch Med, New York, NY 10029 USA. Heriot Watt Univ, Edinburgh, Midlothian, Scotland. Univ N Carolina, Dept Chem, Chapel Hill, NC USA. Univ E Anglia, Sch Chem Sci, Norwich NR4 7TJ, Norfolk, England. Oak Ridge Natl Lab, Oak Ridge, TN USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Rutherford Appleton Lab, Chilton, England. RP Triolo, R (reprint author), Univ Palermo, Dept Phys Chem, Palermo, Italy. RI Triolo, Alessandro/B-7760-2008; Triolo, Alessandro/A-4431-2012; OI Triolo, Alessandro/0000-0003-4074-0743; Wignall, George/0000-0002-3876-3244 NR 23 TC 11 Z9 11 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 641 EP 644 DI 10.1107/S0021889899013539 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600053 ER PT J AU Urban, V Wang, HH Thiyagarajan, P Littrell, KC Wang, HB Yu, L AF Urban, V Wang, HH Thiyagarajan, P Littrell, KC Wang, HB Yu, L TI Self-organization of OPV-PEG diblock copolymers in THF/water SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID BLOCK; SCATTERING AB Oligo(phenylenevinylene)-poly(ethyleneglycol) (OPV-PEG) diblock copolymers in tetrahydrofuran (THF) solution at concentrations of 5 to 25 g/l self-assemble into rod-like structures with a radius of about 80 Angstrom, for an OPV-PEG diblock copolymer comprising 13 PV and 45 EG monomers. These aggregates consist of a liquid crystalline OPV core and a PEG shell. Addition of about 10% water to the solution induces the formation of a phase of packed rods, as revealed by a sudden and dramatic transition of the scattering pattern. Further addition of water leads to swelling and at about 30% ultimately to disruption of the packed-rod phase. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. RP Urban, V (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Urban, Volker/N-5361-2015; Littrell, Kenneth/D-2106-2013 OI Urban, Volker/0000-0002-7962-3408; Littrell, Kenneth/0000-0003-2308-8618 NR 18 TC 16 Z9 16 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 645 EP 649 DI 10.1107/S0021889899013138 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600054 ER PT J AU Lal, J Auvray, L AF Lal, J Auvray, L TI Interaction of polymer with clays SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NY SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Source, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID NEUTRON-SCATTERING; LAYERS; SUSPENSION AB Normally synthetic well defined monodisperse discotic laponite clays are known to form a gel phase at mass concentrations as low as a few percent in distilled water. Hydrosoluble polymer polyethylene oxide was added to this intriguing clay system, it was observed that it either prevents gelation or slows it down extremely depending on the polymer weight, concentration or the laponite concentration. Small Angle Neutron scattering (SANS) was used to study these systems because only by isotopic labelling can the structure of the adsorbed polymer layers be determined. The contrast variation technique is specifically used to determine separately the different partial structure factors of the clay and polymer. In this way the signal of the adsorbed chains is separated from the signal of the free chains. C1 Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. Ctr Etud Saclay, LLB, F-91191 Gif Sur Yvette, France. RP Lal, J (reprint author), Argonne Natl Lab, IPNS, 9700 S Cass Ave, Argonne, IL 60439 USA. EM jlal@anl.gov RI Auvray, Loic/J-7577-2012 OI Auvray, Loic/0000-0003-1736-5578 NR 17 TC 37 Z9 37 U1 2 U2 12 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 673 EP 676 DI 10.1107/S0021889899013308 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600061 ER PT J AU Melnichenko, YB Kiran, E Heath, KD Salaniwal, S Cochran, HD Stamm, M Van Hook, WA Wignall, GD AF Melnichenko, YB Kiran, E Heath, KD Salaniwal, S Cochran, HD Stamm, M Van Hook, WA Wignall, GD TI Comparison of the behaviour of polymers in supercritical fluids and organic solvents via small angle neutron scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID CHAIN COLLAPSE; POLYSTYRENE; POOR AB Small-angle neutron scattering has been used to study the effect of temperature and pressure on the phase behaviour of semidilute solutions of polymers dissolved in organic and supercritical solvents. Above the theta temperature (T-Theta), these systems exhibit a "good solvent" domain, where the molecules expand beyond the unperturbed dimensions in both organic solvents and in CO2. However, this transition can be made to occur at a critical "theta pressure" (P-Theta) in CO2 and this represents a new concept in the physics of polymer-solvent systems. For T < T-Theta, and P < P-Theta, the system enters the "poor solvent" domain, where diverging concentration fluctuations prevent the chains from collapsing and allow them to maintain their unperturbed dimensions. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Maine, Dept Chem Engn, Orono, ME 04468 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Inst Polymerforsch, D-55021 Mainz, Germany. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Melnichenko, YB (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Umlauf, Ursula/D-3356-2014; OI Wignall, George/0000-0002-3876-3244 NR 17 TC 18 Z9 18 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 682 EP 685 DI 10.1107/S0021889899013229 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600063 ER PT J AU Dai, PS Cebe, P Capel, M Alamo, RG Mandelkern, L AF Dai, PS Cebe, P Capel, M Alamo, RG Mandelkern, L TI Small and wide angle X-ray scattering study of metallocene isotactic poly(propylene) SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID POLYPROPYLENE; MORPHOLOGY AB We report a study of metallocene isotactic poly( propylene) (m-iPP) which crystallizes into alpha and gamma crystal modifications. Simultaneous in-situ small- and wide-angle X-ray scattering (SAXS and WAXS) were used to study kinetics during crystallization. Both techniques provide information about time development of crystallinity, while WAXS gives also kinetics of formation of alpha and gamma crystals. During the earliest stages of crystal formation, the SAXS Bragg peak occurs simultaneously, or slightly lags, the appearance of crystalline WAXS reflections. We conclude crystallization occurs by a nucleation and growth process in this m-iPP. C1 Tufts Univ, Dept Phys & Astron, Medford, MA 02155 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Florida State Univ, Dept Chem Engn, Tallahassee, FL 32306 USA. Florida State Univ, Inst Mol Biophys, Tallahassee, FL 32306 USA. Florida State Univ, Dept Chem, Tallahassee, FL 32306 USA. RP Cebe, P (reprint author), Tufts Univ, Dept Phys & Astron, Medford, MA 02155 USA. NR 10 TC 5 Z9 5 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 714 EP 717 DI 10.1107/S0021889899013321 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600070 ER PT J AU Gilbert, E Reynolds, P White, J AF Gilbert, E Reynolds, P White, J TI Application of small-angle scattering to the study of graphite-adsorbed hydrocarbons SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID INTERFACE AB The structure of graphite-adsorbed n-alkanes for 10 less than or equal to n less than or equal to 20 has been investigated by SAXS. Below the bulk melting point, T-m, and for alkanes with even n, two distinct diffraction peaks are observed, one associated with the bulk and the other with the surface structure. For alkanes with odd n, only one peak is observed below T-m; above T-m a significant reduction in intensity is found, indicating melting of the bulk, but a peak remains. The intensity at T-m increases with n and correlates with previous pyknometric and calorimetric measurements. The surface-adsorbed structure has a repeat corresponding to the orthorhombic spacing of the bulk alkane crystal. C1 Australian Natl Univ, Res Sch Chem, Canberra, ACT 0200, Australia. RP Gilbert, E (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Gilbert, Elliot/A-5566-2010 OI Gilbert, Elliot/0000-0001-6413-7813 NR 16 TC 6 Z9 6 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 744 EP 748 DI 10.1107/S0021889800099866 PN 3 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600077 ER PT J AU Seifert, S Winans, RE Tiede, DM Thiyagarajan, P AF Seifert, S Winans, RE Tiede, DM Thiyagarajan, P TI Design and performance of a ASAXS instrument at the Advanced Photon Source SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID X-RAY-SCATTERING; ALLOY AB The SAXS instrument on the high brilliance undulator beam line (ID-12, BESSRC-CAT) at APS has been designed to produce high-resolution scattering patterns in the millisecond time domain. This instrument is equipped with a 18 cm x 18 cm position sensitive gas detector and a 15 cm x 15 cm high-resolution position sensitive CCD mosaic detector. A photodiode detector mounted on a 3.7 mm diameter beam stop permits quick alignment of the instrument as well as precise measurement of the transmitted beam intensity. The exposure time with the CCD detector varies from 0.1 to 10 seconds depending on the scattering cross-section of the samples. Techniques to interface ancillary equipment for time-resolved studies and software for faster online analysis of the data have also been developed. We have obtained data on the unfolding of proteins in the millisecond time domain and ASAXS of metallic alloys using this instrument. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Thiyagarajan, P (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 89 Z9 90 U1 0 U2 7 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 782 EP 784 DI 10.1107/S0021889800001333 PN 3 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600086 ER PT J AU Agamalian, MM Alamo, RG Londono, JD Mandelkern, L Wignall, GD AF Agamalian, MM Alamo, RG Londono, JD Mandelkern, L Wignall, GD TI Phase behavior of blends of linear and branched polyethylenes on micron length scales via ultra-small angle neutron scattering (USANS) SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID LOW-DENSITY POLYETHYLENE; SEGREGATION; FACILITY AB SANS experiments on blends of linear, high density (HD) and long chain branched, low density (LD) polyethylenes indicate that these systems form a one-phase mixture in the melt. However, the maximum spatial resolution of pinhole cameras is approximate to 10(3) Angstrom and it has therefore been suggested that data might also be interpreted as arising from a bi-phasic melt with large a particle size (similar to 1 mu m), because most of the scattering from the different phases would not be resolved. We have addressed this hypothesis by means of USANS experiments, which confirm that HDPE/LDPE blends are homogenous in the melt on length scales up to 20 mm. We have also studied blends of HDPE and short-chain branched linear low density polyethylenes (LLDPEs), which phase separate when the branch content is sufficiently high. LLDPEs prepared with Ziegler-Natta catalysts exhibit a wide distribution of compositions, and may therefore be thought of as a "blend" of different species. When the composition distribution is broad enough, a fraction of highly branched chains may phase separate on mu m-length scales, and USANS has also been used to quantify this phenomenon. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Florida Agr & Mech Univ, Tallahassee, FL 32310 USA. Florida State Univ, Coll Engn, Dept Chem Engn, Tallahassee, FL 32310 USA. Florida State Univ, Inst Mol Biophys, Tallahassee, FL 32306 USA. RP Agamalian, MM (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. OI Agamalian, Michael/0000-0002-9112-2534; Wignall, George/0000-0002-3876-3244 NR 17 TC 9 Z9 9 U1 0 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 843 EP 846 DI 10.1107/S002188989901331X PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600101 ER PT J AU Radlinski, AP Radlinska, EZ Agamalian, M Wignall, GD Lindner, P Randl, OG AF Radlinski, AP Radlinska, EZ Agamalian, M Wignall, GD Lindner, P Randl, OG TI The fractal microstructure of ancient sedimentary rocks SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID SMALL-ANGLE-SCATTERING; NEUTRON-SCATTERING; SURFACES AB Small-angle neutron scattering (SANS), ultra-small-angle neutron scattering and scanning electron microscopy (SEM) were used to analyze the pore-fabric interface in a 1400 million years old shale. The pore-rock fabric interface is a surface fractal (of fractal dimension 2.82) over three orders of magnitude of the length scale and ten orders of magnitude in intensity (macroscopic differential cross section range 10(-1) -10(9) cm(-1)). Both SANS and SEM indicate similar fractal dimension for scales less than 4 mu m and a breakdown of fractal properties for scales larger than 4 mu m. C1 Australian Geol Survey Org, Canberra, ACT 2601, Australia. Australian Natl Univ, Dept Appl Math, Canberra, ACT 0200, Australia. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. RP Radlinski, AP (reprint author), Australian Geol Survey Org, GPO Box 378, Canberra, ACT 2601, Australia. OI Agamalian, Michael/0000-0002-9112-2534; Wignall, George/0000-0002-3876-3244 NR 22 TC 18 Z9 18 U1 2 U2 7 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 860 EP 862 DI 10.1107/S0021889899016246 PN 3 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600105 ER PT J AU Triolo, F Triolo, A Agamalian, MM Lin, JS Heenan, RK Lucido, G Triolo, R AF Triolo, F Triolo, A Agamalian, MM Lin, JS Heenan, RK Lucido, G Triolo, R TI Fractal approach in petrology: combining ultra small angle, small angle and intermediate angle neutron scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article; Proceedings Paper CT XIth International Conference on Small-Angle Scattering CY MAY 17-20, 1999 CL BROOKHAVEN NATL LAB, LONG ISL CITY, NEW YORK SP NatDOE, Off Basic Energy Sci, Int Union Crystallog, Intense Pulsed Neutron Sourch, Neutron Scattering Soc Amer, Stanford Synchrotron Radiat Lab, Oak Ridge Natl Lab, Synchrotron Radiat Res Ctr, Exxon Res & Engn Co, Natl Ctr Neutron Res, USAF Res Lab, Dow Chem Co, Photon Factory, Cornell High energy Synchrotron Source, DSM Res, Brookhaven Sci Associates, BNL Biol Dept, BNL Phys Dept HO BROOKHAVEN NATL LAB ID SANDSTONE PORES; GEOMETRY; ROCKS AB Ultra small angle neutron scattering (USANS) instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering (SANS) instruments on one side and optical microscopy on the other side. New fields of investigations are now open and important areas of material science (ceramics, glass fibers, natural materials) and fundamental physics (phase transition, phase separation and critical phenomena) can be studied in bulk samples with an accuracy previously unobtainable owing to a combination of favourable features of the neutron-matter interaction: high penetrability of neutrons, even cold neutrons, ability to easily manipulate local scattering amplitudes by means of isotopic substitution methods, small absorption for most nuclei and hardly any radiation damage. In particular, neutrons see rocks as two-phase systems, and therefore the data analysis is enormously simplified. Rocks showing fractal behavior in over two decades of momentum transfer and seven orders of magnitude of intensity are examined and fractal parameters are extracted from the combined USANS, SANS and intermediate angle neutron scattering curves. C1 Univ Palermo, Dipartimento Chim Fis, I-90128 Palermo, Italy. CUNY Mt Sinai Sch Med, New York, NY 10029 USA. Heriot Watt Univ, Dept Chem, Edinburgh EH14 4AS, Midlothian, Scotland. Argonne Natl Lab, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Palermo, Dipartimento Chim & Fis Terra, I-90123 Palermo, Italy. RP Triolo, R (reprint author), Univ Palermo, Dipartimento Chim Fis, Vle Sci,Parco Orleans 2, I-90128 Palermo, Italy. RI Triolo, Alessandro/B-7760-2008; Triolo, Alessandro/A-4431-2012; OI Triolo, Alessandro/0000-0003-4074-0743; Agamalian, Michael/0000-0002-9112-2534 NR 23 TC 16 Z9 16 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP 863 EP 866 DI 10.1107/S0021889899014910 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600106 ER PT J AU Schneider, DK Chen, SH Capel, MS Hsiao, B Kostorz, G Pedersen, JS Timmins, P Wignall, GD AF Schneider, DK Chen, SH Capel, MS Hsiao, B Kostorz, G Pedersen, JS Timmins, P Wignall, GD TI XIth International Conference on Small-Angle Scattering SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Editorial Material C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Biol Dept 463, Upton, NY 11973 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. ETH Zurich, Inst Angew Phys, CH-8093 Zurich, Switzerland. Riso Natl Lab, Dept Solid State Phys, DK-4000 Roskilde, Denmark. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Schneider, DK (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RI Pedersen, Jan/A-8346-2008; kostorz, gernot/B-6489-2009 OI Pedersen, Jan/0000-0002-7768-0206; NR 0 TC 0 Z9 0 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD JUN 1 PY 2000 VL 33 IS 1 BP U1 EP U4 PN 3 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 317VX UT WOS:000087248600001 ER PT J AU Hebner, GA Miller, PA AF Hebner, GA Miller, PA TI Electron and negative ion densities in C2F6 and CHF3 containing inductively coupled discharges SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHOTODETACHMENT CROSS-SECTION; REFERENCE CELL; RF PLASMAS; PROBE; CHLORINE; FLUORINE; CF4; LASER AB Electron and negative ion densities have been measured in inductively coupled discharges containing C2F6 and CHF3. Line integrated electron density was determined using a microwave interferometer, negative ion densities were inferred using laser photodetachment spectroscopy, and electron temperature was determined using a Langmuir probe. For the range of induction powers, pressures and bias power investigated, the electron density peaked at 9x10(12) cm(-2) (line-integrated) or approximately 9x10(11) cm(-3). The negative ion density peaked at approximately 1.3x10(11) cm(-3). A maximum in the negative ion density as a function of induction coil power was observed. The maximum is attributed to a power dependent change in the density of one or more of the potential negative ion precursor species since the electron temperature did not depend strongly on power. The variation of photodetachment with laser wavelength indicated that the dominant negative ion was F-. Measurement of the decay of the negative ion density in the afterglow of a pulse modulated discharge was used to determine the ion-ion recombination rate for CF4, C2F6, and CHF3 discharges. (C) 2000 American Institute of Physics. [S0021-8979(00)01411-0]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hebner, GA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 29 Z9 29 U1 0 U2 9 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 JUN 1 PY 2000 VL 87 IS 11 BP 7660 EP 7666 DI 10.1063/1.373437 PG 7 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400007 ER PT J AU Jiang, W Weber, WJ Thevuthasan, S AF Jiang, W Weber, WJ Thevuthasan, S TI In situ ion channeling study of gallium disorder and gold profiles in Au-implanted GaN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RADIATION-DAMAGE; SILICON-CARBIDE; IRRADIATION; MG; AMORPHIZATION; ACCUMULATION; RECOVERY; DEFECTS; FILMS AB Disorder accumulation and annealing behavior on the Ga sublattice in gallium nitride (GaN) implanted with 1.0 MeV Au2+ (60 degrees off surface normal) at 180 or 300 K have been studied using in situ Rutherford backscattering spectrometry in a < 0001 >-channeling geometry. Complete amorphization in GaN is attained at 6.0 and 20 Au2+/nm(2) for irradiation at 180 and 300 K, respectively. A saturation in the Ga disorder at and behind the damage peak was observed at intermediate ion fluences at both 180 and 300 K. No measurable thermal recovery was found at 300 K for the full range of damage produced at 180 K. However, distinct epitaxial regrowth in the bulk and Ga reordering at surface occurred after annealing at 870 K. The implanted Au readily diffuses into the highly damaged regions at elevated temperatures, and the redistribution of the Au atoms in the implanted GaN varies with the damage profiles. A double-peak Au profile developed with the maxima located in the amorphous surface region and near the Au mean projected range. The result is interpreted as Au atom diffusion into the amorphous regime near the surface and Au trapping at irradiation-induced defects in the crystal structure. This trapping effect is also evidenced in this study by the suppressed recovery of the Au-decorated disorder in GaN. (C) 2000 American Institute of Physics. [S0021-8979(00)07111-5]. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jiang, W (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; OI Weber, William/0000-0002-9017-7365; Jiang, Weilin/0000-0001-8302-8313 NR 29 TC 50 Z9 51 U1 1 U2 1 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 JUN 1 PY 2000 VL 87 IS 11 BP 7671 EP 7678 AR PII [S0021-8979(00)07111-5] DI 10.1063/1.373439 PG 8 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400009 ER PT J AU Romano, LT Van de Walle, CG Ager, JW Gotz, W Kern, RS AF Romano, LT Van de Walle, CG Ager, JW Gotz, W Kern, RS TI Effect of Si doping on strain, cracking, and microstructure in GaN thin films grown by metalorganic chemical vapor deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID EDGE-INDUCED STRESS; GALLIUM NITRIDE; RAMAN-SPECTROSCOPY; QUANTUM DOTS; SAPPHIRE; RELAXATION; MECHANISM; SURFACES; DIODES AB The effect of Si doping on the strain and microstructure in GaN films grown on sapphire by metalorganic chemical vapor deposition was investigated. Strain was measured quantitatively by x-ray diffraction, Raman spectroscopy, and wafer curvature techniques. It was found that for a Si concentration of 2x10(19) cm(-3), the threshold for crack formation during film growth was 2.0 mu m. Transmission electron microscopy and micro-Raman observations showed that cracking proceeds without plastic deformation (i.e., dislocation motion), and occurs catastrophically along the low energy {1 (1) under bar 00} cleavage plane of GaN. First-principles calculations were used to show that the substitution of Si for Ga in the lattice causes only negligible changes in the lattice constant. The cracking is attributed to tensile stress in the film present at the growth temperature. The increase in tensile stress caused by Si doping is discussed in terms of a crystallite coalescence model. (C) 2000 American Institute of Physics. [S0021-8979(00)03410-1]. C1 Xerox Corp, Palo Alto Res Ctr, Palo Alto, CA 94304 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. LumiLeds Lighting, San Jose, CA 95131 USA. RP Romano, LT (reprint author), Xerox Corp, Palo Alto Res Ctr, 3333 Coyote Hill Rd, Palo Alto, CA 94304 USA. RI Van de Walle, Chris/A-6623-2012; OI Van de Walle, Chris/0000-0002-4212-5990; Ager, Joel/0000-0001-9334-9751 NR 37 TC 185 Z9 187 U1 7 U2 65 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 JUN 1 PY 2000 VL 87 IS 11 BP 7745 EP 7752 AR PII [S0021-8979(00)03410-1] DI 10.1063/1.373529 PG 8 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400021 ER PT J AU Cooke, DW Bennett, BL McClellan, KJ Roper, JM Whittaker, MT AF Cooke, DW Bennett, BL McClellan, KJ Roper, JM Whittaker, MT TI Oscillator strengths, Huang-Rhys parameters, and vibrational quantum energies of cerium-doped gadolinium oxyorthosilicate SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SCINTILLATORS; LUMINESCENCE; MECHANISM; CRYSTALS AB Temperature-dependent optical absorption of cerium-doped gadolinium oxyorthosilicate (Gd2SiO5:Ce) has been measured and analyzed for impurity-ion-lattice coupling parameters and oscillator strengths. Although the spectrum consists of overlapping Ce3+ bands and Gd3+ lines, two well-resolved Ce3+ bands with 10 K maxima at 3.32 eV (peak a) and 3.61 eV (peak b) are amenable to spectral analysis. These bands, previously assigned to Ce3+ ions occupying crystallographically inequivalent substitutional sites, are characterized by Gaussian line shapes and temperature-dependent half widths that are well described by the linear model of impurity-ion-lattice coupling. Huang-Rhys [Proc. R. Soc. A 204, 404 (1950)] parameters of peaks a and b are 22.7 and 5.7, respectively, indicating strong ion-lattice coupling, with vibrational frequencies 1.83x10(13) s(-1) (peak a) and 5.07x10(13) s(-1) (peak b). Peak b centroid is approximately temperature independent, but peak a centroid shifts to higher energy with increasing temperature. This dependence is adequately described by including higher-order coupling terms in the ion-lattice interaction, although crystal-field contributions cannot be excluded. Absorption band oscillator strengths, f, are calculated from Smakula's [Z. Phys. 59, 603 (1930)] formula and knowledge of cerium concentration for the two inequivalent sites. In the interval 10-300 K, peak a f values range from (9.8 to 26.8)x10(-4) and peak b f values vary from (7.8 to 5.8)x10(-3). From the known correlation between oscillator strength and metal-ion-ligand separation, we identify peaks a and b as the seven- and nine-oxygen-coordinated sites, respectively. (C) 2000 American Institute of Physics. [S0021-8979(00)02011-9]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Cooke, DW (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 14 TC 7 Z9 8 U1 0 U2 3 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 JUN 1 PY 2000 VL 87 IS 11 BP 7793 EP 7797 DI 10.1063/1.373456 PG 5 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400028 ER PT J AU Gago, R Jimenez, I Albella, JM Climent-Font, A Caceres, D Vergara, I Banks, JC Doyle, BL Terminello, LJ AF Gago, R Jimenez, I Albella, JM Climent-Font, A Caceres, D Vergara, I Banks, JC Doyle, BL Terminello, LJ TI Bonding and hardness in nonhydrogenated carbon films with moderate sp(3) content SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID X-RAY-ABSORPTION; DIAMOND-LIKE CARBON; HYDROGENATED AMORPHOUS-CARBON; BIAS-ENHANCED NUCLEATION; STRESS-INDUCED FORMATION; ION-BEAM ASSISTANCE; THIN-FILMS; NEAR-EDGE; ELASTIC-MODULUS; CROSS-SECTIONS AB Amorphous carbon films with an sp(3) content up to 25% and a negligible amount of hydrogen have been grown by evaporation of graphite with concurrent Ar+ ion bombardment. The sp(3) content is maximized for Ar+ energies between 200 and 300 eV following a subplantation mechanism. Higher ion energies deteriorate the film due to sputtering and heating processes. The hardness of the films increases in the optimal assisting range from 8 to 18 GPa, and is explained by crosslinking of graphitic planes through sp(3) connecting sites. (C) 2000 American Institute of Physics. [S0021-8979(00)08911-8]. C1 CSIC, Inst Ciencia Mat Madrid, E-28049 Madrid, Spain. Univ Autonoma Madrid, Dept Fis Aplicada C12, E-28049 Madrid, Spain. Univ Carlos III Madrid, Dept Fis Aplicada, Leganes 28911, Spain. Sandia Natl Labs, Radiat Solid Interact & Proc, Albuquerque, NM 87185 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Gago, R (reprint author), CSIC, Inst Ciencia Mat Madrid, Plaza Murillo 2, E-28049 Madrid, Spain. RI Jimenez, Ignacio/F-7422-2010; Gago, Raul/C-6762-2008; Climent-Font, Aurelio/G-8449-2016 OI Jimenez, Ignacio/0000-0001-5605-3185; Gago, Raul/0000-0003-4388-8241; NR 47 TC 38 Z9 38 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 JUN 1 PY 2000 VL 87 IS 11 BP 8174 EP 8180 AR PII [S0021-8979(00)08911-8] DI 10.1063/1.373514 PG 7 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400087 ER PT J AU Witczak, SC Winokur, PS Lacoe, RC Mayer, DC AF Witczak, SC Winokur, PS Lacoe, RC Mayer, DC TI Charge separation technique for metal-oxide-silicon capacitors in the presence of hydrogen deactivated dopants SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRYSTALLINE SEMICONDUCTORS; MICROSCOPIC STRUCTURE; ACCEPTOR; BORON; NEUTRALIZATION; COMPLEXES; DIODES; TRAPS AB An improved charge separation technique for metal-oxide-silicon (MOS) capacitors is presented which accounts for the deactivation of substrate dopants by hydrogen at elevated irradiation temperatures or small irradiation biases. Using high-frequency capacitance-voltage measurements, radiation-induced inversion voltage shifts are separated into components due to oxide trapped charge, interface traps, and deactivated dopants, where the latter is computed from a reduction in Si capacitance. In the limit of no radiation-induced dopant deactivation, this approach reduces to the standard midgap charge separation technique used widely for the analysis of room-temperature irradiations. The technique is demonstrated on a p-type MOS capacitor irradiated with Co-60 gamma rays at 100 degrees C and zero bias, where the dopant deactivation is significant. (C) 2000 American Institute of Physics. [S0021-8979(00)03811-1]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Aerospace Corp, Los Angeles, CA 90009 USA. RP Witczak, SC (reprint author), Sandia Natl Labs, POB 5800,MS-1083, Albuquerque, NM 87185 USA. NR 18 TC 9 Z9 10 U1 0 U2 2 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 JUN 1 PY 2000 VL 87 IS 11 BP 8206 EP 8208 DI 10.1063/1.373522 PG 3 WC Physics, Applied SC Physics GA 314QP UT WOS:000087067400095 ER PT J AU Baggerly, K Cox, D Picard, R AF Baggerly, K Cox, D Picard, R TI Exponential convergence of adaptive importance sampling for Markov chains SO JOURNAL OF APPLIED PROBABILITY LA English DT Article DE adaptive procedures; biased random walks; learning algorithms; Monte Carlo simulation; particle transport; zero-variance solution ID MONTE-CARLO; TRANSPORT AB We consider adaptive importance sampling for a Markov chain with scoring. It is shown that convergence to the zero-variance importance sampling chain for the mean total score occurs exponentially fast under general conditions. These results extend previous work in Kollman (1993) and in Kollman et al. (1999) for finite state spaces. C1 Rice Univ, Dept Stat, Houston, TX 77005 USA. Natl Ctr Atmospher Res, Geophys Stat Project, Boulder, CO 80307 USA. Univ Calif Los Alamos Natl Lab, Stat Sci Grp, Los Alamos, NM 87545 USA. RP Baggerly, K (reprint author), Rice Univ, Dept Stat, 610 S Main St, Houston, TX 77005 USA. NR 12 TC 11 Z9 11 U1 0 U2 2 PU APPLIED PROBABILITY TRUST PI SHEFFIELD PA THE UNIVERSITY, SCHOOL MATHEMATICS STATISTICS, SHEFFIELD S3 7RH, ENGLAND SN 0021-9002 J9 J APPL PROBAB JI J. Appl. Probab. PD JUN PY 2000 VL 37 IS 2 BP 342 EP 358 PG 17 WC Statistics & Probability SC Mathematics GA 347QK UT WOS:000088940500004 ER PT J AU McAteer, K Kennedy, MA AF McAteer, K Kennedy, MA TI NMR evidence for base dynamics at all TpA steps in DNA SO JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS LA English DT Article ID TRP OPERATOR; CONFORMATIONAL TRANSITIONS; ESCHERICHIA-COLI; ADENINE TRACT; MINOR-GROOVE; PRIBNOW BOX; PROMOTER; CURVATURE; PROTON; SITE AB NMR evidence is presented indicating that the exceptional conformational dynamics found at TpA steps in DNA is general to all immediate sequence contexts. One easily tractable NMR parameter that is sensitive to TpA base dynamics is the resonance linewidth of the TpA adenine H2 proton. This resonance experiences a temperature-dependent broadening due to conformational dynamics. Unusual dynamics at TpA steps were originally observed in the sequence context (T)pTpTpApAp(A). We have since shown that the evidence for TpA dynamics persists when either the thymine preceding the TpA step or the adenine following the TpA step is preserved [McAteer et al., Nucleic Acids Res. 23, 3962-3966 (1995)]. Here, in order establish whether or not exceptional TpA dynamics occurs in all DNA sequence contexts, we investigated a series of DNA sequences of the form GCN(a)TAN(b)N(b)TAN(a)GC, where N=A,T,C,G. In this family of sequences, all 16 possible immediate sequence context environments of the form N(a)TAN(b) were examined using 10 DNA sequences. Our NMR results show that the TpA adenine H2 resonance contains a temperature dependent excess linewidth indicative of dynamics in all 16 sequence context environments. By studying a complete set of sequence contexts, it was possible to recognize trends relating resonance parameters and sequence environment. For example, the magnitude of the maximum linewidth is largely determined by the identity of the nucleotide following the TpA step and the magnitude of the linewidth maximum is moderately correlated (r=0.56) with the temperature of the linewidth maximum. The physical basis for these correlations is discussed. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP McAteer, K (reprint author), Pacific NW Lab, Environm Mol Sci Lab, K8-98, Richland, WA 99352 USA. NR 23 TC 15 Z9 16 U1 0 U2 2 PU ADENINE PRESS INC PI GUILDERLAND PA PO BOX 355/340, GUILDERLAND, NY 12084 USA SN 0739-1102 J9 J BIOMOL STRUCT DYN JI J. Biomol. Struct. Dyn. PD JUN PY 2000 VL 17 IS 6 BP 1001 EP 1009 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 338VL UT WOS:000088443900008 PM 10949167 ER PT J AU Brylawski, BP Cohen, SM Longmire, JL Doggett, NA Cordeiro-Stone, M Kaufman, DG AF Brylawski, BP Cohen, SM Longmire, JL Doggett, NA Cordeiro-Stone, M Kaufman, DG TI Construction of a cosmid library of DNA replicated early in the S phase of normal human fibroblasts SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE DNA replication; human DNA library; cloning; high-density arrays ID C3H 10T1/2 CELLS; GENE; ORIGIN; IDENTIFICATION; INITIATION; SEQUENCES; TRANSFORMATION; APHIDICOLIN; CLONING; REPAIR AB We constructed a subgenomic cosmid library of DNA replicated early in the S phase of normal human diploid fibroblasts. Cells were synchronized by release from confluence arrest and incubation in the presence of aphidicolin. Bromodeoxyuridine (BrdUrd) was added to aphidicolin-containing medium to label DNA replicated as cells entered S phase. Nuclear DNA was partially digested with Sau 3Al, and hybrid density DNA was separated in CsCl gradients. The purified early-replicating DNA was cloned into sCos1 cosmid vector. Clones were transferred individually into ther wells of 96 microtiter plates (9,216 potential clones). Vigorous bacterial growth was detected in 8,742 of those wells. High-density colony hybridization filters (1,536 clones/filter) were prepared from a set of replicas of the original plates. Bacteria remaining in the wells of replica plates were combined, mixed with freezing medium, and stored at -80 degrees C. These pooled stocks were analyzed by polymerase chain reaction to determine the presence of specific sequences in the library. Hybridization of high-density filters was used to identify the clones of interest, which were retrieved from the frozen cultures in the 96-well plates. In testing the library for the presence of 14 known early-replicating genes, we found sequences at or near 5 of them: APRT, beta-actin, beta-tubulin, c-myc, and HPRT. This library is a valuable resource for the isolation and analysis of certain DNA sequences replicated at the beginning of S phase, including potential origins of bidirectional replication. (C) 2000 Wiley-Liss, Inc. C1 Univ N Carolina, Dept Pathol & Lab Med, Chapel Hill, NC 27599 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. RP Kaufman, DG (reprint author), Univ N Carolina, Dept Pathol & Lab Med, CB 7525, Chapel Hill, NC 27599 USA. FU NCI NIH HHS [CA42765] NR 30 TC 9 Z9 10 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PD JUN PY 2000 VL 78 IS 3 BP 509 EP 517 DI 10.1002/1097-4644(20000901)78:3<509::AID-JCB15>3.0.CO;2-D PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 336GJ UT WOS:000088293300015 PM 10861848 ER PT J AU Badyal, YS Saboungi, ML Price, DL Shastri, SD Haeffner, DR Soper, AK AF Badyal, YS Saboungi, ML Price, DL Shastri, SD Haeffner, DR Soper, AK TI Electron distribution in water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIQUID WATER; DIPOLE AB The x-ray structure factor of water measured under ambient conditions with synchrotron radiation is compared with those predicted on the basis of partial structure factors describing the nuclear positions obtained by neutron diffraction and of different assumptions for the electron distribution. The comparison indicates that a charge of approximately 0.5 e is transferred from each hydrogen atom to the oxygen on the same molecule, implying an effective dipole moment of 2.9 D, in good agreement with theoretical estimates. (C) 2000 American Institute of Physics. [S0021- 9606(00)02421-1] C1 Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Argonne Natl Lab, Argonne, IL 60439 USA. RP Saboungi, ML (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 13 TC 199 Z9 201 U1 1 U2 28 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 1 PY 2000 VL 112 IS 21 BP 9206 EP 9208 AR PII [S0021-9606(00)02421-1] DI 10.1063/1.481541 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 315YC UT WOS:000087139700002 ER PT J AU Leininger, ML Allen, WD Schaefer, HF Sherrill, CD AF Leininger, ML Allen, WD Schaefer, HF Sherrill, CD TI Is Moller-Plesset perturbation theory a convergent ab initio method? SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; UNITARY-GROUP-APPROACH; CORRELATED MOLECULAR CALCULATIONS; ELECTRON CORRELATION-PROBLEM; COUPLED-CLUSTER APPROACH; GAUSSIAN-BASIS SETS; SPECTROSCOPIC CONSTANTS; DIVERGENT BEHAVIOR; INTRINSIC ERRORS; FIRST-ROW AB Recent studies have seriously questioned the use of higher-order Moller-Plesset perturbation theory (MPn) in describing electron correlation in atomic and molecular systems. Here we first reinvestigate with improved numerical techniques previously controversial and disturbing MPn energetic series for Ne, F-, HF, BH, C-2 and N-2. Conspicuously absent in previous work is research on the convergence of MPn spectroscopic constants, and thus complete MPn (energy, r(e), omega(e)) series were then computed for (BH, HF, CN+, C-2 and N-2) through the high orders (MP25, MP21, MP13, MP39 and MP19) within the correlation consistent family of basis sets. A persistent, slowly decaying ringing pattern in the C-2 energy series was tracked out to MP155. Finally, new energy series were generated and analyzed through MP167 for Cl- and MP39 for Ar and HCl. The MPn energy and property series variously display rapid or slow convergence, monotonic or oscillatory decay, highly erratic or regular behavior, or early or late divergence, all depending on the chemical system or the choice of one-particle basis set. For oscillatory series the spectroscopic constants computed from low-order MPn methods are often more accurate, with respect to the full configuration interaction (FCI) limit, than those computed via high-order MPn theory. (C) 2000 American Institute of Physics. [S0021- 9606(00)30221-5]. C1 Univ Georgia, Ctr Computat Quantum Chem, Athens, GA 30602 USA. Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. RP Sandia Natl Labs, Livermore, CA 94551 USA. RI Allen, Wesley/C-9867-2010; OI Allen, Wesley/0000-0002-4288-2297; Sherrill, David/0000-0002-5570-7666 NR 61 TC 88 Z9 88 U1 1 U2 12 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 JUN 1 PY 2000 VL 112 IS 21 BP 9213 EP 9222 AR PII [S0021-9606(00)30221-5] DI 10.1063/1.481764 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 315YC UT WOS:000087139700004 ER PT J AU LaViolette, RA Benson, MT AF LaViolette, RA Benson, MT TI Density functional calculations of hypothetical neutral hollow octahedral molecules with a 48-atom framework: Hydrides and oxides of boron, carbon, nitrogen, aluminum, and silicon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GRAPHITIC CARBON; ENERGY; SUPERCUBANE; SYMMETRY; EXCHANGE; PHASE; C-48 AB We computed via first-principles density functional theory calculations (employing both the local density and generalized gradient approximations) the dimensions, bond lengths and angles, binding energy, and HOMO-LUMO gap of the following hypothetical neutral hollow octahedral molecules: B48H24, C48H48, C96H80 (formed by bonding two C48H48 molecules), N48H24, Al48H24, and Si48H48; B24O24, C24O24, N24O24, Al24O24, and Si24O24. Each molecule consists of a large hollow framework of six puckered eight-membered rings whose planes are either mutually perpendicular or parallel, so that each molecule possesses only eight- and nine-membered rings. The hydrides have their hydrogen atoms attached only to the two-atom bridging sites on the framework. The oxides have their oxygen atoms occupying exclusively the two-atom bridging sites of the framework alternating with the (B, C, N, Al, Si) atoms exclusively occupying the three-atom bridging sites. We also calculated the infrared spectra of the C48H48 and the C24O24 molecules. For the sake of comparison, we also examined the hypothetical octahedral C-48 fullerene cuboctohedron (possessing four-, six-, and eight-membered rings) studied by Dunlap and Taylor. The molecules based on carbon would be the most stable; those based on nitrogen would be the least stable, if at all. (C) 2000 American Institute of Physics. [S0021- 9606(00)30421-4]. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP LaViolette, RA (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. RI Benson, Michael/B-8855-2017 OI Benson, Michael/0000-0003-4927-614X NR 32 TC 5 Z9 5 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 1 PY 2000 VL 112 IS 21 BP 9269 EP 9275 AR PII [S0021-9606(00)30421-4] DI 10.1063/1.481584 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 315YC UT WOS:000087139700010 ER PT J AU Sorensen, MR Voter, AF AF Sorensen, MR Voter, AF TI Temperature-accelerated dynamics for simulation of infrequent events SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; DIFFUSION; HYPERDYNAMICS; TRANSITION; CLUSTERS; SURFACES AB We present a method for accelerating dynamic simulations of activated processes in solids. By raising the temperature, but allowing only those events that should occur at the original temperature, the time scale of a simulation is extended by orders of magnitude compared to ordinary molecular dynamics, while preserving the correct dynamics at the original temperature. The main assumption behind the method is harmonic transition state theory. Importantly, the method does not require any prior knowledge about the transition mechanisms. As an example, the method is applied to a study of surface diffusion, where concerted processes play a key role. In the example, times of hours are achieved at a temperature of 150 K. (C) 2000 American Institute of Physics. [S0021-9606(00)70618-0]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sorensen, MR (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Albe, Karsten/F-1139-2011 NR 16 TC 366 Z9 371 U1 3 U2 61 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 1 PY 2000 VL 112 IS 21 BP 9599 EP 9606 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 315YC UT WOS:000087139700046 ER PT J AU Carlson, BC FitzSimons, J AF Carlson, BC FitzSimons, J TI Reduction theorems for elliptic integrands with the square root of two quadratic factors SO JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS LA English DT Article DE elliptic integrals; symbolic integration; integral tables; hypergeometric R-functions; computer algebra AB Recent methods of making integral tables and symbolic integration programs for elliptic integrals depend critically on reduction theorems for two particular integrals. These theorems assume that certain variables have positive real part, and the assumption is not always satisfied if the integrand contains the square root of two quadratic polynomials, each with conjugate complex zeros. A new remedy for this difficulty is the use of duplication theorems, leading to the weaker assumption that only sums of two variables must have positive real part. Numerical examples are given. In an Appendix related methods are used to simplify part of an algorithm for numerical computation of a symmetric elliptic integral of the third kind. (C) 2000 Elsevier Science B.V. All rights reserved. MSC: 33B10; 33C75; 33E05; 65D20; 41-04. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Math, Ames, IA 50011 USA. Saunders & Associates Inc, Scottsdale, AZ 85260 USA. RP Carlson, BC (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0427 J9 J COMPUT APPL MATH JI J. Comput. Appl. Math. PD JUN 1 PY 2000 VL 118 IS 1-2 BP 71 EP 85 DI 10.1016/S0377-0427(00)00282-X PG 15 WC Mathematics, Applied SC Mathematics GA 320DF UT WOS:000087385700005 ER PT J AU Yokoi, H Tozer, S Kim, Y Takeyama, S Wojtowicz, T Karczewski, G Kossut, J AF Yokoi, H Tozer, S Kim, Y Takeyama, S Wojtowicz, T Karczewski, G Kossut, J TI Pressure effect on the exchange interaction in the interface region of a CdTe/CdMnTe quantum-well structure SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 9th International Conference on II-VI Compounds CY NOV 01-05, 1999 CL KYOTO, JAPAN DE CdTe/CdMnTe single quantum well structure; interface; exciton; photoluminescence; sp-d exchange interaction; pressure effect ID CD1-XMNXTE AB Exchange interaction of an exciton in a quantum well with magnetic ions in the interface region and pressure effect on the interaction are investigated for a 1.9 nm thick CdTe/Cd1-xMnxTe (x = 0.24) single quantum well (SQW). Photoluminescence has been measured at 4 K under magnetic fields to 60 T generated by a motor-generator driven long-pulsed magnet and hydrostatic pressures to 2.45 GPa produced in a diamond anvil cell (DAC) with a plastic body. An additional red shift is observed in a Zeeman shift for the SQW above 30 T. This structure has enabled us to evaluate the above mentioned interaction quite accurately and to find that pressure enhances it. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 3058565, Japan. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Chiba Univ, Fac Sci, Chiba 2638522, Japan. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. RP Yokoi, H (reprint author), Natl Inst Mat & Chem Res, Tsukuba, Ibaraki 3058565, Japan. RI Kossut, Jacek/K-9481-2016; Wojtowicz, Tomasz/A-2887-2017 OI Kossut, Jacek/0000-0001-6165-3169; NR 7 TC 3 Z9 3 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 JUN PY 2000 VL 214 BP 428 EP 431 DI 10.1016/S0022-0248(00)00123-8 PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 328WC UT WOS:000087873200091 ER PT J AU Neukirch, U Bolton, SR Fromer, NA Sham, LJ Chemla, DS AF Neukirch, U Bolton, SR Fromer, NA Sham, LJ Chemla, DS TI Polariton-biexciton transitions in a ZnSe-based microcavity SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 9th International Conference on II-VI Compounds CY NOV 01-05, 1999 CL KYOTO, JAPAN DE zinc selenide; excitons; microcavity; coherent nonlinear optics ID 4-WAVE-MIXING SIGNALS; SEMICONDUCTORS; REGIME AB The optical third-order nonlinearity of a ZnSe-based microcavity is investigated by the pump-and-probe method. In the specially designed non-monolithic sample the biexciton binding energy exceeds all damping constants and the normal-mode splitting between exciton and cavity photon. For counter-circular polarized beams the nonlinear response exhibits strong oscillatory structures in the spectral vicinity of the polariton-biexciton transition. Comparison to model calculations shows that in this case the coherent nonlinearity is completely dominated by biexciton-exciton interactions beyond the Hartree-Fock approximation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Williams Coll, Dept Phys, Williamstown, MA 01267 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Neukirch, U (reprint author), Univ Bremen, Inst Festkorperphys, POB 330440, D-28334 Bremen, Germany. OI Sham, Lu/0000-0001-5718-2077 NR 16 TC 0 Z9 0 U1 0 U2 0 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 JUN PY 2000 VL 214 BP 1010 EP 1014 DI 10.1016/S0022-0248(00)00247-5 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 328WC UT WOS:000087873200211 ER PT J AU Robey, HF Potapenko, SY Summerhays, KD AF Robey, HF Potapenko, SY Summerhays, KD TI "Bending" of steps on rapidly grown KH2PO4 crystals due to an inhomogeneous surface supersaturation field SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID SOLUTION FLOW; KDP CRYSTALS; KINETICS; FACES AB The surfaces of large rapidly grown KH2PO4 (KDP) crystals can exhibit the formation of valleys in addition to the well-known growth hillocks and associated intervicinal boundaries between them. Understanding the mechanism of formation of these valleys is extremely important because they are observed to be precursors to the formation of solution inclusions on the crystal surface. Ea situ measurements using a precision coordinate measuring machine (CMM) have been made of the surface topography of rapidly grown KDP crystals. These measurements clearly indicate that these valleys are formed by the "bending'' of macrosteps originating from a single growth hillock. Results from numerical simulations of the hydrodynamics and mass transfer for the conditions used in the rapid growth process show that the surface supersaturation held generated on these crystals is inhomogeneous due to the spatially and temporally varying boundary layer thickness on the rotating crystal surface. These numerical results are used together with a simple model for the propagation of steps in an inhomogeneous surface supersaturation field to simulate the resulting crystal surface features. The qualitative agreement between the surface measurements and the numerical simulations is shown to be quite good. The dependence of the valley formation on parameters such as crystal growth rate, rotation conditions, growth hillock location, and impurity level are studied. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Inertial Confinement Fus Program, Livermore, CA 94550 USA. Sandia Natl Labs, Precis Measurements Grp, Livermore, CA 94550 USA. Univ San Francisco, Dept Chem, San Francisco, CA 94117 USA. Univ San Francisco, Dept Comp Sci, San Francisco, CA 94117 USA. RP Robey, HF (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inertial Confinement Fus Program, Livermore, CA 94550 USA. NR 19 TC 13 Z9 17 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 JUN PY 2000 VL 213 IS 3-4 BP 340 EP 354 DI 10.1016/S0022-0248(99)00869-6 PG 15 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 320EX UT WOS:000087389800019 ER PT J AU Robey, HF Potapenko, SY AF Robey, HF Potapenko, SY TI Ex situ microscopic observation of the lateral instability of macrosteps on the surfaces of rapidly grown KH2PO4 crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID MORPHOLOGICAL INSTABILITY; SOLUTION FLOW; VICINAL FACE AB The lateral instability of macrosteps has been identified theoretically as a mechanism whereby transverse modulations along a propagating macrostep can be amplified leading to the formation of solution inclusions. In this paper, experimental evidence for the occurrence of the lateral instability of macrosteps is presented. Ex situ images obtained by both optical and interferometric microscopy of the surface structure of several, {1 0 1} faces of a rapidly grown KH2PO4 (KDP) crystal are shown. The measurements give quantitative details of both the macrostep and the lateral instability structure. The observed wavelength of the instability is shown to be consistent with predictions from theory. Additional high-resolution surface profilometry measurements of the distribution of surface slopes of these faces show that there is a strong correlation between regions of locally increased vicinal slope and enhanced morphological instability. This is also shown to be consistent with theoretical predictions, and helps to explain the observed location of the surface instability. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Inertial Confinement Fus Program, Livermore, CA 94550 USA. RP Robey, HF (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inertial Confinement Fus Program, POB 5508, Livermore, CA 94550 USA. NR 18 TC 25 Z9 28 U1 0 U2 3 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 JUN PY 2000 VL 213 IS 3-4 BP 355 EP 367 DI 10.1016/S0022-0248(00)00025-7 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 320EX UT WOS:000087389800020 ER PT J AU Christen, HM Harshavardhan, KS Chisholm, MF Specht, ED Budai, JD Norton, DP Boatner, LA Pickering, IJ AF Christen, HM Harshavardhan, KS Chisholm, MF Specht, ED Budai, JD Norton, DP Boatner, LA Pickering, IJ TI The effect of size, strain, and long-range interactions on ferroelectric phase transitions in KTaO3/KNbO3 superlattices studied by X-ray, EXAFS, and dielectric measurements SO JOURNAL OF ELECTROCERAMICS LA English DT Article; Proceedings Paper CT 5th International Workshop on Oxide Electonics CY DEC 07-08, 1998 CL UNIV MARYLAND, BALTIMORE, MARYLAND SP DAPRA, Univ Maryland, Ctr Superconductiv Res, Univ Maryland, NSF, MRSEC, Japan Soc Promot Sci HO UNIV MARYLAND DE ferroelectrics; superlattices; size effects; strain effects; potassium niobate (KNbO3) ID PULSED-LASER DEPOSITION; THIN-FILMS; PBTIO3; GROWTH; MULTILAYERS; EVAPORATION; THICKNESS; TARGETS; NIOBATE AB Epitaxial, uniformly strained superlattices of ferroelectric KNbO3 and paraelectric KTaO3 are studied with respect to their structural and dielectric properties. For dielectric measurements, perfectly lattice-matched conducting Sr(Ru0.5Sn0.5)O-3 electrodes are used, and a broad, frequency-dependent maximum is observed in the capacitance-vs-temperature curves. Niobium K-edge glancing-angle EXAFS provides information regarding the crystal structure of KNbO3 films as thin as two unit cells in superlattices with equal KTaO3 and KNbO3 layer thicknesses, showing a clear difference between these thinnest-layer superlattices and films of the K(Ta0.5Nb0.5) O-3 solid-solution. X-ray diffraction measurements, on the other hand, indicate that these samples exhibit the same transition temperature T-c, indicating the importance of long-range electrostatic interactions. Analysis of the transition temperature for various structures leads to a clear identification of the effect of size and strain on T-c. C1 Neocera Inc, Beltsville, MD 20705 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. RP Christen, HM (reprint author), Neocera Inc, 10000 Virginia Manor Rd,Suite 300, Beltsville, MD 20705 USA. RI Christen, Hans/H-6551-2013; Specht, Eliot/A-5654-2009; Pickering, Ingrid/A-4547-2013; Boatner, Lynn/I-6428-2013; Budai, John/R-9276-2016 OI Christen, Hans/0000-0001-8187-7469; Specht, Eliot/0000-0002-3191-2163; Boatner, Lynn/0000-0002-0235-7594; Budai, John/0000-0002-7444-1306 NR 32 TC 10 Z9 10 U1 1 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1385-3449 J9 J ELECTROCERAM JI J. Electroceram. PD JUN PY 2000 VL 4 IS 2-3 BP 279 EP 287 DI 10.1023/A:1009994004989 PG 9 WC Materials Science, Ceramics SC Materials Science GA 355TY UT WOS:000089405600003 ER PT J AU Lee, YE Norton, DP Budai, JD Rouleau, CM Park, JW AF Lee, YE Norton, DP Budai, JD Rouleau, CM Park, JW TI Epitaxial growth and luminescent properties of Mn2+-activated ZnGa2O4 films SO JOURNAL OF ELECTROCERAMICS LA English DT Article; Proceedings Paper CT 5th International Workshop on Oxide Electonics CY DEC 07-08, 1998 CL UNIV MARYLAND, BALTIMORE, MARYLAND SP DAPRA, Univ Maryland, Ctr Superconductiv Res, Univ Maryland, NSF, MRSEC, Japan Soc Promot Sci HO UNIV MARYLAND DE pulsed laser deposition; luminescence; epitaxial; ZnGa2O4 : Mn; thin-film phosphors ID ELECTROLUMINESCENT DEVICES; PHOSPHOR AB The epitaxial growth and properties of Mn2+-doped ZnGa2O4 thin films on various single crystal substrates using pulsed laser deposition were investigated. Control of Zn/Ga stoichiometry required the use of a mosaic ZnGa2O4/ZnO ablation target to compensate for Zn loss due to evaporation. The photoluminescent intensity was a strong function of the Zn/Ga ratio, and also correlated with changes in the surface morphology. Superior photoluminescent intensity was attained from slightly Zn-deficient films which exhibit distinctive wormlike surface features. Enhanced photoluminescent intensity was observed in epitaxial films as compared to randomly-oriented polycrystalline deposits on glass substrates, suggesting an adverse effect of grain boundaries on luminescence properties. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Lee, YE (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Rouleau, Christopher/Q-2737-2015; Budai, John/R-9276-2016 OI Rouleau, Christopher/0000-0002-5488-3537; Budai, John/0000-0002-7444-1306 NR 11 TC 5 Z9 5 U1 2 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1385-3449 J9 J ELECTROCERAM JI J. Electroceram. PD JUN PY 2000 VL 4 IS 2-3 BP 293 EP 297 DI 10.1023/A:1009946105898 PG 5 WC Materials Science, Ceramics SC Materials Science GA 355TY UT WOS:000089405600005 ER PT J AU Brown, GW Hawley, ME Theis, CD Yeh, J Schlom, DG AF Brown, GW Hawley, ME Theis, CD Yeh, J Schlom, DG TI Atomic force microscopy examination of the evolution of the surface morphology of Bi4Ti3O12 grown by molecular beam epitaxy SO JOURNAL OF ELECTROCERAMICS LA English DT Article; Proceedings Paper CT 5th International Workshop on Oxide Electonics CY DEC 07-08, 1998 CL UNIV MARYLAND, BALTIMORE, MARYLAND SP DAPRA, Univ Maryland, Ctr Superconductiv Res, Univ Maryland, NSF, MRSEC, Japan Soc Promot Sci HO UNIV MARYLAND DE ferroelectrics; atomic force microscopy; Bi4Ti3O12; Stranski-Krastonov; dynamic scaling hypothesis ID SCANNING TUNNELING MICROSCOPY; BISMUTH TITANATE; THIN-FILMS; DEPOSITION; ROUGHNESS; SRTIO3 AB The surface morphology of (0 0 1) Bi4Ti3O12 grown on (0 0 1) SrTiO3 by reactive molecular beam epitaxy (MBE) has been examined using atomic force microscopy (AFM). Initial nucleation of a 1/4 unit cell thick layer is followed by growth of 1/2 unit cell thick layers. Between 9 and 16 layers, a transition to 3-dimensional growth occurs, leading to well-defined mounds. This implies a Stranski-Krastonov growth mode. During growth, the morphology follows a behavior consistent with the dynamic scaling hypothesis and we extract values for the scaling exponents alpha and beta from the AFM data. A thickness variation in alpha is observed and reflects the strain relief associated with the Stranski-Krastonov growth. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div MST8, Los Alamos, NM 87545 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Brown, GW (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RI Schlom, Darrell/J-2412-2013 OI Schlom, Darrell/0000-0003-2493-6113 NR 24 TC 3 Z9 3 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1385-3449 J9 J ELECTROCERAM JI J. Electroceram. PD JUN PY 2000 VL 4 IS 2-3 BP 351 EP 356 DI 10.1023/A:1009918711349 PG 6 WC Materials Science, Ceramics SC Materials Science GA 355TY UT WOS:000089405600013 ER PT J AU Erickson, JC Yao, HW James, RB Hermon, H Greaves, M AF Erickson, JC Yao, HW James, RB Hermon, H Greaves, M TI Time of flight experimental studies of CdZnTe radiation detectors SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1999 US Workshop on the Physics and Chemistry of II-VI Materials CY SEP 22-24, 1999 CL LAS VEGAS, NEVADA SP USA, CECOM, USA, SMDC, USA, Res Lab, USAF, Res Lab, Minerals Met & Mat Soc DE CdZnTe; radiation detectors; time of flight; mobility; electron trapping time AB A time of flight technique was used to study the carrier trapping time, tau, and mobility, mu, in CdZnTe (CZT) and CdTe radiation detectors. Carriers were generated near the surface of the detector by a nitrogen-pumped pulsed dye laser with wavelength similar to 500 nm. Signals from generated electrons or holes were measured by a fast oscilloscope and analyzed to determine the trapping time and mobility of carriers. Electron mobility was observed to change with temperature from 1200 cm(2)/Vs to 2400 cm(2)/Vs between 293 K and 138 K, respectively. Electron mobilities were observed between 900 cm(2)/Vs and 1350 cm(2)/Vs at room temperature for various CZT detectors. Electron mobilities in various CdTe detectors at room temperature were observed between 740 cm(2)/Vs and 1260 cm(2)/Vs. Average electron mobility was calculated to be 1120 cm(2)/Vs and 945 cm(2)/Vs for CZT and CdTe, respectively. Hole mobilities in both CZT and CdTe were found to vary between 27 cm(2)/Vs and 66 cm(2)/Vs. Electron trapping times in CZT at room temperature varied from 1.60 mu s to 4.18 mu s with an average value of about 2.5 mu s. Electron trapping time in CdTe at room temperature varied between 1.7 mu s and 4.15 mu s with an average value of about 3.1 mu s. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Nebraska, Lincoln, NE 68588 USA. RP Erickson, JC (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 6 TC 18 Z9 19 U1 0 U2 5 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 JUN PY 2000 VL 29 IS 6 BP 699 EP 703 DI 10.1007/s11664-000-0208-z PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 349QP UT WOS:000089057400014 ER PT J AU Chattopadhyay, K Hayes, M Ndap, JO Burger, A Lu, WJ McWhinney, HG Grady, T James, RB AF Chattopadhyay, K Hayes, M Ndap, JO Burger, A Lu, WJ McWhinney, HG Grady, T James, RB TI Surface passivation of cadmium zinc telluride radiation detectors by potassium hydroxide solution SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 1999 US Workshop on the Physics and Chemistry of II-VI Materials CY SEP 22-24, 1999 CL LAS VEGAS, NEVADA SP USA, CECOM, USA, SMDC, USA, Res Lab, USAF, Res Lab, Minerals Met & Mat Soc DE gamma-ray detector; surface passivation; etching; CZT; KOH; radiation sensor; surface treatment ID COPLANAR ELECTRODES; CDZNTE AB The spectral resolution of cadmium zinc telluride (CZT) room temperature nuclear radiation detectors is often limited by the presence of conducting surface species that increase the surface leakage current. Surface passivation plays an important role in reducing this surface leakage current and thereby decreasing the noise of the detectors and improving the spectral energy resolution. Chemical etching with a Br-MeOH solution leaves CZT surfaces rich in Te and is considered as one of the primary causes of the increased surface leakage current. Previous studies have shown that hydrogen peroxide (H2O2) forms oxides of tellurium on the CZT surface and thus acts as a good passivating agent. In this study we will present results on the use of potassium hydroxide (KOH) as an alternative passivating agent. The KOH aqueous solution leaves a more stoichiometric (evaluated from the trends in the surface Cd:Te ratio) and smoother CZT surface. The passivation effects of KOH solution on the surface of the CZT have been characterized by current-voltage measurements for different KOH concentrations and etching times for both parallel strip electrodes as well as a metal-semiconductor-metal configuration. The surface chemical composition and its morphology were studied by scanning x-ray photoelectron spectroscopy and atomic force microscopy. The comparison and demonstration of improvements in the spectral resolution of the CZT detectors (based on Am-241 spectra) with and without the KOH treatment are presented. C1 Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. Prairie View A&M Univ, Dept Chem, Prairie View, TX 77446 USA. Sandia Natl Labs, Adv Mat Proc Dept, Livermore, CA 94550 USA. RP Chattopadhyay, K (reprint author), Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. NR 13 TC 23 Z9 25 U1 1 U2 8 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 JUN PY 2000 VL 29 IS 6 BP 708 EP 712 DI 10.1007/s11664-000-0210-5 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 349QP UT WOS:000089057400016 ER PT J AU Mattson, ED Bowman, RS Lindgren, ER AF Mattson, ED Bowman, RS Lindgren, ER TI Electrokinetic remediation using surfactant-coated ceramic casings SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article ID UNSATURATED SOILS; MODIFIED ZEOLITE; REMOVAL; EXTRACTION; MICELLES; SORPTION; CHROMATE; FIELD AB Electrokinetic remediation is an emerging technique that can be used to remove metals from saturated or unsaturated soils. In unsaturated soils, control of the medium's water content is essential. Previously used electrode designs have caused detrimental soil wetting due to excess electroosmotic how out of ceramic-encased anodes. We tested a method to reverse the electroosmotic flow at the anode by treating the ceramic casing with the cationic surfactant hexadecyltrimethylammonium (HDTMA). Laboratory tests showed the untreated ceramic had an electroosmotic permeability of 2.4 x 10(-5) cm(2) V-1 s(-1). Ceramic treated with HDTMA had an electroosmotic permeability of -1.3 x 10(-5) cm(2) V-1 S-1. Under an applied electric potential, electroosmotic flow was reversed in the HDTMA-treated ceramic, indicating a reversed zeta potential due to formation of an HDTMA bilayer on the ceramic surface. Field tests conducted over a 6-month period showed negligible water loss from HDTMA-treated ceramic (0.03 L b(-1)) compared to untreated ceramics (up to 6 L h(-1)). The results indicated that a surfactant treatment to the anode ceramic casing can greatly improve the application of electrokinetics in unsaturated environments. C1 Idaho Nat Engn & Envir Lab, Dept Geosci, Idaho Falls, ID 83415 USA. New Mexico Inst Min & Technol, Dept Earth & Envir Sci, Socorro, NM 87801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mattson, ED (reprint author), Idaho Nat Engn & Envir Lab, Dept Geosci, POB 1625, Idaho Falls, ID 83415 USA. OI Mattson, Earl/0000-0002-2616-0008 NR 31 TC 5 Z9 8 U1 0 U2 5 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD JUN PY 2000 VL 126 IS 6 BP 534 EP 540 DI 10.1061/(ASCE)0733-9372(2000)126:6(534) PG 7 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 317JU UT WOS:000087222900008 ER PT J AU Riley, P Gosling, JT McComas, DJ Forsyth, RJ AF Riley, P Gosling, JT McComas, DJ Forsyth, RJ TI Properties and radial trends of coronal mass ejecta and their associated shocks observed by Ulysses in the ecliptic plane SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; 3-DIMENSIONAL PROPAGATION; INTERACTION REGIONS; TRANSIENT SHOCKS; EVOLUTION; LATITUDES; STREAMER; DRIVEN; CMES; AU AB In this paper, magnetic and plasma measurements are used to analyze 17 interplanetary coronal mass ejections (CMEs) identified by Ulysses during its in-ecliptic passage to Jupiter. We focus on the expansion characteristics of these CMEs (as inferred from the time rate of change of the velocity profiles through the CMEs) and the properties of 14 forward shocks unambiguously associated with these CMEs, We highlight radial trends from 1 to 5.4 AU. Our results indicate that the CMEs are generally expanding at all heliocentric distances. With regard to the shocks preceding these ejecta, we note the following: (1) There is a clear tendency for the shock speed (in the upstream frame of reference) to decrease with increasing heliocentric distance as the CMEs transfer momentum to the ambient solar wind and slow down; (2) 86% of the shock fronts are oriented in the ecliptic plane such that their normals point westward (i.e., in the direction of planetary motion about the Sun); (3) 86% of the shocks are propagating toward the heliographic equator; and (4) no clear trend was found in the strength of the shocks versus heliocentric distance. These results are interpreted using simple dynamical arguments and are supported by fluid and MHD simulations. C1 Sci Applicat Int Corp, San Diego, CA 92121 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. RP Riley, P (reprint author), Sci Applicat Int Corp, San Diego, CA 92121 USA. NR 26 TC 6 Z9 6 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 JUN 1 PY 2000 VL 105 IS A6 BP 12617 EP 12626 DI 10.1029/1999JA000169 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 319QD UT WOS:000087351900006 ER PT J AU Schwartz, SJ Paschmann, G Sckopke, N Bauer, TM Dunlop, M Fazakerley, AN Thomsen, MF AF Schwartz, SJ Paschmann, G Sckopke, N Bauer, TM Dunlop, M Fazakerley, AN Thomsen, MF TI Conditions for the formation of hot flow anomalies at Earth's bow shock SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; DIAMAGNETIC CAVITIES; REFLECTED IONS; DISCONTINUITIES; UPSTREAM; PLASMA AB Hot flow anomalies (HFAs) result from the interaction of an interplanetary current sheet with Earth's bow shock and were discovered over a decade and a half ago. The deflected flow and hot interior of an HFA are consequences of ions reflected at the bow shock being channeled along the current sheet. Previous studies have shown that this requires a solar wind motional electric field pointing toward the current sheet on at least one side and that the current sheet must be a tangential discontinuity. Recent reports of a rapid displacement of the magnetopause by 5 R(e) as the result of an HFA have led us to explore the interplanetary conditions surrounding all reported HFAs. The kinetic aspects of HFA formation suggest that current sheets should pass relatively slowly along the bow shock; that is, their normals should have large cone angles. This hypothesis is confirmed. Individual multispacecraft case studies confirm that the underlying current sheets are tangential discontinuities, but most HFAs have relatively small jumps in field magnitude from before to after and thus would fail traditional identification tests as definite tangential discontinuities. The combination of our results suggests that HFAs should occur at a rate of several per day, and thus they may play a significant role in the solar-terrestrial dynamics. C1 Univ London Queen Mary & Westfield Coll, Astron Unit, London E1 4NS, England. CNRS, Ctr Etud Spatiale Rayonnements, Toulouse, France. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Int Space Sci Inst, Bern, Switzerland. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Schwartz, SJ (reprint author), Univ London Queen Mary & Westfield Coll, Astron Unit, London E1 4NS, England. EM S.J.Schwartz@qmw.ac.uk; gep@mpe.mpg.de; thb@mpe.mpg.de; m.dunlop@ic.ac.uk; anf@mssl.ucl.ac.uk; mthomsen@lanl.gov RI dunlop, malcolm/F-1347-2010 NR 23 TC 80 Z9 80 U1 1 U2 5 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 JUN 1 PY 2000 VL 105 IS A6 BP 12639 EP 12650 DI 10.1029/1999JA000320 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 319QD UT WOS:000087351900008 ER PT J AU Smith, JP Thiffeault, JL Horton, W AF Smith, JP Thiffeault, JL Horton, W TI Dynamical range of the WINDMI model: An exploration of possible magnetospheric plasma states SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GEOMAGNETIC-ACTIVITY; ENERGY; FIELD AB This paper explores the dynamical range of the WINDMI model (Horton and Doxas, 1998]. Such low-dimensional models provide us with the tools to understand the relationships of simple physical quantities within the magnetosphere (such as energy deposition, macroscopic currents, cross-tail voltage, etc.) without the necessity of coping with the more complete but unwieldy models (MHD or particle codes, for example). The model is highly versatile: certain regions of the parameter space support stable fixed points, while others contain periodic states that exhibit period doubling, and sometimes chaos. States in each of these regimes (stable, periodic, chaotic) are investigated for their ability to accurately describe the observed properties of the magnetosphere-ionosphere system. A brief discussion of applications of this model to current space physics problems is included. C1 Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. RP Smith, JP (reprint author), Univ Calif Los Alamos Natl Lab, TSA-2 MS M997, Los Alamos, NM USA. NR 15 TC 10 Z9 10 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUN 1 PY 2000 VL 105 IS A6 BP 12983 EP 12996 DI 10.1029/1999JA000218 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 319QD UT WOS:000087351900037 ER PT J AU Arkani-Hamed, N Murayama, H AF Arkani-Hamed, N Murayama, H TI Holomorphy, rescaling anomalies and exact beta functions in supersymmetric gauge theories SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE renormalization regularization and renormalons; anomalies in field and string theories; supersymmetric effective theories ID YANG-MILLS THEORY; ADLER-BARDEEN THEOREM; ENERGY-MOMENTUM TENSOR; QUANTUM-FIELD-THEORY; DIMENSIONAL REGULARIZATION; INSTANTON CALCULUS; RENORMALIZATION; FINITENESS; MODEL; DEPENDENCE AB There have long been known "exact" beta functions for the gauge coupling in N = 1 supersymmetric gauge theories, the so-called Novikov-Shifman-Vainshtein-Zakharov (NSVZ) beta functions. Shifman and Vainshtein further related these beta functions to the exact 1-loop running of the gauge coupling in a "wilsonian" action. All these results, however, remain somewhat mysterious. We attempt to clarify these issues by presenting new perspectives on the NSVZ beta function. Our interpretation of the results is somewhat different than the one given by Shifman and Vainshtein, having nothing to do with the distinction between "wilsonian" and "1PI" effective actions. Throughout we work in the context of the Wilsonian Renormalization Group; namely, as the cutoff of the theory is changed from M to M', we seek to determine the appropriate changes in the bare couplings needed in order to keep the low energy physics fixed. The entire analysis is therefore free of infrared subtleties. When the bare lagrangian given at the cutoff is manifestly holomorphic in the gauge coupling, we show that the required change in the holomorphic gauge coupling is exhausted at 1-loop to all orders of perturbation theory, and even non-perturbatively in some cases. On the other hand, when the bare lagrangian at the cutoff has canonically normalized kinetic terms, we find that the required change in the gauge coupling is given by the NSVZ beta function. The higher order contributions in the NSVZ beta function are due to anomalous jacobians under the rescaling of the fields done in passing from holomorphic to canonical normalization. We also give prescriptions for regularizing certain N = 1 theories with an ultraviolet cutoff M preserving manifest holomorphy, starting from finite N = 4 and N = 2 theories. It is then at least in principle possible to check the validity of the exact beta function by higher order calculations in these theories. C1 Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, EO Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. EM arkani@thwk1.lbl.gov; murayama@thsrv.lbl.gov RI Murayama, Hitoshi/A-4286-2011 NR 67 TC 130 Z9 131 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 JUN PY 2000 IS 6 AR 030 PG 43 WC Physics, Particles & Fields SC Physics GA 422JK UT WOS:000168114600030 ER PT J AU Grossman, Y Pirjol, D AF Grossman, Y Pirjol, D TI Extracting and using photon polarization information in radiative B decays SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE quark masses and SM parameters; B-physics; CP-violation ID BOTTOM CHARGED CURRENT; HIGGS DOUBLET MODEL; STANDARD-MODEL; CP-ASYMMETRIES; DISCRETE AMBIGUITIES; PROCESS B->S-GAMMA; PHYSICS; CONSTRAINTS; TRANSITIONS; MESONS AB We discuss the uses of conversion electron pairs for extracting photon polarization information in weak radiative B decays. Both cases of leptons produced through a virtual and real photon are considered. Measurements of the angular correlation between the (K pi) and (e(+)e(-)) decay planes in B --> K*(-->K pi)gamma (()*()) (--> e(+)e(-)) decays can be used to determine the helicity amplitudes in the radiative B --> K*gamma decay. A large right-handed helicity amplitude in (B) over bar decays is a signal of new physics. The time-dependent CP asymmetry in the B-0 decay angular correlation is shown to measure sin 2 beta and cos 2 beta with little hadronic uncertainty. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Grossman, Y (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM yuval@slac.stanford.edu; pirjol@wigner.ucsd.edu NR 49 TC 36 Z9 36 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 JUN PY 2000 IS 6 AR 029 PG 19 WC Physics, Particles & Fields SC Physics GA 422JK UT WOS:000168114600029 ER PT J AU Kaplan, DE Tait, TMP AF Kaplan, DE Tait, TMP TI Supersymmetry breaking, fermion masses and a small extra dimension SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE supersymmetry breaking; quark masses and SM parameters; beyond standard model; supersymmetric standard model ID MSSM HIGGS BOSONS; ANOMALOUS U(1); STANDARD MODEL; TEVATRON; SUPERGRAVITY; TRILEPTON; COLLIDER; PHENOMENOLOGY; HIERARCHIES; CONSTRAINTS AB We present a supersymmetric model in which the observed fermion masses and mixings are generated by localizing the three generations of matter and the two Higgs fields at different locations in a compact extra dimension. Supersymmetry is broken by the shining method and the breaking is communicated to standard model fields via gaugino mediation. Quark masses, CKM-mixing angles and the mu term are generated with all dimensionless couplings of O (1). All dimensionful parameters are of order the five-dimensional Planck scale except for the size of the extra dimension which is of order the GUT scale. The superpartner spectrum is highly predictive and is found to have a neutralino LSP over a wide range of parameter space. The resulting phenomenology and interesting extensions of the model are briefly discussed. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. EM dkaplan@theory.uchicago.edu; tait@anl.gov NR 56 TC 91 Z9 91 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 JUN PY 2000 IS 6 AR 020 DI 10.1088/1126-6708/2000/06/020 PG 27 WC Physics, Particles & Fields SC Physics GA 422JK UT WOS:000168114600020 ER PT J AU Lykken, J Randall, L AF Lykken, J Randall, L TI The shape of gravity SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE field theories in higher dimensions; D-branes ID DIMENSIONS; MILLIMETER; HIERARCHY; TEV AB In a non-trivial background geometry with extra dimensions, gravitational effects will depend on the shape of the Kaluza-Klein excitations of the graviton. We investigate a consistent scenario of this type with two positive tension three-branes separated in a five-dimensional anti-de Sitter geometry. The graviton is localized on the "Planck" brane, while a gapless continuum of additional gravity eigenmodes probe the infinitely large fifth dimension. Despite the background five-dimensional geometry, an observer confined to either brane sees gravity as essentially four-dimensional up to a position-dependent strong coupling scale, no matter where the brane is located. We apply this scenario to generate the TeV scale as a hierarchically suppressed mass scale. Arbitrarily light gravitational modes appear in this scenario, but with suppressed couplings. Real emission of these modes is observable at future colliders; the effects are similar to those produced by six large toroidal dimensions. C1 Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08543 USA. RP Lykken, J (reprint author), Fermilab Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. EM lykken@fnal.gov; randall@feynman.princeton.edu NR 9 TC 192 Z9 192 U1 0 U2 4 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 JUN PY 2000 IS 6 AR 014 PG 9 WC Physics, Particles & Fields SC Physics GA 422JK UT WOS:000168114600014 ER PT J AU Dikanov, SA Tyryshkin, AM Bowman, MK AF Dikanov, SA Tyryshkin, AM Bowman, MK TI Intensity of cross-peaks in Hyscore spectra of S=1/2, I=1/2 spin systems SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE pulsed EPR; ESEEM; HYSCORE; lineshape; intensity ID ECHO ENVELOPE-MODULATION; SUBLEVEL CORRELATION SPECTROSCOPY; 2-DIMENSIONAL ESEEM SPECTROSCOPY; PULSED EPR; HYPERFINE COUPLINGS; DISORDERED-SYSTEMS; PHOTOSYSTEM-II; LIGAND; COMPLEXES; HISTIDINE AB The cross-peak intensity for a S = 1/2, I = 1/2 spin system in two-dimensional HYSCORE spectra of single-crystals and powders is analyzed. There is a fundamental difference between these two cases. For single crystals, the cross-peak intensity is distributed between the two (+, +) and (+, -) quadrants of the hyperfine sublevel correlation (HYSCORE) spectrum by the ratio c(2):s(2) (C. Gemperle, G. Aebli, A. Schweiger, and R. R. Ernst, J. Magn. Reson. 88, 241 (1990)). However, for powder spectra another factor becomes dominant and governs cross-peak intensities in the two quadrants. This factor is the phase interference between modulation from different orientations of the paramagnetic species. This can lead to essentially complete disappearance of the cross-peak in one of the two (+, +) or (+, -) quadrants. In the (+, +) quadrant, cross-peaks oriented parallel to the main (positive) diagonal of the HYSCORE spectrum are suppressed, while the opposite is true in the (+, -) quadrant where cross-peaks nearly perpendicular to the main (negative) diagonal of HYSCORE spectra are suppressed. Analytical expressions are derived for the cross-peak intensity profiles in powder HYSCORE spectra for both axial and nonaxial hyperfine interactions (HFI). The intensity is a product of two terms, one depending only an experimental parameter (tau) and the other only on the spin Hamiltonian. This separation provides a rapid way to choose tau for maximum cross-peak intensity in a region of interest in the spectrum, For axial HFI, the Hamiltonian-dependent term has only one maximum and decreases to zero at the canonical orientations. For nonaxial HFI, this term produces three separate ridges which outline the whole powder lineshape. These three ridges have the majority of the intensity in the HYSCORE spectrum. The intensity profile of each ridge resembles that observed for axial HFI. Each ridge defines two principal values of the HFI similar to the ridges from an axial HFI. (C) 2000 Academic Press. C1 Univ Illinois, Illinois EPR Res Ctr, Urbana, IL 61801 USA. Univ Illinois, Dept Vet Clin Med, Urbana, IL 61801 USA. Russian Acad Sci, Inst Chem Kinet & Combust, Novosibirsk 630090, Russia. Pacific NW Natl Lab, WE Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dikanov, SA (reprint author), Univ Illinois, Illinois EPR Res Ctr, Urbana, IL 61801 USA. RI Tyryshkin, Alexei/A-5219-2008; Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 25 TC 43 Z9 43 U1 2 U2 22 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 JUN PY 2000 VL 144 IS 2 BP 228 EP 242 DI 10.1006/jmre.2000.2055 PG 15 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 322RZ UT WOS:000087523700006 PM 10828191 ER PT J AU Volkov, VV Zhu, Y AF Volkov, VV Zhu, Y TI Dynamic magnetization observations and reversal mechanisms of sintered and die-upset Nd-Fe-B magnets SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE mechanisms of magnetization reversal; in situ Lorentz microscopy; magnetic domains; die-upset magnets; sintered magnets ID ELECTRON-MICROSCOPY; MICROSTRUCTURE; REMANENCE AB In situ TEM magnetizing experiments combined with Lorentz microscopy in Fresnel and Foucault mode were used to study local features of magnetization reversal in polycrystalline sintered and die-upset Nd-Fe-B magnets. The die-upset (DU) magnets featured well-aligned grain texture along the c-axis, while the sintered (SI) magnets have a much wider distribution of grain orientations. Despite the similarity of the hysteresis curves, we found their nanoscale behavior of the magnetization reversal was quite different. The predominant mechanism controlling reversal in DU-magnets was nucleation of reversed domains, preferentially at misaligned grain interfaces, followed by domain wan pinning at grain boundaries. In contrast, magnetization reversal in SI-magnet progressed first by nucleation and expansion of reversed domain dipoles predominantly in misaligned grains at a high magnetic field, and then by the major irreversible process via nucleation and splitting of magnetic domains near the grain boundaries of well-aligned grains at more negative fields. This process is completed with lateral expansion of newly created domain walls. A simple model for the strong pinning-trapping centers observed in DU-magnets is discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Volkov, VV (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Bldg 480, Upton, NY 11973 USA. RI Volkov, Vyacheslav/D-9786-2016 NR 14 TC 21 Z9 21 U1 1 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUN PY 2000 VL 214 IS 3 BP 204 EP 216 DI 10.1016/S0304-8853(00)00195-5 PG 13 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 317ZW UT WOS:000087259500008 ER PT J AU Vaidya, RU Rangaswamy, P Castro, RG Petrovic, JJ Butt, DP AF Vaidya, RU Rangaswamy, P Castro, RG Petrovic, JJ Butt, DP TI Use of metallic glasses in molybdenum disilicide-stainless steel joining SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE metallic glasses; brazing; molybdenum disilicide; push-out tests ID TEMPERATURE STRUCTURAL SILICIDES; OXIDATION; MOSI2 AB The successful use of a cobalt-based metallic glass in joining molybdenum disilicide (MoSi2) to stainless steel 316L was demonstrated. The cobalt-based metallic glass (METGLAS(TM) (Allied Signal Inc., Parsippany, NJ) 2714A) was found to met the MoSi2 and stainless steel surfaces and provide high-duality joints. The joining was completed at 1050 degrees C for 60 min. Postbrazing metallographic evaluations coupled with quantitative elemental analysis indicated the presence of a Co-Cr-Si ternary phase with CoSi and CoSi2 precipitates within the braze. Brazing conducted under these process parameters was found to provide interfacial joint strengths in the range of 60 to 80 MPa. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. Ceramatec Inc, Salt Lake City, UT 84119 USA. RP Vaidya, RU (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 13 TC 2 Z9 2 U1 0 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD JUN PY 2000 VL 9 IS 3 BP 280 EP 285 DI 10.1361/105994900770345926 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 333AD UT WOS:000088105800005 ER PT J AU Komarneni, S Kodama, T Paulus, WJ Carlson, C AF Komarneni, S Kodama, T Paulus, WJ Carlson, C TI Synthetic clay excels in Sr-90 removal SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Tests with actual ground water from Hanford site, and fundamental studies of 2Na(+) --> Sr2+ exchange equilibria revealed that a synthetic clay is extremely selective for Sr-90 with a high capacity for uptake. Comparative studies with existing Sr selective ion exchangers clearly revealed that the present synthetic clay exhibited the best performance for Sr-90 removal from actual ground water collected from three different locations at Hanford. This novel Sr ion sieve is expected to be useful for the decontamination of the environment after accidental release and contamination with Sr-90. C1 Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Penn State Univ, Dept Agron, University Pk, PA 16802 USA. Pacific NW Lab, Environm Technol Div, Richland, WA 99352 USA. RP Komarneni, S (reprint author), Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NR 12 TC 15 Z9 15 U1 0 U2 0 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 JUN PY 2000 VL 15 IS 6 BP 1254 EP 1256 DI 10.1557/JMR.2000.0182 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 320BY UT WOS:000087382200008 ER PT J AU Ferber, MK Wereszczak, AA Lance, M Haynes, JA Antelo, MA AF Ferber, MK Wereszczak, AA Lance, M Haynes, JA Antelo, MA TI Application of infrared imaging to the study of controlled failure of thermal barrier coatings SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB A technique that uses high resolution infrared (IR) imaging was developed to track and analyze damage evolution of thermal barrier coatings (TBCs) during controlled mechanical testing of a TBC specimen. Coating debonding and spallation were examined during a monotonic load-to-TBC-failure test. The infrared imaging, in concert with a controlled thermal gradient in the specimen, was particularly effective in identifying and tracking localized damage evolution because the damage in the TBC was always associated with a measurable surface-temperature change. It is demonstrated that the combined use of high-resolution infrared imaging and controlled mechanical testing of TBCs is an effective method to characterize the evolution of their failure. (C) 2000 Kluwer Academic Publishers. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Siemens Westinghouse Power Corp, GT Mat Dev Dept, Orlando, FL 32826 USA. RP Ferber, MK (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Wereszczak, Andrew/I-7310-2016; Lance, Michael/I-8417-2016 OI Wereszczak, Andrew/0000-0002-8344-092X; Lance, Michael/0000-0001-5167-5452 NR 19 TC 9 Z9 10 U1 0 U2 3 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 JUN PY 2000 VL 35 IS 11 BP 2643 EP 2651 DI 10.1023/A:1004781220825 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 303JX UT WOS:000086419700002 ER PT J AU Lessing, PA Erickson, AW Kunerth, DC AF Lessing, PA Erickson, AW Kunerth, DC TI Electrophoretic deposition [EPD] applied to reaction joining of silicon carbide and silicon nitride ceramics SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID MELT INFILTRATION; ALLOYS AB Electrophoretic Deposition (EPD) was used to deposit a mixture of SiC or Si3N4 "filler" and reactive carbon (graphite and carbon black) particles onto various SiC or Si3N4 parts in preparation for reaction bonding. The particles had gained a surface charge when mixed into an organic liquid consisting of 90 w % acetone + 10 w % n-butyl amine to form a slurry. The charged particles then moved when placed under the influence of an electric field to form a "green" deposit on the ceramic parts. The green parts were then dried and subsequently joined using a reaction bonding method. In this reaction bonding, molten Si moves into the joint via capillary action and then dissolves carbon and precipitates additional SiC. An optimum mixture of SiC "filler" to C powder ratio of 0.64 was identified. Residual un-reacted or "free" Si was minimized as a result of selecting powders with well-characterized particle size distributions and mixing them in batch formulas generated as part of the research. Image analysis of resulting microstructures indicated residual "free" Si content as low as 7.0 vol % could be realized. Seven volume percent compares favorably with the lowest "free" Si levels available in experimental samples of bulk siliconized (reaction-bonded) SiC manufactured using conventional reaction-bonding techniques. The joints retained the residual silicon over a large number of high-temperature thermal cycles (cycling from below to above the melting point of silicon). Comparisons to commercial reaction-bonded SiC indicated the majority of residual silicon of the joint was retained in closed porosity. This infers that parts made with these joints might be successfully utilized at very high temperatures. It was demonstrated that the EPD technique could be applied to butt, lap, and scarf type joints, including the capability to fill large gaps or undercut sections between parts to be joined. The overall results indicate that EPD, combined with reaction bonding, should allow for the fabrication of large complex structures manufactured from smaller components consisting of silicon carbide or silicon nitride. (C) 2000 Kluwer Academic Publishers. C1 INEEL Res Ctr, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Lessing, PA (reprint author), INEEL Res Ctr, Idaho Natl Engn & Environm Lab, 2251 North Blvd, Idaho Falls, ID 83415 USA. NR 22 TC 13 Z9 17 U1 2 U2 13 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 JUN PY 2000 VL 35 IS 12 BP 2913 EP 2925 DI 10.1023/A:1004766424209 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 314QV UT WOS:000087069000002 ER PT J AU Hu, MZC Miller, GA Payzant, EA Rawn, CJ AF Hu, MZC Miller, GA Payzant, EA Rawn, CJ TI Homogeneous (co)precipitation of inorganic salts for synthesis of monodispersed barium titanate particles SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID LOW-TEMPERATURE SYNTHESIS; HYDROTHERMAL SYNTHESIS; NANOCRYSTALLINE BATIO3; DIELECTRIC-PROPERTIES; THERMAL HYDROLYSIS; METAL ALKOXIDES; THIN-FILMS; POWDERS; MECHANISMS; GELS AB Various processes of coprecipitation or crystallization of inorganic salts of barium and titanium from homogeneous solutions were studied in this work. In particular, barium hydroxide and barium chloride salt as well as titanium tetrachloride were used as the starting materials for dielectric-tuning homogeneous precipitation in mixed solvents of isopropanol and water. Hydroxypropylcellulose was used as a steric dispersant. Evaluations of size, shape, and composition of synthesized particles were made using scanning electron microscopy, high-temperature X-ray diffractometry, and differential thermal analysis. Results show that salt concentration, pH, and reaction time are important in determining the morphology and composition of the final powder. The titania particles from dielectric-tuning precipitation are perfect microspheres with narrow size distribution (near monodispersed), while the particles from barium salts are flake-like, irregular in shape and size. Instead of particles containing uniform compositions of barium and titanium compounds, dielectric-tuning coprecipitation yielded powders of two separated phases, i.e., monodispersed titania microspheres (similar to 1 mu m) coated on barium chloride salt flakes. Titanium-rich barium titanate was obtained after calcination of coprecipitated powders. However, preliminary results show that the titania particles obtained by dielectric-tuning precipitation can be hydrothermally converted to BaTiO3 particles that are fully crystallized after calcination above 950 degrees C. (C) 2000 Kluwer Academic Publishers. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hu, MZC (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RI Payzant, Edward/B-5449-2009; OI Payzant, Edward/0000-0002-3447-2060; Hu, Michael/0000-0001-8461-9684 NR 47 TC 49 Z9 53 U1 2 U2 17 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 JUN PY 2000 VL 35 IS 12 BP 2927 EP 2936 DI 10.1023/A:1004718508280 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 314QV UT WOS:000087069000003 ER PT J AU Unal, O Okumus, SC AF Unal, O Okumus, SC TI Stable crack growth detection by strain-gage in plasma sprayed chevron-notched fracture toughness specimens SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID BACK-FACE STRAIN; LOAD C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Unal, O (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 8 TC 2 Z9 2 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD JUN PY 2000 VL 19 IS 11 BP 939 EP 941 DI 10.1023/A:1006703902383 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 309YP UT WOS:000086797400007 ER PT J AU Wereszczak, AA Barnes, AS Breder, K Binapal, S AF Wereszczak, AA Barnes, AS Breder, K Binapal, S TI Probabilistic strength of {111} n-type silicon SO JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS LA English DT Article ID SINGLE-CRYSTAL SILICON; FRACTURE STRENGTH; CRACKING; WAFERS AB The two-parameter Weibull strength distribution of {1 1 1} n-type silicon prismatic bars was determined in four-point bending and analyzed as a function of specimen size (width), loading rate, two different crystallographic orientations, and specimen orientation (polished or etched surface in tension). 100% fractography was performed to classify strength-limiting flaw types and to censor the strength data. All flaw types were extrinsic. Machining or cutting damage in the form of chipped edges (an edge-type flaw) was the dominant strength-limiting flaw when the polished surface was subjected to tensile stress, while a flat-bottomed etch pit (a surface-type flaw) was the dominant strength-limiting flaw when the etched surface was subjected to tensile stress. The censored Weibull strength distribution was independent of specimen width, loading rate (indicative of slow crack growth insusceptibility), and the two crystallographic orientations; however, it was dependent on specimen orientation. Pooling of the strength data was employed to tighten the confidence intervals about the censored parameters. The results from this study indicate that different extrinsic strength-limiting flaws and strength distributions will be operative depending on the manner in which a silicon component is stressed. C1 Oak Ridge Natl Lab, Mech Characterizat & Anal Grp, Oak Ridge, TN 37831 USA. Gennum Corp, Burlington, ON L7R 3Y3, Canada. RP Wereszczak, AA (reprint author), USA, Res Lab, Aberdeen Proving Ground, MD 21010 USA. RI Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 34 TC 7 Z9 7 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0957-4522 J9 J MATER SCI-MATER EL JI J. Mater. Sci.-Mater. Electron. PD JUN PY 2000 VL 11 IS 4 BP 291 EP 303 DI 10.1023/A:1008973231053 PG 13 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA 342FY UT WOS:000088635600003 ER PT J AU Romero, LA Dickey, FM Holswade, SC AF Romero, LA Dickey, FM Holswade, SC TI A method for achieving constant rotation rates in a microorthogonal linkage system SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE actuators; drive signals; feedback; micromachines ID SURFACE MICROMACHINED MICROENGINE; PERFORMANCE; FRICTION; MOTION AB Silicon micromachine designs include engines that consist of orthogonally oriented linear comb-drive actuators mechanically connected to a rotating gear. These gears are as small as 50 mu m in diameter and can be driven at rotation rates exceeding 300 000 r/min, Generally, these engines will run with nonuniform rotation rates if the drive signals are not properly designed and maintained over a range of system parameters. We present a method for producing constant rotation rates in a microengine driven by an orthogonal linkage system. We show that, provided the values of certain masses, springs, damping factors, and lever arms are in the right proportions, the system behaves as though it were symmetrical. We will refer to systems built in this way as being quasi-symmetrical. We show that if a system is built quasi-symmetrically, then it is possible to achieve constant rotation rates even if one does not know the form of the friction function or the value of the friction. We analyze this case in some detail. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Romero, LA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 5 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 1057-7157 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD JUN PY 2000 VL 9 IS 2 BP 236 EP 244 DI 10.1109/84.846704 PG 9 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 328GU UT WOS:000087842600009 ER PT J AU Lafferty, WJ Flaud, JM Sams, RL Blake, TA Sharpe, SW AF Lafferty, WJ Flaud, JM Sams, RL Blake, TA Sharpe, SW TI High-resolution infrared spectrum of the ring-puckering band, nu(10), of diborane SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article AB The spectrum of the nu(10) band of diborane, arising from the ring-puckering vibration, has been obtained with a spectral resolution of 0.0015 cm(-1) in the region 275-400 cm(-1). The spectrum of a sample enriched in B-10 was recorded as well as one with naturally abundant boron, i.e., 64% (B2H6)-B-11, 32% (BBH6)-B-10-B-11, and 4% (B2H6)-B-10. This mode is the lowest vibrational level of the molecule and is unperturbed, allowing a complete assignment of not only the fundamental bands but also the 2 nu(10)-nu(10) hot bands of all three boron isotopomers. The intensities of several hundred Lines of the fundamental and hot bands of all isotopomers have been measured and vibrational transition moments have been obtained. Finally, it has been shown that the harmonic approximation does not apply for nu(10). (C) 2000 Academic Press. C1 Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Paris 11, CNRS, Photophys Mol Lab, F-91405 Orsay, France. Pacific NW Lab, Richland, WA 99352 USA. RP Lafferty, WJ (reprint author), Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 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 JUN PY 2000 VL 201 IS 2 BP 285 EP 291 DI 10.1006/jmsp.2000.8095 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 317RC UT WOS:000087239900010 ER PT J AU Feigerle, CS Bililign, S Miller, JC AF Feigerle, C. S. Bililign, S. Miller, John C. TI Nanochemistry - chemical reactions of iron and benzene within molecular clusters SO JOURNAL OF NANOPARTICLE RESEARCH LA English DT Article DE benzene; nanoclusters; ion chemistry; lasers; mass spectrometry; nanoparticles ID ENHANCED MULTIPHOTON IONIZATION; GAS-PHASE; ORGANOMETALLIC CLUSTERS; ION CHEMISTRY; NO; PHOTODISSOCIATION; SPECTROSCOPY; COMPLEXES; SANDWICH; IONIZATION/DISSOCIATION AB Molecular clusters represent a nanoscale test tube where chemical reactions can be examined in a unique way for the effects of the local environment and the possibility of size-dependent reactions. Previous experiments have shown that the ionization/dissociation of iron pentacarbonyl clusters can lead to the formation of iron ions and iron cluster ions and that these species can further react with dopant molecules to yield chemically rearranged products. The present experiments characterize similar reactions with benzene molecules and clusters. Heteroclusters of the form [Fe(CO)(5)](m) (C6H6)(n) Ar-p are created in an expanding supersonic jet of the component molecules. Following ionization by a 30 ps, 266 nm laser pulse, extensive dissociation, aggregation, and chemical rearrangement occurs leading to ionic products which are characterized by mass spectrometry. Cluster ions of the type Fe m ( C6H6) n C are observed as products. The stability of the sandwich form of the ion, Fe(benzene)(2)(+), is inferred from the data. Evidence for a similar special stability for the double-decker, Fe-2(benzene)(3)(+), is presented. C1 [Miller, John C.] Oak Ridge Natl Lab, Biochem & Biophys Sect, Oak Ridge, TN 37831 USA. [Feigerle, C. S.] Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. [Bililign, S.] N Carolina Agr & Tech State Univ, Dept Phys, Greensboro, NC 27411 USA. RP Miller, JC (reprint author), Oak Ridge Natl Lab, Biochem & Biophys Sect, POB 2008, Oak Ridge, TN 37831 USA. EM millerjc@ornl.gov FU office of Health and Environmental Research, U.S. Department of Energy (DOE) [DE-AC05-96OR22464]; NATO [CRG 950660]; NRC FX Research is sponsored by the office of Health and Environmental Research, U.S. Department of Energy (DOE) under contract DE-AC05-96OR22464 with Lockheed Martin Energy Research, Inc. J.C.M. acknowledges the use of a NATO International Collaboration Grant (CRG 950660) during the course of this work and also helpful discussions with M. Velegrakis. S.B. acknowledges support, in part, by an appointment to the Nuclear Regulatory Commission's (NRC) Historically Black Colleges and Universities Research Participation Program administered by the Oak Ridge Institute of Science and Education through a cooperative agreement between the DOE and the NRC. NR 37 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1388-0764 J9 J NANOPART RES JI J. Nanopart. Res. PD JUN PY 2000 VL 2 IS 2 BP 147 EP 155 DI 10.1023/A:1010034122603 PG 9 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA V19IX UT WOS:000208067200005 ER PT J AU Kim, YS AF Kim, YS TI A thermodynamic evaluation of the U-O system from UO2 to U3O8 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID STEAM; OXIDATION AB Thermodynamic constraints and a modified form of Sieverts law were utilized to evaluate the partial thermodynamic functions of the U-O system from UO2 to U3O3 in the temperature range of 500-1800 K. The p-C-T relationships for each phase region obtained in the literature were reassessed and new p-C-T relationships in regions where data were scarce in the literature were proposed. The results are presented as the oxygen isobars superimposed on the phase diagram to characterize the system. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Engn, Idaho Falls, ID 83403 USA. RP Kim, YS (reprint author), Argonne Natl Lab, Div Engn, Idaho Falls, ID 83403 USA. NR 31 TC 17 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 2000 VL 279 IS 2-3 BP 173 EP 180 DI 10.1016/S0022-3115(00)00019-2 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 315BC UT WOS:000087091900006 ER PT J AU Keiser, DD Abraham, DP Sinkler, W Richardson, JW McDeavitt, SM AF Keiser, DD Abraham, DP Sinkler, W Richardson, JW McDeavitt, SM TI Actinide distribution in a stainless steel-15 wt% zirconium high-level nuclear waste form SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID PHASE-DIAGRAM; LAVES PHASE; ALLOYS; MODELS AB Actinide-bearing waste forms are being produced from metallic remnants resulting from the electrometallurgical extraction of uranium from EBR-II spent fuel. The baseline metal waste form (MWF) is a stainless steel-15 wt% zirconium (SS-15Zr) alloy that may contain up to 10 wt% actinides, mostly in the form of uranium. This article presents the results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and neutron diffraction on SS-15Zr alloys containing uranium, plutonium, and neptunium. Neutron diffraction results showed that the addition of uranium to SS-15Zr does not result in the formation of discrete uranium-rich phases. The lattice parameters of the ZrFe2-type intermetallics are larger in uranium-containing SS-15Zr alloys and are consistent with the substitution of uranium at zirconium sites of the ZrFe2 lattice. SEM studies showed that actinides are present only in the ZrFe2-type intermetallics; moreover, both actinide-rich and actinide-deficient areas are found within the Laves compound. TEM showed that the simultaneous presence of multiple Laves polytypes, each with a different preference for the uranium atom, results in the uranium concentration gradients observed within the Laves intermetallics. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Argonne Natl Lab W, Idaho Falls, ID 83403 USA. RP Abraham, DP (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM abraham@cmt.anl.gov NR 34 TC 17 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 2000 VL 279 IS 2-3 BP 234 EP 244 DI 10.1016/S0022-3115(00)00002-7 PG 11 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 315BC UT WOS:000087091900013 ER PT J AU Sohn, YH Dayananda, MA Hofman, GL Strain, RV Hayes, SL AF Sohn, YH Dayananda, MA Hofman, GL Strain, RV Hayes, SL TI Analysis of constituent redistribution in the gamma (bcc) U-Pu-Zr alloys under gradients of temperature and concentrations SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID EFFECTIVE INTERDIFFUSION COEFFICIENTS; ZERO-FLUX PLANES; MULTICOMPONENT DIFFUSION; REVERSALS; BEHAVIOR; COUPLES; DEPTHS; FUEL AB Rods of a ternary alloy (71U-19Pu-10Zr by weight percent) were annealed under a temperature gradient of 220 degrees C/ cm for 41 days and examined for micro-structural development and compositional redistribution. An enrichment of Zr with concurrent depletion of U was observed within the gamma (bcc) phase region on the hot-end side (T congruent to 740 degrees C). The experimental redistribution of the elements in the gamma (bcc) phase was analyzed in the framework of multicomponent mass transport with due consideration of thermotransport and ternary diffusional interactions. Based on a new analysis involving an integration of interdiffusion fluxes in the diffusion zone, kinetic parameters related to the thermotransport and ternary interdiffusion were calculated for each component i over selected ranges of composition. The thermotransport coefficients of U, Pu, and Zr were in the approximate ratio of 1:2:-4.5 in the hot-end region. In addition, the interdiffusion flux contributions arising from the gradients of temperature and concentrations of U and Zr were estimated. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Purdue Univ, Sch Mat Engn, W Lafayette, IN 47907 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Argonne Natl Lab, Idaho Falls, ID 83403 USA. RP Dayananda, MA (reprint author), Purdue Univ, Sch Mat Engn, 1289 MSEE Bldg, W Lafayette, IN 47907 USA. RI Sohn, Yongho/A-8517-2010; Hayes, Steven/D-8373-2017 OI Sohn, Yongho/0000-0003-3723-4743; Hayes, Steven/0000-0002-7583-2069 NR 42 TC 24 Z9 24 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUN PY 2000 VL 279 IS 2-3 BP 317 EP 329 DI 10.1016/S0022-3115(99)00290-1 PG 13 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 315BC UT WOS:000087091900022 ER PT J AU Biglarbigi, K Mohan, H Ray, RM Meehan, DN AF Biglarbigi, K Mohan, H Ray, RM Meehan, DN TI Potential for horizontal-well technology in the US SO JOURNAL OF PETROLEUM TECHNOLOGY LA English DT Article; Proceedings Paper CT SPE/DOE Improved Oil Recovery Symposium CY APR 03-05, 2000 CL TULSA, OKLAHOMA SP SPE, DOE AB Application of horizontal wells has increased tremendously and had significant and positive results in the: U.S. over the past decade. The pace of horizontal drilling for oil has remained high since 1990 (approximately 600 to 1,000 wells/yr). Most of these wells have been drilled in three formations: the Austin chalk in Texas (79%), the Bakken shale in North Dakota (5%), and the Niobrara in Colorado and Wyoming (2%). Wells drilled in other formations constitute approximately 14%. The Dept. of Energy Natl. Petroleum Technology Office (DOE/NPTO), working closely with industry developed a unique analytical system (including models and database) to assess the potential for wider application of this technology to the balance of remaining U.S. oil resources across a variety of formations. The findings of the DOE effort are the primary scope of this paper. C1 Intek Inc, Fairfax, VA USA. US DOE, Tulsa, OK USA. Union Pacific Resources Inc, Ft Worth, TX USA. RP Biglarbigi, K (reprint author), Intek Inc, Fairfax, VA USA. NR 7 TC 0 Z9 0 U1 0 U2 5 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 0149-2136 J9 J PETROL TECHNOL JI J. Pet. Technol. PD JUN PY 2000 VL 52 IS 6 BP 68 EP + PG 6 WC Energy & Fuels; Engineering, Chemical; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA 321PN UT WOS:000087464000022 ER PT J AU Thoman, JW McIlroy, A AF Thoman, JW McIlroy, A TI Absolute CH radical concentrations in rich low-pressure methane-oxygen-argon flames via cavity ringdown spectroscopy of the A(2)Delta-(XII)-I-2 transition SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID LASER-ABSORPTION SPECTROSCOPY; HIGHLY PREDISSOCIATIVE LEVELS; DOWN SPECTROSCOPY; INDUCED FLUORESCENCE; AIR FLAMES; OBSERVABLES; SCATTERING; (CH2)-C-1; SYSTEM; STATE AB We measure absolute methylidyne (CH) radical concentrations in a series of rich 31.0 Torr (4.13 kPa) methane-oxygen-argon flames using cavity ringdown spectroscopy. Probing via the CH A(2)Delta-X(2)Pi transition near 430 nm gives a sensitivity of 3 x 10(9) cm(-3) for our experimental conditions, yielding a signal-to-noise ratio greater than 1000 for the strongest transitions observed. We measure profiles of CH mole fraction as a function of height above a flat-flame burner for rich flames with equivalence ratios of 1.0, 1.2, 1.4, and 1.6. These flames are modeled using the following mechanisms: (1) the GRI Mech 2.11, (2) a mechanism by Prada and Miller, (3) a modified GRI2.11 mechanism, which employs a more realistic increased CH + O-2 rate coefficient, and (4) the new GRI Mech 3.0. Generally good agreement between the models and the data is found, with the GRI 3.0 and modified 2.11 mechanisms best reproducing the data. The greatest discrepancies are observed at the richest stoichiometry, where all of the models predict a wider CH profile shifted further from the burner than experimentally observed. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Williams Coll, Dept Chem, Williamstown, MA 01267 USA. RP McIlroy, A (reprint author), Sandia Natl Labs, Combust Res Facil, MS 9055,POB 969, Livermore, CA 94551 USA. NR 53 TC 39 Z9 40 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 1 PY 2000 VL 104 IS 21 BP 4953 EP 4961 DI 10.1021/jp0001687 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 320WQ UT WOS:000087424200019 ER PT J AU Henning, RW Schultz, AJ Thieu, V Halpern, Y AF Henning, RW Schultz, AJ Thieu, V Halpern, Y TI Neutron diffraction studies of CO2 clathrate hydrate: Formation from deuterated ice SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CARBON-DIOXIDE; TRICALCIUM SILICATE; MECHANICAL-PROPERTIES; SUPERHEATED ICE; DEEP OCEAN; WATER; CRYSTALLIZATION; SPECTROSCOPY; SCATTERING; KINETICS AB The formation of CO2 clathrate hydrate was investigated by using time-of-flight neutron powder diffraction at temperatures ranging from 230 to 290 K with a CO2 gas pressure of 900 psi. CO2 elathrate hydrate was prepared in situ from deuterated ice crystals at 230, 243, 253, and 263 K by pressurizing the system with CO2 gas to produce the hydrate in approximately 70% yield. Nearly complete conversion from the hexagonal ice to the sI type CO2 hydrate was observed as the temperature of the sample was slowly increased through the melting point of D2O ice. The conversion of ice into hydrate is believed to be a two-stage process in which an initial fast conversion rate is followed by a slower, diffusion-limited rate. On the basis of a shrinking core diffusion model, an activation energy of 6.5 kcal/mol was obtained from the temperature dependence of the reaction. Our findings suggest that the formation of the hydrate is through a reaction between CO2 and water molecules in the quasi-liquid layer (QLL). The CO2 hydrate remained stable following removal of excess liquid CO2 and subsequent pressurization with helium, allowing for a low-temperature (14 K) structure analysis from powder diffraction data without the presence of solid CO2. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. RP Halpern, Y (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 34 TC 91 Z9 97 U1 1 U2 29 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 1 PY 2000 VL 104 IS 21 BP 5066 EP 5071 DI 10.1021/jp0001642 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 320WQ UT WOS:000087424200032 ER PT J AU Vargas, R Garza, J Dixon, DA Hay, BP AF Vargas, R Garza, J Dixon, DA Hay, BP TI Conformational analysis of N,N,N ',N '-tetramethylsuccinamide: The role of C-H center dot center dot center dot O hydrogen bonds SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY FUNCTIONAL CALCULATIONS; METAL-AMIDE COMPLEXES; BASIS-SETS; MOLECULAR CALCULATIONS; ENERGY; APPROXIMATION; PREFERENCES; CLUSTERS; ATOMS; BORON AB We report a conformational analysis of N,N,N',N'-tetramethylsuccinamide. An initial set of geometries was obtained through an exhaustive conformer search with molecular mechanics. The structures were further optimized using density functional theory (DFT) with the generalized-gradient approximation. Single-point energies on the DFT geometries are reported at the second-order Moller-Plesset (MP2) levels. The lowest energy conformations were further optimized at the MP2 level. Geometries and relative energies for 22 conformations are reported. The geometries are rationalized in terms of rotational potential energy surfaces in simple compounds, intramolecular C-H ... O hydrogen bonding, and dipole-dipole repulsion. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Autonoma Metropolitana Iztapalapa, Div Ciencias Basicas & Ingn, Dept Quim, Mexico City 09340, DF, Mexico. RP Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Garza, Jorge/H-9395-2016; Garza-Olguin, Jorge/N-3106-2016 OI Garza, Jorge/0000-0003-4249-6078; Garza-Olguin, Jorge/0000-0003-4249-6078 NR 34 TC 29 Z9 29 U1 1 U2 4 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 1 PY 2000 VL 104 IS 21 BP 5115 EP 5121 DI 10.1021/jp000030o PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 320WQ UT WOS:000087424200039 ER PT J AU Bedrov, D Borodin, O Smith, GD Trouw, F Mayne, C AF Bedrov, D Borodin, O Smith, GD Trouw, F Mayne, C TI Simulation and QENS studies of molecular dynamics in aqueous solutions of 1,2-dimethoxyethane SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID EFFECTIVE PAIR POTENTIALS; LIQUID WATER; FIELD AB We compare the composition dependence of the self-diffusion coefficient of water in aqueous solutions of 1,2-dimethoxyethane (DME) as obtained from incoherent quasielastic neutron scattering measurements and molecular dynamics simulations. Simulations were performed using the TIP4P water model and a quantum chemistry based potential for DME and DME/water interactions. Excellent agreement is seen between experiment and simulation, including the minimum in the water self-diffusion coefficient at X-DME approximate to 0.2 predicted by our earlier simulations. Further, we investigated the influence of the water potential on molecular dynamics in DME aqueous solutions by performing simulations using the SPC, SPC/E, and MCY water models. The SPC and MCY models yielded a water self-diffusion coefficient as a function of composition in qualitative agreement with experiment, including the before mentioned minimum. Quantitative agreement with experiment is poorer for these potentials than for the TIP4P model. Surprisingly, simulations employing the SPC/E model, known to provide the best description of self-diffusion in pure water, showed a qualitatively incorrect dependence of water self-diffusion on composition. The failure of the SPC/E water model was attributed to overestimation of the strength of water-water interactions. 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, Manuel Lujan Jr Neutron Scattering Ctr, LANSCE 12, Los Alamos, NM 87545 USA. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. RP Smith, GD (reprint author), Univ Utah, Dept Mat Sci & Engn, 122 S Cent Campus Dr,Room 304, Salt Lake City, UT 84112 USA. RI Borodin, Oleg/B-6855-2012; Lujan Center, LANL/G-4896-2012 OI Borodin, Oleg/0000-0002-9428-5291; NR 17 TC 14 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 1 PY 2000 VL 104 IS 21 BP 5151 EP 5154 DI 10.1021/jp994167u PG 4 WC Chemistry, Physical SC Chemistry GA 320WU UT WOS:000087424500018 ER PT J AU Greatbatch, RJ Nadiga, BT AF Greatbatch, RJ Nadiga, BT TI Four-gyre circulation in a barotropic model with double-gyre wind forcing SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID QUASI-GEOSTROPHIC OCEAN; MULTIPLE EQUILIBRIA; POTENTIAL VORTICITY; REDUCED-GRAVITY; INERTIAL GYRES; DRIVEN; TURBULENCE; RECIRCULATION; EMERGENCE; FLOWS AB Results from a barotropic vorticity equation model driven by symmetric, double-gyre wind forcing are described. The authors work in a regime in which the model reaches a state of turbulent equilibrium. The time-average of the statistically steady state exhibits a four-gyre structure, in contrast to the usual two gyres associated with symmetric double-gyre wind forcing. The four-gyre structure is found in model runs using either free-slip or superslip boundary conditions, and with either Laplacian or biharmonic mixing for the dissipation. It is shown that the vorticity budget of both the inner and outer gyres is dominated by a balance between the wind stress curl and the divergence of the eddy potential vorticity flux, with the explicit dissipation playing a much smaller role. The two inner gyres circulate in the same sense as the wind stress curl and are equilibriated, for the most part, by the eddy flux of potential vorticity. The outer gyres, on the other hand, circulate in the opposite sense to the wind stress curl and are driven by the eddy flux of potential vorticity. It is shown that the gross features of the time-averaged state can be reproduced by a parameterized model in which the divergent part of the potential vorticity flux is represented as a downgradient transfer, and a boundary condition of no normal flux of potential vorticity is applied along the model boundaries. In contrast to the eddy resolving model, the four-gyre structure in the parameterized model depends strongly on the choice of side boundary condition. C1 Dalhousie Univ, Dept Oceanog, Halifax, NS B3H 4J1, Canada. Los Alamos Natl Lab, Los Alamos, NM USA. RP Greatbatch, RJ (reprint author), Dalhousie Univ, Dept Oceanog, Halifax, NS B3H 4J1, Canada. EM richard.greatbatch@dal.ca NR 23 TC 23 Z9 23 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD JUN PY 2000 VL 30 IS 6 BP 1461 EP 1471 DI 10.1175/1520-0485(2000)030<1461:FGCIAB>2.0.CO;2 PG 11 WC Oceanography SC Oceanography GA 330KF UT WOS:000087960700019 ER PT J AU Garner, J Pekarek, T Benedek, R AF Garner, J Pekarek, T Benedek, R TI Specific heat of proximity-coupled superconducting multilayers SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE Ginzburg-Landau equations; specific heat; multilayers; superconductivity ID CRITICAL FIELDS AB The Ginzburg-Landau equations have been solved numerically for Pb-Sn and Nb-Zr multilayer systems. The calculated specific heats as a function of temperature are found to be in good agreement with experiment. In particular, the proximity-effect broadened Sn transition near T = 3 K in the Pb-Sn systems is well reproduced by the calculations. (C) 2000 Published by Elsevier Science Ltd. All rights reserved. C1 Univ N Florida, Dept Nat Sci, Jacksonville, FL 32224 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Garner, J (reprint author), Univ N Florida, Dept Nat Sci, 4567 St Johns Bluff Rd, Jacksonville, FL 32224 USA. EM jgarner@unf.edu NR 14 TC 0 Z9 0 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD JUN PY 2000 VL 61 IS 6 BP 979 EP 984 DI 10.1016/S0022-3697(99)00243-7 PG 6 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 310JX UT WOS:000086823700021 ER PT J AU Lindenbaum, SJ Longacre, RS AF Lindenbaum, SJ Longacre, RS TI Possible striking signals for a quark-gluon plasma at RHIC SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID NUCLEUS COLLISIONS; PARTON; MODEL; DYNAMICS; CASCADES AB We believe that one can have serious reservations as to whether heavy ion collisions (e.g. 100 GeV/n Au + 100 GeV/n Au) can lead to thermal and chemical equilibrium over large regions (particularly if it is assumed that this happens whenever QGP is produced at RHIC-that is, if it is produced). It is at present nor clear that the collision dynamics and times available will lead to this. An alternative scenario has been proposed by Van Hove where localized-in-rapidity bubbles of plasma may well be more probable, and may well occur at least some of the time, and some of the time mainly survive to the final state. We have developed a series of event generators to extend and describe these phenomena. A Van Hove-type (Van Hove L 1983 Z. Phys. C 21 93-8; 1984 Report CERN-TH 3924; 1987 Nucl. Phys. A 46) spherical bubble at eta = 0 is embedded in a reasonable event generator in qualitative agreement with Hijing etc (Wang X N and Gyulassy M 1991 Phys. Rev. D 44 3501; 1992 Phys. Rev D 45 844; 1994 Comput. Phys. Commun. 83 307). The plasma bubble hadronized at a temperature of 170 MeV according to the model developed by Koch et al (Koch P, Muller B and Rafelski J 1986 Phys. Rev. 142 167). The amount of available energy assumed in the bubble is selected as that in a small central circular cross section of radius approximate to 1.3 fm or approximate to 2.5 fm in 100 GeV/n Au + Au central events. The results predict (with the assumptions stated, possible) striking signals which may allow strong evidence for a QGP which cannot be explained by alternative conventional physics arguments, and thus may be crucial elements in establishing a QGP. We are also applying these techniques to investigating Kharzeev and Pisarski bubbles of metastable vacua with odd CP. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. CUNY City Coll, New York, NY 10031 USA. RP Lindenbaum, SJ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 42 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD JUN PY 2000 VL 26 IS 6 BP 937 EP 956 DI 10.1088/0954-3899/26/6/314 PG 20 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 326GB UT WOS:000087723400019 ER PT J AU Fajer, J AF Fajer, J TI Structural effects in chemistry and biology SO JOURNAL OF PORPHYRINS AND PHTHALOCYANINES LA English DT Article; Proceedings Paper CT 1st International Conference on Porphyrins and Phthalocyanines (ICPP-1) CY JUN 25-30, 2000 CL DIJON, FRANCE DE non-planar porphyrins; conformational effects; photosynthesis; catalysis ID PHOTOSYNTHETIC REACTION-CENTER; RHODOBACTER-SPHAEROIDES R-26; PI-CATION RADICALS; NONPLANAR PORPHYRINS; CRYSTAL-STRUCTURE; RHODOPSEUDOMONAS-VIRIDIS; MOLECULAR-STRUCTURE; CONFORMATIONAL FLEXIBILITY; TRIPLE-RESONANCE; STATE AB Conformationally designed, non-planar porphyrins afford new classes of structurally distinct chromophores with significantly altered optical, redox, magnetic, radical and excited state properties. The synthetic, non-planar porphyrins model and illustrate the consequences of the skeletal deformations and plasticity increasingly observed in crystal structures of protein complexes comprising porphyrinic chromophores and prosthetic groups. Conformational variations thus offer attractively simple mechanisms for modulating the physicochemical properties of porphyrins in vivo and in vitro. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Fajer, J (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 46 TC 26 Z9 27 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1088-4246 J9 J PORPHYR PHTHALOCYA JI J. Porphyr. Phthalocyanines PD JUN-JUL PY 2000 VL 4 IS 4 BP 382 EP 385 DI 10.1002/(SICI)1099-1409(200006/07)4:4<382::AID-JPP237>3.3.CO;2-5 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 312MD UT WOS:000086946300017 ER PT J AU Shelnutt, JA AF Shelnutt, JA TI Molecular simulations of porphyrins and heme proteins SO JOURNAL OF PORPHYRINS AND PHTHALOCYANINES LA English DT Article; Proceedings Paper CT 1st International Conference on Porphyrins and Phthalocyanines (ICPP-1) CY JUN 25-30, 2000 CL DIJON, FRANCE DE molecular mechanics; molecular dynamics; porphyrins; hemeproteins; normal-coordinate structural decomposition; porphyrin conformation and dynamics ID NICKEL(II) PORPHYRINS; MECHANICS; DISTORTIONS; MACROCYCLE; METALLOPORPHYRINS; CONFORMATION; CARBON; MODELS; OXYGEN; TERMS AB An overview of the use of classical mechanical molecular simulations of porphyrins, hydroporphyrins and heme proteins is given. The topics cover molecular mechanics calculations of structures and conformer energies of porphyrins, energies of barriers for interconversion between stable conformers, molecular dynamics of porphyrins and heme proteins, and normal-coordinate structural analysis of experimental and calculated porphyrin structures. Molecular mechanics and dynamics are currently a fertile area of research on porphyrins. In the future, other computational methods such as Monte Carlo simulations, which have yet to be applied to porphyrins, will come into use and open new avenues of research into molecular simulations of porphyrins. Copyright (C) 2000 John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Biomol Mat & Interfaces Dept, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. RP Shelnutt, JA (reprint author), Sandia Natl Labs, Biomol Mat & Interfaces Dept, POB 5800, Albuquerque, NM 87185 USA. RI Shelnutt, John/A-9987-2009 OI Shelnutt, John/0000-0001-7368-582X NR 27 TC 12 Z9 12 U1 0 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1088-4246 J9 J PORPHYR PHTHALOCYA JI J. Porphyr. Phthalocyanines PD JUN-JUL PY 2000 VL 4 IS 4 BP 386 EP 389 DI 10.1002/(SICI)1099-1409(200006/07)4:4<386::AID-JPP241>3.0.CO;2-J PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 312MD UT WOS:000086946300018 ER PT J AU Morel, JE AF Morel, JE TI Diffusion-limit asymptotics of the transport equation, the P-1/3 equations, and two flux-limited diffusion theories SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB We compare the asymptotic accuracy of one variant of P-1 theory and two variants of grey diffusion theory in the equilibrium diffusion limit. All of these variants were developed to yield the correct radiation propagation speed in the optically thin streaming limit while presumably retaining full accuracy in the equilibrium diffusion limit. Accuracy in the equilibrium diffusion limit has traditionally meant reproducing the exact transfer asymptotics to leading (zeroth) order. We show that the exact asymptotics must be reproduced to first order to yield full accuracy in the equilibrium diffusion limit. The P-1 variant and one of the grey diffusion variants that we analyze yield first-order accuracy while the other grey diffusion variant yields only zeroth-order accuracy. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Morel, JE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,Mail Stop D409, Los Alamos, NM 87545 USA. NR 4 TC 37 Z9 38 U1 1 U2 3 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 JUN 1 PY 2000 VL 65 IS 5 BP 769 EP 778 DI 10.1016/S0022-4073(99)00148-X PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 290UM UT WOS:000085696300004 ER PT J AU Choe, DO Slaughter, DM Weaver, KD AF Choe, DO Slaughter, DM Weaver, KD TI Utilizing distinct neutron spectra and a system of equations to differentiate competing reactions in activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 10th International Conference on Modern Trends in Activation Analysis (MTAA-10) CY APR 19-23, 1999 CL NIH, BETHESDA, MARYLAND SP Natl Inst Stand & Technol HO NIH AB In activation analysis, the continuous neutron spectrum produced in a nuclear reactor can be both beneficial and detrimental. A continuous spectrum allows for activation of particular elements by using any number of neutron energies. However, upper threshold energies exist for most elements where reactions other than an (n, gamma) absorption will occur. In this situation, two different parent nuclides can be activated to the same product, which creates a problem in performing a quantitative analysis of one or the other nuclide. A methodology is presented where a system of equations is used to solve for the quantities of both nuclides by using different irradiation ports, and using specific neutron filters to "customize" the neutron flux. C1 Univ Utah, CENTER, Dept Civil & Environm Engn, Salt Lake City, UT 84112 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Choe, DO (reprint author), Univ Utah, CENTER, Dept Civil & Environm Engn, 160 S Cent Campus Dr RM 104, Salt Lake City, UT 84112 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUN PY 2000 VL 244 IS 3 BP 681 EP 683 DI 10.1023/A:1006770813063 PG 3 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 338GM UT WOS:000088410800037 ER PT J AU Salem-Sugui, S Goretta, KC AF Salem-Sugui, S Goretta, KC TI Effect of short-time magnetic relaxation on hysteresis curves in single-crystal Bi2Sr2CaCu2Ox SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE Bi2Sr2CaCu2Ox; relaxation; hysteresis curves ID FLUX-CREEP; CU-O; CROSSOVER; PEAK; BEHAVIOR AB We have studied the role of short relaxation time on magnetic hysteresis in a Bi2Sr2CaCu2Ox single crystal. Effects were examined by comparing isothermal magnetization curves obtained over a range of temperatures as a function of the applied magnetic field, H, for magnetic field ramp rates of 3 and 30 Oe/s. At low temperature, a second magnetization peak, H-p, was produced by differences in magnetic relaxation occurring over a short period during the initial stage of relaxation. The data suggested an absence of pinning crossover for H approximate to H-p. C1 UFRJ, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Salem-Sugui, S (reprint author), UFRJ, Inst Fis, CP 68528, BR-21945970 Rio De Janeiro, Brazil. NR 19 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 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 2000 VL 13 IS 3 BP 367 EP 370 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 336MQ UT WOS:000088306600006 ER PT J AU Bussmann-Holder, A Simon, A Buttner, H Bishop, AR AF Bussmann-Holder, A Simon, A Buttner, H Bishop, AR TI Lattice and polarizability effects on singlet and triplet states in an effective hamiltonian for high-T-c cuprates SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE electron-phonon injection; superconductivity ID PHASE-TRANSITIONS; SUPERCONDUCTIVITY; OXIDES; HOLE; TEMPERATURE; OXYGEN; MODEL AB From various theoretical approaches it seems to be rather well established that the Zhang-Rice (ZR) singlet state should play an important role in doped high-temperature superconducting (HTSC) oxides. Yet the conclusion that a one-band model is capable of describing many of the unusual physics observed in HTSC compounds has been questioned because the p(z) states of the oxygen atoms in the planes;as well as those of the apical oxygen atoms hybridize with the Cu d(3z2-r2) orbitals and induce a mixing of the in-plane states with the out-of-plane bands. It is shown that electron-lattice coupling and polarizability effects modify the electronic structure of the effective Hamiltonian considered here. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Bayreuth, Lehrstuhl Theoret Phys 1, D-95440 Bayreuth, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bussmann-Holder, A (reprint author), Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. NR 24 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 2000 VL 13 IS 3 BP 491 EP 496 DI 10.1023/A:1007727714453 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 336MQ UT WOS:000088306600025 ER PT J AU Berryman, JG Berge, PA Bonner, BP AF Berryman, JG Berge, PA Bonner, BP TI Transformation of seismic velocity data to extract porosity and saturation values for rocks SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ELASTIC WAVE-PROPAGATION; FLUID DISTRIBUTION; COMPRESSIONAL-WAVE; POROUS-MEDIA; PORE-FLUID; ATTENUATION; COMPRESSIBILITY; SANDSTONES; DEPENDENCE; LIMESTONES AB For wave propagation at low frequencies in a porous medium, the Gassmann-Domenico relations are well-established for homogeneous partial saturation by a liquid. They provide the correct relations for seismic velocities in terms of constituent bulk and shear moduli, solid and fluid densities, porosity and saturation. It has not been possible. however, to invert these relations easily to determine porosity and saturation when the seismic velocities are known. Also, the state (or distribution) of saturation, i.e., whether or not liquid and gas are homogeneously mixed in the pore space, is another important variable for reservoir evaluation. A reliable ability to determine the state of saturation from velocity data continues to be problematic. It is shown how transforming compressional and shear wave velocity data to the (rho/lambda,mu/lambda)-plane (where lambda and mu are the Lame parameters and rho is the total density) results in a set of quasi-orthogonal coordinates for porosity and liquid saturation that greatly aids in the interpretation of seismic data for the physical parameters of most interest. A second transformation of the same data then permits isolation of the liquid saturation value. and also provides some direct information about the state of saturation. By thus replotting the data in the (lambda/mu, rho/mu)-plane, inferences can be made concerning the degree of patchy (inhomogeneous) versus homogeneous saturation that is present in the region of the medium sampled by the data. Our examples include igneous and sedimentary rocks, as well as man-made porous materials. These results have potential applications in various areas of interest, including petroleum exploration and reservoir characterization. geothermal resource evaluation, environmental restoration monitoring, and geotechnical site characterization. (C) 2000 Acoustical Society of America. [S0001-4966(00)05306-6]. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. RI Berryman, James/A-9712-2008 NR 37 TC 21 Z9 22 U1 0 U2 4 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 EI 1520-8524 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 2000 VL 107 IS 6 BP 3018 EP 3027 DI 10.1121/1.429331 PG 10 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 322KE UT WOS:000087508100007 ER PT J AU Backhaus, S Swift, GW AF Backhaus, S Swift, GW TI A thermoacoustic-Stirling heat engine: Detailed study SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PULSE TUBE REFRIGERATORS; POWER AB A new type of thermoacoustic engine based on traveling waves and ideally reversible heat transfer is described. Measurements and analysis of its performance are presented. This new engine outperforms previous thermoacoustic engines, which are based on standing waves and intrinsically irreversible heat transfer, by more than 50%. At its most efficient operating point, it delivers 710 W of acoustic power to its resonator with a thermal efficiency of 0.30, corresponding to 41% of the Carnot efficiency. At its most powerful operating point, it delivers 890 W to its resonator with a thermal efficiency of 0.22. The efficiency of this engine can be degraded by two types of acoustic streaming. These are suppressed by appropriate tapering of crucial surfaces in the engine and by using additional nonlinearity to induce an opposing time-averaged pressure difference. Data are presented which show the nearly complete elimination of the streaming convective heat loads. Analysis of these and other irreversibilities show which components of the engine require further research to achieve higher efficiency. Additionally, these data show that the dynamics and acoustic power flows are well understood, but the details of the streaming suppression and associated heat convection are only qualitatively understood. (C) 2000 Acoustical Society of America. [S0001-4966(00)00206-X]. C1 Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Backhaus, S (reprint author), Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. RI Backhaus, Scott/F-4285-2012 NR 30 TC 232 Z9 288 U1 12 U2 82 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 2000 VL 107 IS 6 BP 3148 EP 3166 DI 10.1121/1.429343 PG 19 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 322KE UT WOS:000087508100020 ER PT J AU Chou, YS Stevenson, JW Armstrong, TR Pederson, LR AF Chou, YS Stevenson, JW Armstrong, TR Pederson, LR TI Mechanical properties of La1-xSrxCo0.2Fe0.8O3 mixed-conducting perovskites made by the combustion synthesis technique SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE-TOUGHNESS; LANTHANUM CHROMITE; OXIDES; CELLS AB This paper examined the room-temperature mechanical properties of a mixed-conducting perovskite La1-xSrxCo0.2Fe0.8O3 (x = 0.2-0.8), Powders were made by the combustion synthesis technique and sintered at 1250 degrees C in air, Sintered density, crystal phase, and grain size were characterized. Young's and shear moduli, microhardness, indentation fracture toughness, and biaxial flexure strength were determined. The Young's and shear moduli slightly increased with increasing strontium content. Young's modulus of 151-188 GPa and shear modulus of 57-75 GPa were measured, Biaxial flexure strength of similar to 160 MPa was measured for lower strontium content batches. Strength greatly decreased to similar to 40 MPa at higher strontium concentrations (x = 0.6-0.8) because of the formation of extensive cracking, Indentation toughness showed a higher value (similar to 1.5 MPa.m(1/2)) for low strontium (x = 0.2) content and a lower value (similar to 1.1 MPa.m(1/2)) for the other batches (x = 0.4-0.8), Materials with fine and coarse grain size were also tested at various indent loads and showed no dependence of toughness on crack size. In addition, fractography was used to characterize the critical flaw and fracture mode. C1 Pacific NW Lab, Dept Mat, Richland, WA 99352 USA. RP Chou, YS (reprint author), Pacific NW Lab, Dept Mat, POB 999, Richland, WA 99352 USA. RI pelosato, renato/E-9950-2010 NR 32 TC 57 Z9 59 U1 1 U2 5 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 JUN PY 2000 VL 83 IS 6 BP 1457 EP 1464 PG 8 WC Materials Science, Ceramics SC Materials Science GA 325AW UT WOS:000087655000023 ER PT J AU Miller, NL Kim, J AF Miller, NL Kim, J TI Climate change sensitivity analysis for two California watersheds: Addendum to downscaled climate and streamflow study of the southwestern United States (vol 35, pg 1525, 1999) SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Correction AB In the December 1999 JAWRA Special Issue on Water Resources and Climate Change, Miller et al., presented an overview of downscaled climate and streamflow study of the southwestern United States. This manuscript included an initial sensitivity study of a doubled atmospheric carbon dioxide concentration on western U.S. precipitation and streamflow. In the published manuscript, Figure 12a shows the mean annual precipitation for 1981 to 1984 and Figure 15 shows the mean annual precipitation difference between the downscaled control simulation and the 2xCO(2) projection. Both Figure 12a and Figure 15 are in units of mm/month. These units are incorrect, the correct units are mm/year. An additional California watershed is included here, as is more analysis of the streamflow result due to climate change. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Reg Climate Ctr, Berkeley, CA 94720 USA. RP Miller, NL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Reg Climate Ctr, 90-1116,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Miller, Norman/E-6897-2010 NR 5 TC 3 Z9 4 U1 0 U2 0 PU AMER WATER RESOURCES ASSOC PI MIDDLEBURG PA 4 WEST FEDERAL ST, PO BOX 1626, MIDDLEBURG, VA 20118-1626 USA SN 1093-474X J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD JUN PY 2000 VL 36 IS 3 BP 657 EP 661 DI 10.1111/j.1752-1688.2000.tb04295.x PG 5 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 328HL UT WOS:000087844600017 ER PT J AU Song, L Evans, JW AF Song, L Evans, JW TI Electrochemical-thermal model of lithium polymer batteries SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTROLYTE BATTERIES; ION CELLS; CONDUCTIVITY; TEMPERATURE; DISCHARGE; MODULE AB A mathematical model has been developed to study heat transfer and thermal management of lithium polymer batteries. Temperature dependent parameters including the diffusion coefficient of lithium ions, ionic conductivity of lithium ions, transference number of lithium ions, etc., have been added to a previously developed electrochemical model to more completely characterize the thermal behavior of the Lithium polymer system. In addition, experimental studies of the discharge behavior and heat generation rate of lithium polymer cells have been conducted. Comparisons between experimental and mathematical results are presented. Finally different thermal management approaches are discussed. (C) 2000 The Electrochemical Society. S0013-4651(98)11-046-7. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Song, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 21 TC 118 Z9 118 U1 5 U2 50 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 JUN PY 2000 VL 147 IS 6 BP 2086 EP 2095 DI 10.1149/1.1393490 PG 10 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 323JG UT WOS:000087561800014 ER PT J AU Mansour, AN Yang, XQ Sun, X McBreen, J Croguennec, L Delmas, C AF Mansour, AN Yang, XQ Sun, X McBreen, J Croguennec, L Delmas, C TI In situ X-ray absorption spectroscopy study of Li(1-z)Ni(1+z)O2 (z <= 0.02) cathode material SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID FINE-STRUCTURE; LI DEINTERCALATION; SPECTRA; NICKEL; OXYCOMPOUNDS; LINIO2; EXAFS; DIFFRACTION; BEHAVIOR; STATE AB In situ X-ray absorption spectroscopy study of Li(0.98-x)Ni1.02O2 phases shows that the Ni K edge continuously shifts to higher energies with a decrease in Li content in a manner consistent with oxidation of Ni(III) to Ni(IV). The Ni K-edge energy for Ni1.02O2 is consistent with that observed for chemically prepared quadrivalent Ni in KNiIO6. Variations in the coordination numbers, bond lengths, and disorders as a function of state of charge (i.e., the value of x) are consistent with the following facts: (i) a Jahn-Teller distortion for Ni(III), (ii) an undistorted environment for Ni(IV), and (iii) an electrochemical oxidation of Ni(III) to Ni(IV). (C) 2000 The Electrochemical Society. S0013-4651(99)12-107-4. All rights reserved. C1 USN, Surface Warfare Ctr, Carderock Div, Bethesda, MD 20817 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. CNRS, Inst Chim Mat Condensee, F-33608 Pessac, France. Ecole Natl Super Chim & Phys Bordeaux, F-33608 Pessac, France. RP USN, Surface Warfare Ctr, Carderock Div, Bethesda, MD 20817 USA. EM mansouran@nswccd.navy.mil RI Laurence, CROGUENNEC/E-4558-2010; Croguennec, Laurence/R-9512-2016 OI Croguennec, Laurence/0000-0002-3018-0992 NR 28 TC 42 Z9 42 U1 1 U2 15 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2000 VL 147 IS 6 BP 2104 EP 2109 DI 10.1149/1.1393492 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 323JG UT WOS:000087561800016 ER PT J AU Zaghib, K Nadeau, G Kinoshita, K AF Zaghib, K Nadeau, G Kinoshita, K TI Effect of graphite particle size on irreversible capacity loss SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LITHIUM-ION BATTERIES; RECHARGEABLE BATTERIES; SURFACE-STRUCTURE; CARBON; INTERCALATION; ANODE AB Electrolyte decomposition and irreversible capacity loss (ICL) occur on carbon electrodes in Li-ion cells. The nature of the surface sites and their role in the amount of electrolyte decomposition on carbon electrodes is not fully understood. Therefore, a study was undertaken to analyze the relationship between the ICL and the active sires on natural graphite of prismatic structure. The ICL was measured on natural graphite of predominantly two-dimensional platelets of average particle size varying from 2 to 40 mu m. The fraction of edge and basal plane sites was determined for ideal prismatic structures of different particle size and used as a model for the natural graphite particles. This analysis permitted an analysis of the relationship between the electrolyte decomposition and the distribution of surface sites. From this analysis we conclude that these sites play an important role in the magnitude of the irreversible capacity loss on natural graphite. (C) 2000 The Electrochemical Society. S0013-4651(99)08-066-0. All rights reserved. C1 Inst Rech Hydro Quebec, Varennes, PQ J3X 1S1, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Zaghib, K (reprint author), Inst Rech Hydro Quebec, 1800 Montee Ste Julie, Varennes, PQ J3X 1S1, Canada. NR 25 TC 76 Z9 80 U1 1 U2 27 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 JUN PY 2000 VL 147 IS 6 BP 2110 EP 2115 DI 10.1149/1.1393493 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 323JG UT WOS:000087561800017 ER PT J AU Davenport, AJ Oblonsky, LJ Ryan, MP Toney, MF AF Davenport, AJ Oblonsky, LJ Ryan, MP Toney, MF TI The structure of the passive film that forms on iron in aqueous environments SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ENHANCED RAMAN-SPECTROSCOPY; ION MASS-SPECTROMETRY; X-RAY-DIFFRACTION; IN-SITU XANES; BORATE BUFFER; OXIDE FILM; GALVANOSTATIC REDUCTION; MOSSBAUER-SPECTROSCOPY; POTENTIAL DEPENDENCE; CATHODIC REDUCTION AB In situ surface X-ray diffraction was used to identify the detailed structure of the passive film that forms on (001)- and (110)-oriented iron single crystals in a borate buffer solution at +0.4 V vs. mercurous sulfate reference electrode, a high passive potential. The passive film is a new phase: a spinel with a fully occupied oxygen lattice, octahedral site occupancy of 80 +/- 10%, tetrahedral site occupancy of 66 +/- 10%, and an octahedral interstitial sire occupancy of 12 +/- 4%. The passive film forms with an epitaxial relationship to the substrate iron; for growth on Fe(001), film(001)parallel to Fe(001) and film[1 (1) over bar 0]parallel to Fe[100], while for growth on Fe(110), film(111)parallel to Fe(110) and film[1 (1) over bar 0]parallel to Fe[100]. The in-plane lattice parameter for the passive film (the LAMM phase) is 8.39 +/- 0.01 Angstrom for growth on both faces, and the out-of-plane lattice parameter is 8.25 +/- 0.1 Angstrom [Fe(001)] and 8.42 +/- 0.1 Angstrom [Fe(110)]. The passive film forms a nanocrystalline microstructure with numerous defects. Specifically, the grain size is 50-80 Angstrom in-plane and about 30 Angstrom out-of-plane. There is a small mosaic spread of 2.5 to 4.1 degrees and a high density of antiphase boundaries and stacking faults. The structure of the film determined in situ was found to be identical to that found for an emersed sample, indicating that the high potential film studied here is stable on removal from the electrolyte. Some of the implications of the film structure on passivity are discussed. (C) 2000 The Electrochemical Society. S0013-4651(99)10-042-9. Ail rights reserved. C1 Univ Birmingham, Sch Met & Mat, Birmingham B15 2TT, W Midlands, England. DuPont Co Inc, Cent Res & Dev, Wilmington, DE 19880 USA. Brookhaven Natl Lab, Dept Appl Sci, Div Mat Sci, Upton, NY 11973 USA. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. RP Univ Birmingham, Sch Met & Mat, POB 363, Birmingham B15 2TT, W Midlands, England. EM lucy.j.oblonsky@usa.dupont.com RI Davenport, Alison/J-6089-2013 OI Davenport, Alison/0000-0003-0853-515X NR 73 TC 156 Z9 161 U1 5 U2 64 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUN PY 2000 VL 147 IS 6 BP 2162 EP 2173 DI 10.1149/1.1393502 PG 12 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 323JG UT WOS:000087561800026 ER PT J AU Jennings, JD Rubinstein, FM DiBartolomeo, D Blanc, SL AF Jennings, JD Rubinstein, FM DiBartolomeo, D Blanc, SL TI Comparison of control options in private offices in an advanced lighting controls testbed SO JOURNAL OF THE ILLUMINATING ENGINEERING SOCIETY LA English DT Article AB In a major test of different lighting control technologies in a typical office building, we present analyses of seven months' results from five control scenarios in private offices. We compare the energy savings and effectiveness of various combinations of occupant detection, daylight dimming, and switching techniques. Comparing measured energy use with occupant sensors against baseline energy use calculated using wall switch operation only, we found occupant sensors saved 20-26 percent lighting energy compared to manual switching alone. In offices where light sensor controls were: installed and properly commissioned, additional savings up to 27 percent for a total of 46 percent were obtained over a seven-month period, even in an area with unusually high minimum lighting requirements. Dimming the lighting system to desired task levels (task tuning) also resulted in significant (23 percent additional, 43 percent total) energy savings in over lighted areas. On the base case floor, where only bi-level switches were installed, we found significant usage of only one switch resulting in an additional 23 percent savings over single-level switches, an unexpected result with implications for building code requirements. We found the energy savings due to occupant sensing vs. dimming depended on the behavior of occupants. In offices whose occupants tended to stay at their desks all day, dimming controls saved more energy and vice versa. The lighting requirements of occupants appear to depend on their type of work. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Bldg Technol Dept, Berkeley, CA 94720 USA. RP Jennings, JD (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Bldg Technol Dept, Berkeley, CA 94720 USA. NR 11 TC 40 Z9 41 U1 0 U2 4 PU ILLUMINAT ENG SOC NORTH AMER PI NEW YORK PA 120 WALL ST, 17TH FL, NEW YORK, NY 10005-4001 USA SN 0099-4480 J9 J ILLUM ENG SOC JI J. Illum. Eng. Soc. PD SUM PY 2000 VL 29 IS 2 BP 39 EP + PG 23 WC Optics SC Optics GA 369PR UT WOS:000165076600006 ER PT J AU You, CY Shin, SC AF You, CY Shin, SC TI Effects of polarizer and analyzer imperfections in a magneto-optical Kerr spectrometer SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ELLIPSOMETRY; MULTILAYERS AB We have analyzed the effects of polarizer and analyzer imperfections in a phase-modulated magneto-optical Kerr spectrometer, using Jones matrices, and found that these imperfections do not seriously affect measurements of magneto-optical effects, to a first-order approximation. The analysis was experimentally proved in a magneto-optical Kerr spectrometer with a dichroic polarizer and analyzer with an extinction ratio of similar to 10(-2). (C) 2000 Optical Society of America [S0740-3224(00)03006-X]. C1 Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. Korea Adv Inst Sci & Technol, Ctr Nanospin Spintron Mat, Taejon 305701, South Korea. RP You, CY (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Chun-Yeol/B-1734-2010; Shin, Sung-Chul/C-1992-2011 OI You, Chun-Yeol/0000-0001-9549-8611; NR 11 TC 1 Z9 1 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 2000 VL 17 IS 6 BP 910 EP 913 DI 10.1364/JOSAB.17.000910 PG 4 WC Optics SC Optics GA 322XQ UT WOS:000087534900004 ER PT J AU Donati, GP Rodriguez, G Taylor, AJ AF Donati, GP Rodriguez, G Taylor, AJ TI Ultrafast, dynamical imaging of surfaces by use of a scanning tunneling microscope with a photoexcited, low-temperature-grown GaAs tip SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID GENERATION; PULSES; PROBE AB We demonstrate ultrafast dynamical imaging of surfaces, using a scanning tunneling microscope with a low-temperature-grown GaAs tip photoexcited by 100-fs, 800-nm pulses. We use this setup to detect picosecond transients on a coplanar stripline and demonstrate a temporal resolution (full width at half-maximum) of 1.7 ps. The temporal waveform resulting from our low-temperature-grown GaAs tip is compared with waveforms obtained by means of photoconductively gated metal tips in the same setup. By dynamically imaging the stripline we demonstrate that the local conductivity in the sample is reflected in the transient correlated current and that 20-nm spatial resolution is achievable for a 2-ps transient correlated signal. Finally, we report the characterization of a picosecond pulse propagating along the stripline for millimeter-scale distances. (C) 2000 Optical Society of America. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Taylor, AJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Condensed Matter & Thermal Phys Grp, MST-10,MS K764, Los Alamos, NM 87545 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 18 TC 14 Z9 14 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 2000 VL 17 IS 6 BP 1077 EP 1083 DI 10.1364/JOSAB.17.001077 PG 7 WC Optics SC Optics GA 322XQ UT WOS:000087534900026 ER PT J AU Nilsen, J Li, YL Dunn, J AF Nilsen, J Li, YL Dunn, J TI Modeling picosecond-laser-driven neonlike titanium x-ray laser experiments SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TRANSIENT GAIN; PREPULSE TECHNIQUE; 21.2 NM; AMPLIFICATION; TRANSITIONS; SATURATION; EFFICIENT AB The technique of first using a nanosecond pulse to preform and ionize the plasma and then using a picosecond pulse to heat the plasma enables low-Z neonlike and nickellike ions to lase, driven by small lasers, with only 10 J of energy. Recent experiments at the Compact Multipulse Terawatt laser facility at Lawrence Livermore National Laboratory have demonstrated lasing in neonlike titanium by irradiation of 1-cm-long slab targets of titanium with a 4.8-5, 800-ps prepulse that is followed 1.6 ns later by a 6-J, 1-ps drive pulse. In this study we model the neonlike titanium x-ray laser under those experimental conditions. The LASNEX code is used to calculate the hydrodynamic evolution of the plasma and to provide the temperatures and densities to the XRASER code, which then performs the kinetics calculations to determine the gain. The temporal and spatial evolution of the plasma is studied both with and without radiation transport included for the 3d and the 3s --> 2p neonlike titanium resonance lines. Large regions with gains greater than 80 cm(-1) are predicted for the 3p S-1(0) --> 3s (1)p(1) neonlike titanium laser line at 32.6 nm.; The gain is shown to be quasi-steady-state over these time scales with regard to the equilibration of the excited-state populations. The transient nature of the gain is shown to be due to the ionization balance in the plasma. Given the large gain and the large gradients in these plasmas, we calculate x-ray laser propagation, including refraction effects, to understand which regions have the right combination of high gain and low density gradients for an optical contribution to the x-ray laser output. Calculations with different delays between the long and the short pulses and with different durations for the short pulse are presented to provide a better insight into optimization of the laser output. High gain is also predicted and observed for the self-photopumped 3d P-1(1) --> 3p P-1(1) laser line at 30.1 nm in neonlike titanium, and calculations are presented to help understand this lasing mechanism. (C) 2000 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. RP Nilsen, J (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, POB 808,L-15, Livermore, CA 94550 USA. NR 22 TC 27 Z9 29 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 2000 VL 17 IS 6 BP 1084 EP 1092 DI 10.1364/JOSAB.17.001084 PG 9 WC Optics SC Optics GA 322XQ UT WOS:000087534900027 ER PT J AU Li, YL Dunn, J Nilsen, J Barbee, TW Osterheld, AL Shlyaptsev, VN AF Li, YL Dunn, J Nilsen, J Barbee, TW Osterheld, AL Shlyaptsev, VN TI Saturated tabletop x-ray laser system at 19 nm SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID TRANSIENT GAIN; EXCITATION; GENERATION; PULSES AB Saturated operation of a tabletop x-ray laser at 19 nn is demonstrated with a laser-irradiated Mo slab target. The output energy, the intensity, the near-field beam pattern, and the beam divergence are characterized. The wavelength scalability and the high brightness make it a potential tool for x-ray laser applications. (C) 2000 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Livermore, CA 94550 USA. RP Li, YL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, POB 808, Livermore, CA 94550 USA. NR 20 TC 37 Z9 38 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JUN PY 2000 VL 17 IS 6 BP 1098 EP 1101 DI 10.1364/JOSAB.17.001098 PG 4 WC Optics SC Optics GA 322XQ UT WOS:000087534900029 ER PT J AU Konno, H Lomdahl, PS AF Konno, H Lomdahl, PS TI A nonlinear transformation method for obtaining approximate analytic steady-state solutions of nonlinear stochastic differential equations SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE nonlinear transformation; approximate analytic solution; nonlinear stochastic differential equation; Haken-Zwanzing model; Fokker-Planck equation; probability density function AB We exemplify the method of nonlinear transformation (NTR) as a powerful tool for obtaining approximate analytic steady-state solutions of nonlinear stochastic differential equations (SDEs). A number of nonlinear SDEs classified into two-components Haken-Zwanzing model are used to demonstrate its suitability and usefulness. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Konno, H (reprint author), Univ Tsukuba, Inst Engn Mech & Syst, Tsukuba, Ibaraki 3058573, Japan. NR 16 TC 1 Z9 1 U1 1 U2 2 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JUN PY 2000 VL 69 IS 6 BP 1619 EP 1628 DI 10.1143/JPSJ.69.1619 PG 10 WC Physics, Multidisciplinary SC Physics GA 329HH UT WOS:000087901200011 ER PT J AU Konno, H Lomdahl, PS AF Konno, H Lomdahl, PS TI The birth-death stochastic processes of "solitons" in the 1D Benney equation SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE 1D Benney equation; birth-death process of "soliton"; sub-poissonian statistics of "soliton"-number; fluctuation; "soliton-soliton" interaction via radiation; generalized Brody distribution of amplitude; "hole"-like excitation ID NONLINEAR SCHRODINGER-EQUATION; KURAMOTO-SIVASHINSKY EQUATION; CHAOS; SYSTEM; BEHAVIOR; PHYSICS AB The birth-death process of "soliton"-like excitation in the 1D Benney equation is studied. It is shown that the "soliton"-number fluctuation is subjected to the sub-Poissonian statistics, which is caused by the interaction between "solitons" and "radiation". The features of "soliton"-like excitations and the relevance of "hole"-like excitation are described from the points of view of the stochastic process and statistical mechanics. C1 Univ Tsukuba, Inst Informat Sci & Elect, Tsukuba, Ibaraki 3058573, Japan. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Konno, H (reprint author), Univ Tsukuba, Inst Informat Sci & Elect, Tsukuba, Ibaraki 3058573, Japan. NR 39 TC 6 Z9 6 U1 0 U2 1 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JUN PY 2000 VL 69 IS 6 BP 1629 EP 1641 DI 10.1143/JPSJ.69.1629 PG 13 WC Physics, Multidisciplinary SC Physics GA 329HH UT WOS:000087901200012 ER PT J AU Pint, BA Wright, IG Brindley, WJ AF Pint, BA Wright, IG Brindley, WJ TI Evaluation of thermal barrier coating systems on novel substrates SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE thermal barrier coatings; NiAl; FeCrAl; NiCr; chromia; alumina; X-33 reusable launch vehicle ID PREDICTION MODEL DEVELOPMENT; HIGH-TEMPERATURE OXIDATION; REACTIVE ELEMENTS; SCALE ADHESION; ALLOYS; LIFE; PERFORMANCE; PROTECTION AB Testing was conducted on both plasma-sprayed (PS) and electron beam-physical vapor deposited (EB-PVD) Y2O3-stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) applied directly to oxidation-resistant substrates such as beta-NiAl, oxide-dispersed FeCrAl, and NiCr. On an alloy that forms a very adherent alumina scale, beta-NiAl + Zr, the coating Lifetime of YSZ in furnace cyclic tests was 6 or more times longer than on state-of-the-art, YSZ coatings on single crystal Ni-base superalloys with MCrAlY or Pt aluminide bond coats. Coatings on FeCrAl. alloys appear to be a viable option for applications such as the external skin of the X-33, single stage to orbit, reusable launch vehicle. Model chromia-forming bond coat compositions also show promise for power generation applications at temperatures where hot corrosion may be a major problem. In general, while this work examined unique materials systems, many of the same fundamental failure mechanisms observed in conventional TBCs were observed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Pint, BA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 23 TC 18 Z9 18 U1 2 U2 13 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 2000 VL 9 IS 2 BP 198 EP 203 DI 10.1361/105996300770349926 PG 6 WC Materials Science, Coatings & Films SC Materials Science GA 336RM UT WOS:000088316800007 ER PT J AU Wang, H Dinwiddie, RB AF Wang, H Dinwiddie, RB TI Reliability of laser flash thermal diffusivity measurements of the thermal barrier coatings SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE TBC thermal diffusivity; thermal conductivity; laser flash AB The thermal diffusivity of free standing thermal barrier coatings (TBCs) was measured by the laser hash technique. The combination of low thermal conductivity (1 to 2 W/m K) and small TBC thickness (300 to 600 mu m thick) can cause errors in the measurements. Back surface (opposite the laser) temperatures of free standing plasma-sprayed TBCs were measured as a function of time and laser po,ver. The front surface temperatures were calculated using thermal transport equations. In the high power region, thermal diffusivity decreased significantly with increasing laser power. In the moderate power region, thermal diffusivity remained constant. In the low power region, measurement became unreliable because of noise. The detector nonlinearity was believed to be a possible cause of deviation in the high power region. Measurements at different laser power levels should be conducted in order to obtain reliable thermal diffusivity values for TBCs. C1 Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Wang, H (reprint author), Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 11 TC 21 Z9 26 U1 0 U2 6 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD JUN PY 2000 VL 9 IS 2 BP 210 EP 214 DI 10.1361/105996300770349944 PG 5 WC Materials Science, Coatings & Films SC Materials Science GA 336RM UT WOS:000088316800009 ER PT J AU Shevenell, L Goff, F AF Shevenell, L Goff, F TI Temporal geochemical variations in volatile emissions from Mount St. Helens, USA, 1980-1994 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE magmatic volatiles; hydrothermal systems; magma degassing; Mount St. Helens ID MAGMATIC VOLATILES; AUGUSTINE VOLCANO; HYDROGEN ISOTOPE; 1980 ERUPTION; LOOWIT CANYON; WASHINGTON; WATERS; SYSTEM; FLUID; CHEMISTRY AB Fumarole discharges (95-560 degrees C) collected from the dacite dome inside Mount St. Helens crater show temporal changes in their isotopic and chemical compositions. A delta D vs. delta(18)O plot shows that condensed waters from the gases are mixtures of meteoric and magmatic components, but that the apparent magmatic end-member in 1994 was depleted by about 7 parts per thousand in delta D relative to the apparent end-member in 1980. Based on delta D modeling, approximately 63% of shallow, post-1980 magma has yet to degas. Surprisingly, Cl and F contents in the 1994 samples were only 0.47 and 3.8%, respectively, of the concentrations determined for end-member magmatic fluid in 1980. The data indicate that Cl (and F and B) is degassed from magma relatively quickly compared to water and/or that most of the Cl degassed in later years is dissolved into the shallow Mount St. Helens hydrothermal system. Because metals are often transported in magmatic and hydrothermal fluids as Cl complexes, rapid changes in surface volatile compositions may have implications for the timing and location of metals transport and deposition in some volcanoes. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Nevada, Nevada Bur Mines & Geol, Reno, NV 89557 USA. Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Shevenell, L (reprint author), Univ Nevada, Nevada Bur Mines & Geol, MS 178, Reno, NV 89557 USA. EM lisaas@unr.edu; fraser@geology.lanl.gov NR 54 TC 6 Z9 6 U1 2 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 JUN PY 2000 VL 99 IS 1-4 BP 123 EP 138 DI 10.1016/S0377-0273(00)00161-X PG 16 WC Geosciences, Multidisciplinary SC Geology GA 330EN UT WOS:000087950000007 ER PT J AU Goldberg, AP Busby-Whitehead, MJ Katzel, LI Krauss, RM Lumpkin, M Hagberg, JM AF Goldberg, AP Busby-Whitehead, MJ Katzel, LI Krauss, RM Lumpkin, M Hagberg, JM TI Cardiovascular fitness, body composition, and lipoprotein lipid metabolism in older men SO JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES LA English DT Article ID CORONARY HEART-DISEASE; LOW-FAT DIET; HIGH-DENSITY; CHOLESTEROL LEVELS; ASSOCIATION DIET; HDL CHOLESTEROL; LIPASE ACTIVITY; SEDENTARY MEN; RISK-FACTORS; WEIGHT-LOSS AB Background. Lipoprotein lipids in older individuals are affected by family history of coronary artery disease (CAD), obesity, diet, and physical activity habits. Methods. The relationship of obesity and physical fitness ((V)over dot O(2)max) to lipoprotein lipids and postheparin lipases was examined in a cross-sectional study of 12 lean (LS) and 26 obese (OS) sedentary men and 18 master athletes (MAs) aged 65 +/- 1 years (mean +/- SE). The men were healthy, had no family history of CAD, and were weight stable on AHA dirts at the time of study. Results. (V)over dot O(2)max was similar in LS and OS men but higher in the MAs. The OS men had a higher percentage of body far (%BF), waist circumference, and waist:hip ratio (WHR) than the MA and LS men, but MA and LS men differed only in waist circumference. Total and LDL-C levels were comparable, but HDL-C. HDL2-C, and %HDL2b subspecies were higher in MAs than in OS and LS men, and in LS than in OS men. Triglyceride (TG) was similar in MAs and LS men but higher in OS men. Across groups, two multiple regression analyses models ((V)over dot O(2)max, RBF. and WHR or waist circumference) showed that %BF and (V)over dot O(2)max independently predicted HDL-C and HDL2. whereas WHR predicted TG (r(2) = .45) more strongly than waist circumference (r(2) = .39). Postheparin lipoprotein lipase activity (LPL) was comparable among groups and correlated independently with (V)over dot O(2)max;. Total postheparin lipolytic activity (PHLA), hepatic lipase activity (HL), and HL:PHLA ratio were similar in MAs and LS men but higher in OS men. In both multiple regression analysis models, only %BF predicted HL activity and the HL:PHLA ratio. The HL:PHLA ratio independently predicted HDL-C, HDL2-C, %HDL2b, %HDL3 subspecies, and the cholesterol:HDL-C ratio, whereas LPL activity predicted TG. Conclusions. Increased fitness and reduced total and abdominal fatness in MAs are associated with lower HL and higher LPL activities, which may mediate their higher HDL-C and lower TG levels relative to their sedentary peers. C1 Univ Maryland, Sch Med, Dept Med, Div Gerontol, Baltimore, MD 21201 USA. Baltimore Vet Adm Maryland Hlth Care Syst, GRECC, Geriat Serv, Baltimore, MD USA. Johns Hopkins Univ, Sch Med, Bayview Med Ctr, Dep Med,Div Gerontol & Geriatr, Baltimore, MD USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Maryland, Ctr Aging, College Pk, MD 20742 USA. RP Baltimore VA Med Ctr, GRECC, BT-18-GR,10 N Greene St, Baltimore, MD 21201 USA. EM apgoldbe@umaryland.edu FU NIA NIH HHS [P01-AG04402, KO8-AG00383, R01-AG07660] NR 41 TC 20 Z9 21 U1 0 U2 0 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1079-5006 EI 1758-535X J9 J GERONTOL A-BIOL JI J. Gerontol. Ser. A-Biol. Sci. Med. Sci. PD JUN PY 2000 VL 55 IS 6 BP M342 EP M349 PG 8 WC Geriatrics & Gerontology; Gerontology SC Geriatrics & Gerontology GA 331XV UT WOS:000088044700015 PM 10843355 ER PT J AU Dunne, M Edwards, J Graham, P Evans, A Rothman, S Smedley-Stevenson, R Barnes, CW Hsing, W Goldman, SR AF Dunne, M Edwards, J Graham, P Evans, A Rothman, S Smedley-Stevenson, R Barnes, CW Hsing, W Goldman, SR TI AWE experimental laser plasma program SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT 5th Zababakhin Scientific Meeting CY SEP 21-25, 1998 CL SNEZHINSK, RUSSIA AB The achievement of ignition from an Inertial Confinement Fusion capsule will require a detailed understanding of a wide range of high energy density phenomena. This paper presents some recent work aimed at improving our knowledge of the strength and equation of state characteristics of low-Z materials, and outlines data which will provide quantitative benchmarks against which our predictive radiation hydrodynamics capabilities can be tested. Improvements to our understanding in these areas are required if reproducible and predictable fusion energy production is to be achieved on the next generation of laser facilities. In particular, the HELEN laser at AWE has been used to create a thermal X-ray source with 140 eV peak radiation temperature and 3% instantaneous flux uniformity to allow measurements of the Equation of State of materials at pressures up to 20 Mbar to an accuracy of <+/-2% in shock velocity. The same laser has been used to investigate the onset of spallation upon the release of a strong shock at a metal-vacuum boundary, with dynamic radiography used to image the spalled material in flight for the first time. Finally, a range of experiments have been performed to generate quantitative radiation hydrodynamics data on the evolution of gross target defects, driven in both planar and imploding geometry. X-ray radiography was used to record the evolving target deformation in a system where the X-ray drive and unperturbed target response were sufficiently characterized to permit meaningful analysis. The results have been compared to preshot predictions made using a wide variety of fluid codes, highlighting substantial differences between the various approaches, and indicating significant discrepancies with the experimental reality. The techniques developed to allow quantitative comparisons are allowing the causes of the discrepancies to be identified, and are guiding the development of new simulation techniques. C1 AWE Aldermaston, Plasma Expt Div, Dept Radiat Phys, Reading RG7 4PR, Berks, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dunne, M (reprint author), AWE Aldermaston, Plasma Expt Div, Dept Radiat Phys, Bldg N56, Reading RG7 4PR, Berks, England. RI Dunne, Mike/B-4318-2014 OI Dunne, Mike/0000-0001-8740-3870 NR 1 TC 0 Z9 0 U1 0 U2 4 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-4930 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD JUN PY 2000 VL 18 IS 2 BP 213 EP 218 DI 10.1017/S0263034600182096 PG 6 WC Physics, Applied SC Physics GA 407UX UT WOS:000167290100010 ER PT J AU Paunesku, T Zhang, YR Gemmell, MA Woloschak, GE AF Paunesku, T Zhang, YR Gemmell, MA Woloschak, GE TI p53 Gene deletions in paraffin-preserved lymphoid tumors from irradiated mice SO LEUKEMIA RESEARCH LA English DT Article DE p53; radiation carcinogenesis; gene deletions; fission-spectrum neutrons; radiation effects ID POLYMERASE CHAIN-REACTION; LUNG ADENOCARCINOMAS; FISSION NEUTRONS; SUPPRESSOR GENE; MUTANT P53; CELL-LINES; MUTATIONS; MOUSE; ANTIGEN; CANCER AB Experiments were performed to measure deletions in the p53 gene in paraffin-embedded tissues (tumors and control) derived from mice exposed to gamma-rays or neutrons up to 28 years ago. Deletions in exons 1, 3, 4, 5, 6, 7 and 9 were monitored by PCR and Southern blotting techniques. The results of these experiments demonstrated p53 deletions in only 1/6 spontaneous tumors but in 5/6 gamma-ray-induced and 5/6 neutron-induced tumors. Exons deleted in tumors from gamma-ray exposed mice were similar to those deleted in tumors from neutron-exposed mice. They document differences in spectra of p53 deletions in comparing spontaneous radiation-induced tumors. Published by Elsevier Science Ltd. C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Woloschak, GE (reprint author), Argonne Natl Lab, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Paunesku, Tatjana/A-3488-2017; Woloschak, Gayle/A-3799-2017 OI Paunesku, Tatjana/0000-0001-8698-2938; Woloschak, Gayle/0000-0001-9209-8954 NR 32 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0145-2126 J9 LEUKEMIA RES JI Leuk. Res. PD JUN PY 2000 VL 24 IS 6 BP 511 EP 517 DI 10.1016/S0145-2126(00)00005-9 PG 7 WC Oncology; Hematology SC Oncology; Hematology GA 323DD UT WOS:000087548800009 PM 10781686 ER PT J AU Doskey, PV Talbot, TW AF Doskey, PV Talbot, TW TI Sediment chronologies of atmospheric deposition in a precipitation-dominated seepage lake SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; FOSSIL-FUEL COMBUSTION; NORTHERN WISCONSIN; ORGANIC-MATTER; POLLUTION SOURCES; EARLY DIAGENESIS; MICHIGAN; FLUXES; POLLEN; SILICA AB Chronologies of Pb, polycyclic aromatic hydrocarbons (PAHs), Al, carbon, and n-alkanes in pelagic sediments of Crystal Lake, a precipitation-dominated seepage lake in north-central Wisconsin, were determined to investigate the geochemistry of sediments derived from atmospheric deposition and to evaluate the impact of environmental changes in the region on the geochemistry of this oligotrophic lake. Concentrations of Pb and combustion-derived PAHs in Crystal Lake sediments have increased by factors of 8 and 3, respectively, over the past 150 years. In contrast, levels of perylene increased with depth in the sediment, indicating that postdepositional formation of this PAH might be occurring. Atmospheric fluxes of anthropogenic Pb and combustion-derived PAHs were estimated to be 10,000 mu g m(-1) a(-1) and 34 mu g m(-1) a(-1), respectively. The settling sediment fluxes of planktonic n-alkanes (Sigma C-15, C-17, C-19) and terrestrial n-alkanes (Sigma C-25 C-27, C-29, C-31) in Crystal Lake were 4,400 mu g m(-2) a(-1) and 10,500 mu g m(-2) a(-1), respectively, whereas their accumulation rates in pelagic sediments were 270 mu g m(-2) a(-1) and 7,100 mu g m(-2) a(-1), respectively. The large difference between the settling sediment flux and the accumulation rate of the planktonic n-alkanes in the sediments is ascribed to microbial degradation during pr soon after deposition. In contrast, the terrestrial n-alkanes are incorporated in a wax matrix and are protected from degradation. The contribution of terrestrial n-alkanes to the organic carbon of the sediments has remained relatively constant over the past 150 ye,us. About 20% of the organic carbon that is incorporated in the present-day sediments of Crystal Lake can be attributed to the deposition of pine pollen in the lake. Deforestation of the region in the late 1800s apparently caused terrigenous inputs and primary productivity of nonsiliceous plankton to increase, because planktonic and terrestrial n-alkane concentrations in the sediment increased at about the same time. However, since about 1900 concentrations of organic carbon and of terrestrial and planktonic n-alkanes in Crystal Lake sediments have decreased, and concentrations of Al and combustion-derived PAH have increased. These occurrences might reflect a decrease in pollen dispersal in the region and an increase in the atmospheric deposition of fly ash from coal-burning power plants. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ New Hampshire, Complex Syst Res Ctr, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. RP Doskey, PV (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 60 TC 12 Z9 12 U1 0 U2 2 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUN PY 2000 VL 45 IS 4 BP 895 EP 904 PG 10 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 323GZ UT WOS:000087558900013 ER PT J AU Kritchevsky, D Tepper, SA Chen, SC Meijer, GW Krauss, RM AF Kritchevsky, D Tepper, SA Chen, SC Meijer, GW Krauss, RM TI Cholesterol vehicle in experimental atherosclerosis. 23. Effects of specific synthetic triglycerides SO LIPIDS LA English DT Article ID POSITIONAL DISTRIBUTION; FATTY-ACIDS; PALM OIL; PLASMA; RATS; CHYLOMICRONS; METABOLISM; ABSORPTION; CLEARANCE; EMULSIONS AB Earlier work has shown that increasing concentration of palmitic acid at. the sn-2 position of a fat enhances the atherogenic properties of that fat. This effect has been observed with lard, tallow, cottonseed oil, and palm oil. In the experiment reported here, we have studied the atherogenic effects of four synthetic fats fed to rabbits as 58% (w/w) of the total fat (15%) (w/w) Of a semipurified diet containing 0.05% cholesterol. The fats being tested were: 1,3-stearoyl-2-oleoylglycerol (SOS);1,2-stearoyl-3-aleoylglycerol (SSO); 1,3-palmitoyl- 2-oleoylglycerol (POP); and 1,2-palmitoyl-3-oleoylglycerol (PPO). After 20 wk on diet there were no differences among the groups in weight gain, liver weight, serum, or liver lipids. These data are consistent with our previous findings. There were significant differences in atherosclerosis. The most severe atherosclerosis was observed in group PPO and the least in groups SSO and POP. Severity of atherosclerosis was graded visually on a 0-4 scale. The average atherosclerosis [(aortic arch and thoracic aorta) divided by 2] was: SOS-1.35; SSO-0.97; POP-0.83; and PPO-1.80. Fecal fat excretion (an indicator of fat absorption) was higher in the two groups fed the stearic acid-rich fats and lower in groups fed the palmitic acid-rich fats. There were no differences in low density lipoprotein particle size. The results confirm previous findings concerning the increased atherogenicity of fats bearing palmitic acid at the sn-2 position. The mechanism underlying these observations is moot but may, in part, reflect greater absorption of the atherogenic fat. C1 Wistar Inst, Philadelphia, PA 19104 USA. Lipton, Baltimore, MD 21229 USA. Unilever Res Labs Vlaardingen, NL-3130 AC Vlaardingen, Netherlands. EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kritchevsky, D (reprint author), Wistar Inst, 3601 Spruce St, Philadelphia, PA 19104 USA. FU NHLBI NIH HHS [HL18574, HL00734] NR 21 TC 29 Z9 30 U1 0 U2 5 PU AMER OIL CHEMISTS SOC A O C S PRESS PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 USA SN 0024-4201 J9 LIPIDS JI Lipids PD JUN PY 2000 VL 35 IS 6 BP 621 EP 625 DI 10.1007/s11745-000-0565-3 PG 5 WC Biochemistry & Molecular Biology; Nutrition & Dietetics SC Biochemistry & Molecular Biology; Nutrition & Dietetics GA 331FR UT WOS:000088008100006 PM 10901423 ER PT J AU Gao, Y Elder, SA AF Gao, Y Elder, SA TI TEM study of TiO2 nanocrystals with different particle size and shape SO MATERIALS LETTERS LA English DT Article DE TiO2; nanocrystals; TEM ID ORGANIZATION; FILMS AB TiO2 anatase nanocrystals deposited on carbon films from colloidal solutions have been characterized using transmission electron microscopy (TEM). The TiO2 nanocrystals exhibit different sizes, shapes, and facets, depending on the pH value and the type of organic additives in the colloidal solutions. Typically, high pH value results in small cubic-like nanocrystals with {112} and {103} faces, while low pH value leads to truncated tetragonal nanocrystals with {101}, {001} and {010} faces. Excess dilution of the particle density appears to cause partial dissolution of the cubic-like TiO2 nanocrystals to form spherical nanocrystals. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Gao, Y (reprint author), Pacific NW Lab, POB 999,MS K8-93, Richland, WA 99352 USA. NR 9 TC 65 Z9 68 U1 6 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JUN PY 2000 VL 44 IS 3-4 BP 228 EP 232 DI 10.1016/S0167-577X(00)00033-1 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 325CG UT WOS:000087658300019 ER PT J AU Fathy, D Holland, OW Liu, R Wosik, J Chu, WK AF Fathy, D Holland, OW Liu, R Wosik, J Chu, WK TI Cluster ion beam smoothing of SiC and YBCO surfaces SO MATERIALS LETTERS LA English DT Article DE high-temperature superconductors (HTS); SiC; cluster beam; smoothing; surfaces AB Optimization of the surface topography, especially in high-temperature superconductor (HTS) and silicon carbide is crucial for device processing. Surface smoothing in these materials was investigated using gas cluster ion beams (GCIB) capable of delivering cluster ions of greater than or equal to 2000 Ar atoms with energies of up to 30 kV. Examination of the surface topography after cluster ion irradiation was done using cross-sectional transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results indicate that typical as-deposited YBCO films on MgO substrates have an average roughness of the order of 40 m and interpeak distance between 300 and 600 nm. Application of GCIB to the surface planarization reduces the roughness to only 10 nm. Also, power handling and microwave surface resistance of the YBCO film and its relationship to surface smoothness are reported. Similar observations using bulk SiC are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Fathy, D (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. NR 6 TC 6 Z9 6 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD JUN PY 2000 VL 44 IS 3-4 BP 248 EP 252 DI 10.1016/S0167-577X(00)00037-9 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 325CG UT WOS:000087658300023 ER PT J AU De Chant, LJ Andrews, MJ AF De Chant, LJ Andrews, MJ TI A combined analytical singularity subtraction method and compact implicit differencing scheme for aerodynamic mixing SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE singularity subtraction; combined analytical/numerical method; aerodynamic mixing; ejector nozzle AB In spite of the rapid advances in both scalar and parallel computational tools, the large number and breadth of variables involved in both design and inverse problems make the use of sophisticated fluid flow models impractical. With this restriction, it may be concluded that an important family of methods for mathematical/computational development are reduced or approximate models. In this study, a combined perturbation/numerical modeling methodology is developed. The numerical portion of the model uses a compact finite difference scheme, while analytical solutions are used to resolve singular behavior that is inherent to this flow. Solutions are presented to illustrate the efficiency of this methodology. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. RP De Chant, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, POB 1663, Los Alamos, NM 87545 USA. NR 33 TC 6 Z9 6 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD JUN PY 2000 VL 31 IS 13 BP 21 EP 38 DI 10.1016/S0895-7177(00)00109-6 PG 18 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 339TM UT WOS:000088494000003 ER PT J AU Schlamp, S Hornung, HG Cummings, EB AF Schlamp, S Hornung, HG Cummings, EB TI Neural network data analysis for laser-induced thermal acoustics SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE four-wave mixing; velocimetry; thermometry; transient grating; scattering; non-intrusive; neural network; optimal filtering; regression ID IDENTIFICATION; THERMOMETRY; CONVERGENCE AB A general, analytical closed-form solution for laser-induced thermal acoustic (LITA) signals using homodyne or heterodyne detection and using electrostrictive and thermal gratings is derived. A one-hidden-layer feed-forward neural network is trained using back-propagation learning and a steepest descent learning rule to extract the speed of sound and flow velocity from a heterodyne LITA signal. The effect of the network size on the performance is demonstrated. The accuracy is determined with a second set of LITA signals that were not used during the training phase. The accuracy is found to be better than that of a conventional frequency decomposition technique while being computationally as efficient. This data analysis method is robust with respect to noise, numerically stable and fast enough for real-time data analysis. C1 CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. EM stefan@galcit.caltech.edu; hans@galcit.caltech.edu; labsmith@home.com RI Schlamp, Stefan/A-9143-2008 OI Schlamp, Stefan/0000-0002-9933-3096 NR 35 TC 9 Z9 9 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD JUN PY 2000 VL 11 IS 6 BP 784 EP 794 DI 10.1088/0957-0233/11/6/323 PG 11 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 325VH UT WOS:000087696800027 ER PT J AU Walter, PL AF Walter, PL TI Dynamic force, pressure, and acceleration - Part 7 - "Rules of thumb" for data assessment SO MEASUREMENTS & CONTROL LA English DT Article AB The intent of this part is to enable both the test engineer and the data analyst to perform a quick initial assessment of the validity of recorded force, pressure, and acceleration signals. The signals are assumed to be free of any spurious noise. This assumption will be discussed further in Part 9. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Texas Christian Univ, Dept Engn, Ft Worth, TX 76129 USA. RP Walter, PL (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU MEASUREMENTS & DATA CORP PI PITTSBURGH PA 2994 W LIBERTY AVE, PITTSBURGH, PA 15216 USA SN 0148-0057 J9 MEAS CONTROL-US JI Meas. Control PD JUN PY 2000 IS 200 BP 61 EP 65 PG 5 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 338ND UT WOS:000088425400004 ER PT J AU Arnfield, MR Siantar, CH Siebers, J Garmon, P Cox, L Mohan, R AF Arnfield, MR Siantar, CH Siebers, J Garmon, P Cox, L Mohan, R TI The impact of electron transport on the accuracy of computed dose SO MEDICAL PHYSICS LA English DT Article DE dosimetry; dose calculation; Monte Carlo; inhomogeneity ID MEGAVOLTAGE PHOTON BEAMS; ATOMIC-NUMBER INTERFACES; 15-MV X-RAYS; AIR CAVITIES; INHOMOGENEITY CORRECTIONS; CONVOLUTION CALCULATIONS; FILM DOSIMETRY; LUNG; RADIOTHERAPY; IRRADIATION AB The aim of this work was to investigate the accuracy of dose predicted by a Bathe power law correction, and two models which account for electron range: A superposition/convolution algorithm and a Monte Carlo algorithm. The results of these models were compared in phantoms with cavities and low-density inhomogeneities. An idealized geometry was considered with inhomogeneities represented by regions of air and lung equivalent material. Measurements were performed with a parallel plate ionization chamber, thin TLDs (thermoluminescent dosimeters) and film. Dose calculations were done with a generalized Bathe model, the Pinnacle collapsed cone convolution model (CCC), and the Peregrine Monte Carlo dose calculation algorithm. Absolute central axis and off axis dose data at various depths relative to interfaces of inhomogeneities were compared. Our results confirm that for a Bathe correction, dose errors in the calculated depth dose arise from the neglect of electron transport. This effect increases as the field size decreases, as the density of the inhomogeneity decreases, and with the energy of incident photons. The CCC calculations were closer to measurements than the Bathe model, but significant discrepancies remain. Monte Carlo results agree with measurements within the measurement and computational uncertainties. (C) 2000 American Association of Physicists in Medicine. [S0093-2405(00)00906-8]. C1 Virginia Commonwealth Univ, Med Coll Virginia, Dept Radiat Oncol, Richmond, VA 23298 USA. McGuire VA Hosp, Richmond, VA 23298 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Arnfield, MR (reprint author), Virginia Commonwealth Univ, Med Coll Virginia, Dept Radiat Oncol, Richmond, VA 23298 USA. FU NCI NIH HHS [CA 74158] NR 40 TC 88 Z9 88 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD JUN PY 2000 VL 27 IS 6 BP 1266 EP 1274 DI 10.1118/1.599004 PG 9 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 326YN UT WOS:000087765000008 PM 10902555 ER PT J AU Crocker, FH Fredrickson, JK White, DC Ringelberg, DB Balkwill, DL AF Crocker, FH Fredrickson, JK White, DC Ringelberg, DB Balkwill, DL TI Phylogenetic and physiological diversity of Arthrobacter strains isolated from unconsolidated subsurface sediments SO MICROBIOLOGY-UK LA English DT Article DE Arthrobacter; subsurface microbiology; microbial phylogeny ID RIBOSOMAL-RNA SEQUENCES; DEEP SUBSURFACE; TERRESTRIAL SUBSURFACE; HETEROTROPHIC BACTERIA; SOUTHEASTERN SWEDEN; COASTAL-PLAIN; 16S RDNA; COMB-NOV; MICROBIOLOGY; POPULATIONS AB Forty strains of Cram-positive, aerobic, heterotrophic bacteria isolated from saturated subsurface lacustrine, paleosol and fluvial sediments at the US Department of Energy's Hanford Site in south central Washington State were characterized by phylogenetic analysis of 16S rRNA gene sequences and by determination of selected morphological, physiological and biochemical traits. Phylogenetic analyses of 165 rDNA sequences from subsurface isolates in the context of similar sequences from previously described bacterial species indicated that 38 of the subsurface strains were most closely related to Arthrobacter. The other two strains appeared to be most closely related to Kocuria. The subsurface isolates fell into seven phylogenetically coherent and distinct clusters, indicating that there was a significant degree of diversity among them. Additional diversity was detected by analysis of cellular fatty acids and physiological traits. The general morphological. physiological and biochemical traits of the subsurface strains were consistent with those of Arthrobacter, Micrococcus and genera recently separated from Micrococcus, such as Kocuria, Some of the subsurface strains were phylogenetically closely related to certain species of Arthrobacter (16S rDNA sequence similarities > 99 %). However, most of the subsurface isolates did not cluster with previously established species in phylogenetic analyses of 165 rRNA gene sequences or with hierarchical cluster analysis of cellular fatty acid profiles. Moreover, many of the subsurface isolates that were most closely related to Arthrobacter also differed from all established species of that genus in several of their specific physiological characteristics. Most of the subsurface isolates, then, are likely to be novel strains or species of Arthrobacter. C1 Florida State Univ, Dept Sci Biol, Tallahassee, FL 32306 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. RP Balkwill, DL (reprint author), Florida State Univ, Dept Sci Biol, 312 Nucl Res Bldg, Tallahassee, FL 32306 USA. NR 64 TC 41 Z9 41 U1 1 U2 4 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AE, BERKS, ENGLAND SN 1350-0872 J9 MICROBIOL-UK JI Microbiology-(UK) PD JUN PY 2000 VL 146 BP 1295 EP 1310 PN 6 PG 16 WC Microbiology SC Microbiology GA 324AT UT WOS:000087598700009 PM 10846209 ER PT J AU Bedson, TR Nellist, PD Palmer, RE Wilcoxon, JP AF Bedson, TR Nellist, PD Palmer, RE Wilcoxon, JP TI Direct electron beam writing of nanostructures using passivated gold clusters SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 25th International Conference on Micro- and Nano-Engineering CY SEP 21-23, 1999 CL ROME, ITALY ID BLOCKADE-DOMINATED TRANSPORT; LITHOGRAPHY; FABRICATION AB Direct electron beam writing of metallic nanostructures using metallorganic compounds as precursors offers a method of fabricating nanostructures with a reduced number of processing steps compared with conventional electron beam lithography (EBL). We have used passivated gold nanoclusters, prepared as a thin layer on highly orientated pyrolitic graphite (HOPG), to produce gold nanostructures directly. The passivating organic ligands were removed by an electron beam in a scanning electron microscope (SEM), thus allowing the gold to aggregate and form nanostructures. The resulting structures have a width as small as 26nm with a separation as low as 30nm. The nanostructures are stable and remain intact after removal from the SEM. Energy dispersive X-ray analysis confirms that the structures do indeed contain gold. C1 Univ Birmingham, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. Sandia Natl Labs, Nanostruct & Adv Mat Dept, Albuquerque, NM 87185 USA. RP Univ Birmingham, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. RI Palmer, Richard/A-5366-2008 OI Palmer, Richard/0000-0001-8728-8083 NR 14 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 EI 1873-5568 J9 MICROELECTRON ENG JI Microelectron. Eng. PD JUN PY 2000 VL 53 IS 1-4 BP 187 EP 190 DI 10.1016/S0167-9317(00)00293-8 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 341RL UT WOS:000088603300036 ER PT J AU Gianoulakis, S Liddle, J Stanton, S Gallatin, G AF Gianoulakis, S Liddle, J Stanton, S Gallatin, G TI Thermal distortion predictions of a silicon wafer during exposure in a scalpel tool SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 25th International Conference on Micro- and Nano-Engineering CY SEP 21-23, 1999 CL ROME, ITALY AB Lucent Technologies Bell Laboratories is developing a projection electron lithography system known as SCALPEL for post-optical lithography. SCALPEL employs a full die area patterned mask and a 0.25 mm imaging sub-field which is electronically scanned to provide a 3 mm long "effective field" area. This elemental image area is stitched to neighboring areas as mask and wafer stages make complementary motions. SCALPEL utilizes a typical 25 mA current of 100keV electrons. One issue of concern is the thermal distortion of the silicon wafer during exposure, due to power absorbed from the electron beam. This transient thermal expansion needs to be quantified to support the development of optimized writing strategies and associated correction. This paper presents a multi-level distortion characterization of a silicon wafer during exposure in a SCALPEL tool. C1 Sandia Natl Labs, Thermal Sci Dept, Albuquerque, NM 87123 USA. Bell Labs, Lucent Technol, Adv Lithog Res, Murray Hill, NJ 07974 USA. RP Gianoulakis, S (reprint author), Sandia Natl Labs, Thermal Sci Dept, 1515 Eubank SE MSo836, Albuquerque, NM 87123 USA. RI Gallatin, Gregg/H-1998-2012 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 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD JUN PY 2000 VL 53 IS 1-4 BP 357 EP 360 DI 10.1016/S0167-9317(00)00333-6 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 341RL UT WOS:000088603300076 ER PT J AU de Leon, JM Espinosa, FJ Perez, VA Jimenez-Sandoval, S Lopez-Lopez, S Montano, PA AF de Leon, JM Espinosa, FJ Perez, VA Jimenez-Sandoval, S Lopez-Lopez, S Montano, PA TI Local atomic environment of Cu : CdTe thin film alloys SO MICROELECTRONICS JOURNAL LA English DT Article DE semiconductor alloys; solar cells; doping limits; local atomic structure AB We have used X-ray absorption spectroscopy of the K-edge of each element in a Cd0.85Cu0.15Te thin film to investigate the local atomic structure around each constituent element. X-ray absorption near edge spectra reveal that the local electronic structure around Cd and Te atoms is similar to that of undoped CdTe, while that of Cu is different from that encountered in Cu metal. X-ray absorption fine structure spectra show that while the Cd near neighbor environment is similar to that of undoped CdTe, the Te environment shows differences compared with that found in undoped CdTe, consistent with Cu entering substitutionally for Cd. The Cu nearest neighbor environment suggests the presence of Cu-metal ligands characteristic of Cu metal clusters. These results imply the occurrence of microscopic phase separation in this material in variance with X-ray diffraction results that show a single crystalline phase. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 CINVESTAV, Dept Fis Aplicada, Merida 97133, Yucatan, Mexico. CINVESTAV, Lab Invest Mat, Queretaro 76001, Mexico. CINVESTAV, Dept Fis, Mexico City 07000, DF, Mexico. Argonne Natl Lab, Adv Photon Source, CAT, BESSRC, Argonne, IL 60439 USA. RP de Leon, JM (reprint author), CINVESTAV, Dept Fis Aplicada, AP 73, Merida 97133, Yucatan, Mexico. RI Jimenez-Sandoval, Sergio/A-9627-2015 OI Jimenez-Sandoval, Sergio/0000-0002-2143-3759 NR 6 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0026-2692 J9 MICROELECTR J JI Microelectron. J. PD JUN PY 2000 VL 31 IS 6 BP 429 EP 431 DI 10.1016/S0026-2692(00)00010-0 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA 326LT UT WOS:000087737600006 ER PT J AU Xue, Y Bai, XX Lee, I Kallstrom, G Ho, J Brown, J Stevens, A Johnson, AW AF Xue, Y Bai, XX Lee, I Kallstrom, G Ho, J Brown, J Stevens, A Johnson, AW TI Saccharomyces cerevisiae RAI1 (YGL246c) is homologous to human DOM3Z and encodes a protein that binds the nuclear exoribonuclease Rat1p SO MOLECULAR AND CELLULAR BIOLOGY LA English DT Article ID LACKING 5'->3' EXORIBONUCLEASE-1; SMALL NUCLEOLAR RNAS; PRE-RIBOSOMAL-RNA; DEVH-BOX PROTEIN; MESSENGER-RNA; YEAST-CELLS; GENE; EXOSOME; EXONUCLEASES; PURIFICATION AB The RAT1 gene of Saccharomyces cerevisiae encodes a 5'-->3' exoribonuclease which plays an essential role in yeast RNA degradation and/or processing in the nucleus. We have cloned a previously uncharacterized gene (YGL246c) that we refer to as RAI1 (Rat1p interacting protein 1). RAI1 is homologous to Caenorhabditis elegans DOM-3 and human DOM3Z. Deletion of RAI1 confers a growth defect which can be complemented by an additional copy of RAT1 on a centromeric vector or by directing Xrn1p, the cytoplasmic homolog of Rat1p, to the nucleus through the addition of a nuclear targeting sequence. Deletion of RAI1 is synthetically lethal with the rat1-1(ts) mutation and shows genetic interaction with a deletion of SKI2 but not XRN1. Polysome analysis of an rail deletion mutant indicated a defect in 60S biogenesis which was nearly fully reversed by high-copy RAT1. Northern blot analysis of rRNAs revealed that rail is required for normal 5.8S processing. In the absence of RAI1, 5.8S(L) was the predominant form of 5.8S and there was an accumulation of 3'-extended forms but not 5'-extended species of 5.8S. In addition, a 27S pre-rRNA species accumulated in the rail mutant. Thus, deletion of RAI1 affects both 5' and 3' processing reactions of 5.8S rRNA. Consistent with the in vivo data suggesting that RAI1 enhances RAT1 function, purified Rai1p stabilized the in vitro exoribonuclease activity of Rat1p. C1 Univ Texas, Sect Mol Genet & Microbiol, Austin, TX 78712 USA. Univ Texas, Inst Mol & Cellular Biol, Austin, TX 78712 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Johnson, AW (reprint author), Univ Texas, Sect Mol Genet & Microbiol, Austin, TX 78712 USA. RI Lee, Insuk/F-7722-2010 NR 44 TC 78 Z9 81 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 JUN PY 2000 VL 20 IS 11 BP 4006 EP 4015 DI 10.1128/MCB.20.11.4006-4015.2000 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 313UF UT WOS:000087017100025 PM 10805743 ER PT J AU Dai, ZY Hooker, BS Anderson, DB Thomas, SR AF Dai, ZY Hooker, BS Anderson, DB Thomas, SR TI Improved plant-based production of E1 endoglucanase using potato: expression optimization and tissue targeting SO MOLECULAR BREEDING LA English DT Article DE Acidothermus cellulolyticus; cellulase; dual-crop production; E1 endoglucanase; expression optimization; potato ID MATRIX ATTACHMENT REGIONS; ACIDOTHERMUS-CELLULOLYTICUS; TRANSGENIC TOBACCO; GENE-EXPRESSION; PROTEIN; SEQUENCE; ACCUMULATION; INDUCTION; PRECURSOR; TOMATO AB Optimization of Acidothermus cellulolyticus endoglucanase (E1) gene expression in transgenic potato (Solanum tuberosum L.) was examined in this study, where the E1 coding sequence was transcribed under control of a leaf specific promoter (tomato RbcS-3C) or the Mac promoter (a hybrid promoter of mannopine synthase promoter and cauliflower mosaic virus 35S promoter enhancer region). Average E1 activity in leaf extracts of potato transformants, in which E1 protein was targeted by a chloroplast signal peptide and an apoplast signal peptide were much higher than those by an E1 native signal peptide and a vacuole signal peptide. E1 protein accumulated up to 2.6% of total leaf soluble protein, where E1 gene was under control of the RbcS-3C promoter, alfalfa mosaic virus 5'-untranslated leader, and RbcS-2A signal peptide. E1 protein production, based on average E1 activity and E1 protein accumulation in leaf extracts, is higher in potato than those measured previously in transgenic tobacco bearing the same transgene constructs. Comparisons of E1 activity, protein accumulation, and relative mRNA levels showed that E1 expression under control of tomato RbcS-3C promoter was specifically localized in leaf tissues, while E1 gene was expressed in both leaf and tuber tissues under control of Mac promoter. This suggests dual-crop applications in which potato vines serve as enzyme production 'bioreactors' while tubers are preserved for culinary applications. C1 Pacific NW Natl Lab, Environm Technol Div, Bioproc Grp, Richland, WA 99352 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dai, ZY (reprint author), Pacific NW Natl Lab, Environm Technol Div, Bioproc Grp, POB 999,MSIN K2-10, Richland, WA 99352 USA. NR 34 TC 55 Z9 60 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1380-3743 J9 MOL BREEDING JI Mol. Breed. PD JUN PY 2000 VL 6 IS 3 BP 277 EP 285 DI 10.1023/A:1009653011948 PG 9 WC Agronomy; Plant Sciences; Genetics & Heredity; Horticulture SC Agriculture; Plant Sciences; Genetics & Heredity GA 356AW UT WOS:000089421700005 ER PT J AU Balhorn, R Brewer, L Corzett, M AF Balhorn, R Brewer, L Corzett, M TI DNA condensation by protamine and arginine-rich peptides: Analysis of toroid stability using single DNA molecules SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article; Proceedings Paper CT Workshop on Sperm-Mediated Gene Transfer - Advances in Sperm Cell Research and Applications CY MAY 23-26, 1999 CL SIENA, ITALY DE optical trap; sperm chromatin; dissociation rate ID SPERM CELLS; GENE; MICROSCOPY; EGGS; MICE AB Both somatic cells and sperm have been shown to take up exogenous DNA, but the frequency of its integration is usually low. Scanning probe microscopy studies of sperm chromatin and synthetic DNA-protamine complexes indicate that the coiling of DNA into toroidal subunits, a process initiated in the maturing spermatid to prepare its genome for delivery into the egg, can be mimicked by simply adding protamine to DNA in vitro. The increased resistance of DNA-protamine complexes to nuclease digestion and their structural similarity to native sperm chromatin suggest that the packaging of DNA by protamine might offer a new approach for improving the efficiency of DNA uptake by sperm. Decondensation experiments performed with individual DNA molecules have provided a direct measure of the stability of toroids produced using salmon protamine and smaller arginine-rich peptides. These experiments show that the arginine content of protamine-related sequences can have a dramatic effect on their rate of dissociation from DNA. This technique and the information it provides can be used to identify protamine analogs that can be bound to DNA to increase the efficiency of its uptake by sperm and other cells. Published 2000 Wiley-Liss, Inc.(dagger) C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. RP Balhorn, R (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. NR 15 TC 62 Z9 66 U1 0 U2 8 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD JUN PY 2000 VL 56 IS 2 SU S BP 230 EP 234 DI 10.1002/(SICI)1098-2795(200006)56:2+<230::AID-MRD3>3.0.CO;2-V PG 5 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA 311YQ UT WOS:000086914600003 PM 10824973 ER PT J AU Vuille, F O'Donoghue, D Buckley, DAH Massacand, CM Solheim, JE Bard, S Vauclair, G Giovannini, O Kepler, SO Kanaan, A Provencal, JL Wood, MA Clemens, JC Kleinman, SJ O'Brien, MS Nather, RE Winget, DE Nitta, A Klumpe, EW Montgomery, MH Watson, TK Bradley, PA Sullivan, DJ Wu, K Marar, TMK Seetha, S Ashoka, BN Mahra, HS Bhat, BC Babu, VC Leibowitz, EM Hemar, S Ibbetson, P Mashals, E Meistas, E Moskalik, P Zola, S Krzesinski, J Pajdosz, G AF Vuille, F O'Donoghue, D Buckley, DAH Massacand, CM Solheim, JE Bard, S Vauclair, G Giovannini, O Kepler, SO Kanaan, A Provencal, JL Wood, MA Clemens, JC Kleinman, SJ O'Brien, MS Nather, RE Winget, DE Nitta, A Klumpe, EW Montgomery, MH Watson, TK Bradley, PA Sullivan, DJ Wu, K Marar, TMK Seetha, S Ashoka, BN Mahra, HS Bhat, BC Babu, VC Leibowitz, EM Hemar, S Ibbetson, P Mashals, E Meistas, E Moskalik, P Zola, S Krzesinski, J Pajdosz, G TI Normal modes and discovery of high-order cross-frequencies in the DBV white dwarf GD 358 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : individual : GD 358; stars : variables : other; white dwarfs ID WHOLE EARTH TELESCOPE; TIME-SERIES ANALYSIS; ZZ CETI STARS; PULSATIONS; GD-358; LIGHT AB We present a detailed mode identification performed on the 1994 Whole Earth Telescope (WET) run on GD 358. The results are compared with that obtained for the same star from the 1990 WET data. The two temporal spectra show very few qualitative differences, although amplitude changes are seen in most modes, including the disappearance of the mode identified as k = 14 in the 1990 data. The excellent coverage and signal-to-noise ratio obtained during the 1994 run lead to the secure identification of combination frequencies up to fourth order, i.e. peaks that are sums or differences of up to four parent frequencies, including a virtually complete set of second-order frequencies, as expected from harmonic distortion. We show how the third-order frequencies are expected to affect the triplet structure of the normal modes by back-interacting with them. Finally, a search for l = 2 modes was unsuccessful, not verifying the suspicion that such modes had been uncovered in the 1990 data set. C1 Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South Africa. S African Astron Observ, ZA-7935 Observatory, South Africa. Univ Tromso, Nordlysobserv, MR, N-9037 Tromso, Norway. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Fed Rio Grande Sul, Inst Fis, BR-91500970 Porto Alegre, RS, Brazil. Univ Fed Santa Catarina, Dept Fis, BR-88040900 Florianopolis, SC, Brazil. Univ Delaware, Dept Phys & Astron, Sharp Lab, Newark, DE 19716 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Vienna, Inst Astron, A-1180 Vienna, Austria. Southwestern Univ, Informat Technol Serv, Georgetown, TX 78626 USA. Univ Calif Los Alamos Natl Lab, XTA, Los Alamos, NM 87545 USA. Victoria Univ Wellington, Dept Phys, Wellington, New Zealand. Univ Sydney, Sch Phys, Res Ctr Theoret Astrophys, Sydney, NSW 2006, Australia. ISRO, Satellite Ctr, Tech Phys Div, Bangalore 560017, Karnataka, India. Tel Aviv Univ, Dept Phys & Astron, IL-69978 Tel Aviv, Israel. Inst Theoret Phys & Astron, LT-2600 Vilnius, Lithuania. Polish Acad Sci, Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. Cracow Pedag Univ, Mt Suhora Observ, PL-30084 Krakow, Poland. RP Vuille, F (reprint author), Eterpy 49, CH-1020 Renens, Switzerland. RI Kepler, S. O. /H-5901-2012 OI Kepler, S. O. /0000-0002-7470-5703 NR 26 TC 24 Z9 24 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 1 PY 2000 VL 314 IS 4 BP 689 EP 701 DI 10.1046/j.1365-8711.2000.03369.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 321XJ UT WOS:000087480300006 ER PT J AU Kao, CYJ Hang, YH Reisner, JM Smith, WS AF Kao, CYJ Hang, YH Reisner, JM Smith, WS TI Test of the volume-of-fluid method on simulations of marine boundary layer clouds SO MONTHLY WEATHER REVIEW LA English DT Article ID ADVECTION-CONDENSATION PROBLEM; DIURNAL-VARIATION; RADIATIVE PROPERTIES; STRATOCUMULUS; FIRE; DYNAMICS; FLOWS AB The impact of using grid-averaged thermodynamic properties (i.e., neglecting their subgrid variability due to partial cloudiness) to represent forcings for condensation or evaporation has long been recognized. In particular, numerical difficulties in terms of spurious oscillations and/or diffusion in vicinity of a cloud-environment interface have been encountered in most of the conventional finite-difference Eulerian advection schemes. This problem is equivalent to the inability of models to accurately track the cloud boundary within a grid cell, which eventually leads to spurious production or destruction of cloud water at leading or trailing edges of clouds. This paper employs a specialized technique called the "volume-of-fluid" (VOF) method to better parameterize the subgrid-scale advection process that accounts for the transport of material interfaces. VOF also determines the actual location of the partial cloudiness within a grid box. Consequently, relevant microphysical parameterizations in mixed cells can be consistently applied in "cloudy" and "clear" regions. The VOF technique is incorporated in a two-dimensional hydrodynamic model to simulate the diurnal cycle of the marine stratocumulus-capped boundary layer. The fidelity of VOF to advection-condensation processes under a diurnal radiative forcing is assessed by comparing the model simulation with data taken during the ISCCP FIRE observational period as well as with results from simulations without VOF This study shows that the VOF method indeed suppresses the spurious cloud boundary instability and support, a multiday cloud evolution as observed. For the case without VOF, the spurious instability near the cloud top causes the dissipation of the entire cloud layer within a half of a diurnal cycle. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Kao, CYJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, EES-8,MS C300, Los Alamos, NM 87545 USA. NR 32 TC 7 Z9 7 U1 0 U2 0 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 JUN PY 2000 VL 128 IS 6 BP 1960 EP 1970 DI 10.1175/1520-0493(2000)128<1960:TOTVOF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 322WW UT WOS:000087533100021 ER PT J AU Haynes, TE AF Haynes, TE TI Defects and diffusion in silicon technology SO MRS BULLETIN LA English DT Article C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Haynes, TE (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 0 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD JUN PY 2000 VL 25 IS 6 BP 14 EP 15 DI 10.1557/mrs2000.118 PG 2 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 325VL UT WOS:000087697100014 ER PT J AU Istratov, AA Hieslmair, H Weber, ER AF Istratov, AA Hieslmair, H Weber, ER TI Advanced Gettering techniques in ULSI technology SO MRS BULLETIN LA English DT Article ID CZOCHRALSKI-GROWN SILICON; BORON-DOPED SILICON; IRON IMPURITIES; TRANSITION-ELEMENTS; GATE OXIDES; DIFFUSION; FE; CONTAMINATION; IMPACT; COPPER C1 Univ Calif Berkeley, Res Grp, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Istratov, AA (reprint author), Univ Calif Berkeley, Res Grp, Berkeley, CA 94720 USA. OI Hieslmair, Henry/0000-0002-5842-1882 NR 56 TC 16 Z9 16 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD JUN PY 2000 VL 25 IS 6 BP 33 EP 38 DI 10.1557/mrs2000.96 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 325VL UT WOS:000087697100018 ER PT J AU Suhy, J Rooney, WD Goodkin, DE Capizzano, AA Soher, BJ Maudsley, AA Waubant, E Andersson, PB Weiner, MW AF Suhy, J Rooney, WD Goodkin, DE Capizzano, AA Soher, BJ Maudsley, AA Waubant, E Andersson, PB Weiner, MW TI H-1 MRSI comparison of white matter and lesions in primary progressive and relapsing-remitting MS SO MULTIPLE SCLEROSIS JOURNAL LA English DT Article DE primary progressive multiple sclerosis; magnetic resonance spectroscopy ID MAGNETIC-RESONANCE SPECTROSCOPY; MULTIPLE-SCLEROSIS; AXONAL DAMAGE; BRAIN; MRI; DISABILITY; PATHOLOGY; DISEASE AB To compare brain metabolite levels in patients with primary progressive (PP) and relapsing remitting (RR) MS and controls. Hypotheses: (1) creatine (Cr), a putative marker of gliosis, is elevated and N-acetylospartate (NAA), a putative marker of axonal density and functional integrity, is reduced in PPMS lesions and normal appearing white matter (NAWM) compared to control white matter; (2) The pattern of metobolite change in PPMS is different than in RRMS. Methods: MRI and proton magnetic resonance spectroscopic imaging (H-1 MRSI) were collected from 15 PPMS patients, 13 RRMS patients, and 20 controls. Results: Cr was increased in PPMS NAWM compared to controls (P=0.035), and compared to RRMS NAWM (P=0.038). Cr was increased in focal MRI lesions from PPMS compared to lesions from RRMS (P=0.044) and compared to control white matter (P=0.041). NAA was similarly reduced in PPMS and RRMS NAWM compared to control. NAA was similarly reduced in PPMS and RRMS lesions, compared to control white matter. Conclusions: Creatine is higher in PPMS than RRMS NAWM and focal lesions. This observation is consistent with the notion that progressive disability in PPMS reflects increased gliosis and axonal loss whereas disability in RRMS reflects the cumulative effects of acute inflammatory lesions and axonal loss. C1 DNA Med Ctr, Magnet Resonance Unit 114M, San Francisco, CA 94121 USA. Univ Calif San Francisco, Dept Radiol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP DNA Med Ctr, Magnet Resonance Unit 114M, 4150 Clement St, San Francisco, CA 94121 USA. FU NIA NIH HHS [AG12119, R01 AG012119, R01 AG012119-06] NR 40 TC 64 Z9 65 U1 0 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1352-4585 EI 1477-0970 J9 MULT SCLER J JI Mult. Scler. J. PD JUN PY 2000 VL 6 IS 3 BP 148 EP 155 PG 8 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 320PL UT WOS:000087409500003 PM 10871825 ER PT J AU Wei, YY Eres, G AF Wei, YY Eres, G TI Direct fabrication of carbon nanotube circuits by selective area chemical vapour deposition on pre-patterned structures SO NANOTECHNOLOGY LA English DT Article; Proceedings Paper CT 7th Annual Foresight Conference on Molecular Nanotechnology CY OCT 15-17, 1999 CL SANTA CLARA, CALIFORNIA ID GROWTH AB We report on a method for self-assembly of integrated carbon nanotube circuits using selective area chemical vapour deposition on pre-patterned catalyst electrodes. The circuits consist of a multi-wall 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 500 nm thick SiO2 film on Si substrates. Following metal evaporation and lift-off, chemical vapour 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, multi-wall nanotube. The resistance of the carbon nanotube circuits at room temperature is typically less than 100 k Omega. For a few high-resistance samples (>>100 k Omega) transport properties were studied in a temperature range from room temperature to 2 K. At room temperature the I-V is linear. The resistance increases with decreasing temperature, and the I-V gradually becomes nonlinear. At low temperatures a gap appears around V = 0 suggesting semiconducting behaviour. 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 20 TC 7 Z9 7 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD JUN PY 2000 VL 11 IS 2 BP 61 EP 64 DI 10.1088/0957-4484/11/2/304 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 325RP UT WOS:000087690400005 ER PT J AU Milonni, PW AF Milonni, PW TI Quantum decay - A watched pot boils quicker SO NATURE LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Milonni, PW (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 9 TC 4 Z9 4 U1 0 U2 3 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 1 PY 2000 VL 405 IS 6786 BP 525 EP + DI 10.1038/35014719 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 321HF UT WOS:000087449500033 ER PT J AU Hannon, JB Hibino, H Bartelt, NC Swartzentruber, BS Ogino, T Kellogg, GL AF Hannon, JB Hibino, H Bartelt, NC Swartzentruber, BS Ogino, T Kellogg, GL TI Dynamics of the silicon (111) surface phase transition SO NATURE LA English DT Article ID ELECTRON-MICROSCOPY; SI(111); RECONSTRUCTIONS AB The manner in which phase transformations occur in solids determines important structural and physical properties of many materials. The main problem in characterizing the kinetic processes that occur during phase transformations is the difficulty of observing directly, in real time, the growth of one phase at the expense of another. Here we use low-energy electron microscopy to study the real-time kinetics of a phase transformation confined to the silicon (111) surface. We show that the transformation is governed by the rate at which material is exchanged between the first layer of the crystal and the surface. In bulk phase transformations. the dynamics are usually governed either by the rate of diffusion of material to the phase boundaries or by the structural rearrangement of atoms at the phase boundary(1). The kinetic process that we have identified here has no bulk analogue and leads to domain dynamics that are qualitatively different from these expected for bulk systems. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. NTT, Basic Res Labs, Kanagawa 2430198, Japan. Sandia Natl Labs, Livermore, CA 94551 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hannon, JB (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. RI Hibino, Hiroki/D-2072-2014; Hibino, Hiroki/E-9443-2016; OI Hibino, Hiroki/0000-0002-8604-8640; Hibino, Hiroki/0000-0002-8604-8640; Ogino, Toshio/0000-0002-3241-5652 NR 13 TC 36 Z9 38 U1 5 U2 22 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 1 PY 2000 VL 405 IS 6786 BP 552 EP 554 DI 10.1038/35014569 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 321HF UT WOS:000087449500045 ER PT J AU Sikes, EL Samson, CR Guilderson, TP Howard, WR AF Sikes, EL Samson, CR Guilderson, TP Howard, WR TI Old radiocarbon ages in the southwest Pacific Ocean during the last glacial period and deglaciation SO NATURE LA English DT Article ID DEEP-WATER; SOUTHERN-OCEAN; YOUNGER DRYAS; NEW-ZEALAND; CIRCULATION; CLIMATE; RECORDS; TEPHRA; EVENT AB Marine radiocarbon (C-14) dates are widely used for dating oceanic events and as tracers of ocean circulation, essential components for understanding ocean-climate interactions. Past ocean ventilation rates have been determined by the difference between radiocarbon ages of deep-water and surface-water reservoirs, but the apparent age of surface waters (currently similar to 400 years in the tropics and similar to 1,200 years in Antarctic waters(1)) might not be constant through time(2), as has been assumed in radiocarbon chronologies(3,4) and palaeoclimate studies(5). Here we present independent estimates of surface-water and deep-water reservoir ages in the New Zealand region since the last glacial period, using volcanic ejecta (tephras) deposited in both marine and terrestrial sediments as stratigraphic markers. Compared to present-day values, surface-reservoir ages from 11,900 C-14 years ago were twice as large (800 years) and during glacial times were five times as large (2,000 years), contradicting the assumption of constant surface age. Furthermore, the ages of glacial deepwater reservoirs were much older (3,000-5,000 years). The increase in surface-to-deep water age differences in the glacial Southern Ocean suggests that there was decreased ocean ventilation during this period. C1 Univ Auckland, Sch Environm & Marine Sci, Auckland 1, New Zealand. Univ Auckland, Dept Geol, Auckland 1, New Zealand. Antarctic Cooperat Res Ctr, Hobart, Tas, Australia. Univ Tasmania, Inst Antarctic & So Ocean Studies, Hobart, Tas 7001, Australia. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Sikes, EL (reprint author), Univ Auckland, Sch Environm & Marine Sci, Private Bag 92019, Auckland 1, New Zealand. NR 31 TC 174 Z9 176 U1 2 U2 22 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 1 PY 2000 VL 405 IS 6786 BP 555 EP 559 DI 10.1038/35014581 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 321HF UT WOS:000087449500046 ER PT J AU Fisch, NJ AF Fisch, NJ TI Physics of alpha channelling and related TFTR experiments SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 2nd IAEA Technical Committee Meeting on Steady State Operation of Magnetic Fusion Devices, Plasma Control and Plasma Facing Components CY OCT 25-29, 1999 CL FUKUOKA, JAPAN SP Int Atom Energy Agcy, Adv Fus Res Ctr, Kyushu Univ ID CURRENT DRIVE; WAVES; TOKAMAK; PARTICLES; PLASMAS AB Over the last thirty years, there have been increasingly ambitious theories and experiments along the theme of exercising increased control over plasma by means of RF waves. The diversion of energy from energetic alpha particles to waves (alpha channelling) is such an attempt at detailed control over plasma behavior. The effect could accelerate progress towards an economical deuterium-tritium tokamak reactor. Recent simulations and experiments on TFTR support certain separate building blocks that taken together might produce the desired effect. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Fisch, NJ (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM fisch@pppl.gov NR 19 TC 21 Z9 21 U1 1 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 JUN PY 2000 VL 40 IS 6 BP 1095 EP 1100 DI 10.1088/0029-5515/40/6/307 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 327QV UT WOS:000087805000008 ER PT J AU Jardin, SC AF Jardin, SC TI Timescales for non-inductive current buildup in low aspect ratio toroidal geometry SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 2nd IAEA Technical Committee Meeting on Steady State Operation of Magnetic Fusion Devices, Plasma Control and Plasma Facing Components CY OCT 25-29, 1999 CL FUKUOKA, JAPAN SP Int Atom Energy Agcy, Adv Fus Res Ctr, Kyushu Univ ID LOWER-HYBRID WAVES; CURRENT DIFFUSION; PLASMA CURRENT; CURRENT DRIVE; TOKAMAK; SUSTAINMENT; STARTUP; TORUS AB The fundamental differences between inductive and non-inductive current buildup are clarified and the associated timescales and other implications are discussed. A simulation is presented whereby the plasma current in a low aspect ratio torus is increased primarily by self-generated bootstrap current, with only 10% coming from external current drive. The maximum obtainable plasma current from this process is shown to scale with toroidal field strength. The basic physics setting the timescales can be obtained from a 1-D analysis. Comparisons are made between the timescales found here and those reported in the experimental literature. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Jardin, SC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Jardin, Stephen/E-9392-2010 NR 24 TC 14 Z9 14 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 JUN PY 2000 VL 40 IS 6 BP 1101 EP 1112 DI 10.1088/0029-5515/40/6/308 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 327QV UT WOS:000087805000009 ER PT J AU Bonoli, PT Parker, RR Porkolab, M Ramos, JJ Wukitch, SJ Takase, Y Bernabei, S Hosea, JC Schilling, G Wilson, JR AF Bonoli, PT Parker, RR Porkolab, M Ramos, JJ Wukitch, SJ Takase, Y Bernabei, S Hosea, JC Schilling, G Wilson, JR TI Modelling of advanced tokamak scenarios with LHCD in Alcator C-Mod SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 2nd IAEA Technical Committee Meeting on Steady State Operation of Magnetic Fusion Devices, Plasma Control and Plasma Facing Components CY OCT 25-29, 1999 CL FUKUOKA, JAPAN SP Int Atom Energy Agcy, Adv Fus Res Ctr, Kyushu Univ ID HYBRID CURRENT DRIVE AB A combined model for current profile control and MHD stability analysis has been used to identify stable operating modes near the ideal stability limit (beta(N) similar or equal to 3) in the Alcator C-Mod tokamak. These discharges are characterized by relatively high fractions of bootstrap current (f(BS) = 0.70) and non-monotonic profiles of the safety factor with q(min) > 2. In the absence of a conducting shell, stability was determined by the onset of the low (n = 1) external kink mode. In these studies, current profile control in the plasma periphery (r/a greater than or similar to 0.5) was provided by 2.5-3.0 MW of LHCD power. Internal and edge transport barriers were introduced into the model calculations in the form of density transitions. Excellent wave accessibility and absorption were still found in the presence of an H-mode-like edge density barrier. However, the presence of these barriers resulted in about a 10% decrease in the stability limit, from beta(N) similar or equal to 3 to beta(N) similar or equal to 2.7. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Univ Tokyo, Tokyo, Japan. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Bonoli, PT (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 12 TC 19 Z9 19 U1 1 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2000 VL 40 IS 6 BP 1251 EP 1256 DI 10.1088/0029-5515/40/6/319 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 327QV UT WOS:000087805000020 ER PT J AU Murakami, M St John, HE Casper, TA Chu, MS DeBoo, JC Greenfield, CM Kinsey, JE Lao, LL La Haye, RJ Lin-Liu, YR Luce, TC Politzer, PA Rice, BW Staebler, GM Taylor, TS Wade, MR AF Murakami, M St John, HE Casper, TA Chu, MS DeBoo, JC Greenfield, CM Kinsey, JE Lao, LL La Haye, RJ Lin-Liu, YR Luce, TC Politzer, PA Rice, BW Staebler, GM Taylor, TS Wade, MR CA DIII-D Res Team TI Status of advanced tokamak scenario modelling with off-axis electron cyclotron current drive in DIII-D SO NUCLEAR FUSION LA English DT Article; Proceedings Paper CT 2nd IAEA Technical Committee Meeting on Steady State Operation of Magnetic Fusion Devices, Plasma Control and Plasma Facing Components CY OCT 25-29, 1999 CL FUKUOKA, JAPAN SP Int Atom Energy Agcy, Adv Fus Res Ctr, Kyushu Univ ID TEARING MODES; PLASMA; CONDUCTIVITY; STABILITY; TRANSPORT AB The status of modelling work focused on developing the advanced tokamak (AT) scenarios in DIII-D is discussed. The objective of the work is twofold: (a) to develop AT scenarios with ECCD using time dependent transport simulations, coupled with heating and current drive models, consistent with MHD equilibrium and stability; and (b) to use time dependent simulations to help plan experiments and to understand the key physics involved. Time dependent simulations based on transport coefficients derived from experimentally achieved target discharges are used to perform AT scenario modelling. The modelling indicates that off-axis ECCD with approximately 3 MW absorbed power can maintain high performance discharges with q(min) > 1 for 5-10 s. The resultant equilibria are calculated to be stable to n = 1 pressure driven modes. The plasma is well into the second stability regime for high-n ballooning modes over a large part of the plasma volume. The role of continuous localized ECCD is studied for stabilizing m/n = 2/1 tearing modes. Progress towards validating current drive and transport models, consistent with experimental results, and developing self-consistent, integrated high performance AT scenarios is discussed. C1 Gen Atom Co, San Diego, CA USA. RP Murakami, M (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 29 TC 13 Z9 13 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUN PY 2000 VL 40 IS 6 BP 1257 EP 1265 DI 10.1088/0029-5515/40/6/320 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 327QV UT WOS:000087805000021 ER PT J AU Lehner, F AF Lehner, F CA DO Collaboration TI The status of the DO silicon tracker upgrade project SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS AB The current status of the silicon tracker for the Dempty set upgrade project for Run II at the Tevatron is presented. After reviewing the design considerations the status of delivery and testing of the different silicon sensors is presented. The ladder production and assembly process is also discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermilab PPD, Batavia, IL 60510 USA. RP Lehner, F (reprint author), Fermilab PPD, POB 500, Batavia, IL 60510 USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 9 EP 14 DI 10.1016/S0168-9002(00)00167-4 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100003 ER PT J AU Bozzi, C Carassiti, V Ramusino, AC Dittongo, S Folegani, M Piemontese, L Abbott, BK Breon, AB Clark, AR Dow, S Fan, Q Goozen, F Hernikl, C Karcher, A Kerth, LT Kipnis, I Kluth, S Lynch, G Levi, M Luft, P Luo, L Nyman, M Pedrali-Noy, M Roe, NA Zizka, G Roberts, D Barni, D Brenna, E Defendi, I Forti, A Giugni, D Lanni, F Palombo, F Vaniev, V Leona, A Mandelli, E Manfredi, PF Perazzo, A Re, V Angelini, C Batignani, G Bettarini, S Bondioli, M Bosi, F Calderini, G Carpinelli, M Dutra, F Forti, F Gagliardi, D Giorgi, MA Lusiani, A Mammini, P Morganti, M Morsani, F Paoloni, E Profeti, A Rama, M Rampino, G Rizzo, G Sandrelli, F Simi, G Triggiani, G Tritto, S Vitale, R Burchat, P Cheng, C Kirkby, D Meyer, T Roat, C Bona, M Bianchi, F Daudo, F Di Girolamo, B Gamba, D Giraudo, G Grosso, P Romero, A Smol, A Trapani, P Zanin, D Bosisio, L Della Ricca, G Lanceri, L Pompili, A Poropat, P Prest, M Rastelli, C Vallazza, E Vuagnin, G Hast, C Potter, EP Sharma, V Burke, S Callahan, D Campagnari, C Dahmes, B Eppich, A Hale, D Hall, K Hart, P Kuznetsova, N Kyre, S Levy, S Long, O May, J Richman, J Verkerke, W Witherell, M Beringer, J Eisner, AM Frey, A Grillo, A Grothe, M Johnson, R Kroeger, W Lockman, W Pulliam, T Rowe, W Schmitz, R Seiden, A Spencer, E Turri, M Wilder, M Charles, E Elmer, P Nielsen, J Orejudos, W Scott, I Walsh, J Zobernig, H AF Bozzi, C Carassiti, V Ramusino, AC Dittongo, S Folegani, M Piemontese, L Abbott, BK Breon, AB Clark, AR Dow, S Fan, Q Goozen, F Hernikl, C Karcher, A Kerth, LT Kipnis, I Kluth, S Lynch, G Levi, M Luft, P Luo, L Nyman, M Pedrali-Noy, M Roe, NA Zizka, G Roberts, D Barni, D Brenna, E Defendi, I Forti, A Giugni, D Lanni, F Palombo, F Vaniev, V Leona, A Mandelli, E Manfredi, PF Perazzo, A Re, V Angelini, C Batignani, G Bettarini, S Bondioli, M Bosi, F Calderini, G Carpinelli, M Dutra, F Forti, F Gagliardi, D Giorgi, MA Lusiani, A Mammini, P Morganti, M Morsani, F Paoloni, E Profeti, A Rama, M Rampino, G Rizzo, G Sandrelli, F Simi, G Triggiani, G Tritto, S Vitale, R Burchat, P Cheng, C Kirkby, D Meyer, T Roat, C Bona, M Bianchi, F Daudo, F Di Girolamo, B Gamba, D Giraudo, G Grosso, P Romero, A Smol, A Trapani, P Zanin, D Bosisio, L Della Ricca, G Lanceri, L Pompili, A Poropat, P Prest, M Rastelli, C Vallazza, E Vuagnin, G Hast, C Potter, EP Sharma, V Burke, S Callahan, D Campagnari, C Dahmes, B Eppich, A Hale, D Hall, K Hart, P Kuznetsova, N Kyre, S Levy, S Long, O May, J Richman, J Verkerke, W Witherell, M Beringer, J Eisner, AM Frey, A Grillo, A Grothe, M Johnson, R Kroeger, W Lockman, W Pulliam, T Rowe, W Schmitz, R Seiden, A Spencer, E Turri, M Wilder, M Charles, E Elmer, P Nielsen, J Orejudos, W Scott, I Walsh, J Zobernig, H TI The design and construction of the BaBar silicon vertex tracker SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS AB The Silicon Vertex Tracker (SVT) of the BaBar experiment at the PEP-II asymmetric B factory consists of five layers of double-sided, AC-coupled silicon strip detectors. The detectors are readout with a custom IC, capable of simultaneous acquisition, digitization and transmission of data. The SVT geometry is shown and the construction phases of its modules are described in detail, with emphasis on the bending procedures needed for the arch-modules of the outer layers. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Ist Nazl Fis Nucl, I-44100 Ferrara, Italy. Univ Ferrara, I-44100 Ferrara, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Univ Milan, I-20133 Milan, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-24100 Bergamo, Italy. Univ Bergamo, I-24100 Bergamo, Italy. Ist Nazl Fis Nucl, I-56010 Pisa, Italy. Univ Pisa, I-56010 Pisa, Italy. Stanford Univ, Stanford, CA 94305 USA. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Turin, I-10125 Turin, Italy. Ist Nazl Fis Nucl, I-34100 Trieste, Italy. Univ Trieste, I-34100 Trieste, Italy. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Ist Nazl Fis Nucl, Via Paradiso 12, I-44100 Ferrara, Italy. EM stefano.bettarini@pi.infn.it RI Della Ricca, Giuseppe/B-6826-2013; Forti, Francesco/H-3035-2011; Roe, Natalie/A-8798-2012; Lusiani, Alberto/N-2976-2015; Lusiani, Alberto/A-3329-2016 OI Della Ricca, Giuseppe/0000-0003-2831-6982; Bettarini, Stefano/0000-0001-7742-2998; Forti, Francesco/0000-0001-6535-7965; Lusiani, Alberto/0000-0002-6876-3288; Lusiani, Alberto/0000-0002-6876-3288 NR 18 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 15 EP 25 DI 10.1016/S0168-9002(00)00168-6 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100004 ER PT J AU Abe, T AF Abe, T CA SLD Collaboration TI Current performance of the SLD VXD3 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS ID VERTEX DETECTOR; DESIGN; SYSTEM AB During 1996, the SLD collaboration completed construction and began operation of a new charge-coupled device (CCD) vertex detector (VXD3). Since then, its performance has been studied in detail and a new topological vertexing technique has been developed. In this paper, we discuss the design of VXD3, procedures for aligning it, and the tracking and vertexing improvements that have led to its world-record performance. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Abe, T (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 15 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 90 EP 99 DI 10.1016/S0168-9002(00)00176-5 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100012 ER PT J AU Derwent, PF AF Derwent, PF CA CDF Collaboration D0 Collaboration TI Radiation monitoring for vertex detectors at the Tevatron SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS DE radiation; vertex detectors; Tevatron AB I present an overview of radiation monitoring for vertex detectors and the abort system for the Fermilab Tevatron. Details on the detectors, inputs, and measurements for the Run 1 time period are provided. Plans for the monitoring during Run 2 are discussed. The measurements imply an approximately even mix of radiation from beam-beam collisions and beam losses. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Derwent, PF (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 110 EP 115 DI 10.1016/S0168-9002(00)00178-9 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100014 ER PT J AU Collins, P Barnett, IBM Bartalini, P Bell, W Berglund, P de Boer, W Buontempo, S Borer, K Bowcock, T Buytaert, J Casagrande, L Chabaud, V Chochula, P Cindro, V Da Via, C Devine, S Dijkstra, H Dezillie, B Dimcovski, Z Dormond, O Eremin, V Esposito, A Frei, R Granata, V Grigoriev, E Hauler, F Heising, S Janos, S Jungermann, L Li, Z Lourenco, C Mikuz, M Niinikoski, TO O'Shea, V Palmieri, VG Paul, S Parkes, C Ruggiero, G Ruf, T Saladino, S Schmitt, L Smith, K Stavitski, I Verbitskaya, E Vitobello, F Zavrtanik, M AF Collins, P Barnett, IBM Bartalini, P Bell, W Berglund, P de Boer, W Buontempo, S Borer, K Bowcock, T Buytaert, J Casagrande, L Chabaud, V Chochula, P Cindro, V Da Via, C Devine, S Dijkstra, H Dezillie, B Dimcovski, Z Dormond, O Eremin, V Esposito, A Frei, R Granata, V Grigoriev, E Hauler, F Heising, S Janos, S Jungermann, L Li, Z Lourenco, C Mikuz, M Niinikoski, TO O'Shea, V Palmieri, VG Paul, S Parkes, C Ruggiero, G Ruf, T Saladino, S Schmitt, L Smith, K Stavitski, I Verbitskaya, E Vitobello, F Zavrtanik, M TI Cryogenic operation of silicon detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS DE silicon detectors; radiation damage; position resolution ID CHARGE COLLECTION EFFICIENCY; READOUT AB This paper reports on measurements at cryogenic temperatures of a silicon microstrip detector irradiated with 24 GeV protons to a fluence of 3.5 x 10(14) p/cm(2) and of a p-n junction diode detector irradiated to a similar fluence. At temperatures below 130 K a recovery of charge collection efficiency and resolution is observed. Under reverse bias conditions this recovery degrades in time towards some saturated value. The recovery is interpreted qualitatively as changes in the effective space charge of the detector causing alterations in the depletion voltage. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 CERN, Div EP, CH-1211 Geneva 23, Switzerland. Univ Mainz, Inst Kernphys, D-55099 Mainz, Germany. Univ Lausanne, Inst Phys Hautes Energies, CH-1015 Lausanne 20, Switzerland. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Helsinki Univ Technol, FIN-02150 Espoo, Finland. Univ Karlsruhe, IEKP, D-76128 Karlsruhe, Germany. Univ Naples Federico II, Dipartimento Fis, Naples, Italy. Univ Naples Federico II, Ist Nazl Fis Nucl, Naples, Italy. Univ Bern, Lab Hocherergiephys, CH-3012 Bern, Switzerland. Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. LIP, P-1000 Lisbon, Portugal. Comenius Univ, SK-84215 Bratislava, Slovakia. Univ Ljubljana, Jozef Stefan Inst, SI-1000 Ljubljana, Slovenia. Univ Ljubljana, Dept Phys, SI-1000 Ljubljana, Slovenia. Tech Univ Munich, Phys Dept E18, D-85748 Garching, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Geneva, Dept Radiol, Geneva, Switzerland. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Electrotech Lab, Electron Devices Div, Tsukuba, Ibaraki 3058568, Japan. CNR, Ist Cibernet, I-80072 Arco, Italy. Univ Padua, Dipartimento Fis, I-35131 Padua, Italy. Ist Nazl Fis Nucl, I-35131 Padua, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Florence, Florence, Italy. RP Collins, P (reprint author), CERN, Div EP, CH-1211 Geneva 23, Switzerland. RI Zavrtanik, Marko/A-1524-2008; Grigoriev, Eugene/K-6650-2013; O'Shea, Val/G-1279-2010; Verbitskaya, Elena/D-1521-2014; Paul, Stephan/F-7596-2015; Paul, Stephan/K-9237-2016 OI Zavrtanik, Marko/0000-0001-5606-6912; Grigoriev, Eugene/0000-0001-7235-9715; O'Shea, Val/0000-0001-7183-1205; Paul, Stephan/0000-0002-8813-0437; Paul, Stephan/0000-0002-8813-0437 NR 16 TC 3 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 151 EP 159 DI 10.1016/S0168-9002(00)00183-2 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100019 ER PT J AU Grim, GP Bishai, M Gay, C Hill, C Nahn, S Pellett, DE Pope, G Shepard, PF Slaughter, AJ Wester, WC AF Grim, GP Bishai, M Gay, C Hill, C Nahn, S Pellett, DE Pope, G Shepard, PF Slaughter, AJ Wester, WC TI Measurement of SEU cross sections in the CDF SVX3 ASIC using 63 MeV protons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS AB The single event upset (SEU) cross section has been measured for 63 MeV protons incident on static memory cells in the CDF SVX3 pipelined silicon strip readout ASIC. The device was fabricated in the Honeywell 0.8 mu m RICMOS IV bulk process, and contains a number of cells with minimum gate length transistors to control the mode of operation of the chip. Cross sections per cell of (4.4 +/- 1.8) x 10(-16) cm(2), (2.1 +/- 0.7)x 10(-15) cm(2), and (3.9 +/- 0.9) x 10(-15) cm(2) cm were measured for angles of incidence of 0 degrees, 45 degrees, and 80 degrees, respectively, for cells with 0.8 mu m gate length. The SVX3 SEU rate in Run II at the Fermilab Tevatron was estimated to be sufficiently low that it would not affect the performance of the CDF Silicon Tracker. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Yale Univ, New Haven, CT 06520 USA. Univ Pittsburgh, Pittsburgh, PA 15260 USA. RP Grim, GP (reprint author), Univ Calif Davis, Dept Phys, 1 Shield Ave, Davis, CA 95616 USA. RI Hill, Christopher/B-5371-2012 OI Hill, Christopher/0000-0003-0059-0779 NR 11 TC 3 Z9 3 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 1 PY 2000 VL 447 IS 1-2 BP 160 EP 166 DI 10.1016/S0168-9002(00)00184-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100020 ER PT J AU Back, B Betts, R Friedl, M Ganz, R Gulbrandsen, KH Holzman, B Kucewicz, W Lin, WT Mulmenstdt, J van Nieuwenhuizen, GJ Nouicer, R Pernegger, H Reuter, M Sarin, P Tsay, V Vale, CM Wadsworth, B Wuosmaa, A Wyslouch, B AF Back, B Betts, R Friedl, M Ganz, R Gulbrandsen, KH Holzman, B Kucewicz, W Lin, WT Mulmenstdt, J van Nieuwenhuizen, GJ Nouicer, R Pernegger, H Reuter, M Sarin, P Tsay, V Vale, CM Wadsworth, B Wuosmaa, A Wyslouch, B TI The PHOBOS silicon pad sensors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS AB PHOBOS is one of the four experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. PHOBOS utilizes silicon sensors to measure charged particle multiplicity distributions and to track particles in a 2-arm spectrometer. The detector consists of 450 silicon pad sensors. Nine different pad geometries are used to match the different physics needs of the experiment. A relatively high granularity, of up to 1536 channels per sensor, is used in the spectrometer. The multiplicity detector uses 128 and 64 channel sensors and the charge deposition per pad is measured to determine the multiplicity of single events. All sensors are of the double-metal silicon pad type with pad sizes from 1 up to 4 cm(2). They are produced in Taiwan by the ERSO foundry under supervision of Miracle Co. and National Central University. An extensive testing procedure makes it possible to select sensors suited for use in PHOBOS, Detector modules consisting of up to 5 sensors are read out with integrated chips of either 64 or 128 channels. The test results of the sensors and the performance of the assembled detector modules are discussed. (C) 2000 Elsevier Science B.V, All rights reserved. C1 MIT, Cambridge, MA 02139 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Natl Cent Univ, Dept Phys, High Energy Phys Grp, Chungli 32054, Taiwan. Miracle Technol Co Ltd, Hsinchu, Taiwan. RP van Nieuwenhuizen, GJ (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. OI Reuter, Michael/0000-0003-3881-8310 NR 2 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 257 EP 263 DI 10.1016/S0168-9002(00)00197-2 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100032 ER PT J AU Lynn, D Bellwied, R Beuttenmuller, R Caines, H Chen, W DiMassimo, D Dyke, H Elliot, D Eremin, V Grau, M Hoffmann, GW Humanic, T Ilyashenko, I Kotov, I Kraner, HW Kuczewski, P Leonhardt, B Li, Z Liaw, CJ LoCurto, G Middelkamp, P Minor, R Munhoz, M Ott, G Pandey, SU Pruneau, C Rykov, V Schambach, J Sedlmeir, J Soja, B Sugarbaker, E Takahashi, J Wilson, K Wilson, R AF Lynn, D Bellwied, R Beuttenmuller, R Caines, H Chen, W DiMassimo, D Dyke, H Elliot, D Eremin, V Grau, M Hoffmann, GW Humanic, T Ilyashenko, I Kotov, I Kraner, HW Kuczewski, P Leonhardt, B Li, Z Liaw, CJ LoCurto, G Middelkamp, P Minor, R Munhoz, M Ott, G Pandey, SU Pruneau, C Rykov, V Schambach, J Sedlmeir, J Soja, B Sugarbaker, E Takahashi, J Wilson, K Wilson, R TI The STAR silicon vertex tracker: a large area silicon drift detector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 8th International Workshop on Vertex Detectors (VERTEX 99) CY JUN 20-25, 1999 CL TEXEL, NETHERLANDS ID ELECTRON INJECTION AB The Solenoidal Tracker At RHIC-Silicon Vertex Tracker (STAR-SVT) is a three barrel microvertex detector based upon silicon drift detector technology. As designed for the STAR-SVT, silicon drift detectors (SDDs) are capable of providing unambiguous two-dimensional hit position measurements with resolutions on the order of 20 mu m in each coordinate. Achievement of such resolutions, particularly in the drift direction coordinate, depends upon certain characteristics of silicon and drift detector geometry that are uniquely critical for silicon drift detectors hit measurements. Here we describe features of the design of the STAR-SVT SDDs and the front-end electronics that are motivated by such characteristics. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11727 USA. Wayne State Univ, Detroit, MI 48201 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Sao Paulo, Sao Paulo, Brazil. RP Lynn, D (reprint author), Brookhaven Natl Lab, POB 5000,Bldg 510A, Upton, NY 11727 USA. RI Takahashi, Jun/B-2946-2012 OI Takahashi, Jun/0000-0002-4091-1779 NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 1 PY 2000 VL 447 IS 1-2 BP 264 EP 273 DI 10.1016/S0168-9002(00)00198-4 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 323BN UT WOS:000087545100033 ER PT J AU Tarkanyi, F Szelecsenyi, F Takacs, S Hermanne, A Sonck, M Thielemans, A Mustafa, MG Yu, SB Zhuang, YX AF Tarkanyi, F Szelecsenyi, F Takacs, S Hermanne, A Sonck, M Thielemans, A Mustafa, MG Yu, SB Zhuang, YX TI New experimental data, compilation and evaluation for the Cu-nat(alpha, x)Ga-66, Cu-nat(alpha, x)Ga-67 and Cu-nat(alpha, x)Zn-65 monitor reactions SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE copper target; alpha particles; cross-section; Cu-nat(alpha, x)Ga-66; Cu-nat(alpha, x)Ga-67 and Cu-nat(alpha, x)Zn-65 processes; monitor reactions; model calculations; recommended values ID INDUCED NUCLEAR-REACTIONS; DEUTERON INDUCED REACTIONS; EXCITATION-FUNCTIONS; BEAM ENERGY; RADIOISOTOPE PRODUCTION; NATURAL NICKEL; TI-NAT; NI-NAT; ALPHA; PROTON AB In the context of a systematic investigation of monitor reactions for charged particle beams, a detailed compilation and critical comparison of the earlier published data for the Cu-nat(alpha, x)Ga-66, Cu-nat(alpha, x)Ga-67 and Cu-nat(alpha, x)Zn-65 reactions have been performed. To solve the surprisingly large discrepancies found in the literature we also performed a new series of cross-section measurements up to 40 MeV for the above mentioned reactions. We discuss the reasons for the discrepancies and provide reliable numerical Values for a recommended database. The new experimental values and selected literature data were compared with the predictions of different model calculations. The selected experimental data sets were fitted using different methods to obtain recommended values. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Inst Nucl Res, ATOMKI, Cyclotron Dept, H-4026 Debrecen, Hungary. Free Univ Brussels, Cyclotron Dept, B-1090 Brussels, Belgium. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Obninsk Phys & Power Engn Inst, Obninsk 249020, Russia. China INst Atom Energy, China Nucl Data Ctr, Beijing 102413, Peoples R China. RP Szelecsenyi, F (reprint author), Inst Nucl Res, ATOMKI, Cyclotron Dept, Bem Ter 18-C, H-4026 Debrecen, Hungary. NR 72 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUN PY 2000 VL 168 IS 2 BP 144 EP 168 DI 10.1016/S0168-583X(99)00877-0 PG 25 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 317RW UT WOS:000087241600002 ER PT J AU Bern, Z Dixon, L Dunbar, DC Grant, AK Perelstein, M Rozowsky, JS AF Bern, Z Dixon, L Dunbar, DC Grant, AK Perelstein, M Rozowsky, JS TI On perturbative gravity and gauge theory SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 3rd Meeting of Constrained Dynamics and Quantum Gravity CY SEP 13-17, 1999 CL VILLASIMIUS, ITALY SP Ist Nazl Fis Nucl, Univ Torino, Univ Cagliari, Reg Autonoma Sardegna ID ONE-LOOP DIVERGENCES; STRING-BASED METHODS; YANG-MILLS; COLLINEAR LIMITS; TREE AMPLITUDES; SUPERGRAVITY; RENORMALIZABILITY; SCATTERING; GLUON; COUNTERTERMS AB We review some applications of tree-level (classical) relations between gravity and gauge theory that follow from string theory. Together with D-dimensional unitarity, these relations can be used to perturbatively quantize gravity theories, i.e. they contain the necessary information for obtaining loop contributions. We also review recent applications of these ideas showing that N = 1 D = II supergravity diverges, and review arguments that N = 8 D = 4 supergravity is less divergent than previously thought, though it does appear to diverge at five loops. Finally, we describe field variables for the Einstein-Hilbert Lagrangian that help clarify the perturbative relationship between gravity and gauge theory. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Coll Swansea, Dept Phys, Swansea SA2 8PP, W Glam, Wales. Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Univ Florida, Dept Phys, Inst Fundamental Theory, Gainesville, FL 32611 USA. RP Bern, Z (reprint author), Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. OI dunbar, david/0000-0003-2433-1675 NR 47 TC 8 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 88 BP 194 EP 203 DI 10.1016/S0920-5632(00)00768-4 PG 10 WC Physics, Particles & Fields SC Physics GA 323MQ UT WOS:000087569500023 ER PT J AU Liberati, S Bassett, BA Molina-Paris, C Visser, M AF Liberati, S Bassett, BA Molina-Paris, C Visser, M TI chi variable-speed-of-light cosmologies SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 3rd Meeting of Constrained Dynamics and Quantum Gravity CY SEP 13-17, 1999 CL VILLASIMIUS, ITALY SP Ist Nazl Fis Nucl, Univ Torino, Univ Cagliari, Reg Autonoma Sardegna ID VARYING SPEED; VELOCITY; VACUUM AB Variable-speed-of-light (VSL) cosmologies are currently attracting much interest as a possible alternative to cosmological inflation. We discuss the fundamental geometrodynamic aspects of VSL cosmologies, and provide several alternative implementations. These implementations provide a large class of VSL cosmologies that pass the zeroth-order consistency tests of being compatible with both classical Einstein gravity and low-energy particle physics. While they solve the "kinematic" puzzles as well as inflation does, VSL cosmologies typically do not solve the flatness problem since in their purest form no violation of the strong energy condition occurs. Nevertheless, these models are easy to unify with inflation. C1 SISSA, Int Sch Adv Studies, I-34014 Trieste, Italy. Univ Portsmouth, Relat & Cosmol Grp, Portsmouth PO1 2EG, Hants, England. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. RP Liberati, S (reprint author), Ist Nazl Fis Nucl, Sez Trieste, Trieste, Italy. OI Liberati, Stefano/0000-0002-7632-7443 NR 11 TC 8 Z9 8 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 88 BP 259 EP 262 DI 10.1016/S0920-5632(00)00780-5 PG 4 WC Physics, Particles & Fields SC Physics GA 323MQ UT WOS:000087569500035 ER PT J AU Alessandrello, A Brofferio, C Carbone, L Cremonesi, O Fiorini, E Giuliani, A Nucciotti, A Pavan, M Pessina, G Pirro, S Previtali, E Vanzini, M Zanotti, L Beeman, J McDonald, RJ Haller, EE Norman, EB Smith, AR Ventura, G Frossati, G de Waard, A Arpesella, C Bucci, C Gervasio, G Gonin, Y Vuilleumier, JL Avignone, F Creswick, RJ Farach, HA Cebrian, S Garcia, E Gonzales, D Irastroza, IG Morales, A Morales, J Ortiz, A Peruzzi, A Puimedon, J Sarsa, ML Scopel, S Villar, JA AF Alessandrello, A Brofferio, C Carbone, L Cremonesi, O Fiorini, E Giuliani, A Nucciotti, A Pavan, M Pessina, G Pirro, S Previtali, E Vanzini, M Zanotti, L Beeman, J McDonald, RJ Haller, EE Norman, EB Smith, AR Ventura, G Frossati, G de Waard, A Arpesella, C Bucci, C Gervasio, G Gonin, Y Vuilleumier, JL Avignone, F Creswick, RJ Farach, HA Cebrian, S Garcia, E Gonzales, D Irastroza, IG Morales, A Morales, J Ortiz, A Peruzzi, A Puimedon, J Sarsa, ML Scopel, S Villar, JA TI The first step toward CUORE: Cuoricino, a thermal detector array to search for rare events SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE AB Cuoricino is an array of 56 cryogenic thermal detectors teach detector is a 760 g TeO2 bolometer) devoted to Te-130 neutrinoless double beta decay and dark matter searches. The first element of Cuoricino have been succesfully tested in Gran Sasso laboratories reaching an energy resolution and an energy threshold better than the one foreseen in Cuoricino proposal. Cuoricino is also intended as the first milestone of CUORE: an array of similar to 1000 cryogenic thermal detectors to be used to search for rare events. C1 Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Florence, Dipartimento Fis, Florence, Italy. Ist Nazl Fis Nucl, Sez Firenze, I-50125 Florence, Italy. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Lab Nazl Gran Sasso, I-67010 Laquila, Italy. Univ Neuchatel, Inst Phys, CH-2000 Neuchatel, Switzerland. Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Univ Zaragoza, Lab Nucl & High En Phys, E-50009 Zaragoza, Spain. RP Alessandrello, A (reprint author), Univ Milan, Dipartimento Fis, Via Celoria 16, I-20133 Milan, Italy. RI Nucciotti, Angelo/I-8888-2012; Sarsa Sarsa, Maria Luisa/K-6108-2014; Villar, Jose Angel/K-6630-2014; OI Nucciotti, Angelo/0000-0002-8458-1556; Sarsa Sarsa, Maria Luisa/0000-0002-7552-1228; Villar, Jose Angel/0000-0003-0228-7589; Garcia Abancens, Eduardo/0000-0002-9827-2332; pavan, maura/0000-0002-9723-7834; Pessina, Gianluigi Ezio/0000-0003-3700-9757 NR 5 TC 16 Z9 16 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 78 EP 80 DI 10.1016/S0920-5632(00)00637-X PG 3 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400014 ER PT J AU Collar, JI Puibasset, J Girard, TA Miley, HS Limagne, D Waysand, G AF Collar, JI Puibasset, J Girard, TA Miley, HS Limagne, D Waysand, G TI Preliminary dark matter limits from a large-mass, low-background SDD SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE ID RADIATION-INDUCED NUCLEATION; SUPERHEATED DROP DETECTOR; HYDRATE; LIQUID; FLUOROCARBON; RECOIL; WATER AB SDDs (Superheated Droplet Detectors) consist of a superheated liquid dispersed in a gel matrix, which undergoes a detectable phase transition to the gas state by energy deposition of incident high-LET radiation. The development of large-mass, low-background SDDs dedicated to WIMP searches is briefly described and preliminary results on spin-dependent neutralino couplings from prototype devices are presented. We comment on the installation of the first modules in the "Laboratoire Souterrain a Bas Bruit (LSBB) de Rustrel-Pays d'Apt" (1,500 mwe). C1 Univ Paris 07, CNRS, UMR 75 88, Phys Solides Grp, F-75251 Paris, France. Univ Paris 06, CNRS, UMR 75 88, Phys Solides Grp, F-75251 Paris, France. Univ Lisbon, Ctr Fis Nucl, P-1649003 Lisbon, Portugal. Pacific NW Lab, Richland, WA 99352 USA. RP Collar, JI (reprint author), Univ Paris 07, CNRS, UMR 75 88, Phys Solides Grp, F-75251 Paris, France. OI Girard, Thomas/0000-0003-4113-880X NR 23 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 120 EP 122 DI 10.1016/S0920-5632(00)00651-4 PG 3 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400028 ER PT J AU Kafka, T AF Kafka, T CA Soudan-2 Collaboration TI Recent atmospheric neutrino results from Soudan-2 SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE AB An updated measurement of the atmospheric nu(mu)/nu(e) ratio-of-ratios, 0.68 +/- 0.11 +/- 0.06, has been obtained using a 4.6-kty exposure of the Soudan-2 iron tracking calorimeter detector. The L/E distributions have been analyzed for effects of nu(mu) --> nu(x) oscillations, and an allowed region in the Delta m(2) vs. sin(2)2 theta plane has been determined. C1 Tufts Univ, Medford, MA 02155 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Oxford, Rutherford Appleton Lab, Oxford OX1 2JD, England. RP Kafka, T (reprint author), Tufts Univ, 4 Colby St, Medford, MA 02155 USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 186 EP 188 DI 10.1016/S0920-5632(00)00661-7 PG 3 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400038 ER PT J AU Gonzalez, D Aalseth, CE Avignone, FT Brodzinski, RL Cebrian, S Garcia, E Hensley, WK Irastorza, IG Kirpichnikov, IV Klimenko, AA Miley, HS Morales, A Morales, J de Solozano, AO Osetrov, SB Pogosov, VS Puimedon, J Reeves, JH Sarsa, ML Scopel, S Smolnikov, AA Tamanyan, AG Vasenko, AA Vasiliev, SI Villar, JA AF Gonzalez, D Aalseth, CE Avignone, FT Brodzinski, RL Cebrian, S Garcia, E Hensley, WK Irastorza, IG Kirpichnikov, IV Klimenko, AA Miley, HS Morales, A Morales, J de Solozano, AO Osetrov, SB Pogosov, VS Puimedon, J Reeves, JH Sarsa, ML Scopel, S Smolnikov, AA Tamanyan, AG Vasenko, AA Vasiliev, SI Villar, JA TI Current IGEX results for neutrinoless double-beta decay of Ge-76 SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE ID SUPPRESSION; SE-82 AB The International Germanium Experiment (IGEX) is currently operating three 2-kg enriched germanium detectors in the Canfranc Underground Laboratory (Spain) at 2450 mwe, in a search for the neutrinoless double- beta decay of Ge-76. The detectors are equipped with Pulse Shape Analysis electronics. This implementation of Pulse Shape Discrimination results in a rejection of 60%-80% of the background in the 2.0-2.5 MeV energy interval. Analysis of 116.75 mole-years of data yields a lower bound greater than or equal to 1.57 x 10(25)y (or T-1/2(0 nu) greater than or equal to 1.13 x 10(25)y without PSD) (90% C.L.) corresponding to (m(nu)) < (0.33 - 1.31) eV, depending on the theoretical nuclear matrix elements used to extract the neutrino mass parameter. C1 Univ S Carolina, Columbia, SC 29208 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Zaragoza, Lab Nucl & High Energy Phys, E-50009 Zaragoza, Spain. Inst Theoret & Expt Phys, Moscow 117259, Russia. Baksan Neutrino Observ, Inst Nucl Res, Neutrino 361609, Russia. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Gonzalez, D (reprint author), Univ S Carolina, Columbia, SC 29208 USA. RI Irastorza, Igor/B-2085-2012; Sarsa Sarsa, Maria Luisa/K-6108-2014; Villar, Jose Angel/K-6630-2014; OI Irastorza, Igor/0000-0003-1163-1687; Sarsa Sarsa, Maria Luisa/0000-0002-7552-1228; Villar, Jose Angel/0000-0003-0228-7589; Garcia Abancens, Eduardo/0000-0002-9827-2332 NR 14 TC 38 Z9 38 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 278 EP 280 DI 10.1016/S0920-5632(00)00679-4 PG 3 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400055 ER PT J AU Avignone, FT Efremenko, YV AF Avignone, FT Efremenko, YV CA ORLaND Collaboration TI ORLaND - A neutrino facility at the spallation neutron source SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE AB We outline the perspectives for low energy neutrino physics that would come with the proposed construction of the Oak Ridge Laboratory for Neutrino Detectors (ORLaND). This facility would be near the Spallation Neutron Source (SNS), presently under construction at the Oak Ridge National Laboratory (ORNL). It would be located in an underground bunker next to the first target station of the SNS, large enough to house one large general purpose 2 kt liquid scintillation detector and several 100-200 ton detectors optimized for specific neutrino-nucleus cross section measurements. C1 Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Univ Tennessee, ORNL, Dept Phys & Astron, Oak Ridge, TN 37830 USA. RP Avignone, FT (reprint author), Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. NR 3 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 304 EP 308 DI 10.1016/S0920-5632(00)00687-3 PG 5 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400063 ER PT J AU Aalseth, CE Miley, HS AF Aalseth, CE Miley, HS TI A novel method of pulse shape discrimination for germanium spectrometers SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 6th International Workshop on Topics in Astroparticle and Underground Physics CY SEP 06-10, 1999 CL COLL FRANCE, PARIS, FRANCE SP Coll France HO COLL FRANCE ID DETECTORS AB A method for germanium detector pulse-shape discrimination (PSD) is presented which does not require a large library of well-characterized pulses. This method aims to separate detector events with few interaction loci in a germanium crystal from those with many. The usefulness of this method for improving Ge-76 0-nu beta beta-decay experiments is considered. C1 Univ S Carolina, Columbia, SC 29208 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Aalseth, CE (reprint author), Univ S Carolina, Columbia, SC 29208 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 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 87 BP 491 EP 492 DI 10.1016/S0920-5632(00)00726-X PG 2 WC Physics, Particles & Fields SC Physics GA 323MP UT WOS:000087569400098 ER PT J AU Muller, D AF Muller, D TI Recent tests of QCD at SLD SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID LEADING-ORDER CORRECTIONS; JETS AB We present selected results on strong interaction physics from the SLD experiment at the SLAC Linear Collider. We report on several new studies of 3- and 4-jet hadronic Z(0) decays, in which jets are identified as quark, antiquark or gluon. The 3-jet Z(0) --> b (b) over bar g rate is sensitive to the b-quark mass; prospects for measuring mb are discussed. The gluon energy spectrum is measured over the full kinematic range, providing an improved test of QCD and limits on anomalous bbg couplings. The parity violation in Z(0) --> b (b) over bar g decays is consistent with electroweak theory plus QCD. New tests of T- and CP-conservation at the bbg vertex are performed. A new measurement of the rate of gluon splitting into b (b) over bar pairs yields g(b (b) over bar) = 0.0031 +/- 0.0007(stat.) +/- 0.0006(syst.) (Preliminary). We also present a number of new results on jet fragmentation into identified hadrons. The B hadron energy spectrum is measured over the full kinematic range using a new, inclusive technique, allowing stringent tests of predictions for its shape and a precise measurement of [x(B)] = 0.714 +/- 0.005(stat.) +/- 0.007(syst.) (Preliminary). A detailed study of correlations in rapidity y between pairs of identified pi(+/-), K+/- and p/(p) over bar confirms that strangeness and baryon number are conserved locally, and shows local charge conservation between meson-baryon and strange-nonstrange pairs. Flavor-dependent long-range correlations are observed for all combinations of these hadron species, yielding new information on leading particle production. The first study of correlations using rapidities signed such that y > 0 corresponds to the quark direction provides additional new insights into fragmentation, including the first direct observation of baryon number ordering along the q (q) over bar axis. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Muller, D (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. OI Carpinelli, Massimo/0000-0002-8205-930X; Wilson, Robert/0000-0002-8184-4103 NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 7 EP 16 DI 10.1016/S0920-5632(00)00533-8 PG 10 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700003 ER PT J AU Adams, T Alton, A Arroyo, CG Avvakumov, S de Barbaro, L de Barbaro, P Bazarko, AO Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, JM Drucker, RB Formaggio, JA Frey, R Goldman, J Goncharov, M Harris, DA Johnson, RA Kim, JH King, BJ Kinnel, T Koutsoliotas, S Lamm, MJ Marsh, W Mason, D McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, HM Sculli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Stern, EG Tamminga, BM Vakili, M Vaitaitis, A Wu, V Yang, UK Yu, J Zeller, GP AF Adams, T Alton, A Arroyo, CG Avvakumov, S de Barbaro, L de Barbaro, P Bazarko, AO Bernstein, RH Bodek, A Bolton, T Brau, J Buchholz, D Budd, H Bugel, L Conrad, JM Drucker, RB Formaggio, JA Frey, R Goldman, J Goncharov, M Harris, DA Johnson, RA Kim, JH King, BJ Kinnel, T Koutsoliotas, S Lamm, MJ Marsh, W Mason, D McFarland, KS McNulty, C Mishra, SR Naples, D Nienaber, P Romosan, A Sakumoto, WK Schellman, HM Sculli, FJ Seligman, WG Shaevitz, MH Smith, WH Spentzouris, P Stern, EG Tamminga, BM Vakili, M Vaitaitis, A Wu, V Yang, UK Yu, J Zeller, GP TI Recent QCD results from NuTeV/CCFR collaboration SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID DEUTERON STRUCTURE FUNCTIONS; FLAVOR STRUCTURE FUNCTIONS; INELASTIC MUON SCATTERING; CHARM PRODUCTION; GLOBAL ANALYSIS; NEUTRINO; DEPENDENCE; HYDROGEN AB Fermilab experiments CCFR and its successor NuTeV study nucleon structure through deep inelastic scattering of neutrino beams off an iron target. We report on the most recent CCFR measurement of the nu N differential cross section and resulting structure functions Delta xF(3) = sF(3)(nu) - xF(3)(<(nu)over bar>), and R-long = sigma L/sigma T in the framework of massive charm quark. Delta xF(3) is sensitive to strange and charm content of the nucleon. NuTeV's preliminary direct measurement of the strange sea, from dimuon charged-current production, and nucleon charm content probed by neutral-current nu N interaction, are also presented. C1 Univ Cincinnati, Cincinnati, OH 45221 USA. Columbia Univ, New York, NY 10032 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Kansas State Univ, Manhattan, KS 66506 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Adams, T (reprint author), Univ Cincinnati, Cincinnati, OH 45221 USA. RI Frey, Raymond/E-2830-2016; OI Frey, Raymond/0000-0003-0341-2636; Bernstein, Robert/0000-0002-7610-950X NR 23 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 93 EP 101 DI 10.1016/S0920-5632(00)00549-1 PG 9 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700022 ER PT J AU Pellegrino, A AF Pellegrino, A CA H1 Collaboration ZEUS Collaboration TI Structure functions from HERA SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID STRUCTURE-FUNCTION F-2(X,Q(2)); DEUTERON STRUCTURE FUNCTIONS; HIGH STATISTICS MEASUREMENT; PROTON STRUCTURE FUNCTIONS; INELASTIC MUON SCATTERING; HIGH-ENERGY COLLISIONS; OF-MASS ENERGY; PARTON DISTRIBUTIONS; LOW-X; CROSS-SECTIONS AB Structure function results from HERA over 4 decades in x and 5 decades in Q(2) are reviewed. The salient features of the data, the rise of F-2 at low x and scaling violations, are discussed and in conjunction with the results of NLO QCD fits to the data. Recent low-Q(2) data are presented and the transition toward the perturbative regime is discussed. Recent cross-section results and a new method for the extraction of F-L are presented. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Pellegrino, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 39 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 102 EP 111 DI 10.1016/S0920-5632(00)00550-8 PG 10 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700023 ER PT J AU Merino, C Brodsky, SJ Rathsman, J AF Merino, C Brodsky, SJ Rathsman, J TI Jet asymmetry and the detection of Odderon exchange in DIS SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID DEEP-INELASTIC SCATTERING; LARGE RAPIDITY GAP; DIFFRACTIVE PHOTOPRODUCTION; PERTURBATIVE QCD; HERA; POMERON; DISSOCIATION; INTERCEPT; EVENTS AB We show that the asymmetry in the fractional energy of charm versus anticharm jets produced in high energy diffractive photoproduction is sensitive to the interference of the Odderon (C = -) and Pomeron (C = +) exchange amplitudes in QCD. Measurements of this asymmetry at HERA could provide the first evidence for the presence of Odderon exchange in the high energy limit of strong interactions. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Santiago de Compostela, Dept Fis Particulas, Santiago De Compostela 15706, Spain. RP Merino, C (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 28 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 183 EP 188 DI 10.1016/S0920-5632(00)00562-4 PG 6 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700037 ER PT J AU Menke, S AF Menke, S TI Measurement of alpha(s) and the non-strange spectral functions in hadronic tau decays with OPAL SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID QUANTUM-CHROMODYNAMIC CORRECTIONS; ORDERS RENORMALON RESUMMATIONS; STRONG-COUPLING CONSTANT; RESONANCE PHYSICS; E+E ANNIHILATION; PARTICLE PHYSICS; PERTURBATIVE QCD; OBSERVABLES; VECTOR; WIDTH AB The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant cys, the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives alpha(s)(m(tau)(2)) = 0.348 +/- 0.009(exp) +/- 0.019(theo) at the tau-mass scale and alpha(s)(m(Z)(2)) = 0.1219 +/- 0.0010(exp) +/- 0.0017(theo) at the Z(0)-mass scale. The values obtained for alpha(s)(m(Z)(2)) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3 % and 4.1 % smaller, respectively. The 'running' of the strong coupling between s(0) similar or equal to 1.3 GeV2 and s(0) = m(tau)(2) has been tested from direct fits to the integrated differential hadronic decay rate R-tau(s(0)). A test of the saturation of chiral sum rules at the tau-mass scale has been performed. C1 Stanford Linear Accelerator Ctr, Menlo Park, CA 94205 USA. RP Menke, S (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Park, CA 94205 USA. NR 37 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 196 EP 206 DI 10.1016/S0920-5632(00)00564-8 PG 11 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700041 ER PT J AU Pelaez, JR Brodsky, SJ Merino, C Toumbas, N AF Pelaez, JR Brodsky, SJ Merino, C Toumbas, N TI Perturbative QCD relations inspired by hypothetical tau leptons SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID HEAVY QUARKS; TESTING QCD; DECAYS; ANNIHILATION; OBSERVABLES; ALPHA(S); E(+)E(-); HADRONS; VECTOR; MODEL AB We review our recent works on tests of perturbative QCD, inspired by the relation between the hadronic decay of the tau lepton and the e(+)e(-) annihilation into hadrons. First, we present a set of commensurate scale relations that probe the self-consistency of leading-twist QCD predictions for any observable which defines an effective charge. These tests are independent of the renormalization scheme and scale, and are applicable over wide data ranges. As an example we apply this approach to Re+e-. Second, using a differential form of these conmensurate scale relations, we present a method to measure the QCD Gell-Mann-Low Psi function. C1 Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Santiago de Compostela, Dept Fis Particulas, Santiago De Compostela 15706, Spain. RP Pelaez, JR (reprint author), Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain. RI Pelaez, Jose/K-9767-2014; OI Pelaez, Jose/0000-0003-0737-4681; Toumbas, Nicolaos/0000-0001-8879-7330 NR 24 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 216 EP 219 DI 10.1016/S0920-5632(00)00567-3 PG 4 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700045 ER PT J AU Wingate, M AF Wingate, M TI Domain wall fermions and the strange quark mass SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID CHIRAL FERMIONS; LATTICE; QCD; RENORMALIZATION; OPERATORS AB The strange quark mass has been computed using a lattice action which possesses continuum-like chiral symmetry to good precision, namely the domain wall fermion action. This talk surveys this action and the recent calculation of m(s), by the RIKEN/BNL/CU collaboration. This result is put into context by briefly summarizing other recent lattice studies. C1 Brookhaven Natl Lab, RIKEN, Res Ctr, Upton, NY 11973 USA. RP Wingate, M (reprint author), Brookhaven Natl Lab, RIKEN, Res Ctr, Upton, NY 11973 USA. OI Wingate, Matthew/0000-0001-6568-988X NR 21 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 224 EP 227 DI 10.1016/S0920-5632(00)00569-7 PG 4 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700047 ER PT J AU Gasser, J Pich, A Giusti, L Hoang, AH Neubert, M Tournefier, E AF Gasser, J Pich, A Giusti, L Hoang, AH Neubert, M Tournefier, E TI Tau-decay determination of the strange quark mass - Discussion SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Editorial Material C1 CERN, CH-1211 Geneva 23, Switzerland. SLAC, Stanford, CA USA. RI Giusti, Leonardo/F-4311-2011 OI Giusti, Leonardo/0000-0003-2002-8134 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 241 EP 241 PG 1 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700050 ER PT J AU Hsiung, YB AF Hsiung, YB TI An observation of direct-CP violation - epsilon '/epsilon result from KTeV SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID NEUTRAL-KAON; DECAYS; DETECTOR; TESTS AB We report the first KTeV measurement for the search of direct-CP violation by using 23% of the data sample collected in the 1996-97 filed target run at Fermilab,. The result is, Re(epsilon'/epsilon) = (28.0 +/- 4.1) x 10(-4), nearly 7 sigma above zero obtained by a blind analysis. This firmly establishes the lone-sought ''dircct-CP violation" effect in the two-pion system (pi(+)pi(-) versus pi(0)pi(0)) of neutral kaon decays. Other new measurements of Delta m, tau(S), Delta phi and a limit on the diurnal variation of phi(+-) for testing CPT invariance from the same data sample are also presented. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Fermilab Natl Accelerator Lab, POB 500,MS122, Batavia, IL 60510 USA. NR 20 TC 55 Z9 55 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 312 EP 321 DI 10.1016/S0920-5632(00)00581-8 PG 10 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700063 ER PT J AU Nierste, U AF Nierste, U TI Theoretical status of epsilon '/epsilon SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID STRANGE QUARK MASS; HADRONIC MATRIX-ELEMENTS; LEADING ORDER; CP VIOLATION; TOP-QUARK; B-DECAYS; QCD; OPERATORS; RULE AB I give a detailed introduction into the theoretical formalism for epsilon'/epsilon, which measures direct CP-violation in K --> pi pi decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several possible explanations of the unexpectedly high experimental results for epsilon'/epsilon are pointed out: A small strange quark mass, an enhancement of the hadronic parameter B-6((1/2))) from the sigma resonance, an underestimate of isospin breaking and possible new physics contributions in the (s) over bar dZ-vertex and the (s) over bar d-gluon-vertex. C1 Fermi Natl Accelerator Lab, Div Theory, Batavia, IL 60510 USA. RP Nierste, U (reprint author), Fermi Natl Accelerator Lab, Div Theory, MS106, Batavia, IL 60510 USA. NR 61 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 329 EP 338 DI 10.1016/S0920-5632(00)00583-1 PG 10 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700065 ER PT J AU Chung, SU AF Chung, SU TI Current status of exotic mesons SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID FLUX-TUBE MODEL; HYBRID MESONS; 18 GEV/C; QCD; LATTICE; SYSTEM; REST; WAVE AB Current status of J(PC) = 1(-+)-exotic mesons is given. Recent analyses give strong support for the existence of the exotic mesons at masses 1.4 and 1.6 GeV, coupling to pi eta, pi eta', pi rho and pi b(1)(1235). C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 31 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 341 EP 346 DI 10.1016/S0920-5632(00)00584-3 PG 6 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700066 ER PT J AU Hsiung, YB Skubic AF Hsiung, YB Skubic TI Recent results on B and D decays from CLEO - Discussion SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Editorial Material C1 Fermilab, Batavia, IL 60510 USA. RP Hsiung, YB (reprint author), Fermilab, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 476 EP 476 PG 1 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700092 ER PT J AU Neubert, M AF Neubert, M TI Model-independent information on gamma from B-+/- -> pi K decays SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID DIRECT CP VIOLATION; CKM-ANGLE-GAMMA; ELECTROWEAK PENGUINS; B->PI-K DECAYS; RESCATTERING; AMPLITUDES; PHYSICS; PHASES AB Measurements of the rates for the hadronic decays B+/- --> pi K can be used to derive information on the weak phase gamma = arg(V-ub*) in a largely model-independent way. Hadronic uncertainties can be reduced to the level of nonfactorizable contributions to the decay amplitudes that are power-suppressed in Lambda/m(b) and, in addition, either violate SU(3) flavor symmetry or are doubly Cabibbo suppressed. Various strategies to obtain bounds on gamma and to extract its value with small theoretical uncertainty are described. The potential of B+/- --> pi K decays for probing physics beyond the Standard Model is also discussed. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Cornell Univ, Newman Lab Nucl Studies, Ithaca, NY 14853 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 32 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 477 EP 486 DI 10.1016/S0920-5632(00)00607-1 PG 10 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700093 ER PT J AU Petrelli, A AF Petrelli, A TI J/psi production: Tevatron and fixed-target collisions SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT QCD 99 7th Euroconference on Quantum Chromodynamics CY JUL 07-13, 1999 CL MONTPELLIER, FRANCE SP European Commission ID HEAVY QUARKONIUM; ANNIHILATION; DECAYS; MESON AB In this talk I show the results of a fit of the NRQCD matrix elements to the CDF data for direct J/psi, production, by including the radiative corrections to the g g -->(3) S-1([1]) g channel and the effect of the k(T)-smearing. Furthermore I perform the NLO NRQCD analysis of J/psi production in fixed-target proton-nucleon collisions and I fit the colour-octet matric elements to the available experimental data. The results are compared to the Tevatron ones. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Petrelli, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUN PY 2000 VL 86 BP 533 EP 538 DI 10.1016/S0920-5632(00)00618-6 PG 6 WC Physics, Particles & Fields SC Physics GA 317DU UT WOS:000087211700105 ER PT J AU Peplow, DE Verghese, K AF Peplow, DE Verghese, K TI Differential sampling applied to mammography image simulation SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID CARLO PERTURBATION ALGORITHMS; SYNCHROTRON-RADIATION AB Differential sampling is a powerful tool that allows Monte Carlo to compute derivatives of responses with respect to certain problem parameters. This capability has been implemented within an in-house Monte Carlo code that simulates detailed mammographic images from two new digital systems. Differential sampling allows for the calculation of the first and all second derivatives of all of the different tallies computed by the code as well as the first and second derivatives of the mammographic image itself with respect to material parameters, such as density and cross sections. The theory behind differential sampling is explained, the methodology for implementation into the imaging code is discussed, and two problems are used to demonstrate the power of differential sampling. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. N Carolina State Univ, Dept Nucl Engn, Raleigh, NC 27695 USA. RP Peplow, DE (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 6025 Mailstop 6363, Oak Ridge, TN 37831 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 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 JUN PY 2000 VL 135 IS 2 BP 103 EP 122 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 319AZ UT WOS:000087318000001 ER PT J AU Guber, KH Spencer, RR Leal, LC Harvey, JA Hill, NW Dos Santos, G Sayer, RO Larson, DC AF Guber, KH Spencer, RR Leal, LC Harvey, JA Hill, NW Dos Santos, G Sayer, RO Larson, DC TI New high-resolution fission cross-section measurements of U-233 in the 0.4-eV to 700-keV energy range SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID CAPTURE; PU-239 AB In support of the U.S. Department of Energy need for new data for criticality safety applications, new high-resolution fission cross-section measurements of U-233 have been made at the Oak Ridge Electron Linear Accelerator The measurements were carried out over a 0.4-eV to 700-keV energy range at the 80-m flight station using a fission chamber Corrections were made for experimental effects to obtain the average fission cross section in this energy range. Results are compared to previous measurements. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Guber, KH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 17 TC 9 Z9 9 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 JUN PY 2000 VL 135 IS 2 BP 141 EP 149 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 319AZ UT WOS:000087318000003 ER PT J AU Eisenhawer, SW Bott, TF Smith, RE AF Eisenhawer, SW Bott, TF Smith, RE TI An approximate reasoning-based method for screening high-level-waste tanks for flammable gas SO NUCLEAR TECHNOLOGY LA English DT Article DE approximate reasoning; nuclear waste; safety analysis AB The in situ retention of flammable gas produced by radiolysis and thermal decomposition in high-level waste can pose a safety problem if the gases are released episodically into the dome space of a storage tank. Screening efforts at the Hanford site have been directed at identifying tanks in which this situation could exist. Problems encountered in screening motivated an effort to develop an improved screening methodology. Approximate reasoning (AR) is a formalism designed to emulate the kinds of complex judgments made by subject matter experts. It uses inductive logic structures to build a sequence of forward-chaining inferences about a subject. Approximate-reasoning models incorporate natural language expressions known as linguistic variables to represent evidence. The use of fuzzy sets to represent these variables mathematically makes it practical to evaluate quantitative and qualitative information consistently. In a pilot study to investigate the utility of AR for flammable gas screening, the effort to implement such a model was found to be acceptable, and computational requirements were found to be reasonable. The preliminary results showed that important judgments about the validity of observational data and the predictive power of models could be made. These results give new insights into the problems observed in previous screening efforts. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Eisenhawer, SW (reprint author), Univ Calif Los Alamos Natl Lab, MS K557, Los Alamos, NM 87545 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUN PY 2000 VL 130 IS 3 BP 351 EP 361 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 313XH UT WOS:000087024600009 ER PT J AU Rothwell, DG Hang, B Gorman, MA Freemont, PS Singer, B Hickson, ID AF Rothwell, DG Hang, B Gorman, MA Freemont, PS Singer, B Hickson, ID TI Substitution of Asp-210 in HAP1 (APE/Ref-1) eliminates endonuclease activity but stabilises substrate binding SO NUCLEIC ACIDS RESEARCH LA English DT Article ID DNA-REPAIR ENZYME; HUMAN APURINIC ENDONUCLEASE; SITE-DIRECTED MUTAGENESIS; HUMAN APURINIC/APYRIMIDINIC ENDONUCLEASE; HUMAN AP ENDONUCLEASE; COLI EXONUCLEASE-III; MAJOR HUMAN; EXOCYCLIC ADDUCT; OLIGONUCLEOTIDES; RESIDUES AB HAP1, also known as APE/Ref-1, is the major apurinic/apyrimidinic (AP) endonuclease in human cells. Previous structural studies have suggested a possible role for the Asp-210 residue of HAP1 in the enzymatic function of this enzyme, Here, we demonstrate that substitution of Asp-210 by Asn or Ala eliminates the AP endonuclease activity of HAP1, while substitution by Glu reduces specific activity similar to 500-fold, Nevertheless, these mutant proteins still bind efficiently to oligonucleotides containing either AP sites or the chemically unrelated bulky p-benzoquinone (pBQ) derivatives of dC, dA and dG, all of which are substrates for HAP1, These results indicate that Asp-210 is required for catalysis, but not substrate recognition, consistent with enzyme kinetic data indicating that the HAP1-D210E protein has a 3000-fold reduced K-cat for AP site cleavage, but an unchanged K-m. Through analysis of the binding of Asp-210 substitution mutants to oligonucleotides containing either an AP site or a pBQ adduct, we conclude that the absence of Asp-210 allows the formation of a stable HAP1-substrate complex that exists only transiently during the catalytic cycle of wild-type HAP1 protein, We interpret these data in the context of the structure of the HAP1 active site and the recently determined co-crystal structure of HAP1 bound to DNA substrates. C1 Univ Oxford, Inst Mol Med, John Radcliffe Hosp, Imperial Canc Res Fund Labs, Oxford OX3 9DS, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. Imperial Canc Res Fund, Prot Struct & Funct Lab, London WC2A 3PX, England. RP Hickson, ID (reprint author), Univ Oxford, Inst Mol Med, John Radcliffe Hosp, Imperial Canc Res Fund Labs, Oxford OX3 9DS, England. FU NCI NIH HHS [CA72079, R01 CA072079]; NIEHS NIH HHS [ES 07363] NR 39 TC 44 Z9 47 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUN 1 PY 2000 VL 28 IS 11 BP 2207 EP 2213 DI 10.1093/nar/28.11.2207 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 320UA UT WOS:000087417700001 PM 10871340 ER PT J AU Sabatke, DS Descour, MR Dereniak, EL Sweatt, WC Kemme, SA Phipps, GS AF Sabatke, DS Descour, MR Dereniak, EL Sweatt, WC Kemme, SA Phipps, GS TI Optimization of retardance for a complete Stokes polarimeter SO OPTICS LETTERS LA English DT Article ID GENERAL-ANALYSIS; OPTIMUM ANGLES; PHOTOPOLARIMETER; LIGHT AB We present two figures of merit based on singular value decomposition, which can be used to assess the noise immunity of a complete Stokes polarimeter. These are used to optimize a polarimeter featuring a rotatable retarder and a fixed polarizer. A retardance of 132 degrees (approximately three-eighths wave) and retarder orientation angles of +/-51.7 degrees and +/-15.1 degrees are found to be optimal when four measurements are used. Use of this retardance affords a factor-of-1.5 improvement in signal-to-noise ratio over systems employing a quarter-wave plate. A geometric means of visualizing the optimization process is discussed, and the advantages of the use of additional measurements are investigated. No advantage of using retarder orientation angles spaced uniformly through 360 degrees is found over repeated measurements made at the four retarder orientation angles. (C) 2000 Optical Society of America OCIS codes: 120.5410, 120.2130, 260.2130, 260.5430, 100.3190. C1 Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sabatke, DS (reprint author), Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. NR 14 TC 177 Z9 179 U1 2 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 2000 VL 25 IS 11 BP 802 EP 804 DI 10.1364/OL.25.000802 PG 3 WC Optics SC Optics GA 321MH UT WOS:000087458900011 PM 18064189 ER PT J AU Honea, EC Beach, RJ Mitchell, SC Skidmore, JA Emanuel, MA Sutton, SB Payne, SA Avizonis, PV Monroe, RS Harris, DG AF Honea, EC Beach, RJ Mitchell, SC Skidmore, JA Emanuel, MA Sutton, SB Payne, SA Avizonis, PV Monroe, RS Harris, DG TI High-power dual-rod Yb : YAG laser SO OPTICS LETTERS LA English DT Article ID ND-YAG; GENERATION AB We describe a diode-pumped Yb:YAG laser that produces 1080 W of power cw with 27.5% optical optical efficiency and 532 W Q-switched with M-2 = 2.2 and 17% optical-optical efficiency. The laser uses two composite Yb:YAC rods separated by a 90 degrees quartz rotator for bifocusing compensation. A microlensed diode array end pumps each rod, using a hollow lens duct for pump delivery. By changing resonator parameters we can adjust the fundamental mode size and the output beam quality. Using a flattened Gaussian intensity profile to calculate the mode-fill efficiency and clipping losses, we compare experimental data with modeled output power versus beam quality. (C) 2000 Optical Society of America OCIS codes: 140.5680, 140.5560, 140.3480, 140.3540, 140.3570. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Boeing Laser & Electroopt Syst, Canoga Park, CA 91309 USA. RP Honea, EC (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-482,POB 808, Livermore, CA 94551 USA. NR 18 TC 110 Z9 124 U1 3 U2 24 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 2000 VL 25 IS 11 BP 805 EP 807 DI 10.1364/OL.25.000805 PG 3 WC Optics SC Optics GA 321MH UT WOS:000087458900012 PM 18064190 ER PT J AU Berryman, JG AF Berryman, James G. TI Analysis of Approximate Inverses in Tomography I. Resolution Analysis of Common Inverses SO OPTIMIZATION AND ENGINEERING LA English DT Article DE acoustic tomography; resolution matrices; singular value decomposition AB The process of using physical data to produce images of important physical parameters is an inversion problem, and these are often called tomographic inverse problems when the arrangement of sources and receivers makes an analogy to x-ray tomographic methods used in medical imaging possible. Examples of these methods in geophysics include seismic tomography, ocean acoustic tomography, electrical resistance tomography, etc., and many other examples could be given in nondestructive evaluation and other applications. All these imaging methods have two stages: First, the data are operated upon in some fashion to produce the image of the desired physical quantity. Second, the resulting image must be evaluated in essentially the same timeframe as the image is being used as a diagnostic tool. If the resolution provided by the image is good enough, then a reliable diagnosis may ensue. If the resolution is not good enough, then a reliable diagnosis is probably not possible. But the first question in this second stage is always "How good is the resolution?" The concept of resolution operators and resolution matrices has permeated the geophysics literature since the work of Backus and Gilbert in the late 1960s. But measures of resolution have not always been computed as often as they should be because, for very data rich problems, these computations can actually be significantly more difficult/expensive than computing the image itself. It is the purpose of this paper and its companion (Part II) to show how resolution operators/matrices can be computed economically in almost all cases, and to provide a means of comparing the resolution characteristics of many of the common approximate inverse methods. Part I will introduce the main ideas and analyze the behavior of standard methods such as damped least-squares, truncated singular value decomposition, the adjoint method, backprojection formulas, etc. Part II will treat many of the standard iterative inversion methods including conjugate gradients, Lanczos, LSQR, etc. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berryman, JG (reprint author), Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. FU U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory [W-7405-ENG-48]; Environmental Management Science with oversight by the Engineering Research Division of the Office of Basic Energy Sciences, Office of Energy Research; Office of Science and Technology, Office of Environmental Management; Stanford Exploration Project FX I thank S. F. Ashby, R. Burridge, J. F. Claerbout, S. Fomel, D. M. Goodman, J. B. Keller, F. Muir, G. Nolet, G. Papanicolaou, B. N. Parlett, S. Ronen, M. A. Saunders, W. W. Symes, H. A. van der Vorst, and J. J. Zucca for helpful discussions, lectures, collaborations, correspondence and/or criticism. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-ENG-48 and supported by the Environmental Management Science Program with oversight by the Engineering Research Division of the Office of Basic Energy Sciences, Office of Energy Research, and by the Office of Science and Technology, Office of Environmental Management. Early work in this area was performed while the author was visiting the Geophysics Department at Stanford University. Partial support for this visit was provided by the Stanford Exploration Project, whose sponsors are hereby gratefully acknowledged. NR 40 TC 21 Z9 22 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD JUN PY 2000 VL 1 IS 1 BP 87 EP 115 DI 10.1023/A:1010098523281 PG 29 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA V19TO UT WOS:000208094900006 ER PT J AU Pluth, JM Nelson, DO Ramsey, MJ Tucker, JD AF Pluth, JM Nelson, DO Ramsey, MJ Tucker, JD TI The relationship between genotype and chromosome aberration frequencies in a normal adult population SO PHARMACOGENETICS LA English DT Article DE genotype; chromosome aberration frequency; chromosome painting; normal adult population ID MICROSOMAL EPOXIDE HYDROLASE; GLUTATHIONE S-TRANSFERASES; EUROPEAN STUDY-GROUP; LUNG-CANCER; GENETIC POLYMORPHISMS; CYTOGENETIC BIOMARKERS; CIGARETTE SMOKERS; BLADDER-CANCER; BREAST-CANCER; IN-VITRO AB Cancer susceptibility differences may be attributed in part to genetic variation in genes involved in metabolism of environmental procarcinogens. Increased risks for some cancers have been linked to polymorphisms in certain phase I and II genes, and have been associated with genomic instability and chromosomal aberrations, Aberration frequencies in general, and stable aberration frequencies (translocations and insertions) in particular, are used as biomarkers for disease. Thus, knowledge of the genetic factors that influence the frequency of stable aberrations In a normal population is important for cancer risk determination. In this work, genotypes for a number of xenobiotic enzymes (CYP1A1, CYP2D6, GSTM1, GSTT1, GSTP1, NAT1, NAT2 and epoxide hydrolase) and stable aberration frequencies were determined for 65 normal individuals aged 19-77 years. The population was divided at age 60 years for analysis because there was a significant difference in stable aberration frequencies between these groups. Subjects with low levels (0-66th percentile) of stable aberrations were compared to those with high levels (67th percentile and above). Of all the genotypes studied, only NAT2 showed a notable difference between the high and the low stable aberration groups in the percentage of polymorphisms observed, and this was seen only in the older subjects group. All individuals in the older-high stable aberration group were NAT2 rapid acetylator smokers. NAT2 slow acetylator smelters had significantly lower stable aberration frequencies compared to the NAT2 rapid acetylator smokers. Following previous work showing an increased risk of cancer associated with high levels of aberrations (above the 66th percentile), we hypothesize that smokers with the NAT2 rapid acetylator genotype may be at an increased risk for cancer. Pharmacogenetics 10:311-319 (C) 2000 Lippincott Williams & Wilkins. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Tucker, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, POB 808,L-452, Livermore, CA 94551 USA. NR 36 TC 23 Z9 24 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0960-314X J9 PHARMACOGENETICS JI Pharmacogenetics PD JUN PY 2000 VL 10 IS 4 BP 311 EP 319 DI 10.1097/00008571-200006000-00005 PG 9 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Pharmacology & Pharmacy SC Biotechnology & Applied Microbiology; Genetics & Heredity; Pharmacology & Pharmacy GA 321HP UT WOS:000087450300005 PM 10862522 ER PT J AU Tome, CN Christodoulou, N AF Tome, CN Christodoulou, N TI Analysis of accelerated irradiation growth in Zr-2.5% Nb pressure tubes SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID TEXTURED ZIRCONIUM; POINT-DEFECTS; HCP METALS; CREEP; DIFFUSION AB Recent experimental evidence of creep and growth of Zr-2.5% Nb CANDU double dagger pressure tubes under irradiation shows an increase in the growth rate with accumulated fluence. Such a feature has been linked to a climb of c-type dislocation loops produced by a bias in the migration of vacancies and interstitials. In this work we link several material scales in order to relate the macroscopic response of the tubes with the physical mechanisms involving the point defects on the microscopic scale. Our model includes the influence of internal stresses on defect diffusivity, the dependence of creep and growth moduli of the single crystal on the evolving microstructure, and the intergranular stresses responsible for the bias. All these elements are combined in a self-consistent polycrystal model for creep and growth. We show that this approach can explain the observed growth acceleration and we derive physically meaningful values of some of the microstructural parameters. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Atom Energy Canada Ltd, Deformat Technol Branch, Chalk River, ON K0J 1J0, Canada. RP Los Alamos Natl Lab, MST-8,MS G755, Los Alamos, NM 87545 USA. EM tome@lanl.gov RI Tome, Carlos/D-5058-2013 NR 24 TC 10 Z9 10 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUN PY 2000 VL 80 IS 6 BP 1407 EP 1424 PG 18 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 325XP UT WOS:000087702400010 ER PT J AU Brandow, B AF Brandow, B TI Explanation of the exotic superconductors by a valence-fluctuation pairing mechanism SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Review ID ELECTRONIC RAMAN-SCATTERING; HEAVY-FERMION SYSTEMS; UPPER-CRITICAL-FIELD; HIGH-TEMPERATURE SUPERCONDUCTORS; HIGH-TC SUPERCONDUCTORS; COPPER-OXIDE SUPERCONDUCTORS; NORMAL-STATE PSEUDOGAP; 2-DIMENSIONAL HUBBARD-MODEL; QUASI-PARTICLE SCATTERING; HIGH MAGNETIC-FIELDS AB The exotic superconductors considered here are those defined by Uemura and coworkers, the materials which approximately satisfy the empirical relation T(c)proportional to lambda(L)(-2), where lambda(L) is the London penetration depth. This category includes all of the presently known high-temperature superconductors, plus many others which are or have been prominent in basic superconductivity research. In a survey these materials were shown to share many characteristic features: electronic properties which are anomalous from the standpoint of BCS and strong-coupling (Eliashberg) systematics, and also distinctive features in the crystal chemistry. It is now argued that these characteristic features are consistent with and indeed suggestive of a valence-fluctuation pairing mechanism developed for the cuprate superconductors. The explanation is reasonably straightforward, and the match between the expected and the observed properties is remarkably extensive. The crystal chemistry aspects are seen here as enabling features, that is, features which are necessary in order to justify adequately an Anderson-lattice form of model Hamiltonian, and to provide a suitable parameter regime. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. NR 365 TC 8 Z9 8 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD JUN PY 2000 VL 80 IS 6 BP 1229 EP 1297 PG 69 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA 325XR UT WOS:000087702600007 ER PT J AU Robinson, ES Hill, RH Kripke, ML Setlow, RB AF Robinson, ES Hill, RH Kripke, ML Setlow, RB TI The Monodelphis melanoma model: Initial report on large ultraviolet A exposures of suckling young SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID MALIGNANT-MELANOMA; DOMESTICA; RADIATION; OPOSSUMS AB The objective of this study was to determine whether exposure of early suckling young of the opossum Monodelphis domestica to ultraviolet A (UVA) radiation (320-400 nm) can lead to the development of melanocytic lesions similar to those induced after exposure to ultraviolet B (WB) radiation (280-320 nm) to total doses as low as 380 J/m(2). A total of 576 sucklings received nine exposures of 0.6, 2.6 or 15.5 kJ/m(2) per dose (total doses similar to 6, 23 and 140 kJ/m(2), respectively) from a Blak Ray lamp source with a narrow range emission at 365 nm. A further 280 sucklings were exposed in the same way to doses of 2.6 kJ/m(2) per dose (total similar to 23 kJ/m(2)) broad-band UVA with visible wavelengths from a Dermalight lamp. Frequency of litter loss following all of the UVA-exposure protocols was similar to that within the same stocks in the colony at large. Only one of the 856 UVA-exposed individuals possessed a melanocytic lesion at the 5 month assessment point. No radiation-induced lesions of any type were evident on the skin of the other animals exposed as sucklings. The affected male was from a group of 70 individuals exposed to the highest total dose (140 kJ/m(2)) from the Blak Ray light source. The melanocytic hyperplasia was provisionally identified as a potential melanoma but it slowly regressed as the animal aged. We conclude that in the opossum suckling exposure system, the potency of UVA for melanoma induction is extremely low compared with that of UVB. Possible explanations, amenable to further investigations, are given for the low UVA sensitivity of the suckling model compared to the adult exposure model of Ley. C1 SW Fdn Biomed Res, Dept Genet, San Antonio, TX 78245 USA. SW Res Inst, Instrumentat & Space Res Div, San Antonio, TX USA. Univ Texas, MD Anderson Canc Ctr, Dept Immunol, Houston, TX 77030 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Robinson, ES (reprint author), SW Fdn Biomed Res, Dept Genet, POB 760549, San Antonio, TX 78245 USA. FU NCRR NIH HHS [RR-09919] NR 11 TC 24 Z9 24 U1 0 U2 1 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 USA SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD JUN PY 2000 VL 71 IS 6 BP 743 EP 746 DI 10.1562/0031-8655(2000)071<0743:TMMMIR>2.0.CO;2 PG 4 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 321HE UT WOS:000087449400011 PM 10857371 ER PT J AU Chang, MMT Carruthers, JR Glaze, JA AF Chang, MMT Carruthers, JR Glaze, JA TI Two experts on the frontiers of lithography SO PHOTONICS SPECTRA LA English DT Article C1 Intel Corp, Components Res, Santa Clara, CA USA. Univ Calif Lawrence Livermore Natl Lab, Virtual Natl Lab, Livermore, CA USA. RI Carruthers, John/K-7785-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU LAURIN PUBL CO INC PI PITTSFIELD PA BERKSHIRE COMMON PO BOX 1146, PITTSFIELD, MA 01202 USA SN 0731-1230 J9 PHOTON SPECTRA JI Photon. Spect. PD JUN PY 2000 VL 34 IS 6 BP 82 EP 83 PG 2 WC Optics SC Optics GA 321KD UT WOS:000087453900035 ER PT J AU Hochberg, D Molina-Paris, C Perez-Mercader, J Visser, M AF Hochberg, D Molina-Paris, C Perez-Mercader, J Visser, M TI Effective potential for the massless KPZ equation SO PHYSICA A LA English DT Article DE effective potential; KPZ equation; dynamical symmetry breaking ID RENORMALIZATION-GROUP ANALYSIS; FIELD-THEORY RENORMALIZATION; PARISI-ZHANG EQUATION; UNIVERSE; FLUCTUATIONS; DYNAMICS; SYSTEMS AB In previous work we have developed a general method for casting a classical field theory subject to Gaussian noise (that is, a stochastic partial differential equation (SPDE)) into a functional integral formalism that exhibits many of the properties more commonly associated with quantum field theories (QFTs). In particular, we demonstrated how to derive the one-loop effective potential. In this paper we apply the formalism to a specific field theory of considerable interest, the massless KPZ equation (massless noisy Burgers equation), and analyze its behavior in the ultraviolet (short-distance) regime. When this field theory is subject to white noise we can calculate the one-loop effective potential and show that it is one-loop ultraviolet renormalizable in 1, 2, and 3 space dimensions, and fails to be ultraviolet renormalizable in higher dimensions. We show that the one-loop effective potential for the massless KPZ equation is closely related to that for lambda phi(4) QFT. In particular, we prove that the massless KPZ equation exhibits one-loop dynamical symmetry breaking (via an analog of the Coleman-Weinberg mechanism) in 1 and 2 space dimensions, and that this behavior does not persist in 3 space dimensions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lab Astrofis Espacial & Fis Fundamental, Madrid 28080, Spain. INTA, Ctr Astrobiol, Madrid 28850, Spain. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. RP Molina-Paris, C (reprint author), Lab Astrofis Espacial & Fis Fundamental, Apartado 50727, Madrid 28080, Spain. OI Visser, Matt/0000-0003-1088-6485 NR 23 TC 9 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD JUN 1 PY 2000 VL 280 IS 3-4 BP 437 EP 455 DI 10.1016/S0378-4371(99)00611-1 PG 19 WC Physics, Multidisciplinary SC Physics GA 315DA UT WOS:000087096300017 ER PT J AU Tolan, M Seeck, OH Wang, J Sinha, SK Refailovich, MH Sokolov, J AF Tolan, M Seeck, OH Wang, J Sinha, SK Refailovich, MH Sokolov, J TI X-ray scattering from polymer films SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE polymer films; liquid surfaces; capillary waves; wetting ID CAPILLARY WAVES; THIN-FILMS; SURFACES; TEMPERATURE AB The effect of confinement on the surface structure of thin polymer films is investigated by specular and diffuse X-ray scattering. It will be shown to what extent information of the film surfaces and the substrate/film interactions can be obtained. In the case of polymer and liquid films predictions for correlation functions exist which may be quantitatively compared with scattering data. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Kiel, Inst Expt & Angew Phys, D-24098 Kiel, Germany. Argonne Natl Lab, XFD APS, Argonne, IL 60439 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RP Tolan, M (reprint author), Univ Kiel, Inst Expt & Angew Phys, Leibnizstr 17-19, D-24098 Kiel, Germany. NR 19 TC 10 Z9 10 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 1-3 BP 22 EP 26 DI 10.1016/S0921-4526(99)01884-0 PG 5 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300006 ER PT J AU Stearns, DG Gullikson, EM AF Stearns, DG Gullikson, EM TI Nonspecular scattering from extreme ultraviolet multilayer coatings SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE thin film growth; scattering; EUV lithography; multilayer; roughness ID X-RAY-SCATTERING; INTERFACIAL ROUGHNESS; IMAGE QUALITY; MIRRORS; GROWTH; SPECIFICATION; PERFORMANCE; MECHANISMS; SYSTEM AB We review our recent studies of nonspecular scattering from multilayer coatings designed for high reflectivity in the wavelength range of 1-100 nm. A linear, continuum growth model is used to describe the structure of the interfacial roughness in the multilayer coatings. This model accounts for both the partial replication of the substrate roughness and che intrinsic roughness introduced by the multilayer growth. The scattering of radiation from the roughness is calculated within the distorted-wave Born approximation and is compared to experimental measurements. Observations of particular interest are: (1) enhanced nonspecular scattering from the correlated roughness of the coatings and (2) asymmetry in the measured scattering due to phase effects produced by an off-normal angle of deposition during film growth. As an application of our results we consider the effect of nonspecular scattering in EUV lithography. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Ctr Xray Opt, Livermore, CA 94550 USA. OS Associates, Mountain View, CA 94040 USA. RP Stearns, DG (reprint author), OS Associates, 1174 Castro St,Suite 250, Mountain View, CA 94040 USA. EM dgs@orthosport.net NR 29 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 1-3 BP 84 EP 91 DI 10.1016/S0921-4526(99)01897-9 PG 8 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300019 ER PT J AU Brennan, S Munkholm, A Leung, OS Nix, WD AF Brennan, S Munkholm, A Leung, OS Nix, WD TI X-ray measurements of the depth dependence of stress in gold films SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE residual strain; depth profile; X-ray scattering; gold ID STRAIN GRADIENT PLASTICITY; THIN-FILMS; ALUMINUM FILMS; SILICON AB X-rays are used to determine the stress as a function of depth for five evaporated gold films of 0.8-2.5 mu m thickness. The depth dependence is achieved by varying the incident angle of the X-rays, which affects the penetration depth of the X-rays into the film. The films, which have a different thermal expansion coefficient than the silicon substrate, are strained as a result of thermal cycling after deposition. We find essentially no stress variation as a function of depth for these films. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. RP Brennan, S (reprint author), Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd,Melno Pk,Box 4349,MS 69, Stanford, CA 94309 USA. NR 15 TC 11 Z9 13 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 1-3 BP 125 EP 129 DI 10.1016/S0921-4526(99)01904-3 PG 5 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300026 ER PT J AU Toperverg, BP Felcher, GP Metlushko, VV Leiner, V Siebrecht, R Nikonov, O AF Toperverg, BP Felcher, GP Metlushko, VV Leiner, V Siebrecht, R Nikonov, O TI Grazing incidence neutron diffraction from large scale 2D structures SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE neutron diffraction; dot array; grazing incidence ID ARRAY; DOTS AB The distorted wave Born approximation (DWBA) is applied to evaluate the diffraction pattern of neutrons (or X-rays) from a 2D array of dots deposited onto a dissimilar substrate. With the radiation impinging on the surface at a grazing incidence angle alpha, the intensities diffracted both in and out the plane of specular reflection are calculated as a function of the periodicity of the array, height and diameter of the dots. The results are presented in the form of diffracted intensity contours in a plane with coordinates alpha and alpha', the latter being the glancing angle of scattering. The optimization of the experimental conditions for polarized neutron experiments on submicron dots is discussed. The feasibility of such measurements is confirmed by a test experiment. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Petersburg Nucl Phys Inst, St Petersburg 188350, Russia. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Argonne Natl Lab, Argonne, IL USA. Ruhr Univ Bochum, Inst Expt Phys 4, D-44780 Bochum, Germany. Joint Inst Nucl Res, Dubna 141980, Moscow Region, Russia. RP Toperverg, BP (reprint author), Petersburg Nucl Phys Inst, St Petersburg 188350, Russia. OI Toperverg, Boris/0000-0001-5166-7997 NR 7 TC 19 Z9 19 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 JUN PY 2000 VL 283 IS 1-3 BP 149 EP 152 DI 10.1016/S0921-4526(99)01911-0 PG 4 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300031 ER PT J AU Macrander, AT Liu, C Csencsits, R Cook, R Kirk, M Headrick, R AF Macrander, AT Liu, C Csencsits, R Cook, R Kirk, M Headrick, R TI Roughness in sputtered multilayers analyzed by transmission electron microscopy and X-ray diffuse scattering SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE X-ray; diffuse scattering; roughness; correlation ID INTERFACIAL ROUGHNESS; FILM AB Sputtered W/C multilayers with a period of 25 Angstrom have been studied both by cross-section TEM and by X-ray diffuse scattering using 10 keV synchrotron radiation. Fitting to the X-ray data is aided by the TEM images in modeling the roughness and roughness propagation within the Born approximation. We report on a study of the correctness of the often applied small roughness approximation, and we find that is not well justified in the present case. In order to probe short lateral length scales at q(y) = 0.1 Angstrom(-1), diffuse scattering data were obtained in an unconventional scattering geometry. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Cornell Univ, Cornell High Energy Synchrotron Source, Ithaca, NY 14853 USA. RP Macrander, AT (reprint author), Argonne Natl Lab, Adv Photon Source, Bldg 401,Room B3164, Argonne, IL 60439 USA. NR 15 TC 8 Z9 8 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 JUN PY 2000 VL 283 IS 1-3 BP 157 EP 161 DI 10.1016/S0921-4526(99)01918-3 PG 5 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300033 ER PT J AU Klose, F Rehm, C Fieber-Erdmann, M Holub-Krappe, E Bleif, HJ Sowers, H Goyette, R Troger, L Maletta, H AF Klose, F Rehm, C Fieber-Erdmann, M Holub-Krappe, E Bleif, HJ Sowers, H Goyette, R Troger, L Maletta, H TI Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE reflectometry; hydrogen; thin films; multilayers ID INDUCED LATTICE EXPANSION; NB(110) FILMS; SUPERLATTICE AB Hydrogen can be absorbed in large quantities by 100 Angstrom thin Nb layers embedded in epitaxial W/Nb and polycrystalline Fe/Nb multilayers. The solubility and the hydrogen-induced structural changes of the host lattice are explored in situ by small-angle neutron/X-ray reflectometry and high-angle diffraction. These measurements reveal for both systems that the relative our-of-plane expansion of the Nb layers is considerably larger than the relative increase of the Nb interplanar spacing indicating two distinctly different mechanisms of hydrogen absorption. In Fe/Nb multilayers, hydrogen expands the Nb interplanar spacing in a continuous way as function of the external pressure. In contrast, the Nb lattice expansion is discontinuous in epitaxial W/Nb multilayers: A jump in the Nb(0 0 2) Bragg reflection position occurs at a critical hydrogen pressure of 1 mbar. In situ EXAFS spectroscopy also exhibits an irreversible expansion of the Nb lattice in the film plane for PH > 1 mbar. This can be regarded as a structural phase transition from an exclusively out-of-plane to a three-dimensionally expanded state at low and high hydrogen pressures. respectively. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. Deutsch Elektr Synchrotron, Hamburger Synchrontronstschlungslab HASYLAB, D-22603 Hamburg, Germany. RP Klose, F (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 10 TC 6 Z9 6 U1 2 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 JUN PY 2000 VL 283 IS 1-3 BP 184 EP 188 DI 10.1016/S0921-4526(99)01933-X PG 5 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300039 ER PT J AU Munkholm, A Thompson, C Stephenson, GB Eastman, JA Auciello, O Fini, P Speck, JS DenBaars, SP AF Munkholm, A Thompson, C Stephenson, GB Eastman, JA Auciello, O Fini, P Speck, JS DenBaars, SP TI Transition between the 1 x 1 and (root 3 x 2 root 3)R30 degrees surface structures of GaN in the vapor-phase environment SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE GaN; surface reconstruction; MOCVD; phase transition; X-ray scattering ID RAY-DIFFRACTION; GROWTH; DEPOSITION AB Out-of-plane structures of the GaN(0001) surface in the metal-organic chemical vapor deposition (MOCVD) environment have been determined using in situ grazing-incidence X-ray scattering. We measured 11 (2) over bar l crystal truncation rod intensities at a variety of temperatures and ammonia partial pressures on both sides of the 1 x 1 to (root 3 x 2 root 3)R30 degrees surface phase transition. The out-of-plane structure of the (root 3 x 2 root 3)R30 degrees phase appears to be nearly independent of temperature below the transition, while the structure of the 1 x 1 phase changes increasingly rapidly as the phase transition is approached from above. A model for the structure of the 1 x 1 phase with a partially occupied top Ga layer agrees well with the data. The observed temperature dependence is consistent with a simple model of the equilibrium between the vapor phase and the surface coverage of Ga and N. In addition, we present results on the kinetics of reconstruction domain coarsening following a "quench" into the (root 3 x 2 root 3)R30 degrees phase held. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RP Munkholm, A (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Eastman, Jeffrey/E-4380-2011; Speck, James/H-5646-2011 NR 13 TC 8 Z9 8 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 JUN PY 2000 VL 283 IS 1-3 BP 217 EP 222 DI 10.1016/S0921-4526(99)01964-X PG 6 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300046 ER PT J AU Ankner, JF AF Ankner, JF TI Use of advanced optics in a neutron liquids reflectometer SO PHYSICA B LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE reflectometry; liquids; neutron optics AB To access a broad Q range with a moderately polychromatic(Delta lambda approximate to 4.5 Angstrom) neutron beam, we have evaluated the use of a tapered neutron guide. The utility of this device lies not in its focusing power, but in its broad angular dispersion of the incident beam. This beam can then be sampled by slits at a number of angles to cover the required Q range. Preliminary modeling of a liquids reflectometer based on this concept indicates that, by using highly reflective incident optics (4 gamma(c)(Ni) supermirror coatings), one will be able to measure reflectivities of 10(-8) in about 2h counting time at the Spallation Neutron Source, currently under construction at Oak Ridge National Laboratory. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN USA. RP Ankner, JF (reprint author), Argonne Natl Lab, IPNS Bldg 360,9700 S Cass Ave, Argonne, IL 60439 USA. OI Ankner, John/0000-0002-6737-5718 NR 3 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 JUN PY 2000 VL 283 IS 1-3 BP 253 EP 255 DI 10.1016/S0921-4526(99)01988-2 PG 3 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300053 ER PT J AU Mezei, F Russina, M AF Mezei, F Russina, M TI Neutron beam extraction and delivery at spallation neutron sources SO PHYSICA B LA English DT Article; Proceedings Paper CT European Workshop on Neutron Optics for the Next Millennium (NOP 99) CY NOV 25-27, 1999 CL PAUL SCHERRER INST, VILLIGEN, SWITZERLAND SP PSI, FZ Julich, Neutron Round Table HO PAUL SCHERRER INST DE neutron guides; ballistic guides; Monte Carlo AB We address two main issues in neutron beam extraction and delivery at spallation neutron sources: (a) the relatively small divergence of the beams impinging on samples at typical distances of 10-20 m from usual size moderators and (b) the beam losses in long neutron guides used to bridge large distances of the order of 100 m or more between moderator and sample, as required by the desired time-of-flight wavelength resolution or other instrument optimization conditions. Our Monte Carlo simulation results show, that novel neutron optical solutions can substantially enhance neutron fluxes on the sample in both cases, compared to the current practice on existing spallation source instruments. Converging supermirror-coated neutron guides with proper geometry can lead to substantial intensity gains even for wavelengths as short as 0.7 Angstrom at short moderator-sample distances typical for hot and thermal neutron inelastic spectrometers. Ballistic guides, consisting of a supermirror-coated diverging section, an Ni-coated uniform portion and a supermirror-coated converging section can deliver much higher beam fluxes over large distances than the conventional supermirror or Ni-coated guides currently in use. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Hahn Meitner Inst Kernforsch Berlin GmbH, Neurton Scattering Ctr, D-14109 Berlin, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mezei, F (reprint author), Hahn Meitner Inst Kernforsch Berlin GmbH, Neurton Scattering Ctr, Glienicker Str 100, D-14109 Berlin, Germany. RI Russina, Margarita/E-9886-2016 OI Russina, Margarita/0000-0003-2067-606X NR 2 TC 14 Z9 15 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 4 BP 318 EP 322 DI 10.1016/S0921-4526(00)00323-9 PG 5 WC Physics, Condensed Matter SC Physics GA 317UU UT WOS:000087246000009 ER PT J AU Lefmann, K McMorrow, DF Ronnow, HM Nielsen, K Clausen, KN Lake, B Aeppli, G AF Lefmann, K McMorrow, DF Ronnow, HM Nielsen, K Clausen, KN Lake, B Aeppli, G TI Added flexibility in triple axis spectrometers: the two RITAs at Riso SO PHYSICA B LA English DT Article; Proceedings Paper CT European Workshop on Neutron Optics for the Next Millennium (NOP 99) CY NOV 25-27, 1999 CL PAUL SCHERRER INST, VILLIGEN, SWITZERLAND SP PSI, FZ Julich, Neutron Round Table HO PAUL SCHERRER INST DE neutron instrumentation ID NEUTRON-SCATTERING AB The cold-neutron triple-axis spectrometer RITA-I at Rise has been operational for about three years, and in the near future an improved version, RITA-2 will replace the existing triple-axis instrument TAS7. We review the performance of RITA-1 and the operation modes of its flexible secondary spectrometer, giving examples of a few key experiments, and describe the software developed for running it. Further, the design of the new RITA-2 instrument is presented. The two RITA spectrometers are compared with their sister instrument SPINS at NIST and with similar instruments planned elsewhere. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Riso Natl Lab, Condensed Matter Phys & Chem Dept, DK-4000 Roskilde, Denmark. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NEC Res, Princeton, NJ 08540 USA. RP Lefmann, K (reprint author), Riso Natl Lab, Condensed Matter Phys & Chem Dept, Frederiksborgvej 399, DK-4000 Roskilde, Denmark. RI McMorrow, Desmond/C-2655-2008; Lefmann, Kim/M-9228-2014; Ronnow, Henrik/A-4953-2009; OI McMorrow, Desmond/0000-0002-4947-7788; Lefmann, Kim/0000-0003-4282-756X; Ronnow, Henrik/0000-0002-8832-8865; Lake, Bella/0000-0003-0034-0964 NR 22 TC 34 Z9 34 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 4 BP 343 EP 354 DI 10.1016/S0921-4526(00)00335-5 PG 12 WC Physics, Condensed Matter SC Physics GA 317UU UT WOS:000087246000015 ER PT J AU Seeger, PA Daemen, LL Thelliez, TG Hjelm, RP AF Seeger, PA Daemen, LL Thelliez, TG Hjelm, RP TI Neutron instrument simulations in the next millennium SO PHYSICA B LA English DT Article; Proceedings Paper CT European Workshop on Neutron Optics for the Next Millennium (NOP 99) CY NOV 25-27, 1999 CL PAUL SCHERRER INST, VILLIGEN, SWITZERLAND SP PSI, FZ Julich, Neutron Round Table HO PAUL SCHERRER INST DE Monte Carlo; computer simulations; neutron optics; neutron scattering ID MONTE-CARLO TOOL; SCATTERING AB The Neutron Instrument Simulation Package (NISP) is available on the world-wide web at URL http://strider.lansce.lanl.gov/NISP/Welcome.html. With more than 20 years of development, there is a certain amount of maturity in the code, but also the potential for a great deal of growth. As requirements for more sophisticated simulations grow, NISP can be expanded or modified to meet those needs. This report describes features of the NISP structures that make it possible far users to contribute algorithms. Any interaction that can be coded as a Fortran-callable subroutine can be included as a region type in the simulations. New ideas are always solicited, and may be sent by e-mail to PASeeger@aol.com. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Seeger, PA (reprint author), 239 Loma Escolar, Los Alamos, NM 87544 USA. RI Lujan Center, LANL/G-4896-2012 NR 8 TC 6 Z9 6 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 4 BP 433 EP 435 DI 10.1016/S0921-4526(00)00382-3 PG 3 WC Physics, Condensed Matter SC Physics GA 317UU UT WOS:000087246000034 ER PT J AU Johnston, DC AF Johnston, DC TI Heavy fermion behaviors in LiV2O4 SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE heavy-fermion behaviors; LiV2O4 ID MAGNETIC-SUSCEPTIBILITY; SPIN FLUCTUATION; SUPERCONDUCTIVITY; TRANSITIONS; TERNARY; STATE; OXIDE AB Experiments of various types on the metallic transition metal oxide compound LiV2O4 With the FCC normal-spinel structure are reviewed. The low-temperature T less than or similar to 10 R data consistently indicate heavy fermion (HF) behaviors characteristic of those of the heaviest-mass f-electron HF compounds. A crossover is observed above similar to 50 K in the magnetic susceptibility, Li-7 spin-lattice relaxation rate and neutron magnetic scattering function to a magnetic state variously described as an antiferromagnetically coupled local-moment metal or, at the opposite extreme, as an itinerant nearly ferromagnetic metal. Recent theoretical investigations to understand these properties of LiV2O4 are discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Johnston, DC (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 28 TC 22 Z9 22 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 281 BP 21 EP 25 DI 10.1016/S0921-4526(99)01010-8 PG 5 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200011 ER PT J AU Kagayama, T Oomi, G Bud'ko, SL Canfield, PC AF Kagayama, T Oomi, G Bud'ko, SL Canfield, PC TI Pressure effect on magnetoresistance of CeSb2 SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE ferromagnetism; metamagnetic transition; high pressure; electrical resistance AB Temperature and field-dependent electrical resistance of CeSb2, has been measured at high pressure. The Curie temperature and the metamagnetic transition field are enhanced by pressure until they become unobservable in R(T) and R(H) curves at 2.1 GPa. There is pressure-induced large hysteresis behavior in R(T) which could have crystallographic origin. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kumamoto Univ, Fac Gen Educ, Dept Mech Engn & Mat Sci, Kumamoto 8608555, Japan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Kagayama, T (reprint author), Kumamoto Univ, Fac Gen Educ, Dept Mech Engn & Mat Sci, Kumamoto 8608555, Japan. RI Canfield, Paul/H-2698-2014 NR 6 TC 3 Z9 3 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 281 BP 90 EP 91 DI 10.1016/S0921-4526(99)00961-8 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200036 ER PT J AU Nakotte, H Chang, S Torikachvili, MS Bordallo, HN Lacerda, AH Takabatake, T AF Nakotte, H Chang, S Torikachvili, MS Bordallo, HN Lacerda, AH Takabatake, T TI Magnetism in single-crystalline CePtSn SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE Kondo compounds; antiferromagnetism; magnetic transitions ID KONDO AB CePtSn exhibits two antiferromagnetic transitions at low temperatures. We report on magnetoresistance and magnetization studies of single-crystalline CePtSn in magnetic fields up to 18 T. The data were taken to establish the magnetic-phase diagrams for CePtSn in fields applied along the principal directions of the orthorhombic structure. (C) 2000 Elsevier Science B.V. All rights reserved. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. Univ Calif Los Alamos Natl Lab, Pulse Field Facil, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Hiroshima Univ, Higashihiroshima 739, Japan. RP Nakotte, H (reprint author), New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RI Bordallo, Heloisa/I-6836-2012; Takabatake, Toshiro/L-2882-2014 OI Bordallo, Heloisa/0000-0003-0750-0553; Takabatake, Toshiro/0000-0002-3293-8592 NR 3 TC 12 Z9 12 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 JUN PY 2000 VL 281 BP 103 EP 104 DI 10.1016/S0921-4526(99)01199-0 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200042 ER PT J AU Kagawa, A Kagayama, T Oomi, G Mitamura, H Goto, T Canfield, PC Bud'ko, SL AF Kagawa, A Kagayama, T Oomi, G Mitamura, H Goto, T Canfield, PC Bud'ko, SL TI Pressure dependence on metamagnetic-phase transition in PrSb2 SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE magnetization; magnetoresistance; metamagnetism; high pressure ID ELECTRICAL-RESISTANCE AB Magnetic field dependence of magnetization and electrical resistance of the layered compound PrSb2 has been measured under pressure. Two metamagnetic transitions at H-1( = 0.4 T) and H-2( approximate to 1.4 T) were observed in both M(H) and R(H) curves. It is found that H-1 increases but H-2 decreases with pressure. Pressure coefficients of H-1 and H-2 are 0.67 and - 0.24 T GPa(-1). respectively. H-1 begins to decrease and the magnitude of dII(2)/dP changes around 1 GPa. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kumamoto Univ, Fac Engn, Dept Mech Engn & Mat Sci, Kumamoto 8608555, Japan. Univ Tokyo, Inst Solid State Phys, Tokyo 1068666, Japan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Kagayama, T (reprint author), Kumamoto Univ, Fac Engn, Dept Mech Engn & Mat Sci, Kumamoto 8608555, Japan. RI Canfield, Paul/H-2698-2014 NR 7 TC 4 Z9 4 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 JUN PY 2000 VL 281 BP 124 EP 125 DI 10.1016/S0921-4526(99)00964-3 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200052 ER PT J AU Wada, H Mitsuda, A Nakamura, A Shiga, M Thompson, JD AF Wada, H Mitsuda, A Nakamura, A Shiga, M Thompson, JD TI Resistivity anomaly due to valence transition in Eu compounds SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE intermediate valence; valance fluctuations; transport properties; Eu AB Temperature dependence of electrical resistivity, rho, was examined for the intermediate valence (IV) system EuNi2(Ge1-xSix)(2). It was found that the IV compounds show a characteristic peak in the rho-T curve. The origin of the peak is discussed. (C) 2000 Elsevier Science B.V. AU rights reserved. C1 Kyoto Univ, Dept Mat Sci & Engn, Sakyo Ku, Kyoto 6068501, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wada, H (reprint author), Kyoto Univ, Dept Mat Sci & Engn, Sakyo Ku, Kyoto 6068501, Japan. NR 5 TC 1 Z9 1 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 JUN PY 2000 VL 281 BP 132 EP 133 DI 10.1016/S0921-4526(99)01125-4 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200056 ER PT J AU Mikulina, O Syshchenko, O Lacerda, AH Nakotte, H Kamarad, J Beyermann, WP Havela, L Sechovsky, V AF Mikulina, O Syshchenko, O Lacerda, AH Nakotte, H Kamarad, J Beyermann, WP Havela, L Sechovsky, V TI Magnetic phase transitions in UNiGe under pressure SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE UNiGe; magnetic transitions; electrical resistivity; pressure effects AB We report measurements of the electrical resistivity on a UNiGe single crystal as a function of temperature and magnetic field (i\\B\\c-axis) performed under hydrostatic pressures up to 1 GPa. At the magnetic-phase transitions in UNiGe pronounced anomalies are exhibited in the resistivity. Pressure-induced changes of the resistivity and magnetoresistance are primarily a consequence of a varying exchange coupling between the U moments, and from these results Further insight into the nature of the magnetic phases of this material is obtained. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Acad Sci Czech Republ, Inst Phys, Lab High Pressures, Prague 16253 6, Czech Republic. Charles Univ, Dept Elect Struct, Prague 12116 2, Czech Republic. Univ Calif Los Alamos Natl Lab, NHMFL, Pulse Facil, Los Alamos, NM 87545 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RP Kamarad, J (reprint author), Acad Sci Czech Republ, Inst Phys, Lab High Pressures, Cukrovarnicka 10, Prague 16253 6, Czech Republic. RI Kamarad, Jiri/G-5880-2014; Sechovsky, Vladimir/A-5256-2008 OI Kamarad, Jiri/0000-0003-3502-9930; Sechovsky, Vladimir/0000-0003-1298-2120 NR 5 TC 3 Z9 3 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 JUN PY 2000 VL 281 BP 206 EP 207 DI 10.1016/S0921-4526(99)01189-8 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200088 ER PT J AU Kang, JS Olson, CG Min, BI AF Kang, JS Olson, CG Min, BI TI Photoemission spectroscopy of half-metallic manganese compounds: perovskite versus Heusler SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE half-metal; Perovskite-manganites; Heusler; photoemission ID MAGNETORESISTANCE; LA1-XCAXMNO3; TRANSPORT AB We have investigated the electronic structures of the Mn-based half-metallic ferromagnetic systems of Pr1-xSrxMnO3 (PSMO) and PtMnSb Heusler compound, using photoemission spectroscopy. The partial spectral weight (PSW) distributions of Mn 3d, Pr 4f. and Pt 5d electrons have been determined and compared to the LSDA band structure calculations. The overall features of the Mn 3d PSWs of PtMnSb and PSMO are found to be very similar, except for the region near E-F. The reduced spectral intensity at E-F in the Mn 3d PSW of PSMO suggests the localized nature of the Mn e(g) electrons in PSMO due to the lattice polaron formation. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP Kang, JS (reprint author), Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. NR 10 TC 0 Z9 0 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 281 BP 494 EP 495 DI 10.1016/S0921-4526(99)00996-5 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200203 ER PT J AU Fehske, H Wellein, G Buttner, H Bishop, AR Salkola, MI AF Fehske, H Wellein, G Buttner, H Bishop, AR Salkola, MI TI Local mode behavior in quasi-1D CDW systems SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE charge density wave; localized lattice distortions; polarons; MX-chain compounds AB We analyze numerically the ground-state and spectral properties of the three-quarter filled Peierls-Hubbard Hamiltonian. Various charge- and spin-ordered states are identified. In the strong-coupling regime, we find clear signatures of local lattice distortions accompanied by intrinsic multi-phonon localization. The results are discussed in relation to recent experiments on MX chain [-PtCl-] complexes. In particular we are able to reproduce the observed red shift of the overtone resonance Raman spectrum. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Bayreuth, Inst Phys, D-95440 Bayreuth, Germany. Univ Erlangen Nurnberg, Reg Rechenzentrum Erlangen, D-91058 Erlangen, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Superconductor Technol Inc, Santa Barbara, CA 93111 USA. RP Fehske, H (reprint author), Univ Bayreuth, Inst Phys, Univ Str 30, D-95440 Bayreuth, Germany. NR 3 TC 10 Z9 10 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 JUN PY 2000 VL 281 BP 673 EP 674 DI 10.1016/S0921-4526(99)01066-2 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200282 ER PT J AU Allen, JW Denlinger, JD Zhang, YX Gweon, GH Yang, SH Oh, SJ Cho, EJ Ellis, WP Gajewski, DA Chau, R Maple, MB AF Allen, JW Denlinger, JD Zhang, YX Gweon, GH Yang, SH Oh, SJ Cho, EJ Ellis, WP Gajewski, DA Chau, R Maple, MB TI U 5f spectral weight variation in UPd3-xPtx SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE uranium intermetallics; 5f; resonant photoemission; UPd3-xPtx AB We report a photoemission study of the 5f spectral weight variation in UPd3-xPtx. Relative to a previous study the results show both agreement and very significant differences. New spectral detail is resolved. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Harrison M Randall Lab, Dept Phys, Ann Arbor, MI 48109 USA. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Allen, JW (reprint author), Univ Michigan, Harrison M Randall Lab, Dept Phys, Ann Arbor, MI 48109 USA. NR 9 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 281 BP 725 EP 726 DI 10.1016/S0921-4526(99)00935-7 PG 2 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200301 ER PT J AU Kang, JS Onuki, Y Olson, CG Min, BI AF Kang, JS Onuki, Y Olson, CG Min, BI TI Photoemission study of CeRu2 and CeCo2 SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE 4f-photoemission; CeRu2; CeCo2; superconductivity ID TRANSITION AB A resonant photoemission spectroscopy (RPES) study has been performed for the f-electron superconductors of CeRu2 and CeCo2 near the Ce 4d --> 4f absorption edge. The RPES provides evidence for the strong hybridization between Ce 4f and conduction-band electrons in both CeRu2 and CeCo2. Comparison of the photoemission data to the calculated density of states reveals a reasonably good agreement for CeRu2, but a less good agreement for CeCo2. The itinerant nature of Ce 4f electrons suggests that the role of the Ce 4f electrons is important in determining the superconductivity in these systems. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 560, Japan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP Kang, JS (reprint author), Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. NR 8 TC 1 Z9 1 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 JUN PY 2000 VL 281 BP 731 EP 733 DI 10.1016/S0921-4526(99)00983-7 PG 3 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200304 ER PT J AU Matsuda, N Setoguchi, H Kagayama, T Oomi, G Cho, BK Canfield, PC AF Matsuda, N Setoguchi, H Kagayama, T Oomi, G Cho, BK Canfield, PC TI Effect of pressure on the antiferromagnetism and superconductivity of ErNi2B2C SO PHYSICA B LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electon Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE high pressure; superconductivity; antiferromagnetism ID MAGNETISM; TM; ER; HO AB The electrical resistivity of single crystalline ErNi2B2C has been measured at high pressures up to 2.2 GPa and magnetic fields up to 5 T in order to make clear the relation between antiferromagnetism and superconductivity. It is found that the superconducting transition temperature T, is almost independent of pressure, while the upper critical field H-c2 for H perpendicular to c decreases with increasing pressure. The Neel temperature T-N increases with increasing pressure. The present results are compared with those of other borocarbides and discussed taking into account the interplay between the superconductivity and the antiferromagnetism. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Kumamoto Univ, Dept Mech Engn & Mat Sci, Kumamoto 8608555, Japan. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Oomi, G (reprint author), Kumamoto Univ, Dept Mech Engn & Mat Sci, Kurokami 2-39-1, Kumamoto 8608555, Japan. RI Canfield, Paul/H-2698-2014 NR 9 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 JUN PY 2000 VL 281 BP 1001 EP 1003 DI 10.1016/S0921-4526(99)00968-0 PG 3 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200420 ER PT J AU You, H Chu, YS Lister, TE Nagy, Z Ankudiniv, AL Rehr, JJ AF You, H Chu, YS Lister, TE Nagy, Z Ankudiniv, AL Rehr, JJ TI Resonance X-ray scattering from Pt(111) surfaces under water SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 6th International Conference on X-ray and Neutron Scattering CY SEP 12-17, 1999 CL LEEWENHORST CONGRESS CTR, NOORDWIJKERHOUT, NETHERLANDS SP Leeuwenhorst Congress Ctr, Bruker AXS, Delft Univ, Interfacultair Reactor Inst, Koninklijke Nederlandse Akad VanWetenschappen, Koninklijke Nederlandse Chem Vereniging, Philips Analyt, Stichting Phys HO LEEWENHORST CONGRESS CTR DE SRXS; oxidation ID OXIDATION AB The resonance X-ray scattering from the unmodified, clean Pt(1 1 1)surface is compared to theoretically predicted scattering Self-consistent real-space multiple-scattering approach is used to calculate the real and imaginary parts of the atomic platinum scattering factor. The experimentally observed near-edge fine structures of the surface scattering and fluorescence intensities are well reproduced by the calculations. In addition, more details are presented on our previous study [Phys. Rev. Lett. 83, 552 (1999)] of electrochemically formed oxide monolayer an the Pt(1 1 1) surface. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. RP You, H (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hyou@anl.gov RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 12 TC 12 Z9 12 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUN PY 2000 VL 283 IS 1-3 BP 212 EP 216 DI 10.1016/S0921-4526(99)01959-6 PG 5 WC Physics, Condensed Matter SC Physics GA 307CF UT WOS:000086635300045 ER PT J AU Denlinger, JD Gweon, GH Allen, JW Olson, CG Dalichaouch, Y Lee, BW Maple, MB Fisk, Z Canfield, PC Armstrong, PE AF Denlinger, JD Gweon, GH Allen, JW Olson, CG Dalichaouch, Y Lee, BW Maple, MB Fisk, Z Canfield, PC Armstrong, PE TI Advances in photoemission spectroscopy of f-electron materials SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 51st Yamada Conference on Strongly Correlated Electron Systems CY AUG 24-28, 1999 CL NAGANO, JAPAN SP Yamada Sci Fdn, Nagano City DE f-electron; angle-resolved photoemission; URu2Si2; SmB6; d-f hybridization ID FERMI-SURFACE; QUASI-PARTICLES; HIGH-RESOLUTION; MIXED-VALENCE; URU2SI2; MODEL; SYSTEMS; SOLIDS; SMB6; CE AB The recent capability to perform angle-resolved photoemission spectroscopy (ARPES) with improved energy and angle resolution over a wide photon energy range has provided new information about f-electron systems. Results for two rather different systems, 5f-electron heavy fermion metal URu2Si2 and 4f-electron mixed-valent SmBn, are compared and contrasted (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Florida State Univ, NHMFL, Tallahassee, FL 32306 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM jddenlinger@lbl.gov RI Canfield, Paul/H-2698-2014 NR 38 TC 35 Z9 36 U1 2 U2 17 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 JUN PY 2000 VL 281 BP 716 EP 722 DI 10.1016/S0921-4526(99)00915-1 PG 7 WC Physics, Condensed Matter SC Physics GA 305YW UT WOS:000086570200299 ER PT J AU Aoki, Y Koizumi, T Ohtani, N Hasegawa, T Motowidlo, L Sokolowski, RS Scanlan, RM Nagaya, S AF Aoki, Y Koizumi, T Ohtani, N Hasegawa, T Motowidlo, L Sokolowski, RS Scanlan, RM Nagaya, S TI Development of a large current capacity conductor using Bi-system superconductors SO PHYSICA C LA English DT Article; Proceedings Paper CT 9th US-Japan Workshop on High-T Superconductors CY OCT 13-15, 1999 CL YAMANASHI, JAPAN SP Forum Superconduct Sci & Technol Japan DE Rutherford cable; Bi2Sr2CaCu2Oy; superconductor; ceramic barrier layer AB We developed a new strong Rutherford cable using Bi2Sr2CaCu2Oy (Bi-2212) high temperature superconducting (HTS) wire, which consisted of 427 superconducting filaments and AgMgSb alloy outer sheath. This wire exhibited excellent critical current (I-c) and critical current density (J(c)) values at 4.2 K in self-field (285 A and 340 000 A/cm(2), respectively) and a room temperature tensile strength of 180 MPa. The Rutherford cable was prepared with a NiCr alloy strip as a cable core. The degradation of full cable I-c induced by Ni diffusion was reduced by introducing a ceramic barrier layer between the Bi-2212 superconducting wires and the NiCr cable core. A full cable I-c value of 3500 A at 4.2 K in self-field was obtained in short sample fabricated by using a cable core with a ZrO2 film barrier layer. Finally, we fabricated an 80-m-long Rutherford cable by using a cable core with a MgO tape as a barrier layer and evaluated its full cable I-c. I-c values of 17-m-long sections cut from a continuous 80-m-long cable, were greater than 2700 A at 4.2 K in self-field. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Showa Elect Wire & Cable Co Ltd, Kanagawa 2291133, Japan. IGC Adv Supercond, Waterbury, CT 06704 USA. Lawrence Berkeley Lab, Supercond Magnet Grp, Berkeley, CA USA. Chubu Elect Power Inc, Midori Ku, Nagoya, Aichi 4598522, Japan. RP Aoki, Y (reprint author), Showa Elect Wire & Cable Co Ltd, 4-1-1 Minami Hashimoto, Kanagawa 2291133, Japan. NR 4 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN PY 2000 VL 335 IS 1-4 BP 1 EP 5 DI 10.1016/S0921-4534(00)00125-8 PG 5 WC Physics, Applied SC Physics GA 331YY UT WOS:000088047300002 ER PT J AU Willis, JO Arendt, PN Foltyn, SR Jist, QX Groves, JR DePaula, RF Dowden, PC Peterson, EJ Holesinger, TG Coulter, JY Ma, M Maley, MP Peterson, DE AF Willis, JO Arendt, PN Foltyn, SR Jist, QX Groves, JR DePaula, RF Dowden, PC Peterson, EJ Holesinger, TG Coulter, JY Ma, M Maley, MP Peterson, DE TI Advances in YBCO-coated conductor technology SO PHYSICA C LA English DT Article; Proceedings Paper CT 9th US-Japan Workshop on High-T Superconductors CY OCT 13-15, 1999 CL YAMANASHI, JAPAN SP Forum Superconduct Sci & Technol Japan DE YSZ template film; YBCO superconducting film; ion beam-assisted deposition; pulsed-laser deposition ID YTTRIA-STABILIZED-ZIRCONIA; THIN-FILMS; DEPOSITION; TAPES AB Processes for producing both the yttrium-stabilized zirconia (YSZ) template film by ion beam-assisted deposition (IBAD) and the YBa2Cu3Ox (YBCO) superconducting film by pulsed laser deposition (PLD) at 1-m lengths have achieved I-c values of 122 A and J(c) values of 1 MA/cm(2). Improvements have been made in all stages of the process. Variations of I-c along the length of the 1-m samples stimulated development of a new in-field I-c measurement capability. The use of MgO as an IBAD template film has made great progress and can potentially decrease the time to produce the template film by more than an order of magnitude. A combination of electrical and microstructural investigations is being made to understand and improve the properties of the YBCO-coated conductors. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Willis, JO (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, MST STC MS-K763, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 10 TC 41 Z9 44 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN PY 2000 VL 335 IS 1-4 BP 73 EP 77 DI 10.1016/S0921-4534(00)00146-5 PG 5 WC Physics, Applied SC Physics GA 331YY UT WOS:000088047300017 ER PT J AU Krusin-Elbaum, L Blatter, G Thompson, JR Ullmann, J Chu, CW AF Krusin-Elbaum, L Blatter, G Thompson, JR Ullmann, J Chu, CW TI Anisotropy-enhanced vortex pinning by randomly splayed extended defects in high-T-c superconductors SO PHYSICA C LA English DT Article; Proceedings Paper CT 9th US-Japan Workshop on High-T Superconductors CY OCT 13-15, 1999 CL YAMANASHI, JAPAN SP Forum Superconduct Sci & Technol Japan DE vortex pinning; Hg-based cuprate superconductors; columnar defects ID COLUMNAR DEFECTS; YBA2CU3O7 CRYSTALS; ENTANGLEMENT; PRESSURE; MOTION AB Using uniformly splayed pinning landscape as a tool in the family of Hg-based cuprate superconductors, we (i) demonstrate that such splayed correlated disorder pins vortices stronger in materials with higher anisotropy and (ii) find a consistent description of this systematic trend through an effective rescaling scheme. This scheme demonstrates that in highly anisotropic superconductors extended pinning defects need not be aligned for optimal pinning. (C) 2000 Elsevier Science B.V. All rights reserved. C1 IBM Corp, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. ETH Honggerberg, CH-8093 Zurich, Switzerland. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RP Krusin-Elbaum, L (reprint author), IBM Corp, Thomas J Watson Res Ctr, POB 218,Route 134, Yorktown Heights, NY 10598 USA. NR 13 TC 7 Z9 7 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN PY 2000 VL 335 IS 1-4 BP 144 EP 147 DI 10.1016/S0921-4534(00)00160-X PG 4 WC Physics, Applied SC Physics GA 331YY UT WOS:000088047300031 ER PT J AU Thompson, JR Ossandon, JG Krusin-Elbaum, L Song, KJ Kim, HJ Christen, DK Ullmann, JL AF Thompson, JR Ossandon, JG Krusin-Elbaum, L Song, KJ Kim, HJ Christen, DK Ullmann, JL TI Current decay from quantum tunneling of vortices in Bi-2212 superconductors SO PHYSICA C LA English DT Article; Proceedings Paper CT 9th US-Japan Workshop on High-T Superconductors CY OCT 13-15, 1999 CL YAMANASHI, JAPAN SP Forum Superconduct Sci & Technol Japan DE Bi-2212 superconductors; quantum tunneling; vortex pinning ID SPLAYED COLUMNAR DEFECTS; PROTON IRRADIATION; CURRENT-DENSITY; FLUX-CREEP; TAPES; BI2SR2CACU2O8; ENHANCEMENT AB We have created randomly oriented columnar defects in textured Bi2Sr2CaCu2Ox/Ag superconducting tapes and Tl-2212 materials, using a fission process driven by irradiation with 0.8 GeV protons. Vortex pinning was significantly improved, leading to increased persistent current density J. The thermally activated decay of current with time was greatly decreased, compared with unirradiated materials. Nonetheless, temperature-independent vortex motion from quantum tunneling limits J and its stability in time. Analysis of the time-dependent studies provides estimates for the elementary vortex attempt time tau, for both as-formed and ion-processed materials. (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, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thompson, JR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN PY 2000 VL 335 IS 1-4 BP 170 EP 174 DI 10.1016/S0921-4534(00)00165-9 PG 5 WC Physics, Applied SC Physics GA 331YY UT WOS:000088047300036 ER PT J AU Chu, CW Xue, YY Tsui, S Cmaidalka, J Heilman, AK Lorenz, B Meng, RL AF Chu, CW Xue, YY Tsui, S Cmaidalka, J Heilman, AK Lorenz, B Meng, RL TI A possible crypto-superconducting structure in a superconducting ferromagnet SO PHYSICA C LA English DT Article; Proceedings Paper CT 9th US-Japan Workshop on High-T Superconductors CY OCT 13-15, 1999 CL YAMANASHI, JAPAN SP Forum Superconduct Sci & Technol Japan DE crypto-superconductivity; superconducting ferromagnet; high temperature superconductivity; superconductivity; ferromagnetism ID DC MAGNETIZATION; COEXISTENCE; PHASE; MAGNETISM AB We have measured the de and ac electrical and magnetic properties in various magnetic fields of the recently reported superconducting ferromagnet RuSr2GdCu2O8. Our reversible magnetization measurements demonstrate the absence of a bulk Meissner state in the compound below the superconducting transition temperature. Several scenarios that might account for the absence of a bull; Meissner state, including the possible presence of a sponge-like nonuniform superconducting or a crypto-superconducting structure in the chemically uniform Ru-1212, have been proposed and discussed. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Houston, Dept Phys, Houston, TX 77204 USA. Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Lawrence Berkeley Nacl Lab, Berkeley, CA 94720 USA. Univ Houston, Dept Chem, Houston, TX 77204 USA. RP Chu, CW (reprint author), Univ Houston, Dept Phys, Houston, TX 77204 USA. NR 22 TC 75 Z9 75 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN PY 2000 VL 335 IS 1-4 BP 231 EP 238 DI 10.1016/S0921-4534(00)00176-3 PG 8 WC Physics, Applied SC Physics GA 331YY UT WOS:000088047300047 ER PT J AU Berman, GP Doolen, GD Lopez, GV Tsifrinovich, VI AF Berman, GP Doolen, GD Lopez, GV Tsifrinovich, VI TI Simulations of quantum-logic operations in a quantum computer with a large number of qubits SO PHYSICAL REVIEW A LA English DT Article ID SPIN-DIFFUSION; LATTICE; COMPUTATION; DYNAMICS AB We report the simulations of the dynamics of quantum-logic operations with large number of qubits (up to 1000). A nuclear-spin chain in which selective excitations of spins are provided by the gradient of the external magnetic field is considered. The spins interact with their nearest neighbors. We simulate the quantum controlled-Nor (CN) gate implementation for remote qubits, which provides the long-distance entanglement. Our approach can be applied to any implementation of quantum-logic gates involving a large number of qubits. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Univ Guadalajara, Dept Fis, Guadalajara 44430, Jalisco, Mexico. Polytech Univ, IDS Dept, Brooklyn, NY 11201 USA. RP Berman, GP (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 20 TC 22 Z9 22 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 JUN PY 2000 VL 61 IS 6 AR 062305 DI 10.1103/PhysRevA.61.062305 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 323LY UT WOS:000087567900024 ER PT J AU Garrett, WR Peet, VE AF Garrett, WR Peet, VE TI Wave-mixing effects in resonance-enhanced multiphoton ionization of xenon in Bessel beams SO PHYSICAL REVIEW A LA English DT Article ID MULTI-PHOTON IONIZATION; 3RD-HARMONIC GENERATION; HARMONIC-GENERATION; INTERMEDIATE STATE; EXCITATION; SHIFTS AB Three-photon-resonant excitation and subsequent ionization of xenon at high concentrations has been studied utilizing both Bessel and Gaussian beams. Comparisons of analogous results with the two modes of focusing are made. The excitation-ionization profiles can be analyzed on the basis of the well-studied interference effect involving combined contributions of three- and one-photon transition amplitudes in resonant atomic excitation. We show that the principal features of the excitation problem with Bessel beams can be simulated by a simple picture involving crossed plane-wave beams. Using this approach it has been shown that pressure-broadened and shifted lines that result from the interference-based cooperative Lorentzian line shift constitutes the main pressure-dependent peak of off-resonance excitation profiles produced in Bessel beams. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Univ Tartu, Inst Phys, EE-51014 Tartu, Estonia. RP Garrett, WR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Peet, Viktor/J-8588-2014 NR 20 TC 11 Z9 11 U1 1 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 JUN PY 2000 VL 61 IS 6 AR 063804 DI 10.1103/PhysRevA.61.063804 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 323LY UT WOS:000087567900096 ER PT J AU Krivec, R Mandelzweig, VB Varga, K AF Krivec, R Mandelzweig, VB Varga, K TI Local properties of three-body atomic wave functions SO PHYSICAL REVIEW A LA English DT Article ID VARIATIONAL CALCULATIONS; HELIUM; STATES; IONS AB The local properties and accuracy of the positronium negative-ion (Ps(-)) ground-state wave functions obtained by the stochastic variational method (SVM) and by direct solution of the Schrodinger equation with the help of the correlation-function hyperspherical-harmonic method (CFHHM) are studied and compared. Though the energy, calculated by both methods, agrees to up to ten digits, the amplitudes of the values of the operator D = H Psi/E Psi - 1, characterizing local deviation of the wave function from its true value, in all of the coordinate space in the SVM are consistently larger (by up to five orders of magnitude) than in the CFHHM, despite the fact that the SVM observables except [delta(r(k))] converge to significantly more digits than the CFHHM observables for their respective selected bases. C1 Jozef Stefan Inst, Dept Theoret Phys, Ljubljana 1001, Slovenia. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Krivec, R (reprint author), Jozef Stefan Inst, Dept Theoret Phys, POB 3000, Ljubljana 1001, Slovenia. EM rajmund.krivec@ijs.si; victor@helium.fiz.huji.ac.il; varga@theory.phy.anl.gov RI Varga, Kalman/A-7102-2013 NR 14 TC 45 Z9 46 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 2000 VL 61 IS 6 AR 062503 DI 10.1103/PhysRevA.61.062503 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 323LY UT WOS:000087567900036 ER PT J AU Piechocinska, B AF Piechocinska, B TI Information erasure SO PHYSICAL REVIEW A LA English DT Article ID LAW AB Landauer's principle states that in erasing one bit of information, on average, at least k(B)T ln(2) energy is dissipated into the environment (where k(B) is Boltzmann's constant and T is the temperature of the environment at which one erases), Here, Landauer's principle is microscopically derived without direct reference to the second law of thermodynamics. This is done for a classical system with continuous space and time, with discrete space and time, and for a quantum system. The assumption made in all three cases is that during erasure the bit is in contact with a thermal reservoir. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Piechocinska, B (reprint author), Univ Calif Los Alamos Natl Lab, T-6, Los Alamos, NM 87544 USA. EM bpiechocinska@hotmail.com NR 20 TC 90 Z9 90 U1 1 U2 9 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 JUN PY 2000 VL 61 IS 6 AR 062314 DI 10.1103/PhysRevA.61.062314 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 323LY UT WOS:000087567900033 ER PT J AU Yan, YF Pennycook, SJ AF Yan, YF Pennycook, SJ TI Structural model for the Al72Ni20Co8 decagonal quasicrystals SO PHYSICAL REVIEW B LA English DT Article ID AL-CO-NI; QUASI-CRYSTALS; ATOM-CLUSTER; MN; AL65CU20CO15; DISORDER; ALLOYS; PHASE AB We propose a structure model for the Al72Ni,Co-20(8) decagonal quasicrystals based on its tau(2)-inflated Al13Co4 approximant phase: Applying a 10(5) screw operation on a monolayer obtained from the approximant reproduces almost all features of 2-nm clusters seen in atomic-resolution Z-contrast images of Al72Ni20Co8 decagonal quasicrystals. The exception is the central ring, where the symmetry is broken due to chemical ordering of Al and transition metals. By restricting possible overlaps, this enforces the perfect quasiperiodic tiling. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Yan, YF (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 27 TC 17 Z9 17 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2000 VL 61 IS 21 BP 14291 EP 14294 DI 10.1103/PhysRevB.61.14291 PG 4 WC Physics, Condensed Matter SC Physics GA 321DB UT WOS:000087438700008 ER PT J AU Harrison, N Balicas, L Brooks, JS Sarrao, J Fisk, Z AF Harrison, N Balicas, L Brooks, JS Sarrao, J Fisk, Z TI Thermodynamic evidence for bulk charge-density wave rigidity in NbSe3 SO PHYSICAL REVIEW B LA English DT Article ID HIGH MAGNETIC-FIELDS; MAGNETOTRANSPORT; OSCILLATIONS; ETA-MO4O11; DYNAMICS; CRYSTAL AB We show that the split wave form of the magnetic quantum oscillations observed in NbSe3 cannot be attributed to the Zeeman splitting of the Landau levels. Instead, the behavior of the pronounced second harmonic is consistent with the "frequency doubling" effect that occurs when the oscillatory chemical potential interferes with a commensurate charge-density wave. Since the charge-density waves in NbSe3 are most definitely incommensurate, this low temperature rigidity must be caused by pinning mechanisms that involve the bulk of the sample. C1 Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Inst Venezolano Invest Cient, Caracas 1020A, Venezuela. RP Harrison, N (reprint author), Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. NR 22 TC 3 Z9 3 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2000 VL 61 IS 21 BP 14299 EP 14302 DI 10.1103/PhysRevB.61.14299 PG 4 WC Physics, Condensed Matter SC Physics GA 321DB UT WOS:000087438700010 ER PT J AU Kimura, H Matsushita, H Hirota, K Endoh, Y Yamada, K Shirane, G Lee, YS Kastner, MA Birgeneau, RJ AF Kimura, H Matsushita, H Hirota, K Endoh, Y Yamada, K Shirane, G Lee, YS Kastner, MA Birgeneau, RJ TI Incommensurate geometry of the elastic magnetic peaks in superconducting La1.88Sr0.12CuO4 SO PHYSICAL REVIEW B LA English DT Article ID NEUTRON-SCATTERING; SPIN CORRELATIONS; LA2-XSRXCUO4; ORDER; FLUCTUATIONS AB We report magnetic neutron-scattering measurements of incommensurate magnetic order in a superconducting single crystal of La1.88Sr0.12CuO4. We find that the incommensurate wave vectors which describe the static magnetism do not lie along high-symmetry directions of the underlying CuO2 lattice. The positions of the elastic magnetic peaks are consistent with those found in excess-oxygen doped La2CuO4+y. This behavior differs from the precise magnetic order found in the low-temperature tetragonal LB1.6-xNd0.4SrxCuO4 material for which stripes of spin and charge have been observed. These observations have clear implications for any stripe model proposed to describe the static magnetism in orthorhombic La2CuO4-based superconductors. C1 Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 9808578, Japan. Kyoto Univ, Chem Res Inst, Uji, Kyoto 6100011, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RP Kimura, H (reprint author), Tohoku Univ, Res Inst Sci Measurements, Aoba Ku, Katahira 2-1-1, Sendai, Miyagi 9808577, Japan. RI Hirota, Kazuma/C-6797-2008; Yamada, Kazuyoshi/C-2728-2009 NR 11 TC 41 Z9 41 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 JUN 1 PY 2000 VL 61 IS 21 BP 14366 EP 14369 DI 10.1103/PhysRevB.61.14366 PG 4 WC Physics, Condensed Matter SC Physics GA 321DB UT WOS:000087438700027 ER PT J AU Haffner, S Olson, CG Miller, LL Lynch, DW AF Haffner, S Olson, CG Miller, LL Lynch, DW TI Evidence for a strong impact of the electron-photon matrix element on angle-resolved photoelectron spectra of layered cuprate compounds SO PHYSICAL REVIEW B LA English DT Article ID FERMI-SURFACE; PHOTOEMISSION; SR2CUO2CL2; HOLE; GAP; BI2SR2CACU2O8+DELTA; SUPERCONDUCTORS; DISPERSION; PLANE AB Little is known about the impact of the electron-photon matrix element on angle-resolved photoelectron spectra of layered cuprate compounds. Using the example of the model layered cuprate Sr2CuO2Cl2, we demonstrate that the electron-photon matrix element has a significant influence on energy distribution curves, rendering their interpretation as images of the spectral function nontrivial. C1 Iowa State Univ, US DOE, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Haffner, S (reprint author), Iowa State Univ, US DOE, Dept Phys & Astron, Ames, IA 50011 USA. NR 20 TC 12 Z9 12 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 JUN 1 PY 2000 VL 61 IS 21 BP 14378 EP 14381 DI 10.1103/PhysRevB.61.14378 PG 4 WC Physics, Condensed Matter SC Physics GA 321DB UT WOS:000087438700030 ER PT J AU Fultz, B Stephens, TA Alp, EE Hu, MY Sutter, JP Toellner, TS Sturhahn, W AF Fultz, B Stephens, TA Alp, EE Hu, MY Sutter, JP Toellner, TS Sturhahn, W TI Atom cluster and vibrational excitations in chemically-disordered (Pt3Fe)-Fe-57 SO PHYSICAL REVIEW B LA English DT Article ID NUCLEAR RESONANT SCATTERING; FIRST-PRINCIPLES; ENTROPY; NI3AL; STATES; DIFFERENCE; DENSITIES; ALLOYS; ENERGY; FE-57 AB Inelastic nuclear resonant scattering spectra of Fe-57 atoms were measured on crystalline alloys of Pt,Fe-57 that were chemically disordered, partially ordered, and L1(2) ordered. Phonon partial density of states curves for Fe-57 were obtained from these spectra. Upon disordering, about 10% of the spectral intensity underwent a distinct shift from 25 to 19 meV. This change in optical modes accounted for most of the change of the vibrational entropy of disordering contributed by Fe atoms, which was (+0.10 +/- 0.03) k(B) (Fe atom)(-1). Prospects for parametrizing the vibrational entropy with low-order cluster variables were assessed. To calculate the difference in vibrational entropy of the disordered and ordered alloys, the clusters must be large enough to account for the abundances of several of the atom configurations of the first-nearest-neighbor shell about the Fe-57 atoms. C1 CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Fultz, B (reprint author), CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. NR 30 TC 12 Z9 12 U1 2 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 1 PY 2000 VL 61 IS 21 BP 14517 EP 14522 DI 10.1103/PhysRevB.61.14517 PG 6 WC Physics, Condensed Matter SC Physics GA 321DB UT WOS:000087438700048 ER EF