FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Timchalk, C Trease, HE Trease, LL Minard, KR Corley, RA AF Timchalk, C Trease, HE Trease, LL Minard, KR Corley, RA TI Potential technology for studying dosimetry and response to airborne chemical and biological pollutants SO TOXICOLOGY AND INDUSTRIAL HEALTH LA English DT Article; Proceedings Paper CT 36th Annual Conference on Theories and Practices in Toxicology and Risk Assessment CY APR 15-18, 2002 CL CINCINNATI, OHIO SP AFRL/HEST, NHRC/TD, USACEHR, Army Ctr Hlth Promot & Prevent Med, AF Off Sci Res, US EPA, Natl Ctr Environm Assessment-Cincinnati, Agcy Toxic Substances Dis Registry, Natl Inst Occup Safety & Hlth, US FDA, Natl Res Council, Natl Acad Sci DE airflow; computational fluid dynamics; model; particle dosimetry; respiratory tract ID COMPUTATIONAL FLUID-DYNAMICS; PARTICULATE AIR-POLLUTION; UPPER RESPIRATORY-TRACT; MULTIPLE-PATH MODEL; NASAL PASSAGES; RAT LUNG; INHALED FORMALDEHYDE; RISK ASSESSMENT; ANIMAL-MODELS; F344 RAT AB Advances in computational, and imaging techniques have enabled the rapid development of three-dimensional (3-D) models of biological systems in unprecedented detail. Using these advances, 3-D models of the lungs and nasal passages of the rat and human are being developed to ultimately improve predictions of airborne pollutant dosimetry. Techniques for imaging the respiratory tract by magnetic resonance imaging (MRI) were developed to improve the speed and accuracy of geometric data collection for mesh reconstruction. The MRI resolution is comparable to that obtained by manual measurements but at much greater speed and accuracy. Newly developed software (NWGrid) was utilized to translate imaging data from MR into 3-D mesh structures. Together, these approaches significantly reduced the time to develop a 3-D model. This more robust airway structure will ultimately facilitate modeling gas or vapor exchange between the respiratory tract and vasculature as well as enable linkages of dosimetry with cell response models. The 3-D, finite volume, viscoelastic mesh structures form the geometric basis for computational fluid dynamics modeling of inhalation, exhalation and the delivery of individual particles (or concentrations of gas or vapors) to discrete regions of the respiratory tract. The ability of these 3-D models to resolve dosimetry at such a high level of detail will require new techniques to measure regional airflows and particulate deposition for model validation. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Timchalk, C (reprint author), Pacific NW Natl Lab, MSIN-P7-59,902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 37 TC 13 Z9 13 U1 0 U2 2 PU ARNOLD, HODDER HEADLINE PLC PI LONDON PA 338 EUSTON ROAD, LONDON NW1 3BH, ENGLAND SN 0748-2337 J9 TOXICOL IND HEALTH JI Toxicol. Ind. Health PD JUN PY 2001 VL 17 IS 5-10 BP 270 EP 276 DI 10.1191/0748233701th114oa PG 7 WC Public, Environmental & Occupational Health; Toxicology SC Public, Environmental & Occupational Health; Toxicology GA 634CB UT WOS:000180321500015 PM 12539872 ER PT J AU Patzek, TW Silin, DB AF Patzek, TW Silin, DB TI Water injection into a low-permeability rock - 1: Hydrofracture growth SO TRANSPORT IN POROUS MEDIA LA English DT Article DE optimal control; hydrofracture growth; waterflood; transient flow; generalized Carter model; self-similar solution ID TEMPERATURE TRANSIENTS; GEOMETRY AB In this paper, we model water injection through a growing vertical hydrofracture penetrating a low-permeability reservoir. The results are useful in oilfield waterflood applications and in liquid waste disposal through reinjection. Using Duhamel's principle, we extend the Gordeyev and Entov (1997) self-similar 2D solution of pressure diffusion from a growing fracture to the case of variable injection pressure. The flow of water injected into a low-permeability rock is almost perpendicular to the fracture for a time sufficiently long to be of practical interest. We revisit Carter's model of 1D fluid injection (Howard and Fast, 1957) and extend it to the case of variable injection pressure. We express the cumulative injection through the injection pressure and effective fracture area. Maintaining fluid injection above a reasonable minimal value leads inevitably to fracture growth regardless of the injector design and the injection policy. The average rate of fracture growth can be predicted from early injection. A smart injection controller that can prevent rapid fracture growth is needed. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Patzek, TW (reprint author), Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. NR 32 TC 6 Z9 6 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD JUN PY 2001 VL 43 IS 3 BP 537 EP 555 DI 10.1023/A:1010689016442 PG 19 WC Engineering, Chemical SC Engineering GA 446PW UT WOS:000169522500007 ER PT J AU Silin, DB Patzek, TW AF Silin, DB Patzek, TW TI Water injection into a low-permeability rock - 2: Control model SO TRANSPORT IN POROUS MEDIA LA English DT Article DE waterflood; hydrofracture; optimal injection; controller; quadratic optimization AB In Part 1, we have demonstrated the inevitable growth of the fluid injection hydrofractures in low-permeability rocks. Thus, a smart controller that manages fluid injection in the presence of hydrofracture extension is highly desirable. Such a controller will be an essential part of automated waterflood project surveillance and control. Here we design an optimal injection controller using methods of optimal control theory. The controller inputs are the history of the injection pressure and the cumulative injection, along with the fracture size. The output parameter is the injection pressure and the control objective is the injection rate. We demonstrate that the optimal injection pressure depends not only on the instantaneous measurements, but it is determined by the whole history of the injection and of the fracture area growth. We show the controller robustness when the inputs are delayed and noisy and when the fracture undergoes abrupt extensions. Finally, we propose a procedure that allows estimation of the hydrofracture size at no additional cost. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Silin, DB (reprint author), Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD JUN PY 2001 VL 43 IS 3 BP 557 EP 580 DI 10.1023/A:1010600200512 PG 24 WC Engineering, Chemical SC Engineering GA 446PW UT WOS:000169522500008 ER PT J AU Greene, DL Tishchishyna, NI AF Greene, DL Tishchishyna, NI TI Costs of oil dependence: A 2000 update SO TRANSPORTATION QUARTERLY LA English DT Article ID MACROECONOMY; PRICE; MARKET; SHOCKS AB Oil dependence remains a potentially serious economic and strategic problem for the United States. World oil prices leapt from $10 per barrel in January of 1999 to $30 per barrel in the summer of 2000, as a direct consequence of supply restraints by the OPEC cartel. Estimates of the total economic costs to the United States of such oil market upheavals during the last 30 years are in the vicinity of $7 trillion, present value 1998 dollars, about as large as the sum total of payments on the national debt over the same period. Transportation is at the center of the oil dependence issue. More than 25 years after the first world oil crisis in 1973-74. the U.S. transportation system comprises 67% of the U.S. petroleum demand (25% of world oil demand) and relies on oil for more than 95% of its energy needs. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Greene, DL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. NR 52 TC 3 Z9 3 U1 0 U2 2 PU ENO FOUNDATION TRANSPORT INC PI WASHINGTON PA 1634 I ST NW, STE 500, WASHINGTON, DC 20006-4003 USA SN 0278-9434 J9 TRANSPORT Q JI Transp. Q. PD SUM PY 2001 VL 55 IS 3 BP 11 EP 32 PG 22 WC Transportation SC Transportation GA 447CY UT WOS:000169552500003 ER PT J AU Kilaas, R Radmilovic, V AF Kilaas, R Radmilovic, V TI Structure determination and structure refinement of Al2CuMg precipitates by quantitative high-resolution electron microscopy SO ULTRAMICROSCOPY LA English DT Article DE quantitative high-resolution electron microscopy; structure refinement; image comparison; S-phase; Al-Cu-Mg alloy ID AL; IMAGES; ALLOYS; HREM AB The structure of the S-phase (Al2CuMg) precipitate in an Al matrix has been determined by using a combination of image processing, quantitative image comparison, and automatic refinement of imaging and structural parameters. A method for comparing images with unknown origin relationship while quickly estimating a possible translation of the origin is outlined. The optimization algorithm used in the structure determination utilizes space group symmetry, which is deduced from the crystal-zone axis and reduces the number of free parameters. Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94270 USA. Univ Belgrade, Dept Met Phys, Belgrade, Yugoslavia. RP Kilaas, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, MS 72-215,1 Cyclotron Rd, Berkeley, CA 94270 USA. NR 20 TC 22 Z9 23 U1 2 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN PY 2001 VL 88 IS 1 BP 63 EP 72 DI 10.1016/S0304-3991(00)00107-8 PG 10 WC Microscopy SC Microscopy GA 436NA UT WOS:000168940900006 PM 11393452 ER PT J AU Gwo, JP AF Gwo, JP TI In search of preferential flow paths in structured porous media using a simple genetic algorithm SO WATER RESOURCES RESEARCH LA English DT Article ID DIFFUSIVE MASS-TRANSFER; DUAL-POROSITY MODEL; SOLUTE TRANSPORT; FRACTURE NETWORKS; MULTIREGION MODEL; GROUND-WATER; SOIL; MACROPOROSITY; HILLSLOPE; MOVEMENT AB Fracture network and preferential flow path images from exposed outcrops of geological formations, exposed soil pedon faces, and extracted soil columns and rock cores are often used to conceptualize and construct models to predict the fate and transport of subsurface contaminants. Both the scale resolutions inherent in these observations and the upscaling methods used to obtain macroscopic flow and transport parameters may result in uncertainties in the prediction. We present a mechanistic-based approach that utilizes a discrete fracture flow and transport model, a distributed and high performance computational architecture, and a genetic-based search algorithm to invert scale-representative, equivalent fracture networks or the preferential flow paths. Synthetic breakthrough curves (BTCs) and exposed structural information from known fracture networks in hypothetical soil columns are presented to the search algorithm. Using three genetic operators, a simple genetic algorithm (SGA) is able to invert the correct pictures of simple but not complex fracture networks. Solute transport experiments using soil columns often assume that the structure of soil columns is laterally uniform with respect to the macroscopic transport direction and the transport process is longitudinally one-dimensional. This assumption and the one ETC thus collected for each injection of solutes, even with flow interruptions, are not sufficient to guide the search algorithm toward the global optimum. Additional information (e.g., multiple solute BTCs along a cross section of the soil column) is necessary for the SGA to invert the correct fracture network. Three SGA population statistics, fracture network uncertainty, informatic entropy, and matrix-fracture contact area, are proposed to measure the uncertainty of SGA near optima. A positive correlation between the reduction of these statistics and the level of relevant information to better confine the SGA search space was found. The SGA search algorithm is then applied to a laboratory solute transport problem. Multiple scenarios of search constraints, derived from visually traced surface features, are examined. The hypothesis that variation in fracture aperture may reduce the uncertainty of SGA near optima is also tested. The results from these applications suggest that there is a certain degree of uncertainty regarding the flowing nature of the exposed fracture segments that are visually traced. The uncertainty of SGA near optima is not improved by incorporating fracture aperture information into the fracture networks. Breakthrough curves thus calculated have marginal improvement, relative to the uniform aperture SGA near optima, in fitting the observations. The lack of improvement may be caused by the relative uniform structure of the soil and the scale of the problem. It is further suggested that in applying the search algorithm to laboratory and field problems, one explores only the search scenarios that relevant information and search constraints may warrant. C1 Oak Ridge Natl Lab, Dept Math & Comp Sci, Oak Ridge, TN 37830 USA. RP Gwo, JP (reprint author), Univ Maryland Baltimore Cty, Dept Civil & Environm Engn, 1000 Hilltop Circle, Baltimore, MD 21250 USA. NR 52 TC 16 Z9 17 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 2001 VL 37 IS 6 BP 1589 EP 1601 DI 10.1029/2000WR900384 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 434ZF UT WOS:000168845200005 ER PT J AU Chen, JS Hubbard, S Rubin, Y AF Chen, JS Hubbard, S Rubin, Y TI Estimating the hydraulic conductivity at the South Oyster Site from geophysical tomographic data using Bayesian techniques based on the normal linear regression model SO WATER RESOURCES RESEARCH LA English DT Article ID GROUND-PENETRATING-RADAR; PARAMETER-ESTIMATION; SEISMIC DATA; PERMEABILITY; AQUIFER; VELOCITIES; INVERSION AB This study explores the use of ground penetrating radar (GPR) tomographic velocity, GPR tomographic attenuation, and seismic tomographic velocity for hydraulic conductivity estimation at the South Oyster Site, using a Bayesian framework. Since site-specific relations between hydraulic conductivity and geophysical properties are often nonlinear and subject to a large degree of uncertainty such as at this site, we developed a normal linear regression model that allows exploring these relationships systematically. Although the log-conductivity displays a small variation (sigma (2) = 0.30) and the geophysical data vary over only a small range, results indicate that the geophysical data improve the estimates of the hydraulic conductivity. The improvement is the most significant where prior information is limited. Among the geophysical data, GPR and seismic velocity are more useful than GPR attenuation. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Chen, JS (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, 440 Davis Hall, Berkeley, CA 94720 USA. RI Chen, Jinsong/A-1374-2009; Hubbard, Susan/E-9508-2010 NR 44 TC 83 Z9 83 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 2001 VL 37 IS 6 BP 1603 EP 1613 DI 10.1029/2000WR900392 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 434ZF UT WOS:000168845200006 ER PT J AU Kowalsky, MB Dietrich, P Teutsch, G Rubin, Y AF Kowalsky, MB Dietrich, P Teutsch, G Rubin, Y TI Forward modeling of ground-penetrating radar data using digitized outcrop images and multiple scenarios of water saturation SO WATER RESOURCES RESEARCH LA English DT Article ID SUBSURFACE; SIMULATION; DEPOSITS; SITE AB Simple petrophysical models and a sedimentologically interpreted outcrop photograph corresponding to the plane of a ground-penetrating radar (GPR) survey are combined to create models for the simulation of GPR, This makes possible the comparison of GPR field data, synthetic CPR sections, and a lithology image. On the basis of this comparison the usefulness of the method for identifying hydrologically significant lithofacies and the sensitivity of the results to different subsurface conditions may be investigated. In particular, GPR simulations are performed for an outcrop model at three states of water saturation: uniformly drained (uniform residual saturation), nonuniformly saturated, and fully saturated. As predicted by reflection coefficient calculations, comparison among the synthetic simulations highlights the importance of the existing pore water distribution in determining the "visibility" of lithologic elements in GPR sections. Comparisons of the synthetic GPR sections with the field data show overall agreement, though the occurrence of various observed reflections depends on the presence and distribution of pore water. Conclusions are also drawn about extending outcrop analog-derived results to investigations of real (fully saturated) aquifers. C1 Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. Univ Tubingen, Inst Appl Geol, D-72076 Tubingen, Germany. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Kowalsky, MB (reprint author), Univ Calif Berkeley, Dept Civil & Environm Engn, 435 Davis Hall, Berkeley, CA 94720 USA. RI Dietrich, Peter/L-9919-2014 OI Dietrich, Peter/0000-0003-2699-2354 NR 29 TC 27 Z9 31 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 2001 VL 37 IS 6 BP 1615 EP 1625 DI 10.1029/2001WR900015 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 434ZF UT WOS:000168845200007 ER PT J AU Mortensen, AP Glass, RJ Hollenbeck, K Jensen, KH AF Mortensen, AP Glass, RJ Hollenbeck, K Jensen, KH TI Visualization of microscale phase displacement processes in retention and outflow experiments: Nonuniqueness of unsaturated flow properties SO WATER RESOURCES RESEARCH LA English DT Article ID POROUS-MEDIA; X-RAY; FIELDS; LIGHT AB Methods to determine unsaturated hydraulic properties can exhibit random and nonunique behavior. We assess the causes for these behaviors by visualizing microscale phase displacement processes that occur during equilibrium retention and transient outflow experiments. For both types of experiments we observe the drainage process to be composed of a mixture of fast air fingering and slower air back-filling. The influence of each of these microscale processes is controlled by a combination of the size and the speed of the applied boundary step, the initial saturation and its structure, and small-scale heterogeneities. Because the mixture of these microscale processes yields macroscale effective behavior, measured unsaturated flow properties are also a function of these controls, Such results suggest limitations on the current definitions and uniqueness of unsaturated hydraulic properties. C1 Tech Univ Denmark, Dept Hydrodynam & Water Resources, DK-2800 Lyngby, Denmark. Sandia Natl Labs, Flor Visualizat & Proc Lab, Albuquerque, NM 87185 USA. RP Mortensen, AP (reprint author), Tech Univ Denmark, Dept Hydrodynam & Water Resources, Bldg 115, DK-2800 Lyngby, Denmark. RI Jensen, Karsten/E-3469-2015 OI Jensen, Karsten/0000-0003-4020-0050 NR 16 TC 14 Z9 14 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 2001 VL 37 IS 6 BP 1627 EP 1640 DI 10.1029/2000WR900415 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 434ZF UT WOS:000168845200008 ER PT J AU Dave, VR Carpenter, RW Christensen, DT Milewski, JO AF Dave, VR Carpenter, RW Christensen, DT Milewski, JO TI Precision laser brazing utilizing nonimaging optical concentration SO WELDING JOURNAL LA English DT Article ID JOINT AB In the present work, a Nd:YAG laser is used in conjunction with energy-flux concentrators to perform precision brazing of small tube assemblies. Polished copper reflectors in the shape of either a wedge or a cone are used to direct and concentrate infrared laser energy onto the tube joint and alloy preform to accomplish the braze. These reflectors were designed using optical ray-tracing software employing the principles of nonimaging optics and multiple beam reflections to create a tuned waveguide that can be adapted to a variety of shapes. The ray-tracing algorithm also calculates the incident energy flux on the tubes. This information is used in a finite difference thermal model to predict processing times. Experimental trials and metallographic evaluation for brazes made in 304 stainless steel tubing using Au-18% Ni filler material are presented. This method and its enabling models are validated, offering new processing techniques that may be better suited than current methods for some applications. Proposed extensions of this work to other applications are also discussed, including a methodology to adapt brazing utilizing nonimaging optical concentration to complex part geometries. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Rice Univ, Houston, TX 77251 USA. RP Dave, VR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 18 TC 1 Z9 1 U1 0 U2 1 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD JUN PY 2001 VL 80 IS 6 BP 142S EP 147S PG 6 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 746KW UT WOS:000186746400014 ER PT J AU Vargas, R Garza, J Dixon, D Hay, BP AF Vargas, R Garza, J Dixon, D Hay, BP TI Conformational analysis of N-benzylformamide SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE conformation; amide; N-benzyl; ab initio; MM3 ID ION SEQUESTERING AGENTS; HYDROGEN-BOND; BASIS-SETS; MOLECULAR CALCULATIONS; ENTEROBACTIN ANALOGS; FORCE-FIELD; DENSITY; STABILITY; COMPLEXES; AMIDE AB The potential energy surfaces (PES's) at different levels of ah initio electronic structure theory with correlation effects included are reported for rotation about the N(amide)-C(sp(3)) and C(sp(3))-C(aryl) bonds in N-benzylformamide. Fully optimized geometries are in good agreement with crystal structure data and PES's are consistent with the experimental dihedral angle distributions. The results are used to assign MM3 force field parameters to allow calculation on N-benzyl substituted amides, (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Autonoma Metropolitana Iztapalapa, Dept Quim, Div Ciencias Basicas & Ingn, Mexico City 09340, DF, Mexico. RP Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM ben.hay@pnl.gov 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 43 TC 5 Z9 5 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD MAY 31 PY 2001 VL 541 BP 243 EP 251 DI 10.1016/S0166-1280(00)00806-X PG 9 WC Chemistry, Physical SC Chemistry GA 427CJ UT WOS:000168387000026 ER PT J AU Johnson, E Johansen, A Dahmen, U Chen, S Fujii, T AF Johnson, E Johansen, A Dahmen, U Chen, S Fujii, T TI Shapes and sizes of nanoscale Pb inclusions in Al SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 10th International Conference on Rapidly Quenched and Metastable Materials (RQ10) CY AUG 23-27, 1999 CL BANGALORE, INDIA SP Indian Inst Sci DE electron microscopy; Al alloys; equilibrium shapes ID GRAIN-BOUNDARIES; EQUILIBRIUM SHAPE; LEAD INCLUSIONS; SOLIDIFICATION; ALUMINUM; PARTICLES; MATRIX; BEHAVIOR; ENERGY; NUCLEI AB Al-Pb alloys are monotectic and characterized by a large miscibility gap in the liquid phase area and extremely limited mutual solubility in the solid phase. Due to the extent of the miscibility gap the alloys are difficult to make in conventional processing. However, alloys with relatively homogeneous microstructures of fine Pb inclusions in an Al matrix can he made hy metastable processing such as rapid solidification, ion implantation, ball milling and physical vapor deposition. The first two techniques have been employed to make alloys of Al with 0.5-3 at.% Pb. The alloys contain fine dispersions of nanoscale Pb : implantation and from about 10-500 nm after rapid solidification. Inclusions inclusions with sizes in the range from 1 to about 20 nm after ion embedded in the Al matrix are single crystalline, and they grow in parallel cube alignment with the matrix. They have cuboctahedral shape with atomically smooth {111} and {100} facets determined from a minimization of the interface energy. Using high resolution TEM, two types of deviations from the classical Wulff construction which alter the shape of the inclusions, have been studied. The smallest inclusions, less than about 20 nm in size, adopt a series of magic sizes that can be related to the occurrence of periodic minima in the residual strain energy. Likewise, in this size range, the energy contribution from the cuboctahedral edges becomes non-negligible leading to an increase in the aspect ratio of the inclusions with decreasing size. Inclusions located in grain boundaries in general adopt a single crystal morphology where one part is faceted and grows in parallel cube alignment with the matrix grain, while the other part has a shape approximating a spherical cap. In special cases such as twin boundaries and {111} twist boundaries, the inclusions are bicrystalline where each part is aligned with the respective grain and the two parts are separated by a boundary similar to that of the matrix. These shapes can be explained using the Cahn-Hoffman xi -vector construction, which generalizes the Wulff construction to determine equilibrium shapes at anisotropic interfaces and their junctions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Copenhagen, Orsted Lab, DK-2100 Copenhagen O, Denmark. Univ Calif Berkeley, LBNL, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Johnson, E (reprint author), Univ Copenhagen, Orsted Lab, Univ Parken 5, DK-2100 Copenhagen O, Denmark. EM johnson@fys.ku.dk RI Fujii, Toshiyuki/B-9555-2015 OI Fujii, Toshiyuki/0000-0001-9796-724X NR 31 TC 46 Z9 54 U1 1 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAY 31 PY 2001 VL 304 SI SI BP 187 EP 193 DI 10.1016/S0921-5093(00)01462-3 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 428HW UT WOS:000168457100029 ER PT J AU Chemla, DS Shah, J AF Chemla, DS Shah, J TI Many-body and correlation effects in semiconductors SO NATURE LA English DT Review ID FEMTOSECOND SPECTRAL INTERFEROMETRY; 4-WAVE-MIXING SIGNALS; SECONDARY-EMISSION; QUANTUM KINETICS; BULK GAAS; REGIME; SCATTERING; DYNAMICS; WELLS AB Solids consist of 10(22)-10(23) particles per cubic centimetre, interacting through infinite-range Coulomb interactions. The linear response of a solid to a weak external perturbation is well described by the concept of non-interacting 'quasiparticles' first introduced by Landau. But interactions between quasiparticles can be substantial in dense systems. For example, studies over the past decade have shown that Coulomb correlations between quasiparticles dominate the nonlinear optical response of semiconductors, in marked contrast to the behaviour of atomic systems. These Coulomb correlations and other many-body interactions are important not only for semiconductors, but also for all condensed-matter systems. C1 Bell Labs, Lucent Technol, Holmdel, NJ 07733 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Bell Labs, Lucent Technol, 101 Crawford Corner Rd, Holmdel, NJ 07733 USA. EM jags@lucent.com NR 48 TC 229 Z9 230 U1 3 U2 29 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD MAY 31 PY 2001 VL 411 IS 6837 BP 549 EP 557 DI 10.1038/35079000 PG 9 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 437GE UT WOS:000168982500041 PM 11385562 ER PT J AU Lewis, CL Jackson, GP Doorn, SK Majidi, V King, FL AF Lewis, CL Jackson, GP Doorn, SK Majidi, V King, FL TI Spectral, spatial and temporal characterization of a millisecond pulsed glow discharge: copper analyte emission and ionization SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE pulsed glow discharge; optical spectrometry; excitation and ionization; mechanisms; plasma processes ID MASS-SPECTROMETRY; SPUTTERED ATOMS; SIGNAL PROFILES; IONS; DENSITY; PLASMAS AB Two-dimensional maps of the spatial distributions of excited and ionized sputtered copper atoms are presented for a millisecond pulsed argon glow discharge. These maps demonstrate the temporal as well as spatial dependence of different excitation and ionization processes over the pulse cycle. Transitions from the low energy electronic states for the atom, characterized by emission such as that at 324.75 nm (3.82 --> 0.00 eV), dominate the plateau time regime at a distance of 2.5 mm from the cathode surface. These processes originate from the electron excitation of ground state copper atoms. Transitions from high-energy electronic states, such as that characterized by emission at 368.74 nm (7.16 --> 3.82 eV), predominate during the afterpeak time regime at a distance of 5.0-6.0 mm from the cathode surface. This observation is consistent with the relaxation of highly excited copper atoms produced by electron recombination with copper ions during the afterpeak time regime. Analyses of afterpeak and plateau intensities for a series of copper emission lines indicate an electron excitation temperature equivalent to 5.78 eV at 0.8 torr and 1.5 W. Temporal profiles exhibit copper ion emission only during the plateau time regime. (C) 2001 Elsevier Science B.V. All rights reserved. C1 W Virginia Univ, Dept Chem, Morgantown, WV 26505 USA. Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP King, FL (reprint author), W Virginia Univ, Dept Chem, POB 6045, Morgantown, WV 26505 USA. RI Jackson, Glen/D-3518-2014 OI Jackson, Glen/0000-0003-0803-6254 NR 19 TC 43 Z9 43 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD MAY 31 PY 2001 VL 56 IS 5 BP 487 EP 501 DI 10.1016/S0584-8547(01)00175-6 PG 15 WC Spectroscopy SC Spectroscopy GA 454KR UT WOS:000169972200002 ER PT J AU Fadeev, AG Selinskaya, YA Kelley, SS Meagher, MM Litvinova, EG Khotimsky, VS Volkov, VV AF Fadeev, AG Selinskaya, YA Kelley, SS Meagher, MM Litvinova, EG Khotimsky, VS Volkov, VV TI Extraction of butanol from aqueous solutions by pervaporation through poly(1-trimethylsilyl-1-propyne) SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE poly(1-trimethylsilyl-1-propyne); microporous and porous membranes; pervaporation; sorption ID FREE-VOLUME; MEMBRANES; FERMENTATION; SORPTION; SEPARATION; TRANSPORT; RECOVERY; ETHANOL; PTMSP; POLYMERS AB Poly(1-trimethylsilyl-1-propyne) (PTMSP) was synthesized using a TaCl5-Al(i-Bu)(3) catalysis system. Pervaporation and sorption of n-butanol-water mixtures were studied, and the peculiarities of water and butanol co-permeation are discussed. The strong dependence of water partial flux (with a minimum at 1 wt.% butanol in feed) on butanol concentration in feed was observed. S-shaped isotherms of butanol and total sorption were found for PTMSP in 0-1 wt.% concentration range. It appears that blocking of PTMSP nanopores by high sorbing organic molecules controls the pervaporation of butanol from dilute aqueous solutions. Data are discussed in regard with PTMSP morphology. (C) 2001 Elsevier Science B.V. All rights reserved. C1 RAS, AV Topchiev Petrochem Synth Inst, Moscow 117912, Russia. Univ Nebraska, Biol Proc Dev Facil, Lincoln, NE 68583 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Volkov, VV (reprint author), RAS, AV Topchiev Petrochem Synth Inst, 29 Leninsky Prospekt, Moscow 117912, Russia. RI Volkov, Vladimir/J-3757-2013 NR 28 TC 65 Z9 71 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD MAY 30 PY 2001 VL 186 IS 2 BP 205 EP 217 DI 10.1016/S0376-7388(00)00683-9 PG 13 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 427BN UT WOS:000168385100005 ER PT J AU Orme, CJ Harrup, MK Luther, TA Lash, RP Houston, KS Weinkauf, DH Stewart, FF AF Orme, CJ Harrup, MK Luther, TA Lash, RP Houston, KS Weinkauf, DH Stewart, FF TI Characterization of gas transport in selected rubbery amorphous polyphosphazene membranes SO JOURNAL OF MEMBRANE SCIENCE LA English DT Article DE gas and vapor permeation; gas separations; phosphazene membranes ID PHOSPHAZENE POLYMER MEMBRANES; POLY(ORGANOPHOSPHAZENE) MEMBRANES; SEPARATION PROPERTIES; TRADEOFF RELATIONS; FIRE-RESISTANT; CROSS-LINKING; PERMEABILITY; SELECTIVITY; ELECTROLYTES; MODEL AB Gas permeabilities for six different gases have been evaluated for a series of closely related polyphosphazenes. Polyphosphazenes are attractive polymers for use as gas separation membranes due to their inherent chemical, thermal, acid radiation stability. Additionally, polyphosphazenes may be tailored for specific chemical affinities. In this report, polyphosphazenes with three different pendant groups with varied hydrophilicity were characterized for gas permeation. All polymers were characterized as having modest permeabilities for methane, oxygen, nitrogen, helium, and hydrogen. These gases were not observed to have a significant interaction with the polymer structure and transport is attributed to segmental chain motion. Carbon dioxide was found to have a significant intermolecular interaction with the polymer and the permeability was observed to be proportional to the percentage of hydrophilic 2-(2-methoxyethoxy)ethanol on the backbone. Thus, we report a promising method for the development of CO2 selective membranes. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. New Mexico Inst Min & Technol, Dept Chem Engn, Socorro, NM 87801 USA. RP Stewart, FF (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 35 TC 40 Z9 41 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0376-7388 J9 J MEMBRANE SCI JI J. Membr. Sci. PD MAY 30 PY 2001 VL 186 IS 2 BP 249 EP 256 DI 10.1016/S0376-7388(00)00690-6 PG 8 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 427BN UT WOS:000168385100009 ER PT J AU Manson, JL Schlueter, JA Geiser, U Stone, MB Reich, DH AF Manson, JL Schlueter, JA Geiser, U Stone, MB Reich, DH TI Crystal structures and magnetic properties of Mn[N(CN)(2)](2)L {L=2,5-dimethylpyrazine and aminopyrazine} SO POLYHEDRON LA English DT Article; Proceedings Paper CT 7th International Conference on Molecule-Base Magnets (ICMM 2000) CY SEP 16-21, 2000 CL SAN ANTONIO, TEXAS DE molecular magnets; crystal structure; coordination polymer; manganese compounds; dicyanamide; pyrazine ID 1-D COORDINATION POLYMERS; DCA = DICYANAMIDE; CO; M-II(2); FERROMAGNETS; N(CN)(2)(-); PYRIDINE; NETWORK; LIGANDS; NI AB In this paper, the crystal structures and preliminary magnetic properties of two new molecule-based magnets, Mn[N(CN)(2)](2)(H2O)(2)(2,5-me(2)pyz)(2) (1) and Mn[N(CN)(2)](2)(H2O)(NH2-pyz)(1.5) (2) (pyz = pyrazine) are reported. The structure of 1 consists of 2D Mn[N(CN)(2)](2)(H2O)(2) layers which are hydrogen bonded together by the 2,5-me(2)pyz ligands while that of 2 forms a novel 1D ladder structure with mu (1,5)-[N(CN)(2)](-) rungs. Magnetically, 1 exhibits a spin canted phase transition at 1.78 K while 2 remains paramagnetic down to 1.7 K. Published by Elsevier Science Ltd. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Manson, JL (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Stone, Matthew/G-3275-2011 OI Stone, Matthew/0000-0001-7884-9715 NR 24 TC 49 Z9 50 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-5387 J9 POLYHEDRON JI Polyhedron PD MAY 30 PY 2001 VL 20 IS 11-14 BP 1423 EP 1429 DI 10.1016/S0277-5387(01)00631-3 PG 7 WC Chemistry, Inorganic & Nuclear; Crystallography SC Chemistry; Crystallography GA 451LW UT WOS:000169804400050 ER PT J AU Schweizer, J Bencini, A Carbonera, C Epstein, AJ Golhen, S Lelievre-Berna, E Miller, JS Ouahab, L Pontillon, Y Ressouche, E Zheludev, A AF Schweizer, J Bencini, A Carbonera, C Epstein, AJ Golhen, S Lelievre-Berna, E Miller, JS Ouahab, L Pontillon, Y Ressouche, E Zheludev, A TI Magnetization and spin density in [FeCp2*](center dot+) - A look-back at the magnetic interactions in the chains [FeCp2*](center dot+)[TCNE](center dot-) SO POLYHEDRON LA English DT Article; Proceedings Paper CT 7th International Conference on Molecule-Base Magnets (ICMM 2000) CY SEP 16-21, 2000 CL SAN ANTONIO, TX DE molecular ferromagnet; spin density; McConnell mechanism; exchange; ab-initio calculations; polarized neutron diffraction ID POLARIZED NEUTRON-DIFFRACTION; CHARGE-TRANSFER COMPLEXES; DECAMETHYLFERROCENIUM TETRACYANOETHENIDE; FERROMAGNETS; MECHANISM; CRYSTALS AB The discovery of ferromagnetism in the charge transfer salt [FeCp2*](.+)[TCNE](.-) has raised a controversy concerning the nature of the magnetic coupling. The group of J.S. Miller invoked a McConnell II mechanism, with configuration interactions. O. Kahn and his coworkers proposed a McConnell I mechanism, implying a positive exchange due to an overlap between spin densities of opposed signs. In the first interpretation there would be a positive spin density located on the carbon of the Cp* rings, but in the second interpretation, this spin density should be negative. To clarify this mechanism, it was decided to independently determine, by polarized neutron diffraction, the spin density of [TCNE](.-), associated with a nonmagnetic donor and the magnetization density of [FeCp2*](.+) associated with a nonmagnetic acceptor. For [TCNE](.-), the measurement was straightforward, but for [FeCp2*](.+), we had several failures due to a loss of symmetry on cooling the samples. Finally, we could carry on this measurement on a triclinic crystal where [FeCp2*](.+) was associated with a polyoxotungstate anion. On [TCNE](.-), most of the spin density is located on the central carbons, with a noticeable amount on the terminal nitrogens. On [FeCp2*](.+), the Fe atoms carry a moment of 2.0 mu (B), a combination of both spin and orbital moments, the carbon of the rings carry -0.005 +/- 0.001 mu (B), and, surprisingly, the methyl carbons carry + 0.008 +/- 0.001 mu (B). The signs of the spin populations support the McConnell I, but their magnitude accounts for a part of the experimental intrachain exchange interaction only. Ab initio DFT calculations predict the very small densities on the carbon atoms of [FeCp2*](.+), with the correct signs, but with magnitudes which are three times larger than the experimental ones. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 CEA Grenoble, DRFMC, SPSMS, Lab Magnet & Diffract Neutron, F-38054 Grenoble 9, France. Univ Florence, Dipartimento Chim, I-50144 Florence, Italy. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Rennes 1, Chim Solide & Inorgan Mol Lab, UMR 6511, CNRS, F-35042 Rennes, France. Inst Laue Langevin, F-38042 Grenoble 9, France. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Schweizer, J (reprint author), CEA Grenoble, DRFMC, SPSMS, Lab Magnet & Diffract Neutron, 17 Rue Martyrs, F-38054 Grenoble 9, France. EM schweiz@drfmc.ceng.cea.fr NR 29 TC 8 Z9 8 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-5387 J9 POLYHEDRON JI Polyhedron PD MAY 30 PY 2001 VL 20 IS 11-14 BP 1771 EP 1778 DI 10.1016/S0277-5387(01)00687-8 PG 8 WC Chemistry, Inorganic & Nuclear; Crystallography SC Chemistry; Crystallography GA 451LW UT WOS:000169804400104 ER PT J AU Perry, AJ Bull, SJ Dommann, A Michler, M Wood, BP Rafaja, D Matossian, JN AF Perry, AJ Bull, SJ Dommann, A Michler, M Wood, BP Rafaja, D Matossian, JN TI The smoothness, hardness and stress in titanium nitride following argon gas cluster ion beam treatment SO SURFACE & COATINGS TECHNOLOGY LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; SURFACE MODIFICATION; RESIDUAL-STRESS; VAPOR-DEPOSITION; DIAMOND FILMS; IMPLANTATION; AR; BOMBARDMENT; SILICON; IMPACT AB The surface smoothing of TiN coatings, deposited by CVD or PVD methods, by argon ion clusters comprising a few hundred to a few hundred thousand atoms and carrying a single positive charge has been confirmed. In addition, the present work has shown that there was no change in the mechanical condition, nanohardness or residual stress, of the PVD coatings after treatment. In contrast, the nanohardness in the near-surface region of the CVD TIN coating was increased but, remarkably, there was no concomitant increase in residual stress. A comparison is made with the established effects of classical single ion implantation on the near-surface properties of TiN where a high compressive residual stress is developed if the ion energy lies beyond a threshold value. It was concluded that only a fraction of the atoms in the cluster impact the surface and the vast majority of argon atoms move sideways. It appears to be generic that the smaller clusters are responsible for the increase in hardness as well as the well-known lateral sputtering effects associated with the technology. Larger clusters do not carry enough energy per atom to cause such effects and their energy is dissipated in the substrate as heat. (C) 2001 Elsevier Science B.V. All rights reserved. C1 AIMS Mkt, San Diego, CA 92127 USA. Univ Newcastle Upon Tyne, Div Mat, Newcastle Upon Tyne TW20 0EX, Tyne & Wear, England. Interstate Univ Appl Sci, Inst Mikrosystemtech, CH-9470 Buchs SG, Switzerland. Los Alamos Natl Lab, Plasma Phys Grp, Los Alamos, NM 87545 USA. Charles Univ Prague, Dept Semicond Phys, Prague 12116 2, Czech Republic. HRL Labs, Malibu, CA 90265 USA. RP Perry, AJ (reprint author), AIMS Consulting, Frohlweg 16, CH-9470 Buchs SG, Switzerland. EM perry_aims@compuserve.com RI Bull, Stephen/A-5649-2008; Alex, Dommann/K-4583-2013; OI Rafaja, David/0000-0003-2411-7425 NR 52 TC 8 Z9 8 U1 2 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY 30 PY 2001 VL 140 IS 2 BP 99 EP 108 DI 10.1016/S0257-8972(01)01008-8 PG 10 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 429FB UT WOS:000168504400005 ER PT J AU Burgess, I Zamlynny, V Szymanski, G Lipkowski, J Majewski, J Smith, G Satija, S Ivkov, R AF Burgess, I Zamlynny, V Szymanski, G Lipkowski, J Majewski, J Smith, G Satija, S Ivkov, R TI Electrochemical and neutron reflectivity characterization of dodecyl sulfate adsorption and aggregation at the gold-water interface SO LANGMUIR LA English DT Article ID SOLID-LIQUID INTERFACES; DIRECT VISUALIZATION; FORCE MICROSCOPY; SURFACE; MICELLIZATION; MERCURY; MICA; TRANSFORMATIONS; ORGANIZATION; GEOMETRY AB Chronocoulometry and the thermodynamic analysis of charge density data were employed to describe the energetics of sodium dodecyl sulfate (SDS) adsorption at the Au(111) electrode surface. Thermodynamic data such as the Gibbs excess, Gibbs energy of adsorption, and the film pressure of adsorbed SDS were determined for a broad range of electrode potentials, charge densities, and bulk SDS concentrations. The present results, combined with our previous scanning probe microscopy (SPM) studies, show that adsorption of SDS at the Au(111) electrode surface has a two-state character At small or moderate absolute charge densities, the adsorbed SDS molecules aggregate into hemicylindrical stripelike micelles. This state is well-ordered. The unit cell of its two-dimensional lattice consists of two Vectors that are 44 and 5.0 Angstrom long and are oriented at an angle of 70 degrees. The Gibbs excess data indicate that fiveSDS molecules are accommodated into the unit cell. At large positive charge densities, the hemimicellar aggregates melt to form a condensed film. The surface concentration of SDS doubles upon transition from the hemimicellar to the condensed state. We have performed neutron reflectivity experiments to determine the thickness of the hemimicellar and condensed films. The neutron reflectivity data indicate that the thickness of the condensed film is equal to 20.5 Angstrom and is only 30% larger than the thickness of the hemimicellar state. The electrochemical and neutron reflectivity data indicate that the properties of the condensed state are best explained by a model of an interdigitated film in which half of the sulfate groups are turned toward the metal and half toward the solution. C1 Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. Univ Calif Los Alamos Natl Lab, MLNSCE, LANSCE 12, Los Alamos, NM 87545 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. RP Lipkowski, J (reprint author), Univ Guelph, Dept Chem & Biochem, Guelph, ON N1G 2W1, Canada. RI Lujan Center, LANL/G-4896-2012; Ivkov, Robert/A-3902-2015 OI Ivkov, Robert/0000-0002-2930-5276 NR 42 TC 72 Z9 74 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 29 PY 2001 VL 17 IS 11 BP 3355 EP 3367 DI 10.1021/la001628q PG 13 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 436UY UT WOS:000168955300032 ER PT J AU Hasoon, FS Yan, Y Althani, H Jones, KM Moutinho, HR Alleman, J Al-Jassim, MM Noufi, R AF Hasoon, FS Yan, Y Althani, H Jones, KM Moutinho, HR Alleman, J Al-Jassim, MM Noufi, R TI Microstructural properties of Cu(In,Ga)Se-2 thin films used in high-efficiency devices SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Symposium on Thin Film Chalcogenide Photovoltale Materials held at MRS 2000 Spring Conference CY MAY 30-JUN 02, 2000 CL STRASBOURG, FRANCE DE Cu(In,Ga)Se-2; microstructural properties; device performance ID POLYCRYSTALLINE AB Thin-film polycrystalline photovoltaic devices based on Cu(In,Ca)Se-2 have a demonstrated efficiency approaching 19%. The best performance was achieved when the Ga/In + Ga ratio was in the 25-30% range. The short-circuit current density exhibited for the device containing CdS was almost at its expected maximum. The open-circuit voltage was relatively low considering the optical bandgap (Eg) of the above absorber (similar to 1.15 eV); at best, it is 0.6 x Eg. In this work, we examined the microstructural properties, e.g. defects due to misorientation, micro-twinning, stacking faults, and dislocations, for films prepared by our 'three-stage' process, including the CIGS and Mo back-contact. We also attempted to make a correlation between the above observations and device performance. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Hasoon, FS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 6 TC 34 Z9 35 U1 0 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 29 PY 2001 VL 387 IS 1-2 BP 1 EP 5 DI 10.1016/S0040-6090(00)01724-7 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 420PT UT WOS:000168013900002 ER PT J AU Al-Jassim, MM Yan, Y Moutinho, HR Romero, MJ Dhere, RD Jones, KM AF Al-Jassim, MM Yan, Y Moutinho, HR Romero, MJ Dhere, RD Jones, KM TI TEM, AFM, and cathodoluminescence characterization of CdTe thin films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Symposium on Thin Film Chalcogenide Photovoltale Materials held at MRS 2000 Spring Conference CY MAY 30-JUN 02, 2000 CL STRASBOURG, FRANCE DE CdTe; solar cells; transmission electron microscopy (TEM); cathodoluminescence (CL); atomic force microscopy (AFM) ID SOLAR-CELL; ZINCBLENDE AB The morphology, microstructure, and luminescent properties of polycrystalline CdTe films were investigated. The films were deposited by close-spaced sublimation at relatively low temperatures. The evolution of the film morphology and microstructure was studied as a function of deposition temperature and post-deposition heat treatment. Films deposited at low temperature exhibited fine, equiaxed grains. Dramatic grain growth was observed as a consequence of heat treatment. The film microstructure is heavily faulted and strongly dependent on the deposition and post-deposition treatment temperatures. The extended defects are mostly lamellar twins and stacking faults with similar densities. These defects often form a closely spaced arrangement, which leads to the formation of a local hexagonal phase. The presence of this hexagonal phase is expected to have significant effects on the electrical properties of the cubic CdTe films. (C) 2001 Elsevier Science B.V, All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Cadiz, Fac Ciencias, Dept Ciencia Los Mat IM & QI, E-11510 Cadiz, Spain. RP Al-Jassim, MM (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 12 TC 17 Z9 17 U1 1 U2 16 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 29 PY 2001 VL 387 IS 1-2 BP 246 EP 250 DI 10.1016/S0040-6090(00)01707-7 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 420PT UT WOS:000168013900069 ER PT J AU Schneider, HC Fischer, AJ Chow, WW Klem, JF AF Schneider, HC Fischer, AJ Chow, WW Klem, JF TI Temperature dependence of laser threshold in an InGaAsN vertical-cavity surface-emitting laser SO APPLIED PHYSICS LETTERS LA English DT Article ID 1.3 MU-M; GAAS; WAVELENGTH; OPERATION; GAIN AB We present theoretical and experimental results for the temperature dependence of threshold current in an InGaAsN/GaAs vertical-cavity surface-emitting laser (VCSEL) operating at 1.3 mum under continuous-wave current injection. Using a microscopic many-body laser theory, good agreement with experimental data is obtained. The influence of radiative and nonradiative recombination processes on the threshold current-density is investigated theoretically. Also, comparison to a GaAs/AlGaAs VCSEL emitting at 850 nm is made. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Schneider, HC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Schneider, Hans Christian/B-9450-2009 OI Schneider, Hans Christian/0000-0001-7656-4919 NR 19 TC 18 Z9 18 U1 0 U2 2 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 MAY 28 PY 2001 VL 78 IS 22 BP 3391 EP 3393 DI 10.1063/1.1374484 PG 3 WC Physics, Applied SC Physics GA 435MJ UT WOS:000168885000005 ER PT J AU Martin, LP Norton, MA Thomas, G AF Martin, LP Norton, MA Thomas, G TI Ultrasonic monitoring of laser damage in fused silica SO APPLIED PHYSICS LETTERS LA English DT Article ID CONTAMINATION; OPERATION; SURFACE AB The growth of a laser induced, surface damage site in a fused silica window was monitored by the ultrasonic pulse-echo technique. The laser damage was grown using 15 ns pulses of 1.053 mum wavelength light at a fluence of similar to 25 J/cm(2). The ultrasonic signal amplitude exhibited variations with the damage size which are attributable to the changing subsurface morphology of the damage site. The sensitivity to subsurface morphology makes the ultrasonic methodology a promising tool for monitoring laser damage in fused silica optics. This type of diagnostic capability may facilitate the safe deployment of large, high powered laser systems used in high energy and fusion research facilities. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Martin, LP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mail Stn L-333,POB 808, Livermore, CA 94550 USA. NR 9 TC 3 Z9 3 U1 0 U2 5 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 MAY 28 PY 2001 VL 78 IS 22 BP 3403 EP 3405 DI 10.1063/1.1376431 PG 3 WC Physics, Applied SC Physics GA 435MJ UT WOS:000168885000009 ER PT J AU Lee, SR Reno, JL Follstaedt, DM AF Lee, SR Reno, JL Follstaedt, DM TI Suppression of phase separation in (AlAs)(2 ML)(InAs)(2 ML) superlattices using Al0.48In0.52As monolayer insertions SO APPLIED PHYSICS LETTERS LA English DT Article ID SHORT-PERIOD SUPERLATTICES; MOLECULAR-BEAM EPITAXY; LATERAL COMPOSITION MODULATION; LAYER ORDERING PROCESS; SURFACE SEGREGATION; QUANTUM-WELLS; GROWTH; GAAS; MBE AB Al0.48In0.52As monolayers (ML) are inserted at the binary-compound interfaces of (AlAs)(2 ML)(InAs)(2 ML) short-period superlattices (SPSs) during growth on (001) InP. The insertion of Al0.48In0.52As interlayers greater than 2 ML thick tends to suppress the phase separation that normally occurs during molecular beam epitaxy of the SPS. The degree of suppression is a sensitive function of both the monolayer-scale thickness, and the intraperiod growth sequence, of the interlayers in the SPS. Given this sensitivity to monolayer-scale variations in the surface-region composition, we propose that cyclical phase transition of the reconstructed surface initiates SPS decomposition. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lee, SR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 21 TC 1 Z9 1 U1 2 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 MAY 28 PY 2001 VL 78 IS 22 BP 3421 EP 3423 DI 10.1063/1.1374521 PG 3 WC Physics, Applied SC Physics GA 435MJ UT WOS:000168885000015 ER PT J AU Gago, R Jimenez, I Albella, JM Terminello, LJ AF Gago, R Jimenez, I Albella, JM Terminello, LJ TI Identification of ternary boron-carbon-nitrogen hexagonal phases by x-ray absorption spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID BCN THIN-FILMS; NEAR-EDGE; NITRIDE; BC2N; GRAPHITE; CARBIDE; PLANES AB Boron carbon nitride (BCN) films have been grown by B4C evaporation with concurrent N-2(+) ion assistance, and have been characterized by x-ray absorption near edge (XANES) spectroscopy. Upon the nitrogen insertion, the film structure evolves from BxC-like to h-BN-like. The hexagonal structure corresponds to a true ternary BCN compound that can be understood as h-BN with carbon incorporated in substitutional sites. The C(1s)XANES presents pi* states characteristic of the BCN arrangement. The basal planes of the h-BCN phase are oriented perpendicular to the substrate, as derived from the angle dependence of the XANES signal. (C) 2001 American Institute of Physics. C1 CSIC, Inst Ciencia Mat Madrid, Madrid 28049, Spain. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Jimenez, I (reprint author), CSIC, Inst Ciencia Mat Madrid, Campus Cantoblanco, Madrid 28049, Spain. RI Jimenez, Ignacio/F-7422-2010; Gago, Raul/C-6762-2008 OI Jimenez, Ignacio/0000-0001-5605-3185; Gago, Raul/0000-0003-4388-8241 NR 23 TC 42 Z9 43 U1 1 U2 13 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 MAY 28 PY 2001 VL 78 IS 22 BP 3430 EP 3432 DI 10.1063/1.1376428 PG 3 WC Physics, Applied SC Physics GA 435MJ UT WOS:000168885000018 ER PT J AU Thompson, C Munkholm, A Streiffer, SK Stephenson, GB Ghosh, K Eastman, JA Auciello, O Bai, GR Lee, MK Eom, CB AF Thompson, C Munkholm, A Streiffer, SK Stephenson, GB Ghosh, K Eastman, JA Auciello, O Bai, GR Lee, MK Eom, CB TI X-ray scattering evidence for the structural nature of fatigue in epitaxial Pb(Zr, Ti)O-3 films SO APPLIED PHYSICS LETTERS LA English DT Article ID SWITCHABLE POLARIZATION FATIGUE; (PB,LA)(ZR,TI)O-3 THIN-FILMS; CHEMICAL-VAPOR-DEPOSITION; CAPACITORS; SUPPRESSION; ELECTRODES AB We have probed the microscopic distribution of 180 degrees domains as a function of switching history in 40 nm epitaxial films of Pb(Zr0.30Ti0.70)O-3 by analyzing interference effects in the x-ray scattering profiles. These as-grown films exhibit voltage offsets (imprint) in the polarization hysteresis loops, coupled with a strongly preferred polarization direction in the virgin state. Our x-ray results are consistent with models attributing the loss of switchable polarization to the inhibition of the formation of oppositely polarized domains in a unipolar matrix. Using such model epitaxial films, we demonstrate that different microscopic ensembles of domains resulting from, for example, fatigue, may be resolved by this technique. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Thompson, C (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. RI Streiffer, Stephen/A-1756-2009; Eastman, Jeffrey/E-4380-2011; Eom, Chang-Beom/I-5567-2014; OI Eastman, Jeff/0000-0002-0847-4265; Thompson, Carol/0000-0003-3832-4855 NR 14 TC 14 Z9 14 U1 0 U2 4 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 MAY 28 PY 2001 VL 78 IS 22 BP 3511 EP 3513 DI 10.1063/1.1375001 PG 3 WC Physics, Applied SC Physics GA 435MJ UT WOS:000168885000045 ER PT J AU Bowman, KO Shenton, LR AF Bowman, KO Shenton, LR TI Weibull distributions when the shape parameter is defined SO COMPUTATIONAL STATISTICS & DATA ANALYSIS LA English DT Article DE envelope distribution; moment estimator; moments of sample moments; Pade sequences; Taylor series; unbiased estimators ID MAXIMUM-LIKELIHOOD ESTIMATORS AB The Weibull distribution, depending on parameters of location, scale, and shape, is often useful as a model for fracture data sets. If the location parameter is to be estimated then we have shown that maximum likelihood methods are not recommended. In the data set considered here the shape parameter is known to lie between 2 and 3 or so. We therefore studied the two-parameter model for which the shape parameter is known, or has a probability structure. Simple moment estimators are used and some moments of these are studied and verified by simulation. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Georgia, Dept Stat, Athens, GA 30602 USA. NR 11 TC 12 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9473 J9 COMPUT STAT DATA AN JI Comput. Stat. Data Anal. PD MAY 28 PY 2001 VL 36 IS 3 BP 299 EP 310 DI 10.1016/S0167-9473(00)00048-7 PG 12 WC Computer Science, Interdisciplinary Applications; Statistics & Probability SC Computer Science; Mathematics GA 434AD UT WOS:000168792200002 ER PT J AU Fang, XG Scott, BL Watkin, JG Carter, CAG Kubas, GJ AF Fang, XG Scott, BL Watkin, JG Carter, CAG Kubas, GJ TI Metal complexes based on an upper-rim calix[4]arene phosphine ligand SO INORGANICA CHIMICA ACTA LA English DT Article DE phosphacalixarene complexes; transition metal complexes; hydroformylation ID TRANSITION-METAL; COORDINATION; CALIXARENE; FRAGMENTS AB A new upper-rim phosphacalix[4]arene 5,17-bis(diphenylphosphinomethyl)-25,26,27,28-tetrapropoxycalix[4] arene (4) has been prepared starting from commercially available tert-butyl calix[4]arene. Treatment of 4 with (COD)PdMeCl and (COD)PtCl2 gives polymeric phosphine-coordinated Pd(II) and Pt(II) species, respectively. 4 reacts with [(COD)RhCl](2), to give a di-rhodium complex that is an active catalyst for the hydroformylation of 1-octene and styrene. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87544 USA. RP Kubas, GJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87544 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 23 TC 20 Z9 20 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD MAY 28 PY 2001 VL 317 IS 1-2 BP 276 EP 281 DI 10.1016/S0020-1693(01)00328-0 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 442HL UT WOS:000169279100032 ER PT J AU Donnelly, TD Rust, M Weiner, I Allen, M Smith, RA Steinke, CA Wilks, S Zweiback, J Cowan, TE Ditmire, T AF Donnelly, TD Rust, M Weiner, I Allen, M Smith, RA Steinke, CA Wilks, S Zweiback, J Cowan, TE Ditmire, T TI Hard x-ray and hot electron production from intense laser irradiation of wavelength-scale particles SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID FEMTOSECOND LASER; PULSE; ABSORPTION; GENERATION; PLASMAS AB We have examined the production of hard x-rays from the irradiation of similar to1 mum diameter water droplets with a 35 fs laser at an intensity of up to 7 x 10(17) W cm(-2) We observe substantial x-ray production in the photon energy range above 100 keV and find that the implied hot electron temperatures from these micron-scale targets are significantly higher than electron temperatures observed from irradiation of solid planar plastic targets under nearly identical irradiation conditions, The observed enhancement of the hot electron temperature from droplets is consistent with hot electron spectra calculated from particle-in-cell simulations. C1 Harvey Mudd Coll, Dept Phys, Claremont, CA 91711 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England. Harvard Univ, Lyman Lab, Cambridge, MA 02138 USA. Univ Calif Lawrence Livermore Natl Lab, Lasr Program, Livermore, CA 94550 USA. RP Donnelly, TD (reprint author), Harvey Mudd Coll, Dept Phys, Claremont, CA 91711 USA. RI Cowan, Thomas/A-8713-2011 OI Cowan, Thomas/0000-0002-5845-000X NR 16 TC 25 Z9 26 U1 1 U2 2 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 MAY 28 PY 2001 VL 34 IS 10 BP L313 EP L320 DI 10.1088/0953-4075/34/10/101 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 440JT UT WOS:000169172700001 ER PT J AU Carter, CAG Vogels, CM Harrison, DJ Gagnon, MKJ Norman, DW Langler, RF Baker, RT Westcott, SA AF Carter, CAG Vogels, CM Harrison, DJ Gagnon, MKJ Norman, DW Langler, RF Baker, RT Westcott, SA TI Metal-catalyzed hydroboration and diboration of thiocarbonyls and vinyl sulfides SO ORGANOMETALLICS LA English DT Article ID BETA-AMINO ALCOHOLS; BORONIC ACID; COMPLEXES; ALKENES; INHIBITORS; ESTERS; PINACOLBORANE; CHYMOTRYPSIN; SUBTILISIN; CONVERSION AB alpha -Thioboronate esters are obtained directly in high yield and selectivity from metal-catalyzed additions of B-X bonds (X = H, B) to thiocarbonyl compounds and vinyl sulfides. C1 Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos Catalysis Initiat, Los Alamos, NM 87545 USA. Mt Allison Univ, Dept Chem, Sackville, NB E4L 1G8, Canada. RP Baker, RT (reprint author), Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos Catalysis Initiat, MS J514, Los Alamos, NM 87545 USA. NR 39 TC 38 Z9 39 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD MAY 28 PY 2001 VL 20 IS 11 BP 2130 EP 2132 DI 10.1021/om010135t PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 436BX UT WOS:000168917600004 ER PT J AU Fang, XG Scott, BL Watkin, JG Kubas, GJ AF Fang, XG Scott, BL Watkin, JG Kubas, GJ TI Iron(II) and ruthenium(II) complexes containing bidentate, tied-back diphosphonite ligands. X-ray structure of cis-FeMe2[(-OCH2CEt2CH2O-)PCH2CH2P(-OCH2CEt2CHO-)](2) SO ORGANOMETALLICS LA English DT Article ID DIHYDROGEN COMPLEXES; CRYSTAL-STRUCTURE; ACTIVATION AB Trans-RuCl2(PP)(2) (2) and cis-FeCl2(PP)(2) (4) have been synthesized by the reaction of the diphosphonite 1,2-bis((2,2-diethyl-1,3-propanedioxy)phosphino)-ethane (PP) with RuCl2(Ph3P)(3) and FeCl2, respectively. Complex 4 was converted to cis-FeMe2(PP)(2) (5), for which a molecular structure was obtained. C1 Univ Calif Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Kubas, GJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87545 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 23 TC 10 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD MAY 28 PY 2001 VL 20 IS 11 BP 2413 EP 2416 DI 10.1021/om001025+ PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 436BX UT WOS:000168917600040 ER PT J AU Eskildsen, MR Abrahamsen, AB Kogan, VG Gammel, PL Mortensen, K Andersen, NH Canfield, PC AF Eskildsen, MR Abrahamsen, AB Kogan, VG Gammel, PL Mortensen, K Andersen, NH Canfield, PC TI Temperature dependence of the flux line lattice transition into square symmetry in superconducting LuNi2B2C SO PHYSICAL REVIEW LETTERS LA English DT Article ID STRUCTURAL PHASE-TRANSITION; VORTEX LATTICE; NEUTRON-SCATTERING; II SUPERCONDUCTORS; YNI2B2C; STATE; LU(NI1-XCOX)(2)B2C; ERNI2B2C; V3SI AB We have investigated the temperature dependence of the H parallel to c flux line lattice structural phase transition from square to hexagonal symmetry, in the tetragonal superconductor LuNi2B2C (T-c = 16.6 K). At temperatures below 10 K the transition onset field, H-2(T), is only weakly temperature dependent. Above 10 K, H-2(T) rises sharply, bending away from the upper critical field. This contradicts theoretical predictions of H-2(T) merging with the upper critical field and suggests that just below the H-c2(T) curve the flux line lattice might be hexagonal. C1 Riso Natl Lab, DK-4000 Roskilde, Denmark. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Agere Syst, Murray Hill, NJ 07974 USA. RP Eskildsen, MR (reprint author), Riso Natl Lab, POB 49, DK-4000 Roskilde, Denmark. RI Mortensen, Kell/A-5066-2009; Eskildsen, Morten/E-7779-2011; Andersen, Niels/A-3872-2012; Canfield, Paul/H-2698-2014 OI Mortensen, Kell/0000-0002-8998-9390; NR 23 TC 48 Z9 48 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 MAY 28 PY 2001 VL 86 IS 22 BP 5148 EP 5151 DI 10.1103/PhysRevLett.86.5148 PG 4 WC Physics, Multidisciplinary SC Physics GA 437VE UT WOS:000169013600043 PM 11384443 ER PT J AU Movshovich, R Jaime, M Thompson, JD Petrovic, C Fisk, Z Pagliuso, PG Sarrao, JL AF Movshovich, R Jaime, M Thompson, JD Petrovic, C Fisk, Z Pagliuso, PG Sarrao, JL TI Unconventional superconductivity in CeIrIn5 and CeCoIn5: Specific heat and thermal conductivity studies SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNTWINNED YBA2CU3O7-DELTA; DEPENDENCE; STATES AB Low temperature specific heat and thermal conductivity measurements on the ambient pressure heavy fermion superconductors CeIrIn5, and CeCoIn5 reveal power law temperature dependences of these quantities below T-c. The low temperature specific heat in both CeIrIn5 and CeCoIn5 includes T-2 terms, consistent with the presence of nodes in the superconducting energy gap. The thermal conductivity data present a T-linear term consistent with the universal limit (CeIrIn5). and a low temperature T-3 variation in the clean limit (CeCoIn5), also in accord with prediction for an unconventional superconductor with lines of nodes. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, NHMFL, Tallahassee, FL 32306 USA. RP Movshovich, R (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Petrovic, Cedomir/A-8789-2009; Pagliuso, Pascoal/C-9169-2012; Jaime, Marcelo/F-3791-2015 OI Petrovic, Cedomir/0000-0001-6063-1881; Jaime, Marcelo/0000-0001-5360-5220 NR 22 TC 326 Z9 326 U1 8 U2 83 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 28 PY 2001 VL 86 IS 22 BP 5152 EP 5155 DI 10.1103/PhysRevLett.86.5152 PG 4 WC Physics, Multidisciplinary SC Physics GA 437VE UT WOS:000169013600044 PM 11384444 ER PT J AU Varela, M Grogger, W Arias, D Sefrioui, Z Leon, C Ballesteros, C Krishnan, KM Santamaria, J AF Varela, M Grogger, W Arias, D Sefrioui, Z Leon, C Ballesteros, C Krishnan, KM Santamaria, J TI Direct evidence for block-by-block growth in high-temperature superconductor ultrathin films SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN-FILMS; SUPERLATTICES; RESOLUTION; DIFFRACTION; TRANSITION; MICROSCOPY; OXIDES; IMAGES AB Charge neutrality and stoichiometry impose severe restrictions on the mechanisms of epitaxial growth of complex oxides. The fundamental question arises of what is the minimum growth unit when sample thickness is reduced beyond the size of the unit cell. We have investigated the growth mechanism of YBa2Cu3O7 cuprate superconductor, using a consistent approach based on the growth of noninteger numbers of YBa2Cu3O7 layers in YBa2Cu3O7/PrBa2Cu3O7 superlattices. Ex situ chemical and structural analysis evidence a 2D block-by-block mechanism in which the minimum growth units are complete unit cell blocks. growing coherently over large lateral distances. C1 Univ Carlos III Madrid, Dept Fis, Madrid 28911, Spain. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Complutense, Dept Fis Aplicada 3, GFMC, E-28040 Madrid, Spain. RP Santamaria, J (reprint author), Univ Carlos III Madrid, Dept Fis, Ave Univ 30, Madrid 28911, Spain. RI Leon, Carlos/A-5587-2008; Varela, Maria/H-2648-2012; Varela, Maria/E-2472-2014; Santamaria, Jacobo/N-8783-2016; Sefrioui, Zouhair/C-2728-2017; OI Leon, Carlos/0000-0002-3262-1843; Varela, Maria/0000-0002-6582-7004; Santamaria, Jacobo/0000-0003-4594-2686; Sefrioui, Zouhair/0000-0002-6703-3339; BALLESTEROS, CARMEN INES/0000-0002-8983-4751 NR 20 TC 27 Z9 27 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 MAY 28 PY 2001 VL 86 IS 22 BP 5156 EP 5159 DI 10.1103/PhysRevLett.86.5156 PG 4 WC Physics, Multidisciplinary SC Physics GA 437VE UT WOS:000169013600045 PM 11384445 ER PT J AU Watson, BC Kotov, VN Meisel, MW Hall, DW Granroth, GE Montfrooij, WT Nagler, SE Jensen, DA Backov, R Petruska, MA Fanucci, GE Talham, DR AF Watson, BC Kotov, VN Meisel, MW Hall, DW Granroth, GE Montfrooij, WT Nagler, SE Jensen, DA Backov, R Petruska, MA Fanucci, GE Talham, DR TI Magnetic spin ladder (C5H12N)(2)CuBr4: High-field magnetization and scaling near quantum criticality SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEISENBERG-LADDER; PHASE-TRANSITIONS; CU-2(C5H12N2)(2)CL-4; SYSTEM; CHAIN; CU-2(1,4-DIAZACYCLOHEPTANE)(2)CL-4; ANTIFERROMAGNETS; DIMENSIONS; PLATEAUS; NH4CUCL3 AB The magnetization, M(H less than or equal to 30 T, 0.7 less than or equal to T less than or equal to 300 K). of (C5H12N)(2)CuB4 has been used to identify this system as an S = 1/2 Heisenberg two-leg ladder in the strong-coupling limit, J(perpendicular to) = 13.3 K and J(parallel to) = 3.8 K, with H-c1 = 6.6 T and H-c2 = 14.6 T. An inflection point in M(H, T = 0.7 K) at half saturation. M-s/2. is described by an effective XXZ chain. The data exhibit universal scaling behavior in the vicinity of H-c1 and H-c2, indicating that the system is near a quantum critical point. C1 Univ Florida, Dept Phys, Gainesville, FL 32611 USA. Univ Florida, Ctr Condensed Matter Sci, Gainesville, FL 32611 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RP Watson, BC (reprint author), Univ Florida, Dept Phys, Gainesville, FL 32611 USA. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010; Granroth, Garrett/G-3576-2012; Kotov, Valeri/H-8701-2012 OI Nagler, Stephen/0000-0002-7234-2339; Granroth, Garrett/0000-0002-7583-8778; NR 34 TC 125 Z9 125 U1 0 U2 14 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 MAY 28 PY 2001 VL 86 IS 22 BP 5168 EP 5171 DI 10.1103/PhysRevLett.86.5168 PG 4 WC Physics, Multidisciplinary SC Physics GA 437VE UT WOS:000169013600048 PM 11384448 ER PT J AU Huang, JY Zhu, YT Jiang, H Lowe, TC AF Huang, JY Zhu, YT Jiang, H Lowe, TC TI Microstructures and dislocation configurations in nanostructured Cu processed by repetitive corrugation and straightening SO ACTA MATERIALIA LA English DT Article DE repetitive corrugation straightening; microstructure; transmission electron microscopy (TEM); copper ID SEVERE PLASTIC-DEFORMATION; GRAIN-BOUNDARY STRUCTURE; RESOLUTION ELECTRON-MICROSCOPY; DEFORMED METALS; COLD DEFORMATION; COPPER; REFINEMENT; NANOCOMPOSITES; CONSOLIDATION; POLYCRYSTALS AB The microstructures and dislocation configurations in nanostructured Cu processed by a new technique, repetitive corrugation and straightening (RCS), were studied using transmission electron microcopy (TEM) and high resolution TEM. Most dislocations belong to 60 degrees type and tend to pile up along the {111} slip planes. Microstructural features including low-angle grain boundaries (GBs), high-angle GBs, and equilibrium and non-equilibrium GBs and subgrain boundaries were observed. Dislocation structures at an intermediate deformation strain were studied to investigate the microstructural evolutions, which revealed some unique microstructural features such as isolated dislocation cell (LDC), dislocation tangle zones (DTZs), and uncondensed dislocation walls (UDWs). (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Huang, JY (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS G 755, Los Alamos, NM 87545 USA. RI Zhu, Yuntian/B-3021-2008; Huang, Jianyu/C-5183-2008 OI Zhu, Yuntian/0000-0002-5961-7422; NR 51 TC 326 Z9 351 U1 6 U2 64 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 MAY 25 PY 2001 VL 49 IS 9 BP 1497 EP 1505 DI 10.1016/S1359-6454(01)00069-6 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 435WG UT WOS:000168904700001 ER PT J AU Han, K Hirth, JP Embury, JD AF Han, K Hirth, JP Embury, JD TI Modeling the formation of twins and stacking faults in the Ag-Cu system SO ACTA MATERIALIA LA English DT Article DE casting; rapid solidification; copper; phase transformations; twin AB In forming new grains, both in solid slate reactions and in solidification, the formation of twins or stacking-faults is of considerable interest. In the present work, a terrace/ledge nucleation model is used to explore the relationship between the degree of undercooling and the probability of forming twins or stacking-faults, and compared with experimental results for rapid solidification of several alloys in the two-phase Ag-Cu system. The model is consistent with the experimental results and indicates that at an undercooling between 37 K and 55 K, twins or stacking-faults form first in the Ag-rich solid solution. Larger undercooling brings about the formation of twins or stacking-faults in the Cu-rich solid solution. The degree of undercooling required for defect formation can be related to the stacking fault or twin boundary energies of the materials. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 FSU, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. McMaster Univ, Dept Mat Sci & Engn, Hamilton, ON L8S 4L7, Canada. RP Han, K (reprint author), FSU, Natl High Magnet Field Lab, 1800 E Paul Dirac Dr, Tallahassee, FL 32310 USA. NR 11 TC 19 Z9 20 U1 8 U2 27 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 MAY 25 PY 2001 VL 49 IS 9 BP 1537 EP 1540 DI 10.1016/S1359-6454(01)00057-X PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 435WG UT WOS:000168904700005 ER PT J AU Gertsman, VY Bruemmer, SM AF Gertsman, VY Bruemmer, SM TI Study of grain boundary character along intergranular stress corrosion crack paths in austenitic alloys SO ACTA MATERIALIA LA English DT Article DE grain boundaries; stress corrosion; transmission electron microscopy (TEM); scanning electron microscopy (SEM); nickel and iron stainless alloys ID STATISTICS; POLYCRYSTALS; PROPAGATION; TOPOLOGY AB Samples of austenitic stainless alloys were examined by means of scanning and transmission electron microscopy. Misorientations were measured by electron backscattered diffraction. Grain boundary distributions were analyzed with special emphasis on the grain boundary character along intergranular stress corrosion cracks and at crack arrest points. It was established that only coherent twin Sigma3 boundaries could be considered as "special" ones with regard to crack resistance. However, it is possible that twin interactions with random grain boundaries may inhibit crack propagation. The results suggest that other factors besides geometrical ones play an important role in the intergranular stress corrosion cracking of commercial alloys. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gertsman, VY (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 17 TC 160 Z9 167 U1 12 U2 55 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 MAY 25 PY 2001 VL 49 IS 9 BP 1589 EP 1598 DI 10.1016/S1359-6454(01)00064-7 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 435WG UT WOS:000168904700010 ER PT J AU Cavelier, LB Qiu, Y Bielicki, JK Afzal, V Cheng, JF Rubin, EM AF Cavelier, LB Qiu, Y Bielicki, JK Afzal, V Cheng, JF Rubin, EM TI Regulation and activity of the human ABCA1 gene in transgenic mice SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ATP-BINDING CASSETTE; DENSITY-LIPOPROTEIN CHOLESTEROL; TANGIER-DISEASE PATIENTS; ORPHAN NUCLEAR RECEPTOR; APOLIPOPROTEIN-A-I; CELLULAR CHOLESTEROL; HDL CHOLESTEROL; EFFLUX; TRANSPORTER-1; PHOSPHOLIPIDS AB The ABCA1 transporter is one of the limiting steps in cellular cholesterol efflux, To study the expression and activity of the human ABCA1 gene in vivo we have examined mice containing two human BAC transgenes with different 5' ends. Mice containing a 255-kilobase (kb) BAC transgene, including 70 kb upstream of the previously defined exon I, demonstrated a pattern of tissue-specific expression mimicking that of the endogenous mouse gene. Compared with macrophages from control mice, macrophages from these transgenics had increases in apoA-I cholesterol efflux heightened in response to increases in cell cholesterol content. The observed increase in macrophage apoA-I-mediated cholesterol efflux was not accompanied by alterations in plasma high density lipoprotein in the transgenics. Although mice containing a smaller 171-kb human BAC transgene, lacking the previously described exon 1 and ABCA1 promoter, did not express human ABCA1 in macrophages, they did express the human transgene in liver at levels comparable with those of the orthologous mouse gene. Analysis by 5' rapid amplification of cDNA ends of liver mRNA from these animals revealed a new ABCA1 exon 1 (exon 1A) and a previously unrecognized promoter. Analysis of human tissue revealed that exon 1A containing transcripts accounted for a high proportion of the ABCA1 mRNAs present in human liver, This analysis of ABCA1 transgenics showed that the expression of human ABCA1 transgenes can result in increased cholesterol efflux from macrophages, unaccompanied by changes in plasma high density lipoprotein, and identified a new ABCA1 promoter in humans. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Cheng, JF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, 1 Cyclotron Rd,MS-84-171, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL66728-01, HL59483-01A2, HL6398-01] NR 41 TC 70 Z9 72 U1 0 U2 0 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 MAY 25 PY 2001 VL 276 IS 21 BP 18046 EP 18051 DI 10.1074/jbc.M100565200 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 435FJ UT WOS:000168866500058 PM 11279093 ER PT J AU Albers, PH Hoffman, DJ Brisbin, IL AF Albers, PH Hoffman, DJ Brisbin, IL TI Unusual leg malformations in screech owls from a South Carolina Superfund site SO JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A LA English DT Article ID WOOD DUCKS; RESERVOIR; RADIOCESIUM; EGGS AB In 1995, the discovery of leg malformations in several screech owl (Otis asio) nestlings and in their female parent at a Department of Energy (DOE) Superfund site in South Carolina prompted an investigation into the nature of the observed abnormalities. Surviving nestlings and the female parent were transferred to a captive screech owl breeding colony at the USGS Patuxent Wildlife Research Center, Laurel, MD. The malformed female parent and her offspring were each mated with normal owls from the colony for 3 yr. Matings of the malformed female produced five malformed and six normal owls, all owls produced by matings of normal offspring were normal. Malformed offspring were euthanized when it became apparent that their physical distress precluded survival under normal conditions of colony care. Euthanized owls were necropsied and examined for skeletal development. Detailed descriptions of eight malformed owls are presented. Results of the matings indicated that the leg malformations were caused by a genetic trait in the female parent that was heterozygous dominant. The characteristic was lethal except in occasional mild manifestations and resembled an extreme form of a dominant abnormality previously described for domestic fowl called duplicate polydactyly. Other reports of skeletal abnormalities in wild birds and potential environmental causes of genetic mutations at the DOE Superfund site are presented, Other studies performed at the DOE Superfund site do not implicate elevated (above background) ionizing radiation from Cs-137, the dominant radionuclide where the owls were captured, as the cause of the mutation. The cause of this generic abnormality remains unknown. C1 USGS, Patuxent Wildlife Res Ctr, Laurel, MD 20708 USA. Savannah River Ecol Lab, Aiken, SC USA. RP Albers, PH (reprint author), USGS, Patuxent Wildlife Res Ctr, 12011 Beech Forest Rd, Laurel, MD 20708 USA. NR 22 TC 4 Z9 4 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1528-7394 J9 J TOXICOL ENV HEAL A JI J. TOXICOL. ENV. HEALTH PT A PD MAY 25 PY 2001 VL 63 IS 2 BP 89 EP 99 DI 10.1080/15287390151126405 PG 11 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 434HL UT WOS:000168809000002 PM 11393802 ER PT J AU Opresko, DM AF Opresko, DM TI New species of antipatharians (Cnidaria : Anthozoa) from Madeira, with the establishment of a new genus SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new genus, Tanacetipathes, and two new species of antipatharian corals, T. cavernicola and T. wirtzi, are described from the waters off Madeira. Included in the new genus are the species T. tanacetum (Pourtales, 1880), T. hirta (Gray, 1857), T. barbadensis (Brook, 1889), T. thamnea (Warner, 1981), and T. spinescens (Gray, 1857). Species in the genus are differentiated by the branching pattern of the corallum; the number, length, and arrangement of the primary pinnules, the degree of subpinnulation, and the size and density of the spines. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. RP Opresko, DM (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. NR 5 TC 5 Z9 5 U1 1 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAY 25 PY 2001 VL 114 IS 2 BP 349 EP 358 PG 10 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 438RK UT WOS:000169067200001 ER PT J AU Chuang, YD Gromko, AD Dessau, DS Kimura, T Tokura, Y AF Chuang, YD Gromko, AD Dessau, DS Kimura, T Tokura, Y TI Fermi surface nesting and nanoscale fluctuating charge/orbital ordering in colossal magnetoresistive oxides SO SCIENCE LA English DT Article ID ELECTRONIC-STRUCTURE; MANGANESE OXIDES; DOPED MANGANITES; DOUBLE EXCHANGE; PSEUDOGAPS; PHYSICS; LA1-XSRXMNO3; RESISTIVITY; COLLAPSE; SCENARIO AB We used high-resolution angle-resolved photoemission spectroscopy to reveal the Fermi surface and key transport parameters of the metallic state of the layered colossal magnetoresistive oxide La1.2Sr1.8Mn2O7. With these parameters, the calculated in-plane conductivity is nearly one order of magnitude larger than the measured direct current conductivity. This discrepancy can be accounted for by including the pseudogap, which removes at least 90% of the spectral weight at the Fermi energy. Key to the pseudogap and to many other properties are the parallel straight Fermi surface sections, which are highly susceptible to nesting instabilities. These nesting instabilities produce nanoscale fluctuating charge/orbital modulations, which cooperate with Jahn-Teller distortions and compete with the electron itinerancy favored by double exchange. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Tokyo, Dept Appl Phys, Tokyo 113, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Joint Res Ctr Atom Technol, Tsukuba, Ibaraki 3050046, Japan. RP Chuang, YD (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RI Tokura, Yoshinori/C-7352-2009 NR 36 TC 150 Z9 153 U1 2 U2 30 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 MAY 25 PY 2001 VL 292 IS 5521 BP 1509 EP 1513 DI 10.1126/science.1059255 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 436YQ UT WOS:000168963800034 PM 11326084 ER PT J AU Kaibyshev, R Kazakulov, I Gromov, D Musin, F Lesuer, DR Nieh, TG AF Kaibyshev, R Kazakulov, I Gromov, D Musin, F Lesuer, DR Nieh, TG TI Superplasticity in a 2219 aluminum alloy SO SCRIPTA MATERIALIA LA English DT Article DE superplastic deformation; aluminum alloys ID DEFORMATION C1 Inst Met Superplast Problems, Ufa 450001, Russia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kaibyshev, R (reprint author), Inst Met Superplast Problems, Khalturina 39, Ufa 450001, Russia. RI Nieh, Tai-Gang/G-5912-2011; Kaibyshev, Rustam/G-8804-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746; NR 7 TC 21 Z9 24 U1 1 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 MAY 25 PY 2001 VL 44 IS 10 BP 2411 EP 2417 DI 10.1016/S1359-6462(01)00930-7 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 452KV UT WOS:000169857600007 ER PT J AU Hong, SI Hill, MA AF Hong, SI Hill, MA TI Microstructure and conductivity of Cu-Nb microcomposites fabricated by the bundling and drawing process SO SCRIPTA MATERIALIA LA English DT Article DE composite; electrical properties; microstructure; cold working ID IN-SITU COMPOSITES; ELECTRICAL-CONDUCTIVITY; WIRES; STABILITY; STRENGTH; ALLOYS; PRECIPITATION; RESISTIVITY; COPPER C1 Chungnam Natl Univ, Dept Met Engn, Taedok Town 305764, Taejon, South Korea. Chungnam Natl Univ, RASOM, Taedok Town 305764, Taejon, South Korea. Univ Calif Los Alamos Natl Lab, Div Mat Sci, Los Alamos, NM 87545 USA. RP Hong, SI (reprint author), Chungnam Natl Univ, Dept Met Engn, Taedok Town 305764, Taejon, South Korea. NR 21 TC 31 Z9 64 U1 0 U2 2 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 MAY 25 PY 2001 VL 44 IS 10 BP 2509 EP 2515 DI 10.1016/S1359-6462(01)00665-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 452KV UT WOS:000169857600022 ER PT J AU Matsuzawa, NN Ishitani, A Dixon, DA Uda, T AF Matsuzawa, NN Ishitani, A Dixon, DA Uda, T TI Time-dependent density functional theory calculations of photoabsorption spectra in the vacuum ultraviolet region SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; EXCHANGE-CORRELATION POTENTIALS; COUPLED-CLUSTER CALCULATIONS; CORRECT ASYMPTOTIC-BEHAVIOR; ELECTRON-IMPACT EXCITATION; KOHN-SHAM ORBITALS; EXCITED-STATES; CONFIGURATION-INTERACTION; ABSORPTION-SPECTRUM AB The results of time-dependent density functional theory (TD-DFT) calculations of the transition energies and oscillator strengths of the excited states of formaldehyde, benzene, ethylene, and:methane are reported. The local DFT (LDFT) transition energies tend to be smaller than experimental values by 0.1-1.3 eV. Inclusion of nonlocal (NLDFT) (gradient corrected) effects made the calculated energies larger than the LDFT values and thus made the energies closer to the experimental values for formaldehyde, ethylene, and methane. For benzene, no significant change in the calculated transition energies due to the addition of nonlocal effects was observed. The TD-DFT oscillator strengths are much better than those found at the configuration interaction singles (CIS) level. The agreement between the calculated TD-DFT values and the experimental values for the oscillator strengths is quite good, at least semiquantitative at both the LDFT and NLDFT levels. C1 NTT, Atsugi Res & Dev Ctr, ASET, Atsugi Res Ctr, Atsugi, Kanagawa 2430198, Japan. MSIN, Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Natl Inst Adv Interdisciplinary Res, Angstrom Technol Partnership, JRCAT, Tsukuba, Ibaraki 3050046, Japan. RP Matsuzawa, NN (reprint author), NTT, Atsugi Res & Dev Ctr, ASET, Atsugi Res Ctr, 3-1 Morinosato, Atsugi, Kanagawa 2430198, Japan. NR 98 TC 186 Z9 187 U1 0 U2 14 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 MAY 24 PY 2001 VL 105 IS 20 BP 4953 EP 4962 DI 10.1021/jp003937v PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 436AT UT WOS:000168914900021 ER PT J AU Vargas, R Garza, J Friesner, RA Stern, H Hay, BP Dixon, DA AF Vargas, R Garza, J Friesner, RA Stern, H Hay, BP Dixon, DA TI Strength of the N-H center dot center dot center dot O=C and C-H center dot center dot center dot O=C bonds in formamide and N-methylacetamide dimers SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MOLECULAR WAVE-FUNCTIONS; AB-INITIO; HYDROGEN-BOND; FORCE-FIELD; BASIS-SETS; PEPTIDE UNIT; BENCHMARK CALCULATIONS; GLOBULAR-PROTEINS; FORMIC-ACID; ENERGIES AB The structures of the dimers of formamide and N-methylacetamide have been calculated at the ab initio electronic structure theory level, second-order Moller-Plesset perturbation theory (MP2) with augmented correlation consistent basis sets. Five unique structures were optimized for the formamide dimers at the MP2/ aug-cc-pVDZ and MP2/aug-cc-pVTZ levels. At the optimized geometries obtained with the aug-cc-pVTZ basis set, MP2 energies were evaluated with the aug-cc-pVQZ basis set, allowing an extrapolation of the energies to the complete basis set limit. Four structures were found for the N-methylacetamide dimer at the MP2/aug-cc-pVDZ level, and single-point energies were calculated at the MP2/aug-cc-pVTZ level. In both systems, the basis set superposition error was estimated with the counterpoise method. The strength of the N-H O-...=C bond has a mean value of 7.1 kcal/mol in the formamide dimers and a mean value of 8.6 kcal/mol in the N-methylacetamide dimers. The difference in hydrogen bond strengths is attributed to differences in basicity at the carbonyl oxygen receptor site. In several dimers C-(HO)-O-...=C hydrogen bonds play an important role in stabilizing these intermolecular complexes, increasing the interaction energy by 1.1-2.6 kcal/mol per interaction. C1 Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Autonoma Metropolitana Iztapalapa, Div Ciencias Bas & Ingn, Dept Quim, Mexico City 09340, DF, Mexico. Columbia Univ, Dept Chem, New York, NY 10027 USA. RP Pacific NW Natl Lab, William R Wiley 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 70 TC 161 Z9 166 U1 0 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 24 PY 2001 VL 105 IS 20 BP 4963 EP 4968 DI 10.1021/jp003888m PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 436AT UT WOS:000168914900022 ER PT J AU Bouquet, F Marcenat, C Steep, E Calemczuk, R Kwok, WK Welp, U Crabtree, GW Fisher, RA Phillips, NE Schilling, A AF Bouquet, F Marcenat, C Steep, E Calemczuk, R Kwok, WK Welp, U Crabtree, GW Fisher, RA Phillips, NE Schilling, A TI An unusual phase transition to a second liquid vortex phase in the superconductor YBa(2)Cu(3)O(7) SO NATURE LA English DT Article ID II SUPERCONDUCTORS; MELTING TRANSITION; MAGNETIC-FIELD; LATTICE; FLUCTUATIONS; DIAGRAM; BI2SR2CACU2O8; VORTICES; CRYSTALS; DISORDER AB A magnetic field penetrates a superconductor through an array of 'vortices', each of which carries one quantum of flux that is surrounded by a circulating supercurrent. In this vortex state, the resistivity is determined by the dynamical properties of the vortex 'matter'. For the high-temperature copper oxide superconductors (see ref.1 for a theoretical review), the vortex phase can be a 'solid', in which the vortices are pinned, but the solid can 'melt' into a 'liquid' phase, in which their mobility gives rise to a finite resistance. (This melting phenomenon is also believed to occur in conventional superconductors, but in an experimentally inaccessible part of the phase diagram(2).) For the case of YBa(2)Cu(3)O(7), there are indications of the existence of a critical point, at which the character of the melting changes(3-10). But neither the thermodynamic nature of the melting, nor the phase diagram in the vicinity of the critical point, has been well established. Here we report measurements of specific heat and magnetization that determine the phase diagram in this material to 26 T, well above the critical point. Our results reveal the presence of a reversible second-order transition above the critical point. An unusual feature of this transition-namely, that the high-temperature phase is the less symmetric in the sense of the Landau theory(11)-is in accord with theoretical predictions(12-14) of a transition to a second vortex-liquid phase. C1 CEA Grenoble, Serv Phys Magnetisme & Supraconduct, Dept Rech Fondamentale Mat Condensee, F-38054 Grenoble, France. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Zurich, Inst Phys, CH-8057 Zurich, Switzerland. RP Bouquet, F (reprint author), CEA Grenoble, Serv Phys Magnetisme & Supraconduct, Dept Rech Fondamentale Mat Condensee, F-38054 Grenoble, France. EM Frederic_Bouquet@Yahoo.Com.immuno NR 27 TC 88 Z9 88 U1 1 U2 15 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 24 PY 2001 VL 411 IS 6836 BP 448 EP 451 DI 10.1038/35078016 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 435CB UT WOS:000168858700039 PM 11373670 ER PT J AU Hinks, DG Claus, H Jorgensen, JD AF Hinks, DG Claus, H Jorgensen, JD TI The complex nature of superconductivity in MgB2 as revealed by the reduced total isotope effect SO NATURE LA English DT Article AB Magnesium diboride, MgB2, was recently observed to become superconducting(1) at 39 K, which is the highest known transition temperature for a non-copper-oxide bulk material. Isotope-effect measurements, in which atoms are substituted by isotopes of different mass to systematically change the phonon frequencies, are one of the fundamental tests of the nature of the super-conducting mechanism in a material. In a conventional Bardeen-Cooper-Schrieffer (BCS) superconductor, where the mechanism is mediated by electron-phonon coupling, the total isotope-effect coefficient (in this case, the sum of both the Mg and B coefficients) should be about 0.5. The boron isotope effect was previously shown to be large(2) and that was sufficient to establish that MgB2 is a conventional superconductor, but the Mg effect has not hitherto been measured. Here we report the determination of the Mg isotope effect, which is small but measurable. The total reduced isotope-effect coefficient is 0.32, which is much lower than the value expected for a typical BCS superconductor. The low value could be due to complex materials properties, and would seem to require both a large electron-phonon coupling constant and a value of mu* (the repulsive electron-electron interaction) larger than found for most simple metals. C1 Argonne Natl Lab, Div Mat Sci, Chicago, IL 60438 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Hinks, DG (reprint author), Argonne Natl Lab, Div Mat Sci, Chicago, IL 60438 USA. NR 28 TC 260 Z9 271 U1 0 U2 28 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 24 PY 2001 VL 411 IS 6836 BP 457 EP 460 DI 10.1038/35078037 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 435CB UT WOS:000168858700042 PM 11373673 ER PT J AU Oren, R Ellsworth, DS Johnsen, KH Phillips, N Ewers, BE Maier, C Schafer, KVR McCarthy, H Hendrey, G McNulty, SG Katul, GG AF Oren, R Ellsworth, DS Johnsen, KH Phillips, N Ewers, BE Maier, C Schafer, KVR McCarthy, H Hendrey, G McNulty, SG Katul, GG TI Soil fertility limits carbon sequestration by forest ecosystems in a CO2-enriched atmosphere SO NATURE LA English DT Article ID CO2 ENRICHMENT; TERRESTRIAL ECOSYSTEMS; LOBLOLLY-PINE; GLOBAL CHANGE; ELEVATED CO2; BALANCE; GROWTH; AIR; FEEDBACKS; BIOSPHERE AB Northern mid-latitude forests are a large terrestrial carbon sink(1-4). Ignoring nutrient limitations, large increases in carbon sequestration from carbon dioxide (CO2) fertilization are expected in these forests(5). Yet, forests are usually relegated to sites of moderate to poor fertility, where tree growth is often limited by nutrient supply, in particular nitrogen(6,7). Here we present evidence that estimates of increases in carbon sequestration of forests, which is expected to partially compensate for increasing CO2 in the atmosphere, are unduly optimistic(8). In two forest experiments on maturing pines exposed to elevated atmospheric CO2, the CO2-induced biomass carbon increment without added nutrients was undetectable at a nutritionally poor site, and the stimulation at a nutritionally moderate site was transient, stabilizing at a marginal gain after three years. However, a large synergistic gain from higher CO2 and nutrients was detected with nutrients added. This gain was even larger at the poor site (threefold higher than the expected additive effect) than at the moderate site (twofold higher). Thus, fertility can restrain the response of wood carbon sequestration to increased atmospheric CO2. Assessment of future carbon sequestration should consider the limitations imposed by soil fertility, as well as interactions with nitrogen deposition. C1 Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA. Univ Michigan, Sch Nat Resources & Environm, Ann Arbor, MI 48109 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. US Forest Serv, So Res Stn, Res Triangle Pk, NC 27709 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. US Forest Serv, So Global Climate Change Program, Raleigh, NC 27606 USA. RP Oren, R (reprint author), Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA. RI Katul, Gabriel/A-7210-2008; Ewers, Brent/A-9696-2008; OI Katul, Gabriel/0000-0001-9768-3693; Ellsworth, David/0000-0002-9699-2272; McCarthy, Heather R/0000-0002-2219-5182 NR 30 TC 617 Z9 658 U1 35 U2 252 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 24 PY 2001 VL 411 IS 6836 BP 469 EP 472 DI 10.1038/35078064 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 435CB UT WOS:000168858700046 PM 11373677 ER PT J AU Atwood, D Soni, A AF Atwood, D Soni, A TI CP asymmetry measurements in J/psi K-0 and the CKM paradigm SO PHYSICS LETTERS B LA English DT Article ID STANDARD ELECTROWEAK MODEL; B-DECAYS; LATTICE CALCULATION; MATRIX-ELEMENTS; WEAK DECAYS; QUARK MASS; TOP-QUARK; VIOLATION; QCD; PARAMETER AB Recent experimental observations of CP asymmetry in B --> J/psi + K-0 constitute the first significant signal of CP-violation outside the neutral kaon system; thus they represent an important milestone to test the CKM paradigm. We, therefore, undertake a critical appraisal of the existing experimental and theoretical inputs used to deduce constraints on sin 2 beta and other important parameters and thus find, in particular, sin 2 beta > 0.47 at 95% CL which is completely compatible with the combined experimental result: sin2 beta = 0.48 +/- 0.16, representing an important success of the CKM model of CP-violation. Searches for new physics in B decays to J/psi + KO like final states will require improved precision: we make some suggestions to facilitate these. We also present a global fit including the new CP asymmetry measurements in B --> J/psi + K-0 as an additional input yielding, e.g., gamma = (29 degrees --> 67 degrees), (n) over bar = (0.20 --> 0.37), (p) over bar = (0.08 --> 0.36), J(CP) = (1.8 --> 3.1) x 10(-5) Br(K+ --> pi (+)nu<()over bar>) = (0.52 --> 0.92) x 10(-10), Br(K-L --> pi (0)nu<()over bar>) = (0.11 --> 0.31) x 10(-10) and Deltam(Bs) = (15.2-28.3) ps(-1), all 95% CL. (C) 2001 Published by Elsevier Science B.V. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Brookhaven Natl Lab, Theory Grp, Upton, NY 11973 USA. RP Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM atwood@iastate.edu; soni@bnl.gov NR 60 TC 26 Z9 26 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 MAY 24 PY 2001 VL 508 IS 1-2 BP 17 EP 24 DI 10.1016/S0370-2693(01)00477-4 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 440HL UT WOS:000169169800003 ER PT J AU Glaser, T Bertini, I Moura, JJG Hedman, B Hodgson, KO Solomon, EI AF Glaser, T Bertini, I Moura, JJG Hedman, B Hodgson, KO Solomon, EI TI Protein effects on the electronic structure of the [Fe4S4](2+) cluster in ferredoxin and HiPIP SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID IRON-SULFUR CLUSTERS; LIGAND K-EDGE; RAY-ABSORPTION SPECTROSCOPY; REDOX POTENTIALS; ATOMIC-RESOLUTION; MODEL; COVALENCY; FE4S4; METAL; FE2S2 C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Univ Florence, Dept Chem, Florence, Italy. Univ Nova Lisboa, Dept Quim, P-1200 Lisbon, Portugal. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Hedman, B (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Moura, Jose/D-6426-2013; REQUIMTE, SMB/M-5694-2013; REQUIMTE, UCIBIO/N-9846-2013; Glaser, Thorsten/H-5187-2013 OI Moura, Jose/0000-0002-4726-2388; Glaser, Thorsten/0000-0003-2056-7701 FU NCRR NIH HHS [RR-01209] NR 25 TC 41 Z9 41 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 23 PY 2001 VL 123 IS 20 BP 4859 EP 4860 DI 10.1021/ja0155940 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 435ZL UT WOS:000168912000033 PM 11457306 ER PT J AU Zhang, DZ VanderHeyden, WB AF Zhang, DZ VanderHeyden, WB TI High-resolution three-dimensional numerical simulation of a circulating fluidized bed SO POWDER TECHNOLOGY LA English DT Article DE high-resolution; three-dimensional numerical simulation; circulating fluidized bed ID GAS-PARTICLE FLOW; RISER AB A simple averaged equation model for two-phase flows is used to perform high-resolution three-dimensional numerical simulations of aas-solid flow in a fluidized bed. Results are compared to experimental observations of Van den Moortel et al. [Chem. Eng. Sci. 53 (10) (1998) 1883]. It is found that a simple averaged equation model, which accounts directly for only simple fluid-particle interactions, captures the basic physics of the two-phase flow provided sufficient resolution is used. This is because mesoscale structures produced by the nonlinear interactions represented by the nonlinear terms in the averaged equations have dominant effects on the macroscale. Similarities and differences between our results and those of Agrawal et al. [J. Fluid Mech. (2000) submitted for publication] and the implications for future directions in two-phase flow theory for fluidized beds are discussed. Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Zhang, DZ (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,MS B216, Los Alamos, NM 87545 USA. NR 16 TC 52 Z9 56 U1 1 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD MAY 23 PY 2001 VL 116 IS 2-3 SI SI BP 133 EP 141 DI 10.1016/S0032-5910(00)00387-9 PG 9 WC Engineering, Chemical SC Engineering GA 462MN UT WOS:000170424000003 ER PT J AU Guenther, C Syamlal, M AF Guenther, C Syamlal, M TI The effect of numerical diffusion on simulation of isolated bubbles in a gas-solid fluidized bed SO POWDER TECHNOLOGY LA English DT Article DE fluidization; convection; diffusion; bubbles; deferred correction ID HYPERBOLIC CONSERVATION-LAWS; HIGH-RESOLUTION SCHEMES; GRANULAR FLOW; HYDRODYNAMICS; PARTICLES; JET AB A two-fluid hydrodynamic model of a two-dimensional gas-solids fluidized bed is used to calculate the shape of an isolated bubble. The calculations are done by applying four different discretization schemes to the convection term. The bubble shape calculated by using the first-order upwind (FOW) scheme is unphysical and pointed, where as the bubble shape calculated by the second-order schemes SMART, Superbee, and MINMOD is physically realistic and rounded. Grid independence of the solutions is established. Superbee and SMART are found to give the most accurate results for a given grid resolution. Higher order discretization schemes are implemented with a downwind factor (DWF) method and with a deferred correction (DC) method. The DC method is significantly faster than the DWF method. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Energy Technol Lab, Dept Energy, Morgantown, WV 26507 USA. Fluent Inc, Morgantown, WV 26507 USA. RP Guenther, C (reprint author), Natl Energy Technol Lab, Dept Energy, Mail Stop NO4,3610 Collins Ferry Rd,POB 880, Morgantown, WV 26507 USA. NR 35 TC 57 Z9 64 U1 3 U2 15 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD MAY 23 PY 2001 VL 116 IS 2-3 SI SI BP 142 EP 154 DI 10.1016/S0032-5910(00)00386-7 PG 13 WC Engineering, Chemical SC Engineering GA 462MN UT WOS:000170424000004 ER PT J AU Bruehl, RE Dasgupta, F Katsumoto, TR Tan, JH Bertozzi, CR Spevak, W Ahn, DJ Rosen, SD Nagy, JO AF Bruehl, RE Dasgupta, F Katsumoto, TR Tan, JH Bertozzi, CR Spevak, W Ahn, DJ Rosen, SD Nagy, JO TI Polymerized liposome assemblies: Bifunctional macromolecular selectin inhibitors mimicking physiological selectin ligands SO BIOCHEMISTRY LA English DT Article ID SIALYL-LEWIS-X; HIGH ENDOTHELIAL VENULES; LEUKOCYTE ADHESION MOLECULE; O-LINKED OLIGOSACCHARIDES; HIGH-AFFINITY BINDING; MAJOR CAPPING GROUP; P-SELECTIN; CARBOHYDRATE INTERACTIONS; CELL-ADHESION; GLYCOPROTEIN LIGAND AB Monomeric sialyl Lewis(x) (sLe(x)) and sLe(x)-like oligosaccharides are minimal structures capable of supporting selectin binding in vitro. However, their weak binding interactions do not correlate with the high-affinity binding interactions witnessed in vivo. The polyvalent display of carbohydrate groups found on cell surface glycoprotein structures may contribute to the enhanced binding strength of selectin-mediated adhesion. Detailed biochemical analyses of physiological selectin ligands have revealed a complicated composition of molecules that bind to the selectins in vivo and suggest that there are other requirements for tight binding beyond simple carbohydrate multimerization. In an effort to mimic the high-affinity binding, polyvalent scaffolds that contain multicomponent displays of selectin-binding ligands have been synthesized. Here, we demonstrate that the presentation of additional anionic functional groups in the form of sulfate esters, on a polymerized liposome surface containing a multimeric array of sLe(x)-like oligosaccharides, generates a highly potent, bifunctional macromolecular assembly. This assembly inhibits L-, E-, and P-selectin binding to GlyCAM-1, a physiological ligand better than sLe(x)-like liposomes without additional anionic charge. These multivalent arrays are 4 orders of magnitude better than the monovalent carbohydrate. Liposomes displaying 3'-sulfo Lewis(x)-like oligosaccharides, on the other hand, show slight loss of binding with introduction of additional anionic functional groups for E- and P-selectin and negligible change for L-selectin. The ability to rapidly and systematically vary the composition of these assemblies is a distinguishing feature of this methodology and may be applied to the study of other systems where composite binding determinants are important for high-affinity binding. C1 Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. Univ Calif San Francisco, Program Biomed Sci, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Glycomed Inc, Alameda, CA 94501 USA. Korea Univ, Dept Chem Engn, Seoul 136701, South Korea. RP Nagy, JO (reprint author), LigoCyte Pharmaceut Inc, 920 Technol Blvd, Bozeman, MT 59718 USA. FU NIAID NIH HHS [R4 AI 43789A, R43 AI043789-01] NR 76 TC 32 Z9 33 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 22 PY 2001 VL 40 IS 20 BP 5964 EP 5974 DI 10.1021/bi002921s PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 436JN UT WOS:000168932900013 PM 11352731 ER PT J AU Utschig, LM Poluektov, O Schlesselman, SL Thurnauer, MC Tiede, DM AF Utschig, LM Poluektov, O Schlesselman, SL Thurnauer, MC Tiede, DM TI Cu2+ site in photosynthetic bacterial reaction centers from Rhodobacter sphaeroides, Rhodobacter capsulatus, and Rhodopseudomonas viridis SO BIOCHEMISTRY LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; COPPER-BINDING SITE; ECHO ENVELOPE MODULATION; AMINO-ACID SEQUENCE; PROTON-TRANSFER; SPIN-ECHO; SECONDARY QUINONE; PHOTOSYSTEM-II; PULSED EPR; HISTIDINE LIGATION AB The interaction of metal ions with isolated photosynthetic reaction centers (RCs) from the purple bacteria Rhodobacter sphaeroides, Rhodobacter capsulatus, and Rhodopseudomonas viridis has been investigated with transient optical and magnetic resonance techniques. In RCs from all species, the electrochromic response of the bacteriopheophytin cofactors associated with Q(A)-Q(B) --> Q(A)Q(B)(-) electron transfer is slowed in the presence of Cu2+. This slowing is similar to the metal ion effect observed for RCs from Rb. sphaeroides where Zn2+ was bound to a specific site on the surface of the RC [Utschig et al. (1998) Biochemistry 37, 8278]. The coordination environments of the Cu2+ sites were probed with electron paramagnetic resonance (EPR) spectroscopy, providing the first direct spectroscopic evidence for the existence of a second metal site in RCs from Rb, capsulatus and Rps. viridis. In the dark, RCs with Cu2+ bound to the surface exhibit axially symmetric EPR spectra. Electron spin echo envelope modulation (ESEEM) spectral results indicate multiple weakly hyperfine coupled N-14 nuclei in close proximity to Cu2+. These ESEEM spectra resemble those observed for Cu2+ RCS from Rb, sphaeroides [Utschig et al. (2000) Biochemistry 39, 2961] and indicate that two or more histidines ligate the Cu2+ at the surface site in each RC. Thus, RCs from Rb. sphaeroides, Rb. capsulatus, and Rps. viridis each have a structurally analogous Cu2+ binding site that is involved in modulating the Q(A)(-)Q(B)-->Q(A)Q(B)(-) electron-transfer process. Inspection of the Rps, viridis crystal structure reveals four potential histidine ligands from three different subunits (M16, H178, H72, and L211) located beneath the QB binding pocket. The location of these histidines is surprisingly similar to the grouping of four histidine residues (H68, H126, H128, and L211) observed in the Rb. sphaeroides RC crystal structure. Further elucidation of these Cu2+ sites will provide a means to investigate localized proton entry into the RCs of Rb, capsulatus and Rps. viridis as well as locate a site of protein motions coupled with electron transfer. C1 Argonne Natl Lab, Chem Div D 200, Argonne, IL 60439 USA. RP Utschig, LM (reprint author), Argonne Natl Lab, Chem Div D 200, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 80 TC 15 Z9 17 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 22 PY 2001 VL 40 IS 20 BP 6132 EP 6141 DI 10.1021/bi0029191 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 436JN UT WOS:000168932900033 PM 11352751 ER PT J AU Kendrick, BK AF Kendrick, BK TI Quantum reactive scattering calculations for the H+D-2 -> HD+D reaction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID DIFFERENTIAL CROSS-SECTIONS; PRODUCT-STATE DISTRIBUTIONS; POTENTIAL-ENERGY SURFACE; ELEMENTARY CHEMICAL-REACTIONS; KOHN VARIATIONAL PRINCIPLE; HYDROGEN-EXCHANGE REACTION; WAVE-PACKET PROPAGATION; LOG-DERIVATIVE METHOD; EV COLLISION ENERGY; + D-2 COLLISIONS AB The results of accurate 3D quantum scattering calculations in symmetrized hyperspherical coordinates are reported for the H + D-2(v,j)-->HD(v',j') + D reaction at 64 values of total energy in the range 0.5-1.9 eV. Integral and differential cross sections are computed using the Boothroyd-Keogh-Martin-Peterson potential energy surface for all values of total angular momentum J less than or equal to 31. Several transition state resonances survive the sum over J and are observed in many of the fully converged state-to-state integral and differential cross sections. In some cases a series of resonances is observed. The energy spacings between many of the resonances are consistent with the energy spacings between the even or odd bending modes of the quantized transition states of H-3. (C) 2001 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Kendrick, BK (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-12,MS-B268, Los Alamos, NM 87545 USA. NR 111 TC 56 Z9 56 U1 1 U2 6 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 MAY 22 PY 2001 VL 114 IS 20 BP 8796 EP 8819 DI 10.1063/1.1367377 PG 24 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 430NQ UT WOS:000168580500010 ER PT J AU Bise, RT Hoops, AA Neumark, DM AF Bise, RT Hoops, AA Neumark, DM TI Photodissociation and photoisomerization pathways of the HNCN free radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; FLIGHT MASS-SPECTROMETER; TRANSITION-STATE-THEORY; REACTION CH(X2-PI)+N2(X1-SIGMA-G+)->HCN(X1-SIGMA+)+N(4S); AB-INITIO; PROMPT NO; FAST BEAM; MECHANISM; DYNAMICS; SPECTROSCOPY AB The photodissociation spectroscopy and dynamics of the HNCN free radical have been investigated by fast beam photofragment translational spectroscopy. Predissociative transitions for both the (B) over tilde (2)A'<--<(X)over tilde> (2)A " band and a higher-energy band system assigned to the (C) over tilde (2)A "<--<(X)over tilde> (2)A " band were observed. Photofragment mass distributions indicate that N-2 loss is the primary dissociation pathway. Translational energy distributions reveal a resolved vibrational structure of the N-2 fragment, suggesting that the HNCN radical first isomerizes to a cyclic HCN2 intermediate. A dissociation mechanism is proposed in which electronically excited HNCN undergoes internal conversion to the ground state, followed by isomerization to cyclic HCN2 and dissociation through a tight three-center transition state. The HNCN bond dissociation energy D-0 and heat of formation Delta H-f(0)(HNCN) were determined to be 2.80 +/-0.03 eV and 3.35 +/-0.03 eV, respectively. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 63 TC 23 Z9 23 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 2001 VL 114 IS 20 BP 9000 EP 9011 DI 10.1063/1.1367411 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 430NQ UT WOS:000168580500029 ER PT J AU Hoops, AA Bise, RT Gascooke, JR Neumark, DM AF Hoops, AA Bise, RT Gascooke, JR Neumark, DM TI State-resolved translation energy distributions for NCO photodissociation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EMISSION PUMPING SPECTROSCOPY; FLIGHT MASS-SPECTROMETER; FERMI-RESONANCE; SPIN-ORBIT; X2-PI NCO; FAST BEAM; DYNAMICS; HNCO; HEAT; FLUORESCENCE AB The photodissociation dynamics of NCO have been examined using fast beam photofragment translational spectroscopy. Excitation of the 1(0)(2), 3(0)(1), and 1(0)(2)3(0)(2) transitions of the (B) over tilde (2)Pi<--<(X)over tilde> (2)Pi band produces N(S-4) + CO photofragments exclusively, while excitation of the 1(0)(3)3(0)(3) transition yields primarily N(D-2) + CO photoproducts. The translational energy [P(E-T)] distributions yield D-0(N-CO) = 2.34 +/-0.03 eV, and DeltaH(f,0)(0)(NCO) = 1.36 +/-0.03 eV. The P(E-T) distributions exhibit vibrationally resolved structure reflecting the vibrational and rotational distributions of the CO product. The N(D-2) + CO distribution can be fit by phase space theory (PST), while the higher degree of CO rotational excitation for N(S-4) + CO products implies that NCO passes through a bent geometry upon dissociation. The P(E-T) distributions suggest that when the (B) over tilde (2)Pi<--<(X)over tilde> (2)Pi band is excited, NCO undergoes internal conversion to its ground electronic state prior to dissociation. Excitation of NCO at 193 nm clearly leads to the production of N(D-2) + CO fragments. While conclusive evidence for the higher energy O(P-3) + CN(X (2)Sigma (+)) channel was not observed, the presence of this dissociation pathway could not be excluded. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Neumark, DM (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Neumark, Daniel/B-9551-2009; OI Neumark, Daniel/0000-0002-3762-9473; Gascooke, Jason/0000-0002-3236-2247 NR 49 TC 10 Z9 11 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 2001 VL 114 IS 20 BP 9020 EP 9027 DI 10.1063/1.1369132 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 430NQ UT WOS:000168580500031 ER PT J AU Young, JA Cook, RC AF Young, JA Cook, RC TI Helix reversal motion in polyisocyanates SO MACROMOLECULES LA English DT Article ID MOLECULAR-FORCE FIELD; MACROMOLECULAR STEREOCHEMISTRY; CONFORMATIONAL CHARACTERISTICS; TRANSITION-STATES; ENERGY; PATHS; INFORMATION; ISOCYANATE); SYSTEMS; POLYMER AB The geometric pathway and energetic barriers associated with the motion of helix reversal sites in poly(methyl isocyanate) have been studied using the conjugate peak refinement algorithm in conjunction with the Merck molecular force field. Motion of the reversal along the chain backbone involves relatively small net changes in the torsional angles as a pair of distorted trans and cis bonds reverse their direction of twist. The present study shows that this change occurs by the trans bond passing through its nearby planar low torsional energy conformation to assume an opposite twist. However, the cis bond is prevented from passing through its nearby low torsional energy planar cis conformation by strong nonbonded interactions. It is instead forced to rotate through its trans conformation, thus overcoming two torsional barriers to reach its final cis conformation of opposite twist. The net translation of the reversal down the chain one monomer unit requires crossing three energetic barriers, the highest of which is 17.5 kcal/mol, in reasonable agreement with the 19.6 kcal/mol value determined in recent temperature-dependent NMR studies of poly(2-butylhexyl isocyanate). C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Young, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 24 TC 7 Z9 7 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 22 PY 2001 VL 34 IS 11 BP 3646 EP 3653 DI 10.1021/ma001695r PG 8 WC Polymer Science SC Polymer Science GA 434TY UT WOS:000168833000024 ER PT J AU Pearton, SJ Ren, F Zhang, AP Dang, G Cao, XA Lee, KP Cho, H Gila, BP Johnson, JW Monier, C Abernathy, CR Han, J Baca, AG Chyi, JI Lee, CM Nee, TE Chuo, CC Chu, SNG AF Pearton, SJ Ren, F Zhang, AP Dang, G Cao, XA Lee, KP Cho, H Gila, BP Johnson, JW Monier, C Abernathy, CR Han, J Baca, AG Chyi, JI Lee, CM Nee, TE Chuo, CC Chu, SNG TI GaN electronics for high power, high temperature applications SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society CY MAY 29-JUN 02, 2000 CL STRASBOURG, FRANCE SP European Mat Res Soc DE GaN; rectifiers; bipolar transistors; MOSFETs ID MICROWAVE AB A brief review is given of recent progress in fabrication of high voltage GaN and AlGaN rectifiers, GaN/AlGaN heterojunction bipolar transistors and GaN metal-oxide semiconductor field effect transistors. Improvements in epitaxial layer quality and in fabrication techniques have led to significant advances in device performance. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Miryang Natl Univ, Dept Mat Engn, Kyungnam, South Korea. Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Cent Univ, Dept Elect Engn, Chungli 32054, Taiwan. Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Pearton, SJ (reprint author), Univ Florida, Dept Mat Sci & Engn, 100 Rhines Hall,POB 116400, Gainesville, FL 32611 USA. RI Chyi, Jen-Inn/A-1799-2016 NR 6 TC 54 Z9 55 U1 3 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAY 22 PY 2001 VL 82 IS 1-3 SI SI BP 227 EP 231 DI 10.1016/S0921-5107(00)00767-4 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 431EK UT WOS:000168618700067 ER PT J AU Kaminska, E Piotrowska, A Barcz, A Bour, D Zielinski, M Jasinski, J AF Kaminska, E Piotrowska, A Barcz, A Bour, D Zielinski, M Jasinski, J TI Formation of ohmic contacts to MOCVD grown p-GaN by controlled activation of Mg SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT Spring Meeting of the European-Materials-Research-Society CY MAY 29-JUN 02, 2000 CL STRASBOURG, FRANCE SP European Mat Res Soc DE ohmic contact; p-GaN; hydrogen; ZrN; ZrB2 AB We report on the formation of low resistivity ohmic contacts to p-GaN, r(c) < 10(-4) Omega cm(2), by increasing the concentration of the active Mg in the subcontact zone, via Zr-mediated release of hydrogen. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Inst Electron Technol, Warsaw, Poland. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. Agilent Labs, Palo Alto, CA USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Warsaw Univ, Inst Expt Phys, PL-00913 Warsaw, Poland. RP Kaminska, E (reprint author), Inst Electron Technol, Warsaw, Poland. RI Kaminska, Eliana/C-3086-2013; Zielinski, Marcin/F-1690-2011 OI Zielinski, Marcin/0000-0003-1663-3868 NR 4 TC 6 Z9 7 U1 1 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD MAY 22 PY 2001 VL 82 IS 1-3 SI SI BP 265 EP 267 DI 10.1016/S0921-5107(00)00724-8 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 431EK UT WOS:000168618700077 ER PT J AU Resat, H Straatsma, TP Dixon, DA Miller, JH AF Resat, H Straatsma, TP Dixon, DA Miller, JH TI The arginine finger of RasGAP helps Gln-61 align the nucleophilic water in GAP-stimulated hydrolysis of GTP SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ACTIVATING PROTEINS; SIGNAL-TRANSDUCTION; CRYSTAL-STRUCTURE; MECHANISM; P21; SIMULATION; MUTANTS; TRANSITION; MOLECULES; PROGRAM AB The Pas family of GTPases is a collection of molecular switches that link receptors on the plasma membrane to signaling pathways that regulate cell proliferation and differentiation. The accessory GTPase-activating proteins (GAPs) negatively regulate the cell signaling by increasing the slow intrinsic CTP to GDP hydrolysis rate of Ras. Mutants of Ras are found in 25-30% of human tumors. The most dramatic: property of these mutants is their insensitivity to the negative regulatory action of GAPs. All known oncogenic mutants of Pas map to a small subset of amino acids. Gln-61 is particularly important because virtually all mutations of this residue eliminate sensitivity to GAPs. Despite its obvious importance for carcinogenesis, the role of Gln-61 in the GAP-stimulated GTPase activity of Ras has remained a mystery. Our molecular dynamics simulations of the p21ras-p120GAP-GTP complex suggest that the local structure around the catalytic region can be different from that revealed by the x-ray crystal structure. We find that the carbonyl oxygen on the backbone of the arginine finger supplied in trans by p120GAP (Arg-789) interacts with a water molecule in the active site that is forming a bridge between the NH2 group of the Gln-61 and the gamma -phosphate of CTP. Thus, Arg-789 may play a dual role in generating the nucleophile as well as stabilizing the transition state for P-O bond cleavage. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Resat, H (reprint author), Pacific NW Natl Lab, POB 999,Mailstop K1-83, Richland, WA 99352 USA. NR 36 TC 26 Z9 28 U1 1 U2 7 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 22 PY 2001 VL 98 IS 11 BP 6033 EP 6038 DI 10.1073/pnas.091506998 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 435LV UT WOS:000168883700020 PM 11371635 ER PT J AU Pitnick, S Miller, GT Reagan, J Holland, B AF Pitnick, S Miller, GT Reagan, J Holland, B TI Males' evolutionary responses to experimental removal of sexual selection SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE sexual selection; sexual conflict; sperm competition; body size; Drosophila ID SPERM COMPETITION GAMES; FEMALE DROSOPHILA-MELANOGASTER; TESTIS SIZE; EJACULATE QUALITY; MATING PLUG; DISPLACEMENT; COST; INVESTMENT; CONFLICT; BEHAVIOR AB We evaluated the influence of pre- and post-copulatory sexual selection upon male reproductive traits in a naturally promiscuous species, Drosophila melanogaster. Sexual selection was removed in two replicate populations through enforced monogamous mating with random mate assignment or retained in polyandrous controls. Monogamous mating eliminates all opportunities for mate competition, mate discrimination, sperm competition, cryptic female choice and, hence, sexual conflict. Levels of divergence between lines in sperm production and male fitness traits were quantified after 38-81 generations of selection. Three a priori predictions were tested: (i) male investment in spermatogenesis will be lower in monogamy-line males due to the absence of sperm competition selection, (ii) due to the evolution of increased male benevolence, the fitness of females paired with monogamy-line males will be higher than that of females paired with control-line males, and (iii) monogamy-line males will exhibit decreased competitive reproductive success relative to control-line males. The first two predictions were supported, whereas the third prediction was not. Monogamy males evolved a smaller body size and the size of their testes and the number of sperm within the testes were disproportionately further reduced. In contrast, the fitness of monogamous males land their mates) was greater when reproducing in a non-competitive context: females mated once with monogamous males produced offspring at a faster rate and produced a greater total number of surviving progeny than did females mated to control males. The results indicate that sexual selection favours the production of increased numbers of sperm in D. melanogaster and that sexual selection favours some male traits conferring a direct cost to the fecundity of females. C1 Syracuse Univ, Dept Biol, Syracuse, NY 13244 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Pitnick, S (reprint author), Syracuse Univ, Dept Biol, 108 Coll Pl, Syracuse, NY 13244 USA. EM sspitnic@syr.edu NR 83 TC 127 Z9 128 U1 2 U2 32 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD MAY 22 PY 2001 VL 268 IS 1471 BP 1071 EP 1080 PG 10 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 435TB UT WOS:000168896300012 PM 11375092 ER PT J AU Tartakovsky, DM Winter, CL AF Tartakovsky, DM Winter, CL TI Dynamics of free surfaces in random porous media SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE porous media; moving boundary; random; stochastic; moment equations ID DIFFUSION-LIMITED AGGREGATION; CONDITIONAL MOMENT EQUATIONS; STEADY-STATE FLOW; RECURSIVE APPROXIMATIONS; HETEROGENEOUS MEDIA; WETTING FRONTS; TRANSIENT FLOW; LAYERED SOILS; GROWTH; CONDUCTIVITIES AB We consider free surface ow in random porous media by treating hydraulic conductivity of a medium as a random field with known statistics. We start by recasting the boundary-value problem in the form of an integral equation where the parameters and domain of integration are random. Our analysis of this equation consists of expanding the random integrals in Taylor's series about the mean position of the free boundary and taking the ensemble mean. To quantify the uncertainty associated with such predictions, we also develop a set of integro-differential equations satis ed by the corresponding second ensemble moments. The resulting moment equations require closure approximations to be workable. We derive such closures by means of perturbation expansions in powers of the variance of the logarithm of hydraulic conductivity. Though this formally limits our solutions to mildly heterogeneous porous media, our analytical solutions for one-dimensional flows demonstrate that such perturbation expansions may remain robust for relatively large values of the variance of the logarithm of hydraulic conductivity. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T7, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Tartakovsky, DM (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Grp T7, MS B284, Los Alamos, NM 87545 USA. RI Tartakovsky, Daniel/E-7694-2013; Winter, C. Larrabee/D-3918-2013 NR 33 TC 18 Z9 18 U1 0 U2 5 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PD MAY 22 PY 2001 VL 61 IS 6 BP 1857 EP 1876 DI 10.1137/S0036139999358180 PG 20 WC Mathematics, Applied SC Mathematics GA 438TJ UT WOS:000169070100002 ER PT J AU Lindsay, DS Weston, JL Little, SE AF Lindsay, DS Weston, JL Little, SE TI Prevalence of antibodies to Neospora caninum and Toxoplasma gondii in gray foxes (Urocyon cinereoargenteus) from South Carolina SO VETERINARY PARASITOLOGY LA English DT Article DE agglutination test; Neospora caninum; Toxoplasma gondii; Urocyon cinereoargenteus; gray fox; prevalence; epidemiology ID RED-FOXES; DEER; COYOTES AB Little is known about the epidemiology of Neospora caninum in wild mammal populations. It has been suggested that a sylvatic cycle exists for N. caninum. Dogs and potentially other canids are a definitive host for N. caninum. The present study was done to determine the prevalence of antibodies to N. caninum in a population of gray foxes (Urocyon cinereoargenteus) from a nonagricultural setting in South Carolina. We also determined the prevalence of antibodies to Toxoplasma gondii in these animals. Antibody levels were measured in direct agglutination tests using either N. caninum or T. gondii formalin-fixed tachyzoites as antigen. Four (15.4%) of the 26 gray foxes had titers to N. caninum. Titers to N. caninum were low being 1:25 in three gray foxes and 1:50 in the fourth gray fox. Antibodies to T. gondii were observed in 16 (61.5%) gray foxes. Titers to T. gondii were usually >1:50 and two gray foxes had titers of 1:1600. Results of this study indicate that gray foxes have more exposure to T. gondii than to N. caninum in this environment. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Virginia Polytech Inst & State Univ, Virginia Maryland Reg Coll Vet Med, Ctr Mol Med & Infect Dis, Dept Biomed Sci & Pathobiol, Blacksburg, VA 24061 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Coll Vet Med, Dept Med Microbiol & Parasitol, Athens, GA 30602 USA. RP Lindsay, DS (reprint author), Virginia Polytech Inst & State Univ, Virginia Maryland Reg Coll Vet Med, Ctr Mol Med & Infect Dis, Dept Biomed Sci & Pathobiol, 1410 Prices Fork Rd, Blacksburg, VA 24061 USA. RI Lindsay, David/G-8891-2016 OI Lindsay, David/0000-0002-0592-8321 NR 18 TC 21 Z9 21 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4017 J9 VET PARASITOL JI Vet. Parasitol. PD MAY 22 PY 2001 VL 97 IS 2 BP 159 EP 164 DI 10.1016/S0304-4017(01)00390-9 PG 6 WC Parasitology; Veterinary Sciences SC Parasitology; Veterinary Sciences GA 439GT UT WOS:000169103000009 PM 11358632 ER PT J AU Waldrip, KE Han, J Figiel, JJ Zhou, H Makarona, E Nurmikko, AV AF Waldrip, KE Han, J Figiel, JJ Zhou, H Makarona, E Nurmikko, AV TI Stress engineering during metalorganic chemical vapor deposition of AlGaN/GaN distributed Bragg reflectors SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; HIGH-REFLECTIVITY; GAN; EVOLUTION; LASER AB In situ stress monitoring has been employed during metalorganic chemical vapor deposition of AlGaN/GaN distributed Bragg reflectors (DBRs). It was found that the insertion of multiple AlN interlayers is effective in converting the tensile growth stress typically observed in this system into compression, thus alleviating the problem of crack generation. Crack-free growth of a 60 pair Al0.20Ga0.80N/GaN quarter-wavelength DBR was obtained over the entire 2 in. wafer; an accompanying reflectivity of at least 99% was observed near the peak wavelength around 380 nm. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Brown Univ, Div Engn, Providence, RI 02912 USA. RP Waldrip, KE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 124 Z9 124 U1 1 U2 23 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 MAY 21 PY 2001 VL 78 IS 21 BP 3205 EP 3207 DI 10.1063/1.1371240 PG 3 WC Physics, Applied SC Physics GA 432XN UT WOS:000168721200015 ER PT J AU Guo, CL Rodriguez, G Hoffbauer, M Taylor, AJ AF Guo, CL Rodriguez, G Hoffbauer, M Taylor, AJ TI Influence of electronic temperature and distribution on the second-order surface nonlinear susceptibility of metals SO APPLIED PHYSICS LETTERS LA English DT Article ID 2ND-HARMONIC GENERATION; PHASE-TRANSITION; GOLD AB We performed ultrafast, optical pump and second-harmonic-generation (SHG) probe measurements to study the effects of electronic temperature (T-e) and distribution on the second-order nonlinear susceptibility [chi ((2))] for a gold surface. These measurements clarify the physical origin of the recently observed power-law deviation of the SHG signal at high illuminating intensities. The study of SHG is extended to the high T-e regime, and the results agree with a model calculation presented in this letter. The consistency between the experimental and theoretical results in this letter provides a uniform picture of the effects of the electronic temperature and distribution on chi ((2)). (C) 2001 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Guo, CL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 17 TC 4 Z9 4 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 21 PY 2001 VL 78 IS 21 BP 3211 EP 3213 DI 10.1063/1.1374517 PG 3 WC Physics, Applied SC Physics GA 432XN UT WOS:000168721200017 ER PT J AU Haeni, JH Theis, CD Schlom, DG Tian, W Pan, XQ Chang, H Takeuchi, I Xiang, XD AF Haeni, JH Theis, CD Schlom, DG Tian, W Pan, XQ Chang, H Takeuchi, I Xiang, XD TI Epitaxial growth of the first five members of the Srn+1TinO3n+1 Ruddlesden-Popper homologous series SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; O SYSTEM; ELECTRON-MICROSCOPE; DEFECT STRUCTURE; THIN-FILMS; HIGH-TC; PEROVSKITES; OXIDES AB The first five members of the Srn+1TinO3n+1 Ruddlesden-Popper homologous series, i.e., Sr2TiO4, Sr3Ti2O7, Sr4Ti3O10, Sr5Ti4O13, and Sr6Ti5O16, have been grown by reactive molecular beam epitaxy. A combination of atomic absorption spectroscopy and reflection high-energy electron diffraction intensity oscillations were used for the strict composition control necessary for the synthesis of these phases. X-ray diffraction and high-resolution transmission electron microscope images confirm that these films are epitaxially oriented and nearly free of intergrowths. Dielectric measurements indicate that the dielectric constant tensor coefficient epsilon (33) increases from a minimum of 44 +/-4 in the n=1(Sr2TiO4) film to a maximum of 263 +/-2 in the n=infinity (SrTiO3) film. (C) 2001 American Institute of Physics. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Haeni, JH (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI Xiang, Xiaodong/A-9445-2012; Schlom, Darrell/J-2412-2013; Xiang, Xiaodong/A-5936-2017 OI Schlom, Darrell/0000-0003-2493-6113; NR 31 TC 99 Z9 99 U1 9 U2 80 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 MAY 21 PY 2001 VL 78 IS 21 BP 3292 EP 3294 DI 10.1063/1.1371788 PG 3 WC Physics, Applied SC Physics GA 432XN UT WOS:000168721200044 ER PT J AU Geohegan, DB Schittenhelm, H Fan, X Pennycook, SJ Puretzky, AA Guillorn, MA Blom, DA Joy, DC AF Geohegan, DB Schittenhelm, H Fan, X Pennycook, SJ Puretzky, AA Guillorn, MA Blom, DA Joy, DC TI Condensed phase growth of single-wall carbon nanotubes from laser annealed nanoparticulates SO APPLIED PHYSICS LETTERS LA English DT Article ID VAPORIZATION AB Single-wall carbon nanotubes (SWNT) were grown to micron lengths by laser-annealing nanoparticulate soot containing short (similar to 50 nm long) nanotube "seeds." The "seeded" nanoparticulate soot was produced by restricting the time spent by an ablation plume inside an 800 degreesC oven following laser vaporization of a C-Ni-Co target. The soot collected from the laser vaporization apparatus was placed inside graphite crucibles under argon, and heated by a CO2 laser. In situ pyrometry was used to estimate the sample temperature. Length distributions of SWNT bundles in the unannealed and annealed samples were measured by transmission electron microscopy and field emission scanning electron microscopy. Annealing treatments exceeding 1600 degreesC produced no increase in nanotube length, while lower temperatures in the 1000-1300 degreesC range were optimal for growth. These experiments indicate that SWNT grow by the conversion of condensed phase nanomaterial during annealing, a similar mechanism to that proposed for growth during normal laser-vaporization production. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Geohegan, DB (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139 NR 11 TC 50 Z9 51 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 MAY 21 PY 2001 VL 78 IS 21 BP 3307 EP 3309 DI 10.1063/1.1371796 PG 3 WC Physics, Applied SC Physics GA 432XN UT WOS:000168721200049 ER PT J AU Kawano, M Bacon, JW Campana, CF Winger, BE Dudek, JD Sirchio, SA Scruggs, SL Geiser, U Dahl, LF AF Kawano, M Bacon, JW Campana, CF Winger, BE Dudek, JD Sirchio, SA Scruggs, SL Geiser, U Dahl, LF TI High-nuclearity close-packed palladium-nickel carbonyl phosphine clusters: Heteropalladium [Pd16Ni4(CO)(22)(PPh3)(4)](2-) and [Pd33Ni9(CO)(41)(PPh3)(6)](4-) containing pseudo-T-d ccp Pd16Ni4 and pseudo-D-3h hcp Pd33Ni9 cores SO INORGANIC CHEMISTRY LA English DT Review ID TRANSITION-METAL CLUSTERS; X-RAY STRUCTURE; POTENTIAL-DEPENDENT SPECTRA; N = 0; BONDING CAPABILITIES; CO HYDROGENATION; MAGIC NUMBERS; CHEMICAL CHARACTERIZATION; DIANION 2; BIMETALLIC CLUSTERS AB [Pd16Ni4(CO)(22)(PPh3)(4)](2-) (1) and [Pd33Ni9(CO)(41)(PPh3)(6)](4-) (2) were obtained as the two major products from the reduction of PdCl2(PPh3)(2) with [Ni-6(CO)(12)](2-). Their crystal structures as [PPh4](+) salts were unambiguously determined from CCD X-ray crystallographic analyses, the resulting stoichiomotries were ascertained from elemental analyses. Infrared, multinuclear H-1, P-31{H-1} NMR, UV-vis, CV, variable-temperature magnetic susceptibility, and ESI FT/ICR mass spectrometric measurements were performed. The Pd16Ni4 core Of 1 ideally conforms to a ccp nu (3) tetrahedron of pseudo-T-d (43m) symmetry. Its geometry normal to each tetrahedral Pd7Ni3 face (i.e., along each of the four 3-fold axes) may be viewed as a four-layer stacking of 20 metal atoms in a ccp [a(Ni-1) b(Pd-3) c(Pd-6) a(Pd7Ni3)] sequence. A comparative analysis of the different ligand connectivities about the analogous metal-core geometries in 1 and the previously reported [Os-20(CO)(40)](2-) has stereochemical implications pertaining to the different possible modes of carbon monoxide attachment to ccp metal(III) surfaces. The unique geometry of the Pd33Ni9 core of 2, which has pseudo-Dsi, (62m) symmetry, consists of five equilateral triangular layers that are stacked in a hcp [a(Pd7Ni3) b(Pd-6) a(Pd7Ni3) b(Pd-6) a(Pd7Ni3)] sequence. Variable-temperature magnetic susceptibility measurements indicated both 1 and 2 to be diamagnetic over the entire temperature range from 5.0 to 300 K. Neutral Pd-12(CO)(12)(PPh3)(6) (3) and [Pd-29(CO)(28)(PPh3)(7)](2-) (4) as the [PPh4](+) salt were obtained as minor decomposition products from protonation reactions of 1 and 2, respectively, with acetic acid. Compound 3 of pseudo-D-3d (32/m) symmetry represents the second highly deformed hexacapped octahedral member of the previously established homopalladium family of clusters containing uncapped. monocapped. bicapped, and tetracapped Pds octahedra. The unprecedented centered 28-atom polyhedron for the Pd-29 core of 4 of pseudo-C-3 nu, (3m) symmetry may be described as a four-layer stacking of 29 metal atoms in a mixed hcp/ccp [a(Pd-1) b(Pd-3) a(Pd-10) c(Pd-15)] sequence. C1 Univ Wisconsin, Dept Chem, Madison, WI 53706 USA. Bruker Analyt Xray Syst Inc, Madison, WI 53711 USA. Finnigan FT MS Corp, Madison, WI 53711 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Dahl, LF (reprint author), Univ Wisconsin, Dept Chem, 1101 Univ Ave, Madison, WI 53706 USA. NR 125 TC 32 Z9 32 U1 0 U2 14 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 MAY 21 PY 2001 VL 40 IS 11 BP 2554 EP 2569 DI 10.1021/ic000979p PG 16 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 434UN UT WOS:000168834400019 PM 11350234 ER PT J AU Raebiger, JW Manson, JL Sommer, RD Geiser, U Rheingold, AL Miller, JS AF Raebiger, JW Manson, JL Sommer, RD Geiser, U Rheingold, AL Miller, JS TI 1-D and 2-D homoleptic dicyanamide structures, [Ph4P](2){Co-II[N(CN)(2)](4)} and [Ph4P]{M[N(CN)(2)](3)} (M = Mn, Co) SO INORGANIC CHEMISTRY LA English DT Article ID MAGNETIC-PROPERTIES; COORDINATION POLYMERS; NI; N(CN)(2)(-); PYRIDINE; LIGANDS; NETWORK C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Univ Delaware, Dept Chem, Newark, DE 19716 USA. RP Miller, JS (reprint author), Univ Utah, Dept Chem, 315 S 1400 E, Salt Lake City, UT 84112 USA. NR 23 TC 137 Z9 137 U1 0 U2 6 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 MAY 21 PY 2001 VL 40 IS 11 BP 2578 EP 2581 DI 10.1021/ic001379t PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 434UN UT WOS:000168834400021 PM 11350236 ER PT J AU Bera, K Farouk, B Vitello, P AF Bera, K Farouk, B Vitello, P TI Inductively coupled radio frequency methane plasma simulation SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID 2-DIMENSIONAL FLUID MODEL; CARBON-FILM DEPOSITION; 2-D ANALYTIC MODEL; GAS-PHASE PHYSICS; CROSS-SECTIONS; CH2 RADICALS; RF DISCHARGE; REACTOR; CHEMISTRY; UNIFORMITY AB A self-consistent two-dimensional radio frequency inductively coupled glow discharge model has been developed in cylindrical coordinates using a fluid model. The objective of the study is to provide insight into charged species dynamics and investigate their effects on plasma process for a methane discharge. The model includes continuity and energy equations for electrons and continuity, momentum and energy equations for positive and negative ions. An electromagnetic model that considers the electric field due to the space charge within the plasma and due to inductive power coupling is also incorporated. For an inductively coupled methane discharge we expect to find higher fluxes of ions and radicals to the cathode, and hence a higher deposition/etch rate for a high-density plasma. The independent control of ion energy to the cathode in an inductively coupled discharge will facilitate control on film deposition/etch rate and uniformity on the wafer. Swarm data as a function of the electron energy are provided as input to the model. The model predicts the electron density, ion density and their fluxes and energies to the cathode. The radical and neutral densities in the discharge are calculated using a gas phase chemistry model. The diamond-like-carbon thin-film deposition/etch rate is predicted using a surface chemistry model. The gas phase chemistry model considers the diffusion of radicals and neutrals along with creation and loss terms. The surface deposition/etching process involves adsorption-desorption, adsorption layer reaction, ion stitching, direct ion incorporation and carbon sputtering. C1 Drexel Univ, Dept Mech Engn & Mech, Philadelphia, PA 19104 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Farouk, B (reprint author), Drexel Univ, Dept Mech Engn & Mech, Philadelphia, PA 19104 USA. NR 39 TC 19 Z9 21 U1 2 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD MAY 21 PY 2001 VL 34 IS 10 BP 1479 EP 1490 DI 10.1088/0022-3727/34/10/308 PG 12 WC Physics, Applied SC Physics GA 439CP UT WOS:000169093500008 ER PT J AU Molodkin, VB Olikhovskii, SI Kislovskii, EN Krivitsky, VP Len, EG Pervak, EV Ice, GE Larson, BC AF Molodkin, VB Olikhovskii, SI Kislovskii, EN Krivitsky, VP Len, EG Pervak, EV Ice, GE Larson, BC TI Double-crystal x-ray diffractometry of single crystals with microdefects SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 5th Biennial Conference on High Resolution X-Ray Diffraction and Topography (XTOP2000) CY SEP 13-15, 2000 CL USTRON JASZOWIEC, POLAND SP Univ Warsaw, Inst Exptl Phys, Polish Acad Sci, Inst Phys Polish, Polish Acad Sci, High Pressure Res Ctr, Polish Acad Sci, Inst Phys Chem, Inst Atom Energy, Inst Electr Mat Technol, Mining & Metallurgy Acad, Polish Acad Sci, Inst Struct & Low Temp Res ID DISLOCATION-FREE SILICON; OXYGEN PRECIPITATION; DIFFUSE-SCATTERING; CLUSTERS; GROWTH AB The known method of the 'integral' diffuse scattering has been generalized in the Bragg case of x-ray diffraction for crystals, which contain large microdefects commensurable with the extinction length. In the framework of the developed statistical dynamical theory, relatively simple analytical expressions have been derived for coherent and diffuse components of reflectivity of single crystals with randomly distributed microdefects. To test the characterization possibilities of the proposed method, the rocking curves (RCs) of Czochralski-grown silicon single crystal annealed at 1080 degreesC for 6 h have been measured for 111 and 333 reflections of Cu K-alpha1 radiation using a high-resolution double-crystal x-ray diffractometer. The fitting results for the two RCs are in good mutual agreement and demonstrate the high information ability of the method. C1 Natl Acad Sci Ukraine, GV Kurdyumov Inst Met Phys, UA-03680 Kyiv 142, Ukraine. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Molodkin, VB (reprint author), Natl Acad Sci Ukraine, GV Kurdyumov Inst Met Phys, 36 Vernadsky Blvd, UA-03680 Kyiv 142, Ukraine. NR 21 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD MAY 21 PY 2001 VL 34 IS 10A SI SI BP A82 EP A86 DI 10.1088/0022-3727/34/10A/317 PG 5 WC Physics, Applied SC Physics GA 439CR UT WOS:000169093700018 ER PT J AU Bangerter, RO AF Bangerter, RO TI The heavy ion fusion program in the USA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial confinement fusion; IFE; ICF ID TARGET AB The U.S. Department of Energy has established a new, larger inertial fusion energy (IFE) program. To manage program growth, we have developed a new IFE research plan and we have established a Virtual National Laboratory for Heavy Ion Fusion. There has been significant technical progress. Improvements in target design have reduced the predicted energy requirements by approximately a factor of two. There have also been important experiments on chamber dynamics and other inertial fusion technologies. The accelerator program has completed a number of small-scale experiments. Experiments with driver-scale beams are being designed-including experiments with driver-scale ion sources and injectors. Finally we are developing the technologies needed to build a major research facility known as the Integrated Research Experiment (IRE). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Virtual Natl Lab Heavy Ion Fus, Berkeley, CA 94720 USA. RP Bangerter, RO (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 19 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 17 EP 23 DI 10.1016/S0168-9002(00)01323-1 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500004 ER PT J AU Sheffield, J AF Sheffield, J TI The future of fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE fusion energy; population growth; energy resources and demands; hydrogen fuel ID WORLD-POPULATION; ENERGY; GROWTH AB The population of the world is increasing, mainly in the developing world, and is projected to saturate within about 100 years at up to twice the present population of 6 billion people (Bos et al., World Population Projections: 1994-95 Edition, Published for the World Bank). Studies (Goldemberg and Johansson (Eds.), Energy as an Instrument for Socio-Economic Development United Nations Development Programme, New York, 1995, p. 9; United Nations Statistical Yearbooks, 10th issue; 1965; 20th issue; 1975, 22nd issue, 1977; 32nd issue, 1987; and 39th issue 1994, United Nations Publications; Sheffield, J. Technol. Forecasting Social Change 59 (1998) 55.) show that, historically, the population growth rate has varied inversely as the annual per capita energy use in most parts of the developing world, where per capita energy use is typically less than 1 t of oil equivalent energy per year. However, in areas with more than 2-3 t of oil equivalent of energy use per year per person, the growth rate is around zero. If this trend continues, a stable world population will require, allowing for energy efficiency improvements, some 2-3 times the present annual energy use. There is an abundance of energy in the world both exploited and potential to meet this need - fossil, fission, and renewables - but it is not evenly distributed, some are costly, and there are issues of environmental pollution in present use, that may limit use. Fusion energy is a potential longer-term source with attractive environmental features. It is the least-developed energy option and still faces a challenging development path, but there are many areas of the world that would benefit hugely from its deployment from the later part of the 21st century onward, and it is important to consider how it might be deployed. Most fusion power plant options considered today show an economy of scale, owing to the fixed distance needed for shielding fusion neutrons, tritium breeding and handling the heat loads. One interesting approach is to use the power plant to co-produce electricity and hydrogen to facilitate the introduction of lower cost of electricity, multi-gigawatt power plants (Sheffield et al., A study of options for the deployment of large fusion power plants, 2000, to be published). Published by Elsevier Science B.V. C1 Univ Tennessee, Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Joint Inst Energy & Environm, Oak Ridge, TN 37831 USA. RP Sheffield, J (reprint author), Univ Tennessee, Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 33 EP 37 DI 10.1016/S0168-9002(00)01325-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500006 ER PT J AU Meier, WR AF Meier, WR TI Overview of chamber and target technology R&D for heavy ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE fusion; heavy ion; inertial fusion; chambers; targets AB In 1999, the Department of Energy's (DOE) Office of Fusion Energy Sciences (OFES) added an inertial fusion energy (IFE) element to its Virtual Laboratory for Technology (VLT). The scope of the IFE element of the VLT includes the fusion chamber, chamber/driver interface, target fabrication and injection, and safety and environmental assessments for IFE. Critical issues have been identified and an integrated R&D plan for the next 4-5 years has been written to coordinate the research in these areas. This paper provides an overview of the US research activities addressing the critical issues. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Meier, WR (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-446, Livermore, CA 94551 USA. NR 15 TC 4 Z9 4 U1 2 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 103 EP 108 DI 10.1016/S0168-9002(01)00015-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500016 ER PT J AU Schultz, KR Goodin, DT Nobile, A AF Schultz, KR Goodin, DT Nobile, A TI IFE target fabrication and injection - achieving "believability" SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion; targets; fabrication; injection ID INERTIAL FUSION ENERGY AB At the heart of an inertial fusion energy (IFE) power plant is a target that has been compressed and heated to fusion conditions by the incident driver energy beams. The "Target Factory" at an inertial fusion power plant must produce about 500,000 targets per day, fill them with deuterium-tritium fuel, cool them to cryogenic temperature, and layer the solid fuel into a symmetric and smooth shell inside the capsule. The target must then accurately be delivered to the target chamber center at a rate of about 5 Hz, with a precisely predicted target location. These fragile targets must survive injection into the target chamber without damage. While IFE power plant design studies have presented plausible scenarios for IFE target fabrication and injection, these issues have become "believability" issues for IFE, A credible pathway for development of accurate, economic and reliable IFE target fabrication and injection must be demonstrated before we can proceed with the next major step in the IFE Program, the construction of an IFE Integrated Research Experiment. General Atomics is designing, constructing, and testing an experimental Target Injection and Tracking System to develop the scientific understanding necessary for injection of IFE targets into a high temperature reaction chamber. This paper summarizes the requirements for IFE target fabrication and injection, reviews the results from the studies that predict success, discusses the development program now underway, and presents the current status of and results from that program. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Schultz, KR (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 12 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 109 EP 117 DI 10.1016/S0168-9002(01)00016-X PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500017 ER PT J AU Olson, CL AF Olson, CL TI Chamber transport SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion energy; heavy ion fusion; ion beam transport; charge neutralization; current instabilities; plasma instabilities; fusion target chambers ID INERTIAL CONFINEMENT FUSION; HEAVY-ION; DISTRIBUTED RADIATOR; BEAM-TRANSPORT; PLASMA-CHANNEL; TARGET; REACTOR; DRIVEN AB Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes an assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed, All transport options still exist, including (1)vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system. (C) 2001 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Olson, CL (reprint author), Sandia Natl Labs, Org 1600,MS-1188,POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 17 Z9 17 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 118 EP 125 DI 10.1016/S0168-9002(01)00017-1 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500018 ER PT J AU MacLaren, SA de Hoon, M Faltens, A Ghiorso, W Seidl, P AF MacLaren, SA de Hoon, M Faltens, A Ghiorso, W Seidl, P TI Results from the scaled final focus experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ion inertial fusion AB Vacuum ballistic focusing is the straightforward method to obtain a heavy-ion beam spot size necessary to drive an inertial confinement fusion target. The beam is first expanded then focused to obtain the desired convergence angles at the exit of the last element. This is done in an attempt to achieve a focal spot size in which emittance is the limiting factor; however, aberrations and space charge will influence the spot radius. Proper scaling of particle energy, mass, beam current, beam emittance, and magnetic field replicates the dynamics of a full driver beam at the focus in a small laboratory experiment. By scaling the beam current to similar to 100 A, 160 keV Cs+ has been used to study experimentally a proposed driver design at one-tenth scale. Once a nominal focal spot is achieved, the magnet strengths are deliberately de-tuned to simulate the effect of an off-momentum slice of the beam. Additionally, several methods will be used to inject electrons into beam following the last focusing element in order to study the neutralization of space charge and its effect on the focus. Transverse phase space and beam current density measurements at various stages of the focus will be presented as well spot size measurements from the various trials. This data will be compared to the results of a PIC model of the experiment. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP MacLaren, SA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, MS 47-112,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI de Hoon, Michiel/A-6443-2013; de Hoon, Michiel/N-8006-2015 NR 3 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 126 EP 133 DI 10.1016/S0168-9002(01)00018-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500019 ER PT J AU Moir, RW AF Moir, RW TI Chamber, target and final focus integrated design SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion energy powerplant; heavy-ion fusion; liquid walls; flibe ID HEAVY-ION; HYLIFE-II; FUSION AB Liquid wall protection, which challenges chamber clearing, has advantages in Heavy Ion Fusion's (HIF) main line chamber design. Thin liquid protection from X-rays is necessary to avoid erosion of structural surfaces and thick liquid makes structures behind 0.5m of flibe (7 mean free paths for 14 MeV neutrons), last the life of the plant. Liquid wall protection holds the promise of greatly increased economic competitiveness. The illumination must be compatible with liquid wall protection. The "best" values for driver energy, gain, yield and pulse rate comes out of well-known trade-off studies to arrive at the minimum cost of electricity. In order to reduce the driver cost and therefore reduce the cost of electricity, driver designers are attempting to reduce driver energy from the old 10 GeV value and increase the number of beams to about 200 to illuminate recent target designs from two sides. We have not yet succeeded in coming up with an integrated chamber design compatible with 200 beams. The present design iteration and future ones will depend on several key assumptions, such as jet surface smoothness and rapid chamber clearing. Before HIF can be considered feasible and economical, we need an integrated chamber, target, and final focus design and successful resolution of key technical issues by the chamber R&D efforts. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Moir, RW (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 25 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 140 EP 151 DI 10.1016/S0168-9002(01)00025-0 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500021 ER PT J AU Latkowski, JF Meier, WR AF Latkowski, JF Meier, WR TI Final focus shielding designs for modern heavy-ion fusion power plant designs SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion energy; magnet shielding; final focus AB Recent work in heavy-ion fusion accelerators and final focusing systems shows a trend towards less current per beam, and thus, a greater number of beams. Final focusing magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet. Excessive levels of nuclear heating may lead to magnet quench or to an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-II IFE power plant design. We present key magnet results as a function of the number of beams. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Latkowski, JF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mailstop L-446, Livermore, CA 94550 USA. NR 15 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 152 EP 158 DI 10.1016/S0168-9002(01)00026-2 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500022 ER PT J AU Peterson, RR Olson, CL Renk, TJ Rochau, GE Sweeney, MA AF Peterson, RR Olson, CL Renk, TJ Rochau, GE Sweeney, MA TI Chamber dynamic research with pulsed power SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion energy; pulsed power; target chambers; computer code validation ID REACTOR AB In Inertial Fusion Energy (IFE), Target Chamber Dynamics (TCD) is an integral part of the target chamber design and performance. TCD includes target output, deposition of target X-rays, ions and neutrons in target chamber gases and structures, melting and vaporization of target chamber materials, radiation-hydrodynamics in target chamber vapors and gases, and chamber conditions at the time of target and beam injections. Pulsed Dower provides a unique environment for IFE-TCD validation experiments in two important ways: pulsed power devices do not require the very clean conditions that lasers need, and they currently provide large X-ray and ion energy fluences. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Wisconsin, Fus Technol Inst, Madison, WI 53706 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Peterson, RR (reprint author), Univ Wisconsin, Fus Technol Inst, 1500 Engn Dr, Madison, WI 53706 USA. NR 10 TC 4 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 172 EP 179 DI 10.1016/S0168-9002(01)00029-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500025 ER PT J AU Roth, M Cowan, TE Brown, C Christl, M Fountain, W Hatchett, S Johnson, J Key, MH Pennington, DM Perry, MD Phillips, TW Sangster, TC Singh, M Snavely, R Stoyer, M Takahashi, Y Wilks, SC Yasuike, K AF Roth, M Cowan, TE Brown, C Christl, M Fountain, W Hatchett, S Johnson, J Key, MH Pennington, DM Perry, MD Phillips, TW Sangster, TC Singh, M Snavely, R Stoyer, M Takahashi, Y Wilks, SC Yasuike, K TI Intense ion beams accelerated by Petawatt-class lasers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci ID ELECTRONS AB The LLNL Petawatt Laser has achieved focussed intensities up to 6 x 10(20)W/cm(2), which has opened a new, higher energy regime of relativistic laser-plasma interactions in which the quiver energy of target electrons exceeds several MeV. Recent experiments revealed an intense, collimated beam of high-energy protons emitted normal to the rear surface of thin, solid targets. Up to 10(13) particles were emitted in a pulse less than 10 ps resulting in a current in the MA regime. With an overall energy content of 30 J, up to 7% of the incident laser energy is converted into protons. The beam shows a broad particle energy spectrum with a sharp cut off above 55 MeV. Based on our current understanding of the accelerating process, it may be possible to shape and focus the ion beam by using special target geometries. With their short pulse duration, high particle energy and large luminosity these beams are promising candidates in numerous applications, such as short-pulse injectors for large accelerators or as the ignitor for fast ignition ICF. Using intense proton beams the fast ignitor concept may become more attractive in heavy-ion fusion due to the possibility to work with indirectly driven targets. Finally, the acceleration is not restricted to protons and using tailored target surfaces may allow acceleration of more massive ions to similar energy per nucleon. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Huntsville, AL 35812 USA. Osaka Univ, Inst Laser Engn, Suita, Osaka 565, Japan. RP Roth, M (reprint author), Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. RI Cowan, Thomas/A-8713-2011 OI Cowan, Thomas/0000-0002-5845-000X NR 11 TC 6 Z9 6 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 201 EP 205 DI 10.1016/S0168-9002(01)00189-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500030 ER PT J AU Molvik, AW Barnard, JJ AF Molvik, AW Barnard, JJ TI Matching final focus to distributed radiator target requirements with skew quadrupoles SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE skew quadrupole; final focus; distributed radiator target; moment code; heavy-ion fusion ID HEAVY-ION AB We demonstrate that ion-beam elliptical focal spots can be rotated with skew quadrupoles, by arbitrary angles, to map appropriately onto annular rings at either end of distributed-radiator heavy-ion fusion targets. The rotation is accompanied by an increase in the area, a variation in the ellipticity, and a shift in the axial location of the beam focal spot, all of which are small enough that they may be acceptable. Possible further optimizations are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Heavy Ion Fus Virtual Natl Lab, Livermore, CA 94550 USA. RP Molvik, AW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Heavy Ion Fus Virtual Natl Lab, POB 808,L-645, Livermore, CA 94550 USA. NR 8 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 271 EP 277 DI 10.1016/S0168-9002(01)00047-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500043 ER PT J AU de Hoon, MJL MacLaren, SA Lee, EP AF de Hoon, MJL MacLaren, SA Lee, EP TI Simulation of the LBNL scaled final focus experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE space-charge dominated beams; final focus systems; simulation of charged-particle beams; inertial fusion AB In the Scaled Final Focus Experiment at LBNL, the beam dynamics of the HIBALL-II final focus system are studied by scaling its beam parameters down to values suitable for laboratory experiments. The final focus system is based on vacuum ballistic focusing, in which the beam first expands and is subsequently focused onto a small spot. Particle-in-cell simulations using the WARP code were done to understand the behavior of the beam as measured in the experiment. In order to closely resemble the anal focus system under consideration, the experimental conditions were replicated accurately in the simulation. Special attention was given to the non-ideal effects present in the experiment, such as fringe fields, image charges, and chromatic aberrations. It was shown that simulations can be used to determine which of these effects are likely to significantly affect the beam, and which are not. (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Lee, EP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 47-112,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI de Hoon, Michiel/A-6443-2013; de Hoon, Michiel/N-8006-2015 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 278 EP 283 DI 10.1016/S0168-9002(01)00048-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500044 ER PT J AU Sharp, WM Callahan-Miller, DA Langdon, AB Armel, MS Vay, JL AF Sharp, WM Callahan-Miller, DA Langdon, AB Armel, MS Vay, JL TI Improved modeling of chamber transport for heavy-ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci AB Beams for heavy-ion fusion are likely to require at least partial neutralization in a target chamber. Several mechanisms that help neutralize a converging heavy-ion beam are studied here using the axisymmetric electromagnetic particle-in-cell code BICrz. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Sharp, WM (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-440, Livermore, CA 94550 USA. NR 16 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 284 EP 292 DI 10.1016/S0168-9002(01)00049-3 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500045 ER PT J AU Vay, JL Deutsch, C AF Vay, JL Deutsch, C TI Intense ion backslash beam propagation in a reactor sized chamber SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ion fusion; intense ion beams; reaction chamber AB We consider the physics of the ballistic transport of intense ion beams in a heavy ion fusion reactor chamber filled with low pressure Flibe gas. We consider first a single beam envelope model and show via a simple case that emittance growth is an issue in the chamber as well as in the accelerator. We develop a model for the neutralization of beam space-charge by the electrons produced by gas ionization by the beam and derive an expression for the evolution of the neutralization factor as the beam propagates into the chamber. We then extend the envelope model from a one species beam to a beam of ions of several charge states by considering the entire beam as a set of subbeams (one for each charge state) each described with coupled envelope equation. The fully electromagnetic PIC code EPIC was used to investigate the behavior in greater detail. A parametric study of the sensitivity of the final spot radius at the target versus the ion beam stripping and gas ionization cross-sections (which are characterized by large uncertainties) shows that, in the studied regime (Hylife-II parameters), the accessible window of cross-sections for ballistic transport in the chamber through neutral Flibe gas is eventually small. The temperature evolution for each species and the emittance growth for the entire ion beam was studied for a typical scenario and indicates that a fair amount of the initial electric potential energy carried by the beam as it enters the chamber is converted into temperature and transverse emittance. The high temperature of the ionization-produced electrons prevents a full charge neutralization of the ion beam as it approaches the target, It is shown that focusing a beam array or pre-ionizing a fraction of the background gas may help in reducing the focal spot. (C) 2001 Elsevier Science B,V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Paris 11, Phys Gaz & Plasmas Lab, F-91405 Orsay, France. RP Vay, JL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Bldg 47-112,1 Cyclotron Rd, Berkeley, CA 94720 USA. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 293 EP 298 DI 10.1016/S0168-9002(01)00050-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500046 ER PT J AU Rose, DV Welch, DR Oliver, BV Clark, RE Sharp, WM Friedman, A AF Rose, DV Welch, DR Oliver, BV Clark, RE Sharp, WM Friedman, A TI Ballistic-neutralized chamber transport of intense heavy ion beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE ion beam transport; charge neutralization; current neutralization ID CHARGE AB Two-dimensional particle-in-cell simulations of intense heavy ion beams propagating in an inertial confinement fusion (ICF) reactor chamber are presented. The ballistic-neutralized transport scheme studied uses 4 GeV Pb+1 ion beams injected into a low-density, gas-filled reactor chamber and the beam is ballistically focused onto an ICF target before entering the chamber. Charge and current neutralization of the beam is provided by the low-density background gas. The ballistic-neutralized simulations include stripping of the beam ions as the beam traverses the chamber as well as ionization of the background plasma. In addition, a series of simulations are presented that explore the charge and current neutralization of the ion beam in an evacuated chamber. For this vacuum transport mode, neutralizing electrons are only drawn from sources near the chamber entrance. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Mission Res Corp, Albuquerque, NM 87110 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Rose, DV (reprint author), Mission Res Corp, 5001 Indian Sch Rd, Albuquerque, NM 87110 USA. NR 11 TC 28 Z9 28 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 299 EP 304 DI 10.1016/S0168-9002(01)00187-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500047 ER PT J AU Herrmannsfeldt, WB AF Herrmannsfeldt, WB TI Electron trapping in high-current ion beam pipes SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci AB The space charge voltage depression in a drifting heavy ion beam during the final stages of current pulse compression can be hundreds of kV. For example, a 1 kA beam of ions at beta = v/c = 0.4 would have a beam center-to-edge potential difference of 75 kV. With suitable clearance from beam edge to the beam pipe, this amount is typically increased by a factor of 2-3 by the (1 + 2 In(bla)) term that accounts for the ratio of pipe radius, b, to beam radius, a. Such high voltages, and resulting high electric fields at the pipe wall, will result in electrons being pulled into the beam pipe. These electrons which are emitted from the grounded beam pipe, will pass through the ion beam at high velocity and then turn around without (usually) striking the wall and continue to pass through the beam on repeated oscillations. It is possible to control the longitudinal motion of these trapped electrons by suitably varying the pipe size while considering the beam diameter. A segment of the beam pipe that has a larger diameter will result in a potential well that traps the electrons longitudinally. In a constant current scenario in a uniform pipe, the electrons will drift in the direction of the beam. However, the head and especially the tail of the ion beam will have a dramatic effect on the electrons, causing them to be pulled into the ion beam. These complex processes will continue until the ion beam passes through an optical element such as a beam transport magnet that will effectively block the motion of the electron clouds following the ions. In this paper, we will show examples of how electrons can be trapped and controlled by varying the conditions determining their emission and confinement. Ray tracing simulations using the EGN2 (Herrmannsfeldt, SLAG Electron Trajectory Program, SLAC-331 (1988)) computer code will be used to model the electron trajectories in the presence of a high current heavy ion beam. The self-magnetic field of the ion beam, while not sufficient to affect the ions themselves significantly, has a strong influence on the electron orbits. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Park, CA 94025 USA. RP Herrmannsfeldt, WB (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Park, CA 94025 USA. NR 3 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 305 EP 309 DI 10.1016/S0168-9002(01)00052-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500048 ER PT J AU Efthimion, PC Davidson, RC AF Efthimion, PC Davidson, RC TI Development and application of RF techniques for formation of preionized plasma in the target chamber SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE ion beam; space charge; transport ID DEPOSITION AB Recent heavy ion fusion reactor concepts require multiple beam focusing beyond the space-charge limit. Propagating the beams in dilute plasma potentially can achieve charge neutralization. Here, we apply well known plasma waves to the formation of large-volume uniform plasmas to achieve the required plasmas for charge neutralization. A number of plasma waves will be considered including whistlers, electron cyclotron, and helicon waves. The goal is to produce a large-volume plasma design that will be tested and integrated into near-term ion beam focusing experiments. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Davidson, RC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 310 EP 314 DI 10.1016/S0168-9002(01)00053-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500049 ER PT J AU Grisham, LR AF Grisham, LR TI Possible impact of multi-electron loss events on the average beam charge state in an HIF target chamber and a neutral beam approach SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE multi-electron loss events; heavy-ion driver beam; neutral beam AB Experiments were carried out during the early 1980s to assess the obtainable atomic neutralization of energetic beams of negative ions ranging from lithium to silicon. The experiments found (Grisham et al. Rev. Sci. Instrum. 53 (1982) 281; Princeton Plasma Physics Laboratory Report PPPL-1857, 1981) that, for higher atomic number elements than lithium, it appeared that a substantial fraction of the time more than one electron was being lost in a single collision. This result was inferred from the existence of more than one ionization state in the product beam for even the thinnest line densities at which any electron removal took place. Because of accelerator limitations, these experiments were limited to maximum energies of 7 MeV. However, based upon these results, it is possible that multi-electron loss events may also play a significant role in determining the average ion charge state of the much higher Z and more energetic beams traversing the medium in an heavy ion fusion chamber. This could result in the beam charge state being considerably higher than previously anticipated, and might require designers to consider harder vacuum ballistic focusing approaches, or the development of additional space charge neutralization schemes. This paper discusses the measurements that gave rise for these concerns, as well as a description of further measurements that are proposed to be carried out for atomic numbers and energies per amu which would be closer to those required for heavy ion fusion drivers. With a very low current beam of a massive, but low charge state energetic ion, the charge state distribution emerging from a target gas cell could be measured as a function of line density and medium composition. Varying the line density would allow one to simulate the charge state evolution of the beam as a function of distance into the target chamber. This paper also briefly discusses a possible alternative driver approach using photodetachment-neutralized atomic beams, which could reduce plasma complications far from the target, but which would impose more stringent limitations upon chamber pressure and repetition rate. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Grisham, LR (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 12 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 315 EP 320 DI 10.1016/S0168-9002(01)00054-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500050 ER PT J AU Ponce, DM Niemann, C Yu, SS Leemans, WP Fessenden, TJ Dahlbacka, G Sharp, WM Taushwitz, A AF Ponce, DM Niemann, C Yu, SS Leemans, WP Fessenden, TJ Dahlbacka, G Sharp, WM Taushwitz, A TI Diagnostics of plasma channel for HIF transport SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci AB An alternate technique for heavy ion final transport, from the driver to the target, is by the use of the self-standing Z-pinched plasma channel. Experiments conducted at the Lawrence Berkeley National Laboratory have produced 40 cm long stable plasma channels with a peak discharge current of 55 kA in a 7Torr nitrogen gas fill. These channels are produced using a double pulse discharge scheme, namely, a pre-pulse discharge and a main capacitor bank discharge. It is postulated that the channel's insensitivity to MHD instabilities within the time scale relevant to beam transport is due to the wall effect the pre-pulse discharge creates. This is accomplished by leaving a gas density depression on the channel's axis after hydrodynamic expansion. Since the pre-pulse discharge creates the initial conditions for the main bank Z-pinch, it is critical to understand how to control and engineer the pre-pulse. Here we present some of the results of ongoing experiments geared to understand the underlying physics of the LBNL 2-pinch plasma channel. Schlieren and phase contrast measurements show the radial propagation of a shock wave during the pre-pulse discharge and suggest indirectly the evidence of the on axis gas density depression, that is believed to be <1/10 of the original gas fill pressure. For the main bank Z-pinch, interferometry show an integrated electron line density of 1.6 x 10(17) cm(-2) for a 15 kV discharge on axis. These measurements coupled with Faraday rotation measurements will indicate ultimately the current density distribution in the channel. This data will be used to benchmark simulation codes. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. Gesell Schwerionenforsch GmbH, D-6100 Darmstadt, Germany. RP Ponce, DM (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 10 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 331 EP 338 DI 10.1016/S0168-9002(01)00057-2 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500053 ER PT J AU Niemann, C Ponce, DM Yu, SS Dahlbacka, G Fessenden, TJ Leemans, W Tauschwitz, A Hoffmann, DDH AF Niemann, C Ponce, DM Yu, SS Dahlbacka, G Fessenden, TJ Leemans, W Tauschwitz, A Hoffmann, DDH TI Development of a Faraday polarimeter for magnetic field measurements in a discharge channel for ion beam transport SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE HIF final transport; Faraday polarimetry; magnetic field in Z-pinch AB An alternate technique for heavy ion beam transport inside the chamber of an inertial confinement fusion reactor, is by the use of a self standing 2-pinch discharge. The focusing properties of such a channel are determined by the magnetic field distribution inside the plasma column. In order to allow measuremets of the magnetic field in the LBNL channel experiment, a Faraday polarimeter has been developed, consisting of a high power cw CO2 laser (10.6 mum) and two HgCdTe detectors working on the half-shadow principle. The polarimeter was designed for a sensitivity of 0.01 degrees since the expected peak rotation was only about one degree. Preliminary measurements with reduced sensitivity indicate that the current now is confined within a small cylinder of ca. 1 cm diameter. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. RP Niemann, C (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 8 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 339 EP 342 DI 10.1016/S0168-9002(01)00058-4 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500054 ER PT J AU Davidson, RC Qin, H Lee, WWL Strasburg, S AF Davidson, RC Qin, H Lee, WWL Strasburg, S TI Analytical and nonlinear perturbative simulation studies of the equilibrium and stability properties of intense charged particle beams for heavy ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci ID VLASOV-MAXWELL EQUATIONS; PERIODIC FOCUSING FIELD; DELTA-F SIMULATION; SPACE-CHARGE; 2-STREAM INSTABILITY; DOMINATED BEAMS; HALO FORMATION; STORAGE-RINGS; PROPAGATION; MODEL AB This paper presents an overview of recent analytical and numerical investigations of collective processes in intense ion beams at the Plasma Physics Laboratory based on the nonlinear Vlasov-Maxwell equations. The topics covered include: (a) nonlinear stability theorem for quiescent beam propagation at high space-charge intensities; (b) development and application of Hamiltonian averaging techniques for intense beam propagation through alternating-gradient field configurations; (c) kinetic studies of the electron-ion two-stream instability which occurs when an (unwanted) component of electrons is present in the beam transport line: (d) application of the newly developed three-dimensional, multispecies, nonlinear perturbative particle simulation scheme, called the Beam Equilibrium, Stability and Transport (BEST) code, to investigate the linear and nonlinear dynamics of intense beam propagation, including the electron-ion two-stream instability; and (e) investigations of the role of collective mode excitations in the expulsion of particles from the beam core and the production of halo particles, Finally, the linear growth properties of instabilities driven by pressure anisotropy are investigated within the framework of a macroscopic warm-fluid model. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Davidson, RC (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 59 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 358 EP 368 DI 10.1016/S0168-9002(01)00061-4 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500057 ER PT J AU Seidl, PA Bieniosek, FM Celata, CM Faltens, A Kwan, JW MacLaren, SA Ponce, D Shuman, D Yu, S Ahle, L Lund, S Molvik, A Sangster, TC AF Seidl, PA Bieniosek, FM Celata, CM Faltens, A Kwan, JW MacLaren, SA Ponce, D Shuman, D Yu, S Ahle, L Lund, S Molvik, A Sangster, TC TI Experiments at the Virtual National Laboratory for Heavy Ion Fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE beam dynamics; multistage accelerated heavy-ion beams; space-charge-dominated beams AB An overview of experiments is presented, in which the physical dimensions, transverse emittance and generalized perveance are scaled to explore driver-relevant beam dynamics. Among these are beam merging, focusing to a small spot, and bending and recirculating beams. The Virtual National Laboratory for Heavy Ion Fusion (VNL) is also developing two driver-scale beam experiments involving heavy-ion beams with I-beam similar to 1A to provide guidance for the design of an Integrated Research Experiment (IRE) for driver system studies within the next 5 years. Multiple-beam sources and injectors are being designed and a one-beam module will be built and tested. Another experimental effort will be the transport of such a beam through similar to 100 magnetic quadrupoles. The experiment will determine transport limits at high aperture fill factors, beam halo formation, and the influence on beam properties of secondary electron production and neutral atom desorption from the vacuum pipe wall. Research into driver technology will be briefly presented, including the development of ferromagnetic core materials, induction core pulsers, multiple-beam quadrupole arrays and plasma channel formation experiments for pinched transport in reactor chambers. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Seidl, PA (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 20 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 369 EP 378 DI 10.1016/S0168-9002(01)00062-6 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500058 ER PT J AU Kwan, JW Ahle, L Beck, DN Bieniosek, FM Faltens, A Grote, DP Halaxa, E Henestroza, E Herrmannsfeldt, WB Karpenko, V AF Kwan, JW Ahle, L Beck, DN Bieniosek, FM Faltens, A Grote, DP Halaxa, E Henestroza, E Herrmannsfeldt, WB Karpenko, V TI Ion sources and injectors for HIF induction linacs SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE HIF; ion source; injector; matching section; LEBT; ESQ ID FUSION; ACCELERATOR AB Ion source and injector development is one of the major parts of the HIF program in the USA. Our challenge is to design a cost effective driver-scale injector and to build a multiple beam module within the next couple of years. In this paper, several current-voltage scaling laws are summarized for guiding the injector design. Following the traditional way of building injectors for HIF induction linac, we have produced a preliminary design for a multiple beam driver-scale injector. We also developed an alternate option for a high current density injector that is much smaller in size. One of the changes following this new option is the possibility of using other kinds of ion sources than the surface ionization sources. So far, we are still looking for an ideal ion source candidate that can readily meet all the essential requirements. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Kwan, JW (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 19 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 379 EP 387 DI 10.1016/S0168-9002(01)00063-8 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500059 ER PT J AU Mainardi, E Premuda, F Lee, E AF Mainardi, E Premuda, F Lee, E TI Neutronic calculations for a final focus system SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy-ion inertial fusion energy; heavy-ion final focus systems; models for Monte Carlo neutronic calculations; energy deposited by neutrons and photons AB For heavy-ion fusion and for "liquid-protected" reactor designs such as HYLIFE-II (Moir ct al., Fusion Technol. 25 (1994); HYLIFE-II-Progress Report, UCID-21816, 4-82-100), a mixture of molten salts made of F-10, Li-6, Li-7, Be-9 called flibe allows highly compact target chambers. Smaller chambers will have lower costs and will allow the final-focus magnets to be closer to the target with decreased size of the focus spot and of the driver, as well as drastically reduced costs of IFE electricity. Consequently the superconducting coils of the magnets closer to the chamber will suffer higher radiation damage though they can stand only a certain amount of energy deposited before quenching. The scope of our calculations is essentially the total energy deposited on the magnetic lens system by fusion neutrons and induced gamma -rays. Such a study is important for the design of the final focus system itself from the neutronic point of view and indicates some guidelines for a design with six magnets in the beam line. The entire chamber consists of 192 beam lines to provide access of heavy ions that will implode the pellet. A 3-D transport calculation of the radiation penetrating through ducts that takes into account the complexity of the system, requires Monte Carlo methods. The development of efficient and precise models for geometric representation and nuclear analysis is necessary. The parameters are optimized thanks to an accurate analysis of six geometrical models that are developed starting from the simplest. Different configurations are examined employing TART 98 (D.E. Cullen, Lawrence Livermore National Laboratory, UCRL-ID-126455, Rev. 1, November, 1997) and MCNP 4B (Briesmeister (Ed.), Version 4B, La-12625-m, March 1997, Los Alamos National Laboratory): two Monte Carlo codes for neutrons and photons. The quantities analyzed include: energy deposited by neutrons and gamma photons, values of the total fluence integrated on the whole energy range, neutron fluence spectrum, total path length of neutrons in energy, neutron mean free path versus energy. The results of the two codes turned out to be in good agreement with each other for different zones and configurations of the system. The source restriction technique gives reliable results as it is proved comparing re-normalized results with results obtained with a 4 pi source and with sources emitting with different set of solid angles. For this reason, this technique is used in all the six models avoiding other variance reduction techniques. Finally, solutions are suggested for optimizing the system from the neutronic point of view, with respect to both relative position of the magnets and choice of shielding materials. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Rome La Sapienza, I-00186 Rome, Italy. Univ Bologna, Bologna, Italy. LBNL, Berkeley, CA USA. RP Mainardi, E (reprint author), Univ Rome La Sapienza, Cso Vittorio Emanuele 11, I-00186 Rome, Italy. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 410 EP 415 DI 10.1016/S0168-9002(01)00077-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500064 ER PT J AU Reyes, S Latkowski, JF del Rio, JG Sanz, J AF Reyes, S Latkowski, JF del Rio, JG Sanz, J TI Accident consequences analysis of the HYLIFE-II inertial fusion energy power plant design SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE IFE safety analysis; accident consequences; off-site doses AB Previous studies of the safety and environmental aspects of the HYLIFE-II inertial fusion energy power plant design have used simplistic assumptions in order to estimate radioactivity releases under accident conditions. Conservations associated with these traditional analyses can mask the actual behavior of the plant and have revealed the need for more accurate modeling and analysis of accident conditions and radioactivity mobilization mechanisms. In the present work, computer codes traditionally used for magnetic fusion safety analyses (CHEMCON, MELCOR) have been applied for simulating accident conditions in a simple model of the HYLIFE-II IFE design. Here we consider a severe loss of coolant accident (LOCA) in conjunction with simultaneous failures of the beam tubes (providing a pathway for radioactivity release from the vacuum vessel towards the confinement) and of the two barriers surrounding the chamber (inner shielding and confinement building itself). Even though confinement failure would be a very unlikely event it would be needed in order to produce significant off-site doses. CHEMCON code allows calculation of long-term temperature transients in fusion reactor first wall, blanket, and shield structures resulting from decay heating. MELCOR is used to simulate a wide range of physical phenomena including thermal-hydraulics, heat transfer, aerosol physics and fusion product transport and release. The results of these calculations show that the estimated off-site dose is less than 5 mSv (0.5 rem), which is well below the value of 10 mSv (1 rem) given by the DOE Fusion Safety Standards for protection of the public from exposure to radiation during off-normal conditions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Nacl Educ Distancia, Dept Ingn Energet, Escuela Tecn Super Ingenieros Ind, E-28040 Madrid, Spain. RP Reyes, S (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-446, Livermore, CA 94550 USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 416 EP 421 DI 10.1016/S0168-9002(01)00078-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500065 ER PT J AU Latkowski, JF Sanz, J Reyes, S del Rio, JG AF Latkowski, JF Sanz, J Reyes, S del Rio, JG TI Selection of IFE target materials from a safety and environmental perspective SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE inertial fusion energy; safety and environment; target design ID INERTIAL FUSION ENERGY; HYLIFE-II AB Target materials for inertial fusion energy (IFE) power plant designs might be selected for a wide variety of reasons including wall absorption of driver energy, material opacity, cost and ease of fabrication. While each of these issues are of great importance, target materials should also be selected based upon their safety and environmental (S&E) characteristics. The present work focuses on the recycling, waste management and accident dose characteristics of potential target materials. If target materials are recycled so that the quantity is small, isotopic separation may be economically viable. Therefore, calculations have been completed for all stable isotopes for all elements from lithium to polonium. The results of these calculations are used to identify specific isotopes and elements that are most likely to be offensive as well as those most likely to be acceptable in terms of their S&E characteristics. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Nacl Educ Distancia, Dept Ingn Energet, Escuela Tecn Super Ingenieros Ind, E-28040 Madrid, Spain. Inst Fus Nucl, Madrid, Spain. RP Latkowski, JF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mailstop L-446, Livermore, CA 94550 USA. NR 11 TC 10 Z9 10 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 422 EP 427 DI 10.1016/S0168-9002(01)00079-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500066 ER PT J AU Meier, WR Barnard, JJ Bangerter, RO AF Meier, WR Barnard, JJ Bangerter, RO TI A 3.3 MJ, Rb+1 driver design based on an integrated systems analysis SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE fusion; heavy ion; inertial fusion; driver; accelerator; systems model ID HEAVY-ION; MODEL AB A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy. The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Meier, WR (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-446, Livermore, CA 94551 USA. NR 12 TC 15 Z9 15 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 433 EP 439 DI 10.1016/S0168-9002(01)00101-2 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500068 ER PT J AU Molvik, AW Faltens, A AF Molvik, AW Faltens, A TI Induction accelerator efficiency at 5 Hz SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE acceleration; cores; driver ID INERTIAL CONFINEMENT FUSION; HEAVY-ION; TARGET AB We stimulate fusion power plant driver efficiency by pulsing small induction cores at 5Hz (a typical projected power plant repetition rate), with a resistive load in the secondary winding that is scaled to simulate the beam loading for induction acceleration. Starting from a power plant driver design that is based on other constraints, we obtain the core mass and acceleration efficiency for several energy ranges of the driver accelerator and for three magnetic alloys. The resistor in the secondary is chosen to give the same acceleration efficiency, the ratio of beam energy gain to energy input to the core module (core plus acceleration gap), as was computed for the driver. The pulser consists of a capacitor switched by FETs, Field Effect Transistors, which are gated on for the desired pulse duration. The energy to the resistor is evaluated during the portion of the pulse that is adequately flat. We present data over a range of 0.6-5 mus pulse lengths. With 1 mus pulses, the acceleration efficiency at 5 Hz is measured to be 75%, 52%, and 32% for thin-tape-wound cores of nanocrystalline, amorphous, and 3% silicon steel materials respectively, including only core losses. The efficiency increases for shorter pulse durations. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. LBNL, Berkeley, CA 94720 USA. RP Molvik, AW (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-645, Livermore, CA 94550 USA. NR 10 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 445 EP 451 DI 10.1016/S0168-9002(01)00103-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500070 ER PT J AU Burkhart, C Ahle, L Bayless, JR Hanks, R Kelm, E AF Burkhart, C Ahle, L Bayless, JR Hanks, R Kelm, E TI MIA modulator for the LLNL "small recirculator" experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE pulse modulator; inertial fusion; heavy ion fusion AB The Miniature Inductive Adder (MIA) is an innovative topology for high voltage pulse generator applications. A MIA modulator has been developed for the Lawrence Livermore National Laboratory (LLNL) ''small recirculator" experiment. In this paper we examine the MIA fundamentals and design issues relevant to this application. Modulator performance data with a test load and with the recirculator induction cell load are presented. Ongoing work to improve the MIA performance and additional applications to which this modulator topology has been applied are discussed, (C) 2001 Elsevier Science B.V. All rights reserved. C1 First Point Sci Inc, Agoura Hills, CA 91301 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Burkhart, C (reprint author), First Point Sci Inc, 5330 Derry Ave,Suite J, Agoura Hills, CA 91301 USA. NR 6 TC 6 Z9 6 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 452 EP 456 DI 10.1016/S0168-9002(01)00104-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500071 ER PT J AU Batygin, YK AF Batygin, YK TI Self-consistent limited beam current in RF field SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE space charge; self-consistent distribution; RF field AB An analytical solution for a self-consistent particle equilibrium distribution in an RF field with uniform transverse focusing is applied to the problem of the high brightness beam current limit. The distribution function in phase space is determined as a stationary function of the energy integral. Particle distribution of the bright beam always tends to such a share that the space charge beam potential is opposite to the external potential regardless of the applied field. Analytical expressions for r - z equilibrium beam profile and beam current limit in an RF field are obtained. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Amer Sci & Engn Inc, High Energy Syst Div, Santa Clara, CA 95054 USA. RP Batygin, YK (reprint author), Stanford Linear Accelerator Ctr, POB 4349,MS66, Stanford, CA 94309 USA. NR 3 TC 0 Z9 0 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 457 EP 460 DI 10.1016/S0168-9002(01)00107-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500072 ER PT J AU Lee, WW Qin, H Davidson, RC AF Lee, WW Qin, H Davidson, RC TI Nonlinear perturbative electromagnetic (Darwin) particle simulation of high intensity beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE particle simulation; instability; high intensity beam ID ION-BEAM; PLASMAS AB A multi-species perturbative nonlinear (deltaf) electromagnetic particle simulation scheme has been developed for studying the propagation of intense charged particle beams in high-intensity accelerators and transport systems. The scheme is based on the Darwin approximation of Ampere's law, in which the transverse inductive electric field is neglected, resulting in the elimination of high-frequency transverse electromagnetic effects and, consequently, the associated numerical restrictions from the simulation. However, as noted previously, the presence of the time derivative of the vector potential in the equations of motion for the Darwin model can cause numerical instability. To circumvent this difficulty, we have adopted an approach by replacing the mechanical momentum, p(z) in the direction of beam propagation, by the canonical momentum, P-z = p(z) + qA(z)/c, as the phase-space variable. The resulting Ampere's law is then modified by the presence of an additional shielding term associated with the skin depth of the species. In order to minimize the numerical noise and to easily access both linear and nonlinear regimes for the physics of interest, we have also adopted the deltaf formalism for the Darwin model. The absence of unwanted high-frequency waves also enables us to use the adiabatic particle pushing scheme to compensate for the mass-ratio disparities for the various species of charge. The scheme is ideal for studying two-stream and filamentation instabilities, which may cause deterioration of the beam quality in the heavy ion fusion driver and fusion chamber. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Lee, WW (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 465 EP 469 DI 10.1016/S0168-9002(01)00109-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500074 ER PT J AU Sonnendrucker, E Barnard, JJ Friedman, A Grote, DP Lund, SM AF Sonnendrucker, E Barnard, JJ Friedman, A Grote, DP Lund, SM TI Simulation of heavy ion beams with a semi-Lagrangian Vlasov solver SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE accelerator; fusion; heavy-ion; halo; simulation; plasma; beam ID EQUATION; SPACE; CODE AB We introduce the semi-Lagrangian Vlasov method, which computes the distribution function of the particles on a grid in phase space, to beam propagation in a uniform focusing channel. With this new tool, we study halo formation in a mismatched thermal beam, and the evolution of an initial semi-Gaussian beam. For the latter problem comparisons are made with the Particle-In-Cell code WARP. (C) 2001 Elsevier Science B.V, All rights reserved. C1 Univ Strasbourg 1, IRMA, CNRS, F-67084 Strasbourg, France. IECN, Nancy, France. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Sonnendrucker, E (reprint author), Univ Strasbourg 1, IRMA, CNRS, 7 Rue Rene Descartes, F-67084 Strasbourg, France. NR 9 TC 16 Z9 16 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 470 EP 476 DI 10.1016/S0168-9002(01)00186-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500075 ER PT J AU Qin, H Davidson, RC Lee, WW Kolesnikov, R AF Qin, H Davidson, RC Lee, WW Kolesnikov, R TI 3D multispecies nonlinear perturbative particle simulations of collective processes in intense particle beams for heavy ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE ion beam; space charge; stability; perturbative particle simulation; collective modes ID PERIODIC FOCUSING FIELD; DELTA-F SIMULATION; 2-STREAM INSTABILITY; STABILITY PROPERTIES; PROPAGATION; EQUATIONS; THEOREM; PSR AB Collective processes in intense charged particle beams for heavy ion fusion are studied using a 3D multispecies nonlinear perturbative particle simulation method, which solves self-consistently the nonlinear Vlasov-Maxwell equations. The newly-developed Beam Equilibrium Stability and Transport code is used to simulate the nonlinear stability properties of intense beam propagation, surface and body eigenmodes in a high-intensity beam, and the electron-ion two-stream instability, which occurs when a small population of (unwanted) electrons is present in the system. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Qin, H (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 23 TC 16 Z9 16 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 477 EP 483 DI 10.1016/S0168-9002(01)00713-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500076 ER PT J AU Davidson, RC Qin, H Kaganovich, I Lee, WW AF Davidson, RC Qin, H Kaganovich, I Lee, WW TI Stabilizing influence of axial momentum spread on the two-stream instability in intense heavy ion beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE ion beam; space charge; stability; transport ID CHARGED-PARTICLE BEAMS; 2-STREAM INSTABILITY; STORAGE-RINGS; THEOREM AB This paper makes use of the Vlasov-Maxwell equations to describe the electron-ion two-stream instability driven by the directed axial motion of a high-intensity ion beam propagating through a stationary population of (unwanted) background electrons in the acceleration region or beam transport lines. The ion beam is treated as continuous in the z-direction, and the electrons are electrostatically confined in the transverse direction by the space-charge potential produced by the excess ion charge. The analysis is carried out for arbitrary beam intensity, consistent with transverse confinement of the beam particles, and arbitrary fractional charge neutralization by the background electrons. For the case of overlapping step-function ion and electron density profiles, corresponding to Kapchinskij-Vladimirskij (KV) electron and ion distributions ill the transverse direction, detailed stability properties are calculated including parallel kinetic effects over a wide range of system parameters for dipole perturbations with azimuthal mode number l = 1. The instability growth rate is found to increase with increasing beam intensity, increasing fractional charge neutralization, and decreasing proximity of the conducting wall. For space-charge-dominated beams, it is shown that Landau damping associated with a modest axial momentum spread of the beam ions and background electrons has a strong stabilizing influence on the two-stream instability. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Davidson, RC (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 25 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 493 EP 501 DI 10.1016/S0168-9002(01)00117-6 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500078 ER PT J AU Davidson, RC Efthimion, PC Majeski, R Qin, H Shvets, G AF Davidson, RC Efthimion, PC Majeski, R Qin, H Shvets, G TI Paul trap experiment to simulate intense nonneutral beam propagation through a periodic focusing field configuration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE ion beam; space charge; stability; transport ID ION AB This paper describes the design concept for a compact Paul trap experimental configuration that fully simulates the collective processes and nonlinear transverse dynamics of an intense charged particle beam that propagates over large distances through a periodic quadrupole magnetic field. To summarize, a long nonneutral plasma column (L much greater than r(p)) is confined axially by applied DC voltages (V) over cap = const. on end cylinders at z = +/-L, and transverse confinement is provided by segmented cylindrical electrodes (at radius r(w)) with applied oscillatory voltages +/-V-0(t) over 90 degrees segments. Because the transverse focusing force is similar in waveform to that produced by a discrete set of periodic quadrupole magnets in a frame moving with the beam, the: Paul trap configuration offers the possibility of simulating intense beam propagation in a compact experimental facility. The nominal operating parameters in the experimental design are: barium ions (A = 137); plasma column length 2L = 2 m; wall radius r(w) = 10 cm; plasma radius r(p) = 1 cm; maximum wall voltage (V) over cap (0) = 400 V; end electrode voltage up to (V) over cap = 500 V; and voltage oscillation frequency f(0) = 1/T = 60 kHz. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Davidson, RC (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 27 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 502 EP 511 DI 10.1016/S0168-9002(01)00118-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500079 ER PT J AU Chen, CP Pakter, R Davidson, RC AF Chen, CP Pakter, R Davidson, RC TI Ideal matching of heavy ion beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ion fusion; intense ion beam; beam control; beam matching ID INTENSE AB A novel technique is developed, and demonstrated via simulations, which allows ideal matching of an ultrahigh-brightness heavy ion beam in a linear focusing channel with general magnetic focusing field profile. Unlike the conventional rms matching used in accelerator design, this technique is based on a new class of corkscrewing elliptic beam equilibria in a linear focusing channel consisting of uniform solenoidal fields, periodic solenoidal fields, and/or alternating-gradient quadrupole magnetic focusing fields in an arbitrary arrangement including field tapering. As an illustration of the effectiveness of this technique, a perfect matching of an ultrahigh-brightness heavy ion beam from an axisymmetric particle source into alternating-gradient quadrupole focusing channel is achieved without beam hollowing and beam halo formation. Discussions are made of how to implement such a perfect beam matching to avoid beam hollowing observed in the LBNL 2-MV Heavy Ion Injector Experiment. (C) 2001 Published by Elsevier Science B.V. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Chen, CP (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 11 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 518 EP 523 DI 10.1016/S0168-9002(01)00134-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500081 ER PT J AU Strasburg, S Davidson, RC AF Strasburg, S Davidson, RC TI Warm-fluid collective mode excitations in intense charged particle beams with nonlinear equilibrium self-fields: test particle simulations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci ID HALO FORMATION; FOCUSING CHANNEL; STABILITY AB This paper examines analytically and numerically the effects of self-consistent collective oscillations, excited in a charged particle beam with nonlinear equilibrium self-fields, on the motion of a test particle in the beam core and halo region. The infinite set of linearized eigenmodes of a waterbag equilibrium beam have been found in previous work (Sean Strasburg and R.C. Davidson, Phys. Lett. A 269 (2000) 40) using the smooth-focusing approximation and assuming axisymmetric perturbations. These eigenmodes, in combination with the nonlinear equilibrium charge-density and applied fields, cause areas of phase space to break into islands and, in the case of sufficiently large-amplitude perturbations and intense beams, to become stochastic. Nonlinear shifts in the transverse oscillation frequency are determined analytically. Using this frequency shift and the eigenmode frequencies, the location of resonant islands as a function of particle orbit amplitude, beam intensity, and mode number is predicted analytically and confirmed numerically. The dependence of island width on perturbative mode amplitude and beam intensity is explored numerically. Using the Poincare technique, the particle phase space in the beam core and the beam halo region is investigated by numerically integrating the test particle equations over long periods. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Strasburg, S (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 18 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 524 EP 532 DI 10.1016/S0168-9002(01)00136-X PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500082 ER PT J AU Celata, CM Bieniosek, FM Faltens, A AF Celata, CM Bieniosek, FM Faltens, A TI Transverse splitting of intense heavy-ion beams in the IRE and in an HIF driver SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy-ion inertial fusion; ion beam dynamics AB In the planned heavy-ion Integrated Research Experiments (IRE), final beam kinetic energy will be low compared to a driver, giving perveance significantly larger than the driver, and making final focus to a small spot comparatively much more difficult. Splitting of beams ahead of the final focus system would allow economical transport of large beams through the IRE accelerator, while maintaining focusability. Since splitting decouples the number of beams transported in the accelerator from what is required at final focus, it could also lower the cost of a driver. In this paper we consider the effects on beam quality of transverse beam splitting. The system of most interest consists of one or more consecutive magnetic septa. PIC simulations of this case are discussed, along with engineering considerations. (C) 2001 Published by Elsevier Science B.V. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Celata, CM (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 47-112, Berkeley, CA 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 533 EP 538 DI 10.1016/S0168-9002(01)00137-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500083 ER PT J AU Ahle, L Sangster, TC Barnard, J Burkhart, C Craig, G Debeling, A Friedman, A Fritz, W Grote, DP Halaxa, E Hanks, RL Hernandez, M Kirbie, HC Logan, BG Lund, SM Mant, G Molvik, W Sharp, WM Williams, C AF Ahle, L Sangster, TC Barnard, J Burkhart, C Craig, G Debeling, A Friedman, A Fritz, W Grote, DP Halaxa, E Hanks, RL Hernandez, M Kirbie, HC Logan, BG Lund, SM Mant, G Molvik, W Sharp, WM Williams, C TI Results from the recirculator project at LLNL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE circular particle accelerator; space charge; induction; beam dynamics ID HEAVY-ION BEAMS; INERTIAL FUSION; TARGET; DESIGN AB The Heavy Ion Fusion Group at Lawrence Livermore National Laboratory has for several years been developing the world's first circular ion induction accelerator designed for space-charge-dominated beams. Experiments on one quarter of the ring have been completed. The accelerator extended 10 half-lattice periods (HLP) with induction cores for acceleration placed on every other HLP. A network of Capacitive Beam Probes (C-probes) was also enabled for beam position monitoring throughout the bend section. These C-probes have been instrumental in steering experiments, implementation of the acceleration stages and the dipole pulser, and the first attempts at coordinated bending and acceleration. Data from these experiments and emittance measurements will be presented. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Beethel Nevada Corp, Las Vegas, NV 89030 USA. First Point Sci Inc, Agoura Hills, CA 91301 USA. RP Ahle, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-645,POB 808, Livermore, CA 94551 USA. NR 9 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 557 EP 562 DI 10.1016/S0168-9002(01)00141-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500087 ER PT J AU Grote, DP Friedman, A Craig, GD Sharp, WM Haber, I AF Grote, DP Friedman, A Craig, GD Sharp, WM Haber, I TI Progress toward source-to-target simulation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE accelerator; fusion; heavy-ion; induction; simulation; particle-in-cell; plasma; beam AB Source-to-target simulation of an accelerator provides a thorough check on the consistency of the design as well as a detailed understanding of the beam behavior. Issues such as envelope mismatch and emittance growth can be examined in a self-consistent manner, including the details of accelerator transitions, long-term transport, and longitudinal compression. The large range in scales, from centimeter-scale transverse beam size and applied field scale-length, to meter-scale beam length, to kilometer-scale accelerator length, poses a significant computational challenge. The ever-increasing computational power that is becoming available through massively parallel computers is making such simulation realizable. This paper discusses the progress toward source-to-target simulation using the WARP particle-in-cell code. Representative examples are shown, including 3-D, long-term transport simulations of Integrated Research Experiment (IRE) scale accelerators, (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Grote, DP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 10 TC 20 Z9 20 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 563 EP 568 DI 10.1016/S0168-9002(01)00142-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500088 ER PT J AU Anders, A Kwan, JW AF Anders, A Kwan, JW TI Arc-discharge ion sources for heavy ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy Ion Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE vacuum arc ion source; gas arc ion source; heavy ion fusion ID CHARGE-STATE DISTRIBUTIONS; MAGNETIC-FIELD; TEMPORAL DEVELOPMENT; VACUUM; BEAM; PLASMA AB A miniature multiple beamlet approach to an injector system was recently proposed in order to reduce the size, cost, and power requirements of the injector. The beamlets of very high current density are needed to meet the brightness requirement. Besides vacuum are ion sources, cold-cathode gas ion sources are candidates for this application. Vacuum-arc metal ion sources and vacuum-are-like gas ion sources are discussed. Experiments are presented that focus on the short-pulse plasma composition and ion charge state distribution. Mg and Sr have been identified as the most promising metals leading to mono-species beams when 20 mus are pulses are used. It is shown that the efficient production of gas ions requires the presence of a magnetic field. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, MS 53,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM aanders@lbl.gov RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 31 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 569 EP 575 DI 10.1016/S0168-9002(01)00143-7 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500089 ER PT J AU Qi, NS Schein, J Prasad, RR Krishnan, M Anders, A Kwan, J Brown, I AF Qi, NS Schein, J Prasad, RR Krishnan, M Anders, A Kwan, J Brown, I TI Recent advances in high current vacuum arc ion sources for heavy ion fusion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ions; vacuum arc; ion source; plasma initiation AB dFor a heavy ion fusion induction linac driver, a source of heavy ions with charge states I + -3 +, approximate to 0.5A current beams, approximate to 20 mus pulse widths and similar to 10 Hz repetition rates is required. Thermionic sources have been the workhorse for the Heavy Ion Fusion (HIF) program to date, but suffer from heating problems for large areas and contamination. They are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1 +. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum are ion source. The vacuum are ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states in short and long pulse bursts and high beam current density. Under a Phase-I STTR from DOE, the feasibility of the vacuum are ion source for the HIF applications was investigated. We have modified an existing vacuum are ion source at LBNL to produce a gadolinium (A approximate to 158) ion beam with > 0.5A beam current, 120 keV beam energy, approximate to 6 cm diameter extraction aperture and approximate to 20 mus pulse width. The average beam current density at the extraction grids was approximate to 17 mA/cm(2). We have measured that > 85% Gd ions were in the 3 + charge state, the beam current fluctuation level (rms) was approximate to 3%, pulse-to-pulse variation of the beam (rms) was about 3%, the uniformity of the beam density over its 6 cm diameter was greater than or equal to 98% and the ion longitudinal energy spread was less than or equal to1%. Additional measurements were made to improve charge state purity by using other materials and employing an axial magnetic field close to the cathode. Yttrium (cl approximate to 89, lead (A approximate to 207), and B(Ai approximate to 137) were tested at similar current parameters with Ba delivering nearly a purl charge state with >95% being in 2 + state. The results of the experiments indicate that the vacuum are ion source is a good candidate for HIF applications. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Alameda Appl Sci Corp, San Leandro, CA 94577 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Prasad, RR (reprint author), Alameda Appl Sci Corp, Suite 230,2235 Polvorosa Ave, San Leandro, CA 94577 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 7 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 576 EP 581 DI 10.1016/S0168-9002(01)00144-9 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500090 ER PT J AU Bieniosek, FM Kwan, JW Henestroza, E Kim, C AF Bieniosek, FM Kwan, JW Henestroza, E Kim, C TI Development of the 2-MV Injector for HIF SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ion fusion; injector; pulsed power AB The 2-MV Injector consists of a 17-cm-diameter surface ionization source, an extraction diode, and an electrostatic quadrupole (ESQ) accelerator, with maximum current of 0.8 A of potassium beam at 2 MeV. Previous performance of the Injector produced a beam with adequate current and emittance but with a hollow profile at the end of the ESQ section. We have examined the profile of the beam as it leaves the diode. The measured nonuniform beam density distribution qualitatively agrees with EGUN simulation. Implications for emittance growth in the post acceleration and transport phase will be investigated. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Bieniosek, FM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, MS 47-112,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 12 TC 9 Z9 9 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 592 EP 598 DI 10.1016/S0168-9002(01)00147-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500093 ER PT J AU Ahle, L Grote, DP Halaxa, E Henestroza, E Kwan, JW Maclaren, SA AF Ahle, L Grote, DP Halaxa, E Henestroza, E Kwan, JW Maclaren, SA TI The adiabatic matching section solution for the source injector SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE beam injection; beam transport; heavy ion fusion AB Typical designs for a Heavy Ion Fusion Power Plant require the source injector to deliver 100 beams, packed into an array with a spacing of 7 cm. When designing source injectors using a single large aperture source for each beam, the emitter surfaces are packed into an array with a spacing of 30 cm. Thus, the matching section of the source injector must not only prepare the beam for transport in a FODO lattice, but also funnel the beams together. This can be accomplished by an ESQ matching section in which each beam travels on average at a slight angle to the axis of the quadrupoles and uses the focussing effect of the FODO lattice to maintain the angle. At the end of the matching section, doublet steering is used to bring the beams parallel to each other for injection into the main accelerator. A specific solution of this type for an 84-beam source injector is presented. (C) 2001 Elsevier Science B,V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ahle, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-645, Livermore, CA 94551 USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 599 EP 604 DI 10.1016/S0168-9002(01)00148-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500094 ER PT J AU Sangster, TC Ahle, LE Halaxa, EF Karpenko, VP Oldaker, ME Mitchell, JW Beck, DN Bieniosek, FM Henestroza, E Kwan, JW AF Sangster, TC Ahle, LE Halaxa, EF Karpenko, VP Oldaker, ME Mitchell, JW Beck, DN Bieniosek, FM Henestroza, E Kwan, JW TI A new 500-kV ion source test stand for HIF SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE heavy ion sources; heavy ion fusion; pulsed power; high voltage ID BEAMS AB One of the most challenging aspects of ion beam-driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-mus, a pulse width of at least 20-mus, a flattop ripple of less that 0.1% and a repetition rate of at least 5-Hz. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 10(8) pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source, Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arcs. This paper will describe the test stand design specifications as well as the details of the various subsystems and components. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Sangster, TC (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-481, Livermore, CA 94550 USA. NR 3 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 610 EP 615 DI 10.1016/S0168-9002(01)00151-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500096 ER PT J AU Barnard, JJ Ahle, LE Bangerter, RO Bieniosek, FM Celata, CM Faltens, A Friedman, A Grote, DP Haber, I Henestroza, E de Hoon, MJL Karpenko, VP Kishek, RA Kwan, JW Lee, EP Logan, BG Lund, SM Meier, WR Molvik, AW Sangster, TC Seidl, PA Sharp, WM AF Barnard, JJ Ahle, LE Bangerter, RO Bieniosek, FM Celata, CM Faltens, A Friedman, A Grote, DP Haber, I Henestroza, E de Hoon, MJL Karpenko, VP Kishek, RA Kwan, JW Lee, EP Logan, BG Lund, SM Meier, WR Molvik, AW Sangster, TC Seidl, PA Sharp, WM TI Planning for an integrated research experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE fusion; heavy ion; inertial fusion; driver; accelerator; systems model AB We describe the goals and research program leading to the Heavy Ion Integrated Research Experiment (IRE). We review the basic constraints which lead to a design and give examples of parameters and capabilities of an IRE. We also show design tradeoffs generated by the systems code IBEAM. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Maryland, College Pk, MD 20742 USA. RP Barnard, JJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-645, Livermore, CA 94551 USA. RI de Hoon, Michiel/A-6443-2013; de Hoon, Michiel/N-8006-2015 NR 17 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 2001 VL 464 IS 1-3 BP 621 EP 628 DI 10.1016/S0168-9002(01)00153-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500098 ER PT J AU Friedman, A Grote, DP Lee, EP Sonnendrucker, E AF Friedman, A Grote, DP Lee, EP Sonnendrucker, E TI Beam simulations for IRE and driver - status and strategy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th International Symposium on Heavy IOn Inertial Fusion CY MAR 13-17, 2000 CL SAN DIEGO, CALIFORNIA SP Lawrence Berkeley Natl Lab, Fusion Power Associates, US DOE, Off Fus Energy Sci DE accelerator; fusion; heavy-ion; induction; simulation; particle-in-cell; plasma; beam AB The methods and codes employed in the US Heavy Ion Fusion program to simulate the beams in an Integrated Research Experiments (IRE) facility and a Fusion driver are presented in overview. A new family of models incorporating accelerating module impedance, multi-beam and self-magnetic effects is described, and initial WARP3D particle simulations of beams using these models are presented. Finally, plans for streamlining the machine-design simulation sequence, and for simulating beam dynamics from the source to the target in a consistent and comprehensive manner, are described. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Heavy Ion Fus Virtual Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. IRMA Strasbourg, CNRS, Strasbourg, France. IECN, Nancy, France. RP Friedman, A (reprint author), Heavy Ion Fus Virtual Natl Lab, 1 Cyclotron Rd,Mail Stop 47-112, Berkeley, CA 94720 USA. NR 19 TC 17 Z9 17 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 MAY 21 PY 2001 VL 464 IS 1-3 BP 653 EP 661 DI 10.1016/S0168-9002(01)00157-7 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 444XC UT WOS:000169424500102 ER PT J AU Koehler, PE Gledenov, YM Andrzejewski, J Guber, KH Raman, S Rauscher, T AF Koehler, PE Gledenov, YM Andrzejewski, J Guber, KH Raman, S Rauscher, T TI Improving explosive nucleosynthesis models via (n,alpha) measurements SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID P-PROCESS; II SUPERNOVAE AB In explosive environments, (gamma,alpha) reactions constitute some of the most important links in the nucleosynthesis chains. However. it is very unlikely that the rates for most of these reactions will be determined by direct experiments and these rates also are currently very poorly constrained by theory. In this paper, we demonstrate that low-energy (n,alpha) measurements constitute an important new global technique for considerably reducing the uncertainties in (gamma,alpha) reaction rates. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Lodz, Dept Nucl Phys & Radiat Safety, PL-90236 Lodz, Poland. Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. RP Koehler, PE (reprint author), Oak Ridge Natl Lab, Div Phys, MS 6354, Oak Ridge, TN 37831 USA. RI Rauscher, Thomas/D-2086-2009 OI Rauscher, Thomas/0000-0002-1266-0642 NR 15 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 86C EP 89C PG 4 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300018 ER PT J AU Starrfield, S Iliadis, C Truran, JW Wiescher, M Sparks, WM AF Starrfield, S Iliadis, C Truran, JW Wiescher, M Sparks, WM TI Nuclear reaction rates and the nova outburst SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID NUCLEOSYNTHESIS; EXPLOSIONS; OPACITIES; AL-26 AB Classical novae participate in the cycle of Galactic chemical evolution in which grains and metal enriched gas in their ejecta, supplementing those of supernovae, AGE stars, and WR stars, are a source of heavy elements for the ISM. Once in the diffuse gas, this material is cycled through molecular clouds before being incorporated into young stars and planetary systems during star formation. Infrared observations have confirmed the presence of carbon, SiC, hydrocarbons, and oxygen-rich silicate grains in nova ejecta, suggesting that some fraction of the pre-solar grains recently identified in meteoritic material may come from novae. The mean mass returned by a nova outburst to the ISM probably exceeds similar to 2 X 10(-4) M-circle dot. Using the observed nova rate of 35 +/- 11 per year in our Galaxy, it follows that novae introduce more than similar to 7 x 10(-3) M-circle dot yr(-1) of processed matter into the ISM. It is likely, however, that novae ejecta are more massive than believed, and this value is a lower limit. Novae are expected to be the major source of N-15 and O-17 in the Galaxy and to contribute to the abundances of other isotopes in this atomic mass range. In order to understand better their contributions to galactic chemical evolution, we have begun a series of studies with the latest nuclear reaction rate libraries. We report both on how these new rates affect the properties of the outburst and, in addition, how they change the predictions of the contributions of novae to Galactic chemical evolution. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27708 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Notre Dame, Dept Phys & Astron, Notre Dame, IN 46616 USA. Univ Calif Los Alamos Natl Lab, XNH, Los Alamos, NM 87545 USA. RP Starrfield, S (reprint author), Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 110C EP 117C PG 8 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300023 ER PT J AU Blackmon, JC Bardayan, DW Bradfield-Smith, W Champagne, AE Chen, AA Davinson, T Hahn, KI Kozub, RL Ma, Z Parker, PD Rajbaidya, G Runkle, RC Rowland, CM Shotter, AC Smith, MS Swartz, KB Visser, DW Woods, PJ AF Blackmon, JC Bardayan, DW Bradfield-Smith, W Champagne, AE Chen, AA Davinson, T Hahn, KI Kozub, RL Ma, Z Parker, PD Rajbaidya, G Runkle, RC Rowland, CM Shotter, AC Smith, MS Swartz, KB Visser, DW Woods, PJ TI Determination of the O-14(alpha,p)F-17(g.s.) reaction rate by measurement of the H-1(F-17,alpha)O-14 cross section SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID NE-18; BEAMS AB The O-14(alpha ,p)F-17 reaction is important during the ignition phase of x-ray bursts, but significant uncertainties in this reaction rate have persisted due to uncertainties in the properties of excited states in Ne-18 and the unmeasured direct reaction cross section. The H-1(F-17,alpha)O-14 reaction, the time-inverse of the O-14(alpha, p)F-17(g.s.) reaction, was studied using a radioactive F-17 beam at, the Holifield Radioactive Ion Beam Facility. The (p, alpha) reaction and (p, p) elastic-scattering cross sections were measured over the energy range of interest for x-ray bursts, corresponding to E-cm(alpha) = 1.0 - 2.6 MeV. Resonances corresponding to states in Ne-18 with excitation energies E-x = 6.0 - 7.7 MeV were observed, and the direct reaction cross section determined. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. Ewha Womans Univ, Dept Sci Educ, Seoul 120750, South Korea. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Yale Univ, Wright Nucl Struct Lab, New Haven, CT 06511 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. RP Blackmon, JC (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Visser, Dale/A-8117-2009 OI Visser, Dale/0000-0002-2891-4731 NR 8 TC 23 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 142C EP 145C PG 4 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300030 ER PT J AU Mezzacappa, A AF Mezzacappa, A TI Toward a standard model of core collapse supernovae SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID NEUTRINO TRANSPORT; PRESUPERNOVA EVOLUTION; NUMERICAL-METHOD; MASSIVE STARS; DENSE MATTER; EXPLOSIONS; CONVECTION; MECHANISM; DIFFUSION; BOLTZMANN AB In this paper, we discuss the current status of core collapse supernova models and the future developments needed to achieve significant advances in understanding the supernova mechanism and supernova phenomenology, i.e., in developing a supernova standard model. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Mezzacappa, A (reprint author), Oak Ridge Natl Lab, Div Phys, Bldg 6010,MS 6354,POB 2008, Oak Ridge, TN 37831 USA. RI Mezzacappa, Anthony/B-3163-2017 OI Mezzacappa, Anthony/0000-0001-9816-9741 NR 40 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 158C EP 167C PG 10 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300034 ER PT J AU Dean, DJ AF Dean, DJ TI Effect of nuclear structure on Type Ia supernova nucleosynthesis SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID WEAK-INTERACTION RATES; INTERMEDIATE-MASS NUCLEI; MODEL MONTE-CARLO; FP-SHELL NUCLEI; CAPTURE AB The relationship among nuclear structure, the weak processes in nuclei, and astrophysics becomes quite apparent in supernova explosion and nucleosynthesis studies. In this brief article, I report on progress made in the last few years on calculating electron capture and beta-decay rates in iron-group nuclei. I also report on applications of these rates to Type-Is nucleosynthesis studies. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. EM deandj@ornl.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 189C EP 192C PG 4 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300039 ER PT J AU Rauscher, T Heger, A Hoffman, RD Woosley, SE AF Rauscher, T Heger, A Hoffman, RD Woosley, SE TI Nucleosynthesis in massive stars revisited SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID P-PROCESS; MODEL CALCULATIONS; REACTION-RATES; CROSS-SECTION; R-PROCESS; SUPERNOVAE; ENVIRONMENTS; NUCLEI AB We have performed the first calculations to follow the evolution of all stable nuclei and their radioactive progenitors in a finely-zoned stellar model computed from the onset of central hydrogen burning through explosion as a Type II supernova. Calculations were done for 15 M-circle dot, 20 M-circle dot, and 25 M-circle dot Pop I stars using the most recently available set of experimental and theoretical nuclear data, revised opacity tables, and taking into account mass loss due to stellar winds. Here results are presented for one 15 M-circle dot model. C1 Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Rauscher, T (reprint author), Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. RI Rauscher, Thomas/D-2086-2009 OI Rauscher, Thomas/0000-0002-1266-0642 NR 25 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 193C EP 196C PG 4 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300040 ER PT J AU Heger, A Baraffe, I Fryer, CL Woosley, SE AF Heger, A Baraffe, I Fryer, CL Woosley, SE TI Evolution and nucleosynthesis of very massive primordial stars SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID STABILITY; UNIVERSE; HYDROGEN AB We investigate the evolution, final fate, and nucleosynthetic yields of rotating and non-rotating very massive stars (VMS) of zero metallicity. First we address the issue of mass loss during hydrogen burning due to vibrational instabilities. We find that these objects are much more stable than what was found in previous studies of VMS of solar composition, and expect only negligible mass loss driven by the pulsations. As these stars thus reach the end of their evolution with massive helium cores, they encounter the pair-creation instability. We find that for helium core masses of similar to 64...133 M-circle dot these stars are completely disrupted with explosion energies of up to similar to 10(53) erg and eject up to similar to 60 M-circle dot of Ni-56. Stars with more massive helium cores collapse into black holes. We present the first calculations that follow the collapse of such a massive rotating star and predict that X-ray burst and significant gravitational wave emission could result. C1 Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Ecole Normale Super Lyon, CRAL, UMR 5574 CNRS, F-69364 Lyon, France. LANL, T6 Grp, Los Alamos, NM 87454 USA. RP Heger, A (reprint author), Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. NR 29 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 197C EP 200C PG 4 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300041 ER PT J AU Bardayan, DW Blackmon, JC Bradfield-Smith, W Brune, CR Champagne, AE Davinson, T Johnson, BA Kozub, RL Lee, CS Lewis, R Parker, PD Shotter, AC Smith, MS Visser, DW Woods, PJ AF Bardayan, DW Blackmon, JC Bradfield-Smith, W Brune, CR Champagne, AE Davinson, T Johnson, BA Kozub, RL Lee, CS Lewis, R Parker, PD Shotter, AC Smith, MS Visser, DW Woods, PJ TI Determination of the properties of the 7.08 MeV state in Ne-19 by measurement of the H-1(F-18, p)F-18 and H-1(F-18,alpha)O-15 cross sections with a radioactive F-18 beam SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID NOVAE C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Yale Univ, Wright Nucl Struct Lab, New Haven, CT 06511 USA. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. Chung Ang Univ, Dept Phys, Seoul 156756, South Korea. RP Bardayan, DW (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Visser, Dale/A-8117-2009 OI Visser, Dale/0000-0002-2891-4731 NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 475C EP 477C PG 3 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300104 ER PT J AU Hoffman, RD Woosley, SE Weaver, TA AF Hoffman, RD Woosley, SE Weaver, TA TI Nucleosynthesis below A=100 in massive stars SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID MODEL CALCULATIONS; REACTION-RATES; SUPERNOVAE AB The production of nuclei up to and including the light s-process component at A approximate to 60-90 is calculated for all stages of stable and explosive nuclear burning in stars of 15 and 25 M.. An extended nuclear reaction network of 480 isotopes is employed along with approximately two dozen recent revisions to key nuclear reaction rates. As noted previously, the new rates suggest a greatly diminished production of O-17 and O-18 in massive stars. Ne-22 is also moderately enhanced. We find that a combination of pre-explosive s-process, gamma -process, and (mild) r-processes in massive stars give a consistently solar production of almost all isotopes from mass 64 through 90. However, even after the late stages of evolution are complete and the explosion is over, this same group of elements is overproduced compared to what is needed for the sun, especially in the 25 M, model. C1 Univ Calif Lawrence Livermore Natl Lab, Nucl Theory & Modeling Grp, Livermore, CA 94550 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Hoffman, RD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Nucl Theory & Modeling Grp, Livermore, CA 94550 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 481C EP 483C PG 3 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300106 ER PT J AU Heil, M Couture, A Daly, J Detwiler, R Gorres, J Hale, G Kappeler, F Reifarth, R Giesen, U Stech, E Tischhauser, P Ugalde, C Wiescher, M AF Heil, M Couture, A Daly, J Detwiler, R Gorres, J Hale, G Kappeler, F Reifarth, R Giesen, U Stech, E Tischhauser, P Ugalde, C Wiescher, M TI A measurement of the C-13(alpha,alpha) differential cross section and its application to the C-13(alpha,n) reaction. SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID THERMONUCLEAR REACTION-RATES; S-PROCESS AB The C-13(alpha ,n) reaction is considered as the main neutron source for the s process in AGE-stars of 1-3 solar masses. The reaction takes place at temperatures of about 10(8) K which corresponds to a Gamov peak at 190 keV. At this energy a direct measurement of the C-13(alpha ,n) cross section is extremely difficult and therefore one has to extrapolate the measured data to lower energies. Since the cross section is expected to be influenced by a subthreshold resonance and a resonance just above threshold, R-matrix analyses are especially suited for this extrapolation. An exact measurement of the excitation function and the angular distribution of the C-13(alpha ,n) reaction, which represents another decay channel of the O-17 compound nucleus, can provide additional constraints to improve the quality and reliability of the R-matrix extrapolation. New results for the C-13(alpha,alpha) differential cross section in the energy range 2.6 - 6.2 MeV are presented. The experiment was performed with the 10 MV tandem accelerator at the University of Notre Dame. Angular distributions for 29 angles between 44 degrees and 165 degrees could be obtained for 375 energies. Preliminary results for the reaction rate at kT = 8 keV are presented. C1 Forschungszentrum Karlsruhe, IK, D-76021 Karlsruhe, Germany. Univ Notre Dame, Notre Dame, IN 46556 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Heil, M (reprint author), Forschungszentrum Karlsruhe, IK, Postfac 3640, D-76021 Karlsruhe, Germany. NR 17 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 499C EP 501C PG 3 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300112 ER PT J AU Johnson, AS Hale, GM AF Johnson, AS Hale, GM TI Recent R-matrix Results for np-capture SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th International Conference on Nuclei in the Cosmos CY JUN 27-JUL 01, 2000 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS ID CROSS-SECTION AB R-matrix analyses of light systems directed at obtaining capture cross sections for reactions of interest in nuclear astrophysics have been underway at Los Alamos for some time. In this poster we focus on recent results for the H-1(n, gamma)H-2 reaction (np-capture), important in Big-Bang nucleosynthesis (BBN) at energies well up into hundreds of keV. The direct measurements are rather sparse in the energy range important for BBN, however, our analyses makes use of auxiliary data for elastic channels to determine the np-capture cross section over wide ranges of energies, including those of astrophysical interest. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Johnson, AS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 21 PY 2001 VL 688 IS 1-2 BP 566C EP 568C PG 3 WC Physics, Nuclear SC Physics GA 434DF UT WOS:000168799300133 ER PT J AU Kubota, A Caturla, MJ Stolken, JS Feit, MD AF Kubota, A Caturla, MJ Stolken, JS Feit, MD TI Densification of fused silica due to shock waves and its implications for 351 nm laser induced damage SO OPTICS EXPRESS LA English DT Article ID GLASS AB High-power 351 nm (3) laser pulses can produce damaged areas in high quality fused silica optics. Recent experiments have shown the presence of a densified layer at the bottom of damage initiation craters. We have studied the propagation of shock waves through fused silica using large-scale atomistic simulations since such shocks are expected to accompany laser energy deposition. These simulations show that the shocks induce structural transformations in the material that persist long after the shock has dissipated. Values of densification and thickness of densified layer agree with experimental observations. Moreover, our simulations give an atomistic description of the structural changes in the material due to shock waves and their relation to Raman spectra measurements. (C) 2001 Optical Society of America. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kubota, A (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM kubotal@llnl.gov; caturla1@llnl.gov; stolken1@llnl.gov; feit1@llnl.gov RI Feit, Michael/A-4480-2009; Caturla, Maria /D-6241-2012 OI Caturla, Maria /0000-0002-4809-6553 NR 16 TC 51 Z9 52 U1 0 U2 10 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 MAY 21 PY 2001 VL 8 IS 11 BP 611 EP 616 PG 6 WC Optics SC Optics GA 434JW UT WOS:000168812200004 PM 19421249 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Deval, S Fernandez, A Fox, GF Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lichtenstadt, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Deval, S Fernandez, A Fox, GF Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lichtenstadt, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C CA Fermilab E791 Collaboration TI Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE-MOMENTUM; FORM-FACTOR; QUANTUM CHROMODYNAMICS; EXCLUSIVE PROCESSES; QCD; MESONS AB We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi (-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q (q) over bar > light-cone asymptotic wave function describes the data well for Q(2) similar to 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets. C1 Univ Mississippi, University, MS 38677 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. CINVESTAV, Mexico City 14000, DF, Mexico. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. IIT, Chicago, IL 60616 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Massachusetts, Amherst, MA 01003 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Autonoma Puebla, Puebla 72570, Mexico. Univ S Carolina, Columbia, SC 29208 USA. Stanford Univ, Stanford, CA 94305 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Aitala, EM (reprint author), Univ Mississippi, University, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016; Fernandez Tellez, Arturo/E-9700-2017; de Mello Neto, Joao/C-5822-2013 OI Fernandez Tellez, Arturo/0000-0001-5092-9748; Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; Fernandez Tellez, Arturo/0000-0003-0152-4220; de Mello Neto, Joao/0000-0002-3234-6634 NR 22 TC 88 Z9 88 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 MAY 21 PY 2001 VL 86 IS 21 BP 4768 EP 4772 DI 10.1103/PhysRevLett.86.4768 PG 5 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800013 PM 11384344 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lichtenstadt, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, C Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Devmal, S Fernandez, A Fox, GF Gagnon, P Gerzon, S Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lichtenstadt, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, C Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yang, SM Yi, D Yoshida, S Zaliznyak, R Zhang, C CA Fermilab E791 Collaboration TI Observation of color-transparency in diffractive dissociation of pions SO PHYSICAL REVIEW LETTERS LA English DT Article ID LARGE MOMENTUM-TRANSFER; QUANTUM CHROMODYNAMICS; NUCLEAR TRANSPARENCY; ELASTIC-SCATTERING; DEPENDENCE; QCD AB We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min) --> 0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma (0)A(alpha), alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency. C1 Univ Mississippi, University, MS 38677 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. CINVESTAV, Mexico City 14000, DF, Mexico. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. IIT, Chicago, IL 60616 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Massachusetts, Amherst, MA 01003 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Autonoma Puebla, Puebla 72570, Mexico. Univ S Carolina, Columbia, SC 29208 USA. Stanford Univ, Stanford, CA 94305 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Aitala, EM (reprint author), Univ Mississippi, University, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016; de Mello Neto, Joao/C-5822-2013 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; de Mello Neto, Joao/0000-0002-3234-6634 NR 38 TC 85 Z9 85 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 MAY 21 PY 2001 VL 86 IS 21 BP 4773 EP 4777 DI 10.1103/PhysRevLett.86.4773 PG 5 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800014 PM 11384345 ER PT J AU Adler, C Ahammed, Z Allgower, C Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Bland, LC Blyth, CO Bonner, BE Bossingham, R Boucham, A Brandin, A Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chattopadhyay, S Chen, ML Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Conin, L Cormier, TM Cramer, JG Crawford, HJ DeMello, M Deng, WS Derevschikov, AA Didenko, L Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Ferguson, MI Finch, E Fisyak, Y Flierl, D Foley, KJ Gagunashvili, N Gans, J Germain, M Geurts, F Ghazikhanian, V Grabski, J Grachov, O Greiner, D Grigoriev, V Gushin, E Hallman, TJ Hardtke, D Harris, JW Heffner, M Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Hummler, H Igo, GJ Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, E Kaneta, M Kaplan, M Keane, D Khodinov, A Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kotchendra, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lamas-Valverde, J Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lebedev, A LeCompte, T Leontiev, VM Leszczynski, P LeVine, MJ Li, Q Li, Q Lindenbaum, SJ Lisa, MA Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Lynn, D Madansky, L Majka, R Maliszewski, A Margetis, S Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Melnick, Y Meschanin, A Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moltz, D Moore, CF Morozov, V de Moura, MM Munhoz, MG Mutchler, GS Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Nystrand, J Odyniec, G Ogawa, A Ogilvie, CA Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Pinganaud, W Platner, E Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Radomski, S Rai, G Ravel, O Ray, RL Reichhold, SVR Reid, J Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Roy, C Russ, D Rykov, V Sakrejda, I Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schmitz, N Schroeder, LS Schuttauf, A Seger, J Seliverstov, D Seyboth, P Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Stroebele, H Struck, C Suaide, AAP Sugarbaker, E Suire, C Symons, TJM de Toledo, AS Szarwas, P Takahashi, J Tang, AH Thomas, JH Tikhomirov, V Trainor, T Trentalange, S Tokarev, M Tonjes, MB Trofimov, V Tsai, O Turner, K Ullrich, T Underwood, DG Van Buren, G VanderMolen, AM Vanyashin, A Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Wells, R Wenaus, T Westfall, GD Whitten, C Wiemann, H Willson, R Wissink, SW Witt, R Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yokosawa, A Yurevich, VI Zanevski, YV Zhang, J Zhang, WM Zoulkarneev, R Zubarev, AN AF Adler, C Ahammed, Z Allgower, C Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Bland, LC Blyth, CO Bonner, BE Bossingham, R Boucham, A Brandin, A Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chattopadhyay, S Chen, ML Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Conin, L Cormier, TM Cramer, JG Crawford, HJ DeMello, M Deng, WS Derevschikov, AA Didenko, L Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Ferguson, MI Finch, E Fisyak, Y Flierl, D Foley, KJ Gagunashvili, N Gans, J Germain, M Geurts, F Ghazikhanian, V Grabski, J Grachov, O Greiner, D Grigoriev, V Gushin, E Hallman, TJ Hardtke, D Harris, JW Heffner, M Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Hummler, H Igo, GJ Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, E Kaneta, M Kaplan, M Keane, D Khodinov, A Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kotchendra, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lamas-Valverde, J Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lebedev, A LeCompte, T Leontiev, VM Leszczynski, P LeVine, MJ Li, Q Li, Q Lindenbaum, SJ Lisa, MA Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Lynn, D Madansky, L Majka, R Maliszewski, A Margetis, S Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Melnick, Y Meschanin, A Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moltz, D Moore, CF Morozov, V de Moura, MM Munhoz, MG Mutchler, GS Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Nystrand, J Odyniec, G Ogawa, A Ogilvie, CA Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Pinganaud, W Platner, E Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Radomski, S Rai, G Ravel, O Ray, RL Reichhold, SVR Reid, J Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Roy, C Russ, D Rykov, V Sakrejda, I Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schmitz, N Schroeder, LS Schuttauf, A Seger, J Seliverstov, D Seyboth, P Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Stroebele, H Struck, C Suaide, AAP Sugarbaker, E Suire, C Symons, TJM de Toledo, AS Szarwas, P Takahashi, J Tang, AH Thomas, JH Tikhomirov, V Trainor, T Trentalange, S Tokarev, M Tonjes, MB Trofimov, V Tsai, O Turner, K Ullrich, T Underwood, DG Van Buren, G VanderMolen, AM Vanyashin, A Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Wells, R Wenaus, T Westfall, GD Whitten, C Wiemann, H Willson, R Wissink, SW Witt, R Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yokosawa, A Yurevich, VI Zanevski, YV Zhang, J Zhang, WM Zoulkarneev, R Zubarev, AN TI Midrapidity antiproton-to-proton ratio from Au+Au collisions at root s(NN)=130 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID STAR TPC; PB+PB COLLISIONS; PB COLLISIONS; QCD; EQUILIBRATION; SPS AB We report results on the ratio of midrapidity antiproton-to-proton yields in Au + Au collisions at roots(NN) = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of /y/ < 0.5 and 0.4 < p(i) < 1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65 0.01((stat)) +/- 0.07((syst)) for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-(p) over bar pair production becomes important at midrapidity, a significant excess of baryons: over antibaryons is still present. C1 Univ Frankfurt, D-6000 Frankfurt, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Creighton Univ, Omaha, NE 68178 USA. Joint Inst Nucl Res Dubna, Lab High Energy, Dubna, Russia. Joint Inst Nucl Res Dubna, Particle Phys Lab, Dubna, Russia. Indiana Univ, Bloomington, IN 47408 USA. Inst Rech Subatom, Strasbourg, France. Johns Hopkins Univ, Baltimore, MD 21218 USA. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Max Planck Inst Phys, D-80805 Munich, Germany. Michigan State Univ, E Lansing, MI 48824 USA. Moscow Phys Engn Inst, Moscow, Russia. CUNY City Coll, New York, NY 10031 USA. Ohio State Univ, Columbus, OH 43210 USA. Penn State Univ, University Pk, PA 16802 USA. Inst High Energy Phys, Protvino, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77251 USA. Rice Univ, Sao Paulo, Brazil. Univ Sao Paulo, Sao Paulo, Brazil. SUBATECH, Nantes, France. Univ Texas, Austin, TX 78712 USA. Warsaw Univ Technol, Warsaw, Poland. Univ Washington, Seattle, WA 98185 USA. Wayne State Univ, Detroit, MI 48201 USA. Yale Univ, New Haven, CT 06520 USA. RP Adler, C (reprint author), Univ Frankfurt, D-6000 Frankfurt, Germany. RI Skoro, Goran/F-3642-2010; Barnby, Lee/G-2135-2010; Strikhanov, Mikhail/P-7393-2014; Kisiel, Adam/O-8754-2015; Tikhomirov, Vladimir/M-6194-2015; Takahashi, Jun/B-2946-2012; Chen, Yu/E-3788-2012; Witt, Richard/H-3560-2012; Castillo Castellanos, Javier/G-8915-2013; Vanyashin, Aleksandr/H-7796-2013; Voloshin, Sergei/I-4122-2013; Johnson, Ian/I-2439-2013; Skoro, Goran/P-1229-2014; Suaide, Alexandre/L-6239-2016; KHODINOV, ALEKSANDR/D-6269-2015 OI Barnby, Lee/0000-0001-7357-9904; Strikhanov, Mikhail/0000-0003-2586-0405; Kisiel, Adam/0000-0001-8322-9510; Tikhomirov, Vladimir/0000-0002-9634-0581; Takahashi, Jun/0000-0002-4091-1779; Castillo Castellanos, Javier/0000-0002-5187-2779; Vanyashin, Aleksandr/0000-0002-0367-5666; Skoro, Goran/0000-0001-7745-9045; Suaide, Alexandre/0000-0003-2847-6556; KHODINOV, ALEKSANDR/0000-0003-3551-5808 NR 31 TC 120 Z9 122 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 21 PY 2001 VL 86 IS 21 BP 4778 EP 4782 DI 10.1103/PhysRevLett.86.4778 PG 5 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800015 PM 11384346 ER PT J AU Wei, X Shen, YR AF Wei, X Shen, YR TI Motional effect in surface sum-frequency vibrational spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID WATER-MOLECULES; SPECTRUM; ORIENTATION; INTERFACES; RAMAN AB Fast orientational motion of molecules at a surface can affect the sum-frequency vibrational spectra of the surface. Calculation shows that the effect is significant if the molecular orientation varies over a broad range within the vibrational relaxation time. The stretch vibration of the free OH bonds at the vapor/water interface ib used to illustrate the importance of the effect. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Wei, X (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 14 TC 104 Z9 104 U1 0 U2 19 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 21 PY 2001 VL 86 IS 21 BP 4799 EP 4802 DI 10.1103/PhysRevLett.86.4799 PG 4 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800020 PM 11384351 ER PT J AU Dubrovinsky, L Dubrovinskaia, N Abrikosov, IA Vennstrom, M Westman, F Carlson, S van Schilfgaarde, M Johansson, B AF Dubrovinsky, L Dubrovinskaia, N Abrikosov, IA Vennstrom, M Westman, F Carlson, S van Schilfgaarde, M Johansson, B TI Pressure-induced invar effect in Fe-Ni alloys SO PHYSICAL REVIEW LETTERS LA English DT Article ID THERMAL-EXPANSION; IRON; TRANSITION; PHASE AB We have measured the pressure-volume (P-V) relations for cubic iron-nickel alloys for three different compositions: Fe0.64Ni0.36, Fe0.55Ni0.45, and Fe0.20Ni0.80. It is observed that for a certain pressure range the bulk modulus does not change or can even decrease to some minimum value, after which it begins to increase under still higher pressure. In our experiment, we observe for the first time a new effect, namely, that the Fe-Ni alloys with high Ni concentrations, which show positive thermal expansion at ambient pressure, become Invar system upon compression over a certain pressure range. C1 Uppsala Univ, Dept Earth Sci, S-75236 Uppsala, Sweden. Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Inorgan Chem, S-75121 Uppsala, Sweden. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Sandia Natl Labs, Livermore, CA 94551 USA. Royal Inst Technol, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden. RP Dubrovinsky, L (reprint author), Uppsala Univ, Dept Earth Sci, S-75236 Uppsala, Sweden. NR 17 TC 52 Z9 53 U1 1 U2 19 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 MAY 21 PY 2001 VL 86 IS 21 BP 4851 EP 4854 DI 10.1103/PhysRevLett.86.4851 PG 4 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800033 PM 11384364 ER PT J AU Li, JA Akhadov, EA Baker, J Boatner, LA Bonart, D Flaherty, FA Fritsch, J Safron, SA Schroder, U Skofronick, JG Trelenberg, TW Van Winkle, DH AF Li, JA Akhadov, EA Baker, J Boatner, LA Bonart, D Flaherty, FA Fritsch, J Safron, SA Schroder, U Skofronick, JG Trelenberg, TW Van Winkle, DH TI Observation of a metastable periodic structure for the (001) surface of KTaO3 after cleaving in situ SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHONON DISPERSION-CURVES; HELIUM-ATOM SCATTERING; CRYSTAL-SURFACES; STABILITY; DYNAMICS AB Helium atom diffraction experiments carried out under ultrahigh vacuum conditions on a freshly cleaved (001) surface of KTaO3 reveal metastable features which decay over a period of several hours. The initial He diffraction pattern contains large scattering intensity satellite peaks very close to the specular reflection beam. As time from cleaving elapses, the satellite intensities diminish virtually to zero while the specular intensity increases, and the diffraction pattern evolves into one consistent with the (1 X 1) bulk termination surface. The data are compared with model calculations for scattering fi om a series of terraces at two heights with a distribution of terrace lengths [Surf. Sci. 384, 15 (1997)]. C1 Florida State Univ, MARTECH, Tallahassee, FL 32306 USA. Florida State Univ, Dept Chem, Tallahassee, FL 32306 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Valdosta State Univ, Dept Phys, Valdosta, GA 31698 USA. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Li, JA (reprint author), Florida State Univ, MARTECH, Tallahassee, FL 32306 USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 21 TC 8 Z9 8 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 21 PY 2001 VL 86 IS 21 BP 4867 EP 4870 DI 10.1103/PhysRevLett.86.4867 PG 4 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800037 PM 11384368 ER PT J AU Sage, JT Durbin, SM Sturhahn, W Wharton, DC Champion, PM Hession, P Sutter, J Alp, EE AF Sage, JT Durbin, SM Sturhahn, W Wharton, DC Champion, PM Hession, P Sutter, J Alp, EE TI Long-range reactive dynamics in myoglobin SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEAR RESONANT SCATTERING; DENSITY-OF-STATES; LYING SPIN STATES; HEME-PROTEINS; SPECTROSCOPY; MOSSBAUER; VIBRATIONS; RESOLUTION; MODES; IRON AB We report the complete vibrational spectrum of the probe nucleus Fe-57 at the oxygen-binding site of the protein myoglobin. The Fe-pyrrole nitrogen stretching modes of the heme group, identified here, probe asymmetric interactions with the protein environment. Collective oscillations of the polypeptide, rather than localized heme vibrations, dominate the low frequency region. We conclude that the heme "doming" mode is significantly delocalized, so that distant sites respond to oxygen binding on vibrational time scales. This has ramifications for understanding long-range interactions in biomolecules, such as those that mediate cooperativity in allosteric proteins. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Northeastern Univ, Ctr Interdisciplinary Res Complex Syst, Boston, MA 02115 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Sage, JT (reprint author), Northeastern Univ, Dept Phys, Boston, MA 02115 USA. FU NIDDK NIH HHS [DK-35090]; NIGMS NIH HHS [GM-52002] NR 32 TC 84 Z9 84 U1 0 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 MAY 21 PY 2001 VL 86 IS 21 BP 4966 EP 4969 DI 10.1103/PhysRevLett.86.4966 PG 4 WC Physics, Multidisciplinary SC Physics GA 435DH UT WOS:000168861800062 PM 11384393 ER PT J AU Witze, PO Hochgreb, S Kayes, D Michelsen, HA Shaddix, CR AF Witze, PO Hochgreb, S Kayes, D Michelsen, HA Shaddix, CR TI Time-resolved laser-induced incandescence and laser elastic-scattering measurements in a propane diffusion flame SO APPLIED OPTICS LA English DT Article ID SOOT-VOLUME FRACTION; ELECTRON-MICROSCOPY; REFRACTIVE-INDEXES; FLICKERING METHANE; DIESEL SOOT; TEMPERATURE; MORPHOLOGY; AEROSOLS; RANGE; LII AB Laser-induced incandescence (LII) and laser elastic-scattering measurements have been obtained with subnanosecond time resolution from a propane diffusion flame. Results show that the peak and time-integrated values of the LII signal increase with increasing laser fluence to maxima at the time of the onset of significant vaporization, beyond which they both decrease rapidly with further increases in fluence. This latter behavior for the time-integrated value is known to be characteristic for a laser beam with a rectangular spatial profile and is attributed to soot mass loss from vaporization. However, there is no apparent explanation for the corresponding large decrease in the peak value. Analysis shows that the peak value occurs at the time in the laser pulse when the time-integrated fluence reaches approximately 0.2 J/cm(2) and that the magnitude of the peak value is strongly dependent on the rate of energy deposition. One possible explanation for this behavior is that, at high laser fluences, a cascade ionization phenomenon leads to the formation of an absorptive plasma that strongly perturbs the LII process. (C) 2001 Optical Society of America. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Witze, PO (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. EM witze@sandia.gov NR 38 TC 42 Z9 43 U1 0 U2 6 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 MAY 20 PY 2001 VL 40 IS 15 BP 2443 EP 2452 DI 10.1364/AO.40.002443 PG 10 WC Optics SC Optics GA 433KQ UT WOS:000168758900011 PM 18357253 ER PT J AU Podariu, S Nugent, P Ratra, B AF Podariu, S Nugent, P Ratra, B TI Cosmological model parameter determination from satellite-acquired supernova apparent magnitude versus redshift data SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; large-scale structure of universe; space vehicles; supernovae : general ID DARK-MATTER COSMOGONIES; ANISOTROPY MEASUREMENT CONSTRAINTS; UCSB SOUTH-POLE; IA SUPERNOVAE; ACCELERATING UNIVERSE; HUBBLE CONSTANT; COSMIC EQUATION; SCALAR FIELD; WHITE DISH; LAMBDA AB We examine the constraints that satellite-acquired supernova (SN) apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant Lambda. Data that could be acquired in the near future would result in tight constraints on these parameters. For example, if all other parameters of a spatially flat model with a constant ii are known, the SN data should constrain the nonrelativistic matter density parameter Omega (o), to better than 1% (2%, 0.5%) at 1 sigma with neutral (worst case, best case) assumptions about data quality. C1 Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Podariu, S (reprint author), Kansas State Univ, Dept Phys, Cardwell Hall, Manhattan, KS 66506 USA. RI Ratra, Bharat/I-4979-2012 NR 76 TC 39 Z9 39 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 2001 VL 553 IS 1 BP 39 EP 46 DI 10.1086/320639 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 442JA UT WOS:000169280400005 ER PT J AU Chen, B Stoughton, C Smith, JA Uomoto, A Pier, JR Yanny, B Ivezic, Z York, DG Anderson, JE Annis, J Brinkmann, J Csabai, I Fukugita, M Hindsley, R Lupton, R Munn, JA AF Chen, B Stoughton, C Smith, JA Uomoto, A Pier, JR Yanny, B Ivezic, Z York, DG Anderson, JE Annis, J Brinkmann, J Csabai, I Fukugita, M Hindsley, R Lupton, R Munn, JA CA SDSS Collaboration TI Stellar population studies with the SDSS. I. The vertical distribution of stars in the Milky Way SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : stellar content; Galaxy : structure ID DIGITAL SKY SURVEY; NORTH GALACTIC POLE; SURVEY COMMISSIONING DATA; GLOBULAR-CLUSTER SYSTEM; LUMINOSITY FUNCTION; THICK DISK; UBV PHOTOMETRY; MASS DENSITY; FAINT STARS; COUNT DATA AB We present star count data from the Sloan Digital Sky Survey for 5.8 x 10(5) stars brighter than g' = 21 mag over 279 deg(2) in two samples north and south of the Galactic plane. Using these high-latitude (49 degrees < \b\ < 64 degrees) star counts we determine the Sun's distance from the Galactic midplane to be 27 +/- 4 pc and the scale height of the old thin disk to be 330 +/- 3 pc. Because of the photometric accuracy and large area sky coverage of these data, the color-magnitude diagram clearly reveals a significant thick-disk population distinct in color from a Galactic halo population. The position of the thick-disk turnoff is at g'-r' similar to 0.33. Several questions about the existence of the thick disk and its origin are addressed through a set of model fits to the star count data. Our best-fit model gives a thick-disk scale height between 580 and 750 pc, below the original proposal of Gilmore and Reid, and the corresponding space number density normalization is 13%-6.5% of the thin disk. The conclusions reached in this paper favor a scenario in which the thick disk formed through the heating of a preexisting thin disk, with the heating mechanism being the merging of a satellite galaxy. The density law for the Galactic halo population is also investigated. We find that the data support a flattened halo with c/a similar to 0.55 +/- 0.06 and a relatively flat power-law index (2.5 +/- 0.3). The axis ratio of the visible halo found in this paper is compatible with that of dark halo, suggesting that they have the same shape and dynamical origin. C1 Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 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. USN, Remote Sensing Div, Res Lab, Washington, DC 20375 USA. RP Chen, B (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, 3400 N Charles St, Baltimore, MD 21218 USA. RI Csabai, Istvan/F-2455-2012 NR 80 TC 209 Z9 211 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 MAY 20 PY 2001 VL 553 IS 1 BP 184 EP 197 DI 10.1086/320647 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 442JA UT WOS:000169280400016 ER PT J AU Felice, GM Kulsrud, RM AF Felice, GM Kulsrud, RM TI Cosmic-ray pitch-angle scattering through 90 degrees SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; ISM : magnetic fields; methods : analytical; plasmas ID MAGNETIC-FIELD; DIFFUSION; SUPERBUBBLES; EXPLOSIONS; TRANSPORT; DYNAMO AB We study the problem of cosmic-ray diffusion in the Galactic disk with particular attention paid to the problem of particle scattering through the theta = cos(-1) (v(parallel to)/v) = 90 degrees pitch angle in momentum space by wave-particle mirror interaction (here v(parallel to) is the cosmic-ray velocity parallel to the average Galactic magnetic field). We consider the case in which cosmic rays are the only source of magnetic turbulence, which originates as the relativistic particles try to stream through the interstellar plasma faster than the local Alfven speed. The wave growth rate is proportional to the cosmic-ray anisotropy, and the amplitude of hydromagnetic waves generated by this streaming instability is limited by the presence of various damping mechanisms. We study the propagation of cosmic rays in the different phases of the interstellar medium, in particular the coronal regions (where the main form of wave dissipation is nonlinear Landau damping) and the warm regions (where charge exchange between the ions and the neutral atoms gives rise to the dominant form of wave dissipation). We also account for ion-cyclotron damping of small wavelength waves. The effect of a spectrum of waves is to limit the anisotropy of the cosmic-ray distribution function and hence their drift velocity. We show that quasi-linear resonant scattering cannot account for particle diffusion everywhere in momentum space and that particles with theta similar to 90 degrees must change their pitch angle by mirror interaction with long-wavelength waves generated by the theta similar to 0 degrees particles. We match the quasi-linear scattering with the adiabatic mirroring in a small boundary layer in momentum space close to the theta similar to 90 degrees point, and then we calculate the diffusion coefficient together with the cosmic-ray drift velocity. We show that scattering through the 90 degrees point is very efficient, and we calculate the correction to the particle diffusion coefficient due to the presence of mirroring. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08542 USA. RP Felice, GM (reprint author), Max Planck Inst Kernphys, Bereich Astrophys, Saupfercheckweg 1,Postfach 10 39 80, D-69029 Heidelberg, Germany. NR 31 TC 23 Z9 23 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 2001 VL 553 IS 1 BP 198 EP 210 DI 10.1086/320651 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 442JA UT WOS:000169280400017 ER PT J AU Desai, MI Mason, GM Dwyer, JR Mazur, JE Smith, CW Skoug, RM AF Desai, MI Mason, GM Dwyer, JR Mazur, JE Smith, CW Skoug, RM TI Acceleration of He-3 nuclei at interplanetary shocks SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; interplanetary medium; shock waves; solar wind; Sun : abundances; Sun : flares ID ENERGETIC PARTICLE EVENTS; FLARES; SUN AB We have surveyed the 0.5-2.0 MeV nucleon(-1) ion composition of 56 interplanetary (LP) shocks observed with the Ultra-Low-Energy Isotope Spectrometer on board the Advanced Composition Explorer from 1997 October I through 2000 November 30. Our results show the first ever measurement (25 cases) of He-3 ions being accelerated at IP shocks. The He-3/He-4 ratio at the 25 shocks exhibited a wide range of values between 0.0014 and 0.24; the ratios were enhanced between factors of similar to3 and 600 over the solar wind value. During the survey period, the occurrence probability of He-3-rich shocks increased with rising solar activity as measured in terms of the daily occurrence rates of sunspots and X-ray flares. The He-3 enhancements at IP shocks cannot be attributed to a rigidity-dependent acceleration of solar wind ions and are better explained if the shocks accelerate ions from multiple sources, one being remnant impulsive solar hare material enriched in He-3 ions. Our results also indicate that the contribution of impulsive hares to the seed population for IP shocks varies from event to event and that the interplanetary medium is being replenished with impulsive material more frequently during periods of increased solar activity. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. Aerospace Corp, El Segundo, CA 90245 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Desai, MI (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NR 15 TC 57 Z9 57 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 2001 VL 553 IS 1 BP L89 EP L92 DI 10.1086/320503 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 442JB UT WOS:000169280500022 ER PT J AU Kiseleva-Eggleton, L Bois, E AF Kiseleva-Eggleton, L Bois, E TI Effects of perturbing forces on the orbital stability of planetary systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE celestial mechanics, stellar dynamics; planetary systems; stars : individual (v Andromedae) ID UPSILON-ANDROMEDAE AB We consider dynamical effects of additional perturbative forces due to the non-point-mass nature of stars and planets: effects such as quadrupolar distortion and tidal friction in the systems of exoplanets. It is shown that one should not neglect these forces while modeling the dynamics of planetary systems, especially taking into account the undefined real masses of the planets due to unknown orbital inclinations and the unsatisfactory application of Keplerian fits to the radial velocity data in multiple planetary systems. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Observ Bordeaux, F-33270 Floirac, France. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Kiseleva-Eggleton, L (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, L-413,7000 E Ave, Livermore, CA 94550 USA. EM lkisseleva@igpp.ucllnl.org; bois@obsenv.u-bordeaux.fr NR 18 TC 8 Z9 8 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 2001 VL 553 IS 1 BP L73 EP L76 DI 10.1086/320506 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 442JB UT WOS:000169280500018 ER PT J AU Chang, JH Choi, YM Shin, YK AF Chang, JH Choi, YM Shin, YK TI A significant fluorescence quenching of anthrylaminobenzocrown ethers by paramagnetic metal cations SO BULLETIN OF THE KOREAN CHEMICAL SOCIETY LA English DT Article DE fluorescence quenching; paramagnetic effect; nonradiative quenching ID AQUEOUS-SOLUTION; CHEMOSENSOR; COMPLEXES; RECEPTOR; SWITCHES; SENSORS; WATER; STATE; NI2+; IONS C1 Chungbuk Natl Univ, Dept Chem, Cheongju 361763, Chungbuk, South Korea. RP Chang, JH (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 28 TC 28 Z9 28 U1 0 U2 4 PU KOREAN CHEMICAL SOC PI SEOUL PA 635-4 YEOGSAM-DONG, KANGNAM-GU, SEOUL 135-703, SOUTH KOREA SN 0253-2964 J9 B KOR CHEM SOC JI Bull. Korean Chem. Soc. PD MAY 20 PY 2001 VL 22 IS 5 BP 527 EP 530 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 437UA UT WOS:000169010900022 ER PT J AU Glimm, J Grove, JW Li, XL Oh, W Sharp, DH AF Glimm, J Grove, JW Li, XL Oh, W Sharp, DH TI A critical analysis of Rayleigh-Taylor growth rates SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID GROUP FIXED-POINT; FRONT TRACKING; NUMERICAL-SIMULATION; GAS-DYNAMICS; INSTABILITY; INTERFACES; SCHEME; WAVES AB Recent simulations of Rayleigh-Taylor instability growth rates display considerable spread. We provide evidence that differences in numerical dissipation effects (mass diffusion and viscosity) due to algorithmic differences and differences in simulation duration are the dominant factors that produce such different results, Within the simulation size and durations explored here, we provide evidence that the principal discrepancies are due to numerical dispersion through comparison of simulations using different algorithms. We present new 3D front tracking simulations that show tentative agreement with the range of reported experimental values. We begin an exploration of new physical length scales that may characterize a transition to a new Rayleigh-Taylor mixing regime. (C) 2001 Academic Press. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Ctr Data Intens Comp, Upton, NY 11793 USA. Los Alamos Natl Lab, Div Appl Phys, Hydrodynam Methods Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. RP SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. EM glimm@ams.sunysb.edu; jgrove@lanl.gov; linli@ams.sunysb.edu; woh@ams.sunysb.edu; dhs@t13.lanl.gov NR 51 TC 101 Z9 104 U1 2 U2 19 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAY 20 PY 2001 VL 169 IS 2 BP 652 EP 677 DI 10.1006/jcph.2000.6590 PG 26 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 443JW UT WOS:000169338900010 ER PT J AU Dvorak, J Jirsak, T Rodriguez, JA AF Dvorak, J Jirsak, T Rodriguez, JA TI Fundamental studies of desulfurization processes: reaction of methanethiol on ZnO and Cs/ZnO SO SURFACE SCIENCE LA English DT Article DE sulphur; zinc oxide; surface chemical reaction; thermal desorption spectroscopy; synchrotron radiation photoelectron spectroscopy ID ZINC-OXIDE; METAL-SURFACES; POLAR FACES; PHOTOEMISSION; CHEMISTRY; MO(110); CESIUM; THIOL; H2S; CS AB The reaction of methanethiol on ZnO and Cs promoted ZnO surfaces has been studied with synchrotron based photoemission and thermal desorption spectroscopy. On ZnO, methanethiol undergoes selective reaction to produce carbon monoxide (37-58%), methane (23-38%), formaldehyde (12-15%), ethane (1-11%), and a mixture of ethylene and acetylene (3-13%). At low temperatures (< 100 K), methanethiol reacts to yield thiolate intermediate bound to Zn2+ cations. The thiolate is stable to 500 K. Above this temperature, C-S bond cleavage occurs to yield methyl intermediate and atomic S. Carbon is removed from the surface as gaseous products above 500 K, and atomic sulfur remains bound to the zinc sites of the surface. Submonolayer amounts of cesium do not have a significant promotional effect on C-S bond cleavage, whereas Cs multilayers are found to significantly lower the activation barrier for C-S bond cleavage. This study illustrates the chemistry associated with the desulfurization of thiols on a catalytically relevant oxide surface. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 37 TC 37 Z9 39 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 20 PY 2001 VL 479 IS 1-3 BP 155 EP 168 DI 10.1016/S0039-6028(01)00973-6 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 436FP UT WOS:000168926100016 ER PT J AU Lucas, CA Markovic, NM Ball, M Stamenkovic, V Climent, V Ross, PN AF Lucas, CA Markovic, NM Ball, M Stamenkovic, V Climent, V Ross, PN TI Surface structure and relaxation during the oxidation of carbon monoxide on Pt-Pd bimetallic surfaces SO SURFACE SCIENCE LA English DT Article DE surface structure, morphology, roughness, and topography; carbon monoxide; surface relaxation and reconstruction; platinum; palladium; X-ray scattering, diffraction, and reflection; solid-liquid interfaces; electrochemical methods ID INFRARED-SPECTROSCOPY; ELECTRONIC-PROPERTIES; CHEMICAL-PROPERTIES; PT(111) ELECTRODE; ADSORPTION; CO; PALLADIUM; CHEMISORPTION; BEHAVIOR; KINETICS AB The atomic structure and surface relaxation of Pd monolayer on Pt(1 1 1) has been studied by surface X-ray scattering, in an aqueous environment under electrostatic potential control, during the adsorption and oxidation of carbon monoxide. The results show that the Pd Pt layer spacing contracts at the onset of CO oxidation before the Pd adlayer forms an oxide structure that is incommensurate with the Pt lattice. Both the oxide formation and the lattice contraction are fully reversible over many cycles of the applied electrode potential. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Lucas, CA (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. EM clucas@liv.ac.uk RI Climent, Victor/F-6491-2011; OI Climent, Victor/0000-0002-2033-5284; Lucas, Christopher/0000-0001-5743-3868 NR 25 TC 12 Z9 13 U1 0 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 20 PY 2001 VL 479 IS 1-3 BP 241 EP 246 DI 10.1016/S0039-6028(01)00984-0 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 436FP UT WOS:000168926100024 ER PT J AU Brankovic, SR McBreen, J Adzic, RR AF Brankovic, SR McBreen, J Adzic, RR TI Spontaneous deposition of Pd on a Ru(0001) surface SO SURFACE SCIENCE LA English DT Letter DE scanning tunneling microscopy; surface chemical reaction; growth; palladium; ruthenium; metallic films ID IRREVERSIBLY ADSORBED PALLADIUM; PLATINUM-ELECTRODES; ULTRATHIN FILMS; RUTHENIUM; PT(111); ADSORPTION; OXIDATION; BEHAVIOR; AU(111); GROWTH AB Spontaneous deposition of Pd on a Ru(0 0 0 1) single crystal surface has been demonstrated by an in situ scanning tunneling microscopy technique. The immersion of an ultrahigh vacuum prepared Ru single crystal in a palladium ion containing solution results in a formation of an epitaxial and textured multilayer Pd deposit without applying an external potential. The amount of deposited Pd can be indirectly controlled by the amount of Pd ions confined in the solution volume in contact with a Ru surface. The results suggest that the initial Pd growth involves formation of an ordered monolayer, while further growth results in formation of a three-dimensional Pd deposit. (C) 2001 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Energy Sci & Technol Dept, Div Mat & Chem Sci, Upton, NY 11973 USA. RP Adzic, RR (reprint author), Brookhaven Natl Lab, Energy Sci & Technol Dept, Div Mat & Chem Sci, Upton, NY 11973 USA. NR 19 TC 35 Z9 35 U1 0 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 20 PY 2001 VL 479 IS 1-3 BP L363 EP L368 DI 10.1016/S0039-6028(01)01006-8 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 436FP UT WOS:000168926100001 ER PT J AU Gan, S El-azab, A Liang, Y AF Gan, S El-azab, A Liang, Y TI Formation and diffusion of Pt nanoclusters on highly corrugated anatase TiO2(001)-(1 x 4) surface SO SURFACE SCIENCE LA English DT Letter DE diffusion and migration; clusters; platinum; titanium oxide; scanning tunneling microscopy ID SCANNING-TUNNELING-MICROSCOPY; SELF-DIFFUSION; CLUSTERS; TIO2(110); SIZE; TRANSITION; DEPENDENCE; STABILITY; ISLANDS; GROWTH AB We examined a novel heterogeneous system consisting of a metal on a highly corrugated transition-metal-oxide surface by scanning tunneling microscopy (STM). Pt forms three-dimensional nanoclusters with a narrow size distribution on the anatase TiO2(0 0 1)-(1 x 4) surface, Upon annealing in vacuum, Pt clusters that initially existed on terraces migrated without coalescing to step edges via a cluster diffusion mechanism. Time-dependent autocorrelation analysis revealed that the diffusion occurred preferentially along the atomic rows. The diffusion barrier and prefactor along this direction were determined to be similar to0.27 eV and similar to 400 Angstrom (2)/s, respectively. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Liang, Y (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS K8-93,POB 999, Richland, WA 99352 USA. NR 30 TC 14 Z9 14 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 20 PY 2001 VL 479 IS 1-3 BP L369 EP L374 DI 10.1016/S0039-6028(01)01009-3 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 436FP UT WOS:000168926100002 ER PT J AU Hopfner, KP Karcher, A Craig, L Woo, TT Carney, JP Tainer, JA AF Hopfner, KP Karcher, A Craig, L Woo, TT Carney, JP Tainer, JA TI Structural biochemistry and interaction architecture of the DNA double-strand break repair Mre11 nuclease and Rad50-ATPase SO CELL LA English DT Article ID SACCHAROMYCES-CEREVISIAE; IONIZING-RADIATION; MISMATCH REPAIR; CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; PROTEIN COMPLEX; CHROMOSOMES SMC; MAMMALIAN-CELLS; RECOMBINATION; RAD50 AB To clarify functions of the Mre11/Rad50 (MR) complex in DNA double-strand break repair, we report Pyrococcus furiosus Mre11 crystal structures, revealing a protein phosphatase-like, dimanganese binding domain capped by a unique domain controlling active site access. These structures unify Mre11's multiple nuclease activities in a single endo/exonuclease mechanism and reveal eukaryotic macromolecular interaction sites by mapping human and yeast Mre11 mutations. Furthermore, the structure of the P. furiosus Rad50 ABC-ATPase with its adjacent coiled-coil defines a compact Mre11/Rad50-ATPase complex and suggests that Rad50-ATP-driven conformational switching directly controls the Mre11 exonuclease. Electron microscopy, small angle X-ray scattering, and ultracentrifugation data of human and P. furiosus MR reveal a dual functional complex consisting of a (Mre11)(2)/(Rad50)(2) heterotetrameric DNA processing head and a double coiled-coil linker. C1 Scripps Res Inst, Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Scripps Res Inst, Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Maryland, Sch Med, Marlene & Stewart Greenebaum Canc Ctr, Dept Radiat Oncol,Radiat Oncol Res Lab, Baltimore, MD 21201 USA. Univ Maryland, Sch Med, Mol & Cell Biol Grad Program, Baltimore, MD 21201 USA. RP Tainer, JA (reprint author), Scripps Res Inst, Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. RI Hopfner, Karl-Peter/B-6864-2014 OI Hopfner, Karl-Peter/0000-0002-4528-8357 NR 63 TC 311 Z9 323 U1 3 U2 15 PU CELL PRESS PI CAMBRIDGE PA 1100 MASSACHUSETTES AVE,, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD MAY 18 PY 2001 VL 105 IS 4 BP 473 EP 485 DI 10.1016/S0092-8674(01)00335-X PG 13 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 434XG UT WOS:000168840700007 PM 11371344 ER PT J AU Shin, YS Chang, JH Liu, J Williford, R Shin, YK Exarhos, GJ AF Shin, YS Chang, JH Liu, J Williford, R Shin, YK Exarhos, GJ TI Hybrid nanogels for sustainable positive thermosensitive drug release SO JOURNAL OF CONTROLLED RELEASE LA English DT Article DE controlled release; positive release; nanostructures; gels; hybrid ID VOLUME PHASE-TRANSITION; GELS; POLY(N-ISOPROPYLACRYLAMIDE); PERMEATION; HYDROGELS; POLYMERS; MEMBRANE; COLLAPSE; MATRIX AB A hybrid nanogel has been developed based on interpenetrating networks of thermosensitive poly(N-isopropylacrylamide) gels and tailored nanoporous silica. A sustainable positive thermo-responsive drug release profile is obtained. When the temperature rises, the polymer gel shrinks, squeezing the drug into the porous channels, and at the same time, opening the pores to the outside media. The drug slowly diffuses out of the porous channels. The overall release rate can be adjusted by changing the composition of the nanogel. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lucent Bell Labs, Murray Hill, NJ 07947 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Chungbuk Natl Univ, Dept Chem, Chungbuk 361763, South Korea. RP Liu, J (reprint author), Lucent Bell Labs, 600 Mt Ave, Murray Hill, NJ 07947 USA. NR 19 TC 61 Z9 65 U1 3 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-3659 J9 J CONTROL RELEASE JI J. Control. Release PD MAY 18 PY 2001 VL 73 IS 1 BP 1 EP 6 DI 10.1016/S0168-3659(01)00247-4 PG 6 WC Chemistry, Multidisciplinary; Pharmacology & Pharmacy SC Chemistry; Pharmacology & Pharmacy GA 437BG UT WOS:000168969900001 PM 11337054 ER PT J AU Ni, J Coldiron, SJ Zhong, CJ Porter, MD AF Ni, J Coldiron, SJ Zhong, CJ Porter, MD TI Electrochemically-actuated mercury valve for flow rate and direction control: design, characterization, and applications SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE electrochemistry; surface tension; mercury; miniaturization; pump; valve ID SILICON-WAFER; SYSTEMS; MICROPUMP AB An electrochemically actuated mercury column was configured to function as a valve for controlling both flow rate and flow direction. The valving mechanism relies on a glass piston, which is placed on top of a mercury column, to open or block a capillary how channel. The glass piston is actuated by the movement of the mercury column, and is based on an electrochemically induced change in the surface tension at the mercury-electrolyte interface. The position of the piston can be controlled by applying different voltages to the mercury electrode, which changes the surface tension of mercury, and hence the relative height of the mercury column in each of the two arms of a U-shaped tube. The extent of the piston displacement opens, closes, or partially opens the flow channel, thereby altering fluid flow rate. This paper presents the valving concept, and demonstrates its application in controlling both the rate and direction of fluid flow and in flow injection analyses. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, US DOE, Microanalyt Instrumentat Ctr, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Porter, MD (reprint author), Iowa State Univ, US DOE, Microanalyt Instrumentat Ctr, Ames Lab, Ames, IA 50011 USA. RI Zhong, Chuan-Jian/D-3394-2013 NR 22 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD MAY 18 PY 2001 VL 504 IS 2 BP 166 EP 174 DI 10.1016/S0022-0728(01)00412-0 PG 9 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 438AJ UT WOS:000169031300005 ER PT J AU Than, C Morimoto, H Williams, PG Chehade, KAH Andres, DA Spielmann, HP AF Than, C Morimoto, H Williams, PG Chehade, KAH Andres, DA Spielmann, HP TI Preparation, NMR characterization, and labeling reactions of tritiated triacetoxy sodium borohydride SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID REDUCTIVE AMINATION; CARBOXYLIC-ACIDS; TRIACETOXYBOROHYDRIDE; ALDEHYDES; KETONES; MEDIA C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Tritium Labelling Facil, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Kentucky, Dept Biochem, Lexington, KY 40536 USA. Univ Kentucky, Dept Chem, Lexington, KY 40536 USA. Univ Kentucky, Kentucky Ctr Struct Biol, Lexington, KY 40536 USA. RP Than, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Tritium Labelling Facil, Phys Biosci Div, Berkeley, CA 94720 USA. FU NCRR NIH HHS [P41 RR01237]; NEI NIH HHS [EY11231] NR 21 TC 2 Z9 2 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAY 18 PY 2001 VL 66 IS 10 BP 3602 EP 3605 DI 10.1021/jo005753i PG 4 WC Chemistry, Organic SC Chemistry GA 435XP UT WOS:000168907700050 PM 11348153 ER PT J AU Hodell, DA Brenner, M Curtis, JH Guilderson, T AF Hodell, DA Brenner, M Curtis, JH Guilderson, T TI Solar forcing of drought frequency in the Maya lowlands SO SCIENCE LA English DT Article ID CLIMATE VARIABILITY; YUCATAN-PENINSULA; RECORD; LAKE; NIGERIA; AFRICA; EVENTS; CARBON; MEXICO; BE-10 AB We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records of cosmogenic nuclide production (carbon-14 and beryllium-10) that is thought to reflect variations in solar activity. We conclude that a significant component of century-scale variability in Yucatan droughts is explained by solar forcing. Furthermore, some of the maxima in the 208-year drought cycle correspond with discontinuities in Maya cultural evolution, suggesting that the Maya were affected by these bicentennial oscillations in precipitation. C1 Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Hodell, DA (reprint author), Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA. EM dhodell@geology.ufl.edu NR 37 TC 291 Z9 314 U1 8 U2 72 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 MAY 18 PY 2001 VL 292 IS 5520 BP 1367 EP 1370 DI 10.1126/science.1057759 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 435DV UT WOS:000168862900043 PM 11359010 ER PT J AU Kundig, AA Loffler, JF Johnson, WL Uggowitzer, PJ Thiyagarajan, P AF Kundig, AA Loffler, JF Johnson, WL Uggowitzer, PJ Thiyagarajan, P TI Influence of decomposition on the thermal stability of undercooled Zr-Ti-Cu-Ni-Al alloys SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT 5th International Conference on Nanostructured Materials (NANO 2000) CY AUG 20-25, 2000 CL SENDAI, JAPAN SP Int Comm Nanostructrued Mt, Acta Materialia Inc, Inst Mat Res, Tohoku Univ, Inst Sci & Ind Res, Osaka Univ, Sendai City, Japan Soc Promot Sci, Iwatani Naoji Fdn DE metallic glasses; thermal properties; neutron scattering; decomposition ID CRYSTALLIZATION C1 CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. ETH Zurich, Inst Met Forsch, CH-8092 Zurich, Switzerland. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Kundig, AA (reprint author), CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. RI Uggowitzer, Peter/H-3581-2012 OI Uggowitzer, Peter/0000-0002-9504-5652 NR 2 TC 26 Z9 26 U1 2 U2 5 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 MAY 18 PY 2001 VL 44 IS 8-9 BP 1269 EP 1273 DI 10.1016/S1359-6462(01)00691-1 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 444FL UT WOS:000169389400021 ER PT J AU Girt, E Krishnan, KM Thomas, G AF Girt, E Krishnan, KM Thomas, G TI Optimization of magnetic properties of nanostructured Nd-Fe-B: Approaching ideal Stoner-Wohlfarth behaviour SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT 5th International Conference on Nanostructured Materials (NANO 2000) CY AUG 20-25, 2000 CL SENDAI, JAPAN SP Int Comm Nanostructrued Mt, Acta Materialia Inc, Inst Mat Res, Tohoku Univ, Inst Sci & Ind Res, Osaka Univ, Sendai City, Japan Soc Promot Sci, Iwatani Naoji Fdn ID ALLOYS AB By appropriate annealing of rapidly quenched NddeltaFe13.1B (2.05 < delta < 147.6) the amount and microstructure of the Nd2Fe14B grains in the Nd-rich matrix were systematically controlled and correlated with coercivity, mu H-O(c). For optimally annealed NddeltaFe13.1B an increase in Nd concentration enhances mu H-O(c) of the Nd2Fe14B grains (from 1.2 T in Nd2.05Fe13.1B to 2.75 T in Nd147.6Fe13.1B at 290 K) and promotes the growth of the Nd2Fe14B grains elongated in shape. The largest observed coercivity, H-c similar to 2.75 T is over 80% of the theoretical limit expected for Stoner-Wohlfarth coherent rotation behavior including demagnetization effects. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Girt, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 10 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 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD MAY 18 PY 2001 VL 44 IS 8-9 BP 1431 EP 1435 DI 10.1016/S1359-6462(01)00936-8 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 444FL UT WOS:000169389400051 ER PT J AU Youngdahl, CJ Weertman, JR Hugo, RC Kung, HH AF Youngdahl, CJ Weertman, JR Hugo, RC Kung, HH TI Deformation behavior in nanocrystalline copper SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT 5th International Conference on Nanostructured Materials (NANO 2000) CY AUG 20-25, 2000 CL SENDAI, JAPAN SP Int Comm Nanostructrued Mt, Acta Materialia Inc, Inst Mat Res, Tohoku Univ, Inst Sci & Ind Res, Osaka Univ, Sendai City, Japan Soc Promot Sci, Iwatani Naoji Fdn DE copper; nanocrystalline; deformation mechanism ID HALL-PETCH RELATION C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Youngdahl, CJ (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RI Weertman, Julia/B-7540-2009; Kung, Harold/B-7647-2009 NR 11 TC 96 Z9 107 U1 4 U2 27 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 MAY 18 PY 2001 VL 44 IS 8-9 BP 1475 EP 1478 DI 10.1016/S1359-6462(01)00712-6 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 444FL UT WOS:000169389400060 ER PT J AU Nieh, TG Wadsworth, J AF Nieh, TG Wadsworth, J TI High strength freestanding metal-amorphous multilayers SO SCRIPTA MATERIALIA LA English DT Article; Proceedings Paper CT 5th International Conference on Nanostructured Materials (NANO 2000) CY AUG 20-25, 2000 CL SENDAI, JAPAN SP Int Comm Nanostructrued Mt, Acta Materialia Inc, Inst Mat Res, Tohoku Univ, Inst Sci & Ind Res, Osaka Univ, Sendai City, Japan Soc Promot Sci, Iwatani Naoji Fdn DE amorphous; laminates; composites; crystallization ID CU/ZR C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nieh, TG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-350, Livermore, CA 94551 USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 8 TC 7 Z9 8 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 MAY 18 PY 2001 VL 44 IS 8-9 BP 1825 EP 1830 DI 10.1016/S1359-6462(01)00801-6 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 444FL UT WOS:000169389400131 ER PT J AU Shin, YS Liu, J Chang, JH Nie, ZM Exarhos, G AF Shin, YS Liu, J Chang, JH Nie, ZM Exarhos, G TI Hierarchically ordered ceramics through surfactant-templated sol-gel mineralization of biological cellular structures SO ADVANCED MATERIALS LA English DT Article ID INORGANIC HYBRID MATERIALS; SILICA; WOOD; COMPOSITES; MINERALS; PHASE C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liu, J (reprint author), Pacific NW Natl Lab, Battelle Blvd,POB 999,MS K2-44, Richland, WA 99352 USA. NR 29 TC 144 Z9 148 U1 4 U2 26 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD MAY 17 PY 2001 VL 13 IS 10 BP 728 EP 732 DI 10.1002/1521-4095(200105)13:10<728::AID-ADMA728>3.0.CO;2-J PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 438QA UT WOS:000169063500006 ER PT J AU Makote, RD Dai, S AF Makote, RD Dai, S TI Matrix-induced modification of imprinting effect for Cu2+ adsorption in hybrid silica matrices SO ANALYTICA CHIMICA ACTA LA English DT Article; Proceedings Paper CT 1st International Workshop on Molecularly Imprinted Polymers CY JUL 03-05, 2000 CL CARDIFF, WALES SP Welsh Sch Pharmacy, Cardiff Univ, Soc Molecular Imprinting DE sol-gel sorbents; polymer; matrix-induced modification ID POLYMERS; SEPARATION; SORBENTS; BINDING; FILMS AB Matrix-induced modification of the imprinting effect for Cu2+ adsorption in sol-gel sorbents has been investigated. This investigation shows that the hydrophobicity of the sol-gel matrices enhances the imprinting effect and selectivity of the sorbents toward target ions. Modification of the matrix hydrophobicity can be easily achieved by copolymerizing tetramethylorthosilicate and methyltrimethoxysilane or phenyltrimethoxysilane. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Technol, POB 2008, Oak Ridge, TN 37831 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 21 TC 25 Z9 27 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD MAY 17 PY 2001 VL 435 IS 1 BP 169 EP 175 DI 10.1016/S0003-2670(00)01334-9 PG 7 WC Chemistry, Analytical SC Chemistry GA 435JU UT WOS:000168879000023 ER PT J AU Moore, DS AF Moore, DS TI Influence of hot bands on vibrational spectra of shock compressed materials SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID STOKES-RAMAN-SPECTROSCOPY; LIQUID CARBON-MONOXIDE; SCATTERING; NITROMETHANE; MIXTURES; TEMPERATURE; ABSORPTION; NITROGEN; BENZENE; OXYGEN AB For polyatomic molecules, extracting vibrational frequency shifts from spectra recorded under shock loading conditions is complicated by anharmonic coupling of modes and thermal population of low lying vibrational levels, which produce hot bands in the vibrational spectra. Most vibrational frequency shifts with shock pressure reported in the literature have been extracted from inadequately resolved spectral bands fitted with single Gaussians. This paper shows that, in general, for polyatomic molecules, the effect of the hot bands is to push the centroid of the fitted Gaussian away from the frequency of the vibrational fundamental. The direction and magnitude of this effect requires knowledge of the anharmonic coupling coefficients (which are in all likelihood also pressure dependent). To completely characterize the intra- and intermolecular potentials, it is therefore necessary to use the highest spectral resolution possible, and to independently measure or calculate the pressure and temperature dependence of the anharmonic coupling coefficients for the molecules of interest. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Moore, DS (reprint author), Univ Calif Los Alamos Natl Lab, MS-C920, Los Alamos, NM 87545 USA. RI Moore, David/C-8692-2013 NR 29 TC 8 Z9 9 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 MAY 17 PY 2001 VL 105 IS 19 BP 4660 EP 4663 DI 10.1021/jp010148k PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434FC UT WOS:000168803600011 ER PT J AU Barich, DH Nicholas, JB Haw, JF AF Barich, DH Nicholas, JB Haw, JF TI Gauge-including atomic orbital proton chemical shifts of strong hydrogen bonds: The importance of electron correlation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO; ENZYMATIC CATALYSIS; GAS-PHASE; PERTURBATION-THEORY; WAVE-FUNCTIONS; SOLID ACIDS; BASIS-SETS; NMR; COMPLEXES; DIFFRACTION AB The effects of electron correlation are often of little importance in theoretical H-1 NMR chemical shift calculations. Indeed, the differences between uncorrelated and correlated values are typically ca. 0.2 ppm or less for organic compounds. Here we demonstrate a very important case where this assumption breaks down; protons involved in strong hydrogen bonds. We found that the isotropic shifts calculated with the gauge-including atomic orbital (GIAO) approach at the RHF level overestimate the corresponding MP2 values by well over 1 ppm and commonly by 2 ppm. This is true for minimum energy geometries as well as for the transition states for proton transfer. In contrast, electron correlation effects are an order of magnitude smaller for the non-hydrogen-bonding protons in the structures we studied. The systems treated theoretically were FHF-, N2H7+, H3O2-, the enol of 2,4-pentanedione, the monoanion of cis-maleic acid, and the monoanion of dimethylmalonic acid. Geometries were calculated at either the MP2/6-311++G** or MP2/aug-cc-pVTZ Level of theory. The donor-acceptor distances and other geometric parameters for most structures satisfy the standard criteria for "strong" hydrogen bonds, A notable exception is the minimum energy structure for the enol of 2,4-pentanedione, which is better classified as a "moderate" hydrogen bond on the basis of both geometric and chemical shift criteria. The effect of electron correlation on the H-1 chemical shift in the latter case was the smallest of any structure we considered. C1 Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ So Calif, Loker Hydrocarbon Res Inst, Los Angeles, CA 90089 USA. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Nicholas, JB (reprint author), Texas A&M Univ, Dept Chem, POB 30012, College Stn, TX 77842 USA. NR 51 TC 27 Z9 27 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 17 PY 2001 VL 105 IS 19 BP 4708 EP 4715 DI 10.1021/jp004118d PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434FC UT WOS:000168803600019 ER PT J AU Song, WG Nicholas, JB Haw, JF AF Song, WG Nicholas, JB Haw, JF TI A persistent carbenium ion on the methanol-to-olefin catalyst HSAPO-34: Acetone shows the way SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID IN-SITU NMR; CHEMICAL-SHIFT TENSORS; SOLID-STATE NMR; BENZENIUM ION; CHEMISTRY; ZEOLITE; ACIDS; HYDROCARBONS AB In situ C-13 NMR with both CAVERN and pulse-quench methods was used to understand the chemistry of acetone on the silico-aluminophosphate catalyst HSAPO-34. The isotropic shift of [2-C-13]acetone shows that most of the acid sites on this catalyst are weaker than those on aluminosilicate zeolites, but a minority site was resolved with a shift higher than that on zeolite HZSM-5. At elevated temperatures, acetone dimerized to diacetone alcohol and dehydrated to mesityl oxide. Mesityl oxide cracked in the presence of water to acetic acid and isobutylene. Trimerization of butenes formed a significant amount of a persistent carbenium ion with unusual spectroscopic properties, and this is proposed to be the heptamethylcyclopentenyl cation, the first observation of a persistent carbenium ion on a SAPO catalyst. Chemical shift calculations at the GIAO-MP2 level revealed a discrepancy for one signal of the proposed cation but ruled out an alternative assignment. Methylaromatic formation coincided with cyclopentenyl cation synthesis, supporting a mechanistic proposal for aromatic synthesis on zeolites. Conventional flow reactor studies revealed a high selectivity for C-4 olefins and rapid deactivation with acetone as feed. The results of this investigation are interpreted in the context of methanol-to-olefin (MTO) chemistry on HSAPO-34. C1 Univ So Calif, Loker Hydrocarbon Res Inst, Los Angeles, CA 90089 USA. Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Nicholas, JB (reprint author), Genentech Inc, 1 DNA Way, S San Francisco, CA 94080 USA. RI Song, Weiguo/D-6041-2016 OI Song, Weiguo/0000-0001-5390-6787 NR 22 TC 61 Z9 62 U1 2 U2 39 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 MAY 17 PY 2001 VL 105 IS 19 BP 4317 EP 4323 DI 10.1021/jp0041407 PG 7 WC Chemistry, Physical SC Chemistry GA 434FE UT WOS:000168803800040 ER PT J AU Kennis, JTM Gobets, B van Stokkum, IHM Dekker, JP van Grondelle, R Fleming, GR AF Kennis, JTM Gobets, B van Stokkum, IHM Dekker, JP van Grondelle, R Fleming, GR TI Light harvesting by chlorophylls and carotenoids in the photosystem I core complex of Synechococcus elongatus: A fluorescence upconversion study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SYNECHOCYSTIS SP PCC-6803; ELECTRONIC EXCITATION TRANSFER; ULTRAFAST PRIMARY PROCESSES; PRIMARY CHARGE SEPARATION; ENERGY-TRANSFER; RHODOBACTER-SPHAEROIDES; PURPLE BACTERIA; BETA-CAROTENE; S-1 STATE; TRANSIENT ABSORPTION AB The photosystem I (PSI) core complex of oxygenic photosynthesis is an integral pigment-protein complex that incorporates both the antenna and the reaction center (RC). It binds about 100 Chl alpha and 20 beta -carotene molecules. In the PSI core complex of the cyanobacterium Synechococcus elongatus, a total of about 9 antenna Chi a molecules are;ed shifted with respect to the primary electron donor, which absorbs at 700 nm. We have studied energy transfer and trapping processes in trimeric PSI complexes of this species at femtosecond resolution by means of the fluorescence-upconversion technique: By simultaneously analyzing the fluorescence upconversion results and those obtained with a streak camera with picosecond resolution and multichannel detection (Gobets, B.; et al, Biophys. J., in press), we have mapped out the energy transfer processes that follow immediately after photon absorption. Equilibration among Chi a pigments in the bulk antenna was found to occur with a time constant of 360 fs. A major energy equilibration phase between bulk Chi a and the red-shifted antenna Chls occurs in 3.6 s. A slow phase in energy equilibration takes place in 9.8 ps, after which the excitations are trapped by the RC in 38 pst Fluorescence anisotropy measurements indicated an initial anisotropy of 0.30, which decayed biphasically with a major fast phase of 160 fs and a minor slow phase of 1.8 ps to a final anisotropy of 0.06. The 160 fs phase is assigned to elementary energy transfer steps in the bulk Chi a antenna, and the 1.8 ps phase to further equilibration processes, possibly involving energy transfer to or among red-shifted Chls. Energy transfer from p-carotene to Chi a was found to proceed both from the S-2 State and the S-1 state, with the majority of transferred excitations (60%) originating from the S2 state, resulting in an estimated overall yield of similar to 90%. A comparison is made with the PSII core antenna protein CP47, which binds the same pigments but has a substantially lower carotenoid-Chl a energy transfer yield of similar to 35% (van Dorssen R. J.; et al. Biochim. Biophys. Acta 1987, 893, 267). C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Free Univ Amsterdam, Fac Sci, Dept Biophys & Phys Complex Syst, NL-1081 HV Amsterdam, Netherlands. RP Fleming, GR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI van Stokkum, Ivo/E-7175-2015 OI van Stokkum, Ivo/0000-0002-6143-2021 NR 58 TC 73 Z9 79 U1 1 U2 24 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 MAY 17 PY 2001 VL 105 IS 19 BP 4485 EP 4494 DI 10.1021/jp010382a PG 10 WC Chemistry, Physical SC Chemistry GA 434FE UT WOS:000168803800062 ER PT J AU Shkrob, IA Sauer, MC AF Shkrob, IA Sauer, MC TI Metastable electrons, high-mobility solvent anions, and charge transfer reactions in supercritical carbon dioxide SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LASER FLASH-PHOTOLYSIS; PHOTOELECTRON-SPECTROSCOPY; DIFFUSION-COEFFICIENTS; NONPOLAR-SOLVENTS; EXCESS ELECTRONS; INFRARED-SPECTRA; NITROUS-OXIDE; SOLID NEON; FLUIDS; CO2 AB Time-resolved de photoconductivity has been used to observe quasifree electrons and solvent radical anions in supercritical CO2 (rho (c) approximate to 0.468 g/cm(3); T-c approximate to 31 degreesC). The electrons have lifetime tau (e) < 200 ps and mobility mu (e), > 10 cm(2)/(V s). For rho/rho (c) > 0.64, the product mu (e)tau (e) rapidly increases with the solvent density rho, reaching 2.5 x 10(-9) cm(2)/V at rho/rho (c) approximate to 1.82. The mobility of the solvent anions exponentially increases with p, being 2-10 times higher than the mobilities of other ions. The activation energy of the solvent anion migration is 0.46 eV, whereas for solute ions, this energy is less than 20 meV. Electron detachment upon 1.0-3.5 eV photoexcitation of the solvent anion has been observed. The cross section of photodetachment Linearly increases with photon energy above 1.76 eV end exhibits a shoulder at 2.82 eV; the spectrum is similar to photoelectron spectra of (CO2)(n)(-) clusters (n = 6-9) in the gas phase. Both the electrons and solvent anions react with nonpolar electron acceptor solutes whose gas-phase electron affinity (EA(g)) is greater than 0.4 eV. At T = 41 degreesC and rho/rho (c) approximate to 1.77, the rates of the electron attachment and solvent anion scavenging correlate with each other and the solute EA,. Only solutes with EA(g) > 2 eV exhibit diffusion-controlled kinetics. For pip, r 0.85, the scavenging radii of these diffusion-controlled reactions decrease with rho. For O-2, the scavenging of the solvent anion is reversible (DeltaH degrees approximate to -0.44 eV). C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 70 TC 22 Z9 22 U1 0 U2 7 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 MAY 17 PY 2001 VL 105 IS 19 BP 4520 EP 4530 DI 10.1021/jp010325h PG 11 WC Chemistry, Physical SC Chemistry GA 434FE UT WOS:000168803800067 ER PT J AU Bradbury, A AF Bradbury, A TI Sorting out the Smiths SO NATURE LA English DT Letter C1 Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Bradbury, A (reprint author), Univ Calif Los Alamos Natl Lab, Biosci Div, MS-M888,TA-43,HRL-1,Bldg 1, Los Alamos, NM 87545 USA. NR 0 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 MAY 17 PY 2001 VL 411 IS 6835 BP 237 EP 237 DI 10.1038/35077304 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 432RT UT WOS:000168710000017 PM 11357100 ER PT J AU Abe, K Abe, K Abe, T Adam, I Akimoto, H Aston, D Baird, KG Baltay, C Band, HR Barklow, TL Bauer, JM Bellodi, G Berger, R Blaylock, G Bogart, JR Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Calcaterra, A Cassell, R Chou, A Cohn, HO Coller, JA Convery, MR Cook, V Cowan, RF Crawford, G Damerell, CJS Daoudi, M de Groot, N de Sangro, R Dong, DN Doser, M Dubois, R Erofeeva, I Eschenburg, V Etzion, E Fahey, S Falciai, D Fernandez, JP Flood, K Frey, R Hart, EL Hasuko, K Hertzbach, SS Huffer, ME Huynh, X Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Kajikawa, R Kalelkar, M Kang, HJ Kofler, RR Kroeger, RS Langston, M Leith, DWG Lia, V Lin, C Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T McKemey, AK Messner, R Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Narita, S Nauenberg, U Neal, H Nesom, G Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, CH Peruzzi, I Piccolo, M Piemontese, L Plano, RJ Prepost, R Prescott, CY Ratcliff, BN Reidy, J Reinertsen, PL Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schumm, BA Schwiening, J Serbo, VV Shapiro, G Sinev, NB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, H Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Taylor, FE Thom, J Torrence, E Usher, T Va'vra, J Verdier, R Wagner, DL Waite, AP Walston, S Weidemann, AW Weiss, ER Whitaker, JS Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Wright, TR Yamamoto, RK Yashima, J Yellin, SJ Young, CC Yuta, H AF Abe, K Abe, K Abe, T Adam, I Akimoto, H Aston, D Baird, KG Baltay, C Band, HR Barklow, TL Bauer, JM Bellodi, G Berger, R Blaylock, G Bogart, JR Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Calcaterra, A Cassell, R Chou, A Cohn, HO Coller, JA Convery, MR Cook, V Cowan, RF Crawford, G Damerell, CJS Daoudi, M de Groot, N de Sangro, R Dong, DN Doser, M Dubois, R Erofeeva, I Eschenburg, V Etzion, E Fahey, S Falciai, D Fernandez, JP Flood, K Frey, R Hart, EL Hasuko, K Hertzbach, SS Huffer, ME Huynh, X Iwasaki, M Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Kajikawa, R Kalelkar, M Kang, HJ Kofler, RR Kroeger, RS Langston, M Leith, DWG Lia, V Lin, C Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T McKemey, AK Messner, R Moffeit, KC Moore, TB Morii, M Muller, D Murzin, V Narita, S Nauenberg, U Neal, H Nesom, G Oishi, N Onoprienko, D Osborne, LS Panvini, RS Park, CH Peruzzi, I Piccolo, M Piemontese, L Plano, RJ Prepost, R Prescott, CY Ratcliff, BN Reidy, J Reinertsen, PL Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schumm, BA Schwiening, J Serbo, VV Shapiro, G Sinev, NB Snyder, JA Staengle, H Stahl, A Stamer, P Steiner, H Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Taylor, FE Thom, J Torrence, E Usher, T Va'vra, J Verdier, R Wagner, DL Waite, AP Walston, S Weidemann, AW Weiss, ER Whitaker, JS Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Wittlin, JL Woods, M Wright, TR Yamamoto, RK Yashima, J Yellin, SJ Young, CC Yuta, H TI Improved measurement of the probability for gluon splitting into b(b)over-bar in Z(0) decays SO PHYSICS LETTERS B LA English DT Article ID HADRONIC Z-DECAYS; E+E ANNIHILATION; EVENT GENERATOR; MASS TAG; VERTEX; RECONSTRUCTION; ALGORITHM; PAIRS AB We have measured gluon splitting into bottom quarks, g --> b (b) over bar, in hadronic Z(0) decays collected by SLD between 1996 and 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary flavor. 4-jet events were identified. and in each event a topological vertex-mass technique was applied to the two jets closest in angle in order to identify them as b or b;jets. The upgraded CCD-based vertex detector gives very high B-tagging efficiency, especially for B hadrons with the low energies typical of this process. We measured the rate of g --> b (b) over bar production per hadronic event, g(b (b) over bar), to be (2.44 +/- 0.59(stat.) +/- 0.34(syst.)) x 10(-3). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Sendai, Miyagi 980, Japan. Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Mississippi, University, MS 38677 USA. Univ Oxford, Oxford OX1 3RH, England. Univ Oregon, Eugene, OR 97403 USA. Univ Tennessee, Knoxville, TN 37996 USA. Univ Washington, Seattle, WA 98105 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Boston Univ, Boston, MA 02215 USA. MIT, Cambridge, MA 02139 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Bristol, Bristol, Avon, England. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Univ Colorado, Boulder, CO 80309 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Perugia, I-06100 Perugia, Italy. Ist Nazl Fis Nucl, Sez Perugia, I-06100 Perugia, Italy. Brunel Univ, Uxbridge UB8 3PH, Middx, England. Vanderbilt Univ, Nashville, TN 37235 USA. Soongsil Univ, Seoul 156743, South Korea. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Sez Ferrara, I-44100 Ferrara, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Colorado State Univ, Ft Collins, CO 80523 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Aomori Univ, Aomori 030, Japan. RP Abe, K (reprint author), Tohoku Univ, Sendai, Miyagi 980, Japan. EM burrows@slac.stanford.edu RI de Groot, Nicolo/A-2675-2009; Stahl, Achim/E-8846-2011; de Sangro, Riccardo/J-2901-2012; Frey, Raymond/E-2830-2016; Calcaterra, Alessandro/P-5260-2015 OI Stahl, Achim/0000-0002-8369-7506; de Sangro, Riccardo/0000-0002-3808-5455; Frey, Raymond/0000-0003-0341-2636; Calcaterra, Alessandro/0000-0003-2670-4826 NR 34 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 17 PY 2001 VL 507 IS 1-4 BP 61 EP 69 DI 10.1016/S0370-2693(01)00367-7 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 435LB UT WOS:000168882000008 ER PT J AU Breitweg, J Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Stanek, R Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Amelung, C Brock, I Coboken, K Goers, S Hartmann, H Heinloth, K Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wieber, H Bailey, DS Barret, O Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Liu, W Liu, X Mellado, B Paganis, S Sampson, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Klimek, K Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Jelen, K Kisielewska, D Kowal, AM Kowalski, T Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Kotanski, A Bauerdick, LAT Behrens, U Bienlein, JK Borras, K Chiochia, V Crittenden, J Dannheim, D Desler, K Drews, G Fox-Murphy, A Fricke, U Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hebbel, K Hillert, S Koch, W Kotz, U Kowalski, H Labes, H Lohr, B Mankel, R Martens, J Martinez, M Milite, M Moritz, M Notz, D Petrucci, MC Polini, A Rohde, M Savin, AA Schneekloth, U Selonke, F Stonjek, S Wolf, G Wollmer, U Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Straub, PB Barbagli, G Gallo, E Parenti, A Pelfer, PG Bamberger, A Benen, A Coppola, N Eisenhardt, S Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Lee, SW Lupi, A Macdonald, N McCance, GJ Saxon, DH Sinclair, LE Skillicorn, IO Waugh, R Bodmann, B Gendner, N Holm, U Salehi, H Wick, K Yildirim, A Ziegler, A Carli, T Garfagnini, A Geiser, A Gialas, I Kcira, D Lohrmann, E Goncalo, R Long, KR Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Ishii, T Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Lee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Corriveau, F Padhi, S Stairs, DG Wing, M Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Botje, M Engelen, J Grijpink, S Koffeman, E Kooijman, P Schagen, S van Sighem, A Tassi, E Tiecke, H Tuning, N Velthuis, JJ Vossebeld, J Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Grosse-Knetter, J Matsushita, T Ruske, O Sutton, MR Walczak, R Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dusini, S Limentani, S Longhin, A Posocco, M Stanco, L Turcato, M Adamczyk, L Iannotti, L Oh, BY Okrasinski, JR Saull, PRB Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Bailey, DC Fagerstroem, CP Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hayes, ME Heaphy, EA Jones, TW Lane, JB West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Pawlak, R Smalska, B Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Gadaj, T Deppe, O Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Foudas, C Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wildschek, T Wodarczyk, M Deshpande, A Dhawan, S Hughes, VW Bhadra, S Catterall, CD Frisken, WR Hall-Wilton, R Khakzad, M Menary, S AF Breitweg, J Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Stanek, R Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Amelung, C Brock, I Coboken, K Goers, S Hartmann, H Heinloth, K Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wieber, H Bailey, DS Barret, O Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Rodrigues, E Scott, J Tapper, RJ Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Liu, W Liu, X Mellado, B Paganis, S Sampson, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Klimek, K Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Jelen, K Kisielewska, D Kowal, AM Kowalski, T Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Kotanski, A Bauerdick, LAT Behrens, U Bienlein, JK Borras, K Chiochia, V Crittenden, J Dannheim, D Desler, K Drews, G Fox-Murphy, A Fricke, U Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hebbel, K Hillert, S Koch, W Kotz, U Kowalski, H Labes, H Lohr, B Mankel, R Martens, J Martinez, M Milite, M Moritz, M Notz, D Petrucci, MC Polini, A Rohde, M Savin, AA Schneekloth, U Selonke, F Stonjek, S Wolf, G Wollmer, U Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Straub, PB Barbagli, G Gallo, E Parenti, A Pelfer, PG Bamberger, A Benen, A Coppola, N Eisenhardt, S Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Lee, SW Lupi, A Macdonald, N McCance, GJ Saxon, DH Sinclair, LE Skillicorn, IO Waugh, R Bodmann, B Gendner, N Holm, U Salehi, H Wick, K Yildirim, A Ziegler, A Carli, T Garfagnini, A Geiser, A Gialas, I Kcira, D Lohrmann, E Goncalo, R Long, KR Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Ishii, T Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Lee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Corriveau, F Padhi, S Stairs, DG Wing, M Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Botje, M Engelen, J Grijpink, S Koffeman, E Kooijman, P Schagen, S van Sighem, A Tassi, E Tiecke, H Tuning, N Velthuis, JJ Vossebeld, J Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Grosse-Knetter, J Matsushita, T Ruske, O Sutton, MR Walczak, R Bertolin, A Brugnera, R Carlin, R Dal Corso, F Dusini, S Limentani, S Longhin, A Posocco, M Stanco, L Turcato, M Adamczyk, L Iannotti, L Oh, BY Okrasinski, JR Saull, PRB Toothacker, WS Whitmore, JJ Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Shah, TP Epperson, D Heusch, C Sadrozinski, HFW Seiden, A Wichmann, R Williams, DC Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Bailey, DC Fagerstroem, CP Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hayes, ME Heaphy, EA Jones, TW Lane, JB West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Pawlak, R Smalska, B Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Gadaj, T Deppe, O Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Badgett, WF Chapin, D Cross, R Foudas, C Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wildschek, T Wodarczyk, M Deshpande, A Dhawan, S Hughes, VW Bhadra, S Catterall, CD Frisken, WR Hall-Wilton, R Khakzad, M Menary, S CA ZEUS Collaboration TI Measurement of dijet production in neutral current deep inelastic scattering at high Q(2) and determination of alpha(s) SO PHYSICS LETTERS B LA English DT Article ID JET CROSS-SECTIONS; TO-LEADING ORDER; LEPTON-NUCLEON SCATTERING; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; MONTE-CARLO GENERATOR; COLOR DIPOLE MODEL; HADRON-COLLISIONS; PARTON DISTRIBUTIONS; PERTURBATION-THEORY AB Dijet production has been studied in neutral current deep inelastic e(+)p scattering for 470 < Q(2) < 20000 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb(-1). Dijet differential cross sections are presented in a kinematic region where both theoretical and experimental uncertainties are small. Next-to-leading-order (NLO) QCD calculations describe the measured differential cross sections well. A QCD analysis of the measured dijet fraction as a function of Q(2) allows both a precise determination of alpha (s)(M-z) and a test of the energy-scale dependence of the strong coupling constant. A detailed analysis provides an improved estimate of the uncertainties of the NLO QCD cross sections arising from the parton distribution functions of the proton. The value of cu,(Mz), as determined from the QCD fit, is alpha (s)(M-z) = 0.1166 +/- 0.0019(stat.)(-0.0033)(+0.0024)(exp.)(-0.0044)(+0.0057)(th.). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Irvington, NY USA. Inst Phys Nucl, Krakow, Poland. Acad Min & Med, Fac Phys & Nucl Tech, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, Deutsch Elektronen Synchrotron, Hamburg, Germany. DESY, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, Florence, Italy. Univ Freiburg, Fak Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Hamburg, Inst Expt Phys 1, Hamburg, Germany. Univ Hamburg, Inst Expt Phys 2, Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Phys Engn Inst, Moscow, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Chilton, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Seoul Natl Univ, Seoul, South Korea. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys, IL-69978 Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Phys Expt, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI USA. Yale Univ, Dept Phys, New Haven, CT USA. York Univ, Dept Phys, Toronto, ON M3J 2R7, Canada. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Suchkov, Sergey/M-6671-2015; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; De Pasquale, Salvatore/B-9165-2008; Solomin, Anatoly/C-3072-2016; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011 OI dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Graciani Diaz, Ricardo/0000-0001-7166-5198; Capua, Marcella/0000-0002-2443-6525; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Gladilin, Leonid/0000-0001-9422-8636 NR 66 TC 45 Z9 45 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 MAY 17 PY 2001 VL 507 IS 1-4 BP 70 EP 88 DI 10.1016/S0370-2693(01)00421-X PG 19 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 435LB UT WOS:000168882000009 ER PT J AU Sa, BH Faessler, A Fuchs, C Tai, A Wang, XR Xu, N Zabrodin, E AF Sa, BH Faessler, A Fuchs, C Tai, A Wang, XR Xu, N Zabrodin, E TI Enhancement of phi mesons in p+Pb and Pb+Pb collisions at 158A GeV/c SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; QUARK-GLUON PLASMA; PB-PB COLLISIONS; STRANGENESS ENHANCEMENT; FIRECRACKER MODEL; NUCLEAR COLLISIONS; FREEZE-OUT; RESCATTERING; ENERGIES; VERSION AB Using a hadron-string cascade model LUCIAE, the phi -meson production in nuclear collisions (p + Pb and Pb + Pb) and elementary collisions p + p were studied systematically. Within the framework of the model, the experimentally measured phi enhancement in p + Ph and Pb + Pb over p + p collisions can be mostly explained by the collective effects in the gluon string emission and the reduction of the s-quark suppression. (C) 2001 Published by Elsevier Science B.V. C1 China Inst Atom Energy, Beijing 102413, Peoples R China. Univ Tubingen, Inst Theoret Phys, D-72076 Tubingen, Germany. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Acad Sinica, Inst Theoret Phys, Beijing 100080, Peoples R China. Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China. RP China Inst Atom Energy, POB 275 18, Beijing 102413, Peoples R China. EM sabh@iris.ciae.ac.cn NR 31 TC 3 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD MAY 17 PY 2001 VL 507 IS 1-4 BP 104 EP 108 DI 10.1016/S0370-2693(01)00456-7 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 435LB UT WOS:000168882000011 ER PT J AU Kharzeev, D Nardi, M AF Kharzeev, D Nardi, M TI Hadron production in nuclear collisions at RHIC and high-density QCD SO PHYSICS LETTERS B LA English DT Article ID GLUON DISTRIBUTION-FUNCTIONS; HEAVY-ION COLLISIONS; HIGH-ENERGY; SMALL-X; J/PSI SUPPRESSION; STRING MODEL; QUARK; EQUILIBRATION; MULTIPLICITY; RADIATION AB We analyze the first results on charged particle multiplicity at RHIC in the conventional eikonal approach and in the framework of high-density QCD. We extract the fraction F of the hadron multiplicity originating from "hard" (i.e., proportional to the number of binary collisions) processes: we find a strong growth of this fraction with energy: F(roots = 56 GeV) similar or equal to 22%, while F(roots = 130 GeV) similar or equal to 37%. This indicates a rapid increase in the density of the produced particles. We outline the predictions of high-density QCD for the centrality, energy, and atomic number dependence of hadron production. Surprisingly, the predictions of the conventional eikonal approach and of high-density QCD for centrality dependence of hadron multiplicity at roots = 130 GeV appear very similar. (C) 2001 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Turin, Dipartimento Fis Teor, I-10125 Turin, Italy. Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy. RP Kharzeev, D (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. OI Nardi, Marzia/0000-0003-1574-9869 NR 57 TC 539 Z9 541 U1 0 U2 3 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 MAY 17 PY 2001 VL 507 IS 1-4 BP 121 EP 128 DI 10.1016/S0370-2693(01)00457-9 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 435LB UT WOS:000168882000014 ER PT J AU Ligeti, Z Luke, M Wise, MB AF Ligeti, Z Luke, M Wise, MB TI Comment on studying the corrections to factorization in B -> D-(*) X SO PHYSICS LETTERS B LA English DT Article ID MESON DECAYS; QCD FACTORIZATION; HEAVY-QUARK; MODEL AB We propose studying the mechanism of factorization in exclusive decays of the form B --> D-(*X-) by examining the differential decay rate as a function of the invariant mass of the light hadronic state X. If factorization works primarily due to the large N-c limit then its accuracy is not expected to decrease as the X invariant mass increases. However, if factorization is mostly a consequence of perturbative QCD then the corrections should grow with the X invariant mass. Combining data for hadronic tau decays and semileptonic B decays allows tests of factorization to be made for a variety of final states. We discuss the examples of B --> D*pi (+)pi (-)pi (-)pi (0) and B --> D*omega pi (-). The mode B --> D*omega pi (-) will allow a precision study of the dependence of the corrections to factorization on the invariant mass of the light hadronic state. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. CALTECH, Pasadena, CA 91125 USA. RP Ligeti, Z (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 24 TC 35 Z9 35 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 MAY 17 PY 2001 VL 507 IS 1-4 BP 142 EP 146 DI 10.1016/S0370-2693(01)00424-5 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 435LB UT WOS:000168882000017 ER PT J AU Allen, SG Schulman, D Lichwa, J Antal, MJ Jennings, E Elander, R AF Allen, SG Schulman, D Lichwa, J Antal, MJ Jennings, E Elander, R TI A comparison of aqueous and dilute-acid single-temperature pretreatment of yellow poplar sawdust SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID LIQUID HOT-WATER; ENZYMATIC SACCHARIFICATION; SULFURIC-ACID; LIGNOCELLULOSIC MATERIALS; HYDROTHERMAL DEGRADATION; CELLULOSIC MATERIALS; STEAM PRETREATMENT; CORN FIBER; HYDROLYSIS; ETHANOL AB Pretreatment of fresh yellow poplar sawdust (< 6 mm, 25-30 wt % moisture) with hot: liquid water (190-220 degreesC, 2.0-7.5 min, 2-7 wt % solids loading) or steam (220 degreesC, 2.0 min) was compared with dilute acid pretreatment (0.8% w/v sulfuric acid, 175 degreesC, 10 min, 20-25 wt % solids loading). The most favorable conditions for hot liquid water pretreatment (220 degreesC, 2.0 min, 5 wt % solids loading) performed as well as the dilute acid pretreatment (175 degreesC, 10.0 min, 0.8% sulfuric acid, 20 wt % solids loading) for fermentation of the cellulosic fraction of the pretreated fibers by simultaneous saccharification and fermentation (SSF), using Saccharomyces cerevisiae and 25 IFPU cellulase/g of cellulose. Ethanol yields of 97 and 92 wt % of the theoretical yield and xylan recoveries of 85 and 70 wt % (92 and 96 wt % solubilization) were achieved with the hot liquid water and dilute acid pretreatments, respectively. Steam pretreatment (220 degreesC, 2 min) was not as effective as the dilute acid pretreatment, resulting in an ethanol yield of 70 wt % of the theoretical yield, with 88 wt % xylan recovery (54 wt % solubilization). A positive correlation was found between xylan removal and the ethanol yield obtained by SSF. Xylan recovery, however, was inversely proportional to xylan solubilization. Removal of up to 57 wt % of the acid-insoluble lignin in yellow poplar was also possible with hot liquid water pretreatment, with 75 wt % of this acid-insoluble lignin recoverable by simple filtration of the liquid pretreatment products. C1 Univ Hawaii Manoa, Hawaii Nat Energy Inst, Honolulu, HI 96822 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Allen, SG (reprint author), Univ Hawaii Manoa, Hawaii Nat Energy Inst, Honolulu, HI 96822 USA. EM hnei@hawaii.edu NR 51 TC 58 Z9 58 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD MAY 16 PY 2001 VL 40 IS 10 BP 2352 EP 2361 DI 10.1021/ie000579+ PG 10 WC Engineering, Chemical SC Engineering GA 431FE UT WOS:000168620500017 ER PT J AU Manney, GL Michelsen, HA Bevilacqua, RM Gunson, MR Irion, FW Livesey, NJ Oberheide, J Riese, M Russell, JM Toon, GC Zawodny, JM AF Manney, GL Michelsen, HA Bevilacqua, RM Gunson, MR Irion, FW Livesey, NJ Oberheide, J Riese, M Russell, JM Toon, GC Zawodny, JM TI Comparison of satellite ozone observations in coincident air masses in early November 1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CRYOGENIC INFRARED SPECTROMETERS; STRATOSPHERIC POLAR VORTEX; ATMOSPHERIC SOUNDER MAS; TRACE GAS OBSERVATIONS; TRAJECTORY CALCULATIONS; WINTER STRATOSPHERE; POAM-II; VALIDATION; INSTRUMENT; RECONSTRUCTION AB Ozone observed by seven satellite instruments, the Atmospheric Trace Molecule Spectroscopy instrument (ATMOS), Stratospheric Aerosol and Gas Experiment (SAGE) II, Polar Ozone and Aerosol Measurement (POAM) II instrument, Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS), Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA), and Millimeter-wave Atmospheric Sounder (MAS), during early November 1994 is mapped in equivalent latitude/potential temperature (EqL/theta) space to facilitate nearly global comparisons of measurements taken in similar air masses. Ozone from all instruments usually agrees to within 0.5 ppmv (similar to5%) in the upper stratosphere and similar to0.25 ppmv in the lower stratosphere; larger differences in the midstratosphere are primarily due to sampling differences. Individual profile comparisons, selected to match meteorological conditions, show remarkably good agreement between all instruments that sample similar latitudes, although some small differences do not appear to be related to sampling differences. In the Southern Hemisphere (SH) midstratosphere, the instruments (ATMOS, SAGE II, and FOAM II) with observations confined to high latitudes measured low EqLs in air drawn up from low latitudes that had formed a "low-ozone pocket"; they measured much lower ozone at low EqL than those that sampled low latitudes. A low-ozone pocket had also formed in the Northern Hemisphere (NH) midstratosphere (a month earlier than this phenomenon has previously been reported), also resulting in differences between instruments based on their sampling patterns. FOAM If sampled only high latitudes in the NH, where extravortex sampling did not include tropical, high-ozone air, and thus measured lower ozone at a given EqL than other instruments. Ozone laminae appear in coincident profiles from multiple instruments, confirming atmospheric origins for these features and agreement in some detail between ozone observed by several instruments; reverse trajectory calculations indicate such laminae arise from filamentation in and around the polar vortices. Both EqL/theta and profile comparisons indicate overall excellent agreement in ozone observed by all seven instruments in early November 1994. When care is taken to compare similar air masses and to understand sampling effects, much useful information can be obtained from comparisons between instruments with very different observing patterns. C1 USN, Res Lab, Washington, DC 20375 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Berg Univ Gesamthsch Wuppertal, Dept Phys D 07 05, D-42097 Wuppertal, Germany. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Manney, GL (reprint author), New Mexico Highlands Univ, Dept Phys, Las Vegas, NM 87701 USA. RI Oberheide, Jens/C-6156-2011; Riese, Martin/A-3927-2013 OI Oberheide, Jens/0000-0001-6721-2540; Riese, Martin/0000-0001-6398-6493 NR 45 TC 28 Z9 28 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0747-7309 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 16 PY 2001 VL 106 IS D9 BP 9923 EP 9943 DI 10.1029/2000JD900826 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 432ZY UT WOS:000168731900021 ER PT J AU Seo, DK Corbett, JD AF Seo, DK Corbett, JD TI Synthesis, structure, and bonding of open-shell Sr3In5: An unusual electron deficiency in an indium network, beyond the Zintl boundary SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CRYSTAL-STRUCTURE; INTERMETALLIC COMPOUNDS; = CS; PHASE; BA7GA4SB9; CLUSTERS; GALLIUM; LITHIUM; LIMITS; RB AB The new title compound has been synthesized and characterized by physical property measurements and electronic structure calculations. The results ratify the highly uncommon deficiency of one electron that has been long speculated for its Ca3Ga5-type structure on the basis of the simple Zintl electron counting formalism. In the Sr3In5 structure (Cmcm), 4- and 2-bonded indium atoms in a 4:1 ratio form a three-dimensional classical network that encapsulates strontium atoms in its narrow channels. The electrical conductivity of the compound shows typical metallic behavior. The detailed electronic structure analysis suggests that the electron hole is mainly localized on a nonbonding p-orbital on the 2-bonded indium atoms, and that these orbitals, stacked in a a-type way along (a) over right arrow (4.97 Angstrom), interact only weakly with each other to form highly one-dimensional bands. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 48 TC 38 Z9 38 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 16 PY 2001 VL 123 IS 19 BP 4512 EP 4518 DI 10.1021/ja0034242 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 431MH UT WOS:000168634700018 PM 11457237 ER PT J AU Grate, JW Wise, BM AF Grate, JW Wise, BM TI A method for chemometric classification of unknown vapors from the responses of an array of volume-transducing sensors SO ANALYTICAL CHEMISTRY LA English DT Article ID VOLATILE ORGANIC-CHEMICALS; EYE IRRITATION THRESHOLDS; POLYMER; SOLUBILITY; COMPOSITES; SORPTION; SCORES; QSAR AB A method for the characterization and classification of unknown vapors based on the responses on an array of polymer-based volume-transducing vapor sensors is presented. Unlike conventional pattern recognition methods, the sensor array pattern vector is converted into another vector containing vapor descriptors. Equations are developed to show how this approach can be applied to arrays of sensors where each sensor responds to the fractional volume increase of the polymer upon vapor sorption. The vapor sorption step of the response is modeled with linear solvation energy relationships using solvation parameters as vapor descriptors. The response model also includes the vapor concentration, the sensitivity to fractional volume increases, and the specific volume of the vapor as a liquid. The response model can be solved for the vapor descriptors given the array responses and sensitivity factors, following an approach described previously for purely gravimetric sensors. The vapors can then be classified from a database of candidate vapor descriptors. Chemiresistor vapor sensors coated with composite polymer films containing conducting particles represent a volume-transducing sensor technology to which this new classification method should apply. Preliminary equations are also presented for sensors that respond on the basis of both the mass and the volume of a sorbed vapor. Surface acoustic wave sensors with acoustically thin polymer films that respond to both mass and modulus effects may fit this classification approach. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Eigenvector Res Inc, Manson, WA 98831 USA. RP Grate, JW (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 38 TC 25 Z9 25 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 MAY 15 PY 2001 VL 73 IS 10 BP 2239 EP 2244 DI 10.1021/ac001233b PG 6 WC Chemistry, Analytical SC Chemistry GA 432QY UT WOS:000168708200014 PM 11393847 ER PT J AU Yoo, JH Borisov, OV Mao, XL Russo, RE AF Yoo, JH Borisov, OV Mao, XL Russo, RE TI Existence of phase explosion during laser ablation and its effects on inductively coupled plasma-mass spectroscopy SO ANALYTICAL CHEMISTRY LA English DT Article ID ATOMIC EMISSION-SPECTROMETRY; SILICON; VAPORIZATION; INTENSITY; SAMPLES; REMOVAL; GLASS; SIZE AB A sudden increase in crater depth was observed during high irradiance (> 10(10) W/cm(2)) laser ablation of silicon, and his attributed to the phenomenon of phase explosion. The threshold irradiance for phase explosion showed a dependence on two laser parameters: laser beam spot size and wavelength. For a larger beam size and longer incident wavelength, a higher laser irradiance was required to generate phase explosion. The rapid increase of crater depth above the phase explosion threshold irradiance correlated with a significant increase in the ICPMS signal intensity. The ratio of crater volume to ICPMS intensity, which represents entrainment efficiency, remained the lowest at laser irradiances slightly above the phase explosion threshold. However, this Patio increased at irradiances well above the threshold (> 10(11) W/cm(2)). Chemical analysis using laser ablation at irradiance above 10(11) W/Cm-2 provides increased sensitivity via improved entrainment and transport efficiency and increased ablation rate. 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 28 TC 52 Z9 53 U1 4 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 MAY 15 PY 2001 VL 73 IS 10 BP 2288 EP 2293 DI 10.1021/ac001333h PG 6 WC Chemistry, Analytical SC Chemistry GA 432QY UT WOS:000168708200021 PM 11393854 ER PT J AU Ullom, JN Frank, M Gard, EE Horn, JM Labov, SE Langry, K Magnotta, F Stanion, KA Hack, CA Benner, WH AF Ullom, JN Frank, M Gard, EE Horn, JM Labov, SE Langry, K Magnotta, F Stanion, KA Hack, CA Benner, WH TI Discrimination between bacterial spore types using time-of-flight mass spectrometry and matrix free infrared laser desorption and ionization SO ANALYTICAL CHEMISTRY LA English DT Article ID RAPID IDENTIFICATION; WHOLE CELLS; DESORPTION/IONIZATION; MICROORGANISMS; STRAINS; SPORES AB We demonstrate that molecular ions with mass-to-charge ratios (m/z) ranging from a few hundred to 19 050 can be desorbed from whole bacterial spores using infrared laser desorption and no chemical matrix. We have measured the mass of these ions using time-of-flight mass spectrometry and we observe that different ions are desorbed from spores of Bacillus cereus, Bacillus thuringiensis, Bacillus subtilis, and Bacillus niger. Our results raise the possibility of identifying microorganisms using mass spectrometry without conventional sample preparation techniques such as the addition of a matrix. We have measured the dependence of the ion yield from B. subtilis on desorption wavelength over the range 3.05-3.8 mum, and we observe the best results at 3.05 mum, We have also generated mass spectra from whole spores using 337-mm ultraviolet laser desorption, and we find that these spectra are inferior to spectra generated with infrared desorption. Since aerosol analysis is a natural application for matrix-free desorption, we have measured mass spectra from materials such as ragweed pollen and road dust that are likely to form a background to microbial aerosols. We find that these materials are readily differentiated from bacterial spores. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Ullom, JN (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Frank, Matthias/O-9055-2014 NR 23 TC 27 Z9 28 U1 0 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 MAY 15 PY 2001 VL 73 IS 10 BP 2331 EP 2337 DI 10.1021/ac001551a PG 7 WC Chemistry, Analytical SC Chemistry GA 432QY UT WOS:000168708200027 PM 11393860 ER PT J AU Borca, CN Adenwalla, S Choi, J Robertson, L You, H Fridkin, VM Palto, SP Petukhova, N Dowben, PA AF Borca, CN Adenwalla, S Choi, J Robertson, L You, H Fridkin, VM Palto, SP Petukhova, N Dowben, PA TI Changes in electron-phonon coupling across a bulk phase transition in copolymer films of vinylidene fluoride (70%) with trifluoroethylene (30%) SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 10th International Conference on Solid Films and Surfaces (ICSFS-10) CY JUL 09-13, 2000 CL PRINCETON UNIV, PRINCETON, NEW JERSEY SP Princeton Univ, Adv Technol Ctr Photon & Optoelectr Mat, David Sarnoff Res Ctr, Princeton Univ, Dept Chem, Princeton Univ, Dept Elect Engn, Emcore, Epitaxx, Evans E, Int Rectifier Corp, Natl Sci Fdn, Princeton Univ, Princeton Ctr Complex Mat, Princeton Univ, Princeton Mat Inst, Princeton Univ, Sch Engn & Appl Sci, Univ Display Corp HO PRINCETON UNIV DE electron-phonon coupling; bulk phase transition; X-ray scattering techniques; neutron scattering techniques ID POLY(VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE) COPOLYMERS; LANGMUIR-BLODGETT-FILMS; SURFACE-STRUCTURE; PHOTOEMISSION; SCATTERING AB We present evidence for a change in electron-phonon coupling across a bulk phase transition, Below the lattice stiffening transition at around 160 K, there is a change in the diffracted peak width observed by neutron and X-ray scattering techniques. Also, the electronic band structure of the copolymer is shifting in binding energy below 160 K, decreasing the density of states near the Fermi level, The value of the effective Debye temperature above the transition temperature is approximately 50 K, while below 160 K, the value of the Debye parameter is 245 K, We postulate that the coupling between electrons and phonons results in a static distortion of the lattice (below 160 K), and this distortion "melts" above 160 K, (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. Univ Nebraska, Behlen Lab Phys, Ctr Mat Res & Anal, Lincoln, NE 68588 USA. Russian Acad Sci, Inst Crystallog, Moscow 117333, Russia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Oak Ridge Natl Lab, High Flux Isotope Reactor, Oak Ridge, TN 37831 USA. Louisiana State Univ, Ctr Adv Microstruct & Devices, Baton Rouge, LA 70806 USA. RP Dowben, PA (reprint author), Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 19 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY 15 PY 2001 VL 175 BP 265 EP 269 DI 10.1016/S0169-4332(01)00162-3 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 438AT UT WOS:000169032100045 ER PT J AU Brewer, RT Hartman, JW Groves, JR Arendt, PN Yashar, PC Atwater, HA AF Brewer, RT Hartman, JW Groves, JR Arendt, PN Yashar, PC Atwater, HA TI Rheed in-plane rocking curve analysis of biaxially-textured polycrystalline MgO films on amorphous substrates grown by ion beam-assisted deposition SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 10th International Conference on Solid Films and Surfaces (ICSFS-10) CY JUL 09-13, 2000 CL PRINCETON UNIV, PRINCETON, NEW JERSEY SP Princeton Univ, Adv Technol Ctr Photon & Optoelectr Mat, David Sarnoff Res Ctr, Princeton Univ, Dept Chem, Princeton Univ, Dept Elect Engn, Emcore, Epitaxx, Evans E, Int Rectifier Corp, Natl Sci Fdn, Princeton Univ, Princeton Ctr Complex Mat, Princeton Univ, Princeton Mat Inst, Princeton Univ, Sch Engn & Appl Sci, Univ Display Corp HO PRINCETON UNIV DE ion beam-assisted deposition; RHEED; in-plane rocking curve; MgO; texture ID YTTRIA-STABILIZED-ZIRCONIA; THIN-FILMS AB We have developed a method for biaxial texture determination in polycrystalline films using reflection high energy electron diffraction (RHEED) in-plane rocking curves. Experimental RHEED in-plane rocking curves were taken at 25 keV and 2.7 degrees incidence angle from 11 nm thick, nominally [1 0 0]-textured MgO films grown on amorphous Si3N4 by ion beam-assisted deposition (IBAD). The experimental RHEED in-plane rocking curves were analyzed by comparing them with RHEED inplane rocking curves calculated using a kinematical simulation. The model enables a quantitative correlation between biaxial texture and RHEED in-plane rocking curve measurements. RHEED results are compared to X-ray rocking curve film analysis. (C) 2001 Elsevier Science B.V. All rights reserved. C1 CALTECH, Thomas J Watson Lab Appl Phys, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Brewer, RT (reprint author), CALTECH, Thomas J Watson Lab Appl Phys, Pasadena, CA 91125 USA. NR 11 TC 11 Z9 11 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY 15 PY 2001 VL 175 BP 691 EP 696 DI 10.1016/S0169-4332(01)00106-4 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 438AT UT WOS:000169032100113 ER PT J AU Robinson, H Gao, YG Yang, XL Sanishvili, R Joachimiak, A Wang, AHJ AF Robinson, H Gao, YG Yang, XL Sanishvili, R Joachimiak, A Wang, AHJ TI Crystallographic analysis of a novel complex of actinomycin D bound to the DNA decamer CGATCGATCG SO BIOCHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; SEQUENCE; BINDING; RECOGNITION; REFINEMENT; MECHANISMS AB The potent anticancer drug actinomycin D (ActD) acts by binding to DNA, thereby interfering with replication and transcription. ActD inhibits RNA polymerase far more specifically than DNA polymerase, Such discrimination is not easily understood by the conventional DNA binding mode of ActD, We have solved and refined at 1.7 Angstrom resolution the crystal structure of ActD complexed to CGATCGATCG, which contains no canonical GpC binding sequence. The crystal data are space group P4(3)2(1)2, a = b = 47.01 Angstrom, and c = 160.37 Angstrom. The structure was solved by the multiple wavelength anomalous diffraction method using a 5-bromo-U DNA. The asymmetric unit of the unit cell contains two independent dimers of a novel slipped duplex complex consisting of two decamer DNA strands bound with two ActD drug molecules. (The DNA in one dimer is numbered C1 to G10 in one strand and C11 to G20 in the complementary strand and in the second dimer, C101 to G110 and C111 to G120, respectively.) The structure reveals a highly unusual ActD binding mode in which the DNA adopts a slipped duplex with the A3-T4/A13-T14 dinucleotides looped out. ActD intercalates between G2-C11* (C11* being from a symmetry-related molecule) and C5-G20 base pairs, Two such slipped duplex-ActD complexes bound to each other by mutually intercalating their T4/T14 bases into the helix cavities (located between C5-G20 and G6-C19 base pairs) of neighboring complexes, forming a dimer of drug-DNA complexes. The binding site mimics the drug binding at the elongation point during transcription. Modeling studies show that the ActD-DNA complex fits snugly in the active site cavity in RNA polymerase but not in DNA polymerase. This may explain the strong preference of ActD inhibition toward transcription. C1 Univ Illinois, Dept Biochem, Urbana, IL 61801 USA. Argonne Natl Lab, Div Biosci, Struct Biol Ctr, Argonne, IL 60439 USA. Northwestern Univ, Dept Biochem Mol Biol & Cell Biol, Evanston, IL 60208 USA. Acad Sinica, Inst Biol Chem, Taipei, Taiwan. RP Wang, AHJ (reprint author), Univ Illinois, Dept Biochem, Urbana, IL 61801 USA. NR 26 TC 26 Z9 28 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 15 PY 2001 VL 40 IS 19 BP 5587 EP 5592 DI 10.1021/bi002859z PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 431MV UT WOS:000168635900002 PM 11341823 ER PT J AU Schurter, BT Koh, SS Chen, D Bunick, GJ Harp, JM Hanson, BL Henschen-Edman, A Mackay, DR Stallcup, MR Aswad, DW AF Schurter, BT Koh, SS Chen, D Bunick, GJ Harp, JM Hanson, BL Henschen-Edman, A Mackay, DR Stallcup, MR Aswad, DW TI Methylation of histone H3 by coactivator-associated arginine methyltransferase 1 SO BIOCHEMISTRY LA English DT Article ID PROTEIN; NUCLEOSOME; ACETYLATION; PEPTIDES; CELLS; RESOLUTION; CHROMATIN; SEQUENCE AB The preferential in vitro methylation of histone H3 by coactivator-associated arginine methyltransferase 1 (CARM1) has been proposed as a basis for its ability to enhance gene transcription [Chen, D., et al. (1999) Science 284, 2174-2177]. To further evaluate the significance of H3 methylation, we studied the kinetics and site specificity of its modification by CARM1. Affinity-purified CARM1 methylated recombinant chick H3, which is free of posttranslational modifications, and calf thymus H3, which is heterogeneous with regard to preexisting modifications, equally well, exhibiting a V-max of 4500 pmol min(-1) (mg of enzyme)(-1) and an apparent K-m for H3 of less than or equal to0.2 muM. The catalytic efficiency (k(cat)/K-m) of CARM 1 toward H3 was at least 1000 times that toward R1 (GGFGG (R) over bar GGFGG-amide), a highly effective substrate for protein arginine methyltransferase 1. Peptide mapping of H-3-methyl-labeled H3 indicated methylation at Arg-2, Arg-l7, and Arg-26 in the N-terminal region and at one or more of four arginines (128/129/131/134) at the C-terminus. Two of the N-terminal sites, Arg-17 and Arg-26, occur in the sequence KAX (R) over barK and appear to be more efficiently methylated than Arg-2, CARM1 catalyzed formation of N-G,N-G- dimethylarginine (asymmetric) but little or no N-G,N-G-dimethylarginine (symmetric) and no form of methyllysine. Amino acid analysis of untreated calf thymus H3 revealed that 3.7% of the molecules naturally contain asymmetric dimethylarginine and/or monomethylarginine, Our findings support the hypothesis that methylation of H3 may be involved in the mechanism of transcriptional coactivation by CARM1 of genes whose expression is under the control of nuclear receptors. C1 Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. Univ So Calif, Dept Pathol, Los Angeles, CA 90089 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Aswad, DW (reprint author), Univ Calif Irvine, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. RI Hanson, Bryant Leif/F-8007-2010 OI Hanson, Bryant Leif/0000-0003-0345-3702 FU NIA NIH HHS [AG00093]; NIDDK NIH HHS [DK55274]; NIGMS NIH HHS [GM 29181]; NINDS NIH HHS [NS17269] NR 28 TC 173 Z9 176 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 15 PY 2001 VL 40 IS 19 BP 5747 EP 5756 DI 10.1021/bi002631b PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 431MV UT WOS:000168635900019 PM 11341840 ER PT J AU Kaufman, LJ Heo, JY Fleming, GR Sung, JY Cho, MH AF Kaufman, LJ Heo, JY Fleming, GR Sung, JY Cho, MH TI Fifth-order electronically non-resonant Raman scattering: two-dimensional Fourier deconvolution SO CHEMICAL PHYSICS LA English DT Article DE Raman scattering; fourier deconvolution; electronic responses ID DIFFRACTIVE OPTICS; CONDENSED-PHASE; INTERMOLECULAR DYNAMICS; VIBRATIONAL COHERENCE; HETERODYNE-DETECTION; SPECTROSCOPY; LIQUIDS; CS2; PULSES; MODES AB This paper presents an analytical Fourier deconvolution procedure for homodyne detected electronically non-resonant fifth-order signal that reveals the bare nuclear response function free from the influence of the electronic (hyperpolarizability) responses generated by the five potentially overlapping finite duration pulses used in the experiment. In developing the fifth-order deconvolution procedure, an analogous procedure for homodyne detected third-order responses is elaborated. The potential implementation problems with the homodyne deconvolution procedure are evaluated through comparison of the third-order homodyne deconvolution result with that of the well-known third-order heterodyne deconvolution. Then, the homodyne deconvolution is extended to fifth-order where it is used on several measured tenser elements of the direct fifth-order signal. Suggestions are given for improving implementation of the procedure in fifth order so that more information on the direct fifth-order nuclear response as well as the hyperpolarizability responses can be recovered via the deconvolution procedure. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Phys Biosci Div, Dept Chem, Berkeley, CA 94720 USA. Korea Univ, Dept Chem, Seoul 136701, South Korea. Korea Univ, Ctr Multidimens Spect, Seoul 136701, South Korea. RP Fleming, GR (reprint author), Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Phys Biosci Div, Dept Chem, Berkeley, CA 94720 USA. NR 44 TC 14 Z9 14 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD MAY 15 PY 2001 VL 266 IS 2-3 BP 251 EP 271 DI 10.1016/S0301-0104(01)00251-8 PG 21 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 432GZ UT WOS:000168685000010 ER PT J AU Genbacev, O Krtolica, A Kaelin, W Fisher, SJ AF Genbacev, O Krtolica, A Kaelin, W Fisher, SJ TI Human cytotrophoblast expression of the von Hippel-Lindau protein is downregulated during uterine invasion in situ and upregulated by hypoxia in vitro SO DEVELOPMENTAL BIOLOGY LA English DT Article DE pVHL; hypoxia; HIF2 alpha; cytotrophoblast; human placenta; fibronectin ID TUMOR-SUPPRESSOR PROTEIN; ADHESION RECEPTORS; DEFICIENT MICE; HUMAN PLACENTA; IN-VITRO; DIFFERENTIATION; TROPHOBLAST; BINDING; OXYGEN; GENE AB The von Hippel-Lindau tumor-suppressor protein (pVHL) regulates the stability of HIF1 alpha and HIF2 alpha and thus is pivotal in cellular responses to changes in oxygen tension. Paradoxically, human cytotrophoblasts proliferate under hypoxic conditions comparable to those measured in the early gestation placenta (2% O-2), but differentiate into tumorlike invasive cells under well-oxygenated conditions such as those found in the uterus. We sought to explain this phenomenon in terms of pVHL expression. In situ, pVHL immunolocalized to villous cytotrophoblast stem cells, and expression was enhanced at sites of cell column initiation; in both of these relatively hypoxic locations, cytoplasmic staining for HIF2a was also detected. As cytotrophoblasts attached to and invaded the uterus, which results in their increased exposure to oxygen, pVHL staining was abruptly downregulated concordant with localization of HIF2a to the nucleus. In vitro, hypoxia (2% O-2) upregulated cytotrophoblast pVHL expression together with HIF2 alpha, which localized to the cytoplasm; culture under well-oxygenated conditions greatly reduced levels of both molecules. These results, together with the placental defects previously observed in VHL-/- mice, suggest that pVHL is a component of the mechanism that transduces local differences in oxygen tension at the maternal-fetal interface to changes in the biological behavior of cytotrophoblasts. Furthermore, these data provide the first example of oxygen-dependent changes in pVHL abundance. (C) 2001 Academic Press. C1 Univ Calif San Francisco, Dept Stomatol, Div Oral Biol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Cell & Mol Biol, Berkeley, CA 94720 USA. Dana Farber Canc Inst, Howard Hughes Med Inst, Boston, MA 02115 USA. Harvard Univ, Sch Med, Boston, MA 02115 USA. RP Fisher, SJ (reprint author), Univ Calif San Francisco, Dept Stomatol, Div Oral Biol, HSW 604,513 Parnassus Ave, San Francisco, CA 94143 USA. FU NCI NIH HHS [CA68490]; NHLBI NIH HHS [HL64597]; NICHD NIH HHS [HD26732, HD30367] NR 46 TC 58 Z9 59 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0012-1606 J9 DEV BIOL JI Dev. Biol. PD MAY 15 PY 2001 VL 233 IS 2 BP 526 EP 536 DI 10.1006/dbio.2001.0231 PG 11 WC Developmental Biology SC Developmental Biology GA 436JB UT WOS:000168931800020 PM 11336512 ER PT J AU Delire, C Behling, P Coe, MT Foley, JA Jacob, R Kutzbach, J Liu, ZY Vavrus, S AF Delire, C Behling, P Coe, MT Foley, JA Jacob, R Kutzbach, J Liu, ZY Vavrus, S TI Simulated response of the atmosphere-ocean system to deforestation in the Indonesian Archipelago SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPICAL DEFORESTATION; AMAZONIAN DEFORESTATION; REGIONAL CLIMATE; GLOBAL CLIMATE; GCM SIMULATION; INDIAN-OCEAN; IMPACTS; VEGETATION; DYNAMICS AB The climatic effects of large-scale deforestation in the Indonesian Archipelago are investigated using a fully coupled atmosphere-ocean model - the Fast Ocean Atmosphere Model (FOAM). Extremely rapid rates of deforestation across the Archipelago motivate this study. We compare two simulations (one with fixed ocean temperatures, another where the ocean responds to changing atmospheric conditions), to investigate the potential for oceanic feedbacks on deforestation-induced climate change. With fixed sea surface temperatures, evaporation decreases over land but increases over the surrounding oceans where the wind speeds increase. Regional deep convection is enhanced and precipitation increases over the islands. With an interactive ocean the initial decrease in evaporation over the deforested land reduces convergence and increases the easterlies in the Bay of Bengal. More intense equatorial upwelling cools the surface temperatures over that region and reduces ocean evaporation. Regional convection is less intense and precipitation drops by 9% over deforested land. C1 Univ Wisconsin, Ctr Sustainabil & Global Environm, SAGE, Inst Environm Studies, Madison, WI 53706 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Delire, C (reprint author), Univ Wisconsin, Ctr Sustainabil & Global Environm, SAGE, Inst Environm Studies, 1225 W Dayton St, Madison, WI 53706 USA. RI Jacob, Robert/D-2580-2011 OI Jacob, Robert/0000-0002-9444-6593 NR 16 TC 31 Z9 33 U1 0 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 MAY 15 PY 2001 VL 28 IS 10 BP 2081 EP 2084 DI 10.1029/2000GL011947 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 431EB UT WOS:000168617900047 ER PT J AU Bracht, H Nicols, SP Haller, EE Silveira, JP Briones, F AF Bracht, H Nicols, SP Haller, EE Silveira, JP Briones, F TI Self-diffusion in (GaSb)-Ga-69-Sb-121/(GaSb)-Ga-71-Sb-123 isotope heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID V COMPOUND SEMICONDUCTORS; MOLECULAR-BEAM EPITAXY; GALLIUM-ARSENIDE; ELECTRONIC-STRUCTURE; OUT-DIFFUSION; GERMANIUM; GASB; GAAS; DEFECTS; VACANCY AB Gallium and antimony self-diffusion experiments have been performed in undoped (GaSb)-Ga-69-Sb-121/(GaSb)-Ga-71-Sb-123 isotope heterostructures at temperatures between 571 and 708 degreesC under Sb- and Ga-rich ambients. Ga and Sb profiles measured with secondary ion mass spectrometry reveal that Ga diffuses faster than Sb by several orders of magnitude. This strongly suggests that the two self-atom species diffuse independently on their own sublattices. Experimental results lead us to conclude that Ga and Sb diffusion are mediated by Ga vacancies and Sb interstitials, respectively, and not by the formation of a triple defect proposed earlier by Weiler and Mehrer [Philos. Mag. A 49, 309 (1984)]. The extremely slow diffusion of Sb up to the melting temperature of GaSb is proposed to be a consequence of amphoteric transformations between native point defects which suppress the formation of those native defects which control Sb diffusion. Preliminary experiments exploring the effect of Zn indiffusion at 550 degreesC on Ga and Sb diffusion reveal an enhanced intermixing of the Ga isotope layers compared to undoped GaSb. However, under the same conditions the diffusion of Sb was not significantly affected. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CSIC, Ctr Nacl Microelect, Inst Microelectron Madrid, E-28066 Madrid, Spain. RP Bracht, H (reprint author), Univ Munster, Inst Mat Phys, D-48149 Munster, Germany. RI Microelectronica de Madrid, Instituto de/D-5173-2013 OI Microelectronica de Madrid, Instituto de/0000-0003-4211-9045 NR 33 TC 23 Z9 23 U1 0 U2 6 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 MAY 15 PY 2001 VL 89 IS 10 BP 5393 EP 5399 DI 10.1063/1.1363683 PG 7 WC Physics, Applied SC Physics GA 428AF UT WOS:000168438400022 ER PT J AU Qiao, D Jia, L Yu, LS Asbeck, PM Lau, SS Lim, SH Liliental-Weber, Z Haynes, TE Barner, JB AF Qiao, D Jia, L Yu, LS Asbeck, PM Lau, SS Lim, SH Liliental-Weber, Z Haynes, TE Barner, JB TI Ta-based interface ohmic contacts to AlGaN/GaN heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FIELD-EFFECT TRANSISTORS; N-ALGAN; GAN; POLARIZATION; CHARGE; TI/AL AB Al/Ti based metallization is commonly used for ohmic contacts to n-GaN and related compounds. We have previously reported an ohmic contact scheme specially designed for AlGaN/GaN heterostructure field-effect transistors (HFETs) [D. Qiao , Appl. Phys. Lett. 74, 2652 (1999)]. This scheme, referred to as the "advancing interface" contact, takes advantage of the interfacial reactions between the metal layers and the AlGaN barrier layer in the HFET structure. These reactions consume a portion of the barrier, thus facilitating carrier tunneling from the source/drain regions to the channel region. The advancing interface approach has led to consistently low contact resistance on Al0.25Ga0.75N/GaN HFETs. There are two drawbacks of the Al/Ti based advancing interface scheme, (i) it requires a capping layer for the ohmic formation annealing since Ti is too reactive and is easily oxidized when annealing is performed in pure N-2 or even in forming gas, and (ii) the atomic number of Al and that of Ti are too low to yield efficient backscattered electron emission for e-beam lithographic alignment purposes. In this work, we investigated a Ta based advancing interface contact scheme for the HFET structures. We found that the presence of Ta in this ohmic scheme leads to (1) a specific contact resistivity as low as 5x10(-7) Omega cm(2), (2) efficient electron emission for e-beam lithographic alignment, and (3) elimination of the capping layer for the ohmic annealing. (C) 2001 American Institute of Physics. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif San Diego, La Jolla, CA 92093 USA. EM dqiao@ucsd.edu RI Liliental-Weber, Zuzanna/H-8006-2012; Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 19 TC 25 Z9 26 U1 2 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 2001 VL 89 IS 10 BP 5543 EP 5546 DI 10.1063/1.1365431 PG 4 WC Physics, Applied SC Physics GA 428AF UT WOS:000168438400047 ER PT J AU Mailhot, B Komvopoulos, K Ward, B Tian, Y Somorjai, GA AF Mailhot, B Komvopoulos, K Ward, B Tian, Y Somorjai, GA TI Mechanical and friction properties of thermoplastic polyurethanes determined by scanning force microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID NANOMECHANICAL PROPERTIES; BLOCK COPOLYMERS; ELASTIC-MODULUS; CONTACT AREA; ELASTOMERS; POLYETHYLENE; INDENTATION; MORPHOLOGY; POLYMERS; BEHAVIOR AB The mechanical and friction properties of additive-free polyurethane (PUR) consisting of polyether soft segments of polytetramethyleneoxide and hard segments (HS) comprising 4,4'-diphenylmethane diisocyanate and 1,4-butanediol as a chain extender were studied by scanning force microscopy. The hardness and elastic modulus of PUR containing 42, 57, 69, and 100 wt % HS were determined from nanoindentation experiments performed with a diamond tip of nominal radius of curvature equal to similar to 20 mum and maximum indentation load in the range of 10-500 muN. The mechanical properties of PUR were found to strongly depend on the HS content and contact load. The elastic modulus of PUR with 42 wt % HS was found to decrease with increasing load due to the high softness of this material that influenced the measurements. The friction characteristics of the samples with 42, 57, and 69 wt % HS were studied in order to evaluate the dependence of the coefficient of friction on load and sliding speed. The PUR with 57 wt % HS exhibited the lowest coefficient of friction. Depending on the PUR composition, remarkably different friction behaviors were obtained. The observed mechanical behavior and friction characteristics are interpreted in terms of the chemical composition and microstructure of the samples. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Polymer Technol Grp Inc, Berkeley, CA 94710 USA. Ensemble Univ Cezeaux, Photochim Mol & Macromol Lab, CNRS, UMR 6505, F-63177 Aubiere, France. RP Mailhot, B (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 26 TC 14 Z9 14 U1 1 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 MAY 15 PY 2001 VL 89 IS 10 BP 5712 EP 5719 DI 10.1063/1.1360215 PG 8 WC Physics, Applied SC Physics GA 428AF UT WOS:000168438400079 ER PT J AU Rathbone, GJ Poliakoff, ED Bozek, JD Lucchese, RR AF Rathbone, GJ Poliakoff, ED Bozek, JD Lucchese, RR TI Resonantly amplified vibronic symmetry breaking SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RESOLVED PHOTOELECTRON-SPECTROSCOPY; SHAPE-RESONANCE; MOLECULAR PHOTOIONIZATION; SYNCHROTRON-RADIATION; ASYMMETRY PARAMETER; IONIZATION SPECTRA; PHOTO-IONIZATION; CROSS-SECTIONS; CO2; SCATTERING AB The energy dependence of the vibrational branching ratio for exciting one quantum of bending is determined for CO(2) 4 sigma (-1)(g) photoionization. This nominally forbidden transition becomes allowed for a photoionization transition as a result of instantaneous symmetry breaking due to zero point motion, and is strongly enhanced by a continuum shape resonance. (C) 2001 American Institute of Physics. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. RP Poliakoff, ED (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. EM erwin.poliakoff@chem.lsu.edu RI Bozek, John/E-4689-2010; Bozek, John/E-9260-2010; Lucchese, Robert/O-4452-2014 OI Bozek, John/0000-0001-7486-7238; Lucchese, Robert/0000-0002-7200-3775 NR 34 TC 12 Z9 12 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 2001 VL 114 IS 19 BP 8240 EP 8243 DI 10.1063/1.1372334 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 428BC UT WOS:000168440400002 ER PT J AU Striolo, A Prausnitz, JM AF Striolo, A Prausnitz, JM TI Adsorption of branched homopolymers on a solid surface SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATION; 2ND VIRIAL-COEFFICIENTS; POLYMER ADSORPTION; MOLECULAR-DYNAMICS; HARD-WALL; CHAINS; MODEL; MACROMOLECULES; SEMIDILUTE; INTERFACE AB Simulation calculations are reported for single-chain polymer-wall conformation-averaged potentials of mean force and segment-density profiles for homopolymers of different structures as a function of the segment-wall attractive potential. When there is no attraction between the wall and the polymer segments, the presence of the wall generates a polymer-segment depletion layer whose thickness depends on polymer structure and on surface roughness. Segment-density profiles are characterized by three regions. In the proximal region, the segment density is determined by surface roughness and by polymer flexibility. In the distal region, the segment density approaches unity asymptotically. In the central region, the segment density depends on geometric characteristics of the polymer in the bulk solution. When the wall-segment attractive potential is sufficiently large, the depletion layer thickness is reduced and the polymers are adsorbed. When attraction is weak, compact polymers (e.g., dendrimers of high generation) are readily adsorbed. Due to their globular shape, high-generation dendrimers, at weak attractive interactions, are at contact with the surface with numerous segments; globular polymers experience a relatively small entropic penalty for adsorption. By contrast, linear polymers, due to their flexibility at good solvent conditions, pay a high entropic penalty for each segment at contact with the surface. Therefore, at weak attractive interactions, globular polymers are readily adsorbed, whereas linear polymers are more readily adsorbed at stronger attractive interactions. With rising surface roughness, flexible polymers tend to spread on the surface, whereas branched polymers are repelled at larger distances. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Prausnitz, JM (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Striolo, Alberto/G-2926-2011 NR 46 TC 40 Z9 41 U1 1 U2 20 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 MAY 15 PY 2001 VL 114 IS 19 BP 8565 EP 8572 DI 10.1063/1.1362317 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 428BC UT WOS:000168440400040 ER PT J AU Sutton, R Sposito, G AF Sutton, R Sposito, G TI Molecular simulation of interlayer structure and dynamics in 12.4 angstrom Cs-smectite hydrates SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE Cs; smectite; adsorbed water; surface complex ID MONTE-CARLO SIMULATION; CLAY-MINERALS; COMPUTER-SIMULATIONS; EXCHANGED CATION; LAYER CHARGE; WATER; CESIUM; MONTMORILLONITE; IONS; MECHANISM AB A detailed understanding of hydrated Cs-smectites is necessary to predict the permeability of clay liners to radiocesium cations at nuclear waste containment facilities, Monte Carlo (MC) and molecular dynamics (MD) modeling techniques were applied to three representative Cs-smectites to interpret a variety of experimental data on interlayer structure and dynamics. Spectroscopic and surface chemistry methods that attempt to differentiate interlayer water from water residing in micropores have provided data suggesting that, in stable 12.4 Angstrom Cs-smectite hydrates, the interlamellar water content is less than one-half monolayer. Convergence profiles in MC simulations predicted stable hydrates at interlayer water contents of 1/3 or possibly 2/3 water monolayer. Radial distribution functions and coordination number data illustrated the ability of Cs+ to organize water molecules into partial hydration shells and displayed the distortions of water structure induced by the clay surface. Molecular dynamics simulations of the MC-stable Cs-smectites revealed interlayer Cs+ to be strongly bound as innersphere surface complexes, in agreement with published bulk diffusion coefficients. The strongly adsorbed Cs+ can be associated with one of the species identified in Cs-133 NMR spectroscopic studies of hydrated Cs-smectites. These cations typically exhibited jump diffusion, whereas continuous diffusion of H2O occurred. (C) 2001 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Geochem, Div Earth Sci, Berkeley, CA 94720 USA. RP Sutton, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Geochem, Div Earth Sci, Mail Stop 90-1116, Berkeley, CA 94720 USA. NR 39 TC 75 Z9 76 U1 3 U2 22 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD MAY 15 PY 2001 VL 237 IS 2 BP 174 EP 184 DI 10.1006/jcis.2000.7416 PG 11 WC Chemistry, Physical SC Chemistry GA 431HT UT WOS:000168626300004 ER PT J AU Lowrie, RB Morel, JE AF Lowrie, RB Morel, JE TI Issues with high-resolution Godunov methods for radiation hydrodynamics SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE radiation hydrodynamics; Godunov methods; Riemann problem; stiff relaxation ID HYPERBOLIC CONSERVATION-LAWS; NUMERICAL TRANSPORT PROBLEMS; STIFF RELAXATION; ASYMPTOTIC SOLUTIONS; DIFFUSIVE REGIMES; OPTICALLY THICK; RIEMANN PROBLEM; EQUATIONS; SCHEMES; TERMS AB Two issues in the development of high-resolution Godunov methods for radiation hydrodynamics are discussed. First, an analysis of the Riemann problem is given. Second, it is shown that a large class of commonly used high-resolution methods are unable to obtain the equilibrium diffusion limit. The analysis points to several possible fixes. Published by Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Div Appl Phys, Hydrodynam Methods Grp X 3, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Appl Phys, Transport Methods Grp X 6, Los Alamos, NM 87545 USA. RP Lowrie, RB (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Phys, Hydrodynam Methods Grp X 3, MS D413, Los Alamos, NM 87545 USA. NR 32 TC 24 Z9 25 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAY 15 PY 2001 VL 69 IS 4 BP 475 EP 489 DI 10.1016/S0022-4073(00)00097-2 PG 15 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 421PW UT WOS:000168073600007 ER PT J AU Tronin, A Strzalka, J Chen, X Dutton, PL Ocko, BM Blaise, JK AF Tronin, A Strzalka, J Chen, X Dutton, PL Ocko, BM Blaise, JK TI Orientational distributions of the di-alpha-helical synthetic peptide ZnPPM-BBC16 in Langmuir monolayers by X-ray reflectivity and polarized epifluorescence SO LANGMUIR LA English DT Article ID CYTOCHROME-C; PORPHYRIN; FILMS AB The vectorial orientation of the peptide ZnPPM-BBC16 in a Langmuir monolayer was studied by means of X-ray reflectivity and polarized epifluorescence. ZnPPM-BBC16 consists of two alpha -helical 31-mers dimerized via a disulfide bridge between two N-terminal cysteines (alpha -S-S-alpha) so that two bis-his metalloporphyrin binding sites between positions 10,10' and 24,24' are formed. Zn(II) protoporphyrin M was bound to the position 24. To enhance stability at the interface, a palmitoyl (C16) chain was bonded to each N-terminal cysteine. X-ray reflectivity measurements make it possible to infer the orientation of the alpha -helices by determining the electron density profile of the monolayer. Polarized epifluorescence provides the orientation distribution of the porphyrin with respect to the monolayer plane. Both X-ray and fluorescence measurements show that at low surface pressure (pi = 5 mN/m), the peptide alpha -helices lie in the plane of the water surface with a narrow orientational distribution of the porphyrin. At high pressures (pi > 30 mN/m), the peptide alpha -helices are perpendicular to the water surface and the distribution is wider. At intermediate pressures the peptide alpha -helices in the monolayer undergo a transition from the parallel to perpendicular orientation with almost a complete loss of the orientational order of the porphyrin. C1 Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. Univ Penn, Dept Biochem & Biophys, Philadelphia, PA 19104 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Tronin, A (reprint author), Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. NR 13 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 15 PY 2001 VL 17 IS 10 BP 3061 EP 3066 DI 10.1021/la001489c PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 431EJ UT WOS:000168618600024 ER PT J AU Stolyarov, VV Zhu, YT Lowe, TC Valiev, RZ AF Stolyarov, VV Zhu, YT Lowe, TC Valiev, RZ TI Microstructure and properties of pure Ti processed by ECAP and cold extrusion SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE ECAP techique; cold extrusion; microstructure; mechanical properties; thermal stability ID CHANNEL ANGULAR EXTRUSION; HALL-PETCH RELATIONSHIP; GRAIN-SIZE; DEFORMATION; REFINEMENT; EVOLUTION; TITANIUM; ALUMINUM; ALLOY AB Equal channel angular pressing (ECAP) has been used to refine the grain size of commercially pure (CP) Ti as well as other metals and alloys. CP-Ti is usually processed at about 400 degreesC because it lacks sufficient ductility at lower temperatures. The warm processing temperature limits the capability of the ECAP technique in improving the strength of CP-TI. We have employed cold extrusion following warm ECAP to further refine the grains and improve the strength of CP-Ti. Ti billets were first processed for eight passes via ECAP route B(C), with a clockwise rotation of 90 degrees between adjacent passes. They were further processed by successive cold extrusions to an accumulative reduction in cross-section area by 47 or 75%. This paper reports the surface quality, microstructures, microhardness, tensile properties, and thermal stability of these Ti billets processed by a combination of ECAP and cold extrusion. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. EM yzhu@lanl.gov RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 21 TC 209 Z9 239 U1 4 U2 44 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 MAY 15 PY 2001 VL 303 IS 1-2 BP 82 EP 89 DI 10.1016/S0921-5093(00)01884-0 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 409MF UT WOS:000167386900012 ER PT J AU Smith, AV AF Smith, AV TI Group-velocity-matched three-wave mixing in birefringent crystals SO OPTICS LETTERS LA English DT Article ID GENERATION; PULSES AB It is shown that the combination of pulse-front slant, k-vector tilt, and crystal birefringence often permits exact matching of both phase and group velocities for three-wave mixing in birefringent crystals. This exact match makes possible more-efficient mixing of short light pulses, and it permits efficient mixing of chirped or broadband light. I analyze this process and present examples. (C) 2001 Optical Society of America. C1 Sandia Natl Labs, Dept 1118, Albuquerque, NM 87185 USA. RP Smith, AV (reprint author), Sandia Natl Labs, Dept 1118, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 42 Z9 42 U1 1 U2 10 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 MAY 15 PY 2001 VL 26 IS 10 BP 719 EP 721 DI 10.1364/OL.26.000719 PG 3 WC Optics SC Optics GA 431FZ UT WOS:000168622300020 PM 18040431 ER PT J AU Christen, HM Zhai, HY Cantoni, C Paranthaman, M Sales, BC Rouleau, C Norton, DP Christen, DK Lowndes, DH AF Christen, HM Zhai, HY Cantoni, C Paranthaman, M Sales, BC Rouleau, C Norton, DP Christen, DK Lowndes, DH TI Superconducting magnesium diboride films with T-c approximate to 24 K grown by pulsed laser deposition with in situ anneal SO PHYSICA C LA English DT Article DE superconducting films; magnesium diboride; pulsed laser deposition AB Thin superconducting films of magnesium diboride (MgB2) with T-c approximate to 24 K were prepared on various oxide substrates by pulsed laser deposition followed by an in situ anneal. A systematic study of the influence of various in situ annealing parameters shows an optimum temperature of about 600 degreesC in a background of 0.7 atm of Ar/4%H-2 for layers consisting of a mixture of magnesium and boron. Contrary to ex situ approaches (e.g. reacting boron films with magnesium vapor at approximate to 900 degreesC), these films are processed at a temperature at which MgB2 does not decompose rapidly even in vacuum. This may prove enabling in the formation of multilayers, junctions, and epitaxial films in future work. Issues related to the improvement of these films and to the possible in situ growth of MgB2 at elevated temperature are discussed. (C) 2001 Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Florida, Gainesville, FL 32611 USA. RP Christen, HM (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 3150,M-S 6056, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Christen, Hans/H-6551-2013; Paranthaman, Mariappan/N-3866-2015; Rouleau, Christopher/Q-2737-2015 OI Christen, Hans/0000-0001-8187-7469; Paranthaman, Mariappan/0000-0003-3009-8531; Rouleau, Christopher/0000-0002-5488-3537 NR 9 TC 64 Z9 67 U1 0 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 MAY 15 PY 2001 VL 353 IS 3-4 BP 157 EP 161 DI 10.1016/S0921-4534(01)00398-7 PG 5 WC Physics, Applied SC Physics GA 435DA UT WOS:000168861100001 ER PT J AU Meng, RL Lorenz, B Wang, YS Cmaidalka, J Xue, YY Chu, CW AF Meng, RL Lorenz, B Wang, YS Cmaidalka, J Xue, YY Chu, CW TI Synthesis and physical properties of superconducting RuSr2EuCu2O8 SO PHYSICA C LA English DT Article DE RuSr2EuCu2O8; structure; magnetic susceptibility; electrical resistivity; thermoelectric power ID MAGNETIZATION; EU; GD AB RuSr2EuCu2O8 has been synthesized and characterized by X-ray diffraction, magnetization, and electrical transport measurements. Similar to RuSr2GdCu2O8, this compound exhibits ferromagnetic (below 130 K) and superconducting (below 30 K) order. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Houston, Dept Phys, Texas Ctr Superconduct, Houston, TX 77204 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Lorenz, B (reprint author), Univ Houston, Dept Phys, Texas Ctr Superconduct, Houston, TX 77204 USA. NR 5 TC 28 Z9 28 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 MAY 15 PY 2001 VL 353 IS 3-4 BP 195 EP 199 DI 10.1016/S0921-4534(00)01753-6 PG 5 WC Physics, Applied SC Physics GA 435DA UT WOS:000168861100005 ER PT J AU Schirber, JE Morosin, B Kwei, GH Yildirim, T Fischer, JE Jorgensen, JD AF Schirber, JE Morosin, B Kwei, GH Yildirim, T Fischer, JE Jorgensen, JD TI Superconductivity in the polymeric phase of Na2CsC60 SO PHYSICA C LA English DT Article DE organic superconductors; Na2CsC60; Na2RbC60; pressure-induced phase ID FULLERIDE SUPERCONDUCTORS; PRESSURE-DEPENDENCE; NA2RBC60; TRANSITION; TEMPERATURE; C-60 AB We have studied the reversible pressure induced structural transition (primitive cubic to polymeric monoclinic) of Na2CsC60 and the superconductivity in both phases. We have established that the single carbon-carbon bonded polymeric phase of Na2CsC60 is superconducting with an ambient pressure transition temperature about 3 K lower than that for the primitive cubic phase. We believe that an analogous lowering of the transition temperature in the corresponding phase of Na2RbC60 either leads to a very low transition temperature or to a total absence of superconductivity. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Adv Mat Phys & Devices, Albuquerque, NM 87185 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Morosin, B (reprint author), Sandia Natl Labs, Adv Mat Phys & Devices, MS 1421,POB 5800, Albuquerque, NM 87185 USA. RI yildirim, taner/A-1290-2009 NR 18 TC 3 Z9 3 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAY 15 PY 2001 VL 353 IS 3-4 BP 207 EP 212 DI 10.1016/S0921-4534(00)01752-4 PG 6 WC Physics, Applied SC Physics GA 435DA UT WOS:000168861100007 ER PT J AU Foias, C Holm, DD Titi, ES AF Foias, C Holm, DD Titi, ES TI The Navier-Stokes-alpha model of fluid turbulence SO PHYSICA D LA English DT Article DE Navier-Stokes-alpha model; large eddy simulation; Camassa-Holm equations; Euler-alpha model ID CAMASSA-HOLM EQUATIONS; 2ND GRADE FLUIDS; REYNOLDS STRESS; CLASSICAL-SOLUTIONS; HYDRODYNAMICS; VISCOSITY; GEOMETRY; FAMILY; MOTION; FLOWS AB We review the properties of the nonlinearly dispersive Navier-Stokes-alpha (NS-alpha) model of incompressible fluid turbulence - also called the viscous Camassa-Holm equations in the literature. We first re-derive the NS-alpha model by filtering the velocity of the fluid loop in Kelvin's circulation theorem for the Navier-Stokes equations. Then we show that this filtering causes the wavenumber spectrum of the translational kinetic energy for the NS-alpha model to roll off as k(-3) for k alpha < 1 in three dimensions, instead of continuing along the slower Kolmogorov scaling law, k(-5/3), that it follows for k alpha < 1. This roll off at higher wavenumbers shortens the inertial range for the NS-alpha model and thereby makes it more computable. We also explain how the NS-alpha model is related to large eddy simulation (LES) turbulence modeling and to the stress tenser for second-grade fluids. We close by surveying recent results in the literature for the NS-alpha model and its inviscid limit (the Euler-alpha model). (C) 2001 Published by Elsevier Science B.V. C1 Indiana Univ, Dept Math, Bloomington, IN 47405 USA. Univ Calif Los Alamos Natl Lab, T Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. Univ Calif Irvine, Dept Math, Irvine, CA 92697 USA. Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92697 USA. RP Foias, C (reprint author), Indiana Univ, Dept Math, Bloomington, IN 47405 USA. OI Holm, Darryl D/0000-0001-6362-9912 NR 47 TC 223 Z9 225 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD MAY 15 PY 2001 VL 152 BP 505 EP 519 DI 10.1016/S0167-2789(01)00191-9 PG 15 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 437HM UT WOS:000168986300038 ER PT J AU Feit, MD Komashko, AM Rubenchik, AM AF Feit, MD Komashko, AM Rubenchik, AM TI Relativistic self-focusing in underdense plasma SO PHYSICA D LA English DT Article DE underdense plasma; cavitation; self-focusing ID INTENSE LASER-PULSE; ELECTROMAGNETIC-WAVES; PROPAGATION AB We present the description of powerful beam self-focusing in underdense plasma. The importance of electron cavitation, i.e. total electron evacuation under the effect of ponderomotive forces, is emphasized. Cavitation results in suppression of filamentation and the possibility to channel power well above the nominal critical power of self-focusing for a distance of many Rayleigh lengths. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rubenchik, AM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mail Stop L-399, Livermore, CA 94550 USA. RI Feit, Michael/A-4480-2009 NR 20 TC 17 Z9 17 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD MAY 15 PY 2001 VL 152 BP 705 EP 713 DI 10.1016/S0167-2789(01)00203-2 PG 9 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 437HM UT WOS:000168986300050 ER PT J AU Antonov, VN Harmon, BN Yaresko, AN AF Antonov, VN Harmon, BN Yaresko, AN TI Electronic structure and magneto-optical Kerr effect of Tm monochalcogenides SO PHYSICAL REVIEW B LA English DT Article ID POLARIZED LMTO CALCULATIONS; F FERROMAGNETIC MATERIALS; MIXED-VALENT TMSE; RARE-EARTH COMPOUNDS; INTERMEDIATE VALENCE; CORRELATED SYSTEMS; MAGNETIC-STRUCTURE; METAL TRANSITION; LDA+U METHOD; BAND THEORY AB The optical and magneto-optical (MO) spectra of Tm monochalcogenides are investigated theoretically from first principles, using the fully relativistic Dirac linear combination of muffin-tin orbitals band structure method. The electronic structure is obtained with the local-spin-density approximation (LSDA), as well as with the so-called LSDA + U approach. In contrast to LSDA, where the stable solution in TmTe is a metal, the LSDA + U gave an insulating ground state. LSDA + U theory predicts the thulium ion in TmTe to be in an integer divalent state. It also shows a gradual decreasing of the energy gap with reducing of the lattice constant. LSDA + U theoretical calculations produce a similar energy band structure in TmS and TmSe, with twelve 4f bands fully occupied and hybridized with chalcogenide p states. The 14th f hole level was found to be completely unoccupied and well above the Fermi level and a hole 13th f level is partly occupied and pinned at the Fermi level. The occupation number of the 13th f level is equal to 0.12 and 0.27 in TmS and TmSe, respectively (valence 2.88+ and 2.73+). Such an energy band structure of thulium monochalcogenides describes well their measured bremsstrahlung isochromat spectroscopy (BIS), and x-ray and ultraviolet photoemission spectra as well as the optical and MO spectra. The origin of the Kerr rotation realized in the compounds is examined. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany. Ukrainian Acad Sci, Inst Met Phys, UA-252142 Kiev, Ukraine. RP Antonov, VN (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 78 TC 30 Z9 30 U1 2 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 MAY 15 PY 2001 VL 63 IS 20 AR 205112 DI 10.1103/PhysRevB.63.205112 PG 17 WC Physics, Condensed Matter SC Physics GA 436LK UT WOS:000168937200033 ER PT J AU Budde, M Cheney, CP Lupke, G Tolk, NH Feldman, LC AF Budde, M Cheney, CP Lupke, G Tolk, NH Feldman, LC TI Vibrational dynamics of bond-center hydrogen in crystalline silicon SO PHYSICAL REVIEW B LA English DT Article ID INTERSTITIAL HYDROGEN; POLYATOMIC-MOLECULES; RAMAN-SCATTERING; ENERGY EXCHANGE; DENSE MEDIUM; SI-H; RELAXATION; SPECTROSCOPY; ABSORPTION; SURFACES AB The absorption line shape associated with the fundamental transition of the H-related stretch mode of bond-center hydrogen in crystalline silicon is measured as a function of temperature with infrared spectroscopy. In addition to the shift in frequency and increase in linewidth usually observed for local vibrational modes in solids. the absorption line becomes asymmetric at elevated temperatures. A theoretical model is developed, which describes the temperature-dependent line shape in terms of thermal fluctuations in the occupation number of a low-frequency mode coupled anharmonically to the stretch mode. The model successfully describes the shift, broadening, and asymmetry of the absorption line and gives new insight into the nature of the low-frequency mode. The mode has a frequency of 114 cm(-1), is twofold degenerate, and exhibits no isotopic shift when deuterium is substituted for hydrogen. It is assigned to a pseudolocalized, Si-related mode of bond-center hydrogen. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37232 USA. Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Budde, M (reprint author), Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. EM budde@fas.harvard.edu NR 47 TC 26 Z9 26 U1 0 U2 4 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 MAY 15 PY 2001 VL 63 IS 19 AR 195203 DI 10.1103/PhysRevB.63.195203 PG 18 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200038 ER PT J AU Cavalleri, A Siders, CW Rose-Petruck, C Jimenez, R Toth, C Squier, JA Barty, CPJ Wilson, KR Sokolowski-Tinten, K von Hoegen, MH von der Linde, D AF Cavalleri, A Siders, CW Rose-Petruck, C Jimenez, R Toth, C Squier, JA Barty, CPJ Wilson, KR Sokolowski-Tinten, K von Hoegen, MH von der Linde, D TI Ultrafast x-ray measurement of laser heating in semiconductors: Parameters determining the melting threshold SO PHYSICAL REVIEW B LA English DT Article ID FLIGHT MASS-SPECTROSCOPY; ELECTRON-HOLE PLASMAS; FEMTOSECOND LASER; LATTICE-DYNAMICS; GALLIUM-ARSENIDE; DIFFRACTION; ABLATION; SILICON; PULSES; GERMANIUM AB The pulse-width dependence of thermal melting and ablation thresholds in germanium and gallium arsenide is correlated to direct, ultrafast x-ray measurements of laser-heated depths. The heating dynamics, determined by the interplay of nonlinear optical absorption, delayed Auger heating, and high-density carrier diffusion, explain the scaling laws of thermal melting thresholds in different semiconductors. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Essen Gesamthsch, Inst Laser & Plasmaphys, D-45117 Essen, Germany. RP Cavalleri, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Sokolowski-Tinten, Klaus/A-5415-2015 NR 28 TC 54 Z9 54 U1 0 U2 15 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 MAY 15 PY 2001 VL 63 IS 19 AR 193306 DI 10.1103/PhysRevB.63.193306 PG 4 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200010 ER PT J AU Collins, GW Bernat, TP Mapoles, ER Kozioziemski, BJ Duriez, C AF Collins, GW Bernat, TP Mapoles, ER Kozioziemski, BJ Duriez, C TI Heat-flux induced changes to multicrystalline D-2 surfaces SO PHYSICAL REVIEW B LA English DT Article ID TRITIUM; FUSION AB Phase-shifting interferometry reveals that a heat flux normal to the gas-solid interface reduces the surface roughness of thick (10-300 mum) multicrystalline D-2 films. The initial roughness, caused by misaligned crystals and grain boundaries produced during the initial random nucleation and rapid crystal growth used in the experiment decreases with increasing heat flux. A simple energy minimization model quantitatively explains the functional relationship between surface roughness and heat flux. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CEA, Ctr Etud Limeil Valenton, F-94195 Villeneuve St Georges, France. RP Collins, GW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 12 TC 7 Z9 7 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 MAY 15 PY 2001 VL 63 IS 19 AR 195416 DI 10.1103/PhysRevB.63.195416 PG 4 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200086 ER PT J AU Freeland, JW Coulthard, I Antel, WJ Stampfl, APJ AF Freeland, JW Coulthard, I Antel, WJ Stampfl, APJ TI Interface bonding for Fe thin films on GaAs surfaces of differing morphology SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC CIRCULAR-DICHROISM; SEMICONDUCTOR INTERFACE; ELECTRONIC-STRUCTURE; TRANSITION; GROWTH AB Formation of a common type of Fe-As local bonding in Fe thin films on GaAs surfaces of differing orientation and preparation is evidenced through a common charge transfer at the interface. X-ray absorption studies of unoccupied 3d states for Fe thin films on sputtered GaAs(100) and cleaved GaAs(110) display a similar amount of 3d charge transfer into the GaAs substrate even though the mode of surface preparation leads to reduced intermixing in the (100) case. Implications of these results for the understanding of the role of the Fe-GaAs interface in both electronic and magnetic properties are discussed. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Australian Nucl Sci & Technol Org, Div Phys, Lucas Hts, NSW, Australia. RP Freeland, JW (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RI Schaff, William/B-5839-2009 NR 28 TC 36 Z9 37 U1 1 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 MAY 15 PY 2001 VL 63 IS 19 AR 193301 DI 10.1103/PhysRevB.63.193301 PG 4 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200005 ER PT J AU Harrison, N Biskup, N Brooks, JS Balicas, L Tokumoto, M AF Harrison, N Biskup, N Brooks, JS Balicas, L Tokumoto, M TI Origin of the split quantum oscillation wave form in alpha-(BEDT-TTF)(2)KHg(SCN)(4) SO PHYSICAL REVIEW B LA English DT Article ID ORGANIC CONDUCTOR ALPHA-(BEDT-TTF)(2)KHG(SCN)(4); VAN-ALPHEN OSCILLATIONS; TRANSFER SALT ALPHA-(BEDT-TTF)(2)KHG(SCN)(4); SHUBNIKOV-DEHAAS OSCILLATIONS; STRONG MAGNETIC-FIELDS; LOW-TEMPERATURE STATE; CHARGE-DENSITY-WAVE; PHASE-DIAGRAM; MAGNETORESISTANCE OSCILLATIONS; EFFECTIVE-MASS AB We report the results of a detailed study of the field orientation dependence of the de Haas-van Alphen wave form in alpha-( BEDT-TTF)(2)KHg( SCN)(4) over a wide range of angles and fields. By considering the field orientation dependence of the sign and phase of the fundamental alpha frequency, at fields both well above and below the kink transition field, it is found that the product of the effective mass with the electron g factor is approximately constant. This implies that spin splitting cannot occur within the low-magnetic-field phase until the angle between the magnetic field and the normal to the conducting planes is similar to 42 degrees. This finding contrasts greatly with that recently published by Sasaki and Fukase. The results of the present study imply that the electron-electron interactions are largely field independent in this material, while a field dependence of the electron-phonon interactions is still tenable. The manner in which the amplitude of the wave form of the oscillations is damped within the low-magnetic-field phase is suggestive of a nonharmonically indexed reduction of the amplitude, thereby eliminating explanations in terms of magnetic breakdown or impurity scattering. Meanwhile, the presence of a large amplitude second harmonic within the low-magnetic-field phase that has a negative sign over a broad range of angles can be explained only by the frequency doubling effect. C1 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. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. RP Harrison, N (reprint author), Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. RI Messier, Claude/A-2322-2008; Biskup, Neven/N-2132-2014 OI Messier, Claude/0000-0002-4791-1763; Biskup, Neven/0000-0003-0309-0737 NR 44 TC 11 Z9 11 U1 0 U2 4 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 MAY 15 PY 2001 VL 63 IS 19 AR 195102 DI 10.1103/PhysRevB.63.195102 PG 9 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200026 ER PT J AU Janotti, A Wei, SH Zhang, SB Kurtz, S AF Janotti, A Wei, SH Zhang, SB Kurtz, S TI Structural and electronic properties of ZnGeAs2 SO PHYSICAL REVIEW B LA English DT Article ID ABC2 CHALCOPYRITE SEMICONDUCTORS; GAP PRESSURE COEFFICIENTS; BAND OFFSETS; SPECIAL POINTS; ALLOYS; STABILITY; STRAIN; TRENDS; GAAS AB Using a first-principles band-structure method based on density functional theory, we have studied the structural and electronic properties of ZnGeAs2. In agreement with experimental data, ZnGeAs2 is found to be nearly lattice matched to its binary analog GaAs. The calculated band structures show that ZnGeAs2 in the chalcopyrite structure has a direct band gap, about 0.31 eV smaller than the band gap of GaAs. The calculated valence-band offset between ZnGeAs2 and GaAs is 0.18 eV; thus, the band alignment of the ZnGeAs2/GaAs system is type I, with both holes and electrons localized on ZnGeAs2. We also find that at low temperature, (ZnGeAs2)(0.5)(GaAs) forms a stable stannite structure. However, the band gap and the mixing energy of the alloy at higher temperature depend sensitively on the local short-range order. The calculated formation energies of the (ZnGeAs2)(n)(GaAs)(2n) superlattices along the [001] direction show strong nonmonotonic behavior, with the formation energy DeltaH(n) maximized at n = 2. We compared our results for the ZnGeAs2/GaAs system to the well-studied CuGaSe2/ZnSe system. The differences between these two systems are explained in terms of their ionicity and their relative strength of the anion p and cation d couplings. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013; Janotti, Anderson/F-1773-2011 OI Zhang, Shengbai/0000-0003-0833-5860; Janotti, Anderson/0000-0001-5028-8338 NR 36 TC 21 Z9 22 U1 0 U2 15 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 MAY 15 PY 2001 VL 63 IS 19 AR 195210 DI 10.1103/PhysRevB.63.195210 PG 7 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200045 ER PT J AU Joyce, JJ Arko, AJ Morales, LA Sarrao, JL Hochst, H AF Joyce, JJ Arko, AJ Morales, LA Sarrao, JL Hochst, H TI Comment on "Photoemission experiments on YbInCu4: Surface effects and temperature dependence" SO PHYSICAL REVIEW B LA English DT Editorial Material ID SINGLE-IMPURITY MODEL; PHOTOELECTRON-SPECTROSCOPY; HEAVY FERMIONS; TRANSITION; SYSTEMS; SPECTRA AB A recent paper on photoemission of YbInCu4 reports some significant findings that have implications beyond the single material investigated. We find some of the experimental results in the paper to be meritorious but the central premise and conclusion are not supported by additional data. We provide alternative interpretations for the experimental results and exploit advantages in the photoemission process to more clearly elucidate the electronic structure of Yb heavy fermions and the applicability of photoelectron spectroscopy. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wisconsin, Ctr Synchrotron Radiat, Stoughton, WI 53589 USA. RP Joyce, JJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 19 TC 13 Z9 13 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 MAY 15 PY 2001 VL 63 IS 19 AR 197101 DI 10.1103/PhysRevB.63.197101 PG 5 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200089 ER PT J AU Kim, YH Chang, KJ Louie, SG AF Kim, YH Chang, KJ Louie, SG TI Electronic structure of radially deformed BN and BC3 nanotubes SO PHYSICAL REVIEW B LA English DT Article ID BORON-NITRIDE NANOTUBES; CARBON NANOTUBES; TUBULES; PSEUDOPOTENTIALS; MICROTUBULES; DEFORMATION AB We investigate the band-gap modification by radial deformation in BN and BC3 nanotubes through first-principles pseudopotential density-functional calculations. In zigzag BN nanotubes, radial deformations that give rise to transverse pressures of about 10 GPa decrease the gap from 5 to 2 eV, allowing for optical applications in the visible range. When armchair BC3 nanotubes with the gap of about 0.5 eV are collapsed down to the interlayer distance of 3.5 Angstrom, a gap closure occurs due to the lowering of, the unoccupied pi band. On the other hand, the band gaps of armchair BN and zigzag BC3 nanotubes are found to be insensitive to radial deformations. This different behavior between zigzag and armchair nanotubes is attributed to the different characteristics of states near the gap. C1 Korea Inst Adv Study, Sch Phys, Seoul 130012, South Korea. Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Kim, YH (reprint author), Korea Inst Adv Study, Sch Phys, Seoul 130012, South Korea. RI Kim, Yong-Hyun/C-2045-2011; Chang, Kee Joo/C-1989-2011 OI Kim, Yong-Hyun/0000-0003-4255-2068; NR 29 TC 108 Z9 111 U1 1 U2 12 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 MAY 15 PY 2001 VL 63 IS 20 AR 205408 DI 10.1103/PhysRevB.63.205408 PG 5 WC Physics, Condensed Matter SC Physics GA 436LK UT WOS:000168937200082 ER PT J AU Mandrus, D Thompson, JR Gaal, R Forro, L Bryan, JC Chakoumakos, BC Woods, LM Sales, BC Fishman, RS Keppens, V AF Mandrus, D Thompson, JR Gaal, R Forro, L Bryan, JC Chakoumakos, BC Woods, LM Sales, BC Fishman, RS Keppens, V TI Continuous metal-insulator transition in the pyrochlore Cd2Os2O7 SO PHYSICAL REVIEW B LA English DT Article ID TRANSPORT; SUPERCONDUCTIVITY; FERROMAGNETISM; RUSR2GDCU2O8; SCATTERING; PRESSURE; CD2RE2O7; CD2RU2O7; SRRUO3; V2O3 AB Cd2Os2O7 crystallizes in the pyrochlore structure and undergoes a metal-insulator transition (MIT) near 226 K. We have characterized the MIT in Cd2Os2O7 using x-ray diffraction, resistivity at ambient and high pressure, specific heat, magnetization, thermopower, Hall coefficient, and thermal conductivity. Both single crystals and polycrystalline material were examined. The MIT is accompanied by no change in crystal symmetry and a change in unit-cell volume of less than 0.05%. The resistivity shows little temperature dependence above 226 K, but increases by 3 orders of magnitude as the sample is cooled to 4 K. The specific heat anomaly resembles a mean-held transition and shows no hysteresis or latent heat. Cd2Os2O7 orders magnetically at the MIT. The magnetization data are consistent with antiferromagnetic order, with a small parasitic ferromagnetic component. The Hall and Seebeck coefficients are consistent with a semiconducting gap opening at the Fermi energy at the MIT. We have also performed electronic structure calculations on Cd2Os2O7. These calculations indicate that Cd2Os2O7 is metallic, with a sharp peak in the density of states at the Fermi energy. We interpret the data in terms of a Slater transition. In this scenario, the MIT is produced by a doubling of the unit cell due to the establishment of antiferromagnetic order. A Slater transition-unlike a Mott transition-is predicted to be continuous, with a semiconducting energy gap opening much like a BCS gap as the material is cooled below T-MIT. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Ecole Polytech Fed Lausanne, Dept Phys, CH-1015 Lausanne, Switzerland. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Mississippi, Natl Ctr Phys Acoust, University, MS 38677 USA. Univ Mississippi, Dept Phys, University, MS 38677 USA. RP Mandrus, D (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM mandrusdg@ornl.gov RI Fishman, Randy/C-8639-2013; Mandrus, David/H-3090-2014; Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 41 TC 110 Z9 111 U1 4 U2 53 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 MAY 15 PY 2001 VL 63 IS 19 AR 195104 DI 10.1103/PhysRevB.63.195104 PG 12 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200028 ER PT J AU Reinert, F Claessen, R Nicolay, G Ehm, D Hufner, S Ellis, WP Gweon, GH Allen, JW Kindler, B Assmus, W AF Reinert, F Claessen, R Nicolay, G Ehm, D Hufner, S Ellis, WP Gweon, GH Allen, JW Kindler, B Assmus, W TI Reply to "Comment on 'Photoemission experiments on YbInCu4: Surface effects and temperature dependence'" SO PHYSICAL REVIEW B LA English DT Editorial Material ID VALENCE PHASE-TRANSITION; MEAN FREE PATHS; YB COMPOUNDS; YBXIN1-XCU2 AB The stoichiometric rare-earth compound YbInCu4 is known for its first-order valence transition at T-d approximate to 55 K and ambient pressure. Although this valence transition has been extensively studied by various volume-sensitive experimental methods, highly surface-sensitive photoemission measurements in the vuv energy range [ultraviolet photoemission spectroscopy (UPS)] could not observe a sharp valence change of the Yb valence Uyb at the transition temperature. Instead there is only a smooth temperature dependence of U-Yb over a large temperature range. Furthermore, the low-temperature values for the hole-occupation number n(h) = v(Yb)-2 from UPS are significantly below the values of volume-sensitive measurements. Here we present temperature-dependent photoemission data on YbInCu4 measured at photon energies of hv = 1486 eV [x-ray photoemission spectroscopy (XPS)] with a significantly increased information depth in comparison to previous experiments with lower photon energies. These data clearly show the existence of a valence transition at the extended sampling depth of the XPS experiment, in contrast to results from the distorted near-surface region. C1 Univ Saarlandes, Fachrichtung Expt Phys, D-66041 Saarbrucken, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Univ Frankfurt, Inst Phys, D-60054 Frankfurt, Germany. RP Reinert, F (reprint author), Univ Saarlandes, Fachrichtung Expt Phys, D-66041 Saarbrucken, Germany. EM friedel@mx.uni-saarland.de RI Reinert, Friedrich/J-3005-2013; Claessen, Ralph/A-2045-2017 OI Claessen, Ralph/0000-0003-3682-6325 NR 16 TC 16 Z9 16 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 MAY 15 PY 2001 VL 63 IS 19 AR 197102 DI 10.1103/PhysRevB.63.197102 PG 3 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200090 ER PT J AU Strasser, T Solterbeck, C Schattke, W Bartos, I Cukr, M Jiricek, P Fadley, CS Van Hove, MA AF Strasser, T Solterbeck, C Schattke, W Bartos, I Cukr, M Jiricek, P Fadley, CS Van Hove, MA TI One-step photoemission calculations for ideal GaAs(001) and AlAs(001) surfaces and (GaAs)(m)(AlAs)(n) superlattices SO PHYSICAL REVIEW B LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; GAAS(110); GAAS AB Normal photoemission spectra for the (001) surface of (AlAs)(2)(GaAs)(2) and (AlAs)(3)(GaAs)(3) superlattices are calculated. They represent the first calculations within the one-step model for layered superlattices. The aim is to develop tools to extract general features from measured spectra specific to superlattices. The spectra show the opening of band gaps at the Brillouin zone edge, which are characteristic for the modified periodicity of the superlattice. Furthermore, the layer-resolved photocurrent allows to identify emissions from AlAs layers hidden below the first two or three GaAs layers. As a reference, theoretical normal emission spectra from the pure bulk GaAs and AlAs(001) surfaces are shown. C1 Univ Kiel, Inst Theoret Phys & Astrophys, D-24098 Kiel, Germany. Acad Sci Czech Republ, Inst Phys, Prague 16253 6, Czech Republic. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Strasser, T (reprint author), Univ Kiel, Inst Theoret Phys & Astrophys, Leibnizstr 15, D-24098 Kiel, Germany. RI Van Hove, Michel/A-9862-2008; Bartos, Igor/G-5780-2014; Jiricek, Petr/G-6428-2014 OI Van Hove, Michel/0000-0002-8898-6921; NR 19 TC 9 Z9 9 U1 2 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 MAY 15 PY 2001 VL 63 IS 19 AR 195321 DI 10.1103/PhysRevB.63.195321 PG 10 WC Physics, Condensed Matter SC Physics GA 434KT UT WOS:000168814200066 ER PT J AU Varga, K Navratil, P Usukura, J Suzuki, Y AF Varga, K Navratil, P Usukura, J Suzuki, Y TI Stochastic variational approach to few-electron artificial atoms SO PHYSICAL REVIEW B LA English DT Article ID SHELL-MODEL CALCULATIONS; ASSEMBLED QUANTUM DOTS; MAGNETIC-FIELD; CAPACITANCE SPECTROSCOPY; INTERACTING ELECTRONS; SYSTEMS; STATES; SINGLE; RINGS AB The spectra of quantum dots of different geometries (quantum ring, quantum cylinder, spherical square well, and parabolic) are studied. The stochastic variational method on correlated Gaussian basis functions and a large scale shell-model approach have been used to investigate these "artificial" atoms and their properties in magnetic fields. Accurate numerical results are presented for N=2-8 electron systems. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Hungarian Acad Sci ATOMKI, Nucl Res Inst, H-4000 Debrecen, Hungary. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Niigata Univ, Grad Sch Sci & Technol, Niigata 9502181, Japan. Niigata Univ, Dept Phys, Niigata 9502181, Japan. RP Varga, K (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM vargak@ornl.gov RI Varga, Kalman/A-7102-2013 NR 40 TC 51 Z9 51 U1 2 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 MAY 15 PY 2001 VL 63 IS 20 AR 205308 DI 10.1103/PhysRevB.63.205308 PG 15 WC Physics, Condensed Matter SC Physics GA 436LK UT WOS:000168937200055 ER PT J AU Zhang, Y Mascarenhas, A Wang, LW AF Zhang, Y Mascarenhas, A Wang, LW TI Dependence of the band structure on the order parameter for partially ordered GaxIn1-xP alloys SO PHYSICAL REVIEW B LA English DT Article ID LONG-RANGE-ORDER; V SEMICONDUCTOR ALLOYS; GAP REDUCTION; QUANTUM DOTS; GAINP2; PHOTOLUMINESCENCE; ENERGY; GA0.52IN0.48P; GA0.5IN0.5P AB An empirical pseudopotential method is demonstrated for realistically and accurately calculating the band structure of partially CuPt ordered GaxIn1-xP alloys. A sufficiently large supercell of similar to 3500 atoms, with all atomic positions relaxed by applying a valence force field method, is used to simulate the (Ga,In) distribution in the partially ordered alloy with the order parameter eta varying from 0 to 1. While agreeing very well with experimental data in the experimentally verifiable region eta <0.5, our results illustrate that a commonly accepted interpolation scheme (i.e., the (2) rule) is grossly inaccurate for determining certain primary band structure parameters (e.g., the band gap) between eta =0 and eta =1. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM yzhang@nrel.gov NR 35 TC 26 Z9 26 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 MAY 15 PY 2001 VL 63 IS 20 AR 201312 DI 10.1103/PhysRevB.63.201312 PG 4 WC Physics, Condensed Matter SC Physics GA 436LK UT WOS:000168937200018 ER PT J AU Barbieri, R Hall, LJ Nomura, Y AF Barbieri, R Hall, LJ Nomura, Y TI Constrained standard model from a compact extra dimension SO PHYSICAL REVIEW D LA English DT Article ID KALUZA-KLEIN EXCITATIONS; SOFTLY BROKEN SUPERSYMMETRY; TEV-SCALE; LOCAL SUPERSYMMETRY; GRAND UNIFICATION; BREAKING; COLLIDER; COMPACTIFICATION; MILLIMETER; ORBIFOLDS AB An SU(3)xSU(2)xU(1) supersymmetric theory is constructed with a TeV-sized extra dimension compactified on the orbifold S-1/(Z(2) x Z(2)'). The compactification breaks supersymmetry leaving a set of zero modes that correspond precisely to the states of the 1 Higgs doubler standard model. Supersymmetric Yukawa interactions are localized at orbifold fixed points. The top quark hypermultiplet radiatively triggers electroweak symmetry breaking, yielding a Higgs potential that is finite and exponentially insensitive to physics above the compactification scale. This potential depends on only a single free parameter, the compactification scale, yielding a Higgs boson mass prediction of 127+/-8 GeV. The masses of all the superpartners and the Kaluza-Klein excitations are also predicted. The lightest supersymmetric particle is a top squark of mass 197+/-20 GeV. The top Kaluza-Klein tower leads to the rho parameter having quadratic sensitivity to unknown physics in the ultraviolet region. C1 Scuola Normale Super Pisa, I-56126 Pisa, Italy. Ist Nazl Fis Nucl, I-56126 Pisa, Italy. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Barbieri, R (reprint author), Scuola Normale Super Pisa, Piazza Cavalieri 7, I-56126 Pisa, Italy. OI Nomura, Yasunori/0000-0002-1497-1479 NR 63 TC 208 Z9 208 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 MAY 15 PY 2001 VL 63 IS 10 AR 105007 DI 10.1103/PhysRevD.63.105007 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 434RV UT WOS:000168830400054 ER PT J AU Liebendorfer, M Mezzacappa, A Thielemann, FK AF Liebendorfer, M Mezzacappa, A Thielemann, FK TI Conservative general relativistic radiation hydrodynamics in spherical symmetry and comoving coordinates SO PHYSICAL REVIEW D LA English DT Article ID BOLTZMANN NEUTRINO TRANSPORT; STELLAR CORE COLLAPSE; II SUPERNOVAE; BLACK-HOLES; FLOWS; TIME; CODE; SIMULATION; SPACETIMES; EQUATION AB The description of general relativistic radiation hydrodynamics in spherical symmetry is presented in natural coordinate choices. For hydrodynamics, comoving coordinates are chosen and the momentum phase space for the radiation particles is described in comoving frame four-momenta. We also investigate a description of the momentum phase space in terms of the particle impact parameter and energy at infinity and derive a simple approximation to the general relativistic Boltzmann equation. Further developed are, however, the exact equations in comoving coordinates since the description of the interaction between matter and radiation particles is best described in the closely related orthonormal basis comoving with the fluid elements. We achieve a conservative and concise formulation of radiation hydrodynamics that is well suited for numerical implementation by a variety of methods. The contribution of radiation to the general relativistic jump conditions at shock fronts is discussed and artificial viscosity is consistently included in the derivations in order to support approaches relying on this option. C1 Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Liebendorfer, M (reprint author), Univ Basel, Dept Phys & Astron, Klingelbergstr 82, CH-4056 Basel, Switzerland. RI Mezzacappa, Anthony/B-3163-2017 OI Mezzacappa, Anthony/0000-0001-9816-9741 NR 46 TC 59 Z9 60 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 MAY 15 PY 2001 VL 63 IS 10 AR 104003 DI 10.1103/PhysRevD.63.104003 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 434RV UT WOS:000168830400025 ER PT J AU Liebendorfer, M Mezzacappa, A Thielemann, FK Messer, OEB Hix, WR Bruenn, SW AF Liebendorfer, M Mezzacappa, A Thielemann, FK Messer, OEB Hix, WR Bruenn, SW TI Probing the gravitational well: No supernova explosion in spherical symmetry with general relativistic Boltzmann neutrino transport SO PHYSICAL REVIEW D LA English DT Article ID CORE-COLLAPSE SUPERNOVAE; GAMMA-RAY BURSTS; II SUPERNOVAE; WEAK INTERACTION; NUCLEAR-MATTER; DENSE MATTER; MECHANISM; EQUATION; SHOCK; CONVECTION AB We report on the stellar core collapse, bounce, and postbounce evolution of a 13 M. star in a self-consistent general relativistic spherically symmetric simulation based on Boltzmann neutrino transport. We conclude that approximations to exact neutrino transport and the omission of general relativistic effects were not alone responsible for the failure of numerous preceding attempts to model supernova explosions in spherical symmetry. Compared to simulations in Newtonian gravity, the general relativistic simulation results in a smaller shock radius. We however argue that the higher neutrino luminosities and rms energies in the general relativistic case could lead to a larger supernova explosion energy. C1 Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RP Liebendorfer, M (reprint author), Univ Basel, Dept Phys & Astron, Klingelbergstr 82, CH-4056 Basel, Switzerland. RI Hix, William/E-7896-2011; Messer, Bronson/G-1848-2012; Mezzacappa, Anthony/B-3163-2017 OI Hix, William/0000-0002-9481-9126; Messer, Bronson/0000-0002-5358-5415; Mezzacappa, Anthony/0000-0001-9816-9741 NR 70 TC 233 Z9 234 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 15 PY 2001 VL 63 IS 10 AR 103004 DI 10.1103/PhysRevD.63.103004 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 434RV UT WOS:000168830400006 ER PT J AU Peshier, A AF Peshier, A TI Hard thermal loop resummation of the thermodynamic potential SO PHYSICAL REVIEW D LA English DT Article ID QUARK-GLUON PLASMA; HOT GAUGE-THEORIES; FREE-ENERGY; FINITE-TEMPERATURE; QCD PLASMA; EQUATION; STATE; PRESSURE; FERMIONS; G(5) AB Starting from the Phi -derivable approximation scheme at leading-loop order, the thermodynamic potential in a hot scalar theory, as well as in QED and QCD, is expressed in terms of hard thermal loop propagators. This nonperturbative approach is consistent with the leading-order perturbative results, ultraviolet finite, and, for gauge theories, explicitly gauge invariant. For hot QCD it is argued that the resummed approximation is applicable in the large-coupling regime, down to almost twice the transition temperature. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Peshier, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 30 TC 62 Z9 62 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 MAY 15 PY 2001 VL 63 IS 10 AR 105004 DI 10.1103/PhysRevD.63.105004 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 434RV UT WOS:000168830400051 ER PT J AU Burr, TL AF Burr, TL TI Maximally selected measures of evidence of disease clusters SO STATISTICS IN MEDICINE LA English DT Article ID STATISTICS; APPROXIMATIONS; MOMENTS AB It is now common to read reports such as 'city A has a childhood cancer rate 30 per cent higher than the national average'. Because the details about how the data was examined can greatly impact the conclusions, the epidemiologist then wants to know more information, such as 'over what time period' and 'how many other cancer types were examined'. For example, city A might have calculated cancer rates for many age groups within different regions of the city over many time intervals, but reported only the highest cancer rate discovered in a particular group. We will refer to such selective reporting as 'maximally selecting measures of evidence of disease clustering', or less formally as 'fishing for statistical significance'. The objective of this paper is to study the behaviour of maximally selected statistics for measuring the extent of clustering in disease outbreaks. The original data is the time and location of each reported case of the disease. In some cases we are only given aggregates of the original data, such as the number of cases during a time period over a given region. We introduce new and review existing methods for correcting for the effect of making maximal selections in disease cluster detection. We consider three main cases with examples. We demonstrate via simulation and analytical approximations that some types of 'fishing' are simple to correct for while others are not. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Burr, TL (reprint author), Univ Calif Los Alamos Natl Lab, MS E541, Los Alamos, NM 87545 USA. NR 24 TC 3 Z9 3 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0277-6715 J9 STAT MED JI Stat. Med. PD MAY 15 PY 2001 VL 20 IS 9-10 BP 1443 EP 1460 DI 10.1002/sim.681 PG 18 WC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Medicine, Research & Experimental; Statistics & Probability SC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Research & Experimental Medicine; Mathematics GA 429JR UT WOS:000168513900015 PM 11343365 ER PT J AU Richardson, TJ Slack, JL Armitage, RD Kostecki, R Farangis, B Rubin, MD AF Richardson, TJ Slack, JL Armitage, RD Kostecki, R Farangis, B Rubin, MD TI Switchable mirrors based on nickel-magnesium films SO APPLIED PHYSICS LETTERS LA English DT Article ID OPTICAL-PROPERTIES; HYDRIDE FORMATION; HYDROGEN STORAGE; KINETICS; MG2NIH4; MG; ENHANCEMENT; SANDWICHES; DIFFUSION; ANIONS AB An electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin, magnesium-rich Ni-Mg films prepared on glass substrates by co-sputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on cathodic polarization in alkaline electrolyte, the films take up hydrogen and become transparent. When hydrogen is removed, the mirror properties are recovered. The transition is believed to result from reversible formation of Mg2NiH4 and MgH2. A thin overlayer of palladium was found to enhance the kinetics of hydrogen insertion and extraction, and to protect the metal surface against oxidation. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Richardson, TJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 27 TC 261 Z9 266 U1 8 U2 59 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 MAY 14 PY 2001 VL 78 IS 20 BP 3047 EP 3049 DI 10.1063/1.1371959 PG 3 WC Physics, Applied SC Physics GA 430EA UT WOS:000168559600016 ER PT J AU Tobos, V Paulius, LM Petrean, AM Ferguson, S Snyder, JW Olsson, RJ Kwok, WK Crabtree, GW AF Tobos, V Paulius, LM Petrean, AM Ferguson, S Snyder, JW Olsson, RJ Kwok, WK Crabtree, GW TI Effects of successive proton irradiation on the peak effect in YBa2Cu3O7-delta single crystals SO APPLIED PHYSICS LETTERS LA English DT Article ID CU-O CRYSTALS; II SUPERCONDUCTORS; PHASE-DIAGRAM; MAGNETIZATION; EVOLUTION AB The effect of increasing the density of uncorrelated defects on the peak effect is studied in a detwinned YBa2Cu3O7-delta single crystal. The defects were introduced with 9 MeV proton irradiation where the total dose ranged from 0.25 x 10(15) to 2 x 10(15) p/cm(2). With each successive irradiation, the peak effect shifts down in field and is eventually suppressed in both the electrical resistivity and the dc magnetization by a sufficiently high irradiation dose. The peak effect reappears after a high temperature anneal, suggesting that it is primarily the point defects introduced by the irradiation which interfere with the formation of the peak effect. (C) 2001 American Institute of Physics. C1 Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Superconduct, Argonne, IL 60439 USA. RP Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. EM valentina.tobos@wmich.edu NR 27 TC 8 Z9 8 U1 2 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 14 PY 2001 VL 78 IS 20 BP 3097 EP 3099 DI 10.1063/1.1352039 PG 3 WC Physics, Applied SC Physics GA 430EA UT WOS:000168559600033 ER PT J AU Hirai, Y Radisky, D Boudreau, R Simian, M Stevens, ME Oka, Y Takebe, K Niwa, S Bissell, MJ AF Hirai, Y Radisky, D Boudreau, R Simian, M Stevens, ME Oka, Y Takebe, K Niwa, S Bissell, MJ TI Epimorphin mediates mammary luminal morphogenesis through control of C/EBP beta SO JOURNAL OF CELL BIOLOGY LA English DT Article DE transcription factor balance; mammary morphogenesis; epithelial-stromal interactions; CCAAT/enhancer binding protein; transgenic mice ID TRANSCRIPTIONAL INHIBITORY PROTEIN; PRESYNAPTIC GLUTAMATE-RECEPTOR; SIGNAL-ANCHOR PROTEINS; CASEIN GENE-EXPRESSION; ACUTE-PHASE RESPONSE; MESSENGER-RNA; CELL-SURFACE; IN-VITRO; BRANCHING MORPHOGENESIS; DUCTAL MORPHOGENESIS AB We have shown previously that epimorphin (EPM), a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which EPM mediates luminal morphogenesis. Treatment of cells with EPM to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein (C/EBP)beta and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, since constitutive expression of LIP was sufficient to produce lu-men formation, whereas constitutive expression of LAP blocked EPM-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which EPM expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBP beta, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for EPM in luminal morphogenesis through control of C/EBP beta expression. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Sumitomo Elect Ind Ltd, Osaka R&D Lab, Yokohama Lab, Yokohama, Kanagawa 244, Japan. RP Bissell, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA57621, R01 CA057621] NR 77 TC 58 Z9 59 U1 1 U2 3 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD MAY 14 PY 2001 VL 153 IS 4 BP 785 EP 794 DI 10.1083/jcb.153.4.785 PG 10 WC Cell Biology SC Cell Biology GA 433QH UT WOS:000168770900015 PM 11352939 ER PT J AU Zetner, PW Johnson, PV Li, Y Csanak, G Clark, REH Abdallah, J AF Zetner, PW Johnson, PV Li, Y Csanak, G Clark, REH Abdallah, J TI Electron impact excitation of the ( ... 6s6p P-3(J)) levels in ytterbium SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID SUPERELASTIC SCATTERING; COHERENCE PARAMETERS; CROSS-SECTIONS; ...6S6P(1)P(1) TRANSITION; SODIUM; ATOMS; 6S6P; ...6S5D(1)D(2); ORIENTATION; ALIGNMENT AB Differential cross sections (DCS) and electron impact coherence parame ters (EICP) have been measured and calculated for the (...6s6p P-3(J)) levels in ytterbium. DCS for the (...6s6p P-3(1))and (...6s6p P-3(2)) levels were determined at collision energies of 10, 20 and 40 eV. EICP for the (.,.6s6p P-3(1)) intermediate-coupled level were determined at collision energies of 20 and 40 eV. Calculations were made in the unitarized distorted-wave approximation. Measurements were made in a crossed-beam apparatus with EICP measured using the technique of superelastic scattering from atoms laser-excited into the P-3(1) level. C1 Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zetner, PW (reprint author), Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. RI Johnson, Paul/D-4001-2009 OI Johnson, Paul/0000-0002-0186-8456 NR 42 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 MAY 14 PY 2001 VL 34 IS 9 BP 1619 EP 1639 DI 10.1088/0953-4075/34/9/303 PG 21 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 435VZ UT WOS:000168904000007 ER PT J AU Harrison, N Mielke, CH Singleton, J Brooks, JS Tokumoto, M AF Harrison, N Mielke, CH Singleton, J Brooks, JS Tokumoto, M TI Experimental evidence for Frohlich superconductivity in high magnetic fields SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID CHARGE-DENSITY-WAVE; PHASE-DIAGRAM; SYSTEM; STATE; ALPHA-(BEDT-TTF)(2)KHG(SCN)(4) AB Resistivity and irreversible magnetization data taken within the high magnetic field CDWx phase of the quasi-two-dimensional organic metal alpha-(BEDT-TTF)(2)KHg(SCN)(4) are shown to be consistent with a field-induced inhomogeneous superconducting phase. In-plane skin depth measurements show that the resistive transition on entering the CDW, phase is both isotropic and representative of the bulk. 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. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. RP Harrison, N (reprint author), Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. RI Messier, Claude/A-2322-2008; Mielke, Charles/S-6827-2016 OI Messier, Claude/0000-0002-4791-1763; Mielke, Charles/0000-0002-2096-5411 NR 30 TC 15 Z9 15 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAY 14 PY 2001 VL 13 IS 19 BP L389 EP L395 DI 10.1088/0953-8984/13/19/105 PG 7 WC Physics, Condensed Matter SC Physics GA 435YZ UT WOS:000168910900005 ER PT J AU Carena, M Heinemeyer, S Wagner, CEM Weiglein, G AF Carena, M Heinemeyer, S Wagner, CEM Weiglein, G TI Do electroweak precision data and Higgs-mass constraints rule out a scalar bottom quark with mass of order 5 GeV? SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRODUCTION CROSS-SECTION; QCD CORRECTIONS; FERMILAB TEVATRON; STANDARD MODEL; MSSM; BOSON; COLLIDER; SUPERSYMMETRY; SUPERGRAVITY; OBSERVABLES AB We study the implications of a scalar bottom quark, with a mass of O (5 GeV), within the minimal supersymmetric standard model. Light sbottoms may naturally appear for large tan beta and, depending on the decay modes, may have escaped experimental detection. We show that a light sbottom cannot be ruled out by electroweak precision data and the bound on the lightest CP-even Higgs-boson mass. We infer that a light (b) over tilde scenario requires a relatively light scalar top quark whose mass is typically about the top-quark mass. In this scenario the lightest Higgs boson decays predominantly into (b) over tilde pairs and obeys the mass bound mh m(h) less than or similar to 123 GeV. C1 Fermilab, Batavia, IL 60510 USA. Brookhaven Natl Lab, Dept Phys, HET, Upton, NY 11973 USA. Argonne Natl Lab, High Energy Div, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. CERN, Div Theoret Phys, CH-1211 Geneva 23, Switzerland. RP Carena, M (reprint author), Fermilab, Box 500, Batavia, IL 60510 USA. NR 28 TC 37 Z9 37 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4463 EP 4466 DI 10.1103/PhysRevLett.86.4463 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500011 PM 11384260 ER PT J AU Anastassov, A Duboscq, JE Eckhart, E 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 Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Savinov, V Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Xu, Z Godang, R Bonvicini, G Cinabro, D Dubrovin, M McGee, S Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Chen, GP Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Hsu, L Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Romano, A Thayer, JG Urner, D Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Stoeck, H Yelton, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R 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 Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F AF Anastassov, A Duboscq, JE Eckhart, E 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 Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Jessop, CP Savinov, V Coan, TE Fadeyev, V Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Wolf, A Wu, J Kopp, S Mahmood, AH Csorna, SE Danko, I McLean, KW Xu, Z Godang, R Bonvicini, G Cinabro, D Dubrovin, M McGee, S Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Chen, GP Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Hsu, L Jones, CD Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Patterson, JR Peterson, D Riley, D Romano, A Thayer, JG Urner, D Valant-Spaight, B Warburton, A Avery, P Prescott, C Rubiera, AI Stoeck, H Yelton, J Brandenburg, G Ershov, A Gao, YS Kim, DYJ Wilson, R 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 Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F CA CLEO Collaboration TI Study of tau decays to six pions and a neutrino SO PHYSICAL REVIEW LETTERS LA English DT Article AB The tau decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are B(tau (-) --> 2 pi (-)pi (-)3 pi (0)nu (tau)) = (2.2 +/- 0.3 +/- 0.4) X 10(-4) and B(tau (-) --> 3 pi (-)2 pi (+)pi (0)nu (tau)) = (1.7 +/- 0.7 +/- 0.2) X 10(-4). A search for substructure in these decays shows that they are saturated by intermediate states with eta or omega mesons. We present the first observation of the decay tau (-) --> 2 pi (-)pi (+)omega nu (tau) and the branching fraction is measured to be (1.2 +/- 0.2 +/- 0.1) x 10(-4). The measured branching fractions are in good agreement with the isospin expectations but somewhat below the conserved-vector-current predictions. C1 MIT, Cambridge, MA 02139 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas, Edinburg, TX 78539 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 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. RP Anastassov, A (reprint author), Ohio State Univ, Columbus, OH 43210 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 0 TC 16 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4467 EP 4471 DI 10.1103/PhysRevLett.86.4467 PG 5 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500012 PM 11384261 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 Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bocek, 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 Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W 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 Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM 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 Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirby, M Kirk, M 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, J Lancaster, M Lander, R Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W 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 Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, E Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C 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 Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T 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, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T 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 Yu, Z 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 Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bocek, 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 Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W 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 Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM 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 Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirby, M Kirk, M 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, J Lancaster, M Lander, R Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W 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 Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, E Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C 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 Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T 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, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T 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 Yu, Z Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Search for neutral supersymmetric Higgs bosons in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLIDER DETECTOR; FERMILAB-TEVATRON; UPPER LIMIT; ASSOCIATION; MODEL; MASS AB We present the results of a starch for neutral Higgs bosons produced in association with b quarks in p (p) over bar --> b (b) over barb (b) over bar final states with 91 +/- 7 pb(-1) of p (p) over bar collisions at roots = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tan beta values in excess of 35. C1 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 Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Cantabria, CSIC, Inst Fis, 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. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. 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, Ctr High Energy Phys, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. 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), Acad Sinica, Inst Phys, Taipei 11529, Taiwan. RI Gorelov, Igor/J-9010-2015; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; St.Denis, Richard/C-8997-2012; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Scodellaro, Luca/K-9091-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Gorelov, Igor/0000-0001-5570-0133; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Scodellaro, Luca/0000-0002-4974-8330; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 20 TC 47 Z9 47 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4472 EP 4478 DI 10.1103/PhysRevLett.86.4472 PG 7 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500013 PM 11384262 ER PT J AU Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Wang, JC Wolf, A Wu, J Kopp, S Kostin, M Mahmood, AH Csorna, SE Danko, I McLean, KW Xu, Z Godang, R Bonvicini, G Cinabro, D Dubrovin, M McGee, S Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Chen, GP Gritsan, A Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Drell, PS Duboscq, JE Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Hsu, L Jones, CD Kandaswamy, J Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Palmer, M Patterson, JR Peterson, D Riley, D Romano, A Thayer, JG Urner, D Valant-Spaight, B Viehhauser, G Warburton, A Avery, P Prescott, C Rubiera, AI Stoeck, H Yelton, J Brandenburg, G Ershov, A Kim, DYJ Wilson, R Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Eckhart, E 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 Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Savinov, V Coan, TE Fadeyev, V Gao, YS Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T AF Artuso, M Ayad, R Boulahouache, C Bukin, K Dambasuren, E Karamov, S Majumder, G Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Wang, JC Wolf, A Wu, J Kopp, S Kostin, M Mahmood, AH Csorna, SE Danko, I McLean, KW Xu, Z Godang, R Bonvicini, G Cinabro, D Dubrovin, M McGee, S Zhou, GJ Lipeles, E Pappas, SP Schmidtler, M Shapiro, A Sun, WM Weinstein, AJ Wurthwein, F Jaffe, DE Masek, G Paar, HP Potter, EM Prell, S Asner, DM Eppich, A Hill, TS Morrison, RJ Briere, RA Chen, GP Gritsan, A Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Blanc, F Boisvert, V Cassel, DG Drell, PS Duboscq, JE Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Galik, RS Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Hsu, L Jones, CD Kandaswamy, J Kreinick, DL Lohner, M Magerkurth, A Meyer, TO Mistry, NB Nordberg, E Palmer, M Patterson, JR Peterson, D Riley, D Romano, A Thayer, JG Urner, D Valant-Spaight, B Viehhauser, G Warburton, A Avery, P Prescott, C Rubiera, AI Stoeck, H Yelton, J Brandenburg, G Ershov, A Kim, DYJ Wilson, R Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Plager, C Sedlack, C Selen, M Thaler, JJ Williams, J Edwards, KW Janicek, R Patel, PM Sadoff, AJ Ammar, R Bean, A Besson, D Zhao, X Anderson, S Frolov, VV Kubota, Y Lee, SJ Mahapatra, R O'Neill, JJ Poling, R Riehle, T Smith, A Stepaniak, CJ Urheim, J Ahmed, S Alam, MS Athar, SB Jian, L Ling, L Saleem, M Timm, S Wappler, F Anastassov, A Eckhart, E 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 Miller, DH Shibata, EI Shipsey, IPJ Pavlunin, V Cronin-Hennessy, D Lyon, AL Thorndike, EH Savinov, V Coan, TE Fadeyev, V Gao, YS Maravin, Y Narsky, I Stroynowski, R Ye, J Wlodek, T CA CLEO Collaboration TI Observation of new states decaying into Lambda(+)(c)pi(-)pi(+) SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHARMED BARYON; DETECTOR AB Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda (+)(c)pi (-)pi (+) and are more massive than the Lambda (+)(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda (+)(c) baryon; the other is narrow with an invariant mass of 596 +/- 1 +/- 2 MeV above the Lambda (+)(c) mass. C1 MIT, Cambridge, MA 02139 USA. Syracuse Univ, Syracuse, NY 13244 USA. Univ Texas, Austin, TX 78712 USA. Univ Texas, Edinburg, TX 78539 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 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. So Methodist Univ, Dallas, TX 75275 USA. RP Artuso, M (reprint author), Syracuse Univ, Syracuse, NY 13244 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; Poling, Ronald/0000-0001-7305-4702 NR 12 TC 66 Z9 68 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 MAY 14 PY 2001 VL 86 IS 20 BP 4479 EP 4482 DI 10.1103/PhysRevLett.86.4479 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500014 PM 11384263 ER PT J AU Johnson, MB Kopeliovich, BZ Potashnikova, IK McGaughey, PL Moss, JM Peng, JC Garvey, GT Leitch, MJ Adams, MR Alde, DM Baer, HW Barlett, ML Brown, CN Cooper, WE Carey, TA Danner, G Hoffmann, GW Hsiung, YB Kaplan, DM Klein, A Lee, C Lillberg, JW McCarthy, RL Mishra, CS Wang, MJ AF Johnson, MB Kopeliovich, BZ Potashnikova, IK McGaughey, PL Moss, JM Peng, JC Garvey, GT Leitch, MJ Adams, MR Alde, DM Baer, HW Barlett, ML Brown, CN Cooper, WE Carey, TA Danner, G Hoffmann, GW Hsiung, YB Kaplan, DM Klein, A Lee, C Lillberg, JW McCarthy, RL Mishra, CS Wang, MJ CA FNAL E772 Collaborat TI Energy loss of fast quarks in nuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID DRELL-YAN PROCESS; DIMUON PRODUCTION; FACTORIZATION; DISTRIBUTIONS; DEPENDENCE; GLUON; PAIRS AB We report an analysis of the nuclear dependence of the yield of Drell-Yan dimuons from the 800 GeV/c proton bombardment of H-2, C, Ca, Fe, and W targets. Employing a new formulation of the Drell-Yan process in the rest frame of the nucleus, this analysis examines the effect of initial-state energy loss and shadowing on the nuclear-dependence ratios versus the incident proton's momentum fraction and dimuon effective mass. The resulting energy loss per unit path length is -dE/dz = 2.32 +/- 0.52 +/- 0.5 GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in a nuclear environment. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ Illinois, Chicago, IL 60510 USA. Univ Texas, Austin, TX 78712 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. No Illinois Univ, De Kalb, IL 60115 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Johnson, MB (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI HSIUNG, YEE/0000-0003-4801-1238 NR 29 TC 48 Z9 48 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 MAY 14 PY 2001 VL 86 IS 20 BP 4483 EP 4487 DI 10.1103/PhysRevLett.86.4483 PG 5 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500015 PM 11384264 ER PT J AU Stolte, WC Hansen, DL Piancastelli, MN Lopez, ID Rizvi, A Hemmers, O Wang, H Schlachter, AS Lubell, MS Lindle, DW AF Stolte, WC Hansen, DL Piancastelli, MN Lopez, ID Rizvi, A Hemmers, O Wang, H Schlachter, AS Lubell, MS Lindle, DW TI Anionic photofragmentation of CO: A selective probe of core-level resonances SO PHYSICAL REVIEW LETTERS LA English DT Article ID OXYGEN K-EDGE; POST-COLLISION INTERACTION; ION-YIELD SPECTROSCOPY; SHAPE RESONANCE; POSTCOLLISION-INTERACTION; C(1S) EXCITATION; AUGER PROCESSES; MOLECULES; PHOTOIONIZATION; SHELL AB Anion-yield spectroscopy using x rays is shown to be a selective probe of molecular core-level processes, providing unique experimental verification of shape resonances. For CO, partial anion and cation yields are presented for photon energies near the C K edge. The O- yield exhibits features above threshold related only to doubly excited states, in contrast to cation yields which also exhibit pronounced structure due to the well-known sigma* shape resonance. Because the shape resonance is completely suppressed for O-, anion spectroscopy thus constitutes a highly selective probe, yielding information unobtainable with absorption or electron spectroscopy. C1 Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Univ Roma Tor Vergata, Dept Chem Sci & Technol, I-00133 Rome, Italy. Ctr Nacl Metrol, Queretaro 76900, Mexico. Univ Lund, Max Lab, S-22100 Lund, Sweden. CUNY City Coll, Dept Phys, New York, NY 10031 USA. RP Stolte, WC (reprint author), Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. OI Dominguez-Lopez, Ivan/0000-0001-8084-8711 NR 33 TC 48 Z9 48 U1 2 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4504 EP 4507 DI 10.1103/PhysRevLett.86.4504 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500020 PM 11384269 ER PT J AU Greenfield, CM Burrell, KH DeBoo, JC Doyle, EJ Stallard, BW Synakowski, EJ Fenzi, C Gohil, P Groebner, RJ Lao, LL Makowski, MA McKee, GR Moyer, RA Rettig, CL Rhodes, TL Pinsker, RI Staebler, GM West, WP AF Greenfield, CM Burrell, KH DeBoo, JC Doyle, EJ Stallard, BW Synakowski, EJ Fenzi, C Gohil, P Groebner, RJ Lao, LL Makowski, MA McKee, GR Moyer, RA Rettig, CL Rhodes, TL Pinsker, RI Staebler, GM West, WP CA DIII-D Team TI Quiescent double barrier regime in the DIII-D tokamak SO PHYSICAL REVIEW LETTERS LA English DT Article ID INTERNAL TRANSPORT BARRIER; CENTRAL MAGNETIC SHEAR; H-MODE DISCHARGES; HIGH-CONFINEMENT; ASPECT RATIO; PLASMAS; PERFORMANCE AB A new sustained high-performance regime, combining discrete edge and core transport barriers, has been discovered in the DIII-D tokamak. Edge localized modes (ELMs) are replaced by a steady oscillation that increases edge particle transport, thereby allowing particle control with no ELM-induced pulsed divertor heat load. The core barrier resembles those usually seen with a low (L) mode edge, without the degradation often associated with ELMs. The barriers are separated by a narrow region of hi,oh transport associated with a zero crossing in the E x B shearing rate. C1 Gen Atom Co, San Diego, CA 92186 USA. Univ Calif Los Angeles, Los Angeles, CA USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Univ Wisconsin, Madison, WI USA. Univ Calif San Diego, San Diego, CA 92103 USA. RP Greenfield, CM (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. NR 25 TC 100 Z9 100 U1 2 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4544 EP 4547 DI 10.1103/PhysRevLett.86.4544 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500030 PM 11384279 ER PT J AU Cynn, H Yoo, CS Baer, B Iota-Herbei, V McMahan, AK Nicol, M Carlson, S AF Cynn, H Yoo, CS Baer, B Iota-Herbei, V McMahan, AK Nicol, M Carlson, S TI Martensitic fcc-to-hcp transformation observed in xenon at high pressure SO PHYSICAL REVIEW LETTERS LA English DT Article ID RARE-GAS SOLIDS; X-RAY; METALLIZATION; TRANSITIONS; STATE; PHASE; IV AB Angle-resolved x-ray diffraction patterns of Xe to 127 GPa indicate that the fcc-to-hcp transition occurs martensitically between 3 and 70 GPa in diamond-anvil cells without an intermediate phase. These data also reveal that the transition occurs by the introduction of stacking disorder in the fee lattice at low pressure, which grows into hcp domains with increasing pressure. The small energy difference between the hcp and the fee structures may allow the two phases to coexist over a wide pressure range. Evidence of similar stacking disorder and incipient growth of an hcp phase are also observed in solid Kr. C1 Univ Calif Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, H Div, Livermore, CA 94550 USA. Univ Nevada, High Pressure Sci & Engn Ctr, Las Vegas, NV 89154 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Cynn, H (reprint author), Univ Calif Lawrence Livermore Natl Lab, Phys & Adv Technol Directorate, H Div, Livermore, CA 94550 USA. NR 23 TC 64 Z9 64 U1 1 U2 16 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 MAY 14 PY 2001 VL 86 IS 20 BP 4552 EP 4555 DI 10.1103/PhysRevLett.86.4552 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500032 PM 11384281 ER PT J AU Grant, ML Swartzentruber, BS Bartelt, NC Hannon, JB AF Grant, ML Swartzentruber, BS Bartelt, NC Hannon, JB TI Diffusion kinetics in the Pd/Cu(001) surface alloy SO PHYSICAL REVIEW LETTERS LA English DT Article ID ABINITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; ULTRASOFT PSEUDOPOTENTIALS; PD; TRANSITION; CU(100); METALS AB We use atom-tracking scanning tunneling microscopy to study the diffusion of Pd in the Pd/Cu(001) surface alloy as a function of temperature. By following the motion of individual Pd atoms incorporated in the surface, we show that Pd diffuses by a vacancy-exchange mechanism. We measure an activation energy for the diffusion of incorporated Pd atoms of 0.88 eV. which is in good agreement with our ab initio calculated energy of 0.94 eV. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Grant, ML (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. NR 20 TC 55 Z9 56 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4588 EP 4591 DI 10.1103/PhysRevLett.86.4588 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500041 PM 11384290 ER PT J AU Kortus, J Mazin, II Belashchenko, KD Antropov, VP Boyer, LL AF Kortus, J Mazin, II Belashchenko, KD Antropov, VP Boyer, LL TI Superconductivity of metallic boron in MgB2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSITION-METALS AB Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate via zone-center frozen phonon calculations to be between 300 and 700 cm(-1), this produces a high critical temperature, consistent with recent experiments. Thus MgB2 can be viewed as an analog of the long sought, but still hypothetical, superconducting metallic hydrogen. C1 USN, Res Lab, Ctr Computat Mat Sci, Washington, DC 20375 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Georgetown Univ, Washington, DC 20057 USA. RP Kortus, J (reprint author), MPI Festkorperforsch, Postfach 80065, D-70506 Stuttgart, Germany. RI Belashchenko, Kirill/A-9744-2008; Mazin, Igor/B-6576-2008; Karabulut, Erman/G-6679-2011 OI Belashchenko, Kirill/0000-0002-8518-1490; NR 17 TC 936 Z9 955 U1 15 U2 131 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 MAY 14 PY 2001 VL 86 IS 20 BP 4656 EP 4659 DI 10.1103/PhysRevLett.86.4656 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500058 PM 11384307 ER PT J AU Dulic, D Hak, SJ van der Marel, D Hardy, WN Koshelev, AE Liang, RX Bonn, DA Willemsen, BA AF Dulic, D Hak, SJ van der Marel, D Hardy, WN Koshelev, AE Liang, RX Bonn, DA Willemsen, BA TI Effects of cortex pinning and thermal fluctuations on the Josephson plasma resonance in Tl2Ba2CaCu2O8 and YBa2Cu3O6.5 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PENETRATION DEPTH; SUPERCONDUCTORS; BI2SR2CACU2O8+DELTA; FREQUENCY; VORTICES; FILMS AB We investigated the temperature dependence and c-axis magnetic field dependence of the Josephson plasma resonance in optimally doped Tl2Ba2CaCu2O8 thin films and underdoped YBa2Cu3O6.5 (YBCO) ortho-II single crystals using infrared spectroscopy. We obtained the c-axis penetration depths, at low temperature, in zero fields of about 20 and 7 mum, respectively. While the temperature dependencies of the resonances in the two compounds are very similar, the magnetic field dependence in YBCO is much weaker. We attribute this weak magnetic field dependence to the lower anisotropy of YBCO and interpret the observed behaviors in terms of thermal fluctuations and pinning of pancake vortices. C1 Univ Groningen, Ctr Mat Sci, Solid State Phys Lab, NL-9747 AG Groningen, Netherlands. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Superconductor Technol Inc, Santa Barbara, CA 93111 USA. RP Dulic, D (reprint author), Univ Groningen, Ctr Mat Sci, Solid State Phys Lab, Nijenborgh 4, NL-9747 AG Groningen, Netherlands. RI Dulic, Diana/D-5515-2012; Koshelev, Alexei/K-3971-2013; van der Marel, Dirk/G-4618-2012 OI Dulic, Diana/0000-0002-8302-5507; Koshelev, Alexei/0000-0002-1167-5906; van der Marel, Dirk/0000-0001-5266-9847 NR 22 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 14 PY 2001 VL 86 IS 20 BP 4660 EP 4663 DI 10.1103/PhysRevLett.86.4660 PG 4 WC Physics, Multidisciplinary SC Physics GA 431GM UT WOS:000168623500059 PM 11384308 ER PT J AU Autrey, T Foster, N Hopkins, D Price, J AF Autrey, T Foster, N Hopkins, D Price, J TI Tunable ultraviolet visible photoacoustic detection - Analysis of the sensitivity and selectivity provided by a xenon flash lamp SO ANALYTICA CHIMICA ACTA LA English DT Article DE photoacoustic; xenon flashlamp; chromium; cobalt; piezoelectric transducer; spectroscopy ID HEXAVALENT CHROMIUM; SPECTROSCOPY; CALORIMETRY; SPECTROMETRY; WATER; CELL AB A fundamental understanding of the physical and chemical properties that dictate the absorption of pulsed light and subsequent release of heat to generate a transient pressure wave was used to test the concept of a multi-wavelength photoacoustic detector. Analysis of the wave equation predicts that with long-pulse excitation, i.e. microseconds FWHM, absorption by the solvent, and not electrostriction determines the limit of detection. Calculation of the mechanical to electrical conversion efficiencies of piezoelectric transducers shows that absorbed pulse energies of microjoules, typical of pulsed flash lamps, are sufficient to provide measurable photoacoustic signals. A pulsed xenon Rash (amp 12 mus FWHM) which emits a broad spectrum over the UV and visible region is used as an excitation source to detect trace quantities of metals in aqueous solution using pulsed photoacoustic detection. In this work, dielectric mirrors were used to detect two analytes, CrO42- (monitored at 355 nm) and Co2+ (monitored at 532 nm), simultaneously. This approach increases both the flexibility and selectivity of pulsed photoacoustic methods. We obtained a detection limit of 2.6 x 10(-4) absorbance units per centimeter in aqueous samples. This work shows that pulsed lasers are not a necessity for ultra-sensitive photoacoustic spectroscopy. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Environm & Hlth Sci Div, Dept Chem Sci, Richland, WA 99352 USA. RP Autrey, T (reprint author), Pacific NW Natl Lab, Environm & Hlth Sci Div, Dept Chem Sci, POB 999, Richland, WA 99352 USA. NR 28 TC 4 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD MAY 11 PY 2001 VL 434 IS 2 BP 217 EP 222 DI 10.1016/S0003-2670(01)00834-0 PG 6 WC Chemistry, Analytical SC Chemistry GA 430VB UT WOS:000168595200006 ER PT J AU Ahmed, M Peterka, DS Regan, P Liu, XH Suits, AG AF Ahmed, M Peterka, DS Regan, P Liu, XH Suits, AG TI Ion pair imaging spectroscopy: CH3Cl -> CH3++Cl- SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ENHANCED MULTIPHOTON IONIZATION; INFRARED-SPECTRA; DISSOCIATION; PHOTOELECTRON; PHOTODISSOCIATION; HYDROGEN AB Application of the imaging technique to study the photodissociation of molecules to ion pair products can be a powerful means of probing ion energetics and spectroscopy. This approach, analogous to photoelectron spectroscopy. has the advantage that it may be applied to systems for which stable neutral precursors may not exist. In this letter we describe the technique and show the first demonstration of the method: CH3Cl - CH3+ + Cl-. The results provide insight into the vibrational frequencies of the methyl cation and the ion pair dissociation dynamics of methyl chloride, and illustrate the advantages of the method. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RP Suits, AG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Ahmed, Musahid/A-8733-2009 NR 24 TC 17 Z9 17 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 MAY 11 PY 2001 VL 339 IS 3-4 BP 203 EP 208 DI 10.1016/S0009-2614(01)00252-4 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 434BM UT WOS:000168795300008 ER PT J AU Lee, SY Cho, HS Pelton, JG Yan, DL Berry, EA Wemmer, DE AF Lee, SY Cho, HS Pelton, JG Yan, DL Berry, EA Wemmer, DE TI Crystal structure of activated CheY - Comparison with other activated receiver domains SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID RESPONSE REGULATOR PROTEIN; SIGNAL-TRANSDUCTION; BACTERIAL CHEMOTAXIS; ESCHERICHIA-COLI; Y-PROTEIN; PHOSPHORYLATION; BINDING; SWITCH; NTRC; MUTANTS AB The crystal structure of BeF3--activated CheY, with manganese in the magnesium binding site, was determined at 2.4-Angstrom resolution. BeF3- bonds to Asp(57), the normal site of phosphorylation, forming a hydrogen bond and salt bridge with Thr(87) and Lys(109), respectively. The six coordination sites for manganese are satisfied by a fluorine of BeF3-, the side chain oxygens of Asp(13) and Asp(57), the carbonyl oxygen of Asn(59), and two water molecules. All of the active site interactions seen for BeF3-- CheY are also observed in P-Spo0A(r), Thus, BeF3- activates CheY as well as other receiver domains by mimicking both the tetrahedral geometry and electrostatic potential of a phosphoryl group. The aromatic ring of Tyr(106) is found buried within a hydrophobic pocket formed by beta -strand beta4 and helix H4, The tyrosine side chain is stabilized in this conformation by a hydrogen bond between the hydroxyl group and the backbone carbonyl oxygen of Glu(89). This hydrogen bond appears to stabilize the active conformation of the beta4/H4 loop. Comparison of the backbone coordinates for the active and inactive states of CheY reveals that only modest changes occur upon activation, except in the loops, with the largest changes occurring in the beta4/H4 loop. This region is known to be conformationally flexible in inactive CheY and is part of the surface used by activated CheY for binding its target, FliM, The pattern of activation-induced backbone coordinate changes is similar to that seen in FixJ(r). A common feature in the active sites of BeF3--CheY, P-Spo0A(r) P-FixJ(r), and phosphono-CheY is a salt bridge between Lys(109) N zeta and the phosphate or its equivalent, beryllofluoride, This suggests that, in addition to the concerted movements of Thr(87) and Tyr(106) (Thr-Tyr coupling), formation of the Lys(109)-PO3- salt bridge is directly involved in the activation of receiver domains generally. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. NR 47 TC 118 Z9 119 U1 1 U2 12 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 MAY 11 PY 2001 VL 276 IS 19 BP 16425 EP 16431 DI 10.1074/jbc.M101002200 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 431GH UT WOS:000168623100114 PM 11279165 ER PT J AU Broyles, BS Shalliker, RA Guiochon, G AF Broyles, BS Shalliker, RA Guiochon, G TI Visualization of solute migration in chromatographic columns - Influence of the frit porosity SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE visualization of solute migration; band profiles; porosity; axial dispersion; frits; iodine ID LIQUID-CHROMATOGRAPHY; SEPARATIONS AB The dual-perspective, on-column detection method previously described was used to observe the effects of the inlet frit on the profiles of chromatographic bands. Visualization of bands of iodine was achieved by injecting its dilute solutions in carbon tetrachloride into a glass column packed with a C-18-bonded silica and eluted with carbon tetrachloride, which has the same refractive index as the packing material. The bands were photographed on-column with two standard 35-mm SLR cameras oriented at right angle. The photographs were scanned and the digitized images of the sample bands analyzed with proper software. A number of columns, as similar as possible, were fitted with different 2- and 10-mum porosity stainless steel frits. Subsequent analysis of the digitized band images revealed irregularities in the band shape resulting from frit contributions to band dispersion. The 2-mum frits produced more dramatic effects overall than the coarser frits. Local axial dispersion coefficient values, expressed as local reduced plate height, were calculated. The results demonstrate the possibly damaging effects of the frit on the band shape. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 14 TC 22 Z9 22 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 11 PY 2001 VL 917 IS 1-2 BP 1 EP 22 DI 10.1016/S0021-9673(01)00623-9 PG 22 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 431CC UT WOS:000168613500001 PM 11403461 ER PT J AU Jandera, P Skavrada, M Klemmova, K Backovska, V Guiochon, G AF Jandera, P Skavrada, M Klemmova, K Backovska, V Guiochon, G TI Effect of the mobile phase on the retention behaviour of optical isomers of carboxylic acids and amino acids in liquid chromatography on bonded Teicoplanin columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE mobile phase composition; enantiomer separation; retention behaviour; carboxylic acids; amino acids; teicoplanin ID CHIRAL STATIONARY-PHASE; SEPARATION; ENANTIOMERS; ANALOGS AB Conditions for separation of enantiomers of underivatized amino acids phenyl glycine and tryptophan and of mandelic acid as test compounds were studied on a Chirobiotic T column packed with amphoteric glycopeptide Teicoplanin covalently bonded to the surface of silica gel. The effects of the mobile phase composition on the retention and selectivity under analytical conditions, on the profile of the adsorption isotherms of the enantiomers and on the overloaded separation were investigated. The concentration of ethanol or of methanol in aqueous-organic mobile phases and the pH of the mobile phase affect not only the retention and selectivity, the saturation capacity and the isotherm profile, but also the solubility of the acids, which should be taken into account in development of preparative separations. A compromise between the separation selectivity and the solubility should be made in selecting the mobile phase suitable to accomplish preparative separations at acceptable production rate and throughput of the operation. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Pardubice, Dept Analyt Chem, Pardubice 53210, Czech Republic. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN USA. RP Jandera, P (reprint author), Univ Pardubice, Dept Analyt Chem, Nam Legii 565, Pardubice 53210, Czech Republic. NR 17 TC 35 Z9 36 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 11 PY 2001 VL 917 IS 1-2 BP 123 EP 133 DI 10.1016/S0021-9673(01)00701-4 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 431CC UT WOS:000168613500012 PM 11403464 ER PT J AU Ishwara-Chandra, CH Saikia, DJ McCarthy, PJ van Breugel, WJM AF Ishwara-Chandra, CH Saikia, DJ McCarthy, PJ van Breugel, WJM TI A radio and optical study of Molonglo radio sources SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : nuclei; quasars : general; radio continuum : galaxies ID ACTIVE GALACTIC NUCLEI; COMPLETE QUASAR SAMPLE; ASYMMETRIC DEPOLARIZATION; GALAXY IDENTIFICATIONS; PHOTOMETRIC SYSTEM; CORRELATED RADIO; CATALOG; POLARIZATION; SPECTRA; LOBES AB We present multi-wavelength radio observations with the Very Large Array, and narrow- and broad-band optical observations with the 2.5-m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff-Riley class II radio galaxies and quasars, selected from the Molonglo Reference Catalogue l-Jy sample. These observations were carried out as part of a programme to investigate the effects of orientation and environment on some of the observed properties of these sources. We examine the dependence of the Liu-Pooley relationship, which shows that radio lobes with flatter radio spectra are less depolarized, on size, identification and redshift, and show that it is significantly stronger for smaller sources, with the strength of the relationship being similar for both radio galaxies and quasars, In addition to Doppler effects, there appear to be intrinsic differences between the lobes on opposite sides. We discuss the asymmetry in brightness and location of the hotspots, and present estimates of the ages and velocities from matched-resolution observations in the L and C bands. Narrow- and broad-band optical images of some of these sources were made to study their environments and correlate with the symmetry parameters. An extended emission-line region is seen in a quasar, and in four of the objects possible companion galaxies are seen close to the radio axis. C1 TIFR, Natl Ctr Radio Astrophys, Pune 411007, Maharashtra, India. ISRO Satellite Ctr, Tech Phys Div, Bangalore 560017, Karnataka, India. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Ishwara-Chandra, CH (reprint author), TIFR, Natl Ctr Radio Astrophys, Post Bag 3, Pune 411007, Maharashtra, India. NR 30 TC 10 Z9 10 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 MAY 11 PY 2001 VL 323 IS 2 BP 460 EP 470 DI 10.1046/j.1365-8711.2001.04239.x PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 441KM UT WOS:000169229600024 ER PT J AU Beller, DE Van Tuyle, GJ Bennett, D Lawrence, G Thomas, K Pasamehmetoglu, K Li, N Hill, D Laidler, J Fink, P AF Beller, DE Van Tuyle, GJ Bennett, D Lawrence, G Thomas, K Pasamehmetoglu, K Li, N Hill, D Laidler, J Fink, P TI The US accelerator transmutation of waste program SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A national project to develop a future capability to separate actinides and long-lived fission products from spent fuel, to transmute them, and to dispose off the remaining waste in optimal waste forms has begun in the United States. This project is based on the Accelerator-driven Transmutation of Waste (ATW) program developed during the 1990s at Los Alamos National Laboratory. and has its technological roots in several technologies that have been developed by the multi-mission laboratories of the U.S. Department of Energy (DOE). In the Fiscal Year 1999 Energy and Water Appropriation Act. the U.S. Congress directed the DOE to study ATW and by the end of FY99 to prepare a "roadmap" for developing this technology. DOE convened a steering committee. assembled four technical working groups consisting of members from many national laboratories. and consulted with several individual international and national experts. The finished product. "A Roadmap for Developing ATW Technology A Report to Congress," recommends a five-year $281 M. science-based, technical-risk-reduction program. This paper provides an overview of the U.S. Roadmap for developing ATW technology. the organization of the national ATW Project, the critical issues in subsystems and technological options, deployment scenarios. institutional challenges, and academic and international collaboration. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Beller, DE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 20 TC 24 Z9 24 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 2001 VL 463 IS 3 BP 468 EP 486 DI 10.1016/S0168-9002(01)00163-2 PG 19 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 440EN UT WOS:000169163100003 ER PT J AU Van Riper, KA Mashnik, SG Wilson, WB AF Van Riper, KA Mashnik, SG Wilson, WB TI A computer study of radionuclide production in high power accelerators for medical and industrial applications SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE radioisotope production; spallation reactions; evaluation cross-sections; Monte Carlo simulations; APT; CEM 95; MCNPX; LAHET; HMS-ALICE ID PROTON-INDUCED REACTIONS; PRECOMPOUND DECAY MODEL; CASCADE-EXCITON MODEL AB Methods for radionuclide production calculation in a high power proton accelerator have been developed and applied to study production of 22 isotopes by high-energy protons and neutrons. These methods are readily applicable to accelerator. and reactor, environments other than the particular model we considered and to the production of other radioactive and stable isotopes. We have also developed methods for evaluating cross sections from a wide variety of sources into a single cross section set and have produced an evaluated library covering about a third of all natural elements. These methods also are applicable to an expanded set of reactions. A 684 page detailed report on this study, with 37 tables and 264 color figures is available on the Web at http://t2.lanl.gov/publications/publications,html or, if not accessible, in hard copy from the authors. (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. White Rock Sci, Los Alamos, NM 87544 USA. RP Wilson, WB (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-16, Los Alamos, NM 87545 USA. NR 32 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 MAY 11 PY 2001 VL 463 IS 3 BP 576 EP 585 DI 10.1016/S0168-9002(01)00172-3 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 440EN UT WOS:000169163100009 ER PT J AU Wan, JS Schmidt, T Langrock, EJ Vater, P Brandt, R Adam, J Bradnova, V Bamblevski, VP Gelovani, L Gridnev, TD Kalinnikov, VG Krivopustov, MI Kulakov, BA Sosnin, AN Perelygin, VP Pronskikh, VS Stegailov, VI Tsoupko-Sitnikov, VM Modolo, G Odoj, R Phlippen, PW Zamani-Valassiadou, M Adloff, JC Debeauvais, M Hashemi-Nezhad, SR Guo, SL Li, L Wang, YL Dwivedi, KK Zhuk, IV Boulyga, SF Lomonossova, EM Kievitskaja, AF Rakhno, IL Chigrinov, SE Wilson, WB AF Wan, JS Schmidt, T Langrock, EJ Vater, P Brandt, R Adam, J Bradnova, V Bamblevski, VP Gelovani, L Gridnev, TD Kalinnikov, VG Krivopustov, MI Kulakov, BA Sosnin, AN Perelygin, VP Pronskikh, VS Stegailov, VI Tsoupko-Sitnikov, VM Modolo, G Odoj, R Phlippen, PW Zamani-Valassiadou, M Adloff, JC Debeauvais, M Hashemi-Nezhad, SR Guo, SL Li, L Wang, YL Dwivedi, KK Zhuk, IV Boulyga, SF Lomonossova, EM Kievitskaja, AF Rakhno, IL Chigrinov, SE Wilson, WB TI Transmutation of I-291 and (NP)-N-237 using spallation neutrons produced by 1.5, 3.7 and 7.4 GeV protons SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE transmutation; I-129-target; (NP)-N-237-target; Pu-239 production; spallation neutrons; LAHET code; DCM/CEM code ID TARGET; ENERGY; SSNTD; WASTE; IONS AB Small samples of I-129 and Np-237. two long-lived radwaste nuclides. were exposed to spallation neutron fluences from relatively small metal targets of lead and uranium, that were surrounded with a 6cm thick paraffin moderator, and irradiated with 1.5, 3.7 and 7.4GeV protons. The (n,gamma) transmutation rates were determined for these nuclides, Conventional radiochemical La- and U-sensors and a variety of solid-state nuclear track detectors were irradiated simultaneously with secondary neutrons. Compared with results from calculations with well-known cascade codes C1 Inst Phys Chem Kernchem & Makromol Chem, FB 15, Marburg, Germany. Joint Nucl Res Inst, Dubna, Russia. Forschungszentrum Julick, Inst Sicherheitsforsch, Julich, Germany. Aristotle Univ, Dept Phys, Salonika, Greece. Inst Rech Subatom, Strasbourg, France. Univ Sydney, Sch Phys, Dept High Energy Phys, Sydney, NSW 2006, Australia. Inst Atom Energy, Beijing 102413, Peoples R China. NE Hill Univ, Dept Chem, Shillong 793003, Meghalaya, India. Inst Power Engn Problems, Minsk, Byelarus. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. NW Inst Nucl Technol, Xian, Peoples R China. Forsch Buro Dr Langrock, Hoyerswerda, Germany. Acad Sci Czech Republ, Inst Nucl Phys, CZ-25068 Rez, Czech Republic. Natl Phys Inst Sci, Tiblissi, Rep of Georgia. Arunachal Univ, Rono Hills, Itanagar, India. RP Brandt, R (reprint author), Inst Phys Chem Kernchem & Makromol Chem, FB 15, Marburg, Germany. RI Adam, Jindrich /G-9788-2014; OI Modolo, Giuseppe/0000-0001-6490-5595 NR 30 TC 30 Z9 35 U1 0 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 MAY 11 PY 2001 VL 463 IS 3 BP 634 EP 652 DI 10.1016/S0168-9002(01)00175-9 PG 19 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 440EN UT WOS:000169163100012 ER PT J AU Stanford, SA Holden, B Rosati, P Tozzi, P Borgani, S Eisenhardt, PR Spinrad, H AF Stanford, SA Holden, B Rosati, P Tozzi, P Borgani, S Eisenhardt, PR Spinrad, H TI The intracluster medium in z > 1 galaxy clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; X-rays : general ID X-RAY AB The Chandra X-Ray Observatory was used to obtain a 190 ks image of three high-redshift galaxy clusters in one observation. The results of our analysis of these data are reported for the two z > 1 clusters in this Lynx field, which are the most distant known X-ray luminous clusters. Spatially extended X-ray emission was detected from both these clusters, indicating the presence of hot gas in their intracluster media. A fit to the X-ray spectrum of RX J0849 + 4452 at z = 1.26 yields a temperature of kT = 5.8(-1.7)(+2.8) keV. Using this temperature and the assumption of an isothermal sphere, the total mass of RX J0849+4452 is found to be 4.01(-1.9)(+2.4) x 10(14) h(65)(-1) M. within r = 1 h(65)(-1) Mpc. The T-X for RX J0849+4452 approximately agrees with the expectation based on its L-bol = 3.3(-0.5)(+0.9) x 10(44) ergs s(-1) according to the low-redshift L-X-T-X relation. The very different distributions of X-ray-emitting gas and of the red member galaxies in the two z > 1 clusters, in contrast to the similarity of the optical/IR colors of those galaxies, suggests that the early-type galaxies mostly formed before their host clusters. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. European So Observ, D-85748 Garching, Germany. Osservatorio Astron Trieste, I-34131 Trieste, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Stanford, SA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. NR 21 TC 75 Z9 75 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2001 VL 552 IS 2 BP 504 EP 507 DI 10.1086/320583 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 439TM UT WOS:000169133700010 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennet, DP Cook, KH Dalal, N Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, AB Vandehei, T AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennet, DP Cook, KH Dalal, N Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, AB Vandehei, T CA MACHO Collaboration TI The macho project Hubble Space Telescope follow-up: Preliminary results on the location of the large Magellanic Cloud microlensing source stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; Galaxy : halo; Galaxy : structure; gravitational lensing; Magellanic Clouds ID INTERVENING STELLAR POPULATION; HALO; DUST; PHOTOMETRY; FIELDS; LENSES; DARK; DISK; BIAS; OLD AB We attempt to determine whether the MACHO microlensing source stars are drawn from the average population of the LMC or from a population behind the LMC by examining the Hubble Space Telescope (HST) color-magnitude diagram (CMD) of microlensing source stars. We present WFPC2 HST photometry of eight MACHO microlensing source stars and the surrounding fields in the LMC. The microlensing source stars are identified by deriving accurate centroids in the ground-based MACHO images using difference image analysis (DIA) and then transforming the DIA coordinates to the HST frame. We consider in detail a model for the background population of source stars based on that presented by Zhao, Graff, & Guhathakurta. In this model, the source stars have an additional reddening of [E(B - V)] = 0.13 mag and a slightly larger distance modulus, [Delta mu] similar to 0.3 mag, than the average LMC population. We also investigate a series of source star models, varying the relative fraction of source stars drawn from the average and background populations and the displacement of the background population from the LMC. Because of the small number of analyzed events, the distribution of probabilities of different models is rather flat. A shallow maximum occurs at a fraction s(LMC) similar to 0.8 of the source stars in the LMC. This is consistent with the interpretation that a significant fraction of observed microlensing events are due to lenses in the Milky Way halo, but does not definitively exclude other models. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif San Diego, Dept Phys, San Diego, CA 92039 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. European So Observ, D-85748 Garching, Germany. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Quinn, Peter/B-3638-2013; Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 34 TC 34 Z9 34 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2001 VL 552 IS 2 BP 582 EP 590 DI 10.1086/320554 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 439TM UT WOS:000169133700015 ER PT J AU Nelson, CA Eggleton, PP AF Nelson, CA Eggleton, PP TI A complete survey of Case A binary evolution with comparison to observed Algol-type systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : evolution ID R-CANIS-MAJORIS; ABSOLUTE PARAMETERS; VARIABLE-STARS; SPECTROSCOPIC ORBIT; ECLIPSING BINARIES; CLOSE BINARIES; REDISCUSSION; CASSIOPEIAE; MASSES AB We undertake a comparison of observed Algol-type binaries with a library of computed Case A binary evolution tracks. The library consists of 5500 binary tracks with various values of initial primary mass M-10, mass ratio q(0), and period P-0, designed to sample the phase-space of Case A binaries in the range -0.10 less than or equal to log M-10 less than or equal to 1.7. Each binary is evolved using a standard code with the assumption that both total mass and orbital angular momentum are conserved. This code follows the evolution of both stars to the point where contact or reverse mass transfer occurs. The resulting; binary tracks show a rich variety of behavior that we sort into several subclasses of case A and case B. We present the results of this classification, the final mass ratio, and the fraction of time spent in Roche Lobe overflow for each binary system. The conservative assumption under which we created this library is expected to hold for a broad range of binaries, where both components have spectra in the range G0 to B1 and luminosity classes III to V. We gather a list of relatively well-determined, observed hot Algol-type binaries meeting this criterion, as well as a list of cooler Algol-type binaries, for which we expect significant dynamo-driven mass loss and angular momentum loss. We fit each observed binary to our library of tracks using a chi (2)-minimizing procedure. We find that the hot Algols display overall acceptable chi (2), confirming the conservative assumption, while the cool Algols show much less acceptable chi (2), suggesting the need for more free parameters, such as mass and angular momentum loss. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Nelson, CA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 41 TC 100 Z9 100 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2001 VL 552 IS 2 BP 664 EP 678 DI 10.1086/320560 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 439TM UT WOS:000169133700022 ER PT J AU van Dokkum, PG Stanford, SA Holden, BP Eisenhardt, PR Dickinson, M Elston, R AF van Dokkum, PG Stanford, SA Holden, BP Eisenhardt, PR Dickinson, M Elston, R TI The galaxy population of cluster RX J0848+4453 at z=1.27 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (RX J0848+4453); galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies : fundamental parameters; galaxies : interactions ID COLOR-MAGNITUDE RELATION; DISTANT CLUSTERS; EVOLUTION; MORPHOLOGIES; PHOTOMETRY; MS-1054-03; Z=0.83; MODEL AB We present a study of the galaxy population in the IR-selected cluster RX J0848+4453 at z = 1.27, using deep Hubble Space Telescope (HST) NICMOS H-F160W and WFPC2 I-F814W images of the cluster core. We morphologically classify all galaxies to K-s = 20.6 that are covered by the HST imaging and determine photometric redshifts using deep ground-based BRlzJK(s) photometry. Of 22 likely cluster members with morphological classifications, 11 (50%) are classified as early-type galaxies, nine (41%) as spiral galaxies, and two (9%) as "merger/peculiar." At HST resolution, the second brightest cluster galaxy is resolved into a spectacular merger between three red galaxies of similar luminosity, separated from each other by approximate to6 h(50)(-1) kpc, with an integrated magnitude K = 17.6 (similar to 3L(*) at z = 1.27). The two most luminous early-type galaxies also show evidence for recent or ongoing interactions. Mergers and interactions between galaxies are possible because RX J0848+4453 is not yet relaxed. The fraction of early-type galaxies in our sample is similar to that in clusters at 0.5 < z < 1 and consistent with a gradual decrease of the number of early-type galaxies in clusters from z = 0 to z approximate to 1.3. We find evidence that the color-magnitude relation of the early-type galaxies is less steep than in the nearby Coma Cluster. This may indicate that the brightest early-type galaxies have young stellar populations at z = 1.27 but is also consistent with predictions of single-age "monolithic" models with a galactic wind. The scatter in the color-magnitude relation is approximate to0.04 in rest-frame U-V, similar to that in clusters at 0 < z < 1. Taken together, these results show that luminous early-type galaxies exist in clusters at z approximate to 1.3 but that their number density may be smaller than in the local universe. Additional observations are needed to determine whether the brightest early-type galaxies harbor young stellar populations. C1 CALTECH, Pasadena, CA 91125 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94511 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP van Dokkum, PG (reprint author), CALTECH, MS 105-24, Pasadena, CA 91125 USA. NR 33 TC 64 Z9 64 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 2001 VL 552 IS 2 BP L101 EP L104 DI 10.1086/320335 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 439TN UT WOS:000169133800005 ER PT J AU Driessen, BJ Sadegh, N Kwok, KS AF Driessen, BJ Sadegh, N Kwok, KS TI A robust line search for learning control SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article ID ROBOTS AB In this paper a new line search for a Newton-Raphson learning control algorithm is presented. Theorems and rigorous proofs of its increased robustness over existing line searches are provided, and numerical examples are used to further validate the theorems. C1 Sandia Natl Labs, Struct Dynam Dept, Albuquerque, NM 87185 USA. Georgia Inst Technol, Dept Mech Engn, Atlanta, GA 30332 USA. Sandia Natl Labs, Robot Ctr, Albuquerque, NM 87185 USA. RP Driessen, BJ (reprint author), Sandia Natl Labs, Struct Dynam Dept, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 6 Z9 6 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD MAY 10 PY 2001 VL 74 IS 7 BP 732 EP 736 DI 10.1080/00207170010025285 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA 429KW UT WOS:000168517000008 ER PT J AU Perl, ML Kim, PC Halyo, V Lee, ER Lee, IT Loomba, D Lackner, KS AF Perl, ML Kim, PC Halyo, V Lee, ER Lee, IT Loomba, D Lackner, KS TI The search for stable, massive, elementary particles SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article ID FRACTIONAL ELECTRIC CHARGE; DARK-MATTER SEARCH; HEAVY-ION COLLISIONS; E(+)E(-) COLLISIONS; MILLICHARGED PARTICLES; OBSERVATIONAL EVIDENCE; EXCLUSION LIMITS; MACRO DETECTOR; CROSS-SECTION; GALACTIC HALO AB In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches - what is known, what is not known, and what appear to be the most fruitful areas for new searches. h variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ New Mexico, Dept Phys, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Perl, ML (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 92 TC 38 Z9 38 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 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD MAY 10 PY 2001 VL 16 IS 12 BP 2137 EP 2164 DI 10.1142/S0217751X01003548 PG 28 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 436CG UT WOS:000168918500001 ER PT J AU Baker, GA AF Baker, GA TI The MBX Challenge Competition: A neutron matter model SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 10th International Conference on Recent Progress in Many-Body Theories (RPMBT-10) CY SEP 10-15, 1999 CL UNIV WASHINGTON, SEATTLE, WASHINGTON HO UNIV WASHINGTON AB In this paper I report my solution to MBX Challenge Competition. Namely, the Bertsch, nonparametric model of neutron matter is analyzed and strong indications are found that, in the infinite system limit, the ground state is a Fermi liquid with an effective mass. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Baker, GA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 6 TC 37 Z9 37 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD MAY 10 PY 2001 VL 15 IS 10-11 BP 1314 EP 1320 DI 10.1142/S0217979201005775 PG 7 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 440PJ UT WOS:000169183300005 ER PT J AU Carlson, J AF Carlson, J TI Recent studies of the nuclear interaction SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 10th International Conference on Recent Progress in Many-Body Theories (RPMBT-10) CY SEP 10-15, 1999 CL UNIV WASHINGTON, SEATTLE, WASHINGTON HO UNIV WASHINGTON ID MONTE-CARLO CALCULATIONS; 3-NUCLEON; SYSTEMS; FORCE AB Recent studies of light p-shell nuclei reveal that so-called 'realistic' nuclear interactions, those based on the NN scattering data augmented with plausible models of the three-nucleon interaction, provide a good description of nuclei through A=8. However, significant discrepancies exist, primarily in the energies of neutron rich systems and in the L S splittings in the spectra of these nuclei. We briefly describe the methods used in these studies, and describe improved models of the three-nucleon interaction. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Carlson, J (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD MAY 10 PY 2001 VL 15 IS 10-11 BP 1491 EP 1500 DI 10.1142/S0217979201005970 PG 10 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 440PJ UT WOS:000169183300025 ER PT J AU Eroles, J Ortiz, G Balatsky, AV Bishop, AR AF Eroles, J Ortiz, G Balatsky, AV Bishop, AR TI Pairing in inhomogeneous superconductors SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article; Proceedings Paper CT 10th International Conference on Recent Progress in Many-Body Theories (RPMBT-10) CY SEP 10-15, 1999 CL UNIV WASHINGTON, SEATTLE, WASHINGTON HO UNIV WASHINGTON ID T-J MODEL; TEMPERATURE; DEPENDENCE; PHASES AB Starting from a t-J model, we introduce inhomogeneous terms to mimic stripes. We find that if the inhomogeneous terms break the SU(2) spin symmetry the binding between holes is tremendously enhanced in the thermodynamic limit. In any other model (including homogeneous models) the binding in the thermodynamic limit is small or neglible. By including these inhomogeneous terms we can reproduce experimental neutron scattering data. We also discuss the connection of the resulting inhomogeneity-induced superconductivity to recent experimental evidence for a linear relation between magnetic incommensurability and the superconducting transition temperature, as a function of doping. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Ctr Atom Bariloche, RA-8400 Bariloche, Rio Negro, Argentina. Inst Balseiro, RA-8400 Bariloche, Rio Negro, Argentina. RP Eroles, J (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 11 TC 1 Z9 1 U1 0 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD MAY 10 PY 2001 VL 15 IS 10-11 BP 1613 EP 1616 DI 10.1142/S0217979201006112 PG 4 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 440PJ UT WOS:000169183300039 ER PT J AU Haschke, JM Allen, TH AF Haschke, JM Allen, TH TI Plutonium hydride, sesquioxide and monoxide monohydride: pyrophoricity and catalysis of plutonium corrosion SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE corrosion; actinides; catalysis ID WATER; KINETICS; AIR AB Reaction rates of air and oxygen with cubic plutonium hydride (PuHx, 1.9 50 ML) have been epitaxially grown on W(110) and studied by spin- and angle-resolved photoemission spectroscopy utilizing linearly polarized synchrotron radiation. The photoemission spectra display two surface sensitive 3d-derived features. The first, located at <()over bar>, consists of an exchange-split pair (Delta (ex) = 2.3 eV) with a sharp minority peak at about 0.25 eV below E(F) and a broader majority counterpart; the second, located midway along the <()over bar>-(S) over bar symmetry line of the surface Brillouin zone, is a majority peak close to E(F). A comparison of the experimental results with first-principle slab calculations reveals that both features are surface resonances, with a substantial charge density distribution on both the surface and the subsurface Fe(110) layer. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, NSLS, Upton, NY 11973 USA. Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. RP Vescovo, E (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, NSLS, Bldg 725D, Upton, NY 11973 USA. EM vescovo@bnl.gov RI Blugel, Stefan/J-8323-2013 OI Blugel, Stefan/0000-0001-9987-4733 NR 29 TC 17 Z9 18 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 10 PY 2001 VL 478 IS 3 BP 193 EP 202 DI 10.1016/S0039-6028(01)00699-9 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 430NN UT WOS:000168580300007 ER PT J AU Tobin, JG Schumann, FO AF Tobin, JG Schumann, FO TI Element-specific magnetometry with photoelectron dichroism: FeCo and FeNi SO SURFACE SCIENCE LA English DT Article DE semi-empirical models and model calculations; magnetic measurements; synchrotron radiation photoelectron spectroscopy; epitaxy; cobalt; iron; nickel; single crystal surfaces ID CORE-LEVEL PHOTOEMISSION; MAGNETIC CIRCULAR-DICHROISM; LINEARLY POLARIZED-LIGHT; FEXNI1-X ULTRATHIN FILMS; X-RAY; ALLOY-FILMS; THIN-FILMS; FCC FE; PHASE-TRANSITION; 3P PHOTOEMISSION AB We have investigated fee FexCo1-x and FexNi1-x alloys grown on Cu(100) with X-ray magnetic linear dichroism angular distributions in photoemission (XMLDAD). To achieve this end, a simple model has been developed, which accurately describes the experimental spectra and supports our application of XMLDAD as a form of elementally specific magnetometry. This model combines the simplicity and physical insight of a single-electron picture with multielectronic effects, via the utilization of "Doniach-Sunjic" lineshapes for each component within the Fe 3p multiplet. We will also briefly discuss the observed fine structure in the emission of the Fe 3p core level, which was previously predicted but lacking experimental confirmation. We have found different behavior for the dichroism of the Fe 3p level at high and low Fe concentrations upon alloying with Co, compared to alloying with Ni. These contrasting observations can be explained in part by the different behavior of the atomic volume. Both systems show also a change of the in-plane easy axis upon increasing the Fe content. For small concentrations the easy axis is along the {011} direction, which changes to the {001} direction at a higher Fe content. Interestingly the actual transition occurs in both instances at roughly the same electron/atom count. Published by Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94551 USA. RP Tobin, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, POB 808, Livermore, CA 94551 USA. RI Schumann, Frank /K-9364-2014; Tobin, James/O-6953-2015 NR 64 TC 19 Z9 19 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 10 PY 2001 VL 478 IS 3 BP 211 EP 228 DI 10.1016/S0039-6028(01)00955-4 PG 18 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 430NN UT WOS:000168580300009 ER PT J AU Yang, XG Du, XX Shi, JX Swanson, B AF Yang, XG Du, XX Shi, JX Swanson, B TI Molecular recognition and self-assembled polymer films for vapor phase detection of explosives SO TALANTA LA English DT Article DE polymer films; explosives; surface acoustic wave ID CHEMICAL SENSORS; THIN-FILMS; SYSTEM; MONOLAYERS AB Selective and sensitive polymer films for detecting explosives were studied and fabricated onto surface acoustic wave (SAW) devices. Polymers and molecular host species were self-assembled on functionalized silicon oxide surfaces through a catalytic hydrosilylation reaction. The covalently attached thin polymer films are stable, continuous and uniform with film thickness ranging from 15 to 30 nm. The microsensors coated with the polymer films show high sensitivity towards 2,4-dinitrotoluene (DNT) and o-nitrotoluene, an explosive simulant. Sensor responses to possible common interferents in land mine detection were studied and the sensor sensitivities to them were found to be much lower than that to DNT and explosives simulants. Response patterns for interferants and o-nitrotoluene were constructed and the sensors coated with functionalized cyclodextrins were able to detect 2,4-DNT and 2,4,6-trinitrotoluene (TNT) under ambient laboratory conditions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Yang, XG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 17 TC 55 Z9 55 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD MAY 10 PY 2001 VL 54 IS 3 BP 439 EP 445 DI 10.1016/S0039-9140(00)00542-7 PG 7 WC Chemistry, Analytical SC Chemistry GA 432LN UT WOS:000168693400003 PM 18968269 ER PT J AU Ewing, RG Atkinson, DA Eiceman, GA Ewing, GJ AF Ewing, RG Atkinson, DA Eiceman, GA Ewing, GJ TI A critical review of ion mobility spectrometry for the detection of explosives and explosive related compounds SO TALANTA LA English DT Article DE explosives; ion mobility spectrometry; atmospheric pressure chemical ionization ID MASS-SPECTROMETRY; REAGENT IONS; CALIBRATION AB Ion mobility spectrometry has become the most successful and widely used technology for the detection of trace levels of nitro-organic explosives on handbags and carry on-luggage in airports throughout the US. The low detection limits are provided by the efficient ionization process, namely, atmospheric pressure chemical ionization (APCI) reactions in negative polarity. An additional level of confidence in a measurement is imparted by characterization of ions for mobilities in weak electric fields of a drift tube at ambient pressure. Findings from over 30 years of investigations into IMS response to these explosives have been collected and assessed to allow a comprehensive view of the APCI reactions characteristic of nitro-organic explosives. Also, the drift tube conditions needed to obtain particular mobility spectra have been summarized. During the past decade, improvements have occurred in IMS on the understanding of reagent gas chemistries, the influence of temperature on ion stability, and sampling methods. In addition, commercial instruments have been refined to provide fast and reliable measurements for on-site detection of explosives. The gas phase ion chemistry of most explosives is mediated by the fragile C-ONO2 bonds or the acidity of protons. Thus, M- or M.Cl- species are found with only a few explosives and loss of NO2, NO3 and proton abstraction reactions are common and complicating pathways. However, once ions are formed, they appear to have stabilities on time scales equal to or longer than ion drift times from 5-20 ms. As such, peak shapes in IMS are suitable for high selectivity and sensitivity. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. RP Ewing, RG (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 30 TC 348 Z9 365 U1 15 U2 174 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD MAY 10 PY 2001 VL 54 IS 3 BP 515 EP 529 DI 10.1016/S0039-9140(00)00565-8 PG 15 WC Chemistry, Analytical SC Chemistry GA 432LN UT WOS:000168693400009 PM 18968275 ER PT J AU Yang, H Snee, PT Kotz, KT Payne, CK Harris, CB AF Yang, H Snee, PT Kotz, KT Payne, CK Harris, CB TI Femtosecond infrared study of the dynamics of solvation and solvent caging SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID METAL-METAL BOND; MOLECULAR-ORBITAL METHODS; DIMANGANESE DECACARBONYL; DIRHENIUM DECACARBONYL; MATRIX-ISOLATION; SPECTROSCOPIC DETECTION; GEMINATE RECOMBINATION; CARBON-MONOXIDE; PHOTODISSOCIATION; MN2(CO)10 AB The ultrafast reaction dynamics following 295-nm photodissociation of Re-2(CO)(10) were studied experimentally with 300-fs time resolution in the reactive, strongly coordinating CCl4? solution and in the inert. weakly coordinating hexane solution. Density-functional theoretical (DFT) and ab initio calculations were used to further characterize the transient intermediates seen in the experiments. It was found that the quantum yield of the Re-Re bond dissociation is governed by geminate recombination on two time scales in CCl4, similar to 50 and similar to 500 ps. The recombination dynamics are discussed in terms of solvent caging in which the geminate Re(CO)(5) pair has a low probability to escape the first solvent shell in the first few picoseconds after femtosecond photolysis. The other photofragmentation channel resulted in the equatorially solvated dirhenium nonacarbonyl eq-Re-2(CO)(9)(solvent). Theoretical calculations indicated that a structural reorganization energy cost on the order of 6-7 kcal/mol might be required for the unsolvated nonacarbonyl to coordinate to a solvent molecule. These results suggest that for Re(CO)(5) the solvent can be treated as a viscous continuum, whereas for the Re-2(CO)(9) the solvent is best described in molecular terms. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Harris, CB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Payne, Christine/E-5954-2010 NR 53 TC 25 Z9 25 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 9 PY 2001 VL 123 IS 18 BP 4204 EP 4210 DI 10.1021/ja003344y PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 429BH UT WOS:000168495800013 PM 11457185 ER PT J AU Link, G Berthold, T Bechtold, M Weidner, JU Ohmes, E Tang, J Poluektov, O Utschig, L Schlesselman, SL Thurnauer, MC Kothe, G AF Link, G Berthold, T Bechtold, M Weidner, JU Ohmes, E Tang, J Poluektov, O Utschig, L Schlesselman, SL Thurnauer, MC Kothe, G TI Structure of the P-700(+) A(1)(-) radical pair intermediate in photosystem I by high time resolution multifrequency electron paramagnetic resonance: Analysis of quantum beat oscillations SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOSYNTHETIC REACTION CENTERS; BACTERIAL REACTION CENTERS; RHODOBACTER-SPHAEROIDES R-26; TRANSIENT EPR SPECTROSCOPY; FIELD-INDUCED ORIENTATION; W-BAND EPR; PRIMARY DONOR; STATE P(700)(CENTER-DOT+)A(1)(CENTER-DOT-); SINGLE-CRYSTALS; SPIN-RESONANCE AB The geometry of the secondary radical pair, P(700)(+)A(1)(-), in photosystem I (PSI) from the deuterated and N-15-substituted cyanobacterium Synechococcus lividus has been determined by high time resolution electron paramagnetic resonance (EPR), performed at three different microwave frequencies. Structural information is extracted from light-induced quantum bents observed in the transverse magnetization of P(700)(+)A(1)(-) at early times after laser excitation. A computer analysis of the two-dimensional Q-band experiment provides the orientation of the various magnetic tensors of P(700)(+)A(1)(-) with respect to a magnetic reference frame. The orientation of the cofactors of the primary donor in the g-tensor system of P-700(+) is then evaluated by analyzing time-dependent X-band EPR spectra, extracted from a two-dimensional data set. Finally, the cofactor arrangement of P(700)(+)A(1)(-) in the photosynthetic membrane is deduced from angular-dependent W-band spectra, observed fora magnetically aligned sample. Thus, the orientation of the g-tensor of P-700(+) with respect to a chlorophyll based reference system could be determined. The angle between the g(1)(Z) axis and the chlorophyll plane normal is found to be 29 +/- 7 degrees, while the g(1)(Y) axis lies in the chlorophyll plane. In addition, a complete structural model for the reduced quinone acceptor, A;, is evaluated. In this model, the quinone plane of Ar is found to be inclined by 68 +/- 7 degrees relative to the membrane plane, while the P-700(+)-A(1)(-) axis makes an angle of 35 +/- 6 degrees with the membrane normal. All of these values refer to the charge separated state, P(700)(+)A(1)(-), observed at low temperatures, where forward electron transfer to the iron-sulfur centers is partially blocked. Preliminary room temperature studies of P(700)(+)A(1)(-), employing X-band quantum beat oscillations, indicate a different orientation of A(-)(1); in its binding pocket. A comparison with crystallographic data provides information on the electron-transfer pathway in PSI. It appears that quantum beats represent excellent structural probes for the short-lived intermediates in the primary energy conversion steps of photosynthesis. C1 Univ Freiburg, Dept Phys Chem, D-79104 Freiburg, Germany. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Kothe, G (reprint author), Univ Freiburg, Dept Phys Chem, Albertstr 21, D-79104 Freiburg, Germany. EM kothe@pc1.chemie.uni-freiburg.de RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 63 TC 29 Z9 33 U1 1 U2 3 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 MAY 9 PY 2001 VL 123 IS 18 BP 4211 EP 4222 DI 10.1021/ja003382h PG 12 WC Chemistry, Multidisciplinary SC Chemistry GA 429BH UT WOS:000168495800014 PM 11457186 ER PT J AU Grunwell, JR Glass, JL Lacoste, TD Deniz, AA Chemla, DS Schultz, PG AF Grunwell, JR Glass, JL Lacoste, TD Deniz, AA Chemla, DS Schultz, PG TI Monitoring the conformational fluctuations of DNA hairpins using single-pair fluorescence resonance energy transfer SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR BEACONS; DIFFUSING MOLECULES; IN-VITRO; RNA; SPECTROSCOPY; DYNAMICS; PROTEIN; IDENTIFICATION; HYBRIDIZATION; STRANDS AB We present single-pair fluorescence resonance energy transfer (spFRET) observations of individual opening and closing events of surface-immobilized DNA hairpins. Two glass-surface immobilization strategies employing the biotin-streptavidin interaction and a third covalent immobilization strategy involving formation of a disulfide bond to a thiol-derivatized glass surface are described and evaluated. Results from image and time-trace data from surface-immobilized molecules are compared with those from freely diffusing molecules which are unperturbed by surface interactions. Using a simple two-state model to analyze the open and closed time distributions for immobilized hail-pins, we calculate the lifetimes of the two states. For hairpins with a loop size of 40 adenosines and a stem size of either seven or nine bases, the respective closed-state Lifetimes are 45 +/- 2.4 and 103 +/- 6.0 ms, while the respective open-state lifetimes are 133 +/- 5.5 and 142 +/- 22 ms. These results show that the open state of the hairpin is favored over the closed state of the hairpin under these conditions, consistent with previous diffusion fluorescence correlation spectroscopy (FCS) experiments on poly(A)-loop hairpins. The measured open-state lifetime is about 30 times longer than the calculated 3 ms open-state lifetime for both hairpins based on a closing rate scaling factor derived from a previous FCS study for hairpins in diffusion with 12-30 thymidines in their loops. As predicted, the closed-state lifetime is dependent on the stem length and is independent of the loop characteristics. Our findings indicate that current models should consider sequence dependence in calculating ssDNA thermostability. The surface immobilization chemistries and ether experimental techniques described here should prove useful for studies of single-molecule populations and dynamics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Grunwell, JR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM49220] NR 51 TC 103 Z9 104 U1 5 U2 33 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 MAY 9 PY 2001 VL 123 IS 18 BP 4295 EP 4303 DI 10.1021/ja0027620 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 429BH UT WOS:000168495800024 PM 11457196 ER PT J AU Williams, CW Blaudeau, JP Sullivan, JC Antonio, MR Bursten, B Soderholm, L AF Williams, CW Blaudeau, JP Sullivan, JC Antonio, MR Bursten, B Soderholm, L TI The coordination geometry of Np(VII) in alkaline solution SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID EXCHANGE C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. ASC HP, Ohio Supercomp Ctr, Wright Patterson AFB, OH 45433 USA. Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. RP Blaudeau, JP (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 42 Z9 43 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 9 PY 2001 VL 123 IS 18 BP 4346 EP 4347 DI 10.1021/ja005640g PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 429BH UT WOS:000168495800034 PM 11457206 ER PT J AU Ohta, K Larsen, DS Yang, M Fleming, GR AF Ohta, K Larsen, DS Yang, M Fleming, GR TI Influence of intramolecular vibrations in third-order, time-domain resonant spectroscopies. II. Numerical calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ECHO-PEAK SHIFT; NONLINEAR-OPTICAL RESPONSE; PUMP-PROBE SPECTROSCOPY; STIMULATED PHOTON-ECHO; DYNAMIC ABSORPTION-SPECTROSCOPY; MOLECULAR VIBRONIC STRUCTURES; ULTRAFAST SOLVATION DYNAMICS; ULTRASHORT LASER-PULSES; ENERGY-TRANSFER; RHODOBACTER-SPHAEROIDES AB We model recent experimental wavelength dependent Three Pulse Photon Echo Peak Shift (WD-3PEPS) and Transient Grating (WD-TG) signals considering both solvation dynamics and vibrational contributions. We present numerical simulations of WD-3PEPS and WD-TG signals of two probe molecules: Nile Blue and N,N-bisdimethylphenyl-2,4,6,8-perylenetetracarbonyl diamide to investigate the influence of intramolecular vibrations in the signals. By varying the excitation wavelength, we show that the different initial conditions for the vibrational wave packets significantly affect the signals, especially through the contributions associated with high frequency modes, often neglected in experimental analyses. We show that the temporal properties of both WD-TG and WD-3PEPS signals display sensitivities to both the excitation wavelength and the vibronic structure of the specific probe molecule used. Several mechanisms for generating vibronic modulations in the signals are discussed and their effects on the signals are described. Quantitative agreement between experiment and simulated signals requires accurate characterization of the laser pulses, specifically the magnitude and sign of chirp has a significant effect on the initial temporal properties of the signals. We provide a description of the experimental considerations required for accurate determination of molecular dynamics from 3PEPS and TG experiments and conclude with a brief discussion of the implications of our results for previous analyses of such experiments. (C) 2001 American Institute of Physics. C1 Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Fleming, GR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. OI Yang, Mino/0000-0001-9504-0280 NR 82 TC 78 Z9 78 U1 1 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 MAY 8 PY 2001 VL 114 IS 18 BP 8020 EP 8039 DI 10.1063/1.1359241 PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 424VE UT WOS:000168254000036 ER PT J AU Terrones, G Pearlstein, AJ AF Terrones, G Pearlstein, AJ TI Effects of optical attenuation and consumption of a photobleaching initiator on local initiation rates in photopolymerizations SO MACROMOLECULES LA English DT Article ID LASER-LIGHT SOURCE; NONISOTHERMAL PHOTOPOLYMERIZATION; DENTAL COMPOSITES; REACTION BEHAVIOR; PROCESS MODEL; KINETICS; POLYMERIZATION; CURE; PHOTOCHEMISTRY; CONVECTION AB For free-radical photopolymerization with a photobleaching initiator, we develop an unsteady one-dimensional model accounting for initiator consumption and optical attenuation and derive relationships for the spatial and temporal variation of the local initiator concentration and initiation rate. With increasing absorbance, the local initiation rate becomes increasingly nonuniform and assumes the form of a highly localized traveling wave propagating with speed phiI(0)/C-A,C-0, (where phi, I-0, and C-A,C-0 are the quantum yield of photoinitiator consumption, incident intensity, and initial photoinitiator concentration, respectively), independent of photoinitiator absorption coefficient. At high attenuation, the maximum photoinitiation rate las a function of position) is asymptotically one-fourth the initial rate at the front of the layer. Qualitative effects of nonuniform initiation in free-radical photopolymerizations with simple and more complicated kinetics are discussed in terms of the model and results. C1 Pacific NW Natl Lab, Proc Sci & Engn Dept, Richland, WA 99352 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. RP Terrones, G (reprint author), Pacific NW Natl Lab, Proc Sci & Engn Dept, POB 999, Richland, WA 99352 USA. OI Terrones, Guillermo/0000-0001-8245-5022; Pearlstein, Arne/0000-0002-7044-5537 NR 53 TC 66 Z9 68 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 8 PY 2001 VL 34 IS 10 BP 3195 EP 3204 DI 10.1021/ma001235y PG 10 WC Polymer Science SC Polymer Science GA 429LR UT WOS:000168519000015 ER PT J AU Anders, A AF Anders, A TI Energetics of vacuum arc cathode spots SO APPLIED PHYSICS LETTERS LA English DT Article ID CHARGE-STATE DISTRIBUTIONS; ION; PLASMAS AB Vacuum arcs need to generate the current-carrying plasma at cathode spots. The cohesive energy of the cathode material determines the energy the arc needs to provide for the phase transitions of the cathode material. As recent experiments confirm, the greater the cohesive energy the higher the burning voltage ("cohesive energy rule"). This relation is founded in the energy balance of cathode spot operation, regardless of the specific cathode mechanisms involved. A greater power input, as determined by the cohesive energy via the cohesive energy rule, leads to enhanced power output in various forms such as enhanced electron temperature, ion charge states, and ion velocity. Using the Cohesive Energy Rule, secondary relations such as the well known relation between boiling point of the cathode and average ion charge state can be explained. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 15 TC 8 Z9 8 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 MAY 7 PY 2001 VL 78 IS 19 BP 2837 EP 2839 DI 10.1063/1.1370541 PG 3 WC Physics, Applied SC Physics GA 427ZX UT WOS:000168437600007 ER PT J AU Salleo, A Genin, FY Feit, MD Rubenchik, AM Sands, T Mao, SS Russo, RE AF Salleo, A Genin, FY Feit, MD Rubenchik, AM Sands, T Mao, SS Russo, RE TI Energy deposition at front and rear surfaces during picosecond laser interaction with fused silica SO APPLIED PHYSICS LETTERS LA English DT Article ID SHOCK-WAVE GENERATION; ABLATION; NANOSECOND; SIDE; NM AB The difference between front-surface and rear-surface energy deposition of a 35 ps laser pulse (lambda = 1064 nm) in fused silica was investigated using shadowgraphic and laser-deflection techniques. Shock waves were observed in the glass and in air. Shock waves generated in air at the front surface are stronger than at the rear surface. Less than 35% of the energy incident on the surface drives the air shock waves at the rear surface. Up to 90% of the incident energy drives the air shock waves at the front surface. Laser-plasma interaction is responsible for this difference and for limiting the amount of energy deposited inside the sample during front-surface ablation. Energy deposition at the rear surface is mostly limited by self-focusing inside the material. (C) 2001 American Institute of Physics. C1 Univ Calif Lawrence Livermore Natl Lab, Natl Ignit Facil, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Genin, FY (reprint author), Univ Calif Lawrence Livermore Natl Lab, Natl Ignit Facil, Livermore, CA 94550 USA. RI Feit, Michael/A-4480-2009; Sands, Timothy/D-2133-2009 OI Sands, Timothy/0000-0001-9718-6515 NR 18 TC 29 Z9 35 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 MAY 7 PY 2001 VL 78 IS 19 BP 2840 EP 2842 DI 10.1063/1.1362332 PG 3 WC Physics, Applied SC Physics GA 427ZX UT WOS:000168437600008 ER PT J AU Rohlsberger, R Quast, KW Toellner, TS Lee, PL Sturhahn, W Alp, EE Burkel, E AF Rohlsberger, R Quast, KW Toellner, TS Lee, PL Sturhahn, W Alp, EE Burkel, E TI Imaging the temporal evolution of nuclear resonant x-ray scattering SO APPLIED PHYSICS LETTERS LA English DT Article ID SYNCHROTRON-RADIATION AB The time response of resonant nuclei in a rotating sample coherently excited by synchrotron radiation pulses maps to an angular scale. At sufficiently high rotational speeds, the temporal evolution of the nuclear decay can be recorded with a position sensitive detector. This has been demonstrated by nuclear resonant scattering of synchrotron radiation from a Fe-57 metal foil rotating at 10 kHz. The method has the potential to yield time resolutions of a few 10 ps, thus overcoming principal limits of existing techniques. (C) 2001 American Institute of Physics. C1 Univ Rostock, Fachbereich Phys, D-18055 Rostock, Germany. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Rohlsberger, R (reprint author), Univ Rostock, Fachbereich Phys, August Bebel Str 55, D-18055 Rostock, Germany. RI Rohlsberger, Ralf/J-4173-2013 OI Rohlsberger, Ralf/0000-0001-6005-5183 NR 13 TC 7 Z9 7 U1 0 U2 2 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 MAY 7 PY 2001 VL 78 IS 19 BP 2970 EP 2972 PG 3 WC Physics, Applied SC Physics GA 427ZX UT WOS:000168437600052 ER PT J AU Guzei, IA Bakac, A AF Guzei, IA Bakac, A TI Macrocyclic hydroperoxocobalt(III) complex: Photochemistry, spectroscopy, and crystal structure SO INORGANIC CHEMISTRY LA English DT Article ID AQUEOUS-SOLUTION; ELECTROCHEMICAL REDUCTION; MOLECULAR-OXYGEN; METAL COMPLEXES; RADICALS; OXIDATION; DIOXYGEN; LIGANDS; INTERMEDIATE; REACTIVITY AB The hydroperoxocobalt complex [L-2(CH3CN)CoOOH](ClO4)(2). CH3CN (L-2 = meso-5,7,7,12,14,14-Me-6-[14]aneN(4)) crystallizes with discrete anions, cations, and solvate acetonitrile molecules in the lattice. The complex crystallizes in the monoclinic space group P2(1)/n, a = 10.4230(5) Angstrom, b = 16.1561(8) Angstrom, c = 17.4676(9) Angstrom, beta = 92.267(1)degrees, V = 2939.2(3) Angstrom (3), Z = 4. The O-O bond length is 1.397(4) Angstrom, and the O(2)-O(1)-Co angle spans 117.7 degrees. The O-O stretch in the infrared spectrum appears at 815 cm(-1). The 355- and 266-nm photolysis of acidic aqueous solutions of L-2(H2O)CoOOH2+ results in homolytic splitting of the Co-O bond and yields L2Co(H2O)(2)(2+) and HO2./O-2(.-) as the only products. The two fragments were scavenged selectively in separate experiments with Oz and C(NO2)(4). There is no evidence for photochemical O-O bond homolysis, presumably because the appropriate optical transition is masked by the HO2-to-Co LMCT transition. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Bakac, A (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 51 TC 26 Z9 26 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAY 7 PY 2001 VL 40 IS 10 BP 2390 EP 2393 DI 10.1021/ic0013911 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 429NP UT WOS:000168524100029 PM 11327917 ER PT J AU Zhang, CG Guzei, IA Espenson, JH AF Zhang, CG Guzei, IA Espenson, JH TI Synthesis, structure, and catalytic reactivity of N,N,S- and O,N,S-tridentate oxorhenium(V) complexes SO INORGANIC CHEMISTRY LA English DT Article ID OXIDES; MECHANISMS; RHENIUM AB Three new oxorhenium(V) catalysts have been synthesized; the one whose structural formula is shown was characterized crystallographically. These compounds catalyze oxygen atom transfer from pyridine N-oxide to tris(trimethylphenyl)phosphine in chloroform at room temperature. 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 9 TC 17 Z9 17 U1 0 U2 3 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 MAY 7 PY 2001 VL 40 IS 10 BP 2437 EP + DI 10.1021/ic001087s PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 429NP UT WOS:000168524100039 PM 11327927 ER PT J AU Hirsch, J George, SD Solomon, EI Hedman, B Hodgson, KO Burstyn, JN AF Hirsch, J George, SD Solomon, EI Hedman, B Hodgson, KO Burstyn, JN TI Raman and extended X-ray absorption fine structure characterization of a sulfur-ligated Cu(I) ethylene complex: Modeling the proposed ethylene binding site of Arabidopsis thaliana ETR1 SO INORGANIC CHEMISTRY LA English DT Article ID UNSATURATED SMALL MOLECULES; COPPER(I) COMPLEXES; OLEFINS AB An ethylene complex of a thioether-ligated Cu(I) center was synthesized and characterized by Raman spectroscopy and EXAFS. Long Cu(I)-C bonds and low Cu-C vibrational frequencies reveal weak binding of the gaseous ligand. C1 Univ Wisconsin, Dept Chem, Madison, WI 53706 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Burstyn, JN (reprint author), Univ Wisconsin, Dept Chem, 1101 Univ Ave, Madison, WI 53706 USA. RI DeBeer, Serena/G-6718-2012 FU NCRR NIH HHS [RR-01209]; PHS HHS [OK-31450] NR 22 TC 17 Z9 20 U1 1 U2 15 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 MAY 7 PY 2001 VL 40 IS 10 BP 2439 EP + DI 10.1021/ic000671y PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 429NP UT WOS:000168524100040 PM 11327928 ER PT J AU Teber, S Stojkovic, BP Brazovskii, SA Bishop, AR AF Teber, S Stojkovic, BP Brazovskii, SA Bishop, AR TI Statistics of charged solitons and formation of stripes SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article AB The M-fold degeneracy of the ground state of a quasi-one-dimensional system allows it to support topological excitations such as solitons. We study the combined effects of Coulomb interactions and confinement due to interchain coupling on the statistics and thermodynamics of such defects. We concentrate on a two-dimensional case with M = 2 which may correspond to monolayers of doped polyacetylene-type polymers or other charge-density waves and to junctions in field-effect experiments for equivalent materials. Combining analytical and numerical methods, the theory is developed by a mapping to the two-dimensional Ising model with long-range four-spin interactions. We obtain the phase diagram depending on the ratio of Coulomb interaction and interchain coupling with respect to temperature. The latter exhibits deconfined phases for liquids and Wigner crystals of kinks, and confined ones for bikinks. Also we find aggregated phases with either infinite domain walls of kinks or finite rods of bikinks. Roughening effects due to both temperature and Coulomb repulsion are observed. Applications may concern the melting of stripes in doped correlated materials. C1 Univ Paris Sud, Lab Phys Theor & Modeles Stat, F-91406 Orsay, France. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Sci, Los Alamos, NM 87545 USA. RP Teber, S (reprint author), Univ Paris Sud, Lab Phys Theor & Modeles Stat, Batiment 100, F-91406 Orsay, France. RI Brazovskii, Serguei/A-9608-2012 OI Brazovskii, Serguei/0000-0001-8147-9655 NR 18 TC 9 Z9 9 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD MAY 7 PY 2001 VL 13 IS 18 BP 4015 EP 4031 DI 10.1088/0953-8984/13/18/311 PG 17 WC Physics, Condensed Matter SC Physics GA 435YY UT WOS:000168910800014 ER PT J AU Nayak, GC Dumitru, A McLerran, L Greiner, W AF Nayak, GC Dumitru, A McLerran, L Greiner, W TI Equilibration of the gluon-minijet plasma at RHIC and LHC SO NUCLEAR PHYSICS A LA English DT Article ID HEAVY-ION COLLISIONS; ENERGY NUCLEAR COLLISIONS; QUARK-GLUON; PARTON DISTRIBUTIONS; TRANSVERSE ENERGY; THERMALIZATION; EVOLUTION; TRANSPORT; CASCADE AB We study the production and equilibration of the gluon-minijet plasma expected to be formed in the central region of ultrarelativistic heavy-ion collisions at the BNL-RHIC and the CERN-LHC by solving a self-consistent relativistic transport equation. We compute the minijet production within perturbative QCD. Subsequent collisions among the semihard partons are treated by considering the elastic gg --> gg processes with screening of the long-wavelength modes taken into account. We determine the time tau (eq) where close to ideal hydrodynamic flow sets in, and find rather similar numbers for central heavy-ion collisions at BNL-RHIC and CERN-LHC energies. The number densities, energy densities and temperatures of the minijet plasma are found to be different at RHIC and LHC, e.g. T(tau (eq)) similar to 220 MeV and 380 MeV, respectively. (C) 2001 Elsevier Science B,V. All rights reserved. C1 Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. Columbia Univ, Dept Phys, New York, NY 10027 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11979 USA. RP Nayak, GC (reprint author), Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. NR 41 TC 56 Z9 56 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 7 PY 2001 VL 687 IS 3-4 BP 457 EP 474 DI 10.1016/S0375-9474(00)00577-7 PG 18 WC Physics, Nuclear SC Physics GA 423BA UT WOS:000168154500004 ER PT J AU Behrndt, K Gukov, S Shmakova, M AF Behrndt, K Gukov, S Shmakova, M TI Domain walls, black holes, and supersymmetric quantum mechanics SO NUCLEAR PHYSICS B LA English DT Article DE domain walls; black holes; supergravity; supersymmetric vacua; AdS/CFT ID MAXWELL-EINSTEIN SUPERGRAVITY; SUPER-YANG-MILLS; N=2 SUPERGRAVITY; CALABI-YAU; JORDAN ALGEBRAS; CRITICAL-POINTS; 5 DIMENSIONS; COMPACTIFICATIONS; SUPERPOTENTIALS; VACUA AB Supersymmetric solutions, such as BPS domain walls or black holes, in four- and five-dimensional supergravity theories with eight supercharges can be described by effective quantum mechanics with a potential term. We show how properties of the latter theory can help us to learn about the physics of supersymmetric vacua and BPS solutions in these supergravity theories. The general approach is illustrated in a number of specific examples where scalar fields of matter multiplets take values in symmetric coset spaces. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Humboldt Univ, Inst Phys, D-10115 Berlin, Germany. CALTECH, Dept Phys, Pasadena, CA 91125 USA. UCS, CIT USC, Ctr Theoret Phys, Los Angeles, CA 90089 USA. CIPA, Palo Alto, CA 94306 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Humboldt Univ, Inst Phys, D-10115 Berlin, Germany. EM behrndt@physik.hu-berlin.de; gukov@theory.caltech.edu; shmakova@slac.stanford.edu NR 57 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 7 PY 2001 VL 601 IS 1-2 BP 49 EP 76 DI 10.1016/S0550-3213(01)00052-9 PG 28 WC Physics, Particles & Fields SC Physics GA 435QL UT WOS:000168892100003 ER PT J AU Petriello, FJ AF Petriello, FJ TI The Higgs mechanism in non-commutative gauge theories SO NUCLEAR PHYSICS B LA English DT Article ID SPONTANEOUS SYMMETRY-BREAKING; FIELD-THEORY; INDEPENDENCE; DIVERGENCES; INVARIANCE AB This paper investigates the non-commutative version of the Abelian Higgs model at the one loop level. We find that the BRST invariance of the theory is maintained at this order in perturbation theory, rendering the theory one-loop renormalizable. Upon removing the gauge field from the theory we also obtain a consistent continuum renormalization of the broken O(2) linear sigma model. The beta functions for the various couplings of the gauged U(1) theory are presented, as are the divergent contributions to every one particle irreducible (1PI) function. We find that all physical couplings and masses are gauge independent. A brief discussion concerning the symmetries P. C, and T in this theory is also given. (C) 2001 Published by Elsevier Science B.V. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM frankp@stanford.edu NR 39 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 7 PY 2001 VL 601 IS 1-2 BP 169 EP 190 DI 10.1016/S0550-3213(01)00070-0 PG 22 WC Physics, Particles & Fields SC Physics GA 435QL UT WOS:000168892100007 ER PT J AU Berger, EL Harris, BW Kaplan, DE Sullivan, Z Tait, TMP Wagner, CEM AF Berger, EL Harris, BW Kaplan, DE Sullivan, Z Tait, TMP Wagner, CEM TI Low-energy supersymmetry and the tevatron bottom-quark cross section SO PHYSICAL REVIEW LETTERS LA English DT Article ID HADRON-HADRON-COLLISIONS; = 1.8 TEV; P(P)OVER-BAR COLLISIONS; ROOT-S=1.8 TEV; E+E ANNIHILATION; PARTICLE PHYSICS; QCD CORRECTIONS; STANDARD MODEL; UNIFICATION; SEARCH AB A long-standing discrepancy between the bottom-quark production cross section and predictions of perturbative quantum chromodynamics is addressed. We show that pair production of light gluinos, of mass 12 to 16 GeV. with two-body decays into bottom quarks and light bottom squarks. yields a bottom-quark production rate in agreement with hadron collider data. We examine constraints on this scenario from low-energy data and make predictions that may be tested at the next run of the Fermilab Tevatron collider. C1 Argonne Natl Lab, High Energy Phys Div, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Berger, EL (reprint author), Argonne Natl Lab, High Energy Phys Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 43 TC 88 Z9 88 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 MAY 7 PY 2001 VL 86 IS 19 BP 4231 EP 4234 DI 10.1103/PhysRevLett.86.4231 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000010 PM 11328142 ER PT J AU Hou, WS Soni, A AF Hou, WS Soni, A TI Pathways to rare baryonic B decays SO PHYSICAL REVIEW LETTERS LA English DT Article ID EXCLUSIVE DECAYS; CP VIOLATION; MESON DECAYS; ETA'; TESTS AB We point out new ways to starch for charmless baryonic B decays and suggest that enhanced baryon production is favored by reduced energy release on the baryon side. Thus B --> eta ' + baryon pairs might be larger than K pi/pi pi modes: the argument may be extended to B --> gamma + X-s. and perhaps to l nu + X-u. Guess estimates give some branching ratios in the 10(-3)-10(-6) range, with confidence gained from the recent observation of B --> (D) over bar* p(n) over bar, (D) over bar* > not far below (D) over bar* pi and (D) over bar* rho rates. Observation of modes proposed here would help clarify the dynamics of weak decays involving baryons, while the self-analyzing prowess of Lambda decay can be helpful in CP- and T-violation studies. C1 Natl Taiwan Univ, Dept Phys, Taipei 10764, Taiwan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Hou, WS (reprint author), Natl Taiwan Univ, Dept Phys, Taipei 10764, Taiwan. NR 23 TC 77 Z9 77 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 MAY 7 PY 2001 VL 86 IS 19 BP 4247 EP 4250 DI 10.1103/PhysRevLett.86.4247 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000014 PM 11328146 ER PT J AU Ajimura, S Hayakawa, H Kishimoto, T Kohri, H Matsuoka, K Minami, S Mori, T Morikubo, K Saji, E Sakaguchi, A Shimizu, Y Sumihama, M Chrien, RE May, M Pile, P Rusek, A Sutter, R Eugenio, P Franklin, G Khaustov, P Paschke, K Quinn, BP Schumacher, RA Franz, J Fukuda, T Noumi, H Outa, H Gan, L Tang, L Yuan, L Tamura, H Nakano, J Tamagawa, T Tanida, K Sawafta, R AF Ajimura, S Hayakawa, H Kishimoto, T Kohri, H Matsuoka, K Minami, S Mori, T Morikubo, K Saji, E Sakaguchi, A Shimizu, Y Sumihama, M Chrien, RE May, M Pile, P Rusek, A Sutter, R Eugenio, P Franklin, G Khaustov, P Paschke, K Quinn, BP Schumacher, RA Franz, J Fukuda, T Noumi, H Outa, H Gan, L Tang, L Yuan, L Tamura, H Nakano, J Tamagawa, T Tanida, K Sawafta, R TI Observation of spin-orbit splitting in Lambda single-particle states SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUARK-MODEL; N INTERACTIONS; HYPERNUCLEI; O-16(LAMBDA); POTENTIALS; NUCLEI AB The spin-orbit splitting of Lambda single-particle states in C-13(Lambda) was measured. The C-13(K-, pi (+))(Lambda)C-13 reaction was used to excite both the 1/2(-) and 3/2(-) states simultaneously, which have predominantly C-12(0(+)) x p(Lambda) configuration, gamma rays from the states to the ground stale were measured in coincidence with the pi (-)'s. by which Ps splitting was found to be 152 +/- 54 (stat) +/- 36(syst) keV. The value is 20-30 times smaller than exhibited by the Ps splitting in the nuclear shell model. This value gives us new insight into the YN interaction. C1 Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Freiburg, D-79104 Freiburg, Germany. KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. N Carolina Agr & Technol State Univ, Dept Phys, Greensboro, NC 27411 USA. RP Ajimura, S (reprint author), Osaka Univ, Dept Phys, Toyonaka, Osaka 5600043, Japan. RI Schumacher, Reinhard/K-6455-2013; Franklin, Gregg/N-7743-2014; Quinn, Brian/N-7343-2014 OI Schumacher, Reinhard/0000-0002-3860-1827; Franklin, Gregg/0000-0003-4176-1378; Quinn, Brian/0000-0003-2800-986X NR 28 TC 102 Z9 102 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 MAY 7 PY 2001 VL 86 IS 19 BP 4255 EP 4258 DI 10.1103/PhysRevLett.86.4255 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000016 PM 11328148 ER PT J AU Vu, HX DuBois, DF Bezzerides, B AF Vu, HX DuBois, DF Bezzerides, B TI Transient enhancement and detuning of laser-driven parametric instabilities by particle trapping SO PHYSICAL REVIEW LETTERS LA English DT Article ID STIMULATED RAMAN-SCATTERING; ELECTRON-PLASMA; SATURATION; WAVE; SIMULATIONS; BRILLOUIN AB Kinetic simulations of backward stimulated Raman scattering (BSRS), where the Langmuir wave coherence time is greater than the bounce time for trapped electrons, yield transient reflectivity levels far above those predicted by fluidlike models. Electron trapping reduces the Langmuir wave damping and lowers the Langmuir wave frequency, and leads to a secular phase shift between the Langmuir wave and the BSRS beat ponderomotive force. This phase shift detunes and saturates BSRS and a similar effect, due to ion trapping, is the saturation mechanism for backward stimulated Brillouin scattering. Competition with forward SRS is discussed. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Vu, HX (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 21 TC 89 Z9 89 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 7 PY 2001 VL 86 IS 19 BP 4306 EP 4309 DI 10.1103/PhysRevLett.86.4306 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000029 PM 11328161 ER PT J AU Rider, KB Hwang, KS Salmeron, M Somorjai, GA AF Rider, KB Hwang, KS Salmeron, M Somorjai, GA TI Structure and dynamics of dense monolayers of NO adsorbed on Rh(111) in equilibrium with the gas phase in the Torr pressure range SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; TEMPERATURE AB Using scanning tunneling microscopy, we show the phase transition between new structures of NO on Rh(lll) in equilibrium with the gas phase near 300 K, in the Torr pressure range. Two phases with (2 X 2) and (3 X 3) periodicity transform into each other as the pressure and temperature change around the equilibrium P-T line. By measuring P and T at coexistence, we determined the heat of adsorption in the (3 x 3) structure. From the phase boundary dynamics, the activation energy barrier between phases were estimated. The results demonstrate that unique information can be obtained from high-pressure and high-temperature studies. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Salmeron, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 8 TC 47 Z9 47 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 MAY 7 PY 2001 VL 86 IS 19 BP 4330 EP 4333 DI 10.1103/PhysRevLett.86.4330 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000035 PM 11328167 ER PT J AU Coulon, C Penicaud, A Clerac, R Moret, R Launois, P Hone, J AF Coulon, C Penicaud, A Clerac, R Moret, R Launois, P Hone, J TI Metal-insulator and structural phase transition observed by ESR spectroscopy and x-ray diffraction in KC60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLYMER-CHAIN ORIENTATIONS; GROUND-STATE; ELECTRONIC-STRUCTURE; RBC60; AC(60); FULLERIDES; RB; CS; CRYSTAL; CSC60 AB We have performed electron spin resonance (ESR) spectroscopy and x-ray diffraction experiments at low temperature on KC60 single crystals. ESR data reveal the occurrence of a metal-insulator phase transition at about 50 K. In the same temperature range, we observe the stabilization of a superstructure which doubles the volume of the unit cell. We suggest that displacements of the K atoms and a modulation of the C-60 charge may be involved in the mechanism of this phase transition. These results shed new light on the subtle interplay of structure, dimensionality, and electronic properties in the AC(60) fullerides. C1 Univ Bordeaux 1, Ctr Rech Paul Pascal, CNRS, UPR 8641, F-33600 Pessac, France. Univ Paris 11, Phys Solides Lab, CNRS, UMR 8502, F-91405 Orsay, France. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Coulon, C (reprint author), Univ Bordeaux 1, Ctr Rech Paul Pascal, CNRS, UPR 8641, Av Dr Schweitzer, F-33600 Pessac, France. RI Clerac, Rodolphe/C-2800-2008; penicaud, alain/K-4567-2013; Hone, James/E-1879-2011 OI Hone, James/0000-0002-8084-3301 NR 24 TC 14 Z9 14 U1 2 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 MAY 7 PY 2001 VL 86 IS 19 BP 4346 EP 4349 DI 10.1103/PhysRevLett.86.4346 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000039 PM 11328171 ER PT J AU Orgad, D Kivelson, SA Carlson, EW Emery, VJ Zhou, XJ Shen, ZX AF Orgad, D Kivelson, SA Carlson, EW Emery, VJ Zhou, XJ Shen, ZX TI Evidence of electron fractionalization from photoemission spectra in the high temperature superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-PARTICLE PROPERTIES; T-C SUPERCONDUCTORS; FERMI-SURFACE; DOPED ANTIFERROMAGNETS; TOMONAGA-LUTTINGER; BI2SR2CACU2O8+DELTA; STATE; FLUCTUATIONS; CHARGE; YBA2CU3O6.6 AB In the normal state of the high temperature superconductors Bi2Sr2CaCu2O8+delta and La2-xSrxCuO4, and in the related "stripe ordered" material, La1.25Nd0.6Sr0.5CuO4 there is sharp structure in the measured single hole spectral function, A(<)((k) over right arrow, omega), considered as a function of (k) over right arrow at fixed small binding energy omega. At the same time, as a function of w at fixed k on much of the putative Fermi surface, any structure in A(<)((k) over right arrow, omega), other than the Fermi cutoff. is very broad. This is characteristic of the situation in which there are no stable excitations with the quantum numbers of the electron, as is the case in the one-dimensional electron gas. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. NR 33 TC 43 Z9 43 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 7 PY 2001 VL 86 IS 19 BP 4362 EP 4365 DI 10.1103/PhysRevLett.86.4362 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000043 PM 11328175 ER PT J AU Lu, DH Feng, DL Armitage, NP Shen, KM Damascelli, A Kim, C Ronning, F Shen, ZX Bonn, DA Liang, R Hardy, WN Rykov, AI Tajima, S AF Lu, DH Feng, DL Armitage, NP Shen, KM Damascelli, A Kim, C Ronning, F Shen, ZX Bonn, DA Liang, R Hardy, WN Rykov, AI Tajima, S TI Superconducting gap and strong in-plane anisotropy in untwinned YBa2Cu3O7-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; SINGLE-CRYSTALS; T-C; CHAIN; BI2SR2CACU2O8+DELTA; TRANSITION; SURFACE; DENSITY AB With significantly improved sample quality and instrumental resolution, we clearly identify in the (pi, 0) photoemission spectra from YBa2Cu3O6.993, in the superconducting state, the long-sought "peak- dip-hump" structure. This advance allows us to investigate the large a-b anisotropy of the in-plane electronic structure including. in particular, a 50% difference in the magnitude of the superconducting gap that scales with the energy position of the hump feature. This anisotropy, likely induced by the presence of the CuO chains, raises serious questions about attempts to quantitatively explain the YBa2Cu3O7-delta data from various experiments using models based on a perfectly square lattice. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Int Superconduct Technol Ctr, Superconduct Res Lab, Koto Ku, Tokyo 1350062, Japan. RP Lu, DH (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RI Shen, Kyle/B-3693-2008; damascelli, andrea/P-6329-2014 OI damascelli, andrea/0000-0001-9895-2226 NR 17 TC 125 Z9 126 U1 0 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 7 PY 2001 VL 86 IS 19 BP 4370 EP 4373 DI 10.1103/PhysRevLett.86.4370 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000045 PM 11328177 ER PT J AU Karapetrov, G Iavarone, M Kwok, WK Crabtree, GW Hinks, DG AF Karapetrov, G Iavarone, M Kwok, WK Crabtree, GW Hinks, DG TI Scanning tunneling spectroscopy in MgB2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID LATTICE; SUPERCONDUCTOR AB We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39 K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter Gamma. The value of the superconducting gap is 5 meV at 4.2 K, with no experimentally significant variation across the surface of the sample. The temperature dependence of the gap follows the BCS form, fully consistent with phonon-mediated superconductivity in this novel superconductor. The application of a magnetic field induces strong pair breaking as seen in the conductance spectra in fields up to 6 T. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Naples Federico II, INFM, Dipartimento Sci Fis, I-80125 Naples, Italy. RP Karapetrov, G (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Iavarone, Maria/C-3628-2008; Karapetrov, Goran/C-2840-2008 OI Karapetrov, Goran/0000-0003-1113-0137 NR 23 TC 168 Z9 170 U1 0 U2 15 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 MAY 7 PY 2001 VL 86 IS 19 BP 4374 EP 4377 DI 10.1103/PhysRevLett.86.4374 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000046 PM 11328178 ER PT J AU Vlasko-Vlasov, VK Welp, U Jiang, JS Miller, DJ Crabtree, GW Bader, SD AF Vlasko-Vlasov, VK Welp, U Jiang, JS Miller, DJ Crabtree, GW Bader, SD TI Field induced biquadratic exchange in hard/soft ferromagnetic bilayers SO PHYSICAL REVIEW LETTERS LA English DT Article ID MULTILAYERS; SYSTEMS; ORIGIN; FILMS AB The appearance of biquadratic exchange coupling between soft Fe and hard SmCo thin layers is found. The remanent magnetization in the Fe layer reorients from parallel to perpendicular with respect to the SmCo easy axis after application of large enough negative field. To explain such an unexpected behavior in contacting ferromagnetic layers a model is proposed based on Slonczewski's fluctuating exchange mechanism. In our samples a partial remagnetization of the hard layer creates fluctuations of the bilinear interactions. The intralayer exchange averaging of the resulting magnetization fluctuations in the soft layer causes the observed biquadratic coupling. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Inst Solid State Phys, Chernogolovka 142432, Russia. RP Vlasko-Vlasov, VK (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 15 TC 39 Z9 39 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 7 PY 2001 VL 86 IS 19 BP 4386 EP 4389 DI 10.1103/PhysRevLett.86.4386 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000049 PM 11328181 ER PT J AU Leighton, C Fitzsimmons, MR Yashar, P Hoffmann, A Nogues, J Dura, J Majkrzak, CF Schuller, IK AF Leighton, C Fitzsimmons, MR Yashar, P Hoffmann, A Nogues, J Dura, J Majkrzak, CF Schuller, IK TI Two-stage magnetization reversal in exchange biased bilayers SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNIDIRECTIONAL ANISOTROPY; FEF2-FE BILAYERS; THIN-FILMS; INTERFACES; SYSTEMS; MODEL; FERROMAGNET; COERCIVITY AB MnF2/Fe bilayers exhibit asymmetric magnetization reversal that occurs by coherent rotation on one side of the loop and by nucleation and propagation of domain walls on the other side of the loop. Here, we show by polarized neutron reflectometry, magnetization, and magnetotransport measurements that for samples with good crystalline "quality" the rotation is a two-stage process, due to coherent rotation to a stable state perpendicular to the cooling field direction. The result is remarkably asymmetrically shaped hysteresis loops. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Autonoma Barcelona, Dept Fis, Bellaterra 08193, Spain. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Leighton, C (reprint author), Univ Minnesota, Dept Chem Engn & Mat Sci, 421 Washington Ave SE, Minneapolis, MN 55455 USA. RI Dura, Joseph/B-8452-2008; Nogues, Josep/D-7791-2012; Lujan Center, LANL/G-4896-2012; Hoffmann, Axel/A-8152-2009 OI Dura, Joseph/0000-0001-6877-959X; Nogues, Josep/0000-0003-4616-1371; Hoffmann, Axel/0000-0002-1808-2767 NR 28 TC 109 Z9 110 U1 2 U2 19 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 MAY 7 PY 2001 VL 86 IS 19 BP 4394 EP 4397 DI 10.1103/PhysRevLett.86.4394 PG 4 WC Physics, Multidisciplinary SC Physics GA 430TE UT WOS:000168591000051 PM 11328183 ER PT J AU Bozell, JJ Miller, D Hames, BR Loveless, C AF Bozell, JJ Miller, D Hames, BR Loveless, C TI Stereoselective and regioselective reaction of cyclic ortho esters with phenols SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID LIGNIN MODEL COMPOUNDS; BETA-GUAIACYL ETHER; NITROGEN-DIOXIDE; THREO FORMS; OXIDATION; DIALKOXYCARBENIUM; 1,2-DIOLS; EPOXIDES; IONS AB Cyclic ortho esters undergo stereoselective and regioselective reaction with phenols when treated with BF3. OEt2 at low temperatures. Attack of the phenol on the ortho ester occurs at an open carbon pura to electron-donating groups on the phenol ("C-addition") or at the phenolic hydroxyl group ("O-addition") depending on the nature of the cation formed from reaction of the ortho ester and BF3. OEt2 Products resulting from O-addition undergo reversion to a mixture of starting phenol, C-addition product, and O-addition product if treated with BF3. OEt2 at room temperature, but e-addition products are stable under the same conditions, X-ray structural analysis of the C-addition compound. indicates that its stereochemistry is opposite to that observed in reaction of similar ortho esters with chloride from TMSCl. However, the stereochemistry of the reaction can be rationalized by the ability of the ortho ester to isomerize via an intermediate benzylic cation and examination of the preferred trajectory of attack of the nucleophile on the intermediate oxonium ion. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bozell, JJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 49 TC 5 Z9 5 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAY 4 PY 2001 VL 66 IS 9 BP 3084 EP 3089 DI 10.1021/jo005736t PG 6 WC Chemistry, Organic SC Chemistry GA 428KY UT WOS:000168461900024 PM 11325273 ER PT J AU Fowler, JS Volkow, ND Logan, J Franceschi, D Wang, GJ MacGregor, R Shea, C Garza, V Pappas, N Carter, P Netusil, N Bridge, P Liederman, D Elkashef, A Rotrosen, J Hitzemann, R AF Fowler, JS Volkow, ND Logan, J Franceschi, D Wang, GJ MacGregor, R Shea, C Garza, V Pappas, N Carter, P Netusil, N Bridge, P Liederman, D Elkashef, A Rotrosen, J Hitzemann, R TI Evidence that L-deprenyl treatment for one week does not inhibit MAO A or the dopamine transporter in the human brain SO LIFE SCIENCES LA English DT Article DE L-deprenyl; monoamine oxidase A; dopamine transporter ID MONOAMINE-OXIDASE INHIBITORS; IN-VIVO; PARKINSONS-DISEASE; STRIATAL DOPAMINE; RAT STRIATUM; B INHIBITOR; BLOOD-FLOW; LONG-TERM; SELEGILINE; BINDING AB In this study, we investigated whether treatment with L-deprenyl, a selective monoamine oxidase B (MAO B) inhibitor, also inhibits MAO A or the dopamine transporter in the human brain. Six normal volunteers (age 46 +/- 6 yrs) had two PET sessions, one at baseline and one following L-deprenyl (10 mg/day) for 1 week. Each session included one scan with [(11)C]clorgyline (to assess MAO A) and one scan 2 hours later with [(11)C]cocaine (to assess dopamine transporter availability). A 3-compartment model was used to compare the plasma-to-brain transfer constant, K, (a:function of blood flow) and Xk, (a kinetic term proportional to brain MAO A) before and after treatment. Dopamine transporter availability was measured as the ratio of distribution volumes of the striatum to cerebellum (DVR) which is equal to Bmax/K(D) + 1. L-Deprenyl treatment for 1 week did not affect either brain MAO A activity or dopamine transporter availability. There was a non-significant trend for an increase in K, after L-deprenyl. These results confirm that L-deprenyl after one week of treatment at doses typically used clinically is selective for MAO B and that it does not produce a measurable affect on the dopamine transporter, suggesting that MAO A inhibition and dopamine transporter blockade do not contribute tb its pharmacological effects. (C) 2001 Elsevier Science Inc. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Fowler, JS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM fowler@bnl.gov NR 48 TC 15 Z9 15 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0024-3205 J9 LIFE SCI JI Life Sci. PD MAY 4 PY 2001 VL 68 IS 24 BP 2759 EP 2768 DI 10.1016/S0024-3205(01)01079-7 PG 10 WC Medicine, Research & Experimental; Pharmacology & Pharmacy SC Research & Experimental Medicine; Pharmacology & Pharmacy GA 432RK UT WOS:000168709300012 PM 11400918 ER PT J AU Yusupov, MM Yusupova, GZ Baucom, A Lieberman, K Earnest, TN Cate, JHD Noller, HF AF Yusupov, MM Yusupova, GZ Baucom, A Lieberman, K Earnest, TN Cate, JHD Noller, HF TI Crystal structure of the ribosome at 5.5 angstrom resolution SO SCIENCE LA English DT Article ID ESCHERICHIA-COLI RIBOSOME; PEPTIDYL TRANSFERASE CENTER; SECONDARY STRUCTURE MODEL; TRANSFER-RNA; A-SITE; 70S RIBOSOME; P-SITE; CRYOELECTRON MICROSCOPY; CONFORMATIONAL SWITCH; THERMUS-THERMOPHILUS AB We describe the crystal structure of the complete Thermus thermophilus 70S ribosome containing bound messenger RNA and transfer RNAs (tRNAs) at 5.5 angstrom resolution. All of the 16S, 23S, and 5S ribosomal RNA (rRNA) chains, the A-, P-, and E-site tRNAs, and most of the ribosomal proteins can be fitted to the electron density map. The core of the interface between the 30S small subunit and the 50S large subunit, where the tRNA substrates are bound, is dominated by RNA, with proteins located mainly at the periphery, consistent with ribosomal function being based on rRNA. In each of the three tRNA binding sites, the ribosome contacts all of the major elements of tRNA, providing an explanation for the conservation of tRNA structure. The tRNAs are closely juxtaposed with the intersubunit bridges, in a way that suggests coupling of the 20 to 50 angstrom movements associated with tRNA translocation with intersubunit movement. C1 Univ Calif Santa Cruz, Ctr Mol Biol RNA, Sinsheimer Labs, Santa Cruz, CA 95064 USA. Lawrence Berkeley Natl Lab, Berkeley Ctr Struct Biol, Phys Biosci Div, Berkeley, CA 94720 USA. Whitehead Inst, Cambridge, MA 01242 USA. RP Noller, HF (reprint author), IGBMC, CNRS, UPR Biol & Genom Struct 9004, BP 163,1 Rue L Fries, F-67404 Illkirch, CU Strasbourg, France. RI Yusupov, Marat/I-6126-2013; Yusupova , Gulnara/E-1877-2014 OI Yusupov, Marat/0000-0001-5544-0597; NR 86 TC 1416 Z9 1503 U1 13 U2 98 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 MAY 4 PY 2001 VL 292 IS 5518 BP 883 EP 896 DI 10.1126/science.1060089 PG 14 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 429KB UT WOS:000168514900033 PM 11283358 ER PT J AU Mao, HK Xu, J Struzhkin, VV Shu, J Hemley, RJ Sturhahn, W Hu, MY Alp, EE Vocadlo, L Alfe, D Price, GD Gillan, MJ Schwoerer-Bohning, M Hausermann, D Eng, P Shen, G Giefers, H Lubbers, R Wortmann, G AF Mao, HK Xu, J Struzhkin, VV Shu, J Hemley, RJ Sturhahn, W Hu, MY Alp, EE Vocadlo, L Alfe, D Price, GD Gillan, MJ Schwoerer-Bohning, M Hausermann, D Eng, P Shen, G Giefers, H Lubbers, R Wortmann, G TI Phonon density of states of iron up to 153 gigapascals SO SCIENCE LA English DT Article ID EARTHS INNER-CORE; NUCLEAR RESONANT SCATTERING; HIGH-PRESSURE; ELASTIC-CONSTANTS; LIQUID-IRON; ALPHA-IRON; TEMPERATURES; ROTATION; MODEL AB We report phonon densities of states (DOS) of iron measured by nuclear resonant inelastic x-ray scattering to 153 gigapascals and calculated from ab initio theory. Qualitatively, they are in agreement, but the theory predicts density at higher energies. From the DOS, we derive elastic and thermodynamic parameters of iron, including shear modulus, compressional and shear velocities, heat capacity, entropy, kinetic energy, zero-point energy, and Debye temperature. In comparison to the compressional and shear velocities from the preliminary reference Earth model (PREM) seismic model, our results suggest that Earth's inner core has a mean atomic number equal to or higher than pure iron, which is consistent with an iron-nickel alloy. C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Carnegie Inst Washington, Ctr High Pressure Res, Washington, DC 20015 USA. Adv Photon Source, Argonne, IL 60439 USA. UCL, London WC1E 6BT, England. Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. Univ Paderborn, Fachbereich Phys, D-33095 Paderborn, Germany. High Pressure Collaborat Access Team, Adv Photon Source, Argonne, IL 60439 USA. RP Mao, HK (reprint author), Carnegie Inst Washington, Geophys Lab, 5251 Broad Branch Rd NW, Washington, DC 20015 USA. RI Alfe`, Dario/C-1521-2008; Price, Geoffrey/C-1545-2008; Gillan, Michael/C-2130-2008; Vocadlo, Lidunka/C-4197-2008; Shen, Guoyin/D-6527-2011; Struzhkin, Viktor/J-9847-2013 OI Alfe`, Dario/0000-0002-9741-8678; Price, Geoffrey/0000-0001-8232-6853; Struzhkin, Viktor/0000-0002-3468-0548 NR 36 TC 197 Z9 203 U1 7 U2 46 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 MAY 4 PY 2001 VL 292 IS 5518 BP 914 EP 916 DI 10.1126/science.1057670 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 429KB UT WOS:000168514900039 PM 11340201 ER PT J AU Pecharsky, VK Gschneidner, KA AF Pecharsky, VK Gschneidner, KA TI Gd-5(SixGe1-x)(4): An extremum material SO ADVANCED MATERIALS LA English DT Article ID ADIABATIC TEMPERATURE-CHANGE; MAGNETIC-FIELD; ELECTRICAL-RESISTANCE; PHASE-TRANSITION; GIANT; GD-5(SI2GE2); MAGNETORESISTANCE; GD-5(SI1.8GE2.2); REFRIGERATION; GD5SI2GE2 AB The large shear displacements of atomic layers in Gd-5(SixGe1-(x))(4) materials, coupled with the change of crystallographic symmetry and magnetic order, characterizes these transformations as magnetic-martensitic, which are extremely rare. The start and the end of the magnetic-martensitic transitions depends strongly on the direction of change (i.e., increasing or decreasing) of either or both the temperature and magnetic field. These profound bonding, structural, electronic, and magnetic changes, which occur in the Gd-5(SixGe1-(x)) system, bring about some extreme changes of the materials' behavior resulting in a rich variety of unusually powerful magneto-responsive properties, such as the giant magnetocaloric effect, colossal magnetostriction, and giant magnetoresistance. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Pecharsky, VK (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 25 TC 200 Z9 211 U1 6 U2 59 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD MAY 3 PY 2001 VL 13 IS 9 BP 683 EP 686 DI 10.1002/1521-4095(200105)13:9<683::AID-ADMA683>3.0.CO;2-O PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 431KR UT WOS:000168630800017 ER PT J AU Hodgson, D Zhang, HY Nimlos, MR McKinnon, JT AF Hodgson, D Zhang, HY Nimlos, MR McKinnon, JT TI Quantum chemical and RRKM investigation of the elementary channels of the reaction C6H6+O(P-3) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; TRANSITION-STATES; AB-INITIO; ATMOSPHERIC CHEMISTRY; HYDROGEN-ATOM; GAS-PHASE; BENZENE; ENERGY; COMBUSTION; TOLUENE AB We performed a computational study of an important reaction in the combustion of hydrocarbons, C6H6, + O (P-3), using ab initio and RRKM methods. Density functional theory (B3LYP) was used to optimize geometries and obtain molecular vibrational frequencies. and complete basis set extrapolation (CBS-QB3) was used to obtain the energies for the reactants several transition states and products. The initial formation of a stabilized adduct is characterized by a barrier of 4.9 kcal mol(-1), in good agreement with the measured activation energy for this reaction. All product channels originate from rearrangement or decomposition of this adduct, which our calculations suggest is a triplet ground state, All of our ab initio calculations are thus conducted on the triplet surface. There are several products that are energetically accessible at combustion temperatures, but the formation of phenoxy radical, C6H5O, and H atom dominate the product slate at low temperatures. Rearrangement to form formylcyclopentadiene, C5H5CHO, is also important at low temperatures, and the decomposition of this species to form cyclopentadienyl radical, C5H5, and HCO may be significant at higher temperatures. Rearrangement to form phenol is unimportant at all temperatures. C1 Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP McKinnon, JT (reprint author), Colorado Sch Mines, Dept Chem Engn, Golden, CO 80401 USA. NR 68 TC 28 Z9 28 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 MAY 3 PY 2001 VL 105 IS 17 BP 4316 EP 4327 DI 10.1021/jp004134a PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 428BT UT WOS:000168441800021 ER PT J AU Wilson, KR Rude, BS Catalano, T Schaller, RD Tobin, JG Co, DT Saykally, RJ AF Wilson, KR Rude, BS Catalano, T Schaller, RD Tobin, JG Co, DT Saykally, RJ TI X-ray spectroscopy of liquid water microjets SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID ABSORPTION FINE-STRUCTURE; MOLECULAR-DYNAMICS; VAPOR INTERFACE; EXCITATION; H2O AB We present the first results from studies of Liquid water microjets by soft X-ray absorption spectroscopy. Near the oxygen K-edge (similar to 530 eV) a fine-structure pattern very similar to that found for gaseous water monomers is observed when the surface-selective total ion yield (TIY) is measured, but a broadened and blue-shifted spectrum emerges when detecting the bulk-sensitive total electron yield (TEY). TIY EXAFS measurements produce a nearest neighbor O-O distance for surface molecules (3.00 Angstrom) slightly longer than that of the isolated water dimer (2.98 Angstrom), whereas the O-O distance extracted from TEY EXAFS corresponds to that accepted for bulk water (2.85 Angstrom). Together, these results evidence an equilibrium liquid water surface dominated by water molecules interacting weakly at longer distances than in the bulk, thus supporting predictions from computer simulations. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Saykally, RJ (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Tobin, James/O-6953-2015; OI Co, Dick/0000-0003-0698-3004 NR 20 TC 112 Z9 112 U1 1 U2 30 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 MAY 3 PY 2001 VL 105 IS 17 BP 3346 EP 3349 DI 10.1021/jp010132u PG 4 WC Chemistry, Physical SC Chemistry GA 428BW UT WOS:000168442100002 ER PT J AU Lee, CT Johnston, KP Dai, HJ Cochran, HD Melnichenko, YB Wignall, GD AF Lee, CT Johnston, KP Dai, HJ Cochran, HD Melnichenko, YB Wignall, GD TI Droplet interactions in water-in-carbon dioxide microemulsions near the critical point: A small-angle neutron scattering study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID OIL MICROEMULSIONS; WATER-IN-CO2 MICROEMULSIONS; CRITICAL-BEHAVIOR; ORGANIC-SYNTHESIS; PERCOLATION; SURFACTANT; EMULSIONS; MICELLES; ENVIRONMENT; SYSTEMS AB Droplet interactions in water-in-carbon dioxide (W/C) microemulsions formed with a perfluoropolyether-based surfactant for droplet volume fractions from 0.05 to 0.10 are studied with small-angle neutron scattering (SANS) to understand the mechanism of microemulsion stability. The water-to-surfactant ratio (W-o) is fixed at 12.5. Droplet interactions increase as the upper critical solution pressure is approached with decreasing pressure at constant. temperature, increasing temperature at constant pressure, or increasing droplet: volume fraction. These interactions are quantified in terms of the structure factor at zero momentum vector, S(0), and the correlation length, xi, for an Omstein-Zernicke structure factor, or the square-well depth for the structure factor of a square-well potential. Near the critical solution pressure, the interaction strength (il) approaches the value predicted for a hard-sphere fluid with a van der Waals attractive term. The observed interaction strength between droplets is larger in W/C relative to water-in-oil microemulsions due to stronger tail-tail interactions resulting from the weak solvation by CO2. Overcoming these larger droplet interactions is the key challenge in forming stable W/C microemulsions. Pressure and volume fraction have a negligible effect on the droplet size; however, drop size decreases with temperature. C1 Univ Texas, Dept Chem Engn, Austin, TX 78712 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Johnston, KP (reprint author), Univ Texas, Dept Chem Engn, Austin, TX 78712 USA. NR 51 TC 61 Z9 61 U1 0 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD MAY 3 PY 2001 VL 105 IS 17 BP 3540 EP 3548 DI 10.1021/jp0033059 PG 9 WC Chemistry, Physical SC Chemistry GA 428BW UT WOS:000168442100027 ER PT J AU Greenbaum, E Blankinship, SL Lee, JW Ford, RM AF Greenbaum, E Blankinship, SL Lee, JW Ford, RM TI Solar photobiochemistry: Simultaneous photoproduction of hydrogen and oxygen in a confined bioreactor SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHLAMYDOMONAS-REINHARDTII; ATMOSPHERE AB Simultaneous photoevolution of hydrogen and oxygen by an aqueous suspension of the unicellular green alga Chlamydomonas reinhardii was measured in a confined bioreactor. The headspace above the liquid was about three times the volume of the liquid. The objective of the experiments was to determine the extent to which Henry's Law partitioning between the liquid and gas phases of the reactor volume can be used to minimize the antagonistic effect of photosynthetically produced oxygen on the evolution of molecular hydrogen by photosynthesis. The results indicate, to within upper limits, that light-driven oxygen and hydrogen produced by microalgal water oxidation in the aqueous phase can partition favorably into the gas phase such that photosynthetically produced oxygen does not inhibit the hydrogenase enzyme. Continual cycles of light-driven hydrogen and oxygen production, with intervals of added gas-phase carbon dioxide for rejuvenating the algae, were performed for about 60 days on the same culture. Absolute yields of hydrogen and oxygen plus computed stoichiometric ratios are reported. The average stoichiometric ratio of hydrogen to oxygen was 2.8, indicating that reducing equivalents for molecular hydrogen were derived from endogenous reductants, most likely starch, as well as water. Additional experiments on the effect of illumination and dwell time on hydrogen and oxygen yields are presented, as are "before" and "after" photomicrographs of the algae, illustrating the effects of prolonged anaerobiosis on the cells. A mathematical model of gas formation in the liquid phase and its equilibrium with the headspace above the liquid is presented. An estimate of the mass transfer coefficient on movement of oxygen from the liquid phase into the gas phase yielded a time constant of less than 2 s. This characteristic time is much shorter than the time scale over which the accumulated yields of hydrogen and oxygen are measured. The data suggest that Henry's Law partitioning may be a rational approach to addressing the issue of oxygen sensitivity of algal hydrogen production, especially when combined with C. reinhardtii mutants that are selected for improved oxygen tolerance. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. Univ Virginia, Dept Chem Engn, Charlottesville, VA 22904 USA. RP Greenbaum, E (reprint author), Oak Ridge Natl Lab, Div Chem Technol, POB 2008, Oak Ridge, TN 37831 USA. NR 18 TC 13 Z9 13 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 MAY 3 PY 2001 VL 105 IS 17 BP 3605 EP 3609 DI 10.1021/jp0042821 PG 5 WC Chemistry, Physical SC Chemistry GA 428BW UT WOS:000168442100035 ER PT J AU Fryer, C Woosley, S AF Fryer, C Woosley, S TI Astronomy - A new twist on neutron stars SO NATURE LA English DT Editorial Material ID ROTATING RELATIVISTIC STARS; GAMMA-RAY BURSTS; EXPLOSIONS; SUPERNOVAE C1 Univ Calif Los Alamos Natl Lab, Dept Theoret Astrophys, Los Alamos, NM 87545 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Fryer, C (reprint author), Univ Calif Los Alamos Natl Lab, Dept Theoret Astrophys, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 4 Z9 4 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 MAY 3 PY 2001 VL 411 IS 6833 BP 31 EP 34 DI 10.1038/35075184 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 427XY UT WOS:000168432800027 PM 11333959 ER PT J AU Muggli, P Lee, S Katsouleas, T Assmann, R Decker, FJ Hogan, MJ Iverson, R Raimondi, P Siemann, RH Walz, D Blue, B Clayton, CE Dodd, E Fonseca, RA Hemker, R Joshi, C Marsh, KA Mori, WB Wang, SQ AF Muggli, P Lee, S Katsouleas, T Assmann, R Decker, FJ Hogan, MJ Iverson, R Raimondi, P Siemann, RH Walz, D Blue, B Clayton, CE Dodd, E Fonseca, RA Hemker, R Joshi, C Marsh, KA Mori, WB Wang, SQ TI Boundary effects - Refractioin of a particle beam SO NATURE LA English DT Article ID LASER C1 Univ So Calif, Los Angeles, CA 90089 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RP Muggli, P (reprint author), Univ So Calif, Los Angeles, CA 90089 USA. RI Fonseca, Ricardo/B-7680-2009; Assmann, Ralph/L-8457-2016 OI Fonseca, Ricardo/0000-0001-6342-6226; NR 7 TC 20 Z9 20 U1 0 U2 4 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 3 PY 2001 VL 411 IS 6833 BP 43 EP 43 DI 10.1038/35075144 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 427XY UT WOS:000168432800035 PM 11333969 ER PT J AU He, T Huang, Q Ramirez, AP Wang, Y Regan, KA Rogado, N Hayward, MA Haas, MK Slusky, JS Inumara, K Zandbergen, HW Ong, NP Cava, RJ AF He, T Huang, Q Ramirez, AP Wang, Y Regan, KA Rogado, N Hayward, MA Haas, MK Slusky, JS Inumara, K Zandbergen, HW Ong, NP Cava, RJ TI Superconductivity in the non-oxide perovskite MgCNi3 SO NATURE LA English DT Article ID TEMPERATURE AB The interplay of magnetic interactions, the dimensionality of the crystal structure and electronic correlations in producing superconductivity is one of the dominant themes in the study of the electronic properties of complex materials. Although magnetic interactions and two-dimensional structures were long thought to be detrimental to the formation of a superconducting state, they are actually common features of both the high transition-temperature (T-c) copper oxides and low-T-c material Sr2RuO4, where they appear to be essential contributors to the exotic electronic states of these materials(1). Here we report that the perovskite-structured compound MgCNi3 is superconducting with a critical temperature of 8 K. This material is the three-dimensional analogue of the LnNi(2)B(2)C family of superconductors, which have critical temperatures up to 16 K (ref. 2). The itinerant electrons in both families of materials arise from the partial filling of the nickel d-states, which generally leads to ferromagnetism as is the case in metallic Ni. The high relative proportion of Ni in MgCNi3 suggests that magnetic interactions are important, and the lower T-c of this three-dimensional compound-when compared to the LnNi(2)B(2)C family-contrasts with conventional ideas regarding the origins of superconductivity. C1 Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. Princeton Univ, Princeton Mat Inst, Princeton, NJ 08544 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Maryland, Dept Mat & Nucl Engn, College Pk, MD 20742 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Calif Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM USA. RP Cava, RJ (reprint author), Princeton Univ, Dept Chem, Princeton, NJ 08544 USA. RI Inumaru, Kei/J-9292-2015; OI Hayward, Michael/0000-0002-6248-2063 NR 8 TC 385 Z9 393 U1 13 U2 76 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 3 PY 2001 VL 411 IS 6833 BP 54 EP 56 DI 10.1038/35075014 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 427XY UT WOS:000168432800039 PM 11333973 ER PT J AU Amro, H Varmette, PG Ma, WC Herskind, B Hagemann, GB Sletten, G Janssens, RVF Bergstrom, M Bracco, A Carpenter, M Domscheit, J Frattini, S Hartley, DJ Hubel, H Khoo, TL Kondev, F Lauritsen, T Lister, CJ Million, B Odegard, SW Piercey, RB Riedinger, LL Schmidt, KA Siem, S Wiedenhover, I Wilson, JN Winger, JA AF Amro, H Varmette, PG Ma, WC Herskind, B Hagemann, GB Sletten, G Janssens, RVF Bergstrom, M Bracco, A Carpenter, M Domscheit, J Frattini, S Hartley, DJ Hubel, H Khoo, TL Kondev, F Lauritsen, T Lister, CJ Million, B Odegard, SW Piercey, RB Riedinger, LL Schmidt, KA Siem, S Wiedenhover, I Wilson, JN Winger, JA TI First evidence for triaxial superdeformation in Hf-168 SO PHYSICS LETTERS B LA English DT Article DE triaxial superdeformed structures; lifetime measurements; potential energy surface calculations ID LIFETIME MEASUREMENTS; HIGH-SPIN; BANDS; CRANKING; STATES; LU-163 AB Three superdeformed (SD) bands have been found in Hf-168. Lifetime measurements revealed a large quadrupole moment, Q(t) similar to 11.4 e b, for the strongest band (TSD1). Theoretical calculations using the Ultimate Cranker code predict high-spin SD minima (epsilon (2) similar to 0.43) with stable triaxial deformations of gamma similar to +20 degrees and gamma similar to -15 degrees. The measured Q(t) value suggests that band TSD1 corresponds, most likely, to a deformation with a positive gamma value. This constitutes the first evidence for triaxial superdeformation in an even proton system. (C) 2001 Published by Elsevier Science B.V. C1 Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Milan, Dipartimento Fis, I-20122 Milan, Italy. Univ Bonn, Inst Strahlen & Kernphys, D-53115 Bonn, Germany. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. RP Amro, H (reprint author), Mississippi State Univ, Dept Phys & Astron, Mississippi State, MS 39762 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 22 TC 63 Z9 65 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 MAY 3 PY 2001 VL 506 IS 1-2 BP 39 EP 44 DI 10.1016/S0370-2693(01)00369-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 430NJ UT WOS:000168579900006 ER PT J AU Fryzuk, MD Johnson, SA Patrick, BO Albinati, A Mason, SA Koetzle, TF AF Fryzuk, MD Johnson, SA Patrick, BO Albinati, A Mason, SA Koetzle, TF TI New mode of coordination for the dinitrogen ligand: Formation, bonding, and reactivity of a tantalum complex with a bridging N-2 unit that is both side-on and end-on SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL COMPLEXES; P2N2 = PHP(CH2SIME2NSIME2CH2)(2)PPH; X-RAY STRUCTURE; MOLECULAR-STRUCTURES; NITROGEN-FIXATION; CRYSTAL-STRUCTURE; CHEMISTRY; CLEAVAGE; ACTIVATION; COMPOUND AB The reaction of a mixture of 1 equiv of PhPH2 and 2 equiv of PhNHSiMe2CH2Cl with 4 equiv of (BuLi)-Li-n followed by the addition of THF generates the lithiated ligand precursor [NPN]Li-2. (TKF)2(where [NPN] = PhP(CH2SiMe2NPh)(2)). The reaction of [NPN]Li-2. (THF)(2) with TaMe3Cl2 produces [NPN]TaMe3, which reacts under HZ to yield the diamagnetic dinuclear Ta(IV! tetrahydride ([NPN]Ta)(2)(mu -H)4 This hydride reacts with N-2 with the loss of H-2 to produce ([NPN]Ta(mu -H))(2)(mu-eta (1):eta (2)-N-2), which was characterized both in solution and in the solid state, and contains strongly activated Nz bound in the unprecedented side-on end-on dinuclear bonding mode. A density functional theory calculation on the model complex [(H3P)(H2N)(2)Ta(mu -H)](2)-mu-eta (1):eta (2)-N-2) provides insight into the molecular orbital interactions involved in the side-on end-on bonding mode of dinitrogen. The reaction of ([NPN]Ta(mu -H))(2)(mu-eta (1):eta (2)-N-2) with propene generates the end-on bound dinitrogen complex ([NPN]Ta(CH2CH2CH3))(2)(mu-eta (1):eta (1)-N-2), and the reaction of [NPN]Li-2. (THF)(2) with NbCl3-(DME) generates the end-on bound dinitrogen complex ([NPN]NbCl)(2)(mu-eta (1):eta (1)-N-2). These two end-on bound dinitrogen complexes provide evidence that the bridging hydride ligands are responsible for the unusual bonding mode of dinitrogen in ([NPN]Ta(mu -H))(2)(mu-eta (1):eta (2)-N-2). The dinitrogen moiety in the side-on end-on mode is amenable to functionalization; the reaction of ([NPN]Ta(mu -H))(2)(mu-eta (1):eta (2)-N-2) with PhCH2Br results in C-N bond formation to yield [NPN]Ta(mu-eta (1):eta (2)-N2CH2Ph)(mu -H)(2)TaBr[NPN]. Nitrogen-15 NMR spectral data an provided for all the tantalum-dinitrogen complexes and derivatives described. C1 Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada. Univ Milan, Ist Chim Farmaceut, I-20131 Milan, Italy. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Fryzuk, MD (reprint author), Univ British Columbia, Dept Chem, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada. RI mason, sax /E-6738-2011; Johnson, Samuel/M-8167-2013; Fryzuk, Michael/B-7440-2015; Albinati, Alberto/I-1262-2015 OI Johnson, Samuel/0000-0001-6856-0416; Albinati, Alberto/0000-0002-8779-3327 NR 91 TC 125 Z9 125 U1 6 U2 35 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 MAY 2 PY 2001 VL 123 IS 17 BP 3960 EP 3973 DI 10.1021/ja0041371 PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 428CC UT WOS:000168442700013 PM 11457146 ER PT J AU Wesolowski, SS Leininger, ML Pentchev, PN Schaefer, HF AF Wesolowski, SS Leininger, ML Pentchev, PN Schaefer, HF TI Electron affinities of the DNA and RNA bases SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DENSITY-FUNCTIONAL THEORY; GAUSSIAN BASIS FUNCTIONS; THEORETICAL AB-INITIO; ATOMIC BASIS SETS; FIRST-ROW ATOMS; REDUCTION POTENTIALS; MOLECULAR CALCULATIONS; IONIZATION-POTENTIALS; NEGATIVE-IONS; THYMINE AB Adiabatic electron affinities (AEAs) for the DNA and RNA bases are predicted by using a range of density functionals with a double-zeta plus polarization plus diffuse (DZP++) basis set in an effort to bracket the true EAs. Although the AEAs exhibit moderate fluctuations with respect to the choice of functional, systematic trends show that the covalent uracil (U) and thymine (T) anions are bound by 0.05-0.25 eV while the adenine (A) anion is clearly unbound. The computed AEAs for cytosine (C) and guanine (G) oscillate between small positive and negative values for the three most reliable functional combinations (BP86, B3LYP, and BLYP), and it remains unclear if either covalent anion is bound. AEAs with B3LYP/TZ2P++ single points are 0.19 (U), 0.16 (T), 0.07 (G), -0.02 (C), and -0.17 eV (A.). Favorable comparisons are made to experimental estimates extrapolated from photoelectron spectra data for the complexes of the nucleobases with water. However, experimental values scaled from liquid-phase reduction potentials are shown to overestimate the AEAs by as much as 1.5 eV. Because the uracil and thymine covalent EAs are in energy ranges near those of their dipole-bound counterparts, preparation and precise experimental measurement of the thermodynamically stable covalent anions may prove challenging. C1 Univ Georgia, Ctr Computat Quantum Chem, Athens, GA 30602 USA. Sandia Natl Labs, Livermore, CA 94551 USA. Paisij Hilendarski Univ Plovdiv, Ctr Chem Anal & Appl Spect, Plovdiv, Bulgaria. RP Schaefer, HF (reprint author), Univ Georgia, Ctr Computat Quantum Chem, Athens, GA 30602 USA. NR 47 TC 206 Z9 206 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 2 PY 2001 VL 123 IS 17 BP 4023 EP 4028 DI 10.1021/ja003814o PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 428CC UT WOS:000168442700020 PM 11457153 ER PT J AU Michelsen, HA AF Michelsen, HA TI The reaction of Cl with CH4: A connection between kinetics and dynamics SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID QUANTUM SCATTERING CALCULATIONS; LOWER ANTARCTIC STRATOSPHERE; DIFFERENTIAL CROSS-SECTIONS; POTENTIAL-ENERGY SURFACE; LARGE (CO)-C-13 DEFICIT; TRANSITION-STATE THEORY; OZONE HOLE CHEMISTRY; CL+CH4->HCL+CH3 REACTION; ATOM REACTIONS; CL+CH4-REVERSIBLE-ARROW-HCL+CH3 REACTION AB This paper presents an analysis of the reaction of Cl with CH4 by combining measurements of thermal rate constants and state-dependent reaction cross sections. State-dependent measurements have shown that the reaction probability is enhanced by vibrational excitation of CH4. Measured thermal rate constants were fit with a model incorporating this information. The results provide estimates of rate constants at extreme temperatures and information about the temperature and collision energy dependence of the vibrational enhancement. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Michelsen, HA (reprint author), Sandia Natl Labs, Combust Res Facil, MS 9055,POB 969, Livermore, CA 94551 USA. NR 76 TC 22 Z9 22 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD MAY PY 2001 VL 34 IS 5 BP 331 EP 337 DI 10.1021/ar000066z PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 436AK UT WOS:000168914200001 PM 11352711 ER PT J AU Lienert, U Poulsen, HF Kvick, A AF Lienert, U Poulsen, HF Kvick, A TI Mesoscale structural characterization within bulk materials by high-energy x-ray microdiffraction SO AIAA JOURNAL LA English DT Article ID DIFFRACTION AB A novel diffraction technique for the local three-dimensional characterization within polycrystalline bulk materials is presented. The technique uses high-energy synchrotron radiation (40 keV 2.0.CO;2 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 471WP UT WOS:000170951900003 PM 11434435 ER PT J AU Piacitelli, GM Sieber, WK O'Brien, DM Hughes, RT Glaser, RA Catalano, JD AF Piacitelli, GM Sieber, WK O'Brien, DM Hughes, RT Glaser, RA Catalano, JD TI Metalworking fluid exposures in small machine shops: an overview SO AIHAJ LA English DT Article DE machine shops; machining; metalworking fluids; oil mists; particle-size distributions; thoracic particulate ID SOLUBLE OIL DERMATITIS; METAL-WORKING FLUIDS; RESPIRATORY SYMPTOMS; AUTOMOBILE-INDUSTRY; OCCUPATIONAL ASTHMA; GRINDING FLUIDS; LUNG-FUNCTION; AUTO WORKERS; PART 2; AEROSOLS AB Sampling was conducted in 79 small machine shops to assess airborne exposures to metalworking fluids (MWFs). Measured exposures were compared with data from the literature and exposure criteria currently recommended by the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration MWF Standards Advisory Committee. Sixty-two percent of 942 personal samples collected were less than the recommended exposure limit (REL) of 0.50 mg/m(3) for total particulate. However, at least 1 sample exceeded the REL in 61 of the 79 facilities studied; 100% of the samples collected in 10 shops were greater than the REL. Similar trends were found for thoracic particulate exposures where 75% of 238 samples were below the thoracic particulate REL of 0.40 mg/m(3). The ratio between thoracic and total particulate for 238 paired samples was 0.55 (r(2) =0.73). Workers exposed to straight fluids had the highest exposures (GM=0.67 mg/m(3)) when compared with workers exposed to other classes of MWFs. The highest exposures were measured for grinding and hobbing (GM=0.67 and 0.60 mg/m(3), respectively). Measurements using personal impactors indicated that particle size distributions of MWF aerosols had an average mass median aerodynamic diameter of 5.3 mum. Straight oils and soluble fluids tended to be associated with larger particles than were other fluid types; grinding and turning produced the largest particles, whereas hobbing resulted in the smallest. In general, exposures were similar in magnitude and particle size to those previously reported in large automotive plants. Therefore, workers in these small shops may have risks of adverse health effects similar to those demonstrated in the automotive industry. C1 NIOSH, Cincinnati, OH 45226 USA. Battelle Ctr Publ Hlth, Seattle, WA 98105 USA. Battelle Ctr Evaluat, Seattle, WA 98105 USA. RP Piacitelli, GM (reprint author), NIOSH, 4676 Columbia Pkwy, Cincinnati, OH 45226 USA. NR 55 TC 36 Z9 36 U1 1 U2 5 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 USA SN 1529-8663 J9 AIHAJ JI AIHAJ PD MAY-JUN PY 2001 VL 62 IS 3 BP 356 EP 370 DI 10.1202/0002-8894(2001)062<0356:MFEISM>2.0.CO;2 PG 15 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 471WP UT WOS:000170951900010 PM 11434442 ER PT J AU Hanchar, JM Finch, RJ Hoskin, PWO Watson, EB Cherniak, DJ Mariano, AN AF Hanchar, JM Finch, RJ Hoskin, PWO Watson, EB Cherniak, DJ Mariano, AN TI Rare earth elements in synthetic zircon: Part 1. Synthesis, and rare earth element and phosphorus doping SO AMERICAN MINERALOGIST LA English DT Article ID PARTITION-COEFFICIENTS; ELECTRON-MICROPROBE; CRYSTAL-GROWTH; NATURAL ZIRCON; ION MICROPROBE; CATHODOLUMINESCENCE; GRANITES; MINERALS; ORIGIN; PB AB Zircon crystals were grown from a Li-Mo flux (7.5 mol% Li2MoO4; 86.5 mol% MoO3) to which equal molar proportions ZrO2 and Li2SiO3 were added (3 mol% each). The crystals were initially grown undoped, but later Dy was added to the flux without any other charge-compensating species. With Dy and P added, in equal molar proportions, the zircon crystals incorporated 1.37 mol% (6.99 wt%) Dy and 1.36 mol% (1.33 wt%) P, a factor of 5.3 increase in Dy over the crystals grown without P intentionally added to the flux. The other P+REE-doped zircon crystals displayed an approximately 1000-fold increase in REE and P from La through Lu, a result of decreasing ionic radii. The incorporation of P5+ allowed, in a general sense, the xenotime-type coupled substitution of (REE3+ Y3+) + P5+ = Zr4+ + Si4+. From La to Nd. however, P exceeds REE, from Sm to Gd, the REE are generally equal to P,and from Tb to Lu the REE exceed P. The Y- and P-doped zircon behaved more like middle-REE (MREE)-doped zircon than heavy-REE (HREE)-doped zircon crystals in their ability to incorporate Y (and P) and to maintain charge neutrality. To investigate: the incorporation of Dy with no P added to the flux, the P to LREE excess, and the HREE to P excess in the doped zircon, secondary ion mass spectrometry (SIMS) analyses were completed on selected crystals. In the Dy-doped crystals, the SIMS analyses revealed minor amounts of P, Li, and Mo in the crystals. These elements contributed to charge balance required by the excess Dy. In REE- and P-doped zircon, the SIMS analyses detected Li and Mo, and the Li and Mo may also provide charge balance for excess REE in the HREE+P-doped crystals. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Australian Natl Univ, Res Sch Earth Sci, Inst Adv Studies, Canberra, ACT 0200, Australia. Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY 12180 USA. RP George Washington Univ, Dept Earth & Environm Sci, Washington, DC 20052 USA. EM jhanch@gwu.edu RI Finch, Robert/D-9553-2013 OI Finch, Robert/0000-0001-9342-5574 NR 70 TC 136 Z9 141 U1 5 U2 28 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD MAY-JUN PY 2001 VL 86 IS 5-6 BP 667 EP 680 PG 14 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 430BZ UT WOS:000168554800007 ER PT J AU Finch, RJ Hanchar, JM Hoskin, PWO Burns, PC AF Finch, RJ Hanchar, JM Hoskin, PWO Burns, PC TI Rare-earth elements in synthetic zircon: Part 2. A single-crystal X-ray study of xenotime substitution SO AMERICAN MINERALOGIST LA English DT Article ID OXYGEN-ISOTOPE RATIOS; KIDD CREEK MINE; PARTITION-COEFFICIENTS; HYDROTHERMAL ALTERATION; QUARTZ PHENOCRYSTS; NATURAL ZIRCON; CRUSTAL MELTS; LIQUID; PB; CHEMISTRY AB Zircon crystals synthesized in a Li-Mo oxide melt and doped with trivalent lanthanides and Y (REE), both with and without P, were examined by single-crystal X-ray diffraction (XRD). REE are incorporated into the Zr site in the zircon structure, and some Zr appears to be displaced to the Si site. Crystals doped with middle REE (MREE, Sm to Dy) and Y, plus P follow the xenotime substitution (REE3+ + P5+ = Zr4+ + Si4+) rather closely, whereas crystals doped with heavy REE (HREE, Er to Lu) deviate from the xenotime substitution, having REE:P atomic ratios significantly greater than one. Xenotime substitution requires that P5+ replace Si4+, but this substitution becomes limited by strain at the Si sire in HREE-doped crystals. As Si sites become saturated with P5+, additional charge balance in synthetic zircon crystals may be provided by Mo6+ and Li- from the flux entering interstitial sites, accounting for an additional 0.3 to 0.6 at% HREE beyond that balanced by P5+ ions. Heavy REE are more compatible in the zircon structure than are LREE and MREE, and HREE substitution is ultimately limited by the inability of the zircon structure to further accommodate charge-compensating elements. Thus the limit on REE concentrations in zircon is not a simple function of REE3+ ionic radii but depends in a complex way on structural strain at Zr and Si sites, which act together to limit REE and P incorporation. The mechanisms that limit the coupled xenotime substitution change from LREE to HREE. This change means that REE fractionation in zircon may vary according to the availability of charge-compensating elements. REE partition coefficients between zircon and melt must also depend in part on the availability of charge-compensating elements and their compatibility in the zircon structure. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Australian Natl Univ, Inst Adv Studies, Res Sch Earth Sci, Canberra, ACT 0200, Australia. Univ Notre Dame, Dept Civil Engn & Geol Sci, Indiana, IN 46556 USA. RP Finch, RJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Finch, Robert/D-9553-2013; Burns, Peter/J-3359-2013 OI Finch, Robert/0000-0001-9342-5574; NR 47 TC 70 Z9 73 U1 2 U2 10 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD MAY-JUN PY 2001 VL 86 IS 5-6 BP 681 EP 689 PG 9 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 430BZ UT WOS:000168554800008 ER PT J AU Wilke, M Farges, F Petit, PE Brown, GE Martin, F AF Wilke, M Farges, F Petit, PE Brown, GE Martin, F TI Oxidation state and coordination of Fe in minerals: An FeK-XANES spectroscopic study SO AMERICAN MINERALOGIST LA English DT Review ID X-RAY-ABSORPTION; CRYSTAL-STRUCTURE REFINEMENT; NEAR-EDGE STRUCTURE; FE-57 MOSSBAUER-SPECTROSCOPY; ESRF BEAMLINE ID26; CATION DISTRIBUTION; FERRIC IRON; PRE-EDGE; SYNTHETIC HERCYNITE; MICROPROBE ANALYSIS AB High-resolution Fe K-edge XANES spectra of a series of crystalline Fe2+- and Fe3+-bearing model compounds were measured in an effort to correlate characteristics of the pre-edge feature with oxidation state and local coordination environment of Fe atoms. The model compounds comprise 30 natural minerals and synthetic compounds, with Fe coordination environments ranging from 4 to 12 O atoms for Fe2+, including 5-coordinated trigonal bipyramidal Fe2+, and from 4 to 6 O atoms For Fe3+. Most pre-edge spectra show two components (due to crystal-field splitting) that are located just above the Fermi level. The most useful characteristics of the Fe-K pre-edge for determining Fe oxidation state and coordination number are the position of its centroid and its integrated intensity. The separation between the average pre-edge centroid positions for Fe2+ and Fe3+ is 1.4 +/- 0.1 eV. Thus, the position of the pre-edge feature can be used as a measure of the average Fe-redox state, with the average pre edge position for mixed Fe2+-Fe3+ compounds occurring between positions for Fe2+ and Fe3+. The lowest pre-edge normalized heights and integrated intensities are observed for the most centrosymmetric sites of Fe, in agreement with previous studies (see Waychunas et al. 1983). Examination of the pre-edge features of mechanical mixtures of phases containing different proportions of Fe2+ and Fe3+ suggests that the pre-edge position and intensity for these mixtures can vary quite non-linearly with the average redox state of Fe. However, distinctly different trends of pre-edge position vs, pre-edge intensity can be observed, depending on the coordination environment of Fe2+ and Fe3+, with an accuracy in redox determination of +/- 10 mol% provided that the site geometry for each redox state is known. These methods have been used to estimate the Fe3+/Fe2+ ratio in 12 minerals (magnetite, vesuvianite, franklinite, rhodonite, etc.) containing variable/unknown amounts of Fe2+/Fe3+. C1 Univ Paris 12, Lab Geomat, F-77454 Marne La Vallee, France. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Toulouse 3, Equipe Geomarg, CNRS, UMR 5563, F-31000 Toulouse, France. RP Wilke, M (reprint author), Univ Potsdam, Inst Geowissensch, Postfach 601553, D-14415 Potsdam, Germany. RI martin, francois/B-5107-2015 NR 101 TC 535 Z9 539 U1 20 U2 193 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD MAY-JUN PY 2001 VL 86 IS 5-6 BP 714 EP 730 PG 17 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 430BZ UT WOS:000168554800012 ER PT J AU Tillib, SV Strizhkov, BN Mirzabekov, AD AF Tillib, SV Strizhkov, BN Mirzabekov, AD TI Integration of multiple PCR amplifications and DNA mutation analyses by using oligonucleotide microchip SO ANALYTICAL BIOCHEMISTRY LA English DT Article DE microarray; oligonucleotide microchip; PCR; M. tuberculosis; mutations AB We have developed a method for parallel independent on-chip amplification and the following sequence variation analysis of multiple DNA regions directly using microchip with an array of nanoliter gel pads containing specific sets of tethered primers. The method has three key features, First, DNA to be amplified is enriched at gel pads by its hybridization with immobilized primers, Second, different sets of specific primers are immobilized within various gel pads, and primers are detached within gel pads just before polymerase chain reaction to enhance the amplification. A gel pad may contain an additional permanently immobilized dormant primer that is activated to carry out the allele-specific primer extension reaction to detect mutations. Third, multiple polymerase chain reactions are confined within nanoliter gel pads covered and separated from each other with mineral oil. The method was applied to simultaneously identify several abundant drug-resistant mutations in three genes of Mycobacterium tuberculosis. (C) 2001 Academic Press. C1 Argonne Natl Lab, Biochip Technol Ctr, Argonne, IL 60439 USA. Russian Acad Sci, Engelhardt Inst Mol Biol, Moscow 119991, Russia. RP Mirzabekov, AD (reprint author), Argonne Natl Lab, Biochip Technol Ctr, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 37 Z9 44 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD MAY 1 PY 2001 VL 292 IS 1 BP 155 EP 160 DI 10.1006/abio.2001.5082 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 428YH UT WOS:000168488900021 PM 11319830 ER PT J AU Engen, JR Smith, DL AF Engen, JR Smith, DL TI Investigating protein structure and dynamics by hydrogen exchange MS SO ANALYTICAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; CRYSTAL-STRUCTURE; MUSCLE ALDOLASE; SH3 DOMAINS; RATES; EQUILIBRIUM; HCK; IDENTIFICATION; STABILITY; INHIBITOR C1 Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Engen, JR (reprint author), Univ Nebraska, Dept Chem, Lincoln, NE 68588 USA. EM dsmith7@unl.edu FU NIGMS NIH HHS [GM RO1 40,384] NR 33 TC 132 Z9 136 U1 0 U2 19 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 MAY 1 PY 2001 VL 73 IS 9 BP 256A EP 265A DI 10.1021/ac012452f PG 10 WC Chemistry, Analytical SC Chemistry GA 429LZ UT WOS:000168519800004 PM 11354508 ER PT J AU Isola, NR Allman, SL Golovlev, VV Chen, CH AF Isola, NR Allman, SL Golovlev, VV Chen, CH TI MALDI-TOF mass spectrometric method for detection of hybridized DNA oligomers SO ANALYTICAL CHEMISTRY LA English DT Article ID HIGH-DENSITY; PROBES; POLYMORPHISMS AB Two new approaches for nucleic acid hybridizations by MALDI-TOF mass spectrometry are described. Hybridization using genomic DNA without polymerase chain reaction sns demonstrated. Total genomic DNA of bacteriophages bound to charge-modified nylon membranes was identified by the hybridization of species-specific oligonucleotide probes, lambda -Phage DNA and M13 were used for the test with good success. Since MALDI-TOF mass spectrometry c;tn be used to measure the molecular weights of different probes, mass spectrometry can be used for the detection of hybridizations with multiple probes. We demonstrate that multiple-probe hybridization can be resolved by mass spectrometry.. Six probes with different mass tag were used for hybridization on a single spot. MALDI-TOF mass spectrometry was successfully used to measure these probes simultaneously. This provides a simple nonradioactive method for multiplex hybridization analysis. It has the potential to drastically increase the speed for microarray hybridization analysis hl the future. C1 Oak Ridge Natl Lab, Div Life Sci, Photophys Grp, Oak Ridge, TN 37831 USA. RP Chen, CH (reprint author), Oak Ridge Natl Lab, Div Life Sci, Photophys Grp, POB 2008, Oak Ridge, TN 37831 USA. RI Allman, Steve/A-9121-2011 OI Allman, Steve/0000-0001-6538-7048 NR 21 TC 9 Z9 9 U1 0 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 MAY 1 PY 2001 VL 73 IS 9 BP 2126 EP 2131 DI 10.1021/ac0013711 PG 6 WC Chemistry, Analytical SC Chemistry GA 429LZ UT WOS:000168519800037 PM 11354500 ER PT J AU Conrads, TP Alving, K Veenstra, TD Belov, ME Anderson, GA Anderson, DJ Lipton, MS Pasa-Tolic, L Udseth, HR Chrisler, WB Thrall, BD Smith, RD AF Conrads, TP Alving, K Veenstra, TD Belov, ME Anderson, GA Anderson, DJ Lipton, MS Pasa-Tolic, L Udseth, HR Chrisler, WB Thrall, BD Smith, RD TI Quantitative analysis of bacterial and mammalian proteomes using a combination of cysteine affinity tags and N-15-Metabolic labeling SO ANALYTICAL CHEMISTRY LA English DT Article ID RESONANCE MASS-SPECTROMETRY; LINEAR ION-TRAP; ELECTROSPRAY-IONIZATION; PROTEIN EXPRESSION; ELECTROPHORESIS AB We describe the combined use of N-15-metabolic labeling and a cysteine-reactive biotin affinity tag to isolate and quantitate cysteine-containing polypeptides (Cys-polypeptides) from Deinococcus radiodurans as well as from mouse B16 melanoma cells. D, radiodurans were cultured in both natural isotopic abundance and N-15-enriched media. Equal numbers of cells from both cultures were combined and the soluble proteins extracted, This mixture of isotopically distinct proteins was derivatized using a commercially available cysteine-reactive reagent that contains a biotin group. Following trypsin digestion, the resulting modified peptides were isolated using immobilized avidin. The mixture was analyzed by capillary reversed-phase liquid chromatography (LC) on-line with ion trap mass spectrometry (RIS) as well as Fourier transform ion cyclotron resonance (FTICR) MS. The resulting spectra contain numerous pairs of Cys-polypeptides whose mass difference corresponds to the number of nitrogen atoms present in each of the peptides. Designation of Cys-polypeptide pairs is also facilitated by the distinctive isotopic distribution of the N-15-labeled peptides versus their N-14-labeled counterparts, Studies with mouse B16 cells maintained in culture allowed the observation of hundreds of isotopically distinct pairs of peptides by LC-FTICR analysis. The ratios of the areas of the pairs of isotopically distinct peptides showed the expected 1:I labeling of the N-14 arid N-15 versions of each peptide. An additional benefit from the present strategy Is that the N-15-labeled peptides do not display significant isotope-dependent chromatographic shifts from their N-14-labeled counterparts, therefore improving the precision for quantitating peptide abundances. The methodology presented offers an alternate, cost-effective strategy for conducting global, quantitative proteomic measurements. C1 Pacific NW Natl Lab, Mol Biosci Dept, Richland, WA 99352 USA. Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Mol Biosci Dept, POB 999,MSIN K8-98, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA86340] NR 27 TC 220 Z9 228 U1 0 U2 19 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 MAY 1 PY 2001 VL 73 IS 9 BP 2132 EP 2139 DI 10.1021/ac001487x PG 8 WC Chemistry, Analytical SC Chemistry GA 429LZ UT WOS:000168519800038 PM 11354501 ER PT J AU Cisale, HO Fischman, ML Blasi, CD Fernandez, HA Gledhill, BL AF Cisale, HO Fischman, ML Blasi, CD Fernandez, HA Gledhill, BL TI Enrichment of high-quality spermatozoa in bovine semen: relative effectiveness of three filtration matrixes SO ANDROLOGIA LA English DT Article DE bull; column filtration; semen quality ID GLASS WOOL FILTRATION; GRADIENT CENTRIFUGATION; PERCOLL GRADIENTS; BEAD COLUMN; SEPARATION; SPERM; MOTILITY; INTEGRITY; EJACULATE; FERTILITY AB To be practical, any method for improving bull semen must yield a large quantity of motile spermatozoa. Some separation methods based on physical properties, e.g. filtration, chromatography, centrifugation, washing and pooling, have been reported as satisfactory, but generally are not repeatable. Nevertheless, filtration methods appear to allow the attainment of an acceptable number of spermatozoa, thus allowing such a technique to he introduced in the production of standard bovine semen doses for artificial insemination. The aim of this work was to evaluate systematically the relative effects: of three filtration matrixes (silica oxide, glass beads or Sephadex (TM)) on the improvement of whole ejaculate quality. Analysis of the type of matrix and the volume and height of the filtration column was performed. The only characteristic of the columns that appears to influence ejaculate quality after filtering is the matrix volume. While all matrixes: produced improvement of semen quality, Sephadex (TM) was better than the other matrixes tested. An explanation for the mechanism of column filtration is proposed. C1 Univ Buenos Aires, Fac Cs Vet, Lab Espermatol, Area Fis Biol, RA-1427 Buenos Aires, DF, Argentina. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. City Coll San Francisco, Natl ATE Ctr Biotechnol Educ, Bio Link, San Francisco, CA USA. RP Cisale, HO (reprint author), Univ Buenos Aires, Fac Cs Vet, Lab Espermatol, Area Fis Biol, Chorroarin 280, RA-1427 Buenos Aires, DF, Argentina. NR 45 TC 6 Z9 6 U1 0 U2 2 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0303-4569 J9 ANDROLOGIA JI Andrologia PD MAY PY 2001 VL 33 IS 3 BP 143 EP 150 DI 10.1046/j.1439-0272.2001.00413.x PG 8 WC Andrology SC Endocrinology & Metabolism GA 438TE UT WOS:000169069700003 PM 11380329 ER PT J AU Ni, J Zhang, XS Scurlock, JMO AF Ni, J Zhang, XS Scurlock, JMO TI Synthesis and analysis of biomass and net primary productivity in Chinese forests SO ANNALS OF FOREST SCIENCE LA English DT Article DE biomass measurement; Chinese forests; environmental factors; estimate and comparison of net primary productivity; spatial patterns ID GLOBAL CLIMATE-CHANGE; CARBON; MODEL; VEGETATION; RESPONSES; STORAGE; SOUTH AB An extant dataset is presented on biomass and net primary productivity (NPP) of 6 forest biomes, including 690 stands from 17 forest types of China. Data on latitude, longitude, elevation, field measurements of stand age, leaf area index (LAI) and total biomass were collected for 29 provinces from forestry inventory data of the Forestry Ministry of China, as well as a wide range of published literature. The individual site-based NPP was estimated from field biomass measurements based on a common methodology. The range of measured LAI, biomass and estimated NPP is from 0.17 to 41.78 m(2) m(-2) (mean = 8.94), from 31.14 to 1569.85 t ha(-1) (means = 185.41), and from 2.41 to 40.27 t ha(-1) yr(-1) (mean = 14.4), respectively. Analyses and synthesis between NPP and environmental factors showed that, in eastern China, NPP of forests increases from north to south, whereas NPP of major forests in southern China decreases in relation to longitude from east to west. In mountainous areas, the distribution of NPP is related to elevation. On a regional basis, the NPP of Chinese forests is highly correlated with annual mean temperature and rainfall, as well as the annual potential evapotranspiration, especially on the basis of site-based comparison. Strong positive correlation also existed between NPP and growing degree-days on a 0 degreesC base and on a 5 degreesC base. These all indicated that temperature and moisture are the dominant factors controlling the spatial distribution of NPP in China. A site-based comparison between estimated NPP and NPP modelled by the BIOME3 model showed a fair agreement with a linear regression. A higher correlation occurred in the forest-based comparison between estimated and modelled NPP, whereas the highest correlation was found in the plant functional type (PFT)-based comparison. However, there are many limitations in the current data set and methodologies, such as the lack of some components of biomass and NPP, especially with respect to root production. More detailed field measurements and methodologies covering all components of NPP should be addressed in China in the future. C1 Chinese Acad Sci, Inst Bot, Lab Quantitat Vegetat Ecol, Beijing 100093, Peoples R China. Univ Lund, Dept Ecol, S-22362 Lund, Sweden. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Ni, J (reprint author), Chinese Acad Sci, Inst Bot, Lab Quantitat Vegetat Ecol, Xiangshan Nanxincun 20, Beijing 100093, Peoples R China. RI Ni, Jian/I-7067-2012 OI Ni, Jian/0000-0001-5411-7050 NR 38 TC 45 Z9 58 U1 1 U2 19 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1286-4560 J9 ANN FOR SCI JI Ann. For. Sci. PD MAY-JUN PY 2001 VL 58 IS 4 BP 351 EP 384 PG 34 WC Forestry SC Forestry GA 437GR UT WOS:000168984400002 ER PT J AU Giedt, J AF Giedt, J TI Completion of standard-like embeddings SO ANNALS OF PHYSICS LA English DT Article ID SUPERSYMMETRY BREAKING; GAUGINO CONDENSATION; ORBIFOLDS; STRINGS AB Inequivalent standard-like observable sector embeddings in Z(3) orbifolds with two discrete Wilson lines, as determined by Casas, Mondragon, and Munoz, are completed by examining all possible ways of embedding the hidden sector. The hidden sector embeddings are relevant to twisted matter in nontrivial representations of thr Standard Model and to scenarios where supersymmetry breaking is generated in a hidden sector. We find a set of 175 models which have a hidden sector gauge group which is viable for dynamical supersymmetry breaking. Only four different hidden sector gauge groups are possible in these models, (C) 2001 Academic Press. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Giedt, J (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 11 TC 39 Z9 39 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD MAY 1 PY 2001 VL 289 IS 2 BP 251 EP 265 DI 10.1006/aphy.2001.6139 PG 15 WC Physics, Multidisciplinary SC Physics GA 427DR UT WOS:000168390000005 ER PT J AU Dobrin, PB Hodgett, D Canfield, T Mrkvicka, R AF Dobrin, PB Hodgett, D Canfield, T Mrkvicka, R TI Mechanical determinants of graft kinking SO ANNALS OF VASCULAR SURGERY LA English DT Article ID VEIN GRAFTS; PATENCY; TWIST; FLOW AB Vascular grafts can be twisted inadvertently during implantation. If twisted excessively, they may kink and obstruct flow, in this study, in vitro experiments were performed to identify the mechanical factors that determine graft kinking. These included graft material, graft length, graft diameter, graft wall thickness, perfusion pressure, and flow rate. Six-millimeter-diameter saphenous veins were obtained from humans at autopsy. Six-millimeter standard-wall and 6-mm thin-wall polytetrafluoroethylene (PTFE) grafts also were obtained. Both fixed-length and stretchable PTFE grafts were examined. Grafts 15, 30, 50, and 70 cm in length were evaluated. Finally, PTFE grafts 4, 6, 8, 10, 12, and 14 mm in diameter were studied to determine the effect of diameter. The vessels were mounted horizontally in vitro and were perfused with saline at 50, 100, or 150 mmHg pressure at low (49 mL/min), medium (105 mL/min), and high (239 mL/min) flow rates. Each graft was twisted 90 degrees, then subjected to perfusion for 15 sec. Pressure and flow were interrupted, and an additional 90 degrees twist was imposed for another 15 sec. This sequence was repeated until a visible kink developed. We conclude from our results that, when constructing a bypass, particular care should be taken with vein, short grafts, thin-wall grafts, and large-diameter grafts, as these are especially susceptible to kinking. C1 Loyola Univ, Med Ctr, Dept Surg, Maywood, IL 60153 USA. Vet Affairs Edward Hines Jr Hosp, Dept Surg, Hines, IL USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Dobrin, PB (reprint author), POB 1005, Warrenville, IL 60555 USA. NR 7 TC 16 Z9 17 U1 1 U2 6 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0890-5096 J9 ANN VASC SURG JI Ann. Vasc. Surg. PD MAY PY 2001 VL 15 IS 3 BP 343 EP 349 DI 10.1007/s100160010078 PG 7 WC Surgery; Peripheral Vascular Disease SC Surgery; Cardiovascular System & Cardiology GA 438BV UT WOS:000169034600011 PM 11414086 ER PT J AU Mittler, J Essunger, P Yuen, GJ Clendeninn, N Markowitz, M Perelson, AS AF Mittler, J Essunger, P Yuen, GJ Clendeninn, N Markowitz, M Perelson, AS TI Short-term measures of relative efficacy predict longer-term reductions in human immunodeficiency virus type 1 RNA levels following nelfinavir monotherapy SO ANTIMICROBIAL AGENTS AND CHEMOTHERAPY LA English DT Article ID ACTIVE ANTIRETROVIRAL THERAPY; DYNAMICS IN-VIVO; HIV-1 INFECTION; MATHEMATICAL-ANALYSIS; PROTEASE INHIBITOR; IMMUNE FUNCTION; VIRAL-LOAD; BASE-LINE; RITONAVIR; DECAY AB We calculated the relative efficacy of treatment, defined as the rate of decline of virus levels in plasma during treatment relative to the rate of decline during highly potent combination therapy, in human immunodeficiency virus type 1 (HIV-1) patients treated for 56 days with different doses of the protease inhibitor nelfinavir, Relative efficacies based on the rate of decline of HIV-1 RNA levels in plasma over the first 14 to 21 days correlated with drug dose and viral Load reduction by day 56, Calculation of relative treatment efficacies over the first 2 to 3 weeks of treatment can allow rapid assessment of new antiretroviral agents and dosing regimens, reducing the need to keep subjects in clinical trials on monotherapy for prolonged periods of time. Relative efficacy may also serve as a measure of treatment efficacy in patients in initiating established therapies. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Washington, Dept Microbiol, Seattle, WA 98195 USA. Agouron Pharmaceut Inc, La Jolla, CA 92137 USA. Rockefeller Univ, Aaron Diamond AIDS Res Ctr, Taipei 10016, Taiwan. RP Perelson, AS (reprint author), Univ Calif Los Alamos Natl Lab, MS-K710, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR06555, R01 RR006555]; NIAID NIH HHS [P30 AI027757, R01 AI047033, AI27757, AI47033] NR 41 TC 22 Z9 22 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0066-4804 J9 ANTIMICROB AGENTS CH JI Antimicrob. Agents Chemother. PD MAY PY 2001 VL 45 IS 5 BP 1438 EP 1443 DI 10.1128/AAC.45.5.1438-1443.2001 PG 6 WC Microbiology; Pharmacology & Pharmacy SC Microbiology; Pharmacology & Pharmacy GA 424PH UT WOS:000168240300018 PM 11302807 ER PT J AU Lehman, RM Roberto, FF Earley, D Bruhn, DF Brink, SE O'Connell, SP Delwiche, ME Colwell, FS AF Lehman, RM Roberto, FF Earley, D Bruhn, DF Brink, SE O'Connell, SP Delwiche, ME Colwell, FS TI Attached and unattached bacterial communities in a 120-meter corehole in an acidic, crystalline rock aquifer SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID DEEP SUBSURFACE; MICROBIAL COMMUNITIES; ACIDOPHILIC BACTERIA; SOLID MEDIUM; GROUNDWATER; SEDIMENTS; WATER; BIODEGRADATION; CONTAMINANTS; ENUMERATION AB The bacteria colonizing geologic core sections (attached) were contrasted with those found suspended in the groundwater (unattached) by examining the microbiology of 16 depth-paired core and groundwater samples using a suite of culture-independent and culture-dependent analyses, One hundred twenty-two meters was continuously cored from a buried chalcopyrite ore hosted in a biotite-quartz-monzonite porphyry at the Mineral Park Mine near Kingman, Ariz. Every fourth 1.5-m core was acquired using microbiologically defensible methods, and these core sections were aseptically processed for characterization of the attached bacteria, Groundwater samples containing unattached bacteria were collected from the uncased corehole at depth intervals corresponding to the individual cores using an inflatable straddle packer sampler. The groundwater was acidic (pH 2.8 to 5.0), with low levels of dissolved oxygen and high concentrations of sulfate and metals, including ferrous iron, Total numbers of attached cells were less than 10(5) cells g of core material(-1) while unattached cells numbered about 10(5) cells mi of groundwater(-1). Attached and unattached acidophilic heterotrophs were observed throughout the depth profile. In contrast, acidophilic chemolithotrophs were not found attached to the rock but were commonly observed in the groundwater. Attached communities were composed of low numbers (< 40 CFU g(-1)) of neutrophilic heterotrophs that exhibited a high degree of morphologic diversity, while unattached communities contained higher numbers (ca, 10(3) CFU ml(-1)) of neutrophilic heterotrophs of limited diversity. Sulfate reducing bacteria were restricted to the deepest samples of both core and groundwater. 16S ribosomal DNA sequence analysis of attached, acidophilic isolates indicated that organisms closely related to heterotrophic, acidophilic mesophiles such as Acidiphilium organovorum and, surprisingly, to the moderately thermophilic Alicyclobacillus acidocaldarius were present. The results indicate that viable (but possibly inactive) microorganisms were present in the buried ore and that there was substantial distinction in biomass and physiological capabilities between attached and unattached populations. C1 Idaho Natl Engn & Environm Lab, Biotechnol Dept, Idaho Falls, ID 83415 USA. US Bur Mines, Twin Cities Res Ctr, Minneapolis, MN 55417 USA. RP Lehman, RM (reprint author), Idaho Natl Engn & Environm Lab, Biotechnol Dept, POB 1625, Idaho Falls, ID 83415 USA. OI Lehman, Michael/0000-0002-3391-3178 NR 47 TC 50 Z9 52 U1 0 U2 11 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 MAY PY 2001 VL 67 IS 5 BP 2095 EP 2106 DI 10.1128/AEM.67.5.2095-2106.2001 PG 12 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 428YC UT WOS:000168488400016 PM 11319087 ER PT J AU Kang, N Xu, YZ Ferraro, JR Li, WH Weng, SF Xu, DF Wu, JG Soloway, RD Xu, GX AF Kang, N Xu, YZ Ferraro, JR Li, WH Weng, SF Xu, DF Wu, JG Soloway, RD Xu, GX TI New cryogenic apparatus for FT-IR spectroscopic studies SO APPLIED SPECTROSCOPY LA English DT Article DE FT-IR spectroscopy; cryogenic; apparatus ID FOURIER SELF-DECONVOLUTION; INFRARED-SPECTROSCOPY; SPECTRA; BANDS AB Cryogenic Fourier transform infrared (PT-IR) spectroscopy, being an effective technique in improving the spectral resolution and signal-to-noise ratio, is utilized in our group. However, we have found the traditional cryogenic apparatus inconvenient in the following aspects: (1) The system does not work very well in preventing moisture/frost from condensing on the salt windows or samples. (2) The indirect way of cooling using a metal cold finger limits the efficiency of the system, We have designed a new cryogenic apparatus. The apparatus is composed of a cooling stage and a measuring stage, In the cooling stage, the sample is directly immersed in Liquid nitrogen, In the measuring stage, the sample is lifted just above the surface of liquid nitrogen, and the FT-IR spectrum is recorded. The dry cold nitrogen gas evaporated from liquid nitrogen forms a protective layer surrounding the sample and prevents moisture from condensing on the sample. Thus, neither vacuum nor salt windows are needed in cryogenic spectroscopic experiments using this method. The experimental results show that our method is effective in cryogenic FT-IR spectroscopic studies. C1 Peking Univ Univ Hong Kong Joint Lab Rare Earth M, Dept Chem, State Key Lab Rare Earth Mat Chem & Applicat, Beijing 100871, Peoples R China. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Chinese Acad Sci, Inst Chem, Beijing 100080, Peoples R China. Univ Texas, Med Branch, Galveston, TX 77550 USA. RP Wu, JG (reprint author), Peking Univ Univ Hong Kong Joint Lab Rare Earth M, Dept Chem, State Key Lab Rare Earth Mat Chem & Applicat, Beijing 100871, Peoples R China. NR 14 TC 2 Z9 2 U1 0 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAY PY 2001 VL 55 IS 5 BP 643 EP 646 DI 10.1366/0003702011952271 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 439BX UT WOS:000169091900017 ER PT J AU Nagle, RD Rowe, CL Congdon, JD AF Nagle, RD Rowe, CL Congdon, JD TI Accumulation and selective maternal transfer of contaminants in the turtle Trachemys scripta associated with coal ash deposition SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID CHELYDRA-SERPENTINA-SERPENTINA; TRACE-ELEMENT CONCENTRATIONS; STANDARD METABOLIC-RATE; COMBUSTION WASTE; RANA-CATESBEIANA; BUFO-TERRESTRIS; LARUS-ATRICILLA; SOUTHERN TOADS; LAUGHING GULL; CADMIUM AB Coal combustion wastes are enriched in a number of potentially toxic compounds and may pose risks to biota exposed to the wastes. Slider turtles (Trachemys scripta) are common inhabitants of coal ash settling basins in South Carolina, USA, where they feed on contaminated prey items and accumulate high levels of potentially toxic compounds in their tissues. Furthermore, female sliders sometimes nest in contaminated spill piles and thus may expose embryos to contaminated soils. We examined two potential pathways by which female T. scripta may influence the survivorship and quality of their offspring in a contaminated habitat: (1) nesting in contaminated soil and (2) maternal transfer of pollutants. Eggs were collected from turtles captured in coal ash-polluted or unpolluted sites; individual clutches were incubated in both ash-contaminated and uncontaminated soil in outdoor, artificial nests. Incubation in contaminated soil was associated with reduced embryo survivorship. Adult females from the polluted site accumulated high levels of As, Cd, Cr, and Se in their tissues, yet Se was the only element transferred maternally to hatchlings at relatively high levels. Hatchlings from polluted-site females exhibited reduced O-2 consumption rates compared to hatchlings from reference sites. Relatively high levels of Se transferred to hatchlings by females at the ash-polluted site might contribute to the observed differences in hatchling physiology. C1 Univ Georgia, Savannah River Ecol Lab, Reprints Dept, Aiken, SC 29802 USA. Juniata Coll, Huntingdon, PA 16652 USA. Univ Maryland, Chesapeake Biol Lab, Ctr Environm Sci, Solomons, MD 20688 USA. RP Nagle, RD (reprint author), Univ Georgia, Savannah River Ecol Lab, Reprints Dept, Drawer E, Aiken, SC 29802 USA. RI Rowe, Christopher/D-5271-2012 NR 51 TC 54 Z9 54 U1 0 U2 18 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAY PY 2001 VL 40 IS 4 BP 531 EP 536 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 426PL UT WOS:000168357500011 PM 11525496 ER PT J AU Richards, GT Fan, XH Schneider, DP Vanden Berk, DE Strauss, MA York, DG Anderson, JE Anderson, SF Annis, J Bahcall, NA Bernardi, M Briggs, JW Brinkmann, J Brunner, R Burles, S Carey, L Castander, FJ Connolly, AJ Crocker, JH Csabai, I Doi, M Finkbeiner, D Friedman, SD Frieman, JA Fukugita, M Gunn, JE Hindsley, RB Ivezic, Z Kent, S Knapp, GR Lamb, DQ Leger, RF Long, DC Loveday, J Lupton, RH McKay, TA Meiksin, A Merrelli, A Munn, JA Newberg, HJ Newcomb, M Nichol, RC Owen, R Pier, JR Pope, A Richmond, MW Rockosi, CM Schlegel, DJ Siegmund, WA Smee, S Snir, Y Stoughton, C Stubbs, C Rao, MS Szalay, AS Szokoly, GP Tremonti, C Uomoto, A Waddell, P Yanny, B Zheng, W AF Richards, GT Fan, XH Schneider, DP Vanden Berk, DE Strauss, MA York, DG Anderson, JE Anderson, SF Annis, J Bahcall, NA Bernardi, M Briggs, JW Brinkmann, J Brunner, R Burles, S Carey, L Castander, FJ Connolly, AJ Crocker, JH Csabai, I Doi, M Finkbeiner, D Friedman, SD Frieman, JA Fukugita, M Gunn, JE Hindsley, RB Ivezic, Z Kent, S Knapp, GR Lamb, DQ Leger, RF Long, DC Loveday, J Lupton, RH McKay, TA Meiksin, A Merrelli, A Munn, JA Newberg, HJ Newcomb, M Nichol, RC Owen, R Pier, JR Pope, A Richmond, MW Rockosi, CM Schlegel, DJ Siegmund, WA Smee, S Snir, Y Stoughton, C Stubbs, C Rao, MS Szalay, AS Szokoly, GP Tremonti, C Uomoto, A Waddell, P Yanny, B Zheng, W TI Colors of 2625 quasars at 0 < z < 5 measured in the Sloan Digital Sky Survey photometric system SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; quasars : general; surveys ID HIGH-REDSHIFT QUASARS; SURVEY COMMISSIONING DATA; FIELD MULTICOLOR SURVEY; HOBBY-EBERLY TELESCOPE; SPECTROSCOPIC CCD SURVEYS; OPTICALLY SELECTED QSOS; GRISM SURVEY CATALOG; STELLAR OBJECTS; LUMINOSITY FUNCTION; EQUATORIAL STRIPE AB We present an empirical investigation of the colors of quasars in the Sloan Digital Sky Survey (SDSS) photometric system. The sample studied includes 2625 quasars with SDSS photometry: 1759 quasars found during SDSS spectroscopic commissioning and SDSS follow-up observations on other telescopes, 50 matches to FIRST quasars, 573 matches to quasars from the NASA Extragalactic Database, and 243 quasars from two or more of these sources. The quasars are distributed in a wide stripe centered on 2.degrees5 the celestial equator covering similar to 529 deg(2). Positions (accurate to and SDSS magnitudes are given for 0."2) the 898 quasars known prior to SDSS spectroscopic commissioning. New SDSS quasars, which range in brightness from i* = 15.39 to the photometric magnitude limit of the survey, represent an increase of over 200% in the number of known quasars in this area of the sky. The ensemble average of the observed colors of quasars in the SDSS passbands are well represented by a power-law continuum with and are close to those predicted by previous simulations. However, the contributions a(nu) = 0.5 (f(nu) proportional to nu (alpha)) of the "small blue (or lambda 3000) bump" and other strong emission lines have a significant effect upon the colors. The color-redshift relation exhibits considerable structure, which may be of use in determining photometric redshifts for quasars from their colors alone. The range of colors at a given redshift can generally be accounted for by a range in the optical spectral index with a distribution alpha (nu) = -0.5 +/- 0.65 (95% confidence), but there is a red tail in the distribution. This tail may be a sign of internal reddening, especially since fainter objects at a given redshift tend to exhibit redder colors than the average. Finally, we show that there is a continuum of properties between quasars and Seyfert galaxies, and we test the validity of the traditional dividing line (M(B) = -23) between the two classes of active galactic nuclei. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Inst Adv Study, Princeton, NJ 08540 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Apache Point Observ, Sunspot, NM 88349 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Univ Calif Berkeley, Dept Phys & Astron, Berkeley, CA 94720 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. RP Richards, GT (reprint author), Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RI Stubbs, Christopher/C-2829-2012; Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; OI Stubbs, Christopher/0000-0003-0347-1724; McKay, Timothy/0000-0001-9036-6150; Meiksin, Avery/0000-0002-5451-9057; Csabai, Istvan/0000-0001-9232-9898 NR 71 TC 170 Z9 170 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 2001 VL 121 IS 5 BP 2308 EP 2330 DI 10.1086/320392 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 430UA UT WOS:000168592800004 ER PT J AU Castander, FJ Nichol, RC Merrelli, A Burles, S Pope, A Connolly, AJ Uomoto, A Gunn, JE Anderson, JE Annis, J Bahcall, NA Boroski, WN Brinkmann, J Carey, L Crocker, JH Csabai, I Doi, M Frieman, JA Fukugita, M Friedman, SD Hilton, EJ Hindsley, RB Ivezic, Z Kent, S Lamb, DQ Leger, RF Long, DC Loveday, J Lupton, RH Macgillivray, H Meiksin, A Munn, JA Newcomb, M Okamura, S Owen, R Pier, JR Rockosi, CM Schlegel, DJ Schneider, DP Seigmund, W Smee, S Snir, Y Starkman, L Stoughton, C Szokoly, GP Stubbs, C Rao, MS Szalay, A Thakar, AR Tremonti, C Waddell, P Yanny, B York, DG AF Castander, FJ Nichol, RC Merrelli, A Burles, S Pope, A Connolly, AJ Uomoto, A Gunn, JE Anderson, JE Annis, J Bahcall, NA Boroski, WN Brinkmann, J Carey, L Crocker, JH Csabai, I Doi, M Frieman, JA Fukugita, M Friedman, SD Hilton, EJ Hindsley, RB Ivezic, Z Kent, S Lamb, DQ Leger, RF Long, DC Loveday, J Lupton, RH Macgillivray, H Meiksin, A Munn, JA Newcomb, M Okamura, S Owen, R Pier, JR Rockosi, CM Schlegel, DJ Schneider, DP Seigmund, W Smee, S Snir, Y Starkman, L Stoughton, C Szokoly, GP Stubbs, C Rao, MS Szalay, A Thakar, AR Tremonti, C Waddell, P Yanny, B York, DG TI The first hour of extragalactic data of the Sloan Digital Sky Survey spectroscopic commissioning: The Coma cluster SO ASTRONOMICAL JOURNAL LA English DT Article DE catalogs; cosmology : observations; galaxies : clusters : individual (Coma); galaxies : fundamental parameters; methods : data analysis ID PRINCIPAL COMPONENT ANALYSIS; OLD STELLAR POPULATIONS; STAR-FORMATION HISTORY; HUBBLE-DEEP-FIELD; LUMINOSITY FUNCTION; GALAXY SPECTRA; DISTANT CLUSTERS; REDSHIFT SURVEY; RICH CLUSTERS; XMM-NEWTON AB On 1999 May 26, one of the Sloan Digital Sky Survey (SDSS) fiber-fed spectrographs saw astronomical first light. This was followed by the first spectroscopic commissioning run during the dark period of 1999 June. We present here the first hour of extragalactic spectroscopy taken during these early commissioning stages : an observation of the Coma cluster of galaxies. Our data samples the southern part of this cluster, out to a radius of 1.degrees5 (1.8 h(-1) Mpc, approximately to the virial radius) and thus fully covers the NGC 4839 group. We outline in this paper the main characteristics of the SDSS spectroscopic systems and provide redshifts and spectral classifications for 196 Coma galaxies, of which 45 redshifts are new. For the 151 galaxies in common with the literature, we find excellent agreement between our redshift determinations and the published values, e.g., for the largest homogeneous sample of galaxies in common (63 galaxies observed by Colless & Dunn) we find a mean offset of 3 km s(-1) and an rms scatter of only 24 km s(-1). As part of our analysis, we have investigated four different spectral classification algorithms : measurements of the spectral line strengths, a principal component decomposition, a wavelet analysis and the fitting of spectral synthesis models to the data. We find that these classification schemes are in broad agreement and can provide physical insight into the evolutionary histories of our cluster galaxies. We find that a significant fraction (25%) of our observed Coma galaxies show signs of recent star formation activity and that the velocity dispersion of these active galaxies (emission-line and poststarburst galaxies) is 30% larger than the absorption-line galaxies. We also find no active galaxies within the central (projected) 200 h(-1) kpc of the cluster. The spatial distribution of our Coma active galaxies is consistent with that found at higher redshift for the CNOC1 cluster survey. Beyond the core region, the fraction of bright active galaxies appears to rise slowly out to the virial radius and are randomly distributed within the cluster with no apparent correlation with the potential merger or postmerger of the NGC 4839 group. We briefly discuss possible origins of this recent galaxy star formation. C1 Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Apache Point Observ, Sunspot, NM 88349 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1117 Budapest, Hungary. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Inst Cosm Ray Res, Midori Ku, Tokyo 1888502, Japan. Inst Adv Study, Princeton, NJ 08540 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. RP Castander, FJ (reprint author), Yale Univ, POB 208101, New Haven, CT 06520 USA. RI Stubbs, Christopher/C-2829-2012; Csabai, Istvan/F-2455-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Meiksin, Avery/0000-0002-5451-9057; Csabai, Istvan/0000-0001-9232-9898 NR 65 TC 50 Z9 50 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 2001 VL 121 IS 5 BP 2331 EP 2357 DI 10.1086/320384 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 430UA UT WOS:000168592800005 ER PT J AU Blanton, MR Dalcanton, J Eisenstein, D Loveday, J Strauss, MA Rao, MS Weinberg, DH Anderson, JE Annis, J Bahcall, NA Bernardi, M Brinkmann, J Brunner, RJ Burles, S Carey, L Castander, FJ Connolly, AJ Csabai, I Doi, M Finkbeiner, D Friedman, S Frieman, JA Fukugita, M Gunn, JE Hennessy, GS Hindsley, RB Hogg, DW Ichikawa, T Ivezic, Z Kent, S Knapp, GR Lamb, DQ Leger, RF Long, DC Lupton, RH McKay, TA Meiksin, A Merelli, A Munn, JA Narayanan, V Newcomb, M Nichol, RC Okamura, S Owen, R Pier, JR Pope, A Postman, M Quinn, T Rockosi, CM Schlegel, DJ Schneider, DP Shimasaku, K Siegmund, WA Smee, S Snir, Y Stoughton, C Stubbs, C Szalay, AS Szokoly, GP Thakar, AR Tremonti, C Tucker, DL Uomoto, A Berk, DV Vogeley, MS Waddell, P Yanny, B Yasuda, N York, DG AF Blanton, MR Dalcanton, J Eisenstein, D Loveday, J Strauss, MA Rao, MS Weinberg, DH Anderson, JE Annis, J Bahcall, NA Bernardi, M Brinkmann, J Brunner, RJ Burles, S Carey, L Castander, FJ Connolly, AJ Csabai, I Doi, M Finkbeiner, D Friedman, S Frieman, JA Fukugita, M Gunn, JE Hennessy, GS Hindsley, RB Hogg, DW Ichikawa, T Ivezic, Z Kent, S Knapp, GR Lamb, DQ Leger, RF Long, DC Lupton, RH McKay, TA Meiksin, A Merelli, A Munn, JA Narayanan, V Newcomb, M Nichol, RC Okamura, S Owen, R Pier, JR Pope, A Postman, M Quinn, T Rockosi, CM Schlegel, DJ Schneider, DP Shimasaku, K Siegmund, WA Smee, S Snir, Y Stoughton, C Stubbs, C Szalay, AS Szokoly, GP Thakar, AR Tremonti, C Tucker, DL Uomoto, A Berk, DV Vogeley, MS Waddell, P Yanny, B Yasuda, N York, DG TI The luminosity function of galaxies in SDSS commissioning data SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : fundamental parameters; galaxies : photometry; galaxies : statistics ID DIGITAL SKY SURVEY; CAMPANAS REDSHIFT SURVEY; LOCAL SPACE DENSITY; SURFACE BRIGHTNESS; SPIRAL GALAXIES; BAND PHOTOMETRY; DWARF GALAXIES; FIELD; EVOLUTION; SAMPLE AB In the course of its commissioning observations, the Sloan Digital Sky Survey (SDSS) has produced one of the largest redshift samples of galaxies selected from CCD images. Using 11,275 galaxies complete to r* = 17.6 over 140 deg(2), we compute the luminosity function of galaxies in the r* band over a range (for h = 1 ). The result is well-described by a Schechter function with parameters phi (*) = (1.46 +/- 0.12) x 10(-2) h(3) Mpc(-3), M-* = -20.83 +/- 0.03, and alpha = -120 +/- 0.03. The implied luminosity density in r* is j approximate to (2.6 +/- 0.3) x 10(8)h L. Mpc(-3). We find that the surface brightness selection threshold has a negligible impact for M-r* < -18. Using subsets of the data, we measure the luminosity function in the u*, g*, i*, and z* bands as well; the slope at low luminosities ranges from = -1.35 to alpha = -1.2. We measure the bivariate distribution of r* luminosity with half-light surface brightness, intrinsic g*-r* color, and morphology. In agreement with previous studies, we find that high surface brightness, red, highly concentrated galaxies are on average more luminous than low surface brightness, blue, less concentrated galaxies. An important feature of the SDSS luminosity function is the use of Petrosian magnitudes, which measure a constant fraction of a galaxy's total light regardless of the amplitude of its surface brightness profile. If we synthesize results for R-GKC band or b(j) band using these Petrosian magnitudes, we obtain luminosity densities 2 times that found by the Las Campanas Redshift Survey in R-GKC and 1.4 times that found by the Two Degree Field Galaxy Redshift Survey in b(j). However, we are able to reproduce the luminosity functions obtained by these surveys if we also mimic their isophotal limits for defining galaxy magnitudes, which are shallower and more redshift dependent than the Petrosian magnitudes used by the SDSS. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. Univ Sussex, Sussex Astron Ctr, Brighton BN1 9QJ, E Sussex, England. Princeton Univ Observ, Princeton, NJ 08544 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Apache Point Observ, Sunspot, NM 88349 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Tokyo, Sch Sci, Res Ctr Early Universe, Tokyo 1130033, Japan. Univ Tokyo, Dept Astron, Tokyo 1130033, Japan. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Tokyo, Inst Cosm Ray Res, Tokyo 1888502, Japan. Inst Adv Study, Princeton, NJ 08540 USA. USN Observ, Washington, DC 20392 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Natl Astron Observ, Tokyo 1818588, Japan. RP Blanton, MR (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RI Stubbs, Christopher/C-2829-2012; Yasuda, Naoki/A-4355-2011; Csabai, Istvan/F-2455-2012; McKay, Timothy/C-1501-2009; OI Stubbs, Christopher/0000-0003-0347-1724; McKay, Timothy/0000-0001-9036-6150; Meiksin, Avery/0000-0002-5451-9057; Csabai, Istvan/0000-0001-9232-9898; Hogg, David/0000-0003-2866-9403 NR 63 TC 501 Z9 501 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 2001 VL 121 IS 5 BP 2358 EP 2380 DI 10.1086/320405 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 430UA UT WOS:000168592800006 ER PT J AU Hui, L Burles, S Seljak, U Rutledge, RE Magnier, E Tytler, D AF Hui, L Burles, S Seljak, U Rutledge, RE Magnier, E Tytler, D TI On estimating the QSO transmission power spectrum SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; intergalactic medium; large-scale structure of universe; methods : data analysis; quasars : absorption lines ID LY-ALPHA FOREST; PHOTOIONIZED INTERGALACTIC MEDIUM; MASS FLUCTUATIONS; REDSHIFT SURVEYS; GRAVITATIONAL COLLAPSE; VARIANCE; CLOUDS; MODEL; SPECTROSCOPY; ABSORPTION AB The Ly alpha forest has become an important tool for measuring the mass power spectrum at high redshifts (z = 2-4). A crucial intermediate step is the measurement of the transmission power spectrum. We present new methods to minimize the systematic and random errors for such a measurement and discuss their implications for observing strategies. Sources of systematic errors explored include metal line contamination and continuum fitting. We advocate the technique of trend removal in place of traditional continuum fitting: here a spectrum is normalized by its (smoothly varying) mean rather than its continuum; this method is easily automated and removes biases introduced by continuum fitting. Moreover, trend removal can be easily applied to spectra where continuum fitting is difficult, such as when the resolution or signal-to-noise ratio (S/N) is low, or for spectra at high redshifts. We further show that a measurement of the continuum power spectrum (plus a related quantity) using trend removal, from either low-redshift quasar spectra or the red side of Ly alpha, can be used to constrain the amount of spurious large-scale power introduced by the uncertain continuum and in principle allows the removal of such contamination and thereby expanding scales probed to larger ones. We also derive expressions for the shot noise bias and variance of the power spectrum estimate, taking into account the non-Poissonian nature of the shot noise and the non-Gaussianity of the cosmic fluctuations. An appropriate minimum variance weighting of the data is given. Finally, we give practical suggestions on observing strategy: the desired resolution and S/N for different purposes and instruments, as well as how to distribute one's finite observing time among quasar targets. Also discussed is the quasar spectroscopic study of the Sloan Digital Sky Survey (SDSS), which has the potential to measure the power spectrum accurate to better than 1% per mode (Deltak similar to 10(-4) s km(-1)). The techniques presented here will be useful for tackling the anticipated issues of shot noise and continuum contamination. C1 Fermi Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Inst Adv Study, Princeton, NJ 08540 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. RP Hui, L (reprint author), Inst Adv Study, Olden Lane, Princeton, NJ 08540 USA. NR 63 TC 41 Z9 41 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 15 EP 35 DI 10.1086/320436 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100003 ER PT J AU Reichart, DE Lamb, DQ Fenimore, EE Ramirez-Ruiz, E Cline, TL Hurley, K AF Reichart, DE Lamb, DQ Fenimore, EE Ramirez-Ruiz, E Cline, TL Hurley, K TI A possible Cepheid-like luminosity estimator for the long gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts ID 28 FEBRUARY 1997; 25 APRIL 1998; UNUSUAL SUPERNOVA; ERROR BOX; AFTERGLOW; CONNECTION; ENERGY; DISCOVERY; TRANSIENT; REDSHIFT AB We present a possible Cepheid-like luminosity estimator for the long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use CGRO/BATSE data for 13 bursts, Wind/Konus data for fie bursts, Ulysses/GRB data for one burst, and NEAR/XGRS data for one burst. Spectroscopic redshifts, peak fluxes, and high-resolution light curves are available for 11 of these bursts; partial information is available for the remaining nine bursts. We find that the isotropic equivalent peak luminosities L of these bursts positively correlate with a rigorously constructed measure V of the variability of their light curves. We fit to these data a model that accommodates both intrinsic scatter (statistical variance) and extrinsic scatter (sample variance). We find that L similar to V--0.9(3.3 +/-)+1.1. If one excludes GRB 980425 from the fit, on the grounds that its association with SN 1998bw at a redshift of z = 0.0085 is not secure, the luminosity estimator spans approximate to2.5 orders of magnitude in L, and the slope of the correlation between L and V is positive with a probability of 1 - (1.4 x 10(-4)) (3.8 sigma). Although GRB 980425 is excluded from this fit, its L and V values are consistent with the fitted model, which suggests that GRB 980425 may well be associated with SN 1998bw and that GRB 980425 and the cosmological bursts may share a common physical origin. If one includes GRB 980425 in the fit, the luminosity estimator spans approximate to6.3 orders of magnitude in L, and the slope of the correlation is positive with a probability of 1--(9.3 x 10(-7)) (4.9 sigma). In either case, the luminosity estimator yields best-estimate luminosities that are accurate to a factor of approximate to4, or best-estimate luminosity distances that are accurate to a factor of approximate to2. Regardless of whether GRB 980425 should be included in the fit, its light curve is unique in that it is much less variable than the other approximate to 17 light curves of bursts in our sample for which the signal-to-noise ratio is reasonably good. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Reichart, DE (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 43 TC 228 Z9 233 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 57 EP 71 DI 10.1086/320434 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100007 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, AB Vandehei, T Welch, D AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, CA Peterson, BA Popowski, P Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, AB Vandehei, T Welch, D CA MACHO Collaboration TI MACHO 96-LMC-2: Lensing of a binary source in the Large Magellanic Cloud and constraints on the lensing object SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; dark matter; gravitational lensing; stars : low-mass, brown dwarfs ID MICROLENSING EVENTS; HALO; PROJECT; STARS; DUST; CALIBRATION; PHOTOMETRY; SEARCH AB We present photometry and analysis of the microlensing alert MACHO 96-LMC-2 (event LMC-14 in an earlier paper). This event was initially detected by the MACHO Alert System and subsequently monitored by the Global Microlensing Alert Network (GMAN). The similar to3% photometry provided by the GMAN follow-up effort reveals a periodic modulation in the light curve. We attribute this to binarity of the lensed source. Microlensing fits to a rotating binary source magnified by a single lens converge on two minima, separated by Delta chi (2) similar to 1. The most significant fit X1 predicts a primary which contributes similar to 100% of the light, a dark secondary, and an orbital period (T) of similar to 9.2 days. The second fit X2 yields a binary source with two stars of roughly equal mass and luminosity and T = 21.2 days. Observations made with the Hubble Space Telescope (HST)(18) resolve stellar neighbors which contribute to the MACHO object's baseline brightness. The actual lensed object appears to lie on the upper LMC main sequence. We estimate the mass of the primary component of the binary system, M similar to 2 M-.. This helps to determine the physical size of the orbiting system and allows a measurement of the lens proper motion. For the preferred model X1, we explore the range of dark companions by assuming 0.1 M-. and 1.4 M-. objects in models X1a and X1b, respectively. We find lens velocities projected to the LMC in these models of (v) over cap (X1a) = 18.3 +/- 3.1 km s(-1) and (v) over cap = 188 + 32 km s(-1). In both these cases, a likelihood analysis suggests an LMC lens is preferred over a Galactic halo lens, although only marginally so in model X1b. We also find (v) over cap (X2) = 39.6 +/- 6.1 km s(-1) where the likelihood for the lens location is strongly dominated by the LMC disk. In all cases, the reds mass is consistent with that of an M dwarf. Additional spectra of the lensed source system are necessary to further constrain and/or refine the derived properties of the lensing object. The LMC self-lensing rate contributed by 96-LMC-2 is consistent with model self-lensing rates. Thus, even if the lens is in the LMC disk, it does not rule out the possibility of Galactic halo microlenses altogether. Finally, we emphasize the unique capability of follow-up spectroscopic observations of known microlensed LMC stars, combined with the nondetection of binary source effects, to locate lenses in the Galactic halo. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Calif San Diego, Dept Phys, San Diego, CA 92039 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. European So Observ, D-85748 Garching, Germany. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Hamilton, ON L8S 4M1, Canada. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 31 TC 31 Z9 31 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 259 EP 267 DI 10.1086/320457 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100026 ER PT J AU Deupree, RG AF Deupree, RG TI Stellar evolution with arbitrary rotation laws. IV. Survey of zero-age main-sequence models SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : evolution; stars : interiors; stars : rotation ID TURBULENT COMPRESSIBLE CONVECTION; DIFFERENTIAL ROTATION; MERIDIONAL CIRCULATION; ANGULAR-MOMENTUM; STARS; OSCILLATIONS; CORES AB A variety of fully two-dimensional, rotating zero-age main-sequence models are presented. The models include four rotation rates for each of five masses between 3 and 20 M-.. The sequence of models for each mass might be regarded as having one small, one moderate, and two fairly rapid rotations. The convective core rotation law and overshooting are determined by two-dimensional, fully implicit hydrodynamic calculations. All models exhibit convective core overshooting. The slowly rotating models show primarily radial convective motion, while the instantaneous flow patterns of the more rapidly rotating models show that the motion is primarily parallel to the rotation axis. The resulting core rotation rate may be fitted by a power law in the distance from the rotation axis, with a cutoff at small distances from the axis, at least for the moderately and rapidly rotating models. The rotation law in the radiative region external to the convective core was chosen to be uniform for the first models calculated, but some models with negative power laws were constructed. These showed that the power law could not be too steep, or the model developed a density inversion near the rotation axis because the pressure gradient must essentially balance the rotational variation, since the gradient of the gravitational potential is too shallow to aid significantly in the balance. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Deupree, RG (reprint author), Univ Calif Los Alamos Natl Lab, DX-7,MS-P947,POB 1663, Los Alamos, NM 87545 USA. NR 43 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 268 EP 277 DI 10.1086/320464 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100027 ER PT J AU Alard, C Blommaert, JADL Cesarsky, C Epchtein, N Felli, M Fouque, P Ganesh, S Genzel, R Gilmore, G Glass, IS Habing, H Omont, A Perault, M Price, S Robin, A Schultheis, M Simon, G van Loon, JT Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, C Peterson, BA Popowski, P Pratt, MR Quinn, PJ Sutherland, W Tomaney, AB Vandehei, T Welch, DL AF Alard, C Blommaert, JADL Cesarsky, C Epchtein, N Felli, M Fouque, P Ganesh, S Genzel, R Gilmore, G Glass, IS Habing, H Omont, A Perault, M Price, S Robin, A Schultheis, M Simon, G van Loon, JT Alcock, C Allsman, RA Alves, DR Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Geha, M Griest, K Lehner, MJ Marshall, SL Minniti, D Nelson, C Peterson, BA Popowski, P Pratt, MR Quinn, PJ Sutherland, W Tomaney, AB Vandehei, T Welch, DL CA ISOGAL Collaboration MACHO Collaboration TI Mass-losing semiregular variable stars in Baade's windows SO ASTROPHYSICAL JOURNAL LA English DT Article DE astronomical data bases : miscellaneous; Galaxy : bulge; infrared : stars; stars : AGB and post-AGB; stars : fundamental parameters; stars : late-type; stars : variables : other ID ASYMPTOTIC GIANT BRANCH; LONG-PERIOD VARIABLES; SHOCK-WAVE INTERPRETATION; LARGE-MAGELLANIC-CLOUD; SOUTH-GALACTIC-CAP; MIRA VARIABLES; RED GIANTS; CIRCUMSTELLAR CO; PULSATION MODE; EMISSION-LINES AB By cross-correlating the results of two recent large-scale surveys, the general properties of a well-defined sample of semiregular variable stars have been determined. ISOGAL mid-infrared photometry (7 and 15 mum) and MACHO V and R light curves are assembled for approximately 300 stars in the Baade's windows of low extinction toward the Galactic bulge. These stars are mainly giants of late M spectral type, evolving along the asymptotic giant branch (AGB). They are found to possess a wide and continuous distribution of pulsation periods and to obey an approximate log P-M-bol relation or set of such relations. Approximate mass-loss rates (M) over dot in the range of similar to 1x10(-8) to 5 x 10(-7) M-. yr(-1) are derived from ISOGAL mid-infrared photometry and models of stellar spectra adjusted for the presence of optically thin circumstellar silicate dust. Mass-loss rates depend on luminosity and pulsation period. Some stars lose mass as rapidly as short-period Mira variables but do not show Mira-like amplitudes. A period of 70 days or longer is a necessary but not sufficient condition for mass loss to occur. For AGE stars in the mass-loss ranges that we observe, the functional dependence of mass-loss rate on temperature and luminosity can be expressed as (M) over dot proportional to (TLbeta)-L-alpha, where a = -8.80(-0.24)(+0.96) and beta = + 1.74(-0.24)(+0.16), in agreement with recent theoretical predictions. If we include our mass-loss rates with a sample of extreme mass-losing AGE stars in the Large Magellanic Cloud and ignore T as a variable, we get the general result for AGE stars that (M) over dot proportional to L-2.7, valid for AGB stars with 10(-8) < (M) over dot ( 10(-4) M-. yr(-1). C1 Observ Paris, DASGAL, CNRS, UMR 335, F-75014 Paris, France. CNRS, Inst Astrophys Paris, F-75014 Paris, France. ESA, Dept Space Sci, Div Astrophys, ISO Data Ctr, E-28080 Madrid, Spain. ESO, D-85740 Garching, Germany. Observ Cote Azur, Dept Fresnel, F-06304 Nice 4, France. Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. ESO, Santiago, Chile. Phys Res Lab, Astron & Astrophys Div, Ahmedabad 380009, Gujarat, India. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. The Observatories, Inst Astron, Cambridge CB3 0HA, England. S African Astron Observ, ZA-7935 Observatory, South Africa. Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands. ENS, Lab Radioastron Millimetr, F-75005 Paris, France. CNRS, F-75005 Paris, France. AFRL, Hanscom AFB, MA 01731 USA. Observ Besancon, F-25010 Besancon, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston Creek, ACT 2611, Australia. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Calif Santa Cruz, Dept Astron, Santa Cruz, CA 95064 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Dept Phys, Hamilton, ON L8S 4M1, Canada. McMaster Univ, Dept Astron, Hamilton, ON L8S 4M1, Canada. RP Alard, C (reprint author), Observ Paris, DASGAL, CNRS, UMR 335, 21 Ave Observ, F-75014 Paris, France. RI Quinn, Peter/B-3638-2013; OI Ganesh, Shashikiran/0000-0002-7721-3827; Lehner, Matthew/0000-0003-4077-0985 NR 57 TC 52 Z9 52 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 289 EP 308 DI 10.1086/320440 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100029 ER PT J AU Bradley, PA AF Bradley, PA TI Asteroseismological constraints on the structure of the ZZ Ceti stars L19-2 and GD 165 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : evolution; stars : individual (L19-2, GD 165); stars : oscillations; white dwarfs ID DA WHITE-DWARFS; EARTH TELESCOPE OBSERVATIONS; THERMONUCLEAR REACTION-RATES; MASS-DISTRIBUTION; MAIN-SEQUENCE; EVOLUTION; MODELS; COOL; HOT; HELIUM AB This study compares the theoretical pulsation periods from an extensive grid of evolutionary DA white dwarf models with the observed periods of the ZZ Ceti white dwarfs L19-2 and GD 165, in order to constrain their internal structure. Our analysis of the rotational fine-structure splitting and comparison of our theoretical periods with observations for L19-2 and GD 165 enable us to identify the observed modes as low-order l = 1 and 2 g-modes. Because the period structure of GD 165 is quite similar to that of L19-2, we believe that the interior structure of GD 165 is similar. The short period of the l = 1 118.5 s mode of L19-2 (120.4 s mode of GD 165) implies a hydrogen layer mass of about 10(-4) M(*), independent of constraints from the other pulsation modes. Detailed model fitting shows that L19-2 has a hydrogen layer mass of 1.0 x 10(-4) M(*), a helium layer mass of 1.0 x 10(-2) M(*), a 20:80 C/O core that extends out to 0.60 M(*), a stellar mass of 0.72 M(.), and a rotation period of about 13 hr. The best-fitting models for GD 165 have a hydrogen layer mass of 1.5 to 2.0 x 10(-4) M(*), a helium layer mass of 1.5 to 2.0 x 10(-2) M(*), a 20:80 C/O core that extends out to 0.65 M(*), a stellar mass of 0.65-0.68 M(.), and a rotation period of about 58 hr. In both cases, the best-fitting models are consistent with the spectroscopic log g-value, and the seismological parallax is within 1 sigma of the observed parallax value. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bradley, PA (reprint author), Los Alamos Natl Lab, X-2,MS B220, Los Alamos, NM 87545 USA. EM pbradley@lanl.gov NR 46 TC 44 Z9 44 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY PY 2001 VL 552 IS 1 BP 326 EP 339 DI 10.1086/320454 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EX UT WOS:000168803100032 ER PT J AU Burles, S Nollett, KM Turner, MS AF Burles, S Nollett, KM Turner, MS TI Big bang nucleosynthesis predictions for precision cosmology SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; nuclear reactions, nucleosynthesis, abundances ID PRIMORDIAL HELIUM ABUNDANCE; DEUTERIUM ABUNDANCE; SPATIAL VARIATIONS; LITHIUM ABUNDANCE; REACTION-RATES; LOCAL ISM; STARS; RATIO; HE-4; UNCERTAINTIES AB The determination of the primeval deuterium abundance has opened a precision era in big bang nucleosynthesis, making accurate predictions more important than ever before. We present in analytic form new, more precise predictions for the light-element abundances and their error matrix. Using our predictions and the primeval deuterium abundance, we infer a baryon density of (3)Omega (beta)h(2) = 0.020 +/- 0.002 (95% confidence level) and find no evidence for stellar production (or destruction) of He-3 beyond burning D into He-3. Conclusions about He-4 and Li-7 currently hinge on possible systematic errors in their measurements. C1 Fermi Natl Accelerator Lab, Expt Astrophys Dept, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. CALTECH, Dept Phys, Pasadena, CA 91125 USA. Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, NASA, Batavia, IL 60510 USA. RP Burles, S (reprint author), Fermi Natl Accelerator Lab, Expt Astrophys Dept, MS 127,POB 500,500 Wilson Rd, Batavia, IL 60510 USA. OI Nollett, Kenneth/0000-0002-0671-320X NR 49 TC 335 Z9 335 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 2001 VL 552 IS 1 BP L1 EP L5 DI 10.1086/320251 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 434EY UT WOS:000168803200001 ER PT J AU Raman, S Nestor, CW Tikkanen, P AF Raman, S Nestor, CW Tikkanen, P TI Transition probability from the ground to the first-excited 2(+) state of even-even nuclides SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Review ID INELASTIC ELECTRON-SCATTERING; HIGH-SPIN STATES; PICOSECOND LIFETIME MEASUREMENTS; LOW-LYING STATES; THOMAS-FERMI APPROACH; NUCLEAR-MASS FORMULA; NEUTRON-RICH NUCLEI; FIRST 2+ STATES; REORIENTATION EFFECT MEASUREMENTS; RARE-EARTH NUCLEI AB Adopted values for the reduced electric quadrupole transition probability, B(E2)up arrow, from the ground state to the first-excited 2(+) state of even-even nuclides are given in Table I. Values of ir, the mean life of the 2(+) state; E, the energy; and B, the quadrupole deformation parameter, are also listed there. The ratio of B to the value expected from the single-particle model is presented. The intrinsic quadrupole moment, eo, is deduced from the B(E2)up arrow value. The product E x B(E2)up arrow is expressed as a percentage of the energy-weighted total and isoscalar E2 sum-rule strengths. Table II presents the data on which Table I is based, namely the experimental results for B(E2)up arrow values with quoted uncertainties. Information is also given on the quantity measured and the method used. The literature has been covered to November 2000. The adopted B(E2)up arrow values are compared in Table III with the values given by systematics and by Various theoretical models. Predictions of unmeasured B(E2)up arrow values are also given in Table III. (C) 2001 Academic Press. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Helsinki, Accelerator Lab, FIN-00014 Helsinki, Finland. RP Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 1058 TC 1048 Z9 1073 U1 5 U2 18 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X EI 1090-2090 J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD MAY PY 2001 VL 78 IS 1 BP 1 EP 128 DI 10.1006/adnd.2001.0858 PG 128 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 451BH UT WOS:000169780900001 ER PT J AU Gilmanshin, R Gulotta, M Dyer, RB Callender, RH AF Gilmanshin, R Gulotta, M Dyer, RB Callender, RH TI Structures of apomyoglobin's various acid-destabilized forms SO BIOCHEMISTRY LA English DT Article ID MOLTEN GLOBULE INTERMEDIATE; PROTEIN SECONDARY STRUCTURE; MOLAR HEAT-CAPACITY; FAST EVENTS; FOLDING INTERMEDIATE; RELAXATION DYNAMICS; INFRARED-SPECTRA; SPECTROSCOPY; PEPTIDES; ASSIGNMENT AB The structures and the cold and hot melting thermodynamics of the acid- and salt-destabilized states of horse heart apomyoglobin (apoMb), including the E (extended) and various I forms, are studied using probes of tertiary structure (tryptophan fluorescence and FTIR spectroscopy) and secondary structure (far-UV CD and FTIR spectroscopy). These forms likely resemble early structures in the folding of the largely helical protein. Both the I and E farms retain the AGH core whereby the two ends of the protein an tied together with sufficient numbers of tertiary contacts, involving a number of hydrophobic residues, to show cooperative melting, The melting thermodynamics of E and I are distinctly different, E contains no other tertiary structure and probably little other secondary structure apart from the core. The more destabilized E form appears to contain ''random" buried runs of polypeptide backbone which convert to alpha -helix in the I form(s). Most interestingly, E consists not of a single structure but is composed of a heterogeneous mixture of conformations, all showing corelike cooperative melting characteristics, and consisting presumably of varying contacts between the A portion of apomyoglobin and the G-H hairpin. These results bear on the energy landscape and structural features of the early part of apomyoglobin's folding pathway. C1 Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Callender, RH (reprint author), Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. FU NIGMS NIH HHS [GM53640, GM35183] NR 42 TC 31 Z9 31 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 1 PY 2001 VL 40 IS 17 BP 5127 EP 5136 DI 10.1021/bi002255v PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 427YV UT WOS:000168435100003 PM 11318634 ER PT J AU Gulotta, M Gilmanshin, R Buscher, TC Callender, RH Dyer, RB AF Gulotta, M Gilmanshin, R Buscher, TC Callender, RH Dyer, RB TI Core formation in apomyoglobin: Probing the upper reaches of the folding energy landscape SO BIOCHEMISTRY LA English DT Article ID MOLTEN GLOBULE INTERMEDIATE; INITIATION SITES; PEPTIDE MODELS; FAST EVENTS; PROTEIN; MYOGLOBIN; KINETICS; SECONDARY; FORMS AB An acid-destabilized form of apomyoglobin, the so-called E state, consists of a set of heterogeneous structures that are all characterized by a stable hydrophobic core composed of 30-40 residues at the intersection of the a, G, and H helices of the protein, with little other secondary structure and no other tertiary structure. Relaxation kinetics studies were carried out to characterize the dynamics of core melting and formation in this protein. The unfolding and/or refolding response is induced by a laser-induced temperature jump between the folded and unfolded forms of E, and structural changes are monitored using the infrared amide I' absorbance at 1648-1651 cm(-1) that reports on the formation of solvent-protected, native-like helix in the core and by fluorescence emission changes from apomyoglobin's Trp14, a measure of burial of the indole group of this residue. The fluorescence kinetics data are monoexponential with a relaxation time of 14 mus. However, infrared kinetics data are best fit to a biexponential function with relaxation times of 14 and 59 mus. These relaxation times are very fast, close to the limits placed on folding reactions by diffusion. The 14 mus relaxation time is weakly temperature dependent and thus represents a pathway that is energetically downhill. The appearance of this relaxation time in both the fluorescence and infrared measurements indicates that this folding event proceeds by a concomitant formation of compact secondary and tertiary structures. The 59,mus relaxation time is much more strongly temperature dependent and has no fluorescence counterpart, indicating an activated process with a large energy barrier wherein nonspecific hydrophobic interactions between helix A and the G and H helices cause some helix burial but Trp14 remains solvent exposed. These results are best fit by a multiple-pathway kinetic model when U collapses to form the various folded core structures of E, Thus, the results suggest very robust dynamics for core formation involving multiple folding pathways and provide significant insight into the primary processes of protein folding. C1 Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Callender, RH (reprint author), Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. FU NIGMS NIH HHS [GM35183, GM53640] NR 24 TC 34 Z9 34 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 1 PY 2001 VL 40 IS 17 BP 5137 EP 5143 DI 10.1021/bi002256n PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 427YV UT WOS:000168435100004 PM 11318635 ER PT J AU Franzen, S Bailey, J Dyer, RB Woodruff, WH Hu, RB Thomas, MR Boxer, SG AF Franzen, S Bailey, J Dyer, RB Woodruff, WH Hu, RB Thomas, MR Boxer, SG TI A photolysis-triggered heme ligand switch in H93G myoglobin SO BIOCHEMISTRY LA English DT Article ID RESONANCE RAMAN-SPECTROSCOPY; SOLUBLE GUANYLATE-CYCLASE; CYTOCHROME-C PEROXIDASE; CARBON-MONOXIDE; INFRARED-SPECTROSCOPY; TRANSCRIPTION FACTOR; PROXIMAL LIGAND; NITRIC-OXIDE; BINDING; COOA AB Resonance Raman spectroscopy and step-scan Fourier transform infrared (FTIR) spectroscopy have been used to identify the ligation state of ferrous heme iron for the H93G proximal cavity mutant of myoglobin in the absence of exogenous ligand on the proximal side. Preparation of the H93G mutant of myoglobin has been previously reported for a variety of axial ligands to the heme iron (e.g., substituted pyridines and imidazoles) [DePillis, G., Decatur, S. M,, Barrick, D., and Boxer, S. G. (1994) J. Am. Chem. Soc. 116, 6981-6982]. The present study examines the ligation states of heme in preparations of the H93G myoglobin with no exogenous ligand. In the deoxy form of H93G, resonance Raman spectroscopic evidence shows water to be the axial (fifth) ligand to the deoxy heme iron. Analysis of the infrared C-O and Raman Fe-C stretching frequencies for the CO adduct indicates that it is six-coordinate with a histidine trans ligand. Following photolysis of CO, a time-dependent change in ligation is evident in both step-scan FTIR and saturation resonance Raman spectra, leading to the conclusion that a conformationally driven ligand switch exists in the H93G protein. In the absence of exogenous nitrogenous ligands, the CO trans effect stabilizes endogenous histidine ligation, while conformational strain favors the dissociation of histidine following photolysis of CO. The replacement of histidine by water in the five-coordinate complex is estimated to occur in <5 mus. The results demonstrate that the H93G myoglobin cavity mutant has potential utility as a model system for studying the conformational energetics of ligand switching in heme proteins such as those observed in nitrite reductase, guanylyl cyclase and possibly cytochrome c oxidase. C1 N Carolina State Univ, Dept Chem, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Biosci & Biotechnol Grp, Los Alamos, NM 87545 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Franzen, S (reprint author), N Carolina State Univ, Dept Chem, Box 8204, Raleigh, NC 27695 USA. FU NIGMS NIH HHS [GM27738] NR 40 TC 17 Z9 17 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 1 PY 2001 VL 40 IS 17 BP 5299 EP 5305 DI 10.1021/bi0023403 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 427YV UT WOS:000168435100023 PM 11318654 ER PT J AU Gaschen, B Kuiken, C Korber, B Foley, B AF Gaschen, B Kuiken, C Korber, B Foley, B TI Retrieval and on-the-fly alignment of sequence fragments from the HIV database SO BIOINFORMATICS LA English DT Article AB Motivation: The amount of HIV-1 sequence data generated (presently around 42 000 sequences, of which more than 22 000 are from the V3 region of the viral envelope) presents a challenge for anyone working on the analysis of these data. A major problem is obtaining the region of interest from the stored sequences, which often contain but are not limited to that region. In addition, multiple alignment programs generally cannot deal with the large numbers of sequences that are available for many HIV-1 regions. We set out to provide our users with a tool that will retrieve and create an initial alignment of the HIV sequences that are available for a given genomic region. Results: The MPAlign (Multiple Pairwise Alignment) web interface is a collection of Perl scripts that retrieves sequences from the Los Alamos HIV sequence database based on a number of search parameters. All sequences were pairwise-aligned to a model sequence using the Hidden Markov Model-based program HMMER. The HMMER model is general enough to accommodate virtually all HIV-1 sequences stored in the database. To create a multiple sequence alignment, gaps were inserted into the sequences during retrieval, so that they are aligned to one another. Retrieving and aligning the almost 560 gp120 sequences (similar to 1500 nt) stored in the database is at least 1500 times faster than a similar Clustal alignment. C1 Univ Calif Los Alamos Natl Lab, HIV Database & Anal Grp T10, Los Alamos, NM 87545 USA. RP Gaschen, B (reprint author), Univ Calif Los Alamos Natl Lab, HIV Database & Anal Grp T10, Mail Stop K710, Los Alamos, NM 87545 USA. OI Foley, Brian/0000-0002-1086-0296; Korber, Bette/0000-0002-2026-5757 NR 4 TC 32 Z9 33 U1 1 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD MAY PY 2001 VL 17 IS 5 BP 415 EP 418 DI 10.1093/bioinformatics/17.5.415 PG 4 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 433FZ UT WOS:000168750700005 PM 11331235 ER PT J AU Vigil, D Gallagher, SC Trewhella, J Garcia, AE AF Vigil, D Gallagher, SC Trewhella, J Garcia, AE TI Functional dynamics of the hydrophobic cleft in the N-domain of calmodulin SO BIOPHYSICAL JOURNAL LA English DT Article ID LIGHT-CHAIN KINASE; SEQUENCE-INDEPENDENT RECOGNITION; TROPONIN-C; CONFORMATIONAL TRANSITION; STRUCTURAL DYNAMICS; SOLUTION SCATTERING; MOLECULAR-DYNAMICS; NEUTRON-SCATTERING; PEPTIDE COMPLEX; PROTEINS AB Molecular dynamics studies of the N-domain (amino acids 1-77; CaM1-77) of Ca2+-loaded calmodulin (CaM) show that a solvent exposed hydrophobic cleft in the crystal structure of CaM exhibits transitions from an exposed (open) to a buried (closed) state over a time scale of nanoseconds. As a consequence of burying the hydrophobic cleft, the R-g of the protein is reduced by 1.5 Angstrom. Based on this prediction, x-ray scattering experiments were conducted on this domain over a range of concentrations. Models built from the scattering data show that the R-g and general shape is consistent with the simulation studies of CaM1-77. Based on these observations we postulate a model in which the conformation of CaM fluctuates between two different states that expose and bury this hydrophobic cleft. In aqueous solution the closed state dominates the population, while in the presence of peptides, the open state dominates. This inherent flexibility of CaM may be the key to its versatility in recognizing structurally distinct peptide sequences. This model conflicts with the currently accepted hypothesis based on observations in the crystal structure, where upon Ca2+ binding the hydrophobic cleft is exposed to solvent. We postulate that crystal packing forces stabilize the protein conformation toward the open configuration. C1 Univ Calif Los Alamos Natl Lab, Theoret Biol & Biophys Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Garcia, AE (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Biol & Biophys Grp, T10 MS K710, Los Alamos, NM 87545 USA. OI Trewhella, Jill/0000-0002-8555-6766 FU NIGMS NIH HHS [GM40528] NR 47 TC 62 Z9 63 U1 0 U2 3 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD MAY PY 2001 VL 80 IS 5 BP 2082 EP 2092 PG 11 WC Biophysics SC Biophysics GA 428WZ UT WOS:000168485800006 PM 11325712 ER PT J AU Wiese, C Galande, S AF Wiese, C Galande, S TI Elimination of reducing agent facilitates quantitative detection of p53 antigen SO BIOTECHNIQUES LA English DT Article ID APOPTOSIS; LINES C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Natl Ctr Cell Sci, NCCS Complex,Ganeshkhind Rd, Pune 411007, Maharashtra, India. EM sanjeev@nccs.res.in FU NCI NIH HHS [R01 CA39681] NR 9 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 MAY PY 2001 VL 30 IS 5 BP 960 EP 963 PG 4 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 431NB UT WOS:000168636500015 PM 11355357 ER PT J AU Nagel, AC Fleming, JT Sayler, GS Beattie, KL AF Nagel, AC Fleming, JT Sayler, GS Beattie, KL TI Screening for ribosomal-based false positives following prokaryotic mRNA differential display SO BIOTECHNIQUES LA English DT Article ID ARBITRARILY PRIMED PCR; MESSENGER-RNA; TOUCHDOWN AB Differential display (DD) and the closely related RNA arbitrarily primed PCR (RAP-PCR) have become the molecular tools of choice for identifying and isolating differentially expressed genes in both eukaryotic and prokaryotic systems. However, one of the current drawbacks of both techniques is the high number of false positives generated. In prokaryotic applications, the many false positives typically generated by DD are subsequently identified as rRNAs because of their greater abundance compared to mRNAs. To circumvent this problem, full-length 16S and 23S rDNA probes, derived from Pseudomonas FRD1, respectively, were used as a pre-screening approach to discriminate between those bands, which appear to be differentially expressed mRNAs, but in fact are rRNAs, following prokaryotic mRNA DD. C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Fleming, JT (reprint author), Univ Tennessee, Ctr Environm Biotechnol, 676 Dabney Hall, Knoxville, TN 37996 USA. NR 17 TC 10 Z9 10 U1 0 U2 1 PU EATON PUBLISHING CO PI NATICK PA 154 E. CENTRAL ST, NATICK, MA 01760 USA SN 0736-6205 J9 BIOTECHNIQUES JI Biotechniques PD MAY PY 2001 VL 30 IS 5 BP 988 EP + PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 431NB UT WOS:000168636500020 PM 11355362 ER PT J AU McComas, C Sublette, KL Jenneman, G Bala, G AF McComas, C Sublette, KL Jenneman, G Bala, G TI Characterization of a novel biocatalyst system for sulfide oxidation SO BIOTECHNOLOGY PROGRESS LA English DT Article ID THIOBACILLUS-DENITRIFICANS; OIL-FIELD; MICROBIAL TREATMENT; HYDROGEN-SULFIDE; BACTERIA; STRAINS; BRINE AB It has been demonstrated that an enrichment culture dominated by Thiomicrospira sp. CVO may be cultured on H2S(g) as an energy source under sulfide-limiting conditions in suspended culture with nitrate as the electron acceptor. Hydrogen sulfide (10,000 ppmv) was completely removed from the feed gas and oxidized to sulfate in <3 s of gas-liquid contacting time. Maximum loading of the biomass for sulfide oxidation was observed to be 5.8 mmol H2S/h-g biomass protein, comparable to that reported previously for Thiobacillus denitrificans under similar conditions. However, the enrichment culture was shown to be more tolerant of extremes in pH and elevated temperature than T. denitrificans. Coupled with a reported tolerance of CVO for up to 10% NaCl, these observations suggest that a CVO-based culture is potentially a more robust biocatalyst system for sulfide oxidation than cultures based on Thiobacilli. C1 Univ Tulsa, Ctr Environm Res & Technol, Tulsa, OK 74104 USA. Phillips Petr Co, Bartlesville, OK 74004 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Sublette, KL (reprint author), Univ Tulsa, Ctr Environm Res & Technol, 600 S Coll Ave, Tulsa, OK 74104 USA. NR 22 TC 26 Z9 30 U1 3 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD MAY-JUN PY 2001 VL 17 IS 3 BP 439 EP 446 DI 10.1021/bp0100169 PG 8 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 440ER UT WOS:000169163400008 PM 11386863 ER PT J AU Askari, M Alarie, JP Moreno-Bondi, M Vo-Dinh, T AF Askari, M Alarie, JP Moreno-Bondi, M Vo-Dinh, T TI Application of an antibody biochip for p53 detection and cancer diagnosis SO BIOTECHNOLOGY PROGRESS LA English DT Article ID BREAST-CANCER; MOLECULAR EPIDEMIOLOGY; CLINICAL-SIGNIFICANCE; PROGNOSTIC FACTORS; COLON-CANCER; LUNG-CANCER; PROTEIN; CARCINOMA; ANTIGEN; GENE AB Detection of the p53 tumor suppressor gene is important in early cancer diagnostics because alterations in the gene have been associated with carcinogenic manifestations in several tissue types in humans. We have developed an antibody-based detection instrument, the biochip, to detect the presence of the anti-p53 antibody in human serum. The design of this highly integrated detector system is based on miniaturized phototransistors having multiple optical sensing elements, amplifiers, discriminators, and logic circuitry on an IC board. The system utilizes laser excitation and fluorescence signals to detect complex formation between the p53 monoclonal antibody and the p53 antigen. Recognition antibodies are immobilized on a nylon membrane platform and incubated in solutions containing antigens labeled with Cy5, a fluorescent cyanine dye. Subsequently, this membrane is placed on the detection platform of the biochip and fluorescence signal is induced using a 632.8-nm He-Ne laser. Using this immuno-biochip, we have been able to detect binding of the p53 monoclonal antibody to the human p53 cancer protein in biological matrices. The performance of the integrated phototransistors and amplifier circuits of the biochip, previously evaluated through measurement of the signal output response for various concentrations of fluorescein-labeled molecules, have illustrated the linearity of the microchip necessary for quantitative analysis. The design of this biochip permits sensitive, selective and direct measurements of a variety of antigen-antibody formations at very low concentrations. Furthermore, the acquisitions of the qualitative and quantitative results are accomplished rapidly, in about 15 min. These features demonstrate the potential. of this antibody-based biochip for simple, rapid and early biomedical diagnostics of cancer. C1 Oak Ridge Natl Lab, Adv Monitoring Dev Grp, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Grad Sch Biomed Sci, Oak Ridge, TN 37830 USA. Univ Complutense, Dept Quim Analit, E-28040 Madrid, Spain. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Adv Monitoring Dev Grp, Div Life Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Moreno-Bondi, Maria/H-3138-2011 OI Moreno-Bondi, Maria/0000-0002-3612-0675 NR 55 TC 20 Z9 20 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD MAY-JUN PY 2001 VL 17 IS 3 BP 543 EP 552 DI 10.1021/bp010008s PG 10 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 440ER UT WOS:000169163400022 PM 11386877 ER PT J AU Auffray, I Marfatia, S de Jong, K Lee, G Huang, CH Paszty, C Tanner, MJA Mohandas, N Chasis, JA AF Auffray, I Marfatia, S de Jong, K Lee, G Huang, CH Paszty, C Tanner, MJA Mohandas, N Chasis, JA TI Glycophorin A dimerization and band 3 interaction during erythroid membrane biogenesis: in vivo studies in human glycophorin A transgenic mice SO BLOOD LA English DT Article ID TRANSMEMBRANE ALPHA-HELICES; RED-BLOOD-CELL; WRIGHT ANTIGENS; XENOPUS-OOCYTES; PROTEIN; EXPRESSION; AE1; ASSOCIATION; ANTIBODIES; DEFICIENCY AB Band 3 and glycophorin A (GPA) are the 2 most abundant integral proteins in the human erythrocyte membrane. Earlier studies suggested that the 2 proteins may associate not only in the mature erythrocyte membrane, but also during their posttranslational processing and intracellular trafficking. The purpose of this study was to directly examine the CPA-band 3 interaction in vivo and determine the nature of this association during erythroid membrane biogenesis. Transgenic mice were generated expressing the human glycophorin A gene and were used to examine how the induction of hu-man GPA expression affected the levels of murine GPA and band 3 expression in the red cell membrane. Murine CPA expression was reduced in erythrocytes expressing human GPA, whereas the level of band 3 expression remained constant, implying a tight coupling of band 3 and GPA expression in the membrane of mature red cells. In vivo GPA dimerization was not modulated solely by the GPA transmembrane motif, but the distance between this motif and the basic residues on the cytoplasmic side of the transmembrane domain may also be important. In addition, GPA monomers with varying degrees of glycosylation dimerized, providing clear evidence that carbohydrate structures on the extracellular domain do not affect dimerization. The association between the multiple transmembrane-spanning protein, band 3, and the single transmembrane-spanning sialoglycoprotein, GPA, may serve as a model for interactions of other multi-pass and single-pass polypep tides during membrane biogenesis. (Blood, 2001;91:2872-2878) (C) 2001 by The American Society of Hematology. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Childrens Hosp Oakland, Res Inst, Oakland, CA 94609 USA. New York Blood Ctr, Lindsley F Kimball Res Inst, New York, NY 10021 USA. Univ Bristol, Bristol BS8 1TH, Avon, England. RP Chasis, JA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Bldg 74,1 Cyclotron Rd, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [HL31579]; NIDDK NIH HHS [DK26263, DK32094, DK56267] NR 42 TC 56 Z9 58 U1 0 U2 2 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD MAY 1 PY 2001 VL 97 IS 9 BP 2872 EP 2878 DI 10.1182/blood.V97.9.2872 PG 7 WC Hematology SC Hematology GA 429KP UT WOS:000168516200049 PM 11313283 ER PT J AU Lopez, ARD Martinez, JJM Routbort, JL Cruse, TA Korilata, RE Goretta, KC AF Lopez, ARD Martinez, JJM Routbort, JL Cruse, TA Korilata, RE Goretta, KC TI Plastic deformation of mullite/yttria composites SO BOLETIN DE LA SOCIEDAD ESPANOLA DE CERAMICA Y VIDRIO LA Spanish DT Article DE mullite; yttria; plastic deformation; microstructurea ID BOUNDARY GLASS PHASE; SILICON-NITRIDE; SUPERPLASTIC DEFORMATION; MECHANICAL-PROPERTIES; COMPRESSIVE CREEP; CERAMICS; MICROSTRUCTURE; BEHAVIOR; STRENGTH; SIALON AB Mullite (3Al(2)O(3).2SiO(2)) based composites have excellent mechanical and thermal properties. The same characteristics that give mullite good resistance to plastic deformation also make its sintering difficult. Yttria is one of the most commonly used additives to reduce sintering temperatures in mullite. Additionally vitreous silicates (Y2Si2O7) could improve ductility. In this work we have used mullite samples with various amounts of Y2O3 (0, 5 and 9 wt.%). Details of processing and characterization of these composites have been the subject of a previous publication. We have compared the ductility of these composites by means of compressive deformation tests at elevated temperatures. Creep tests were performed at temperatures between 1300 and 1400 degreesC, in air, in a stress range of 0.69 to 34.5 MPa. C1 Univ Seville, Dept Fis Mat Condensada, Seville, Spain. Argonne Natl Lab, Energy Technol Dept, Argonne, IL 60439 USA. RP Univ Seville, Dept Fis Mat Condensada, Seville, Spain. NR 40 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0366-3175 EI 2173-0431 J9 BOL SOC ESP CERAM V JI Bol. Soc. Esp. Ceram. Vidr. PD MAY-JUN PY 2001 VL 40 IS 3 BP 215 EP 219 PG 5 WC Materials Science, Ceramics SC Materials Science GA 452TC UT WOS:000169874100007 ER PT J AU Tellers, DM Bergman, RG AF Tellers, DM Bergman, RG TI Mechanistic study of ligand substitution processes in TpIr(III) complexes SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article DE iridium; hydridotris(pyrazolyl) borate; methylene chloride and dinitrogen complexes; dissociative substitution ID H BOND ACTIVATION; HYDRIDOTRIS(PYRAZOLYL)BORATE; IRIDIUM; REACTIVITY; HYDROGEN; RHODIUM AB The synthesis of the cationic hydridotris(pyrazolyl)borate iridium(III) complex [Tp(PMe3)IrMe(ClCH2Cl)][BArf] (2-CH2Cl2) is reported. Spectroscopic characterization of 2-CH2Cl2 in CH2Cl2 solution indicates that exchange of bound CH2Cl2 with free CH2Cl2 is slow on the NMR time scale. Under 50 atm (1 atm = 101.325 kPa) of N-2, the CH2Cl2 in 2-CH2Cl2 is displaced by N-2 to yield [Tp(PMe3)IrMe(N-2)][BArf] (2-N-2). The stronger nucleophile CH3CN reacts rapidly with 2-CH2Cl2 to produce [Tp(PMe3)IrMe(NCCH3)][BArf] (4). A kinetic study was performed on CH2Cl2 substitution in 2-CH2Cl2 by CD3CN. The data are most consistent with dissociative loss of CH2Cl2 to generate the unsaturated species ([Tp(PMe3)IrMe][BArf]) which then reacts with CD3CN to generate [Tp(PMe3)IrMe(NCCD3)][BArf]. Further evidence for a dissociative mechanism was obtained by comparison of ligand substitution rates for the Tp complexes with the analogous Tp(Me2) complexes (Tp(Me2) = hydridotris(3,5-dimethylpyrazolyl)borate). The relevance of these substitution experiments to C-H activation by cationic iridium(III) complexes is discussed. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Bergman, RG (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM bergman@cchem.berkeley.edu NR 12 TC 8 Z9 8 U1 0 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD MAY PY 2001 VL 79 IS 5-6 BP 525 EP 528 DI 10.1139/cjc-79-5-6-525 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 456EV UT WOS:000170070900009 ER PT J AU Gao, HR Angelici, RJ AF Gao, HR Angelici, RJ TI Rh2Cl2(CO)(4) adsorbed and tethered on gold powder: IR spectroscopic characterization and olefin hydrogenation activity SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Review DE catalysis; olefin hydrogenation; gold powder; tethered rhodium complexes; infrared studies; adsorption; rhodium complexes ID SELF-ASSEMBLED MONOLAYERS; RHODIUM AMINE COMPLEXES; PALLADIUM HETEROGENEOUS CATALYST; ORGANIZED MOLECULAR ASSEMBLIES; ARENE HYDROGENATION; ALKANETHIOLATE MONOLAYERS; ASYMMETRIC HYDROGENATION; TRANSITION-METALS; ALKYL ISOCYANIDES; CARBON-MONOXIDE AB Catalysts were prepared by adsorbing Rh2Cl2(CO)(4) directly on gold powder or on gold that contained the tethered ligands 2-(diphenylphosphino)ethane-1-thiol (DPET) or methyl 2-mercaptonicotinate (MMNT). Infrared (IR) studies (diffuse reflectance infrared Fourier transform (DRIFT)) of the catalyst Rh-Au prepared by adsorbing Rh2Cl2(CO)(4) directly on Au indicate that a Rh-I(CO)(2) species is present. IR studies of Rh-DPET-Au suggest that tethered cis-Rh(DPET)(CO)(2)Cl is the major species at relatively high Rh2Cl2(CO)(4) loadings, but trans-Rh(DPET)(2)(CO)Cl is observable at low Rh2Cl2(CO)(4) loadings. Spectral investigations of the catalyst Rh-MMNT-Au prepared by adsorbing Rh2Cl2(CO)(4) on MMNT-Au suggest that tethered [cis-Rh(MMNT)(2)(CO)(2)]Cl-+(-) and (or) Rh(MMNT)(CO)(2)Cl are the major species at low Rh2Cl2(CO)(4) loadings, while a new unidentified species predominates at high Rh2Cl2(CO)(4) loadings. All three catalysts are active 1-hexene hydrogenation catalysts under the mild conditions of 40 degreesC and 1 atm of H-2; they are much more active than Au powder or Rh2Cl2(CO)(4) in solution. Of the three catalysts, Rh-Au is the most active with a maximum turnover frequency (TOF) of 800 mol H-2 per mol Rh per min while its turnover (TO) is 29 600 mol H-2 per mol Rh during a 2-hour run. Under the conditions of 1-hexene hydrogenation, the catalysts lose their CO ligands. Thus, it appears that a form of Rh metal on Au is the catalytically active species. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Angelici, RJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM angelici@iastate.edu NR 108 TC 4 Z9 4 U1 1 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD MAY PY 2001 VL 79 IS 5-6 BP 578 EP 586 DI 10.1139/cjc-79-5-6-578 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 456EV UT WOS:000170070900017 ER PT J AU Mahajan, D Krisdhasima, V Sproull, RD AF Mahajan, D Krisdhasima, V Sproull, RD TI Kinetic modeling of homogeneous methanol synthesis catalyzed by base-promoted nickel complexes SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article DE homogeneous catalysis; syngas conversion; methanol synthesis; alkoxides; carbonyls of nickel ID CARBON-MONOXIDE AB Nickel complexes promoted by alkoxide bases can affect facile conversion of synthesis gas into methanol under thermodynamically favorable temperatures. At 100 degreesC, syngas conversion of 99% with turnover frequency of 66 h(-1) is reported. The reaction is truly catalytic in Ni as well as in base. A kinetic study of the Ni(CO)(4)-KOMe catalyst system in 1,2-bis(2-methoxy ethoxy)ethane (triglyme)-MeOH solvent mixture is presented. The kinetic expression includes terms of zero-order in H-2 and first-order in CO with syngas of H-2-CO stoichiometry of similar to2:1 and less than first-order in Ni (0.03-0.10 M), similar to third-order in base (2.0-4.75 M), and an exponential dependence on methanol concentration (13.0-23.7 M at 2.0 M base; 15.8-22.6 M at 3.0 M base). The activation energy of 42.2 kJ mol(-1) was estimated from the Arrhenius plot of the data between 374 and 393 K. Gas phase IR spectrum at the end of each run showed an intense signature peak at 2060 cm(-1) for Ni(CO)(4). Process uncertainties to commercialization of this versatile homogenous catalyst system for CO hydrogenation to methanol are discussed. C1 Brookhaven Natl Lab, Energy Sci & Technol Dept, Adv Fuels Grp, Upton, NY 11973 USA. RP Mahajan, D (reprint author), Brookhaven Natl Lab, Energy Sci & Technol Dept, Adv Fuels Grp, Bldg 815, Upton, NY 11973 USA. EM dmahajan@bnl.gov NR 18 TC 5 Z9 6 U1 2 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD MAY PY 2001 VL 79 IS 5-6 BP 848 EP 853 DI 10.1139/cjc-79-5-6-848 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 456EV UT WOS:000170070900052 ER PT J AU Vincent, JM Rabion, A Yachandra, VK Fish, RH AF Vincent, JM Rabion, A Yachandra, VK Fish, RH TI Fluorous biphasic catalysis. 2. Synthesis of fluoroponytailed amine ligands along with fluoroponytailed carboxylate synthons, [M(C8F17(CH2)(2)CO2)(2)] (M = Mn2+ or Co2+): Demonstration of a perfluoroheptane soluble precatalyst for alkane and alkene functionalization in the presence of tert-butyl hydroperoxide and oxygen gas SO CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE LA English DT Article DE fluorous solvents; biphasic catalysis; alkane/alkene oxidation ID BIOMIMETIC OXIDATION; IN-SITU; SEPARATION; COMPLEXES; WATER; TAILS AB Fluorous biphasic catalysis (FBC) is a relatively new concept for homogeneous catalysis where the fluorocarbon soluble catalyst resides in a separate phase from the substrate and products. Therefore, separation of the catalyst and the products occurs by a facile decantation process. In this contribution, we present the synthesis of new R-f-fluoroponytailed synthons, 2-iodo-1-perfluorooctyl-3-propanol (1), 3-perfluorooctyl-1-propanol (2), and 3-perfluorooctyl-1-iodopropane (3), a variety of new R-f-fluoroponytailed ligands (4-8), with starting amines, 1,4,7-triazacyclononane, bis-picolylamine, and bis-picolylaminoethylenediamine, as well as new RfMn2+ and RfCo2+ fluoroponytailed carboxylate synthons, [Mn(O2C(CH2)(2)C8F17)(2)] (9), and [Co(O2C(CH2)(2)C8F17)(2)] (10), where R-f is C8F17. The only totally perfluoralkane soluble ligand we found was 1,4,7-tris-N-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoroundecyl)-1,4,7-triazacyclononane (R(f)TACN, 4), and it was utilized, along with synthons 9 and 10, to generate in situ RfMn2+-R(f)TACN and RfCo2+-R(f)TACN complexes as precatalysts for functionalization of alkanes and alkenes. We will demonstrate that indeed this novel FBC approach for the separation of the precatalyst from the substrates and (or) products is viable for oxidation of alkanes and alkenes in the presence of the necessary oxidants, tert-butyl hydroperoxide (TBHP), and O-2 gas. We will also show that these oxidation reactions occur via an autoxidation mechanism under our FBC conditions, while using electron spin resonance (ESR) techniques to ascertain the redox chemistry occurring with the starting mononuclear RfMn2+-R(f)TACN complex. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fish, RH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM rhfish@lbl.gov NR 20 TC 27 Z9 27 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4042 J9 CAN J CHEM JI Can. J. Chem.-Rev. Can. Chim. PD MAY PY 2001 VL 79 IS 5-6 BP 888 EP 895 DI 10.1139/cjc-79-5-6-888 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 456EV UT WOS:000170070900057 ER PT J AU Dilmanian, FA Morris, GM Le Duc, G Huang, X Ren, B Bacarian, T Allen, JC Kalef-Ezra, J Orion, I Rosen, EM Sandhu, T Sathe, P Wu, XY Zhong, Z Shivaprasad, HL AF Dilmanian, FA Morris, GM Le Duc, G Huang, X Ren, B Bacarian, T Allen, JC Kalef-Ezra, J Orion, I Rosen, EM Sandhu, T Sathe, P Wu, XY Zhong, Z Shivaprasad, HL TI Response of avian embryonic brain to spatially segmented X-ray microbeams SO CELLULAR AND MOLECULAR BIOLOGY LA English DT Article DE microbeam radiation therapy; microplanar beams; developing brain; tissue sparing; pediatric brain tumors ID SYNCHROTRON-WIGGLER; MICROPLANAR BEAM; EGS4 CODE; SCATTERING; PHOTON AB Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-raps, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 mum and height of 11 mm, and a center-to-center spacing of 100 mum. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue, i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Oxford, Oxford, England. Beth Israel Med Ctr, New York, NY 10003 USA. Univ Ioannina, GR-45110 Ioannina, Greece. Long Isl Jewish Med Ctr, New Hyde Park, NY 11042 USA. Cornell Univ, Duck Res Lab, Eastport, NY USA. Univ Calif Davis, Davis, CA 95616 USA. RP Dilmanian, FA (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490, Upton, NY 11973 USA. RI ORION, ITZHAK/F-2034-2012 NR 17 TC 80 Z9 81 U1 2 U2 7 PU CELLULAR & MOLECULAR BIOLOGY PI NOISY-LE-GRAND PA PROF R WEGMANN RESIDENCE HAUSSMANN 1 AVENUE DU PAVE NEUF, 93160 NOISY-LE-GRAND, FRANCE SN 0145-5680 J9 CELL MOL BIOL JI Cell. Mol. Biol. PD MAY PY 2001 VL 47 IS 3 BP 485 EP 493 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 445QK UT WOS:000169468600013 PM 11441956 ER PT J AU Baltrus, JP LaCount, RB AF Baltrus, JP LaCount, RB TI Measurement of adsorption of air-entraining admixture on fly ash in concrete and cement SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE adsorption; fly ash; cement; concrete; air-entraining admixture ID CARBON; COAL AB A method using UV-Vis spectrophotometry for measuring the adsorption of air-entraining admixture (AEA) on the components of cements was optimized. The method was then used to measure the adsorption of AEA on a series of Class F fly ash samples with carbon concentrations of up to 14.6%. Class F fly ash carbons were found to have a very low capacity for AEA compared to Portland cement. The adsorption capacities of the fly ashes were compared to their carbon concentrations and foam index values. A lack of correlation between adsorption capacity and foam index was primarily due to differences in equilibration times used for the two measurements. Ultimately the Foam Index Test was found to be unsatisfactory for measuring the adsorption of AEA by fly ash carbon. The UV-Vis method is not necessarily a better choice for measuring AEA adsorption by carbon because soluble Ca2+ and Mg2+ ions from the fly ash were found to interfere with the UV-Vis method due to the formation of precipitates. Published by Elsevier Science Ltd. All rights reserved. C1 US Dept Energy, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. Waynesburg Coll, Dept Chem, Waynesburg, PA 15370 USA. RP Baltrus, JP (reprint author), US Dept Energy, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. RI Chen, Wei/A-5694-2010 NR 18 TC 19 Z9 19 U1 4 U2 9 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 MAY PY 2001 VL 31 IS 5 BP 819 EP 824 DI 10.1016/S0008-8846(01)00494-X PG 6 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 441AV UT WOS:000169209600019 ER PT J AU Zhang, Q Harada, K Cho, HS Frankel, AD Wemmer, DE AF Zhang, Q Harada, K Cho, HS Frankel, AD Wemmer, DE TI Structural characterization of the complex of the Rev response element RNA with a selected peptide SO CHEMISTRY & BIOLOGY LA English DT Article DE peptide-RNA complex; RNA recognition; selected peptide; solution structure ID PROTEIN SECONDARY STRUCTURE; CHEMICAL-SHIFT INDEX; BASE-PAIRS; IN-VIVO; RECOGNITION; BINDING; IDENTIFICATION; DYNAMICS AB Introduction: The RSG-1.2 peptide was selected for specific binding to the Rev response element RNA, as the natural Rev peptide does. The RSG-1.2 sequence has features incompatible with the helical structure of the bound Rev peptide, indicating that it must bind in a different conformation. Results: The binding of the RSG-1,2 peptide to the Rev response element RNA was characterized using multinuclear, multidimensional NMR. The RSG-1.2 peptide is shown to bind with the N-terminal segment of the peptide along the major groove in an extended conformation and turn preceding a C-terminal helical segment, which crosses the RNA groove in the region widened by the presence of purine-purine base pairs. These features make the details of the bound state rather different than that of the Rev peptide which targets the same RNA sequence binding as a single helix along the groove axis. Conclusions: These studies further demonstrate the versatility of arginine-rich peptides in recognition of specific RNA elements and the lack of conserved structural features in the bound state. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Biophys & Biochem, San Francisco, CA 94143 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Dept Chem, MC-1460, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM43129, GM47478, GM56531] NR 31 TC 18 Z9 18 U1 0 U2 1 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD MAY PY 2001 VL 8 IS 5 BP 511 EP 520 DI 10.1016/S1074-5521(01)00027-8 PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 437XP UT WOS:000169024900010 PM 11358697 ER PT J AU Landry, CC Tolbert, SH Gallis, KW Monnier, A Stucky, GD Norby, F Hanson, JC AF Landry, CC Tolbert, SH Gallis, KW Monnier, A Stucky, GD Norby, F Hanson, JC TI Phase transformations in mesostructured silica/surfactant composites. Mechanisms for change and applications to materials synthesist SO CHEMISTRY OF MATERIALS LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; ORDER-DISORDER TRANSITION; DIBLOCK COPOLYMERS; EPITAXIAL RELATIONSHIPS; LIQUID-CRYSTAL; WATER SYSTEMS; SURFACTANT; SILICA; ORGANIZATION; BILAYERS AB In this study, phase transformation of the hexagonal mesostructure MCM-41 to the cubic mesostructure MCM-48 is examined by in situ X-ray diffraction (XRD) of the transforming mesostructure and by XRD of products from bulk transformation experiments in Parr autoclaves. Transformations were studied under conditions of high pH and temperatures between 100 and 190 degreesC. Heating events took place after the hexagonal mesophase had assembled, but before it had fully polymerized. On the basis of these and previous results on transformations in silica-surfactant-water and surfactant-water systems, a model is proposed to explain the expected hexagonal --> cubic transformation as well as the brief existence of a lamellar phase during the transformation. Additional experiments to establish synthetic parameters for the transformation included varying the silicon alkoxide source, replacing the supernatant prior to heating, and adding fluoride or aluminum to the reaction mixture. The results, taken together, illustrate the strong cooperativity between the organic and inorganic regions in controlling the assembly of the mesostructure and provide a better understanding of the effects that control phase transformations in these systems. C1 Univ Vermont, Dept Chem, Burlington, VT 05405 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Geneva, Dept Chim Phys Sci 2, CH-1211 Geneva, Switzerland. Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Oslo, Dept Chem, N-0315 Oslo, Norway. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Landry, CC (reprint author), Univ Vermont, Dept Chem, Burlington, VT 05405 USA. RI Hanson, jonathan/E-3517-2010; Tolbert, Sarah/L-2321-2016 NR 47 TC 120 Z9 122 U1 1 U2 19 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 MAY PY 2001 VL 13 IS 5 BP 1600 EP 1608 DI 10.1021/cm000373z PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 435DB UT WOS:000168861200028 ER PT J AU Fujdala, KL Tilley, TD AF Fujdala, KL Tilley, TD TI Thermolytic transformation of tris(alkoxy)siloxychromium(IV) single-source molecular precursors to catalytic chromia-silica materials SO CHEMISTRY OF MATERIALS LA English DT Article ID SOL-GEL PROCESS; OXIDATIVE DEHYDROGENATION; OXIDE CATALYSTS; TRIALKOXYSILOXY COMPLEXES; PROPANE DEHYDROGENATION; ETHYLENE POLYMERIZATION; ZIRCONIA CATALYSTS; METAL-OXIDES; VANADIUM; ROUTES AB Reactions of 1 and 2 equiv of HOSi((OBu)-Bu-t)(3) with Cr((OBu)-Bu-t)(4) afforded the first Cr(IV) alkoxysiloxy complexes ((BuO)-Bu-t)(3)CrOSi((OBu)-Bu-t)(3) (1) and ((BuO)-Bu-t)(2)Cr[OSi((OBu)-Bu-t)(3)](2) (2), respectively. Both 1 and 2 contain pseudotetrahedral d2 chromium centers and crystallize in the monoclinic space group P2(1)/n with four molecules in the unit cell. The high-yielding, convenient synthesis of 1 makes this complex a useful single-source molecular precursor, via the thermolytic molecular precursor method, to Cr/Si/O materials. The thermal transformations of 1 and 2 to chromia-silica materials occurred at low temperatures (less than or equal to 180 degreesC), to give isobutene as the major carbon-containing product. The material generated from the solid-state conversion of 1 (CrOSiss) contained both micro- and mesoporosity with an unexpectedly high surface area of 315 m(2)/g that was slightly reduced to 275 m(2)/g after calcination at 500 degreesC in Oz. The xerogel obtained by the thermolysis of an n-octane solution of 1 (CrOSixg) had a surface area of 315 m(2)/g that was reduced to 205 m(2)/g upon calcination at 500 degreesC. The nitrogen adsorption-desorption isotherm for the xerogel had characteristics indicating both microporosity and textural mesoporosity. Powder X-ray diffraction (PXRD) analysis was used to demonstrate that Cr2O3 was the only species that crystallized in CrOSiss and CrOSixg after calcination at temperatures up to 1200 degreesC in O-2. Elemental analyses of these materials revealed that the Cr:Si ratio was very close to 1:1, indicating that the original stoichiometry of the precursor is retained upon thermal conversion to Cr/Si/O materials. Both materials contained very low amounts of carbon after calcination in O-2 at 500 degreesC. In the oxidative dehydrogenation of propane, CrOSixg (calcined at 500 degreesC) displayed intrinsic activities for propene formation that were up to 3 times higher than those for CrOSixg (calcined at 500 degreesC). In addition, the selectivity for propene formation was higher for the more active CrOSixg catalyst. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 75 TC 39 Z9 40 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAY PY 2001 VL 13 IS 5 BP 1817 EP 1827 DI 10.1021/cm010027x PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 435DB UT WOS:000168861200058 ER PT J AU Zhang, T Hou, JD Tang, BY Chu, PK Brown, IG AF Zhang, T Hou, JD Tang, BY Chu, PK Brown, IG TI Guiding of plasma by electric field and magnetic field SO CHINESE PHYSICS LA English DT Article DE cathodic arc; plasma; transport; magnetic filter ID VACUUM-ARC DEPOSITION; CATHODIC ARC; ION-IMPLANTATION; TRANSPORT; FILMS; FILTERS AB The relationship between the transported ion current and the cathodic are current is determined in a vacuum are plasma source equipped with a curved magnetic filter. Our results suggest that the outer and inner walls of the duct interact with the plasma independently. The duct magnetic field is a critical factor of the plasma output. The duct transport efficiency is to maximize at a value of bias plate voltage in the range +10 V to +20 V, and independent (within our limit of measurement) of the magnetic field strength in the duct. The plasma flux is composed of two components: a diffusion flux in the transverse direction due to particle collisions, and a drift flux due to the ion inertia. The inner wall of the magnetic duct sees only the diffusion flux while the outer wall receives both fluxes. Thus, applying a positive potential to the outer duct wall can reflect the ions and increase the output current. Our experimental data also show that biasing both sides of the duct is more effective than biasing the outer wall alone. C1 Beijing Normal Univ, Inst Low Energy Nucl Phys, Beijing Radiat Ctr, Beijing 100875, Peoples R China. City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Beijing Normal Univ, Inst Low Energy Nucl Phys, Beijing Radiat Ctr, Beijing 100875, Peoples R China. EM zh-t@263.net RI Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 20 TC 5 Z9 5 U1 2 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1009-1963 J9 CHINESE PHYS JI Chin. Phys. PD MAY PY 2001 VL 10 IS 5 BP 424 EP 428 PG 5 WC Physics, Multidisciplinary SC Physics GA 440GL UT WOS:000169167500012 ER PT J AU Echekki, T Kerstein, AR Dreeben, TD Chen, JY AF Echekki, T Kerstein, AR Dreeben, TD Chen, JY TI 'One-dimensional turbulence' simulation of turbulent jet diffusion flames: Model formulation and illustrative applications SO COMBUSTION AND FLAME LA English DT Article ID TRANSPORT; FLOWS AB A novel modeling approach to the simulation of turbulent jet diffusion flames based on the One-Dimensional Turbulence (ODT) model is presented. The approach is based on the mechanistic distinction between molecular processes (reaction and diffusion), implemented by the direct solution of unsteady boundary-layer reaction-diffusion equations, and turbulent advection in a time-resolved simulation on a 1D domain. The 1D domain corresponds to a direction transverse to the mean Row of the jet. Temporal simulations of jet diffusion flames are performed to illustrate the model's predictions of turbulence-chemistry interactions in jet diffusion flames. ODT predictions of flow entrainment, finite-rate chemistry and differential diffusion effects are investigated in hydrogen-air diffusion flames at two Reynolds numbers. Two-dimensional renderings of stirring events from a single realization show that ODT reproduces a number of salient features of simple developing turbulent shear flows that reflect the growth of the boundary layer and the mechanisms of turbulence cascade and spatial intermittency. Multiple realizations of jet simulations are used to compute axial and conditional statistics of streamwise velocity, major species, NO, and temperature. Comparison with experimental measurements indicates that chemical properties of interest can be captured by a model that involves a simplified representation of the flow structure. The results show, strong differential diffusion effects in the near field, with attenuation farther downstream. (C) 2001 by The Combustion Institute. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. RP Echekki, T (reprint author), Sandia Natl Labs, Combust Res Facil, MS 9051, Livermore, CA 94551 USA. RI Echekki, Tarek/C-7394-2009; OI Echekki, Tarek/0000-0002-0146-7994 NR 26 TC 66 Z9 72 U1 5 U2 15 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD MAY PY 2001 VL 125 IS 3 BP 1083 EP 1105 DI 10.1016/S0010-2180(01)00228-0 PG 23 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 439XF UT WOS:000169142300002 ER PT J AU Li, YA AF Li, YA TI Linear stability of solitary waves of the Green-Naghdi equations SO COMMUNICATIONS ON PURE AND APPLIED MATHEMATICS LA English DT Article ID ASYMPTOTIC STABILITY; 2-FLUID SYSTEM; SHALLOW-WATER; INSTABILITY AB We investigate the eigenvalue problem obtained from linearizing the Green-Naghdi equations about solitary wave solutions. Unlike weakly nonlinear water wave models, the physical system considered here has nonlinearity in its highest derivative term. This results in more detailed asymptotic analysis of the eigenvalue problem in the presence of a large parameter. Combining the technique of singular perturbation with the Evans function, we show that for solitary waves of small amplitude, the problem has no eigenvalues of positive real part and the Evans function is nonvanishing everywhere except the origin. This fact then leads to the linear stability of these solitary waves. (C) 2001 John Wiley & Sons, Inc. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Li, YA (reprint author), Stevens Inst Technol, Dept Math Sci, Castle Point Hudson, Hoboken, NJ 07030 USA. NR 34 TC 14 Z9 14 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0010-3640 J9 COMMUN PUR APPL MATH JI Commun. Pure Appl. Math. PD MAY PY 2001 VL 54 IS 5 BP 501 EP 536 DI 10.1002/cpa.1 PG 36 WC Mathematics, Applied; Mathematics SC Mathematics GA 413AA UT WOS:000167586700001 ER PT J AU Nielsen, IMB Janssen, CL AF Nielsen, IMB Janssen, CL TI Novel pseudospectral Fourier method for solving Poisson's equation for a solute in a non-uniform dielectric SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE Poisson's equation; Poisson-Boltzmann equation; pseudospectral method; solvation energy; linear solvers; linear scaling ID NONSEPARABLE ELLIPTIC-EQUATIONS; NUMERICAL-SOLUTION AB A novel pseudospectral method is presented for solving Poisson's equation for a solute in a non-uniform dielectric. Poisson's equation is transformed to a Helmholtz-like equation which is solved iteratively, as a linear system of equations, by introducing a grid and employing fast Fourier transforms. Several algorithms have been rested for solution of the linear system, and application of an appropriately preconditioned linear solver has been found to provide a robust, rapidly convergent procedure. The method scales nearly linearly with system size, and its implementation is straightforward Application of the method is demonstrated for computation of the electrostatic contribution to the solvation energy for a wide range of solute molecules, and convergence of the method is shown to be nearly independent of solute and grid size. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nielsen, IMB (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. NR 18 TC 6 Z9 6 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 MAY 1 PY 2001 VL 136 IS 1-2 BP 29 EP 36 DI 10.1016/S0010-4655(00)00250-2 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 427AY UT WOS:000168383700003 ER PT J AU Chen, WYC Galbraith, HW Louck, JD AF Chen, WYC Galbraith, HW Louck, JD TI Angular momentum theory, umbral calculus, and combinatorics SO COMPUTERS & MATHEMATICS WITH APPLICATIONS LA English DT Article DE angular momentum theory; umbral calculus; MacMahon's master theorem; generating function; 3n-j coefficients ID MACMAHONS MASTER THEOREM AB The theory of the unitary irreducible representations of the unitary group SU(2) is reviewed with the objective of demonstrating the fundamental role that the umbral calculus and combinatorics play. For the physicist, the study of the group SU(2) is synonymous with the theory of angular momentum in quantum theory, and Kronecker products of irreducible unitary representations comprise the mathematical apparatus for building composite systems from simpler constituents. The Clebsch-Gordon coefficients, which are essential to the binary theory of composite systems, are shown to have an umbral calculus origin. MacMahon's master theorem is shown to be the basic result for generating the mathematical quantities needed for bringing comprehension to the properties of composite systems. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Nankai Univ, Res Ctr Combinator, Tianjin 300071, Peoples R China. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. RP Chen, WYC (reprint author), Univ Calif Los Alamos Natl Lab, T-7,Mail Stop B284, Los Alamos, NM 87545 USA. NR 41 TC 3 Z9 4 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0898-1221 J9 COMPUT MATH APPL JI Comput. Math. Appl. PD MAY PY 2001 VL 41 IS 9 BP 1199 EP 1214 DI 10.1016/S0898-1221(01)00091-8 PG 16 WC Mathematics, Applied SC Mathematics GA 419PR UT WOS:000167958100010 ER PT J AU Darve, C Casas, J AF Darve, C Casas, J TI Measurements of temperature on LHC thermal models SO CRYOGENICS LA English DT Article; Proceedings Paper CT US-Japan Joint Seminar on Innovative Measurement Techniques in Cryogenics CY DEC 03-06, 2000 CL TALLAHASSEE, FLORIDA DE temperature sensors; HeII systems; heat exchangers; cryostats AB Full-scale thermal models for the Large Hadron Collider (LHC) accelerator cryogenic system have been studied at CERN and at Fermilab. Thermal measurements based on two different models permitted us to evaluate the performance of the LHC dipole cryostats as well as to validate the LHC Interaction Region (IR) inner triplet cooling scheme. The experimental procedures made use of temperature sensors supplied by industry and assembled on specially designed supports. The described thermal models took the advantage of advances in cryogenic thermometry which will be implemented in the future LHC accelerator to meet the strict requirements of the LHC for precision, accuracy, reliability, and ease-of-use. The sensors used in the temperature measurement of the superfluid (He II) systems are the primary focus of this paper, although some aspects of the LHC control system and signal conditioning are also reviewed. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. CERN, European Lab Particle Phys, LHC Div, CH-1211 Geneva, Switzerland. RP Darve, C (reprint author), Fermilab Natl Accelerator Lab, POB 500,MS 316, Batavia, IL 60510 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD MAY-JUN PY 2001 VL 41 IS 5-6 BP 319 EP 326 DI 10.1016/S0011-2275(01)00106-0 PG 8 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA 474GW UT WOS:000171098800007 ER PT J AU Jiang, JS Kaper, HG Leaf, GK AF Jiang, JS Kaper, HG Leaf, GK TI Hysteresis in layered spring magnets SO DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B LA English DT Article DE micromagnetics; spring magnets; hysteresis; Landau-Lifshitz-Gilbert equation ID PERMANENT-MAGNETS AB This article addresses a problem of micromagnetics: the reversal of magnetic moments in layered spring magnets. A one-dimensional model is used of a film consisting of several atomic layers of a soft material on top of several atomic layers of a hard material. Each atomic layer is taken to be uniformly magnetized, and spatial inhomogeneities within an atomic layer are neglected. The state of such a system is described by a chain of magnetic spin vectors. Each spin vector behaves like a spinning top driven locally by the effective magnetic field and subject to damping (Landau-Lifshitz-Gilbert equation). A numerical integration scheme for the LLG equation is presented that is unconditionally stable and preserves the magnitude of the magnetization vector at all times. The results of numerical investigations for a bilayer in a rotating in-plane magnetic field show hysteresis with a basic period of 2pi at moderate fields and hysteresis with a basic period of pi at strong fields. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Jiang, JS (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 15 TC 15 Z9 15 U1 0 U2 1 PU AMER INST MATHEMATICAL SCIENCES PI SPRINGFIELD PA PO BOX 2604, SPRINGFIELD, MO 65801-2604 USA SN 1531-3492 J9 DISCRETE CONT DYN-B JI Discrete Contin. Dyn. Syst.-Ser. B PD MAY PY 2001 VL 1 IS 2 BP 219 EP 232 PG 14 WC Mathematics, Applied SC Mathematics GA 537WG UT WOS:000174782200005 ER PT J AU Burrows, PE Graff, GL Gross, ME Martin, PM Shi, MK Hall, M Mast, E Bonham, C Bennett, W Sullivan, MB AF Burrows, PE Graff, GL Gross, ME Martin, PM Shi, MK Hall, M Mast, E Bonham, C Bennett, W Sullivan, MB TI Ultra barrier flexible substrates for flat panel displays SO DISPLAYS LA English DT Article DE transparent plastic substrate; flat panel display; organic light emitting device ID LIGHT-EMITTING DEVICES; DIODES AB We describe a flexible, transparent plastic substrate for flat panel display applications. Using roll-coating techniques, we apply a composite thin film barrier to commercially available polymers, which restricts moisture and oxygen permeation to undetectable levels using conventional permeation test equipment. The barrier film can be capped with a thin film of transparent conductive oxide in the same roll-coater, yielding an engineered substrate (Barix(TM)) for next generation, rugged, lightweight or flexible displays. The substrate is sufficiently impermeable to moisture and oxygen for application to moisture-sensitive display applications, such as organic light emitting displays. This enables, for the first time, lightweight and flexible emissive organic displays. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Vitex Syst Inc, Sunnyvale, CA USA. RP Burrows, PE (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 10 TC 184 Z9 185 U1 4 U2 46 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0141-9382 J9 DISPLAYS JI Displays PD MAY PY 2001 VL 22 IS 2 BP 65 EP 69 DI 10.1016/S0141-9382(00)00064-0 PG 5 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Computer Science; Engineering; Instruments & Instrumentation; Optics GA 438NB UT WOS:000169059000005 ER PT J AU Shank, BB Wiley, HS Kurten, RC AF Shank, BB Wiley, HS Kurten, RC TI Structural and functional characterization of the human gene for sorting nexin 1 (SNX1) SO DNA AND CELL BIOLOGY LA English DT Article ID MEMBRANE-FUSION; PROTO-ONCOGENE; RECEPTORS; GOLGI; MAP; DNA; ASSOCIATION; SEQUENCES; PROMOTER; COMPLEX AB The aim of the present study was to identify the gene for sorting nexin 1 (SNX1) to evaluate the potential for tissue-specific alternative splicing and to analyze the activity of the SNX1 promoter. The coding DNA for SNX1 was divided between 15 exons in 43 kb of genomic DNA located on human chromosome 15q22, Although SNX1 mRNA expression was widespread in human tissues, alternative splicing is thought to generate skipped exons in SNX1 cDNAs. By determination of the SNX1 gene structure and an analysis of the mRNAs in a variety of tissues using RT-PCR, we demonstrated that SNX1 mRNAs are alternatively spliced, Exon-skipped products were less abundant than full-length SNX1 mRNA species, but the ratio of skipped to full-length mRNA indicated that alternative splicing may be developmentally regulated in the liver. Consistent with widespread mRNA expression, the SNX1 promoter was GC rich and lacked a TATA box, features characteristic of housekeeping promoters. The promoter activity was dependent on the presence of proximal sequences that contained initiator elements and predicted binding sites for the transcription factors Spl and E2F, These findings indicate that regulation of SNX1 gene expression at the transcriptional level is likely minor. Rather, developmentally specific exon skipping provides a potential mechanism for regulating the activity of SNX1. C1 Univ Arkansas Med Sci, Dept Physiol & Biophys, Arkansas Canc Res Ctr, Little Rock, AR 72205 USA. Pacific NW Natl Lab, Environm & Hlth Sci Div, Richland, WA USA. RP Kurten, RC (reprint author), Univ Arkansas Med Sci, Dept Physiol & Biophys, Arkansas Canc Res Ctr, Slot 750,4301 W Markham, Little Rock, AR 72205 USA. OI Wiley, Steven/0000-0003-0232-6867 NR 29 TC 0 Z9 0 U1 0 U2 1 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1044-5498 J9 DNA CELL BIOL JI DNA Cell Biol. PD MAY PY 2001 VL 20 IS 5 BP 287 EP 296 DI 10.1089/104454901750232481 PG 10 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA 437FG UT WOS:000168979900005 PM 11410165 ER PT J AU Heimsath, AM Dietrich, WE Nishiizumi, K Finkel, RC AF Heimsath, AM Dietrich, WE Nishiizumi, K Finkel, RC TI Stochastic processes of soil production and transport: Erosion rates, topographic variation and cosmogenic nuclides in the Oregon Coast Range SO EARTH SURFACE PROCESSES AND LANDFORMS LA English DT Article DE erosion; soil production; landscape evolution; dynamic equilibrium; Be-10 and Al-26 ID CASCADIA SUBDUCTION-ZONE; LANDSCAPE EVOLUTION; SEDIMENT PRODUCTION; SOUTHERN OREGON; SCALING FACTORS; DEBRIS-FLOW; SANTA-CRUZ; BE-10; AL-26; HILLSLOPE AB Landscapes in areas of active uplift and erosion can only remain soil-mantled if the local production of soil equals or exceeds the local erosion rate. The soil production rate varies with soil depth, hence local variation in soil depth may provide clues about spatial variation in erosion rates. If uplift and the consequent erosion rates are sufficiently uniform in space and time, then there will be tendency toward equilibrium landforms shaped by the erosional processes. Soil mantle thickness would adjust such that soil production matched the erosion. Previous work in the Oregon Coast Range suggested that there may be a tendency locally toward equilibrium between hillslope erosion and sediment yield. Here results from a new methodology based on cosmogenic radionuclide accumulation in bedrock minerals at the base of the soil column are reported. We quantify how soil production varies with soil thickness in the southern Oregon Coast Range and explore further the issue of landscape equilibrium. Apparent soil production is determined to be an inverse exponential function of soil depth, with a maximum inferred production rate of 268 m Ma(-1) occurring under zero soil depth. This rate depends, however, on the degree of weathering of the underlying bedrock. The stochastic and large-scale nature of soil production by biogenic processes leads to large temporal and spatial variations in soil depth; the spatial variation of soil depth neither supports nor rejects equilibrium morphology. Our observed catchment-averaged erosion rate of 117 m Ma(-1) is, however, similar to that estimated for the region by others, and to soil production rates under thin and intermediate soils typical for the steep ridges. We suggest that portions of the Oregon Coast Range may be eroding at roughly the same rate, but that local competition between drainage networks and episodic erosional events leads to landforms that are out of equilibrium locally and have a spatially varying soil mantle. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA. Univ Calif Berkeley, Dept Geol & Geophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Heimsath, AM (reprint author), Dartmouth Coll, Dept Earth Sci, 6105 Fairchild Hall, Hanover, NH 03755 USA. NR 90 TC 154 Z9 155 U1 4 U2 43 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0197-9337 J9 EARTH SURF PROC LAND JI Earth Surf. Process. Landf. PD MAY PY 2001 VL 26 IS 5 BP 531 EP 552 DI 10.1002/esp.209 PG 22 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 431JB UT WOS:000168627100006 ER PT J AU Huesemann, MH AF Huesemann, MH TI Can pollution problems be effectively solved by environmental science and technology? An analysis of critical limitations SO ECOLOGICAL ECONOMICS LA English DT Article DE environmental science and technology; pollutant remediation; entropy; mechanistic reductionism; industrial ecology; paradigm shift; post-normal science ID POST-NORMAL SCIENCE; ECOLOGICAL ECONOMICS; RENEWABLE ENERGY; ENTROPY; INDICATOR AB It is currently believed that science and technology can provide effective solutions to most, if not all, environmental problems facing western industrial societies. The validity of this optimistic assumption is highly questionable for at least three reasons: First, current mechanistic, reductionist science is inherently incapable of providing the complete and accurate information which is required to successfully address environmental problems. Second, both the conservation of mass principle and the second law of thermodynamics dictate that most remediation technologies while successful in solving specific pollution problems - cause unavoidable negative environmental impacts elsewhere or in the future. Third, it is intrinsically impossible to design industrial processes that have no negative environmental impacts. This follows not only from the entropy law but also from the fact that any generation of energy is impossible without negative environmental consequences. It can therefore be concluded that science and technology have only very limited potential in solving current and future environmental problems. Consequently, it will be necessary to address the root cause of environmental deterioration, namely, the prevailing materialistic values that are the main driving force for both overpopulation and overconsumption. The long-term protection of the environment is, therefore, not primarily a technical problem but rather a social and moral problem that can only be solved by drastically reducing the strong influence of materialistic values. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Marine Sci Lab, Sequim, WA 98382 USA. RP Huesemann, MH (reprint author), Pacific NW Natl Lab, Marine Sci Lab, 1529 W Sequim Bay Rd, Sequim, WA 98382 USA. NR 63 TC 28 Z9 29 U1 3 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8009 J9 ECOL ECON JI Ecol. Econ. PD MAY PY 2001 VL 37 IS 2 BP 271 EP 287 DI 10.1016/S0921-8009(00)00283-4 PG 17 WC Ecology; Economics; Environmental Sciences; Environmental Studies SC Environmental Sciences & Ecology; Business & Economics GA 435FR UT WOS:000168867200008 ER PT J AU Zhang, AP Han, J Ren, F Waldrip, KE Abernathy, CR Luo, B Dang, G Johnson, JW Lee, KP Pearton, SJ AF Zhang, AP Han, J Ren, F Waldrip, KE Abernathy, CR Luo, B Dang, G Johnson, JW Lee, KP Pearton, SJ TI GaN bipolar junction transistors with regrown emitters SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID HIGH-TEMPERATURE; OPERATION; SUPERLATTICES; EFFICIENCY; REDUCTION; GROWTH AB Small-area (3 X 10 mum emitter) GaN bipolar junction transistors (BJTs) incorporating a superlattice GaN(Mg)/AlGaN(Mg) base contact layer and a selectively regrown emitter were fabricated using a self-aligned dry etch process. The dc current gains were typically 10 at 25 degreesC, and the devices were operated up to emitter current densities of 15 kA cm(-2). The BJTs exhibited high emitter injection efficiency, indicating the presence of a good interface between the initial epi structure and the regrown emitter. (C) 2001 The Electrochemical Society. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Zhang, AP (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. NR 24 TC 1 Z9 1 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 MAY PY 2001 VL 4 IS 5 BP G39 EP G41 DI 10.1149/1.1357697 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 418ED UT WOS:000167877200011 ER PT J AU Kropf, AJ Tostmann, H Johnson, CS Vaughey, JT Thackeray, MM AF Kropf, AJ Tostmann, H Johnson, CS Vaughey, JT Thackeray, MM TI An in situ X-ray absorption spectroscopy study of InSb electrodes in lithium batteries SO ELECTROCHEMISTRY COMMUNICATIONS LA English DT Article DE lithium batteries; in situ EXAFS; indium-antimony/antimonide; intermetallic ID CATHODE; OXIDES AB We present a detailed in situ extended X-ray absorption fine-structure spectroscopy (EXAFS) study of structural and compositional changes in InSb intermetallic electrodes under electrochemical cycling conditions in a lithium battery. Analysis of the EXAFS data shows that Li is inserted into and In is extruded from the zinc-blende-type InSb network during the first discharge from 1.5 to 0.5 V. yielding changing Lix+vIn1-vSb compositions (0 < x 2, 0 < y 1), with a lattice parameter that varies between that of InSb (a = 6.478 Angstrom) and Li3Sb (a = 6.572 Angstrom). The structural features of tetragonal metallic In and lithiated (i.e., In depleted) InSb are evident. The fully recharged electrode, at 1.2 V, has a zinc-blende framework closely resembling InSb. However, 40% of the In remains permanently outside the face-centered-cubic Sb lattice, explaining a loss in capacity after the first discharge. After the second discharge, at 0.51 V, Li has replaced about 80% of the indium in the InSb lattice, while the LixInxSb volume has expanded less than 4% compared to the initial electrode. Finally, as the cell is discharged below 0.51 V, Li reacts with the In metal, forming LiIn. Our results indicate that intermetallic electrodes are promising alternative negative electrodes for Li batteries. (C) 2001 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RP Kropf, AJ (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI ID, MRCAT/G-7586-2011; Kropf, Arthur/B-8665-2015; OI Vaughey, John/0000-0002-2556-6129 NR 22 TC 25 Z9 25 U1 0 U2 12 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1388-2481 J9 ELECTROCHEM COMMUN JI Electrochem. Commun. PD MAY PY 2001 VL 3 IS 5 BP 244 EP 251 DI 10.1016/S1388-2481(01)00152-7 PG 8 WC Electrochemistry SC Electrochemistry GA 434LJ UT WOS:000168816000008 ER PT J AU Smith, RD Pasa-Tolic, L Lipton, MS Jensen, PK Anderson, GA Shen, YF Conrads, TP Udseth, HR Harkewicz, R Belov, ME Masselon, C Veenstra, TD AF Smith, RD Pasa-Tolic, L Lipton, MS Jensen, PK Anderson, GA Shen, YF Conrads, TP Udseth, HR Harkewicz, R Belov, ME Masselon, C Veenstra, TD TI Rapid quantitative measurements of proteomes by Fourier transform ion cyclotron resonance mass spectrometry SO ELECTROPHORESIS LA English DT Article; Proceedings Paper CT Conference on From Genome to Proteome CY SEP 04-07, 2000 CL SIENA, ITALY DE capillary isoelectric focusing; Fourier transform ion cyclotron resonance mass; spectrometry; proteome; complex biological mixture separation Deinococcus radiodurans; Escherichia coli ID ELECTROSPRAY-IONIZATION; 2-DIMENSIONAL ELECTROPHORESIS; PROTEIN IDENTIFICATION; SEQUENCE DATABASES; INFORMATION; EXPRESSION; MIXTURES; UTILITY; GELS AB The patterns of gene expression, post-translational modifications, protein/biomolecular interactions, and how these may be affected by changes in the environment, cannot be accurately predicted from DNA sequences. Approaches for proteome characterization are generally based upon mass spectrometric analysis of in-gel digested two dimensional polyacrylamide gel electrophoresis (2-D PAGE) separated proteins, allowing relatively rapid protein identification compared to conventional approaches. This technique, however, is constrained by the speed of the 2-D PAGE separations, the sensitivity limits intrinsic to staining necessary for protein visualization, the speed and sensitivity of subsequent mass spectrometric analyses for identification, and the limited ability for accurate quantitative measurements based on differences in spot intensity. We are presently developing alternative approaches for proteomics based upon the combination of fast capillary electrophoresis, or other suitable chromatographic separations, and the high mass accuracy and sensitivity obtainable with unique Fourier transform ion cyclotron resonance (FTICR) mass spectrometers available at our laboratory. Several approaches are presently being pursued; one based upon the analysis of intact proteins and the second upon approaches for global protein digestion and accurate peptide mass analysis. Quantitation of protein/peptide levels are based on using two or more stable-isotope labeled versions of proteomes which are combined to obtain precise quantitation of relative protein abundances. We describe the status of our efforts towards the development of a high-throughput proteomics capability and present initial results for application to several microorganisms and discuss our efforts for extending the developed capability to mammalian proteomes. 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,Mail Stop K8-98, Richland, WA 99352 USA. RI Masselon, Christophe/A-2340-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCI NIH HHS [CA81654, CA86340]; NINDS NIH HHS [NS39617] NR 28 TC 88 Z9 90 U1 0 U2 6 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0173-0835 J9 ELECTROPHORESIS JI Electrophoresis PD MAY PY 2001 VL 22 IS 9 BP 1652 EP 1668 DI 10.1002/1522-2683(200105)22:9<1652::AID-ELPS1652>3.0.CO;2-E PG 17 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 442RN UT WOS:000169298900008 PM 11425221 ER PT J AU Worrell, E Price, L Martin, N AF Worrell, E Price, L Martin, N TI Energy efficiency and carbon dioxide emissions reduction opportunities in the US iron and steel sector SO ENERGY LA English DT Article AB This article presents an in-depth analysis of cost-effective energy efficiency and carbon dioxide emissions reduction opportunities in the US iron and steel industry. We show that physical energy intensity for iron and steelmaking (at the aggregate level, standard Industrial Classification 331, 332) dropped 27%, from 35.6 GJ/tonne to 25.9 GJ/tonne between 1958 and 1994, while carbon dioxide intensity (carbon dioxide emissions expressed in tonnes of carbon per tonne of steel) dropped 391c. We provide a baseline for 1994 energy use and carbon dioxide emissions from US blast furnaces and steel mills (SIC 3312) disaggregated by the processes used in steelmaking. Energy-efficient practices and technologies are identified and analyzed for each of these processes. Examination of 47 specific energy efficiency technologies and measures found a total cost-effective reduction potential of 3.8 GJ/t, having a payback period of three years or less. This is equivalent to a potential energy efficiency improvement of 18% of 1994 US iron and steel energy use and is roughly equivalent to 19% reduction of 1994 US iron and steel carbon dioxide emissions. The measures have been ranked in a bottom-up energy conservation supply-curve. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Energy Anal Dept, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Worrell, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Energy Anal Dept, Environm Energy Technol Div, 1 Cyclotron Rd,Mail Stop 90-4000, Berkeley, CA 94720 USA. RI Worrell, Ernst/L-5455-2013 OI Worrell, Ernst/0000-0002-0199-9755 NR 24 TC 104 Z9 109 U1 4 U2 37 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD MAY PY 2001 VL 26 IS 5 BP 513 EP 536 DI 10.1016/S0360-5442(01)00017-2 PG 24 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA 430WF UT WOS:000168597900005 ER PT J AU Danneskiold, J AF Danneskiold, J TI Toxic beryllium and genetic testing SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Letter C1 Univ Calif Los Alamos Natl Lab, Publ Affairs Off, Los Alamos, NM USA. RP Danneskiold, J (reprint author), Univ Calif Los Alamos Natl Lab, Publ Affairs Off, POB 1663, Los Alamos, NM USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD MAY PY 2001 VL 109 IS 5 BP A200 EP A200 PG 1 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 438YA UT WOS:000169080800003 PM 11401769 ER PT J AU McCormick, RL Graboski, MS Alleman, TL Herring, AM AF McCormick, RL Graboski, MS Alleman, TL Herring, AM TI Impact of biodiesel source material and chemical structure on emissions of criteria pollutants from a heavy-duty engine SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID DIESEL-ENGINES; COMBUSTION AB Biodiesel is an oxygenated diesel fuel m ade from vegetable oils and animal fats by conversion of the triglyceride fats to esters via transesterification. In this study we examined biodiesels produced from a variety of real-world feedstocks as well as pure (technical grade) fatty acid methyl and ethyl esters for emissions performance in a heavy-duty truck engine. The objective was to understand the impact of biodiesel chemical structure, specifically fatty acid chain length and number of double bonds, an emissions of NOx and particulate matter (PM). A group of seven biodiesels produced from real-world feedstocks and 14 produced from pure fatty acids were tested in a heavy-duty truck engine using the U.S, heavy-duty federal test procedure (transient test). It was found that the molecular structure of biodiesel can have a substantial impact on emissions. The properties of density, cetane number, and iodine number were found to be highly correlated with one another. For neat biodiesels, PM emissions were essentially constant at about 0.07 g/bhp-h for all biodiesels as long as density was less than 0.89 g/cm(3) or cetane number was greater than a bout 45. NOx emissions in creased with increasing fuel density or decreasing fuel cetane number. Increasing the number of double bonds, quantified as iodine number, correlated with increasing emissions of NOx Thus the increased NOx observed for some fuels cannot be explained by the NOx/PM tradeoff and is therefore not driven by thermal NO formation. For fully saturated fatty acid chains the NOx emission increased with decreasing chain length for tests using 18, 16, and 12 carbon chain molecules. Additionally, there was no significant difference in NOx or PM emissions for the methyl and ethyl esters of identical fatty acids. C1 Colorado Sch Mines, Colorado Inst Fuels & Engine Res, Golden, CO 80401 USA. Colorado Sch Mines, Dept Chem Engn & Petr Refining, Golden, CO 80401 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP McCormick, RL (reprint author), Colorado Sch Mines, Colorado Inst Fuels & Engine Res, Golden, CO 80401 USA. RI Herring, Andy/E-7088-2010; Alleman, Teresa/F-6281-2011; McCormick, Robert/B-7928-2011; OI Herring, Andrew/0000-0001-7318-5999 NR 12 TC 329 Z9 338 U1 1 U2 33 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 MAY 1 PY 2001 VL 35 IS 9 BP 1742 EP 1747 DI 10.1021/es001636t PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 429HD UT WOS:000168509600023 PM 11355187 ER PT J AU Zawislanski, PT Chau, S Mountford, H Wong, HC Sears, TC AF Zawislanski, PT Chau, S Mountford, H Wong, HC Sears, TC TI Accumulation of selenium and trace metals on plant litter in a tidal marsh SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE trace elements; selenium; intertidal marsh; litter bags; sediment flux; San Francisco Bay ID SAN-FRANCISCO BAY; SPARTINA-ALTERNIFLORA MARSH; SALT-MARSH; LEAF-LITTER; HEAVY-METALS; COASTAL LOUISIANA; ORGANIC-MATTER; DECOMPOSITION; IRON; DYNAMICS AB Research in a San Francisco Bay intertidal marsh has shown the accumulation of Se and trace metals (Cu, Ni, Zn, Pb, Cd, Fe) on bagged litter of five common estuarine marsh plant species, over periods of months to a year. Metal concentrations increased as much as 150-fold relative to plant tissue initially placed in mesh litter bags. Concentrations of metals increased with the amount of time litter was submerged, though mass accumulation was moderated by the concomitant decay of the litter. The association of very fine particulate matter with the litter, as determined based on Si concentrations, was the main mechanism for enrichment. Further accumulation occurs during winter months via the sorption onto or precipitation with Fe-rich phases, particularly in lower marsh plants. The resultant annual fluxes of Se and most metals to sediments via litter were estimated to be equivalent to between 1 and 16% of the primary flux on suspended particulate matter and may be an important mechanism for scavenging dissolved and colloid-associated metals. Previous studies, which ignored the particulate contribution, may have incorrectly assumed the predominance of sorption and co-precipitation mechanisms. The degree to which litter bags enhance fine sediment trapping over natural conditions needs to be evaluated. (C) 2001 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Zawislanski, PT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Mail Stop 90-1116, Berkeley, CA 94720 USA. NR 60 TC 29 Z9 30 U1 2 U2 8 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD MAY PY 2001 VL 52 IS 5 BP 589 EP 603 DI 10.1006/ecss.2001.0772 PG 15 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 459PT UT WOS:000170260400005 ER PT J AU Appella, E Anderson, CW AF Appella, E Anderson, CW TI Post-translational modifications and activation of p53 by genotoxic stresses SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Review DE DNA damage; phosphorylation; acetylation; stability; transcriptional activation; CBP; p300; MDM2; PML; ATM ID DEPENDENT PROTEIN-KINASE; TUMOR-SUPPRESSOR PROTEIN; DAMAGE-INDUCED PHOSPHORYLATION; GLOBAL GENOMIC REPAIR; DNA-DAMAGE; IN-VIVO; P53-DEPENDENT APOPTOSIS; ENHANCED PHOSPHORYLATION; PREMATURE SENESCENCE; CATALYTIC SUBUNIT AB In unstressed cells, the tumor suppressor protein p53 is present in a latent state and is maintained at low levels through targeted degradation. A variety of genotoxic stresses initiate signaling pathways that transiently stabilize the p53 protein, cause it to accumulate in the nucleus, and activate it as a transcription factor. Activation leads either to growth arrest at the G(1)/S or G(2)/M transitions of the cell cycle or to apoptosis. Recent studies point to roles for multiple post-translational modifications in mediating these events in response to genotoxic stresses through several potentially interacting but distinct pathways. The approximate to 100 amino-acid N-terminal and approximate to 90 amino-acid C-terminal domains are highly modified by post-translational modifications. The N-terminus is heavily phosphorylated while the C-terminus contains phosphorylated, acetylated and sumoylated residues. Antibodies that recognize p53 only when it has been modified at specific sites have been developed, and studies with these reagents show that most known post-translational modifications are induced when cells are exposed to genotoxic stresses. These recent results, coupled with biochemical and genetic studies, suggest that N-terminal phosphorylations are important for stabilizing p53 and are crucial for acetylation of C-terminal sites, which in combination lead to the full p53-mediated response to genotoxic stresses. Modifications to the C-terminus inhibit the ability of this domain to negatively regulate sequence-specific DNA binding; additionally, they modulate the stability, the oligomerization state, the nuclear import/export process and the degree of ubiquitination of p53. C1 NCI, Cell Biol Lab, NIH, Bethesda, MD 20892 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Appella, E (reprint author), NCI, Cell Biol Lab, NIH, Bldg 37, Bethesda, MD 20892 USA. NR 80 TC 754 Z9 773 U1 11 U2 57 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD MAY PY 2001 VL 268 IS 10 BP 2764 EP 2772 DI 10.1046/j.1432-1327.2001.02225.x PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 437AP UT WOS:000168968300002 PM 11358490 ER PT J AU Itahana, K Dimri, G Campisi, J AF Itahana, K Dimri, G Campisi, J TI Regulation of cellular senescence by p53 SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Review DE cellular senescence; cyclin-dependent kinase inhibitors; DNA repair proteins; E2F1; p14/ARF; p21; p53; PML; RAS; telomeres; tumor suppressors ID HUMAN-DIPLOID FIBROBLASTS; MAMMARY EPITHELIAL-CELLS; REPLICATIVE LIFE-SPAN; DNA-DAMAGE; PREMATURE SENESCENCE; TELOMERASE ACTIVITY; SIMIAN VIRUS-40; ONCOGENIC RAS; POLY(ADP-RIBOSE) POLYMERASE; ATAXIA-TELANGIECTASIA AB Many normal cells respond to potentially oncogenic stimuli by undergoing cellular senescence, a state of irreversibly arrested proliferation and altered differentiated function. Cellular senescence very likely evolved to suppress tumorigenesis. In support of this idea, it is regulated by several tumor suppressor genes. At the heart of this regulation is p53. p53 is essential for the senescence response to short telomeres, DNA damage, oncogenes and supraphysiological mitogenic signals, and overexpression of certain tumor suppressor genes. Despite the well-documented central role for p53 in the senescence response, many questions remain regarding how p53 senses senescence-inducing stimuli and how it elicits the senescent phenotype. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. New England Med Ctr, Dept Radiat Oncol, Boston, MA 02111 USA. RP Campisi, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mailstop 84-171,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Itahana, Koji/J-5505-2013 OI Itahana, Koji/0000-0002-7241-2894 NR 78 TC 210 Z9 232 U1 2 U2 16 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD MAY PY 2001 VL 268 IS 10 BP 2784 EP 2791 DI 10.1046/j.1432-1327.2001.02228.x PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 437AP UT WOS:000168968300005 PM 11358493 ER PT J AU Kolbe, E Langanke, K Riisager, K AF Kolbe, E Langanke, K Riisager, K TI Muon capture on neutron-rich nuclei SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID R-PROCESS NUCLEOSYNTHESIS; RANDOM-PHASE-APPROXIMATION; VECTOR COUPLING-CONSTANT; WEAK INTERACTION RATES; MODEL MONTE-CARLO; N = 20; DEFORMATION; SCATTERING; RESONANCE; EMISSION AB Future facilities will allow the exploration of extremely neutron-rich nuclei far from the valley of stability. It is discussed that the strong-neutron excess results in changes in the collective excitations of such nuclei compared to conventional stable nuclei. We propose muon capture as an experimental tool to explore such changes. We will quantify our discussion by the calculation of the total and differential union capture rates on selected calcium isotopes between Ca-40 and Ca-60. Our calculations are based on the random phase approximation and agree nicely with the measured rates for Ca-40 and Ca-44. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus, Denmark. RP Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM langanke@ifa.au.dk NR 41 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1434-6001 EI 1434-601X J9 EUR PHYS J A JI Eur. Phys. J. A PD MAY PY 2001 VL 11 IS 1 BP 39 EP 45 DI 10.1007/s100500170094 PG 7 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 460XV UT WOS:000170336000006 ER PT J AU Airapetian, A Akopov, N Akopov, Z Akushevich, I Amarian, M Arrington, J Aschenauer, EC Avakian, H Avakian, R Avetissia, A Avetissian, E Bailey, P Bains, B Baumgarten, C Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Bottcher, H Borissov, A Bouwhuis, M Brack, J Brauksiepe, S Braun, B Bruckner, W Brull, A Budz, P Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Leo, R De Nardo, L De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Djordjadze, V Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Fechtchenko, A Felawka, L Ferro-Luzzi, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Garber, Y Garibaldi, F Garutti, E Gavrilov, G Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Gute, A Haeberli, W Hartig, M Hasch, D Heesbeen, D Heinsius, FH Henoch, M Hertenberger, R Hesselink, WHA Hofman, G Holler, Y Holt, RJ Hommez, B Iarygin, G Iodice, M Izotov, A Jackson, HE Jgoun, A Jung, P Kaiser, R Kanesaka, J Kinney, E Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolster, H Korotkov, V Kotik, E Kozlov, V Krivokhijine, VG Kyle, G Lagamba, L Laziev, A Lenisa, P Lindemann, T Lorenzon, W Makins, NCR Martin, JW Marukyan, H Masoli, F McAndrew, M McIlhany, K McKeown, RD Meissner, F Menden, F Metz, A Meyners, N Mikloukho, O Miller, CA Milner, R Muccifora, V Mussa, R Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaeva, K Nowak, WD Oganessyan, K O'Neill, TG Openshaw, R Ouyang, J Owen, BR Pate, SF Potashov, S Potterveld, DH Rakness, G Rappoport, V Redwine, R Reggiani, D Reolon, AR Ristinen, R Rith, K Robinson, D Rostonivan, A Ruh, M Ryckbosch, D Sakemi, Y Sato, T Savin, I Scarlett, C Schafer, A Schill, C Schmidt, F Schnell, G Schuler, KP Sebwind, A Seibert, J Seitz, J Shibata, TA Shin, T Shutov, V Simani, MC Simon, A Sinram, K Steffens, E Steijger, JJM Stewart, J Stosslein, U Suetsugu, K Sutter, M Taroian, S Terkulov, A Tessarin, S Thomas, E Tipton, B Tytgat, M Urciuoli, G van den Brand, JFJ van der Steenhoven, G van de Vyver, R van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Weiskopf, C Wendland, J Wilbert, J Wise, T Yen, S Yoneyama, S Zohrabian, H AF Airapetian, A Akopov, N Akopov, Z Akushevich, I Amarian, M Arrington, J Aschenauer, EC Avakian, H Avakian, R Avetissia, A Avetissian, E Bailey, P Bains, B Baumgarten, C Beckmann, M Belostotski, S Bernreuther, S Bianchi, N Bottcher, H Borissov, A Bouwhuis, M Brack, J Brauksiepe, S Braun, B Bruckner, W Brull, A Budz, P Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Leo, R De Nardo, L De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Djordjadze, V Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Fechtchenko, A Felawka, L Ferro-Luzzi, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Garber, Y Garibaldi, F Garutti, E Gavrilov, G Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Gute, A Haeberli, W Hartig, M Hasch, D Heesbeen, D Heinsius, FH Henoch, M Hertenberger, R Hesselink, WHA Hofman, G Holler, Y Holt, RJ Hommez, B Iarygin, G Iodice, M Izotov, A Jackson, HE Jgoun, A Jung, P Kaiser, R Kanesaka, J Kinney, E Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolster, H Korotkov, V Kotik, E Kozlov, V Krivokhijine, VG Kyle, G Lagamba, L Laziev, A Lenisa, P Lindemann, T Lorenzon, W Makins, NCR Martin, JW Marukyan, H Masoli, F McAndrew, M McIlhany, K McKeown, RD Meissner, F Menden, F Metz, A Meyners, N Mikloukho, O Miller, CA Milner, R Muccifora, V Mussa, R Nagaitsev, A Nappi, E Naryshkin, Y Nass, A Negodaeva, K Nowak, WD Oganessyan, K O'Neill, TG Openshaw, R Ouyang, J Owen, BR Pate, SF Potashov, S Potterveld, DH Rakness, G Rappoport, V Redwine, R Reggiani, D Reolon, AR Ristinen, R Rith, K Robinson, D Rostonivan, A Ruh, M Ryckbosch, D Sakemi, Y Sato, T Savin, I Scarlett, C Schafer, A Schill, C Schmidt, F Schnell, G Schuler, KP Sebwind, A Seibert, J Seitz, J Shibata, TA Shin, T Shutov, V Simani, MC Simon, A Sinram, K Steffens, E Steijger, JJM Stewart, J Stosslein, U Suetsugu, K Sutter, M Taroian, S Terkulov, A Tessarin, S Thomas, E Tipton, B Tytgat, M Urciuoli, G van den Brand, JFJ van der Steenhoven, G van de Vyver, R van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Weiskopf, C Wendland, J Wilbert, J Wise, T Yen, S Yoneyama, S Zohrabian, H CA HERMES Collaboration TI Hadron formation in deep-inelastic positron scattering in a nuclear environment SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID COLOR TRANSPARENCY; ELECTROMAGNETIC CORRECTIONS; VECTOR-MESONS; LUND MODEL; ELECTROPRODUCTION; TARGETS; QUARKS; MATTER; FRAGMENTATION; ATTENUATION AB The influence of the nuclear medium on the production of charged hadrons in semi-inclusive deep-inelastic scattering has been studied by the HERMES experiment at DESY using a 27.5 GeV positron beam. The differential multiplicity of charged hadrons and identified charged pions from nitrogen relative to that from deuterium has been measured as a function of the virtual photon energy nu and the fraction z of this energy transferred to the hadron. There are observed substantial reductions of the multiplicity ratio R-M(h) at low nu and at high z, both of which are well described by a gluon-bremsstrahlung model of hadronization. A significant difference of the nu -dependence of R-M(h) is found between positive and negative A hadrons. This is interpreted in terms of a difference between the formation times of protons and pions, using a phenomenological model to describe the nu- and z-dependence of R-M(h). C1 Yerevan Phys Inst, Yerevan 375036, Armenia. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Ist Nazl Fis Nucl, Sezione Bari, I-70124 Bari, Italy. CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA. Univ Colorado, Phys Nucl Lab, Boulder, CO 80309 USA. DESY, D-22603 Hamburg, Germany. DESY, D-15738 Zeuthen, Germany. Joint Inst Nucl Res, Dubna 141980, Russia. Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Sezione Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Freiburg, Fak Phys, D-79104 Freiburg, Germany. State Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Liverpool, Dept Phys, Liverpool L69 7ZE, Merseyside, England. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. Univ Munich, Sekt Phys, D-85748 Garching, Germany. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy. Ist Super Sanita, Phys Lab, I-00161 Rome, Italy. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Tokyo Inst Technol, Dept Phys, Tokyo 152, Japan. Vrije Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany. RP Airapetian, A (reprint author), Yerevan Phys Inst, Yerevan 375036, Armenia. RI Arrington, John/D-1116-2012; Gavrilov, Gennady/C-6260-2013; Holt, Roy/E-5803-2011; Messier, Claude/A-2322-2008; Kozlov, Valentin/M-8000-2015; Terkulov, Adel/M-8581-2015; Cisbani, Evaristo/C-9249-2011; OI Arrington, John/0000-0002-0702-1328; Messier, Claude/0000-0002-4791-1763; Cisbani, Evaristo/0000-0002-6774-8473; Lagamba, Luigi/0000-0002-0233-9812; Heinsius, Fritz-Herbert/0000-0002-9545-5117; Mussa, Roberto/0000-0002-0294-9071 NR 38 TC 121 Z9 122 U1 1 U2 3 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD MAY PY 2001 VL 20 IS 3 BP 479 EP 486 DI 10.1007/s100520100697 PG 8 WC Physics, Particles & Fields SC Physics GA 457HV UT WOS:000170132000005 ER PT J AU Amaral, P Amorini, A Anderson, K Artikov, A Benetta, R Berglund, S Biscarat, C Blanch, O Blanchot, G Bogush, A Bolm, C Boldea, V Borisov, O Bosman, T Bromberg, C Bravo, S Budagov, J Burdin, S Caloba, L Camarena, F Carvalho, J Castillo, MV Cavalli-Sforza, J Cavasinni, V Cerqueira, AS Chadelas, R Chirikov-Zorin, I Chlachidze, G Cobal, M Cogswell, F Cologna, S Constantinescu, S Costanzo, D Cowan, B Crouau, M Daudon, F David, M Davidek, T Dawson, J De, K Delfino, N Del Prete, T De Santo, A Di Girolamo, B Dita, S Downing, R Engstrom, M Errede, D Errede, S Fassi, F Fenyuk, A Ferrer, A Flaminio, V Flix, J Garabik, R Gil, I Gildemeister, O Glagolev, V Gomes, A Gonzalez, V De La Hoz, SG Grabski, V Grenier, P Hakopian, H Haney, M Hellman, S Henriques, A Hebrard, C Higon, E Holik, P Holmgren, S Hruska, I Huston, J Jon-And, K Kakurin, S Karyukhin, A Khubua, J Kopikov, S Krivkova, P Kukhtin, V Kulchitsky, Y Kuzmin, M Lami, S Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Lomakin, Y Lomakin, O Lokajicek, N Amengual, JML Maio, A Malyukov, S Marroquin, F Mataix, L Mazzoni, E Merrit, F Miller, R Minashvili, I Miralles, L Montarou, G Nemecek, S Nessi, M Onofre, A Ostankov, A Pacheco, A Pallin, D Pantea, D Paoletti, R Park, IC Pilcher, J Pinhao, J Price, L Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Roda, C Roldan, J Romance, JB Romanov, V Rosnet, P Ruiz, H Russakovich, N Sanchis, E Sanders, H Santoni, C Santos, J Says, LP Seixas, JM Sellden, B Semenov, A Shchelchkov, A Shochet, M Silva, J Simaitis, V Sissakian, A Solodkov, A Solovianov, O Sosebee, M Soustruznik, K Spano, F Stanek, R Starchenko, E Stavina, P Suk, M Sykora, I Tang, F Tas, P Thaler, J Thome-Filho, ZD Tokar, S Topilin, N Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A AF Amaral, P Amorini, A Anderson, K Artikov, A Benetta, R Berglund, S Biscarat, C Blanch, O Blanchot, G Bogush, A Bolm, C Boldea, V Borisov, O Bosman, T Bromberg, C Bravo, S Budagov, J Burdin, S Caloba, L Camarena, F Carvalho, J Castillo, MV Cavalli-Sforza, J Cavasinni, V Cerqueira, AS Chadelas, R Chirikov-Zorin, I Chlachidze, G Cobal, M Cogswell, F Cologna, S Constantinescu, S Costanzo, D Cowan, B Crouau, M Daudon, F David, M Davidek, T Dawson, J De, K Delfino, N Del Prete, T De Santo, A Di Girolamo, B Dita, S Downing, R Engstrom, M Errede, D Errede, S Fassi, F Fenyuk, A Ferrer, A Flaminio, V Flix, J Garabik, R Gil, I Gildemeister, O Glagolev, V Gomes, A Gonzalez, V De La Hoz, SG Grabski, V Grenier, P Hakopian, H Haney, M Hellman, S Henriques, A Hebrard, C Higon, E Holik, P Holmgren, S Hruska, I Huston, J Jon-And, K Kakurin, S Karyukhin, A Khubua, J Kopikov, S Krivkova, P Kukhtin, V Kulchitsky, Y Kuzmin, M Lami, S Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Lomakin, Y Lomakin, O Lokajicek, N Amengual, JML Maio, A Malyukov, S Marroquin, F Mataix, L Mazzoni, E Merrit, F Miller, R Minashvili, I Miralles, L Montarou, G Nemecek, S Nessi, M Onofre, A Ostankov, A Pacheco, A Pallin, D Pantea, D Paoletti, R Park, IC Pilcher, J Pinhao, J Price, L Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Roda, C Roldan, J Romance, JB Romanov, V Rosnet, P Ruiz, H Russakovich, N Sanchis, E Sanders, H Santoni, C Santos, J Says, LP Seixas, JM Sellden, B Semenov, A Shchelchkov, A Shochet, M Silva, J Simaitis, V Sissakian, A Solodkov, A Solovianov, O Sosebee, M Soustruznik, K Spano, F Stanek, R Starchenko, E Stavina, P Suk, M Sykora, I Tang, F Tas, P Thaler, J Thome-Filho, ZD Tokar, S Topilin, N Valkar, S Varanda, MJ Vartapetian, A Vazeille, F Vichou, I Vinogradov, V Vorozhtsov, S White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Zaitsev, A CA ATLAS TileCal Collaboration TI A precise measurement of 180 GeV muon energy losses in iron SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID PAIR PRODUCTION; BREMSSTRAHLUNG; CALORIMETER AB The energy loss spectrum of 180 GeV muons has been measured with the 5.6 m long finely segmented Module 0 of the ATLAS hadron Tile Calorimeter at the CERN SPS. The differential probability dP/d nu per radiation length of a fractional energy loss nu = DeltaE(mu)/E-mu has been measured in the range 0.025 less than or equal to nu less than or equal to 0.97: it is compared with theoretical predictions for energy losses due to bremsstrahlung, production of electron-positron pairs. and energetic knock-on electrons. The iron elastic form factor correction Delta (el)(Fe) = 1.63 +/-0.17(stat)+/-0.23(syst)+/- (0.20)(0.14theor) to muon bremsstrahlung in the region of no screening of the nucleus by atomic electrons has been measured for the first time, and is compared with different theoretical predictions. C1 LIP, P-1000 Lisbon, Portugal. Univ Lisbon, FCUL, P-1699 Lisbon, Portugal. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, Arlington, TX 76019 USA. Univ Autonoma Barcelona, Inst Fis Altes Energies, E-08193 Barcelona, Spain. Comenius Univ, Bratislava, Slovakia. Inst Atom Phys, R-76900 Bucharest, Romania. Univ Chicago, Chicago, IL 60637 USA. Univ Clermont Ferrand, LPC, CNRS, IN2P3, Clermont Ferrand, France. Joint Inst Nucl Res Dubna, Dubna, Russia. Michigan State Univ, E Lansing, MI 48824 USA. CERN, Geneva, Switzerland. LIP, Coimbra, Portugal. Univ Coimbra, FCTUC, Coimbra, Portugal. Natl Acad Sci, Inst Phys, Minsk, Byelarus. Univ Pisa, Pisa, Italy. Ist Nazl Fis Nucl, Pisa, Italy. Charles Univ, Prague, Czech Republic. Acad Sci Czech Republ, Prague, Czech Republic. Inst High Energy Phys, Protvino, Russia. COPPE EE UFRJ, Rio De Janeiro, Brazil. Stockholm Univ, S-10691 Stockholm, Sweden. Univ Illinois, Champaign, IL 61820 USA. Univ Valencia, CSIC, Ctr Mixto, IFIC, E-46100 Burjassot, Valencia, Spain. Yerevan Phys Inst, Yerevan 375036, Armenia. RP Amaral, P (reprint author), LIP, P-1000 Lisbon, Portugal. RI Nemecek, Stanislav/G-5931-2014; Camarena, Francisco/L-9349-2014; Gil Botella, Ines/H-8991-2015; Ferrer, Antonio/H-2942-2015; Carvalho, Joao/M-4060-2013; Gonzalez de la Hoz, Santiago/E-2494-2016; Delfino, Manuel/A-1545-2012; Pacheco Pages, Andres/C-5353-2011; David, Mario/C-4664-2012; Flix, Josep/G-5414-2012; Ruiz, Hugo/H-4141-2013; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; SANCHIS, ENRIQUE/J-7348-2016; Gonzalez Millan, Vicente/J-3023-2012; Solodkov, Alexander/B-8623-2017; Zaitsev, Alexandre/B-8989-2017; Fassi, Farida/F-3571-2016; Karyukhin, Andrey/J-3904-2014; OI Camarena, Francisco/0000-0002-6713-1414; Ferrer, Antonio/0000-0003-0532-711X; Carvalho, Joao/0000-0002-3015-7821; Gonzalez de la Hoz, Santiago/0000-0001-5304-5390; Delfino, Manuel/0000-0002-9468-4751; Pacheco Pages, Andres/0000-0001-8210-1734; Flix, Josep/0000-0003-2688-8047; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Amorim, Antonio/0000-0003-0638-2321; SANCHIS, ENRIQUE/0000-0002-9689-9131; Gonzalez Millan, Vicente/0000-0001-6014-2586; Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368; Gomes, Agostinho/0000-0002-5940-9893; Fassi, Farida/0000-0002-6423-7213; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Lami, Stefano/0000-0001-9492-0147 NR 35 TC 3 Z9 3 U1 0 U2 4 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD MAY PY 2001 VL 20 IS 3 BP 487 EP 495 DI 10.1007/s100520100645 PG 9 WC Physics, Particles & Fields SC Physics GA 457HV UT WOS:000170132000006 ER PT J AU Mao, G Saboungi, ML Price, DL Badyal, YS Fischer, HE AF Mao, G Saboungi, ML Price, DL Badyal, YS Fischer, HE TI Lithium environment in PEO-LiClO4 polymer electrolyte SO EUROPHYSICS LETTERS LA English DT Article ID INTERMEDIATE-RANGE ORDER; POLY(ETHYLENE OXIDE); CRYSTAL-STRUCTURE; PEO-LITFSI; CONDUCTIVITY; DIFFRACTION; LIQUID; SCATTERING; RELAXATION; TRANSITION AB The average local structure around Li cations in a polymer electrolyte, P(EO)(7.5)LiClO4, has been determined by neutron diffraction with Li isotope substitution. In this environment, the Li ions are predominantly coordinated by 4 similar to 5 ether oxygens. The intermediate-range order is enhanced relative to the pure polymer by the expansion of the network on the addition of the salt. The excess volume introduced must play a key role in facilitating the lithium ion conduction. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Orleans, Ctr Rech Mat Divisee, CRMD, CNRS,UMR 6619, F-45071 Orleans 2, France. Inst Max Von Laue Paul Langevin, F-38041 Grenoble, France. RP Mao, G (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; Fischer, Henry/D-5299-2012 OI Saboungi, Marie-Louise/0000-0002-0607-4815; Fischer, Henry/0000-0002-1204-0750 NR 30 TC 51 Z9 51 U1 1 U2 18 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD MAY PY 2001 VL 54 IS 3 BP 347 EP 353 DI 10.1209/epl/i2001-00249-7 PG 7 WC Physics, Multidisciplinary SC Physics GA 425GX UT WOS:000168283800012 ER PT J AU Tse, JS Shpakov, VP Belosludov, VR Trouw, F Handa, YP Press, W AF Tse, JS Shpakov, VP Belosludov, VR Trouw, F Handa, YP Press, W TI Coupling of localized guest vibrations with the lattice modes in clathrate hydrates SO EUROPHYSICS LETTERS LA English DT Article ID INELASTIC NEUTRON-SCATTERING; THERMAL-CONDUCTIVITY; DYNAMICS; METHANE; ICE AB The thermal conductivity of a gas hydrate is much lower than that of ice and more intriguingly, in spite of the crystalline structure, the temperature profile resembles an amorphous solid. Here we present results from neutron incoherent inelastic scattering (IINS) experiments and theoretical relaxation time calculations to demonstrate unambiguously the coupling of guest and water framework vibrations. The coupling is the consequence of symmetry forbidden crossings of the localized guest motions with the acoustic branches of the lattice vibrations. This phonon interaction leads to an energy exchange mechanism that explains the anomalous thermal behaviour. C1 Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R7, Canada. Russian Acad Sci, Inst Inorgan Chem, Novosibirsk 630090, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. Natl Res Council Canada, Inst Chem Proc & Environm Technol, Ottawa, ON K1A 0R7, Canada. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. RP Tse, JS (reprint author), Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R7, Canada. NR 26 TC 67 Z9 68 U1 2 U2 14 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD MAY PY 2001 VL 54 IS 3 BP 354 EP 360 DI 10.1209/epl/i2001-00250-2 PG 7 WC Physics, Multidisciplinary SC Physics GA 425GX UT WOS:000168283800013 ER PT J AU Gray, ML Champagne, KJ Soong, Y Finseth, DH AF Gray, ML Champagne, KJ Soong, Y Finseth, DH TI Parametric study of the column oil agglomeration of fly ash SO FUEL LA English DT Article; Proceedings Paper CT 3rd International Ash Utilization Symposium CY OCT 18-20, 1999 CL LEXINGTON, KENTUCKY SP Univ Kentuckey, Ctr Appl Energy Res, US DOE DE fly ash; agglomeration; combustion by-products AB A promising oil agglomeration process has been developed for the beneficiation of fly ash using a six-ft agglomeration column. Carbon concentrates have been isolated in recoveries greater than 60% and purities of 55-70%. The parameters studied include agitation speeds, airflow rates, slurry feed rates, solvent/ash ratios, and the use of various solvents as agglomerating agents. The effects of these variables on the quality of separation are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US Dept Energy, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. Winchester Thurston, Pittsburgh, PA 15213 USA. RP Gray, ML (reprint author), US Dept Energy, Fed Energy Technol Ctr, POB 10940,Cochran Mills Rd, Pittsburgh, PA 15236 USA. NR 7 TC 16 Z9 18 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0016-2361 J9 FUEL JI Fuel PD MAY PY 2001 VL 80 IS 6 SI SI BP 867 EP 871 DI 10.1016/S0016-2361(00)00151-4 PG 5 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 407ZT UT WOS:000167302600013 ER PT J AU Soong, Y Schoffstall, MR Link, TA AF Soong, Y Schoffstall, MR Link, TA TI Triboelectrostatic beneficiation of fly ash SO FUEL LA English DT Article; Proceedings Paper CT 3rd International Ash Utilization Symposium CY OCT 18-20, 1999 CL LEXINGTON, KENTUCKY SP Univ Kentuckey, Ctr Appl Energy Res, US DOE DE triboelectrostatic; fly ash; biomass AB Dry triboelectrostatic separations of fly ash derived from both coal combustion and the combustion of coal mixed with 10 wt% biomass were conducted. Two different types of triboelectrostatic separators - parallel plate and louvered plate separators - were used for this study. It is found that the material of construction for the tribocharger in the louvered plate separator affects both the deposition pattern and the quantity of recovery of the separated products. The poor quality of separation for the biomass fly ash studied is probably due to the physical/chemical nature of the biomass fly ash which is signiftcantly different from that of coal Ay ash. Published by Elsevier Science Ltd. C1 US Dept Energy, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Soong, Y (reprint author), US Dept Energy, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 13 TC 22 Z9 23 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0016-2361 J9 FUEL JI Fuel PD MAY PY 2001 VL 80 IS 6 SI SI BP 879 EP 884 DI 10.1016/S0016-2361(00)00150-2 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 407ZT UT WOS:000167302600015 ER PT J AU Kim, SH Chung, KH Lee, DK AF Kim, SH Chung, KH Lee, DK TI A continuous winding scheme for superconducting tokamak coils with cable-in-conduit conductor SO FUSION ENGINEERING AND DESIGN LA English DT Article DE tokamak; superconducting magnet; cable-in-conduit conductor; continuous winding; joint AB Superconducting magnet coils are essential for steady-state or long-pulse operation of tokamaks. In an advanced tokamak, the central solenoid (CS) coils are usually divided into several pairs of modules to provide for an extra plasma shaping capability in addition to those available from the shaping (poloidal field) coils. In the conventional pancake winding scheme of superconducting coils, each coil consists of separate superconducting 'double-pancake' coils connected together in series; however, such joints are not superconducting, which is one of the major disadvantages, especially in pulsed operations. A new type of winding was adopted for the ITER CS coil, which consists of cylindrical shell 'layers' joined in series. A disadvantage of this layer winding is its inability to yield modular coils that can provide certain degree of plasma shaping. Joints can be removed in a coil winding pack with the conventional pancake winding scheme, if the conductor is sufficiently long and the winding machine is properly equipped. The compactness, however, cannot be preserved with this scheme. The winding compactness is important since the radial build of the CS coils is one of the major parameters that determine the machine size. In this paper, we present a continuous winding scheme that requires no joints, allows coil fabrication at minimum dimension, and meets the flux swing requirement and other practical aspects. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Seoul Natl Univ, Dept Nucl Engn, Seoul 151742, South Korea. Korea Basic Sci Inst, Taejon 305333, South Korea. RP Kim, SH (reprint author), Spallat Neutron Source Project, 701 Scarboro Rd,MS 6473, Oak Ridge, TN 37831 USA. OI KIM, SANG-HO/0000-0001-5190-9909 NR 5 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAY PY 2001 VL 55 IS 1 BP 21 EP 33 DI 10.1016/S0920-3796(01)00168-5 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 442FU UT WOS:000169275200003 ER PT J AU Raffray, AR Jones, R Aiello, G Billone, M Giancarli, L Golfier, H Hasegawa, A Katoh, Y Kohyama, A Nishio, S Riccardi, B Tillack, MS AF Raffray, AR Jones, R Aiello, G Billone, M Giancarli, L Golfier, H Hasegawa, A Katoh, Y Kohyama, A Nishio, S Riccardi, B Tillack, MS TI Design and material issues for high performance SiCf/SiC-based fusion power cores SO FUSION ENGINEERING AND DESIGN LA English DT Article DE silicon carbide composites; fusion power cores; design; material issues ID CERAMIC-MATRIX COMPOSITES; SILICON-CARBIDE; HELIUM IMPLANTATION; NEUTRON-IRRADIATION; FATIGUE BEHAVIOR; REACTOR; RATIO AB The SiCf/SiC composite is a promising structural material candidate for fusion power cores and has been considered internationally in several power plant studies. It offers safety advantages arising from its low induced radioactivity and afterheat, and the possibility of high performance through high temperature operation. However, its behavior and performance at high temperatures and under irradiation are still not well known and need to be better characterized. This paper summarizes the current SiCf/SiC design and R&D status. The latest SiCf/SiC-based power core design studies are summarized, and the key SiCf/SiC parameters affecting the performance of power core components are highlighted. The current status of the material R&D is discussed, with the focus on fabrication and joining, baseline properties and properties under irradiation, as well as the desirable evolution of these properties. In the light of this, the R&D plans are summarized and assessed. Finally, to help present-day design studies and in the expectation of future confirmatory R&D results, recommendations are provided on SiCf/SiC parameters and properties to be assumed for present design analysis of long term SiCf/SiC-based power plants. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif San Diego, EBU2, FERP, La Jolla, CA 92093 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. CEA, Ctr Etud Saclay, DRN, DMT,SERMA,LCA, F-91191 Gif Sur Yvette, France. Argonne Natl Lab, Argonne, IL 60439 USA. Tohoku Univ, Dept Quantum Sci & Energy Engn, Aoba Ku, Sendai, Miyagi 9808579, Japan. Kyoto Univ, Inst Adv Energy, Kyoto 6110011, Japan. Japan Atom Energy Res Inst, Naka Fus Res Estab, Dept Fus Plasma Res, Naka, Ibaraki 3110193, Japan. ENEA, CR Frascati, I-00044 Frascati, Rome, Italy. RP Raffray, AR (reprint author), Univ Calif San Diego, EBU2, FERP, Room 458,9500 Gilman Dr, La Jolla, CA 92093 USA. OI Katoh, Yutai/0000-0001-9494-5862 NR 81 TC 119 Z9 121 U1 3 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD MAY PY 2001 VL 55 IS 1 BP 55 EP 95 DI 10.1016/S0920-3796(01)00181-8 PG 41 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 442FU UT WOS:000169275200006 ER PT J AU Wang, YF Xu, HF AF Wang, YF Xu, HF TI Prediction of trace metal partitioning between minerals and aqueous solutions: A linear free energy correlation approach SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID GIBBS FREE-ENERGIES; SOLID-SOLUTION; CRYSTALLINE SOLIDS; CALCITE CEMENT; NEW-MEXICO; ELEMENTS; COEFFICIENTS; CARBONATES; PHASES; MN AB Trace metal partitioning between authigenic minerals and aqueous solutions is of great interest to both geochemical and environmental communities. In this paper, we have developed a linear free energy correlation model that correlates metal partition coefficients with metal cation properties: -2.303 RT logK(d) DeltaG(f,M)(o)(z+) = alpha*(MHx)DeltaG(n,M)(0)(Z-) + beta*(r)(MHX) (z-)(M) + b*(MHX) where alpha*(MHX), beta*(MHX), and b*(MHX) are constants, which can be determined by a regression analysis. For isovalent metal partitioning, because of the constraint of K-d = 1 for the host metal, this correlation can be also expressed as: -2.303 RT log K-d = alpha*(MHX)(DeltaG(n,M)(0)(1-) - DeltaG(n,)(0)M(H)(z-)) + beta*(MHX) (r(M)(z-) - r(M)(H)(z)(+)) - (DeltaG(f,M)(0)(z+) - DeltaG(f,M)(H)(0)(z)(-)). Host minerals from an isostructural family have the same linear free energy relationship. as long as the relationship is expressed as a function of the differences in cation properties between substituent and host metals. We have applied our model to both isovalent and non-isovalent metal partitioning in carbonate minerals. The model closely fits experimental data. demonstrating the robustness of the proposed linear fret: energy relationship. Using the model, we have predicted the partition coefficients of divalent acid trivalent metals between various carbonate minerals and aqueous solutions. The differences between the predicted and experimental values are generally less than 1 logarithmic unit for divalent cations and less than 0.4 logarithmic unit for trivalent cations. Magnesite is predicted to have the largest partition coefficients among the carbonate minerals with a calcite structure and therefore. can be a good scavenger for toxic metals. The kinetic effect on metal partitioning can be described graphically by a "seesaw" line anchored at a host cation. To explain the rate dependence of partition coefficients, we have proposed a conceptual model that relates metal partitioning to surface adsorption. The conceptual model suggests that as the rare of host mineral precipitation increases, the ratio of substituent to host cation in a solid approaches what is in the adsorbed layer. The linear free energy correlation model developed in this paper provides a useful tool for systematizing the existing experimental data and for predicting unknown partition coefficients. Copyright (C) 2001 Elsevier Science Ltd. C1 Sandia Natl Labs, Carlsbad, NM 88220 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP Wang, YF (reprint author), Sandia Natl Labs, 4100 Natl Parks Highway, Carlsbad, NM 88220 USA. NR 48 TC 46 Z9 48 U1 0 U2 4 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 MAY PY 2001 VL 65 IS 10 BP 1529 EP 1543 DI 10.1016/S0016-7037(01)00551-8 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 433ME UT WOS:000168762600001 ER PT J AU Farges, F Brown, GE Petit, PE Munoz, M AF Farges, F Brown, GE Petit, PE Munoz, M TI Transition elements in water-bearing silicate glasses/melts. Part I. A high-resolution and anharmonic analysis of Ni coordination environments in crystals, glasses, and melts SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; NEAR-EDGE-STRUCTURE; ESRF BEAMLINE ID26; K-EDGE; INTRACRYSTALLINE DISTRIBUTION; COMPOSITIONAL DEPENDENCE; GEOCHEMICAL IMPLICATIONS; STRUCTURAL ENVIRONMENT; MODEL COMPOUNDS; NICKEL AB The local structural environment around Ni(II) in a series of crystalline model compounds and K-Ni-, Na-Ni-, and Ca-Ni-silicate glasses and melts has been evaluated by using high-resolution Ni K-edge XANES spectroscopy and anharmonic EXAFS data analysis. The glasses show NBO/T contents ranging from 0 (albitic composition) to 1 (alkali-disilicate composition) and Ni contents ranging from 40 ppm to 2 wt.%. The pre-edge feature for model compounds vary not only in normalized height as a function of Ni-coordination but also in position (by similar to0.5 eV) as confirmed by ab initio XANES calculations. In addition, the pre-edge position is indirectly correlated with the average Ni-O distance. By using these correlations, Ni is predicted to be 4-coordinated, on average, in the potassic glasses, similar to5-coordinated in the sodic glasses, and >5-coordinated in the calcic glasses. The EXAFS-derived distances and coordination numbers are consistent with these conclusions. with the average Ni-O distances ranging between 1.96 and 2.03(2) Angstrom. In contrast, NiO4 units are dominant in the melts examined (Na-disilicate composition with 4000 ppm of Ni). Variation in NBO/T or in Ni concentration does not affect the local environment of Ni in these silicate glasses whereas the type of network modifier present in the glass (K vs. Na vs. Ca + Mg) does. This finding explains the overall good agreement between this study and a previous XAFS study on silicate glasses with higher Ni concentrations and less polymerization (Galoisy and Calas, 1993a). In Part 2 of this series, these new correlations between Ni K-pre-edge features and Ni coordination number are used to characterize Ni structural environments in sodium trisilicate and albitic glasses containing 2000 ppm of Ni and exposed to pressures up to 5 kbars with 0 to 8 wt.% water. These hydrated glasses show major changes in their crystal held spectra. which correspond to major changes in the local coordination environment of Ni as revealed by XAFS spectroscopy. Copyright (C) 2001 Elsevier Science Ltd. C1 Univ Marne la Vallee, Lab Geomat, F-77454 Marne La Vallee, France. Ecole Natl Mines Paris, F-77454 Marne La Vallee, France. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Univ Marne la Vallee, Lab Geomat, F-77454 Marne La Vallee, France. EM farges@univ-mlv.fr RI Munoz, Manuel/E-7278-2012 NR 55 TC 53 Z9 53 U1 2 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 2001 VL 65 IS 10 BP 1665 EP 1678 DI 10.1016/S0016-7037(00)00625-6 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 433ME UT WOS:000168762600010 ER PT J AU Farges, F Munoz, M Siewert, R Malavergne, V Brown, GE Behrens, H Nowak, M Petit, PE AF Farges, F Munoz, M Siewert, R Malavergne, V Brown, GE Behrens, H Nowak, M Petit, PE TI Transition elements in water-bearing silicate glasses/melts. Part II. Ni in water-bearing glasses SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HYDROUS ALBITE GLASSES; NEAR-EDGE STRUCTURE; K-EDGE; HIGH-TEMPERATURE; IN-SITU; SPECTROSCOPIC DETERMINATION; COMPOSITIONAL DEPENDENCE; STRUCTURAL ENVIRONMENT; CATION COORDINATION; OXIDE COMPOUNDS AB The local coordination environment around Ni(II) in a series of sodium trisilicate (NS3) and albitic (ALB) glasses has been evaluated by using high-resolution XANES and anharmonic EXAFS spectroscopies. The glasses contain similar to 1000 to 4000 ppm of Ni and from 0 to 8.1 wt.% water. They were synthesized at pressures between 2.2 and 5 kbars and temperatures between 1050 and 1350 K. The bulk: glasses were characterized by using X-ray diffraction, transmission electron microscopy. Raman, and ultraviolet-Vis-NIR spectroscopies. Both hydrous NS3 and ALE glasses show dominant amounts of Ni(II) in relatively regular 6-coordinated environments, in contrast with their anhydrous counterparts, where 5-coordinated Ni dominates. There are also significant differences in the average medium-range environment (2-3.5 Angstrom) around Ni between the anhydrous and hydrous glasses. In the ALE glasses, the presence of water in amounts >2 wt.% induces the formation of nanocrystallites, with an average diameter of similar to 40 Angstrom and an atomic arrangement similar to that of nepouite ((Ni3Si2O5)-Ni-[6](OH)(4)) or Ni-talc ((Ni3Si4O10)-Ni-[6](OH)(2)) or a related hydrous No-silicate. The presence of Ni-bearing nanocrystallites is thought to be due to the relatively slow quench rate of the high-temperature-high-pressure synthesis apparatus used. These nanophases are difficult to detect by using conventional characterization methods and can cause misleading interpretations of the glass structure if not detected. In contrast, there is no evidence for Ni-rich, nanocrystalline domains in NS3 glasses containing high water contents (up to 8.2 wt.%); instead, two to three Si second neighbors are observed around Ni in all NS3 glasses (and in ALE glasses with water contents <4 wt.%). The bonding of Ni to oxygens in the tetrahedral framework is inconsistent with the presence of large amounts of Ni(H2O)(6)(2+) complexes in these glasses However, Ni(II) may form Ni(OH)(n) O-6-n((4+n)-) (n similar to 6) complexes in hydrous glasses. Our results for Ni combined with results from other studies of 3-d divalent transition metal cations in hydrous silicate glasses suggest that water in silicate melts helps these cations form their preferred coordination environments [6-coordinated for Mn(II), Fe(II), and Ni(II)]. Ni(II) may occur in natural hydrous silicate melts dominantly in 6-coordinated environments. rather than dominantly in 4-coordinated environments, as in anhydrous melts and supercritical aqueous fluids, explaining the compatible behavior of Ni in magmas. However, in situ experiments are required to test this suggestion. Copyright (C) 2001 Elsevier Science Ltd. C1 Univ Marne la Vallee, Lab Geomat, F-77454 Marne La Vallee, France. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. Leibniz Univ Hannover, Inst Mineral, D-30167 Hannover, Germany. European Synchrotron Radiat Facil, F-38043 Grenoble, France. RP Univ Marne la Vallee, Lab Geomat, F-77454 Marne La Vallee, France. EM farges@univ-mlv.fr RI Munoz, Manuel/E-7278-2012 NR 58 TC 26 Z9 26 U1 8 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 2001 VL 65 IS 10 BP 1679 EP 1693 DI 10.1016/S0016-7037(00)00624-4 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 433ME UT WOS:000168762600011 ER PT J AU Nelson, ST Karlsson, HR Paces, JB Tingey, DG Ward, S Peters, MT AF Nelson, ST Karlsson, HR Paces, JB Tingey, DG Ward, S Peters, MT TI Paleohydrologic record of spring deposits in and around Pleistocene pluvial Lake Tecopa, southeastern California SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE hydrology; isotope geochemistry; nuclear waste; paleoclimate; paleohydrology ID DEATH-VALLEY; DEVILS-HOLE; NEVADA; CARBONATES; CALCITE; AGES AB Tufa (spring) deposits in the Tecopa basin, California, reflect the response of arid groundwater regimes to wet climate episodes. Two types of tufa are represented, informally defined as (1) an easily disaggregated, fine-grained mixture of calcite and quartz (friable tufa) in the southwest Tecopa Valley, and (2) hard, vuggy micrite, laminated carbonate, and carbonate-cemented sands and gravels (indurated tufa) along the eastern margin of Lake Tecopa, High delta O-18(VSMOW) (Vienna standard mean ocean water) water values, field relations, and the texture of friable tufa suggest rapid nucleation of calcite as subaqueous, fault-controlled groundwater discharge mixed with high-pa, hypersaline lake water. Variations between delta O-18(VSMOW) and delta C-13(PDB) (Peedee belemnite) values relative to other closed basin lakes such as the Great Salt Lake and Lake Lahontan suggest similarities in climatic and hydrologic settings. Indurated tufa, also fault controlled, formed mounds and associated feeder systems as well as stratabound carbonate-cemented ledges, Both deposits represent discharge of deeply circulated, high total dissolved solids, and high pCO(2) regional groundwater with kinetic enrichments of as much as several per mil for delta O-18(VSMOW) values. Field relations show that indurated tufa represents episodic discharge, and U-series ages imply that discharge was correlated with cold, wet climate episodes. In response to both the breaching of the Tecopa basin and a modern arid climate, most discharge has changed from fault-controlled locations near basin margins to topographic lows of the Amargosa River drainage at elevations 30-130 m lower, Because of episodic climate change, spring flows may have relocated from basin margin to basin center multiple times. C1 Brigham Young Univ, Dept Geol, Provo, UT 84602 USA. Texas Tech Univ, Dept Geosci, Lubbock, TX 79409 USA. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Univ Calif Los Alamos Natl Lab, Las Vegas, NV 89134 USA. RP Nelson, ST (reprint author), Brigham Young Univ, Dept Geol, S389 ESC, Provo, UT 84602 USA. NR 43 TC 19 Z9 19 U1 1 U2 10 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD MAY PY 2001 VL 113 IS 5 BP 659 EP 670 DI 10.1130/0016-7606(2001)113<0659:PROSDI>2.0.CO;2 PG 12 WC Geosciences, Multidisciplinary SC Geology GA 428DV UT WOS:000168446800012 ER PT J AU Riebe, CS Kirchner, JW Granger, DE Finkel, RC AF Riebe, CS Kirchner, JW Granger, DE Finkel, RC TI Minimal climatic control on erosion rates in the Sierra Nevada, California SO GEOLOGY LA English DT Article DE cosmogenic nuclides; erosion rates; climate ID SITU-PRODUCED BE-10; DENUDATION RATES; ALLUVIAL SEDIMENT; MOUNTAIN-RANGES; PUERTO-RICO; UPLIFT; RIVER; EQUILIBRIUM; DISCHARGE; OCEAN AB Climate is widely thought to regulate erosion rates, but the relationships among precipitation, temperature, and erosion rate have remained speculative, because long-term erosion rates have been difficult to measure. We used cosmogenic nuclides to measure long-term erosion rates at climatically diverse sites in the Sierra Nevada, California, spanning 20-180 cm/yr in annual precipitation and;4-15 degreesC in mean annual temperature. Average erosion rates vary by only 2.5 fold across these sites and are not correlated with climate, indicating that climate only weakly regulates nonglacial erosion rates in mountainous granitic terrain. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Riebe, CS (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. RI Kirchner, James/B-6126-2009; Riebe, Clifford/B-7670-2012 OI Kirchner, James/0000-0001-6577-3619; NR 35 TC 118 Z9 120 U1 2 U2 27 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD MAY PY 2001 VL 29 IS 5 BP 447 EP 450 DI 10.1130/0091-7613(2001)029<0447:MCCOER>2.0.CO;2 PG 4 WC Geology SC Geology GA 428DJ UT WOS:000168445700018 ER PT J AU McAdams, KL Reeves, GD AF McAdams, KL Reeves, GD TI Non-adiabatic response of relativistic radiation belt electrons to GEM magnetic storms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTHS INNER MAGNETOSPHERE; SCATTERING LOSS; ACCELERATION; PARAMETERS; DRIVEN; MODEL AB The importance of fully adiabatic effects in the relativistic radiation belt electron response to magnetic storms is poorly characterized due to many difficulties in calculating adiabatic flux response. Using the adiabatic flu?; model of Kim and Chan [1997a] and Los Alamos National Laboratory geosynchronous satellite data, we examine the relative timing of the adiabatic and non-adiabatic flux responses. In the three storms identified by the GEM community for in depth study, the non-adiabatic energization occurs hours earlier than the adiabatic re-energization. The adiabatic energization can account for only 10-20% of the flux increases in the first recovery stages, and only 1% of the Aux increase if there is continuing activity. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McAdams, KL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS D466, Los Alamos, NM 87545 USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 15 TC 15 Z9 15 U1 0 U2 0 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 MAY 1 PY 2001 VL 28 IS 9 BP 1879 EP 1882 DI 10.1029/2000GL011998 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100053 ER PT J AU Li, XL Temerin, M Baker, DN Reeves, GD Larson, D AF Li, XL Temerin, M Baker, DN Reeves, GD Larson, D TI Quantitative prediction of radiation belt electrons at geostationary orbit based on solar wind measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ADVANCED-COMPOSITION-EXPLORER; RELATIVISTIC ELECTRONS; MAGNETOSPHERE; ACCELERATION; STORM AB Solar wind measurements are used to predict the MeV electron radiation belt flux at the position of geostationary orbit. Using a model based on the standard radial diffusion equation, a prediction efficiency of 0.81 and a linear correlation of 0.90 were achieved for the years 1995-1996 for the logarithm of average daily flux. Model parameters based on the years 1995-1990 gave a prediction efficiency and a linear correlation for the years 1995-1999 of 0.59 and 0.80, respectively. The radial diffusion equation is solved after making the diffusion coefficient a function of the solar wind velocity and interplanetary magnetic field. The solar wind velocity is the most important parameter governing relativistic electron fluxes at geostationary orbit. The model also provides a physical explanation to several long standing mysteries of the variation of the MeV electrons. C1 Univ Colorado, LASP, Boulder, CO 80303 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Li, XL (reprint author), Univ Colorado, LASP, 1234 Innovat Dr, Boulder, CO 80303 USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 21 TC 156 Z9 166 U1 2 U2 12 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 MAY 1 PY 2001 VL 28 IS 9 BP 1887 EP 1890 DI 10.1029/2000GL012681 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 424QN UT WOS:000168243100055 ER PT J AU Badea, EA Everett, ME Newman, GA Biro, O AF Badea, EA Everett, ME Newman, GA Biro, O TI Finite-element analysis of controlled-source electromagnetic induction using Coulomb-gauged potentials SO GEOPHYSICS LA English DT Article ID EDDY CURRENTS; EQUATIONS; COMPUTATION; SERIES; FIELDS; TIME AB A 3-D finite-element solution has been used to solve controlled-source electromagnetic (EM) induction problems in heterogeneous electrically conducting media. The solution is based on a weak formulation of the governing Maxwell equations using Coulomb-gauged EM potentials. The resulting sparse system of linear algebraic equations is solved efficiently using the quasi-minimal residual method with simple Jacobi scaling as a preconditioner. The main aspects of this work include the implementation of a 3-D cylindrical mesh generator with high-quality local mesh refinement and a formulation in terms of secondary EM potentials that eliminates singularities introduced by the source. These new aspects provide quantitative induction-log interpretation for petroleum exploration applications. Examples are given for 1-D, 2-D, and 3-D problems, and favorable comparisons are presented against other, previously published multidimensional EM induction codes. The method is general and can also be adapted for controlled-source EM modeling in mining, groundwater, and environmental geophysics in addition to fundamental studies of EM induction in heterogeneous media. C1 Halliburton Energy Serv, Houston, TX USA. Texas A&M Univ, Dept Geol & Geophys, College Stn, TX 77843 USA. Sandia Natl Labs, Dept Geophys, Albuquerque, NM 87185 USA. Graz Tech Univ, Inst Grundlagen & Theorie Elektrontech, A-8010 Graz, Austria. RP Badea, EA (reprint author), Univ Houston, Dept Elect & Comp Engn, Houston, TX 77204 USA. RI Biro, Oszkar/F-9812-2015; Newman, Gregory/G-2813-2015; OI Biro, Oszkar/0000-0003-0792-8955 NR 38 TC 59 Z9 74 U1 0 U2 6 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD MAY-JUN PY 2001 VL 66 IS 3 BP 786 EP 799 DI 10.1190/1.1444968 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 441LH UT WOS:000169231500008 ER PT J AU Keers, H Vasco, DW Johnson, LR AF Keers, H Vasco, DW Johnson, LR TI Viscoacoustic crosswell imaging using asymptotic waveforms SO GEOPHYSICS LA English DT Article ID UNCONSOLIDATED SAND; IMMISCIBLE LIQUIDS; CROSSHOLE DATA; ATTENUATION; INVERSION; TOMOGRAPHY; VELOCITY AB We present a method to invert viscoacoustic waveforms. The waveform inversion is based on a new forward algorithm for waves propagating through viscoacoustic media. The algorithm represents the wavefield in terms of a summation over nonstationary raypaths. The amplitudes at the caustics are computed correctly. The inclusion of nonstationary raypaths makes it possible to compute sensitivity functions for both velocity and attenuation. The sensitivity functions lead to a linearized formulation of the waveform inversion. The inversion is applied to two 2-D data sets that previously had been matched using only velocity. The first data set consists of crosswell data obtained from a tank filled with a water-saturated sand. The second data set was obtained after injecting a nonaqueous-phase liquid into the tank. The inclusion of attenuation significantly improves the fit to the data, especially in the case of the second experiment. A misfit reduction of 80% was obtained, whereas the misfit: reduction after inversion for velocity only was 40%. The Q values obtained for the two experiments (Q = 60-100 before the injection and Q = 10-20 in the second experiment) fall within the range predicted by other experiments. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Schlumberger Cambridge Res Ltd, POB 153, Cambridge CB3 0EL, England. EM dwvasco@lbl.gov; lrj@ccs.lbl.gov RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 21 TC 9 Z9 10 U1 1 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 EI 1942-2156 J9 GEOPHYSICS JI Geophysics PD MAY-JUN PY 2001 VL 66 IS 3 BP 861 EP 870 DI 10.1190/1.1444975 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 441LH UT WOS:000169231500015 ER PT J AU Smith, SJ Pitcher, H Wigley, TML AF Smith, SJ Pitcher, H Wigley, TML TI Global and regional anthropogenic sulfur dioxide emissions SO GLOBAL AND PLANETARY CHANGE LA English DT Article DE sulfur dioxide; aerosols; climate forcing; acid rain ID TURKISH LIGNITES; GREENHOUSE GASES; CLIMATE-CHANGE; ATMOSPHERE; CYCLE; ATTRIBUTION; AEROSOLS; OCEAN; MODEL; ASIA AB We present a new inventory of global sulfur dioxide emissions from anthropogenic activities for the years 1980-2000. Emissions were estimated in 11 world regions using country-level emissions inventories and regional fossil fuel sulfur content information. Estimated global emissions in 1990 are 72 TgS with an estimated uncertainty of +/-8% due to random errors with additional systematic errors that suggest that true emissions may be higher than this central value. We estimate that 56% of 1990 world emissions are from coal, 24% from oil, 15% from industrial processes and 3% from biomass burning. When our results are compared with other studies, they are similar at the global-mean level, but show marked differences at the regional level. Globally, emissions have been roughly constant from 1980 to the present. However, a significant shift has occurred in the spatial distribution of emissions. While 60% of global emissions in 1980 were from around the North Atlantic basin, this region contributed less than 40% of the global total by 1995 and will contribute even less in the future. Currently, based on our estimates, the centrally planned Asia (CPA) region, dominated by China, is the largest contributor to global sulfur dioxide emissions. A gridded data set for 1990 emissions is also produced, including a consistent seasonal cycle and a stratification of emissions into low and elevated releases. Implications for climate modeling and detection studies are discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Washington, DC 20024 USA. Natl Ctr Atmospher Res, Boulder, CO USA. RP Smith, SJ (reprint author), Pacific NW Natl Lab, 901 D St,SW,Suite 900, Washington, DC 20024 USA. RI Wigley, Tom/B-4705-2008 NR 65 TC 159 Z9 169 U1 5 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8181 J9 GLOBAL PLANET CHANGE JI Glob. Planet. Change PD MAY PY 2001 VL 29 IS 1-2 BP 99 EP 119 DI 10.1016/S0921-8181(00)00057-6 PG 21 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 449ET UT WOS:000169671900005 ER PT J AU Kocher, DC AF Kocher, DC TI Drinking water standards for radionuclides: The dilemma and a possible resolution SO HEALTH PHYSICS LA English DT Article DE regulations; safety standards; water; exposure, population AB The U,S, Environmental Protection Agency (EPA) is undertaking a revision of existing standards for radionuclides in drinking water. The Safe Drinking Water Act specifies that any revision "shall maintain or provide for greater protection of the health of persons." This provision appears to require that existing standards (maximum contaminant levels, MCLs) cannot be relaxed. Such a requirement presents a dilemma for two reasons. First, EPA has shown that the MCL for radium was not cost-effective. Second, MCLs for beta/gamma-emitting radionuclides incorporate outdated approaches to estimating dose from ingestion of radionuclides and, thus, appear to violate provisions of the Safe Drinking Water Act concerning the use of sound science in setting standards, We suggest that this dilemma can be resolved based on an argument that the standard for protection of public health mandated by the Safe Drinking Water Act is one of applying best-available technology for removal of contaminants from drinking water at a reasonable cost, not one of meeting previously established MCLs. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. EM dck@ornl.gov NR 19 TC 4 Z9 4 U1 1 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAY PY 2001 VL 80 IS 5 BP 486 EP 490 DI 10.1097/00004032-200105000-00009 PG 5 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 421KV UT WOS:000168064300009 PM 11316079 ER PT J AU Ryan, MT Skrable, KW French, CS Potter, CA AF Ryan, MT Skrable, KW French, CS Potter, CA TI A simple method for assessing exposure to internal emitters SO HEALTH PHYSICS LA English DT Article DE operational topics; exposure, internal; alpha particles; intake, radionuclide ID CLEARANCE AB One of The most challenging aspects of regulatory compliance can be demonstrating compliance with internal dosimetry requirements. For long-lived alpha-emitting radionuclides in particular, the sensitivity and accuracy of bioassay analysis and whole body counting may not allow for adequate assessment of intakes. Simple and effective measures can be used to control the workplace for the internal hazards associated with long-lived radioactive material using methods that measure directly the air to which workers are exposed. This paper provides an easy assessment tool that uses direct measurement of the specific activity of dusts in breathing zone air to evaluate internal exposures. Using this method sensitive assessments can be made to determine if intakes are likely to have occurred and, if so, at what magnitude. It is not a substitute for confirmatory bioassay or whole body counting but a simple method To evaluate expectations for internal exposures. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Massachusetts, Radiol Sci Program, Lowell, MA 01854 USA. Med Univ S Carolina, Dept Hlth Adm & Policy, Ctr Hlth Profess, Charleston, SC 29425 USA. EM ryanmt@musc.edu NR 9 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 MAY PY 2001 VL 80 IS 5 SU S BP S51 EP S54 DI 10.1097/00004032-200105001-00005 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 423HE UT WOS:000168169200003 PM 11316083 ER PT J AU Filman, RE AF Filman, RE TI Medicine on the Net - From isolation to universal Connectivity SO IEEE INTERNET COMPUTING LA English DT Editorial Material C1 NASA, Ames Res Ctr, Adv Comp Sci Res Inst, Ames, IA USA. RP Filman, RE (reprint author), NASA, Ames Res Ctr, Adv Comp Sci Res Inst, Ames, IA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1089-7801 J9 IEEE INTERNET COMPUT JI IEEE Internet Comput. PD MAY-JUN PY 2001 VL 5 IS 3 BP 40 EP 41 DI 10.1109/MIC.2001.935175 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 436BH UT WOS:000168916300006 ER PT J AU Artz, D AF Artz, D TI Digital steganography: Hiding data within data SO IEEE INTERNET COMPUTING LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Artz, D (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 120 Z9 120 U1 1 U2 8 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1089-7801 J9 IEEE INTERNET COMPUT JI IEEE Internet Comput. PD MAY-JUN PY 2001 VL 5 IS 3 BP 75 EP 80 DI 10.1109/4236.935180 PG 6 WC Computer Science, Software Engineering SC Computer Science GA 436BH UT WOS:000168916300011 ER PT J AU Patel, FD Beach, RJ AF Patel, FD Beach, RJ TI New formalism for the analysis of passively Q-switched laser systems SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE chromium (Cr); excited-state absorption; modeling; neodymium (Nd); numerical analysis; Q-switched lasers; saturable absorber; solid lasers (solid-state lasers); YAG lasers; Ytterbium (Yb) ID EXCITED-STATE ABSORPTION; ND-YAG LASER; SATURABLE ABSORBERS; QUASI-3-LEVEL LASERS; MICROCHIP LASERS; CR,ND-YAG LASER; OPTIMIZATION; CR4+; OPERATION; CRYSTALS AB We present a new formalism for the analysis of passively Q-switched laser systems that facilitates the performance of sensitivity studies and system optimizations. The developed formalism is general enough to include the impact of an ESA process in the saturable absorber Q-switch and, therefore, is applicable to Cr4+:YAG passively Q-switched systems. To illustrate the use of the developed formalism, we have applied it to a comparative analysis of two laser systems based on Nd:YAG and Yb:YAG. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Patel, FD (reprint author), Agilent Technol Inc, Palo Alto, CA 94304 USA. NR 35 TC 30 Z9 31 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAY PY 2001 VL 37 IS 5 BP 707 EP 715 DI 10.1109/3.918585 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 426PX UT WOS:000168358500013 ER PT J AU Dixon, WE Zergeroglu, E AF Dixon, WE Zergeroglu, E TI Comments on "Adaptive variable structure set-point control of underactuated robots" SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Lucent Technol, Sturbridge, MA 01566 USA. RP Dixon, WE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dixon, Warren/F-5238-2015 OI Dixon, Warren/0000-0002-5091-181X NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD MAY PY 2001 VL 46 IS 5 BP 812 EP 812 DI 10.1109/TAC.2001.920809 PG 1 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 431FL UT WOS:000168621100024 ER PT J AU Warne, LK Lee, KSH AF Warne, LK Lee, KSH TI Some remarks on antenna response in a reverberation chamber SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE antenna response; correlation tenser; dyadic Green's function; reverberation chamber ID CAVITIES; FIELDS AB The simple formula, [P-r] = (E-o(2)/eta)(lambda (2)/8 pi), for the received power of an antenna with a matched load in an over-moded cavity actually holds for an antenna of any shape and size. This can be seen from the close connection between the correlation tenser of the cavity field at two different points and the imaginary part of the free-space dyadic Green's function. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. ITT Ind, Los Angeles, CA 90024 USA. RP Warne, LK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 10 Z9 10 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 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD MAY PY 2001 VL 43 IS 2 BP 239 EP 240 DI 10.1109/15.925546 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 438ER UT WOS:000169041200017 ER PT J AU Huang, XJ Lee, WC Kuo, C Hisamoto, D Chang, LL Kedzierski, J Anderson, E Takeuchi, H Choi, YK Asano, K Subramanian, V King, TJ Bokor, J Hu, CM AF Huang, XJ Lee, WC Kuo, C Hisamoto, D Chang, LL Kedzierski, J Anderson, E Takeuchi, H Choi, YK Asano, K Subramanian, V King, TJ Bokor, J Hu, CM TI Sub-50 nm p-channel FinFET SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE double-gate MOSFETs; fully depleted; MOS devices; scaled CMOS; short-channel effect; silicon-germanium (SiGe); SOI MOSFETs ID POLYCRYSTALLINE SIXGE1-X FILMS; MOSFET AB High-performance PMOSFETs with sub-50-nm gate-length are reported. A self-aligned double-gate MOSFET structure (FinFET) is used to suppress the short-channel effects. This vertical double-gate SOI MOSFET features: 1) a transistor channel which is formed on the vertical surfaces of an ultrathin Si fin and controlled by gate electrodes formed on both sides of the fin; 2) two gates which are self-aligned to each other and to the source/drain (S/D) regions; 3) raised S/D regions; and 4) a short (50 nm) Si fin to maintain quasi-planar topology for ease of fabrication. The 45-nm gate-length p-channel FinFET showed an I-dsat of 820 muA/mum at V-ds = V-gs = 1.2 V and T-ox = 2.5 nm, Devices showed good performance down to a gate-length of 18 nm, Excellent short-channel behavior was observed. The fin thickness (corresponding to twice the body thickness) is found to be critical for suppressing the short-channel effects, Simulations indicate that the FinFET structure can work down to 10 nm gate length, Thus, the FinFET is a very promising structure for scaling CMOS beyond 50 nm. C1 Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. Hitachi Ltd, Cent Res Lab, Tokyo, Japan. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NKK Corp, Tokyo, Japan. RP Huang, XJ (reprint author), Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RI Bokor, Jeffrey/A-2683-2011; Subramanian, Vivek/K-9818-2016 OI Subramanian, Vivek/0000-0002-1783-8219 NR 11 TC 140 Z9 142 U1 5 U2 67 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD MAY PY 2001 VL 48 IS 5 BP 880 EP 886 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 426QZ UT WOS:000168361000010 ER PT J AU Hill, ME Callin, RS Whittum, DH AF Hill, ME Callin, RS Whittum, DH TI High-power vacuum window in WR10 SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article AB Results are presented in this paper for fabrication and test of a WR10 waveguide window for use in ultrahigh vacuum at 91.4 GHz, Low-power bench measurements are compared with analytic and simulation results. Operation at approximate to4-kW peak power, duty factor 10(-6), and 10(-9)-scale vacuum is noted. C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Hill, ME (reprint author), Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. NR 4 TC 13 Z9 12 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 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD MAY PY 2001 VL 49 IS 5 BP 994 EP 995 DI 10.1109/22.920160 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 429KK UT WOS:000168515800021 ER PT J AU Hill, ME Fowkes, WR Lin, XE Whittum, DH AF Hill, ME Fowkes, WR Lin, XE Whittum, DH TI Beam-cavity interaction circuit at W-band SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article ID MICROWAVE AB In this paper, we describe the design, fabrication, and bench study of a millimeter-wave cavity employed as a relativistic klystron output structure. The oxygen-free electronic-grade copper cavity was prepared by electro-discharge machining and diffusion bonding, and cleaned and tuned to 91.4 GHz, Measured cavity characteristics are presented and compared with theory, including quality factor Q, coupling parameter beta, scattering matrix S-11, and axial electric field profile E-z. This paper provides the basis fur an understanding of the cavity as a transfer structure. C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Hill, ME (reprint author), Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. NR 6 TC 5 Z9 4 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 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD MAY PY 2001 VL 49 IS 5 BP 998 EP 1000 DI 10.1109/22.920162 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 429KK UT WOS:000168515800023 ER PT J AU Yang, Z Shen, C Zhang, L Crow, ML Atcitty, S AF Yang, Z Shen, C Zhang, L Crow, ML Atcitty, S TI Integration of a StatCom and battery energy storage SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article DE battery energy storage; control system synthesis; FACTS; power system dynamic stability AB The integration of an energy storage system, such as battery energy storage (BESS), into a FACTS device can provide dynamic decentralized active power capabilities and much needed flexibility for mitigating transmission level power flow problems. This paper will introduce an integrated StatCom/BESS for the improvement of dynamic and transient stability and transmission capability; compare the performance of the different FACTS/BESS combinations, and provide experimental verification of the proposed controls on a scaled StatCom/BESS system. C1 Univ Missouri, Rolla, MO 65409 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Yang, Z (reprint author), Univ Missouri, Rolla, MO 65409 USA. OI Crow, Mariesa/0000-0002-2087-9599 NR 13 TC 114 Z9 121 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD MAY PY 2001 VL 16 IS 2 BP 254 EP 260 DI 10.1109/59.918295 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 424LK UT WOS:000168233600012 ER PT J AU Baek, SO Jenkins, RA AF Baek, SO Jenkins, RA TI Performance evaluation of simultaneous monitoring of personal exposure to environmental tobacco smoke and volatile organic compounds SO INDOOR AND BUILT ENVIRONMENT LA English DT Article; Proceedings Paper CT International Conference on Monitoring Indoor Air Pollution CY APR 18-19, 2001 CL MANCHESTER METROPOLITAN UNIV, MANCHESTER, ENGLAND HO MANCHESTER METROPOLITAN UNIV DE personal exposure; environmental tobacco smoke; volatile organic compounds; indoor air; monitoring; respirable suspended particulates; benzene ID AIR AB The objective of this study was to develop and demonstrate a methodology to determine human exposure to a variety of indoor air contaminants by personal monitoring. Target analytes included respirable suspended particulates, components of environmental tobacco smoke (ETS) and a wide range of volatile organic compounds (VOCs). A total of 60 non-smoking, non-occupational residents at homes in metropolitan Taegu, Korea, were recruited for this study. The subjects were classified into two groups, i.e. subjects living in homes with smokers and without smokers. Seasonal air samples were collected using three-channel personal samplers for each subject in two phases over a 24-hour period, i.e. awake time and sleeping time separately. Performance of sampling and analytical methods used for the simultaneous measurements of ETS and VOCs were evaluated with respect to sensitivity, repeatability and field application. Copyright (C) 2002 S, Karger AG, Basel. C1 Yeungnam Univ, Dept Environm Engn, Sch Civil Urban & Environm Engn, Kyongsan 712749, South Korea. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Baek, SO (reprint author), Yeungnam Univ, Dept Environm Engn, Sch Civil Urban & Environm Engn, Kyongsan 712749, South Korea. NR 14 TC 7 Z9 7 U1 0 U2 3 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1420-326X J9 INDOOR BUILT ENVIRON JI Indoor Built Environ. PD MAY-AUG PY 2001 VL 10 IS 3-4 BP 200 EP 208 DI 10.1159/000049237 PG 9 WC Construction & Building Technology; Engineering, Environmental; Public, Environmental & Occupational Health SC Construction & Building Technology; Engineering; Public, Environmental & Occupational Health GA 529BA UT WOS:000174279100013 ER PT J AU Gall, K Yang, N Sehitoglu, H Chumlyakov, YI AF Gall, K Yang, N Sehitoglu, H Chumlyakov, YI TI Fracture of precipitated NiTi shape memory alloys SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE cleavage fracture; growth and coalescence; scanning electron microscopy; single crystal and polycrystalline NiTi; solutionized and aged; void nucleation ID MARTENSITE START TEMPERATURES; TENSION-COMPRESSION ASYMMETRY; TRANSFORMATION STRESS LEVELS; TI-NI; CLEAVAGE FRACTURE; SINGLE-CRYSTAL; CYCLIC DEFORMATION; PSEUDOELASTICITY CHARACTERISTICS; POLYCRYSTALLINE NITI; FATIGUE AB The fracture mechanisms in single crystal and polycrystalline Ti-50.8at%Ni shape memory alloys containing Ti3Ni4 precipitates are studied using the scanning electron microscope (SEM). Aged materials with three different precipitate sizes (50 nm, 150 nm, and 400 nm), which have interfaces ranging from semi-coherent to incoherent, are considered. The mechanisms of material fracture identified in the single crystal NiTi are: 1. Nucleation, growth, and coalescence of voids from the Ti3Ni4 precipitates, 2. Cleavage fracture on {100} and {110} crystallographic planes, 3. Nucleation, growth, and coalescence of voids from fractured Ti-C inclusions. Cleavage and ductile tearing mechanisms also operate in polycrystalline NiTi, however, since the Ti-C inclusions are an artifact of single crystal growth processes, mechanism 3 was not discovered in the polycrystalline materials. Cleavage fracture and ductile tearing are found to act in conjunction, with the relative dominance of one over the other depending on the local precipitate size and concentration. As the Ti3Ni4 precipitate size increases to about 400 nm, the overall fracture is dominated by failure mechanism 1, and the cleavage markings become diffuse. Finally, we assert that the high tensile ductility of drawn NiTi polycrystals is due partially to the fact that drawn bar and wire stock usually have a strong {111} fiber texture. Such a texture promotes the initiation of the transformation at low stresses and concurrently prevents primary cleavage on the {100} or {110} planes. C1 Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Sandia Natl Labs, Microstruct Res Dept, Livermore, CA 94550 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. Siberian Phys & Tech Inst, Phys Plast & Strength Mat Lab, Tomsk 634050, Russia. RP Gall, K (reprint author), Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. RI yuriy, chumlyakov/C-6033-2009; Chumlyakov, Yuriy/R-6496-2016 NR 40 TC 49 Z9 49 U1 3 U2 18 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PD MAY PY 2001 VL 109 IS 2 BP 189 EP 207 DI 10.1023/A:1011069204123 PG 19 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 441TP UT WOS:000169245900004 ER PT J AU Regueiro, RA Borja, RI AF Regueiro, RA Borja, RI TI Plane strain finite element analysis of pressure sensitive plasticity with strong discontinuity SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE localized deformation; geomaterials; failure model; strong discontinuity; pressure sensitive nonassociative plasticity; assumed enhanced strain finite element method ID NUMERICAL-SIMULATION; LOCALIZATION; MODELS; SOLIDS; FORMULATION; DEFORMATION; CONTINUUM; IMPLEMENTATION; MECHANICS; MEDIA AB Numerical simulations of localized deformation in solids should capture the structural phenomenon of localization and associated loss of material body strength in a manner independent of spatial discretization, Many regularization techniques have been proposed to address the ill posedness associated with rate-independent softening plasticity that leads to mesh-dependent numerical simulations. One approach to alleviating mesh dependence is the strong discontinuity approach, which represents localized deformation as a slip surface within a plasticity model; a strong discontinuity is a discontinuous displacement held. This approach is used in this paper to formulate a plane strain, pressure sensitive, nonassociative plasticity model with strong discontinuity and to implement the model, along with an enhanced bilinear quadrilateral element, via an assumed enhanced strain method. Numerical examples demonstrate mesh independence of the method for pressure sensitive materials. (C) 2001 Elsevier Science Ltd. Ah rights reserved. C1 Sandia Natl Labs, Ctr Mat & Engn Sci, Livermore, CA 94551 USA. Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. RP Regueiro, RA (reprint author), Sandia Natl Labs, Ctr Mat & Engn Sci, POB 969,MS 9405, Livermore, CA 94551 USA. OI Regueiro, Richard/0000-0002-1669-1753 NR 56 TC 54 Z9 58 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD MAY PY 2001 VL 38 IS 21 BP 3647 EP 3672 DI 10.1016/S0020-7683(00)00250-X PG 26 WC Mechanics SC Mechanics GA 427RU UT WOS:000168419900001 ER PT J AU Gautesen, AK AF Gautesen, AK TI Scattering of a Rayleigh wave by an elastic wedge whose angle is greater than 180 degrees SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB The steady-state problem of scattering of an incident Rayleigh wave by an elastic wedge whose angle is greater than 180 degrees is considered The problem is reduced to the numerical solution of a pair of Fredholm integral equations of the second kind whose kernels consist of elementary functions. Numerical results are given for the amplitude and phase of the Rayleigh waves transmitted and reflected by the corner. C1 Iowa State Univ Sci & Technol, Dept Math, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Gautesen, AK (reprint author), Iowa State Univ Sci & Technol, Dept Math, 136 Wilhelm Hall, Ames, IA 50011 USA. NR 12 TC 7 Z9 7 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD MAY PY 2001 VL 68 IS 3 BP 476 EP 479 DI 10.1115/1.1365156 PG 4 WC Mechanics SC Mechanics GA 436QT UT WOS:000168947100015 ER PT J AU Floro, JA Hearne, SJ Hunter, JA Kotula, P Chason, E Seel, SC Thompson, CV AF Floro, JA Hearne, SJ Hunter, JA Kotula, P Chason, E Seel, SC Thompson, CV TI The dynamic competition between stress generation and relaxation mechanisms during coalescence of Volmer-Weber thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ABNORMAL GRAIN-GROWTH; METAL-FILMS; INTRINSIC STRESS; INTERNAL-STRESS; SUBSTRATE-TEMPERATURE; COPPER; POLYCRYSTALLINE; STRAIN; DEPENDENCE; SURFACE AB Real-time measurements of stress evolution during the deposition of Volmer-Weber thin films reveal a complex interplay between mechanisms for stress generation and stress relaxation. We observed a generic stress evolution from compressive to tensile, then back to compressive stress as the film thickened, in amorphous and polycrystalline Ge and Si, as well as in polycrystalline Ag, Al, and Ti. Direct measurements of stress relaxation during growth interrupts demonstrate that the generic behavior occurs even in the absence of stress relaxation. When relaxation did occur, the mechanism depended sensitively on whether the film was continuous or discontinuous, on the process conditions, and on the film/substrate interfacial strength. For Ag films, interfacial shear dominated the early relaxation behavior, whereas this mechanism was negligible in Al films due to the much stronger bonding at the Al/SiO2 interface. For amorphous Ge, selective relaxation of tensile stress was observed only at elevated temperatures, consistent with surface-diffusion-based mechanisms. In all the films studied here, stress relaxation was suppressed after the films became continuous. (C) 2001 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Brown Univ, Div Engn, Providence, RI 02912 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. RP Floro, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Kotula, Paul/A-7657-2011 OI Kotula, Paul/0000-0002-7521-2759 NR 38 TC 207 Z9 207 U1 6 U2 77 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 MAY 1 PY 2001 VL 89 IS 9 BP 4886 EP 4897 DI 10.1063/1.1352563 PG 12 WC Physics, Applied SC Physics GA 422QE UT WOS:000168130100032 ER PT J AU Tsang, T Castillo, V Larsen, R Lazarus, DM Nikas, D Ozben, C Semertzidis, YK Srinivasan-Rao, T Kowalski, L AF Tsang, T Castillo, V Larsen, R Lazarus, DM Nikas, D Ozben, C Semertzidis, YK Srinivasan-Rao, T Kowalski, L TI Electro-optical measurements of picosecond bunch length of a 45 MeV electron beam SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRYSTAL; PULSES; PROBE AB We have measured the temporal duration of 45 MeV picosecond electron beam bunches using a noninvasive electro-optical (EO) technique. The amplitude of the EO modulation was found to increase linearly with electron beam charge and decrease inversely with distance from the electron beam. The rise time of the temporal signal was limited by our detection system to similar to 70 ps. The EO signal due to ionization caused by the electrons traversing the EO crystal was also observed. It has a distinctively long decay time constant and signal polarity opposite to that due to the field induced by the electron beam. The electro-optical technique may be ideal for the measurement of bunch length of femtosecond, relativistic, high energy, charged, particle beams. (C) 2001 American Institute of Physics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Montclair State Univ, Upper Montclair, NJ 07043 USA. RP Tsang, T (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Semertzidis, Yannis K./N-1002-2013; Francisco, Suely/D-9065-2014 NR 18 TC 9 Z9 9 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 MAY 1 PY 2001 VL 89 IS 9 BP 4921 EP 4926 DI 10.1063/1.1358322 PG 6 WC Physics, Applied SC Physics GA 422QE UT WOS:000168130100037 ER PT J AU Wasik, D Baj, M Siwiec-Matuszyk, J Gronkowski, J Jasinski, J Karczewski, G AF Wasik, D Baj, M Siwiec-Matuszyk, J Gronkowski, J Jasinski, J Karczewski, G TI Effect of hydrostatic pressure on degradation of CdTe/CdMgTe heterostructures grown by molecular beam epitaxy on GaAs substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID QUANTUM-WELL STRUCTURES; HETEROJUNCTIONS; DIFFRACTOMETER; LAYERS; DIODE; LASER AB We have shown that external hydrostatic pressure leads to the creation of structural defects, mainly in the vicinity of the II-VI/GaAs interface in the CdTe/Cd1-xMgxTe heterostructures grown by the molecular beam epitaxy method on GaAs substrates. These defects propagating across the epilayer cause permanent damage to the samples from the point of view of their electrical properties. In contrast, photoluminescence spectra are only weakly influenced by pressure. Our results shed light on the degradation process observed even without pressure in II-VI-based heterostructures. (C) 2001 American Institute of Physics. C1 Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Polish Acad Sci, Inst Phys, PL-02668 Warsaw, Poland. RP Wasik, D (reprint author), Univ Warsaw, Inst Expt Phys, Hoza 69, PL-00681 Warsaw, Poland. NR 20 TC 3 Z9 3 U1 0 U2 0 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 MAY 1 PY 2001 VL 89 IS 9 BP 5025 EP 5030 DI 10.1063/1.1360217 PG 6 WC Physics, Applied SC Physics GA 422QE UT WOS:000168130100051 ER PT J AU Weygand, JM Murphree, JS Henderson, MG Enno, GA AF Weygand, JM Murphree, JS Henderson, MG Enno, GA TI Simultaneous closed magnetic field line polar arcs and substorms SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE polar arc; substorm; magnetic field line ID SUN-ALIGNED ARCS; MAGNETOSPHERIC SUBSTORMS; THERMAL CATASTROPHE; EARTHS MAGNETOTAIL; VIKING SPACECRAFT; BOUNDARY-LAYER; AURORAL ARCS; CAP ARCS; MODEL; DYNAMICS AB Viking UV images of the northern hemisphere auroral region were examined during simultaneous substorms and polar arcs. Of 120 substorm events, 43 recorded polar arcs. In all events the substorm. and polar are were identified with the images, and a strict definition of the term polar arc has been applied to rigorously eliminate any ambiguous cases from this study. In addition, simultaneous events of substorms and polar arcs were separated into four cases: dawnside polar area before substorm onset, dawnside polar arcs after onset, duskside polar arcs before onset, and duskside polar arcs after onset. Superposition epoch plots of the average polar are intensity over time with respect to substorm onset were created. Overall, these plots suggest a weak coupling between the polar are and the substorm mechanisms. In most of the simultaneous cases, little or no motion of the polar are was measured. This observation, combined with the various intensity minimum determined in the superposition epoch plots, suggests little or no change occurs in the thickness of the plasma sheet as many substorm models predict. Furthermore, magnetic field line mapping frequently indicates magnetic field lines of polar arcs stretch far down the magnetotail (i.e., greater than 50 Earth Radii), while substorms appear to be located within 20 R-e. This concept, combined with the theory that the interaction between the polar arcs and substorms is weak, suggests that substorms cannot be a distant magnetotail event, otherwise there would be a stronger interaction between the two. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. Univ Calgary, Dept Phys, Calgary, AB T2N 1N4, Canada. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Univ Bern, Inst Phys, Sidlerstr 5, CH-3012 Bern, Switzerland. EM weygand@soho.unibe.ch; murphree@phys.ucalgary.ca; mghenderson@lanl.gov; alla@phys.ucalgary.ca RI Henderson, Michael/A-3948-2011 OI Henderson, Michael/0000-0003-4975-9029 NR 37 TC 2 Z9 2 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 EI 1879-1824 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAY PY 2001 VL 63 IS 7 BP 643 EP 655 DI 10.1016/S1364-6826(00)00184-X PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 432EM UT WOS:000168679300003 ER PT J AU Smith, RA Paulus, MJ Branning, JM Phillips, PJ AF Smith, RA Paulus, MJ Branning, JM Phillips, PJ TI X-ray computed tomography on a cellular polysiloxane under compression SO JOURNAL OF CELLULAR PLASTICS LA English DT Article AB X-ray tomographic images were collected for polydimethylsiloxane (PDMS) foam material under various levels of compression. The goal was to implement a systematic analysis method of correlating some aspect of these images to the cell morphology in order to enhance understanding of the material characteristics. X-ray attenuation of the cellular PDMS was clearly observed to increase with the specimen density as the foam material was mechanically compressed. The stochastic data derived from the digital images was used to calculate macroscopic mechanical properties at each foam compression. C1 Lockheed Martin Energy Syst, Plant Y12, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Purdue Univ, W Lafayette, IN 47906 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Smith, RA (reprint author), Lockheed Martin Energy Syst, Plant Y12, POB 2009,Bldg 9202,MS-8094, Oak Ridge, TN 37831 USA. NR 9 TC 6 Z9 7 U1 2 U2 7 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-955X J9 J CELL PLAST JI J. Cell. Plast. PD MAY PY 2001 VL 37 IS 3 BP 231 EP 248 DI 10.1106/3BWD-3D89-3JLL-MPJN PG 18 WC Chemistry, Applied; Polymer Science SC Chemistry; Polymer Science GA 431LT UT WOS:000168633300004 ER PT J AU de Graaf, RA Pan, JW Telang, F Lee, JH Brown, P Novotny, EJ Hetherington, HP Rothman, DL AF de Graaf, RA Pan, JW Telang, F Lee, JH Brown, P Novotny, EJ Hetherington, HP Rothman, DL TI Differentiation of glucose transport in human brain gray and white matter SO JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM LA English DT Article DE glucose transport; nuclear magnetic resonance spectroscopy; human brain; gray matter; white matter ID MAGNETIC-RESONANCE SPECTROSCOPY; RAT-BRAIN; IN-VIVO; METABOLITE CONCENTRATIONS; NMR-SPECTROSCOPY; BLOOD; H-1-NMR; SPECTRA; BARRIER; GLUT1 AB Localized H-1 nuclear magnetic resonance spectroscopy has been applied to determine human brain gray matter and white matter glucose transport kinetics by measuring the steady-stare glucose concentration under normoglycemia and two levels of hyperglycemia. Nuclear magnetic resonance spectroscopic measurements were simultaneously performed on three 12-mL volumes. containing predominantly gray or white matter. The exact volume compositions were determined from quantitative T-1 relaxation magnetic resonance images. The absolute brain glucose concentration as a function of the plasma glucose level was fitted with two kinetic transport models, based on standard (irreversible) or reversible Michaelis-Menten kinetics. The steady-state brain glucose levels were similar for cerebral gray and white matter, although the white matter levels were consistently 15% to 20% higher. The ratio of the maximum glucose transport rate, V-max, to the cerebral metabolic utilization rate of glucose, CMRGlc, was 3.2 +/- 0.10 and 3.9 +/- 0.15 for gray matter and white matter using the standard transport model and 1.8 +/- 0.10 and 2.2 +/- 0.12 for gray matter and white matter using the reversible transport model. The Michaelis-Menten constant K-m was 6.2 +/- 0.85 and 7.3 +/- 1.1 mmol/L for gray matter acid white matter in the standard model and 1.1 +/- 0.66 and 1.7 +/- 0.88 mmol/L in the reversible model. Taking into account the threefold lower rate of CMRGlc in white matter, this finding suggests that blood-brain barrier glucose transport activity is lower by a similar amount in white matter. The regulation of glucose transport activity at the blood-brain barrier may be an important mechanism for maintaining glucose homeostasis: throughout the cerebral cortex. C1 Yale Univ, Sch Med, Dept Pediat, New Haven, CT 06520 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Yale Univ, Sch Med, Dept Radiol, New Haven, CT 06520 USA. RP de Graaf, RA (reprint author), Yale Univ, Sch Med, Dept Diagnost Radiol, Magnet Resonance Ctr, POB 208043,333 Cedar St, New Haven, CT 06520 USA. RI Lee, Jing-Huei/J-3978-2016 OI Lee, Jing-Huei/0000-0001-9921-7629 FU NINDS NIH HHS [NS032126] NR 39 TC 47 Z9 47 U1 0 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0271-678X J9 J CEREBR BLOOD F MET JI J. Cereb. Blood Flow Metab. PD MAY PY 2001 VL 21 IS 5 BP 483 EP 492 PG 10 WC Endocrinology & Metabolism; Hematology; Neurosciences SC Endocrinology & Metabolism; Hematology; Neurosciences & Neurology GA 428XT UT WOS:000168487500002 PM 11333358 ER PT J AU Fu, JW Paduano, L Rard, JA Albright, JG Miller, DG AF Fu, JW Paduano, L Rard, JA Albright, JG Miller, DG TI Mutual diffusion coefficients and densities at 298.15 K of aqueous mixtures of NaCl and Na2SO4 at high concentrations with NaCl solute fractions of 0.9000 SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID ISOPIESTIC DETERMINATION; RAYLEIGH INTERFEROMETRY; OSMOTIC COEFFICIENTS; CONCENTRATION RATIO; TERNARY DIFFUSION; TOTAL MOLARITY; WIDE-RANGE; THERMODYNAMIC PROPERTIES; ELECTROLYTE-SOLUTIONS; MGCL2 CONCENTRATIONS AB Isothermal mutual, diffusion coefficients (interdiffusion coefficients) were measured for ternary aqueous mixtures of NaCl and Na2SO4 at a constant NaCl molarity fraction z(1) = 0.9000 at 298.15 K, using high precision Rayleigh interferometry with computerized data acquisition. The experiments were performed at total molarities of(2.0000, 3.0003, 4.0010, and 5.0071) mol.dm(-3). Diffusion coefficients of NaCl(aq) were also measured at essentially these same four concentrations, those of Na2SO4(aq) at (1.3500 and 1.6998) mol.dm(-3), as were the densities of all solutions. These measurements supplement our earlier ones at total molarities of(0.5000, 1.0002(5), and 1.4990) mol.dm(-3) with various ratios of NaCl to Na2SO4, which also included compositions with z(1) = 0.9000. At nearly all of the ternary solution compositions, the Na2SO4 cross-term diffusion coefficient is small and negative whereas the NaCl cross-term diffusion coefficient is larger and positive. However, at the fixed NaCl molarity fraction z(1) = 0.9000, the Na2SO4 cross-term diffusion coefficient changes from negative to positive values as the total concentration exceeds about 4.0 mol.dm(-3), and above 3.0 mol.dm(-3) the size of the NaCl cross-term diffusion coefficient exceeds that of the corresponding Na2SO4 main-term diffusion coefficient. This indicates that, at high concentrations, a concentration gradient of Na2SO4 causes the transport of more NaCl than of itself In contrast, cotransport of Na2SO4 by a concentration gradient of NaCl is quite small. C1 Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Energy & Environm Direc, Livermore, CA 94550 USA. Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. Univ Naples Federico II, Dipartimento Chim, I-80126 Naples, Italy. RP Rard, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Energy & Environm Direc, Livermore, CA 94550 USA. OI PADUANO, Luigi/0000-0002-1105-4237 NR 55 TC 6 Z9 6 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD MAY-JUN PY 2001 VL 46 IS 3 BP 601 EP 608 DI 10.1021/je000357i PG 8 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA 435JE UT WOS:000168877700020 ER PT J AU Randic, M Balaban, AT Basak, SC AF Randic, M Balaban, AT Basak, SC TI On structural interpretation of several distance related topological indices SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article; Proceedings Paper CT 2nd Indo-US Workshop on Mathermatical Chemistry with Applications to Drug Discovery, Cheminformatics, and Bioinformatics CY MAY 30-JUN 03, 2000 CL UNIV MINNESOTA DULUTH, DULUTH, MINNESOTA SP Univ Minnesota Duluth, Nat Resources Res Inst, Visva Bharati Univ, Santinietan, W Bengal HO UNIV MINNESOTA DULUTH ID MOLECULAR CONNECTIVITY INDEXES; CHEMICAL GRAPHS; BOILING POINTS; WIENER MATRIX; SHAPE INDEX; DESCRIPTORS; ALKANES; HYDROCARBONS; INVARIANTS; COMPUTATION AB We consider the role that individual bonds play in bond-additivities in order to better understand the structural basis of various topological indices. In particular we consider indices closely related to the Wiener index (W) and the distance matrix and search for optimal weights of terminal and interior CC bonds in alkanes for a selection of physicochemical properties. It is interesting to note that different properties are associated with different relative roles of the exterior and the interior CC bonds. C1 Univ Minnesota, Nat Resources Res Inst, Duluth, MN 55811 USA. Iowa State Univ Sci & Technol, Ames Lab, DOE, Ames, IA 50011 USA. Natl Inst Chem, Ljubljana, Slovenia. Polytech Univ, Bucharest, Romania. Texas A&M Univ, Dept Oceanog & Marine Sci, Galveston, TX 77553 USA. RP Randic, M (reprint author), Univ Minnesota, Nat Resources Res Inst, 5013 Miller Trunk Highway, Duluth, MN 55811 USA. NR 69 TC 35 Z9 35 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD MAY-JUN PY 2001 VL 41 IS 3 BP 593 EP 601 DI 10.1021/ci0001051 PG 9 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 438UV UT WOS:000169073400015 PM 11410034 ER PT J AU Randic, M Basak, SC AF Randic, M Basak, SC TI On use of the variable connectivity index (1)chi(f) in QSAR: Toxicity of aliphatic ethers SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article; Proceedings Paper CT 2nd Indo-US Workshop on Mathermatical Chemistry with Applications to Drug Discovery, Cheminformatics, and Bioinformatics CY MAY 30-JUN 03, 2000 CL UNIV MINNESOTA DULUTH, DULUTH, MINNESOTA SP Univ Minnesota Duluth, Nat Resources Res Inst, Visva Bharati Univ, Santinietan, W Bengal HO UNIV MINNESOTA DULUTH ID MOLECULAR CONNECTIVITY; HETEROATOMS AB The number of non-hydrogen atoms in a molecule, N, appears as a very good molecular descriptor for the toxicity of aliphatic ethers, despite the fact that it does not differentiate among isomers. The regression based on N as a descriptor for the toxicity in mice of 21 alkyl ethers was reported to yield the regression coefficient r = 0.9751. The simple connectivity index (1)chi produced for the same data a less satisfactory regression: r = 0.9548. To see if variable connectivity index (1)chi (f) can improve the regression characterized by N we examined the same data using the variable connectivity index (1)chi (f) as a molecular descriptor. By varying x, y, the variables that discriminate between carbon and oxygen atoms, we obtained regression which approaches in quality the best reported regression using weighted paths as descriptor and which is marginally better than the regression based on N. C1 Drake Univ, Dept Math & Comp Sci, Des Moines, IA 50311 USA. Univ Minnesota, Nat Resources Res Inst, Duluth, MN 55811 USA. Iowa State Univ Sci & Technol, Ames Lab, DOE, Ames, IA 50011 USA. Natl Inst Chem, Lab Chemometr, Ljubljana, Slovenia. RP Randic, M (reprint author), Drake Univ, Dept Math & Comp Sci, Des Moines, IA 50311 USA. NR 14 TC 66 Z9 66 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD MAY-JUN PY 2001 VL 41 IS 3 BP 614 EP 618 DI 10.1021/ci000114u PG 5 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 438UV UT WOS:000169073400018 PM 11410037 ER PT J AU Wang, XB Wang, LS Brown, R Schwerdtfeger, P Schroder, D Schwarz, H AF Wang, XB Wang, LS Brown, R Schwerdtfeger, P Schroder, D Schwarz, H TI The electronic structure of CuCl2 and CuBr2 from anion photoelectron spectroscopy and ab initio calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; FOURIER-TRANSFORM SPECTRA; MULTIPLY-CHARGED ANIONS; GROUND-STATE; RED EMISSION; GAS-PHASE; PHOTODETACHMENT; TRANSITION; COPPER; ISOTOPOMERS AB The electronic structures of CuX2 (X=Cl and Br) have been investigated in the gas phase by means of anion photodetachment photoelectron spectroscopy and ab initio theory. The photoelectron spectra of CuX2- were recorded at two photon energies, 193 and 157 nm. Well-resolved and rich photodetachment features in the spectra provide unprecedented details for the low-lying electronic states of CuCl2 and CuBr2. The excitation energies for five low-lying electronic states of CuX2 were determined, and they explain well the two previously observed optical absorption bands. The electron affinities for CuCl2 and CuBr2 were determined to be identical, 4.35 +/-0.05 eV within the experimental uncertainty. Both the anions and neutral CuX2 species were calculated to be linear with only a slight bond length variation between the charged and neutral species. The calculated electron affinities and vertical excitation energies for the excited states agree well with the experimental values, yielding a definite assignment for the electronic states of CuCl2 and CuBr2. (C) 2001 American Institute of Physics. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Auckland, Dept Chem, Auckland, New Zealand. Tech Univ Berlin, Inst Organ Chem, D-10623 Berlin, Germany. RP Wang, XB (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. NR 48 TC 47 Z9 48 U1 1 U2 16 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 MAY 1 PY 2001 VL 114 IS 17 BP 7388 EP 7395 DI 10.1063/1.1362289 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 423GT UT WOS:000168168100011 ER PT J AU Skurski, P Gutowski, M Simons, J AF Skurski, P Gutowski, M Simons, J TI Ab initio electronic structure of HCN- and HNC- dipole-bound anions and a description of electron loss upon tautomerization SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; POLAR-MOLECULES; NEGATIVE-IONS; WAVE-FUNCTIONS; STATE; FIELD; ISOMERIZATION; AFFINITIES; STABILITY; SPECTRUM AB The binding of an excess electron to HCN and HNC was studied at the coupled cluster level of theory with single, double, and noniterative triple excitations and with extended basis sets to accommodate the loosely bound excess electron. The HCN molecule, with a dipole moment of 3.05 Debye, binds an electron by 10 cm(-1), whereas the HNC tautomer possesses a similar dipole moment (3.08 Debye) and binds the electron by 43 cm(-1). The electronic stability of the anionic system along the minimum energy HCN --> HNC tautomerization path has been investigated, and it was concluded that the excess electron autodetaches during the tautomerization. Unusually large electron correlation energy contributions to the total electron binding energy were found and are discussed. (C) 2001 American Institute of Physics. C1 Univ Utah, Dept Chem, Henry Eyring Ctr Theoret Chem, Salt Lake City, UT 84112 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Simons, J (reprint author), Univ Utah, Dept Chem, Henry Eyring Ctr Theoret Chem, Salt Lake City, UT 84112 USA. EM simons@chemistry.utah.edu NR 42 TC 26 Z9 27 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 1 PY 2001 VL 114 IS 17 BP 7443 EP 7449 DI 10.1063/1.1358863 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 423GT UT WOS:000168168100016 ER PT J AU Koneshan, S Rasaiah, JC Dang, LX AF Koneshan, S Rasaiah, JC Dang, LX TI Computer simulation studies of aqueous solutions at ambient and supercritical conditions using effective pair potential and polarizable potential models for water SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; SOLVENT DENSITY INHOMOGENEITIES; SODIUM-CHLORIDE SOLUTIONS; HYDROGEN-BOND DYNAMICS; LIQUID WATER; CHEMICAL-REACTIONS; ION ASSOCIATION; FREE-ENERGY; 683 K; SOLVATION AB This paper discusses the computer simulation of the diffusion coefficients and structure of infinitely dilute aqueous ionic solutions at ambient (298 K, solvent density 0.997 g cm(-3)) and supercritical (683 K, solvent density 0.35 g cm(-3)) conditions using two different models for water. They are the extended simple point charge (SPC/E) and renormalized polarizability (RPOL) models in which the electronic polarizations of the water molecule are treated differently. The effect of polarizability is implicit in the SPC/E model and explicit in the RPOL model. The RPOL model shows slightly greater hydrogen bonding, at room temperature than the SPC/E model, but less hydrogen bonding at 683 K. It is concluded that the explicit neglect of electronic polarization of the solvent and ions in calculations based on the SPC/E model of water, has only a small effect on the diffusion coefficients of the ions. Both models predict diffusion coefficients of ions in supercritical water that are weakly dependent on their size in contrast to their behavior under ambient conditions discussed in previous work [S. Koneshan , J. Phys. Chem. 102, 4193 (1998)]. The simulations suggest that the mechanism of diffusion at the ambient and supercritical states of the solvent water is different. (C) 2001 American Institute of Physics. C1 Univ Maine, Dept Chem, Orono, ME 04469 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Koneshan, S (reprint author), Cornell Univ, Dept Comp Sci, Upson Hall, Ithaca, NY 14853 USA. NR 45 TC 66 Z9 66 U1 0 U2 9 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 MAY 1 PY 2001 VL 114 IS 17 BP 7544 EP 7555 DI 10.1063/1.1350447 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 423GT UT WOS:000168168100028 ER PT J AU Protopopescu, VA Hively, LM Gailey, PC AF Protopopescu, VA Hively, LM Gailey, PC TI Epileptic event forewarning from scalp EEG SO JOURNAL OF CLINICAL NEUROPHYSIOLOGY LA English DT Review DE nonlinear measures; event forewarning; scalp EEG; artifact filter ID NONLINEAR TIME-SERIES; OBSERVED CHAOTIC DATA; CORRELATION INTEGRALS; COMPLEXITY-MEASURES; STRANGE ATTRACTORS; DYNAMICAL CHANGE; REAL-TIME; SEIZURES; NONSTATIONARITY; BRAIN AB The authors present a model-independent approach to quantify changes in the dynamics underlying nonlinear time-serial data. From time-windowed datasets, the authors construct discrete distribution functions on the phase space. Condition change between base case and test case distribution functions is assessed by dissimilarity measures via L-1 distance and chi (2) statistic, The discriminating power of these measures is first tested on noiseless data from the Lorenz and Bondarenko models, and is then applied to detecting dynamic change in multichannel clinical scalp EEG data. The authors compare the dissimilarity measures with the traditional nonlinear measures used in the analysis of chaotic systems. They also assess the potential usefulness of the new measures for robust, accurate, and timely forewarning of epileptic events. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. RP Protopopescu, VA (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 57 TC 26 Z9 28 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0736-0258 J9 J CLIN NEUROPHYSIOL JI J. Clin. Neurophysiol. PD MAY PY 2001 VL 18 IS 3 BP 223 EP 245 DI 10.1097/00004691-200105000-00003 PG 23 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 475AH UT WOS:000171139100003 PM 11528295 ER PT J AU Ingber, MS Kempka, SN AF Ingber, MS Kempka, SN TI A Galerkin implementation of the generalized Helmholtz decomposition for vorticity formulations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE vorticity methods; generalized Helmholtz decomposition; Galerkin method ID NAVIER-STOKES EQUATIONS; VISCOUS INCOMPRESSIBLE FLOWS; BOUNDARY-CONDITIONS; VORTEX METHODS; DYNAMICS AB Vorticity formulations for the incompressible Navier-Stokes equations have certain advantages over primitive-variable formulations including the fact that the number of equations to be solved is reduced. However, the accurate implementation of the boundary conditions seems to continue to be an impediment to the acceptance and use of numerical methods based on vorticity formulations. Velocity boundary conditions can be implicitly satisfied by maintaining the kinematic compatibility of the velocity and vorticity fields as described by the generalized Helmholtz decomposition (GHD). This can be accomplished in one of two ways by either solving for boundary vorticity (leading to a Dirichlet boundary condition for the vorticity equation) or solving for boundary vortex sheet strengths (leading to a Neumann condition). In the past, vortex sheet strengths have often been determined by solving an over-specified set of linear equations. The over-specification arose because integral constraints were imposed on the vortex sheet strengths. These integral constraints are not necessary and typically are included to mitigate errors in determining the vortex sheet strengths themselves. Further, the constraints overspecify the linear system requiring least-squares solution techniques. To more accurately satisfy both components of the velocity boundary conditions, a Galerkin formulation is applied to the generalized Helmholtz decomposition. This formulation implicitly satisfies an integral constraint that is more general than many of the integral constraints that have been explicitly imposed. Two implementations of the Galerkin GHD are considered in the current work, one based on determining the boundary vorticity and one based on determining the boundary vortex sheet strengths. A finite element method (FEM) is implemented to solve the vorticity equation along with the boundary data generatedfrom the GHD. (C) 2001 Academic Press. C1 Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ingber, MS (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. NR 33 TC 14 Z9 14 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAY 1 PY 2001 VL 169 IS 1 BP 215 EP 237 DI 10.1006/jcph.2001.6724 PG 23 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 427ZN UT WOS:000168436800008 ER PT J AU Maruhn, JA Burvenich, T Madland, DG AF Maruhn, JA Burvenich, T Madland, DG TI Calculating the Fierz transformation for higher orders SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Dirac algebra; Fierz transformation; relativistic quantum mechanics AB We consider the higher-order Fierz transformation, which corresponds to expanding a product of <()over bar>Gamma psi terms into a sum of products of Dirac densities and currents. It is shown that the Fierz transformation can be obtained by solving a large system of linear equations with fractional complex coefficients, which is practical at least up to fourth power. (C) 2001 Academic Press. C1 Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Maruhn, JA (reprint author), Univ Frankfurt, Inst Theoret Phys, POB 111932, D-60054 Frankfurt, Germany. NR 5 TC 13 Z9 13 U1 0 U2 0 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 MAY 1 PY 2001 VL 169 IS 1 BP 238 EP 245 DI 10.1006/jcph.2001.6727 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 427ZN UT WOS:000168436800009 ER PT J AU Ataie-Ashtiani, B Hassanizadeh, SM Oostrom, M Celia, MA White, MD AF Ataie-Ashtiani, B Hassanizadeh, SM Oostrom, M Celia, MA White, MD TI Effective parameters for two-phase flow in a porous medium with periodic heterogeneities SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE effective parameters; two-phase flow; heterogeneous porous media; upscaling; capillary pressure-saturation curve ID HYDRAULIC CONDUCTIVITY; RELATIVE PERMEABILITY; 2-PHASE FLOW; RENORMALIZATION; SIMULATION; LIQUID; MODEL; SOILS AB Computational simulations of two-phase flow in porous media are used to investigate the feasibility of replacing a porous medium containing heterogeneities with an equivalent homogeneous medium. Simulations are performed for the case of infiltration of a dense nonaqueous phase liquid (DNAPL) in a water-saturated. heterogeneous porous medium. For two specific porous media, with periodic and rather simple heterogeneity patterns, the existence of a representative elementary volume (REV) is studied. Upscaled intrinsic permeabilities and upscaled nonlinear constitutive relationships for two-phase flow systems are numerically calculated and the effects of heterogeneities are evaluated. Upscaled capillary pressure-saturation curves for drainage are found to be distinctly different from the lower-scale curves for individual regions of heterogeneity. irreducible water saturation for the homogenized medium is found to be much larger than the corresponding lower-scale values. Numerical simulations for both heterogeneous and homogeneous representations of the considered porous media are carried out. Although the homogenized model simulates the spreading behavior of DNAPL reasonably well, it still fails to match completely the results form the heterogeneous simulations. This seems to be due, in part, to the nonlinearities inherent to multiphase flow systems. Although we have focussed on a periodic heterogeneous medium in this study, our methodology is applicable to other forms of heterogeneous media. In particular, the procedure for identification of a REV, and associated upscaled constitutive relations, can be used for randomly heterogeneous or layered media as well. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Delft Univ Technol, Fac Civil Engn & Geosci, Hydrol & Ecol Sect, NL-2600 GA Delft, Netherlands. Delft Univ Technol, Ctr Tech Geosci, NL-2600 GA Delft, Netherlands. Sharif Univ Technol, Dept Civil Engn, Tehran, Iran. Pacific NW Natl Lab, Environm Technol Div, Richland, WA USA. Princeton Univ, Dept Civil Engn, Princeton, NJ 08544 USA. RP Hassanizadeh, SM (reprint author), Delft Univ Technol, Fac Civil Engn & Geosci, Hydrol & Ecol Sect, POB 5048, NL-2600 GA Delft, Netherlands. RI Ataie-Ashtiani, Behzad/B-9127-2013; OI Ataie-Ashtiani, Behzad/0000-0002-1339-3734 NR 32 TC 30 Z9 30 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD MAY PY 2001 VL 49 IS 1-2 BP 87 EP 109 DI 10.1016/S0169-7722(00)00190-X PG 23 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 424BQ UT WOS:000168212600005 PM 11351517 ER PT J AU Schieber, M Hermon, H Zuck, A Vilensky, A Melekhov, L Shatunovsky, R Meerson, E Saado, Y Lukach, M Pinkhasy, E Ready, SE Street, RA AF Schieber, M Hermon, H Zuck, A Vilensky, A Melekhov, L Shatunovsky, R Meerson, E Saado, Y Lukach, M Pinkhasy, E Ready, SE Street, RA TI Thick films of X-ray polycrystalline mercuric iodide detectors SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, CO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE physical vapor deposition processes; polycrystalline deposition; semiconducting mercury compounds ID VLSI READOUT AB Polycrystalline HgI2 thick film detectors are among the leading semiconductor materials to be used as direct converters in X-ray digital radiography. Their properties along with a survey of the properties of alternative materials, such as PbI2 or A-Se, will be given. The preparation of HgI detector plates, both by direct evaporation (Physical vapor deposition, (PVD)) and by binding the individual crystallites with polymeric glue, forming screen-printed (SP) detector plates, will be described. The microstructure of the PVD thick films showing a columnar morphology, as determined by SEM measurements, will be shown. The X-ray response to radiological X-ray generator of 85 kVp using the current integration mode will be reported for both PVD and SP films. Finally, some X-ray images taken at Xerox-Parc using HgI, polycrystalline detectors will be shown. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Hebrew Univ Jerusalem, Grad Sch Appl Sci, IL-91904 Jerusalem, Israel. Sandia Natl Labs, Livermore, CA 94550 USA. Real time Radiog Readout, IL-91487 Jerusalem, Israel. Xerox Corp, Palo Alto Res Ctr, Palo Alto, CA 94304 USA. RP Schieber, M (reprint author), Hebrew Univ Jerusalem, Grad Sch Appl Sci, IL-91904 Jerusalem, Israel. EM schieber@vms.huji.ac.il NR 19 TC 60 Z9 61 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 EI 1873-5002 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 2001 VL 225 IS 2-4 BP 118 EP 123 DI 10.1016/S0022-0248(01)00832-6 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300005 ER PT J AU Canfield, PC Fisher, IR AF Canfield, PC Fisher, IR TI High-temperature solution growth of intermetallic single crystals and quasicrystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE solvents; growth from solutions; single crystal growth; antimonides; rare earth compounds; zinc compounds; superconducting materials ID R = Y; QUASI-CRYSTALS; TERNARY MELT; AL; PHASE; TB; DY; HO; ER AB Solution growth continues to be one of the most powerful techniques for the production of single crystals for basic and applied research. It is a versatile technique that allows for the growth of congruently and incongruently melting materials with equal ease. The primary requirement for growth is that there be an exposed primary solidification surface in the appropriate equilibrium alloy phase diagram. In this paper, we will review some of the systems that we have applied this technique to over the past several years. These range from binary and ternary intermetallic compounds such as RFe2 (R = Rare earth) and RT2Ge2 (T = Ni and Cu) to the refractory RNi2B2C family of magnetic superconductors to several families of quasicrystals. In each case, specific nuances of the relatively simple growth technique will be discussed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Canfield, PC (reprint author), Iowa State Univ, Ames Lab, 59 Phys, Ames, IA 50011 USA. RI Canfield, Paul/H-2698-2014 NR 11 TC 104 Z9 104 U1 5 U2 31 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 MAY PY 2001 VL 225 IS 2-4 BP 155 EP 161 DI 10.1016/S0022-0248(01)00827-2 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300012 ER PT J AU Jo, W Peng, LSJ Wang, W Ohnishi, T Marshall, AF Hammond, RH Beasley, MR Peterson, EJ AF Jo, W Peng, LSJ Wang, W Ohnishi, T Marshall, AF Hammond, RH Beasley, MR Peterson, EJ TI Thermodynamic stability and kinetics of Y-Ba-Cu-O film growth at high rates in atomic and molecular oxygen SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE vapor phase epitaxy; superconducting materials; cuprates ID INSITU GROWTH; THIN-FILMS; COEVAPORATION; YBA2CU3O7-X AB High temperature superconductor YBa2CU3O7-x thin films have been grown using in situ electron beam evaporation at deposition rates over 1-10 nm/s. The higher activity of atomic oxygen is being explored along with molecular oxygen at reduced pressure (5 x 10(-5) Torr). Preliminary observations indicate that YBa2CU3O7-x is Stable within a band of atomic oxygen flux and temperature, similar to that published for YBa2Cu3O7-x in molecular oxygen but many orders of magnitude lower in flux. The phase equilibrium appears to be different from that found for molecular oxygen at low rates. (C) 2001 Published by Elsevier Science B.V. C1 Stanford Univ, Theodore H Geballe Lab Adv Mat, Stanford, CA 94305 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Hammond, RH (reprint author), Stanford Univ, Theodore H Geballe Lab Adv Mat, Stanford, CA 94305 USA. NR 13 TC 15 Z9 15 U1 2 U2 7 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 MAY PY 2001 VL 225 IS 2-4 BP 183 EP 189 DI 10.1016/S0022-0248(01)00872-7 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300017 ER PT J AU Lim, SH Shindo, D Kang, HB Nakamura, K AF Lim, SH Shindo, D Kang, HB Nakamura, K TI Study of defects and interfaces in epitaxial ZnO films on (1 1 (2)over-bar 0) Al2O3 grown by electron cyclotron resonance-assisted molecular beam epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE characterization; defects; interfaces; molecular beam epitaxy; oxides; semiconducting II-VI materials ID THIN-FILMS; DISLOCATIONS; GAN; SAPPHIRE; MICROSCOPY; SUBSTRATE AB The detailed defects and interface in the ZnO films on (1 1 (2) over bar 0) a-plane of sapphire have been characterized using transmission electron microscopy. The single crystal ZnO films are grown by electron cyclotron resonance-assisted molecular beam epitaxy. The orientation relationship between ZnO films and sapphire is (0 0 0 1)(ZnO)parallel to (1 1 (2) over bar 0)sapphire and [2 (1) over bar (1) over bar 0]ZnO parallel to [0 0 0 1](sapphire). A majority of the threading dislocations was found to be screw or mixed. When the interfaces are observed in [0 0 0 1]sapphire direction, the interfaces appear structurally semicoherent with a comparative regular array of misfit dislocations at an interface accommodating a mismatch of about 2.45%. Good matches between simulated and experimental images of the ZnO/a-plane sapphire were obtained. The structural model for the atomic arrangements of the interface was proposed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Inst Adv Mat Proc, Sendai, Miyagi 9808577, Japan. Tohoku Univ, Dept Elect & Commun Engn, Sendai, Miyagi 9808577, Japan. RP Lim, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 62-203, Berkeley, CA 94720 USA. RI Shindo, Daisuke/I-3865-2012 NR 17 TC 23 Z9 24 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 2001 VL 225 IS 2-4 BP 202 EP 207 DI 10.1016/S0022-0248(01)00875-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300020 ER PT J AU Lim, SH Shindo, D Kang, HB Nakamura, K AF Lim, SH Shindo, D Kang, HB Nakamura, K TI Structural characterization of epitaxial ZnO films grown on (0001) Al2O3 by electron cyclotron resonance-assisted molecular beam epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE defects; molecular beam epitaxy; oxides; semiconducting II-VI materials ID THIN-FILMS; GAN FILMS; SAPPHIRE; SUBSTRATE; DEFECTS AB Detailed structure of epitaxial ZnO films grown on (0 0 0 1) sapphire has been investigated extensively using transmission electron microscopy. Through the cross-sectional observations, in addition to the basic crystallographic epitaxial relationship of (0 0 0 1)ZnO parallel to (0 0 0 1)(sapphire) and [2 (1) over bar (1) over bar0]ZnO parallel to [1 (1) over bar 0 0](sapphire). The line directions of most threading dislocations in the ZnO films were found to be normal to the interface. On the other hand, from the plan-view high-resolution observations, the sub-grains being accompanied by the threading dislocations with Burgers vectors b of 1/3(1 1 (2) over bar 0) were clearly observed. It was found that the size of the sub-grains ranges from 15 to 150 nm and the crystals of the sub-grains are rotated by 1 degrees -5 degrees with respect to the matrix ZnO films. The overlapping of the ZnO films and the sapphire substrate in the sub-grains was discussed taking into account the Moire fringes of HREM image. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Tohoku Univ, Inst Adv Mat Proc, Sendai, Miyagi 9808577, Japan. Tohoku Univ, Dept Elect & Commun Engn, Sendai, Miyagi 9808579, Japan. RP Lim, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci 62 203, Berkeley, CA 94720 USA. RI Shindo, Daisuke/I-3865-2012 NR 10 TC 8 Z9 8 U1 0 U2 2 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 MAY PY 2001 VL 225 IS 2-4 BP 208 EP 213 DI 10.1016/S0022-0248(01)00876-4 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300021 ER PT J AU Rawn, CJ Chaudhuri, J AF Rawn, CJ Chaudhuri, J TI High temperature X-ray diffraction study of LiGaO2 SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE high-temperature X-ray diffraction; thermal expansion; oxides ID MOLECULAR-BEAM EPITAXY; GAN; FILMS AB In recent years LiGaO2 has been gaining attention as a substrate material for the growth of GaN. Since film deposition is generally carried out at high temperatures the behavior of the substrate at processing temperatures should be known. The lattice constants of polycrystalline LiGaO2 were measured from room temperature to 1423 K and the linear thermal expansion coefficients in the temperature range between 293 and 1423k were determined to be alpha (a) = 10.1 +/- 0.2 x 10(-6) K-1, alpha (b) = 21.1 +/- 0.3 x 10(-6) K-1, and alpha (c) = 13.6 +/- 0.2 x 10(-6) K-1. High temperature X-ray powder diffraction data show that at above 1173 K the Ga rich phases, LiGa5O8 and Ga2O3, start to form indicating volatilization of the Li from the structure. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. Wichita State Univ, Dept Mech Engn, Wichita, KS 67226 USA. RP Rawn, CJ (reprint author), Oak Ridge Natl Lab, High Temp Mat Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 12 TC 20 Z9 20 U1 0 U2 11 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 MAY PY 2001 VL 225 IS 2-4 BP 214 EP 220 DI 10.1016/S0022-0248(01)00835-1 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300022 ER PT J AU Burger, A Chattopadhyay, K Ndap, JO Ma, X Morgan, SH Rablau, CI Su, CH Feth, S Page, RH Schaffers, KI Payne, SA AF Burger, A Chattopadhyay, K Ndap, JO Ma, X Morgan, SH Rablau, CI Su, CH Feth, S Page, RH Schaffers, KI Payne, SA TI Preparation conditions of chromium doped ZnSe and their infrared luminescence properties SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE diffusion; doping; growth from vapor; zinc compounds; semiconducting II-VI materials; solid state lasers ID TRACE GAS-DETECTION; ZINC CHALCOGENIDES; SPECTROSCOPY; LASER; CRYSTALS AB We report the investigation by photoluminescence lifetime measurements of the near-IR emissions from a series of chromium-doped ZnSe samples, correlated to their preparation conditions. The samples were polycrystalline or single crystals prepared by post growth diffusion doping or single crystals doped during growth by the physical vapor transport method. Room temperature lifetime values between 6 and 8 mus were measured for samples with Cr2+ concentrations from low 10(17) to high 10(18)cm(-3) range. Lifetime data taken down to 78 K was found to be rather temperature independent, reconfirming previous reports indicating a quantum yield of the corresponding emission of close to 100% at room temperature. A strong decrease in the room temperature lifetime was found for chromium concentrations higher than 10(19) cm(-3). (C) 2001 Elsevier Science B.V. Ah rights reserved. C1 Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate SD 47, Huntsville, AL 35812 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Burger, A (reprint author), Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. RI Feth, Shari/F-6302-2013 OI Feth, Shari/0000-0003-3545-5649 NR 18 TC 37 Z9 41 U1 1 U2 5 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 MAY PY 2001 VL 225 IS 2-4 BP 249 EP 256 DI 10.1016/S0022-0248(01)00845-4 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300028 ER PT J AU Jafri, I Chandra, M Zhang, H Prasad, V Reddy, C Amato-Wierda, C Landry, M Ciszek, T AF Jafri, I Chandra, M Zhang, H Prasad, V Reddy, C Amato-Wierda, C Landry, M Ciszek, T TI Enhanced bulk polysilicon production using silicon tubes SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE chemical vapor deposition processes; polycrystalline deposition; elemental solids; solar cells AB A novel technique using silicon tubes for the production of bulk polysilicon via chemical vapor deposition is presented. Our experimental studies with a model reactor indicate that the polysilicon growth inside the silicon tube (15.3 g) exceeds that of the calculated polysilicon growth on silicon slim rods (4.3 g) over 55 h of deposition time. A computational model is also being developed to simulate the growth rates of the model reactor. Preliminary computational results from this model show a slightly asymmetric temperature distribution at the reactor center line with a 1000sccm argon flow at 850 degreesC reactor temperature. Both these experimental and computational modeling studies have identified key criteria for the prototype reactor being designed for bulk polysilicon growth. (C) 2001 Elsevier Science B.V. All rights reserved. C1 GT Equipment Technol Inc, Nashua, NH 03063 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ New Hampshire, Mat Sci Program, Durham, NH 03824 USA. SUNY Stony Brook, Dept Mech Engn, Stony Brook, NY 11794 USA. RP Chandra, M (reprint author), GT Equipment Technol Inc, 472 Amherst St, Nashua, NH 03063 USA. NR 8 TC 1 Z9 1 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 MAY PY 2001 VL 225 IS 2-4 BP 330 EP 334 DI 10.1016/S0022-0248(01)00905-8 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300041 ER PT J AU Geisz, JF Friedman, DJ Kurtz, S Olson, JM Swartzlander, AB Reedy, RC Norman, AG AF Geisz, JF Friedman, DJ Kurtz, S Olson, JM Swartzlander, AB Reedy, RC Norman, AG TI Epitaxial growth of BGaAs and BGaInAs by MOCVD SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE metalorganic chemical vapor deposition; semiconducting III-V materials ID ALLOYS; GAAS AB The growth of epitaxial zinc-blende BxGa1-xAs and BxGa1-x-yInyAs alloys using diborane is complicated by a thermodynamic miscibility gap and complex gas-phase chemistry. We have characterized the growth behavior of these alloys when they are grown using trimethylgallium (TMG), triethylgallium (TEG), trimethylindium (TMI), and arsine by low-pressure and atmospheric-pressure metal-organic chemical-vapor-deposition. Boron incorporation into BxGa1-xAs exhibits qualitatively different behavior using TEG and TMG, but the incorporation efficiency and maximum achievable boron concentration decrease dramatically at growth temperatures greater than 600 degreesC using either Ga source. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Geisz, JF (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Norman, Andrew/F-1859-2010 OI Norman, Andrew/0000-0001-6368-521X NR 9 TC 37 Z9 39 U1 0 U2 2 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 MAY PY 2001 VL 225 IS 2-4 BP 372 EP 376 DI 10.1016/S0022-0248(01)00883-1 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300048 ER PT J AU Biefeld, RM Cederberg, JG Peake, GM Kurtz, SR AF Biefeld, RM Cederberg, JG Peake, GM Kurtz, SR TI The growth and characterization of GaInAsSb and AlGaAsSb on GaSb by metal-organic chemical vapor deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE metalorganic chemical vapor deposition; antimonides; semiconducting aluminum compounds; semiconducting indium compounds; semiconducting quaternary compounds ID PROGRESS AB The growth conditions for GaInAsSb and AlGaAsSb using metal-organic chemical vapor deposition in an high speed rotating disk reactor are described. Trimethylindium, triethylgallium, arsine, and trimethylantimony were used as precursors for the growth of GaInAsSb. Triethylgallium, ethyldimethylamine alane, triethylantimony, and arsine were the precursors used for the growth of AlGaAsSb. These materials were doped both n- and p-type using a mixture of diethyltellurium and diethylzinc as sources. An optimum growth temperature of 520 degreesC was determined for the growth of GaInAsSb. Growth at this temperature yielded a root-mean-square (rms) surface roughness of 0.142 nm. AlGaAsSb could be grown over the range of 500-600 degreesC with somewhat rougher surfaces (rms > 0.7 nm). The photoluminescence was found to correlate with surface roughness, increasing with smoother surfaces. AlCaAsSb mesa isolated diodes were prepared and characterized. These diodes showed good current-voltage characteristics with breakdown voltages greater than -6V. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Dept 01125MS 0601, Albuquerque, NM 87185 USA. RP Biefeld, RM (reprint author), Sandia Natl Labs, Dept 01125MS 0601, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 13 Z9 13 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 MAY PY 2001 VL 225 IS 2-4 BP 384 EP 390 DI 10.1016/S0022-0248(01)00886-7 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300050 ER PT J AU McMahon, WE Olson, JM AF McMahon, WE Olson, JM TI A scanning tunneling microscopy study of As/Ge(mnn) and P/Ge(mnn) surfaces SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE scanning tunneling microscopy; metalorganic vapor phase epitaxy; germanium; arsine; phosphine ID ATOMIC-RESOLUTION; VICINAL GE(100); EPITAXY; STEPS AB Ge(mnn) surfaces between (100) and (111) were annealed under either arsine or phosphine in a metal-organic chemical vapor deposition chamber, then imaged with a scanning tunneling microscope. In general, arsine-exposed Ge surfaces are facetted, while phosphine-exposed surfaces remain Rat. For the arsine-exposed Ge surfaces, four stable facetting directions have been identified: (1 0 0), (1 1,3, 3), (9 5 5), and (1 1 1). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP McMahon, WE (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 11 TC 6 Z9 6 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 2001 VL 225 IS 2-4 BP 410 EP 414 DI 10.1016/S0022-0248(01)00901-0 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300054 ER PT J AU Garces, NY Stevens, KT Halliburton, LE Yan, M Zaitseva, NP DeYoreo, JJ AF Garces, NY Stevens, KT Halliburton, LE Yan, M Zaitseva, NP DeYoreo, JJ TI Optical absorption and electron paramagnetic resonance of Fe ions in KDP crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE impurities; point defects; growth from solutions; phosphates; nonlinear optic materials; harmonic generators ID GROWTH AB Optical absorption and electron paramagnetic resonance (EPR) have been used to study the sites and the charge states associated with Fe ions in single crystals of KH2PO4 (KDP). Doping KDP with 5 ppm of Fe introduced a broad charge-transfer absorption band near 270 nm. At the same time, room-temperature EPR showed that two Fe3+ centers were present. Although their intensities are different, the two EPR centers have similar zero-field splittings. Spin-Hamiltonian parameters, including fourth order in crystal field, were determined for the dominant center. We suggest that these EPR-active Felt ions substitute for KI ions, presumably with charge-compensating cation vacancies (i.e., potassium or hydrogen) nearby. Crystals containing both the 270-nm absorption band and the Fe3+ EPR spectra were X-ray irradiated at room temperature and then subjected to a series of thermal anneals up to 150 degreesC. These treatments caused changes in both the absorption band and the EPR spectra, but the behaviors of the optical and EPR features did not correlate. This can be explained if a portion of the Fe ions occupy a site in the KDP crystals other than the K+ site. We suggest that most of the optical absorption in the 200-to-300nm region is due to Fe ions substituting for phosphorus; i.e., (FeO4)(2-) molecular units are present in the KDP crystals and give rise to ultraviolet absorption. (C) 2001 Elsevier Science B.V. All rights reserved. C1 W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Halliburton, LE (reprint author), W Virginia Univ, Dept Phys, POB 6315, Morgantown, WV 26506 USA. NR 10 TC 43 Z9 51 U1 2 U2 9 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 MAY PY 2001 VL 225 IS 2-4 BP 435 EP 439 DI 10.1016/S0022-0248(01)00911-3 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300059 ER PT J AU Schaffers, KI Tassano, JB Waide, PA Payne, SA Morris, RC AF Schaffers, KI Tassano, JB Waide, PA Payne, SA Morris, RC TI Progress in the growth of Yb : S-FAP laser crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE czochralski method; inorganic compounds; oxides; solid state lasers AB Growth of Yb:S-FAP [Yb3+ :Sr-5(PO4)(3)F] crystals is being studied for 1.047 mum laser operation. These crystals are not yet routinely available and the growth of high optical quality, low loss crystals poses a challenge due to a number of crystal growth issues, including, cloudiness, bubble core defects, anomalous absorption, Pow-angle grain boundaries, and cracking. At this time, a growth process has been formulated to simultaneously eliminate or greatly diminish each of the defects to yield high quality material. Laser slabs of dimension 4.0 x 6.0 x 0.75 cm are being fabricated from subscale pieces using the diffusion bonding technique. (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Schaffers, KI (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-482, Livermore, CA 94551 USA. NR 13 TC 8 Z9 10 U1 1 U2 6 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 MAY PY 2001 VL 225 IS 2-4 BP 449 EP 453 DI 10.1016/S0022-0248(01)00914-9 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300062 ER PT J AU Burger, A Ndap, JO Cui, Y Roy, U Morgan, S Chattopadhyay, K Ma, X Faris, K Thibaud, S Miles, R Mateen, H Goldstein, JT Rawn, CJ AF Burger, A Ndap, JO Cui, Y Roy, U Morgan, S Chattopadhyay, K Ma, X Faris, K Thibaud, S Miles, R Mateen, H Goldstein, JT Rawn, CJ TI Preparation and thermophysical properties of AgGaTe2 crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th American Conference on Crystal Growth and Epitaxy CY AUG 13-18, 2000 CL VAIL, COLORADO SP NASA Micrograv Res Div, Natl Renewable Energy Lab, Adv Ceram Corp, Bicron, Crystal Assoc Inc, Crystal Syst Inc, Delron Crystal Ind Inc, Engelhard CLAL LP, Engis Corp, Sawyer Res Prod, Sensors Unltd Inc, S Bay Technol, ThermCraft, II VI Inc, Tyco Electr DE X-ray diffraction; non-linear optical materials; semiconducting materials ID NONLINEAR-OPTICAL MATERIALS; GROWTH AB The preparation and thermophysical properties of AgGaTe2 crystals are reported. The synthesis from pure elements was performed in a rocking oven and scanning electron microscopy and energy dispersive X-ray elemental analysis show the presence of additional phases. From simultaneous differential calorimetry and thermogravimetric analysis (SDT) measurements we have found that AgGaTe2 melts at 725.7 degreesC, with a heat of fusion of 104.8J/g(-1). High temperature powder X-ray diffraction data confirmed the chalcopyrite structure and yielded the thermal expansion coefficients along the a- and c-axes to 500 degreesC. Heating above that temperature, under inert gas flow, causes the material to sublime incongruently and produce a film of gallium rich surface. Experimental values of thermal diffusivity and estimates of the thermal conductivity values are also presented. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Burger, A (reprint author), Fisk Univ, Ctr Photon Mat & Devices, Dept Phys, Nashville, TN 37208 USA. NR 19 TC 9 Z9 10 U1 1 U2 6 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 MAY PY 2001 VL 225 IS 2-4 BP 505 EP 511 DI 10.1016/S0022-0248(01)00957-5 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 444HP UT WOS:000169394300073 ER PT J AU Punshon, T Adriano, DC Weber, JT AF Punshon, T Adriano, DC Weber, JT TI Effect of flue gas desulfurization residue on plant establishment and soil and leachate quality SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID COMBUSTION BY-PRODUCTS; FLY-ASH; BORON; GROWTH AB Effects on soil quality and crop establishment after incorporation of flue gas desulfurization by-product (FGD) into soil as an amendment was assessed in a mesocosm study. Mesocosm units received applications equivalent to 0, 2.5, 5.0, 7.5, and 10% FGD residue [0, 25, 50, 75, and 100 tons acre(-1)]. Germination, biomass production, and elemental composition of corn (Zea mays L. var. Dekalb DK683), soybean [Glycine max (L.) Merr. var. Haskell Pupa 94], radish (Raphanus sativus L. var. Sparkler), and cotton (Gossypius hirsutus L. var. Deltapine 51) were determined. The quality of leachates and soil were also determined periodically. Flue gas desulfurization residue did not affect germination and all application rates stimulated aboveground biomass. Plants grown in FGD-amended soil contained significantly elevated tissue concentrations of As, B, Se, and Rile. The FGD residue elevated surface soil pH from 55 (Control) to 8.1 (at 10% FGD). Leachate pH was unaffected by FGD, but salinity rose sharply with increasing application rates of FGD. Leachates contained higher concentrations of B, with small increases in Se and As. Flue gas desulfurization residue application caused an increase in total B, As, Mo, Se, and extractable Ca in the soil, but decreased Mn and Zn. Using FGD residues could have beneficial effects on crop establishment without detrimental effects on soil or leachate quality, at an optimum rate of approximately 2.5%. This material could alleviate surface acidity, and B and Mo deficiencies in plants. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Adelaide, Dept Soil Sci, Glen Osmond, SA 5064, Australia. RP Punshon, T (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 27 TC 14 Z9 15 U1 2 U2 13 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 2001 VL 30 IS 3 BP 1071 EP 1080 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA 445KA UT WOS:000169455600043 PM 11401255 ER PT J AU Zawislanski, PT Mountford, HS Gabet, EJ McGrath, AE Wong, HC AF Zawislanski, PT Mountford, HS Gabet, EJ McGrath, AE Wong, HC TI Selenium distribution and fluxes in intertidal wetlands, San Francisco Bay, California SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID TIDAL SALT MARSHES; SEDIMENT ACCUMULATION; CHESAPEAKE BAY; CLAY-MINERALS; TRACE-METALS; WATER; RATES; SELENATE; SOILS; ADSORPTION AB Selenium (Se) concentrations exceeding ecological guidelines for sediments and suspended particulate matter (SPM) have been observed in the northern reach of the San Francisco Bay estuary. Long term availability of elevated Se in wetland sediments depends in part on the fluxes controlling Se distribution. The relative contribution of sedimentary vs. post-depositional Se fluxes in two San Francisco Bay intertidal wetlands was estimated. Selenium concentrations on surface wetland sediments were compared with levels on SPM, and with previously established background levels in San Francisco Bay sediments. Sediment Se fluxes to the wetlands were measured directly using sediment traps. Although dissolved Se concentrations are higher than particulate Se concentrations in San Francisco Bay water, sediment input into the system provides the major flux of Se. Strong correlation between Se and C on SPM (r(2) = 0.81) indicates the importance of organic particulate deposition. Dependence on sediment texture was qualitatively established by measuring Se on particle-size separates. Normalization to Al showed that 65% of Se spatial variability is related to sediment texture. Selenium is further enriched in the marsh via post-depositional inputs, probably due to in situ adsorption from overlying water and chemical reduction. According to sediment flux measurements, enrichment in the marsh is equivalent to 20 to 25% of the particulate Se flux, thereby defining the marsh as a Se sink. These findings highlight the need for more intensive monitoring of SPM as the major source of Se to intertidal wetlands. C1 Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Zawislanski, PT (reprint author), Lawrence Berkeley Natl Lab, Div Earth Sci, Mail Stop 90-1116, Berkeley, CA 94720 USA. NR 54 TC 13 Z9 14 U1 1 U2 7 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 2001 VL 30 IS 3 BP 1080 EP 1091 PG 12 WC Environmental Sciences SC Environmental Sciences & Ecology GA 445KA UT WOS:000169455600044 PM 11401256 ER PT J AU Rho, JY Currey, JD Zioupos, P Pharr, GM AF Rho, JY Currey, JD Zioupos, P Pharr, GM TI The anisotropic Young's modulus of equine secondary osteones and interstitial bone determined by nanoindentation SO JOURNAL OF EXPERIMENTAL BIOLOGY LA English DT Article DE bone; Young's modulus; anisotropy; nanoindentation; osteone; horse; Equus caballus ID COLLAGEN FIBER ORIENTATION; CORTICAL BONE; MECHANICAL-PROPERTIES; ELASTIC PROPERTIES; LAMELLAR BONE; HORSE RADIUS; LOCOMOTION; FORELIMB; STRESS; MODE AB The equine radius is a useful subject for examining the adaptation of bone histology to loading because in life the anterior cortex is loaded almost entirely in tension, the posterior cortex in compression. The histology of the two cortices is correspondingly different, the osteones and the interstitial lamellae in the posterior cortex having a more transversely oriented fibre arrangement than those in the anterior cortex. Presumably as a result of this histological difference, the posterior cortex is stronger in compression than the anterior cortex; the anterior cortex is stronger in tension than the posterior cortex. We here use nanoindentation to examine how the Young's modulus of elasticity of secondary osteones and interstitial lamellae in the anterior and posterior cortices varied as a function of angle. The anterior osteones were stiffer than the posterior osteones when tested in the direction parallel to the bone's long axis, but became progressively relatively less stiff as the angle increased; at 90 degrees, they were less stiff than the posterior osteones. Although the interstitial lamellae were stiffer than their neighbouring osteones, the same relationship between anterior and posterior interstitial lamellae as a function of angle was found as for the osteones. The anisotropy of these Young's moduli determined by nanoindentation shows a close relationship with what was to be expected from the histological findings. C1 Univ York, Dept Biol, York YO10 5YW, N Yorkshire, England. Univ Memphis, Dept Biomed Engn, Memphis, TN 38152 USA. Cranfield Univ, Dept Mat & Med Sci, Shrivenham SN6 8LA, England. Univ Tennessee, Dept Mat Sci, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Currey, JD (reprint author), Univ York, Dept Biol, POB 373, York YO10 5YW, N Yorkshire, England. OI ZIOUPOS, PETER/0000-0002-0123-2706 FU NIAMS NIH HHS [AR45297] NR 18 TC 45 Z9 45 U1 0 U2 7 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE CB4 4DL, CAMBS, ENGLAND SN 0022-0949 J9 J EXP BIOL JI J. Exp. Biol. PD MAY PY 2001 VL 204 IS 10 BP 1775 EP 1781 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 438GB UT WOS:000169044300012 PM 11316498 ER PT J AU Bogen, KT Keating, GA AF Bogen, KT Keating, GA TI US dietary exposures to heterocyclic amines SO JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY LA English DT Article DE age; cancer; cooked-food mutagens; energy; meat; prostate; race; sex; variability ID DONE MEAT INTAKE; PROSTATE-CANCER; UNITED-STATES; COOKED FOODS; WELL-DONE; DNA-ADDUCTS; RED MEAT; GENETIC SUSCEPTIBILITY; METABOLIC-ACTIVATION; MUTAGENIC ACTIVATION AB Heterocyclic amines (HAs) formed in fried, broiled or grilled meats are potent mutagens that increase rates of colon, mammary, prostate and other cancers in bioassay rodents. Studies of how human dietary HA exposures may affect cancer risks have so far relied on fairly crudely defined HA - exposure categories. Recently, an integrated, quantitative approach to HA-exposure assessment (HAEA) was developed to estimate compound-specific intakes for particular individuals based on corresponding HA-concentration estimates that reflect their meat-type, intake-rate, cooking-method and meat-doneness preferences. This method was applied in the present study to U.S. national Continuing Survey of Food Intakes by Individuals (CSFII) data on meats consumed and cooking methods used by > 25,000 people, after adjusting for underreported energy intake and conditional on meat-doneness preferences estimated from additional survey data. The U.S. population average lifetime time-weighted average of total HAs consumed was estimated to be similar to9 ng/kg/day, with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) estimated to comprise about two thirds of this intake. Pan-fried meats were the largest source of HA in the diet and chicken the largest source of HAs among different meat types. Estimated total HA intakes by male vs. female children were generally similar, with those by (0- to 15-year-old) children -25% greater than those by (16+-year-old) adults. Race-, age- and sex-specific mean HA intakes were estimated to be greatest for African American males, who were estimated to consume similar to2- and similar to3- fold more PhIP than white males at ages < 16 and 30+ years, respectively, after considering a relatively greater preference for more well-done items among African Americans based on national survey data. This difference in PhIP intakes may at least partly explain why prostate cancer (PC) kills similar to2- fold more African American than white men, in view of experimental data indicating that PhIP mutates prostate DNA and causes prostate tumors in rats. C1 Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div L 396, Livermore, CA 94550 USA. RP Bogen, KT (reprint author), Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div L 396, 7000 East Ave, Livermore, CA 94550 USA. EM bogen@LLNL.gov FU NCI NIH HHS [P01 CA44861-01] NR 90 TC 56 Z9 57 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 1053-4245 J9 J EXPO ANAL ENV EPID JI J. Expo. Anal. Environ. Epidemiol. PD MAY-JUN PY 2001 VL 11 IS 3 BP 155 EP 168 DI 10.1038/sj.jea.7500158 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 456HM UT WOS:000170077100001 PM 11477514 ER PT J AU Klepeis, NE Nelson, WC Ott, WR Robinson, JP Tsang, AM Switzer, P Behar, JV Hern, SC Engelmann, WH AF Klepeis, NE Nelson, WC Ott, WR Robinson, JP Tsang, AM Switzer, P Behar, JV Hern, SC Engelmann, WH TI The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants SO JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY LA English DT Article DE environmental pollutants; environmental tobacco smoke; exposure assessment; exposure modeling; exposure survey; household pollutants; human-activity patterns; human exposure; population survey; time activity; time budget ID TOBACCO-SMOKE; CALIFORNIA; BENZENE AB Because human activities impact the timing, location, and degree of pollutant exposure, they play a key role in explaining exposure variation. This fact has motivated the collection of activity pattern data for their specific use in exposure assessments. The largest of these recent efforts is the National Human Activity Pattern Survey (NHAPS), a 2-year probability-based telephone survey (n = 9386) of exposure-related human activities in the United States (U.S.) sponsored by the U.S. Environmental Protection Agency (EPA). The primary purpose of NHAPS was to provide comprehensive and current exposure information over broad geographical and temporal scales, particularly for use in probabilistic population exposure models. NHAPS was conducted on a virtually daily basis from late September 1992 through September 1994 by the University of Maryland's Survey Research Center using a computer-assisted telephone interview instrument (CATI) to collect 24-h retrospective diaries and answers to a number of personal and exposure-related questions from each respondent. The resulting diary records contain beginning and ending times for each distinct combination of location and activity occurring on the diary day (i.e., each microenvironment). Between 340 and 1713 respondents of all ages were interviewed in each of the 10 EPA regions across the 48 contiguous states. Interviews were completed in 63% of the households contacted. NHAPS respondents reported spending an average of 87% of their time in enclosed buildings and about 6% of their time in enclosed vehicles. These proportions are fairly constant across the various regions of the U.S. and Canada and for the California population between the late 1980s, when the California Air Resources Board (CARB) sponsored a state-wide activity pattern study, and the mid-1990s, when NHAPS was conducted. However, the number of people exposed to environmental tobacco smoke (ETS) in California seems to have decreased over the same time period, where exposure is determined by the reported time spent with a smoker. In both California and the entire nation, the most time spent exposed to ETS was reported to take place in residential locations. C1 Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RP Klepeis, NE (reprint author), Lawrence Berkeley Natl Lab, Indoor Environm Dept, 1 Cyclotron Rd,MS 90-3058, Berkeley, CA 94720 USA. OI Klepeis, Neil/0000-0002-6934-3242 NR 75 TC 779 Z9 825 U1 25 U2 145 PU NATURE PUBLISHING GROUP PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 1053-4245 J9 J EXPO ANAL ENV EPID JI J. Expo. Anal. Environ. Epidemiol. PD MAY-JUN PY 2001 VL 11 IS 3 BP 231 EP 252 DI 10.1038/sj.jea.7500165 PG 22 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 456HM UT WOS:000170077100008 PM 11477521 ER PT J AU Loiseau, J Fouquet, E Fish, RH Vincent, JM Verlhac, JB AF Loiseau, J Fouquet, E Fish, RH Vincent, JM Verlhac, JB TI A new carboxylic acid with branched ponytails for the solubilization of Mn(II) and Co(II) ions in perfluorocarbons SO JOURNAL OF FLUORINE CHEMISTRY LA English DT Article DE fluorinated carboxylic acid; solubilization of manganese and cobalt complexes in fluorocarbons; preparation; malonic synthesis; fluorophilicity ID FLUOROUS BIPHASIC CATALYSIS; PERFLUORINATED SOLVENTS; HOMOGENEOUS CATALYSIS; SUPERCRITICAL FLUIDS; SEPARATION; COMPLEXES; HYDROFORMYLATION; ALKENES; PHASE; MN AB The synthesis of a carboxylic acid (C8F17(CH2)(3))(2)CHCOOH 3 bearing two long branched perfluoroalkyl-alkyl chains is described. This acid is highly soluble in perfluorocarbons and is 3 useful ligand fur the preparation of transition metal complexes that are soluble in fluorinated media. This is illustrated by the preparation of the manganese(II)- and cobalt(II)-carboxylate: complexes, both of which are soluble in perfluorocarbons and are thus potentially interesting starting materials for metal-catalyzed reactions under fluorous biphasic procedures. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Bordeaux 1, Lab Chim Organ & Organomet, CNRS, UMR 5802, F-33405 Talence, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Vincent, JM (reprint author), Univ Bordeaux 1, Lab Chim Organ & Organomet, CNRS, UMR 5802, 351 Cours Liberat, F-33405 Talence, France. OI FOUQUET, ERIC/0000-0002-2081-8155 NR 19 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-1139 J9 J FLUORINE CHEM JI J. Fluor. Chem. PD MAY PY 2001 VL 108 IS 2 BP 195 EP 197 DI 10.1016/S0022-1139(01)00355-4 PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 435KB UT WOS:000168879700008 ER PT J AU Stawicki, O Gary, SP Li, H AF Stawicki, O Gary, SP Li, H TI Solar wind magnetic fluctuation spectra: Dispersion versus damping SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID KINETIC DISSIPATION; HELIOS-OBSERVATIONS; POWER SPECTRA; MODE WAVES; TURBULENCE; FIELD; RANGE; EVOLUTION; DYNAMICS AB Solar wind magnetic fluctuation power spectra at frequencies f < 1 Hz are commonly observed to have the approximate power law dependence f(-5/3). These observations may be described by Kolmogorov diffusion in wavenumber space which defines what is called the inertial range. At wavelengths shorter than the inertial range, spectra often are observed to have steeper power laws. This intermediate wavelength regime is sometimes called the dissipation range because it has been suggested that this steeper slope is caused by collisionless damping of Alfven and magnetosonic waves. Here it is argued that, at intermediate wavenumbers, Alfven fluctuations are suppressed by proton cyclotron damping, so the observed power spectra are likely to consist of weakly damped magnetosonic/whistler waves which have an increased wavenumber diffusion rate due to their dispersion. Numerical calculations at beta (p) less than or similar to 2.5 with a model representing this picture yield fluctuation spectra with steep power laws at intermediate wavenumbers and with sharp cutoffs due to electron cyclotron damping at still shorter wavelengths. The term "dispersion range" is more appropriate to describe steep power law spectra in the intermediate wavenumber regime. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Stawicki, O (reprint author), Ruhr Univ Bochum, Inst Theoret Phys, D-44780 Bochum, Germany. EM os@tp4.ruhr-unibochum.de; pgary@lanl.gov; hli@lanl.gov NR 28 TC 164 Z9 164 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 MAY 1 PY 2001 VL 106 IS A5 BP 8273 EP 8281 DI 10.1029/2000JA000446 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 428VL UT WOS:000168482300015 ER PT J AU Riley, P Gosling, JT Pizzo, VJ AF Riley, P Gosling, JT Pizzo, VJ TI Investigation of the polytropic relationship between density and temperature within interplanetary coronal mass ejections using numerical simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WIND THERMAL ELECTRONS; SOLAR-WIND; MAGNETIC CLOUDS; EVOLUTION; PARAMETERS; ULYSSES; PLASMA; INDEX AB Single-point spacecraft. measurements within coronal mass ejections (CMEs) often exhibit a negative correlation between electron density and temperature. At least two opposing interpretations ha c:e been suggested for this relationship. If, on one hand, these single spacecraft. observations provide direct measures of the polytropic properties of the plasma, then they imply that the polytropic index for the electrons gamma (e) is often < 1. Moreover, since the electrons carry the bulk of the pressure (via their significantly higher temperature), this further implies that the dynamics of CME evolution are dominated by an effective polytropic index gamma (eff) < 1. On the other hand, gamma < 1 implies that as the ejecta propagate away from the Sun and expand, they also heat up; a result clearly at odds with in situ observations. In contrast to these CME intervals, many studies have shown that the quiescent solar wind exhibits a positive correlation between electron density and temperature, suggesting that gamma (e) > 1. In this study we simulate the evolution of a variety of CME-like disturbances in the solar wind using a one-dimensional, single-fluid model, to address the interpretation of the relationship between electron density and temperature within CMEs at fixed locations in space. Although we strictly impose a polytropic relationship (with gamma = constant) throughout our simulations, we demonstrate that a variety of correlations can ex-ist between density and temperature at fixed points. Furthermore, we demonstrate that the presence of only local uncorrelated random fluctuations in density and temperature can produce a negative correlation. Consequently, we conclude that these single-point observations of negative correlations between electron density and temperature cannot be used to infer the value of gamma (e). Instead, we suggest that entropy variations, together with the plasma's tendency to achieve pressure balance with its surroundings, are responsible for the observed profiles. C1 Sci Applicat Int Corp, San Diego, CA 92121 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Riley, P (reprint author), Sci Applicat Int Corp, San Diego, CA 92121 USA. NR 25 TC 15 Z9 15 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 2001 VL 106 IS A5 BP 8291 EP 8300 DI 10.1029/2000JA000276 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 428VL UT WOS:000168482300017 ER PT J AU Thomsen, MF Birn, J Borovsky, JE Morzinski, K McComas, DJ Reeves, GD AF Thomsen, MF Birn, J Borovsky, JE Morzinski, K McComas, DJ Reeves, GD TI Two-satellite observations of substorm injections at geosynchronous orbit SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; PARTICLE; MAGNETOTAIL; BOUNDARY; SIMULATIONS; DISRUPTION; SIGNATURES; DIVERSION; FIELDS; REGION AB Energetic particle and plasma measurements from three fairly closely spaced geosynchronous satellites are used to examine the simultaneous behavior of substorm particle injections at spatially separated locations. A total of 43 injection events are identified as dispersionless at two or more satellites. The observations confirm that the ion and electron injection regions are spatially offset in the azimuthal direction, as previously deduced statistically from single-satellite observations and revealed by test-particle trajectories in MHD simulations of geomagnetic tail reconnection. The two-spacecraft observations show further that the injection regions for both ions and electrons expand azimuthally in both the eastward and westward directions over a timescale of several minutes. The observed expansion rates are comparable to expansion rates derived from the test particle/MHD simulations, lending further support to the identification of such reconnection as the ultimate cause of substorm particle injections. C1 Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. RP Thomsen, MF (reprint author), Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, MS D466, Los Alamos, NM 87545 USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 35 TC 43 Z9 43 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 2001 VL 106 IS A5 BP 8405 EP 8416 DI 10.1029/2000JA000080 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 428VL UT WOS:000168482300028 ER PT J AU Traylor, TD AF Traylor, TD TI The PrePRINT Network - A new dynamic in information access from the US Department of Energy SO JOURNAL OF GOVERNMENT INFORMATION LA English DT Article DE Internet library; preprints; scientific communication; information dissemination AB The PrePRINT Network provides convenient access to online preprints and reprints in the sciences and some areas of technological development. Initiated by the U.S. Department of Energy (DOE) Office of Scientific and Technical Information (OSTI), the PrePRINT Network is the newest addition to an interrelated family of products supporting better integration and utilization of scientific and technological achievements; achievement documented in these communications. The posting of preprints on the Internet by scientists, which began in earnest with members of the physics community, is now expanding rapidly in the information technologies, and some posting of these e-prints. is now occurring in most of the sciences. The PrePRINT Network was designed to be flexible with respect to how scientists post their preprints. and to be adaptable as this method of sharing preprints expands throughout the disciplines. The PrePRINT Network is one of three Web-based products created to provide scientists with the professional information that is so essential to the scientific community. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US DOE, Off Sci & Tech Informat, Oak Ridge, TN 37831 USA. RP Traylor, TD (reprint author), US DOE, Off Sci & Tech Informat, POB 62, Oak Ridge, TN 37831 USA. NR 11 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-0237 J9 J GOV INFORM JI J. Gov. Inf. PD MAY-JUN PY 2001 VL 28 IS 3 BP 249 EP 266 DI 10.1016/S1352-0237(01)00297-0 PG 18 WC Information Science & Library Science SC Information Science & Library Science GA 493XF UT WOS:000172248200001 ER PT J AU Ball, RD Ellis, RK AF Ball, RD Ellis, RK TI Heavy quark production at high energy SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE heavy quarks physics; QCD; NLO computations; hadronic colliders ID X ANOMALOUS DIMENSIONS; HADRON-COLLISIONS; FLAVOR PRODUCTION; CROSS-SECTION; LEADING ORDER; QCD; POMERON; FACTORIZATION; RESUMMATION; EVOLUTION AB We report on QCD radiative corrections to heavy quark production valid at high energy. The formulae presented will allow a matched calculation of the total cross section which is correct at O(alpha (3)(s)) and includes resummation of all terms of order alpha (3)(s) [alpha (s) 1n(s/m(2))](n). We also include asymptotic estimates of the effect of the high energy resummation. A complete description of the calculation of the heavy quark impact factor is included in an appendix. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Edinburgh, Dept Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland. Fermilab Natl Accelerator Lab, Theory Dept, Batavia, IL 60510 USA. RP Ball, RD (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. EM richard.ball@cern.ch; ellis@fnal.gov NR 50 TC 10 Z9 10 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD MAY PY 2001 IS 5 AR 053 PG 33 WC Physics, Particles & Fields SC Physics GA 465TL UT WOS:000170606000053 ER PT J AU Kaloper, N Susskind, L Silverstein, E AF Kaloper, N Susskind, L Silverstein, E TI Gauge symmetry and localized gravity in M-theory SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE extra large dimensions; p-branes; AdS-CFT correspondance ID STRING THEORY; BLACK-HOLES; DIMENSIONS; COMPACTIFICATION; ORBIFOLDS; SOLITONS AB We discuss the possibility of having gravity "localized" in dimension d in a system where gauge bosons propagate in dimension d+1. In such a circumstance - depending on the rate of falloff of the field strengths in d dimensions - one might expect the gauge symmetry in d+1 dimensions to behave like a global symmetry in d dimensions, despite the presence of gravity. Naive extrapolation of warped long-wavelength solutions of general relativity coupled to scalars and gauge fields suggests that such an effect might be possible. However, in some basic realizations of such solutions in M theory, we find that this effect does not persist microscopically. It turns over either to screening or the Higgs mechanism at long distances in the d-dimensional description of the system. We briefly discuss the physics of charged objects in this type of system. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Kaloper, N (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. EM kaloper@leland.stanford.edu; susskind@sewerrat.stanford.edu; evas@slac.stanford.edu NR 35 TC 10 Z9 10 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 MAY PY 2001 IS 5 AR 031 PG 14 WC Physics, Particles & Fields SC Physics GA 465TL UT WOS:000170606000031 ER PT J AU Weier, HUG Zitzelsberger, HF Hsieh, HB Sun, MV Wong, M Lersch, RA Yaswen, P Smida, J Kuschnick, C Clark, OH AF Weier, HUG Zitzelsberger, HF Hsieh, HB Sun, MV Wong, M Lersch, RA Yaswen, P Smida, J Kuschnick, C Clark, OH TI Monitoring signal transduction in cancer: Tyrosine kinase gene expression profiling SO JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY LA English DT Article; Proceedings Paper CT Joint Meeting of the Histocheical-Society /International-Society-for-Analytical-and-Molecular-Morphology CY FEB 02-07, 2001 CL SANTA FE, NEW MEXICO SP Histochem Soc, Int Soc Analyt & Molec Morphol DE tyrosine kinase; tumors; RT-PCR; genes ID HUMAN BREAST-CANCER AB Abnormal expression of tyrosine kinase (TK) genes is common in tumors, in which it is believed to alter cell growth and response to external stimuli such as growth factors and hormones. Although the etiology and pathogenesis of carcinomas of the thyroid or breast remain unclear, there is evidence that the expression of TK genes, such as receptor tyrosine kinases, or mitogen-activated protein kinases, is dysregulated in these tumors, and that overexpression of particular TK genes due to gene amplification, changes in gene regulation, or structural alterations leads to oncogenic transformation of epithelial cells. We developed a rapid scheme to measure semiquantitatively the expression levels of 50-100 TK genes. Our assay is based on RT-PCR with mixed based primers that anneal to conserved regions in the catalytic domain of TK genes to generate gene-specific fragments. PCR products are then labeled by random priming and hybridized to DNA microarrays carrying known TK gene targets. Inclusion of differently labeled fragments from reference or normal cells allows identification of TK genes that show altered expression levels during malignant transformation or tumor progression. Examples demonstrate how this innovative assay might help to define new markers for tumor progression and potential targets for disease intervention. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. GSF Forschungszentrum Umwelt & Gesundheit, Abeitsgrp Zytogenet, Neuherberg, Germany. Univ Calif San Francisco, Dept Surg, San Francisco, CA 94143 USA. RP Weier, HUG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,MS 74-157, Berkeley, CA 94720 USA. RI Smida, Jan/P-2486-2014 NR 8 TC 2 Z9 2 U1 0 U2 0 PU HISTOCHEMICAL SOC INC PI SEATTLE PA UNIV WASHINGTON, DEPT BIOSTRUCTURE, BOX 357420, SEATTLE, WA 98195 USA SN 0022-1554 J9 J HISTOCHEM CYTOCHEM JI J. Histochem. Cytochem. PD MAY PY 2001 VL 49 IS 5 BP 673 EP 674 PG 2 WC Cell Biology SC Cell Biology GA 427ZT UT WOS:000168437200018 PM 11304810 ER PT J AU Shi, T Fredrickson, JK Balkwill, DL AF Shi, T Fredrickson, JK Balkwill, DL TI Biodegradation of polycyclic aromatic hydrocarbons by Sphingomonas strains isolated from the terrestrial subsurface SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE polycyclic aromatic hydrocarbons; PAH degradation; Sphingomonas; subsurface bacteria; fluoranthene; phenanthrene ID SURFACTANT-ENHANCED BIODEGRADATION; DEEP-SUBSURFACE; DEGRADING BACTERIA; CATABOLIC PLASMID; MYCOBACTERIUM SP; SP-NOV; DEGRADATION; FLUORANTHENE; PHENANTHRENE; MINERALIZATION AB Several strains of Sphingomonas isolated from deep Atlantic coastal plain aquifers at the US Department of Energy Savannah River Site (SRS) near Aiken, SC were shown to degrade a variety of aromatic hydrocarbons in a liquid culture medium. Sphingomonas aromaticivorans strain B0695 was the most versatile of the five strains examined. This strain was able to degrade acenaphthene, anthracene, phenanthrene, 2,3-benzofluorene, 2- methyl naphthalene, 2,3-dimethylnaphthalene, and fluoranthene in the presence of 400 mg l(-1) Tween 80. Studies involving microcosms composed of aquifer sediments showed that S. aromaticivorans B0695 could degrade phenanthrene effectively in sterile sediment and could enhance the rate at which this compound was degraded in nonsterile sediment. These findings indicate that it may be feasible to carry out (or, at least, to enhance) in situ bioremediation of phenanthrene-contaminated soils and subsurface environments with S. aromaticivorans B0695. In contrast, strain B0695 was unable to degrade fluoranthene in microcosms containing aquifer sediments, even though it readily degraded this polynuclear aromatic hydrocarbon (PAH) in a defined liquid growth medium. C1 Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Balkwill, DL (reprint author), Florida State Univ, Dept Biol Sci, 312 Nucl Res Bldg, Tallahassee, FL 32306 USA. NR 29 TC 59 Z9 59 U1 1 U2 5 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD MAY PY 2001 VL 26 IS 5 BP 283 EP 289 DI 10.1038/sj.jim.7000130 PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 460QT UT WOS:000170320600006 PM 11494104 ER PT J AU Studenov, AR Wegner, AM Ding, YS AF Studenov, AR Wegner, AM Ding, YS TI Radiosynthesis and PET studies of [C-11]RJR-2403, a nicotinic agonist SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE [C-11]RJR-2403; [C-11]metanicotine; nAChR; Alzhieimer's disease; position emission tomography ID POSITRON-EMISSION-TOMOGRAPHY; IN-VITRO CHARACTERIZATION; ACETYLCHOLINE-RECEPTORS; C-11 FORMALDEHYDE; CNS SELECTIVITY; RJR-2403; EPIBATIDINE; DERIVATIVES; METHYLATION AB (E)-N-methyl-4-(3-pyridinyl)-3-butene-1-amine (RJR-2403, or metanicotine), a nicotinic agonist developed as a cognitive-enhancing drug for Alzheimer's disease, was labeled with carbon-ii using [C-11]methyl iodide via a simple and efficient one-step procedure. Regioselectivity of [C-11]methylation on the aliphatic nitrogen versus pyridine nitrogen is strongly dependent on the reaction solvent. The reaction in acetonitrile exclusively yields aliphatic N-[C-11-methyl]alkylation ([C-11]RJR-2403), while only a byproduct is formed when DMF is used as a solvent. Positron emission tomographic (PET) studies in baboon showed a homogeneous distribution of radioactivity within baboon brain with a slow clearance. [C-11]RJR-2403 was metabolized very rapidly as evidenced by the fact that at 2 min after intravenous injection only 50% of the total carbon-ii in plasma is parent compound. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Brookhaven Natl Lab, Dept Chem, Neurosci & Imaging Grp, Upton, NY 11973 USA. RP Ding, YS (reprint author), Brookhaven Natl Lab, Dept Chem, Neurosci & Imaging Grp, Upton, NY 11973 USA. NR 27 TC 3 Z9 3 U1 1 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD MAY PY 2001 VL 44 IS 6 BP 425 EP 436 DI 10.1002/jlcr.472 PG 12 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA 442VG UT WOS:000169305200004 ER PT J AU Fthenakis, VM AF Fthenakis, VM TI Water-spray systems for mitigating accidental indoor releases of water-soluble gases SO JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES LA English DT Article DE hydrogen fluoride; mitigation; water sprays; indoor releases ID TOXIC GASES AB Water-spray systems have been designed for mitigating accidental outdoor releases of water-soluble gases. This paper describes the new application of water systems to mitigating indoor releases. The performance of spray systems is studied by using models of atmospheric release and spray mitigation, having adjusted them for the indoor environment. A case study is presented of a mitigation system for a railcar-tank HF unloading station, designed to absorb HF released through an open 1 in. valve, with the highest achievable effectiveness. We considered HF releases from the tank at different temperatures and pressures, and spray systems with different type of nozzles at different elevations. The type of release, flow rates and airborne concentrations were determined by the HGSYSTEM package of models and mass-balance calculations. The effectiveness of HF removal of alternative deluge systems was estimated using the model HGSPRAY5. This effectiveness ranged from 64% to 98%, depending on the conditions of the release, the water flow rates, and the type and positioning of the nozzles. Published by Elsevier Science Ltd. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Fthenakis, VM (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 10 TC 10 Z9 10 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0950-4230 J9 J LOSS PREVENT PROC JI J. Loss Prev. Process Ind. PD MAY PY 2001 VL 14 IS 3 BP 205 EP 211 DI 10.1016/S0950-4230(00)00025-5 PG 7 WC Engineering, Chemical SC Engineering GA 408KW UT WOS:000167326200007 ER PT J AU Crew, DC Lewis, LH Panchanathan, V AF Crew, DC Lewis, LH Panchanathan, V TI Multiscale magnetic domains observed in die-upset melt-spun magnets using magnetic force microscopy SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE magnetic force microscopy; magnetic domain; permanent magnet; nanocrystalline; magnetic reversal ID NANOCRYSTALLINE NDFEB; PERMANENT-MAGNETS; MICROSTRUCTURE; IMAGES; MFM AB Magnetic force microscopy (MFM) has been used to examine the magnetic reversal process in samples of Nd-13.9(Fe92Co8)(80.3)B5.5Ga0.5, one made by hot-pressing and one made by thermomechanical deformation, or die-upsetting, Both samples were imaged in various magnetic states under zero-field conditions. In both the hot-pressed and die-upset samples, the finest scale contrast observable consisted of individual magnetic clusters of approximately 10 grains in volume, on a scale between 150 and 300 nm. In the hot-pressed sample this fine-scale contrast was similar regardless of the magnetic state of the sample and no larger-scale contrast was observed, indicating that exchange interactions do not greatly affect the locality of the magnetic reversal in this sample. The die-upset sample in the thermally demagnetized state showed only fine-scale magnetic contrast. Once the sample was saturated, however, interaction domains formed which extended over many microns, although the fine-scale contrast could still be observed within these larger interaction domains. The increased crystallographic alignment between grains in the die-upset sample as compared with the hot-pressed sample, underlies the hypothesis that intergranular exchange interactions cause the reversal to be localized at the peripheries of previously reversed regions, leading to the creation of large interaction domains. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Mat & Chem Sci Div, Dept Energy Sci & Technol, Upton, NY 11973 USA. Magnequench Int Inc, Anderson, IN USA. RP Lewis, LH (reprint author), Brookhaven Natl Lab, Mat & Chem Sci Div, Dept Energy Sci & Technol, Bldg 480, Upton, NY 11973 USA. NR 12 TC 14 Z9 14 U1 2 U2 12 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 MAY PY 2001 VL 231 IS 1 BP 57 EP 64 DI 10.1016/S0304-8853(00)01273-7 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 437BJ UT WOS:000168970100012 ER PT J AU Thompson, JD Movshovich, R Fisk, Z Bouquet, F Curro, NJ Fisher, RA Hammel, PC Hegger, H Hundley, MF Jaime, M Pagliuso, PG Petrovic, C Phillips, NE Sarrao, JL AF Thompson, JD Movshovich, R Fisk, Z Bouquet, F Curro, NJ Fisher, RA Hammel, PC Hegger, H Hundley, MF Jaime, M Pagliuso, PG Petrovic, C Phillips, NE Sarrao, JL TI Superconductivity and magnetism in a new class of heavy-fermion materials SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE heavy-fermion compounds; superconductivity; antiferromagnetism; phase transitions - pressure effects ID CECU2SI2; STATES; CEIN3 AB We report a new family of Cc-based heavy-fermion compounds whose electronic specific heat coefficients range from about 400 to over 700 mJ/mol-Ce K-2. Crystals in this family form as CenTmIn3n+2m, where T = Rh or Ir, n = 1 or 2, and m = 1, with a tetragonal structure that can be viewed as n-layers of CeIn3 units stacked sequentially along the c-axis with intervening m-layers of TIn2. Ambient and high-pressure studies show that the quasi-2D layers Of CeIn3 produce unconventional superconducting and magnetic ground states. This family should enable new understanding of the relationship between magnetism and superconductivity in heavy-fermion materials and more generally of why heavy-fermion superconductivity prefers to develop in one structure type and not another. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, NHMFL, Tallahassee, FL 32306 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94270 USA. Bayer AG, D-5090 Leverkusen, Germany. RP Thompson, JD (reprint author), Los Alamos Natl Lab, MS K765, Los Alamos, NM 87545 USA. RI Petrovic, Cedomir/A-8789-2009; Pagliuso, Pascoal/C-9169-2012; Hammel, P Chris/O-4845-2014; Jaime, Marcelo/F-3791-2015; Curro, Nicholas/D-3413-2009 OI Petrovic, Cedomir/0000-0001-6063-1881; Hammel, P Chris/0000-0002-4138-4798; Jaime, Marcelo/0000-0001-5360-5220; Curro, Nicholas/0000-0001-7829-0237 NR 19 TC 122 Z9 122 U1 1 U2 21 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 MAY PY 2001 VL 226 SI SI BP 5 EP 10 DI 10.1016/S0304-8853(00)00602-8 PN 1 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600003 ER PT J AU Torikachvili, MS Lacerda, AH Sarrao, JL Fisk, Z AF Torikachvili, MS Lacerda, AH Sarrao, JL Fisk, Z TI Magnetic properties of the dense Kondo system CeB6 in high magnetic fields SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE Kondo systems; quadrupole ordering; magnetic phase diagram ID QUADRUPOLAR AB This work reports on the phase diagram study of the dense Kondo system CeB6 by means of magnetization (M) and transverse magnetoresistance (MR) measurements in magnetic fields (B) to 18 T, in the temperature (T) range from 1.8 to 40 K. The zero field resistivity displays Kondo behavior in the paramagnetic P-phase, while two discontinuities at low T were observed at T-Q approximate to 3.5 K and T-N approximate to 2.3 K, the boundaries of the antiferro-quadrupolar (AFQ). and antiferromagnetic (AF) phases, respectively. The isothermal transverse MR is large and negative at low T. and it shows a distinct feature when the P-AFQ line of the B-T phase diagram is crossed. Similarly, the M vs. B curves at low temperatures show upward discontinuities at the phase boundary. Both the features in MR and Al at the P-AFQ line correlate well in T, revealing the gradual increase of the T for the onset of AFQ ordering with B. No evidence for reentrant behavior could be observed in fields to 18T. (C) 2001 Published by Elsevier Science B.V. C1 San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. RP Torikachvili, MS (reprint author), San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. NR 8 TC 2 Z9 2 U1 0 U2 2 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 MAY PY 2001 VL 226 SI SI BP 145 EP 147 DI 10.1016/S0304-8853(01)00117-2 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600048 ER PT J AU de Medeiros, SN Bud'ko, SL Fontes, MB Continentino, MA Baggio-Saitovitch, EM AF de Medeiros, SN Bud'ko, SL Fontes, MB Continentino, MA Baggio-Saitovitch, EM TI Phase diagram of Ce(Co1-xFex)Ge-3: from complex magnetic ordering to a non-magnetic Fermi liquid SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE quantum critical point; Kondo lattice; magnetic order ID HEAVY FERMIONS; BEHAVIOR; COMPOUND AB The evolution from an antiferromagnetic Kondo lattice, with two magnetic ordering transitions (CeCoGe3) to a non-magnetic. moderate heavy fermion compound (CeFeGe3) in the Ce(Co1-xFex)Ge-3 series was studied by magnetic and transport measurements. A tentative magnetic x-T phase diagram for the series was constructed. The experimental results suggest the existence of a quantum critical point close to x(C) = 0.6. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Fed Fluminense, Inst Fis, BR-24210340 Niteroi, RJ, Brazil. Ctr Brasileiro Pesquisas Fis, BR-22290180 Rio De Janeiro, Brazil. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Continentino, MA (reprint author), Univ Fed Fluminense, Inst Fis, Av Litoranea S-N,Boa Viagem, BR-24210340 Niteroi, RJ, Brazil. RI Continentino, Mucio/B-7271-2013; Saitovitch, Elisa/A-6769-2015 OI Continentino, Mucio/0000-0003-0167-8529; NR 10 TC 0 Z9 0 U1 0 U2 4 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 MAY PY 2001 VL 226 SI SI BP 152 EP 154 DI 10.1016/S0304-8853(00)00653-3 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600051 ER PT J AU Paiva, T Huscroft, C McMahan, AK Scalettar, RT AF Paiva, T Huscroft, C McMahan, AK Scalettar, RT TI Local moment and specific heat in the Hubbard model SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE correlated electron systems; Hubbard model; local moment; specific heat ID THERMODYNAMIC PROPERTIES AB We discuss the local moment and specific heat of the two-dimensional half-filled Hubbard model. For small values of U the local moment displays not only a strucure at T similar to U, but also an additional increase at low T. leading to a two-peak structure for C(T) down to U = t. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Paiva, T (reprint author), Univ Calif Davis, Dept Phys, 1 Shields Ave, Davis, CA 95616 USA. RI Paiva, Thereza/B-9778-2013 OI Paiva, Thereza/0000-0002-4199-3809 NR 9 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 224 EP 226 DI 10.1016/S0304-8853(00)00911-2 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600077 ER PT J AU Martin, I Ortiz, G Eroles, J Balatsky, AV Bishop, AR AF Martin, I Ortiz, G Eroles, J Balatsky, AV Bishop, AR TI The physics of inhomogeneous striped superconductors SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE superconductivity-high-T(c); correlated electron systems; antiferromagnets-quantum; phase transitions ID MAGNETIC FLUCTUATIONS; NEUTRON-SCATTERING; EXCITATIONS; ORDER; LA1.85SR0.15CUO4; STATE AB We present a minimal model of a doped Mott insulator that simultaneously supports antiferromagnetic stripes and d-wave superconductivity. At the unrestricted mean-field level, the various phases of the cuprates, including weak and strong pseudogap phases, and two different types of superconductivity in the underdoped and the overdoped regimes, find a natural interpretation. We argue that on the underdoped side, the superconductor is intrinsically inhomogeneous - striped nanoscale coexistence of superconductivity and magnetism - and global phase coherence is achieved through Josephson-like coupling of the superconducting stripes. On the overdoped side, the state is overall homogeneous and the superconductivity is of the classical BCS type. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Martin, I (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM i-martin@lanl.gov NR 16 TC 0 Z9 0 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 355 EP 357 DI 10.1016/S0304-8853(00)01054-4 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600128 ER PT J AU Gardner, JS Ehlers, G Heffner, RH Mezei, F AF Gardner, JS Ehlers, G Heffner, RH Mezei, F TI Neutron spin echo studies of the glass-like pyrochlore Y2Mo2O7 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE magnetic frustration; neutron scattering; pyrochlore ID ANTIFERROMAGNET; FERROMAGNET; DYNAMICS; LIQUID AB We performed neutron spin echo measurements. on the geometrically frustrated antiferromagnet Y2Mo2O7 to reveal the magnetic nature of this glass-like system close to the freezing temperature. Tf. Diffuse magnetic scattering S(Q), indicative of spatial correlations. were observed to peak at a wave vector, Q approximate to 0.45 Angstrom (-1) below 25 K. The normalized intermediate scattering function, S(Q,t)/S(Q,0), was measured as a function of temperature and Q. This provides evidence of the dynamics within the system and reveals at least two relaxation processes above and below T-f approximate to 22.5 K. Crown Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserved. C1 Natl Res Council Canada, Chalk River Labs, NPMR, Chalk River, ON K0J 1J0, Canada. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. RP Gardner, JS (reprint author), Natl Res Council Canada, Chalk River Labs, NPMR, Bldg 459 Stn 18, Chalk River, ON K0J 1J0, Canada. RI Gardner, Jason/A-1532-2013; Ehlers, Georg/B-5412-2008 OI Ehlers, Georg/0000-0003-3513-508X NR 15 TC 11 Z9 11 U1 0 U2 9 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 MAY PY 2001 VL 226 SI SI BP 460 EP 462 DI 10.1016/S0304-8853(00)00770-8 PN 1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600168 ER PT J AU Rhyne, JJ Kaiser, H Stumpe, L Mitchell, JF McCloskey, T Chourasia, AR AF Rhyne, JJ Kaiser, H Stumpe, L Mitchell, JF McCloskey, T Chourasia, AR TI Composition dependence of the spin wave stiffness parameter in La1-xCaxMnO3CMR materials SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE manganites; CMR; spin waves AB Long-wavelength spin waves in La1-xCaxMnO3 CMR materials exhibit conventional Heisenberg dispersion (E = Dq(2) + Delta), but with an anomalous temperature dependence for the spin dispersion parameter D. For x approximate to 0.33, near the optimum CMR composition, D remains approximately 50% of its T = 0 K value before exhibiting a near-first-order transition at T-c, instead of following the expected power law decrease as T approaches T-c. No temperature hysteresis was observed in either D or in the magnetization. Compositions with x = 0.40 and 0.45 show more conventional temperature renormalization. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Missouri, Dept Phys, Columbia, MO 65211 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Texas A&M Univ Commerce, Dept Phys, Commerce, TX 75429 USA. RP Rhyne, JJ (reprint author), Univ Missouri, Dept Phys, Columbia, MO 65211 USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 775 EP 776 DI 10.1016/S0304-8853(00)00746-0 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600281 ER PT J AU Cullen, JR Clark, AE Wun-Fogle, M Restorff, JB Lograsso, TA AF Cullen, JR Clark, AE Wun-Fogle, M Restorff, JB Lograsso, TA TI Magnetoelasticity of Fe-Ga and Fe-Al alloys SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE magnetoelasticity; magnetostriction; iron-gallium alloys; iron-aluminum alloys; alfer; alfenol AB Measurements of the saturation magnetostriction lambda (100) on single crystals of Fe1-xGax with 0.21 less than or equal to x less than or equal to 0.35 are presented. The temperature dependences of lambda (100) and the magnetization of the x = 0.35 sample are discussed along with prior results in terms of a collapse of the magnetization into an inhomogeneous arrangement of iron moments (cluster glass). The anomalous behaviors of lambda (100) and c(11)-C-12 vs. x seen in both Fe1-xGax and Fe1-xAlx alloys are attributed to internal stresses associated with short-range atomic ordering. (C) 2001 Elsevier Science B.V. All rights reserved. C1 USN, Carderock Div, Surface Warface Ctr, Bethesda, MD 20817 USA. Univ Maryland, College Pk, MD 20742 USA. Clark Associates, Adelphi, MD 20783 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Wun-Fogle, M (reprint author), USN, Carderock Div, Surface Warface Ctr, 9500 MacArthur Blvd Code 681, Bethesda, MD 20817 USA. NR 8 TC 142 Z9 150 U1 3 U2 35 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 MAY PY 2001 VL 226 SI SI BP 948 EP 949 DI 10.1016/S0304-8853(00)00612-0 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600345 ER PT J AU Martinho, H Sanjurjo, JA Rettori, C Canfield, PC Pagliuso, PG AF Martinho, H Sanjurjo, JA Rettori, C Canfield, PC Pagliuso, PG TI Raman scattering study of crystal-field excitations in ErNi2B2C SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE superconductivity-magnetic superconductors Raman scattering; crystal-field excitation; crystal-field splitting ID BOROCARBIDE SUPERCONDUCTORS AB In this work we present Raman scattering and specific heat measurements in the superconducting magnetic borocarbide ErNi2B2C. The data is interpreted in terms of crystal electric field splitting (CEF) of the Er3+ ground-state multiplet. Two Raman CEF active transitions were observed. at 46 and 146 cm(-1). with polarization selection rules corresponding to Gamma (6)--> Gamma (7) electronic transitions. A Schottky anomaly in the specific heat was also observed. The fitting of the C-upsilon/T vs. T curve enabled us to obtain the CEF energy splitting of the Er3+ (J = 15/2) ground-state multiplet, which is in agreement with the observed Raman CEF transitions. These results are comparable to those previously reported in inelastic neutron scattering and magnetic susceptibility measurements. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Estadual Campinas, Grp Propriedades Opt & Magnet Solidos, Dep Eletron Quant, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Martinho, H (reprint author), Univ Estadual Campinas, Grp Propriedades Opt & Magnet Solidos, Dep Eletron Quant, Inst Fis Gleb Wataghin, Cidade Univ Zeferino Vaz, BR-13083970 Campinas, SP, Brazil. RI Rettori, Carlos/C-3966-2012; Pagliuso, Pascoal/C-9169-2012; Canfield, Paul/H-2698-2014; Martinho, Herculano/F-4684-2015; Optica e Eletronica, Laboratorio/A-8669-2014; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rettori, Carlos/0000-0001-6692-7915; NR 4 TC 2 Z9 2 U1 0 U2 1 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 MAY PY 2001 VL 226 SI SI BP 978 EP 979 DI 10.1016/S0304-8853(00)01165-3 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600357 ER PT J AU Colarieti-Tosti, M Eriksson, O Nordstrom, L Brooks, MSS Wills, J AF Colarieti-Tosti, M Eriksson, O Nordstrom, L Brooks, MSS Wills, J TI Crystal field levels in lanthanide systems SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE crystal field; rare earths; theory AB Crystal field levels in lanthanide compounds have been calculated by first-principles theory, combining the strength of the standard model for rare earths in treating the localized 4f electrons and the power of Density Functional Theory in describing the, weakly correlated, delocalized, electrons. The stability of our calculations has been checked against changes of the constraints in the Full Potential-LMTO implementation. The assumption of weak 4f-4f inter-atomic interactions has also been checked by means of supercell calculations. Suggestions for the treatment of magnetic systems on a similar basis are given. (C) 2001 Elsevier Science BN. All rights reserved. C1 Univ Uppsala, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Colarieti-Tosti, M (reprint author), Univ Uppsala, Condensed Matter Theory Grp, Box 530, S-75121 Uppsala, Sweden. RI Eriksson, Olle/E-3265-2014; Colarieti Tosti, Massimiliano/D-1360-2015 OI Eriksson, Olle/0000-0001-5111-1374; Colarieti Tosti, Massimiliano/0000-0002-2036-1060 NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1027 EP 1028 DI 10.1016/S0304-8853(00)00901-X PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467MP UT WOS:000170708600375 ER PT J AU Goff, JP Sarthour, RS McMorrow, DF Yakhou, F Vigliante, A Gibbs, D Ward, RCC Wells, MR AF Goff, JP Sarthour, RS McMorrow, DF Yakhou, F Vigliante, A Gibbs, D Ward, RCC Wells, MR TI X-ray resonant scattering study of an intermediate-valence Ho-Ce alloy SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE rare earth; X-ray diffraction; intermediate valence ID MAGNETIC SCATTERING; POLARIZATION AB The magnetism of a DHCP Ho-Ce alloy has been investigated using X-ray magnetic resonant scattering. A self-consistent magnetic structure is proposed that agrees with diffraction data for three different cross sections (neutron, dipolar and quadrupolar). The spectroscopic valence of the Cc is found to be 3.27(5), and the Ce is in an intermediate-valence state in this alloy. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Riso Natl Lab, Condensed Matter Phys & Chem Dept, DK-4000 Roskilde, Denmark. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Goff, JP (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Oxford St, Liverpool L69 7ZE, Merseyside, England. RI McMorrow, Desmond/C-2655-2008 OI McMorrow, Desmond/0000-0002-4947-7788 NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1113 EP 1115 DI 10.1016/S0304-8853(01)00092-0 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400022 ER PT J AU Krusin-Elbaum, L Shibauchi, T Argyle, B Gignac, L Zabel, T Weller, D AF Krusin-Elbaum, L Shibauchi, T Argyle, B Gignac, L Zabel, T Weller, D TI Dynamics of one-dimensional domain walls interacting with disorder potential SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE anisotropy-perpendicular; domain wall motion; Kerr measurements AB Dynamics of 1D perpendicular-anisotropy domain walls in a few monolayer-thin Co films is imaged by polar Kerr microscopy. When domain walls, driven by a square-pulsed magnetic fields, travel through a random disordered potential landscape, they display Gaussian-distributed roughness characteristic of this landscape. Average velocity of the domain wall driven by a constant magnetic field strongly depends on a strain field which modifies (increases) the elastic energy of the wall and reduces the wall velocity. (C) 2001 Elsevier Science B.V. All rights reserved. C1 IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. Los Alamos Natl Lab, MST, STC, Los Alamos, NM 87545 USA. RP Krusin-Elbaum, L (reprint author), IBM Corp, Thomas J Watson Res Ctr, POB 218,Route 132, Yorktown Hts, NY 10598 USA. RI Shibauchi, Takasada/B-9349-2008 OI Shibauchi, Takasada/0000-0001-5831-4924 NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1317 EP 1318 DI 10.1016/S0304-8853(00)00839-8 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400092 ER PT J AU Snyder, JE Lo, CCH Chen, R Kriegermeier-Sutton, B Leib, J Lee, SJ Kremer, MJ Jiles, DC Kief, MT AF Snyder, JE Lo, CCH Chen, R Kriegermeier-Sutton, B Leib, J Lee, SJ Kremer, MJ Jiles, DC Kief, MT TI The effect of nitrogen on the microstructure, stress, and magnetic properties of RF-sputtered FeSiAl(N) thin films SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE soft magnetic materials; sputtering; RF; anisotropy-stress induced; domain pattern ID SENDUST FILMS; SOFT AB In a series of RF-sputtered soft FeSiAl(N) films, the partial pressure (pp) of N in the plasma was observed to have a profound effect on the magnetic properties, stress, and microstructure. 1% (pp) N caused the coercivity (H-c) to more than double. H-c peaked for 3% (pp) N, then decreased steeply for N > 4% (pp). Stress appears to have a major influence on the magnetic properties. Film stress correlated quite closely with H-c. Hysteresis loops appear to indicate a stripe domain structure in which the magnetization has in-plane components which are aligned parallel, but perpendicular components which alternate up and down. Stripe domains were observed directly by magnetic force microscopy. The microstructure also changed significantly with added N. 1% (pp) N caused the strong (110) texture to become very weak. For > 4% (pp) N, there was a transition from textured columnar 100 nm diameter BCC grains to a mixture of randomly-oriented, equiaxed BCC nanograins (10 nm or less) in an amorphous matrix. Transmission electron microscopy observations appear to indicate that the grain refinement and phase separation take place by a decomposition process. Saturation magnetization also decreased with added N for > 4% (pp) N, indicating that one of the two phases has a lower M-s value. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50010 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50010 USA. Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50010 USA. Seagate Technol, Minneapolis, MN 55435 USA. RP Snyder, JE (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50010 USA. RI Jiles, David/H-9548-2012 NR 7 TC 6 Z9 7 U1 0 U2 11 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 MAY PY 2001 VL 226 SI SI BP 1669 EP 1671 DI 10.1016/S0304-8853(00)00820-9 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400217 ER PT J AU Langer, J Sellmann, R Hunter-Dunn, J Hahlin, A Karis, O Arvanitis, D Maletta, H AF Langer, J Sellmann, R Hunter-Dunn, J Hahlin, A Karis, O Arvanitis, D Maletta, H TI A circularly polarized X-ray study of the temperature-dependent spin-reorientation transition of thin Co films SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE X-ray dichroism; spin-reorientation; thin films ID MAGNETIC-ANISOTROPY; MICROSCOPIC ORIGIN; DICHROISM AB Utilizing vector magnetometry by means of X-ray circular dichroism, the temperature-driven spin reorientation from an in-plane to out-of-plane orientation in thin Co films is studied in an epitaxially grown Au/Co/Au trilayer with decreasing temperature. Probing the remanent state by changing the photon helicity provides evidence for a smooth transition and the formation of a metastable magnetic multi-domain state at temperatures below the transition temperature. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Hahn Meitner Inst Berlin GmbH, Dept SF2, D-14109 Berlin, Germany. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Uppsala, S-75121 Uppsala, Sweden. RP Maletta, H (reprint author), Hahn Meitner Inst Berlin GmbH, Dept SF2, Glienicker Str 100, D-14109 Berlin, Germany. NR 8 TC 3 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD MAY PY 2001 VL 226 SI SI BP 1675 EP 1677 DI 10.1016/S0304-8853(00)01017-9 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400219 ER PT J AU Sanchez-Hanke, C Kao, CC AF Sanchez-Hanke, C Kao, CC TI An element-sensitive hysteresis loop study of an exchange-biased Co/NiO bilayer SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE hysteresis; bi layers; exchange bias ID MULTILAYERS; DICHROISM; MODEL AB An exchange-biased Co/NiO bilayer was studied by measuring element specific hysteresis loops. A phase-sensitive detection scheme based on fast switching of the polarization of the X-rays was developed for this measurement. Uncompensated Ni2+ spins at the Co/NiO interface were observed for the first time. In addition, part of the Ni2+ spins were found to switch with the Co layer. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Sanchez-Hanke, C (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. NR 11 TC 13 Z9 13 U1 0 U2 1 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 MAY PY 2001 VL 226 SI SI BP 1803 EP 1805 DI 10.1016/S0304-8853(00)00935-5 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400264 ER PT J AU Guedes, I Mitchell, JF Argyriou, D Grimsditch, M AF Guedes, I Mitchell, JF Argyriou, D Grimsditch, M TI Raman study of phonons in Sr3Mn2O6.54 and Sr3Mn2O7 layered manganites SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY AUG 06-11, 2000 CL RECIFE, BRAZIL SP CNPq, FINEP, CAPES, FACEPE, FAPEST, FAPERJ DE Raman scattering; oxygen stoichiometry; magnetoresistance; manganite AB Polycrystalline Sr3Mn2O6.54 and Sr3Mn2O7 layered manganites were studied at room temperature using Raman spectroscopy. While the phonon spectrum of the stoichiometric Sr3Mn2O7 sample is consistent with the group theoretical analysis for the I4/min structure, three additional modes are observed in the phonon spectrum of the oxygen-deficient Sr3Mn2O6.54 sample. Based on an analysis of the temperature dependence of the Raman spectrum of Sr3Mn2O6.54. and a comparison with the Raman spectrum of LaSr2Mn2O7, we conclude that the 'extra' modes should be viewed as disorder-induced Raman scattering. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Guedes, I (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI GUEDES, ILDE/C-3451-2013; UFC, DF/E-1564-2017; Universidade Federal do Ceara, Physics Department/J-4630-2016; OI Universidade Federal do Ceara, Physics Department/0000-0002-9247-6780; GUEDES, ILDE/0000-0002-1040-5891 NR 4 TC 1 Z9 1 U1 1 U2 10 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 MAY PY 2001 VL 226 SI SI BP 1998 EP 1999 DI 10.1016/S0304-8853(00)00675-2 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 466DE UT WOS:000170628400333 ER PT J AU Garfield, N Maltrud, ME Collins, CA Rago, TA Paquette, RG AF Garfield, N Maltrud, ME Collins, CA Rago, TA Paquette, RG TI Lagrangian flow in the California Undercurrent, an observation and model comparison SO JOURNAL OF MARINE SYSTEMS LA English DT Article; Proceedings Paper CT 31st International Liege Colloquium on Ocean Hydrodynamics CY MAY 03-07, 1999 CL LIEGE, BELGIUM DE Lagrangian flow; California Undercurrent; eddy field ID CURRENT SYSTEM; SEASONAL VARIABILITY; STATISTICAL-ANALYSIS; SURFACE CIRCULATION; DRIFTERS; OCEAN AB During the period 1992-1998, 38 isobaric RAFOS floats were deployed to sample the subsurface flow of the California Undercurrent. The deployments, released over the California continental slope west of San Francisco, have sampled robust year-round poleward subsurface flow associated with the Undercurrent most seasons and the combined inshore current and Undercurrent in winter. Two other types of flow have been seen: a region of weak flow with little net displacement just west of the California Undercurrent, and an active westward propagating eddy field. This eddy field appears to be the primary mechanism for moving floats from the Undercurrent into the ocean interior. The observations and statistics from the RAFOS floats are compared with Lagrangian estimates of particles tracked in a global high resolution ocean simulation in order to evaluate the fidelity of the model along an eastern boundary. The results show that the model reproduces the general character of the flow reasonably well, but underestimates both the mean and eddy energies by a substantial amount. (C) 2001 Published by Elsevier Science B.V. C1 San Francisco State Univ, Romberg Tiburon Ctr, Tiburon, CA 94920 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. RP Garfield, N (reprint author), San Francisco State Univ, Romberg Tiburon Ctr, POB 855, Tiburon, CA 94920 USA. NR 32 TC 21 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD MAY PY 2001 VL 29 IS 1-4 BP 201 EP 220 DI 10.1016/S0924-7963(01)00017-3 PG 20 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 449XE UT WOS:000169711800012 ER PT J AU Laskin, J Lifshitz, C AF Laskin, J Lifshitz, C TI Kinetic energy release distributions in mass Spectrometry SO JOURNAL OF MASS SPECTROMETRY LA English DT Review DE kinetic energy release (KER); laboratory frame; center of mass frame; kinetic energy release distribution (KERD); metastable ions; mass-analyzed Ion Kinetic Energy (MIKE); electrospray ionization (ESI); matrix-assisted laser desorption/ionization (MALDI); RRKM/QET; phase space theory (PST); finite heat bath theory (FHBT); the Gspann parameter; surprisal; organometallic ions; clusters; fullerenes; biomolecules; Coulomb explosion; PEPICO; average KER; Maxwell-Boltzmann-like distribution; avoided crossing; conical intersection; angular momentum; reaction cross-section; detailed balance; density of states; centrifugal barrier; prior distribution; momentum gap law; energy randomization ID UNIMOLECULAR REACTION DYNAMICS; H BOND ACTIVATION; CHARGE-SEPARATION REACTIONS; VISIBLE WAVELENGTH RANGE; C-2 BINDING-ENERGY; PHASE-SPACE THEORY; CLUSTER IONS; GAS-PHASE; C-H; PHOTODISSOCIATION DYNAMICS AB Kinetic energy releases (KERs) in unimolecular fragmentations of singly and multiply charged ions provide information concerning ion structures, reaction energetics and dynamics. This topic is reviewed covering both early and more recent developments. The subtopics discussed are as follows: (1) introduction and historical background; (2) ion dissociation and kinetic energy release: kinematics; potential energy surfaces; (3) the kinetic energy release distribution (KERD); (4) metastable peak observations: measurements on magnetic sector and time-of-flight instruments; energy selected results by photoelectron photoion coincidence (PEPICO); (5) extracting KERDs from metastable peak shapes; (6) ion structure determination and reaction mechanisms: singly and multiply charged ions; biomolecules and fullerenes; (7) theoretical approaches: phase space theory (PST), orbiting transition state (OTS)/PST, finite heat bath theory (FHBT) and the maximum entropy method; (8) exit channel interactions; (9) general trends: time and energy dependences; (10) thermochemistry: organometallic reactions, proton-bound clusters, fullerenes; and (11) the efficiency of phase space sampling. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Farkas Ctr Light Induced Proc, IL-91904 Jerusalem, Israel. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. EM chavalu@vms.huji.ac.il RI Laskin, Julia/H-9974-2012 OI Laskin, Julia/0000-0002-4533-9644 NR 123 TC 82 Z9 82 U1 4 U2 43 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1076-5174 EI 1096-9888 J9 J MASS SPECTROM JI J. Mass Spectrom. PD MAY PY 2001 VL 36 IS 5 BP 459 EP 478 DI 10.1002/jms.164 PG 20 WC Biochemical Research Methods; Chemistry, Analytical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 439KG UT WOS:000169115600001 PM 11391803 ER PT J AU Chen, CK Gleiman, S Phillips, J AF Chen, CK Gleiman, S Phillips, J TI Low-power plasma torch method for the production of crystalline spherical ceramic particles SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THERMAL-CONDUCTIVITY; ULTRAFINE PARTICLES; ALUMINA; TEMPERATURE; JET; DEPOSITION; POWDER; GAS; REACTOR; RUNAWAY AB A low-power, atmospheric pressure, microwave plasma torch was used to make spherical alumina particles of controlled size from irregularly shaped precursor powders. Detailed studies of the impact of operating parameters, particularly gas identity (argon or air), gas flow rates, and applied power, showed that particle size changed in a predictable fashion. The most important factor in controlling particle size appears to be precursor particle density in the aerosol stream that enters the plasma hot zone. This and other facts suggest that particle collision rate is primarily responsible for determining ultimate particle size, although atomic addition also plays a role. Reproducible volume average particle sizes ranging from 97 to 1150 mum(3) were formed from precursor particles of order 14 mum(3). Moreover, for the first time we report the creation of an atmospheric pressure low-power air plasma (<1 kW). C1 Univ Calif Los Alamos Natl Lab, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. Univ New Mexico, Ceram & Composite Mat Ctr, Ferris Engn Ctr 209, Albuquerque, NM 87131 USA. Penn State Univ, Dept Chem Engn, University Pk, PA 16802 USA. RP Phillips, J (reprint author), Univ Calif Los Alamos Natl Lab, Engn Sci & Applicat Div, POB 1663,MS C930, Los Alamos, NM 87545 USA. RI Phillips, Jonathan/D-3760-2011 NR 53 TC 12 Z9 12 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAY PY 2001 VL 16 IS 5 BP 1256 EP 1265 DI 10.1557/JMR.2001.0177 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 429AW UT WOS:000168494700010 ER PT J AU Fayon, F Massiot, D Suzuya, K Price, DL AF Fayon, F Massiot, D Suzuya, K Price, DL TI P-31 NMR study of magnesium phosphate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID CHEMICAL-SHIFT TENSORS; QUANTUM NMR; DIFFRACTION AB 1-D magic angle spinning (MAS) and 2-D double quantum solid-state P-31 nuclear magnetic resonance (NMR) investigations have been carried out on (MgO)(x)(P2O5)(1-x) glasses over compositional range from x = 0.44 to 0.59. The distribution of the Q, phosphate units, obtained from the simulation of P-31 MAS spectra, is close to a binary distribution of bridging and non-bridging oxygen atoms, indicating that the Mg2+ cations act as network modifiers. High-resolution P-31 double quantum NMR is used to probe the intermediate range order in phosphate glasses and suggests that the anomalous behavior near the metaphosphate composition is due to a change from ring structures to phosphate chains. (C) 2001 Elsevier Science B.V. All rights reserved. C1 CNRS, CRMHT, F-45071 Orleans 2, France. JAERI, SPring8, Sayo, Hyogo 6795143, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP CNRS, CRMHT, F-45071 Orleans 2, France. EM fayon@cnrs-orleans.fr RI Fayon, Franck/C-1835-2008; Massiot, Dominique/C-1287-2008; Price, David Long/A-8468-2013 OI Massiot, Dominique/0000-0003-1207-7040; NR 24 TC 37 Z9 37 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD MAY PY 2001 VL 283 IS 1-3 BP 88 EP 94 DI 10.1016/S0022-3093(01)00357-X PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 432EK UT WOS:000168679100010 ER PT J AU Li, LY Li, H Qian, MX Strachan, DM AF Li, LY Li, H Qian, MX Strachan, DM TI Gadolinium solubility in peralkaline borosilicate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; TERNARY-SYSTEM NA2O-B2O3-SIO2; LANTHANIDE BORATE GLASSES; LEVEL LIQUID WASTES; SILICATE-GLASSES; OXIDE GLASSES; SODIUM; NMR; IONS; ALUMINOSILICATE AB This paper discusses the results of a study, using 25 peralkaline (Na/Al > 1) borosilicate glasses, to understand the effect of glass composition on the Gd solubility. In the glasses with the ratio of excess Na2O, i.e., moles of Na2O minus the moles of Al2O3, to B2O3 less than 0.5, phase separation occurs above the Gd solubility. In the glasses, with excess Na/B ratio greater than 0.5, sodium gadolinium silicate crystallizes above the Gd solubility. For the samples in which phase separation occurs, the Gd solubility is determined by the concentration of excess Na. Increasing excess Na increases the Gd solubility. For the samples in which crystallization occurs, the Gd solubility is determined by the concentration of each glass former. Increasing B and Si increases the Gd solubility, but increasing Al decreases it. The solution mechanism of Gd in peralkaline borosilicate glasses is discussed. (C) 2001 Published by Elsevier Science B.V. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Pacific NW Natl Lab, POB 999,K8-93, Richland, WA 99352 USA. EM liyu.li@pnl.gov NR 53 TC 18 Z9 18 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD MAY PY 2001 VL 283 IS 1-3 BP 237 EP 245 DI 10.1016/S0022-3093(01)00480-X PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 432EK UT WOS:000168679100030 ER PT J AU Singh, BN Edwards, DJ Eldrup, M Toft, P AF Singh, BN Edwards, DJ Eldrup, M Toft, P TI Effect of bonding and bakeout thermal cycles on the properties of copper alloys irradiated at 350 degrees C SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID PRECIPITATION; CHROMIUM AB Screening experiments were carried out to determine the effect of bonding and bakeout thermal cycles on microstructure, mechanical properties and electrical resistivity of the oxide dispersion strengthened (GlidCop, CuAl-25) and the precipitation hardened (CuCrZr, CuNiBe) copper alloys. Tensile specimens were given heat treatments corresponding to solution anneal, prime-aging, bonding thermal treatment followed by re-aging and the reactor bakeout treatment. A number of specimens were irradiated at 350 degreesC to a dose level of similar or equal to0.3 dpa in the DR-3 reactor at Riso. Both unirradiated and irradiated specimens were tensile tested at 350 degreesC. The microstructure and electrical resistivity were determined in the unirradiated and irradiated conditions. The post-deformation microstructure and fracture surfaces of unirradiated and irradiated specimens were examined. The main results are described and their salient features discussed. The most significant effect of neutron irradiation is a severe loss of ductility in the case of CuNiBe alloys. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. Pacific NW Natl Lab, Mat Dev Grp, MSIN P815, Richland, WA 99352 USA. RP Singh, BN (reprint author), Riso Natl Lab, Mat Res Dept, DK-4000 Roskilde, Denmark. NR 11 TC 8 Z9 8 U1 4 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 MAY PY 2001 VL 295 IS 1 BP 1 EP 15 DI 10.1016/S0022-3115(01)00507-4 PG 15 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 436DE UT WOS:000168920600001 ER PT J AU DiStefano, JR Chitwood, LD AF DiStefano, JR Chitwood, LD TI Oxidation and its effects on the mechanical properties of Nb-1Zr SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ALLOYS AB The alloy Nb-1Zr is a high temperature material that is often considered for applications where strength and resistance to alkali metals are required. However, these favorable properties can be compromised because it lacks oxidation resistance in many environments. After reviewing the oxidation behavior of Nb-1Zr, additional studies were conducted in high temperature, low pressure gaseous oxygen environments to determine the effects of oxidation on the tensile properties and hardness of Nb-1Zr for a specific space system application. Strengthening and loss of ductility were found to occur from room temperature to 900 degreesC following low pressure oxidation in vacuum or argon at 750 degreesC and 900 degreesC, respectively. In general, oxygen that is associated with zirconium as extremely fine zirconium-oxygen zones is responsible for the strengthening/embrittlement that is observed. Heat treatments that result in non-coherent ZrO2 precipitates can neutralize the effects of oxygen on mechanical properties provided the total oxygen content is below that required to convert all of the Zr to oxide. (C) 2001 Published by Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP DiStefano, JR (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 14 Z9 14 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY PY 2001 VL 295 IS 1 BP 42 EP 48 DI 10.1016/S0022-3115(01)00495-0 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 436DE UT WOS:000168920600006 ER PT J AU Klein, GJ Jamsheed, HC Reutter, BW Saloner, DA Schreck, CE Botvinick, EH Budinger, TF Huesman, RH AF Klein, GJ Jamsheed, HC Reutter, BW Saloner, DA Schreck, CE Botvinick, EH Budinger, TF Huesman, RH TI PET cardiac contractile motion compensation via tagged MRI priors. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 27 BP 8P EP 8P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900028 ER PT J AU Gifford, AN Rice, OV Gatley, SJ Huemmer, CL Rogoz, R Dejesus, OT Shea, CE Volkow, ND AF Gifford, AN Rice, OV Gatley, SJ Huemmer, CL Rogoz, R Dejesus, OT Shea, CE Volkow, ND TI Effects of endogenous neurotransmitters on the in vivo binding of dopamine and 5-HT radiotracers in mice. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Wisconsin, Madison, WI USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 53 BP 15P EP 15P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900054 ER PT J AU Schiffer, WK Gerasimov, MR Fowler, JS Volkow, ND Logan, J Alexoff, DL Shea, C Brodie, JD Dewey, SL AF Schiffer, WK Gerasimov, MR Fowler, JS Volkow, ND Logan, J Alexoff, DL Shea, C Brodie, JD Dewey, SL TI Positron emission tomography (PET) investigations of synaptic dopamine (DA) release and re-uptake in phencyclidine (PCP) treated primates. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NYU, Sch Med, New York, NY USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 52 BP 15P EP 15P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900053 ER PT J AU Schiffer, WK Gerasimov, MR Fowler, JS Volkow, ND Gifford, A Ashby, CR Brodie, JD Dewey, SL AF Schiffer, WK Gerasimov, MR Fowler, JS Volkow, ND Gifford, A Ashby, CR Brodie, JD Dewey, SL TI MK-801 increases dopamine transporter (DAT) availability: A positron emission tomography (PET) investigation in non-human primates. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. St Johns Univ, Jamaica, NY 11439 USA. NYU, Sch Med, New York, NY USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 56 BP 16P EP 16P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900057 ER PT J AU Li, Z Meinken, GE James, JL Srivastava, S AF Li, Z Meinken, GE James, JL Srivastava, S TI Synthesis and structural characterization of the promising therapeutic agent Sn-117m DTPA. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Diatide Res Labs, Londonderry, NH USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 77 BP 21P EP 21P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900078 ER PT J AU Liepe, K Hliscs, R Kropp, J Knapp, F Franke, WG AF Liepe, K Hliscs, R Kropp, J Knapp, F Franke, WG TI Bone marrow radiation dose of rhenium-186-HEDP in palliative treatment of metastatic bone pain. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Hosp Dresden, Dresden, Germany. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 82 BP 23P EP 23P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900083 ER PT J AU Feng, B Sitek, A Veress, AI Gullberg, GT AF Feng, B Sitek, A Veress, AI Gullberg, GT TI Calculation of the wall-thickening of the left ventricle from gated SPECT images without edge detection. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Berkeley, CA USA. Univ Utah, Dept Radiol, Salt Lake City, UT USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 193 BP 52P EP 52P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900194 ER PT J AU Bishayee, A Rao, DV Srivastava, SC Howell, RW AF Bishayee, A Rao, DV Srivastava, SC Howell, RW TI High-let type cell killing by Sn-117m(4+)DTPA: Implications for therapy of bone metastases. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Med & Dent New Jersey, New Jersey Med Sch, Newark, NJ 07103 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 253 BP 68P EP 68P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900254 ER PT J AU Vanbrocklin, HF Lohman, JW Hanrahan, SM Schustz, AM Taylor, SE Powers-Risius, P Marshall, RC AF Vanbrocklin, HF Lohman, JW Hanrahan, SM Schustz, AM Taylor, SE Powers-Risius, P Marshall, RC TI Iodophenylpiperazinium quaternary amine cardiac perfusion tracers: In vivo distribution and in vitro perfusion analysis. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 270 BP 72P EP 72P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900271 ER PT J AU Woody, CL Stoll, S Schlyer, DJ Shokouhi, S Gerasimov, M Volkow, N Fowler, J Dewey, S AF Woody, CL Stoll, S Schlyer, DJ Shokouhi, S Gerasimov, M Volkow, N Fowler, J Dewey, S TI An intracerebral beta microprobe for studying radiotracer kinetics in freely moving animals. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 377 BP 101P EP 101P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900378 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Logan, J Maynard, L Jayne, M Gately, SJ Wong, C Franceschi, D Gifford, A Hitzemann, R Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Logan, J Maynard, L Jayne, M Gately, SJ Wong, C Franceschi, D Gifford, A Hitzemann, R Pappas, N TI Effects of alcohol detoxification on brain dopamine transporters and D2 receptors in alcoholics. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 400 BP 107P EP 107P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900401 ER PT J AU Volkow, ND Wang, GJ Fischman, MW Foltin, RW Fowler, JS Logan, J Gatley, J Ding, YS Franceschi, D Gifford, A AF Volkow, ND Wang, GJ Fischman, MW Foltin, RW Fowler, JS Logan, J Gatley, J Ding, YS Franceschi, D Gifford, A TI Effects of dopamine transporter pre-blockade on the effects of low dose cocaine. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Columbia Univ, New York, NY USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 403 BP 108P EP 108P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900404 ER PT J AU Volkow, ND Chang, L Wang, GJ Fowler, JS Sedler, L Hitzemann, R Ding, YS Logan, J Gatley, SJ Franceschi, D Wong, C Pappas, N AF Volkow, ND Chang, L Wang, GJ Fowler, JS Sedler, L Hitzemann, R Ding, YS Logan, J Gatley, SJ Franceschi, D Wong, C Pappas, N TI Loss of dopamine transporters in methamphetamine abusers recovers with detoxification. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 2001 VL 42 IS 5 SU S MA 402 BP 108P EP 108P PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 434NG UT WOS:000168821900403 ER EF