FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Van Blarigan, P Keller, JO AF Van Blarigan, P Keller, JO TI A hydrogen fuelled internal combustion engine designed for single speed/power operation SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB Sandia National Laboratory is developing from first principles a hydrogen fuelled internal combustion engine for driving an electrical generator that can be utilized either as a stationary power set or the auxiliary power unit in a hybrid vehicle. The intent is to take advantage of hydrogen's unique fuel characteristics and the constant speed characteristics of generator sets to maximize thermal efficiency while minimizing emissions. The current experiments utilize a flat cylinder combustion chamber shape with two ignition points at high (14: 1) compression ratio. Emissions and indicated thermal efficiency measurements with fuels of hydrogen, natural gas and a blend confirm low emissions and high thermal efficiency. CFD modelling done by Los Alamos National Laboratory (Los Alamos, NM) using their KIVA code is helping to further direct variations in the experimental design space. (C) 1998 International Association for Hydrogen Energy. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Van Blarigan, P (reprint author), Sandia Natl Labs, 7011 East Ave, Livermore, CA 94550 USA. NR 4 TC 21 Z9 21 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD JUL PY 1998 VL 23 IS 7 BP 603 EP 609 DI 10.1016/S0360-3199(97)00100-6 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA ZN252 UT WOS:000073627300011 ER PT J AU Frew, DJ Hanchak, SJ Green, ML Forrestal, MJ AF Frew, DJ Hanchak, SJ Green, ML Forrestal, MJ TI Penetration of concrete targets with ogive-nose steel rods SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article DE penetration; ogive-nose steel rods; geometric and material scales ID PROJECTILES AB We conducted depth of penetration experiments in concrete targets with 3.0 caliber radius-head, steel rod projectiles. The concrete targets with 9.5 mm diameter limestone aggregate had a nominal unconfined compressive strength of 58.4 MPa (8.5 ksi) and density 2320 kg/m(3). To explore geometric projectile scales, we conducted two sets of experiments. Projectiles with length-to-diameter ratio of ten were machined from 4340R(c), 45 steel, round stock and had diameters and masses of 20.3 mm, 0.478 kg and 30.5 mm, 1.62 kg. Powder guns launched the projectiles to striking velocities between 400 and 1200 m/s. For these experiments, penetration depth increased as striking velocity increased. When depth of penetration data was divided by a length scale determined from our model, the data collapsed on a single curve. Thus, a single dimensionless penetration depth versus striking velocity prediction was in good agreement with the data at two geometric projectile scales for striking velocities between 400 and 1200 m/s. In addition, we conducted experiments with AerMet 100R(c), 53 steel projectiles and compared depth of penetration and post-test nose erosion data with results from the 4340R(c), 45 steel projectiles. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Waterways Expt Stn, Vicksburg, MS 39180 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Forrestal, MJ (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 4 TC 115 Z9 159 U1 3 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD JUL PY 1998 VL 21 IS 6 BP 489 EP 497 DI 10.1016/S0734-743X(98)00008-6 PG 9 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 102NC UT WOS:000074929600006 ER PT J AU Kodama, T Donangelo, R Guidry, MW AF Kodama, T Donangelo, R Guidry, MW TI Inclusion of retardation effects in hydrodynamical calculations SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE retardation effects; hydrodynamics; supernova explosion ID CORE COLLAPSE SUPERNOVAE; II SUPERNOVAE; CONVECTION; EXPLOSIONS; MECHANISM AB In numerical large-scale hydrodynamics calculations, such as the description of a supernova explosion, instantaneous thermalization of the fluid matter is assumed independently of the size of the volume element used in the calculation. One expects, however, the appearance of transient processes such as convection currents, vortices, and other collective motion on smaller and smaller scales, which can delay equilibration. To account for these effects in a simple one-dimensional hydrodynamical calculation, we introduce retardation in the hydrodynamic equations and show that, when strong shocks are present, such effects may have considerable influence on the evolution of the system. C1 Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Kodama, T (reprint author), Univ Fed Rio de Janeiro, Inst Fis, CP 68528, BR-21945970 Rio De Janeiro, Brazil. RI Kodama, Takeshi/H-2381-2011 OI Kodama, Takeshi/0000-0001-7718-9874 NR 19 TC 8 Z9 8 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD JUL PY 1998 VL 9 IS 5 BP 745 EP 758 DI 10.1142/S0129183198000650 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 118AX UT WOS:000075816000009 ER PT J AU Zhang, Y Woloschak, GE AF Zhang, Y Woloschak, GE TI Detection of codon 12 point mutations of the K-ras gene from mouse lung adenocarcinoma by 'enriched' PCR SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID AQUATICUS DNA-POLYMERASE; PROCESSED PSEUDOGENE; THYMIC LYMPHOMA; TUMOR-ANTIGEN; ACTIVATION; RADIATION; ONCOGENES; CELLS; TRANSFORMATION; CARCINOGENESIS AB Purpose: Recent studies have shown that chemical carcinogens induce a high frequency of point mutations in the K-ras oncogene from mouse lung tumours at codons 12, 13 and 61. These experiments were performed to identify K-ras mutations in tissues from control and radiation-exposed mice. Materials and methods: By modifying the technique of the 'enriched' polymerase chain reaction (PCR), it was possible to detect point mutations at codon 12 of the K-ras oncogene from 25-year-old paraffin-embedded normal lungs and lung adenocarcinomas from mice exposed to radiation. Together, a total of 120 lung tissues were screened for point mutations at codon 12 of the K-ras oncogene in this study. Results: A significant increase in K-ras codon 12 point mutations was observed in the normal lungs from mice exposed to 24 once-weekly neutron irradiations (100%), compared with normal lungs from mice with sham-irradiation (50%) (p<0.05). Lung adenocarcinomas from mice receiving 24 once-weekly neutron irradiations also had a significantly higher frequency of K-ras codon 12 point mutations (100%) than the lung adenocarcinomas of mice receiving 24 or 60 once-weekly gamma-ray irradiations (50%), but the higher frequency was not significantly different from that in spontaneous lung adenocarcinomas from mice (75%; p>0 05). The validity of the technique was confirmed by sequencing two of the mutants. In doing so, a K-ras 13(Asp) point mutation was observed. Conclusions: The data suggest that high-linear energy transfer (LET) neutron radiation was more effective than low-LET gamma-rays in inducing K-ras point mutations at codon 12 in the lungs of BGCF(1) mice. C1 Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, Argonne, IL 60439 USA. RP Woloschak, GE (reprint author), Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM woloschak@anl.gov RI Woloschak, Gayle/A-3799-2017 OI Woloschak, Gayle/0000-0001-9209-8954 FU NIEHS NIH HHS [ES 07141-02] NR 41 TC 5 Z9 5 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD JUL PY 1998 VL 74 IS 1 BP 43 EP 51 PG 9 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA ZZ889 UT WOS:000074778800005 PM 9687974 ER PT J AU Strobel, GL AF Strobel, GL TI Rest frame properties of the proton SO INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS LA English DT Article ID 2-BODY DIRAC-EQUATION; QUARK-MODEL; POTENTIALS AB The proton is modeled as three quarks of small current quark mass. The three-body Dirac equation is solved with spin-independent central diagonal linear confining potentials with an attractive Coulombic term in a relativistic three-quark model. Hyperspherical coordinates are used, and the bound state is found analytically. After integrating over the hyperangles, the Hamiltonian is an 8 by 8 matrix of coupled first-order differential equations in one variable, the hyperradius. These are analytically solved in hypercentral approximation. For the (1/2(+))(3) ground-state configuration in the nonrelativistic large-quark-mass limit, there are no nodes in the wave function. However, in the extreme relativistic limit of small current quark masses of a few MeV, the expectation value of the number of nodes is about 1.30 when the potential parameters are chosen to reproduce the proton rms charge radius. The quarks are assumed to possess a Pauli anomalous magnetic moment, like that of the electron and muon of (alpha/2 pi)(e/m). Assuming all three quarks have equal mass, one can fit the rest energy, magnetic moment, rms charge radius, and axial charge of the proton with this relativistic three-body Dirac equation model. The solution found shows the necessity of including all components of the composite three-quark wave function, as the upper component contributes only 0.585 to the norm. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Georgia, Dept Phys, Athens, GA 30602 USA. RP Strobel, GL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 22 TC 6 Z9 6 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0020-7748 J9 INT J THEOR PHYS JI Int. J. Theor. Phys. PD JUL PY 1998 VL 37 IS 7 BP 2001 EP 2019 DI 10.1023/A:1026621415068 PG 19 WC Physics, Multidisciplinary SC Physics GA 121UK UT WOS:000076032300007 ER PT J AU Reddy, TV Olson, GR Wiechman, B Reddy, G Torsella, J Daniel, FB AF Reddy, TV Olson, GR Wiechman, B Reddy, G Torsella, J Daniel, FB TI Subchronic toxicity of 1,3,5-trinitrobenzene in Fischer 344 rats SO INTERNATIONAL JOURNAL OF TOXICOLOGY LA English DT Article; Proceedings Paper CT 33rd Annual Meeting of the Society-of-Toxicology CY MAR 13-17, 1994 CL DALLAS, TEXAS SP Soc Toxicol DE Fischer 344 rats; nitroaromatic compounds; subchronic toxicity; 1,3,5-trinitrobenzene ID LONG-TERM SEQUELAE; REPRODUCTIVE TOXICITY; 1,3-DINITROBENZENE; TRINITROTOLUENE AB The subchronic toxicity of 1,3,5-trinitrobenzene (TNB) in, male and female Fischer 344 rats was evaluated by feeding a powdered certified laboratory diet containing 0, 66.7, 400 and 800 mg TNB/kg diet for 90 days. The calculated average TNB intake was 4.29, 24.70 and 49.28 mg/kg body weight (BW)/day for females and 3.91, 22.73, and 44.16 mg/kg BW/day for males. Food intake in the 400 and 800 mg/kg diet dose groups of both sexes was decreased throughout the study and resulted in, a significant decrease in absolute body weights. A significant decrease in relative testicular weights and a significant increase in the relative liver weight were observed in, male rats receiving 400 or 800 mg TNB/kg diet. A significant increase in the relative spleen weights of both sexes receiving 400 or 800 mg TNB diet was noted. The relative liver weight was also increased only in female rats maintained on the 800 mg TNB diet. Histopathological examinations revealed that the susceptible organs for TNB toxicity were kidney (hyaline droplets) in all male dose groups and testes (seminiferous tubular degeneration) in rats receiving 400 and 800 mg TNB diet groups. The spleen was also affected (extramedullary hematopoiesis) in both sexes in the 400 and 800 mg close groups. Hematological studies at both 45 (data not given) and 90 days in the 400 and 800 mg dose groups indicated decreased values for red blood cell counts and hemoglobin content, while reticulocytes and methemoglobin levels were increased. Clinical chemistry parameters were unaffected. Based on Kidney toxicity and hematological effects, a Low Observed Adverse Effect Level (LOAEL) of 3.91 mg/kg BW/day was suggested for subchronic toxicity studies on TNB. C1 USA, Ctr Hlth Promot & Prevent Med, Aberdeen Proving Ground, MD 21010 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. US EPA, Natl Exposure Res Lab, Cincinnati, OH 45268 USA. Pathol Associates Inc, W Chester, OH USA. RP Reddy, G (reprint author), USA, Ctr Hlth Promot & Prevent Med, Bldg E-2100, Aberdeen Proving Ground, MD 21010 USA. NR 33 TC 6 Z9 6 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1091-5818 J9 INT J TOXICOL JI Int. J. Toxicol. PD JUL-AUG PY 1998 VL 17 IS 4 BP 393 EP 411 PG 19 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA ZW829 UT WOS:000074452500002 ER PT J AU Bischof, CH Mauer, A Jones, WT Samareh, J AF Bischof, CH Mauer, A Jones, WT Samareh, J TI Experiences with automatic differentiation applied to a volume grid generation code SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 34th Aerospace Sciences Meeting and Exhibit CY JAN 15-19, 1996 CL RENO, NV SP Amer Inst Aeronaut & Astronaut AB Automatic differentiation (AD) is a methodology for developing reliable sensitivity-enhanced versions of arbitrary computer programs with little human effort. As such, it can vastly accelerate the use of advanced simulation codes in a multidisciplinary design optimization context because the time for generating and verifying derivative codes is greatly reduced. The application of the recently developed automatic differentiation of C programs (ADIC) prototype tool for ANSI-C programs on the coordinate and sensitivity calculator for multidisciplinary design optimization multiblock three-dimensional volume grid generator are reported. The ADIC-generated code can easily be interfaced with Fortran derivative codes generated with the ADIFOR AD tool for Fortran 77 programs; thus providing efficient sensitivity-enhancement techniques for multilanguage, multidiscipline problems. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Comp Sci Corp, Hampton, VA 23666 USA. RP Bischof, CH (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM bischof@mcs.anl.gov; mauer@math.uiuc.edu; w.t.jones@larc.nasa.gov; j.a.samareh@larc.nasa.gov RI Bischof, Christian/D-2897-2009 NR 14 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JUL-AUG PY 1998 VL 35 IS 4 BP 569 EP 573 DI 10.2514/2.2361 PG 5 WC Engineering, Aerospace SC Engineering GA 107FJ UT WOS:000075196300008 ER PT J AU Marathe, MV Ravi, R Sundaram, R Ravi, SS Rosenkrantz, DJ Hunt, HB AF Marathe, MV Ravi, R Sundaram, R Ravi, SS Rosenkrantz, DJ Hunt, HB TI Bicriteria network design problems SO JOURNAL OF ALGORITHMS LA English DT Article ID DECOMPOSABLE GRAPHS; SPANNING-TREES; APPROXIMATION; TIME; COMPUTATION; ALGORITHMS; BROADCAST AB We study a general class of bicriteria network design problems. A generic problem in this class is as follows: Given an undirected graph and two minimization objectives (under different cost functions), with a budget specified on the first objective, find a subgraph from a given subgraph-class that minimizes the second objective subject to the budget on the first objective. We consider three different criteria - the total edge cost, the diameter, and the maximum degree of the network. Here, we present the first polynomial-time approximation algorithms for a large class of bicriteria network design problems for the previously mentioned criteria. The following general types of results are presented. First, we develop a framework for bicriteria problems and their approximations. Second, when the two criteria are the same we present a "black box" parametric search technique. This black box takes in as input an (approximation) algorithm for the unicriterion situation and generates an approximation algorithm for the bicriteria case with only a constant factor loss in the performance guarantee. Third, when the two criteria are the diameter and the total edge costs we use a cluster-based approach to devise a approximation algorithms - the solutions output violate both the criteria by a logarithmic factor. Finally, for the class of treewidth-bounded graphs, we provide pseudo-polynomial-time algorithms for a number of bicriteria problems using dynamic programming. We show how these pseudo-polynomial-time algorithms can be converted to fully polynomial-time approximation schemes using a scaling technique. (C) 1998 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, GSIA, Pittsburgh, PA 15213 USA. Delta Trading Co, Cambridge, MA USA. SUNY Albany, Dept Comp Sci, Albany, NY 12222 USA. Princeton Univ, DIMACS, Princeton, NJ 08544 USA. MIT, LCS, Cambridge, MA 02139 USA. RP Marathe, MV (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS B265, Los Alamos, NM 87545 USA. NR 34 TC 93 Z9 93 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0196-6774 J9 J ALGORITHM JI J. Algorithms PD JUL PY 1998 VL 28 IS 1 BP 142 EP 171 DI 10.1006/jagm.1998.0930 PG 30 WC Computer Science, Theory & Methods; Mathematics, Applied; Logic SC Computer Science; Mathematics; Science & Technology - Other Topics GA ZU153 UT WOS:000074167600007 ER PT J AU Van Berkel, GJ AF Van Berkel, GJ TI Electrolytic corrosion of a stainless-steel electrospray emitter monitored using an electrospray-photodiode array system SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE electrospray; stainless steel; emitter corrosion; photodiode array; tris(1,10-phenanthroline)iron(II); electrospray mass spectrometry ID MASS-SPECTROMETRY; CELL; CHEMISTRY AB An electrospray-photodiode array (ES-PDA) system provides a useful alternative to ES-RIS for the study of the electrolytic reactions that occur at the point of high voltage (or ground) contact in an ES ion source emitter. These electrolytic reactions charge-balance the loss of an excess of ions of one polarity in the charged ES droplets. This ES-PDA approach is particularly useful when the redox products are either neutral or difficult to detect in the pas phase unaltered. The latter is the case for the multiply charged metal ions derived from ES emitter corrosion. In this study, the anodic corrosion of iron in a stainless-steel ES emitter, detected optically as tris(1,10-phenanthroline)iron(II), [Fe(phen)(3)](2+), was found using the ES-PDA system to account for the majority of the charge-balancing current under the conditions used. The metal ions derived from emitter corrosion may be produced at levels sufficient to cause chemical background problems in ES-MS. Probably because of the relatively high concentration detection Limits of ES-MS for multiply charged inorganic species, this problem has not yet been a major issue. One expects further use of ES as a nebulization source for ICP-AES and ICP-R IS, because of the much better concentration detection limits of these techniques, to bring this issue to the forefront. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 18 TC 27 Z9 27 U1 0 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD JUL PY 1998 VL 13 IS 7 BP 603 EP 607 DI 10.1039/a800373d PG 5 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 103HX UT WOS:000074965100003 ER PT J AU Cleghorn, SJC Derouin, CR Wilson, MS Gottesfeld, S AF Cleghorn, SJC Derouin, CR Wilson, MS Gottesfeld, S TI A printed circuit board approach to measuring current distribution in a fuel cell SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article DE fuel cell; segmented electrode; current distribution; water distribution ID POLYMER-ELECTROLYTE; MODEL; MANAGEMENT; WATER AB A new method of measuring current distribution in a polymer electrolyte fuel cell of active area 100 cm(2) has been demonstrated, using a printed circuit board (PCB) technology to segment the current collector and flow field. The PCB technique was demonstrated to be an effective approach to fabricating a segmented electrode and provide a useful tool for analysing cell performance at different reactant gas flow rates and humidification strategies. In this initial chapter of work with the segmented cell, we describe measured effects on current distribution of cathode and anode gas stream humidification levels in a hydrogen/air cell, utilizing a Nafion(TM) 117 membrane and single serpentine channel flow fields, and operating at relatively high gas flow rates. Effects of the stoichiometric Bow of air are also shown. A clear trend is seen, apparently typical for a thick ionomeric membrane, of lowering in membrane resistance down the flow channel, bringing about the highest local current density near the air outlet. This trend is reversed at low stoichiometric hows of air. At an air flow rate less than three times stoichiometry, the local performance starts to drop significantly from inlet to outlet, as local oxygen concentration drop overshadows the lowering in resistance along the direction of flow. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Cleghorn, SJC (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS D429, Los Alamos, NM 87545 USA. NR 15 TC 181 Z9 187 U1 2 U2 22 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD JUL PY 1998 VL 28 IS 7 BP 663 EP 672 DI 10.1023/A:1003206513954 PG 10 WC Electrochemistry SC Electrochemistry GA 122AJ UT WOS:000076048000001 ER PT J AU Ramasubramanian, M Popov, BN White, RE Chen, KS AF Ramasubramanian, M Popov, BN White, RE Chen, KS TI Solution equilibrium characteristics of electroless copper deposition on thermally-activated palladium-catalysed polyimide substrates SO JOURNAL OF APPLIED ELECTROCHEMISTRY LA English DT Article DE electroless copper; solution equilibrium model; deposition rate AB Solution equilibrium characteristics of two electroless copper baths containing EDTA and tartrate as the complexing agents were studied as functions of pH. Equilibrium diagrams were constructed for both Cu-tartrate and Cu-EDTA systems. It was determined that copper is chiefly complexed as Cu2L2 in acidic conditions and as Cu(OH)(2)L-2(-4) in alkaline conditions in the tartrate bath, and as CuA(-2) in the EDTA bath, where L and A are the complexing tartrate and EDTA ligands, respectively. Electroless copper deposition rates were studied from a tartrate bath on thermally activated palladium-catalysed polyimide substrates as functions of copper and formaldehyde concentrations, and pH. C1 Univ S Carolina, Dept Chem Engn, Columbia, SC 29208 USA. Sandia Natl Labs, Engn Sci Ctr, Albuquerque, NM 87185 USA. RP Ramasubramanian, M (reprint author), Univ S Carolina, Dept Chem Engn, Columbia, SC 29208 USA. NR 15 TC 10 Z9 10 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0021-891X J9 J APPL ELECTROCHEM JI J. Appl. Electrochem. PD JUL PY 1998 VL 28 IS 7 BP 737 EP 743 DI 10.1023/A:1003202413045 PG 7 WC Electrochemistry SC Electrochemistry GA 122AJ UT WOS:000076048000010 ER PT J AU Malyshev, MV Donnelly, VM Kornblit, A Ciampa, NA AF Malyshev, MV Donnelly, VM Kornblit, A Ciampa, NA TI Percent dissociation of Cl-2 in inductively coupled, chlorine-containing plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DENSITY; SIMULATION; REACTOR; SI AB percent dissociation of Cl-2 was determined for two configurations of a,commercial transformer-coupled plasma (TCP) reactor (LAM Research Alliance metal etcher), using Cl-2 and BCl3/Cl-2 feed gases, during slow etching of SiO2 covered Si wafers. Emission from Cl-2 at 305 nm was recorded as a function of TCP source power, along with emission from 1% Ar and Xe, added as part of an equal mixture of the five rare gases. Absolute Cl-2 number densities were determined from the Cl-2-to-rare gas emission intensity ratios. The CI, percent dissociation increases with power, reaching 70% between 1 and 2 mTorr at the highest power (900 W, 0.080 W/cm(3)). The percent dissociation decreases with increasing pressure between 1 and 10 mTorr. Decreasing the gap between the TCP window and the wafer chuck from 11 to 6.5 cm decreases dissociation at pressures between 0.5 and 2 mTorr, and-increases dissociation slightly at 10 mTorr. The percent dissociation as a function of power, and for the most part as a function of pressure and gap, is reproduced by a zero-dimensional model that includes electron-impact dissociation and dissociative attachment of Cl-2, and diffusion-controlled recombination of Cl at the walls. Addition of BCl3 to Cl-2 increases the percent dissociation of Cl-2, most likely due to a passivation of the chamber walls by adsorbed BCl,, lowering the CI-atom recombination coefficient. (C) 1998 American Institute of Physics. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08544 USA. RP Malyshev, MV (reprint author), AT&T Bell Labs, Lucent Technol, 600 Mt Ave, Murray Hill, NJ 07974 USA. EM vmd@bell-labs.com NR 24 TC 87 Z9 87 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1998 VL 84 IS 1 BP 137 EP 146 DI 10.1063/1.368010 PG 10 WC Physics, Applied SC Physics GA 108GP UT WOS:000075258100016 ER PT J AU Edgar, JH Gao, Y Chaudhuri, J Cheema, S Casalnuovo, SA Yip, PW Sidorov, MV AF Edgar, JH Gao, Y Chaudhuri, J Cheema, S Casalnuovo, SA Yip, PW Sidorov, MV TI Selective epitaxial growth of silicon carbide on SiO2 masked Si(100): The effects of temperature SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The effect of substrate temperature on the growth rate, crystal grain size, and SiO2 mask stability in; the selective epitaxial growth of silicon carbide deposited, from SiH4, C2H4, and HCl1 on silicon dioxide masked silicon (100) was examined. Depositing at atmospheric pressure and a Cl/Si input ratio of 50 to achieve good selectivity, increasing the substrate temperature from 950 to 1000 degrees C increased the growth rate and the crystal size, and improved the film's surface morphology, but also enhanced the SiO2 mask degradation rate, causing a loss of selectivity for long deposition times. For prolonged deposition times at 1000 degrees C, SiC nucleation occurred at both voids formed in the mask from its reaction with the silicon substrate and on the SiO2 mask itself-a consequence of increasing oxide surface roughness. C1 Kansas State Univ, Dept Chem Engn, Manhattan, KS 66506 USA. Wichita State Univ, Dept Engn Mech, Wichita, KS 67260 USA. Sandia Natl Labs, Albuquerque, NM 87123 USA. USAF Lab, Bedford, MA 01731 USA. Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. RP Edgar, JH (reprint author), Kansas State Univ, Dept Chem Engn, Durland Hall, Manhattan, KS 66506 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 12 TC 19 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1998 VL 84 IS 1 BP 201 EP 204 DI 10.1063/1.368017 PG 4 WC Physics, Applied SC Physics GA 108GP UT WOS:000075258100025 ER PT J AU You, CY Shin, SC AF You, CY Shin, SC TI Generalized analytic formulae for magneto-optical Kerr effects SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FILMS; MULTILAYERS; TRANSITION; ANISOTROPY; CO AB We have developed simplified analytic expressions for magneto-optical Kerr effects of both optically thick and ultrathin films in the general case, where a magnetic medium had an arbitrary direction of magnetization and a beam of light was obliquely incident to the medium. It was found that the simplified analytic formulae for the Kerr effects of p and s waves consisted of a product of two factors for both optically thick and ultrathin films: the prefactor dependent only on the optical parameters of the system and the main factor of the polar Kerr effect for a normal incidence case. We have also derived some useful relations among the Kerr effects in the polar and longitudinal configurations. We-have demonstrated that the theoretical calculations using the present analytic formulae could well match the experimental polar and longitudinal Kerr rotation angles of magnetic films measured with varying incident angles. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. RP You, CY (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shin@cais.kaist.ac.kr RI You, Chun-Yeol/B-1734-2010; Shin, Sung-Chul/C-1992-2011 OI You, Chun-Yeol/0000-0001-9549-8611; NR 21 TC 42 Z9 43 U1 4 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUL 1 PY 1998 VL 84 IS 1 BP 541 EP 546 DI 10.1063/1.368058 PG 6 WC Physics, Applied SC Physics GA 108GP UT WOS:000075258100077 ER PT J AU Saka, O Kitamura, T Tachihara, H Shinohara, M Trivedi, NB Reeves, GD Hansen, TL AF Saka, O Kitamura, T Tachihara, H Shinohara, M Trivedi, NB Reeves, GD Hansen, TL TI Amplitude modulation of the equatorial electrojet (EEJ) during a magnetospheric storm SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID DISTURBANCE DYNAMO AB An encounter of the Earth with a high velocity solar wind-stream triggered the magnetic storm of 29 January 1995. The storm lasted for the following seven days, keeping the level of the Dst index in the range of -25-50 nT. At the dip-equator, a regular enhancement of the magnetic H component during daytime, referred to as the Equatorial Electrojet (EEJ), was seen to be suppressed and modified during this storm interval. We attempted to classify the type of the EEJ modification by analyzing magnetometer data from two stations at the dip-equator but located in the opposite hemisphere, and energetic particle data from two geosynchronous satellites located close to the ground magnetometer meridian. As a result, three different types of modulation of EEJ amplitudes, with time scales of 15 min to 1 day, were found to appear during the periods when the flux level of low energy charged particles (>30 keV) in-the midnight magnetosphere was increased above the quiet level. These modulations were characterized by referring to the nightside particle signatures. We argue that, although the EEJ is a local enhancement of the ionospheric currents at the dayside dip-equator, the EEJ is definitely affected by changes of the magnetosphere, probably in various ways arising from the complexities of the storm effects. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Kurume Natl Coll Technol, Dept Phys, Kurume, Fukuoka 830, Japan. Kyushu Univ, Dept Earth & Planetary Sci, Fukuoka, Japan. Inst Nacl Pesquisas Espaciais, BR-12201 Sao Jose Dos Campos, SP, Brazil. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Tromso, Inst Math & Phys Sci, Tromso, Norway. RP Saka, O (reprint author), Kurume Natl Coll Technol, Dept Phys, Kurume, Fukuoka 830, Japan. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 13 TC 2 Z9 2 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD JUL PY 1998 VL 60 IS 11 BP 1129 EP 1137 DI 10.1016/S1364-6826(98)00068-6 PG 9 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 142HN UT WOS:000077194800007 ER PT J AU Loehle, C AF Loehle, C TI Height growth rate tradeoffs determine northern and southern range limits for trees SO JOURNAL OF BIOGEOGRAPHY LA English DT Article DE biogeography; trees; range limits; ecotone; climate change; North America ID LIFE-HISTORY STRATEGIES; CLIMATE-CHANGE; FOREST SUCCESSION; SIMULATION-MODEL; TEMPERATURES; POPULATIONS; PROVENANCES; RESPONSES; REGIONS; PLANTS AB Identifying the biological determinants of range limits of trees is an unsolved problem of critical importance for predicting the effects of climate change on forests. Data showing that many boreal trees can grow in temperate climates indicate that southern range limits do not necessarily result from excessive temperature per se. A growth tradeoff could exist between freezing tolerance and height growth rate if adaptations to tolerate cold climates interfered with growth. Analysis of height growth rate versus freezing tolerance for twenty-two North American trees provided evidence for such a tradeoff. Provenance trials of numerous tree species also showed that a tradeoff exists within species, indicating a genetic basis for these traits. The result of this tradeoff is that at their southern range margins most species do not suffer from too much heat but rather face competitors with a faster growth rate. The implication for future climate change is that forests will not suffer catastrophic dieback due to increased temperatures but will rather be replaced gradually by faster growing types, perhaps over hundreds of years. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Loehle, C (reprint author), Natl Council Air & Stream Improvement, 552 G Washington St,Suite 224, Naperville, IL 60540 USA. NR 48 TC 153 Z9 157 U1 2 U2 55 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0305-0270 J9 J BIOGEOGR JI J. Biogeogr. PD JUL PY 1998 VL 25 IS 4 BP 735 EP 742 DI 10.1046/j.1365-2699.1998.2540735.x PG 8 WC Ecology; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 146ZA UT WOS:000077462700011 ER PT J AU Keij, JF Jiang, YJ Sotiropoulos, DA Ben-Hur, E Visser, JWM AF Keij, Jan F. Jiang, Yajuan Sotiropoulos, Damianos A. Ben-Hur, Ehud Visser, Jan W. M. TI EVALUATION OF THE SILICON PHTHALOCYANINE PC 4 FOR PHOTODYNAMIC BONE MARROW PURGING SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE cobble stone area; murine; early progenitor cells; photosensitization AB The silicon phthalocyanine Pc 4 was tested as a photosensitizer for the selective photoinactivation of malignant cells in bone marrow transplantation samples. Using a murine model system, incubation of 1.5x10(7) cells/mL with 15 nM Pc 4 followed by exposure to red light (lambda>600 nm, fluence of 18 J/cm(2)) was shown to result in a greater than 6 log(10) reduction of the clonogenic growth for the murine cell lines ABE-8.1/2, BC3A and L1210. The clonogenic growth of WEHI-3 and P815 cells was reduced by more than 5 log(10) and more than 3 log(10), respectively. Late murine hematopoietic progenitor cells were less sensitive than cancer cells; the surviving fractions were 0.084 for the colony forming unit, megakaryocyte (CFU-Mk); 0.038 for the colony forming unit, granulocyte macrophage (CFU-GM); 0.0018 for the colony forming unit, mix (CFU-mix) and <0.003 for burst forming units, erythroid (BFU-E). Early hematopoietic progenitor cells, assayed by the in vitro cobble stone area forming cell assay, were not affected by the photodynamic treatment. Likewise, in vivo assays of early hematopoietic progenitor cells showed no reduction of their ability to repopulate the bone marrow. Irradiation of the samples following incubation of 1.5x10(6) cells/mL with Pc 4 resulted in increased photosensitivity of all cell types, including the early and late hematopoietic progenitor cells. Flow cytometric analysis of Pc 4 uptake by the cells revealed that the increased photosensitivity could be traced to increased Pc 4 uptake; however, Pc 4 uptake among cell types did not correlate with photosensitivity. When mixed with bone marrow (BM) cells, Pc 4 uptake in the cell lines increased as the fraction of BM increased from 0.5 to 0.95. These observations suggest that Pc 4 may be a suitable photosensitizer for bone marrow purging. (C) 1998 Society of Photo-Optical Instrumentation Engineers. C1 [Keij, Jan F.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Jiang, Yajuan; Sotiropoulos, Damianos A.; Visser, Jan W. M.] New York Blood Ctr, New York, NY 10021 USA. [Ben-Hur, Ehud] VITEX, Audubon Ctr, New York, NY 10032 USA. RP Ben-Hur, E (reprint author), New York Blood Ctr, New York, NY 10021 USA. EM ehud-ben-hur@juno.com FU National Heart, Lung and Blood Institute [2RO1-HL41221]; Starr Foundation FX This work was supported in part by Award No. 2RO1-HL41221 from the National Heart, Lung and Blood Institute and in part by The Starr Foundation. Thanks are due to Dr. M. E. Kenney for a gift of Pc 4. NR 39 TC 0 Z9 0 U1 0 U2 0 PU SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 1083-3668 EI 1560-2281 J9 J BIOMED OPT JI J. Biomed. Opt. PD JUL PY 1998 VL 3 IS 3 BP 286 EP 295 DI 10.1117/1.429855 PG 10 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA V32RL UT WOS:000208968200009 PM 23015082 ER PT J AU Krishnan, VV Cosman, M AF Krishnan, VV Cosman, M TI An empirical relationship between rotational correlation time and solvent accessible surface area SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE rotational correlation time; solvent accessible surface area; structure and dynamics ID NMR RELAXATION MEASUREMENTS; EGG-WHITE LYSOZYME; DNA-BINDING DOMAIN; BACKBONE DYNAMICS; SPIN RELAXATION; HYDRODYNAMIC PROPERTIES; TRANSLATIONAL FRICTION; INTRINSIC-VISCOSITY; MAIN-CHAIN; PROTEIN AB Structure-dynamics interrelationships are important in understanding protein function. We have explored the empirical relationship between rotational correlation times (tau(c)) and the solvent accessible surface areas (SASA) of 75 proteins with known structures. The theoretical correlation between SASA and tau(c) through the equation SASA = K(r)tau(c)((2/3)) is also considered. SASA was determined from the structure, tau(c)(calc) was determined from diffusion tensor calculations, and tau(c)(expt) was determined from NMR backbone C-13 or N-15 relaxation rate measurements. The theoretical and experimental values of tau(c) correlate with SASA with regression analyses values of K-r as 1696 and 1896 m(2)s(-(2/3)), respectively, and with corresponding correlation coefficients of 0.92 and 0.70. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Krishnan, VV (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RI Krishnan, Krish/A-6859-2010 NR 48 TC 39 Z9 39 U1 1 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD JUL PY 1998 VL 12 IS 1 BP 177 EP 182 DI 10.1023/A:1008226330666 PG 6 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 111ZZ UT WOS:000075470000013 PM 20700691 ER PT J AU McGee, BCW Vermeulen, FE Chute, FS Vinsome, PKW Buettner, HM AF McGee, BCW Vermeulen, FE Chute, FS Vinsome, PKW Buettner, HM TI In situ decontamination of soil SO JOURNAL OF CANADIAN PETROLEUM TECHNOLOGY LA English DT Article AB Methods for decontamination of soil in situ are receiving increased attention, as the requirement to clean these sites has become a national concern. The continual and costly liability is an important corporate incentive to clean contaminated soils. The development of an effective technology for in situ decontamination is a priority issue. Some in situ decontamination processes are similar to enhanced oil recovery schemes and use an integrated heating approach. One such method consists of heating by conduction and convection in conjunction with electrical heating. Advantages of electrical heating are that the energy can be focussed and the soil heated uniformly. The integrated heating approach has been extensively tested in the United States in a joint venture between Lawrence Livermore National Laboratories (LLNL) and the University of California at Berkeley. The most significant test was done at an abandoned Naval Air Base, now named the LLNL Gasoline Spill Site. It has been demonstrated that such an integrated approach can remove hydrocarbon contaminates from in situ at an accelerated rate. The objective of this paper is to present a mathematical model that solves the heat transfer problem for the integrated heating process. The model is also used to investigate the practicality of the process in terms of energy requirements and the time it takes to clean the soil. The mathematical model combines all of the principal heat transfer mechanisms of the process. These an electrical heating, convection, conduction and accumulation of energy. In addition, conductive heat losses from the sides and bottom of the heated volume and the substantial variation of electrical resistivity with temperature are included. Calculations made using the mathematical model developed in this paper are in good agreement with results obtained with the general-purpose reservoir simulator, TETRAD. C1 Univ Alberta, Edmonton, AB T6G 2M7, Canada. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU CANADIAN INST MINING METALLURGY PETROLEUM PI CALGARY PA 101 6TH AVE SW, STE 320, CALGARY, ALBERTA TZP 3P4, CANADA SN 0021-9487 J9 J CAN PETROL TECHNOL JI J. Can. Pet. Technol. PD JUL PY 1998 VL 37 IS 7 BP 15 EP 22 PG 8 WC Energy & Fuels; Engineering, Chemical; Engineering, Petroleum SC Energy & Fuels; Engineering GA 102MZ UT WOS:000074929300006 ER PT J AU Freyer, JP AF Freyer, JP TI Decreased mitochondrial function in quiescent cells isolated from multicellular tumor spheroids SO JOURNAL OF CELLULAR PHYSIOLOGY LA English DT Article ID FLOW CYTOMETRIC ANALYSIS; NONYL-ACRIDINE-ORANGE; NUCLEAR-MAGNETIC-RESONANCE; OXYGEN-CONSUMPTION; GROWTH SATURATION; DIFFERENT REGIONS; LEUKEMIC-CELLS; RHODAMINE 123; GLUCOSE; CYCLE AB Cells in the inner region of multicellular spheroids markedly reduce their oxygen consumption rate, presumably in response to their stressful microenvironment. To determine the mechanism behind this metabolic adaptation, we have investigated relative mitochondrial mass and mitochondrial function in cells isolated from different regions of tumor spheroids by using a combination of mitochondrial-specific fluorescent stains and flow cytometric analysis. Uptake of rhodamine 123 (R123) is driven by the mitochondrial membrane potential and thus reflects mitochondrial activity. Uptake of 10-nonyl-acridine orange (NAO) reflects total mitochondrial mass independently of activity because this compound binds to cardiolipin in the inner mitochondrial membrane. NAO fluorescence per unit cell volume only decreased 10-20% for cells from the inner spheroid region compared with those near the surface. There was greater than a twofold reduction in R123 fluorescence in the inner region cells, however. Thus, tumor cells in spheroids alter their rate of respiration predominately by downregulating mitochondrial function as opposed to degradation of mitochondria. There was a correlation between R123 staining per unit cell volume and the growth fraction of the cells from spheroids, but not for monolayer cultures. We also show a linear correlation between R123 staining and the rate of oxygen consumption for both monolayer-and spheroid-derived cells. After separating the inner region cells from the spheroid and replating them in monolayer culture, the R123 uptake recovered to normal levels prior to entry of the cells into S-phase. This reduction in mitochondrial function in quiescent cells from spheroids can explain the long period required for these cells to re-enter the cell cycle and may have important implications for the regulation of tu mor cell oxygenation in vivo. (C) 1998 Wiley-Liss, Inc. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Cell & Mol Biol Grp, Los Alamos, NM 87545 USA. RP Freyer, JP (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, Cell & Mol Biol Grp, Mail Stop M888, Los Alamos, NM 87545 USA. FU NCI NIH HHS [CA-51150]; NCRR NIH HHS [RR01315] NR 55 TC 55 Z9 57 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9541 J9 J CELL PHYSIOL JI J. Cell. Physiol. PD JUL PY 1998 VL 176 IS 1 BP 138 EP 149 DI 10.1002/(SICI)1097-4652(199807)176:1<138::AID-JCP16>3.0.CO;2-3 PG 12 WC Cell Biology; Physiology SC Cell Biology; Physiology GA ZP476 UT WOS:000073757300016 PM 9618154 ER PT J AU Mio, C Kiritsov, S Thio, Y Brafman, R Prausnitz, J Hawker, C Malmstrom, EE AF Mio, C Kiritsov, S Thio, Y Brafman, R Prausnitz, J Hawker, C Malmstrom, EE TI Vapor-liquid equilibria for solutions of dendritic polymers SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID SOLVENT-INDUCED CRYSTALLIZATION; ISOTACTIC POLYPROPYLENE; DENDRIMERS; PROBE AB Vapor-liquid equilibrium data were obtained for dendritic polymer solutions using a classic isothermal gravimetric-sorption method; the amount of solvent absorbed by the dendrimer was measured at increasing solvent activity. The polymers were polyamidoamine (PAMAM) dendrimers of generations 1, 2, and 4 and benzyl ether dendrimers with different end groups (aromatic rings, dodecyl chains, methyl ester groups, perfluoroalkyl chains) of generations 2 to 6, and two series of benzyl ether linear polymers that are analogues of the dendrimers. Solvents were acetone, acetonitrile, chloroform, cyclohexane, methanol, n-pentane, n-propylamine, tetrahydrofuran, and toluene. The temperature range was 35 to 89 degrees C. The amount of solvent absorbed by the dendrimers depends, sometimes strongly, on the kind of dendrimer end groups. The relation between solvent absorption and dendrimer generation number, or molecular weight, depends on the solvent-dendrimer system and on temperature. Solvent absorption in linear polymers is below that for corresponding dendrimers, all or in part owing to crystallinity in the linear polymers. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. IBM Corp, Almaden Res Ctr, Ctr Polymer Interfaces & Macromol Assemblies, San Jose, CA 95120 USA. RP Prausnitz, J (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. NR 35 TC 34 Z9 34 U1 2 U2 4 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 JUL-AUG PY 1998 VL 43 IS 4 BP 541 EP 550 DI 10.1021/je970226q PG 10 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA ZZ680 UT WOS:000074755800010 ER PT J AU Albright, JG Gillespie, SM Rard, JA Miller, DG AF Albright, JG Gillespie, SM Rard, JA Miller, DG TI Ternary solution mutual diffusion coefficients and densities of aqueous mixtures of NaCl and Na2SO4 at 298.15 K for six different solute fractions at a total molarity of 1.000 mol center dot dm(-3) SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID RAYLEIGH INTERFEROMETRY; CONCENTRATION RATIO; ISOPIESTIC DETERMINATION; OSMOTIC COEFFICIENTS; MGCL2 CONCENTRATIONS; WIDE-RANGE; 25-DEGREES-C; NACL-MGCL2-H2O; INSTABILITIES; SODIUM AB Isothermal mutual diffusion coefficients (interdiffusion coefficients) were measured for ternary aqueous mixtures of NaCl and Na2SO4 at a constant total molarity of 1.000 mol . dm(-3) and 298.15 K. Measurements were performed using Rayleigh interferometry with computerized data acquisition at NaCl molarity fractions of z(1) = 1, 0.90, 0.75, 0.50, 0.25, and 0. Densities of the solutions were measured with a vibrating tube densimeter. At all ternary solution compositions, one cross-term diffusion coefficient has negative values whereas the other has positive values. These measurements supplement our earlier results at 0.500 mol . dm(-3). Both main-term diffusion coefficients are significantly smaller at 1.000 mol . dm(-3) than at 6.500 mol . dm(-3) at any fixed value of z(1), whereas both cross-term coefficients are shifted in a positive direction. Trace diffusion coefficients D*(Cl-) and D*(SO42-) were extrapolated from these results for the Cl-(aq) ion in 1.0 mol . dm(-3) Na2SO4(aq) and for the SO42-(aq) ion in 1.0 mol . dm(-3) NaCl(aq). Values of D*(Cl-) in Na2SO4(aq) and in NaCl(aq) were found to be essentially identical, as were D*(SO42-) in these same two electrolytes, provided the comparisons were made at the same volumetric ionic strengths. C1 Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. Univ Calif Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94550 USA. RP Albright, JG (reprint author), Texas Christian Univ, Dept Chem, Ft Worth, TX 76129 USA. NR 45 TC 9 Z9 9 U1 0 U2 3 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 JUL-AUG PY 1998 VL 43 IS 4 BP 668 EP 675 DI 10.1021/je9800196 PG 8 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA ZZ680 UT WOS:000074755800037 ER PT J AU Bond, AH Rogers, RD AF Bond, AH Rogers, RD TI Synthesis and X-ray crystallographic characterization of [Cd(NO3)(2)(15-crown-5)] and [Cd(NO3)(2)(18-crown-6)] SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE cadmium; crown ether; 15-crown-5; 18-crown-6; crystal structure ID POLYETHYLENE-GLYCOL COMPLEXATION; MACROCYCLIC LIGANDS; MOLECULAR-STRUCTURE; CROWN-ETHER; O2N3-DONOR MACROCYCLES; CADMIUM(II) CHLORIDE; CRYSTAL-STRUCTURES; 15-CROWN-5 ETHER; LONE-PAIR; ZINC(II) AB Reaction of 15-crown-5 or 18-crown-6 in 3:1 (v/v) CH3CN:CH3OH with Cd(NO3)(2). 4H(2)O followed by slow evaporation produces [Cd(NO3)(2)(15-crown-5)] or [Cd(NO3)(2)(18-crown-6)]. Crystals of [Cd(NO3)(2)(15-crown-5)] are orthorhombic with space group Pbca and cell parameters a = 13.562(5), b = 15.941(9), and c = 15.011(7) Angstrom at 295 K. [Cd(NO3)(2)(18-crown-6)] crystallizes in the monoclinic space group C2/c with a = 11.235(2), b = 11.196(5), c = 15.385(3) Angstrom, and beta = 99.89(2)degrees at 295 K. The metal center in [Cd(NO3)(2)(15-crown-5)] rests atop the macrocyclic donor array with two cis-bound nitrate anions and adopts a distorted tricapped trigonal prismatic geometry. [Cd(NO3)(2)(18-crown-6)] resides on an equatorial twofold rotation axis with Cd2+ coordinated in the 18-crown-6 cavity and the nitrate anions oriented in twisted trans positions. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. RP Bond, AH (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Rogers, Robin/C-8265-2013; G, Neela/H-3016-2014 OI Rogers, Robin/0000-0001-9843-7494; NR 48 TC 16 Z9 16 U1 0 U2 4 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD JUL PY 1998 VL 28 IS 7 BP 521 EP 527 DI 10.1023/A:1023239921542 PG 7 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA 152PM UT WOS:000077786000003 ER PT J AU Curtiss, LA Redfern, PC Raghavachari, K Pople, JA AF Curtiss, LA Redfern, PC Raghavachari, K Pople, JA TI Assessment of Gaussian-2 and density functional theories for the computation of ionization potentials and electron affinities SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUADRATIC CONFIGURATION-INTERACTION; SET MODEL CHEMISTRY; MOLECULAR-ENERGIES; 2ND-ROW COMPOUNDS; APPROXIMATION; EXCHANGE; ACCURATE; GAS AB A set of 146 well-established ionization potentials and electron affinities is presented. This set, referred to as the G2 ion test set, includes the 63 atoms and molecules whose ionization potentials and electron affinities were used to test Gaussian-2 (G2) theory [J. Chem. Phys. 94, 7221 (1991)] and 83 new atoms and molecules. It is hoped that this new test set combined with the recently published test set of enthalpies of neutral molecules [J. Chem. Phys. 106, 1063 (1997)] will provide a means for assessing and improving theoretical models. From an assessment of G2 and density functional theories on this test set, it is found that G2 theory is the most reliable method. It has an average absolute deviation of 0.06 eV for both ionization potentials and electron affinities. The two modified versions of G2 theory, G2(MP2, SVP) and G2(MP2) theory, have average absolute deviations of 0.08-0.09 eV for both ionization potentials and electron affinities. The hybrid B3LYP density functional method has the smallest average absolute deviation (0.18 eV) of the seven density functional methods tested for ionization potentials. The largest deviation for the density functional methods is for the ionization potential of CN (>1 eV). The BLYP density functional method has the smallest average absolute deviation (0.11 eV) of the seven density functional methods tested for electron affinities. while the BPW91, B3LYP, and B3PW91 methods also do quite well. (C) 1998 American Institute of Physics. [S0021-9606(98)02519-7]. C1 Argonne Natl Lab, Div Chem, Div Mat Sci, Argonne, IL 60439 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 34 TC 442 Z9 443 U1 4 U2 35 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1998 VL 109 IS 1 BP 42 EP 55 DI 10.1063/1.476538 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FL UT WOS:000075255300006 ER PT J AU McCormack, EF Di Teodoro, F Grochocinski, JM Pratt, ST AF McCormack, EF Di Teodoro, F Grochocinski, JM Pratt, ST TI Dynamics of Rydberg states of nitric oxide probed by two-color resonant four-wave mixing spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID OPTICAL DOUBLE-RESONANCE; INDUCED GRATING SPECTROSCOPY; MULTIPHOTON IONIZATION TECHNIQUE; EXCITED-STATES; QUANTUM DEFECT; NO MOLECULE; 4-WAVE-MIXING SPECTROSCOPY; ROTATIONAL AUTOIONIZATION; MULTISTATE INTERACTIONS; SPECTRA AB Two-color resonant four-wave mixing (TC-RFWM) spectroscopy has been used to probe highly excited v = 0 and v = 1 Rydberg states of nitric oxide. Transitions to n = 16-30, v = 0, Rydberg states, and the 8p, 9p, 7f, 8f, 8s, and 9s, v = 1 Rydberg states from the A (2)Sigma(+), v' = 0 and 1 states have been recorded. The decay rate of the 8p and 9p, v = 1 states has been extracted from the observed line profiles by using a recently developed model for the excitation of quasibound resonances in TC-RFWM spectroscopy. Transitions from the A (2)Sigma(+), v' = 1 state to the X (2)Pi(3/2), v " = 10 state have also been observed, allowing an absolute calibration of the TC-RFWM signal intensity. This calibration is used to determine an excited-state absorption cross section for the 9p, v = 1 Rydberg state. (C) 1998 American Institute of Physics. [S0021-9606(98)01625-0]. C1 Bryn Mawr Coll, Bryn Mawr, PA 19010 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bryn Mawr Coll, Bryn Mawr, PA 19010 USA. NR 66 TC 15 Z9 15 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1998 VL 109 IS 1 BP 63 EP 71 DI 10.1063/1.476540 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FL UT WOS:000075255300008 ER PT J AU Germann, TC Miller, WH AF Germann, TC Miller, WH TI Quantum mechanical calculation of resonance tunneling in acetylene isomerization via the vinylidene intermediate SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; DISCRETE VARIABLE REPRESENTATION; VIBRATIONALLY EXCITED ACETYLENE; MINIMAL RESIDUAL ALGORITHM; LINEAR-SYSTEMS; PHOTOELECTRON-SPECTROSCOPY; UNIMOLECULAR REACTION; KETENE ISOMERIZATION; GROUND-STATE; SCATTERING AB Microcanonical rate constants for the acetylene isomerization reaction have been computed using the direct cumulative reaction probability methodology of Seideman and Miller [J. Chem, Phys. 96, 4412 (1992); 97, 2499 (1992)] and Manthe and Miller [J. Chem. Phys. 99, 3411 (1993)]. Two- and three-degree-of-freedom calculations an reported using a normal mode Hamiltonian based on the geometry of the vinylidene intermediate. Due to the vinylidene well, numerous resonances are found in the isomerization rate. Little coupling is found between the CH2 rock reaction coordinate and the other normal modes, so that the resonances are readily assignable as normal mode progressions. Qualitatively similar results are obtained using two different potential energy surfaces, or different reduced dimensionality sets of coordinates. (C) 1998 American Institute of Physics. [S0021-9606(98)02225-9]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Germann, TC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-11,MS B262, Los Alamos, NM 87545 USA. NR 33 TC 23 Z9 23 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1998 VL 109 IS 1 BP 94 EP 101 DI 10.1063/1.476544 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FL UT WOS:000075255300012 ER PT J AU Fanourgakis, GS Farantos, SC Luder, C Velegrakis, M Xantheas, SS AF Fanourgakis, GS Farantos, SC Luder, C Velegrakis, M Xantheas, SS TI Photofragmentation spectra and structures of Sr+Arn, n=2-8 clusters: Experiment and theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; DISSOCIATION-ENERGIES; WAVE-FUNCTIONS; ATOMS; PHOTODISSOCIATION; DYNAMICS; AR; SPECTROSCOPY; POTENTIALS AB The total photofragmentation cross sections of size selected Sr+ Ar-n, n = 2-8, clusters have been recorded in a time of flight (TOF) mass spectrometer, In the energy range of 21 000-27 000 cm(-1) three absorption bands are observed that are attributed to transitions from the ground to the three excited stales that correlate to the 5p orbitals of strontium. No vibrational structure in the spectral bands is observed, even in regions where the spectrum is recorded with a resolution of 1 cm(-1). The absorption spectra are calculated within a semiclassical approximation. Accurate ab initio calculations for the ground X (2)Sigma and the A (2)Pi and B (2)Sigma excited slates of Sr+Ar are combined with a perturbative one-electron model, which includes the spin-orbit coupling, to construct potential energy surfaces for the excited states of all clusters. The theoretical spectra obtained without using any adjustable parameters reproduce the patterns and trends of the experimental spectra, but they are shifted to higher frequencies. A better agreement between theoretical and experimental spectra is obtained by adjusting the depth of the potential wells of the ground X (2)Sigma and excited A (2)Pi states of the Sr+Ar dimer to the experimentally estimated values. From both calculations we conclude that Sr+Ar3 is a trigonal pyramid of C-3v Symmetry and Sr+Ar6 has a C-5v symmetry with five argon atoms forming a regular pentagon, one argon atom below and the cation above the pentagon plane. For these clusters, theory reproduces the characteristic blue shifts found in the absorption spectra and the splittings of the doubly degenerate states encountered in these symmetric complexes. (C) 1998 American Institute of Physics. [S0021-9606(98)02125-4]. C1 Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Greece. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Crete, Dept Chem, Rethymnon, Greece. RP Fanourgakis, GS (reprint author), Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Greece. RI Velegrakis, Michalis/F-7810-2011; FARANTOS, STAVROS/H-5429-2011; Xantheas, Sotiris/L-1239-2015 OI FARANTOS, STAVROS/0000-0003-1909-7976; NR 52 TC 29 Z9 29 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1998 VL 109 IS 1 BP 108 EP 120 DI 10.1063/1.476527 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FL UT WOS:000075255300014 ER PT J AU Palmer, BJ AF Palmer, BJ TI Direct simulation of hydrodynamic relaxation in microchannels SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; SOLID-SURFACES; LIQUID; TEMPERATURE; SHEAR; FLOW; FLUIDS; FILMS; WATER AB Simulations were performed on a fluid confined between two parallel walls. The fluid is modeled by a Lennard-Jones potential and the walls by a simple cubic lattice of harmonically bonded sites. A Lennard-Jones potential is also used to model the interactions between the wall and the fluid. The simulation consisted of over 30 000 sites arranged to form a liquid film approximately 35 Lennard-Jones diameters in thickness. This is large enough to begin approximating the range where classical hydrodynamics is expected to be applicable. Both equilibrium simulations and simulations of velocity transients were performed on the system. Two values of the wall-fluid interaction strength were examined, which appear to correspond to a wetting and nonwetting surface. Results from equilibrium simulations show that both the density and the stress tensor relax to their bulk values within a short distance of the wall. Furthermore, examination of the relaxation of spontaneous momentum fluctuations indicates that there is little change in the value of transport coefficients near the boundary compared to the bulk fluid. Nonequilibrium simulations on the decay of a parabolic velocity profile, however, suggest that the decay of the profile is faster than would be predicted from classical hydrodynamics and that the type of boundary conditions that should be used in a hydrodynamic analysis may depend on the details of the wall-fluid interaction. (C) 1993 American Institute of Physics. [S0021-9606(98)50725-8]. C1 Pacific NW Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. RP Palmer, BJ (reprint author), Pacific NW Natl Lab, Environm & Mol Sci Lab, Box 999, Richland, WA 99352 USA. NR 29 TC 5 Z9 6 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 1 PY 1998 VL 109 IS 1 BP 196 EP 207 DI 10.1063/1.476549 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FL UT WOS:000075255300024 ER PT J AU Sever, LE AF Sever, LE TI Environmental contamination and health effects: What is the evidence? SO JOURNAL OF CLEAN TECHNOLOGY ENVIRONMENTAL TOXICOLOGY AND OCCUPATIONAL MEDICINE LA English DT Article DE congenital malformations; environmental contamination; environmental hazards; exposure classification; low birth weight; reporting bias ID LOW-BIRTH-WEIGHT; CONGENITAL-MALFORMATIONS; RESIDENTS; SITE C1 Battelle Ctr Publ Hlth Res & Evaluat, Seattle, WA USA. RP Sever, LE (reprint author), Battelle Seattle Res Ctr, 4000 NE 41st St, Seattle, WA 98105 USA. NR 25 TC 0 Z9 0 U1 1 U2 1 PU PRINCETON SCIENTIFIC PUBL INC PI PRINCETON PA PO BOX 2155, PRINCETON, NJ 08543 USA SN 1052-1062 J9 J CLEAN TECHNOL E T JI J. Clean Technol. Environ. Toxicol. Occup. Med. PD JUL-SEP PY 1998 VL 7 IS 3 BP 313 EP 329 PG 17 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA ZZ032 UT WOS:000074688500006 ER PT J AU Swayne, EN Newman, J Radke, CJ AF Swayne, EN Newman, J Radke, CJ TI Surface conductivity and disjoining pressure of common black films stabilized with sodium dodecyl sulfate SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE foam films; AC impedance spectroscopy; surface conductivity; disjoining pressure ID FOAM FILMS; IONIC SURFACTANT; POROUS-MEDIA AB We have conducted simultaneous measurements of the disjoining pressure and the film conductance for sodium dodecyl sulfate- (SDS-) stabilized foam films in aqueous electrolyte solutions and over a range of film thicknesses. The disjoining pressure ascertains the repulsive forces within the film while the conductance gauges the possible changes in mobilities and concentrations of the ions within the thin-film region, relative to their bulk values. The disjoining pressure is measured using a modified version of the porous-glass-plate technique. To permit electrical measurements in the same apparatus, a novel film holder was designed in which the film is formed in the annular region between two concentric, porous stainless steel disks. The inner and outer disks serve as electrodes, and they constrain the current to flow radially through the him. To avoid electroosmosis, the film conductance is obtained using AC impedance spectroscopy. New data are reported for the disjoining pressure, conductance, and film thickness of 0.002-M SDS foam films with and without added sodium nitrate. Film conductances exhibit a decrease with decreasing film thickness, which suggests a decrease in the mobility of the film ions relative to their bulk values, even for films as thick as 40 mn. Surface-charge densities are estimated from the conductance data and are consistent with available surface tension data. However, the surface-charge densities estimated from the disjoining-pressure data are more than an order of magnitude smaller than the values estimated from conductance and surface-tension data. Improvements in both experimental precision and theory are needed to overcome this discrepancy. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Radke, CJ (reprint author), Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RI Newman, John/B-8650-2008 OI Newman, John/0000-0002-9267-4525 NR 34 TC 7 Z9 7 U1 0 U2 6 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 JUL 1 PY 1998 VL 203 IS 1 BP 69 EP 82 DI 10.1006/jcis.1998.5520 PG 14 WC Chemistry, Physical SC Chemistry GA ZV944 UT WOS:000074358000007 ER PT J AU O'Rourke, PJ Sahota, MS AF O'Rourke, PJ Sahota, MS TI A variable explicit/implicit numerical method for calculating advection on unstructured meshes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE fluid advection; unstructured meshes; explicit/implicit numerical method ID HYPERBOLIC CONSERVATION-LAWS; FINITE-ELEMENT METHOD; INCOMPRESSIBLE-FLOW; ADAPTIVE STENCILS; SCHEME AB A variable explicit/implicit numerical method is presented for calculating fluid advection on hybrid unstructured meshes. The method is intended for unsteady flows that have a large range of advective time scales, with subregions where the how may be quasi-steady on time scales of interest. The method generalizes the method of Collins, Collela, and Glaz by providing an explicit-to-implicit switching criterion that is suitable for use on unstructured meshes. No directional splitting is used; upwinding is in the direction of the material velocity, and thus we define and use a new multidimensional limited gradient that generalizes Van Leer's MUSCL limiting [7]. After reviewing the one-dimensional method of Collins, Collela, and Glaz, we present the generalization to hybrid unstructured grids and detail the results of four example calculations that demonstrate the accuracy and flexibility of the new method. (C) 1998 Academic Press. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM pjor@lanl.gov NR 24 TC 24 Z9 25 U1 2 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUL 1 PY 1998 VL 143 IS 2 BP 312 EP 345 DI 10.1006/jcph.1998.5903 PG 34 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZY201 UT WOS:000074596400002 ER PT J AU Najm, HN Wyckoff, PS Knio, OM AF Najm, HN Wyckoff, PS Knio, OM TI A semi-implicit numerical scheme for reacting flow I. Stiff chemistry SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE implicit; stiff; chemistry; reacting; flow; projection ID JET DIFFUSION FLAMES; CHEMICAL-KINETICS; ATMOSPHERIC CHEMISTRY; TURBULENT COMBUSTION; ODE SOLVER; EQUATIONS; MODELS; VORTEX; INTEGRATION; SIMULATIONS AB An additive semi-implicit projection scheme for the simulation of unsteady combustion in two dimensions is constructed. The scheme relies on a zero-Mach number formulation of the compressible conservation equations with detailed chemistry. The governing equations are discretized in space using second-order differences and integrated in time using a semi-implicit approach. Time integration of the evolution equations for species mass fraction, thermodynamic pressure, and density is performed using a semi-implicit, nonsplit scheme that combines a second-order predictor-corrector treatment of convection and diffusion terms, and a stiff integrator for the reaction source terms. Meanwhile, the momentum equations are integrated using a second-order projection scheme. The projection scheme is based on a predictor-corrector approach that couples the evolution of the Velocity and density fields in order to stabilize computations of reacting flows with large density variations. A pressure Poisson equation is inverted following both the predictor and corrector steps using a fast solver. The advantages of the stiff integration of reaction source terms are analyzed by comparing the performance of the scheme to that of a predictor-corrector scheme in which reaction and diffusion are integrated in a similar nonstiff fashion. The comparison in based on both one-dimensional (1D) unsteady tests of a premixed methane-air flame, and unsteady two-dimensional tests of the same flame interacting with a counterrotating Vortex pair. In both cases, the GRImech 1.2 reaction mechanism with 32 species and 177 elementary reactions is used. Computed results show that the stiff reaction scheme enables selection of larger time steps and thus leads to substantial improvement in the performance of the computations. For the present reaction mechanism and flame conditions, speedup factors of about 10 are achieved in the 1D tests and about five in two dimensions. Possible extensions of the present scheme to further improve efficiency are also discussed. (C) 1998 Academic Press. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. RP Najm, HN (reprint author), Sandia Natl Labs, POB 969,MS 9051, Livermore, CA 94551 USA. RI Knio, Omar/A-3318-2010 NR 62 TC 134 Z9 136 U1 1 U2 11 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 JUL 1 PY 1998 VL 143 IS 2 BP 381 EP 402 DI 10.1006/jcph.1997.5856 PG 22 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZY201 UT WOS:000074596400004 ER PT J AU Brooks, SC Herman, JS Hornberger, GM Mills, AL AF Brooks, SC Herman, JS Hornberger, GM Mills, AL TI Biodegradation of cobalt-citrate complexes: Implications for cobalt mobility in groundwater SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE in situ bioremediation; biogeochemistry; contaminant transport; metal-ligand complexes; sandy aquifer material; groundwater ID METAL-IONS; MANGANESE-DIOXIDE; ORGANIC-ACIDS; HYDROUS OXIDE; ADSORPTION; TRANSPORT; DISSOLUTION; SPECIATION; INTERFACE; MIGRATION AB The bacterial consumption of chelating agents that are present in low-level radioactive and mixed wastes may help to immobilize chelated metals and radionuclides accidentally released to groundwater. We investigated the influence of the bacterial consumption of citrate complexed with cobalt on cobalt transport through packed sand columns. Experiments were conducted using each of three types of column packing material using minerals common to subsurface environments: clean quartz sand; ferric oxide (Fe(OH)(3))-coated sand; hausmannite (Mn3O4)-coated sand. Separate control column experiments were conducted to examine citrate's influence on cobalt transport without the bacterial consumption of citrate. The bacterial community consumed all the citrate; the pore water pH decreased by up to one unit before reaching a steady-state value of 6.9-7.1, which was lower than the influent pH (7.4). These results were in contrast to open batch experiments conducted with the same culture, where the pH increased by more than one unit. The dissolved oxygen exhibited similar dynamics, reaching a steady-state value of 3-4 mg/l, well below the influent value of 7.5 mg/l. The dynamics in pore water pH and dissolved oxygen were associated with the presence of the bacterial community because these parameters remained steady in control experiments in which the bacteria were not included. Cobalt transport was most rapid for the columns packed with quartz sand followed by the Fe-coated sand and finally the Mn-coated sand. Most of the cobalt retained by the quartz sand and Fe-coated sand was easily exchanged with Mg2+ whereas most of the cobalt retained by the Mn-coated sand required an acetic acid solution for its removal. The bacterially mediated pH decrease, driven by the consumption of citrate, decreased cobalt sorption to the solid phase resulting in enhanced cobalt transport. The results of these experiments suggest that geochemical changes, driven by the bacterial consumption of citrate, enhanced cobalt transport although the complexing ligand had been removed from the system. (C) 1998 Elsevier Science B.V. ALI rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Virginia, Dept Environm Sci, Program Interdisciplinary Res Contaminant Hydroge, Charlottesville, VA 22903 USA. RP Brooks, SC (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,MS 6038, Oak Ridge, TN 37831 USA. RI Brooks, Scott/B-9439-2012 OI Brooks, Scott/0000-0002-8437-9788 NR 53 TC 11 Z9 12 U1 1 U2 7 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 JUL PY 1998 VL 32 IS 1-2 BP 99 EP 115 DI 10.1016/S0169-7722(97)00083-1 PG 17 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA ZV988 UT WOS:000074362500006 ER PT J AU Gao, Y Edgar, JH Chaudhuri, J Cheema, SN Sidorov, MV Braski, DN AF Gao, Y Edgar, JH Chaudhuri, J Cheema, SN Sidorov, MV Braski, DN TI Low-temperature chemical-vapor deposition of 3C-SiC films on Si(100) using SiH4-C2H4-HCl-H-2 SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE 3C-SiC; CVD; crystal growth; epitaxy ID ELECTRICAL-PROPERTIES; BETA AB The benefits of adding HCl on the low-temperature (1000 degrees C) epitaxial growth of 3C-SiC on Si(1 0 0) were examined. At either silicon rich (C/Si < 1) or carbon rich (C/Si > 1) inlet gas ratios, the SiC him composition approached stoichiometry by adding HCl, but only at an inlet C/Si ratio of 1 was the composition of the SIC film approximate 1.0 with a Cl/Si input ratio of 50. The structure of the films improved with the addition of HCl, confirmed by both X-ray diffraction and TEM. For epitaxial films, the FWHM of X-ray diffraction rocking curves decreased to 0.37 degrees or 1348 arcs with increasing Cl/Si to 50 at a C/Si ratio of 1. The him dislocation density was reduced from 1.1 x 10(10) cm(-2) for a 2.0 mu m thick firm for a Cl/Si ratio of 0 to 4.27 x 10(9) cm(-2) for a 0.75 mu m thick film at a Cl/Si ratio of 50. The benefits of adding HCl are attributed to the suppression of pure silicon nucleation and the reduction in growth rate. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Kansas State Univ, Dept Chem Engn, Manhattan, KS 66506 USA. Wichita State Univ, Dept Engn Mech, Wichita, KS 67260 USA. Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Edgar, JH (reprint author), Kansas State Univ, Dept Chem Engn, Durland Hall, Manhattan, KS 66506 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 12 TC 16 Z9 17 U1 1 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 JUL PY 1998 VL 191 IS 3 BP 439 EP 445 DI 10.1016/S0022-0248(98)00212-7 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 104TY UT WOS:000075032500018 ER PT J AU Kikuma, J Warwick, T Shin, HJ Zhang, J Tonner, BP AF Kikuma, J Warwick, T Shin, HJ Zhang, J Tonner, BP TI Chemical state analysis of heat-treated polyacrylonitrile fiber using soft X-ray spectromicroscopy SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article DE NEXAFS; STXM; X-ray microscopy; spectromicroscopy; polyacrylonitrile; heat treatment ID PAN; STABILIZATION; EXCITATION; NEXAFS AB Chemical state analyses of heat-treated polyacrylonitrile (PAN) fibers with a spatial resolution of 200 nm have been performed using scanning transmission X-ray microscopy (STXM) at a third generation synchrotron radiation facility. Near-edge X-ray absorption fine structure (NEXAFS) spectra and chemical state images have been obtained on the cross-sectioned fiber specimens. A clear 'core-rim' structure has been observed in the heat-treated fibers. The spectral characteristics show that the fiber has less nitrile group in the core region, suggesting that, contrary to the model widely believed, the conversion of the nitrile to other chemical species proceeds faster in the core of the fibers. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Asahi Chem Ind Co Ltd, Analyt Res Lab, Fuji, Shizuoka 4168501, Japan. Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Pohang Light Source, Pohang 790784, Kyungbuk, South Korea. Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA. RP Kikuma, J (reprint author), Asahi Chem Ind Co Ltd, Analyt Res Lab, 2-1 Samejima, Fuji, Shizuoka 4168501, Japan. NR 22 TC 18 Z9 21 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD JUL PY 1998 VL 94 IS 3 BP 271 EP 278 DI 10.1016/S0368-2048(98)00196-0 PG 8 WC Spectroscopy SC Spectroscopy GA 106WJ UT WOS:000075173500007 ER PT J AU Cho, HU Hong, J Maeda, T Donovan, SM Abernathy, CR Pearton, SJ Shul, RJ Han, J AF Cho, HU Hong, J Maeda, T Donovan, SM Abernathy, CR Pearton, SJ Shul, RJ Han, J TI High selectivity plasma etching of InN over GaN SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE GaN; InN; selectivity plasma etching ID DRY; NITRIDE AB Etch selectivities for InN over GaN as high as 40 and 100 are achieved in BBr3/Ar and BI3/Ar, respectively, under inductively coupled plasma conditions. Previous work on Cl-2-based plasma chemistries has produced selectivity in the reverse direction, i.e., GaN over InN, and therefore the introduction of these new Br-2- and I-2-based mixtures facilitates device fabrication involving double heterostructures of GaN/InxGa1-xN/GaN. Selectivities up to 10 for InN over the common mask materials SiO2 and SiNx were obtained in both BI3 and BBr3. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Fujitsu Labs Ltd, Kanagawa, Japan. RP Cho, HU (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 14 TC 8 Z9 8 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JUL PY 1998 VL 27 IS 7 BP 915 EP 917 DI 10.1007/s11664-998-0118-z PG 3 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 101QX UT WOS:000074880600017 ER PT J AU Nakata, T AF Nakata, T TI Reaction of fuel NOx formation for gas turbine conditions SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT ASME/JSME/JSES International Solar Energy Conference CY MAR 19-24, 1995 CL MAUI, HAWAII SP ASME, JSME, JSES AB Ammonia contained in coal-gasified fuel is converted to nitrogen oxides (NOx) in the combustion process of a gas turbine in integrated coal gasification combined cycle (IGCC) system. Research data on fuel-NOx formation are insufficient, and there still remains a wide explored domain. The present research aims at obtaining fundamental knowledge of fuel-NOx formation characteristics by applying reaction kinetics to gas turbine conditions. An instantaneous mixing condition was assumed in the cross section of a gas turbine combustor and both gradual mixing condition and instantaneous mixing condition were assumed at secondary air inlet section. The results may be summarized as follows: (1) in the primary combustion zone under fuel rich condition, HCN and other intermediate products are formed as ammonia contained in the fuel decomposes; (2) formation characteristics of fuel-NOx are affected by the condition of secondary air mixing; and (3) the conversion ratio from ammonia to NOx declines as the pressure inside the combustor rises under the condition of gradual miring at the secondary air inlet. These results obtained agreed approximately with the experimentation. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Cent Res Inst Elect Power Ind, Yokosuka 24001, Japan. RP Nakata, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-644, Livermore, CA 94550 USA. RI Nakata, Toshihiko/E-3161-2010 OI Nakata, Toshihiko/0000-0003-0088-9498 NR 19 TC 4 Z9 4 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1998 VL 120 IS 3 BP 474 EP 480 DI 10.1115/1.2818169 PG 7 WC Engineering, Mechanical SC Engineering GA 110QZ UT WOS:000075393000007 ER PT J AU Daisey, JM Mahanama, KRR Hodgson, AT AF Daisey, JM Mahanama, KRR Hodgson, AT TI Toxic volatile organic compounds in simulated environmental tobacco smoke: Emission factors for exposure assessment SO JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY LA English DT Article DE air toxics; emission factors; environmental tobacco smoke; volatile organic compounds ID LIQUID-CHROMATOGRAPHY; CHEMICAL-COMPOSITION; INDOOR AIR; NICOTINE; MASS; PARTICLES AB Environmental tobacco smoke (ETS) is suspected to be a major source of exposure to many of the compounds identified as toxic air contaminants. However, we lack emission factors for many of the ETS air toxics for the brands of cigarettes which currently dominate the market and therefore cannot adequately estimate contributions of ETS to such exposures. This study provides up-to-date emission factors for Selected air toxics and other volatile organic compounds (VOCs) in simulated ETS and uses them in a mass balance model to evaluate the potential contribution of ETS to air toxics in indoor air and, therefore to indoor exposures to air toxics. Emission factors (mu g/cigarette) were determined for 21 VOCs (including two aldehydes), nicotine and particulate matter in a room-sized (20-m(3)) environmental chamber with stainless-steel walls, operated under static conditions, using diluted sidestream smoke (no exhaled mainstream smoke) to simulate ETS. Experiments were conducted for Kentucky Reference cigarette 1R4F and for each of six commercial cigarette brands with major market shares. The variabilities in the ETS emission factors among brands of cigarettes were relatively small, ranging from 16 to 31% (expressed as the coefficient of variation) among the six brands. The concentrations of most of the VOCs did not change over the 4-hour periods of the experiments. However concentrations of 3-ethenylpyridine, phenol, o-cresol and m,p-cresol showed consistent decreases over time, indicating removal by means other than the very low air infiltration rate (0.03 h(-1)), e.g., deposition onto the chamber surfaces. Emission factors for these compounds were calculated to take these losses into account and the rate constants for these losses were estimated. To estimate indoor concentrations and inhalation exposures to 16 VOCs, nicotine and PM-2.5, the average emission factors for the six commercial brands were used in a time-dependent mass-balance model for two scenarios: a typical office building and art average residence. In general, the indoor concentrations of the air toxics from ETS, under conditions selected to be "typical" rather than extreme, are comparable in magnitude to average outdoor concentrations, indicating that ETS can be a significant contributor to the total indoor concentration and the inhalation exposure for these species. At higher smoking rates, exposures To VOCs from ETS could be several times higher than those modeled under more "typical" conditions. C1 Lawrence Berkeley Natl Lab, Div Energy & Environm, Indoor Environm Program, Berkeley, CA 94720 USA. RP Daisey, JM (reprint author), Lawrence Berkeley Natl Lab, Div Energy & Environm, Indoor Environm Program, Berkeley, CA 94720 USA. EM jmdaisey@lbl.gov FU NHLBI NIH HHS [R01-HL42490] NR 47 TC 50 Z9 51 U1 0 U2 4 PU PRINCETON SCIENTIFIC PUBL INC PI PRINCETON PA PO BOX 2155, PRINCETON, NJ 08543 USA SN 1053-4245 J9 J EXPO ANAL ENV EPID JI J. Expo. Anal. Environ. Epidemiol. PD JUL-SEP PY 1998 VL 8 IS 3 BP 313 EP 334 PG 22 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 100GL UT WOS:000074807800003 PM 9679214 ER PT J AU Tsuruta, H Irving, TC Taylor, SR AF Tsuruta, H Irving, TC Taylor, SR TI Activity-dependent changes of lattice spacings in frog skeletal muscle SO JOURNAL OF GENERAL PHYSIOLOGY LA English DT Meeting Abstract C1 Mayo Clin & Mayo Fdn, Dept Pharmacol, Rochester, MN 55905 USA. IIT, Div Biol, Chicago, IL 60616 USA. Stanford Univ, SSRL, Stanford, CA 94305 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0022-1295 J9 J GEN PHYSIOL JI J. Gen. Physiol. PD JUL PY 1998 VL 112 IS 1 MA 33 BP 14A EP 14A PG 1 WC Physiology SC Physiology GA ZZ047 UT WOS:000074690300040 ER PT J AU Aschieri, P Castellani, L AF Aschieri, P Castellani, L TI Universal enveloping algebra and differential calculi on inhomogeneous orthogonal q-groups SO JOURNAL OF GEOMETRY AND PHYSICS LA English DT Article DE multiparametric quantum groups; universal enveloping algebra; Hopf algebra; bimodules ID QUANTUM GROUPS; GRAVITY; FIELDS; GL(N) AB We review the construction of the multiparametric quantum group ISOq,r(N) as a projection from SOq,r(N + 2) and show that it is a bicovariant bimodule over SOq,r(N). The universal enveloping algebra U-q,U-r(iso(N)), characterized as the Hopf algebra of regular functionals on ISOq,r(N), is found as a Hopf subalgebra of U-q,U-r(so(N + 2)) and is shown to be a bicovariant bimodule over U-q,U-r(so(N)). An R-matrix formulation of U-q,U-r(iso(N)) is given and we prove the pairing U-q,U-r(iso(N)) <-> ISOq,r(N). We analyze the subspaces of U-q,U-r(iso(N)) that define bicovariant differential calculi on ISOq,r(N). C1 Univ Turin, Dipartimento Fis Teor, Fac Sci Matemat 2, Dipartimento Sci & Tecnol Avanzate, I-10125 Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Castellani, L (reprint author), Univ Turin, Dipartimento Fis Teor, Fac Sci Matemat 2, Dipartimento Sci & Tecnol Avanzate, Via P Giuria 1, I-10125 Turin, Italy. EM aschieri@theor3.lbl.gov; castellani@to.infn.it RI Aschieri, Paolo/J-2965-2012; OI Castellani, Leonardo/0000-0002-7954-5622 NR 32 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0393-0440 J9 J GEOM PHYS JI J. Geom. Phys. PD JUL PY 1998 VL 26 IS 3-4 BP 247 EP 271 DI 10.1016/S0393-0440(97)00045-4 PG 25 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA ZX412 UT WOS:000074513200004 ER PT J AU Feldman, WC Barraclough, BL Gosling, JT McComas, DJ Riley, P Goldstein, BE Balogh, A AF Feldman, WC Barraclough, BL Gosling, JT McComas, DJ Riley, P Goldstein, BE Balogh, A TI Ion energy equation for the high-speed solar wind: Ulysses observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HEAT-FLUX; PLASMA; PARAMETERS; HEMISPHERES; TURBULENCE; ELECTRONS; NORTHERN; SOUTHERN; FIELD; WAVES AB Ulysses data in the high-speed solar wind that cover a wide range of latitudes centered on the solar poles were studied to test whether a polytrope law can be used to close the ion energy equation. Three approaches were taken, We determined the correlation between proton temperature and density (1) in the free expansion of the highspeed solar wind between 1.5 and 4.8 AU, (2) in steepened microstreams at high latitudes, and (3) at the edges of the equatorial band of solar wind variability. Strong correlations were observed in all data subsets that are consistent with a single polytrope relation, T(p) = aN(p)((gamma*-1)), where our best estimate gamma* is between 1.5 and 1.7. The best fitting relation T(p) = (2.0 +/- 0.13) x 10(5) N(p)(0.57). C1 Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87544 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. RP Feldman, WC (reprint author), Los Alamos Natl Lab, Space & Atmospher Sci Grp, Mail Stop D466, Los Alamos, NM 87544 USA. EM wfeldman@lanl.gov NR 36 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1998 VL 103 IS A7 BP 14547 EP 14557 DI 10.1029/98JA00963 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZY130 UT WOS:000074589300004 ER PT J AU Gary, SP Newbury, JA Goldstein, BE AF Gary, SP Newbury, JA Goldstein, BE TI Lower bound for electron core beta in the solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA DEPLETION LAYER; EARTHS MAGNETOSHEATH; HEAT-FLUX; ION; INSTABILITIES; ULYSSES; TEMPERATURE; ANISOTROPY AB Solar wind electrons, especially under conditions of relatively low speed flow, often can be represented as two bi-Maxwellian components, a cooler, more dense core (denoted by the subscript c) and a hotter, more tenuous halo. Solar wind observations from Ulysses between 1.5 and 2 AU further indicate that the beta for electron core temperatures parallel to the background magnetic field, beta(parallel to c) has a distinct lower bound near 0.1. To seek the cause of this possible constraint, numerical solutions of the full Vlasov linear dispersion equation are used for four heat flux instabilities under a core/halo model with parameters representative of the solar wind near 1 AU. In this model the whistler heat flux instability is the growing mode of lowest threshold at most observed values beta(parallel to c). As beta(parallel to c) decreased, however, the growth of this c mode is reduced, so that at entry small values of this parameter the Alfven heat flux instability or the electron/ion acoustic instability becomes the fastest growing mode. The critical condition corresponding to this transition is calculated as a function of T-parallel to c/T-p (where T-p is the proton temperature) and approximately corresponds to the observed constraint at beta(parallel to c) similar or equal to 0.1. The Alfven and ion acoustic instabilities both resonate with core electrons; the hypothesis is proposed that core beating by these two modes at the critical condition establishes a lower bound on beta(parallel to c). C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. EM pgary@lanl.gov; newbury@igpp.ucla.edu; bgoldstein@jplsp.jpl.nasa.gov NR 27 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1998 VL 103 IS A7 BP 14559 EP 14566 DI 10.1029/98JA01172 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZY130 UT WOS:000074589300005 ER PT J AU Gary, SP Li, H O'Rourke, S Winske, D AF Gary, SP Li, H O'Rourke, S Winske, D TI Proton resonant firehose instability: Temperature anisotropy and fluctuating field constraints SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CYCLOTRON INSTABILITY; HOSE INSTABILITY; MAGNETIC-FIELD; PLASMA; MAGNETOSHEATH; DEPLETION; PRESSURE; BETA AB The electromagnetic proton firehose instability may grow in a plasma if the proton velocity distribution is approximately bi-Maxwellian and T-parallel to p > T-perpendicular to p, where the directional subscripts denote directions relative to the background magnetic field. Linear Vlasov dispersion theory in a homogeneous electron-proton plasma implies an instability threshold condition at constant maximum growth rate l-T-perpendicular to p/T-parallel to p = S-p/beta(parallel to p)(alpha p) over 1 < beta(parallel to p) less than or equal to 10 where beta(parallel to p) = 8 pi n(p)T(parallel to p)/B-0(2) and B-0 is the background magnetic field. Here S-p and alpha(p) are fitting parameters and alpha(p) similar or equal to 0.7. One- and two-dimensional initial value hybrid simulations of this growing mode are carried out under proton cyclotron resonant conditions in a homogeneous plasma on the initial domain 2 less than or similar to beta(parallel to p) less than or equal to 100. The two-dimensional simulations show that enhanced fluctuations from this instability impose a bound on the proton temperature anisotropy of the form of the above equation with the fluid theory result alpha(p) similar or equal to 1.0. On this domain both one- and two-dimensional simulations yield a new form for the upper bound on the fluctuating field energy density from the proton resonant firehose instability /delta B/(2) / B-0(2) = S-B + alpha(B)ln (beta(parallel to p)) where S-B and alpha(B) are empirical parameters which are functions of the initial growth rate. This logarithmic behavior is qualitatively different from a fluid theory prediction and, like the anisotropy bound, should be subject to observational verification in any sufficiently homogeneous plasma in which the proton velocity distribution is approximately bi-Maxwellian. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gary, SP (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. NR 29 TC 71 Z9 71 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1998 VL 103 IS A7 BP 14567 EP 14574 DI 10.1029/98JA01174 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZY130 UT WOS:000074589300006 ER PT J AU Mora, CJ AF Mora, CJ TI Bridging the Cold War and the twenty-first century: Chronicling the history of Sandia National Laboratories SO JOURNAL OF GOVERNMENT INFORMATION LA English DT Article; Proceedings Paper CT Annual Meeting of the Society-for-History-in-the-Federal-Government and the National Archives Assembly CY APR 03-04, 1997 CL COLLEGE PK, MARYLAND SP Soc Hist Fed Govt DE history of Sandia National Laboratories; nuclear weapons; US Department of Energy History; history of the Cold War; archives; history of US National Laboratories AB Sandia National Laboratories, located in Albuquerque, New Mexico, was originally a part of Los Alamos Laboratory. In 1949, AT&T agreed to manage Sandia, which they did for the next 44 years. During those Cold War years, Sandia was the prime weapons engineering laboratory for Los Alamos and Lawrence Livermore. As such, it bore prime responsibility for designing and adapting nuclear weapons for the military services' delivery systems, and ensuring the safety and reliability of the stockpile. The Labs' history has been unevenly documented, hindered by the secret nature of its work and the desire of management to maintain a low public profile. There have been three history programs at Sandia: a restricted history published internally in 1963, another history program in the early 1980s that resulted in a history of the Labs' first decade; and the current history program dating from the mid-1990s, which has published a general history and several monographs. This article discusses the challenges and problems inherent in documenting the history of a national weapons laboratory during the last 50 years. (C) 1998 Elsevier Science Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Mora, CJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 0 Z9 0 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 JUL-AUG PY 1998 VL 25 IS 4 BP 321 EP 330 DI 10.1016/S1352-0237(98)00012-4 PG 10 WC Information Science & Library Science SC Information Science & Library Science GA 112WQ UT WOS:000075518000001 ER PT J AU Alvin, KF Peterson, LD AF Alvin, KF Peterson, LD TI Determination of modal residues and residual flexibility for time-domain system realization SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID IDENTIFICATION; ALGORITHM AB A linear least-squares procedure for the determination of modal residues using time-domain system realization theory is presented.The present procedure is intended to complement existing techniques for time-domain system identification and is shown to be theoretically equivalent to residue determination in realization algorithms such as the eigensystem realization algorithm and e-Markov covariance equivalent realization method. However, isolating the optimal residue estimation problem from the general realization problem affords several alternative strategies as compared to standard realization algorithms for structural dynamics identification. Primary among these are alternative techniques for handling data sets with large numbers of sensors using small numbers of reference point responses and the inclusion of terms that accurately model the effects of residual flexibility. The accuracy and efficiency of the present realization theory-based procedure is demonstrated for both simulated and experimental data. C1 Sandia Natl Labs, Dept 9234, Albuquerque, NM 87185 USA. Univ Colorado, Dept Aerosp Engn, Boulder, CO 80309 USA. RP Alvin, KF (reprint author), Sandia Natl Labs, Dept 9234, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JUL-AUG PY 1998 VL 21 IS 4 BP 588 EP 594 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZZ102 UT WOS:000074695900009 ER PT J AU Jones, AG Stockwell, CA Walker, D Avise, JC AF Jones, AG Stockwell, CA Walker, D Avise, JC TI The molecular basis of a microsatellite null allele from the white sands pupfish SO JOURNAL OF HEREDITY LA English DT Article ID GENETIC-RELATIONSHIPS; MARKERS; POPULATION; PARENTAGE; LOCI AB Microsatellite loci were cloned and characterized from the White Sands pupfish (Cyprinodon tularosa), a New Mexico state-listed endangered species. One locus exhibited a high-frequency nonamplifying allele localized to a single population. This null allele was PCR amplified by redesign of one of the original primers and multiple individuals homozygous for null as well as for nonnull alleles were sequenced using the new primer. These molecular dissections revealed that the original failure to amplify some alleles from this microsatellite locus was due to a 4 bp deletion in one of the original PCR priming sites. Furthermore, the reamplifications revealed five distinct size classes of alleles that had been masquerading as the original null. These null alleles did not overlap in length with the nonnull alleles, and they also differed consistently by a linked nucleotide substitution. Results suggest that the original null allele (as well as the nonnull class) has diversified considerably since its origin and has not recombined frequently with the nonnull class of alleles. C1 Univ Georgia, Dept Genet, Athens, GA 30602 USA. Savannah River Ecol Lab, Aiken, SC USA. RP Avise, JC (reprint author), Univ Georgia, Dept Genet, Athens, GA 30602 USA. NR 16 TC 61 Z9 78 U1 0 U2 4 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD JUL-AUG PY 1998 VL 89 IS 4 BP 339 EP 342 DI 10.1093/jhered/89.4.339 PG 4 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 106YF UT WOS:000075178500010 ER PT J AU Coriano, C Li, HN Savkli, C AF Coriano, C Li, HN Savkli, C TI Exclusive processes at intermediate energy, quark-hadron duality and the transition to perturbative QCD SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE QCD; sum rules ID PION FORM-FACTOR; LARGE-MOMENTUM-TRANSFER; SUM-RULES; COMPTON-SCATTERING; QUANTUM-CHROMODYNAMICS; ASYMPTOTIC-BEHAVIOR; RESONANCE PHYSICS; TRANSVERSE-MOMENTUM; SUDAKOV SUPPRESSION; ELECTROPRODUCTION AB Experiments at CEBAF will scan the intermediate-energy region of the QCD dynamics for the nucleon form factors and for Compton Scattering. These experiments will definitely clarify the role of resummed perturbation theory and of quark-hadron duality (QCD sum rules) in this regime. With this perspective in mind, we review the factorization theorem of perturbative QCD for exclusive processes at intermediate energy scales, which embodies the transverse degrees of freedom of a parton and the Sudakov resummation of the corresponding large logarithms. We concentrate on the pion and proton electromagnetic form factors and on pion Compton scattering. New ingredients, such as the evolution of the pion wave function and the complete two-loop expression of the Sudakov factor, are included. The sensitivity of our predictions to the infrared cutoff for the Sudakov evolution is discussed. We also elaborate on QCD sum rule methods for Compton Scattering, which provide an alternative description of this process. We show that, by comparing the local duality analysis to resummed perturbation theory, it is possible to describe the transition of exclusive processes to perturbative QCD. C1 Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. Natl Cheng Kung Univ, Dept Phys, Tainan 70101, Taiwan. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RP Coriano, C (reprint author), Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. EM coriano@jlab.org; hnli@mail.ncku.edu.tw; csavkli@physics.wm.edu OI Coriano', Claudio/0000-0003-0479-8075 NR 71 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD JUL PY 1998 IS 7 AR 008 PG 51 WC Physics, Particles & Fields SC Physics GA 124DB UT WOS:000076165100008 ER PT J AU Rosenthal, DS Simbulan-Rosenthal, CMG Iyer, S Spoonde, A Smith, W Ray, R Smulson, ME AF Rosenthal, DS Simbulan-Rosenthal, CMG Iyer, S Spoonde, A Smith, W Ray, R Smulson, ME TI Sulfur mustard induces markers of terminal differentiation and apoptosis in keratinocytes via a Ca2+-calmodulin and caspase-dependent pathway SO JOURNAL OF INVESTIGATIVE DERMATOLOGY LA English DT Article DE BAPTA; caspase-3; poly(ADP-ribose) polymerase; W-7 ID EXTRACELLULAR CALCIUM CONCENTRATIONS; INTRACELLULAR FREE CALCIUM; PROTEIN-KINASE-C; POLY(ADP-RIBOSE) POLYMERASE; GRANZYME-B; DNA FRAGMENTATION; CELL-DEATH; IN-VITRO; CALMODULIN ANTAGONISTS; MURINE KERATINOCYTES AB Sulfur mustard (SM) induces vesication via poorly understood pathways. The blisters that are formed result primarily from the detachment of the epidermis from the dermis at the level of the basement membrane. In addition, there is toxicity to the basal cells, although no careful study has been performed to determine the precise mode of cell death biochemically. We describe here two potential mechanisms by which SM causes basal cell death and detachment: namely, induction of terminal differentiation and apoptosis. In the presence of 100 mu M SM, terminal differentiation was rapidly induced in primary human keratinocytes that included the expression of the differentiation-specific markers K1 and K10 and the cross-linking of the cornified envelope precursor protein involucrin. The expression of the attachment protein, fibronectin, was also reduced in a time- and dose-dependent fashion. features common to both differentiation and apoptosis were also induced in 100 mu M SM, including the rapid induction of p53 and the reduction of Bcl-2. At higher concentrations of SM (i.e., 300 mu M), formation of the characteristic nucleosome-sized DNA ladders, TUNEL-positive staining of cells, activation of the cysteine protease caspase-3/apopain, and cleavage of the death substrate poly(ADP-ribose) polymerase, were observed both in vivo and in vitro. Both the differentiation and the apoptotic processes appeared to be calmodulin dependent, because the calmodulin inhibitor W-7 blocked the expression of the differentiation-specific markers, as well as the apoptotic response in a concentration-dependent fashion. In addition, the intracellular Ca2+ chelator, BAPTA-AM, blocked the differentiation response and attenuated the apoptotic response. These results suggest a strategy for designing inhibitors of SM vesication via the Ca2+-calmodulin or caspase-3/PARP pathway. C1 Georgetown Univ, Sch Med, Dept Biochem & Mol Biol, Washington, DC 20007 USA. Pacific NW Natl Lab, Richland, WA USA. USA, Med Res Inst Chem Def, Aberdeen Proving Ground, MD 21010 USA. RP Rosenthal, DS (reprint author), Georgetown Univ, Sch Med, Dept Biochem & Mol Biol, 3900 Reservoir Rd NW, Washington, DC 20007 USA. NR 65 TC 77 Z9 79 U1 0 U2 5 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0022-202X J9 J INVEST DERMATOL JI J. Invest. Dermatol. PD JUL PY 1998 VL 111 IS 1 BP 64 EP 71 DI 10.1046/j.1523-1747.1998.00250.x PG 8 WC Dermatology SC Dermatology GA ZW467 UT WOS:000074413900010 PM 9665388 ER PT J AU Pathare, PM Hamlin, DK Wilbur, DS Brechbiel, MW Bray, LA AF Pathare, PM Hamlin, DK Wilbur, DS Brechbiel, MW Bray, LA TI Synthesis and radiolabeling of a biotin-CHX-B chelate for Bi-213 SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE bismuth-213; biotin derivative; pretargeting; radioimmunotherapy ID PARTICLE-MEDIATED RADIOIMMUNOTHERAPY; MONOCLONAL-ANTIBODY; EMITTING RADIONUCLIDES; AVIDIN; STREPTAVIDIN; SYSTEM AB The synthesis and radiolabeling of a biotin derivative which contains a chelating group (CHX-B) for binding the alpha-emitting radionuclide, Bi-213, is described. The biotin-CHX-B derivative was readily prepared in high yield through a convergent synthesis that coupled N-methylglycylbiotinamide with anilino-CHX-B. Bismuth-213 labeling of the biotin-CHX-B molecule was facile at room temperature, resulting in >95 % radiochemical yield within 10 min reaction time. C1 Univ Washington, Dept Radiat Oncol, Seattle, WA 98195 USA. NCI, Radiat Oncol Branch, NIH, Bethesda, MD 20892 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Pathare, PM (reprint author), Univ Washington, Dept Radiat Oncol, Seattle, WA 98195 USA. NR 24 TC 2 Z9 2 U1 1 U2 1 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 JUL PY 1998 VL 41 IS 7 BP 595 EP 603 DI 10.1002/(SICI)1099-1344(199807)41:7<595::AID-JLCR116>3.0.CO;2-O PG 9 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA ZY753 UT WOS:000074655900003 ER PT J AU Murdoch, KM Nguyen, AD Edelstein, NM AF Murdoch, KM Nguyen, AD Edelstein, NM TI One- and two-photon spectroscopy of Eu3+ in LuPO4 SO JOURNAL OF LUMINESCENCE LA English DT Article DE two-photon absorption; polarization analysis; crystal-field analysis ID 2-PHOTON ABSORPTION-SPECTROSCOPY; POLARIZATION DEPENDENCE; INTENSITIES; TRANSITION; CRYSTALS; LINES; SM-2+; YPO4; CM3+ AB One-photon laser excitation and fluorescence spectra have been recorded for the Eu3+ ion diluted in single crystals of LuPO4. Analysis of these spectra resulted in the assignment of 23 energy levels of the F-7(J) and D-5(J) multiplets, which were fitted to the parameters of an empirical Hamiltonian with an rms deviation of 8.7 cm(-1). The intensities of the two-photon absorption transitions to the D-5(0) and D-5(2) multiplets have been investigated. The polarization dependences of transitions to all five of the crystal-field levels were measured and are compared with theoretical predictions. The intensity model included the third-order spin-orbit interaction. Good agreement was found for three of the five transitions observed. However, the polarization dependences of the other two did not agree with the predicted behavior, as they exhibited an additional isotropic component. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, MS 70A-1150, Berkeley, CA 94720 USA. EM murdoch@chem.wisc.edu NR 29 TC 4 Z9 4 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 EI 1872-7883 J9 J LUMIN JI J. Lumines. PD JUL PY 1998 VL 79 IS 1 BP 55 EP 64 DI 10.1016/S0022-2313(98)00014-3 PG 10 WC Optics SC Optics GA 111QD UT WOS:000075448400007 ER PT J AU Javorsky, P Nakotte, H Robinson, RA Kelley, TM AF Javorsky, P Nakotte, H Robinson, RA Kelley, TM TI Crystal field in ErNiAl studied by inelastic neutron scattering SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE neutron scattering; rare-earth intermetallic compounds; crystal field; heat capacities AB We present an inelastic neutron scattering study of the crystal field in the ErNiAl intermetallic compound. The results are compared with the specific heat data and the lower portion of the crystal-field energy level scheme was determined. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Charles Univ, Dept Met Phys, CR-12116 Prague 2, Czech Republic. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. RP Javorsky, P (reprint author), Charles Univ, Dept Met Phys, KE Karlovu 5, CR-12116 Prague 2, Czech Republic. EM javor@mag.mff.cuni.cz RI Javorsky, Pavel/C-2132-2015 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 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUL PY 1998 VL 186 IS 3 BP 373 EP 376 DI 10.1016/S0304-8853(98)00101-2 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZX370 UT WOS:000074508700013 ER PT J AU Gibbons, MR AF Gibbons, MR TI Micromagnetic simulation using the dynamic alternating direction implicit method SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE micromagnetic simulation; spin-valves; magnetoresistive head simulation ID SPIN-VALVE SENSORS; GIANT MAGNETORESISTANCE; DOMAIN-WALLS; EXCHANGE; HEADS AB We have developed a 3-D micromagnetic algorithm using finite-differences and the iterative matrix solution method, dynamic alternating direction implicit (DADI), for the magnetostatic potential equation. As in previous work, the magnetization is integrated in time toward equilibrium with the Landau-Lifshitz-Gilbert (LLG) equation. We have found that only one iteration of DADI is needed for each time step of the LLG equation. The resulting algorithm has relatively short computation times even for simulations with linearly permeable structures of various shapes. In addition to the magnetostatic field the effective H-field includes exchange coupling, crystalline anisotropy, interlayer exchange coupling, and current-induced fields allowing the simulation of a wide range of devices. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gibbons, MR (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-395,POB 808, Livermore, CA 94550 USA. NR 32 TC 24 Z9 24 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 EI 1873-4766 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JUL PY 1998 VL 186 IS 3 BP 389 EP 401 DI 10.1016/S0304-8853(98)00105-X PG 13 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZX370 UT WOS:000074508700017 ER PT J AU Galkin, VY Ortiz, WA Fishman, RS AF Galkin, VY Ortiz, WA Fishman, RS TI Local Fe moment in commensurate and incommensurate spin-density wave Cr matrix SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Letter DE spin-density wave; paramagnetism; antiferromagnetism; Cr alloys ID IMPURITY RESONANCE SCATTERING; MAGNETIC PHASE-DIAGRAMS; TERNARY ALLOYS; CHROMIUM; ANTIFERROMAGNETISM; TEMPERATURE; MN AB It is well known that Fe is the only impurity atom which exhibits Pauli paramagnetism below the Neel temperature of a dilutely doped Cr host. Magnetic measurements on two complementary Cr alloys now reveal that the Fe moment is about 6% larger in the incommensurate than in the commensurate spin-density wave state. A phenomenological model is presented which explains this difference by dividing the Fe moment into bound and unbound parts. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Fed Sao Carlos, Dept Fis, BR-13560 Sao Carlos, SP, Brazil. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013; Ortiz, Wilson/K-7379-2012 NR 18 TC 3 Z9 3 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 JUL PY 1998 VL 186 IS 1-2 BP L1 EP L6 DI 10.1016/S0304-8853(98)00100-0 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZV938 UT WOS:000074357300001 ER PT J AU Stephenson, JL McLuckey, SA AF Stephenson, JL McLuckey, SA TI Charge manipulation for improved mass determination of high-mass species and mixture components by electrospray mass spectrometry SO JOURNAL OF MASS SPECTROMETRY LA English DT Article DE electrospray mass spectrometry; multiply charged ions; ion-ion reactions, quadrupole ion trap; transformation algorithms ID PROTON-TRANSFER REACTIONS; ION-MOLECULE REACTIONS; GAS-PHASE; IONIZATION; DECONVOLUTION; PRINCIPLES; PROTEINS; SPECTRA AB The manipulation of the charge states of high-mass ions can facilitate mass determination in electrospray (ES) mass spectrometry. Specifically, the reduction of charge (which leads to ions of higher mass-to-charge ratios) can significantly reduce peak overlap. Signals associated with various charge states of high-mass ions are more easily resolved at low charge states and chemical noise tends to be significantly lower at high mass-to-charge ratios than in the normal mass-to-charge window typically associated with electrospray. Algorithms that transform ES mass spectra to zero-charge spectra are most likely to yield unambiguous results when charge states are clearly resolved and when signal-to-noise ratios are relatively high. Charge manipulation can enhance the value of the transformation algorithms in cases in which compromises their utility. Such situations include ES mass spectra of high-mass species that yield charge states that are not baseline resolved, mixtures with many components and mixtures in which the signals from major components overwhelm signals from minor components. Examples of improved mass determination are illustrated for proteins using ion-ion chemistry as the means for charge state manipulation and the quadrupole ion trap as the mass analyzer. (C) 1998 John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP McLuckey, SA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 27 TC 44 Z9 44 U1 0 U2 8 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD JUL PY 1998 VL 33 IS 7 BP 664 EP 672 DI 10.1002/(SICI)1096-9888(199807)33:7<664::AID-JMS663>3.0.CO;2-P PG 9 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 102VJ UT WOS:000074945900011 PM 9692249 ER PT J AU Aselage, TL AF Aselage, TL TI The coexistence of silicon borides with boron-saturated silicon: Metastability of SiB3 SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB The silicon-rich end of the Si-B phase diagram, defining the silicon boride(s) that coexist in equilibrium with boron-saturated silicon, is poorly known. Understanding this equilibrium has implications for the processing of p(+) silicon wafers, whose boron concentrations are near the solubility limit. Additionally, silicon boride precipitates produced by boron-ion-implantation and annealing of crystalline silicon have recently been shown to be efficient internal getters of transition metal ions. The experiments described in this paper probe the stability of these silicon borides. A phase with a boron-carbide-like structure. SiB3, grows from boron-saturated silicon in both the solid and the liquid state. However, SiB3 is not found to be stable in either circumstance. Rather, SiB3 is a metastable phase whose formation is driven by the relative ease of its nucleation and growth. The silicon boride that exists in stable equilibrium with boron-saturated silicon is SiB6.A qualitative understanding of the metastability of SiB3 comes from recognizing the conflict between the bonding requirements of icosahedral borides such as SiB3 and the size mismatch between silicon and boron atoms. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Aselage, TL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 40 TC 26 Z9 28 U1 2 U2 19 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1998 VL 13 IS 7 BP 1786 EP 1794 DI 10.1557/JMR.1998.0252 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZX311 UT WOS:000074502800013 ER PT J AU Indacochea, JE Bloom, I Krumpelt, M Benjamin, TG AF Indacochea, JE Bloom, I Krumpelt, M Benjamin, TG TI A comparison of two aluminizing methods for corrosion protection in the wet seal of molten carbonate fuel cells SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB The corrosion behavior of aluminized Type 310S stainless steel (SS) in the wet seal of molten carbonate fuel cells was investigated. Coupons of Type 310S SS were aluminized by two different aluminizing methods: thermal spray and slurry-coating. In both types of samples Fe and Cr diffused readily into the Al layer at 650 degrees C. At first this interdiffusion is limited to the interfacial area. With time, Fe and Cr aluminides precipitate in the Al layer. The slurry-coated layer contains a higher concentration of FeAl and Fe3Al than does the thermal spray layer. Consequently, the slurry-coated layer also displays a greater degree of corrosion than the thermal spray layer. C1 Argonne Natl Lab, Electrochem Technol Program, Argonne, IL 60439 USA. MC Power Corp, Burr Ridge, IL 60521 USA. RP Bloom, I (reprint author), Argonne Natl Lab, Electrochem Technol Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 7 Z9 8 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1998 VL 13 IS 7 BP 1834 EP 1839 DI 10.1557/JMR.1998.0260 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA ZX311 UT WOS:000074502800021 ER PT J AU Chen, SP AF Chen, SP TI Compositional and physical changes on perovskite crystal surfaces SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID THIN-FILMS; RELAXATION; OXIDES; NIO AB The surface composition of BaTiO3, SrTiO3, and CaTiO3 perovskite(100) surface is determined by shell-model calculations. The TiO2-terminaled surface is energetically favorable for BaTiO3 and SrTiO3, which is consistent with experimental observations on SrTiO3. On the other hand, the CaO-terminated surface is preferred for CaTiO3 where Ca2+ is the smallest 2+ cation in these titanates. Ions on (100) surface rumple and induce surface dipoles. The surface ferroelectric polarization stabilizes the surface and changes its sign as the surface composition changes from TiO2 to CaO. This phenomenon is expected to affect the stability and properties of epitaxial films on perovskite substrates. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chen, SP (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 21 TC 16 Z9 17 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1998 VL 13 IS 7 BP 1848 EP 1852 DI 10.1557/JMR.1998.0262 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA ZX311 UT WOS:000074502800023 ER PT J AU Gao, Y Kim, YJ Chambers, SA AF Gao, Y Kim, YJ Chambers, SA TI Preparation and characterization of epitaxial iron oxide films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MOLECULAR-BEAM EPITAXY; SCANNING-TUNNELING-MICROSCOPY; ENERGY-ELECTRON-DIFFRACTION; SURFACE-STRUCTURE; FE3O4 FILMS; DEFECT STRUCTURE; WUSTITE PHASE; THIN-FILMS; GROWTH; PT(111) AB Well-ordered, pure-phase epitaxial films of FeO, Fe3O4, and gamma-Fe2O3 were prepared on MgO(001) by oxygen-plasma-assisted MBE. The stoichiometries of these thin films were controlled by varying the growth rate and oxygen partial pressure. Selective growth of gamma-Fe2O3 and alpha-Fe2O3 was achieved by controlling the growth conditions in conjunction with the choice of appropriate substrates. Growth of the iron oxide epitaxial films on MgO at greater than or equal to 350 degrees C is accompanied by significant Mg outdiffusion. The FeO(001) film surface exhibits a (2 x 2) reconstruction, which is accompanied by a significant amount of Fe3+ in the surface region. Fe3O4(001) has been found to reconstruct to a (root 2 x root 2)R45 degrees structure. gamma-Fe2O3(001) film surface is unreconstructed. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Gao, Y (reprint author), Pacific NW Lab, POB 999,MS K8-93, Richland, WA 99352 USA. NR 40 TC 43 Z9 43 U1 1 U2 33 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1998 VL 13 IS 7 BP 2003 EP 2014 DI 10.1557/JMR.1998.0281 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA ZX311 UT WOS:000074502800042 ER PT J AU Haridoss, P Uribe, FA Garzon, FH Zawodzinski, TA AF Haridoss, P Uribe, FA Garzon, FH Zawodzinski, TA TI Structural modifications of disordered mesocarbon microbeads with lower temperatures of heat treatment SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHARGE-DISCHARGE CHARACTERISTICS; LITHIUM; CARBON; GRAPHITE; INTERCALATION; ELECTRODES; BATTERIES; FIBER; CELLS AB We describe the variation of structural and physical properties of mesocarbon microbeads, a potential anode material for rechargeable lithium batteries, as a function of heat-treatment temperature in the range 400-1100 degrees C. Scanning electron microscopy (SEM) studies indicated changes in the morphology of the mesocarbons with heat treatment. X-ray studies show that average crystallite size varies considerably with heat treatment. The d(002) spacing decreases with increasing heat-treatment temperatures. The electronic conductivity of the mesocarbon microbeads also increases substantially with increasing heat-treatment temperature. Eased on thermogravimetric analysis (TGA) and other measurements, we find that organic fractions volatilizes out of these carbons in two distinct stages. The observed weight loss correlates with the structural changes observed. We suggest that these observations are consistent with two types of hydrogenated fractions present in the "green" mesocarbons. C1 Univ Calif Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, Los Alamos, NM 87545 USA. RP Haridoss, P (reprint author), Univ Calif Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, POB 1663, Los Alamos, NM 87545 USA. NR 22 TC 7 Z9 7 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1998 VL 13 IS 7 BP 2015 EP 2022 DI 10.1557/JMR.1998.0282 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZX311 UT WOS:000074502800043 ER PT J AU Nakashima, K Makino, T Mori, K Glaeser, AM AF Nakashima, K Makino, T Mori, K Glaeser, AM TI Wettability and interfacial reaction between alumina and Cu-based alloys SO JOURNAL OF MATERIALS SYNTHESIS AND PROCESSING LA English DT Article DE PTLP bonding; alumina; wettability; Cu-based alloy AB In PTLP (partial transient liquid-phase) bonding, the transient liquid phase is sandwiched between a ceramic and a refractory core metal. A transient liquid phase chemistry that reduces the contact angle on the ceramic is necessary to improve strength characteristics. in this study, the effect of additions on the wetting characteristics of liquid Cu on an alumina substrate has been studied in parallel with the study of the joining of alumina through the use of microdesigned multilayer Cu/80Ni . 20Cr/Cu interlayers. While Ni additions do not reduce the contact angle of liquid Cu on an Al2O3 substrate, additions of 80Ni . 20Cr or Cr alone do reduce the contact angle. The contact angle reduction depends upon the Cr content of the sessile drop. The average strength and the standard deviation of PTLP bonded alumina were 259 +/- 25 MPa for 99.5% Al2O3 and 494 +/- 61 MPa for 99.9% Al2O3, respectively. The resulting joints can exhibit a high bend strength at room temperature, strengths approaching those of the unbonded alumina, and a relatively narrow strength distribution. In both cases, failure occurred either entirely within the ceramic or primarily in the ceramic, with limited crack propagation along the alumina/interlayer interface. C1 Kyushu Univ, Fac Engn, Dept Mat Sci & Engn, Higashi Ku, Fukuoka 812, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Nakashima, K (reprint author), Kyushu Univ, Fac Engn, Dept Mat Sci & Engn, Higashi Ku, 6-10-1 Hakozaki, Fukuoka 812, Japan. NR 12 TC 2 Z9 3 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA CONSULTANTS BUREAU, 233 SPRING ST, NEW YORK, NY 10013 USA SN 1064-7562 J9 J MATER SYNTH PROCES JI J. Mater. Synth. Process PD JUL PY 1998 VL 6 IS 4 BP 271 EP 277 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 154GN UT WOS:000077881000010 ER PT J AU Joy, DC AF Joy, DC TI The efficiency of X-ray production at low energies SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article DE X-ray ionization cross-section; fluorescent yield; X-ray generation cross-section; X-ray efficiency; Monte Carlo modelling ID ELECTRON-SOLID INTERACTIONS; K-SHELL IONIZATION; CROSS-SECTIONS; IMPACT AB The absolute efficiency of X-ray production has been determined for the It-lines of Al, Si and Cu: for the L-lines of Fe, Co, Cu, Ge and As: and for the M-lines of Hf. Ir, Pt, Au and Pi, using overvoltage ratios in the range 1-10, These emissions, with the exception of the Cu It, have critical excitation energies below 2.6keV and are therefore typical of the lines used for X-ray microanalysis at low beam energies, For It-lines it is found that the experimental results are in good agreement with a Bethe, or a Casnati, cross-section model, For the L- and M-lines a Monte Carlo technique has been used to find an effective X-ray generation cross-section for each of the elements. The functional forms of these cross-sections are found to be in general agreement with proposed theoretical models. C1 Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Joy, DC (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 29 TC 29 Z9 29 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD JUL PY 1998 VL 191 BP 74 EP 82 PN 1 PG 9 WC Microscopy SC Microscopy GA 109CN UT WOS:000075303800009 PM 9723191 ER PT J AU Hacker, BC AF Hacker, BC TI The chemical weapons taboo SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hacker, BC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD JUL PY 1998 VL 62 IS 3 BP 637 EP 638 DI 10.2307/120453 PG 2 WC History SC History GA 102KQ UT WOS:000074923800020 ER PT J AU Kerns, L Weinberg, MC Myers, S Assink, R AF Kerns, L Weinberg, MC Myers, S Assink, R TI Al coordination in sol-gel and conventional calcium aluminate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Conference on the Structure of Non-Crystalline Materials (NCM7) CY SEP 15-19, 1997 CL CAGLIARI, ITALY SP Presidenza Giunta Reg, Reg Autonoma Sardegna, Assessorato Affari Gen, Camera Commercio Ind Artigianato & Agr, EMSA, Ente Minerario Sardo, Fdn Banco Sardegna, Univ Cagliari, CNR, Com Chim, INCM, Consorzio Interuniv Nazl Chim Mat, SARAS Raffinerie Sarde, Comune Iglisias, Assoc Univ Sulcis Iglesiente, Ente Sardo Ind Turistiche ID NUCLEAR-MAGNETIC-RESONANCE; AL-27 NMR; SPECTROSCOPY; RAMAN AB We present the results of a study in which we compared one aspect of structure for a conventionally prepared glass and sol-gel material in the calcium aluminate (CA) family of composition 50CaO . 50Al(2)O(3) (wt%). The work was directed towards a comparison of the aluminum coordination in the two materials, which was determined via (27)Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Also, infra red (IR) spectroscopy was utilized to compare the hydroxyl content and the structural features of the materials. The Al coordination was examined in gels which were subjected to various heat treatments, some of which produced partial or nearly complete crystallization. We observed, as found previously by others, that in the conventionally prepared glass all the Al atoms are tetrahedrally (4-fold) coordinated. On the other hand, in all the sol-gel materials, regardless of heat treatment schedule, a fraction of the Al is found to be in octahedral (G-fold) coordination. We found that. as the hydroxyl content of the gel increases, the ratio of 6-fold to 4-fold Al increased. Hence, the presence of octahedral coordination in the gel is largely, and most likely totally, due to the water content of this material. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Arizona, Dept Mat Sci & Engn, Arizona Mat Lab, Tucson, AZ 85721 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Weinberg, MC (reprint author), Univ Arizona, Dept Mat Sci & Engn, Arizona Mat Lab, Bldg 12,4715 E Ft Lowell Rd, Tucson, AZ 85721 USA. EM mcw@u.arizona.edu NR 20 TC 15 Z9 15 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1998 VL 232 BP 86 EP 92 DI 10.1016/S0022-3093(98)00376-7 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 113NU UT WOS:000075558800013 ER PT J AU Sales, BC Boatner, LA Ramey, JO AF Sales, BC Boatner, LA Ramey, JO TI Intermediate-range order in simple metal-phosphate glasses: The effect of metal cations on the phosphate-anion distribution SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Conference on the Structure of Non-Crystalline Materials (NCM7) CY SEP 15-19, 1997 CL CAGLIARI, ITALY SP Presidenza Giunta Reg, Reg Autonoma Sardegna, Assessorato Affari Gen, Camera Commercio Ind Artigianato & Agr, EMSA, Ente Minerario Sardo, Fdn Banco Sardegna, Univ Cagliari, CNR, Com Chim, INCM, Consorzio Interuniv Nazl Chim Mat, SARAS Raffinerie Sarde, Comune Iglisias, Assoc Univ Sulcis Iglesiente, Ente Sardo Ind Turistiche ID STRUCTURAL-PROPERTIES AB The technique of high-performance liquid chromatography (HPLC) has been used to determine the phosphate-anion distribution in a variety of metal phosphate glasses-including glasses made with the trivalent metal cations: Al, In, Ga, and La. The composition of each glass was chosen so that the average phosphate chain length was between 2 and 4 PO(4) tetrahedra. The widths of the resulting phosphate-anion chain-length distributions were determined directly from an analysis of the HPLC chromatograms. Literature values for the free energy of formation of the crystalline metal-orthophosphate compounds with respect to P(2)O(5) and the metal oxide were compared to the width of the phosphate-anion chain-length distributions. We found that the smaller the energy of formation, the wider the distribution of phosphate chains, and the greater the ease of glass formation. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Sales, BC (reprint author), Oak Ridge Natl Lab, Div Solid State, MS-6056,Bldg 3150,POB 2008, Oak Ridge, TN 37831 USA. EM vb4@ornl.gov RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 11 TC 16 Z9 16 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1998 VL 232 BP 107 EP 112 DI 10.1016/S0022-3093(98)00379-2 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 113NU UT WOS:000075558800016 ER PT J AU Suzuya, K Price, DL Loong, CK Martin, SW AF Suzuya, K Price, DL Loong, CK Martin, SW TI Structure of vitreous P2O5 and alkali phosphate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Conference on the Structure of Non-Crystalline Materials (NCM7) CY SEP 15-19, 1997 CL CAGLIARI, ITALY SP Presidenza Giunta Reg, Reg Autonoma Sardegna, Assessorato Affari Gen, Camera Commercio Ind Artigianato & Agr, EMSA, Ente Minerario Sardo, Fdn Banco Sardegna, Univ Cagliari, CNR, Com Chim, INCM, Consorzio Interuniv Nazl Chim Mat, SARAS Raffinerie Sarde, Comune Iglisias, Assoc Univ Sulcis Iglesiente, Ente Sardo Ind Turistiche ID X-RAY-DIFFRACTION; ULTRAPHOSPHATE GLASSES; SHORT-RANGE; NEUTRON AB The structure of vitreous P2O5 (v-P2O5), sodium ultraphosphate glasses, (Na2O)(x)(P2O5)(100-x) (x = 10, 20), and alkali metaphosphate glasses, MePO3 (Me = Li, Na, K, Rb and Cs), have been studied by neutron diffraction. Structural features in the neutron structure factors. S(Q), characteristic of intermediate-range (Q less than or similar to 3 A(-1)) order were identified. The feature of intermediate-range order in V-P2O5 is accounted for by the P4O10 molecule packing model. The addition of the alkali metal modifier, Na, has an effect on the intermediate-range structure due to destruction of the PO4 network structure. Around x similar to 50 a new peak appears at lower Q than the intermediate-range order peak, which is found in the S(Q)'s of all alkali metaphosphate glasses, which may be associated with extended-range order. The length scale of the extended-range order increases with Me+ size. These phenomena can be explained by the affects of oxygen atoms, i.e. PO4 chain-like units, ordering around the Me+. (C) 1998 Elsevier Science B.V. AII rights reserved. C1 Japan Atom Energy Res Inst, Dept Synchrotron Radiat Res, Ako, Hyogo 67812, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Suzuya, K (reprint author), Japan Atom Energy Res Inst, Dept Synchrotron Radiat Res, Ako, Hyogo 67812, Japan. EM suzuya@spring8.or.jp RI Price, David Long/A-8468-2013 NR 29 TC 47 Z9 47 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1998 VL 232 BP 650 EP 657 DI 10.1016/S0022-3093(98)00529-8 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 113NU UT WOS:000075558800099 ER PT J AU Green, PF Sidebottom, DL Brow, RK Hudgens, JJ AF Green, PF Sidebottom, DL Brow, RK Hudgens, JJ TI Mechanical relaxation anomalies in mixed alkali oxides SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID IONIC-TRANSPORT-PROPERTIES; CONDUCTING GLASSES; ATOMIC-STRUCTURE; RESONANCE; PHOSPHATE; MODEL; NMR; DC AB Mechanical relaxation (MR) processes were investigated in single and mixed alkali (MA) metaphosphate glasses using a dynamic mechanical analyzer (DMA) over a range of frequencies, 0.1-50 Hz, and temperatures, 24-250 degrees C. The mechanical loss modulus, M ", of each mixed, sodium and lithium, alkali glass exhibited two characteristic maxima, a large maximum just below T-g, and a well developed, yet considerably diminished in amplitude, maximum at a much lower temperature. The single alkali analogs, on the other hand, exhibited only a single maximum and this maximum appeared in the same location as the lower temperature peak observed in the MA glasses. The location of these maxima are identified with dynamic processes within the glass which occur with average frequencies, nu(mu)(Na, Li), for the high T maximum in the mixed glasses, and nu(mu) (Li) and nu(mu) (Na) for the lithium and sodium glasses, respectively. These frequencies nu(mu)(Na, Li), nu(mu) (Li) and nu(mu) (Na), varied exponentially with 1/T; nu(mu) (Na, Li) had the largest activation energy. In addition nu(mu)(Na, Li) << nu(mu)(Na) < nu(mu)(Li) for T < T-g. Two other important observations were made, the high temperature maximum in M " reached its largest amplitude when the mole fractions of Na2O and Li2O were comparable and nu(mu) (Na, Li) exhibited a maximum in the same composition range. Our observations are discussed in light of a local site-memory relaxation model based on the notion that below T,, cation hopping dynamics are intimately coupled with local glass network relaxations. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Texas Mat Inst, Dept Chem Engn, Austin, TX 78712 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87110 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Green, PF (reprint author), Univ Texas, Texas Mat Inst, Dept Chem Engn, ETC 9-104, Austin, TX 78712 USA. EM green@che.utexas.edu NR 32 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1998 VL 231 IS 1-2 BP 89 EP 98 DI 10.1016/S0022-3093(98)00447-5 PG 10 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY347 UT WOS:000074611500009 ER PT J AU Treacy, MMJ Gibson, JM Keblinski, PJ AF Treacy, MMJ Gibson, JM Keblinski, PJ TI Paracrystallites found in evaporated amorphous tetrahedral semiconductors SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID SILICON; CRYSTALLIZATION; RELAXATION; SCATTERING; COHERENCE; FILMS; ORDER; SI; GE AB Variable coherence microscopy shows that as-deposited amorphous germanium and silicon contain medium-range order. The ordering can be explained by a fine-grained paracrystallite material in which intergranular stress has been relaxed by deformation. On annealing, the paracrystallite structure transforms towards the lower-energy continuous random network (CRN). We present data on a variety of vacuum-evaporated samples, and on molecular dynamics simulations of candidate structures. (C) 1998 Elsevier Science B.V. All rights reserved. C1 NEC Res Inst Inc, Princeton, NJ 08540 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Dept Mat Sci, Urbana, IL 61801 USA. Argonne Natl Labs, Argonne, IL 60439 USA. RP Treacy, MMJ (reprint author), NEC Res Inst Inc, 4 Independence Way, Princeton, NJ 08540 USA. EM treacy@research.nj.nec.com; j-gibson@uiuc.edu; pawel_keblinski@qmgate.anl.gov RI Gibson, Murray/E-5855-2013 OI Gibson, Murray/0000-0002-0807-6224 NR 31 TC 101 Z9 101 U1 3 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1998 VL 231 IS 1-2 BP 99 EP 110 DI 10.1016/S0022-3093(98)00371-8 PG 12 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY347 UT WOS:000074611500010 ER PT J AU Sunwoo, AJ Accardo, RN Gourdin, WH AF Sunwoo, AJ Accardo, RN Gourdin, WH TI Effects of heat treatment on grain refinement in cast uranium 0.25 wt% vanadium alloy SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB The feasibility of refining the grain size of large castings of uranium-0.25 wt% vanadium alloy has been successfully demonstrated using a helium-mediated 'isothermal' heat treatment in a large commercial vacuum furnace. Using th:is method, the grains of 10-20 kg hemispherical castings were refined from 180 mu m diameter to 35 mu m, a reduction similar to that achieved in both laboratory-scale isothermally transformed material and carefully controlled wrought-processed uranium. The results of compression and tension tests on the cast alloy and the wrought uranium at a strain rate of 10(-3) s(-1) indicate that up to a strain of 30%, the cast and heat-treated uranium-0.25% vanadium alloy exhibits a higher compressive flow stress than that of comparable wrought uranium. In tension, the cast and heat treated alloy continues to exhibit high strengths, but displays a lower ductility. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Sunwoo, AJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,7000 East Ave, Livermore, CA 94551 USA. NR 18 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUL PY 1998 VL 256 IS 1 BP 53 EP 64 DI 10.1016/S0022-3115(98)00052-X PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 107FU UT WOS:000075197200006 ER PT J AU Shen, S DeNardo, GL Jones, TD Wilder, RB O'Donnell, RT DeNardo, SJ AF Shen, S DeNardo, GL Jones, TD Wilder, RB O'Donnell, RT DeNardo, SJ TI A preliminary cell kinetics model of thrombocytopenia after radioimmunotherapy SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE radionuclide therapy; radioimmunotherapy; marrow cell kinetics; radiation dosimetry; thrombocytopenia ID BONE-MARROW; I-131 LYM-1; STEM-CELLS; RADIATION AB Thrombocytopenia is often the dose-limiting toxicity for radionuclide therapy. Prediction of platelet counts after therapy is important for treatment planning. Simple prediction methods based on linear correlation between radiation dose and blood count nadir have been insufficient because they have not considered time, because of the complicated hierarchical structure of the hematopoietic system in which platelets are not directly injured by low dose rate radiation and because of changing radiation dose rates to marrow with time, This study addresses these problems using a cell kinetics model. Methods: The model consists of compartments for progenitor cells, megakaryocytes, platelets and stromal cells. A linear quadratic formula was used for progenitor cell survival. Stromal cells were described by a model based on a maximum likelihood estimate for cellular damage, repair and proliferation. Reported values for murine cellular turnover rates and radiosensitivity of progenitor cells were used in the model calculations. Experimental mice received 4 Gy of external beam radiation for tumor implantation and 12.4-23.3 MBq Cu-67-2-iminothiolane-BAT-Lym-1 (BAT = 6-[p-(bromoacetamido) benzyl]-1,4,8,11-tetra-azacyclotetradecane-N,N',N",N"'-tetraacetic acid) 19-30 days later. Blood counts were measured three times each week. Results: The model predicted the severity of thrombocytopenia, and the time of the nadir corresponded to measured values in mice. For a dose of 14.2 MBq Cu-67-2-iminothiolane-BAT-Lym-1 that induced a platelet nadir of 20% of baseline (Grade II), the model predicted that at least 20 days were needed before a second 14.2-MBq injection if a subsequent nadir of <10% of baseline (Grade IV) was to be avoided. Conclusion: The nadir and duration of thrombocytopenia predicted by the model were similar to those observed in the mice. Predicted information could be useful for planning the dose and timing of fractionated radionuclide therapy. This model provides a stepping stone for future development of a predictive model for patients. C1 Univ Calif Davis, Radiodiag & Therapy Sect, Div Hematol Oncol & Radiat Oncol, Sacramento, CA 95816 USA. Oak Ridge Natl Lab, Chem & Biol Phys Sect, Oak Ridge, TN USA. Vet Adm No Calif Hlth Care Syst, Martinez, CA USA. RP Shen, S (reprint author), Univ Calif Davis, Radiodiag & Therapy Sect, Div Hematol Oncol & Radiat Oncol, 1508 Alhambra Blvd,Room 214, Sacramento, CA 95816 USA. FU NCI NIH HHS [CA47829] NR 27 TC 11 Z9 11 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 JUL PY 1998 VL 39 IS 7 BP 1223 EP 1229 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZZ059 UT WOS:000074691600026 PM 9669399 ER PT J AU Gaiser, EE Philippi, TE Taylor, BE AF Gaiser, EE Philippi, TE Taylor, BE TI Distribution of diatoms among intermittent ponds on the Atlantic Coastal Plain: development of a model to predict drought periodicity from surface-sediment assemblages SO JOURNAL OF PALEOLIMNOLOGY LA English DT Article DE diatoms; Carolina bays; paleolimnology; calibration set; non-metric multidimensional scaling; weighted-averaging ID COLUMBIA CANADA LAKES; SOUTH-CAROLINA; RECONSTRUCTION; REGRESSION; HYDROLOGY; PATTERNS; SALINITY; HISTORY; BAYS AB Inferences of past climate from the fossil record in lakes rely on the accurate quantification of a relationship of fossilizing organisms to their environment Whereas the relationship of diatoms to water chemistry parameters has been modeled in many systems, few studies adequately address the relationship of diatoms to physical properties, such as water depth or hydrology, that may be more directly tied to climate. We examined the composition of modern diatoms in surface sediments of 75 isolated ponds (mostly Carolina bays) of the Atlantic Coastal Plain to: (1) assess the influence of physical and chemical variables on the distribution of diatoms among ponds of the region, and (2) develop a model that predicts hydroperiod (a measure of pond permanence) from diatom assemblages. We constructed two hydroperiod calibration models: the first infers hydroperiod from the weighted-average optima and tolerances of taxa along the hydroperiod gradient, the second bases inferences on the hydroperiod estimates of compositionally similar samples. Both approaches incorporate a-priori and post-hoc tests of assumptions often inherent in the construction of transfer functions. Diatom assemblage composition had strong, approximately linear relationships to hydroperiod, water depth, and calcium concentration in non-metric multidimensional ordination space; effects of other variables, including pH, were non-linear or ambiguous. Overall, the assemblages reflected the dilute, acidic chemical characteristics of bays. The assemblages contained differing abundances of euterrestrial, benthic and planktonic taxa, depending on a pond's susceptibility to drying. A weighted-averaging regression model based on taxon-specific hydroperiod optima generated adequate, unbiased hydroperiod inferences from diatom species composition (r(2) = 0.81). This model may be used to infer past drought episodes from fossil diatom assemblages at appropriate sites on the Atlantic Coastal Plain. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Gaiser, EE (reprint author), Florida Int Univ, SE Environm Res Program, Miami, FL 33199 USA. NR 77 TC 30 Z9 31 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-2728 J9 J PALEOLIMNOL JI J. Paleolimn. PD JUL PY 1998 VL 20 IS 1 BP 71 EP 90 DI 10.1023/A:1007969500673 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Limnology SC Environmental Sciences & Ecology; Geology; Marine & Freshwater Biology GA 103BA UT WOS:000074959700006 ER PT J AU Santarius, JF Logan, BG AF Santarius, JF Logan, BG TI Generic magnetic fusion rocket model SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID SPACE PROPULSION; POWER; FUEL; HE-3 AB A generic magnetic fusion rocket model is developed and used to explore the limits of magnetic fusion propulsion systems. Two fusion fuels are examined, D-T and D-He-3, and the D-He-3 fuel cycle is predicted to give a higher specific power for optimized parameters. Other findings are that magnetic fusion should ultimately be able to deliver specific powers of similar to 10 kW/kg and that specific powers of 1-5 kW/kg should be achievable with only modest extrapolations of present technology. C1 Univ Wisconsin, Fus Technol Inst, Madison, WI 53706 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Santarius, JF (reprint author), Univ Wisconsin, Fus Technol Inst, 1500 Engn Dr, Madison, WI 53706 USA. NR 34 TC 9 Z9 9 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 1998 VL 14 IS 4 BP 519 EP 524 DI 10.2514/2.5308 PG 6 WC Engineering, Aerospace SC Engineering GA 100HK UT WOS:000074810600014 ER PT J AU Thode, LE Cline, MC Howe, SD AF Thode, LE Cline, MC Howe, SD TI Vortex formation and stability in a scaled gas-core nuclear rocket configuration SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 33rd Joint Propulsion Conference CY JUL 06-09, 1997 CL SEATTLE, WASHINGTON SP Amer Inst Aeronaut & Astronaut, ASME, SAE, ASEE AB Realistic interplanetary space exploration depends critically upon the development of a high-specific-impulse propulsion system. Previous studies indicate that the specific impulse of an open-cycle gas-core nuclear rocket (OCGCNR) might approach 3000 s, Although the OCGCNR is deceptively simple in concept, it will be difficult to develop in practice because the core is a uranium plasma that must be nearly totally confined. Before constructing a more comprehensive model for this engine, there is a requirement to understand the limits of present full-scale simulation models and recent scaled experiments. In this scoping study we have used a two-dimensional, axisymmetric, finite difference code to investigate the formation and stability of a recirculation region observed in a scaled experiment, It has been proposed that such a recirculation region, or vortex, might provide improved confinement of the uranium fuel. Our simulation results indicate that a more comprehensive model must treat the rocket nozzle in a self-consistent fashion to properly calculate the confinement of the uranium plasma. Under conditions that lead to vortex formation, the position of the vortex depends upon the inlet geometry and injection velocity, the nozzle position and subsonic convergence angle, the base-bleed injection rate, and turbulence. With a large base-bleed injection rate, a vortex forms but is then swept away through the nozzle, a result that resolves an inconsistency between a full-scale engine simulation model and recent scaled experiments. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Div, Los Alamos, NM 87544 USA. RP Thode, LE (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Div, POB 1663, Los Alamos, NM 87544 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JUL-AUG PY 1998 VL 14 IS 4 BP 530 EP 536 DI 10.2514/2.5310 PG 7 WC Engineering, Aerospace SC Engineering GA 100HK UT WOS:000074810600016 ER PT J AU Nash, TJ Sanford, TWL Deeney, C Spielman, RB Seaman, J McGurn, J Jobe, DO Mock, RC Gilliland, TL Apruzese, JP Whitney, KG AF Nash, TJ Sanford, TWL Deeney, C Spielman, RB Seaman, J McGurn, J Jobe, DO Mock, RC Gilliland, TL Apruzese, JP Whitney, KG TI High temperature, dense cores in an aluminum wire array z-pinches observed by spatially-resolved spectroscopy SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID X-RAY-EMISSION; LABORATORY PLASMAS; IMPLOSIONS AB We have observed a hot, dense plasma core from an aluminum wire-array z pinch on the accelerator Saturn. A spatially resolved and temporally integrated crystal spectrometer shows aluminum K-shell free-bound continuum emission to be localized to less than 1 mm in diameter and to have a slope indicating a 1.4 keV electron temperature. A keV-filtered temporally resolved pinhole camera corroborates the I mm diameter plasma and a filtered photoconducting detector shows the temporal FWHM of the 4 TW of Al K-shell emission to be 5 ns. Roughly half of the Al K-shell emissions are due to free-bound recombinations. The intensity of the free-bound continuum indicates a core electron density of 3e21/cc. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. USN, Res Lab, Washington, DC 20375 USA. RP Nash, TJ (reprint author), Sandia Natl Labs, MS 1194, Albuquerque, NM 87185 USA. NR 18 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 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL PY 1998 VL 60 IS 1 BP 97 EP 102 PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA ZM063 UT WOS:000073501000010 ER PT J AU Morton, JS Verwolf, MC Woolf, S AF Morton, JS Verwolf, MC Woolf, S TI The preparation and application of performance evaluation materials SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The Radiological and Environmental Sciences Laboratory administers three separate programs that include the use of prepared evaluation material to assess the performance of the participant laboratories. The performance materials include a simple liquid matrix to soil containing organic compounds to synthetic excreta containing known concentrations of radionuclides. The paper discusses the quality control associated with the preparation of these materials. The concept of synthetic-standard enhancement of a natural matrix is briefly discussed to demonstrate homogeneity. The use of verified standards and the assurance of homogeneity by preparation method and characterization are shown to be the necessary components of useful and accurate performance evaluation materials. Because each of the performance programs is tailored to the specific needs of the participants, a discussion of the acceptance criteria is also included. C1 US DOE, Radiol & Environm Sci Lab, Idaho Falls, ID 83402 USA. RP Morton, JS (reprint author), US DOE, Radiol & Environm Sci Lab, Idaho Falls, ID 83402 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 37 EP 41 DI 10.1007/BF02389644 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300007 ER PT J AU Wong, AS Marshall, RS AF Wong, AS Marshall, RS TI Radiometric measurements on non-destructive assay standards fabrication for WIPP Performance Demonstration Program SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The Inorganic Elemental Analysis Group of LANL has prepared several different sets of working reference materials (WRMs). These WRMs are prepared by blending quantities of nuclear materials (plutonium, americium, and enriched uranium) with diatomaceous earth. The blends are encapsulated in stainless steel cylinders. These WRMs are being measured as blind controls in neutron and gamma based non-destructive assay (NDA) instruments. Radiometric measurements on the blending homogeneity and verification on a set of sixty-three plutonium based WRMs are discussed in this paper. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wong, AS (reprint author), Univ Calif Los Alamos Natl Lab, MS G740, Los Alamos, NM 87545 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 43 EP 48 DI 10.1007/BF02389645 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300008 ER PT J AU Heath, RL AF Heath, RL TI Development of new expanded editions of the Gamma-ray Spectrum Catalogues in electronic format SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB A program has been developed at the INEL to produce new enhanced editions of the original Gamma-ray Spectrum Catalogues for presentation in electronic format. This program has produced the first version of the Catalogues in CD-ROM format and will offer them on the Internet through the Gamma-ray Spectrometry Center Web Site at INEEL. The original content of the Catalogues has been expanded to include integrated decay scheme drawings, tables of related decay data, and updated material on the techniques of gamma-ray spectrometry. All of the original spectral plots, gamma-ray energy and intensity data, and text were converted to digital format, related decay data from the Evaluated Nuclear Structure Data File (ENSDF) and decay scheme graphics were then added, and all data converted to the Adobe Acrobat (PDF) format. Follow-on versions of the catalogues are being expanded to include prompt neutron capture and n-n' spectra and spectra representing the response of large-volume Ge detectors. Large-volume Ge detector spectra will be calculated using Monte Carlo and parametric fitting techniques presently under development. Examples of content and details of the advanced technology applied to produce these new volumes will be presented. Services and content of the Gamma-ray Spectrometry Center Web Site will also be described. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Heath, RL (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 7 TC 2 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 81 EP 89 PG 9 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300014 ER PT J AU Hensley, WK Lepel, EA AF Hensley, WK Lepel, EA TI SYNTH: A new tool for estimating interferences in instrumental neutron activation analysis SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB SYNTH, a Windows(TM) based software package developed for generating synthetic gamma-ray spectra, has been updated and extended to include the ability to generate gamma-ray spectra resulting from neutron activation. Along with a new gamma-ray library (based on the NNDC PCNuDat compilation), and the best available neutron cross-sections, it is now possible to simply, and quickly predict the interference effects of different bulk and trace element compositions by generating a synthetic gamma-ray spectrum that will be representative of a specific set of input parameters. The parameters include, but are not limited to: elemental composition (bulk, and trace) of the sample; irradiation, decay, and count times; thermal, and resonance neutron flux; sample to detector distance; detector specifications; and electronics configuration. Using existing data reduction codes, it is then possible to generate Minimum Detectable Activities (MDA's) for other trace elements that you may wish to detect in this type of matrix. C1 Pacific NW Lab, Nucl Chem Sect, Richland, WA 99352 USA. RP Hensley, WK (reprint author), Pacific NW Lab, Nucl Chem Sect, POB 999, Richland, WA 99352 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 91 EP 94 DI 10.1007/BF02389652 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300015 ER PT J AU Gardner, RP Guo, P Sood, A Mayo, CW Gehrke, RJ Dobbs, CL AF Gardner, RP Guo, P Sood, A Mayo, CW Gehrke, RJ Dobbs, CL TI Monte Carlo aided treatments of the nonlinear inverse PGNAA measurement problem for various continuous on-line applications SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB A review of our work on the application of the PGNAA method as applied to five industrial applications is given. Some introductory material is first given on the importance and use of Monte Carlo simulation in this area, some comments on the place of PGNAA in elemental analysis, and a brief description of the Monte Carlo - Library Least-Squares (MCLLS) approach to the nonlinear inverse PGNAA analysis problem. Then the applications of PGNAA are discussed for: (1) on-line bulk coal analysis, (2) nuclear oil well logging, (3) vitrified waste, (4) the analysis of sodium and aluminum in "green liquor" in the presence of chlorine, and (5) the conveyor belt sorting of aluminum alloy samples. It is concluded that PGNAA is a rapidly emerging important new technology and measurement approach. C1 N Carolina State Univ, Ctr Engn Applicat Radioisotopes, Raleigh, NC 27695 USA. EG&G Idaho Inc, Idaho Natl Engn Lab, Idaho Falls, ID USA. ALCOA, Ctr Tech, Alcoa Center, PA USA. RP Gardner, RP (reprint author), N Carolina State Univ, Ctr Engn Applicat Radioisotopes, Raleigh, NC 27695 USA. NR 6 TC 3 Z9 3 U1 1 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 105 EP 107 DI 10.1007/BF02389655 PG 3 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300018 ER PT J AU Killian, EW East, LV AF Killian, EW East, LV TI PCGAP: Application to analyze gamma-ray pulse-height spectra on a personal computer under Windows NT (R) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB PCGAP is a software code, which was written to provide gamma-ray pulse height spectrum analysis on a personal computer platform. The code was specifically developed for Windows NT for either an Intel(R) or DEC Alpha(R) based processor. PCGAP includes programs which can be used to control data collection using a Canberra INSPECTOR(R) multichannel pulse-height analyzer. With suitable spectrum conversion routines PCGAP can be used to analyze data from almost any multi-channel analyzer. Besides the normal functions associated with a robust spectrum analysis package, PCGAP can be used for radionuclide analysis for actinides via LX and gamma-ray spectrometry. It can be used to control and analyze data from an INEEL developed pulse injection system for individual spectrum validation. The package includes programs for the manual analysis of spectra using displays which permit the spectroscopist to interactively define the spectral continuum and peak fitting limits, and display the resulting function fitting forms. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Killian, EW (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. NR 4 TC 13 Z9 13 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 109 EP 114 DI 10.1007/BF02389656 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300019 ER PT J AU Aalseth, CE Avignone, FT Brodzinski, RL Miley, HS Reeves, JH AF Aalseth, CE Avignone, FT Brodzinski, RL Miley, HS Reeves, JH TI Using pulse shape discrimination to sort individual energy deposition events in a germanium crystal SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol ID DETECTORS AB A fast digital oscilloscope based pulse shape discrimination (PSD) system has been tested with intrinsic germanium detectors large enough to allow ionizing events which generate localized electron-hole pairs at a single site to be segregated from those depositing energy at several different sites in the crystal. Drift velocities of the electrons and holes result in pulses several hundred nanoseconds long. Since the electric field varies by almost a factor of 10 between the outer and inner surfaces, collection of electrons and holes can frequently be distinguished, and pulses due to multi-site events can be distinguished from single site events. C1 Univ S Carolina, Columbia, SC 29208 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Aalseth, CE (reprint author), Univ S Carolina, Columbia, SC 29208 USA. NR 7 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 119 EP 123 DI 10.1007/BF02389658 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300021 ER PT J AU Giles, JR Dooley, KJ AF Giles, JR Dooley, KJ TI High resolution gamma-spectroscopy well logging system SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries were modeled using commercially available shielding software and correction factors were developed based on relative gamma-ray fluence rates. Examination of varying porosity and moisture content showed that as porosity increases, and as the formation saturation ratio decreases, relative gamma-ray fluence rates increase linearly for all energies. Correction factors for iron and water cylindrical shields were found to agree well with correction factors determined during previous studies allowing for the development of correction factors for type-304 stainless steel and low-carbon steel casings. Regression analyses of correction factor data produced equations for determining correction factors applicable to spectral gamma-ray well logs acquired under non-standard borehole conditions. C1 Lockheed Martin Idaho Technol Co, Idaho Falls, ID USA. RP Giles, JR (reprint author), Lockheed Martin Idaho Technol Co, Idaho Falls, ID USA. NR 15 TC 1 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 125 EP 130 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300022 ER PT J AU Brodzinski, RL Penswick, LB AF Brodzinski, RL Penswick, LB TI A miniature stirling cycle cooler for radiation detectors SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB Germanium spectrometers must be operated at liquid nitrogen temperatures. Other detectors operate better when cooled. Many applications, because of hostile environments, inaccessibility, remote location, long duration, etc., are compromised, or totally precluded, by the requirement for liquid nitrogen. A Stirling cycle refrigerator based on a linear motor design, which is acoustically and vibrationally quiet, does not require secondary cooling, and operates unattended for years, is under development. System design and specifications are presented. Applications to cooled laser monitoring equipment, SQUID-based detection systems, environmental cleanup and monitoring, medical diagnostics, non-destructive resting systems, communication equipment, computer electronics, and imaging systems are discussed. C1 Pacific NW Lab, Richland, WA 99352 USA. Stirling Technol Co, Kennewick, WA 99336 USA. RP Brodzinski, RL (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 131 EP 135 DI 10.1007/BF02389660 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300023 ER PT J AU Koskelo, MJ Woodward, GH Gehrke, RJ Hoggan, JM McLaughlin, GD AF Koskelo, MJ Woodward, GH Gehrke, RJ Hoggan, JM McLaughlin, GD TI Performance testing of two dual-energy pulsers SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The Idaho National Engineering Laboratory (INEL) has been developing a dual energy pulser for dead time and random summing corrections, and for the assessment of the quality of the data for many years. This effort now includes several revisions of the original concept. Recently, Canberra has developed a version of this dual energy pulser as part of a technology transfer from INEL to Canberra Industries. This new design includes many of the same characteristics as the original INEL design. In this paper, we will present the results of a series of tests performed at INEL with both the latest INEL pulser design and the Canberra design. These test results include measurement results of pulser peak width, energy equivalence and dead rime and random summing correction capability as a function of count rate and temperature. It is demonstrated that both designs perform comparably with count rate and temperature when operated over a limited temperature range. In applications where extreme temperature variations are likely during the measurements, the INEL design is the better choice. C1 Canberra Ind, Meriden, CT 06450 USA. Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Koskelo, MJ (reprint author), Canberra Ind, Meriden, CT 06450 USA. NR 9 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 137 EP 141 DI 10.1007/BF02389661 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300024 ER PT J AU Bowers, DL Rhodes, EA Dickerman, CE AF Bowers, DL Rhodes, EA Dickerman, CE TI A switchable radioactive neutron source: Proof-of-principle SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The feasibility of a practical switchable radioactive neutron source (SRNS) that can be switched on and off like an accelerator and is field portable has been demonstrated. A stable, thin film of Pu-238 oxide deposited on a stainless steel planchet was the alpha source and beryllium was the light element target that produced neutrons. This device requires minimal, if any, shielding when not in use. Design specifications and performance of this proof-in-principle instrument are discussed. C1 Argonne Natl Lab, Div Chem Technol, Analyt Chem Lab, Argonne, IL 60439 USA. Argonne Natl Lab, Reactor Engn Div, Argonne, IL 60439 USA. RP Bowers, DL (reprint author), Argonne Natl Lab, Div Chem Technol, Analyt Chem Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 161 EP 165 DI 10.1007/BF02389665 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300028 ER PT J AU Lepel, EA Brodzinski, RL Kohli, R Reeves, JH AF Lepel, EA Brodzinski, RL Kohli, R Reeves, JH TI A flexible, self-contained germanium spectrometer for the in-situ measurement of gamma-ray emitting radionuclides in and around piping SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB In order to certify that process and drain lines which had been used for transporting radioactive materials, and their surrounding environments, are now free of residual contamination, it is both desirable and cost effective to make in situ measurements during the decontamination and decommissioning process. A 4.83-cm diameter modular probe consisting of a liquid nitrogen reservoir, a preamplifier, and a high-resolution germanium gamma-ray spectrometer with flexible connections between the modules has been developed for the measurement of gamma rays in and around piping. The assembly is sufficiently flexible to navigate through a "3-inch diameter p-trap." The probe design and specifications are discussed. Results from an application are presented. C1 Pacific NW Lab, Richland, WA 99352 USA. Battelle Mem Inst, Columbus Labs, Columbus, OH 43201 USA. RP Lepel, EA (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 173 EP 176 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300030 ER PT J AU Lund, JC Hilton, NR McKisson, JE Van Scyoc, JM Brunett, BA Hermon, H James, RB AF Lund, JC Hilton, NR McKisson, JE Van Scyoc, JM Brunett, BA Hermon, H James, RB TI Gamma-ray imaging and spectroscopy system using room-temperature semiconductor detector elements SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB We report on the design, construction, and testing of a gamma-ray imaging system with spectroscopic capabilities. The imaging system consists of an orthogonal strip detector made from either HgI2 or CdZnTe crystals. The detectors utilize an 8x8 orthogonal strip configuration with 64 effective pixels. Both HgI2 or CdZnTe detectors are 1 cm(2) devices with a strip pitch of approximately 1.2 mm (producing pixels of 1.2 mm x x 1.2 mm). The readout electronics consist of parallel channels of preamplifier, shaping amplifier, discriminators, and peak sensing ADC. The preamplifiers are configured in hybrid technology, and the rest of the electronics are implemented in NIM and CAMAC with control via a Power Macintosh computer. The software used to readout the instrument is capable of performing intensity measurements as well as spectroscopy on all 64 pixels of the device. We report on the performance of the system imaging gamma-rays in the 20-500 keV energy range and using a pin-hole collimator to form the image. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Arizona, Tucson, AZ 85724 USA. RTI Inc, Alachua, FL 32615 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RP Lund, JC (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. EM jlund@sandia.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 177 EP 183 DI 10.1007/BF02389668 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300031 ER PT J AU McDonald, RJ Smith, AR Hurley, DL Norman, EB AF McDonald, RJ Smith, AR Hurley, DL Norman, EB TI Low-level measurement of alpha-particle emitting nuclei in ceramics and lead SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB Nearly all natural materials contain trace quantities of uranium (U) and thorium (Th) and their daughter nuclides, many of which emit alpha-particles in their decay. Lead, at the end of the U-decay chain, typically contains some radioactive Pb-210 which is chemically inseparable from the other Pb isotopes, alpha-particle emission from these decays can affect sensitive electronic components, such as memory chips or processors. Measurement of alpha-particle emitters can be accomplished by direct detection of the alpha-particles (which typically provides no positive identification of the emitting isotope because of energy loss in the sample) or by low-background gamma-ray spectroscopy (which does provide positive identification via characteristic gamma-rays.) The latter is by far the best method for screening kg-sized samples of materials like ceramics, aluminum, iron, or copper. The difference between alpha counting and gamma-ray spectroscopy is less for measuring Pb-210 in Pb since the 46.5 keV characteristic gamma-rays directly following the Pb-210 decay are strongly absorbed and both methods are limited to thin layers. This paper discusses these two cases and concludes that a large n-type germanium gamma-ray spectrometer is probably the best overall system for both measurements. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP McDonald, RJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd,MS 72-150, Berkeley, CA 94720 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 185 EP 189 DI 10.1007/BF02389669 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300032 ER PT J AU McDonald, RJ Smith, AR Hurley, DL Norman, EB Schoonover, MR AF McDonald, RJ Smith, AR Hurley, DL Norman, EB Schoonover, MR TI Rapid detailed characterization of concrete shielding blocks utilizing internal natural radionuclides for calibration SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB Following many years of productive research, the 184-inch Cyclotron, the SuperHILAC, and the BEVALAC accelerators at the Berkeley Laboratory were closed, leaving thousands of concrete shielding blocks available for reuse, recycling, or disposal. The process history of these blocks precludes free release pending radiological characterization. This paper describes a procedure whereby a high efficiency shielded germanium spectrometer is used to rapidly characterize natural and man-made activity within the blocks. The spectrometer is moved up to the block and 5 minutes of data are collected at the point on the block that registers highest on a micro-R meter. Sensitivity is better than 1 pCi/g (0.037 Bq/g) for Co-60 and Eu-152, the prominent man-made activities observed. One-time calibration of the detector system is obtained from a sample of concrete, drilled with a hammer drill, counted in our low-background facility, and compared to crushed rock with known U, Th, and K activity. A simple relationship exists between the counts/minute observed in a characteristic gamma-ray peak and the activity in the block. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Hlth & Safety Div, Berkeley, CA 94720 USA. RP McDonald, RJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 191 EP 194 DI 10.1007/BF02389670 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300033 ER PT J AU Brodzinski, RL Hensley, WK Lepel, EA Smith, MR AF Brodzinski, RL Hensley, WK Lepel, EA Smith, MR TI Detecting Cs-137 breakthrough in an ion exchange process SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB High-level radioactive wastes can be transformed to low-level wastes by removing Cs-137 through selective ion exchange processes. Since the short-lived daughter, Ba-137m produces the 662-keV gamma-ray normally attributed to Cs-137, equilibrium may be broken, and observation of the 662-keV gamma-ray cannot be used to detect cesium breakthrough. Two detectors viewing the output line, but separated sufficiently to measure the Ba-137m decay between them, are used to detect Cs-137 breakthrough based on deviation from the normal Ba-137m decay. Detectors evaluated for the process, separation time, counting time, fractional breakthrough detectable, and accuracy and confidence of the measurements are discussed. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Brodzinski, RL (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 207 EP 210 DI 10.1007/BF02389673 PG 4 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300036 ER PT J AU Lepel, EA Geelhood, BD Hensley, WK Quam, WM AF Lepel, EA Geelhood, BD Hensley, WK Quam, WM TI A field-deployable, aircraft-mounted sensor for the environmental survey of radionuclides SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB The Environmental Radionuclide Sensor System (ERSS)(3) is an extremely sensitive sensor, which has been cooperatively developed by Pacific Northwest National Laboratory (PNNL) and Special Technologies Laboratory (STL) for environmental surveys of radionuclides. The ERSS sensors fit in an airborne pod and include twenty High-Purity Germanium (HPGe) detectors for the high-resolution measurement of gamma-ray emitting radionuclides, twenty-four He-3 detectors for possible neutron measurements, and two video cameras for visual correlation. These aerial HPGe sensors provide much better gamma-ray energy resolution than can be obtained with NaI(TI) detectors. The associated electronics fit into three racks. The system can be powered by the 28 V DC electrical supply of typical aircraft or 120 V AC. The data acquisition hardware is controlled by customized software and a real-time display is provided. Each gamma-ray event is time stamped and stored for later analysis. This paper will present the physical design, discuss the software used to control the system, and provide some examples of its use. C1 Pacific NW Lab, Richland, WA 99352 USA. Special Technol Lab, Santa Barbara, CA 93111 USA. RP Lepel, EA (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 1 TC 5 Z9 6 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 211 EP 215 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300037 ER PT J AU Gehrke, RJ Killian, EW East, LV Hoggan, JM Goodwin, SG McLaughlin, GD AF Gehrke, RJ Killian, EW East, LV Hoggan, JM Goodwin, SG McLaughlin, GD TI A portable, photon analysis spectrometer for the assay of X- and gamma-ray emitting radionuclides SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB A portable, battery-powered, multichannel analyzer (MCA) for use with Ge spectrometers has been developed for in-field use for the assay of x- and gamma-ray emitting radionuclides. The spectrometer is capable of operating to rates greater than 150,000 counts per second. The analyzer is a Canberra InSpector MCA, that is equipped with the INEEL ultra-stable dual-energy pulser, and pulse injection with subsequent removal (PISR) circuitry. PCGAP, a set of MCA control and spectral analysis programs, was developed for use on a PC with a Windows NT Operating System. It includes an interactive peak analysis program as well as automatic spectral analysis programs for the X- and gamma-ray regions, and a number of utility programs. The pulser peaks are calibrated with radioactive sources in terms of energy (i.e., their energy equivalents are measured) using the PCGAP spectral analysis package so that energy shifts, including those due to changes in temperature or count rate, do not cause a loss of energy calibration. The number of injected low- and high-energy-equivalent pulses is known so the stored pulser pulses can be used for a dead-time and random summing correction. The pulser peaks are also used to monitor any deterioration in spectral quality caused by noise, ground loops, etc. The results of performance tests to demonstrate the capabilities of this pulser-equipped InSpector are reported. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Gehrke, RJ (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 225 EP 231 DI 10.1007/BF02389676 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300039 ER PT J AU Prettyman, TH Cooper, CS Luke, PN Russo, PA Amman, M Mercer, DJ AF Prettyman, TH Cooper, CS Luke, PN Russo, PA Amman, M Mercer, DJ TI Physics-based generation of gamma-ray response functions for CdZnTe detectors SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol ID RADIATION DETECTORS; CD1-XZNXTE AB A physics-based approach to gamma-ray response-function generation is presented in which the response of CdZnTe detectors is modeled from first principles. Numerical modeling is used to generate response functions needed for spectrum analysis for general detector configurations (e.g., electrode design, detector materials and geometry, and operating conditions). With numerical modeling, requirements for calibration and characterization are significantly reduced. Elements of the physics-based model, including gamma-ray transport, charge carrier drift and diffusion, and circuit response, are presented. Calculated and experimental gamma-ray spectra are compared for a coplanar-grid CdZnTe detector. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. RP Prettyman, TH (reprint author), Univ Calif Los Alamos Natl Lab, NIS-5 MS E540, Los Alamos, NM 87545 USA. OI Prettyman, Thomas/0000-0003-0072-2831 NR 12 TC 10 Z9 10 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 257 EP 264 DI 10.1007/BF02389681 PG 8 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300044 ER PT J AU Ebara, SB Enghauser, MW AF Ebara, SB Enghauser, MW TI Quantitative portable gamma-spectroscopy sample analysis for non-standard sample geometries SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 4th International Conference on Methods and Applications of Radioanalytical Chemistry CY APR 06-11, 1997 CL KAILUA KONA, HAWAII SP Amer Nucl Soc, Isotopes & Radiat Div, Amer Nucl Soc, Biol & Med Div, Canadian Nucl Soc, Amer Chem Soc, Div Nucl Chem & Technol AB Utilizing a portable spectroscopy system, a quantitative method for analysis of samples containing a mixture of fission and activation products in nonstandard geometries was developed. This method was not developed to replace other methods such as Monte Carlo or Discrete Ordinates but rather to offer an alternative rapid solution. The method can be used with various sample and shielding configurations where analysis on a laboratory based gamma-spectroscopy system is impractical. The portable gamma-spectroscopy method involves calibration of the detector and modeling of the sample and shielding to identify and quantify the radionuclides present in the sample. The method utilizes the intrinsic efficiency of the detector and the unattenuated gamma fluence rate at the detector surface per unit activity from the sample to calculate the nuclide activity and Minimum Detectable Activity (MDA). For a complex geometry, a computer code written for shielding applications (MICROSHIELD) is utilized to determine the unattenuated gamma fluence rate per unit activity at the detector surface. Lastly, the method is only applicable to nuclides which emit gamma-rays and cannot be used for pure beta or alpha emitters. In addition, if sample self absorption and shielding is significant, the attenuation will result in high MDA's for nuclides which solely emit low energy gamma-rays. The following presents the analysis technique and presents verification results using actual experimental data, rather than comparisons to other approximations such as Monte Carlo techniques, to demonstrate the accuracy of the method given a known geometry and source term. C1 Sandia Natl Labs, Personal Monitoring & Lab Serv, Radiat Protect Sample Diagnost, Albuquerque, NM 87185 USA. Sci Applicat Int Corp, Las Vegas, NV 89134 USA. RP Ebara, SB (reprint author), Sandia Natl Labs, Personal Monitoring & Lab Serv, Radiat Protect Sample Diagnost, POB 5800,MS 0651, Albuquerque, NM 87185 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1998 VL 233 IS 1-2 BP 273 EP 279 DI 10.1007/BF02389683 PG 7 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 106BR UT WOS:000075110300046 ER PT J AU Dimonte, G Nelson, D Weaver, S Schneider, M Flower-Maudlin, E Gore, R Baumgardner, JR Sahota, MS AF Dimonte, G Nelson, D Weaver, S Schneider, M Flower-Maudlin, E Gore, R Baumgardner, JR Sahota, MS TI Comparative study of viscoelastic properties using virgin yogurt SO JOURNAL OF RHEOLOGY LA English DT Article ID YIELD STRESS; FLOW PROPERTIES; BEHAVIOR; FOODS AB (W)e describe six different tests used to obtain a consistent set of viscoelastic properties for yogurt. Prior to yield, the shear modulus mu and viscosity eta are measured nondestructively using the speed and damping of elastic waves. Although new to foodstuff's, this technique has been applied to diverse materials from metals to the earth's crust. The resultant shear modulus agrees with mu similar to E/3 for incompressible materials, where the Young's modulus E is obtained from a stress-strain curve in compression. The tensile yield stress tau(o) is measured in compression and tension, with good agreement. The conventional vane and cone/plate rheometers measured a shear stress yield tau(os) similar to tau(o)/root 3 as expected theoretically, but the inferred "apparent" viscosity from the cone/plate rheometer is much larger than the wave measurement due to the finite yield (tau(os) not equal 0). Finally, we inverted an open container of yogurt for 10(6) s much greater than eta/mu and observed no motion. This demonstrates unequivocally that yogurt possesses a finite yield stress rather than a large viscosity. We present a constitutive model with a pre-yield viscosity to describe the damping of the elastic waves and use a simulation code to describe yielding in complex geometry. (C) 1998 The Society of Rheology. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Dimonte, G (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 40 TC 12 Z9 13 U1 2 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0148-6055 J9 J RHEOL JI J. Rheol. PD JUL-AUG PY 1998 VL 42 IS 4 BP 727 EP 742 DI 10.1122/1.550915 PG 16 WC Mechanics SC Mechanics GA ZY213 UT WOS:000074597600002 ER PT J AU Woodward, PM Vogt, T AF Woodward, PM Vogt, T TI Electronic band structure calculations of the MNX (M = Zr, Ti; X = Cl, Br, I) system and its superconducting member, Li-doped beta-ZrNCl SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE extended Huckel calculations; electronic band structure; nitride halides; superconductivity AB Electronic band structure calculations have been performed for beta-ZrNCl, beta-ZrNBr, alpha-ZrNBr, alpha-ZrNl, and alpha-TiNX (X = Cl, Br, I) using the extended Huckel method. These calculations reveal that n-doped beta-ZrNCl has a single narrow band at the Fermi level which is stabilized by overlap of 4dz(2) orbitals on zirconium with respect to the remainder of the conduction band states, This band shows only a small degree of dispersion and can essentially be described as a localized Zr-Zr bond when the carrier concentrations are low. The calculated band structure is consistent with the experimental observations of activated carrier transport, and an indirect optical band gap in beta-ZrNCl and beta-ZrNBr, A simple picture is presented which describes a mechanism for strong electron-phonon coupling in the beta-ZrNX structure, suggesting that beta-LixZrNCl is a classical BCS superconductor. This localized 4dz(2) band at the Fermi level is absent in the electronic band structures of alpha-ZrNX and alpha-TiNX compounds. The dispersion relations for these compounds show a direct optical band gap, as observed experimentally. The absence of significant metal-metal bonding in alpha-MNX compounds implies that n-doping will be more difficult to achieve in compounds adopting this structure. The relative stability of alpha- and beta-polymorphs is also discussed. (C) 1998 Academic Press. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Woodward, PM (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 22 TC 21 Z9 21 U1 0 U2 7 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1998 VL 138 IS 2 BP 207 EP 219 DI 10.1006/jssc.1997.7601 PG 13 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 110FM UT WOS:000075369600004 ER PT J AU Woodward, P Vogt, T AF Woodward, P Vogt, T TI Structure of Sn(ND3)(2)F-4 - A molecular precursor for the synthesis of nitride fluorides SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE synthesis; nitride fluorides; crystal structures; neutron diffraction; infrared spectroscopy; Huckel calculations ID VERNIER AB The molecular and crystal structure of Sn(ND3)(2)F-4 has been determined at room temperature using high resolution neutron powder diffraction. The compound crystallizes in a monoclinic unit cell containing two formula units with a = 7.7673(7) Angstrom, b = 6.2765(5) Angstrom, c = 5.1708(4) Angstrom, beta = 102.871(5) degrees, and space-group P2(1)/n. The structure consists of isolated tin-centered octahedra with ammonia groups in trans configuration. The intramolecular stability of this compound has been investigated using Huckel molecular orbital calculations. Compared to Si(NH3)(2)F-4, the metal-nitrogen bonding interaction is found to be stronger, while the metal-fluorine bond is weaker in Sn(ND3)(2)F-4. Due to a different hydrogen bonding network the intermolecular orientation and packing of the octahedral M(NH3)(2)F-4 molecules in Sn(ND3)(2)F-4 is different from the arrangement observed in Si(NH3)(2)F-4. The implications for the use of these compounds as molecular precursors for the synthesis of SiNF and SnNF are discussed. (C) 1998 Academic Press. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tubingen, Inst Anorgan Chem, D-72076 Tubingen, Germany. RP Vogt, T (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 24 TC 7 Z9 7 U1 2 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1998 VL 138 IS 2 BP 350 EP 360 DI 10.1006/jssc.1997.7545 PG 11 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 110FM UT WOS:000075369600025 ER PT J AU Seront, B Wong, TF Caine, JS Forster, CB Bruhn, RL Fredrich, JT AF Seront, B Wong, TF Caine, JS Forster, CB Bruhn, RL Fredrich, JT TI Laboratory characterization of hydromechanical properties of a seismogenic normal fault system SO JOURNAL OF STRUCTURAL GEOLOGY LA English DT Article ID HYDROTHERMAL ALTERATION; PRESSURE; PERMEABILITY; ZONES; EARTHQUAKES; NEVADA; STRESS; ROCKS AB The Stillwater seismogenic normal fault in Dixie Valley. Nevada has been historically active and is located in an al ea of high heat flow and hydrothermal activity. Three primary structural elements are identified in the fault zone: a relatively wide fault core (with breccia pods embedded in cataclasites), a damage zone (with arrays of mesoscopic fractures), and protolith. Hydromechanical properties of representative core samples were characterized in the laboratory. and microstructural analyses were conducted using optical and scanning electron microscopy. When deformed in conventional triaxial compression, dilatancy and brittle fracture were observed in each sample. Samples from the core of the fault were relatively weak, with strengths similar to that of unconsolidated fault gouge, whereas granodiorite samples from the protolith were as weak as the core and damage zone samples were stronger. Permeability is dependent on effective pressure, porosity and connectivity of the pore space, with values ranging over four orders of magnitude among the core samples. The lowest permeability of 3 x 10(-20) m(2) was measured in a fault core sample with a microstructure indicative of implosion brecciation. In conjunction with field measurements. the laboratory data suggest that fluid How and changes in fluid storage are concentrated in the damage zone, with permeability several orders of magnitude higher than the protolith and fault core. Permeability contrast tone order of magnitude) at the core sample scale exists between the cataclasite and implosion breccia in the fault core. Because of dilatancy and poor drainage in the breccia pods, anomalously low pore pressures may develop in localized clusters due to dilatancy hardening during the preseismic period. These clusters of low pore pressure can act similarly to fault jogs, locally inhibiting fault rupture and inducing brecciation when the delayed failure finally occurs by catastrophic implosion. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Utah, Dept Geol & Geophys, Salt Lake City, UT 84112 USA. Sandia Natl Labs, Geomech Dept, Albuquerque, NM 87185 USA. RP Seront, B (reprint author), SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. OI Caine, Jonathan/0000-0002-7269-6989 NR 33 TC 71 Z9 72 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-8141 J9 J STRUCT GEOL JI J. Struct. Geol. PD JUL PY 1998 VL 20 IS 7 BP 865 EP 881 DI 10.1016/S0191-8141(98)00023-6 PG 17 WC Geosciences, Multidisciplinary SC Geology GA 109BE UT WOS:000075300700004 ER PT J AU Mochizuki, T Sakurai, Y Shu, D Kuzay, TM Kitamura, H AF Mochizuki, T Sakurai, Y Shu, D Kuzay, TM Kitamura, H TI Design of compact absorbers for high-heat-load X-ray undulator beamlines at SPring-8 SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE undulator beamlines; front ends; high-heat-load components; absorbers AB A compact and high-heat-load absorber for the SPring-8 X-ray undulator beamline has been developed and installed. It consists of an upper heat-absorber part and a lower photon duct part, which are configured together in a water-cooled GlidCop body. The absorber part has a horizontal notch shape and the photon duct part forms a rectangular open channel under the absorber part. Two types of absorber are designed: one, with wire mesh channels, is 386 mm long, 70 mm high and 64 mm wide; the other, with smooth-bore channels, is 610 mm long, 75 mm high and 70 mm wide. Thermal and stress analyses show that they withstand the 12.3 kW heat load and the maximum heat flux of 940 W mm(-2) at normal incidence. C1 JASRI, Kamigori, Hyogo 67812, Japan. RIKEN, Kamigori, Hyogo 67812, Japan. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Mochizuki, T (reprint author), JASRI, Kamigori, Hyogo 67812, Japan. NR 2 TC 12 Z9 12 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JUL 1 PY 1998 VL 5 BP 1199 EP 1201 DI 10.1107/S0909049598000387 PN 4 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 105ZP UT WOS:000075105500003 PM 16687820 ER PT J AU Zhang, K Rosenbaum, G Bunker, G AF Zhang, K Rosenbaum, G Bunker, G TI Energy-resolving X-ray fluorescence detection using synthetic multilayers SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE fluorescence detectors; X-ray absorption spectroscopy; synthetic multilayers ID ARRAY; EXAFS AB The potential of synthetic multilayers for energy-resolving the X-ray fluorescence in X-ray absorption fine structure (XAFS) experiments is discussed. Two detection systems, one using curved multilayers and the other using graded multilayers to select X-ray fluorescence photons, have been designed to cover a wide energy range with a usefully large solid angle. Such a detector will be more advantageous than the barrel-like crystal-array detector because of the unique properties of synthetic multilayers, such as larger horizontal acceptance angles and bandwidth. In addition, the detector should be much simpler to construct and readily accommodates energy changes, especially the detector using graded multilayers. Comparison of the multilayer array detector with conventional detectors, such as ionization chambers and conventional 13-element Ge detectors, shows that the proposed system will be superior, particularly with the increased photon fluxes available from insertion devices and with decreased sample concentration, since this detection system eliminates the 'bad' photons before they enter any X-ray detector. Consequently, the X-ray detector proper for this system does not suffer from the incident-count-rate bottleneck common to current X-ray fluorescence detectors with energy resolution by signal processing. Thus, this new fluorescence detection system will provide tremendous opportunities for XAFS measurements on dilute systems, such as biological systems, at third-generation synchrotron sources. C1 IIT, Dept Biol Chem & Phys Sci, Chicago, IL 60616 USA. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP Zhang, K (reprint author), IIT, Dept Biol Chem & Phys Sci, Chicago, IL 60616 USA. EM ke@biocat1.iit.edu RI ID, BioCAT/D-2459-2012 NR 15 TC 15 Z9 15 U1 0 U2 5 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JUL 1 PY 1998 VL 5 BP 1227 EP 1234 DI 10.1107/S0909049597019535 PN 4 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 105ZP UT WOS:000075105500009 PM 16687826 ER PT J AU Friedersdorf, FJ Holcomb, GR AF Friedersdorf, FJ Holcomb, GR TI Pin-on-disk corrosion-wear test SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE wear; abrasion; corrosion; pin-on-disk; tool steel; stainless steel; low-alloy steel; sulfuric acid; sodium sulfate; potentiodynamic scan; testing ID STAINLESS-STEEL AB An electrochemical pin-on-disk corrosion-wear apparatus was developed at the Albany Research Center of the U.S. Department of Energy. The instrument was qualified on a low-alloy T1 tool steel [ASTM A 514] and a 304 stainless steel (Type 304). The apparatus incorporates simple specimen and counterface geometry and is instrumented for simultaneous corrosion and wear testing. The electrochemical and wear parameters of potential, current, charge, sliding speed, frictional force, and normal acceleration can be continuously displayed and recorded. After a break-in period, the electrochemical pin-on-disk produced constant wear rates independent of path length for both ASTM A 514 steel and 304 stainless steel. Results for 304 stainless steel in sulfate solutions show that abrasive wear causes the corrosion potential to shift by 0.4 V in the active direction and the passive current density to increase by three orders of magnitude, compared with the condition of no wear. Current density was a linear function of the sliding speed at a constant applied anodic potential. The open circuit corrosion potential exhibits a decay function behavior with respect to the sliding speed. Volume loss and corrosion measurements showed that mechanical removal of material was responsible for 95% of the corrosion-wear losses for 304 stainless steel. Continual corrosion exposure, however, increased the mechanical removal of material by 35 to 48%. C1 US Dept Energy, Albany Res Ctr, Albany, OR USA. RP Friedersdorf, FJ (reprint author), Bethlehem Steel Corp, Homer Res Labs, Bethlehem, PA 18016 USA. RI Holcomb, Gordon/G-9070-2013 OI Holcomb, Gordon/0000-0003-3542-5319 NR 15 TC 1 Z9 1 U1 0 U2 3 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JUL PY 1998 VL 26 IS 4 BP 352 EP 357 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 102DH UT WOS:000074907700008 ER PT J AU Landes, JD Brown, K AF Landes, JD Brown, K TI Results from a round robin on a standard method for measurement of fracture toughness SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE fracture toughness; test standard; common method; round robin; procedure verification AB A paper round robin was conducted to evaluate the workability and reproducibility of a unified draft fracture toughness test standard titled "Standard Method for Measurement of Fracture Toughness." The paper round robin consisted of 19 records from fracture toughness tests conducted separately from this round-robin exercise. These test records were given to the participants with the requirement that they use the draft standard to evaluate the fracture toughness values from the tests. The round robin was conducted between February 1991 and June 1992. Originally more than 30 organizations were invited to participate; however, only five finally responded with complete analyses of all of the test records. The five participants were all experienced in fracture testing and analyses. To subject the method to an evaluation by persons with less experience, some of the test records were analyzed by graduate students whose only experience with fracture testing and analyses was a course on fracture mechanics. The round robin was conducted on Draft 10 of the proposed standard: "Standard Method for Measurement of Fracture Toughness." This paper contains a brief description of the draft test method, a discussion of the specimens and test records supplied, a brief summary of results, and a discussion of the changes made to the test method as a result of the round-robin exercise. All tests and analyses were conducted using English units; therefore, to accurately transmit the results, English rather than SI are used as the primary units of this paper. C1 Univ Tennessee, Knoxville, TN 37996 USA. Sandia Natl Labs, Mat & Struct Mech Dept, Albuquerque, NM 87185 USA. RP Landes, JD (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JUL PY 1998 VL 26 IS 4 BP 396 EP 403 PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA 102DH UT WOS:000074907700015 ER PT J AU Adeff, JA Hofler, TJ Atchley, AA Moss, WC AF Adeff, JA Hofler, TJ Atchley, AA Moss, WC TI Measurements with reticulated vitreous carbon stacks in thermoacoustic prime movers and refrigerators SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Reticulated vitreous carbon has been successfully used as a stack material in thermoacoustic prime movers and refrigerators. It is a rigid glassy carbon material, with a porous spongelike structure. Test results indicate peak pressure amplitudes of up to 32% in a prime mover, and refrigeration performance comparable to that of a traditional plastic roll stack. (C) 1998 Acoustical Society of America. [S0001-4966(98)05505-2]. C1 USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Adeff, JA (reprint author), USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. NR 10 TC 29 Z9 32 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUL PY 1998 VL 104 IS 1 BP 32 EP 38 DI 10.1121/1.424055 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZY164 UT WOS:000074592700004 ER PT J AU Candy, JV Sullivan, EJ AF Candy, JV Sullivan, EJ TI Broadband model-based processing for shallow ocean environments SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DOMAIN SIGNAL TRANSMISSION; SOURCE LOCALIZATION; TIME-DOMAIN; WAVE-GUIDE; SOURCE LOCATION; TRANSIENT; WATER AB Most acoustic sources found in the ocean environment are spatially complex and broadband, In the case of shallow water propagation, these source characteristics complicate the analysis of received acoustic data considerably. A common approach to the broadband problem is to decompose the received signal into a set of narrow-band lines. This then allows the problem to be treated as a multiplicity of narrow-band problems. Here a model-based approach is developed for the processing of data received on a vertical array from a broadband source where it is assumed that the propagation is governed by the normal-mode model. The goal of the processor is to provide an enhanced (filtered) version of the pressure at the array and the modal functions. Thus a pre-processor is actually developed, since one could think of several applications for these enhanced quantities such as localization, modal estimation, etc. It is well-known that in normal-mode theory a different modal structure evolves for each temporal frequency; thus it is not surprising that the model-based solution to this problem results in a scheme that requires a "bank" of narrow-band model-based processors-each with its own underlying modal structure for the narrow frequency band it operates over. The "optimal" Bayesian solution to the broadband pressure field enhancement and modal function extraction problem is developed. It is shown how this broadband processor can be implemented (using a suboptimal scheme) in pseudo real time due to its inherent parallel structure. A set of noisy broadband data is synthesized to demonstrate how to construct the processor and achieve a minimum variance (optimal Bayesian) design. It is shown that both broadband pressure-field and modal function estimates can be extracted illustrating the feasibility of this approach. (C) 1998 Acoustical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Candy, JV (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-156, Livermore, CA 94550 USA. NR 31 TC 5 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUL PY 1998 VL 104 IS 1 BP 275 EP 287 DI 10.1121/1.423278 PG 13 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZY164 UT WOS:000074592700032 ER PT J AU Black, F Tejada, S Gurevich, M AF Black, F Tejada, S Gurevich, M TI Alternative fuel motor vehicle tailpipe and evaporative emissions composition and ozone potential SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID REACTIVITY AB The 1988 Alternative Motor Fuels Act and the 1990 Clean Air Act Amendments require examination of the potential to favorably influence air quality by changing the composition of motor vehicle fuels. Motor vehicle tailpipe and evaporative emissions were characterized using laboratory simulations of roadway driving conditions and a variety of vehicle-fuel technologies (reformulated gasoline (RFG), methanol (M85), ethanol (E85), and natural gas (CNG)). Speciated organic compound (with Carter MIR ozone potential), CO, and NOx emission rates and fuel economy were characterized. The Carter MIR clone potential of combined Federal Test Procedure (FTP) tailpipe and evaporative emissions was reduced more than 90% with CNG relative to RFG, M85, and E85 fuels. FTP toxic compound emissions (benzene, formaldehyde, acetaldehyde, and 1,3-butadiene) were greater with M85 and E85 fuels than with RFG fuel, and less with CNG fuel than RFG fuel. The most abundant toxic compound was benzene with RFG fuel, formaldehyde with M85 fuel, and acetaldehyde with E85 fuel. FTP MPG fuel economies were reduced with M85 and E85 fuels relative to RFG fuel, consistent with their lower BTU/gal. Energy efficiencies (BTU/mi) were improved with all the alternative fuels relative to RFG. Carter MIR ozone potential was generally reduced with the alternative fuels relative to RFG fuel under REP05 (high speeds and acceleration rates) driving conditions (most significantly with CNG). Toxic aldehyde emissions were reduced under REP05 conditions relative to FTP conditions with all the tested fuels, and toxic benzene emissions were elevated under high acceleration conditions. C1 US EPA, Natl Exposure Res Lab, Source Apportionment & Characterizat Branch, Res Triangle Pk, NC 27711 USA. US DOE, Washington, DC USA. RP Black, F (reprint author), US EPA, Natl Exposure Res Lab, Source Apportionment & Characterizat Branch, MD-48, Res Triangle Pk, NC 27711 USA. NR 33 TC 23 Z9 23 U1 1 U2 9 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 USA SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD JUL PY 1998 VL 48 IS 7 BP 578 EP 591 PG 14 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 106GH UT WOS:000075121200001 PM 9706038 ER PT J AU Plucknett, KP Becher, PF Waters, SB AF Plucknett, KP Becher, PF Waters, SB TI Flexure strength of melt-infiltration-processed titanium carbide nickel aluminide composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MECHANICAL-PROPERTIES; TERNARY ADDITION; NI3AL; DUCTILITY; BEHAVIOR; ELEMENTS; ALLOYS; BORON; SIZE AB TiC/Ni3Al composites were prepared using a simple melt-infiltration process, performed at either 1300 degrees or 1400 degrees C, with the Ni(3)AI content varied over the range of 8-25 vol%, Densities >96% of theoretical were obtained for all composites. Four-point flexure strengths at 22 degrees C increased as the Ni(3)AI content increased (i.e., similar to 1100 MPa at 20 vol% Ni(3)AI), with the highest strengths being observed for composites processed at 1300 degrees C, because of reduced TiC grain size. Strengths at elevated temperatures increased with test temperature, up to similar to 1000 degrees C, As with the yielding behavior of the Ni,AI alloy used, a maximum in composite strength (similar to 1350 MPa) versus temperature was observed; this occurred at 950 degrees C, which is similar to 300 degrees C above the yield maximum for the alloy. Extensive plastic strain was achieved in the composites even at high loading rates at 1135 degrees C, and the yield stress was dependent on the applied loading rate. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Plucknett, KP (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 27 TC 28 Z9 30 U1 1 U2 8 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1839 EP 1844 PG 6 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400016 ER PT J AU Schneibel, JH Sabol, SM Morrison, J Ludeman, E Carmichael, CA AF Schneibel, JH Sabol, SM Morrison, J Ludeman, E Carmichael, CA TI Cyclic thermal shock resistance of several advanced ceramics and ceramic composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ALUMINA AB The cyclic thermal shock behavior of two Si3N4 ceramics, two SiC-whisker-reinforced alumina composites (Al2O3/SiCw), a SiC-particulate-reinforced alumina (Al2O3/SiCp), and an alumina continuously reinforced with SiC fibers (Al2O3/SiCf) composite has been studied. Specimens were repeatedly quenched from 1473 K into a fluidized bed with a heat transfer coefficient of 1400 W/(K . m(2)) [250 Btu/(h . ft(2). F)]. The thermal shock damage was assessed by room-temperature flexure strength measurements. Si3N4 and Al2O3/SiCp showed no noticeable damage after 100 cycles, whereas Al2O3/SiCw and Al2O3/SiCf degraded substantially. The experimental results are discussed and rationalized in terms of finite element simulations and microstructural observations. Our analysis suggests that the thermal shock performance of other materials may be estimated from comparisons with the present work. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Westinghouse Power Generat, Orlando, FL 32826 USA. RP Schneibel, JH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 10 TC 15 Z9 15 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1888 EP 1892 PG 5 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400023 ER PT J AU Becher, PF Lin, HT More, KL AF Becher, PF Lin, HT More, KL TI Lifetime-applied stress response in air of a SiC-based Nicalon-fiber-reinforced composite with a carbon interfacial layer: Effects of temperature (300 degrees to 1150 degrees C) SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MATRIX COMPOSITES; STRENGTH AB The lifetimes in air as a function of applied flexure stress and temperature (300-1150 degrees C) are described for a Si-O-C based (Nicalon) fiber plain-weave cloth reinforced SiC-matrix composite (similar to 7% closed porosity) with an similar to 0.3 mu m thick carbon interfacial layer. The measured lifetimes of both samples with and without an external SiC seal coating were similar and decreased with applied flexural stress (for stresses greater than -90 MPa) and with temperature. At temperatures of greater than or equal to 600 degrees C, the external CVD SIC coating had negligible effect on the lifetimes; however, at 425 degrees C, a detectable improvement in the lifetime was observed with an external SiC coating. When the applied stress was decreased below an apparent "threshold stress" (e.g., similar to 90 MPa) for tests conducted at temperatures less than or equal to 950 degrees C, no failures were observed for times of greater than or equal to 1000 h, Electron microscopy observations show that the interfacial carbon layer is progressively removed during tests at 425 degrees and 600 degrees C, In these cases, failure is associated with fiber failure and pullout. At 950 degrees and 1150 degrees C, the carbon interface layer is eliminated and replaced by a thick silica layer due to the oxidation of the Nicalon fiber and the SiC matrix. This results in embrittling the composite. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Becher, PF (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI More, Karren/A-8097-2016 OI More, Karren/0000-0001-5223-9097 NR 24 TC 9 Z9 9 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1919 EP 1925 PG 7 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400028 ER PT J AU Bae, YW Lee, WY Besmann, TM Cavin, OB Watkins, TR AF Bae, YW Lee, WY Besmann, TM Cavin, OB Watkins, TR TI Effects of processing parameters on alumina coatings deposited on nickel substrates by reacting aluminum chloride and hydrogen/carbon dioxide gas mixtures SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CHEMICAL VAPOR-DEPOSITION AB Pure nickel coupons were used as substrates in the deposition of alumina (Al2O3) from the reaction of aluminum chloride (AlCl3) with hydrogen/carbon dioxide gas mixtures in the temperature range of 954 degrees-1100 degrees C and system pressures of 2.7-13.3 kPa, The apparent activation energy estimated from the coating growth rate averaged 320 kJ/mol at 13.3 kPa, At temperatures <1000 degrees C, transition theta, kappa, and delta modifications were codeposited with alpha-Al2O3, whereas single-phase alpha-Al2O3 was deposited at higher temperatures. At high AlCl3 partial pressures, nickel aluminide phases were sometimes codeposited with Al2O3, which was attributed to the reaction of AlCl3 with the nickel substrate in the presence of hydrogen gas. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Bae, YW (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Watkins, Thomas/D-8750-2016 OI Watkins, Thomas/0000-0002-2646-1329 NR 14 TC 16 Z9 16 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1945 EP 1948 PG 4 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400033 ER PT J AU Spearing, DR Huang, JY AF Spearing, DR Huang, JY TI Zircon synthesis via sintering of milled SiO2 and ZrO2 SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID WEAPONS PLUTONIUM; RADIATION-DAMAGE; ZRSIO4 AB The formation of zircon (ZrSiO4) via sintering of milled SiO2 and ZrO2 powders was studied, and the effects of slurry vs dry milling, sintering time, and particle size on zircon yield were examined. It was found that very high zircon yields could be obtained via slurry milling, cold pressing, and sintering of the oxide precursors. The controlling factor in determining zircon yield was found to be the particle size of the SiO2 and ZrO2 powders. Zircon yield as a function of sintering time was examined, and found to be similar to previous studies in which sol-gel precursors seeded with zircon were used. SEM studies reveal a homogeneous product with particle sizes on the order of 1-5 mu m. It was found that complete reaction to zircon can be achieved from a once-through milling, pressing, and sintering process of SiO2-ZrO2 powders. C1 Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Spearing, DR (reprint author), Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RI Huang, Jianyu/C-5183-2008 NR 10 TC 13 Z9 15 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1964 EP 1966 PG 3 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400038 ER PT J AU Krishnan, S Ansell, S Price, DL AF Krishnan, S Ansell, S Price, DL TI X-ray diffraction from levitated liquid yttrium oxide SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB We report the first measurements of the structure factor, S(Q), and radial distribution function, G(r), of yttrium oxide in the normal and supercooled liquid states in the temperature range 2500-3100 K, Measurements were obtained by synchrotron X-ray scattering on levitated, laser-heated liquid specimens, At temperatures far in excess of the melting point, the first and second coordination shells begin to merge, indicative of increased ionicity in the liquid. As the temperature is lowered into the supercooled region, there is substantial sharpening and strengthening in the first peaks in both see, and G(r), Supercooling causes a decrease in the first shell coordination and Il values together with an increase in the Y-O interionic distance. C1 Certainerless Res Inc, Evanston, IL 60201 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Krishnan, S (reprint author), Certainerless Res Inc, Evanston, IL 60201 USA. RI Price, David Long/A-8468-2013 NR 16 TC 19 Z9 19 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1998 VL 81 IS 7 BP 1967 EP 1969 PG 3 WC Materials Science, Ceramics SC Materials Science GA 100UH UT WOS:000074833400039 ER PT J AU Levanon, H Galili, T Regev, A Wiederrecht, GP Svec, WA Wasielewski, MR AF Levanon, H Galili, T Regev, A Wiederrecht, GP Svec, WA Wasielewski, MR TI Determination of the energy levels of radical pair states in photosynthetic models oriented in liquid crystals with time-resolved electron paramagnetic resonance SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ARTIFICIAL PHOTOSYNTHESIS; TRANSFER RATES; TRIPLET-STATE; SPECTROSCOPY; DYNAMICS; ASSEMBLIES AB We report the results of time-resolved electron paramagnetic resonance (TREPR) studies of photoinduced charge separation in a series of biomimetic supramolecular compounds dissolved in oriented liquid crystal solvents. The molecules contain a chlorophyll-like (zinc 9-desoxomethylpyropheophorbide a) electron donor, D (ZC), and two electron accepters with different reduction potentials, i.e., pyromellitimide, A(1) (PI), and 1,8:4,5-naphthalenediimide, A(2) (NI). The compounds investigated are ZCPI, ZCNI, and ZCPINI, and they have small but well-defined differences of their ion-pair energies. Temperature-dependent TREPR studies on this series of compounds permit the determination of the radical pair energy levels as the solvent reorganization energy increases from the low-temperature crystalline phase, through the soft glass phase, to the nematic phase of the liquid crystal. As the temperature is increased, the radical pair with the lowest energy is the first to exhibit triplet-initiated charge separation as the solvent reorganization energy increases in the liquid crystal. The energy levels of the radical pairs and the solvent reorganization energy are determined by using the known singlet: and triplet excited state energy levels of ZC, the electrochemically determined relative energies between the radical ion pairs in polar isotropic solvents, and the TREPR data. All these yield information about the ordering of the radical ion pair energy levels relative to the excited-state energy levels of ZC. C1 Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. Hebrew Univ Jerusalem, Farkas Ctr Light Induced Proc, IL-91904 Jerusalem, Israel. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Levanon, H (reprint author), Hebrew Univ Jerusalem, Dept Phys Chem, IL-91904 Jerusalem, Israel. NR 30 TC 51 Z9 51 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUL 1 PY 1998 VL 120 IS 25 BP 6366 EP 6373 DI 10.1021/ja980409c PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA ZY238 UT WOS:000074600100021 ER PT J AU McLuckey, SA AF McLuckey, SA TI Focus on oligonucleotides SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP McLuckey, SA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 0 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUL PY 1998 VL 9 IS 7 BP 659 EP 659 DI 10.1016/S1044-0305(98)00054-3 PG 1 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA ZU137 UT WOS:000074166000001 ER PT J AU Gorshkov, MV Tolic, LP Udseth, HR Anderson, GA Huang, BM Bruce, JE Prior, DC Hofstadler, SA Tang, LA Chen, LZ Willett, JA Rockwood, AL Sherman, MS Smith, RD AF Gorshkov, MV Tolic, LP Udseth, HR Anderson, GA Huang, BM Bruce, JE Prior, DC Hofstadler, SA Tang, LA Chen, LZ Willett, JA Rockwood, AL Sherman, MS Smith, RD TI Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry at 11.5 tesla: Instrument design and initial results SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID LARGE MOLECULES; MAGNETIC-FIELD; RESOLUTION; TIME; SPECTROSCOPY; BIOMOLECULES; AXIALIZATION; BIOPOLYMERS; PRINCIPLES; EXCITATION AB Initial results obtained using a new electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometer operated at a magnetic field 11.5 tesla are presented. The new instrument utilized an electrostatic ion guide between the ESI source and FTICR trap that provided up to 5% overall transmission efficiency for Light ions and up to 30% efficiency for heavier biomolecules. The higher magnetic field in combination with an enlarged FTICR ion trap made it possible to substantially improve resolving power and operate in a more robust fashion for large biopolymers compared to lower field instruments. Mass resolution up to 10(6) has been achieved for intermediate size biopolymers such as bovine ubiquitin (8.6 kDa) and bovine cytochrome c (12.4 kDa) without the use of frequency drift correction methods. A mass resolution of 370,000 has been demonstrated for isotopically resolved molecular ions of bovine serum albumin (66.5 kDa). Comparative measurements were made with the same spectrometer using a lower field 3.5-tesla magnet allowing the performance gains to be more readily quantified. Further improvements in pumping capacity of the vacuum system and efficiency of ion transmission from the source are expected to lead to further substantial sensitivity gains. (C) 1998 American Society for Mass Spectrometry. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-98, Richland, WA 99352 USA. RI Gorshkov, Mikhail/E-8522-2010; Smith, Richard/J-3664-2012; Gorshkov, Mikhail/N-4984-2013 OI Smith, Richard/0000-0002-2381-2349; Gorshkov, Mikhail/0000-0001-9572-3452 NR 29 TC 45 Z9 47 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUL PY 1998 VL 9 IS 7 BP 692 EP 700 DI 10.1016/S1044-0305(98)00037-3 PG 9 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA ZU137 UT WOS:000074166000006 PM 9879379 ER PT J AU Miller, MA Jensen, MP Clothiaux, EE AF Miller, MA Jensen, MP Clothiaux, EE TI Diurnal cloud and thermodynamic variations in the stratocumulus transition regime: A case study using in situ and remote sensors SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MARINE BOUNDARY-LAYER; RADIATION BUDGET EXPERIMENT; ASTEX; PARAMETERIZATION AB Radiosonde, in situ, and surface-based remote sensor data from the Atlantic Stratocumulus Transition Experiment are used to study the diurnal cycle of cloud and thermodynamic structure. A cloud layer and decoupled subcloud layer separated by a stable transition layer, often observed in the vicinity of cumulus cloud base, characterizes the thermodynamic structure during the study period. The mode of cloud structure is cumulus with bases below decoupled stratus. Data are presented that support the hypothesis that diurnal variations in cumulus development are modulated by the stability in the transition layer. The frequency of cumulus convection decreases during the afternoon, but mesoscale regions of vigorous cumulus with cloud tops overshooting the base of the trade inversion and increased surface drizzle rates are present during the late afternoon and early evening, when the transition layer is the most stable. It is postulated that mesoscale organization may be required to accumulate enough water vapor in the subcloud layer to produce the convective available potential energy needed for developing cumulus to overcome transition layer stability. The mesoscale regions appear to fit the description of cyclic cumulus convection proposed in a previous study, and this theory is expanded to account for diurnal variations in the stability of the transition layer. The occurrence of these mesoscale clusters of vigorous convection makes it difficult to determine if the latent heat flux in the cloud layer has actually decreased in the late afternoon and early evening, when the transition layer is the most stable. Liquid water structure was examined and no pronounced diurnal signal was found. Results showed that clouds thicker than approximately 450 m tended to have subadiabatic integrated liquid water contents, presumably due to evaporation of drizzle in the subcloud layer, removal of liquid water at the surface, and the evaporation of cloud water at cloud top. A significant fraction of clouds less than 450 m thick produced liquid water contents that were greater than adiabatic, and there may be a physical mechanism that could produce such values in this cloud system (i.e., lateral detrainment of cloud water from convective elements mixing with existing liquid water in decoupled stratus or with liquid water detrained by nearby convective elements). Unfortunately, instrument limitations may have also produced these greater-than-adiabatic values and the extent of instrument artifacts in these results is unclear. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP Miller, MA (reprint author), Brookhaven Natl Lab, Dept Appl Sci, POB 5000, Upton, NY 11973 USA. NR 21 TC 23 Z9 23 U1 0 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JUL 1 PY 1998 VL 55 IS 13 BP 2294 EP 2310 DI 10.1175/1520-0469(1998)055<2294:DCATVI>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZZ230 UT WOS:000074708600004 ER PT J AU Kim, J Song, X Kinoshita, K Madou, M White, B AF Kim, J Song, X Kinoshita, K Madou, M White, B TI Electrochemical studies of carbon films from pyrolyzed photoresist SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID DIAMOND-LIKE CARBON; AMORPHOUS-CARBON; GLASSY-CARBON; DEPOSITION; ELECTRODES; OXYGEN; ARC AB Carbon film electrodes were prepared by pyrolysis of photoresists on silicon-wafers at temperatures ranging from 600 to 1100 degrees C. The physical properties of the carbon films were characterized by scanning and transmission electron microscopies, thermal gravimetric analysis, and four-point probe electrical resistivity measurements. The electrochemical properties of the carbon films were investigated by cyclic voltammetry to observe the kinetics of the Fe(CN)(6)(4-)/Fe(CN)(6)(3-) redox couple. The carbon film electrodes prepared at temperatures greater than or equal to 700 degrees C showed electrochemical behavior Similar to that of glassy carbon. Better electrocatalytic behavior was obtained with carbon films prepared at the higher pyrolysis temperatures which is attributed to different film compositions at different pyrolysis temperatures. The electrochemical properties of the:carbon film electrodes are very stable, exhibiting reproducible behavior even after storing at room temperature in air for 3 months. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley Sensor & Actuator Ctr, Berkeley, CA 94720 USA. RP Kim, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Madou, Marc/E-5869-2013 OI Madou, Marc/0000-0003-4847-3117 NR 35 TC 88 Z9 89 U1 3 U2 29 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1998 VL 145 IS 7 BP 2314 EP 2319 DI 10.1149/1.1838636 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZX043 UT WOS:000074474500016 ER PT J AU Song, L Evans, JW AF Song, L Evans, JW TI The thermal stability of lithium polymer batteries SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTROLYTE BATTERIES; TEMPERATURE; MODULE AB The electrical. (ionic) conductivity of polymer electrolytes for lithium-polymer cells increases greatly with increasing temperature (in contrast to the thermal conductivity). This paper examines, by both a Linear perturbation analysis and by numerical calculation, an instability that could arise from this temperature dependence. The instability is one where a local perturbation to a higher temperature results in higher electrical conductivity and therefore the passage of more current in this region with an attendant increase in heat generation. If this excess heat generation cannot be conduced into adjacent cooler regions, instability (growth of the perturbation) results. The numerical calculations were carried out for constant potential drop across the electrolyte, for constant mean current density, and for constant mean power discharge schedules. The calculations suggest that this instability is unlikely for small batteries (of the order of 0.1 m in the directions parallel to the electrodes) but may occur for larger batteries such as those intended for use in an electric vehicle. However, the growth rates of the perturbations do not appear to be high. Changes in cell materials /thickness have little effect on the instability. The Linear perturbation analysis is in approximate agreement with the numerical calculations. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Song, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. NR 17 TC 12 Z9 12 U1 0 U2 4 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1998 VL 145 IS 7 BP 2327 EP 2334 DI 10.1149/1.1838638 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZX043 UT WOS:000074474500018 ER PT J AU Kostecki, R Richardson, T McLarnon, D AF Kostecki, R Richardson, T McLarnon, D TI Photochemical and photoelectrochemical behavior of a novel TiO2/Ni(OH)(2) electrode SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ATOMIC-FORCE MICROSCOPY; TIO2 COATING FILMS; SEMICONDUCTOR PARTICLES; NICKEL; OXIDE; REDUCTION; WO3; MECHANISM; COLLOIDS; CLUSTERS AB Transparent Ni(OH)(2) films were electrochemically deposited onto TiO2 layers which had been formed on conductive glass. This optically transparent composite electrode exhibited strong, reversible photochromic and electrochromic properties when either illuminated by a 75 W Xe lamp at open circuit or anodically polarized in 1.0 M aqueous NaOH electrolyte. The extent of electrode darkening depended on the intensity of UV light, exposure time, and applied potential. Electrochemical and optical-absorption measurements indicated that W-photogenerated holes in the TiO2 valence band recombined with electrons from the electrochromic Ni(OH)(2) layer, which consequently oxidized the Ni(OH)(2) tb NiOOH and darkened the composite electrode. Because the darkening process occurred only on the specific electrode areas which were exposed to Light, nonuniform illumination produced a patterned optical state of the;electrode. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kostecki, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 37 TC 24 Z9 24 U1 1 U2 20 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1998 VL 145 IS 7 BP 2380 EP 2385 DI 10.1149/1.1838647 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZX043 UT WOS:000074474500027 ER PT J AU Wolverton, C Zunger, A AF Wolverton, C Zunger, A TI Prediction of Li intercalation and battery voltages in layered vs. cubic LixCoO2 SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LASER-ABLATION DEPOSITION; SECONDARY LITHIUM CELLS; LICOO2; OXIDES; SPINEL; DENSITY; LINIO2; STATE; GAS AB It is now possible to use a quantum-mechanical electronic structure theory of solids and derive, completely from "first-principles,'' the voltage of a battery based on intercalation reaction energetics. Using such techniques, we investigate the structural stability, intercalation energies, and battery voltages of the two observed ordered phases ("layered" and cubic) of LiCoO2. We perform calculations for not only fully lithiated LiCO2, but also fully delithiated square CoO2 and partially delithiated Li0.5CoO2. Our calculations demonstrate that removal of Li from the cubic phase results in movement of the Li atoms from their original octahedral sites-to tetrahedral sites, forming a low-energy LiCo2O4 spine structure. The energetics of the spinel phase are shown to account for the observed marked differences in battery voltages between the cubic and layered phases of LiCoO2. A small energy barrier exists for Li motion between octahedral and tetrahedral sites, thus indicating the metastability of the high-energy octahedral sites. Finally, we point out a possible pressure-induced layered --> cubic transition in LiCoO2. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wolverton, C (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Wolverton, Christopher/B-7542-2009; Zunger, Alex/A-6733-2013 NR 32 TC 88 Z9 90 U1 3 U2 40 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 EI 1945-7111 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1998 VL 145 IS 7 BP 2424 EP 2431 DI 10.1149/1.1838653 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA ZX043 UT WOS:000074474500033 ER PT J AU Shida, K Hoover, WG AF Shida, K Hoover, WG TI Maxwell's thermal creep in two space dimensions SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE statistical mechanics; molecular dynamics; kinetic theory; convection; converting heat to work AB "Thermal Creep" is a steady streaming motion. induced by a temperature gradient parallel to a fluid boundary, in the absence of gravity. Thermal creep has been studied by Maxwell, analyzed by Kennard, and simulated by Ibsen: Soto, and Cordero. Here we report several two-dimensional simulations. We find that the creep velocity is sensitive to the imposed macroscopic boundary conditions and that the agreement with existing theoretical predictions is only semiquantitative. C1 Univ Calif Davis Livermore, Dept Appl Sci, Livermore, CA 94551 USA. Musashi Inst Technol, Setagaya Ku, Tokyo 158, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Shida, K (reprint author), Univ Calif Davis Livermore, Dept Appl Sci, Livermore, CA 94551 USA. EM shida@cs.musashi-tech.ac.jp NR 6 TC 5 Z9 5 U1 0 U2 0 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JUL PY 1998 VL 67 IS 7 BP 2277 EP 2280 DI 10.1143/JPSJ.67.2277 PG 4 WC Physics, Multidisciplinary SC Physics GA 104UZ UT WOS:000075035400027 ER PT J AU Wenski, TE Olson, T Rettner, CT Garcia, AL AF Wenski, TE Olson, T Rettner, CT Garcia, AL TI Simulations of air slider bearings with realistic gas-surface scattering SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB We have calculated the pressure distribution for an infinitely wide plane slider air bearing by using a particle-based direct simulation Monte Carlo method. These simulations include a sophisticated gas-surface scattering model and take measured accommodation coefficients as inputs. Our results are in good agreement with the molecular gas lubrication theory of Fukui and Kaneko for both glass and disk-drive surfaces. C1 Lightwave Elect, Div Res & Dev, Mt View, CA 95112 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95112 USA. Lawrence Berkeley Lab, Ctr Comp Sci & Engn, Berkeley, CA USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Wenski, TE (reprint author), Lightwave Elect, Div Res & Dev, Mt View, CA 95112 USA. NR 13 TC 4 Z9 4 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD JUL PY 1998 VL 120 IS 3 BP 639 EP 641 DI 10.1115/1.2834599 PG 3 WC Engineering, Mechanical SC Engineering GA 102NQ UT WOS:000074930900033 ER PT J AU Madden, HH Landers, R Kleiman, GG Zehner, DM AF Madden, HH Landers, R Kleiman, GG Zehner, DM TI Characteristic losses in metals: Al, Be, and Ni SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID ENERGY-LOSS SPECTROSCOPY; APPEARANCE POTENTIAL SPECTROSCOPY; QUANTITATIVE-ANALYSIS; LOSS SPECTRA; REFLECTION; PHOTOEMISSION; BIS AB Information about the occupied portion of the surface density of states of materials can be derived from electron-excited Auger electron spectroscopy (AES), which is a standard experimental technique in most surface science laboratories. Surface sensitive experimental techniques that provide information regarding the unoccupied portion of the surface density of states are often not standard and are not so readily available. Here we explore the possibility of utilizing the same experimental equipment as in AES to derive information about the unoccupied portion of the surface density of states from a characteristic loss spectroscopy, in particular, from core-level inelastic electron-scattering spectroscopy (CLIESS). An important application of this technique is in comparative studies. CLIESS spectra from clean surfaces of aluminum, beryllium and nickel are presented. These data were taken in the first-derivative mode using the reflection of monoenergetic primary beams of 450 eV energy for Be, and 300 eV for Al and Ni. The Al and Be spectra had to be extracted from overlapping plasmon signals using synthesized plasmon spectra based on the behavior of these spectra between the elastic peak energy and the respective core level threshold energies. After applying loss-deconvolution techniques to remove secondary loss spectral distortions, integral spectra were obtained which compared well to corresponding experimental soft x-ray absorption and transmission electron-energy loss data as well as to theoretical calculations of the unoccupied density-of-states for these materials. Comparison similarities as well as some differences are discussed. Finally, in order to illustrate the potential these signals have in serving as ''fingerprints'' of surface chemistry, derivative metal-CLIESS curves for the three oxide surfaces of the metals are also presented. (C) 1998 American Vacuum Society. [S0734-2101 (98)00504-1]. C1 Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13081970 Campinas, SP, Brazil. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Landers, R (reprint author), Univ Estadual Campinas, Inst Fis Gleb Wataghin, Caixa Postal 6165, BR-13081970 Campinas, SP, Brazil. EM landers@ifi.unicamp.br RI LANDERS, Richard/C-7472-2013; Inst. of Physics, Gleb Wataghin/A-9780-2017 NR 49 TC 2 Z9 2 U1 1 U2 5 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD JUL-AUG PY 1998 VL 16 IS 4 BP 2595 EP 2603 DI 10.1116/1.581388 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700091 ER PT J AU Blain, MG Jarecki, RL Simonson, RJ AF Blain, MG Jarecki, RL Simonson, RJ TI Chemical downstream etching of tungsten SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MIXTURES; SURFACES AB The downstream etching of tungsten and tungsten oxide has been investigated. Etching of chemical vapor deposited tungsten and e-beam deposited tungsten oxide samples was performed using atomic fluorine generated by a microwave discharge of argon and NF3. Etching was found to be highly activated with activation energies approximated to be 6.0 +/- 0.5 kcal/mol and 5.4 +/- 0.4 kcal/mol for W and WO3, respectively. In the case of F etching of tungsten, the addition of undischarged nitric oxide (NO) directly into the reaction chamber results in the competing effects of catalytic etch rate enhancement and the formation of a nearly stoichiometric WO3 passivating tungsten oxide film, which ultimately stops the etching process. For F etching of tungsten oxide, the introduction of downstream NO reduces the etch rate. (C) 1998 American Vacuum Society. [S0734-2101(98)00404-7]. C1 Sandia Natl Labs, Microelect Dev Lab, Albuquerque, NM 87185 USA. RP Blain, MG (reprint author), Sandia Natl Labs, Microelect Dev Lab, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 4 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2115 EP 2119 DI 10.1116/1.581511 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700017 ER PT J AU Wang, JJ Lambers, ES Pearton, SJ Ostling, M Zetterling, CM Grow, JM Ren, F Shul, RJ AF Wang, JJ Lambers, ES Pearton, SJ Ostling, M Zetterling, CM Grow, JM Ren, F Shul, RJ TI Inductively coupled plasma etching of bulk 6H-SiC and thin-film SiCN in NF3 chemistries SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SILICON-CARBIDE; POWER DEVICES; SEMICONDUCTOR AB A parametric study of the etching characteristics of 6H p(+) and n(+) SiC and thin-film SiC0.5N0.5 in inductively coupled plasma (ICP) NF3/O-2 and NF3/Ar discharges has been performed. The etch rates in both chemistries increase monotonically with NF3 percentage and rf chuck power. The etch rates go through a maximum with increasing ICP source power, which is explained by a trade-off between the increasing ion flux and the decreasing ion energy. The anisotropy of the etched features is also a function of ion flux, ion energy and atomic fluorine neutral concentration. Indium-tin-oxide masks display relatively good etch selectivity over SiC (maximum of similar to 70:1), while photoresist etches more rapidly than SiC. The surface roughness of SiC is essentially independent of plasma composition for NF3/O-2 discharges, while extensive surface degradation occurs for SiCN under high NF3:O-2 conditions. (C) 1998 American Vacuum Society. [S0734-2101(98) 10104-5]. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Royal Inst Technol, S-16428 Kista, Sweden. New Jersey Inst Technol, Newark, NJ 07102 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wang, JJ (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RI Zetterling, Carl-Mikael/E-5764-2015 OI Zetterling, Carl-Mikael/0000-0001-8108-2631 NR 34 TC 49 Z9 50 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2204 EP 2209 DI 10.1116/1.581328 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700029 ER PT J AU Meeks, E Ho, P Ting, AL Buss, RJ AF Meeks, E Ho, P Ting, AL Buss, RJ TI Simulations of BCl3/Cl-2/Ar plasmas with comparisons to diagnostic data SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; 2-DIMENSIONAL FLUID MODEL; COLLISION CROSS-SECTIONS; REFERENCE CELL; CHLORINE; TEMPERATURE; DENSITY; ARGON AB A reaction mechanism is reported that describes BCl3/CI2/Ar plasmas used in the etching of metal lines in microelectronics fabrication processes. Although many of the fundamental electron-impact cross sections for this system are not well known, a reasonable set of reaction paths and rate coefficients has been derived to describe low-pressure reactors with high plasma density. The reaction mechanism describes 59 possible gas-phase events and 18 plasma-surface interactions. A well-mixed reactor model is used to develop the reaction set and to test it against absolute experimental measurements of electron and Cl- densities, as well as relative measurements of BCl and Cl radicals in an inductively coupled research reactor. The experimental data cover a wide range of operating conditions and gas mixtures. The model provides quantitative agreement with measurements over the whole range of conditions and diagnostics, capturing most of the observed trends. in addition, the model predicts relative ion ratios and Cl/Cl-2 density ratios as measured by molecular beam mass spectrometry. Comparisons of results from the zero-dimensional model and a two-dimensional continuum plasma model, using the same reaction mechanisms, further validate the chemistry set and show the strengths and weaknesses of the well-stirred reactor approach. Sensitivity analysis shows the dominant reactions contributing to model predictions of species densities. (C) 1998 American Vacuum Society. [S0734-2101(98)09904-7]. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Meeks, E (reprint author), React Design, 6500 Dublin Blvd, Dublin, CA 94568 USA. EM pho@sandia.gov NR 49 TC 62 Z9 62 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2227 EP 2239 DI 10.1116/1.581332 PG 13 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700033 ER PT J AU Ferry, D Suzanne, J Panella, V Barbieri, A Van Hove, MA Biberian, JP AF Ferry, D Suzanne, J Panella, V Barbieri, A Van Hove, MA Biberian, JP TI MgO(100) surface relaxation by symmetrized automated tensor low energy electron diffraction analysis SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MGO(001) SURFACE; LEED; MGO; MONOLAYERS; INSITU; CHARGE; RHEED AB We present a low energy electron diffraction study of the surface relaxation of MgO(100) at T = 80 K down to the second atomic layer using in situ cleaved MgO crystals. We find that the main perturbation from the bulk structure is a topmost surface layer rumpling of 3.3 +/- 1.5% and a very small second layer rumpling of 0.2 +/- 2%. In both cases the oxygen atom is displaced outward. The first interlayer spacing is slightly reduced by 0.2 +/- 0.7% whereas there is no change in the second interlayer spacing. (C) 1998 American Vacuum Society. [S0734-2101(98)02104-6]. C1 Fac Sci Luminy, Dept Phys, CNRS, CRMC2, F-13288 Marseille 9, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Suzanne, J (reprint author), Fac Sci Luminy, Dept Phys, CNRS, CRMC2, F-13288 Marseille 9, France. RI Van Hove, Michel/A-9862-2008; Ferry, Daniel/O-2664-2014 OI Van Hove, Michel/0000-0002-8898-6921; Ferry, Daniel/0000-0003-1469-9871 NR 27 TC 13 Z9 13 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2261 EP 2266 DI 10.1116/1.581337 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700038 ER PT J AU Li, DQ Keavney, DJ Pearson, J Jiang, JS Bader, SD Keune, W AF Li, DQ Keavney, DJ Pearson, J Jiang, JS Bader, SD Keune, W TI Growth and characterization of epitaxial fcc Fe wedges on diamond (100) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CALIFORNIA SP Amer Vacuum Soc ID MAGNETIC PHASES; FILMS; TEMPERATURE; FE/CU(100); FE(100); CU(100); LAYERS; IRON AB Epitaxial Fe wedges with a thickness gradation from 0 to 20 Angstrom were grown on diamond (100) at room temperature, subsequently annealed, and investigated with reflection high-energy electron diffraction and the surface magneto-optical Kerr effect. The results indicate that for <5 monolayer thicknesses the Fe grows on C(100) as smooth, epitaxial fee films, which are not ferromagnetic, but that thicker films undergo a transition to become rough and the ordinary bcc ferromagnetic phase. (C) 1998 American Vacuum Society. [S0734-2101(98)09104-0]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Gerhard Mercator Univ, Lab Angew Phys, D-47048 Duisburg, Germany. RP Li, DQ (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 23 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2326 EP 2329 DI 10.1116/1.581347 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700049 ER PT J AU Levinson, JA Hamza, AV Shaqfeh, ESG Balooch, M AF Levinson, JA Hamza, AV Shaqfeh, ESG Balooch, M TI Growth of SiC films via C-60 precursors and a model for the profile development of the silicon underlayer SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; CHEMICAL VAPOR-DEPOSITION; VARIABLE-TEMPERATURE STM; SURFACE-DIFFUSION; MOLECULAR-DYNAMICS; CARBIDE FILMS; ADSORPTION; SIMULATION; SI(111)-(7X7); SI(100)-(2X1) AB We report on an experimental and theoretical study of the growth of SiC films and of the profile development of the silicon underlayer. SIC features were grown via the direct reaction of the silicon substrate with C-60 precursors. Two masking configurations were used to investigate the effects of bulk and surface diffusion on SiC film growth. Without a diffusion barrier (i.e., a patterned SiO2 mask with regions of silicon initially exposed directly to C60) voids formed in the substrate beneath the growing SiC layer, which ultimately controlled the final thickness of the SiC film. Pronounced faceting was observed at the early stages of growth on crystalline silicon. When a tungsten diffusion barrier was used to prevent bulk diffusion (i.e., tungsten covering silicon in non-SiO2 masked regions), significant undercutting resulted beneath the oxide and SiC layers without void formation. A profile simulation was developed to model the time evolution of the silicon underlayer when this diffusion barrier is used. The simulation incorporated an adatom hopping and surface diffusion model to describe the generation and transport of silicon atoms along the evolving profile. A single fitting parameter was required. The agreement between simulation and experiment was good, and a corresponding value of the hopping coefficient was calculated. As an alternative to direct reaction with the silicon substrate, we also demonstrate experimentally that silicon atoms can be co-sublimed with fullerenes to produce SiC films on wafer surfaces, which avoids the consumption of substrate material. Co-sublimation was used to create SiC membranes and also to coat silicon microcantilevers. Force-deflection measurements for the microcantilevers revealed that the stiffness properties were enhanced with the application of a SIC film and that the co-sublimed SiC had mechanical properties like those of bulk material. (C) 1998 American Vacuum Society. [S0734-2101(98)08404-8]. C1 Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Levinson, JA (reprint author), Stanford Univ, Dept Chem Engn, Stanford, CA 94305 USA. NR 37 TC 7 Z9 8 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2385 EP 2394 DI 10.1116/1.581357 PG 10 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700059 ER PT J AU Proskurovsky, DI Rotshtein, VP Ozur, GE Markov, AB Nazarov, DS Shulov, VA Ivanov, YF Buchheit, RG AF Proskurovsky, DI Rotshtein, VP Ozur, GE Markov, AB Nazarov, DS Shulov, VA Ivanov, YF Buchheit, RG TI Pulsed electron-beam technology for surface modification of metallic materials SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ION-BEAMS; INTENSE AB This article concerns the foundations of a new technology for surface modification of metallic materials based on the use of original sources of low-energy, high-current electron beams. The sources contain an electron gun with an explosive-emission cathode and a plasma anode, placed in a guide magnetic field. The acceleration gap and the transportation channel are prefilled with plasma with the use of spark plasma sources or a low-pressure reflected discharge. The electron-beam sources produce electron beams with the parameters as follows: electron energy 10-40 keV; pulse duration 0.5-5 mu s; energy density 0.5-40 J/cm(2), and beam cross-section area 10-50 cm(2). They are simple and reliable in operation. Investigations performed with a variety of constructional and tool materials (steels, aluminum and titanium alloys, hard alloys) have shown that the most pronounced changes of the structure-phase state occur in the near-surface layers quenched from the liquid state, where the crystallization front velocity reaches its maximum. In these layers partial or complete dissolving of second phases and formation of oversaturated solid solutions and ordered nanosized structures may take place. This makes it possible to improve substantially the electrochemical and strength properties of the surface layers. It has been established that the deformation processes occurring in the near-surface layers have the result that the thickness of the modified layer with improved strength properties is significantly greater than that of the heat-affected zone. Some examples of the use of low-energy, high-current electron beams for improving the performance of materials and articles are given. (C) 1998 American Vacuum Society. [S0734-2101(98)03604-5]. C1 Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. Moscow Aviat Inst, Moscow 125871, Russia. State Univ Architecture & Bldg, Tomsk 634003, Russia. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Proskurovsky, DI (reprint author), Russian Acad Sci, Inst High Current Elect, 4 Academichesky, Tomsk 634055, Russia. RI Ivanov, Yurii/A-9268-2014; Ozur, Grigory/E-5992-2017 OI Ivanov, Yurii/0000-0001-8022-7958; Ozur, Grigory/0000-0003-3899-9246 NR 32 TC 174 Z9 219 U1 0 U2 34 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2480 EP 2488 DI 10.1116/1.581369 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700072 ER PT J AU Chen, CL Jia, QX Lu, YC Smith, JL Mitchell, TE AF Chen, CL Jia, QX Lu, YC Smith, JL Mitchell, TE TI Heteroepitaxial growth of RuO2 thin films on alpha-Al2O3 substrates with CeO2 buffer layers by pulsed laser deposition SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID FATIGUE AB Metallic conductive ruthenium oxide thin films have been grown epitaxially on sapphire (01 (1) over bar 2) with a cerium oxide buffer layer by pulsed laser deposition. We used transmission electron microscopy, high-resolution electron microscopy, and x-ray diffraction to characterize the growth behavior of the films and the orientation relationship between the films and the substrate. Our electron diffraction and x-ray diffraction studies indicate that the orientation relationships are (200)(RuO2)//(200)(CeO2)//(01 (1) over bar 2)(Al2O3) and [011](RuO2)//[001](CeO2)//[2 (2) over bar 01](Al2O3). All Of the interfaces were seen to be atomically sharp by cross-sectional, high-resolution transmission electron microscopy in the as-grown samples. No precipitates or additional phases were found in the films or at their interfaces. (C) 1998 American Vacuum Society. [S0734-2101(98)05904-1]. C1 Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Chen, CL (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RI Jia, Q. X./C-5194-2008 NR 10 TC 1 Z9 1 U1 0 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1998 VL 16 IS 4 BP 2725 EP 2727 DI 10.1116/1.581407 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 101CU UT WOS:000074852700112 ER PT J AU Suh, BJ Hammel, PC Zhang, Z Midzor, MM Roukes, ML Childress, JR AF Suh, BJ Hammel, PC Zhang, Z Midzor, MM Roukes, ML Childress, JR TI Ferromagnetic resonance imaging of Co films using magnetic resonance force microscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 25th Annual Conference on the Physics and Chemistry of Semiconductor Interfaces CY JAN 18-22, 1998 CL SALT LAKE CITY, UTAH ID ELECTRON-SPIN-RESONANCE AB Lateral one-dimensional imaging of cobalt (Co) films by means of microscopic ferromagnetic resonance (FMR) detected using the magnetic resonance force microscope (MRFM) is demonstrated. A novel approach involving scanning a localized magnetic probe is shown to enable FMR imaging in spite of the broad resonance linewidth. We introduce a spatially selective local field by means of a small, magnetically polarized spherical crystallite of yttrium iron garnet (YIG). Using MRFM-detected FMR signals from a sample consisting of two Co films, we can resolve the similar to 20 mu m lateral separation between the films. The results can be qualitatively understood by consideration of the calculated spatial profiles of the magnetic field generated by the YIG sphere. (C) 1998 American Vacuum Society. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Pasadena, CA 91125 USA. Univ Florida, Gainesville, FL 32611 USA. RP Hammel, PC (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Roukes, Michael/E-9787-2010; Hammel, P Chris/O-4845-2014 OI Hammel, P Chris/0000-0002-4138-4798 NR 15 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1998 VL 16 IS 4 BP 2275 EP 2279 DI 10.1116/1.590161 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 110LN UT WOS:000075381400087 ER PT J AU Garrott, RA Cook, JG Bernoco, MM Kirkpatrick, JF Cadwell, LL Cherry, S Tiller, B AF Garrott, RA Cook, JG Bernoco, MM Kirkpatrick, JF Cadwell, LL Cherry, S Tiller, B TI Antibody response of elk immunized with porcine zona pellucida SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE adjuvants; Cervus elaphus; contraception; fertility control; immunocontraception; porcine zona pellucida antibody; reproduction; Rocky Mountain elk; vaccine ID WHITE-TAILED DEER; REMOTELY-DELIVERED IMMUNOCONTRACEPTION; OVARIAN-FUNCTION; FERAL HORSES; CONTRACEPTION; STREPTAVIDIN; MARES; SERUM AB Immunocontraception using porcine zona pellucida (PZP) vaccines is being explored as a nonlethal method of solving the problems of locally overabundant wildlife populations. This study characterized the immunological response of captive elk (Cervus elaphus nelsoni) to PZP challenge using 18 3-yr-old cows and was conducted from 14 September 1994 to 13 December 1995. All animals were given a single PZP inoculation and 1 mo later six of these animals were randomly chosen and received a booster inoculation. Blood samples were drawn from all animals at the time of the initial inoculation and 1, 2, 4, 6, 10, and 15 mo later. Immunological response was assessed by measuring anti-PZP antibody levels in serum. All animals demonstrated a strong immune response with no evidence that the booster enhanced antibody levels. Antibody levels rose from between 0 and 4 at the time of the initial injection to peak levels of 85 to 163 within 2 to 6 mo, followed by a noticeable decline by 15 mo post-vaccination, Limited data suggest that antibody levels >100 may be required to effect contraception. High individual variability in immune response observed in this study suggests it may be difficult to predict the proportion of animals effectively treated. Disruption of seasonal synchrony in calving also could occur if antibody levels in individuals fall below effective levels while animals are still cycling. These results indicate that immunocontraception using PZP vaccines is possible for elk. However, carefully controlled population experiments will be required in order to assess the potential and limitations for management applications of this technique. C1 Montana State Univ, Dept Biol, Fish & Wildlife Management Program, Bozeman, MT 59717 USA. Natl Council Paper Ind Air & Stream Improvement In, Forestry & Range Sci Lab, La Grande, OR 97850 USA. Univ Calif Davis, Dept Populat Hlth & Reprod, Davis, CA 95616 USA. ZooMontana, Billings, MT 59108 USA. Pacific NW Lab, Richland, WA 99352 USA. Montana State Univ, Dept Math Sci, Bozeman, MT 59717 USA. RP Garrott, RA (reprint author), Montana State Univ, Dept Biol, Fish & Wildlife Management Program, 310 Lewis Hall, Bozeman, MT 59717 USA. EM ubirg@montana.edu NR 30 TC 24 Z9 24 U1 0 U2 0 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JUL PY 1998 VL 34 IS 3 BP 539 EP 546 PG 8 WC Veterinary Sciences SC Veterinary Sciences GA 107EH UT WOS:000075193700014 PM 9706563 ER PT J AU Birtcher, RC Donnelly, SE AF Birtcher, RC Donnelly, SE TI Plastic flow in FCC metals induced by single-ion impacts SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article; Proceedings Paper CT 4th IUMRS International Conference CY SEP 16-18, 1997 CL OVERSEAS VOCAT TRAINING ASSOC, CHIBA, JAPAN HO OVERSEAS VOCAT TRAINING ASSOC DE plastic flow; FCC metals; single-ion impacts ID IRRADIATION; GOLD AB Irradiation of Au and ph foils with Xe ions at temperatures between 30 and 450 K has been monitored using in situ transmission electron microscopy. Single ion impacts give rise to surface craters on the irradiated surface with sizes as large as 12 nm. Approximately 2%-5% of impinging ions produce craters on Au while only about 0.6% produce craters on Pb. Larger craters on Au frequently have expelled material associated with them. Temporal details of crater formation and annihilation has been recorded on video with a time-resolution of 33 ms. Craters annihilate in discrete steps due to subsequent ion impacts or anneal in a continuous manner due to surface diffusion. Craters production (those persisting for one or more video-frames) as a function of temperature indicates that the surface diffusion process responsible for thermal annealing of craters has an activation energy of 0.76 eV in Au. Crater creation results from plastic flaw associated with near surface cascades. Crater annihilation in discrete steps results from plastic flow induced by subsequent ion impacts, including those that do not themselves produce a crater. Crown Copyright (C) 1998 Published by Elsevier Science S.A. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Salford, Joule Phys Lab, Sci Res Inst, Salford M5 4WT, Lancs, England. RP Birtcher, RC (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Donnelly, Stephen/0000-0002-9749-5550 NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD JUL PY 1998 VL 54 IS 1-3 BP 111 EP 115 DI 10.1016/S0254-0584(98)00019-4 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA ZY880 UT WOS:000074671500021 ER PT J AU Davis, HA Wood, BP Munson, CP Bitteker, LJ Nastasi, MA Rej, DJ Waganaar, WJ Walter, KC Coates, DM Schleinitz, HM AF Davis, HA Wood, BP Munson, CP Bitteker, LJ Nastasi, MA Rej, DJ Waganaar, WJ Walter, KC Coates, DM Schleinitz, HM TI Ion beam and plasma technology development for surface modification at Los Alamos National Laboratory SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article; Proceedings Paper CT 4th IUMRS International Conference CY SEP 16-18, 1997 CL OVERSEAS VOCAT TRAINING ASSOC, CHIBA, JAPAN HO OVERSEAS VOCAT TRAINING ASSOC DE plasma; implantation; ion beams; ions; coatings; surface treatment ID IMPLANTATION AB We are developing two high-throughput technologies for materials modification. The first is a repetitive intense ion beam source for materials modification through rapid surface melt and resolidification (up to 10(10) K s(-1) cooling rates) and for ablative deposition of coatings. The short range of the ions (typically 0.1 to 10 mu m) allows vaporization or melting at moderate beam energy density (typically 1-50 J cm(-2)).A new repetitive intense ion beam accelerator called CHAMP is under development at Los Alamos. The design beam parameters are: E= 200-250 keV, I= 15 kA, tau=1 mu s, and I Hz. This accelerator will enable applications such as film deposition, alloying and mixing, cleaning and polishing, corrosion and wear resistance, polymer surface treatments, and nanophase powder synthesis. The second technology is plasma source ion implantation (PSII) using plasmas generated from both gas phase (using radio frequency excitation) and solid phase (using a cathodic are) sources. We have used PSII to directly implant ions for surface modification and as a method for generating graded interfaces to enhance the adhesion of surface coatings. Surfaces with areas of up to 16 m(2) and weighing more than a thousand kilograms have been treated in the Los Alamos PSII chamber. In addition, PSII in combination with cathodic source deposition has been used to form highly adherent, thick Er2O3 coatings on steel for reactive metal containment in casting. These coatings resist delamination under extreme mechanical and thermal stress. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Dupont Co, Cent Res & Dev, Wilmington, DE 19880 USA. RP Davis, HA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 12 TC 24 Z9 27 U1 2 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD JUL PY 1998 VL 54 IS 1-3 BP 213 EP 218 DI 10.1016/S0254-0584(98)00102-3 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA ZY880 UT WOS:000074671500043 ER PT J AU Holcomb, GR Cryer, CB AF Holcomb, GR Cryer, CB TI Cost of impressed current cathodic protection for coastal Oregon bridges SO MATERIALS PERFORMANCE LA English DT Article AB The State of Oregon is using arc-sprayed zinc coatings to serve as anodes in impressed current cathodic protection (CP) systems on corrosion-damaged portions of reinforced concrete coastal bridges. Total project costs are detailed, including zinc coating anode application and other CP materials and installation. Repair procedures are described. C1 US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. Oregon Dept Transportat, Bridge Sect, Salem, OR 97310 USA. RP Holcomb, GR (reprint author), US Dept Energy, Albany Res Ctr, Albany, OR 97321 USA. RI Holcomb, Gordon/G-9070-2013 OI Holcomb, Gordon/0000-0003-3542-5319 NR 6 TC 4 Z9 4 U1 1 U2 3 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORMANCE JI Mater. Perform. PD JUL PY 1998 VL 37 IS 7 BP 22 EP 26 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA ZZ398 UT WOS:000074725400006 ER PT J AU Kloc, M Larabell, C Chan, APY Etkin, LD AF Kloc, M Larabell, C Chan, APY Etkin, LD TI Contribution of METRO pathway localized molecules to the organization of the germ cell lineage SO MECHANISMS OF DEVELOPMENT LA English DT Article DE development; oogenesis; RNA localization; Xenopus laevis; germ plasm ID BOX TRANSCRIPTION FACTOR; MATERNAL MESSENGER-RNA; XENOPUS-OOCYTES; DROSOPHILA OOGENESIS; VEGETAL CORTEX; ENDOPLASMIC-RETICULUM; MESODERM FORMATION; STEM-CELLS; PLASM; EMBRYOS AB To elucidate the potential role of localized components in the specification of the germ cell lineage we analyzed the composition of the germ plasm in Xenopus laevis oocytes and early embryos with respect to the vegetally-localized RNAs. We focused on Xlsirts, Xcat2, and Xwnt11 transcripts that are localized to the vegetal cortex through a region of the mitochondrial cloud called the messenger transport organizer (METRO) that also contains the nuage or germ plasm. At the ultrastructural level Xcat2 mRNA was detected on germinal granules while Xlsirts and Xwnt11 were associated with a fibrillar network of the germ plasm in stage-1 and stage-4 oocytes. In embryos, we found that all three RNAs remained associated with the germ plasm. Vg1 mRNA, a transcript localized through the late pathway, was excluded from the germ plasm in oocytes and embryos. Addtionally, we detected the protein spectrin within 16 cell nests of germ cells, in a structure reminiscent of the Drosophila spectrosome. Spectrin was detected in the mitochondrial cloud and was found in the germ plasm during embryogrenesis. These data indicate that the various RNAs found within METRO and the protein spectrin are integral components of the Xenopus germ plasm with the RNAs being associated with different subcellular structures. They also suggest that the pathway through which RNAs are localized during oogenesis may be an important factor in biasing their distribution into specific cell lineages. The presence of Xwnt11 in the germ cell lineage suggests that a wnt-directed signaling pathway may be involved in germ cell specification, differentiation or migration. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved. C1 Univ Texas, MD Anderson Canc Ctr, Dept Mol Genet, Houston, TX 77030 USA. Univ Calif Berkeley, Lawrence Berkeley Labs, Berkeley, CA 94720 USA. RP Etkin, LD (reprint author), Univ Texas, MD Anderson Canc Ctr, Dept Mol Genet, 1515 Holcombe Blvd, Houston, TX 77030 USA. EM lde@mdacc.tmc.edu FU NCI NIH HHS [CA 16672] NR 75 TC 66 Z9 67 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-4773 J9 MECH DEVELOP JI Mech. Dev. PD JUL PY 1998 VL 75 IS 1-2 BP 81 EP 93 DI 10.1016/S0925-4773(98)00086-0 PG 13 WC Developmental Biology SC Developmental Biology GA 121PX UT WOS:000076023500006 PM 9739112 ER PT J AU Turchi, PEA Schwarz, RB Perepezko, JH AF Turchi, PEA Schwarz, RB Perepezko, JH TI Symposium on Structure and Properties of Bulk Amorphous Alloys - Foreword SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Editorial Material C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Wisconsin, Madison, WI 53706 USA. RP Turchi, PEA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1775 EP 1776 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100001 ER PT J AU Gottschall, RJ AF Gottschall, RJ TI Structure and properties of bulk amorphous alloys - Foreword address SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Editorial Material ID GLASSES C1 US DOE, Off Basic Energy Sci, Div Sci Mat, Germantown, MD 20874 USA. RP Gottschall, RJ (reprint author), US DOE, Off Basic Energy Sci, Div Sci Mat, Germantown, MD 20874 USA. NR 13 TC 4 Z9 4 U1 2 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1777 EP 1778 PG 2 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100002 ER PT J AU He, Y Shen, TD Schwarz, RB AF He, Y Shen, TD Schwarz, RB TI Bulk amorphous metallic alloys: Synthesis by fluxing techniques and properties SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Structure and Properties of Bulk Amorphous Alloys Symposium at the 1997 Annual Meeting of TMS CY FEB 10-11, 1997 CL ORLANDO, FL SP TMS-EMPMD/SMD Alloy Phases & MDMD Solidificat Comm, ASM-MSD Thermodynam & Phase Equilibria, Atom Transport Comm ID GLASS-TRANSITION TEMPERATURE; MOLD CASTING METHOD; UNDERCOOLED MELTS; CRYSTAL-GROWTH; ELASTIC-MODULI; HEAT-CAPACITY; NI; LIQUID; PD; SOLIDIFICATION AB Bulk amorphous alloys having dimensions of at least 1 cm in diameter have been prepared in the Pd-Ni-P, Pd-Cu-P, Pd-Cu-Ni-P, and Pd-Ni-Fe-P systems using a fluxing and water-quenching technique. The compositions for bulk glass formation have been determined in these systems. For these bulk metallic glasses, the difference between the crystallization temperature (T-x) and the glass transition temperature (T-g, Delta T = T-x - T-g) ranges from 60 to 110 K. These large values of Delta T open the possibility for the fabrication of amorphous near-net-shaped components using techniques such as injection molding. The thermal, elastic, and magnetic properties of these alloys have been studied, and we have found that bulk amorphous Pd40Ni22.5Fe17.5P20 has spin glass behavior for temperatures below 30 K. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP He, Y (reprint author), Intel Corp, Chandler, AZ 85226 USA. NR 61 TC 50 Z9 51 U1 2 U2 15 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1795 EP 1804 DI 10.1007/s11661-998-0002-8 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100004 ER PT J AU Egami, T Dmowski, W He, Y Schwarz, RB AF Egami, T Dmowski, W He, Y Schwarz, RB TI Structure of bulk amorphous Pd-Ni-P alloys determined by synchrotron radiation SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Structure and Properties of Bulk Amorphous Alloys Symposium at the 1997 Annual Meeting of TMS CY FEB 10-11, 1997 CL ORLANDO, FL SP TMS-EMPMD/SMD Alloy Phases & MDMD Solidificat Comm, ASM-MSD Thermodynam & Phase Equilibria, Atom Transport Comm ID X-RAY-SCATTERING; GLASS-FORMATION; METALLIC-GLASS; TEMPERATURE AB The atomic structure of Pd-Ni-P bulk amorphous alloys was studied by the anomalous (resonance) X-ray scattering technique using synchrotron radiation tuned near the Pd K-edge. Bulk samples of Pd(40)Ni(40)P(20), Pd(30)Ni(50)P(20), and Pd(50)Ni(34)P(16) amorphous alloys were prepared by the flux method in the form of rods. The results show that the structure of these alloys can be described basically by the dense random packed structure with small chemical short-range order. It is suggested that the exceptional stability of these glasses originates mainly from the instability of the competing crystalline phases rather than the atomic ordering in these glasses. C1 Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Egami, T (reprint author), Univ Penn, Dept Mat Sci & Engn, 3231 Walnut St, Philadelphia, PA 19104 USA. NR 20 TC 31 Z9 32 U1 1 U2 8 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1805 EP 1809 DI 10.1007/s11661-998-0003-7 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100005 ER PT J AU Liu, CT Heatherly, L Easton, DS Carmichael, CA Schneibel, JH Chen, CH Wright, JL Yoo, MH Horton, JA Inoue, A AF Liu, CT Heatherly, L Easton, DS Carmichael, CA Schneibel, JH Chen, CH Wright, JL Yoo, MH Horton, JA Inoue, A TI Test environments and mechanical properties of Zr-base bulk amorphous alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Structure and Properties of Bulk Amorphous Alloys Symposium at the 1997 Annual Meeting of TMS CY FEB 10-11, 1997 CL ORLANDO, FLORIDA SP TMS-EMPMD/SMD Alloy Phases & MDMD Solidificat Comm, ASM-MSD Thermodynam & Phase Equilibria, Atom Transport Comm ID SUPERCOOLED LIQUID REGION; METALLIC GLASSES; TEMPERATURE EMBRITTLEMENT; NI; FRACTURE; FE; STABILITY; BEHAVIOR; FLOW; CO AB The mechanical properties of two Zr-base bulk amorphous alloys (BAA), Zr-1oAl-30Cu-5Ni (BAA-10) and Zr-10Al-5Ti-17.9Cu-14.6Ni (BAA-11), were studied by both tensile and compressive tests at room temperature in various test environments. The BAA ingots up to 7 mm in diameter were successfully produced by both are melting and drop casting and induction melting and injection casting. The BAA specimens deformed mainly elastically, followed by catastrophic failure along shear bands. Examination of the fracture region revealed ductile fracture features resulting from a substantial increase in temperature, which was attributable to the conversion of the stored elastic strain energy to heat. Surprisingly, "liquid droplets" located at major shear-band cracks adjacent to the fracture section were observed, indicating the occurrence of local melting during fracture. The angle orientation of shear bands, shear-band cracks, and fracture surfaces relative to the stress axis is quite different for BAA specimens tested in tension and compression. This suggests that both shear stress and normal stress may play a role in developing shear bands during plastic deformation. The tensile properties of BAAs were found to be insensitive to the test environment at room temperature. However, the reaction of BAAs with distilled water and heavy water was detected by laser desorption mass spectrometry (LDMS). These results suggest that moisture-induced hydrogen embrittlement in BAAs may be masked by catastrophic fracture following shear bands. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. RP Liu, CT (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Inoue, Akihisa/E-5271-2015; OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 35 TC 435 Z9 468 U1 10 U2 105 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1811 EP 1820 DI 10.1007/s11661-998-0004-6 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100006 ER PT J AU Nicholson, DMC Stocks, GM Shelton, WA Wang, Y Swihart, JC AF Nicholson, DMC Stocks, GM Shelton, WA Wang, Y Swihart, JC TI Ab initio studies of the electronic structure and energetics of bulk amorphous metals SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Structure and Properties of Bulk Amorphous Alloys Symposium at the 1997 Annual Meeting of TMS CY FEB 10-11, 1997 CL ORLANDO, FLORIDA SP TMS-EMPMD/SMD Alloy Phases & MDMD Solidificat Comm, ASM-MSD Thermodynam & Phase Equilibria, Atom Transport Comm ID COPPER MOLD; X-RAY; ALLOYS; GLASSES; ORDER; CRYSTALLIZATION; TEMPERATURE; ENERGY AB Bulk amorphous metals (BAMs) are an interesting class of new materials possessing unique properties that offer exciting possibilities for applications to a broad range of technologies. In contrast to the previous generation of amorphous metals, BAMs can be produced in bulk form at cooling rates as low as similar to 1 K/s. The understanding of the structure, properties, and required cooling rates for BAM formation is hindered by the large number of constituents in typical alloys. In this article, we present the results of first principles local density approximation studies of the electronic structure and energetics of model Ni-Pd-P, Zr-Ni-Cu, and Zr-Ni-Al amorphous alloys that relate to two of the simplest BAMs, namely, Ni0.4Pd0.4P0.2 and Zr0.6Al0.15Ni0.25. The calculations are based on large unit cell (similar to 300-atom) structural models for which the electronic structure is calculated using the first principles order-N locally self-consistent multiple scattering method. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Pittsburgh Super Comp Ctr, Pittsburgh, PA 15213 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. RP Nicholson, DMC (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Stocks, George Malcollm/Q-1251-2016 OI Stocks, George Malcollm/0000-0002-9013-260X NR 30 TC 12 Z9 12 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1845 EP 1851 DI 10.1007/s11661-998-0009-1 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100011 ER PT J AU Pike, LM Liu, CT Chang, YA AF Pike, LM Liu, CT Chang, YA TI Effect of Ni on vacancy concentrations and hardness in FeAl alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID EMBRITTLEMENT; ADDITIONS AB The effects of nickel additions to iron aluminides are investigated with respect to vacancy concentrations and solid-solution hardening. Lattice parameters, densities, vacancy concentrations, and hardnesses were measured for FeAl alloys (40, 45, 48, 50, and 51 at. pct Al) with up to 12 at. pct Ni additions, as quenched at both 700 degrees C and 1000 degrees C. It is found that Ni does not prevent the elimination of thermal vacancies, as has been suggested in previous studies. However, the equilibrium vacancy concentrations are affected by the Ni additions. No clear evidence of solid-solution hardening by the Ni additions themselves was found. Instead, it appears that the role of Ni in hardening FeAl is through the effect the Ni has on the vacancy concentration. It was found that the hardness of most of the Ni-containing FeAl alloys could be directly correlated to the square root of the vacancy concentration. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Pike, LM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 23 TC 14 Z9 15 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1998 VL 29 IS 7 BP 1911 EP 1915 DI 10.1007/s11661-998-0015-3 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 104BJ UT WOS:000074992100017 ER PT J AU Treiman, AH Romanek, CS AF Treiman, AH Romanek, CS TI Bulk and stable isotopic compositions of carbonate minerals in Martian meteorite Allan Hills 84001: No proof of high formation temperature SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SYSTEM CACO3-MGCO3-FECO3; DIAGENETIC SIDERITE; AQUEOUS ALTERATION; SNC METEORITES; ALH84001; DOLOMITE; CHEMISTRY; CALCITE; MARS; CONCRETIONS AB Understanding the origin of carbonate minerals in the Martian meteorite Allan Hills (ALH) 84001 is crucial to evaluating the hypothesis that they contain traces of ancient Martian life. Using arguments based on chemical equilibria among carbonates and fluids, an origin at >650 degrees C (inimical to life) has been proposed. However, the bulk and stable isotopic compositions of the carbonate minerals are open to multiple interpretations and so lend no particular support to a high-temperature origin. Other methods (possibly less direct) will have to be used to determine the formation temperature of the carbonates in ALH 84001. C1 Lunar & Planetary Inst, Houston, TX 77058 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Treiman, AH (reprint author), Lunar & Planetary Inst, 3600 Bay Area Blvd, Houston, TX 77058 USA. NR 41 TC 39 Z9 39 U1 0 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 BP 737 EP 742 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 114GV UT WOS:000075601500019 PM 11543073 ER PT J AU Romanek, CS Perry, EC Treiman, AH Socki, RA Jones, JH Gibson, EK AF Romanek, CS Perry, EC Treiman, AH Socki, RA Jones, JH Gibson, EK TI Oxygen isotopic record of silicate alteration in the Shergotty-Nakhla-Chassigny meteorite Lafayette SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID MARS VOLATILE EVOLUTION; SNC METEORITES; AQUEOUS ALTERATION; MARTIAN VOLATILES; STABLE ISOTOPES; ALH84001; CARBONATE; ORIGIN; TEMPERATURE; EETA-79001 AB Samples from a suite of Shergotty-Nakhla-Chassigny (SNC) meteorites were analyzed for their O isotopic ratios by a modified version of the laser fluorination technique. Measured isotopic ratios (O-17/O-16 and O-18/O-16) from bulk samples of the Shergottites, EETA79001, Shergotty and Zagami; the Nakhlite Lafayette; and Chassigny are similar to those reported in the literature, as are those from olivine and pyroxene mineral separates from Lafayette. Iddingsite, a preterrestrial alteration product of Lafayette, was measured for the first time as a separate phase. Oxygen isotopic ratios increase with the percentage of iddingsite in a sample to a maximum delta(18)O of 14.4 parts per thousand for a similar to 90% separate. Based on these measurements, end-member iddingsite has a delta(18)O of 15.6 parts per thousand, which places it among other O-18-enriched secondary phases (carbonate and silica) observed in SNC meteorites. The relatively large difference in delta(18)O between iddingsite and the olivine and pyroxene it replaces (similar to 11 parts per thousand) is typical of low-temperature alteration products. A range of crustal fluid delta(18)O values can be interpreted from the delta(18)O for end-member iddingsite, assuming isotopic equilibrium was achieved during low-temperature hydrous alteration (<100 degrees C; Treiman et al., 1993). The calculated range of values, -15 to 5 parts per thousand, depends on many factors including: (1) the modal mineralogy of iddingsite, (2) potential isotopic exchange among other O-bearing phases such as host silicate and carbonate, and (3) exchange with evolved or exotic O reservoirs on Mars. Despite the lack of constraints, the calculated range is consistent with isotopic exchange, and possibly equilibria, among components of the CO2-carbonate-iddingsite-H2O system at low temperature. The SNC meteorite samples in this study have Delta(17)O values that are indistinguishable from bulk Mars (0.30 parts per thousand), except for a single, small sample of iddingsite that has an anomalous Delta(17)O of similar to 1.4 parts per thousand. While analytical difficulties make isotopic measurements for this sample problematic, the Delta(17)O is similar in direction to Delta(17)O reported for waters extracted from bulk samples of Lafayette (Karlsson et al., 1992). If the Delta(17)O for iddingsite is confirmed, it can be concluded that evolved or exotic fluids on Mars have contributed volatiles to the O reservoir from which iddingsite formed 130 to 700 Ma ago. C1 Univ Georgia, Dept Geol, Aiken, SC 29802 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. No Illinois Univ, Dept Geol, De Kalb, IL 60115 USA. Lunar & Planetary Inst, Houston, TX 77058 USA. Lockheed Martin, Houston, TX 77058 USA. NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Univ Georgia, Dept Geol, Drawer E, Aiken, SC 29802 USA. EM romanek@srel.edu NR 76 TC 37 Z9 37 U1 1 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 BP 775 EP 784 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 114GV UT WOS:000075601500023 ER PT J AU Fisler, DK Cygan, RT AF Fisler, DK Cygan, RT TI Cation diffusion in calcite: Determining closure temperatures and the thermal history for the Allan Hills 84001 meteorite SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ALH84001; CARBONATE; EXCHANGE; SYSTEMS; ORIGIN; MARS AB The presence of zoned Fe, Mg, Ca, and Mn in the carbonate phases associated with the cracks and inclusions of the Allan Hills (ALH) 84001 meteorite provides evidence for constraining the thermal history of the meteorite. Using self- and tracer-diffusion coefficients obtained from laboratory experiments on natural calcite, cooling rates are calculated for various temperatures and diffusion distances to assist in the evaluation of the compositional zoning associated with the carbonate phases in ALH 84001. The closure temperature model provides the average temperature below which compositional zoning will be preserved for a given cooling rate, that is, the temperature at which diffusion will be ineffective in homogenizing the phase. The validity of various theories for the formation of the carbonate globules may be examined, therefore, in view of the diffusion-limited kinetic constraints. Experiments using a thin film-mineral diffusion couple and ion microprobe for depth profiling analysis were performed for the temperature range of 550-800 degrees C to determine self- and tracer-diffusion coefficients for Ca and Mg and in calcite. The resulting activation energies for Ca (E-a(Ca) = 271 +/- 80 kJ/mol) and for Mg (E-a(Mg) = 284 +/- 74 kJ/mol) were used then to calculate a series of cooling rate, grain size, and closure temperature curves. The data indicate, for example, that by the diffusion of Mg in calcite, a 10 mu m compositional zone would be completely homogenized at a temperature of 300 degrees C for cooling rates <100 K/Ma. These data provide no constraint on formation models that propose a low-temperature fluid precipitation mechanism; however, they indicate that the carbonate globules were not exposed to a high-temperature environment for long time scales following formation. C1 Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Fisler, DK (reprint author), Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. FU NIDCR NIH HHS [DE-AC04-94AL85000] NR 24 TC 12 Z9 12 U1 0 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 BP 785 EP 789 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 114GV UT WOS:000075601500024 PM 11543076 ER PT J AU Daulton, TL Lewis, RS Amari, S AF Daulton, TL Lewis, RS Amari, S TI Polytype variations in presolar silicon carbide grains: Microstructural characterization by transmission electron microscopy. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID MURCHISON METEORITE; SIC GRAINS C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. NR 4 TC 4 Z9 5 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A37 EP A38 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000064 ER PT J AU Greenwood, JP Riciputi, LR Taylor, LA McSween, HY AF Greenwood, JP Riciputi, LR Taylor, LA McSween, HY TI Hydrothermal modification of sulfides in Nakhla, Lafayette, and Chassigny. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID SHERGOTTITES; METEORITES C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Geol Sci, Knoxville, TN 37996 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A62 EP A63 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000109 ER PT J AU Hutcheon, ID Krot, AN Keil, K Phinney, DL Scott, ERD AF Hutcheon, ID Krot, AN Keil, K Phinney, DL Scott, ERD TI Manganese-53/chromium-53 dating of fayalite in Mokoia: Evidence for asteroidal alteration of CV chondrites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A72 EP A73 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000129 ER PT J AU Jull, AJT Bland, PA Klandrud, S McHargue, LR Nishiizumi, K Caffee, MW AF Jull, AJT Bland, PA Klandrud, S McHargue, LR Nishiizumi, K Caffee, MW TI Cosmogenic radionuclide studies of desert meteorites, including a new lunar meteorite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID TERRESTRIAL C1 Univ Arizona, Natl Sci Fdn, AMS Facil, Tucson, AZ 85721 USA. Open Univ, Milton Keynes MK7 6AA, Bucks, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A80 EP A80 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000142 ER PT J AU Lawrence, DJ Feldman, WC Binder, AB Maurice, S Barraclough, BL Elphic, RC AF Lawrence, DJ Feldman, WC Binder, AB Maurice, S Barraclough, BL Elphic, RC TI Mapping the elemental composition of the moon: Current results of the lunar prospector gamma-ray spectrometer SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Observ Midi Pyrenees, F-31400 Toulouse, France. Lunar Res Inst, Gilroy, CA 95020 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 3 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A92 EP A92 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000166 ER PT J AU Nicolussi, GK Pellin, MJ Lewis, RS Davis, AM Clayton, RN Amari, S AF Nicolussi, GK Pellin, MJ Lewis, RS Davis, AM Clayton, RN Amari, S TI Strontium isotopes in single presolar silicon carbide grains. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Argonne Natl Lab, Div Chem & Mat Sci, Argonne, IL 60439 USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 8 TC 2 Z9 2 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A116 EP A117 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000209 ER PT J AU Nishiizumi, K Caffee, MW AF Nishiizumi, K Caffee, MW TI Measurements of cosmogenic calcium-41 and calcium-41/chlorine-36 terrestrial ages. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID EXPOSURE C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NR 3 TC 11 Z9 11 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A117 EP A117 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000210 ER PT J AU Reedy, RC AF Reedy, RC TI Variations in solar-proton fluxes over the last million years. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM rreedy@lanl.gov RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 6 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A127 EP A127 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000231 ER PT J AU Reedy, RC Feldman, WC Barraclough, BL Binder, AB Elphic, RC Lawrence, DJ Maurice, S Masarik, J AF Reedy, RC Feldman, WC Barraclough, BL Binder, AB Elphic, RC Lawrence, DJ Maurice, S Masarik, J TI Fast neutrons from the moon: Measured and calculated fluxes. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Comenius Univ, Bratislava, Slovakia. Observ Midi Pyrenees, F-31400 Toulouse, France. Lunar Res Inst, Gilroy, CA 95020 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Lawrence, David/E-7463-2015 OI Lawrence, David/0000-0002-7696-6667 NR 5 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A127 EP A128 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000232 ER PT J AU Sexton, AS Bland, PA Wolf, SF Franchi, IA Hough, RM Jull, AJT Klandrud, SE Berry, FJ Pillinger, CT AF Sexton, AS Bland, PA Wolf, SF Franchi, IA Hough, RM Jull, AJT Klandrud, SE Berry, FJ Pillinger, CT TI Anomalous chondrites from the Sahara. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Open Univ, Dept Chem, Milton Keynes MK7 6AA, Bucks, England. Univ Arizona, Arizona AMS Facil, Natl Sci Fdn, Tucson, AZ 85721 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Western Australian Museum, Perth, WA 6000, Australia. Open Univ, Planetary Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. NR 3 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A143 EP A143 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000261 ER PT J AU Wacker, JF Hildebrand, AR Brown, P Crawford, D Boslough, M Chael, E Revelle, D Doser, D Tagliaferri, E Rathbun, D Cooke, D Adcock, C Karner, J AF Wacker, JF Hildebrand, AR Brown, P Crawford, D Boslough, M Chael, E Revelle, D Doser, D Tagliaferri, E Rathbun, D Cooke, D Adcock, C Karner, J TI The Juancheng and El Paso superbolides of February 15, 1997, and October 9, 1997: Preatmospheric meteoroid sizes. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID ROBERT C1 Pacific NW Lab, Richland, WA 99352 USA. Geol Survey Canada, Ottawa, ON, Canada. Univ Western Ontario, Dept Phys, London, ON N6A 3K7, Canada. Sandia Natl Labs, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Texas, Dept Geol Sci, El Paso, TX 79968 USA. El Paso Med Ctr, El Paso, TX 79902 USA. Univ Texas, Dept Comp Sci, El Paso, TX 79968 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. ET Space Syst, Camarilo, CA 93012 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A160 EP A161 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000293 ER PT J AU Welten, KC Nishiizumi, K Caffee, MW Wieler, R AF Welten, KC Nishiizumi, K Caffee, MW Wieler, R TI Terrestrial ages of H chondrites from Frontier Mountain, Antarctica. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID METEORITES C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. ETH Zurich, CH-8092 Zurich, Switzerland. NR 6 TC 0 Z9 0 U1 1 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A166 EP A167 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000304 ER PT J AU Zito, KL McKeegan, KD Kerridge, JF Hutcheon, ID Leshin, LA AF Zito, KL McKeegan, KD Kerridge, JF Hutcheon, ID Leshin, LA TI Aqueous alteration on the CI parent-body evidence from oxygen- and carbon-isotopic studies of single carbonate grains from Orgueil. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID CHONDRITES; METEORITES C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif San Diego, Dept Chem, La Jolla, CA 92093 USA. Univ Calif Lawrence Livermore Natl Lab, Isotope Sci Div, Livermore, CA 94551 USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 9 TC 2 Z9 2 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1998 VL 33 IS 4 SU S BP A171 EP A172 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 117JK UT WOS:000075778000313 ER PT J AU Gross, C Tobin, KW Jensen, D Mehta, D AF Gross, C Tobin, KW Jensen, D Mehta, D TI Assessing future technology requirements for rapid isolation and sourcing of faults SO MICRO LA English DT Editorial Material ID CLASSIFICATION C1 Intel Corp, Fab 17, Hudson, MA 01479 USA. Oak Ridge Natl Lab, Image Sci & Machine Vis Grp, Oak Ridge, TN 37831 USA. SEMATECH, AMD, Austin, TX 78741 USA. Semicond Res Corp, Res Triangle Pk, NC USA. RP Gross, C (reprint author), Intel Corp, Fab 17, Hudson, MA 01479 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU CANON COMMUNICATIONS INC PI SANTA MONICA PA 3340 OCEAN PARK BLVD, SUITE 1000, SANTA MONICA, CA 90405 USA SN 1081-0595 J9 MICRO JI Micro PD JUL-AUG PY 1998 VL 16 IS 7 BP 57 EP + PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 147ZR UT WOS:000077528200040 ER PT J AU Chandler, DP Brockman, FJ Bailey, TJ Fredrickson, JK AF Chandler, DP Brockman, FJ Bailey, TJ Fredrickson, JK TI Phylogenetic diversity of archaea and bacteria in a deep subsurface paleosol SO MICROBIAL ECOLOGY LA English DT Article ID RIBOSOMAL-RNA SEQUENCES; LENGTH-POLYMORPHISM ANALYSIS; COMMUNITY STRUCTURE; UNCULTURED MICROORGANISMS; HETEROTROPHIC BACTERIA; MICROBIAL-POPULATIONS; INSITU HYBRIDIZATION; PROBE HYBRIDIZATION; SEDIMENTS; GENES AB A low-biomass paleosol 188 m below the ground surface at the Department of Energy's Hanford Site in south-central Washington State was recovered and maintained at the in situ temperature (17 degrees C) as an intact core or homogenized sediment for 0, 1, 3, 10, and 21 weeks post-sampling. Bacterial and archaeal 16S rRNA genes were amplified by PCR and cloned. Of 746 bacterial and 190 archaeal clones that were categorized by restriction fragment length polymorphism (RFLP), 242 bacterial and 16 archaeal clones were partially sequenced and compared against the small subunit ribosomal RNA database (RDP) and GenBank. Six bacterial and 16 archaeal clones sequences, with little similarity to those in public databases, were sequenced in their entirety, and subjected to more detained phylogenetic analysis. The most frequently occurring clones types were related to Pseudomonas, Bacillus, Micrococcus, Clavibacter, Nocardioides, Burkholderia, Comamonas, and Erythromicrobium. Clone sequences whose RDP similarity value was greater than or equal to 0.6 consistently grouped with their nearest RDP neighbor during phylogenetic analysis. Six truly novel eubacterial sequences were identified; they consistently cluster with or near the Chloroflexaceae and sequences recovered from the Sargasso Sea. Sixteen unique archaeal RFLP groups were identified from 190 randomly-sampled clones. The novel archaeal rDNA clones formed a coherent clade along the major Crenarchaea branch containing all previously described mesophilic crenarchae clones, but remained firmly associated with 16S rDNA clones previously obtained from a thermal Fe/S spring in Yellowstone National Park. The wealth of group-specific genetic information identified during this study will now allow us to address specific hypotheses related to in situ stimulation of these deep subsurface microorganisms and changes in microbial community composition resulting from subsurface contamination or remediation processes at the Hanford Site. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Chandler, DP (reprint author), Pacific NW Lab, 900 Battelle Blvd, Richland, WA 99352 USA. EM dp_chandler@pnl.gov NR 72 TC 91 Z9 98 U1 1 U2 12 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0095-3628 J9 MICROBIAL ECOL JI Microb. Ecol. PD JUL-AUG PY 1998 VL 36 IS 1 BP 37 EP 50 DI 10.1007/s002489900091 PG 14 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA ZU805 UT WOS:000074236700005 ER PT J AU Leganes, F Fernandez-Pinas, F Wolk, CP AF Leganes, F Fernandez-Pinas, F Wolk, CP TI A transposition-induced mutant of Nostoc ellipsosporum implicates an arginine-biosynthetic gene in the formation of cyanophycin granules and of functional heterocysts and akinetes SO MICROBIOLOGY-UK LA English DT Article DE akinete; arginine; cyanophycin; differentiation; heterocyst ID SP-STRAIN PCC-7120; BLUE-GREEN-ALGA; GAMMA-SEMIALDEHYDE DEHYDROGENASE; ANABAENA-CYLINDRICA; NUCLEOTIDE-SEQUENCE; ESCHERICHIA-COLI; ARGC GENE; CYANOBACTERIUM; DIFFERENTIATION; POLYSACCHARIDES AB In strain NE1 of Tn5-1058-mutagenized Nostoc ellipsosporum, the transposon was found within a gene whose translation product is similar in amino acid sequence to the arginine-biosynthetic protein N-acetylglutamate semialdehyde dehydrogenase encoded by argC of Bacillus subtilis. The argC reported from Anabaena sp. strain PCC 7120 hybridized to a sequence different from the one interrupted by the transposon in NE1. The newly identified gene from N. ellipsosporum was denoted argL. The argL mutation renders certain processes in strain NE1 conditionally dependent on provision of L-arginine. Heterocysts and apparent akinetes that formed in the absence of added L-arginine failed to fix dinitrogen or to germinate, respectively, and lacked granules of cyanophycin, composed of copolymers of arginine and aspartic acid. However, apparent akinetes that differentiated upon growth of the mutant in the presence of L-arginine plus nitrate formed cyanophycin granules and could regenerate a new culture. C1 Univ Autonoma Madrid, Fac Ciencias, Dept Biol, E-28049 Madrid, Spain. Michigan State Univ, MSU DOE, Plant Res Lab, E Lansing, MI 48824 USA. RP Leganes, F (reprint author), Univ Autonoma Madrid, Fac Ciencias, Dept Biol, E-28049 Madrid, Spain. EM francisco.leganes@uam.es OI Fernandez-Pinas, Francisca/0000-0002-7444-7601 NR 40 TC 16 Z9 17 U1 0 U2 1 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING, BERKS, ENGLAND RG7 1AE SN 1350-0872 J9 MICROBIOL-UK JI Microbiology-(UK) PD JUL PY 1998 VL 144 BP 1799 EP 1805 PN 7 PG 7 WC Microbiology SC Microbiology GA 103KR UT WOS:000075000100011 PM 9695912 ER PT J AU Song, JJ Bajikar, S Decarlo, F Kang, YW Kustom, RL Mancini, DC Nassiri, A Lai, B Feinerman, AD White, V AF Song, JJ Bajikar, S Decarlo, F Kang, YW Kustom, RL Mancini, DC Nassiri, A Lai, B Feinerman, AD White, V TI LIGA-fabricated compact mm-wave linear accelerator cavities SO MICROSYSTEM TECHNOLOGIES LA English DT Article AB Millimeter-wave rf cavities for use in linear accelerators, free-electron lasers, and mm-wave undulators are under development at Argonne National Laboratory. Typical cavity dimensions are in the 1000 mu m range, and the overall length of the accelerator structure, which consists of 30-100 cavities, is about 50-100 mm. An accuracy of 0.2% in the cavity dimensions is necessary in order to achieve a high Q-factor of the cavity. To achieve this, these structures are being fabricated using deep X-ray lithography, electroforming, and assembly (LIGA). The first prototype cavity structures are designed for 108 GHz and 2 pi/3-mode operation. Input and output couplers are integrated with the cavity structures. The cavities are fabricated on copper substrates by electroforming copper into 1 mm-thick PMMA resists patterned by deep x-ray lithography and polishing the copper down to the desired thickness. These are fabricated separately and subsequently assembled with precision spacing and alignment using microspheres, optical fibers, or microfabricated spacers/alignment pieces. Details of the fabrication process, alignment, and assembly work are presented in here. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Illinois, Microfabricat Lab, Chicago, IL 60607 USA. Univ Wisconsin, Ctr Xray Lithog, Madison, WI 53706 USA. RP Song, JJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-7076 J9 MICROSYST TECHNOL JI Microsyst. Technol. PD JUL PY 1998 VL 4 IS 4 BP 193 EP 196 DI 10.1007/s005420050129 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 106EA UT WOS:000075115900009 ER PT J AU Lebensohn, RA Turner, PA Signorelli, JW Canova, GR Tome, CN AF Lebensohn, RA Turner, PA Signorelli, JW Canova, GR Tome, CN TI Calculation of intergranular stresses based on a large-strain viscoplastic self-consistent polycrystal model SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID PLASTIC-DEFORMATION; ZIRCONIUM; TEXTURE; CREEP AB We present here an extension of the viscoplastic self-consistent (VPSC) polycrystal model for the calculation of the intergranular Cauchy stresses in an aggregate. This method, which is based on the self-consistent treatment of incompressible aggregates proposed in 1987 by Molinari el al, is formulated using the inclusion formalism and full anisotropy is incorporated into it. The complete stress state in the grains is obtained by computing the deviatoric and the hydrostatic local deviations with respect to the overall corresponding magnitudes applied to the polycrystal. The extended VPSC model, followed by an elastic self-consistent unloading, is used to obtain the intergranular residual strains in the aggregate after large plastic deformation. The texture evolution and the hardening of the material are explicitly taken into account in the model. As an application, the model is used to predict intergranular residual states in Incoloy-800 plate after uniaxial deformation. C1 Univ Nacl Rosario, CONICET, Inst Fis Rosario, RA-2000 Rosario, Santa Fe, Argentina. Ecole Natl Super Phys Grenoble, GPM2, F-38402 St Martin Dheres, France. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Lebensohn, RA (reprint author), Univ Nacl Rosario, CONICET, Inst Fis Rosario, 27 Febrero 210 Bis, RA-2000 Rosario, Santa Fe, Argentina. RI Lebensohn, Ricardo/A-2494-2008; Tome, Carlos/D-5058-2013 OI Lebensohn, Ricardo/0000-0002-3152-9105; NR 21 TC 34 Z9 35 U1 1 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 1998 VL 6 IS 4 BP 447 EP 465 DI 10.1088/0965-0393/6/4/011 PG 19 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 121GH UT WOS:000076004600011 ER PT J AU Rhee, M Zbib, HM Hirth, JP Huang, H de la Rubia, T AF Rhee, M Zbib, HM Hirth, JP Huang, H de la Rubia, T TI Models for long-/short-range interactions and cross slip in 3D dislocation simulation of BCC single crystals SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID INTERNAL-STRESSES; DEFORMATION; TENSILE AB Models and rules for short-range interactions, cross slip and long-range interactions of dislocation segments for implementation in a 3D dislocation dynamics (3DD) model are developed. Dislocation curves of arbitrary shapes are discretized into sets of straight segments of mixed dislocations. Long-range interactions are evaluated explicitly based on results from the theory of dislocations. Models for short-range interactions, including, annihilation, formation of jogs, junctions, and dipoles, are developed on the basis of a 'critical-force' criterion that captures the effect of the local fields from surrounding dislocations. In addition, a model for the cross-slip mechanism is developed and coupled with a Monte Carlo type analysis to simulate the development of double cross slip and composite slip. The model is then used to simulate stage I (easy glide) stress-strain behaviour in BCC single crystals, illustrating the feasibility of the 3DD model in predicting macroscopic properties such as dow stress and hardening, and their dependence on microscopic parameters such as dislocation mobility, dislocatjon structure, and pinning points. C1 Sch Mech & Mat Engn, Pullman, WA 99164 USA. Lawrence Livermore Natl Lab, Livermore, CA 90224 USA. RP Zbib, HM (reprint author), Sch Mech & Mat Engn, Pullman, WA 99164 USA. RI Huang, Hanchen/A-9323-2008 NR 41 TC 134 Z9 139 U1 3 U2 28 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 1998 VL 6 IS 4 BP 467 EP 492 DI 10.1088/0965-0393/6/4/012 PG 26 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 121GH UT WOS:000076004600012 ER PT J AU Halpern, AL Bruno, WJ AF Halpern, AL Bruno, WJ TI Evolutionary distances for protein-coding sequences: Modeling site-specific residue frequencies SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE site-specific frequencies; evolutionary distances; selection; maximum likelihood; saturation; variable-rate models ID HIDDEN MARKOV-MODELS; MAXIMUM-LIKELIHOOD APPROACH; DNA-SEQUENCES; NUCLEOTIDE SUBSTITUTION; PHYLOGENY; MATRICES; TREES AB Estimation of evolutionary distances from coding sequences must take into account protein-level selection to avoid relative underestimation of longer evolutionary distances. Current modeling of selection via site-to-site rate heterogeneity generally neglects another aspect of selection, namely position-specific amino acid frequencies. These frequencies determine the maximum dissimilarity expected for highly diverged but functionally and structurally conserved sequences, and hence are crucial for estimating long distances. We introduce a codon-level model of coding sequence evolution in which position-specific amino acid frequencies are free parameters. In our implementation, these are estimated from an alignment using methods described previously. We use simulations to demonstrate the importance and feasibility of modeling such behavior; our model produces linear distance estimates over a wide range of distances, while several alternative models underestimate long distances relative to short distances. Site-to-site differences in rates, as well as synonymous/nonsynonymous and first/second/third-codon-position differences, arise as a natural consequence of the site-to-site differences in amino acid frequencies. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Halpern, AL (reprint author), Univ New Mexico, Hlth Sci Ctr, Dept Mol Genet & Microbiol, 915 Camino Salud, Albuquerque, NM 87131 USA. EM ahalpern@ender.unm.edu NR 36 TC 149 Z9 150 U1 0 U2 3 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD JUL PY 1998 VL 15 IS 7 BP 910 EP 917 PG 8 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA ZX078 UT WOS:000074477200013 PM 9656490 ER PT J AU Li, GC Ouyang, HH Li, XL Nagasawa, H Little, JB Chen, DJ Ling, CC Fuks, Z Cordon-Cardo, C AF Li, GC Ouyang, HH Li, XL Nagasawa, H Little, JB Chen, DJ Ling, CC Fuks, Z Cordon-Cardo, C TI Ku70: A candidate tumor suppressor gene for murine T cell lymphoma SO MOLECULAR CELL LA English DT Article ID DEPENDENT PROTEIN-KINASE; SEVERE COMBINED IMMUNODEFICIENCY; V(D)J RECOMBINATION; HIRSCHSPRUNG DISEASE; CATALYTIC SUBUNIT; STRANDED-DNA; SCID MICE; MUTATION; REPAIR; MOUSE AB We present evidence that inactivation of the Ku70 gene leads to a propensity for malignant transformation both in vitro and in vivo. In vitro, Ku70(-/-) mouse fibroblasts displayed an increased rate of sister chromatid exchange and a high frequency of spontaneous neoplastic transformation. In vivo, Ku70(-/-) mice, known to be defective in B but not T lymphocyte maturation, developed thymic and disseminated T cell lymphomas at a mean age of 6 months with CD4(+)CD8(+) tumor cells. These findings directly demonstrate that Ku70 deficiency facilitates neoplastic growth and suggest a novel role of the Ku70 locus in tumor suppression. C1 Mem Sloan Kettering Canc Ctr, Dept Radiat Oncol, New York, NY 10021 USA. Mem Sloan Kettering Canc Ctr, Dept Phys Med, New York, NY 10021 USA. Mem Sloan Kettering Canc Ctr, Dept Pathol, New York, NY 10021 USA. Harvard Univ, Sch Publ Hlth, Radiobiol Lab, Boston, MA 02115 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Li, GC (reprint author), Mem Sloan Kettering Canc Ctr, Dept Radiat Oncol, 1275 York Ave, New York, NY 10021 USA. EM g-li@ski.mskcc.org FU NCI NIH HHS [CA-31397, CA-56909] NR 47 TC 171 Z9 171 U1 0 U2 2 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 1097-2765 J9 MOL CELL JI Mol. Cell. PD JUL PY 1998 VL 2 IS 1 BP 1 EP 8 DI 10.1016/S1097-2765(00)80108-2 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 106WR UT WOS:000075174500001 PM 9702186 ER PT J AU Heffelfinger, GS Ford, DM AF Heffelfinger, GS Ford, DM TI Massively parallel dual control volume grand canonical molecular dynamics with LADERA I. Gradient driven diffusion in Lennard-Jones fluids SO MOLECULAR PHYSICS LA English DT Article ID SIMULATION; ENSEMBLE; ALGORITHM; FLOW AB A new algorithm to enable the implementation of dual control volume grand canonical molecular dynamics (DCV-GCMD) on massively parallel (MP) architectures is presented. DCV-GCMD can be thought of as hybridization of molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) and was developed recently to make possible the simulation of gradient-driven diffusion. The method has broad application to such problems as membrane separations, drug delivery systems, diffusion in polymers and zeolites, etc. The massively parallel algorithm for the DCV-GCMD method has been implemented in a code named LADERA which employs the short range Lennard-Jones potential for pure fluids and multicomponent mixtures including bulk and confined (single pore as well as amorphous solid materials) systems. Like DCV-GCMD, LADERA's MP algorithm can be thought of as a hybridization of two different algorithms, spatial MD and spatial GCMC. The DCV-GCMD method is described fully followed by the DCV-GCMD parallel algorithm employed in LADERA. The scaling characteristics of the new MP algorithm are presented together with the results of the application of LADERA to ternary and quaternary Lennard-Jones mixtures. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Heffelfinger, GS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Ford, David/C-4027-2008 NR 29 TC 36 Z9 36 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUL PY 1998 VL 94 IS 4 BP 659 EP 671 DI 10.1080/002689798167827 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZY609 UT WOS:000074640800008 ER PT J AU Ford, DM Heffelfinger, GS AF Ford, DM Heffelfinger, GS TI Massively parallel dual control volume grand canonical molecular dynamics with LADERA II. Gradient driven diffusion through polymers SO MOLECULAR PHYSICS LA English DT Article AB This paper, the second part of a series, extends the capabilities of the LADERA FORTRAN code for massively parallel dual control volume grand canonical molecular dynamics (DCV-GCMD). DCV-GCMD is a hybrid of two more common molecular simulation techniques (grand canonical Monte Carlo and molecular dynamics)which allows the direct molecular-level modelling of diffusion under a chemical potential gradient. The present version of the code, LADERA-B has the capability of modelling systems with explicit intramolecular interactions such as bonds, angles, and dihedral rotations. The utility of the new code for studying gradient-driven diffusion of small molecules through polymers is demonstrated by applying it to two model systems. LADERA-B includes another new feature, which is the use of neighbour lists in force calculations. This feature increases the speed of the code but presents several challenges in the parallel hybrid algorithm. There is discussion on how these problems were addressed and how our implementation results in a significant increase in speed over the original LADERA. Scaling results are presented for LADERA-B on two massively parallel message-passing machines. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ford, DM (reprint author), Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA. RI Ford, David/C-4027-2008 NR 12 TC 39 Z9 39 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUL PY 1998 VL 94 IS 4 BP 673 EP 683 DI 10.1080/002689798167836 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZY609 UT WOS:000074640800009 ER PT J AU Bench, G Corzett, MH De Yebra, L Oliva, R Balhorn, R AF Bench, G Corzett, MH De Yebra, L Oliva, R Balhorn, R TI Protein and DNA contents in sperm from an infertile human male possessing protamine defects that vary over time SO MOLECULAR REPRODUCTION AND DEVELOPMENT LA English DT Article DE sperm chromatin; reproduction; male infertility; single-cell elemental analysis ID 2 FORMS; CHROMATIN AB Sperm from 2 semen samples collected 6 months apart from an infertile male and 3 semen samples collected over an 18-month period from a fertile human male volunteer have been analyzed for their protamine and DNA content. Hup1M and Hup2b antibodies were used to detect the presence of protamines and protamine precursors in western blots of nuclear proteins isolated from pools of sperm. Phosphorus and sulfur contents, which can be used to estimate the nuclear DNA and protamine contents of sperm from fertile males, were measured within individual sperm heads from each semen sample by particle induced x-ray emission (PIXE). The single-cell data reveal no significant differences in the phosphorus and sulfur contents of sperm heads in the three semen samples obtained from the fertile male. For the initial semen sample produced by the infertile male, Western blot data show a normal complement of protamine 1, small amounts of mature protamine 2, and reveal large amounts of anti-protamine 2 reactive proteins with electrophoretic mobilities similar to protamine 2 precursors. Data from PIXE show elevated levels of sulfur within sperm heads compared with sperm from the fertile male. Western blot data exhibit no evidence of protamines or protamine 2 precursors in the second semen sample produced by the infertile male. Data from PIXE suggest that these sperm are highly deficient in sulfur and protamines. These results show that the degree of maturation of sperm cells present in the semen of some infertile males can vary with time. (C) 1998 Wiley-Liss, Inc. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA USA. Univ Barcelona, Fac Med, Human Genome Res Grp, Barcelona 7, Spain. RP Bench, G (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, L-397, Livermore, CA 94550 USA. EM bench1@llnl.gov RI Oliva, Rafael/C-9741-2009 OI Oliva, Rafael/0000-0003-4876-2410 NR 24 TC 37 Z9 39 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-452X J9 MOL REPROD DEV JI Mol. Reprod. Dev. PD JUL PY 1998 VL 50 IS 3 BP 345 EP 353 DI 10.1002/(SICI)1098-2795(199807)50:3<345::AID-MRD11>3.0.CO;2-3 PG 9 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Reproductive Biology GA ZQ661 UT WOS:000073890400011 PM 9621311 ER PT J AU Gaasterland, T AF Gaasterland, T TI Structural genomics: Bioinformatics in the driver's seat SO NATURE BIOTECHNOLOGY LA English DT Article C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Gaasterland, T (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM gaasterland@mcs.anl.gov NR 9 TC 40 Z9 42 U1 0 U2 2 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD JUL PY 1998 VL 16 IS 7 BP 625 EP 627 DI 10.1038/nbt0798-625 PG 3 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZX494 UT WOS:000074521800022 PM 9661193 ER PT J AU Nolan, JP Sklar, LA AF Nolan, JP Sklar, LA TI The emergence of flow cytometry for sensitive, real-time measurements of molecular interactions SO NATURE BIOTECHNOLOGY LA English DT Review DE technology; biosensor; fluorescence; fusion proteins ID FACTOR-VIII; RECEPTOR DYNAMICS; KINETIC-ANALYSIS; BINDING-SITES; MICROSPHERES; PURIFICATION; SPECIFICITY; ANTIBODIES; MEMBRANES; PROTEINS AB The analysis of macromolecular interactions is an essential element of biomedical research. Flow cytometry is uniquely capable of making sensitive and quantitative measurements of molecular interactions. These measurements can be made in real time with subsecond kinetic resolution using purified biomolecules or living cells. Combined with automated sample handling, these features make flow cytometry a versatile and robust technology for the analysis of molecular interactions. C1 Univ Calif Los Alamos Natl Lab, Natl Flow Cytometry Resource & Life Sci Div, Los Alamos, NM 87545 USA. Univ New Mexico, Ctr Canc, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Pathol, Albuquerque, NM 87131 USA. RP Nolan, JP (reprint author), Univ Calif Los Alamos Natl Lab, Natl Flow Cytometry Resource & Life Sci Div, POB 1663, Los Alamos, NM 87545 USA. EM nolan@telomere.lanl.gov; lsklar@salud.unm.edu FU NCRR NIH HHS [RR01315] NR 47 TC 94 Z9 96 U1 0 U2 24 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD JUL PY 1998 VL 16 IS 7 BP 633 EP 638 DI 10.1038/nbt0798-633 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZX494 UT WOS:000074521800025 PM 9661195 ER PT J AU Connolly, KM Wojciak, JM Clubb, RT AF Connolly, KM Wojciak, JM Clubb, RT TI Site-specific DNA binding using a variation of the double stranded RNA binding motif SO NATURE STRUCTURAL BIOLOGY LA English DT Letter ID CONJUGATIVE TRANSPOSITION; PROTEIN STRUCTURES; NMR; RECOMBINATION; REARRANGEMENT; SEQUENCES; PROGRAM; DOMAIN AB The integrase family of site-specific recombinases catalyze a diverse array of DNA rearrangements in archaebacteria, eubacteria and yeast. The solution structure of the DNA binding domain of the integrase protein from the conjugative transposon Tn916 has been determined using NMR spectroscopy. The structure provides the first insights into distal site DNA binding by a site-specific integrase and reveals that the N-terminal domain is structurally similar to the double stranded RNA binding domain (dsRBD). The results of chemical shift mapping experiments suggest that the integrase protein interacts with DNA using residues located on the face of its three stranded beta-sheet. This surface differs from the proposed RNA binding surface in dsRBDs, suggesting that different surfaces on the same protein fold can be used to bind DNA and RNA. C1 Univ Calif Los Angeles, Dept Biochem & Chem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, US DOE, Lab Struct Biol & Genet, Los Angeles, CA 90095 USA. RP Clubb, RT (reprint author), Univ Calif Los Angeles, Dept Biochem & Chem, 405 Hilgard Ave, Los Angeles, CA 90095 USA. EM rclubb@mbi.ucla.edu NR 39 TC 35 Z9 36 U1 0 U2 0 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUL PY 1998 VL 5 IS 7 BP 546 EP 550 DI 10.1038/799 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZW821 UT WOS:000074451700012 PM 9665166 ER PT J AU Bittner, AC Echeverria, D Woods, JS Aposhian, HV Naleway, C Martin, MD Mahurin, RK Heyer, NJ Cianciola, M AF Bittner, AC Echeverria, D Woods, JS Aposhian, HV Naleway, C Martin, MD Mahurin, RK Heyer, NJ Cianciola, M TI Behavioral effects of low-level exposure to Hg-0 among dental professionals: A cross-study evaluation of psychomotor effects SO NEUROTOXICOLOGY AND TERATOLOGY LA English DT Article DE elemental mercury; dental exposures; psychomotor; CNS; occupational; chronic ID ELEMENTAL MERCURY; INORGANIC MERCURY; URINARY MERCURY; WORKERS; DENTISTS; VAPOR; PERFORMANCE AB A cross-study design was used to evaluate the sensitivities of five psychomotor tasks previously used to assess preclinical effects of low-level Hg-0 (urinary less than or equal to 55 mu g/l). Pooling dental professional subject populations from six studies conducted over the last 6 years, a larger study population was obtained with a high degree of uniformity (N = 230). The five psychomotor tests were: Intentional Hand Steadiness Test (IHST); Finger Tapping; The One-Hole Test; NES Simple Reaction Time (SRT); and Hand Tremor. Multivariate analyses were conducted following the hierarchical analysis of multiple responses (HAMR) approach. First, multiple scores of each test were combined into a single-factor (or related summary) variable and its reliability was estimated. Second, multiple regression analyses were conducted including log-transformed [Hg-0]U levels, age, gender, and alcohol consumption in each model. Computed were both B and b(u), the magnitudes of the log-Hg-0 standardized coefficient, respectively uncorrected and corrected for dependent variable attenuation due to unreliability. Results indicated remarkable differences in the effects of relative level of Hg-0 on psychomotor performance. Significant associations were found for the IHST factor (B = 0.415, p < 10(-6)), followed by finger tapping, which was relatively meager and insignificant (B = 0.141, p = 0.17). The IHST results hold the greatest occupational relevance for dental professionals who rely on manual dexterity in restorative dentistry. Further, this statistical approach is recommended in future studies for condensation of multiple scores into summary scores with enhanced reliabilities useful in correcting for attenuation relationships (B(u)s) with exposure levels. (C) 1998 Elsevier Science Inc. C1 Battelle Seattle Res Ctr, Ctr Publ Hlth Res & Evaluat, Seattle, WA 98105 USA. Univ Washington, Dept Environm Hlth, Seattle, WA 98195 USA. Univ Arizona, Dept Mol & Cellular Biol, Tucson, AZ 85721 USA. Amer Dent Assoc Hlth Fdn, Chicago, IL USA. Univ Washington, Dept Oral Med, Seattle, WA 98195 USA. Univ Washington, Dept Psychiat, Seattle, WA 98195 USA. RP Echeverria, D (reprint author), Battelle Seattle Res Ctr, Ctr Publ Hlth Res & Evaluat, 4000 NE 41st St, Seattle, WA 98105 USA. FU NIDCR NIH HHS [DE11712]; NIEHS NIH HHS [ES04696, ES04940] NR 40 TC 38 Z9 39 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0892-0362 J9 NEUROTOXICOL TERATOL JI Neurotoxicol. Teratol. PD JUL-AUG PY 1998 VL 20 IS 4 BP 429 EP 439 DI 10.1016/S0892-0362(98)00006-3 PG 11 WC Neurosciences; Toxicology SC Neurosciences & Neurology; Toxicology GA 105TF UT WOS:000075089100007 PM 9697969 ER PT J AU Saxe, H Ellsworth, DS Heath, J AF Saxe, H Ellsworth, DS Heath, J TI Tree and forest functioning in an enriched CO2 atmosphere SO NEW PHYTOLOGIST LA English DT Review DE elevated carbon dioxide (CO2); drought; forests; nutrients; photosynthesis; stomatal conductance ID ELEVATED CARBON-DIOXIDE; PICEA-ABIES L; PONDEROSA PINE-SEEDLINGS; BETULA-PENDULA ROTH; GAS-EXCHANGE RESPONSES; LONG-TERM EXPOSURE; CO2-INDUCED GROWTH ENHANCEMENTS; BEECH FAGUS-SYLVATICA; WATER-LOSS REGULATION; SITCHENSIS BONG CARR AB Forests exchange large amounts of CO2 with the atmosphere and can influence and be influenced by atmospheric CO2. There has been a recent proliferation of literature on the effects of atmospheric CO2 on forest trees. More than 300 studies of trees on five different continents have been published in the last five years. These include an increasing number of field studies with a long-term focus and involving CO2 x stress or environment interactions. The recent data on long-term effects of elevated atmospheric CO2 on trees indicate a potential for a persistent enhancement of tree growth for several years, although the only relevant long-term datasets currently available are for juvenile trees. The current literature indicates a significantly larger average long-term biomass increment under elevated CO2 for conifers (130%) than for deciduous trees (49%) in studies not involving stress components. However, stimulation of photosynthesis by elevated CO2 in long-term studies was similar for conifers (62 %) and deciduous trees (53 %). Recent studies indicate that elevated CO2 causes a more persistent stimulation of biomass increment and photosynthesis than previously expected. Results of seedling studies, however, might not be applicable to other stages of tree development because of complications of age-dependent and size-dependent shifts in physiology and carbon allocation, which are accelerated by elevated CO2. In addition, there are many possible avenues to down-regulation, making the predicted canopy CO2 exchange and growth of mature trees and forests in a CO2-rich atmosphere uncertain. Although, physiological down-regulation of photosynthetic rates has been documented in field situations, it is rarely large enough to offset entirely photosynthetic gains in elevated CO2. A persistent growth stimulation of individual mature trees has been demonstrated although this effect is more uncertain in trees in natural stands. Resource interactions can both constrain tree responses to elevated CO2 and be altered by them. Although drought can reduce gas-exchange rates and offset the benefits of elevated CO2, even in well watered trees, stomatal conductance is remarkably less responsive to elevated CO2 than in herbaceous species. Stomata of a number of tree species have been demonstrated to be unresponsive to elevated CO2. We conclude that positive effects of CO2 on leaf area can be at least as important in determining canopy transpiration as negative, direct effects of CO2 on stomatal aperture. With respect to nutrition, elevated CO2 has the potential to alter tree-soil interactions that might influence future changes in ecosystem productivity. There is continued evidence that in most cases nutrient limitations diminish growth and photosynthetic responses to elevated CO2 at least to some degree, and that elevated CO2 can accelerate the appearance of nutrient limitations with increasing time of treatment. In many studies, tree biomass responses to CO2 are artefacts in the sense that they are merely responses to CO2-induced changes in internal nutritional status of the tree. There are numerous interactions between CO2 and factors of the biotic and abiotic environment. The importance of increasing atmospheric CO2 concentrations for productivity is likely to be overestimated if these are not taken into account. Many interactions, however, are simply additive rather than synergistic or antagonistic. This appears to hold true for many parameters under elevated CO2 in combination with temperature, elevated O-3, and other atmospheric pollutants. However, there is currently little evidence that elevated CO2 will counteract O-3 damage. When the foliage content of C, mineral nutrients and secondary metabolites is altered by elevated CO2, tree x insect interactions are modified. In most trees, mycorrhizal interactions might be less important for direct effects of CO2 than for alleviating general nutrient deficiencies. Since many responses to elevated CO2 and their interactions with stress show considerable variability among species/genotypes, one principal research need is for comparative studies of a large variety of woody species and ecosystems under realistic conditions. We still need more long-term experiments on mature trees and stands to address critical scaling issues likely to advance our understanding of responses to elevated CO2 at different stages of forest development and their interactions with climate and environment. The only tools available at present for coping with the consequences of rising CO2 are management of resources and selection of genotypes suitable for the future climate and environment. C1 Royal Vet & Agr Univ, Arboretum, Inst Bot Dendrol & Forest Genet, DK-2970 Horsholm, Denmark. Brookhaven Natl Lab, Environm Biol & Instrumentat Div, Upton, NY 11973 USA. Univ Lancaster, Inst Environm & Nat Sci, Lancaster LA1 4YQ, England. RP Saxe, H (reprint author), Royal Vet & Agr Univ, Arboretum, Inst Bot Dendrol & Forest Genet, Kirkegaardsvej 3A, DK-2970 Horsholm, Denmark. EM hsa@kvl.dk OI Ellsworth, David/0000-0002-9699-2272 NR 275 TC 503 Z9 534 U1 19 U2 200 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0028-646X J9 NEW PHYTOL JI New Phytol. PD JUL PY 1998 VL 139 IS 3 BP 395 EP 436 DI 10.1046/j.1469-8137.1998.00221.x PG 42 WC Plant Sciences SC Plant Sciences GA 107VB UT WOS:000075230700001 ER PT J AU Lazarus, EA Hyatt, AW Jackson, GL Humphreys, DA AF Lazarus, EA Hyatt, AW Jackson, GL Humphreys, DA TI Using a multipole expansion for startup in the DIII-D tokamak SO NUCLEAR FUSION LA English DT Article ID BORONIZATION; PLASMA AB The magnetic field null conditions for plasma startup in DIII-D are established using a multipole expansion of the flux contribution from each element of the poloidal coil set to compute the vacuum magnetic field in real time using the measured coil currents. The use of this procedure has improved the breakdown conditions, as evidenced by the formation of the current channel with a toroidal electric field as low as 0.4 V/m without RF assistance. This represents a significant improvement over previous normal operation. Improved null conditions enhance the sensitivity of the minimum loop voltage to the wall conditions of the vacuum vessel. Results relating the breakdown voltage to carbon impurities are presented. It is shown that the observed difference between the radius of the poloidal field null and the radius of plasma initiation is a manifestation of finite aspect ratio, explained by the variation of the electric potential along the field line from the breakdown region to the wall. C1 Gen Atom Co, San Diego, CA 92186 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Lazarus, EA (reprint author), Gen Atom Co, San Diego, CA 92186 USA. NR 15 TC 14 Z9 14 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 1998 VL 38 IS 7 BP 1083 EP 1096 DI 10.1088/0029-5515/38/7/310 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 116QP UT WOS:000075736300010 ER PT J AU Jardin, SC Schmidt, JA AF Jardin, SC Schmidt, JA TI Numerical simulation of feedback stabilization of axisymmetric modes in tokamaks using driven halo currents SO NUCLEAR FUSION LA English DT Article ID TSC AB The Tokamak Simulation Code (TSC) has been used to model a new method of feedback stabilization of the axisymmetric instability in tokamaks using driven halo (or scrape-off layer) currents. The method appears to be feasible for a wide range of plasma edge parameters. It may offer advantages over the more conventional method of controlling this instability when applied in a reactor environment. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Jardin, SC (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Jardin, Stephen/E-9392-2010 NR 7 TC 3 Z9 3 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 1998 VL 38 IS 7 BP 1105 EP 1112 DI 10.1088/0029-5515/38/7/312 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 116QP UT WOS:000075736300012 ER PT J AU Hara, K Hata, K Kim, S Mishina, M Sano, M Seiya, Y Takikawa, K Tanaka, M Yasuoka, K AF Hara, K Hata, K Kim, S Mishina, M Sano, M Seiya, Y Takikawa, K Tanaka, M Yasuoka, K TI Radiation hardness and mechanical durability of Kuraray optical fibers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE fiber tracker; scintillating fiber; radiation damage; fiber transmittance AB The radiation hardness of Kuraray 3HF scintillating and clear optical fibers has been investigated using Co-60 gamma-rays in the dose range 0.4-500 krad. Significant initial degradation in the attenuation length was observed both for 3HF and clear fibers at a dose as small as 10 krad. The radiation hardness of both the scintillating and clear fibers is identical if it is expressed in terms of the ratio of the attenuation lengths after to before irradiation. The radiation damage of 3HF fibers was observed to recover substantially with a time scale of a few months. The attenuation length and mechanical durability against bending were measured for clear fibers by changing S parameter which characterizes the softness of the fibers. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 305, Japan. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Hara, K (reprint author), Univ Tsukuba, Inst Phys, Tsukuba, Ibaraki 305, Japan. NR 10 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1998 VL 411 IS 1 BP 31 EP 40 DI 10.1016/S0168-9002(98)00281-2 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VK UT WOS:000074835900003 ER PT J AU Shiltsev, VD AF Shiltsev, VD TI Fast PIN-diode beam loss monitors at Tevatron SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The article is devoted to results of fine temporal structure of particle losses in the Tevatron ring obtained with use of fast beam loss monitors (BLM) based on PIN-diodes. In the Tevatron fixed target operation regime, these monitors were able to distinguish proton losses from bunches spaced by only 19 ns. Besides measurements of main characteristics of the BLMs, we studied the proton losses over 10 decades of time intervals - from a dozen of minutes to a dozen of nanoseconds. Due to huge dynamical range and fast response the PIN-BLMs perfectly ht the task of the beam loss detection at the Tevatron collider upgrade with as small as 132 ns bunch spacing. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Shiltsev, VD (reprint author), Fermi Natl Accelerator Lab, MS 221,POB 500, Batavia, IL 60510 USA. NR 20 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 JUL 1 PY 1998 VL 411 IS 1 BP 81 EP 92 DI 10.1016/S0168-9002(98)00297-6 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VK UT WOS:000074835900009 ER PT J AU Muhrer, G Russell, GJ Ferguson, PD AF Muhrer, G Russell, GJ Ferguson, PD TI Flat target neutronics SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE spallation source; target station AB In this paper we will discuss the possibility of using a flat tungsten target as the target of a neutron spallation source. Therefore we investigated what influence the components of the target station, such as reflector material, moderator geometry, decoupler and target geometry, have on the neutronics of the target. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Hahn Meitner Inst Kernforsch Berlin GmbH, D-14109 Berlin, Germany. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Muhrer, G (reprint author), Hahn Meitner Inst Kernforsch Berlin GmbH, Glienicker Str 100, D-14109 Berlin, Germany. RI Lujan Center, LANL/G-4896-2012; OI Ferguson, Phillip/0000-0002-7661-4223 NR 6 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1998 VL 411 IS 1 BP 137 EP 152 DI 10.1016/S0168-9002(98)00309-X PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VK UT WOS:000074835900015 ER PT J AU Pogorelsky, IV AF Pogorelsky, IV TI Ultra-bright X-ray and gamma sources by Compton backscattering of CO2 laser beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE X-rays; CO2 laser; electron beam; Compton scattering ID THOMSON SCATTERING; PULSES; ACCELERATION; COLLIDERS; LIGHT AB A picosecond laser interacting with a relativistic electron beam behaves like a virtual wiggler of an extremely short period equal to half of the laser wavelength. This approach opens a route to compact, high-brightness laser synchrotron sources (LSS). We discuss how the emerging terawatt picosecond CO2 laser technology facilitates achieving the ultra-high peak flux and brightness desirable for LSS applications in science and technology. The first laser of this class is under development at the BNL Accelerator Test Facility (ATF). Together with the high-brightness 50 MeV electron beam available at the ATF, this laser will be used for a prototype LSS demonstration. Flashes of collimated 4.7 keV (2.6 Angstrom) X-rays of 3 ps pulse duration, with a flux of similar to 10(22) photons/s, may be produced via linear Compton backscattering. This is several orders of magnitude above the peak numbers attained by the conventional synchrotron sources. Exploiting the promising approach to a high-gradient laser wakefield accelerator, a "table-top" wakefield gamma LSS may become feasible in the near future. The prospective gamma-gamma and e(+/-)-gamma colliders in the TeV energy range are among the advanced applications of picosecond CO2 laser technology. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Accelerator Test Facil, Upton, NY 11973 USA. RP Pogorelsky, IV (reprint author), Brookhaven Natl Lab, Accelerator Test Facil, 725C, Upton, NY 11973 USA. EM igor@bnl.gov NR 20 TC 24 Z9 30 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 JUL 1 PY 1998 VL 411 IS 1 BP 172 EP 187 DI 10.1016/S0168-9002(98)00259-9 PG 16 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VK UT WOS:000074835900018 ER PT J AU Schweikhard, L Beiersdorfer, P Brown, GV Lopez-Urrutia, JRC Utter, SB Widmann, K AF Schweikhard, L Beiersdorfer, P Brown, GV Lopez-Urrutia, JRC Utter, SB Widmann, K TI Pulsed gas injection for X-ray spectroscopy of highly charged ions stored in the magnetic trapping mode of an electron beam ion trap SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE EBIT; X-ray spectroscopy; Penning trap; charge exchange; uranium; highly charged ions ID CAPTURE; COLLISIONS AB Highly charged atoms produced in an electron beam ion trap were stored after the electron beam was turned off by operating the trap in the magnetic trapping mode. Such storage allowed monitoring charge exchange reactions between the stored ions and residual neutral gas present in the trap by X-ray detection. The charge exchange reactions were enhanced by the application of a pulse of neutral gas. The method was exemplified for the case of H-like uranium interacting with neutral neon, where the K-shell X-rays and the series limit for the electron capture of U91+ were observed. Published by Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94550 USA. Univ Mainz, Inst Phys, D-55099 Mainz, Germany. RP Beiersdorfer, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, POB 808,Mailstop L-421, Livermore, CA 94550 USA. RI Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 23 TC 21 Z9 21 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1998 VL 142 IS 3 BP 245 EP 252 DI 10.1016/S0168-583X(98)00281-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 104UN UT WOS:000075034400002 ER PT J AU Wutte, D Freedman, S Gough, R Lee, Y Leitner, M Leung, KN Lyneis, C Pickard, DS Williams, MD Xie, ZQ AF Wutte, D Freedman, S Gough, R Lee, Y Leitner, M Leung, KN Lyneis, C Pickard, DS Williams, MD Xie, ZQ TI Development of an rf driven multicusp ion source for nuclear science experiments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article DE multicusp ion source; rf driven multicusp ion source; plasma ion source; radioactive ion beams AB A compact 13.56 MHz radio-frequency (rf) driven multicusp ion source is under development at Lawrence Berkeley National Laboratory (LBNL) for radioactive ion beam applications. In this paper we describe the ion source design and the general ion source performance using H-2, Ar, Xe gas and a 90% Ar/10% CO gas mixture for generating the discharge plasma. The following ion source characteristics have been analyzed: extractable ion current, ion species distributions, ionization efficiency for nobel gases, axial energy spread and ion beam emittance measurements. This ion source can generate ion current densities of approximately 60 mA/cm(2). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tech Univ Vienna, Inst Allgemeine Phys, Vienna, Austria. RP Wutte, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM dwutte@mhl.lbl.gov NR 6 TC 9 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1998 VL 142 IS 3 BP 409 EP 416 DI 10.1016/S0168-583X(98)00221-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 104UN UT WOS:000075034400020 ER PT J AU Gatley, SJ Ding, YS Brady, D Gifford, AN Dewey, SL Carroll, FI Fowler, JS Volkow, ND AF Gatley, SJ Ding, YS Brady, D Gifford, AN Dewey, SL Carroll, FI Fowler, JS Volkow, ND TI In vitro and ex vivo autoradiographic studies of nicotinic acetylcholine receptors using [F-18]fluoronorchloroepibatidine in rodent and human brain SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article DE epibatidine; nicotinic receptor; thalamus; fluorine-18; phosphor imaging ID H-3 CYTISINE BINDING; RAT-BRAIN; CHOLINERGIC RECEPTORS; MOUSE-BRAIN; REGIONAL DISTRIBUTION; ALPHA-BUNGAROTOXIN; EPIBATIDINE; SITES; MEMBRANES; THALAMUS AB A fluorine-18-labeled analog of the potent nicotinic agonist epibatidine is a candidate radioligand for positron emission tomographic (PET) studies of nicotinic acetylcholine receptors (nAcChR). Following intravenous administration of [F-18]exo-2-(2'-fluoro-5'-pyridinyl)-7-azabicylo[2.2.1]heptane (NFEP), high uptake in thalamus was visualized in sections of mouse and rat brain by autoradiography using a phosphor imaging, device. Binding of [[F-18]NFEP to rat thalamic homogenate was consistent with a single class of binding site with a Kd value of 71 FM. In vitro autoradiography of thaw-mounted sections of human thalamus revealed a heterogeneous pattern of binding; Bmax values for ventrolateral nucleus, insular cortex and dorsomedial nucleus, and internal capsule were 20, 8, and 3 pmol/cc of tissue, respectively. However, similar Kd values close to 50 pM were calculated for all regions. These studies support the suitability of [F-18]NFEP as a radioligand for PET studies of nAcChR in the living human brain. NUCL MED BIOL 25;5: 449-454 1998. (C) 1998 Elsevier Science Inc. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NIA, Neurosci Lab, Bethesda, MD 20892 USA. Res Triangle Inst, Res Triangle Pk, NC 27709 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11786 USA. RP Gatley, SJ (reprint author), Brookhaven Natl Lab, Dept Med, 490 Bell Ave, Upton, NY 11973 USA. FU NINDS NIH HHS [NS15380] NR 48 TC 20 Z9 21 U1 2 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0969-8051 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD JUL PY 1998 VL 25 IS 5 BP 449 EP 454 DI 10.1016/S0969-8051(98)00007-9 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZV536 UT WOS:000074314800002 PM 9720662 ER PT J AU Ooguri, H AF Ooguri, H TI Gauge theories on branes SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT 2nd Trieste Conference on Duality Symmetries in String Theory / Spring School on String Theory, Gauge Theory and Quantum Gravity CY APR 01-12, 1997 CL TRIESTE, ITALY ID YANG-MILLS THEORY; SUPERSYMMETRIC QCD; F-THEORY; N=2; DUALITY; COMPACTIFICATIONS; SINGULARITIES; BREAKING C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Theory Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, 366 Le Conte Hall, Berkeley, CA 94720 USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 25 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 EI 1873-3832 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 67 BP 172 EP 179 DI 10.1016/S0920-5632(98)00129-7 PG 8 WC Physics, Particles & Fields SC Physics GA ZH804 UT WOS:000073149300017 ER PT J AU Demarteau, M AF Demarteau, M TI Electroweak results from hadron colliders SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID W-BOSON MASS; YAN K-FACTOR; ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; PARTON DISTRIBUTIONS; CONTACT INTERACTION; PBARP COLLISIONS; GAMMA COUPLINGS; SECTOR; LIMITS AB A review of recent electroweak results from hadron colliders is given. Properties of the W+/- and Z(0) gauge bosons using final states containing electrons and muons based on large integrated luminosities are presented. The emphasis is placed on the measurement of the mass of the W boson and the measurement of trilinear gauge boson couplings. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Demarteau, M (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 45 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 12 EP 24 DI 10.1016/S0920-5632(98)00003-6 PG 13 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000003 ER PT J AU Landsberg, G AF Landsberg, G TI Trilinear gauge couplings at the Fermilab Tevatron SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; PHOTON COUPLINGS; GAMMA COUPLINGS; WZ PRODUCTION; LIMITS; WW; SEARCH AB Recent trilinear gauge boson couplings measurements by the CDF and DO Collaborations at the Fermilab Tevatron are presented. The measurements were done by analyzing diboson production in multiple decay channels and final states. No deviations from the Standard Model description of the WWZ, WW gamma, ZZ gamma and Z gamma gamma vertices were found. Limits on anomalous gauge couplings set by these analyses are the tightest available to date. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Landsberg, G (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. OI Landsberg, Greg/0000-0002-4184-9380 NR 15 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 79 EP 82 DI 10.1016/S0920-5632(98)00014-0 PG 4 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000014 ER PT J AU Flattum, E AF Flattum, E TI Measurement of the W boson mass at the Tevatron SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID DECAY AB Presented are measurements of the W boson mass from the Dempty set and CDF collaborations at the Tevatron from the 1994-1996 run. The W events are produced in collisions at root s = 1.8 TeV. The W mass extracted from W --> e nu decays at Dempty set is determined to be 80.45+/-0.12 GeV; and from W --> mu nu decays at CDF is 80.43+/-0.16 GeV. The world average W mass from the hadron collider measurements is 80.41+/-0.09 GeV. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Flattum, E (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 108 EP 111 DI 10.1016/S0920-5632(98)00021-8 PG 4 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000021 ER PT J AU Para, A AF Para, A TI Neutrino oscillations experiments: A review SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept AB This is an attempt to summarize three sessions of lively discussions, presentations of results and exchanges of new ideas. Present status and outlook of the future searches for neutrino oscillations is summarized. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Para, A (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 335 EP 341 DI 10.1016/S0920-5632(98)00058-9 PG 7 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000058 ER PT J AU Mills, GB AF Mills, GB TI Neutrino oscillation results from LSND SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID (NU)OVER-BAR(MU)->(NU)OVER-BAR(E) OSCILLATIONS; SEARCH; FACILITY; PHYSICS; BEAM; ISIS AB The Liquid Scintillator Neutrino Detector (LSND) experiment at Los Alamos has conducted searches for <(nu)over bar>(mu) --> <(nu)over bar>(e) oscillations by using <(nu)over bar>(mu) from mu(+) decay at rest and for nu(mu) --> nu(e) oscillations using nu(mu) from pi(+) decay in flight. For the <(nu)over bar>(mu) --> <(nu)over bar>(e) search, a total excess of 51.8(-16.9)(+18.7) +/- 8.0 events is observed with e(+) energy between 20 and 60 MeV, while for the nu(mu) --> nu(e) search, a total excess of 18.1 +/- 6.6 +/- 4.0 events is observed with e(-) energy between 60 and 200 MeV. If attributed to neutrino oscillations, these excesses correspond to oscillation probabilities (averaged over the experimental energies and spatial acceptances) of (0.31 +/- 0.12 +/- 0.05)% and (0.26 +/- 0.10 +/- 0.05)%, respectively. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mills, GB (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 382 EP 386 DI 10.1016/S0920-5632(98)00069-3 PG 5 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000069 ER PT J AU Adler, S AF Adler, S TI Status report on the search for K+->pi(+)nu(nu)over-bar and prospects for the search for K-L ->pi(0)nu(nu)over-bar SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID K->PI-NU(NU)OVER-BAR; MATRIX AB The status of the search for K+ --> pi(+)nu(nu)over-bar and future prospects for the search for K-L --> pi(0)nu(nu)over-bar are outlined in this report. AGS experiment 787, currently searching for the charged decay mode, has reached a single event sensitivity of 4.2 x 10(-10) with total background similar to 3 x 10(-11). Proposed AGS experiment 926 will search for the neutral version of this decay. Initial studies indicate that at the current Standard Model predicted rate for this decay, and 80 weeks of AGS 2000 running time [1], on the order of 70 K-L --> pi(0)nu(nu)over-bar should be recorded with a background level of less than 10 events. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Adler, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 466 EP 468 DI 10.1016/S0920-5632(98)00086-3 PG 3 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000086 ER PT J AU Ben-David, R AF Ben-David, R TI Status of the KTeV experiment at Fermilab SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID CP-VIOLATION; BRANCHING RATIO; LIMIT; DECAYS AB The KTeV experiment is a fixed target experiment at Fermilab. Its primary goal is the search for direct CP violation in the decay of neutral kaons. Its current status and some preliminary results will be discussed. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Ben-David, R (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 473 EP 477 DI 10.1016/S0920-5632(98)00088-7 PG 5 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000088 ER PT J AU Greenlee, H AF Greenlee, H TI Top quark results from the Tevatron SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept ID PRODUCTION CROSS-SECTION; COLLISIONS AB The CDF and Dempty set collaborations have collected top quark data samples consisting of several dozen events each. Using these data samples, the two Tevatron experiments have measured the top quark mass and pair production cross section in a variety of decay channels, including the act-called dilepton, lepton plus jets and all jets channels. The combined top quark mass from both experiments in the lepton plus jets channels is m(t) = 175.6+/-5.5 GeV/c(2). Additionally, upper limits have been obtained for certain rare or nonstandard (FCNC and charged Higgs) top quark decays. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Greenlee, H (reprint author), Fermi Natl Accelerator Lab, MS 357,POB 500, Batavia, IL 60510 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 502 EP 505 DI 10.1016/S0920-5632(98)00095-4 PG 4 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000095 ER PT J AU Crawford, G AF Crawford, G TI Recent progress in B-s mixing measurements SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XVI Workshop on Weak Interactions and Neutrinos (WIN 97) CY JUN 22-28, 1997 CL CAPRI, ITALY SP Univ Napoli, Phys Dept, Ist Nazl Fis Nucl, Azienda Autonoma Cura Soggiomo Turismo, Isola Capri, Hamamatsu Photon Italia Srl, CAEN, Nikon Europe B V Instruments Dept AB We review the status of B-s mixing measurements from LEP experiments, including new results from DELPHI. We briefly review the various experimental techniques used and their limitations and discuss the possibilities for improving these measurements in the near future. Including the new DELPHI results the combined world average limit on the B-s oscillation frequency is Delta m(s) > 8.4ps(-1) at 95% CL. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Crawford, G (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 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 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JUL PY 1998 VL 66 BP 510 EP 513 DI 10.1016/S0920-5632(98)00097-8 PG 4 WC Physics, Particles & Fields SC Physics GA ZH781 UT WOS:000073147000097 ER PT J AU McLaughlin, HE Hendricks, JS AF McLaughlin, HE Hendricks, JS TI Performance of scientific computing platforms with MCNP4B SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Several computing platforms were evaluated with the MCNP4B Monte Carlo radiation transport code. The DEC AlphaStation 500/500 was the fastest to run MCNP4B. Compared to the HP 9000-735, the fastest platform 4 yr ago, the AlphaStation is 335% faster the HP C180 is 133% faster the SGI Origin 2000 is 82% faster the Sun UltraSparc-1 200E is 54% faster the Micron Millennia Pro personal computer is 10% faster; the Gray T94/4128 is 1% faster the IBM RS/6000-590 is 93% as fast, the DEC 3000/600 is 81% as fast, the Sim Sparc20 is 57% as fast, the Gray YMP 8/8128 is 57% as fast, the Sun Sparc5 is 33% as fast, and the Sun Sparc2 is 13% as fast. All results presented are reproducible and allow for comparison to computer platforms not included in this study. Timing studies are seen to be very problem dependent. The performance gains resulting from advances in software were also investigated. Various compilers and operating systems were seen to have a modest impact on performance, whereas hardware improvements have resulted in a factor of 4 improvement. MCNP4B also ran approximately as fast as MCNP4A. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, XTM, Los Alamos, NM 87545 USA. RP McLaughlin, HE (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, XTM, MS B226, Los Alamos, NM 87545 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD JUL PY 1998 VL 129 IS 3 BP 311 EP 319 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 102LX UT WOS:000074926800009 ER PT J AU Bandini, BR Ivanov, KN Baratta, AJ Steinke, RG AF Bandini, BR Ivanov, KN Baratta, AJ Steinke, RG TI Verification of a three-dimensional nodal transient neutronics routine for the TRAC-PF1/MOD3 thermal-hydraulic system analysis code SO NUCLEAR TECHNOLOGY LA English DT Article AB The verification of a three-dimensional nodal transient neutronics routine in the TRAC-PF1/MOD3 Version 1.0 thermal-hydraulic system analysis computer code is discussed. This neutronics algorithm is based on a fully implicit transient version of the well-known nodal expansion method Results from running; TRAC-PF1/MOD3 with this new neutronics routine were compared with the results of running two established neutronics/thermal-hydraulic space-time codes, HERMITE and ARROTTA. The transient chosen for this code verification was a rapid ejection of an off-center control rod in a: Westinghouse pressurized water reactor which is initially at hot standby This severe prompt-critical transient provides a stringent test of TRAC-PF1/MOD3's new multidimensional neutronics routine and its coupling to the existing thermal-hydraulic solution methodology. Because of its speed, the transient tests only the fuel rod heat conduction coupling and nor the coolant thermal-hydraulic coupling. Acceptable agreement was obtained among the results from TRAC-PF1/MOD3, HERMITE, and ARROTTA during all phases of this transient. Agreement was in the areas of time dependence of total-core and peak-assembly powers, as well as the time dependence of the core-average and peak-assembly fuel temperatures. In addition, comparison of several steady-state calculations that provide initial conditions for the transient analysis showed acceptable agreement in the calculated eigenvalues and normalized assembly-power distributions. C1 Bettis Atom Power Lab, W Mifflin, PA 15122 USA. Penn State Univ, Dept Nucl Engn, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bandini, BR (reprint author), Bettis Atom Power Lab, POB 79, W Mifflin, PA 15122 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1998 VL 123 IS 1 BP 1 EP 20 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZY932 UT WOS:000074677400001 ER PT J AU Sargent, TN Overcamp, TJ Bickford, DF Cicero-Herman, CA AF Sargent, TN Overcamp, TJ Bickford, DF Cicero-Herman, CA TI Vitrification of cesium-laden organic ion-exchange resin in a stirred melter SO NUCLEAR TECHNOLOGY LA English DT Article AB Tests were conducted using a stirred-tank melter to vitrify nonradioactive, cesium-laden organic ion-exchange resin. This resin, which is highly effective in removing cesium from solution, was developed to replace the complex sodium tetraphenylborate precipitation process used at the Defense Waste Processing Facility at the Savannah River Site to remove Cs-137 from a wastewater solution. The glass produced had a Fe2+/Fe-Total ratio that was acceptable for high-level waste glass. No damage to the melter was observed. Lower-bound estimates of overall cesium retention in the glass range from 70.5 to 73.9%. Only, 2.1 to 4.3% of the cesium was emitted from the melter Because between 21.8 and 27.4% of the cesium was not recovered, the overall cesium retention may have been substantially higher. C1 Clemson Univ, Anderson, SC 29625 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Sargent, TN (reprint author), Clemson Univ, 342 Comp Court, Anderson, SC 29625 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1998 VL 123 IS 1 BP 60 EP 66 PG 7 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZY932 UT WOS:000074677400005 ER PT J AU McGrail, BP AF McGrail, BP TI Analytical solutions for diffusive mass transport from a sphere, considering a surface flux boundary condition SO NUCLEAR TECHNOLOGY LA English DT Article ID RADIONUCLIDE; MIGRATION; MATRIX AB Analytical solutions to the unsteady diffusion equation in spherical geometry are presented for uniform and composite porous media. In this case, a Neumann (prescribed flux) boundary condition is assumed as opposed to a Dirichlet (prescribed concentration) boundary condition used in previously published derivations. For radionuclides that have very high solubility under a given set of geochemical conditions, such as Tc-99 and Se-79 Under oxidizing conditions, a prescribed flux boundary condition is more appropriate. C1 Pacific NW Natl Lab, Appl Geol & Geochem Dept, Richland, WA 99352 USA. RP McGrail, BP (reprint author), Pacific NW Natl Lab, Appl Geol & Geochem Dept, POB 999, Richland, WA 99352 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1998 VL 123 IS 1 BP 82 EP 89 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZY932 UT WOS:000074677400007 ER PT J AU Dulloo, AR Ruddy, FH Congedo, TV Seidel, JG Gehrke, RJ AF Dulloo, AR Ruddy, FH Congedo, TV Seidel, JG Gehrke, RJ TI Detection limits of a laboratory pulsed gamma neutron activation analysis system for the nondestructive assay of mercury, cadmium, and lead SO NUCLEAR TECHNOLOGY LA English DT Article AB Detection of Hg, Cd, and Pb within concrete matrices located in 8-gal drums was successfully demonstrated using a pulsed gamma neutron activation analysis system. Real-time assays of 600 s led to the detection of these metals at concentration levels ranging, in parts per million (ppm) by weight, from 487 to 19 820 for Hg, 485 to 8181 for Cd, and 9927 to 19 950 for Pb. The measurements of Hg and Cd relied on the observation of thermal neutron-induced prompt gamma rays, whereas the Pb measurements relied on the observation of decay gamma rays from Pb-207m, a product of fast neutron-induced reactions in Pb. The projected bower limits of detection of the current system for a 600-s run are 15, 170, and 8600 ppm for Cd Hg, and Pb, respectively. Up to a one-order magnitude of improvement in sensitivity is anticipated through the enhancement of the system's detector and neutron source. The results obtained confirm the potential of prompt and decay gamma neutron activation analysis as an effective method for the nondestructive analysis of hazardous metals in mixed-waste drums. C1 Westinghouse Elect Co, Ctr Sci & Technol, Pittsburgh, PA 15235 USA. Lockheed Martin Idaho Technol, Idaho Falls, ID 83415 USA. RP Dulloo, AR (reprint author), Westinghouse Elect Co, Ctr Sci & Technol, 1310 Beulah Rd, Pittsburgh, PA 15235 USA. NR 6 TC 12 Z9 12 U1 0 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 USA SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1998 VL 123 IS 1 BP 103 EP 112 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA ZY932 UT WOS:000074677400009 ER PT J AU Brown, FC Heald, SM Brewe, DL Jiang, DT AF Brown, FC Heald, SM Brewe, DL Jiang, DT TI Point defect production by X-rays above and below the bromine K-edge in KBr SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS LA English DT Article ID F-CENTER FORMATION; ALKALI-HALIDES; EXCITATION; CRYSTALS AB F-center formation by monochromatic X-rays has been studied above and below the bromine K-edge in single crystals of KBr at 77 K. A concentrated beam from an undulator at the Advanced Photon Source was used to produce these point defects, which were detected by a sensitive laser-induced luminescence method. Experiments were carried out over an especially wide range of monochromatic X-ray intensity. Contrary to our previous reports, a large increase in F-center formation efficiency was not found upon crossing the bromine K-edge, which suggests that additional Auger-cascade mechanisms do not compete strongly with the usual multiple ionization electron-hole recombination processes known to generate point defects. C1 Univ Washington, Dept Phys, Seattle, WA 98195 USA. Argonne Natl Lab, Adv Photon Source, Pacific NW Lab, Argonne, IL 60439 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. RP Brown, FC (reprint author), Univ Washington, Dept Phys, Box 351560, Seattle, WA 98195 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0392-6737 J9 NUOVO CIMENTO D JI Nuovo Cimento Soc. Ital. Fis. D-Condens. Matter At. Mol. Chem. Phys. Fluids Plasmas Biophys. PD JUL-AUG PY 1998 VL 20 IS 7-8 BP 853 EP 858 PG 6 WC Physics, Multidisciplinary SC Physics GA 132GL UT WOS:000076621900002 ER PT J AU Goldberg, L Koplow, JP Moeller, RP Kliner, DAV AF Goldberg, L Koplow, JP Moeller, RP Kliner, DAV TI High-power superfluorescent source with a side-pumped Yb-doped double-cladding fiber SO OPTICS LETTERS LA English DT Article ID AMPLIFIER AB A compact superfluorescent source based on an Yb-doped double-cladding fiber amplifier is described. The packaged amplifier is pumped at 975 nm by side-coupling emission from a 2.0-W broad-stripe laser diode through an imbedded V groove. The fiber source generates 485 mW of broadband emission centered at 1055 nm with a 41-nm FWHM flat power spectrum. OCIS codes: 160.6630, 160.3510, 140.4480, 060.2380, 060.2320, 060.2310. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Goldberg, L (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 14 TC 49 Z9 54 U1 1 U2 4 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 JUL 1 PY 1998 VL 23 IS 13 BP 1037 EP 1039 DI 10.1364/OL.23.001037 PG 3 WC Optics SC Optics GA ZY167 UT WOS:000074593000019 PM 18087421 ER PT J AU Fittinghoff, DN Squier, JA Barty, CPJ Sweetser, JN Trebino, R Muller, M AF Fittinghoff, DN Squier, JA Barty, CPJ Sweetser, JN Trebino, R Muller, M TI Collinear type II second-harmonic-generation frequency-resolved optical gating for use with high-numerical-aperture objectives SO OPTICS LETTERS LA English DT Article AB Ultrashort-pulse lasers are now commonly used for multiphoton microscopy, and optimizing the performance of such systems requires careful characterization of the pulses at the tight focus of the microscope objective. We solve this problem by use of a collinear geometry in frequency-resolved optical gating that uses type II second-harmonic generation and that allows the full N.A. of the microscope objective to be used. We then demonstrate the technique by measuring the intensity and the phase of a 22-fs pulse focused by a 20x, 0.4-N.A. air objective. (C) 1998 Optical Society of America OCIS codes: 140.7090,320.7100, 320.7160. C1 Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. Univ Calif San Diego, Dept Elect Engn & Comp Sci, La Jolla, CA 92093 USA. Sandia Natl Labs, Livermore, CA 94551 USA. BioCetrum Amsterdam, Inst Mol Cell Biol, NL-1098 SM Amsterdam, Netherlands. RP Fittinghoff, DN (reprint author), Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. NR 7 TC 45 Z9 45 U1 0 U2 6 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 JUL 1 PY 1998 VL 23 IS 13 BP 1046 EP 1048 DI 10.1364/OL.23.001046 PG 3 WC Optics SC Optics GA ZY167 UT WOS:000074593000022 PM 18087424 ER PT J AU Viano, AM Majzoub, EH Stroud, RM Kramer, MJ Misture, ST Gibbons, PC Kelton, KF AF Viano, AM Majzoub, EH Stroud, RM Kramer, MJ Misture, ST Gibbons, PC Kelton, KF TI Hydrogen absorption and storage in quasicrystalline and related Ti-Zr-Ni alloys SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID PHASE AB Detailed studies of the absorption and storage of hydrogen by icosahedral quasicrystalline Ti-Zr-Ni are presented. Two different absorption methods, one at room temperature and another requiring elevated temperatures, successfully introduce hydrogen into Ti-Zr-Ni alloys. Absorption is accompanied by an expansion of the quasilattice, and results correlating the rate of expansion to the hydrogen concentration are presented. The absorption rates suggest that a surface oxide layer acts as a barrier to hydrogen absorption and this is confirmed by surface depth profiling studies made with scanning Auger spectroscopy. Desorption studies also indicate some hydrogen cycling ability for the quasicrystal. The hydrogen storage ability of the quasicrystal is compared to, and found to be better than, those of the related phases in this system. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Viano, AM (reprint author), Rhodes Coll, Dept Phys, Memphis, TN 38112 USA. RI Stroud, Rhonda/C-5503-2008 OI Stroud, Rhonda/0000-0001-5242-8015 NR 20 TC 71 Z9 72 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUL PY 1998 VL 78 IS 1 BP 131 EP 141 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA ZU426 UT WOS:000074195900006 ER PT J AU Jin, Z Gray, GT Yamaguchi, M AF Jin, Z Gray, GT Yamaguchi, M TI Mechanical twinning in a 45 degrees ((3)over-bar-21) oriented polysynthetically twinned TiAl crystal at a high strain rate and a high temperature SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID ROOM-TEMPERATURE; DEFORMATION STRUCTURES; PLASTIC-DEFORMATION; INTERSECTIONS; BEHAVIOR; ALLOYS; STRESS; AL AB Mechanical twinning behaviour in a 45 degrees [<(3)over bar 21>] oriented (the lamellar interface was tilted 45 degrees from the loading axis about the [<(3)over bar 21>] direction in the lamellar interface) polysynthetically twinned crystal deformed in compression at a strain rate of 3000 s(-1) and a temperature of 800 degrees C was characterized. (111) [11(2) over bar] parallel twinning was observed to be the dominant deformation mode in domains [III] and [IV] where the transmission electron microscopy foil normals were close to [10(1) over bar] and [1(1) over bar 0] respectively. Cross-twinning of the (<(1)over bar 11>) [(1) over bar 1 (2) over bar], (1(1) over bar 1) [1 (1) over bar (2) over bar] and (111) [112] variants in the remaining domains was found to be a complementary deformation mode to accommodate deformation. The mechanical twin propagation stress was found to be less than 150 MPa at 3000s(-1) and 800 degrees C in TiAl. Mechanical twin propagation was found to respond to the global sample stress state and thus the crystal yield and Bow stresses. When mechanical twinning was the dominant deformation mode in a domain, it was observed to obey Schmid's law. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Kyoto Univ, Dept Met Sci & Technol, Sakyo Ku, Kyoto 606, Japan. RP Jin, Z (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 31 TC 10 Z9 11 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD JUL PY 1998 VL 78 IS 1 BP 239 EP 253 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA ZU426 UT WOS:000074195900013 ER PT J AU Jones, ED Millunchick, JM Follstaedt, D Lee, S Reno, J Twesten, RD Zhang, Y Mascarenhas, A AF Jones, ED Millunchick, JM Follstaedt, D Lee, S Reno, J Twesten, RD Zhang, Y Mascarenhas, A TI Detection of lateral composition modulation by magnetoexciton spectroscopy SO PHYSICA E LA English DT Article; Proceedings Paper CT 8th International Conference on Modulated Semiconductor Structures CY JUL 14-18, 1997 CL UNIV CA, SANTA BARBARA, CALIFORNIA HO UNIV CA DE composition modulation; photoluminescence; magnetoexciton; quantum wires ID QUANTUM-WIRE HETEROSTRUCTURES; SUPERLATTICES; GROWTH AB An experimental signature for detecting spontaneous lateral composition modulation in a (InAs)(n)/(GaAs)(m) short period superlattice on a InP substrate based on magnetoexciton spectroscopy is described. We find by aligning the magnetic field in three crystallographic directions, one parallel to and the other two perpendicular to the composition modulation direction, that the magnetoexciton shifts are anisotropic and are a good indicator for the presence of composition modulation. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Renewable Energy Lab, Golden, CO USA. RP Jones, ED (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 11 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD JUL PY 1998 VL 2 IS 1-4 BP 44 EP 48 DI 10.1016/S1386-9477(98)00011-3 PG 5 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 110LT UT WOS:000075383500010 ER PT J AU Jones, ED Tozer, SW Schmiedel, T AF Jones, ED Tozer, SW Schmiedel, T TI Pressure dependence of the band-gap energy and the conduction-band mass for an n-type InGaAs/GaAs strained single-quantum well SO PHYSICA E LA English DT Article; Proceedings Paper CT 8th International Conference on Modulated Semiconductor Structures CY JUL 14-18, 1997 CL UNIV CA, SANTA BARBARA, CALIFORNIA HO UNIV CA DE magnetoluminescence; pressure; quantum well; strain ID MAGNETOLUMINESCENCE AB We report the measurement of the pressure dependence for the band-gap energy E-g and conduction-band mass m(c) for an 80 Angstrom-wide n-type In0.20Ga0.80As/GaAs strained-single-quantum well at 4.2 K for pressures between 0 and 35 kbar and fields up to 30 T. The band-gap energy E-g, at each pressure, was determined by extrapolating the magnetoluminescence "fan-diagram" to zero magnetic field. The pressure dependence of the band-gap energy was found to be quadratic with a linear term of about 10.3 meV/kbar and a small, -2 x 10(-2) mev/kbar(2), quadratic contribution. Analyses of the pressure-dependent 4.2 K magnetoluminescence data yield a conduction-band mass logarithmic pressure derivative delta log(m(c))/delta P = 0.58% kbar(-1). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl High Magnet Field Lab, Tallahassee, FL USA. RP Jones, ED (reprint author), Sandia Natl Labs, POB 4800, Albuquerque, NM 87185 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD JUL PY 1998 VL 2 IS 1-4 BP 146 EP 150 DI 10.1016/S1386-9477(98)00032-0 PG 5 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 110LT UT WOS:000075383500031 ER PT J AU Silveira, E Dondl, W Abstreiter, G Haller, EE AF Silveira, E Dondl, W Abstreiter, G Haller, EE TI Raman scattering in annealed isotopic (Ge-70)(n)(Ge-74)(m) superlattices SO PHYSICA E LA English DT Article; Proceedings Paper CT 8th International Conference on Modulated Semiconductor Structures CY JUL 14-18, 1997 CL UNIV CA, SANTA BARBARA, CALIFORNIA HO UNIV CA DE self-diffusion; Raman scattering; isotopic superlattices ID SELF-DIFFUSION; GERMANIUM AB Raman scattering by optical phonons is used to study the interface intermixing in isotopic (Ge-70)(n)(Ge-74)(m) thin superlattices, with n and rn equal to 8, 12, 16 and 24 atomic monolayers, for annealling at 500 degrees C and various times. The experimental results compares very well with theoretical calculations within the planar force constant model and the bond polarizability approach. The diffusion is simulated by a combination of the virtual crystal approximation and the solution of the Fick's diffusion equation for the superlattice geometry. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Tech Univ Munich, Walter Schottky Inst, D-85748 Garching, Germany. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Silveira, E (reprint author), Tech Univ Munich, Walter Schottky Inst, Coulombwall, D-85748 Garching, Germany. EM silveira@wsi.tu-muenchen.de NR 5 TC 1 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD JUL PY 1998 VL 2 IS 1-4 BP 291 EP 294 DI 10.1016/S1386-9477(98)00061-7 PG 4 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 110LT UT WOS:000075383500061 ER PT J AU Follstaedt, DM Twesten, RD Millunchick, JM Lee, SR Jones, ED Ahrenkiel, SP Zhang, Y Mascarenhas, A AF Follstaedt, DM Twesten, RD Millunchick, JM Lee, SR Jones, ED Ahrenkiel, SP Zhang, Y Mascarenhas, A TI Spontaneous lateral composition modulation in InAlAs and InGaAs short-period superlattices SO PHYSICA E LA English DT Article; Proceedings Paper CT 8th International Conference on Modulated Semiconductor Structures CY JUL 14-18, 1997 CL UNIV CA, SANTA BARBARA, CALIFORNIA HO UNIV CA DE lateral composition modulation; InAlAs; InGaAs; strain; short-period superlattice ID GROWTH AB The microstructure of spontaneous lateral composition modulation along the [1 1 0] direction has been studied in (InAs)(n)/(AlAs)(m) short-period superlattices grown by molecular beam epitaxy on (0 0 1) InP. X-ray diffraction and transmission electron microscopy show that global strain (epsilon) in the superlattice reduces the degree of composition modulation, which disappears for /epsilon/ > 0.7%. For tensile strains of epsilon approximate to + 0.4%, we find that In-rich columns become regularly spaced and correlated with cusps in the growth surface. A similar correlation is seen in (InAs)(n)/(GaAs)(m) short-period superlattices between the enriched columns and the peaks and valleys of {1 1 4}(A) facets on the surface. The enriched columns in the (InAs)(n)/(GaAs)(m) layer land the facets) extend for much longer distances(similar to 0.2-0.4 mu m) in the [1 (1) over bar 0] direction than do the columns in the (InAs)(n)/(AlAs)(m) layer (similar to 56 nm). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Follstaedt, DM (reprint author), Sandia Natl Labs, Mail Stop 1056, Albuquerque, NM 87185 USA. NR 9 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1386-9477 J9 PHYSICA E JI Physica E PD JUL PY 1998 VL 2 IS 1-4 BP 325 EP 329 DI 10.1016/S1386-9477(98)00068-X PG 5 WC Nanoscience & Nanotechnology; Physics, Condensed Matter SC Science & Technology - Other Topics; Physics GA 110LT UT WOS:000075383500068 ER PT J AU Rydberg, B Lobrich, M Cooper, PK AF Rydberg, B Lobrich, M Cooper, PK TI Repair of clustered DNA damage caused by high LET radiation in human fibroblasts SO PHYSICA MEDICA LA English DT Article DE DNA damage; DNA double-strand breaks; DNA repair; ionizing radiation ID DOUBLE-STRAND BREAKS; FIELD GEL-ELECTROPHORESIS; HIGH-ENERGY NEON; IONIZING-RADIATION; IRON IONS; FRAGMENTS; MECHANISMS; CELLS AB It has recently been demonstrated experimentally that DNA damage induced by high LET radiation in mammalian cells is non-randomly distributed along the DNA molecule in the form of clusters of various sizes. The sizes of such clusters range from a few base-pairs to at least 200 kilobase-pairs. The high biological efficiency of high LET radiation for induction of relevant biological endpoints is probably a consequence of this clustering, although the exact mechanisms by which the clustering affects the biological outcome is not known. We discuss here results for induction and repair of base damage, single-strand breaks and double-strand breaks for low and high LET radiations. These results are discussed in the context of clustering. Of particular interest is to determine how clustering at different scales affects overall rejoining and fidelity of rejoining of DNA double-strand breaks. However, existing methods for measuring repair of DNA strand breaks are unable to resolve breaks that are close together in a cluster. This causes problems in interpretation of current results from high LET radiation and will require new methods to be developed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NIDCR NIH HHS [DE-AC03-76SF00098] NR 18 TC 8 Z9 8 U1 0 U2 0 PU GIARDINI EDITORI S A LUGANO PI LUGANO PA PIAZZA MONTE CENERI 13,, CH6901 LUGANO, SWITZERLAND SN 1120-1797 J9 PHYS MEDICA JI Phys. Medica PD JUL PY 1998 VL 14 SU 1 BP 24 EP 28 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 135QF UT WOS:000076813600004 PM 11542637 ER PT J AU Batinic, M Dadic, I Slaus, I Svarc, A Nefkens, BMK Lee, TSH AF Batinic, M Dadic, I Slaus, I Svarc, A Nefkens, BMK Lee, TSH TI The new determination of the eta N S-wave scattering length from a three-channel, multi-resonance amplitude analysis SO PHYSICA SCRIPTA LA English DT Article ID MODEL AB A three-channel multi-resonance, unitary model developed in 1995 is used to determine the pi N --> eta N and eta N --> eta N amplitudes by re-analyzing the available data on pi N elastic scattering and the weighted data for the pi N --> eta N total and differential cross sections. The input pi N elastic scattering amplitude in the S-11 channel has been improved, following suggestions of G. Hohler. Our new result of eta N scattering length, a(eta N) = (0.717 +/- 0.030) + i . (0.263 +/- 0.025) fm, suggests that the eta d system is unbound or loosely bound. C1 Rudjer Boskovic Inst, Zagreb, Croatia. Univ Calif Los Angeles, Los Angeles, CA USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Batinic, M (reprint author), Rudjer Boskovic Inst, Zagreb, Croatia. NR 17 TC 60 Z9 60 U1 0 U2 2 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD JUL PY 1998 VL 58 IS 1 BP 15 EP 18 DI 10.1088/0031-8949/58/1/002 PG 4 WC Physics, Multidisciplinary SC Physics GA 100EQ UT WOS:000074802600003 ER PT J AU Lopez-Urrutia, JRC Beiersdorfer, P Savin, DW Widmann, K AF Lopez-Urrutia, JRC Beiersdorfer, P Savin, DW Widmann, K TI Precision measurement of the lifetime of the 1s2s S-3(1) metastable level in heliumlike O6+ SO PHYSICAL REVIEW A LA English DT Article ID BEAM ION-TRAP; RADIATIVE LIFETIME; TEMPERATURE; DIAGNOSTICS; PLASMAS; DENSITY; STATE AB The lifetime of the 1s2s S-3(1) level of the He-like O6+ ion has been measured using the Electron Beam Ion Trap in the magnetic trapping mode. A value of 956(-4)(+5): ps is found, which corresponds to a radiative transition rate of 1046(-5)(+4) s(-1) for the magnetic dipole transition to the 1s(2) S-1(0) ground state. This value is in excellent agreement with recent theoretical predictions and distinguishes among different treatments of negative energy states and correlation in multiconfiguration Dirac-Fock calculations. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94550 USA. Columbia Univ, Dept Phys, New York, NY 10025 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10025 USA. RP Lopez-Urrutia, JRC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94550 USA. RI Savin, Daniel/B-9576-2012; Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Savin, Daniel/0000-0002-1111-6610; Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 19 TC 32 Z9 32 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 238 EP 241 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500036 ER PT J AU Huang, SW Goodson, DZ Lopez-Cabrera, M Germann, TC AF Huang, SW Goodson, DZ Lopez-Cabrera, M Germann, TC TI Large-order dimensional perturbation theory for diatomic molecules within the Born-Oppenheimer approximation SO PHYSICAL REVIEW A LA English DT Article ID GROUND-STATE ENERGY; VARIABLE DIMENSIONALITY; 1/D EXPANSION; LIMIT; SERIES; ATOMS; H-2+; H2+; RENORMALIZATION; 1/N-EXPANSION AB A renormalization of the D-dimensional Hamiltonian is developed to ensure that the large-D limit corresponds to a single well at any value of the internuclear distance R. This avoids convergence problems caused by a symmetry-breaking transition that is otherwise expected to occur when R is approximately equal to the equilibrium bond distance R(eq), With larger R giving a double well. This symmetry breaking has restricted the applicability of large-order perturbation theory in 1/D to cases where R is significantly less than R(eq). The renormalization greatly extends the range of R for which the large-order expansion can be summed. A numerical demonstration is presented for H(2)(+). The 1/D expansions are summed using Pade-Borel approximants with modifications that explicitly model known singularity structure. C1 So Methodist Univ, Dept Chem, Dallas, TX 75275 USA. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. Los Alamos Natl Lab, Theoret Div T11, Los Alamos, NM 87545 USA. RP Huang, SW (reprint author), So Methodist Univ, Dept Chem, Dallas, TX 75275 USA. NR 50 TC 6 Z9 6 U1 2 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 250 EP 257 DI 10.1103/PhysRevA.58.250 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500038 ER PT J AU Djuric, N Zhou, S Dunn, GH Bannister, ME AF Djuric, N Zhou, S Dunn, GH Bannister, ME TI Electron-impact dissociative excitation of CDn+ (n=2-5): Detection of light fragment ions D+ and D-2(+) SO PHYSICAL REVIEW A LA English DT Article ID BEAM AB Absolute cross sections are reported for the electron-impact dissociative excitation of the deuterated hydrocarbon ions CDn+ (n=2-5) from threshold to 70 eV using a crossed beams technique. The method focuses on detecting and measuring Light dissociation-product ions from a heavy target. The ion targets are typical of those formed in the discharge ion source, and some may be in excited electronic and/or vibrational states. A common feature of the studied targets was a dominant D+ formation cross section with almost the same absolute value of 2 x 10(-16) cm(2) for all n from 25 to 70 eV. The present measurements are compared with the available data, and for D+ from CD2+ and CD5+ the data agree well with recent results obtained with the storage-ring technique. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Djuric, N (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. OI Bannister, Mark E./0000-0002-9572-8154 NR 20 TC 16 Z9 16 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 304 EP 308 DI 10.1103/PhysRevA.58.304 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500044 ER PT J AU Isaacs, WA McCurdy, CW Rescigno, TN AF Isaacs, WA McCurdy, CW Rescigno, TN TI Theoretical support for a Ramsauer-Townsend minimum in electron-CF4 scattering SO PHYSICAL REVIEW A LA English DT Article ID EFFECTIVE POTENTIAL METHODS; LOW-ENERGY ELECTRONS; CROSS-SECTIONS; VARIATIONAL TREATMENTS; MOLECULE COLLISIONS; CF4; ABINITIO; HALOMETHANES; CCL2F2; CCL3F AB We describe complex Kohn calculations for elastic e(-)-CF4, scattering at incident electron energies of 0.04-20 eV. An accurate representation of the electronic correlation effects involving target polarization is critical in the explicit demonstration of a Ramsauer-Townsend minimum. We use a set of polarized virtual orbitals to form a compact representation of closed channels in the trial scattering function to include these effects. These are the first ab initio calculations to verify the Ramsauer-Townsend minimum in CF4. We find excellent comparison between the complex Kohn results and measured differential and integral cross sections. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Livermore, CA 94550 USA. RP Isaacs, WA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 22 TC 23 Z9 23 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 309 EP 313 DI 10.1103/PhysRevA.58.309 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500045 ER PT J AU Macek, JH Cavagnero, MJ AF Macek, JH Cavagnero, MJ TI Demkov-Osherov model reformulated in terms of conventional scattering theory SO PHYSICAL REVIEW A LA English DT Article ID STURMIAN EXPANSION; GREEN-FUNCTION; IONIZATION; THRESHOLD; HYDROGEN AB One of the few exactly solvable time-dependent quantum-mechanics problems was first analyzed by Demkov and Osherov 30 years ago (Zh. Eksp. Teor. Fit. 53, 1589 (1967) [Sov. Phys. JETP 26, 916 (1968)]). This model problem describes the interaction of a set of approximate stationary states with an additional state whose energy, in zeroth approximation, is a linear function of time. The Demkov-Osherov model is reexamined here using conventional Fourier transform methods. Emphasis on forward propagation in time eliminates the need for a Laplace transform of the wave function, as well as the resultant choice of contours for the evaluation of transition amplitudes. The evolution operator for the model Hamiltonian is expressed in terms of a single, frequency-dependent Sturmian. Such Sturmian functions are of considerable current interest in the analysis of nonadiabatic phenomena. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Macek, JH (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 14 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 348 EP 356 DI 10.1103/PhysRevA.58.348 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500049 ER PT J AU Guo, DS Freeman, RR Wu, YS AF Guo, DS Freeman, RR Wu, YS TI Schrodinger-like equation for a nonrelativistic electron in a photon field of arbitrary intensity SO PHYSICAL REVIEW A LA English DT Article ID QUANTIZED RADIATION-FIELD; MULTIPHOTON IONIZATION; STATIONARY SOLUTIONS; LASER FIELD AB The Schrodinger equation with minimal coupling for a nonrelativistic electron interacting with a single-mode photon field is not satisfied by the nonrelativistic limit of the exact solutions to the corresponding Dirac equation. A Schrodinger-like equation valid for arbitrary photon intensity is derived from the Dirac equation without the weak-field assumption. The "eigenvalue" in the present equation is an operator in a Cartan subalgebra. An approximation consistent with the nonrelativistic energy level derived from its relativistic value replaces the eigenvalue operator by an ordinary number, recovering the Schrodinger eigenvalue equation used in the formal scattering formalism. The Schrodinger-like equation for the multimode case is also presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Inst Adv Study, Princeton, NJ 08540 USA. So Univ & A&M Coll, Dept Phys, Baton Rouge, LA 70813 USA. RP Guo, DS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 15 TC 14 Z9 14 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 521 EP 525 DI 10.1103/PhysRevA.58.521 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500068 ER PT J AU White, AG Mitchell, JR Nairz, O Kwiat, PG AF White, AG Mitchell, JR Nairz, O Kwiat, PG TI "Interaction-free" imaging SO PHYSICAL REVIEW A LA English DT Article AB Using the complementary wavelike and particlelike natures of photons, it is possible to make "interaction-free" measurements where the presence of an object can be determined with no photons being absorbed. We investigated several "interaction-free" imaging systems, i.e., systems that allow optical imaging of photosensitive objects with less than the classically expected amount of light being absorbed or scattered by the object. With the most promising system, we obtained high-resolution (10-mu m), one-dimensional profiles of a variety of objects (human hair, glass and metal wires, and cloth fibers) by raster scanning each object through the system. We discuss possible applications and the present and future limits for interaction-free imaging. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP White, AG (reprint author), Univ Calif Los Alamos Natl Lab, P-23,MS-H803, Los Alamos, NM 87545 USA. RI White, Andrew/A-1088-2009 OI White, Andrew/0000-0001-9639-5200 NR 14 TC 46 Z9 46 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 605 EP 613 DI 10.1103/PhysRevA.58.605 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500078 ER PT J AU Deng, L Payne, MG Garrett, WR AF Deng, L Payne, MG Garrett, WR TI Nonlinear frequency conversion with short laser pulses and maximum atomic coherence SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; DISPERSIVE PROPERTIES; GENERATION; HYDROGEN; SYSTEMS AB A perturbation treatment for Raman generation with a combination of long, short, and delayed laser pulses is presented. When the coupling and probe lasers are applied in a counterintuitive sequence, the fast oscillatory contributions to populations and coherence are eliminated by robust adiabatic passage, allowing a much simpler solution to the problem. Such counterintuitive and on-resonance operation allows effective electromagnetically induced transparency to evolve so that the probe laser photons will experience no absorption yet still fully participate in the nonlinear frequency conversion. Consequently, better conversion efficiency should be possible. C1 Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. Natl Inst Stand & Technol, Atom Phys Div, Gaithersburg, MD 20899 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. RI Deng, Lu/B-3997-2012 NR 20 TC 18 Z9 18 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 707 EP 712 DI 10.1103/PhysRevA.58.707 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500091 ER PT J AU Vasilyev, A Jasper, E Berry, HG Livingston, AE Curtis, LJ Cheng, S Dunford, RW AF Vasilyev, A Jasper, E Berry, HG Livingston, AE Curtis, LJ Cheng, S Dunford, RW TI Lifetime of the 3p P-2(3/2) level in sodiumlike bromine (Br XXV) SO PHYSICAL REVIEW A LA English DT Article ID RESONANCE TRANSITIONS; BEAM-FOIL; ENERGIES; CESIUM; STATES; IONS; VII AB Using the beam-foil spectroscopy technique, we have measured the decay time of the 3p P-2(3/2) level in sodiumlike bromine. The results, using an arbitrarily normalized decay curves analysis, are in good agreement with the most recent theoretical calculations. They also confirm an earlier experimental result in sodiumlike krypton, suggesting that some previous measurements of the lifetimes of 3p P-2(3/2) states of nearby isoelectronic ions are too high. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Toledo, Dept Phys, Toledo, OH 43606 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Vasilyev, A (reprint author), Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. NR 27 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP 732 EP 735 DI 10.1103/PhysRevA.58.732 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500097 ER PT J AU Halfmann, T Yatsenko, LP Shapiro, M Shore, BW Bergmann, K AF Halfmann, T Yatsenko, LP Shapiro, M Shore, BW Bergmann, K TI Population trapping and laser-induced continuum structure in helium: Experiment and theory SO PHYSICAL REVIEW A LA English DT Article ID HARMONIC-GENERATION; IONIZATION; SODIUM; APPROXIMATION; TRANSITIONS; RESONANCE; ATOMS; XENON AB We report the observation of laser-induced structure (LICS) in the flat photoionization continuum of helium. The structure is a strong and spectrally sharp resonance, showing both enhanced and diminished ionization (a Beutler-Fano profile). Our observations show, in an otherwise unstructured continuum, pronounced ionization suppression (as much as 70%), which is due to population trapping associated with LICS. We also show the effect of dynamic Stark shifts upon the LICS profile. A discussed theoretical model, incorporating significant dynamic Stark shifts, gives a quantitatively accurate description of the line profile for a wide range of pulse intensities. C1 Ukrainian Acad Sci, Inst Phys, UA-252650 Kiev, Ukraine. Weizmann Inst Sci, Dept Chem Phys, IL-76100 Rehovot, Israel. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Halfmann, T (reprint author), Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. RI Halfmann, Thomas/O-4588-2014; BERGMANN, KLAAS/D-5543-2011 OI Halfmann, Thomas/0000-0002-1222-2669; NR 29 TC 48 Z9 49 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUL PY 1998 VL 58 IS 1 BP R46 EP R49 DI 10.1103/PhysRevA.58.R46 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZZ998 UT WOS:000074790500013 ER PT J AU Chau, R Maple, MB Robinson, RA AF Chau, R Maple, MB Robinson, RA TI Crystallographic evidence for chemical ordering in UCu5-xPdx SO PHYSICAL REVIEW B LA English DT Article ID FERMI-LIQUID BEHAVIOR; ELECTRON MATERIALS; KONDO DISORDER; ALLOYS AB We report elastic neutron-diffraction measurements on UCu5-xPdx (x=0.65, 1.0, and 1.5) using the High-Intensity Powder Diffractometer instrument at the Los Alamos Neutron Science Center. Data from six detector banks were simultaneously refined using Rietveld analysis. From the refinements of the data, we find that for Pd concentrations x1, Pd atoms fully occupy the minority sites and a mixture of Cu and Pd atoms occupy the 16e sites. Al the special concentration x=1, we find that the Pd and Cu atoms occupy separate crystallographic sites. This arrangement of atoms is indicative of chemical ordering, although no superlattice peaks were observed. The implications of chemical ordering in UCu5-xPdx on disorder-driven models of non-Fermi-liquid behavior will be discussed. [S0163-1829(98)00825-X]. C1 Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Calif San Diego, Inst Pure & Appl Phys Sci, La Jolla, CA 92093 USA. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Chau, R (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. NR 18 TC 22 Z9 22 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 1 BP 139 EP 143 DI 10.1103/PhysRevB.58.139 PG 5 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200037 ER PT J AU Lange, RJ Lee, SJ Lynch, DW Canfield, PC Harmon, BN Zollner, S AF Lange, RJ Lee, SJ Lynch, DW Canfield, PC Harmon, BN Zollner, S TI Ellipsometric and Kerr-effect studies of Pt-3-X (X= Mn,Co) SO PHYSICAL REVIEW B LA English DT Article ID PERPENDICULAR MAGNETIC-ANISOTROPY; MAGNETOOPTICAL PROPERTIES; OPTICAL-PROPERTIES; DISPERSION-RELATIONS; BAND-STRUCTURE; SPIN; ALLOYS; MNPT3; CO; CALIBRATION AB The conductivity tensor of polycrystalline Pt3X (X=Mn, Co) was determined between 1.6 and 5.2 eV. Samples were are melted, mechanically polished, and annealed at 500 degrees C for 1 h in Ar. The complex dielectric function was measured from 1.3 to 5.2 eV at room temperature with a rotating analyzer ellipsometer. The magneto-optic Kerr effect was studied between 10 and 293 K in magnetic fields up to 3 T. We used the tight-binding linear-muffin-tin-orbital method in the local spin-density approximation to determine the band structure, density of states, and optical conductivity. Including an empirical quasiparticle self-energy and a lifetime broadening yields good agreement of experimental and calculated spectra. [S0163-1829(98)07625-5]. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Lange, RJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Zollner, Stefan/B-4858-2012; Canfield, Paul/H-2698-2014 OI Zollner, Stefan/0000-0001-7752-7941; NR 51 TC 24 Z9 26 U1 1 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 JUL 1 PY 1998 VL 58 IS 1 BP 351 EP 358 DI 10.1103/PhysRevB.58.351 PG 8 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200066 ER PT J AU Sarrao, JL Ramirez, AP Darling, TW Freibert, F Migliori, A Immer, CD Fisk, Z Uwatoko, Y AF Sarrao, JL Ramirez, AP Darling, TW Freibert, F Migliori, A Immer, CD Fisk, Z Uwatoko, Y TI Thermodynamics of the first-order valence transition in YbInCu4 SO PHYSICAL REVIEW B LA English DT Article ID KONDO VOLUME-COLLAPSE; PHASE-TRANSITION; PRESSURE; YBXIN1-XCU2; NEUTRON; CERIUM; ALLOYS; STATE; CE; YB AB We present measurements of the specific heat and complete elastic moduli of YbInCu4 as a function of temperature in order to complement existing thermal expansion data. Together these data allow a complete analysis of the thermodynamics of the first-order isostructural valence transition in YbInCu4. The Clausius-Clapeyron equation predicts well the measured pressure dependence of the valence transition temperature. Estimates of the Gruneisen parameter from thermodynamic measurements and from pressure-dependent magnetic susceptibility in both the high-temperature and low-temperature phases of YbInCu4 are in good agreement. On the other hand, a Gruneisen analysis of the change in Kondo temperature at the valence transition fails, emphasizing the importance of carrier-density changes associated with the valence transition, unlike in the case of the gamma-alpha transition in elemental Ce. Finally, we address the issue of precursive rounding in the elastic moduli for temperatures greater than the valence transition temperature and argue that thermodynamically YbInCu4's valence transition is indeed first order. [S0163-1829(98)00526-8]. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Saitama Univ, Dept Phys, Urawa, Saitama 338, Japan. RP Sarrao, JL (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. OI Freibert, Franz/0000-0003-4434-3446 NR 32 TC 58 Z9 58 U1 1 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 1 BP 409 EP 413 DI 10.1103/PhysRevB.58.409 PG 5 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200073 ER PT J AU Fishman, RS Jiang, XW Liu, SH AF Fishman, RS Jiang, XW Liu, SH TI First-order paramagnetic-to-commensurate phase transition in Cr alloys SO PHYSICAL REVIEW B LA English DT Article ID DENSITY WAVES; CHROMIUM; ANTIFERROMAGNETISM; ENERGY; CHARGE AB The coexistence of spin- and charge-density waves in pure Cr and its dilute alloys continues to fascinate both experimentalists and theorists. Using a three-band model, we show that the charge-density wave (CDW) in incommensurate (I) Cr alloys is governed by the same Coulomb interaction that produces a first-order Neel transition in commensurate (C) alloys. Therefore, we predict that the first-order paramagnetic-to-commensurate transition observed in CrFe and CrSi alloys is preceded by the growth of a large CDW in the I phase of each alloy. We also provide a justification for the three-band model in the I phase and show that it reduces to the correct form in the C limit. [S0163-1829(98)01225-9]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. N Dakota State Univ, Dept Phys, Fargo, ND 58105 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Fishman, RS (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Fishman, Randy/C-8639-2013 NR 26 TC 5 Z9 5 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 JUL 1 PY 1998 VL 58 IS 1 BP 414 EP 424 DI 10.1103/PhysRevB.58.414 PG 11 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200074 ER PT J AU Pecharsky, VK Miller, LL AF Pecharsky, VK Miller, LL TI Low-temperature behavior of two ternary lanthanide nickel carbides: Superconducting LaNiC2 and magnetic CeNiC2 SO PHYSICAL REVIEW B LA English DT Article ID GROUP-METALS; RARE-EARTH AB A study of the magnetic properties and the heat capacity as functions of temperature and magnetic field of two ternary carbides RNiC2, where R = La and Ce, confirms that LaNiC2 becomes superconducting at T-c = 2.7 K, and that CeNiC2 orders antiferromagnetically below 18 K. LaNiC2 is a conventional superconductor with a critical field of 900 Oe at T = 2 K. CeNiC2 obeys the Curie-Weiss law between 50 and 300 K showing the nearly full Ce3+ magnetic moment, p(eff) = 2.47(1)mu(B), and has a negative paramagnetic Weiss temperature Theta(p) = -18.3(8) K. A low net magnetic moment in the ordered state, which is far from saturation in a magnetic field of 5 T, is consistent with an antiferromagnetic ground state. Below 20 K CeNiC2 shows multiple-step magnetic transitions at 18, 10, and 2.4 K. Both LaNiC2 (in the normal state) and CeNiC2 have the same electronic heat capacity, gamma = 6.5(2) mJ/mol K-2, which is typical for many lanthanide-based intermetallic compounds. The Debye temperature of LaNiC2 determined from the heat capacity in the normal state below 5.5 K is Theta(D) = 388(9) K. [S0163-1829(98)06425-X]. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Pecharsky, VK (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 17 TC 36 Z9 37 U1 2 U2 16 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 1 BP 497 EP 502 DI 10.1103/PhysRevB.58.497 PG 6 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200084 ER PT J AU Yi, YS Yu, ZG Bishop, AR Gammel, JT AF Yi, YS Yu, ZG Bishop, AR Gammel, JT TI Signatures of stripe phases in hole-doped La2NiO4 SO PHYSICAL REVIEW B LA English DT Article ID HUBBARD-MODEL; DOPING STATES; HARTREE-FOCK; SUPERCONDUCTORS; MAGNETISM; ANTIFERROMAGNETS; APPROXIMATION; FLUCTUATIONS; OXIDES; SPINS AB We model nickelate-centered and oxygen-centered stripe phases in doped La2NiO4 materials. We use an inhomogeneous Hartree-Fock and random-phase approximation approach including both electron-electron and electron-lattice (e-l) coupling for a layer of La2NiO4. We find that whether the ground state after commensurate hole doping comprises Ni-centered or O-centered charge-localized stripes depends sensitively on the e-l interaction. With increasing e-l interaction strength, a continuous transition from an O-centered stripe phase to a Ni-centered one is found. Various low- and high-energy signatures of these two kinds of stripe phases are predicted, which can clearly distinguish them. These signatures reflect the strongly correlated spin-charge-lattice features in the vicinity of Ni-centered or O-centered stripe domains. The importance of e-l interaction for recent experiments on stripe phases is discussed. [S0163-1829(98)06925-2]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Yi, YS (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Yu, Z/B-5547-2009; OI , Zhi-Gang/0000-0002-1376-9025 NR 32 TC 17 Z9 17 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 1 BP 503 EP 513 DI 10.1103/PhysRevB.58.503 PG 11 WC Physics, Condensed Matter SC Physics GA ZY633 UT WOS:000074643200085 ER PT J AU Seeck, OH Hupfeld, D Krull, H Tolan, M Press, W AF Seeck, OH Hupfeld, D Krull, H Tolan, M Press, W TI Order-disorder transition of ND4Cl and NH4Cl SO PHYSICAL REVIEW B LA English DT Article ID HALIDES; NH4BR AB ND4Cl and NH4Cl single crystals, as model systems for orientational order-disorder phase transitions, were investigated at atmospheric pressure with x-ray diffraction methods. NH4Cl undergoes a first-order transition whereas for ND4Cl the transition is very cll,se to a tricritical point (TCP). The order parameter m(T), which describes a low-temperature phase with ferro-ordered NH4+ or ND4+ tetrahedra, is obtained by analyzing the temperature dependence of the lattice constant a. It is shown that the temperature dependence of a strongly modifies the critical exponent beta(TCP) Of the order parameter. In particular, the data yield beta(TCP)=0.16+/-0.01 in direct neighborhood to the TCP, in good agreement with published values. The departure from the expected mean field value (beta(TCP)=0.25) is explained by rescaling the critical temperature due to the order-parameter-dependent lattice contraction. For ND4Cl we got quantitative results for the lattice contraction using a microscopic electrostatic model. Fluctuations related to local antiferro (AF) ordering of the tetrahedra were observed, too. Previously, AF ordering and fluctuations were only observed in NH4Br and ND4Br. The correlation length xi(AF) Of these AF fluctuations exhibits values of 30 Angstrom for NH4Cl and 10 Angstrom (2-3 lattice constants) for ND4Cl. [S0163-1829(98)01026-1]. C1 Univ Kiel, Inst Expt & Angew Phys, D-24098 Kiel, Germany. RP Seeck, OH (reprint author), XFD Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 30 TC 19 Z9 19 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP 623 EP 632 DI 10.1103/PhysRevB.58.623 PG 10 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600020 ER PT J AU Cote, M Grossman, JC Cohen, ML Louie, SG AF Cote, M Grossman, JC Cohen, ML Louie, SG TI Theoretical study of a three-dimensional all-sp(2) structure SO PHYSICAL REVIEW B LA English DT Article ID CARBON; SOLIDS; PHASE AB We present a study of a highly symmetric crystal made of exclusively sp(2) bonded atoms. Calculations of the structural and electronic properties are performed within the pseudopotential-density-functional approach for two different compositions made of (i) pure carbon and (ii) carbon and nitrogen compound. In both solids, one of the carbon-carbon bond lengths is found to be 1.35 Angstrom, which is considerably smaller than any carbon-carbon bond length found in other carbon solids. The bulls: moduli are calculated to be 241 and 286 GPa for the pure carbon and the carbon-nitride compounds, respectively. We demonstrate that the relatively low bulk moduli, considering the short bond lengths found in the structure, is due to the disruption of the carbon pi bonding states. This is probably unavoidable when trying to form a three-dimensional structure out of a planar configuration like the sp2 bonds. The calculated density of states and band structures show that the pure carbon form is metallic whereas the carbon nitride is semiconducting. When carbon atoms are added to the interstitial regions, the carbon solid becomes insulating and the bulk modulus increases to 282 GPa. [S0163-1829(98)01726-3]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Cote, Michel/H-3942-2012 OI Cote, Michel/0000-0001-9046-9491 NR 13 TC 30 Z9 31 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP 664 EP 668 DI 10.1103/PhysRevB.58.664 PG 5 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600025 ER PT J AU Ross, M AF Ross, M TI Linear-mixing model for shock-compressed liquid deuterium SO PHYSICAL REVIEW B LA English DT Article ID INERTIAL CONFINEMENT FUSION; HIGH-DENSITY; MOLECULAR DISSOCIATION; STATISTICAL-MECHANICS; FLUID HYDROGEN; HIGH-PRESSURE; STATE; EQUATION; NITROGEN; PHYSICS AB A model has been developed for the equation of state of deuterium that builds in the correct limiting behavior for the molecular fluid at low pressure and extends smoothly through dissociation to the very high-density monatomic-metallic fluid. The key assumption is that the Helmholtz free energy of the dissociating mixture is a function that can be approximated by the composition average of the free energy of the pure molecular and metallic hydrogen equations of state. The composition is determined by minimizing the free energy. In comparison to earlier studies this model leads to an enhancement of molecular dissociation and a lowering of shock temperatures and pressures. Calculations for shock-compressed liquid deuterium are in agreement with experiments to a pressure of 2.1 Mbar. At about 1 Mbar and 20 000 K liquid deuterium is 90% dissociated and is a nearly degenerate metal.The model predicts that molecular dissociation will lead to negative values of (partial derivative P/partial derivative T)(v) in the range 4000 to 10 000 K and volumes below 7 cc/mol, This feature suggests the formation of covalently bonded species in the partially dissociated mixture. [S0163-1829(98)05825-1]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ross, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 39 TC 154 Z9 155 U1 0 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP 669 EP 677 DI 10.1103/PhysRevB.58.669 PG 9 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600026 ER PT J AU Choudhury, N Ghose, S Chowdhury, CP Loong, CK Chaplot, SL AF Choudhury, N Ghose, S Chowdhury, CP Loong, CK Chaplot, SL TI Lattice dynamics, Raman spectroscopy, and inelastic neutron scattering of orthoenstatite Mg2Si2O6 SO PHYSICAL REVIEW B LA English DT Article ID PHONON-DISPERSION RELATION; AB-INITIO; DENSITY; FORSTERITE; ENSTATITE; STATES; HEAT; PROTOENSTATITE; PEROVSKITE; FAYALITE AB Enstatite Mg2Si2O6 is an important rock-forming silicate of the pyroxene group. It exists in several polymorphs, the structures of which are characterized by double [MgO6] octahedral bands and single silicate chains. This paper reports lattice-dynamical rigid-ion model calculations and polarized Raman and inelastic-neutron-scattering measurements of orthoenstatite Mg2Si2O6, which is orthorhombic (Pbca) with 80 atoms in the unit cell. The calculated elastic constants, phonon frequencies, density of slates, and specific heat are in good agreement with the experimental data. The optical-phonon branches along the Sigma and Delta directions are relatively flat without significant dispersion, but have moderate dispersion along the Lambda direction, reflecting the strong structural anisotropy id orthoenstatite, Orthoenstatite undergoes a displacive-reconstructive phase transformation at similar to 1360 K to protoenstatite Mg2Si2O6, which is also orthorhombic (Pbcn) with 40 atoms in the unit cell and the a dimension half that of orthoenstatite. However, the computed phonon-dispersion relations in orthoenstatite do not exhibit any lattice instability in the entire Brillouin zone. The calculations predict that at the Gamma point the lowest optic A(g) mode Involving translations of Mg2+ ions and translations and rotations of the tetrahedral silicate groups softens from 104 cm(-1) in protoenstatite to 82 cm(-1) in orthoenstatite, which is consistent with the single-crystal polarized Raman-scattering measurements. The phonon spectra obtained from inelastic-neutron-scattering measurements have been interpreted on the basis of model calculations. The broad peak in the 20-8O-meV range in orthoenstatite is mainly due to Mg translations and the librations of the nearly rigid tetrahedral [SiO4] groups, whereas the internal Si-O bond stretching vibrations of the [SiO4] groups contribute mainly above SO meV. The bridging oxygens in the silicate chains are vibrationally distinct from the nonbridging oxygens, leading to significant differences in the vibrational spectra of orthoenstatite and protoenstatite with tetrahedral silicate chains from those in forsterite Mg2SiO4 with isolated silicate tetrahedra. The band gaps found in the phonon density of states of forsterite are filled by the vibrations of the bridging oxygens in the silicate chains in the phonon densities of states of orthoenstatite and protoenstatite. [S0163-1829(98)06125-6]. C1 Univ Washington, Dept Geol Sci, Mineral Phys Grp, Seattle, WA 98195 USA. Argonne Natl Lab, Div Chem & Mat Sci, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Bhabha Atom Res Ctr, Div Solid State Phys, Bombay 400085, Maharashtra, India. RP Choudhury, N (reprint author), Bhabha Atom Res Ctr, Div Solid State Phys, Bombay 400085, Maharashtra, India. RI Garcia-Sanchez, Almudena/B-3303-2009 NR 26 TC 29 Z9 29 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 JUL 1 PY 1998 VL 58 IS 2 BP 756 EP 765 DI 10.1103/PhysRevB.58.756 PG 10 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600036 ER PT J AU Klemm, RA Rieck, CT Scharnberg, K AF Klemm, RA Rieck, CT Scharnberg, K TI Angular dependence of the Josephson critical current in c-axis twist junctions of high-temperature superconductors SO PHYSICAL REVIEW B LA English DT Article ID TUNNEL-JUNCTIONS; ORDER-PARAMETER; UNCONVENTIONAL SUPERCONDUCTORS; LAYERED SUPERCONDUCTORS; PAIRING SYMMETRY; YBA2CU3O7-DELTA; STATE; SURFACE; GAP; BI2SR2CACU2O8 AB We have investigated theoretically the case of a highly anisotropic layered superconductor consisting of two identical parts that are twisted with respect to each other by an angle phi(0) about the c axis. This work was motivated by recent high-quality c-axis twist Josephson junctions prepared with Bi2Sr2CaCu2O8+delta by Li et al. Our interest lies in studying whether the Josephson critical voltage IcRn measured along the c axis in high-temperature superconductors as a function of phi(0) could give;valuable information regarding the orbital symmetry of the superconducting order parameter. We assume both coherent and incoherent interlayer tunneling processes, and ordinary intralayer impurity scattering. We have derived and studied the effective Lawrence-Doniach model appropriate for the cases of pure s-wave and d(x2-y2)-wave order parameters, a dominant d(x2-y2) and subdominant d(xy) mixed order parameter, and a dominant d(x2-y2) with a subdominant s-wave mixed order parameter. Our results suggest that Josephson tunneling across the c-axis twist junctions can indeed be a useful tool for probing the superconducting order-parameter symmetry. Further experiments to clarify the situation are suggested. [S0163-1829(98)05226-6]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Hamburg, Fachbereich Phys, D-20355 Hamburg, Germany. RP Klemm, RA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 53 TC 43 Z9 43 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP 1051 EP 1067 DI 10.1103/PhysRevB.58.1051 PG 17 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600069 ER PT J AU Lin, Y Eldridge, JE Wang, HH Kini, AM Kelly, ME Williams, JM Schlueter, J AF Lin, Y Eldridge, JE Wang, HH Kini, AM Kelly, ME Williams, JM Schlueter, J TI Effect of magnetic fluctuations on Raman scattering in kappa-(BEDT-TTF)(2)Cu(NCS)(2) SO PHYSICAL REVIEW B LA English DT Article ID ORGANIC SUPERCONDUCTOR; C-13 NMR; BEDT-TTF; AMBIENT PRESSURE; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE; KAPPA-(BEDT-TTF)2CU(NCS)2; KAPPA-(ET)2CUCL; SPECTRA AB The temperature dependence of the intensity and frequency of two intense features in the Raman spectrum of kappa-(BEDT-TTF)(2)Cu(NCS)(2) have been measured. The spectra were taken with a Fourier Raman spectrometer equipped with an infrared laser. The two lines are due to a strongly resonant nu(9)(A(g)) doublet, and a sharp line due to nu(60) (B-3g). The frequencies of these modes are observed to soften below 80 K, in the temperature range where antiferromagnetic spin fluctuations have been observed with NMR, providing evidence of interactions between the phonons and the magnetism. [S0163-1829(98)50926-5]. C1 Univ British Columbia, Dept Phys, Vancouver, BC V6T 1Z1, Canada. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lin, Y (reprint author), Univ British Columbia, Dept Phys, 6224 Agr Rd, Vancouver, BC V6T 1Z1, Canada. RI Kini, Aravinda/F-4467-2012 NR 29 TC 8 Z9 8 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP R599 EP R602 DI 10.1103/PhysRevB.58.R599 PG 4 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600014 ER PT J AU Saxena, A Dandoloff, R AF Saxena, A Dandoloff, R TI Heisenberg spins on a cylinder in an axial magnetic field SO PHYSICAL REVIEW B LA English DT Article ID STATISTICAL-MECHANICS; ANTI-FERROMAGNET; SOLITONS; INSTABILITY; TRANSITIONS; BEHAVIOR; DYNAMICS; MODEL AB For classical Heisenberg spins in the continuum limit (i.e., the nonlinear (sigma model) on an elastic cylinder in an external axial magnetic field we find that the corresponding Euler-Lagrange equation is the double sine-Gordon (DSG) equation. The DSG soliton adopts a characteristic length xi which is smaller than the radius of the cylinder. This mismatch of length scales results in a geometric :Frustration in the region of the soliton and is relieved by the deformation of the cylinder. We also find the DSG kink soliton lattice and pulse soliton lattice solutions and show that they cause a periodic deformation of the cylinder. [S0163-1829(98)51126-5]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Cergy Pontoise, Lab Phys Theor & Modelisat, F-95302 Cergy Pontoise, France. RP Saxena, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM abs@aegir.lanl.gov; rossen@u-cergy.fr NR 29 TC 15 Z9 15 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP R563 EP R566 DI 10.1103/PhysRevB.58.R563 PG 4 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600005 ER PT J AU Yoshizawa, H Kawano, H Fernandez-Baca, JA Kuwahara, H Tokura, Y AF Yoshizawa, H Kawano, H Fernandez-Baca, JA Kuwahara, H Tokura, Y TI Anisotropic spin waves in a metallic antiferromagnet Nd0.45Sr0.55MnO3 SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-FIELD; TRANSITION AB We demonstrate that Nd0.45Sr0.55MnO3 is an example of a metallic antiferromagnetic manganite, and that it exhibits very anisotropic spin-wave dispersion relations with intra- and interplanar exchange parameters 8JS = 32.6 +/- 0.9 meV and 4J' S= - 10.1 +/- 0.5 meV, respectively. This anisotropy reflects underlying d(x)2(-y)2-type orbital ordering, and the metallic behavior indicates that a charge ordering is decoupled from the orbital ordering in this system. [S0163-1829(98)51926-1]. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Joint Res Ctr Atom Technol, Tsukuba, Ibaraki 305, Japan. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 113, Japan. RP Yoshizawa, H (reprint author), Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RI Tokura, Yoshinori/C-7352-2009; Fernandez-Baca, Jaime/C-3984-2014; Kawano-Furukawa, Hazuki/M-7695-2016; Kawano-Furukawa, Hazuki/M-7646-2016 OI Fernandez-Baca, Jaime/0000-0001-9080-5096; Kawano-Furukawa, Hazuki/0000-0003-4713-3727; Kawano-Furukawa, Hazuki/0000-0003-4713-3727 NR 18 TC 40 Z9 40 U1 2 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1998 VL 58 IS 2 BP R571 EP R574 DI 10.1103/PhysRevB.58.R571 PG 4 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600007 ER PT J AU Zhou, JS Goodenough, JB Mitchell, JF AF Zhou, JS Goodenough, JB Mitchell, JF TI Unusual thermoelectric power of single-crystal La1.2Sr1.8Mn2O7 SO PHYSICAL REVIEW B LA English DT Article AB Anisotropic resistivity and thermoelectric power of a single crystal of the mixed-valent, bilayered perovskite La1.2Sr1.8Mn2O7 have been measured under hydrostatic pressure P less than or equal to 14 kbar. The transport properties measured parallel to an a-b plane can be interpreted with a model of two-manganese Zener polarons, that, on cooling to T-c, progressively condense out into clusters, but are released to form a polaron Liquid below a T(o)less than or equal to T-c. Conduction along the c axis can be described by conventional small-polaron transport that is unaltered by clustering in the basal planes. [S0163-1829(98)50526-1]. C1 Univ Texas, Ctr Mat Sci & Engn, Austin, TX 78712 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Superconductiv, Argonne, IL 60439 USA. RP Zhou, JS (reprint author), Univ Texas, Ctr Mat Sci & Engn, ETC 9-102, Austin, TX 78712 USA. NR 9 TC 27 Z9 28 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 JUL 1 PY 1998 VL 58 IS 2 BP R579 EP R582 DI 10.1103/PhysRevB.58.R579 PG 4 WC Physics, Condensed Matter SC Physics GA ZZ014 UT WOS:000074686600009 ER PT J AU Pietralla, N von Brentano, P Gelberg, A Otsuka, T Richter, A Smirnova, N Wiedenhover, I AF Pietralla, N von Brentano, P Gelberg, A Otsuka, T Richter, A Smirnova, N Wiedenhover, I TI Symmetry changing transitions in gamma-soft nuclei studied in the interacting boson model SO PHYSICAL REVIEW C LA English DT Article ID INELASTIC ELECTRON-SCATTERING; MIXED-SYMMETRY; SCISSORS MODE; SHELL-MODEL; STATES; PROTON; REGION; BA-134; EXCITATIONS; DEFORMATION AB Within the framework of the interacting boson model (IBM-2) we analyze F-vector gamma transitions in gamma-soft nuclei for which the O(6) dynamical symmetry of the IBM provides an analytical description. For certain parameter combinations, the IBM-2 Hamiltonian is invariant with respect to the d-parity operation which changes the sign of each d boson. This:symmetry of the Hamiltonian is responsible for the existence of the d-parity quantum number which leads to selection rules for electromagnetic transitions. The breaking of the d-parity symmetry can be studied in mixed E2/M1 transitions, and especially the E2/M1 mixing ratio of the 1(1)(+)-->2(1)(+) gamma transition turns out to be a sensitive measure of IBM-2 parameters for gamma-soft nuclei. C1 Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. EM pietrall@ikp.uni-koeln.de RI OTSUKA, TAKAHARU/G-5072-2014 NR 42 TC 25 Z9 25 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 191 EP 197 DI 10.1103/PhysRevC.58.191 PG 7 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000026 ER PT J AU Reinhold, J Friese, J Korner, HJ Schneider, R Zeitelhack, K Geissel, H Magel, A Munzenberg, G Summerer, K AF Reinhold, J Friese, J Korner, HJ Schneider, R Zeitelhack, K Geissel, H Magel, A Munzenberg, G Summerer, K TI Projectile fragmentation of Xe-129 at E-lab=790A MeV SO PHYSICAL REVIEW C LA English DT Article ID RELATIVISTIC HEAVY-IONS; MOMENTUM DISTRIBUTIONS; ISOTOPES; COLLISIONS; NUCLEON AB We have measured production yields and longitudinal momentum distributions of projectilelike fragments in the reaction Xe-129+ Al-27 at, energy of E-lab=790A MeV. Production cross sections higher than expected from systematics were observed for nuclei in the neutron-deficient tails of the isotopic distributions. A comparison with previously measured data from the fragmentation of Xe-136 ions shows that the production yields strongly depend on the neutron excess of the projectile with respect to the line of beta stability. The momentum distributions exhibit a dependence on the fragment neutron-to-proton ratio in isobaric chains, which was not expected from systematics so far. This can be interpreted by a higher excitation of the projectile during the formation of neutron-deficient fragments. C1 Tech Univ Munchen, Phys Dept E12, D-85747 Garching, Germany. Gesell Schwerionenforsch GmbH, D-64220 Darmstadt, Germany. RP Reinhold, J (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 32 TC 21 Z9 21 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 247 EP 255 DI 10.1103/PhysRevC.58.247 PG 9 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000033 ER PT J AU Popescu, R Glasmacher, T Dinius, JD Gaff, SJ Gelbke, CK Handzy, DO Huang, MJ Kunde, GJ Lynch, WG Martin, L Montoya, CP Tsang, MB Colonna, N Celano, L Tagliente, G Margagliotti, GV Milazzo, PM Rui, R Vannini, G Bruno, M D'Agostino, M Fiandri, ML Gramegna, F Ferrero, A Iori, I Moroni, A Petruzzelli, F Mastinu, PF Phair, L Tso, K AF Popescu, R Glasmacher, T Dinius, JD Gaff, SJ Gelbke, CK Handzy, DO Huang, MJ Kunde, GJ Lynch, WG Martin, L Montoya, CP Tsang, MB Colonna, N Celano, L Tagliente, G Margagliotti, GV Milazzo, PM Rui, R Vannini, G Bruno, M D'Agostino, M Fiandri, ML Gramegna, F Ferrero, A Iori, I Moroni, A Petruzzelli, F Mastinu, PF Phair, L Tso, K TI Sensitivity of two-fragment correlation functions to initial-state momentum correlations SO PHYSICAL REVIEW C LA English DT Article ID 2-PROTON CORRELATION-FUNCTIONS; INTERMEDIATE-MASS FRAGMENTS; HEAVY-ION COLLISIONS; IMF IMF CORRELATIONS; AR-36+AU-197 COLLISIONS; NUCLEAR FRAGMENTATION; TIME-SCALE; STATISTICAL MULTIFRAGMENTATION; CSI(TL) SCINTILLATORS; 35 MEV/U AB Two-fragment reduced-velocity correlation functions were measured for small-impact-parameter collisions of Kr-86+Nb-93 at E/A=50 MeV and compared to results of many-body Coulomb-trajectory calculations performed for instantaneous and sequential multifragment breakup scenarios. The correlation functions indicate emission on a very shea time scale and appear consistent with an instantaneous breakup scenario, even though they exhibit a pronounced dependence on fragment kinetic energy when fragments are emitted at large transverse momenta. For the case of instantaneous breakup, sensitivities to initial-state momentum correlations due to total momentum conservation and to different emission patterns are investigated. For fragments emitted with large transverse momenta, momentum conservation constraints can cause a dependence of reduced-velocity correlation functions on fragment energy and fragment charge similar to those observed experimentally. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Ist Nazl Fis Nucl, I-70126 Bari, Italy. Dipartimento Fis, Trieste, Italy. Ist Nazl Fis Nucl, Trieste, Italy. Dipartimento Fis, Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy. Univ Milan, Dipartimento Fis, Milano, Italy. Ist Nazl Fis Nucl, I-20133 Milano, Italy. Univ Padua, Dipartimento Fis, Padova, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Popescu, R (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RI Glasmacher, Thomas/C-4462-2008; Lynch, William/I-1447-2013; Glasmacher, Thomas/H-9673-2014; Gramegna, Fabiana/B-1377-2012; Popescu, Razvan/H-6521-2016; Rui, Rinaldo/L-1926-2015 OI Lynch, William/0000-0003-4503-176X; Glasmacher, Thomas/0000-0001-9436-2448; Gramegna, Fabiana/0000-0001-6112-0602; Popescu, Razvan/0000-0003-1989-764X; Rui, Rinaldo/0000-0002-6993-0332 NR 42 TC 17 Z9 17 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 270 EP 280 DI 10.1103/PhysRevC.58.270 PG 11 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000035 ER PT J AU Whisnant, CS Mize, WK Pomarede, D AF Whisnant, CS Mize, WK Pomarede, D TI Multipole analysis of H-2(gamma,p)n in the Delta resonance region SO PHYSICAL REVIEW C LA English DT Article ID DEUTERON PHOTODISINTEGRATION; OBSERVABLES; THRESHOLD; SYSTEMS AB An energy-dependent multipole analysis of the photodisintegration of deuterium has been performed, for photon energies between 187 and 314 MeV using recent data taken with linearly polarized photons. A good fit is obtained With 11 free parameters determining :eight multipoles. A wide variety of multipole solutions has been examined and in all cases the cross-section with photon polarization parallel to the reaction plane is dominated by electric transitions, with E2.E1 interference responsible for the observed forward-backward angular asymmetry. The cross sections observed in perpendicular kinematics are dominated by magnetic multipoles. Several recent N Delta/NN coupled-channel calculations have predicted a pronounced 90 degrees dip in the cross section that is absent from the data. This dip can be reproduced by changing the M2 strength distribution in our fit. A comparison is made with multipoles calculated by Wilhelm and Arenhovel at 300 MeV. C1 Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Whisnant, CS (reprint author), Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. OI Pomarede, Daniel/0000-0003-2038-0488 NR 22 TC 3 Z9 3 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 289 EP 294 DI 10.1103/PhysRevC.58.289 PG 6 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000037 ER PT J AU Wong, CY Wang, H AF Wong, CY Wang, H TI Effects of parton intrinsic transverse momentum on photon production in hard-scattering processes SO PHYSICAL REVIEW C LA English DT Article ID QUARK-GLUON PLASMA; DILEPTON EMISSION; PP COLLISIONS; HADRONIC GAS; QCD; DISTRIBUTIONS; SEARCH; RATES AB We calculate the photon production cross section arising from the hard scattering of partons in nucleon-nucleon collisions by taking into account the intrinsic parton transverse momentum distribution and the next-to-leading-order contributions. As first pointed out by Owens, the inclusion of the intrinsic transverse momentum distribution of partons leads to an enhancement of photon production cross section in the region of photon transverse momenta of a few GeV/c for nucleon-nucleon collisions at a center-of-mass energy of a few tens of GeV. The enhancement increases as root s decreases. Such an enhancement is an important consideration in the region of photon momenta under investigation in high-energy heavy-ion collisions. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. China Inst Atom Energy, Beijing, Peoples R China. RP Wong, CY (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. OI Wong, Cheuk-Yin/0000-0001-8223-0659 NR 47 TC 79 Z9 80 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 376 EP 388 DI 10.1103/PhysRevC.58.376 PG 13 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000048 ER PT J AU Dean, DJ Langanke, K Chatterjee, L Radha, PB Strayer, MR AF Dean, DJ Langanke, K Chatterjee, L Radha, PB Strayer, MR TI Electron capture on iron group nuclei SO PHYSICAL REVIEW C LA English DT Article ID GAMOW-TELLER STRENGTH; WEAK-INTERACTION RATES; INTERMEDIATE-MASS NUCLEI; SD-SHELL NUCLEI; MONTE-CARLO; PF SHELL; MODEL; FE-54; SYSTEMATICS AB We present Gamow-Teller strength distributions from shell model Monte Carlo studies of fp-shell nuclei that may play an important role in the precollapse evolution of supernovas. We then use these strength distributions to calculate the electron-capture cross sections and rates in the zero-momentum transfer limit. We also discuss the thermal behavior of the cross sections. We find large differences in these cross sections and rates when compared to the naive single-particle estimates. These differences need to be taken into account for improved modeling of the early stages of type-Il supernova evolution. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Aarhus Univ, Inst Phys & Astron, Aarhus, Denmark. Aarhus Univ, Theoret Ctr Astrophys, Aarhus, Denmark. Cumberland Univ, Lebanon, TN 37087 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. RP Oak Ridge Natl Lab, Div Phys, POB 2008, Oak Ridge, TN 37831 USA. OI Dean, David/0000-0002-5688-703X NR 41 TC 46 Z9 46 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP 536 EP 544 DI 10.1103/PhysRevC.58.536 PG 9 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000059 ER PT J AU Hsi, WC Kwiatkowski, K Wang, G Bracken, DS Cornell, E Ginger, DS Viola, VE Yoder, NR Korteling, RG Gimeno-Nogues, F Ramakrishnan, E Rowland, D Yennello, SJ Huang, R Lynch, WG Tsang, MB Xi, H Breuer, H Morley, KB Gushue, S Remsberg, LP Friedman, WA Botvina, A AF Hsi, WC Kwiatkowski, K Wang, G Bracken, DS Cornell, E Ginger, DS Viola, VE Yoder, NR Korteling, RG Gimeno-Nogues, F Ramakrishnan, E Rowland, D Yennello, SJ Huang, R Lynch, WG Tsang, MB Xi, H Breuer, H Morley, KB Gushue, S Remsberg, LP Friedman, WA Botvina, A TI Sideways-peaked angular distributions in hadron-induced-multifragmentation: Shock waves, geometry, or kinematics? SO PHYSICAL REVIEW C LA English DT Article ID HE-3+ AG-NAT; INTERMEDIATE ENERGIES; FRAGMENT PRODUCTION; AU-197 REACTIONS; COLLISIONS; PROTONS; 4-PI; SPECTRA; AU AB Exclusive studies of sideways-peaked angular distributions for intermediate-mass fragments (IMFs) produced in hadron-induced reactions have been performed with the Indiana silicon sphere (ISiS) detector array. The effect becomes prominent for beam momenta above about 10 GeV/c. Both the magnitude of the effect and the peak angle increase as a function of fragment multiplicity and charge. When gated on IMF kinetic energy, the angular distributions evolve from forward peaked to nearly isotropic as the fragment energy decreases. Fragment-fragment correlation studies show no evidence for a preferred angle that might signal a fast dynamic breakup mechanism. Moving-source and intranuclear cascade simulations suggest a possible kinematic origin arising from significant transverse momentum imparted to the recoil nucleus during the fast cascade. A two-step cascade and statistical multifragmentation calculation is consistent with the data. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, IUCF, Bloomington, IN 47405 USA. Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Michigan State Univ, Dept Phys, E Lansing, MI USA. Michigan State Univ, Nscl, E Lansing, MI 48824 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Bologna, Dept Phys, I-40126 Bologna, Italy. RP Hsi, WC (reprint author), Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RI Ginger, David/C-4866-2011; Lynch, William/I-1447-2013; Rowland, Douglas/F-3104-2014; Yennello, Sherry/B-5803-2015 OI Ginger, David/0000-0002-9759-5447; Lynch, William/0000-0003-4503-176X; Rowland, Douglas/0000-0001-8059-6905; Yennello, Sherry/0000-0003-3963-5217 NR 28 TC 5 Z9 5 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP R13 EP R17 DI 10.1103/PhysRevC.58.R13 PG 5 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000004 ER PT J AU Nieminen, JM Flibotte, S Gervais, G Haslip, DS Lee, IY Macchiavelli, AO MacLeod, RW Stezowski, O Svensson, CE Waddington, JC Wilson, JN AF Nieminen, JM Flibotte, S Gervais, G Haslip, DS Lee, IY Macchiavelli, AO MacLeod, RW Stezowski, O Svensson, CE Waddington, JC Wilson, JN TI Population of superdeformed bands at extreme angular momenta SO PHYSICAL REVIEW C LA English DT Article ID RAY COINCIDENCE DATA; BACKGROUND SUBTRACTION; CHANNEL; DYNAMICS; GD-147; NUCLEI AB A study of superdeformed band population at very high angular moments was undertaken with the reactions Ge-76 + Ge-76 and Si-28 + Sn-124. Both reactions formed the compound nucleus Gd-152 at excitation energy of 87 MeV. Relative to normally deformed states, the yrast superdeformed band in-the residual nucleus Gd-147 was found to be populated 4.6 +/- 0.2 times more strongly for the mass-symmetric reaction compared to,the mass-asymmetric reaction. Such a large difference in the population was not expected; Also, the superdeformed continuum feeding the yrast superdeformed states in Gd-147 was found to be at least 12 times stronger for the mass-symmetric reaction. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Inst Rech Subatom, F-67037 Strasbourg, France. RP Nieminen, JM (reprint author), McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. NR 26 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD JUL PY 1998 VL 58 IS 1 BP R1 EP R4 DI 10.1103/PhysRevC.58.R1 PG 4 WC Physics, Nuclear SC Physics GA ZZ010 UT WOS:000074686000001 ER PT J AU Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peryshkin, S Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisenko, N Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peryshkin, S Peters, M Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Determination of the mass of the W boson using the D0 detector at the Fermilab Tevatron SO PHYSICAL REVIEW D LA English DT Article ID CERN PBARP COLLIDER; TOP-QUARK; RADIATIVE-CORRECTIONS; PARTON DISTRIBUTIONS; P(P)OVER-BAR COLLISIONS; TRANSVERSE-MOMENTUM; ROOT-S=1.8 TEV; QCD; ELECTRONS; ENERGY AB A measurement of the mass of the W boson is presented which is based on a sample of 5982 W --> e nu decays observed in p (p) over bar collisions at root s = 1.8 TeV with the D0 detector during the 1992-1983 run: From a fit to the transverse mass spectrum, combined with. measurements of the Z boson mass, the W boson mass is measured to be M-W = 80.350 +/- 0.140(stat) +/- 0.165(syst) +/- 0.160(scale) GeV/c(2). Detailed discussions of the determination of the absolute energy scale, the measured efficiencies, and all systematic uncertainties are presented. [S0556-2821(98)01613-0]. C1 NYU, New York, NY 10003 USA. Univ Los Andes, Bogota, Colombia. Univ Arizona, Tucson, AZ 85721 USA. Boston Univ, Boston, MA 02215 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Brown Univ, Providence, RI 02912 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 14000, DF, Mexico. Columbia Univ, New York, NY 10027 USA. Univ Delhi, Delhi 110007, India. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60607 USA. Indiana Univ, Bloomington, IN 47405 USA. Iowa State Univ, Ames, IA 50011 USA. Korea Univ, Seoul 136701, South Korea. Kyungsung Univ, Pusan 608736, South Korea. Inst Nucl Phys, Krakow, Poland. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Moscow MV Lomonosov State Univ, Moscow, Russia. Univ Nebraska, Lincoln, NE 68588 USA. Northeastern Univ, Boston, MA 02115 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Univ Oklahoma, Norman, OK 73019 USA. Panjab Univ, Chandigarh 160014, India. Inst High Energy Phys, Protvino 142284, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77005 USA. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Univ Rochester, Rochester, NY 14627 USA. CE SACLAy, CEA, DAPNIA, Serv Phys Particules, Gif Sur Yvette, France. Seoul Natl Univ, Seoul, South Korea. SUNY Stony Brook, Stony Brook, NY 11794 USA. Tata Inst Fundamental Res, Colaba 400005, Mumbai, India. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP NYU, New York, NY 10003 USA. RI Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Leflat, Alexander/D-7284-2012; Dudko, Lev/D-7127-2012; Merkin, Mikhail/D-6809-2012; Klyukhin, Vyacheslav/D-6850-2012; Roe, Natalie/A-8798-2012; De, Kaushik/N-1953-2013 OI Kim, Sun Kee/0000-0002-0013-0775; Sznajder, Andre/0000-0001-6998-1108; Belyaev, Alexander/0000-0002-1733-4408; Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489 NR 58 TC 24 Z9 24 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 012002 DI 10.1103/PhysRevD.58.012002 PG 49 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500002 ER PT J AU Adler, S Atiya, MS Chiang, IH Frank, JS Haggerty, JS Kycia, TF Li, KK Littenberg, LS Sambamurti, A Stevens, A Strand, RC Witzig, C Louis, WC Akerib, DS Ardebili, M Convery, M Ito, MM Marlow, DR McPherson, R Meyers, PD Selen, MA Shoemaker, FC Smith, AJS Blackmore, EW Bryman, DA Felawka, L Konaka, A Kuno, Y Macdonald, JA Numao, T Padley, P Poutissou, JM Poutissou, R Roy, J Turcot, AS Kitching, P Nakano, T Rozon, M Soluk, R AF Adler, S Atiya, MS Chiang, IH Frank, JS Haggerty, JS Kycia, TF Li, KK Littenberg, LS Sambamurti, A Stevens, A Strand, RC Witzig, C Louis, WC Akerib, DS Ardebili, M Convery, M Ito, MM Marlow, DR McPherson, R Meyers, PD Selen, MA Shoemaker, FC Smith, AJS Blackmore, EW Bryman, DA Felawka, L Konaka, A Kuno, Y Macdonald, JA Numao, T Padley, P Poutissou, JM Poutissou, R Roy, J Turcot, AS Kitching, P Nakano, T Rozon, M Soluk, R TI Upper limit on the decay K+-> e(+)nu mu(+)mu(-) SO PHYSICAL REVIEW D LA English DT Article AB An upper limit on the branching ratio for the decay K+ --> e(+)nu mu(+)mu(-) is set at 5.0 X 10(-7) at a 90% confidence level, consistent with predictions from chiral perturbation theory. [S0556-2821(98)01615-4]. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Los Alamos Natl Lab, Medium Energy Phys Div, Los Alamos, NM 87545 USA. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. Univ Alberta, Ctr Subatom Res, Edmonton, AB T6G 2N5, Canada. RP Adler, S (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Marlow, Daniel/C-9132-2014 NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 012003 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500003 ER PT J AU Albright, CH Barr, SM AF Albright, CH Barr, SM TI Fermion masses in SO(10) with a single adjoint Higgs field SO PHYSICAL REVIEW D LA English DT Article ID GRAND UNIFIED THEORIES; SUPERSYMMETRIC SO(10); MODEL; UNIFICATION AB It has recently been shown how to break SO(10) down to the standard model in a realistic way with only one adjoint Higgs field. The expectation value of this;adjoint must point in the B-L direction. This has consequences for the possible form of the quark and lepton mass matrices. These consequences are explored in this paper, and it is found that one is naturally led to consider a particular form for the masses of the heavier generations. This form implies typically that there should be large (nearly maximal) mixing of the mu and tau neutrinos. An explanation that does not involve large tan beta also emerges for the fact that b and tau are light compared to the top quark. [S0556-2821(98)01413-1]. C1 No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Albright, CH (reprint author), No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA. EM albright@fnal.gov; smbarr@bartol.udel.edu OI Albright, Carl/0000-0002-2252-6359 NR 19 TC 110 Z9 110 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 013002 DI 10.1103/PhysRevD.58.013002 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500005 ER PT J AU Arkani-Hamed, N Luty, MA Terning, J AF Arkani-Hamed, N Luty, MA Terning, J TI Composite quarks and leptons from dynamical supersymmetry breaking without messengers SO PHYSICAL REVIEW D LA English DT Article ID STRONGLY COUPLED SUPERSYMMETRY; GAUGE-THEORIES; UNIFIED THEORIES; STANDARD MODEL; FIXED-POINTS; FLAVOR; MASS; SUPERGRAVITY; CONFINEMENT; TECHNICOLOR AB We present new theories of dynamical supersymmetry breaking in which the strong interactions that break supersymmetry also give rise to composite quarks and leptons with naturally small Yukawa couplings. In these models, supersymmetry breaking is communicated directly to the composite fields without "messenger" interactions. The compositeness scale can be anywhere between 10 TeV and the Planck scale. These models can naturally solve the supersymmetric favor problem, and generically predict sfermion mass unification independent from gauge unification. [S0556-2821(98)03711-4]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Theory Grp, Berkeley, CA USA. RP Arkani-Hamed, N (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM nima@slac.stanford.edu; miuty@physics.umd.edu; terning@alvin.lbl.gov NR 58 TC 41 Z9 41 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 015004 DI 10.1103/PhysRevD.58.015004 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500045 ER PT J AU Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, JE McNeile, C Rummukainen, K Sugar, B Toussaint, D AF Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, JE McNeile, C Rummukainen, K Sugar, B Toussaint, D TI Quenched hadron spectroscopy with improved staggered quark action SO PHYSICAL REVIEW D LA English DT Article ID LATTICE GAUGE-THEORIES; SUSSKIND FERMIONS; PERTURBATION-THEORY; QCD AB We investigate light hadron spectroscopy with an improved quenched staggered quark action. We compare the results obtained with an improved gauge plus an improved quark action, an improved gauge plus standard quark action, and the standard gauge plus standard quark action. Most of the improvement in the spectroscopy results is due to the improved gauge sector. However, the improved quark action substantially reduces violations of Lorentz invariance, as evidenced by the meson dispersion relations. [S0556-2821(98)03513-9]. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. Univ Pacific, Dept Phys, Stockton, CA 95211 USA. NORDITA, DK-2100 Copenhagen O, Denmark. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. RP Washington Univ, Dept Phys, St Louis, MO 63130 USA. NR 33 TC 43 Z9 43 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014503 DI 10.1103/PhysRevD.58.014503 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500038 ER PT J AU Bernard, C Blum, T Soni, A AF Bernard, C Blum, T Soni, A TI SU(3) flavor breaking in hadronic matrix elements for B-(B)over-bar oscillations SO PHYSICAL REVIEW D LA English DT Article ID QUENCHED WILSON FERMIONS; DECAY CONSTANTS; 4-FERMION OPERATORS; PERTURBATION-THEORY; CHIRAL LOGARITHMS; B-MESONS; LATTICE; QCD AB Results in the quenched approximation for SU(3) breaking ratios of the heavy-light decay constants and the Delta F=2 mixing matrix elements are reported. Using lattice simulations at 6/g(2)=5.7, 5.85, 6.0, and 6.3, we directly compute the mixing matrix element M-hl=[(P) over bar(hl)\(h) over bar gamma(mu)(1-gamma(5))l (h) over bar gamma(mu)(1-gamma(5))l\P-hl]. Extrapolating to the physical B meson states, B-0 and B-s(0), we obtain M-bs/M-bd=1.76(10)(-42)(+57) in the continuum limit. The systematic error includes the errors within the quenched approximation but not the errors of quenching. We also obtain the ratio of decay constants, f(bs)/f(bd)=1.17(2)(-6)(+12). For the B parameters we find B-bs(2 GeV)=B-bd(2 GeV)=1.02(13); we cannot resolve the SU(3) breaking effects in this case. [S0556-2821(98)01313-7]. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Washington Univ, Dept Phys, St Louis, MO 63130 USA. NR 29 TC 31 Z9 31 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014501 DI 10.1103/PhysRevD.58.014501 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500036 ER PT J AU El-Khadra, AX Kronfeld, AS Mackenzie, PB Ryan, SM Simone, JN AF El-Khadra, AX Kronfeld, AS Mackenzie, PB Ryan, SM Simone, JN TI B and D meson decay constants in lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID HEAVY; QUARKS AB We have calculated the decay constants of B and D mesons with lattice QCD. We use an O(a)-improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses of the b and c quarks. Our results are f(B)=164(-11)(+14)+/-8 MeV, f(Bs)=185(-8)(+13)+/-9 MeV, f(D)=194(-10)(+14) +/-10 MeV, and f(Ds)=213(-11)(+14)+/-11 MeV in the quenched approximation. The first error in each case is statistical, and the second is from perturbation theory. We show that discretization errors are under control in our approach and smaller than our statistical errors. The effects of the quenched approximation may raise our quenched result by up to 10%. [S0556-2821(98)07013-1]. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. OI Kronfeld, Andreas/0000-0003-2716-1149 NR 29 TC 76 Z9 76 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014506 DI 10.1103/PhysRevD.58.014506 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500041 ER PT J AU Grossman, Y Quinn, HR AF Grossman, Y Quinn, HR TI Bounding the effect of penguin diagrams in a(CP)(B-0 ->pi(+)pi(-)) SO PHYSICAL REVIEW D LA English DT Article ID ISOSPIN ANALYSIS; CP ASYMMETRIES; B-DECAYS; PHYSICS AB A clean determination of the angle ct of the unitary triangle from B-->pi pi decays requires an isospin analysis. If the B-->pi(0)pi(0) and (B) over bar-->pi(0)pi(0) decay rates are small it may be hard to carry out this analysis. Here we show that an upper bound on the error an sin 2 alpha due to penguin diagram effects can be obtained using only the measured rate B (B+/---> pi(+/-)pi(0)) and an upper bound on the combined rate B(B-->pi(0)pi(0)) + B((B) over bar-->pi(0)pi(0)). Since no b flavor tagging is needed to measure this combined rate, the bound that can be achieved may be significantly better than any approach which requires separate flavor-tagged neutral pion information. [S0556-2821(98)00915-1]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Grossman, Y (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 10 TC 92 Z9 93 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 017504 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500060 ER PT J AU Hambye, T Kohler, GO Paschos, EA Soldan, PH Bardeen, WA AF Hambye, T Kohler, GO Paschos, EA Soldan, PH Bardeen, WA TI 1/N-c corrections to the hadronic matrix elements of Q(6) and Q(8) in K ->pi pi decays SO PHYSICAL REVIEW D LA English DT Article ID NONLEPTONIC DECAYS; CP VIOLATION; QUARK; EPSILON'/EPSILON; MODEL; MASS; EVOLUTION; OPERATORS; RATIOS; LIMIT AB We calculate long-distance contributions to the amplitudes A (K-0-->2 pi, 1) induced by the gluon and the electroweak penguin operators Q(6) and Q(8), respectively. We use the 1/N-c expansion within the effective chiral Lagrangian for pseudoscalar mesons. In addition, we adopt a modified prescription for the identification of meson momenta in the chiral loop corrections in order to achieve a consistent matching to the short-distance part. Our approach leads to an explicit classification of the loop diagrams into non-factorizable and factorizable, the scale dependence of the latter being absorbed in the low-energy coefficients of the effective theory. Along these lines we calculate the one-loop corrections to the O(p(0)) term in the chiral expansion of both operators. In the numerical results, we obtain moderate corrections to B-6((1/2)) and a substantial reduction of B-8((3/2)). [S0556-2821(98)06013-5]. C1 Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. Fermilab, Batavia, IL 60510 USA. RP Hambye, T (reprint author), Univ Dortmund, Inst Phys, D-44221 Dortmund, Germany. NR 40 TC 72 Z9 72 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014017 DI 10.1103/PhysRevD.58.014017 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500032 ER PT J AU Hashimoto, S Ishikawa, KI Matsufuru, H Onogi, T Yamada, N AF Hashimoto, S Ishikawa, KI Matsufuru, H Onogi, T Yamada, N TI Lattice study of B ->pi semileptonic decay using nonrelativistic lattice QCD SO PHYSICAL REVIEW D LA English DT Article ID HEAVY-QUARK; PERTURBATION-THEORY; MESON AB We present an exploratory lattice study of B-->pi semileptonic decay form factors using nonrelativistic lattice QCD for a heavy quark with a Wilson light quark on a 16(3)x32 quenched lattice at beta=5.8. The matrix elements are calculated at eight values of the heavy quark mass in the range of 1.5-8 GeV and with three values of light quark mass. The 1/m(B) corrections to the matrix elements are found to be fairly small except for the spatial component proportional to the B-meson momentum. We find that the q(2) dependence of the form factor f(+)(q(2)) near q(max)(2) becomes much stronger for a larger heavy quark mass, which may suggest an increase in the pole contribution. We perform a model independent fit of the form factors and study whether the q(2) dependence is consistent with the pole contribution. Although the soft pion theorem predicts f(0)(q(max)(2))=f(B)/f(pi) in the chiral limit, we observe a significant violation of this relation. [S0556-2821(98)00413-5]. C1 Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. Hiroshima Univ, Dept Phys, Higashihiroshima 7398526, Japan. High Energy Accelerator Res Org KEK, Ctr Res Comp, Tsukuba, Ibaraki 3050801, Japan. RP Fermilab Natl Accelerator Lab, Dept Theoret Phys, POB 500, Batavia, IL 60510 USA. NR 20 TC 17 Z9 17 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014502 DI 10.1103/PhysRevD.58.014502 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500037 ER PT J AU Raja, R Tollestrup, A AF Raja, R Tollestrup, A TI Calibrating the energy of a 50x50 GeV muon collider using spin precession SO PHYSICAL REVIEW D LA English DT Article AB The neutral Higgs boson is expected to have a mass in the region 90-150 GeV/c(2) in various schemes within the minimal supersymmetric extension of the standard model. A first generation muon collider is uniquely; suited to investigate the mass, width, and decay modes of the Higgs boson, since the coupling of the Higgs boson to muons is expected to be strong enough for it to be produced in the s channel mode in the muon collider. Because BE the narrow width of the Higgs boson, it is necessary to measure and control the energy of the individual muon bunches to a precision of a few parts in a million. We investigate the feasibility of determining the energy scale of a muon collider ring with circulating muon beams of 50 GeV energy by measuring the turn by turn variation of the energy deposited by electrons produced by the decay of the muons. This variation is caused by the existence of an average initial polarization of the muon beam and a nonzero value of g-2 for the muon. We demonstrate that it is feasible to determine the energy scale of the machine with this method to a few parts per million using data collected during 1000 turns. [S0556-2821(98)02213-9]. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Raja, R (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 11 TC 24 Z9 24 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 013005 DI 10.1103/PhysRevD.58.013005 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500008 ER PT J AU Swartz, ML AF Swartz, ML TI Complete order-alpha(3) calculation of the cross section for polarized Compton scattering SO PHYSICAL REVIEW D LA English DT Article ID SPIN POLARIZATION; HERA AB The construction of a computer code to calculate the cross sections for the spin-polarized processes e(-)gamma --> e(-)gamma, e(-)gamma gamma, e(-)e(+)e(-) to order alpha(3) is described. The code calculates cross sections for circularly polarized initial-state photons and arbitrarily polarized initial-state electrons. The application of the code to the SLD Compton polarimeter indicates that the order-alpha(3) corrections produce a fractional shift in the SLC polarization scale of -0.1% which is too small and of the wrong sin to account for the discrepancy in the Z-pole asymmetries measured by the SLD Collaboration and the CERN LEP Collaborations. [S0556-2821(98)03413-4]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Swartz, ML (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 11 TC 14 Z9 14 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1998 VL 58 IS 1 AR 014010 DI 10.1103/PhysRevD.58.014010 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZY626 UT WOS:000074642500025 ER PT J AU Cook, SR Hoffbauer, MA Clark, DD Cross, JB AF Cook, SR Hoffbauer, MA Clark, DD Cross, JB TI Measurements of the reduced force coefficients for H-2, N-2, CO, and CO2 incident upon a solar panel array material, SiO2-coated Kapton, Kapton, and Z-93-coated Al SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-BEAM; VIBRATIONAL-EXCITATION; SURFACE SCATTERING AB The reduced force coefficients were measured for H-2, N-2, CO, and CO2 incident upon a solar panel array material, SiO2-coated Kapton, Kapton, and Z-93-coated Al. The coefficients were determined by measuring both the magnitude and direction of the force exerted on the surfaces by molecular beams of the gases. Measurements were made at angles of incidence of 0 degrees, 25 degrees, 50 degrees, 75 degrees: and 85 degrees. The forces were measured using a torsion balance with the surfaces mounted on the end of the lever arm. The absolute flux densities of the molecular beams were measured using a second torsion balance with a beam stop mounted on the lever arm that nullified the force of the scattered molecules. Flux measurements were also made using the effusive method. Standard time-of-flight techniques were used to determine the flux-weighted average velocities of the molecular beams. These velocities ranged from 1670 to 4620 m/s. The overall uncertainty in the reduced force coefficient measurements was estimated to be less than +/-10%. These measurements were used to obtain the magnitude and direction of the flux-weighted average velocity of the scattered molecules, and also the flux-weighted translational kinetic energy of the scattered molecules. Analysis of this information provided insight into the microscopic details of the gas-surface interaction potential energy surface. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cook, SR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 32 TC 2 Z9 2 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP 492 EP 503 DI 10.1103/PhysRevE.58.492 PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400066 ER PT J AU Cook, SR Hoffbauer, MA AF Cook, SR Hoffbauer, MA TI Analyzing gas-surface interactions using the reduced force coefficients SO PHYSICAL REVIEW E LA English DT Article ID MOLECULAR-BEAM; SCATTERING AB The reduced force coefficients are introduced as a new set of parameters that can be used to analyze the momentum transfered to surfaces by; incident molecules in rarefied flow regimes. These coefficients are well-defined for all angles of incidence, thereby eliminating the singularity problems associated with the momentum accommodation coefficients. The reduced force coefficients can be obtained from measurements of the forces exerted on surfaces by molecular beams, and can be used to obtain the flux-weighted average velocity of the molecules scattered from surfaces. Also, a method is developed that can be used to approximate the flux-weighted average translational energy of the scattered molecules and the energy accommodation coefficient for many gas-surface interactions, Measurements of the forces exerted on SiO2-coated Kapton and Z-93-coated Al by molecular beams of N-2 and H-2 are used to demonstrate the singularity problems associated with the momentum accommodation coefficients. The same force measurements are then used to calculate the reduced force coefficients and several macroscopic average quantities of the scattered molecules. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cook, SR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 24 TC 4 Z9 4 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP 504 EP 511 DI 10.1103/PhysRevE.58.504 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400067 ER PT J AU Wallace, DC AF Wallace, DC TI Liquid dynamics theory of the velocity autocorrelation function and self-diffusion SO PHYSICAL REVIEW E LA English DT Article ID NORMAL-MODE ANALYSIS; MOLECULAR-DYNAMICS; ELEMENTS AB In equilibrium liquid dynamics theory, the potential energy surface is supposed to consist of a large number of many-particle nearly harmonic random structural valleys. The passage of the system from one valley to another is a transit, and the transit motion has to be accounted for in order to apply liquid dynamics theory to nonequilibrium processes. The role of transits in liquid dynamics theory is equivalent to the role of collisions in gas dynamics theory. In a classical monatomic Liquid, transits are so frequent that each ion "sees" a rapidly fluctuating well during one mean vibrational period. This condition is represented approximately by an independent ion model, in which each ion moves in a smooth harmonic well of frequency omega, and at each classical turning point the ion enters a new well with probability mu, or returns in its old well with probability 1 - mu. The corresponding velocity autocorrelation function, which depends on w and a simple function xi(mu), can be made to fit previously published computer calculations. The frequency w is close to the mean phonon frequency of the crystalline slate, confirming a prediction of equilibrium liquid dynamics theory, and the transit probability mu is around,. Analysis of experimental diffusion data suggests that xi is approximately a universal function of T/T-m. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wallace, DC (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 42 TC 17 Z9 18 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP 538 EP 545 DI 10.1103/PhysRevE.58.538 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400072 ER PT J AU Wang, JM AF Wang, JM TI Microwave instability as a coherent light source SO PHYSICAL REVIEW E LA English DT Article AB We suggest that the coherent radiation observed recently at SURF II and the National Snychrotron Light Source vacuum ultraviolet ring is due to coherent microwave instability or, equivalently, to "microbunching" of the electron beams in the storage rings. We formulate in this paper the problem of microwave instability in the lime domain. A linear homogeneous integro-differential equation for the perturbed current distribution is derived to describe the microwave coherent motion inside the electron bunch. For a specific band-limited high-frequency impedance, the equation can be diagonalized analytically and the eigensolution manifests explicitly the characteristics of microbunching. Coherent radiation power is also calculated for this solvable model, assuming the instability to be initiated by the shot noise inherent in the electron beam. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Wang, JM (reprint author), Brookhaven Natl Lab, Bldg 725C, Upton, NY 11973 USA. NR 15 TC 10 Z9 10 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP 984 EP 991 DI 10.1103/PhysRevE.58.984 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400125 ER PT J AU Rasmussen, KO Bishop, AR Gronbech-Jensen, N AF Rasmussen, KO Bishop, AR Gronbech-Jensen, N TI Creation and annihilation of intrinsic localized excitations SO PHYSICAL REVIEW E LA English DT Article ID NONLINEAR SCHRODINGER-EQUATIONS; WEAKLY COUPLED OSCILLATORS; HAMILTONIAN NETWORKS; ENERGY LOCALIZATION; MODES; STABILITY; CHAOS; BREATHERS; LATTICES; SYSTEMS AB Creation and annihilation of intrinsic localized excitations in a nonintegrable discrete one-dimensional nonlinear Schrodinger system is studied numerically. We demonstrate that the distribution p(x) of the amplitudes x. Of the created excitations has the form p(x)= x(alpha)exp(beta alpha(gamma)). The log-normal form y=2 has previously been found in non-Hamiltonian continuous systems. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Rasmussen, Kim/B-5464-2009 OI Rasmussen, Kim/0000-0002-4029-4723 NR 30 TC 5 Z9 5 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP R40 EP R43 DI 10.1103/PhysRevE.58.R40 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400011 ER PT J AU Zharnitsky, V Mitkov, I Gronbech-Jensen, N AF Zharnitsky, V Mitkov, I Gronbech-Jensen, N TI pi kinks in strongly ac driven sine-Gordon systems SO PHYSICAL REVIEW E LA English DT Article ID JOSEPHSON-JUNCTION; SOLITONS AB We demonstrate that pi kinks exist in nonparametrically ac driven sine-Gordon systems if the ac drive is sufficiently fast. It is found that. at a critical value of the drive amplitude, there are two stable and two unstable equilibria in the sine-Gordon phase. The pairwise symmetry of these equilibria implies the existence of a one-parameter family of pi-kink solutions in the reduced system. In the dissipative case of the ac driven sine-Gordon systems, corresponding to Josephson junctions, the velocity is selected by the balance between the perturbations. The results are derived from a perturbation analysis and verified by direct numerical simulations. C1 Brown Univ, Div Appl Math, Providence, RI 02912 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Computat Sci Methods Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Zharnitsky, V (reprint author), Brown Univ, Div Appl Math, Providence, RI 02912 USA. NR 13 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUL PY 1998 VL 58 IS 1 BP R52 EP R55 DI 10.1103/PhysRevE.58.R52 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 101XL UT WOS:000074893400014 ER PT J AU Klimenko, AA Osetrov, SB Smolnikov, AA Vasilyev, SI Avignone, FT Brodzinski, RL Miley, HS Reeves, JH AF Klimenko, AA Osetrov, SB Smolnikov, AA Vasilyev, SI Avignone, FT Brodzinski, RL Miley, HS Reeves, JH TI Search for annual and daily dark-matter modulations with Ge detectors at Baksan SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 1st International Workshop on Nonaccelerator New Physics CY JUL 07-11, 1997 CL DUBNA, RUSSIA SP Joint Inst Nucl Res, Nucl Problems Lab, Russian Fdn Basic Res ID CANDIDATES; EXCITATION AB An energy threshold of 2 keV was achieved for the 1-kg HP Ge detector in a long-term experiment aimed at searches for cold-dark-matter (CDM) particles. Data from two (Ge-76 and natural Ge) detectors were accumulated and analyzed for a period from May 1995 to March 1997. The effective passive and active shielding, together with pulse-shape discrimination, allowed one to achieve a background of 0.26 count/(kg keV d) for both detectors. New restrictions on the masses of weakly interacting massive particles (WIMP) and on the cross section for their elastic scattering on nuclei are obtained. The Dirac neutrino as a WIMP is ruled out in the range 13 GeV-4.5 TeV, Annual and daily modulations of the CDM signal are investigated. The possibility of detecting CDM particles by means of their inelastic interaction with Ge-73 is considered. C1 Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. Univ S Carolina, Dept Phys, Columbia, SC 29208 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Klimenko, AA (reprint author), Russian Acad Sci, Inst Nucl Res, Pr Shestidesyatiletiya Oktyabrya 7A, Moscow 117312, Russia. NR 16 TC 1 Z9 1 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 USA SN 1063-7788 J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD JUL PY 1998 VL 61 IS 7 BP 1129 EP 1136 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 122AB UT WOS:000076047300009 ER PT J AU Avignone, FT Abriola, D Brodzinski, RL Collar, JI Creswick, RJ DiGregorio, DE Farach, HA Gattone, AO Guerard, CK Hasenbalg, F Huck, H Miley, HS Morales, A Morales, J Nussinov, S de Solorzano, AO Reeves, JH Villar, JA Zioutas, K AF Avignone, FT Abriola, D Brodzinski, RL Collar, JI Creswick, RJ DiGregorio, DE Farach, HA Gattone, AO Guerard, CK Hasenbalg, F Huck, H Miley, HS Morales, A Morales, J Nussinov, S de Solorzano, AO Reeves, JH Villar, JA Zioutas, K CA SOLAX Collaboration TI First results from solar: A new technique to detect axions from the sun SO PHYSICS OF ATOMIC NUCLEI LA English DT Article; Proceedings Paper CT 1st International Workshop on Nonaccelerator New Physics CY JUL 07-11, 1997 CL DUBNA, RUSSIA SP Joint Inst Nucl Res, Nucl Problems Lab, Russian Fdn Basic Res ID BRAGG SCATTERING AB A new technique has been used to seek solar axions with a single-crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies the Bragg condition with a crystalline plane, The analysis of approximately 1.94 kg yr of data from the 1-kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on the axion-photon coupling constant (g(ayy) < 2.7 x 10(-9) GeV-1), irrespective of the axion mass up to similar to 1 keV. C1 Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. Comis Nacl Energia Atom, TANDAR Lab, RA-1429 Buenos Aires, DF, Argentina. Pacific NW Lab, Richland, WA 99352 USA. CERN, CH-1211 Geneva 23, Switzerland. Univ Zaragoza, Lab Fis Nucl & Altas Energias, E-50009 Zaragoza, Spain. Tel Aviv Univ, Dept Phys, IL-69978 Tel Aviv, Israel. Aristotle Univ Thessaloniki, Dept Phys, GR-54006 Thessaloniki, Greece. RP Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. RI Villar, Jose Angel/K-6630-2014 OI Villar, Jose Angel/0000-0003-0228-7589 NR 12 TC 3 Z9 3 U1 0 U2 0 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 1063-7788 EI 1562-692X J9 PHYS ATOM NUCL+ JI Phys. Atom. Nuclei PD JUL PY 1998 VL 61 IS 7 BP 1137 EP 1142 PG 6 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 122AB UT WOS:000076047300010 ER PT J AU Berning, M Rubenchik, AM AF Berning, M Rubenchik, AM TI A weakly nonlinear theory for the dynamical Rayleigh-Taylor instability SO PHYSICS OF FLUIDS LA English DT Article ID RICHTMYER-MESHKOV INSTABILITY; SINGLE-MODE; 3 DIMENSIONS; FRONTS; NOVA AB The dynamics of an interface between two incompressible, inviscid, irrotational, and immiscible liquids with densities rho(1) and rho(2) under the influence of a time-dependent gravitational field g(t) is investigated. A Hamiltonian formulation of the system is adopted leading to a perturbative expansion of the equations of motion for the canonical variables. Equations, accurate up to third order in the perturbation amplitude are derived. They are able to describe the initial stage of instability "saturation." The latter equations are integrated iteratively for two standard limiting cases: constant gravity (classical Rayleigh-Taylor instability), g(t) = g(0), and impulsive Richtmyer-Meskov loading, g(t)= upsilon(0)delta(t-t(0)). The comparative growth of various two-dimensional structures and rectangular and hexagonal cells is evaluated. Surface tension effects are considered. (C) 1998 American Institute of Physics. C1 Univ Dusseldorf, Inst Theoret Phys 1, D-40225 Dusseldorf, Germany. Univ Calif Lawrence Livermore Natl Lab, Davis, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 94550 USA. RP Berning, M (reprint author), Univ Dusseldorf, Inst Theoret Phys 1, Univ Str 1, D-40225 Dusseldorf, Germany. NR 28 TC 33 Z9 34 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUL PY 1998 VL 10 IS 7 BP 1564 EP 1587 DI 10.1063/1.869677 PG 24 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 110KC UT WOS:000075379100003 ER PT J AU Barnes, DC Nebel, RA AF Barnes, DC Nebel, RA TI Stable, thermal equilibrium, large-amplitude, spherical plasma oscillations in electrostatic confinement devices SO PHYSICS OF PLASMAS LA English DT Article ID FUSION AB The problem of large-amplitude spherical oscillations of an ion cloud in an Inertial Electrostatic Confinement (IEC) device is examined. It is shown that ion fluctuations of a Gaussian profile in a spherical, harmonic well are stable to all hydrodynamic modes, and stable oscillations about the oscillating equilibrium state may be damped by continuum damping. It is also shown that the ion state forms a thermal equilibrium, in spite of the orders of magnitude, density, and temperature changes during the oscillation cycle. Finally, a brief discussion of how to experimentally realize the required electron distributions for these oscillations is presented. [S1070-664X(98)012307-2] C1 Univ Calif Los Alamos Natl Lab, Div Appl Theoret Phys, Los Alamos, NM 87545 USA. RP Barnes, DC (reprint author), Univ Calif Los Alamos Natl Lab, Div Appl Theoret Phys, B-259, Los Alamos, NM 87545 USA. NR 11 TC 27 Z9 27 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2498 EP 2503 DI 10.1063/1.872933 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400005 ER PT J AU Deeney, C Peterson, DL Spielman, RB Struve, KW Chandler, GA AF Deeney, C Peterson, DL Spielman, RB Struve, KW Chandler, GA TI Optimization of power density by decreasing the length of tungsten wire array Z pinches SO PHYSICS OF PLASMAS LA English DT Article ID IMPLOSIONS; RADIUS AB Reducing the length of 30 mm diam tungsten wire arrays on the 20 MA Z pulsed power accelerator [R. B. Spielman, S. F. Breeze, C. Deeney et al., Proceedings of the 11th International Conference on Particle Beams, Prague, Czech Republic, edited by K. Junwirth and J. Ullschmied (Czech Academy of Sciences, Prague, 1996), p. 150] from 2 to 0.75 cm has shown that the radiated powers are energies that remain constant at 170+/-30 TW and 1600+/-150 kJ. The length-independent nature of the power and energy results in the radiated power per unit length increasing from 85 +/- 10 to 240+/-30 TW/cm. These high-power densities should result in approximately a 20% increase in radiation temperatures produced by a Z-pinch-driven vacuum or internal hohlarums. Two-dimensional radiation magnetohydrodynamic calculations indicate that the constant radiated energies with varying pinch lengths is consistent with the energy input being due to the work done by the Lorentz forces during the radial collapse, resulting in kinetic energy and during the on-axis pinch phase, resulting in pdV or compressional heating. (C) 1998 American Institute of Physics. [S1070-664X(98)00107-4] C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Deeney, C (reprint author), Sandia Natl Labs, POB 5800,MS-1194, Albuquerque, NM 87185 USA. NR 11 TC 14 Z9 14 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2605 EP 2608 DI 10.1063/1.872947 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400019 ER PT J AU Carreras, BA Owen, LW Maingi, R Mioduszewski, PK Carlstrom, TN Groebner, RJ AF Carreras, BA Owen, LW Maingi, R Mioduszewski, PK Carlstrom, TN Groebner, RJ TI Effect of edge neutrals on the low-to-high confinement transition threshold in the DIII-D tokamak SO PHYSICS OF PLASMAS LA English DT Article ID GRADIENT-DRIVEN TURBULENCE; POLOIDAL FLOW GENERATION; H-MODE TRANSITION; PLASMA; TRANSPORT; ROTATION; JT-60U AB To study the effect of edge neutrals on the low-to-high confinement transition threshold, a broad range of plasma discharges has been analyzed. These discharges vary by gas puffing and pumping rates, position of the X point, and line-averaged density. It is shown that the determination of the neutral density (or neutral pressure) in the scrape-off layer (SOL) can give a misleading indication of the neutral population inside the separatrix. An increase of neutral density in the SOL creates an increase of plasma density that, in turn, increases the opacity to the neutrals and results in reduced neutral penetration. At a constant magnetic field, the transition power divided by the density appears to be a function of a single parameter measuring the neutrals effect. From this analysis, this parameter cannot be uniquely identified. For instance, it may be the radial decay length of the neutral profile or the charge-exchange damping rate at about r/a approximate to 0.95. A similar correlation exists between these neutral parameters and local plasma parameters such as electron and ion temperature. This indicates that a missing parameter linked to the neutrals exists in the power threshold scaling laws. (C) 1998 American Institute of Physics. [S1070-664X(98)01007-6] C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Gen Atom Co, San Diego, CA 92186 USA. RP Carreras, BA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 55 TC 34 Z9 35 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2623 EP 2636 DI 10.1063/1.872949 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400021 ER PT J AU Hirshman, SP Breslau, J AF Hirshman, SP Breslau, J TI Explicit spectrally optimized Fourier series for nested magnetic surfaces SO PHYSICS OF PLASMAS LA English DT Article AB The nonuniqueness of the poloidal angle a in the parametric representation of a space curve x(theta) = [R(theta), Z( theta)] can be exploited to condense the Fourier spectra of R and Z. The nonlinear equation describing this spectral condensation was previously derived and solved numerically using Lagrange multipliers. Here a special case of the condensation equation is shown to be exactly solvable, leading to an explicit representation for x. A family of such representations is generated that possesses increasingly condensed spectra as a parameter is varied. Applications to a variety of curves are considered as models for three-dimensional magnetohydrodynamic (MHD) equilibria with nested flux surfaces. A substantial improvement occurs in spectral convergence compared with a polar representation, while retaining the numerical simplicity of the polar constraint. The asymptotic behavior for the R and Z spectral coefficients near a magnetic axis is analyzed. Implications for improvements of MHD equilibrium calculations are discussed. (C) 1998 American Institute of Physics. [S1070-664X(98)03107-3]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hirshman, SP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM hirshman@ornl.gov NR 6 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2664 EP 2675 DI 10.1063/1.872954 PG 12 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400026 ER PT J AU Strauss, HR Park, W AF Strauss, HR Park, W TI Magnetohydrodynamic effects on pellet injection in tokamaks SO PHYSICS OF PLASMAS LA English DT Article ID DIVERTOR TOKAMAKS AB The location at which pellets are injected into a plasma can have a significant effect on what fraction of the pellet mass remains in the plasma for refueling purposes. Magnetohydrodynamic (MHD) simulations presented here, confirm the results of pellet injection experiments: toroidal curvature makes it favorable to inject pellets from the inboard side or from the top or bottom, rather than from the outboard side. Sufficiently large pellets injected at the inboard edge can reach the plasma center, and in the process drive magnetic reconnection to produce negative central shear. Injection at the top (or bottom) of the tokamak causes relatively little displacement of the pellet. A scaling law is obtained for pellet displacement which agrees well with the simulations. The MHD simulations were carried out with a new unstructured mesh finite element version of the MH3D full MHD code. (C) 1998 American Institute of Physics. [S1070-664X(98)03907-X]. C1 NYU, Courant Inst Math Sci, New York, NY 10012 USA. Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Strauss, HR (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. NR 9 TC 31 Z9 33 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2676 EP 2686 DI 10.1063/1.872955 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400027 ER PT J AU Lefebvre, E Berger, RL Langdon, AB MacGowan, BJ Rothenberg, JE Williams, EA AF Lefebvre, E Berger, RL Langdon, AB MacGowan, BJ Rothenberg, JE Williams, EA TI Reduction of laser self-focusing in plasma by polarization smoothing SO PHYSICS OF PLASMAS LA English DT Article ID INDUCED SPATIAL INCOHERENCE; EXPLODING FOIL PLASMAS; SCALE-LENGTH PLASMAS; RAMAN-SCATTERING; FILAMENTATION; LIGHT; SUPPRESSION; INSTABILITY AB Dramatic reductions in the filamentation of an intense speckled laser beam in a hot, high-density plasma are reported in simulations of polarization smoothing (PS), which consists of irradiating the plasma with two superimposed, orthogonally polarized and uncorrelated speckle patterns. PS instantaneously smooths the spatial beam structure, and thus can be more effective than temporal smoothing techniques. Even greater reduction in filamentation, offering improved prospects for inertial fusion, results from combining these two methods. (C) 1998 American Institute of Physics. [S1070-664X(98)00607-7]. C1 CEA, DRIF DPTA, F-91680 Bruyeres Le Chatel, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lefebvre, E (reprint author), CEA, DRIF DPTA, BP 12, F-91680 Bruyeres Le Chatel, France. RI Lefebvre, Erik/B-9835-2009 NR 22 TC 51 Z9 52 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2701 EP 2705 DI 10.1063/1.872957 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400029 ER PT J AU Bezzerides, B AF Bezzerides, B TI Intrinsic bending of a laser beam in a flowing plasma SO PHYSICS OF PLASMAS LA English DT Article ID DEFLECTION AB In this paper a simple analytic model for deflection of a laser beam in the presence of flowing plasma is presented. The model utilizes a nonlinear solution of the paraxial wave equation in the random phase approximation. This approximation excludes any contribution from hot-spot induced self-focusing, but allows for the effects of intensity fluctuations of the beam. For a speckled beam the solution for the beam intensity in wave number space depends sensitively on the properties of the incident beam. It is shown that for an incident beam whose initial spectrum in wave number space is Gaussian, the final spectrum is also Gaussian with the overall spectrum rotated in wave number space by a radius of curvature function that is an explicit expression of the Mach number of the flow, the local acoustic damping, and the local average intensity. This result is applicable to the case in which the speckle develops upon transmission of the beam through a random phase plate (RPP). The bending rate thus calculated for a RPP-smoothed beam is compared to the bending rate in the absence of the RPP. This comparison provides some insight into the efficacy of the RPP in reducing the bending of the laser beam. (C) 1998 American Institute of Physics. [S1070-664X(98)01607-3]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bezzerides, B (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1998 VL 5 IS 7 BP 2712 EP 2720 DI 10.1063/1.872959 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 110KR UT WOS:000075380400031 ER PT J AU Auciello, O Scott, JF Ramesh, R AF Auciello, O Scott, JF Ramesh, R TI The physics of ferroelectric memories SO PHYSICS TODAY LA English DT Article ID RANDOM-ACCESS MEMORIES; FILMS C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ New S Wales, Sydney, NSW, Australia. Univ Maryland, College Pk, MD 20742 USA. RP Auciello, O (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 14 TC 932 Z9 951 U1 20 U2 170 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUL PY 1998 VL 51 IS 7 BP 22 EP 27 DI 10.1063/1.882324 PG 6 WC Physics, Multidisciplinary SC Physics GA ZX733 UT WOS:000074549200008 ER PT J AU Bond, PD Chasman, C AF Bond, PD Chasman, C TI Gertrude Scharff Goldhaber - Obituaries SO PHYSICS TODAY LA English DT Biographical-Item C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bond, PD (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUL PY 1998 VL 51 IS 7 BP 82 EP 83 DI 10.1063/1.882309 PG 2 WC Physics, Multidisciplinary SC Physics GA ZX733 UT WOS:000074549200025 ER PT J AU Clark, DJ Craddock, M AF Clark, DJ Craddock, M TI John Reginald Richardson - Obituaries SO PHYSICS TODAY LA English DT Biographical-Item C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ British Columbia, Vancouver, BC V5Z 1M9, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. RP Clark, DJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JUL PY 1998 VL 51 IS 7 BP 83 EP 84 DI 10.1063/1.882310 PG 2 WC Physics, Multidisciplinary SC Physics GA ZX733 UT WOS:000074549200026 ER PT J AU Clark, R Wadsworth, B AF Clark, R Wadsworth, B TI A new spin on nuclei SO PHYSICS WORLD LA English DT Article C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Clark, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8585 J9 PHYS WORLD JI Phys. World PD JUL PY 1998 VL 11 IS 7 BP 25 EP 28 PG 4 WC Physics, Multidisciplinary SC Physics GA ZZ486 UT WOS:000074734200027 ER PT J AU Garcia, RL Long, SP Wall, GW Osborne, CP Kimball, BA Nie, GY Pinter, PJ Lamorte, RL Wechsung, F AF Garcia, RL Long, SP Wall, GW Osborne, CP Kimball, BA Nie, GY Pinter, PJ Lamorte, RL Wechsung, F TI Photosynthesis and conductance of spring-wheat leaves: field response to continuous free-air atmospheric CO2 enrichment SO PLANT CELL AND ENVIRONMENT LA English DT Article DE acclimation; atmospheric change; climate change; elevated carbon dioxide; FACE; phenology; photosynthesis; Rubisco; stomatal conductance ID CARBON-DIOXIDE ENRICHMENT; WATER-USE EFFICIENCY; ELEVATED CO2; WINTER-WHEAT; GROWTH; LEAF; PRODUCTIVITY; ACCLIMATION; CAPACITY; PROTEINS AB Spring wheat was grown from emergence to grain maturity in two partial pressures of CO2 (pCO(2)): ambient air of nominally 37 Pa and air enriched with CO2 to 55 Pa using a free-air CO2 enrichment (FACE) apparatus. This experiment was the first of its kind to be conducted within a cereal field without the modifications or disturbance of microclimate and rooting environment that accompanied previous studies, It provided a unique opportunity to examine the hypothesis that continuous exposure of wheat to elevated pCO(2) will lead to acclimatory loss of photosynthetic capacity. The diurnal courses of photosynthesis and conductance for upper canopy leaves were followed throughout the development of the crop and compared to model-predicted rates of photosynthesis. The seasonal average of midday photosynthesis rates was 28% greater in plants exposed to elevated pCO(2) than in contols and the seasonal average of the daily integrals of photosynthesis was 21% greater in elevated pCO(2) than in ambient air. The mean conductance at midday was reduced by 36%. The observed enhancement of photosynthesis in elevated pCO(2) agreed closely with that predicted from a mechanistic biochemical model that assumed no acclimation of photosynthetic capacity. Measured values fell below predicted only in the flag leaves in the mid afternoon before the onset of grain-filling and over the whole diurnal course at the end of grain-filling. The loss of enhancement at this final stage was attributed to the earlier senescence of flag leaves in elevated pCO(2). In contrast to some controlled-environment and field-enclosure studies, this field-scale study of wheat using free-air CO2 enrichment found little evidence of acclimatory loss of photosynthetic capacity with growth in elevated pCO(2) and a significant and substantial increase in leaf photosynthesis throughout the life of the crop. C1 LI Cor Inc, Environm Div, Lincoln, NE 68504 USA. Univ Essex, John Tabor Labs, Dept Biol Sci, Colchester CO4 3SQ, Essex, England. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. USDA ARS, US Water Conservat Lab, Phoenix, AZ 85040 USA. Potsdam Inst Climate Impact Res, Nat Syst Dept, D-11412 Potsdam, Germany. RP Garcia, RL (reprint author), LI Cor Inc, Environm Div, 4421 Super,POB 4425, Lincoln, NE 68504 USA. RI Long, Stephen/A-2488-2008 OI Long, Stephen/0000-0002-8501-7164 NR 36 TC 92 Z9 106 U1 1 U2 20 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD JUL PY 1998 VL 21 IS 7 BP 659 EP 669 DI 10.1046/j.1365-3040.1998.00320.x PG 11 WC Plant Sciences SC Plant Sciences GA 117KL UT WOS:000075780400002 ER PT J AU Osborne, CP LaRoche, J Garcia, RL Kimball, BA Wall, GW Pinter, PJ LaMorte, RL Hendrey, GR Long, SP AF Osborne, CP LaRoche, J Garcia, RL Kimball, BA Wall, GW Pinter, PJ LaMorte, RL Hendrey, GR Long, SP TI Does leaf position within a canopy affect acclimation of photosynthesis to elevated CO2? Analysis of a wheat crop under free-air CO2 enrichment SO PLANT PHYSIOLOGY LA English DT Article ID CARBON-DIOXIDE ENRICHMENT; ATMOSPHERIC CO2; GAS-EXCHANGE; NITROGEN; GROWTH; FIELD; REDISTRIBUTION; PERSPECTIVE; APPARATUS; PLANTS AB Previous studies of photosynthetic acclimation to elevated CO2 have focused on the most recently expanded, sunlit leaves in the canopy. We examined acclimation in a vertical profile of leaves through a canopy of wheat (Triticum aestivum L.). The crop was grown at an elevated CO2 partial pressure of 55 Pa within a replicated field experiment using free-air CO2 enrichment. Cas exchange was used to estimate in vivo carboxylation capacity and the maximum rate of ribulose-1,5-bisphosphate-limited photosynthesis. Net photosynthetic CO2 uptake was measured for leaves in situ within the canopy. Leaf contents of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), light-harvesting-complex (LHC) proteins, and total N were determined. Elevated CO2 did not affect carboxylation capacity in the most recently expanded leaves but led to a decrease in lower, shaded leaves during grain development. Despite this acclimation, in situ photosynthetic CO2 uptake remained higher under elevated CO2. Acclimation at elevated CO2 was accompanied by decreases in both Rubisco and total leaf N contents and an increase in LHC content. Elevated CO2 led to a larger increase in LHC/Rubisco in lower canopy leaves than in the uppermost leaf. Acclimation of leaf photosynthesis to elevated CO2 therefore depended on both vertical position within the canopy and the developmental stage. C1 Univ Essex, Dept Biol Sci, John Tabor Labs, Colchester CO4 3SQ, Essex, England. Brookhaven Natl Lab, Environm Biol & Instrumentat Div, Upton, NY 11973 USA. USDA ARS, Water Conservat Lab, Phoenix, AZ 85040 USA. RP Long, SP (reprint author), Univ Essex, Dept Biol Sci, John Tabor Labs, Colchester CO4 3SQ, Essex, England. EM stevel@essex.ac.uk RI Long, Stephen/A-2488-2008; LaRoche, Julie/A-1109-2010 OI Long, Stephen/0000-0002-8501-7164; NR 34 TC 59 Z9 63 U1 3 U2 20 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1998 VL 117 IS 3 BP 1037 EP 1045 DI 10.1104/pp.117.3.1037 PG 9 WC Plant Sciences SC Plant Sciences GA 101KA UT WOS:000074867100033 ER PT J AU Tobin, SJ DeMichelis, C Hogan, JT Monier-Garbet, P Klepper, CC Guilhem, D AF Tobin, SJ DeMichelis, C Hogan, JT Monier-Garbet, P Klepper, CC Guilhem, D TI Particle flux and temperature dependence of carbon impurity production from an inertially-cooled limiter in Tore Supra SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID PUMP LIMITER; GRAPHITE; EROSION; BOMBARDMENT; JET AB A visible endoscope system and an infrared camera system have been used to study the flux of carbon from an inertially-cooled graphite limiter in Tore Supra. From the variation in the carbon flux with plasma parameters, new data have been obtained, describing the dependence of radiation enhanced sublimation (RES) and chemical sputtering on incident ion flux. Other characteristics of RES under plasma operation conditions have also been studied. The dependence of RES on incident deuterium particle flux density is found to be in reasonable agreement with the expected particle flux scaling over a range of particle fluxes varying by a factor of similar to 25, extending the present scaling to higher flux density values. Chemical sputtering has been observed, but only in regions of the limiter with low incident deuterium fluxes. Values inferred for the chemical sputtering yield are similar to those measured with a temperature-controlled test limiter in Textor. C1 Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. CEA Cadarache, EURATOM Assoc, CEA Fus Controlee, DRFC SPPF, F-13108 St Paul Durance, France. RP Tobin, SJ (reprint author), No Kentucky Univ, Dept Phys, Highland Heights, KY 41099 USA. NR 25 TC 5 Z9 5 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD JUL PY 1998 VL 40 IS 7 BP 1335 EP 1348 DI 10.1088/0741-3335/40/7/009 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 105RH UT WOS:000075087000009 ER PT J AU Mohanty, S Sahni, V Chakraborty, S Goyal, A Dutta, S Choudhury, D Mahajan, S Mukherjee, A Widyan, H Yajnik, U Grifols, JA Mahanta, U Sahu, S Souradeep, T Stebbins, A Waga, I Soni, V Panchapakesan, N Brandenberger, R AF Mohanty, S Sahni, V Chakraborty, S Goyal, A Dutta, S Choudhury, D Mahajan, S Mukherjee, A Widyan, H Yajnik, U Grifols, JA Mahanta, U Sahu, S Souradeep, T Stebbins, A Waga, I Soni, V Panchapakesan, N Brandenberger, R TI Astroparticle physics: Working group report SO PRAMANA-JOURNAL OF PHYSICS LA English DT Editorial Material DE cosmology; neutron stars; compact objects; supergravity; baryogenesis; large scale structure; cosmic microwave background ID STRINGS; GRAVITINO; MASS AB The astroparticle physics working group witnessed intense discussion and activity covering a broad range of topics ranging from supergravity and baryogenesis to compact stars and the large scale structure of the Universe. A summary of some of the subject areas in which collaborations were initiated during WHEPP-5 is presented below. C1 Phys Res Lab, Ahmedabad 380009, Gujarat, India. Interuniv Ctr Astron & Astrophys, Poona 411007, Maharashtra, India. Univ Kalyani, Dept Phys, Kalyani 741235, W Bengal, India. Univ Delhi, Dept Phys & Astrophys, Delhi 110007, India. Univ Delhi, Dept Phys Elect, SGTB Khalsa Coll, New Delhi 110085, India. Mehta Res Inst, Allahabad 221019, Uttar Pradesh, India. Indian Inst Technol, Mumbai 400076, India. Univ Autonoma Barcelona, Dept Fis, Bellaterra 08193, Spain. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Natl Phys Lab, New Delhi 110012, India. Brown Univ, Dept Phys, Providence, RI USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. RP Mohanty, S (reprint author), Phys Res Lab, Ahmedabad 380009, Gujarat, India. RI Sahni, Varun/H-3336-2012; Waga, Ioav/B-6288-2014; Mukherjee, Amitabha/A-5252-2012; OI Mukherjee, Amitabha/0000-0003-1492-7950; Yajnik, Urjit/0000-0002-0949-994X NR 21 TC 1 Z9 1 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JUL-AUG PY 1998 VL 51 IS 1-2 SI SI BP 273 EP 286 DI 10.1007/BF02827497 PG 14 WC Physics, Multidisciplinary SC Physics GA 139KV UT WOS:000077028600024 ER PT J AU Datta, A Mukhopadhyaya, B Raychaudhuri, S Agashe, K Aleksan, R Bhattacharya, G Boudjema, F Chakrabarti, S Datta, A Datta, AK Deshpande, NG Dighe, A Drees, M Ghoshal, A Ghosh, D Kundu, A Roy, DP AF Datta, A Mukhopadhyaya, B Raychaudhuri, S Agashe, K Aleksan, R Bhattacharya, G Boudjema, F Chakrabarti, S Datta, A Datta, AK Deshpande, NG Dighe, A Drees, M Ghoshal, A Ghosh, D Kundu, A Roy, DP TI B physics and collider physics: Working group report SO PRAMANA-JOURNAL OF PHYSICS LA English DT Editorial Material ID INCLUSIVE SEMILEPTONIC-B; LOCAL-DUALITY; D-DECAY; V-UB; APPROXIMATION; SPECTRUM; QCD C1 Jadavpur Univ, Dept Phys, Calcutta 700032, W Bengal, India. Mehta Res Inst, Allahabad 221506, Uttar Pradesh, India. CERN, Div Theory, CH-1211 Geneva, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. Carleton Univ, Ottawa, ON K1S 5B6, Canada. ENSLAPP, LAPP, CNRS, F-74941 Annecy Le Vieux, France. Univ Calcutta, Dept Phys, Calcutta 700009, W Bengal, India. Univ Oregon, Dept Phys, Eugene, OR 97405 USA. ICTP, High Energy Sect, I-34100 Trieste, Italy. Asia Pacif Ctr Theoret Studies, Seoul, South Korea. Indian Inst Sci, Ctr Theoret Studies, Bangalore 560012, Karnataka, India. Tata Inst Fundamental Res, Dept Theoret Phys, Mumbai 400005, India. RP Datta, A (reprint author), Jadavpur Univ, Dept Phys, Calcutta 700032, W Bengal, India. NR 21 TC 0 Z9 0 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JUL-AUG PY 1998 VL 51 IS 1-2 SI SI BP 287 EP 295 DI 10.1007/BF02827498 PG 9 WC Physics, Multidisciplinary SC Physics GA 139KV UT WOS:000077028600025 ER PT J AU Green, MA Emery, K Bucher, K King, DL Igari, S AF Green, MA Emery, K Bucher, K King, DL Igari, S TI Solar cell efficiency tables (version 12) SO PROGRESS IN PHOTOVOLTAICS LA English DT Article ID PERFORMANCE AB Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since January 1998 are briefly described. (C) 1998 John Wiley & Sons, Ltd. C1 Univ New S Wales, Photovoltaics Special Res Ctr, Sydney, NSW 2052, Australia. Natl Renewable Energy Lab, Golden, CO 80401 USA. Fraunhofer Inst Solar Energy Syst, D-79100 Freiburg, Germany. Sandia Natl Labs, Div 6224, Albuquerque, NM 87185 USA. Japan Qual Assurance Org, Solar Techno Ctr, Solar Cell Test Res Div, Hamamatsu, Shizuoka 43112, Japan. RP Green, MA (reprint author), Univ New S Wales, Photovoltaics Special Res Ctr, Sydney, NSW 2052, Australia. NR 49 TC 11 Z9 11 U1 2 U2 7 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JUL-AUG PY 1998 VL 6 IS 4 BP 265 EP 270 DI 10.1002/(SICI)1099-159X(199807/08)6:4<265::AID-PIP235>3.0.CO;2-7 PG 6 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 115JQ UT WOS:000075661500005 ER PT J AU Beamer, LJ Fischer, D Eisenberg, D AF Beamer, LJ Fischer, D Eisenberg, D TI Detecting distant relatives of mammalian LPS-binding and lipid transport proteins SO PROTEIN SCIENCE LA English DT Article DE lipid transport proteins; LPS binding; sequence-structure compatibility ID PERMEABILITY-INCREASING PROTEIN; SECONDARY STRUCTURE; RECOGNITION AB Ln mammals, a family of four lipid binding proteins has been previously defined that includes two lipopolysaccharide binding proteins and two lipid transfer proteins. The first member of this family to have its three-dimensional structure determined is bactericidal/permeability-increasing protein (BPI). Using both the sequence and structure of BPI, along with recently developed sequence-sequence and sequence-structure similarity search methods, we have identified 13 distant members of the family in a diverse set of eukaryotes, including rat, chicken, Caenorhabditis elegans, and Biomphalaria galbrata. Although the sequence similarity between these 13 new members and any of the 4 original members of the BPI family is well below the "twilight zone," their high sequence-structure compatibility with BPI indicates they are likely to share its fold. These findings broaden the BPI family to include a member found in retina and brain, and suggest that a primitive member may have contained only one of the two similar domains of BPI. C1 Univ Calif Los Angeles, UCLA DOE Lab Struct Biol, Inst Mol Biol, Los Angeles, CA 90095 USA. RP Univ Calif Los Angeles, UCLA DOE Lab Struct Biol, Inst Mol Biol, POB 951570, Los Angeles, CA 90095 USA. EM david@mbi.ucla.edu NR 16 TC 28 Z9 28 U1 0 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0961-8368 EI 1469-896X J9 PROTEIN SCI JI Protein Sci. PD JUL PY 1998 VL 7 IS 7 BP 1643 EP 1646 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZZ732 UT WOS:000074761600021 PM 9684900 ER PT J AU Dingfelder, M Hantke, D Inokuti, M Paretzke, HG AF Dingfelder, M Hantke, D Inokuti, M Paretzke, HG TI Electron inelastic-scattering cross sections in liquid water SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID LOW-ENERGY ELECTRONS; FAST CHARGED-PARTICLES; K-SHELL IONIZATION; CONDENSED MATTER; RADIATION ACTION; STOPPING POWERS; COLLISION DATA; OPTICAL-DATA; MOLECULES; ATOMS AB Electron inelastic-scattering cross-section data for use as input in electron track-structure calculations in liquid water are re-examined and improved. The dielectric-response function used in such cross-sections is estimated on the basis of optical data and other experimental and theoretical information. The mean excitation energy for stopping power is obtained to be 81.8 eV, which is close to the recent experimental value, 79.75 +/- 0.5 eV, of Bichsel and Hiraoka. Inelastic-scattering cross sections are evaluated within the first Born approximation. Electron-exchange effects and semi-empirical corrections to account for non-Born effects at low energies are also incorporated. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 GSF, Natl Res Ctr Environm & Hlth, Inst Radiat Protect, D-85764 Neuherberg, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Dingfelder, M (reprint author), GSF, Natl Res Ctr Environm & Hlth, Inst Radiat Protect, Ingolstadter Landstr 1, D-85764 Neuherberg, Germany. EM dingfelder@gsf.de NR 67 TC 172 Z9 174 U1 3 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD JUL PY 1998 VL 53 IS 1 BP 1 EP 18 PG 18 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA ZX724 UT WOS:000074548100001 ER PT J AU Gilbert, ES Griffith, WC Boecker, BB Dagle, GE Guilmette, RA Hahn, FF Muggenburg, BA Park, JF Watson, CR AF Gilbert, ES Griffith, WC Boecker, BB Dagle, GE Guilmette, RA Hahn, FF Muggenburg, BA Park, JF Watson, CR TI Statistical modeling of carcinogenic risks in dogs that inhaled (PuO2)-Pu-238 SO RADIATION RESEARCH LA English DT Article ID INDUCTION; RADON; LUNG; RATS AB Combined analyses of data on 260 life-span beagle dogs that inhaled (PuO2)-Pu-238 at the Inhalation Toxicology Research Institute (ITRI) and at Pacific Northwest National Laboratory (PNNL) were conducted. The hazard functions (age-specific risks) for incidence of lung, bone and liver tumors were modeled as a function of cumulative radiation dose, and estimates of lifetime risks based on the combined data were developed. For lung tumors, linear-quadratic functions provided an adequate fit to the data from both laboratories, and linear functions provided an adequate fit when analyses were restricted to doses less than 20 Gy. The estimated risk coefficients for these functions were significantly larger when based on ITRI data compared to PNNL data, and dosimetry biases are a possible explanation for this difference. There was also evidence that the bone tumor response functions differed for the two laboratories, although these differences occurred primarily at high doses. These functions were clearly nonlinear (even when restricted to average skeletal doses less than 1 Gy), and evidence of radiation-induced bone tumors was found for doses less than 0.5 Gy in both laboratories. Liver tumor risks were similar for the two laboratories, and linear functions provided an adequate fit to these data. Lifetime risk estimates for lung and bone tumors derived from these data had wide confidence intervals, but were consistent with estimates currently used in radiation protection. The dog-based lifetime liver tumor risk estimate was an order of magnitude larger than that used in radiation protection, but the latter also carries large uncertainties. The application of common statistical methodology to data from two studies has allowed the identification of differences in these studies and has provided a basis for common risk estimates based on both data sets. (C) 1998 by Radiation Research Society. C1 NCI, Div Canc Epidemiol & Genet, Bethesda, MD 20892 USA. Lovelace Resp Res Inst, Albuquerque, NM 87185 USA. Washington State Univ, US Transuranium & Uranium Registries, Richland, WA 99352 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Washington, Dept Environm Hlth, Consortium Risk Evaluat Stakeholder Participat, Seattle, WA 98105 USA. RP Gilbert, ES (reprint author), NCI, Div Canc Epidemiol & Genet, Bethesda, MD 20892 USA. RI WSU, USTUR/I-1056-2013 NR 30 TC 13 Z9 13 U1 0 U2 2 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUL PY 1998 VL 150 IS 1 BP 66 EP 82 DI 10.2307/3579647 PG 17 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA ZV652 UT WOS:000074327300011 PM 9650604 ER PT J AU Medley, SS Roquemore, AL AF Medley, SS Roquemore, AL TI Construction and operation of parallel electric and magnetic field spectrometers for mass/energy resolved multi-ion charge exchange diagnostics on the Tokamak Fusion Test Reactor SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ANALYZER; ENERGY; MASS; DESIGN; SYSTEM AB A novel charge exchange-spectrometer using a dee-shaped region of parallel electric and magnetic fields was developed at the Princeton Plasma Physics Laboratory for neutral particle diagnostics on the Tokamak Fusion Test Reactor (TFTR). The E parallel to B spectrometer has an energy range of 0.5 less than or equal to A (amu) E (keV) less than or equal to 600 and provides mass-resolved energy spectra of H+, D+ and T+ (or He-3(+)) ion species simultaneously during a single discharge. The detector plane exhibits parallel rows of analyzed ions, each row containing the energy dispersed ions of a given mass-to-charge ratio. The detector consists of a large area microchannel plate (MCP) which is provided with three rectangular, semicontinuous active area strips, one coinciding with each of the mass rows for detection of H+, D+, and T+ (or He-3(+)) and each mass row has 75 energy channels. To suppress spurious signals attending operation of the plate in the magnetic fringe field of the spectrometer, the MCP was housed in a double-walled iron shield with a wire mesh ion entrance window. Using an accelerator neutron generator, the MCP neutron detection efficiency was measured to be 1.7 X 10(-3) and 6.4 X 10(-3) counts/neutron/cm(2) for 2.5 MeV-DD and 14 MeV-DT neutrons, respectively. The design and calibration of the spectrometer are described in detail, including the effect of MCP exposure to tritium, and results obtained during high performance D-D operation on TFTR are presented to illustrate the performance of the E parallel to B spectrometer. The spectrometers were not used during D-T plasma operation due to the cost of providing the required radiation shielding. (C) 1998 American Institute of Physics. [S0034-6748(98)03107-4] C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Medley, SS (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 51 TC 29 Z9 29 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUL PY 1998 VL 69 IS 7 BP 2651 EP 2662 DI 10.1063/1.1148994 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 108RL UT WOS:000075279200011 ER PT J AU Carlson, J Schiavilla, R AF Carlson, J Schiavilla, R TI Structure and dynamics of few-nucleon systems SO REVIEWS OF MODERN PHYSICS LA English DT Review ID ELECTROMAGNETIC FORM-FACTORS; MESON-EXCHANGE CURRENTS; DEUTERON ELASTIC-SCATTERING; HIGH MOMENTUM-TRANSFER; MONTE-CARLO CALCULATIONS; INCLUSIVE ELECTRON-SCATTERING; LONGITUDINAL RESPONSE FUNCTIONS; THERMAL-NEUTRON CAPTURE; PHASE-SHIFT ANALYSIS; COULOMB SUM-RULE AB Few-nucleon physics is a field rich with high-quality experimental data and possibilities for accurate calculations of strongly correlated quantum systems. In this article the authors discuss the traditional model of the nucleus as a system of interacting nucleons and outline many recent experimental results and theoretical developments in the field of few-nucleon physics. The authors describe nuclear structure and spectra, clustering and correlations, elastic and inelastic electromagnetic form factors, low-energy electroweak reactions, and nuclear scattering and response in the quasielastic regime. Through a review of the rich body of experimental data and a variety of theoretical developments, a coherent description of the nuclear strong- and electroweak-interaction properties emerges. In this article, the authors attempt to provide some insight into the practice and possibilities in few-nucleon physics today. [S0034-6861 (98)00703-X]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Jefferson Lab, Theory Grp, Newport News, VA 23606 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Carlson, J (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 499 TC 344 Z9 347 U1 3 U2 13 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 1998 VL 70 IS 3 BP 743 EP 841 DI 10.1103/RevModPhys.70.743 PG 99 WC Physics, Multidisciplinary SC Physics GA 109EG UT WOS:000075307800004 ER PT J AU Jain, AK Sheline, RK Headly, DM Sood, PC Burke, DG Hrivnacova, I Kvasil, J Nosek, D Hoff, RW AF Jain, AK Sheline, RK Headly, DM Sood, PC Burke, DG Hrivnacova, I Kvasil, J Nosek, D Hoff, RW TI Nuclear structure in odd-odd nuclei, 144 <= A <= 194 SO REVIEWS OF MODERN PHYSICS LA English DT Review ID INTRINSIC REFLECTION ASYMMETRY; HIGH-SPIN STATES; EVEN-EVEN NUCLEI; ROTATIONAL BANDS; OCTUPOLE DEFORMATION; SIGNATURE INVERSION; DEFORMED-NUCLEI; ENERGY-LEVELS; MASS NUCLEI; GAMMA-RAY AB A comprehensive review of the present understanding, bath theoretical and experimental, of intrinsic and rotational level structures in medium-heavy deformed odd-odd nuclei is presented. A discussion of the various experimental methods is presented, emphasizing the need for a variety of experimental approaches. The odd-odd nuclei that are immediately amenable to fruitful additional study are pointed out. A discussion of the intrinsic level structures, Gallagher-Moszkowski (GM) splittings, Newby (N) shifts, and role of the residual p-n interaction is presented. Currently available data in the rare-earth region allow the empirical determination of 137 GM splittings and 36 N shifts for 25 odd-odd nuclei in the mass region 152 less than or equal to A less than or equal to 188. A new parametrization of the residual p-n interaction is presented which also takes into account the 27 GM splittings and 12 N shifts from the actinide region. Newly discovered features of rotational bands, such as odd-even staggering, and other high-spin phenomena, such as signature inversion and delay in bandcrossing frequency, are discussed. The role of higher-order Coriolis coupling is pointed out. Systematics of the two-quasiparticle excitations, shape coexistence, isomers, and four-quasiparticle states are presented. Calculated results of the two-quasiparticle intrinsic excitations using two methods, the intrinsic level spacings for odd-A neighboring nuclei and the quasiparticle-plus-phonon coupling model, are compared with experiment. [S0034-6861(98)00203-7]. C1 Univ Roorkee, Dept Phys, Roorkee 247667, Uttar Pradesh, India. Florida State Univ, Dept Chem, Tallahassee, FL 32306 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Banaras Hindu Univ, Dept Phys, Varanasi 221005, Uttar Pradesh, India. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Charles Univ Prague, Dept Nucl Phys, CR-18000 Prague 8, Czech Republic. Lawrence Livermore Natl Lab, Isotope Sci Div, Livermore, CA 94551 USA. RP Jain, AK (reprint author), Univ Roorkee, Dept Phys, Roorkee 247667, Uttar Pradesh, India. RI Nosek, Dalibor/F-1129-2017 OI Nosek, Dalibor/0000-0001-6219-200X NR 171 TC 83 Z9 83 U1 3 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 1998 VL 70 IS 3 BP 843 EP 895 DI 10.1103/RevModPhys.70.843 PG 53 WC Physics, Multidisciplinary SC Physics GA 109EG UT WOS:000075307800005 ER PT J AU Kastner, MA Birgeneau, RJ Shirane, G Endoh, Y AF Kastner, MA Birgeneau, RJ Shirane, G Endoh, Y TI Magnetic, transport, and optical properties of monolayer copper oxides SO REVIEWS OF MODERN PHYSICS LA English DT Review ID HIGH-ENERGY SPIN; HEISENBERG-ANTIFERROMAGNET SR2CUO2CL2; HIGH-TEMPERATURE SUPERCONDUCTORS; INSULATOR-METAL TRANSITION; HIGH-TC SUPERCONDUCTIVITY; SINGLE-CRYSTAL GROWTH; SOFT-PHONON BEHAVIOR; DOPED CUO2 PLANES; NEUTRON-SCATTERING; QUANTUM ANTIFERROMAGNETS AB The authors review the results of a wide variety of experiments on materials such as La(2)CuO(4) and Nd(2)CuO(4) that contain weakly coupled CuO(2) layers. These materials are antiferromagnetic insulators with very large Heisenberg exchange energies, which become high-temperature superconductors when charge carriers are added to the CuO(2) layers. The growth of large single crystals has made it possible to carry out neutron scattering, as well as anisotropic optical, transport, and magnetization measurements. The properties of the undoped CuO(2) layer are reviewed, and the evolution of magnetic, optical, and transport properties with the addition of charge carriers is discussed. The emphasis is on the pure and lightly doped materials, although the magnetism in the superconductors is discussed. [S0034-6861(98)00403-6]. C1 MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Tohoku Univ, Dept Phys, Aoba Ku, Sendai, Miyagi 980, Japan. RP Kastner, MA (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA. NR 172 TC 639 Z9 647 U1 27 U2 153 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 1998 VL 70 IS 3 BP 897 EP 928 DI 10.1103/RevModPhys.70.897 PG 32 WC Physics, Multidisciplinary SC Physics GA 109EG UT WOS:000075307800006 ER PT J AU Bergmann, K Theuer, H Shore, BW AF Bergmann, K Theuer, H Shore, BW TI Coherent population transfer among quantum states of atoms and molecules SO REVIEWS OF MODERN PHYSICS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; STIMULATED RAMAN-SCATTERING; COARSE-GRAINED THEORY; 3-STATE MODEL DRIVEN; DELAYED LASER-PULSES; MULTILEVEL SYSTEMS; ADIABATIC PASSAGE; 3-LEVEL SYSTEMS; VIBRATIONAL LEVELS; PHOTO-EXCITATION AB The authors discuss the technique of stimulated Raman adiabatic passage (STIRAP), a method of using partially overlapping pulses (from pump and Stokes lasers) to produce complete population transfer between two quantum states of an atom or molecule. The procedure relies on the initial creation of a coherence (a population-trapping state) with subsequent adiabatic evolution. The authors present the basic theory, with some extensions, and then describe examples of experimental utilization. They note some applications of the technique not only to preparation of selected states for reaction studies, but also to quantum optics and atom optics. [S0034-6861(98)00803-4]. C1 Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bergmann, K (reprint author), Univ Kaiserslautern, Fachbereich Phys, Postfach 3049, D-67653 Kaiserslautern, Germany. RI BERGMANN, KLAAS/D-5543-2011 NR 84 TC 1437 Z9 1471 U1 12 U2 120 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JUL PY 1998 VL 70 IS 3 BP 1003 EP 1025 DI 10.1103/RevModPhys.70.1003 PG 23 WC Physics, Multidisciplinary SC Physics GA 109EG UT WOS:000075307800009 ER PT J AU Budinger, TF AF Budinger, TF TI PET instrumentation: What are the limits? SO SEMINARS IN NUCLEAR MEDICINE LA English DT Review ID POSITRON EMISSION TOMOGRAPHY; OF-FLIGHT INFORMATION; FDG-SPECT; ATTENUATION CORRECTION; MYOCARDIAL VIABILITY; IMAGE-RECONSTRUCTION; SCATTERED RADIATION; COMPUTED-TOMOGRAPHY; RETRACTABLE SEPTA; BLOCK DETECTORS AB This report has emphasized the attributes of positron emission tomography (PET) through a discussion of the historical development with attention to limitations or factors that are of importance in using and further developing this technology. As is the case for all nuclear detector developments, the factors that require consideration are spatial resolution, uniformity of resolution, sensitivity, distortions (attenuation), background noise (scatter and randoms), image volume, data acquisition capabilities (count-rate saturation), and limitations based on allowable radiation doses to the subject, forty years ago, the fact gamma-cameras could not handle the count-rates from the short half-life radionuclides that had clinical applications at that time tie, O-15, C-11, N-13) precluded their acceptance in nuclear medicine. With the advent of F-18 applications particularly with FDG in oncology, this limitation was no longer a barrier. Twenty years ago and until recently, the promise of time-of-flight PET78.79 has been stifled by the fact that the appropriately fast scintillator BaF2 had too low an efficiency (low density) to be useful in improving the signal to noise of a time-of-flight tomograph over contemporary systems. With the development of dense scintillators with high light output and high speed such as LSO30 the time-of-flight potentials are now once again worth pursuing. Twenty years ago systems that theoretically would have improved sensitivity by minimal or no septa with spherical geometric arrangements of detectors(8.21) were ignored because it appeared that scatter backgrounds would lead to a signal to noise less than 1. But in the last 5 years, cylindrical systems without septa have shown that noise effective sensitivity improvements of a factor of 4 can be realized. With time-of-flight additional improvements in sensitivity will be realized. Horizons for detector development include discovery of new scintillators, new methods of registering scintillation light,(81) deployment of larger field of view systems and methods of compensating for scatter, randoms, attenuation, and irregular sampling associated with new geometries which can encircle most of the body. The expected limit for PET is 2 mm isotropic resolution for the head and appendages including joints and breasts. Clinical realization of this resolution for the thorax and abdomen requires compensation for motion and even in this area strategies are underdevelopment which rely on the improvement in sensitivity being realized by 3D systems. Copyright (C) 1998 by W.B. Saunders Company. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Div Life Sci,US Dept Energy, Berkeley, CA 94720 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Div Life Sci,US Dept Energy, 1 Cyclotron Rd,Mailstop 55-121, Berkeley, CA 94720 USA. FU NHLBI NIH HHS [P01 HL25840] NR 81 TC 54 Z9 59 U1 1 U2 9 PU W B SAUNDERS CO-ELSEVIER INC PI PHILADELPHIA PA 1600 JOHN F KENNEDY BOULEVARD, STE 1800, PHILADELPHIA, PA 19103-2899 USA SN 0001-2998 EI 1558-4623 J9 SEMIN NUCL MED JI Semin. Nucl. Med. PD JUL PY 1998 VL 28 IS 3 BP 247 EP 267 DI 10.1016/S0001-2998(98)80030-5 PG 21 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 107JR UT WOS:000075205100007 PM 9704366 ER PT J AU Jastrow, JD Miller, RM Lussenhop, J AF Jastrow, JD Miller, RM Lussenhop, J TI Contributions of interacting biological mechanisms to soil aggregate stabilization in restored prairie SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article ID ARBUSCULAR MYCORRHIZAL FUNGI; MICROBIAL BIOMASS-C; TALLGRASS PRAIRIE; ORGANIC-MATTER; SPRING WHEAT; SIZE CLASSES; ROOT; PHOSPHORUS; STABILITY; NITROGEN AB A better understanding of the soil aggregation process is needed to address a variety of concerns, including soil quality and erosion, agricultural sustainability, soil C sequestration, the mobility of hazardous chemicals and remediation of contaminated sites. We used data from a chronosequence of tallgrass prairie restorations and a path analysis approach to evaluate how the lengths of two dia size classes of fibrous roots, the length of external mycorrhizal hyphae, microbial biomass C, hut-water soluble carbohydrate C and soil organic C interact to promote the stabilization of soil aggregates. The measured binding agents accounted for 88% of the variation in macroaggregates >212 mu m diameter and goodness-of-fit indexes indicated a good practical fit of the path model to the data. The restoration of macroaggregate structure in this system was apparently driven by the direct and indirect effects of roots and external hyphae, with lesser relative contributions by the three measured C pools. Although the two root size classes had similar direct effects on the percentage of macroaggregates, their indirect contributions differed substantially. Fine roots (0.2-1 mm diameter) exerted considerable indirect effects via their strong influences on external hyphae and microbial biomass C. Very fine roots ( < O.2 mm dia) made a stronger contribution to soil organic C than fine roots, but their overall indirect contribution to aggregation was minimal. In addition, the relative importance of each binding agent varied for different size fractions of macroaggregates and generally supported the hypothesis that the effectiveness of various binding mechanisms depends oil the physical dimensions of the binding agents relative to the spatial scales of the aggregate planes of weakness being bridged. Published by Elsevier Science Ltd. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ Illinois, Dept Biol Sci, Chicago, IL 60680 USA. RP Jastrow, JD (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. EM jdjastrow@anl.gov NR 64 TC 215 Z9 238 U1 11 U2 98 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-0717 J9 SOIL BIOL BIOCHEM JI Soil Biol. Biochem. PD JUL PY 1998 VL 30 IS 7 BP 905 EP 916 DI 10.1016/S0038-0717(97)00207-1 PG 12 WC Soil Science SC Agriculture GA ZU774 UT WOS:000074233500008 ER PT J AU Lemke, RL Izaurralde, RC Malhi, SS Arshad, MA Nyborg, M AF Lemke, RL Izaurralde, RC Malhi, SS Arshad, MA Nyborg, M TI Division S-8 - Nutrient management & soil & plant analysis - Nitrous oxide emissions from agricultural soils of the Boreal and Parkland regions of Alberta SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID FIELD MEASUREMENT; LANDSCAPE SCALE; NITRIC-OXIDE; DENITRIFICATION; FERTILIZERS; WATER; FLUX AB The contribution of agricultural soils to atmospheric N2O in the Boreal and Parkland regions of Alberta is largely unknown. Field data are required to quantify the flux of N2O from these regions, as are methodologies to scale up from site-specific measurements to large geographical areas. Climate-soil-management combinations (CSMCs) aggregated to an ecodistrict le,el have recently been proposed as a technique for scaling up greenhouse gas flux estimates for Canadian agriculture, Our objective was to calculate seasonal N2O losses and investigate large-scale spatial variability using field data from selected sites in the Boreal and Parkland regions. We used vented soil covers to measure N2O emissions during spring and summer of 1993 and 1994, and the spring of 1995, from six representative CSMCs in five ecodistricts in Alberta, Substantial and consistent differences in the magnitude of N2O-N loss among sites were observed, with annual estimated losses of N2O-N ranging from 0.4 to 2.6 kg ha(-1) Up to 70% of the total annual N2O-N loss occurred during brief but intense bursts at spring thaw. Soil clay content was found to be strongly correlated with annual N2O-N loss. This relationship suggests that clay content, readily available from soil data bases, could be used as a N2O-loss predictor variable when applying scaling-up methodologies. C1 Agr & Agri Food Canada, Lethbridge Res Ctr, Lethbridge, AB T1J 4B1, Canada. Battelle Pacific Natl Lab, Washington, DC 20024 USA. Agr & Agri Food Canada, Melfort, SK S0E 1A0, Canada. Agr & Agri Food Canada, Beaverlodge, AB T0H 0C0, Canada. Univ Alberta, Dept Renewable Resources, Edmonton, AB T6G 2E3, Canada. RP Lemke, RL (reprint author), Agr & Agri Food Canada, Lethbridge Res Ctr, Lethbridge, AB T1J 4B1, Canada. EM lemker@em.agr.ca RI Izaurralde, Roberto/E-5826-2012 NR 32 TC 46 Z9 47 U1 1 U2 10 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JUL-AUG PY 1998 VL 62 IS 4 BP 1096 EP 1102 PG 7 WC Soil Science SC Agriculture GA 111UF UT WOS:000075455900035 ER PT J AU Guan, J Dorris, SE Balachandran, U Liu, ML AF Guan, J Dorris, SE Balachandran, U Liu, ML TI Transport properties of SrCe0.95Y0.05O3-delta and its application for hydrogen separation SO SOLID STATE IONICS LA English DT Article DE fuel cell; gas separation; mixed conductor; solid-state electrolyte; H-2 separation ID SOLID ELECTROLYTES; MIXED CONDUCTORS; IONIC-CONDUCTION; PROTON AB Transport properties of SrCe0.95Y0.05O3-delta were studied by impedance spectroscopy and by measuring open-cell voltage (OCV) and gas permeation. Ionic transference numbers were determined by measuring the OCV of concentration cells and water vapor evolution of an O-2/H-2 fuel cell. We observed interfacial polarization on the basis of the I-V curves obtained by discharging a hydrogen concentration cell or an O-2/H-2 fuel cell. The observed high protonic conductivity (high proton and low oxide ion transference numbers) makes SrCe0.95Y0.05O3-delta a potential material for hydrogen separation. From proton conductivity measurements, under a given hydrogen partial pressure difference of 4%/0.48&%, the hydrogen permeation rate (of a dense membrane with 0.11 cm in thickness) was calculated to be approximate to 0.072 cm(3) (STP) cm(-2) min(-1) at 800 degrees C, whereas the permeation rate calculated from shea-circuit current measurements was, approximate to 0.023 cm(3) (STP) cm(-2) min(-1) at 800 degrees C. The difference between calculated and observed permeation rates is probably due to interfacial polarization. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. RP Balachandran, U (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Liu, Meilin/E-5782-2010 OI Liu, Meilin/0000-0002-6188-2372 NR 18 TC 61 Z9 63 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD JUL PY 1998 VL 110 IS 3-4 BP 303 EP 310 DI 10.1016/S0167-2738(98)00148-9 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 112XN UT WOS:000075520200017 ER PT J AU Ferraro, JR AF Ferraro, JR TI Symposium commemorating 30 years of FT-IR spectroscopy takes shape - Planned for EAS'98, symposium will attract several FT-IR pioneers SO SPECTROSCOPY LA English DT Editorial Material C1 Argonne Natl Lab, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ADVANSTAR COMMUNICATIONS PI DULUTH PA 131 W FIRST ST, DULUTH, MN 55802 USA SN 0887-6703 J9 SPECTROSCOPY JI Spectroscopy PD JUL PY 1998 VL 13 IS 7 BP 11 EP 11 PG 1 WC Spectroscopy SC Spectroscopy GA 100MA UT WOS:000074818800001 ER PT J AU Cerda, J Van Hove, MA Sautet, P Salmeron, M AF Cerda, J Van Hove, MA Sautet, P Salmeron, M TI The role of surface relaxations in determining the STM images of sulfur adatoms and clusters on Re(0001): theory versus experiment SO SURFACE SCIENCE LA English DT Article DE rhenium; semi-empirical models and model calculations; sulfur; surface relaxation and reconstruction; tunneling ID SCANNING TUNNELING MICROSCOPE; OVERLAYERS; ADSORPTION AB We apply our recent Green's function based STM formalism to study the adsorption of S monomers and clusters on Re(0001). Starting from previous STM experimental data and LEED results, we consider surface relaxations common to the different S structures observed on this system. The role of such relaxations on the final shape of the theoretical STM images is then examined, and we find that the sensitivity of the images to these structural parameters can be considerable in certain cases. The consistency of proposed relaxed models is also confirmed after a theory-experiment comparison of the STM images. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain. Inst Rech Catalyse, CNRS, F-69626 Villeurbanne, France. Ecole Normale Super Lyon, Chim Theor Lab, F-69364 Lyon 07, France. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008; Cerda, Jorge/F-4043-2010; Sautet, Philippe/G-3710-2014 OI Van Hove, Michel/0000-0002-8898-6921; Cerda, Jorge/0000-0001-6176-0191; Sautet, Philippe/0000-0002-8444-3348 NR 17 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUL 1 PY 1998 VL 409 IS 2 BP 145 EP 159 DI 10.1016/S0039-6028(98)00164-2 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 102CT UT WOS:000074906200002 ER PT J AU Mullins, DR Overbury, SH Huntley, DR AF Mullins, DR Overbury, SH Huntley, DR TI Electron spectroscopy of single crystal and polycrystalline cerium oxide surfaces SO SURFACE SCIENCE LA English DT Article DE cerium; cerium oxide; electron energy loss spectroscopy (EELS); low index single crystal surfaces; near edge extended X-ray absorption fine structure (NEXAFS); oxidation; photoelectron emission; polycrystalline surfaces; soft X-ray photoelectron spectroscopy; synchrotron radiation photoelectron spectroscopy ID X-RAY PHOTOELECTRON; ENERGY LOSS SPECTROSCOPY; TRANSITION-METAL OXIDES; FINE-STRUCTURE; CEO2 SURFACES; CO OXIDATION; REDUCTION; ABSORPTION; CATALYSTS; XPS AB Valence band photoemission (XPS), valence band electron energy loss spectroscopy (EELS), Ce 3d and 4d XPS, O 1s XPS and O 1s X-ray absorption (XAS) have been investigated for oxidized and sputtered single crystal CeO2 films and for oxidized Ce foil. Features were identified that distinguish between the Ce4+ or Ce3+ oxidation states. Ce4+ was identified by the highest binding energy peaks in the Ce 4d spectrum at 122.8 eV and 126.0 eV and lowest energy peak in the O 1s XAS spectrum at 530 eV. Ce3+ was identified by the lowest binding energy peak in the Ce 4d spectrum at 105.4 eV, the Ce 4f valence level peak at 2.0 eV and excitations in the band gap in EELS. The Ce 4d spectra are similar to the Ce 3d spectra in that satellite peaks that are related to the final state occupation of the Ce 4f level dominate the spectra, The interpretation of the Ce 4d spectra is more complicated than that of the Ce 3d spectra, however, due to multiplet splitting which has a greater influence in the Ce 4d spectra. The O 1s XAS are much easier to interpret than XAS spectra from the Ce core levels. The O 1s XAS spectra reflect the unoccupied density of states of the cerium oxide without being significantly affected by final stare relaxation of the Ce energy levels. The O 1s xPS spectra show only a 0.3 eV difference in binding energy between Ce4+ and Ce3+ in the oxides provided the spectra are corrected for band bending. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. EM mullinsdr@ornl.gov RI Overbury, Steven/C-5108-2016 OI Overbury, Steven/0000-0002-5137-3961 NR 47 TC 505 Z9 528 U1 39 U2 281 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD JUL 1 PY 1998 VL 409 IS 2 BP 307 EP 319 DI 10.1016/S0039-6028(98)00257-X PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 102CT UT WOS:000074906200019 ER PT J AU Creighton, JR Baucom, KC AF Creighton, JR Baucom, KC TI Reflectance-difference spectroscopy of adsorbate-covered GaAs(100) surfaces: a combined surface science and in-situ OMVPE study SO SURFACE SCIENCE LA English DT Article DE Auger electron spectroscopy (AES); chemical vapor deposition; chemisorption; gallium arsenide; low energy electron diffraction (LEED); reflection spectroscopy; thermal desorption; thermal desorption spectroscopy; trimethyl gallium ID ATOMIC LAYER EPITAXY; CHEMICAL-VAPOR-DEPOSITION; BANDGAP OPTICAL ANISOTROPIES; MOLECULAR-BEAM EPITAXY; GALLIUM-RICH GAAS(100); 001 GAAS-SURFACES; X-RAY-SCATTERING; PHASE EPITAXY; GROWTH; TRIMETHYLGALLIUM AB Using two experimental approaches, we have examined the role of adsorbates during organometallic vapor phase epitaxy (OMVPE) and atomic layer epitaxy (ALE). One set of experiments extended the RDS database to include well-defined CaAs(100) reconstructions involving CHx adsorbates, whereas the other experiments examined the RD spectra over a wide range of OMVPE conditions. We have found that the Type III OMVPE condition present at lower temperatures and higher TMGa concentration is due to a newly discovered As-rich (1 x 2)-CH3 reconstruction. The ALE condition following the trimethylgallium exposure cycle is due to the presence of a Ga-rich (1 x 4)-CH2 reconstruction. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Dept 1126, Albuquerque, NM 87185 USA. RP Creighton, JR (reprint author), Sandia Natl Labs, Dept 1126, MS 0601, Albuquerque, NM 87185 USA. NR 53 TC 28 Z9 28 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUL 1 PY 1998 VL 409 IS 2 BP 372 EP 383 DI 10.1016/S0039-6028(98)00291-X PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 102CT UT WOS:000074906200024 ER PT J AU Zou, JY Schrader, GL AF Zou, JY Schrader, GL TI Deposition of multiphase molybdate thin films by reactive sputtering SO THIN SOLID FILMS LA English DT Article DE deposition; molybdate thin films; reactive sputtering ID SELECTIVE OXIDATION; CATALYSTS; NIMOO4; MICROSTRUCTURE; MOLYBDENUM; 1-BUTENE; OXIDE AB Deposition parameters for reactive sputtering of thin films of MoO3 and NiMoO4 were examined with an emphasis of the effect of temperature, O-2/Ar flow rate, pressure, and sputtering power (RF source) or voltage (DC source). Films of alpha- and beta-MoO3 could be produced having oriented structures. alpha-NiMoO4 could only be formed as a multicrystalline film at higher temperatures. Multilayer films of NiMoO4 on alpha-MoO3 were found to include an interfacial material identified as beta-NiMoO4. This metastable material was detected at relatively low temperatures in the bilayer structures. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Iowa State Univ, Dept Chem Engn, Ctr Interfacial Mat & Crystallizat, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Schrader, GL (reprint author), Iowa State Univ, Dept Chem Engn, Ctr Interfacial Mat & Crystallizat, Ames, IA 50011 USA. NR 33 TC 11 Z9 11 U1 0 U2 4 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 JUL 1 PY 1998 VL 324 IS 1-2 BP 52 EP 62 DI 10.1016/S0040-6090(97)01031-6 PG 11 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZZ598 UT WOS:000074746200008 ER PT J AU Wu, YS Pruess, K Persoff, P AF Wu, YS Pruess, K Persoff, P TI Gas flow in porous media with Klinkenberg effects SO TRANSPORT IN POROUS MEDIA LA English DT Article DE gas flow; Klinkenberg effect; Klinkenberg constant; pneumatic analysis; unsaturated-zone flow; air venting; air permeability tests ID UNSATURATED ZONE; AIR PERMEABILITY; SUBSURFACE; MODEL; CONTAMINATION; FORMULATION; SOILS AB Gas flow in porous media differs from liquid flow because of the large gas compressibility and pressure-dependent effective permeability. The latter effect, named after Klinkenberg, may have significant impact on gas flow behavior, especially in low permeability media, but it has been ignored in most of the previous studies because of the mathematical difficulty in handling the additional nonlinear term in the gas flow governing equation. This paper presents a set of new analytical solutions developed for analyzing steady-state and transient gas flow through porous media including Klinkenberg effects. The analytical solutions are obtained using a new form of gas flow governing equation that incorporates the Klinkenberg effect. Additional analytical solutions for one-, two- and three-dimensional gas flow in porous media could be readily derived by the following solution procedures in this paper. Furthermore, the validity of the conventional assumption used for linearizing the gas flow equation has been examined. A generally applicable procedure has been developed for accurate evaluation of the analytical solutions which use a linearized diffusivity for transient gas flow. As application examples, the new analytical solutions have been used to verify numerical solutions, and to design new laboratory and field testing techniques to determine the Klinkenberg parameters. The proposed laboratory analysis method is also used to analyze data from steady-state flow tests of three core plugs from The Geysers geothermal field. We show that this new approach and the traditional method of Klinkenberg yield similar results of Klinkenberg constants for the laboratory tests; however, the new method allows one to analyze data from both transient and steady-state tests in various flow geometries. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Wu, YS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Wu, Yu-Shu/A-5800-2011 NR 38 TC 119 Z9 144 U1 4 U2 31 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 JUL PY 1998 VL 32 IS 1 BP 117 EP 137 DI 10.1023/A:1006535211684 PG 21 WC Engineering, Chemical SC Engineering GA 111VY UT WOS:000075460200006 ER PT J AU Rubin, EM Mockrin, S AF Rubin, EM Mockrin, S TI Giving genomics a heart SO TRENDS IN GENETICS LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Genome Sci, Berkeley, CA 94720 USA. NIH, Bethesda, MD 20892 USA. RP Rubin, EM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Genome Sci, Bldg 74,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0168-9525 J9 TRENDS GENET JI Trends Genet. PD JUL PY 1998 VL 14 IS 7 BP 260 EP 261 DI 10.1016/S0168-9525(98)01505-4 PG 2 WC Genetics & Heredity SC Genetics & Heredity GA ZZ556 UT WOS:000074742000004 PM 9676525 ER PT J AU Johnson, DW Hanson, PJ Todd, DE Susfalk, RB Trettin, CF AF Johnson, DW Hanson, PJ Todd, DE Susfalk, RB Trettin, CF TI Precipitation change and soil leaching: Field results and simulations from Walker Branch Watershed, Tennessee SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT 3rd International Symposium on Ecosystem Behavior CY JUN 21-25, 1997 CL VILLANOVA UNIV, PHILADELPHIA, PENNSYLVANIA SP Natl Sci Fdn, Elect Power Res Inst, NOAA, Valley Forge Brewing Co HO VILLANOVA UNIV DE leaching; Nutrient Cycling Model; rainfall; soil solution chemistry; Walker Branch Watershed ID FOREST AB To investigate the potential effects of changing precipitation on a deciduous forest ecosystem, an experiment was established on Walker Branch Watershed, Tennessee that modified the amount of throughfall at -33 %, ambient (no change), and +33 % using a system of rain gutters and sprinklers. We hypothesized that the drier treatments would cause: 1) disproportionate changes in soil water flux, 2) increased total ionic concentrations in soil solution that would in turn cause 3) decreased SO42-/Cl- ratios, 4) decreased HCO3- concentrations, and 5) increased ratios of Al to (Ca2+ + Mg2+) and of (Ca2+ + Mg2+) to K+. Hypothesis 1 was supported by simulation results. Hypotheses 2 and 3 were supported in part by field results, although interpretation of these was complicated by pre-treatment biases. Hypotheses 4 and 5 were not supported by the field results. Comparisons of field data and Nutrient Cycling Model (NuCM) simulations were favorable for most ions except Cl- and K+. The disparities may be due to underestimation of soil buffering in the case of Cl- and overestimation of soil buffering in the case of K+ in the model. Long-term simulations with NuCM suggest that reducing water inputs will slow the rate of soil acidification and P loss, but will not materially affect growth or ecosystem N status. C1 Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. US Forest Serv, Charleston, SC USA. RP Johnson, DW (reprint author), Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 15 TC 18 Z9 19 U1 1 U2 12 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD JUL PY 1998 VL 105 IS 1-2 BP 251 EP 262 DI 10.1023/A:1005039711434 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA 108QN UT WOS:000075277100025 ER PT J AU Boopathy, R Manning, J AF Boopathy, R Manning, J TI Biodegradation of tetryl (2,4,6-trinitrophenylmethylnitramine) in a soil-slurry reactor SO WATER ENVIRONMENT RESEARCH LA English DT Article DE tetryl; explosives; soil-slurry reactor; cosubstrate; co-metabolism; nitroaniline; aniline; metabolites; decontamination; biodegradation ID 2,4,6-TRINITROTOLUENE TNT; PSEUDOMONAS-CONSORTIUM; METABOLISM AB A laboratory study was conducted to determine whether tetryl can be biodegraded by native soil bacteria under soil-slurry conditions with molasses as cosubstrate. A 2-L laboratory reactor was set up with a 15% (weight/volume) slurry of contaminated soil in deionized water. The soil slurry was mixed continuously at 80 r/min. Molasses at 0.3% (volume/volume) was added weekly as a cosubstrate. A no-carbon control reactor was also set up without molasses addition. The concentration of tetryl in the soil was monitored periodically. The results showed 100% removal of tetryl from the soil within 3 months of operation. In the no-carbon control, no significant degradation of tetryl was observed. The gas chromatographic/mass spectrometric analysis of the aqueous phase of the soil slurry showed metabolites identified as trinitro-n-methylaniline, trinitrobenzeneamine, dinitrobenzenediamine, nitroaniline, and aniline. None of these metabolites persisted more than a week after they appeared in the reactor system. The parameters relevant to biodegradation and process control, such as pH, dissolved oxygen, bacterial counts, and metabolites produced in the reactor, are discussed. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Boopathy, R (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 19 TC 9 Z9 9 U1 1 U2 2 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 USA SN 1061-4303 EI 1554-7531 J9 WATER ENVIRON RES JI Water Environ. Res. PD JUL-AUG PY 1998 VL 70 IS 5 BP 1049 EP 1055 DI 10.2175/106143098X123381 PG 7 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 106QV UT WOS:000075141100010 ER PT J AU Chilakapati, A Ginn, T Szecsody, J AF Chilakapati, A Ginn, T Szecsody, J TI An analysis of complex reaction networks in groundwater modeling SO WATER RESOURCES RESEARCH LA English DT Article ID DIFFERENTIAL-ALGEBRAIC EQUATIONS; CONSISTENT INITIALIZATION; SOLUTE TRANSPORT; INDEX; SYSTEMS; EDTA; SIMULATION; KINETICS AB The complex chemistry describing the biogeochemical dynamics in the natural subsurface environments gives rise to heterogeneous reaction networks, the individual segments of which can feature a wide range of timescales. This paper presents a formulation of the mass balance equations for the batch chemistry and the transport of groundwater contaminants Participating in such arbitrarily complex networks of reactions. We formulate the batch problem as an initial-value differential algebraic equation (DAE) system and compute its "index" so that the ease of solvability of the system is determined. We show that when the equilibrium reactions obey the law of mass action, the index of this initial-value DAE system is always unity (thus solvable with well-developed techniques) and that the system can be decoupled into a set of linearly implicit ordinary differential equations and a set of explicit algebraic equations. The formulations for the transport of these reaction networks can take advantage of their solvability properties under batch conditions. To avoid the error associated with time splitting fast reactions from transport, we present a split-kinetics approach where the fast equilibrium reactions are combined with transport equations while only the slower kinetic reactions are time split. These results are used to formulate and solve a simplified reaction network for the biogeochemical transformation of Co(II) ethylenediaminetetraacetic acid (EDTA) in the presence of iron-coated sediments. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Chilakapati, A (reprint author), Pacific NW Lab, POB 999,Mail Stop K9-36, Richland, WA 99352 USA. NR 41 TC 43 Z9 44 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUL PY 1998 VL 34 IS 7 BP 1767 EP 1780 DI 10.1029/98WR01041 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA ZW923 UT WOS:000074461900016 ER PT J AU Machonkin, TE Zhang, HH Hedman, B Hodgson, KO Solomon, EI AF Machonkin, TE Zhang, HH Hedman, B Hodgson, KO Solomon, EI TI Spectroscopic and magnetic studies of human ceruloplasmin: Identification of a redox-inactive reduced Type 1 copper site SO BIOCHEMISTRY LA English DT Article ID RAY ABSORPTION-EDGE; ACTIVE-SITE; ELECTRONIC-STRUCTURE; REDUCTION POTENTIALS; ASCORBATE OXIDASE; RHUS-VERNICIFERA; SUBSTRATE-SPECIFICITY; CIRCULAR-DICHROISM; SPECTRAL FEATURES; CRYSTAL-STRUCTURE AB Ceruloplasmin is unique among the multicopper oxidases in that in addition to the usual copper stoichiometry of one Type 1 copper site and a Type 2/Type 3 trinuclear copper cluster, it contains two other Type 1 sites. This assignment of copper sites, based on copper quantitation, sequence alignment, and crystallography, is difficult to reconcile with the observed spectroscopy. Furthermore, some chemical or spectroscopic differences in ceruloplasmin have been reported depending on the method of purification. We have studied the resting (as isolated by a fast, one-step procedure) and peroxide-oxidized forms of human ceruloplasmin. Using a combination of X-ray absorption spectroscopy, a chemical assay, magnetic susceptibility, electron paramagnetic resonance spectroscopy, and absorption spectroscopy, we have determined that peroxide-oxidized ceruloplasmin contains one permanently reduced Type 1 site. This site is shown to have a reduction potential of similar to 1.0 V. Thus, one of the additional Type 1 sites in ceruloplasmin cannot be catalytically relevant in the form of the enzyme studied. Furthermore, the resting form of the enzyme contains an additional reducing equivalent, which is distributed among the remaining five copper sites as expected from their relative potentials. This may indicate that the resting form of ceruloplasmin in plasma under aerobic conditions is a four-electron oxidized form, which is consistent with its function in the four-electron reduction of dioxygen to water. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Solomon, EI (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. EM solomon@chem.stanford.edu FU NIDDK NIH HHS [DK31450] NR 87 TC 70 Z9 71 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JUN 30 PY 1998 VL 37 IS 26 BP 9570 EP 9578 DI 10.1021/bi980434v PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZY085 UT WOS:000074585100040 PM 9649340 ER PT J AU Stephenson, GJ Goldman, T McKellar, BHJ AF Stephenson, GJ Goldman, T McKellar, BHJ TI Neutrino clouds SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article ID TRITIUM BETA-DECAY; ANTINEUTRINO REST MASS; MOLECULAR TRITIUM; OBJECTS; MATTER; RANGE; LIMIT; HALO AB We consider the possibility that neutrinos (but no other light fermions) are coupled very weakly to an extremely light scalar boson. We first analyze the simple problem of one generation of neutrino and show that, for ranges of parameters that are allowed by existing data, such a system can have serious consequences for the evolution of stars and could impact precision laboratory measurements. We discuss the extension to more generations and show that the general conclusion remains viable. Finally, we note that, should such a scalar field be present, experiments give information about effective masses, not the masses that arise in unified held theories. C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. RP Stephenson, GJ (reprint author), Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. NR 30 TC 46 Z9 46 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JUN 30 PY 1998 VL 13 IS 16 BP 2765 EP 2790 DI 10.1142/S0217751X98001414 PG 26 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA ZX320 UT WOS:000074503700005 ER PT J AU Turner, CM Sheller, NB Foster, MD Lee, B Corona-Galvan, S Quirk, RP Annis, B Lin, JS AF Turner, CM Sheller, NB Foster, MD Lee, B Corona-Galvan, S Quirk, RP Annis, B Lin, JS TI Effect of chain topology on ordered structure in block copolymers: Comparison of a heteroarm A(2)B(2) star with its linear diblock analog SO MACROMOLECULES LA English DT Article ID MOLECULAR-WEIGHT DEPENDENCE; MORPHOLOGY; POLYMERS C1 Univ Akron, Inst Polymer Sci, Akron, OH 44325 USA. Oak Ridge Natl Lab, CASD, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, SSD, Oak Ridge, TN 37831 USA. RP Foster, MD (reprint author), Univ Akron, Inst Polymer Sci, Akron, OH 44325 USA. NR 21 TC 24 Z9 24 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 JUN 30 PY 1998 VL 31 IS 13 BP 4372 EP 4375 DI 10.1021/ma980218u PG 4 WC Polymer Science SC Polymer Science GA ZY494 UT WOS:000074627400044 ER PT J AU Hopkins, AR Rasmussen, PG Basheer, RA Annis, BK Wignall, GD AF Hopkins, AR Rasmussen, PG Basheer, RA Annis, BK Wignall, GD TI Comparison of phase separation structures in blends of polyaniline/camphor sulfonic acid and nylons 6 and 12 SO SYNTHETIC METALS LA English DT Article DE polyaniline; camphor sulfonic acid; phase separation; nylon ID ANGLE X-RAY; COUNTERION INDUCED PROCESSIBILITY; CONDUCTING POLYANILINE; NEUTRON-SCATTERING; POLY(METHYL METHACRYLATE); FRACTAL GEOMETRY; POLYMER BLENDS; MORPHOLOGY; SILICA AB Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) techniques were used to characterize the PANI-0.5-HCSA morphology in nylon blends. SAXS shows that the polyaniline (PANI) salt resides mainly in the inter-spherulitic region of the nylon host. The morphology of the conducting salt component was analyzed by SANS data and was treated by two standard models: Debye-Bueche (D-B) and inverse power law (IPL). Due to deviations in the linear curve fitting over a large scattering range, neither the D-B nor the IPL model could be used to characterize the size and shape of all PANI-0.5-HCSA/nylon blend systems. At 3 vol.% PANI loading concentrations, the D-B model suggested salt domains with characteristic lengths of 22 nm for the nylon 12 blend. This differs in the blend reported with nylon 6 where the IPL model indicated a fractal geometry. As salt concentrations are increased in both nylons, the structures are observed to change, but there is no simple structural model that provides a suitable basis for comparison. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Michigan, Ctr Macromol Sci & Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Gen Motors Res & Dev Ctr, Polymers Dept, Warren, MI 48090 USA. Oak Ridge Natl Lab, Div Solid State, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. RP Rasmussen, PG (reprint author), Univ Michigan, Ctr Macromol Sci & Engn, Ann Arbor, MI 48109 USA. OI Wignall, George/0000-0002-3876-3244 NR 44 TC 7 Z9 7 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD JUN 30 PY 1998 VL 95 IS 3 BP 179 EP 184 DI 10.1016/S0379-6779(98)00051-4 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA 112HU UT WOS:000075488700003 ER PT J AU Nicholson, JW Rudolph, W Hager, G AF Nicholson, JW Rudolph, W Hager, G TI Generation of 14 GHz radiation using a two frequency iodine laser SO APPLIED PHYSICS LETTERS LA English DT Article ID HETERODYNE AB A mode-locked and gain-switched photolytic iodine laser Zeeman tuned to operate simultaneously on the two strongest hyperfine transitions is shown to emit 1.315 mu m radiation modulated at 13.9 GHz. The interaction of this laser radiation with suitable targets leads to die generation of microwave pulses that consist of only a few cycles at 13.9GHz, making the system attractive for ultra-wide-band. short pulse radar applications. (C) 1998 American Institute of Physics. C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. RP Nicholson, JW (reprint author), Univ Calif Los Alamos Natl Lab, MS C920, Los Alamos, NM 87545 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3402 EP 3404 DI 10.1063/1.121646 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700002 ER PT J AU Qin, LC Zhou, D Krauss, AR Gruen, DM AF Qin, LC Zhou, D Krauss, AR Gruen, DM TI Growing carbon nanotubes by microwave plasma-enhanced chemical vapor deposition SO APPLIED PHYSICS LETTERS LA English DT Article ID FIELD-EMISSION; MICROTUBULES; YIELD AB A processing route has been developed to grow bundles of carbon nanotubes on substrates from methane and hydrogen mixtures by microwave plasma-enhanced chemical vapor deposition, catalyzed by iron particles reduced from ferric nitrate. Growth takes place at about 900 degrees C leading to nanotubes with lengths of more than 20 mu m and diameters on the nanometer scale. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Qin, LC (reprint author), IBM Corp, Dept MXQ 014, 5600 Cottle Rd, San Jose, CA 95193 USA. EM qin@ibm.net NR 21 TC 131 Z9 138 U1 0 U2 19 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3437 EP 3439 DI 10.1063/1.121658 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700014 ER PT J AU Wright, AF Furthmuller, J AF Wright, AF Furthmuller, J TI Theoretical investigation of edge dislocations in AlN SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; GAN; DEFECTS; GROWTH; FILMS AB The structures and formation energies of neutral and charged edge dislocations in AlN are investigated via density-functional-theory calculations. Stoichiometric structures having full and open cores are considered as well as nonstoichiometric structures having aluminum or nitrogen vacancies along the dislocation core. Formation energies are found to depend strongly on the Fermi level, due to the presence of defect levels in the band gap, and on growth conditions for the case of the nonstoichiometric structures. A structure having aluminum vacancies along the dislocation core is predicted to be most stable in n-type material grown under nitrogen-rich conditions, whereas a nitrogen-vacancy structure is most stable in p-type material grown under aluminum-rich conditions. Estimates are also given for defect energy levels in the gap. (C) 1998 American Institute of Physics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Friedrich Schiller Univ, Inst Festkorpertheorie & Theoret Opt, D-07743 Jena, Germany. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM afwrigh@sandia.gov RI Furthmueller, Juergen/B-2346-2008 NR 20 TC 37 Z9 37 U1 1 U2 12 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3467 EP 3469 DI 10.1063/1.121668 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700024 ER PT J AU Ahrenkiel, RK Ellingson, R Johnston, S Wanlass, M AF Ahrenkiel, RK Ellingson, R Johnston, S Wanlass, M TI Recombination lifetime of In0.53Ga0.47As as a function of doping density SO APPLIED PHYSICS LETTERS LA English DT Article ID MINORITY-CARRIER LIFETIME; GAAS AB We have fabricated devices with the structure InP/In0.53Ga0.47As/InP, with a InGaAs doping range varying from 2x10(14) to 2x10(19) cm(-3) These isotype double heterostructures were doped both n and p type and were used to measure the minority-carrier lifetime of InGaAs over this doping range. At the low doping end of the series, recombination is dominated by the Shockley-Read-Hall effect. At the intermediate doping levels, radiative recombination is dominant. At the highest doping levels, Auger recombination dominates as the lifetime varies with the inverse square of the doping concentration. From fitting these data, the radiative- and Auger-recombination coefficients are deduced. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahrenkiel, RK (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Ellingson, Randy/H-3424-2013 NR 12 TC 88 Z9 92 U1 2 U2 18 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3470 EP 3472 DI 10.1063/1.121669 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700025 ER PT J AU McHugo, SA Thompson, AC Perichaud, I Martinuzzi, S AF McHugo, SA Thompson, AC Perichaud, I Martinuzzi, S TI Direct correlation of transition metal impurities and minority carrier recombination in multicrystalline silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID POLYCRYSTALLINE SILICON; MISFIT DISLOCATIONS; DEFECTS AB Impurity and minority carrier lifetime distributions were studied in as-grown multicrystalline silicon used for terrestrial-based solar cells. Synchrotron-based x-ray fluorescence and the light beam induced current technique were used to measure impurity and lifetime distributions, respectively. The purpose of this work was to determine the spatial relation between transition metal impurities and minority carrier recombination in multicrystalline silicon solar cells. Our results reveal a direct correlation between chromium, iron: and nickel impurity precipitates with regions of high minority carrier recombination. The impurity concentration was typically 5 X 10(16) atoms/cm(2), indicating the impurity-rich regions possess nanometer-scale precipitates. These results provide the first direct evidence that transition metal agglomerates play a significant role in solar cell performance. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Marseille, Lab Photoelect Semicond, F-13397 Marseille 20, France. RP McHugo, SA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Perichaud, Isabelle/A-3763-2015 NR 15 TC 64 Z9 68 U1 4 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3482 EP 3484 DI 10.1063/1.121673 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700029 ER PT J AU Biswas, R Li, YP Pan, BC AF Biswas, R Li, YP Pan, BC TI Enhanced stability of deuterium in silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID OXIDE-SEMICONDUCTOR TRANSISTORS; HOT-ELECTRON DEGRADATION; VIBRATION; REDUCTION; SURFACES; SI(111) AB Tight-binding molecular dynamics has been used to simulate vibrationally excited Si-H and Si-D modes. Simulations find that vibrationally excited Si-D bending modes decay much more rapidly than SI-H bending modes, re-suiting in SiD bonds having much higher stability than SiH bonds. This provides a viable mechanism for reduced degradation in deuterated metal-oxide-semiconductor transistors and deuterated amorphous silicon devices. (C) 1998 American Institute of Physics. C1 Iowa State Univ, Dept Phys & Astron, Ctr Microelect Res, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. RP Biswas, R (reprint author), Iowa State Univ, Dept Phys & Astron, Ctr Microelect Res, Ames, IA 50011 USA. EM biswasr@ameslab.gov RI Pan, Bicai/A-1235-2010 NR 18 TC 35 Z9 35 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 29 PY 1998 VL 72 IS 26 BP 3500 EP 3502 DI 10.1063/1.121640 PG 3 WC Physics, Applied SC Physics GA 108PM UT WOS:000075274700035 ER PT J AU Yersin, H Trumbach, D Strasser, J Patterson, HH Assefa, Z AF Yersin, H Trumbach, D Strasser, J Patterson, HH Assefa, Z TI Tunable radiationless energy transfer in Eu[Au(CN)(2)](3)center dot 3H(2)O by high pressure SO INORGANIC CHEMISTRY LA English DT Article ID LANTHANIDE ION COMPLEXES; SOLID-STATE CLASS; EXCITED-STATE; SPECTROSCOPIC PROPERTIES; CESIUM DICYANOAURATE(I); ELECTRONIC-STRUCTURES; SILVER DICYANIDES; GOLD INTERACTIONS; EMISSION-SPECTRA; THALLIUM-GOLD AB The title compound consists of two-dimensional layers of [Au(CN)(2)](-) complexes alternating with layers of Eu3+ ions. Due to this structure type, the lowest electronic transitions of the dicyanoaurates(I) exhibit an extreme red shift of Delta<(nu)over bar/Delta p = -130 +/- 10 cm(-1)/kbar under high-pressure application at least up to approximate to 60 kbar (T = 20 K), while the shifts of the different Eu3+ transitions lie between -0.70 and -0.94 cm(-1)/kbar. At ambient pressure, the usually very intense emission of the dicyanoaurates(I) is completely quenched due to radiationless energy transfer to the Eu3+ accepters. As a consequence, one observes a strong emission from Eu3+, which is assigned to stem mainly from D-5(0) but also weakly from D-5(1). At T = 20 K, D-5(3) seems to be the dominant acceptor term. It is a highlight of this investigation that, with increasing pressure, the emission from the dicyanoaurate(I) donor states can continuously be tuned in by tuning off the resonance condition (spectral overlap) for radiationless energy transfer to D-5(3). With further increase of pressure, successively, D-5(2) and D-5(1) become acceptor terms, however, being less efficient. Interestingly, D-5(0) does not act as an acceptor term even with maximum spectral overlap. Between 30 and 60 kbar, when only the F-7(0) --> D-5(1) acceptor absorption overlaps with the donor emission, one finds a linear dependence of the (integrated) D-5(0) emission intensity on the spectral overlap integral, as is expected for resonance energy transfer. As the dominant transfer mechanism, the Dexter exchange mechanism is proposed. Besides the high-pressure studies of the Eu3+ line structure at T = 20 Kt the Eu3+ emission is also investigated at T = 1.2 K (p = 0 kbar) by time-resolved emission spectroscopy, which strongly facilitates the assignments of the emitting terms. C1 Univ Regensburg, Inst Theoret & Phys Chem, D-93040 Regensburg, Germany. Univ Maine, Dept Chem, Orono, ME 04469 USA. Oak Ridge Natl Lab, Transuranium Res Grp, Oak Ridge, TN 37831 USA. RP Yersin, H (reprint author), Univ Regensburg, Inst Theoret & Phys Chem, D-93040 Regensburg, Germany. NR 65 TC 27 Z9 27 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 JUN 29 PY 1998 VL 37 IS 13 BP 3209 EP 3216 DI 10.1021/ic980252p PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZY027 UT WOS:000074579300012 ER PT J AU Tilley, DR Cheves, CM Kelley, CH Raman, S Weller, HR AF Tilley, DR Cheves, CM Kelley, CH Raman, S Weller, HR TI Energy levels of light nuclei, A=20 SO NUCLEAR PHYSICS A LA English DT Review DE compilation N-20, O-20, F-20, Ne-20, Na-20, Mg-20; compiled, evaluated nuclear data ID SD-SHELL NUCLEI; RELATIVISTIC MEAN-FIELD; HEAVY-ION COLLISIONS; REACTION CROSS-SECTIONS; CHARGE-EXCHANGE REACTIONS; DELAYED NEUTRON EMISSION; TIME-REVERSAL INVARIANCE; ALPHA-CLUSTER STRUCTURE; GAMOW-TELLER STRENGTH; SHAPE ISOMERIC STATES AB Compilation of energy levels of A = 20 nuclei, with emphasis on the review of material leading to information about the structure of the A = 20 systems. (C) 1998 Elsevier Science B.V. C1 Triangle Univ Nucl Lab, Durham, NC 27708 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Triangle Univ Nucl Lab, Durham, NC 27708 USA. NR 783 TC 122 Z9 122 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 29 PY 1998 VL 636 IS 3 BP 249 EP 364 DI 10.1016/S0375-9474(98)00129-8 PG 116 WC Physics, Nuclear SC Physics GA ZX481 UT WOS:000074520400001 ER PT J AU de Boer, J Hori, K Ooguri, H Oz, Y AF de Boer, J Hori, K Ooguri, H Oz, Y TI Branes and dynamical supersymmetry breaking SO NUCLEAR PHYSICS B LA English DT Article DE M theory fivebrane; supersymmetric gauge theories; dynamical supersymmetry breaking ID GAUGE-THEORIES; SPACE; VACUA AB We study dynamical supersymmetry breaking in four dimensions using the fivebrane of M theory, in particular for the Izawa-Yanagida-Intriligator-Thomas (IYIT) model, which we realize as the worldvolume theory of a certain Al theory fivebrane configuration. From the brane point of view, supersymmetry is broken when a holomorphic configuration with the proper boundary conditions does not exist. We discuss the difference between explicit and spontaneous supersymmetry breaking and between runaway behavior and having a stable vacuum. As a preparation for the study of the IYIT model, we examine a realization of the orientifold four-plane in M theory. We derive known as well as new results on the moduli spaces of N = 2 and N = 1 theories with symplectic gauge groups. These results are based on a hypothesis that a certain intersection of the fivebrane and the Z(2) fixed plane breaks supersymmetry. In the IYIT model, we show that the brane exhibits runaway behavior when the flavor group is gauged. On the other hand, if the flavor group is not gauged, we find that the brane does not run away, We suggest that a stable supersymmetry-breaking vacuum is realized in the region beyond the reach of the supergravity approximation. (C) 1998 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, 366 Le Conte Hall, Berkeley, CA 94720 USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 73 TC 29 Z9 29 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 JUN 29 PY 1998 VL 522 IS 1-2 BP 20 EP 68 DI 10.1016/S0550-3213(98)00252-1 PG 49 WC Physics, Particles & Fields SC Physics GA ZY481 UT WOS:000074626100002 ER PT J AU Hagios, C Lochter, A Bissell, MJ AF Hagios, C Lochter, A Bissell, MJ TI Tissue architecture: the ultimate regulator of epithelial function? SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES LA English DT Review DE mammary gland; intestine; epithelium; basement membrane; cell adhesion ID CELL-CELL-ADHESION; E-CADHERIN EXPRESSION; RECONSTITUTED BASEMENT-MEMBRANE; EXTRACELLULAR-MATRIX COMPONENTS; MOUSE INTESTINAL EPITHELIUM; TRANSCRIPTION FACTOR LEF-1; BREAST-CANCER PROGRESSION; PROTEIN GENE-EXPRESSION; POLYPOSIS-COLI PROTEIN; HUMAN CARCINOMA-CELLS AB The architecture of a tissue is defined by the nature and the integrity of its cellular and extracellular compartments, and is based on proper adhesive cell-cell and cell-extracellular matrix interactions. Cadherins and integrins are major adhesion-mediators that assemble epithelial cells together laterally and attach them basally to a subepithelial basement membrane, respectively. Because cell adhesion complexes are linked to the cytoskeleton and to the cellular sir:nalling pathways, they represent checkpoints for regulation of cell shape and gene expression and thus are instructive for cell behaviour and function. This organization allows a reciprocal flow of mechanical and biochemical information between the cell and its microenvironment, and necessitates that cells actively maintain a state of homeostasis within a given tissue context. The loss of the ability of tumour cells to establish correct adhesive interactions with their microenvironment results in disruption of tissue architecture with often fatal consequences for the host organism. This review discusses the role of cell adhesion in the maintenance of tissue structure and analyses how tissue structure regulates epithelial function. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Bissell, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. EM mjbissell@lbl.gov FU NCI NIH HHS [CA 64786, CA 57621] NR 161 TC 80 Z9 81 U1 0 U2 3 PU ROYAL SOC LONDON PI LONDON PA 6 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 J9 PHILOS T ROY SOC B JI Philos. Trans. R. Soc. Lond. Ser. B-Biol. Sci. PD JUN 29 PY 1998 VL 353 IS 1370 BP 857 EP 870 DI 10.1098/rstb.1998.0250 PG 14 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 111JG UT WOS:000075433100006 PM 9684283 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassman, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartman, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Henzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Xu, X Wyss, J Yagil, A Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, D Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassman, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartman, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Henzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Xu, X Wyss, J Yagil, A Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S TI Observation of hadronic W decays in t(t)over-bar events with the Collider Detector at Fermilab SO PHYSICAL REVIEW LETTERS LA English DT Article ID SILICON VERTEX DETECTOR; TOP-QUARK PRODUCTION; P(P)OVER-BAR COLLISIONS; TEV AB We observe hadronic W decays in t (t) over bar --> W(--> l nu) + greater than or equal to 4 jet events using a 109 pb(-1) data sample of p (p) over bar collisions at root s = 1.8 TeV collected with the Collider Detector at Fermilab. A peak in the dijet invariant mass distribution is obtained that is consistent with W decay and inconsistent with the background prediction by 3.3 sigma. From this peak we measure the W mass to be 77.2 +/- 4.6(stat + syst) GeV/c(2). This result demonstrates the presence of a second W boson in t (t) over bar candidates in the W(--> l nu) + greater than or equal to 4 jet channel. C1 Natl Lab High Energy Phys, KEK, Tsukuba, Ibaraki 305, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Chicago, Chicago, IL 60637 USA. Duke Univ, Durham, NC 27708 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. 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. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 315, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Abe, F (reprint author), Natl Lab High Energy Phys, KEK, Tsukuba, Ibaraki 305, Japan. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Introzzi, Gianluca/K-2497-2015; OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Introzzi, Gianluca/0000-0002-1314-2580; Meschi, Emilio/0000-0003-4502-6151 NR 16 TC 12 Z9 12 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 1998 VL 80 IS 26 BP 5720 EP 5725 DI 10.1103/PhysRevLett.80.5720 PG 6 WC Physics, Multidisciplinary SC Physics GA ZW862 UT WOS:000074455800003 ER PT J AU Bonnell, JW Schuck, PW Pincon, JL Seyler, CE Kintner, PM AF Bonnell, JW Schuck, PW Pincon, JL Seyler, CE Kintner, PM TI Observation of bound states and counterrotating lower hybrid eigenmodes in the auroral ionosphere SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE ION-ACCELERATION; DENSITY DEPLETIONS; WAVES AB Definitive evidence from a plasma wave interferometer carried on a sounding rocket is presented for the observation of counterrotating electric field structures observed at frequencies above and below the local lower hybrid resonance frequency, f(LHR), Of the ambient plasma. These counterrotating structures were observed within the context of a lower hybrid solitary structure (LHSS), and were found to rotate in a right-handed (left-handed) sense around the geomagnetic field at frequencies above (below) f(LHR), in accord with previous predictions for and observations of electric field eigenmodes within a density depletion. The presence of a narrow band feature below f(LHR) indicates the presence of trapped waves, and represents clear evidence of a bound state of lower hybrid waves in the auroral ionosphere. C1 Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. RP Bonnell, JW (reprint author), Univ Calif Los Alamos Natl Lab, NIS-1,MS D466, Los Alamos, NM 87501 USA. EM jbonnell@lanl.gov NR 14 TC 29 Z9 29 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 1998 VL 80 IS 26 BP 5734 EP 5737 DI 10.1103/PhysRevLett.80.5734 PG 4 WC Physics, Multidisciplinary SC Physics GA ZW862 UT WOS:000074455800006 ER PT J AU Liu, R Olson, CG Tonjes, WC Frindt, RF AF Liu, R Olson, CG Tonjes, WC Frindt, RF TI Momentum dependent spectral changes induced by the charge density wave in 2H-TaSe2 and the implication on the CDW mechanism SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSITION-METAL DICHALCOGENIDES; BAND STRUCTURES; LAYER COMPOUNDS AB We report a high energy and high angular resolution angle resolved photoemission study of 2H-TaSe2 at temperatures both above and below the charge-density-wave (CDW) transition. In the normal state, an extended saddle band very close to the Fermi energy was observed. The CDW-induced energy gap is near zero on a well defined Fermi surface and large in the extended saddle band region. The implication of these results on the CDW mechanism is discussed. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Univ Wisconsin, Ctr Synchrotron Radiat, Madison, WI 53706 USA. RP Liu, R (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. NR 9 TC 46 Z9 46 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 1998 VL 80 IS 26 BP 5762 EP 5765 DI 10.1103/PhysRevLett.80.5762 PG 4 WC Physics, Multidisciplinary SC Physics GA ZW862 UT WOS:000074455800013 ER PT J AU Maslov, S Zheludev, A AF Maslov, S Zheludev, A TI Universal behavior of one-dimensional gapped antiferromagnets in a staggered magnetic field SO PHYSICAL REVIEW LETTERS LA English DT Article ID STATE; MODEL; NENP AB We study the properties of one-dimensional gapped Heisenberg antiferromagnets in the presence of a strong staggered magnetic field. For these systems we predict a universal form for the staggered magnetization curve. This function, as well as the effect the staggered field has on the energy gaps in longitudinal and transversal excitation spectra, is determined from the universal form of the effective potential in O(3)-symmetric (1 + 1)-dimensional field theory. Our theoretical findings are in excellent agreement with recent neutron scattering data on R2BaNiO5 (R = magnetic rare earth) linear-chain mixed spin antiferromagnets. [S0031-9007(98)06459-X]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Maslov, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 16 TC 42 Z9 43 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 1998 VL 80 IS 26 BP 5786 EP 5789 DI 10.1103/PhysRevLett.80.5786 PG 4 WC Physics, Multidisciplinary SC Physics GA ZW862 UT WOS:000074455800019 ER PT J AU Tsekouras, AA Iedema, MJ Cowin, JP AF Tsekouras, AA Iedema, MJ Cowin, JP TI Amorphous water-ice relaxations measured with soft-landed ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID TIME-RESOLVED CONDUCTIVITY; IONIZED ICE; SURFACE AB D3O+ and Cs+ ions (less than or equal to 1 eV) were soft landed on vacuum-deposited amorphous water ice at 30 K. The samples charged capacitively with an initial dielectric constant of 2. Then the voltage was measured via a Kelvin probe while the sample temperature was ramped. A sharp drop in voltage occurred near 50 K, due to dielectric responses occurring at much less than the expected 135 K. This was due to relaxations of the highly strained amorphous ice. Preannealing the ice could move the electrical relaxation up to as high as 120 K. Ion migration through the ice was not observed below 190 K. [s0031-9007(98)06347-9]. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Tsekouras, AA (reprint author), Univ Athens, Chem Phys Lab, GR-15771 Athens, Greece. OI Tsekouras, Athanassios/0000-0002-4757-324X NR 26 TC 42 Z9 42 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 29 PY 1998 VL 80 IS 26 BP 5798 EP 5801 DI 10.1103/PhysRevLett.80.5798 PG 4 WC Physics, Multidisciplinary SC Physics GA ZW862 UT WOS:000074455800022 ER PT J AU Liberman, DA AF Liberman, DA TI Modified exchange potential for local density calculations of atoms SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID QUANTUM-MECHANICAL INTERPRETATION; FUNCTIONAL THEORY; INTEGER DISCONTINUITY; OPTICAL-RESPONSE; APPROXIMATION; SYSTEMS; PROGRAM AB The local density exchange potential which is used in most atomic calculations is based on the degenerate electron gas. It is proposed that it should be augmented by a term that has the correct large radius behaviour and which contains an adjustable parameter. The parameter is determined by minimizing the total energy. Better calculations of several physical quantities are obtained. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Liberman, DA (reprint author), 5235 Fiore Terrace C407, San Diego, CA 92122 USA. EM dal@icf.llnl.gov NR 28 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JUN 28 PY 1998 VL 31 IS 12 BP 2681 EP 2688 DI 10.1088/0953-4075/31/12/006 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZY747 UT WOS:000074655300006 ER PT J AU Rakov, VA Uman, MA Rambo, KJ Fernandez, MI Fisher, RJ Schnetzer, GH Thottappillil, R Eybert-Berard, A Berlandis, JP Lalande, P Bonamy, A Laroche, P Bondiou-Clergerie, A AF Rakov, VA Uman, MA Rambo, KJ Fernandez, MI Fisher, RJ Schnetzer, GH Thottappillil, R Eybert-Berard, A Berlandis, JP Lalande, P Bonamy, A Laroche, P Bondiou-Clergerie, A TI New insights into lightning processes gained from triggered-lightning experiments in Florida and Alabama SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article; Proceedings Paper CT 10th International Conference on Atmospheric Electricity (ICAE 10) CY JUN 10-13, 1996 CL OSAKA, JAPAN SP Int Commiss Atmospher Electr, Meterol Soc Japan, Int Union Radio Sci, Inst Electr Engn Japan, Japan Res Grp Electr Discharge, Sci Council Japan, Commemorat Assoc Japan World Expoosit ID CHANNEL-BASE; CURRENTS AB Analyses of electric and magnetic fields measured at distances from tens to hundreds of meters from the ground strike point of triggered lightning at Camp Blanding, Florida, and at 10 and 20 m at Fort McClellan, Alabama, in conjunction with currents measured at the lightning channel base and with optical observations, allow us to make new inferences on several aspects of the lightning discharge and additionally to verify the recently published "two-wave" mechanism of the lightning M component. At very close ranges (a few tens of meters or less) the time rate of change of the final portion of the dart leader electric field can be comparable to that of the return stroke. The variation of the close dart leader electric field change with distance is somewhat slower than the inverse proportionality predicted by the uniformly charged leader model, perhaps because of a decrease of leader charge density with decreasing height associated with an incomplete development of the corona sheath at the bottom of the channel. There is a positive linear correlation between the leader electric field change at close range and the succeeding return stroke current peak at the channel base. The formation of each step of a dart-stepped leader is associated with a charge of a few millicoulombs and a current of a few kiloamperes. In an altitude-triggered lightning the downward negative leader of the bidirectional leader system and the resulting return stroke serve to provide a relatively low-impedance connection between the upward moving positive leader tip and the ground, the processes that follow likely being similar to those in classical triggered lightning. Lightning appears to be able to reduce, via breakdown processes in the soil and on the ground surface, the grounding impedance which it initially encounters at the strike point, so at the time of channel-base current peak the reduced grounding impedance is always much lower than the equivalent impedance of the channel. At close rangers the measured M-component magnetic fields have waveshapes that are similar to those of the channel-base currents, whereas the measured M-component electric fields have waveforms that appear to be the time derivatives of the channel-base current waveforms, in further confirmation of the "two-wave" M-component mechanism. C1 Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Uppsala Univ, Inst Hogspanningsforskning, S-75228 Uppsala, Sweden. Ctr Etud Nucl Grenoble, Lab Applicat Speciales & Phys, F-38054 Grenoble 9, France. Elect France, Lab Genie Elect, F-77250 Moret Sur Loing, France. Off Natl Etud & Rech Aerosp, F-92190 Meudon, France. RP Rakov, VA (reprint author), Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA. EM rakov@admin.ee.ufl.edu RI Rakov, Vladimir/A-8775-2009 OI Rakov, Vladimir/0000-0002-4582-9483 NR 31 TC 101 Z9 107 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 27 PY 1998 VL 103 IS D12 BP 14117 EP 14130 DI 10.1029/97JD02149 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZW708 UT WOS:000074439500036 ER PT J AU Ban, N Freeborn, B Nissen, P Penczek, P Grassucci, RA Sweet, R Frank, J Moore, PB Steitz, TA AF Ban, N Freeborn, B Nissen, P Penczek, P Grassucci, RA Sweet, R Frank, J Moore, PB Steitz, TA TI A 9 angstrom resolution x-ray crystallographic map of the large ribosomal subunit SO CELL LA English DT Article ID ESCHERICHIA-COLI RIBOSOME; 3-DIMENSIONAL RECONSTRUCTION; CRYOELECTRON MICROSCOPY; ELECTRON-MICROSCOPY; PROTEIN; CRYSTALLIZATION; REFINEMENT; EXTENSION; PARTICLES; SYMMETRY AB The 50S subunit of the ribosome catalyzes the peptidyl-transferase reaction of protein synthesis. We have generated X-ray crystallographic electron density maps of the large ribosomal subunit from Haloarcula marismortui at various resolutions up to 9 Angstrom using data from crystals that diffract to 3 Angstrom. Positioning a 20 Angstrom resolution EM image of these particles in the crystal lattice produced phases accurate enough to locate the bound heavy atoms in three derivatives using difference Fourier maps, thus demonstrating the correctness of the EM model and its placement in the unit cell. At 20 Angstrom resolution, the X-ray map is similar to the EM map; however, at 9 Angstrom it reveals long, continuous, but branched features whose shape, diameter, and right-handed twist are consistent with segments of double-helical RNA that crisscross the subunit. C1 Yale Univ, Dept Mol Biophys & Biochem, New Haven, CT 06520 USA. Yale Univ, Dept Chem, New Haven, CT 06520 USA. Yale Univ, Howard Hughes Med Inst, New Haven, CT 06520 USA. New York State Dept Hlth, Wadsworth Ctr Labs & Res, Albany, NY 12201 USA. SUNY Albany, Dept Biomed Sci, Albany, NY 12201 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Steitz, TA (reprint author), Yale Univ, Dept Mol Biophys & Biochem, POB 6666, New Haven, CT 06520 USA. RI Steitz, Thomas/C-6559-2009; Nissen, Poul/D-5774-2014 FU NIGMS NIH HHS [GM-22778, GM-29169, GM-54216] NR 56 TC 194 Z9 201 U1 4 U2 8 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 USA SN 0092-8674 J9 CELL JI Cell PD JUN 26 PY 1998 VL 93 IS 7 BP 1105 EP 1115 DI 10.1016/S0092-8674(00)81455-5 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZX217 UT WOS:000074491100006 PM 9657144 ER PT J AU Tang, J AF Tang, J TI Structural implications of transient X-, K- and W-band EPR spectra of deuterated and protonated reaction centers of Rhodobacter sphaeroides R-26 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SUBSTITUTED REACTION CENTERS; SEQUENTIAL ELECTRON-TRANSFER; BACTERIAL REACTION CENTERS; HIGH-FIELD EPR; RADICAL PAIRS; PHOTOSYSTEM-I; SPECTROSCOPY; POLARIZATION; PHOTOSYNTHESIS; ACCEPTOR AB We have reexamined the X-ray structural implications of reaction center proteins (bRCs) of Rhodobacter sphaeroides R-26 by simultaneous least-squares fitting of six different transient EPR spectra at three frequencies (X-, K- and W-band) for both deuterated and protonated bRCs, Several possible g-tensor orientations from X-ray structure are found to produce similar spectral features by a small change in the g factor. We have obtained the fitted principal g values that are slightly different from a previous report. No exchange coupling J between P+ and Q(-) is needed for the fit. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Tang, J (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM tang@anlchm.anl.gov RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 30 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 26 PY 1998 VL 290 IS 1-3 BP 49 EP 57 DI 10.1016/S0009-2614(98)00484-9 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW963 UT WOS:000074466600008 ER PT J AU Brunner, E Haake, M Pines, A Reimer, JA Seydoux, R AF Brunner, E Haake, M Pines, A Reimer, JA Seydoux, R TI Enhancement of C-13 NMR signals in solid C-60 and C-70 using laser-polarized xenon SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; IN-SITU NMR; XE-129 NMR; MAS-NMR; DYNAMICS; CATALYSTS; ZEOLITES; PROBE; FLOW; C60 AB NMR signals emanating from surface nuclei of solids may be enhanced by the transfer of spin polarization from laser-polarized noble gases via SPINOE (spin polarization induced nuclear Overhauser effect). The present contribution describes experiments in which the spin polarization is transferred under magic angle spinning (MAS) from laser-polarized Xe-129 to C-13, a nuclear spin with a low gyromagnetic ratio in the fullerenes C-60 and C-70, polycrystalline materials with a low surface area. In C-70, differential enhancement of the NMR is observed for the different atomic sites in the molecule. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Brunner, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 31 TC 33 Z9 34 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 26 PY 1998 VL 290 IS 1-3 BP 112 EP 116 DI 10.1016/S0009-2614(98)00473-4 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW963 UT WOS:000074466600018 ER PT J AU Zeng, LM Franzen, HF AF Zeng, LM Franzen, HF TI Crystal structure of Nd4Fe1.3Ge7.5 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE single crystal; crystal structure; neodymium; iron; germanium AB The crystal structure of the ternary rare-earth compound Nd4Fe1.3Ge7.5 has been determined from single-crystal X-ray data. The compound crystallizes in tetragonal, space group Cmcm, No. 63), with a=4.121(1) A, b=30.446(8) A, c=4.2180(9) Angstrom, V=529.2(4) Angstrom(3) and Z=2 at room temperature. The structure refinement (R=0.024, R-w=0.031) showed the compound to be a new structure-type. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Franzen, HF (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 8 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 26 PY 1998 VL 274 IS 1-2 BP 179 EP 181 DI 10.1016/S0925-8388(98)00535-0 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 105DT UT WOS:000075058000030 ER PT J AU Bernstein, BE Williams, DM Bressi, JC Kuhn, P Gelb, MH Blackburn, GM Hol, WGJ AF Bernstein, BE Williams, DM Bressi, JC Kuhn, P Gelb, MH Blackburn, GM Hol, WGJ TI A bisubstrate analog induces unexpected conformational changes in phosphoglycerate kinase from Trypanosoma brucei SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE phosphoglycerate kinase; bisubstrate analog; hinge; inhibitor; X-ray crystallography ID 3-PHOSPHOGLYCERATE KINASE; SUBSTRATE-BINDING; COMPLEX; ENZYME; 3-PHOSPHO-D-GLYCERATE; ISOENZYMES; SEQUENCE; ANGSTROM AB The glycolytic enzyme phosphoglycerate kinase (PGK) catalyzes phosphoryl transfer between 1,3-bis-phosphoglycerate and ADP to form 3-phosphoglycerate and ATP. During catalysis, a major hinge bending motion occurs which brings the N and C-terminal enzyme domains and their bound substrates together and in-line for phosphoryl transfer. We have crystallized Trypanosoma brucei PGK in the presence of the bisubstrate analog, adenylyl 1,1,5,5-tetrafluoropentane-1,5-bisphosphonate, and solved the structure of this complex in two different crystal forms at 1.6 and 2.0 Angstrom resolution, obtained from PEG 8000 and ammonium phosphate solutions, respectively. These high resolution structures of PGK:inhibitor complexes are of particular interest for drug design since Trypanosoma brucei, the causative agent of African sleeping sickness, relies on glycolysis as its sole energy source. In both structures, the inhibitor is bound in a fully extended conformation with its adenosine moiety assuming exactly the same position as in ADP:PGK complexes and with its 5' phosphonate group occupying part of the 1,3-bis-phosphoglycerate binding site. The bisubstrate analog forces PGK to assume a novel, "inhibited" conformation, intermediate in hinge angle between the native structures of open and closed form PGK. These structures of enzyme-inhibitor complexes demonstrate that PGK has two distinct hinge points that can each be independently activated. In the "PEG" structure, the C-terminal hinge is partially activated while the N-terminal hinge point remains in an open state. In the "phosphate" structure, closure of the N-terminal hinge point is also evident. Finally and most unexpectedly, both complex structures also contain a 3 Angstrom shift of a helix that lies outside the flexible hinge region. We propose that a transient shift of this helix is a required element of PGK hinge closure during catalysis. (C) 1998 Academic Press. C1 Univ Washington, Howard Hughes Med Inst, Dept Biol Struct, Seattle, WA 98195 USA. Univ Washington, Howard Hughes Med Inst, Dept Biochem, Seattle, WA 98195 USA. Univ Washington, Biomol Struct Ctr, Seattle, WA 98195 USA. Univ Sheffield, Dept Chem, Krebs Inst, Sheffield S3 7HF, S Yorkshire, England. Univ Washington, Dept Chem, Seattle, WA 98195 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Hol, WGJ (reprint author), Univ Washington, Howard Hughes Med Inst, Dept Biol Struct, Box 357742, Seattle, WA 98195 USA. RI Williams, David/J-9627-2013 NR 28 TC 34 Z9 37 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD JUN 26 PY 1998 VL 279 IS 5 BP 1137 EP 1148 DI 10.1006/jmbi.1998.1835 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZY738 UT WOS:000074654400010 PM 9642090 ER PT J AU Maruenda, H Chenna, A Liem, LK Singer, B AF Maruenda, H Chenna, A Liem, LK Singer, B TI Synthesis of 1,N-6-ethano-2 '-deoxyadenosine, a metabolic product of 1,3-bis(2-chloroethyl)nitrosourea, and its incorporation into oligomeric DNA SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID DERIVATIVES; ADENOSINE AB 1,N-6-Ethano-2'-deoxyadenosine (1) is one of the adducts formed during DNA reaction with the antitumor agent, 1,3-bis(2-chloroethyl)nitrosourea (BCNU), and was synthesized and incorporated into a site-specific deoxyoligonucleotide for the first time. The product 6-chloropurine-2'-deoxyriboside (11) was prepared in high yield by the reaction of 2'-deoxyinosine (6) with SOCl2, which then was derivatized to give compound 12 using tert-butyldimethylsilyl chloride, which was then reacted with 2-hydroxyethylamine to produce compound 13 in 86% yield. Reaction of 13 with (PhO)(8)P+MeI- in DMF gave the cyclized 1,N-6-ethano derivative 10 in 67% yield. Desilylation of 10 with triethylamine trihydrofluoride in THF gave 1,N-6-ethano-dA (1) in 91% yield. Tritylation of compound 1 with DMT+BF4- gave the 5'-O-DMT product 14 in 62% yield, which then was phosphitylated with 2-cyanoethyl N,N-diisopropylchlorophosphoramidite, which yielded a 1:1 mixture of the diastereoisomers 15 in 71% yield. This fully protected compound 15 was incorporated site-specifically into a 25-mer oligonucleotide. The coupling efficiency of ethano-dA phosphoramidite was 93%. Enzymatic hydrolysis and analysis by HPLC confirmed the incorporation of ethano-dA and base composition of the DNA oligomer. The latter is now under investigation for its biochemical and physical properties. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. RP Singer, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Berkeley, CA 94720 USA. NR 18 TC 20 Z9 20 U1 0 U2 5 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 JUN 26 PY 1998 VL 63 IS 13 BP 4385 EP 4389 DI 10.1021/jo980170i PG 5 WC Chemistry, Organic SC Chemistry GA ZY295 UT WOS:000074605800032 ER PT J AU Holian, BL Lomdahl, PS AF Holian, BL Lomdahl, PS TI Plasticity induced by shock waves in nonequilibrium molecular-dynamics simulations SO SCIENCE LA English DT Article ID DEFORMATION; STRESS AB Nonequilibrium molecular-dynamics simulations of shock waves in three-dimensional 10-million atom face-centered cubic crystals with cross-sectional dimensions of 100 by 100 unit cells show that the system slips along all of the available {111} slip planes, in different places along the nonplanar shock front. Comparison of these simulations with earlier ones on a smaller scale not only eliminates the possibility that the observed slippage is an artifact of transverse periodic boundary conditions, but also reveals the richness of the nanostructure left behind. By introducing a piston face that is no longer perfectly flat, mimicking a line or surface inhomogeneity in the unshocked material, it is shown that for weaker shock waves (below the perfect-crystal yield strength), stacking faults can be nucleated by preexisting extended defects. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Holian, BL (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM blh@lanl.gov NR 27 TC 272 Z9 278 U1 4 U2 44 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 26 PY 1998 VL 280 IS 5372 BP 2085 EP 2088 DI 10.1126/science.280.5372.2085 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZW680 UT WOS:000074435900034 ER PT J AU Stone, EC Lindsley, DH Pigott, V Harbottle, G Ford, MT AF Stone, EC Lindsley, DH Pigott, V Harbottle, G Ford, MT TI From shifting silt to solid stone: The manufacture of synthetic basalt in ancient Mesopotamia SO SCIENCE LA English DT Article AB Slabs and fragments of gray-black vesicular "rock," superficially resembling natural basalt but distinctive in chemistry and mineralogy, were excavated at the second-millennium B.C. Mesopotamian city of Mashkan-shapir, about 80 kilometers south of Baghdad, iraq. Most of this material appears to have been deliberately manufactured by the melting and slow cooling of local alluvial silts. The high temperatures (about 1200 degrees C) required and the large volume of material processed indicate an industry in which lithic materials were manufactured ("synthetic basalt") for grinding grain and construction. C1 SUNY Stony Brook, Dept Anthropol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA. Univ Penn, Museum Archaeol & Anthropol, Museum Appl Sci Ctr Archaeol, Philadelphia, PA 19104 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Alfred Univ, Dept Geol, Alfred, NY 14802 USA. RP Stone, EC (reprint author), SUNY Stony Brook, Dept Anthropol, Stony Brook, NY 11794 USA. NR 5 TC 3 Z9 3 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 26 PY 1998 VL 280 IS 5372 BP 2091 EP 2093 DI 10.1126/science.280.5372.2091 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZW680 UT WOS:000074435900036 ER PT J AU Krishnan, VV AF Krishnan, VV TI Radiation damping: Suryan's line broadening revisited in high resolution solution NMR SO CURRENT SCIENCE LA English DT Review ID NUCLEAR-MAGNETIC-RESONANCE; DIPOLAR DEMAGNETIZING FIELD; LIQUID NMR; PROTEIN NMR; WATER REAL; SUPPRESSION; SPECTROSCOPY; SENSITIVITY; FEEDBACK; EXCITATION AB Radiation damping is a combined manifestation of the nuclear spins and the resonant circuit. Radiation damping effects are becoming increasingly important in the high field NMR spectra of biological macromolecules when dissolved in aqueous solutions. This phenomenon was first discovered by Suryan in 1949 and a complete mathematical treatment was provided by Bloembergen and Pound in 1954. In this review, a historical perspective of Suryan's line broadening, commonly known as radiation damping is presented and methods that can suppress or utilize it advantageously are discussed with an emphasis of this phenomenon in the current state of high resolution solution NMR spectroscopy. C1 Univ Calif Lawrence Livermore Natl Lab L 452, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Univ Calif Lawrence Livermore Natl Lab L 452, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RI Krishnan, Krish/A-6859-2010 NR 59 TC 7 Z9 7 U1 0 U2 3 PU INDIAN ACAD SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0011-3891 J9 CURR SCI INDIA JI Curr. Sci. PD JUN 25 PY 1998 VL 74 IS 12 BP 1049 EP 1053 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZY336 UT WOS:000074610200011 ER PT J AU Binder, PM Perondi, LF Gosnell, TR AF Binder, PM Perondi, LF Gosnell, TR TI Model showing effect of impurity sub-lattice topology on upconversion in Er3+-doped glasses SO ELECTRONICS LETTERS LA English DT Article ID EXCITED-STATE ABSORPTION; DOPED FIBER AMPLIFIERS AB Monte Carlo methods are used to simulate a spatial model of uniform upconversion and commensurate excited-state depletion in high-concentration Er3+-doped solids. It is found that the topology of the impurity sublattice affects the value of the upconversion coefficient, a result in accord with recent measurements on samples prepared with compositions and ion concentrations. C1 Univ Los Andes, Dept Fis, Bogota, Colombia. Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, Brazil. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Binder, PM (reprint author), Univ Los Andes, Dept Fis, Apartado Aereo 4976, Bogota, Colombia. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 25 PY 1998 VL 34 IS 13 BP 1348 EP 1349 DI 10.1049/el:19980960 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 103AC UT WOS:000074957600053 ER PT J AU Shkrob, IA Sauer, MC Liu, AD Crowell, RA Trifunac, AD AF Shkrob, IA Sauer, MC Liu, AD Crowell, RA Trifunac, AD TI Reactions of photoexcited aromatic radical cations with polar solvents SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID ELECTRON-SPIN RESONANCE; AQUEOUS CHLORIDE-ION; QUANTUM MOLECULAR-DYNAMICS; EXCITED-STATE PROCESSES; LIQUID WATER; COMPUTER-SIMULATION; HYDRATED ELECTRON; PHOTO-IONIZATION; RATE CONSTANTS; TRANS-DECALIN AB Reactions of electronically excited radical cations of various simple aromatic hydrocarbons (e.g., naphthalene, biphenyl, perylene) and amines (indole and L-tryptophan) with polar solvents (alcohols, ethers, and water) were studied. The radical cations were generated by biphotonic (248 nm) photoionization of aromatic solutes in oxygen-saturated solutions and subsequently excited by 2.3 eV photons from a Nd:YAG laser. The photobleaching is initiated by a transfer of the valence electron of the solvent to the solute radical cation ("hole injection"). In the polar liquids, a proton transfer occurs concurrently with this electron transfer and may occur in several ways. Hole injection is the general mechanism for decay of photoexcited radical cations, in both polar and nonpolar media. The efficiency of this process correlates with the ionization potential (IP) of the solute and optical absorbance of the corresponding radical cation. For high-IF solutes, the quantum yield of the photobleaching is 0.3-0.5. From scavenging of the photoexcited radical cations, it was found that while some of these states have the lifetimes below 1 ps, other have lifetimes of 10-40 ps (in acetonitrile). C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Shkrob, IA (reprint author), Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 140 TC 26 Z9 26 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 25 PY 1998 VL 102 IS 26 BP 4976 EP 4989 DI 10.1021/jp981065f PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZY136 UT WOS:000074589900005 ER PT J AU Guo, Y Sewell, TD Thompson, DL AF Guo, Y Sewell, TD Thompson, DL TI Semiclassical calculations of tunneling splitting in tropolone SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CLASSICAL TRAJECTORY SIMULATIONS; TRANSITION-STATE THEORY; JET-COOLED TROPOLONE; VIBRATIONAL-EXCITATION; NONSEPARABLE SYSTEMS; X-STATE; SPECTRUM; MALONALDEHYDE; COLLISIONS; MODEL AB Energy level splittings in tropolone are calculated by using a semiclassical approach for tunneling in multidimensional systems. A potential-energy surface that includes all 39 vibrational degrees of freedom was constructed for the ground electronic stale on the basis of ab initio results. Since the method incorporates tunneling within standard trajectory simulations, the full-dimensional dynamics were explicitly treated to provide a clear picture of the dynamical behavior of the system and its effect on tunneling. Level splittings for the ground states of the normal and deuterated species were calculated. We also studied the sensitivity of the splittings to the choice of tunneling path. Mode-selective excitations were used to study the effect of vibrational excitation on the tunneling. It is found that some modes promote tunneling, some suppress it, and some do not affect it. This demonstrates the multidimensional nature of the tunneling process and the importance of properly treating heavy-atom motions. C1 Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Thompson, DL (reprint author), Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA. NR 34 TC 23 Z9 23 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 25 PY 1998 VL 102 IS 26 BP 5040 EP 5048 DI 10.1021/jp980445y PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZY136 UT WOS:000074589900012 ER PT J AU Baboul, AG Schlegel, HB AF Baboul, AG Schlegel, HB TI Structures and energetics of some potential intermediates in titanium nitride chemical vapor deposition: TiClm(NH2)(n), TiClm(NH2)(n)NH, and TiClm(NH2)(n)N. An ab initio molecular orbital study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID QUADRATIC CONFIGURATION-INTERACTION; DENSITY-FUNCTIONAL THEORY; VIBRATIONAL FREQUENCIES; THIN-FILMS; INFRARED-SPECTRA; IMIDO COMPLEXES; TIN; ENERGIES; EXCHANGE AB The various potential intermediates in the chemical vapor deposition production of TiN films have been studied using a variant of the G2 level of theory. The structures of TiClm(NH2)(n), 0 less than or equal to m + n less than or equal to 4, TiClm(NH2)(n)NH, 0 less than or equal to m + n less than or equal to 2, and TiClm(NH2)(n)N, 0 less than or equal to m + n less than or equal to 1, were optimized at B3LYP level of theory with the Wachters-Hay basis set for Ti and the 6-311G(d) basis set for H, N, and Cl. The energies were calculated at the MP4 and QCI levels with these basis sets augmented by multiple sets of polarization and diffuse functions using the B3LYP optimized geometries. Bond dissociation energies, heals of atomization, heats of formation, and entropies have been calculated at this modified G2 level of theory. C1 Wayne State Univ, Dept Chem, Detroit, MI 48202 USA. RP Schlegel, HB (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 40 TC 18 Z9 18 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 25 PY 1998 VL 102 IS 26 BP 5152 EP 5157 DI 10.1021/jp9810668 PG 6 WC Chemistry, Physical SC Chemistry GA ZY137 UT WOS:000074590000021 ER PT J AU Piskoti, C Yarger, J Zettl, A AF Piskoti, C Yarger, J Zettl, A TI C-36, a new carbon solid SO NATURE LA English DT Article ID C-60; BUCKMINSTERFULLERENE AB Under appropriate non-equilibrium growth conditions, carbon atoms form relatively stable hollow clusters of well-defined mass number(1), collectively known as fullerenes. The mass production, purification and condensation of such dusters into a molecular solid is generally essential to full experimental characterization: the initial discovery(2) of C-60, for example, had to await a bulk synthesis method(3) six years later before detailed characterization of the molecule was possible. Gas-phase experiments(1,4,5) have indicated the existence of a wide range of fullerene clusters, but beyond Cs, only a few pure fullerene solids have been obtained(6), most notably C-70. Low-mass fullerenes are of particular interest because their high curvature and increased strain energy owing to adjacent pentagonal rings could lead to solids with unusual intermolecular bonding and electronic properties. Here we report the synthesis of the solid form of C-36 by the are-discharge method(3). We have developed purification methods that separate C-36 from amorphous carbon and other fullerenes, to yield saturated solutions, thin films and polycrystalline powders of the pure solid form. Solid-state NMR measurements suggest that the molecule has D-6h symmetry, and electron-diffraction patterns are consistent with a tightly bound molecular solid with an intermolecular spacing of 6.6 Angstrom. We observe large increases in the electrical conductivity of the solid on doping with alkali metals. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Zettl, A (reprint author), Univ Calif Berkeley, Dept Phys, 366 LeConte Hall, Berkeley, CA 94720 USA. RI Yarger, Jeff/L-8748-2014; Zettl, Alex/O-4925-2016 OI Yarger, Jeff/0000-0002-7385-5400; Zettl, Alex/0000-0001-6330-136X NR 12 TC 354 Z9 366 U1 2 U2 33 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUN 25 PY 1998 VL 393 IS 6687 BP 771 EP 774 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZW652 UT WOS:000074433100044 ER PT J AU Vogt, R AF Vogt, R TI psi suppression in Pb+Pb collisions: a new look at hadrons vs. plasma SO PHYSICS LETTERS B LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; QUARK-GLUON PLASMA; J/PSI-SUPPRESSION; GAUGE-THEORY AB A reexamination of hadronic comover scattering indicates that this mechanism cannot explain the observed psi suppression in Pb + Pb interactions. The possibility of quark-gluon plasma formation is therefore considered. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Vogt, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 48 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 25 PY 1998 VL 430 IS 1-2 BP 15 EP 22 DI 10.1016/S0370-2693(98)00486-9 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 102XZ UT WOS:000074952700003 ER PT J AU Aharony, O Oz, Y Yin, Z AF Aharony, O Oz, Y Yin, Z TI M theory on AdS(p)xS(11-p) and superconformal field theories SO PHYSICS LETTERS B LA English DT Article ID SUPERGRAVITY AB We study the large N limit of the interacting superconformal field theories associated with N M5 branes or M2 branes using the recently proposed relation between these theories and M theory on AdS spaces. We first analyze the spectrum of chiral operators of the 6d (0,2) theory associated with M5 branes in flat space, and find full agreement with earlier results obtained using its DLCQ description as quantum mechanics on a moduli space of instantons. We then perform a similar analysis for the D-N type 6d (0,2) theories associated with M5 branes at an R-5/Z(2) singularity, and for the 3d N = 8 superconformal field theories associated with M2 branes in flat space and at an R-8/Z(2) singularity respectively. Little is known about these three theories, and our study yields for the first time their spectrum of chiral operators (in the large N limit). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08855 USA. Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Aharony, O (reprint author), Rutgers State Univ, Dept Phys & Astron, POB 849, Piscataway, NJ 08855 USA. NR 36 TC 67 Z9 67 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 25 PY 1998 VL 430 IS 1-2 BP 87 EP 93 DI 10.1016/S0370-2693(98)00508-5 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 102XZ UT WOS:000074952700014 ER PT J AU Bettencourt, LMA Wetterich, C AF Bettencourt, LMA Wetterich, C TI Time evolution of correlation functions in non-equilibrium field theories SO PHYSICS LETTERS B LA English DT Article AB We investigate the non-equilibrium propel-ties of an N-component scalar field theory. The time evolution of the equal-time correlation functions for an arbitrary ensemble of initial conditions is described by an exact functional differential equation. In leading order in the 1/N expansion the system can be understood in terms of infinitely many conserved quantities. They forbid the approach to the canonical thermal distribution. Beyond leading order only energy conservation is apparent generically. Nevertheless, we find a large manifold of stationary distributions both for classical and quantum fields. They are the fixed points of the evolution equation. For small deviations of the correlation functions from a large range of fixed points we observe stable oscillations. These results raise the question of if and in what sense the particular fixed point corresponding to thermal equilibrium dominates the large time behavior of the system. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Heidelberg, Inst Theoret Phys, D-69120 Heidelberg, Germany. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bettencourt, LMA (reprint author), Univ Heidelberg, Inst Theoret Phys, Philosophenweg 16, D-69120 Heidelberg, Germany. RI Wetterich, Christof/J-6995-2016 OI Wetterich, Christof/0000-0002-2563-9826 NR 12 TC 32 Z9 32 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 JUN 25 PY 1998 VL 430 IS 1-2 BP 140 EP 150 DI 10.1016/S0370-2693(98)00509-7 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 102XZ UT WOS:000074952700021 ER PT J AU Wang, AW Kiwan, R White, RM Ceriani, RL AF Wang, AW Kiwan, R White, RM Ceriani, RL TI A silicon-based ultrasonic immunoassay for detection of breast cancer antigens SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT 9th International Conference on Solid-State Sensors and Actuators CY JUN 16-19, 1997 CL CHICAGO, ILLINOIS SP IEEE Electron Devices Soc DE acoustic; agitation; biosensor; gravimetric; immunosensor ID IMMOBILIZATION; PROTEIN; ASSAY AB The authors report on a silicon-based immunosensor package that has direct application to the diagnostic detection of a breast cancer antigen in the sera of breast cancer patients. The authors couple the flexural plate wave (FPW) gravimetric sensor (S.W. WenzeI, R.M. White, IEEE Trans. Electron Devices 35 (1988) 735-743) with a novel mass-amplifying label that increases sensor signal level (a shift of resonant frequency) from that of previous acoustic immunoassays, in which frequency shifts were due solely to the weight of the immunoglobulins. The use of a gravimetric immunoassay with a mass-amplifying label provides an alternative to radioimmunoassay, eliminating the need for radioactive labels that require costly disposal. In addition to gravimetric sensing, the FPW device is also capable of providing a source of ultrasonic agitation, which results in localized mixing near the active immunoglobulin binding area of the device. The authors have observed increased antibody binding using ultrasonic agitation during immunoglobulin incubation periods. Consequently, with ultrasonic agitation, the authors are able to reduce the length of time necessary to complete the immunoassay and also affect the amount of antibody binding. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Berkeley Sensor & Actuator Ctr, Berkeley, CA 94720 USA. Canc Res Fund Contra Costa, Walnut Creek, CA USA. RP Wang, AW (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave L-222, Livermore, CA 94550 USA. NR 16 TC 31 Z9 31 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD JUN 25 PY 1998 VL 49 IS 1-2 BP 13 EP 21 DI 10.1016/S0925-4005(98)00127-0 PG 9 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 115FG UT WOS:000075652400003 ER PT J AU Chason, E Sinclair, MB Floro, JA Hunter, JA Hwang, RQ AF Chason, E Sinclair, MB Floro, JA Hunter, JA Hwang, RQ TI Spectroscopic light scattering for real-time measurements of thin film and surface evolution SO APPLIED PHYSICS LETTERS LA English DT Article ID MICROSCOPY; ROUGHNESS; GROWTH AB We describe a light scattering technique for measuring the real-time evolution of thin film and surface morphology. By using spectroscopic detection, the technique requires no motion of the sample during the measurement, which makes it compatible with many processing geometries. Results from the growth of strained heteroepitaxial layers of SixGe1-x on Si(001) are presented to demonstrate the technique. (C) 1998 American Institute of Physics. [S0003-6951(98)04325-3]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chason, E (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 30 Z9 30 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 22 PY 1998 VL 72 IS 25 BP 3276 EP 3278 DI 10.1063/1.121622 PG 3 WC Physics, Applied SC Physics GA 108PJ UT WOS:000075274400012 ER PT J AU Merkulov, VI Fox, JR Li, HC Si, WD Sirenko, AA Xi, XX AF Merkulov, VI Fox, JR Li, HC Si, WD Sirenko, AA Xi, XX TI Metal-oxide bilayer Raman scattering in SrTiO3 thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; SPECTRA AB We have used a metal-oxide bilayer Raman scattering technique to study lattice dynamics in SrTiO3 thin films. The SrTiO3 thin films were epitaxially grown on a conducting metal-oxide layer which reflects the exciting laser beam so that it does not enter the LaAlO3 substrate. Raman scattering from the SrTiO3 thin films was clearly observed, including the first-order Raman peaks forbidden by the cubic symmetry in single crystals. We suggest that strain exists in the films, which changes the crystal symmetry and will affect the dielectric properties of the SrTiO3 thin films. (C) 1998 American Institute of Physics. [S0003-6951(98)02725-9]. C1 Chinese Acad Sci, Inst Phys, Natl Lab Superconduct, Beijing 100080, Peoples R China. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. RP Merkulov, VI (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 28 Z9 28 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 22 PY 1998 VL 72 IS 25 BP 3291 EP 3293 DI 10.1063/1.121627 PG 3 WC Physics, Applied SC Physics GA 108PJ UT WOS:000075274400017 ER PT J AU Grant, PM AF Grant, PM TI Response to letters to the editor of Forensic Science International SO FORENSIC SCIENCE INTERNATIONAL LA English DT Letter C1 Univ Calif Lawrence Livermore Natl Lab, Forens Sci Ctr, Livermore, CA 94550 USA. RP Grant, PM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Forens Sci Ctr, Livermore, CA 94550 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0379-0738 J9 FORENSIC SCI INT JI Forensic Sci.Int. PD JUN 22 PY 1998 VL 94 IS 3 BP 223 EP 230 PG 8 WC Medicine, Legal SC Legal Medicine GA 103ZL UT WOS:000074987700008 ER PT J AU Glaesemann, KR Gordon, MS AF Glaesemann, KR Gordon, MS TI Investigation of a grid-free density functional theory (DFT) approach SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EFFICIENT RECURSIVE COMPUTATION; CORRELATION-ENERGY; BASIS-SETS; HARTREE-FOCK; MOLECULAR CALCULATIONS; EXACT-EXCHANGE; ATOMS; REPRESENTATION; APPROXIMATIONS; OPTIMIZATION AB Density functional theory (DFT) has gained popularity, because it can frequently give accurate energies and geometries. Because evaluating DFT integrals fully analytically is usually impossible, most implementations use numerical quadrature over grid points, which can lead to numerical instabilities. To avoid these instabilities, the Almlof-Zheng (AZ) grid-free approach was developed. This approach involves application of the resolution of the identity (RI) to evaluate the integrals. The focus of the current work is on the implementation of the AZ approach into the electronic structure code GAMESS, and on the convergence of the resolution of the identity with respect to basis set in the grid-free approach. Both single point energies and gradients are calculated for a variety of functionals and molecules. Conventional atomic basis sets are found to be inadequate for fitting the RI, particularly for gradient corrected functionals. Further work on developing auxiliary basis set approaches is warranted. (C) 1998 American Institute of Physics.. C1 Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Glaesemann, KR (reprint author), Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RI Glaesemann, Kurt/B-4841-2010; OI Glaesemann, Kurt/0000-0002-9512-1395 NR 68 TC 18 Z9 18 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 1998 VL 108 IS 24 BP 9959 EP 9969 DI 10.1063/1.476494 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FV UT WOS:000075256200001 ER PT J AU Taylor, TR Xu, CS Neumark, DM AF Taylor, TR Xu, CS Neumark, DM TI Photoelectron spectra of the C2nH- (n=1-4) and C2nD- (n=1-3) anions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID ELECTRONIC ABSORPTION-SPECTRA; LASER KINETIC SPECTROSCOPY; LINEAR CARBON CHAINS; MULTIREFERENCE CONFIGURATION-INTERACTION; THRESHOLD PHOTODETACHMENT SPECTROSCOPY; HIGHLY UNSATURATED-HYDROCARBONS; DIFFUSE INTERSTELLAR BANDS; RADICAL V3 BAND; AB-INITIO; INDUCED FLUORESCENCE AB Anion photoelectron spectra of the carbon monohydrides, C2nH- for n = 1 - 4 and C2nD- for n = 1 - 3, have been measured. The spectra were recorded at a wavelength of 266 nm (4.657 eV) and yield electron affinities for each species. The spectra are vibrationally resolved, and some of the vibrational modes in the neutral C2nH(D) radicals are assigned. In addition, photoelectron angular distributions allow one to distinguish between photodetachment transitions to the (2)Sigma(+) and (II)-I-2 states of the neutrals. The spectra confirm previous work showing that C2H and C4H have (2)Sigma(+) ground states, while C6H and C8H have (II)-I-2 ground states. In addition, we observe the low-lying (II)-I-2 or (2)Sigma(+) excited states for all four radicals. The photoelectron angular distributions also serve as a probe of vibronic coupling between the (2)Sigma(+) and (II)-I-2 states. These effects are particularly prominent in the C2H- and C4H- spectra. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Taylor, TR (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 103 TC 89 Z9 89 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 22 PY 1998 VL 108 IS 24 BP 10018 EP 10026 DI 10.1063/1.476462 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FV UT WOS:000075256200008 ER PT J AU Mielke, CH Harrison, N Lacerda, AH Bud'ko, SA Canfield, PC AF Mielke, CH Harrison, N Lacerda, AH Bud'ko, SA Canfield, PC TI High magnetic field investigation of the Fermi surface of the pnictinide compound SmSb2 SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article AB The Fermi surface of the pnictinide compound SmSb2 has been studied by means of the Shubnikov-de Haas and de Haas-van Alphen quantum oscillatory effects in pulsed magnetic fields to 60 T. Spectral analysis of the magnetoresistance and magnetization shows several closed-pocket regions of the Fermi surface. Closed pockets of 65, 190, 700, and 760 T are determined to account for the Fermi surface. The respective effective masses were found to be of the order of the free electron mass. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Mielke, CH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Canfield, Paul/H-2698-2014; Mielke, Charles/S-6827-2016 OI Mielke, Charles/0000-0002-2096-5411 NR 10 TC 5 Z9 5 U1 6 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 22 PY 1998 VL 10 IS 24 BP 5289 EP 5294 DI 10.1088/0953-8984/10/24/007 PG 6 WC Physics, Condensed Matter SC Physics GA ZX652 UT WOS:000074540300007 ER PT J AU Arnold, R Augier, C Baker, J Barabash, A Blum, D Brudanin, V Caffrey, AJ Campagne, JE Caurier, E Dassie, D Egorov, V Eschbach, R Filipova, T Gurriaran, R Guyonnet, JL Hubert, F Hubert, P Jullian, S Kisel, I Kochetov, O Kornoukhov, VN Kovalenko, V Lalanne, D Laplanche, F Leccia, F Linck, I Longuemare, C Marquet, C Mauger, F Mennrath, P Nicholson, HW Pilugin, I Piquemal, F Purtov, O Reyss, JL Sarazin, X Scheibling, F Suhonen, J Sutton, CS Szklarz, G Timkin, V Torres, R Tretyak, VI Umatov, V Vanyushin, I Vareille, A Vasilyev, Y Vylov, T Zerkin, V AF Arnold, R Augier, C Baker, J Barabash, A Blum, D Brudanin, V Caffrey, AJ Campagne, JE Caurier, E Dassie, D Egorov, V Eschbach, R Filipova, T Gurriaran, R Guyonnet, JL Hubert, F Hubert, P Jullian, S Kisel, I Kochetov, O Kornoukhov, VN Kovalenko, V Lalanne, D Laplanche, F Leccia, F Linck, I Longuemare, C Marquet, C Mauger, F Mennrath, P Nicholson, HW Pilugin, I Piquemal, F Purtov, O Reyss, JL Sarazin, X Scheibling, F Suhonen, J Sutton, CS Szklarz, G Timkin, V Torres, R Tretyak, VI Umatov, V Vanyushin, I Vareille, A Vasilyev, Y Vylov, T Zerkin, V CA NEMO Collaboration TI Double-beta decay of Se-82 SO NUCLEAR PHYSICS A LA English DT Article DE RADIOACTIVITY Se-82(2 beta); measured 2 nu associated 2 beta decay T-1/2, O nu associated 2 beta decay T-1/2 lower limits ID MAJORON EMISSION; HALF-LIVES; TE-130; DETECTOR; XE-136; STATES; MODEL; GE-76 AB The NEMO-2 tracking detector located in the Frejus Underground Laboratory was designed as a prototype of the NEMO-3 detector to study neutrinoless (Ov) and two neutrino (2v) double-beta decay (PP) physics. After 10357 h of running with an isotopically enriched selenium source (2.17 mol yr of Se-82) a beta beta 2v decay half-life of T-1/2 = (0.83 +/- 0.10 (stat) +/- 0.07 (syst)) x 10(20) yr was measured. Limits with a 90% C.L. on the Se-82 half-lives of 9.5 x 10(21) yr for beta beta Ov decay to the ground state, 2.8 x 10(21) yr to the (2(+)) excited state and 2.4 x 10(21) yr for beta beta Ov chi(0) decay with a Majoron (chi(0)) were also obtained. (C) 1998 Elsevier Science B.V. C1 CNRS, IN2P3, CENBG, F-33170 Gradignan, France. Univ Bordeaux, F-33170 Gradignan, France. Univ Caen, F-14032 Caen, France. CNRS, IN2P3, LPC, F-14032 Caen, France. Joint Inst Nucl Res, Dubna 141980, Russia. CNRS, CFR, F-91190 Gif Sur Yvette, France. INEL, Idaho Falls, ID 83415 USA. Univ Jyvaskyla, Jyvaskyla 40351, Finland. ITEP, UA-252028 Kiev, Ukraine. Univ Paris Sud, F-91405 Orsay, France. CNRS, IN2P3, LAL, F-91405 Orsay, France. MHC, S Hadley, MA 01075 USA. Univ Strasbourg 1, F-67037 Strasbourg, France. CNRS, IN2P3, IReS, F-67037 Strasbourg, France. RP Laplanche, F (reprint author), CNRS, IN2P3, CENBG, F-33170 Gradignan, France. EM laplanch@lal.in2p3.fr RI Caffrey, Augustine/C-2005-2009; Barabash, Alexander/S-8851-2016 NR 38 TC 80 Z9 81 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 22 PY 1998 VL 636 IS 2 BP 209 EP 223 DI 10.1016/S0375-9474(98)00208-5 PG 15 WC Physics, Nuclear SC Physics GA ZX480 UT WOS:000074520300006 ER PT J AU Csoto, A Langanke, K AF Csoto, A Langanke, K TI Effects of B-8 size on the low-energy Be-7(p,gamma)B-8 cross section SO NUCLEAR PHYSICS A LA English DT Article DE Be-7(p,gamma)B-8; radiative capture; solar neutrinos; astrophysical S factor ID BE-7; NUCLEI; MODEL; RADII; HALO AB We calculate several "size-like" B-8 observables within the microscopic three-cluster model and study their potential constraints on the zero-energy astrophysical S-17(0) factor of the Be-7(p,gamma)B-8 reaction. We find within our three-cluster model that a simultaneous reproduction of the experimental data for the B-8 radius and quadrupole moment and of the B-8-Li-8 Coulomb displacement energy implies S-17(0) = (23-25) eV b. (C) 1998 Elsevier Science B.V. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus, Denmark. Aarhus Univ, Ctr Theoret Astrophys, DK-8000 Aarhus, Denmark. Eotvos Lorand Univ, Dept Atom Phys, H-1088 Budapest, Hungary. RP Csoto, A (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 31 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 22 PY 1998 VL 636 IS 2 BP 240 EP 246 DI 10.1016/S0375-9474(98)00200-0 PG 7 WC Physics, Nuclear SC Physics GA ZX480 UT WOS:000074520300008 ER PT J AU Pietsch, MA Russo, TV Murphy, RB Martin, RL Rappe, AK AF Pietsch, MA Russo, TV Murphy, RB Martin, RL Rappe, AK TI LReO3 epoxidizes, cis-dihydroxylates, and cleaves alkenes as well as alkenylates aldehydes: Toward an understanding of why SO ORGANOMETALLICS LA English DT Article ID EFFECTIVE CORE POTENTIALS; OLEFINS; TRIOXORHENIUM; EPOXIDATION; MECHANISM; CHLORIDE AB The relative reaction thermodynamics for the probable pathways leading to alkene epoxidation, cis-dihydroxylation, and C-C cleavage as well as alkenylation of aldehydes have been investigated for the reaction of ethylene with LReO3, L = CH3, Cl, OH, OCH3, O-, C5H5(Cp), and C-5(CH3)(5) (Cp*) We find the reaction pathway exothermicities to be quite sensitive to the ligand. For ClReO3, CH3ReO3, HOReO3, CH3OReO3, and O-ReO3, reaction with ethylene is endothermic with metallaoxetane preferred over dioxylate formation. For CpReO3 and Cp*ReO3, the reaction with ethylene is exothermic but nearly thermoneutral with dioxylate formation preferred. The pi-binding attributes of the ligand are found to correlate with thermodynamic preference. C1 Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Schrodinger Inc, Portland, OR 97204 USA. RP Rappe, AK (reprint author), Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. NR 30 TC 44 Z9 44 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 EI 1520-6041 J9 ORGANOMETALLICS JI Organometallics PD JUN 22 PY 1998 VL 17 IS 13 BP 2716 EP 2719 DI 10.1021/om9800501 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZW792 UT WOS:000074448800009 ER PT J AU Yates, A Zurek, WH AF Yates, A Zurek, WH TI Vortex formation in two dimensions: When symmetry breaks, how big are the pieces? SO PHYSICAL REVIEW LETTERS LA English DT Article ID COSMOLOGICAL EXPERIMENTS; LIQUID-CRYSTALS; COSMIC STRINGS AB We investigate the dynamics of second-order phase transitions in two dimensions, breaking a gauged U(1) symmetry. Using numerical simulations, we show that the density of the topological defects formed scales with the quench time scale tau(Q) as n similar to tau(Q)(-1/2) when the dynamics is overdamped at the instant when the freeze-out of thermal fluctuations takes place, and n similar to tau(Q)(-2/3) in the underdamped case. This is predicted by the scenario proposed by one of us (W. H. Z.). C1 Los Alamos Natl Lab, Los Alamos, NM 87455 USA. Univ Geneva, Dept Theoret Phys, CH-1211 Geneva 4, Switzerland. RP Yates, A (reprint author), Los Alamos Natl Lab, MS B-288, Los Alamos, NM 87455 USA. NR 18 TC 84 Z9 84 U1 2 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5477 EP 5480 DI 10.1103/PhysRevLett.80.5477 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000005 ER PT J AU Eichten, E Lane, K Womersley, J AF Eichten, E Lane, K Womersley, J TI Narrow technihadron production at the first muon collider SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOPCOLOR-ASSISTED TECHNICOLOR; CHIRAL HIERARCHIES; SCALE; HYPERCOLOR; SIGNATURES; BREAKING AB In modern technicolor models, there exist very narrow spin-zero and spin-one neutral technihadrons - pi(T)(0),( )rho(T)(0), and omega(T )- with masses of a few 100 GeV. The large coupling of pi(T)(0 )mu(+)mu(-), the direct coupling of rho(T)(0) and omega(T) to the photon and Z(0), and the superb energy resolution of the First Muon Collider may make it possible to resolve these technihadrons and produce them at extraordinarily large rates. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. RP Eichten, E (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. 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 JUN 22 PY 1998 VL 80 IS 25 BP 5489 EP 5492 DI 10.1103/PhysRevLett.80.5489 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000008 ER PT J AU Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C AF Athanas, M Avery, P Jones, CD Lohner, M Patton, S Prescott, C Yelton, J Zheng, J Brandenburg, G Briere, RA Ershov, A Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Kotov, S Kravchenko, I Kwak, N Zhou, L Anderson, S Kubota, Y Lee, SJ O'Neill, JJ Poling, R Riehle, T Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Timm, S Wappler, F Anastassov, A Duboscq, JE Fujino, D Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Glenn, S Kwon, Y Lyon, AL Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Savinov, V Ugolini, D Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Azfar, F Efimov, A Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Schuh, S Skwarnicki, T Stone, S Viehhauser, G Wang, JC Xing, X Bartelt, J Csorna, SE Jain, V McLean, KW Marka, S Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Zhou, GJ Chadha, M Chan, S Eigen, G Miller, JS Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Bliss, DW Masek, G Paar, HP Prell, S Sharma, V Asner, DM Gronberg, J Hill, TS Lange, DJ Morrison, RJ Nelson, HN Nelson, TK Roberts, D Behrens, BH Ford, WT Gritsan, A Roy, J Smith, JG Alexander, JP Baker, R Bebek, C Berger, BE Berkelman, K Bloom, K Boisvert, V Cassel, DG Crowcroft, DS Dickson, M von Dombrowski, S Drell, PS Ecklund, KM Ehrlich, R Foland, AD Gaidarev, P Gibbons, L Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Kandaswamy, J Kim, PC Kreinick, DL Lee, T Liu, Y Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Valant-Spaight, B Ward, C CA CLEO Collaboration TI First observation of the Cabibbo suppressed decay B+->(D)over-bar(0)K(+) SO PHYSICAL REVIEW LETTERS LA English DT Article ID CP-VIOLATION; B-DECAY AB We have observed the decay B+ --> (D) over bar(0)K(+), using 3.3 x 10(6) pairs collected with the CLEO II detector at the Cornell Electron Storage Ring. We find the ratio of branching fractions R = B(B+ --> (D) over bar(0)K(+))/B(B+ --> (D) over bar(0)pi(+)) = 0.055 +/- 0.014 +/- 0.005. C1 Univ Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. Univ Minnesota, Minneapolis, MN 55455 USA. SUNY Albany, Albany, NY 12222 USA. Ohio State Univ, Columbus, OH 43210 USA. Univ Oklahoma, Norman, OK 73019 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. So Methodist Univ, Dallas, TX 75275 USA. Syracuse Univ, Syracuse, NY 13244 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. Wayne State Univ, Detroit, MI 48202 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Colorado, Boulder, CO 80309 USA. Cornell Univ, Ithaca, NY 14853 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. BINP, RU-630090 Novosibirsk, Russia. Yonsei Univ, Seoul 120749, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Texas, Austin, TX 78712 USA. RP Athanas, M (reprint author), Univ Florida, Gainesville, FL 32611 USA. RI Briere, Roy/N-7819-2014 OI Briere, Roy/0000-0001-5229-1039 NR 13 TC 32 Z9 32 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5493 EP 5497 DI 10.1103/PhysRevLett.80.5493 PG 5 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000009 ER PT J AU Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amos, N Anderson, EW Astur, R Baarmand, MM Babukhadia, L Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Glenn, S Gobbi, B Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmanov, D Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klima, B Klopfenstein, C Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kuleshov, S Kunori, S Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oliveira, E Oltman, E Oshima, N Owen, D Padley, P Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pishalnikov, Y Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sosebee, M Sotnikova, N Souza, M Spadafora, AL Steinbruck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhou, Z Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amos, N Anderson, EW Astur, R Baarmand, MM Babukhadia, L Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Barberis, E Bartlett, JF Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Coney, L Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, MK Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Gavrilov, V Geld, TL Genik, RJ Genser, K Gerber, CE Gershtein, Y Gibbard, B Glenn, S Gobbi, B Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Greenlee, H Grinstein, S Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, G Gutierrez, P Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Karmanov, D Karmgard, D Kehoe, R Kelly, ML Kim, CL Kim, SK Klima, B Klopfenstein, C Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovsky, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kuleshov, S Kunori, S Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Manankov, V Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Norman, D Oesch, L Oguri, V Oliveira, E Oltman, E Oshima, N Owen, D Padley, P Para, A Park, YM Partridge, R Parua, N Paterno, M Pawlik, B Perkins, J Peters, M Piegaia, R Piekarz, H Pishalnikov, Y Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roco, M Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, E Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sosebee, M Sotnikova, N Souza, M Spadafora, AL Steinbruck, G Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoker, D Stolin, V Stoyanova, DA Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhou, Z Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A CA DO Collaboration TI Measurement of the shape of the transverse momentum distribution of W bosons produced in p(p)over-bar collisions at root s=1.8TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID TO-BACK JETS; = 1.8 TEV; PARTON DISTRIBUTIONS; PBARP COLLISIONS; SQUARE; QCD AB The shape of the transverse momentum distribution of W bosons (p(T)(W)) produced in collisions at root s = 1.8 TeV is measured with the DO detector at Fermilab. The result is compared with QCD perturbative and resummation calculations over the p(T)(W) range from 0 to 200 GeV/c. The shape of the distribution is consistent with the theoretical prediction. C1 NYU, New York, NY 10003 USA. Univ Los Andes, Bogota, Colombia. Univ Arizona, Tucson, AZ 85721 USA. Boston Univ, Boston, MA 02215 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Brown Univ, Providence, RI 02912 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 14000, DF, Mexico. Columbia Univ, New York, NY 10027 USA. Univ Delhi, Delhi 110007, India. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60607 USA. Indiana Univ, Bloomington, IN 47405 USA. Iowa State Univ, Ames, IA 50011 USA. Korea Univ, Seoul 136701, South Korea. Kyungsung Univ, Pusan 608736, South Korea. Inst Nucl Phys, Krakow, Poland. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Inst Theoret & Expt Phys, Moscow 117259, Russia. Moscow MV Lomonosov State Univ, Moscow, Russia. Univ Nebraska, Lincoln, NE 68588 USA. Northeastern Univ, Boston, MA 02115 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Univ Oklahoma, Norman, OK 73019 USA. Panjab Univ, Chandigarh 160014, India. Protvino High Energy Phys Inst, Protvino 142284, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77005 USA. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Univ Rochester, Rochester, NY 14627 USA. Ctr Etud Saclay, CEA, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France. Seoul Natl Univ, Seoul, South Korea. SUNY Stony Brook, Stony Brook, NY 11794 USA. Tata Inst Fundamental Res, Mumbai 400005, India. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Gutierrez, Phillip/C-1161-2011; Leflat, Alexander/D-7284-2012; Dudko, Lev/D-7127-2012; Merkin, Mikhail/D-6809-2012; Kuleshov, Sergey/D-9940-2013; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016 OI Dudko, Lev/0000-0002-4462-3192; Kuleshov, Sergey/0000-0002-3065-326X; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Aihara, Hiroaki/0000-0002-1907-5964; Sznajder, Andre/0000-0001-6998-1108 NR 24 TC 25 Z9 25 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5498 EP 5503 DI 10.1103/PhysRevLett.80.5498 PG 6 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000010 ER PT J AU Gormezano, C Baranov, YF Challis, CD Coffey, I Cottrell, GA Ekedahl, AC Greenfield, CM Howman, AC Huysmans, GTA Keilhacker, M Litaudon, X Luce, TC Rice, BW Rochard, F Sadler, GJ Schild, PAJ Sips, ACC Soldner, FX Strait, EJ Tubbing, BJD Wade, MR Ward, DJ AF Gormezano, C Baranov, YF Challis, CD Coffey, I Cottrell, GA Ekedahl, AC Greenfield, CM Howman, AC Huysmans, GTA Keilhacker, M Litaudon, X Luce, TC Rice, BW Rochard, F Sadler, GJ Schild, PAJ Sips, ACC Soldner, FX Strait, EJ Tubbing, BJD Wade, MR Ward, DJ TI Internal transport barriers in JET deuterium-tritium plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID REVERSED MAGNETIC SHEAR; CONFINEMENT AB The observation of internal transport barriers (ITBs) in which ion thermal diffusivity is reduced to a neoclassical level has been made for the first time in tokamak plasmas fueled with deuterium and tritium ions using a broad current density profile. The heating and current profiles required to obtain an ITB are similar in D-T and D-D plasmas. Central ion temperatures of 40 keV and plasma pressure gradients of 10(6) Pa/m were observed in a D-T plasma, leading to a fusion triple product n(i)T(i)tau(E) = 1.10(21) m(-3) keVs and 8.2 MW of fusion power. There is potential for further optimization as a step towards the development of efficient tokamak fusion reactors. C1 Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. Gen Atom Co, San Diego, CA 92186 USA. CEA, Cadarache, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gormezano, C (reprint author), Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. NR 11 TC 102 Z9 102 U1 3 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5544 EP 5547 DI 10.1103/PhysRevLett.80.5544 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000021 ER PT J AU Thomas, PR Andrew, P Balet, B Bartlett, D Bull, J de Esch, B Gibson, A Gowers, C Guo, H Huysmans, G Jones, T Keilhacker, M Koenig, R Lennholm, M Lomas, P Maas, A Marcus, F Nave, F Parail, V Rimini, F Strachan, J Zastrow, KD Zornig, N AF Thomas, PR Andrew, P Balet, B Bartlett, D Bull, J de Esch, B Gibson, A Gowers, C Guo, H Huysmans, G Jones, T Keilhacker, M Koenig, R Lennholm, M Lomas, P Maas, A Marcus, F Nave, F Parail, V Rimini, F Strachan, J Zastrow, KD Zornig, N TI Observation of alpha heating in JET DT plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOKAMAK AB An experiment at the Joint European Torus (JET) has demonstrated clear self-heating of a deuterium-tritium plasma by alpha particles produced in fusion reactions. The alpha heating was identified by scanning the plasma and neutral beam mixtures together from pure deuterium to nearly pure tritium in a 10.5 MW hot ion H mode. At an optimum mixture of (60 +/- 20)% T, the fusion gain (= P-fusion/P-absorbed) was 0.65 and the alpha heating showed clearly as a maximum in electron temperature. The change in temperature produced by alpha heating was T-e(0) = 1.3 +/- 0.23 keV in 12.2 keV. The effect of the heating could also be seen in the ion temperature and energy content. C1 Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. EURATOM, IST, P-1096 Lisbon, Portugal. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Thomas, PR (reprint author), Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. RI Nave, Maria/A-5581-2013 OI Nave, Maria/0000-0003-2078-6584 NR 9 TC 84 Z9 84 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5548 EP 5551 DI 10.1103/PhysRevLett.80.5548 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000022 ER PT J AU Grigorian, L Williams, KA Fang, S Sumanasekera, GU Loper, AL Dickey, EC Pennycook, SJ Eklund, PC AF Grigorian, L Williams, KA Fang, S Sumanasekera, GU Loper, AL Dickey, EC Pennycook, SJ Eklund, PC TI Reversible intercalation of charged iodine chains into carbon nanotube ropes SO PHYSICAL REVIEW LETTERS LA English DT Article AB We report intercalation of charged polyiodide chains into the interstitial channels in a single-wall carbon nanotube (SWNT) rope lattice, suggesting a new carbon chemistry for nanotubes, distinctly different from that of graphite and C-60. This structural model is supported by results from Raman spectroscopy, x-ray diffraction, Z-contrast electron microscopy, and electrical transport data. Iodine-doped SWNTs are found to be air stable, permitting the use of a variety of techniques to explore the effect of charge transfer on the physical properties of these novel quantum wires. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Kentucky, Ctr Appl Energy Res, Lexington, KY 40511 USA. Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Grigorian, L (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RI Dickey, Elizabeth/A-3368-2011 OI Dickey, Elizabeth/0000-0003-4005-7872 NR 23 TC 214 Z9 216 U1 4 U2 31 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5560 EP 5563 DI 10.1103/PhysRevLett.80.5560 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000025 ER PT J AU Schwoerer-Bohning, M Macrander, AT Arms, DA AF Schwoerer-Bohning, M Macrander, AT Arms, DA TI Phonon dispersion of diamond measured by inelastic x-ray scattering SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; 2-PHONON SPECTRUM; LATTICE-DYNAMICS; RAMAN-SPECTRUM; FREQUENCIES AB We report on a study of phonons in diamond using a new instrument for high resolution inelastic x-ray scattering at the Advanced Photon Source. We have paid particular attention to possible overbending of the most energetic branches, i.e., LO along both Gamma - X (= Delta) and Gamma - L (= Lambda) and the elliptically polarized Sigma(3) branch along Gamma - K (= Sigma). Overbending along all three directions has been invoked in recent years to explain a famous and extraordinary peak in the two-phonon Raman spectrum. Our data reveal overbending only along Delta. C1 Argonne Natl Lab, Adv Photon Source, Expt Facil Div, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. RP Schwoerer-Bohning, M (reprint author), Argonne Natl Lab, Adv Photon Source, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM schwoere@aps.anl.gov NR 24 TC 62 Z9 62 U1 2 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 JUN 22 PY 1998 VL 80 IS 25 BP 5572 EP 5575 DI 10.1103/PhysRevLett.80.5572 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000028 ER PT J AU Verdozzi, C Jennison, DR Schultz, PA Sears, MP Barbour, JC Potter, BG AF Verdozzi, C Jennison, DR Schultz, PA Sears, MP Barbour, JC Potter, BG TI Unusual structural relaxation for rare-earth impurities in sapphire: Ab initio study of lanthanum SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; CORUNDUM; PSEUDOPOTENTIALS; ALPHA-AL2O3; SIMULATION; ALUMINA; STATES; MODEL AB A first-principles density-functional local density approximation study of substitutional La, using 120-atom supercells of alpha-Al2 O3, shows that La assumes a highly displaced position, moving over 0.5 Angstrom from the original Al site. The La-O nearest neighbor distance is much smaller than the sum of standard La+3 and O-2 ionic radii. This is due to La being more ionic than in its own oxide, and to the role of the 5d shell, as the electron density within the displaced La is quite anisotropic. We discuss the implications for a systematic description of rare-earth ions implanted in sapphire. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Liverpool, IRCSS, Liverpool L69 3BX, Merseyside, England. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM drjenni@sandia.gov NR 35 TC 38 Z9 39 U1 0 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 JUN 22 PY 1998 VL 80 IS 25 BP 5615 EP 5618 DI 10.1103/PhysRevLett.80.5615 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000039 ER PT J AU Requardt, H Nad, FY Monceau, P Currat, R Lorenzo, JE Brazovskii, S Kirova, N Grubel, G Vettier, C AF Requardt, H Nad, FY Monceau, P Currat, R Lorenzo, JE Brazovskii, S Kirova, N Grubel, G Vettier, C TI Direct observation of charge density wave current conversion by spatially resolved synchrotron x-ray studies in NbSe3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE-SLIP; NIOBIUM TRISELENIDE; GENERATION; NOISE AB We present results on the normal-collective current conversion processes and associated deformation profile for a charge density wave in the sliding state. High resolution x-ray measurements of the satellite positional shift have been performed on NbSe3 at 90 K. The shift q has been determined in the vicinity of the contacts by applying direct currents. We observe a steep variation of g near the contact, modeled in terms of dislocation loops (DL) nucleated at host defects. A small constant gradient in the sample's central part indicates incomplete conversion, consistent with DL pinning. C1 CNRS, Ctr Rech Tres Basses Temp, F-38042 Grenoble, France. Inst Max Von Laue Paul Langevin, F-38042 Grenoble, France. Russian Acad Sci, Inst Radio Engn & Elect, Moscow 103907, Russia. CNRS, Cristallog Lab, F-38042 Grenoble, France. LD Landau Theoret Phys Inst, Moscow, Russia. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Requardt, H (reprint author), CNRS, Ctr Rech Tres Basses Temp, BP 166, F-38042 Grenoble, France. RI Brazovskii, Serguei/A-9608-2012 OI Brazovskii, Serguei/0000-0001-8147-9655 NR 25 TC 72 Z9 72 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 22 PY 1998 VL 80 IS 25 BP 5631 EP 5634 DI 10.1103/PhysRevLett.80.5631 PG 4 WC Physics, Multidisciplinary SC Physics GA ZV521 UT WOS:000074313000043 ER PT J AU Mobarak, M Berger, H Lorusso, GF Capozzi, V Perna, G Ibrahim, MM Margaritondo, G AF Mobarak, M Berger, H Lorusso, GF Capozzi, V Perna, G Ibrahim, MM Margaritondo, G TI The growth and properties of single crystals of GaInTe2, a ternary chalcogenide semiconductor SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID GALLIUM SELENIDE; GASE; TLINS2; TEMPERATURE; EXCITONS AB Single crystals of GaInTe2 were grown from a melt and characterized by various experimental techniques, such as x-ray diffraction, x-ray photoelectron spectroscopy (XPS), and electrical and photoluminescence (PL) measurements. Our investigation evaluated important parameters of this challenging material. In particular, we studied here for the first time the electronic structure, the excitonic effects and the impurity bound states of GaInTe2, by means of XPS and by analysing dependences on the temperature and the excitation intensity of the PL spectra. C1 Quena S Valley Univ, Dept Phys, CH-1015 Lausanne, Switzerland. Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Bari, Dipartimento Fis, I-70126 Bari, Italy. Ist Nazl Fis Mat, I-70126 Bari, Italy. Fac Sci, Dept Phys, Sohag, Egypt. RP Mobarak, M (reprint author), Quena S Valley Univ, Dept Phys, CH-1015 Lausanne, Switzerland. RI Margaritondo, Giorgio/B-1367-2008 NR 20 TC 1 Z9 1 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD JUN 21 PY 1998 VL 31 IS 12 BP 1433 EP 1437 DI 10.1088/0022-3727/31/12/006 PG 5 WC Physics, Applied SC Physics GA ZY742 UT WOS:000074654800006 ER PT J AU Tajima, T Chen, P AF Tajima, T Chen, P TI Near- and long-term applications of plasma-based accelerators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN DE intense laser; wakefield accelerator; colliders; X-rays; snow-plow acceleration; inverse Compton scattering; ion acceleration; positron source AB A variety of near-term applications has been suggested and several long-term goals? including high-energy colliders, have been discussed. Applications of laser (or beam)-driven accelerators along with applications of advanced laser itself have been considered, such as for X-ray sources. Some of the near term applications are realistic and exciting enough that they deserve serious further investigations. We Feint out some of these future opportunities. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Dept Phys, Inst Fus Studies, Austin, TX 78712 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Tajima, T (reprint author), Univ Texas, Dept Phys, Inst Fus Studies, Austin, TX 78712 USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 344 EP 346 DI 10.1016/S0168-9002(98)00163-6 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700004 ER PT J AU Assmann, R Chen, P Decker, FJ Iverson, R Raimondi, P Raubenheimer, T Rokni, S Siemann, R Walz, D Whittum, D Chattopadhyay, S Leemans, W Katsouleas, T Lee, S Clayton, C Joshi, C Marsh, K Mori, W Wang, G AF Assmann, R Chen, P Decker, FJ Iverson, R Raimondi, P Raubenheimer, T Rokni, S Siemann, R Walz, D Whittum, D Chattopadhyay, S Leemans, W Katsouleas, T Lee, S Clayton, C Joshi, C Marsh, K Mori, W Wang, G TI Proposal for a one GeV plasma wakefield acceleration experiment at SLAC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN ID WAKE-FIELD ACCELERATOR; WAVE-BREAKING AB A plasma-based wakefield acceleration experiment E-157 has been approved at SLAG to study acceleration of parts of an SLC bunch by up to 1 GeV/m over a length of 1 m. A single SLC bunch is used to both induce wakefields in the 1 m long plasma and to witness the resulting beam acceleration. The experiment will explore and further develop the techniques that are needed to apply high-gradient plasma wakefield acceleration to large-scale accelerators. The Im length of the experiment is about two orders of magnitude larger than for other high gradient plasma wakefield acceleration experiments and the 1 GeV/m accelerating gradient is roughly ten times larger than that achieved with conventional metallic structures. Using existing SLAG facilities, the experiment will study high gradient acceleration at the forefront of advanced accelerator research. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ So Calif, Los Angeles, CA 90089 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM assmann@slac.stanford.edu; chen@slac.stanford.edu; katsoule@usc.edu; cclayton@ea.ucla.edu; mori@physics.ucla.edu RI Assmann, Ralph/L-8457-2016 NR 24 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 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 396 EP 406 DI 10.1016/S0168-9002(98)00169-7 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700012 ER PT J AU Chen, P Cline, D Craddock, W Decker, FJ Iverson, R Katsouleas, T Kwok, P Leemans, W Masuda, S Meyerhofer, DD Nakajima, K Ogata, A Raimondi, P Sessler, A Walz, D Weidemann, A AF Chen, P Cline, D Craddock, W Decker, FJ Iverson, R Katsouleas, T Kwok, P Leemans, W Masuda, S Meyerhofer, DD Nakajima, K Ogata, A Raimondi, P Sessler, A Walz, D Weidemann, A TI Plasma lens experiment at the final focus test beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN ID CHIRPED-PULSE-AMPLIFICATION; ELECTRON-BEAM; ACCELERATION; SUPPRESSION; COLLIDERS AB The proposed plasma lens experiment at the Final focus Test Beam (FFTB) facility of the Stanford Linear Accelerator Center (Chen et al. SLAG, 1997) [1] has been approved by the adminstration. The experiment would allow the examination of plasma focusing devices for particle beams in the parameter regime of interest to future high-energy colliders. It is expected to lead to compact plasma lens designs capable of focusing the beam to unprecedented small spot sizes. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Los Angeles, Los Angeles, CA USA. Univ So Calif, Los Angeles, CA USA. Lawrence Berkeley Lab, Berkeley, CA USA. Univ Rochester, Rochester, NY USA. Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. Univ Tennessee, Knoxville, TN USA. RP Chen, P (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, POB 4349 MS26, Stanford, CA 94309 USA. NR 31 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 407 EP 417 DI 10.1016/S0168-9002(98)00153-3 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700013 ER PT J AU Gai, W Li, X Conde, M Power, J Schoessow, P AF Gai, W Li, X Conde, M Power, J Schoessow, P TI A high-charge and short-pulse RF photocathode gun for wake-field acceleration SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN DE high current; photoinjector; emittance; wake-field acceleration AB In this paper we present a design report on 1-1/2 cell, L-Band RF photocathode gun which is capable of generating and accelerating electron beams with peak currents > 10 kA. We address several critical issues of high-current RF photoinjectors such as longitudinal space charge effect, and transverse emittance growth. Unlike conventional short electron pulse generation, this design does not require magnetic pulse compression. Based on numerical simulations using SUPERFISH and PARMELA, this design will produce 100 nC beam at 18 MeV with r.m.s. bunch length 1.25 mm and normalized transverse emittance 108 mm mrad. Applications of this source beam for wake-field acceleration are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Gai, W (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 16 TC 6 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 431 EP 436 DI 10.1016/S0168-9002(98)00174-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700016 ER PT J AU Chen, P Spitkovsky, A Katsouleas, T Mori, WB AF Chen, P Spitkovsky, A Katsouleas, T Mori, WB TI Transformer ratio and pulse shaping in laser wakefield accelerator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN ID PLASMA AB We show that, in complete analogy to the electron-beam driven Plasma Wakefield Accelerator (PWFA), an optimal transformer ratio can be attained in the laser driven Laser Wakefield Accelerator (LWFA), by properly shaping the longitudinal profile of the driving laser pulse. The concept of transformer ratio in LWFA is introduced and the optimal laser pulse shape is derived in the linear regime of laser-plasma interaction. We show that in the linear regime of plasma perturbation the requirement for the laser pulse shape and the resultant optimal transformer ratio are identical for LWFA and PWFA concepts. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ So Calif, Dept EE & Electrophys, Los Angeles, CA 90089 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. RP Chen, P (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 13 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 JUN 21 PY 1998 VL 410 IS 3 BP 488 EP 492 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700022 ER PT J AU Pogorelsky, IV AF Pogorelsky, IV TI Prospects for laser wakefield accelerators and colliders using CO2 laser drivers SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN ID ELECTRON ACCELERATION; PLASMA-WAVES; PULSES; LIGHT AB Energy directly acquired by an electron from the laser electromagnetic field is quadratically proportional to the laser wavelength. Exploiting this feature, the emerging terawatt picosecond (TWps) CO2 lasers, having an order of magnitude longer wavelength than the well-known table-top terawatt (T-3) picosecond solid state lasers, offer new opportunities for strong-field physics research. Laser accelerators serve as an example when application of the new class of lasers will result in enhancement in gas ionization, plasma wave excitation, and relativistic self-focusing. Ponderomotively strong CO2 laser permits a 100 times reduction in the plasma density without impeding the acceleration. The improved performance of the low-pressure laser wakefield accelerators (LWFA) is potentially due to higher electric charge per accelerated bunch and better monochromaticity. The multi-kilowatt average power high repetition rate capability of the TWps-CO2 laser technology opens new opportunities in development of compact, similar to 1 m long, GeV accelerators and <1km long high-luminosity multi-stage LWFA colliders of the TeV scale. The first TWps-CO2, laser is under construction at the BNL Accelerator Test Facility (ATF). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Accelerator Test Facil, Upton, NY 11973 USA. RP Pogorelsky, IV (reprint author), Brookhaven Natl Lab, Accelerator Test Facil, 725C, Upton, NY 11973 USA. NR 21 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 524 EP 531 DI 10.1016/S0168-9002(98)00160-0 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700029 ER PT J AU Rosenzweig, J Barov, N Murokh, A Colby, E Colestock, P AF Rosenzweig, J Barov, N Murokh, A Colby, E Colestock, P TI Towards a plasma wake-field acceleration-based linear collider SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN ID INJECTOR; PULSE AB A proposal for a linear collider based on an advanced accelerator scheme, plasma wake-field acceleration in the extremely nonlinear regime, is discussed. In this regime, many of the drawbacks associated with preservation of beam quality during acceleration in plasma are mitigated. The scaling of all beam and wake parameters with respect to plasma wavelength is examined. Experimental progress towards high-gradient acceleration in this scheme is reviewed. We then examine a linear collider based on staging of many modules of plasma wake-field accelerator, all driven by a high average current, pulse compressed, RF photoinjector-fed linac. Issue of beam lending, efficiency, optimized stage length, and power efficiency are discussed. A proof-of-principle experimental test of the staging concept at the Fermilab test facility is discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Calif Los Angeles, Dept Phys & Astron, 405 Hilgard Ave, Los Angeles, CA 90095 USA. NR 27 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 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 532 EP 543 DI 10.1016/S0168-9002(98)00186-7 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700030 ER PT J AU Assmann, R Yokoya, K AF Assmann, R Yokoya, K TI Transverse beam dynamics in plasma-based linacs SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 13th Advanced ICFA Beam Dynamics Workshop / 1st ICFA Novel and Advanced Accelerator Workshop - The 2nd Generation Plasma Accelerators CY JUL 14-18, 1997 CL KYOTO RES PARK, JAPAN AB The transverse beam dynamics in plasma channels of possible future plasma-based linacs is discussed. We represent the transverse focusing of both a beam-driven and a laser-driven plasma wakefield accelerator by a uniform focusing channel. The transverse beam sizes and a basic offset tolerance are calculated, finding that sub-micron beams must be transported with even smaller offset tolerances. The results emphasize the need to pursue further ideas for plasma structures with high-acceleration gradients but reduced transverse wakefields.;(C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. RP Assmann, R (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Assmann, Ralph/L-8457-2016 NR 6 TC 17 Z9 17 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1998 VL 410 IS 3 BP 544 EP 548 DI 10.1016/S0168-9002(98)00187-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 100VH UT WOS:000074835700031 ER PT J AU Kulp, TJ Powers, P Kennedy, R Goers, UB AF Kulp, TJ Powers, P Kennedy, R Goers, UB TI Development of a pulsed backscatter-absorption gas-imaging system and its application to the visualization of natural gas leaks SO APPLIED OPTICS LA English DT Article AB The design and evaluation of a backscatter-absorption gas-imaging sensor that operates in a pulsed mode is described. It is capable of video visualization of natural gas leaks. Its development was motivated by the need for a methane imaging system to operate at ranges and sensitivities useful to the natural gas industry. The imager employs pulsed laser illumination at a repetition rate of 30 Hz and an average power of similar to 150 mW to image gas at standoff ranges of as long as 100 m, using a backscatter target with a reflectivity of 0.016 sr(-1). This is a tenfold improvement over an earlier raster-scanned imager. Natural gas leaks as small as 1.6 X 10(-4) standard liters/s [equal to 0.02 standard cubic feet per hour (scfh)] were imaged at short ranges; leaks as low as 7.9 X 10(-4) standard liters/s (0.1 scfh) were observed at long ranges. Data are compared with model predictions, and potential extensions to a fieldable prototype are discussed. The optimization of a direct-injection focal-plane array for detecting short (nanosecond) laser pulses is described. (C) 1998 Optical Society of America. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Kulp, TJ (reprint author), Sandia Natl Labs, MS 9051,POB 969, Livermore, CA 94551 USA. NR 12 TC 16 Z9 16 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUN 20 PY 1998 VL 37 IS 18 BP 3912 EP 3922 DI 10.1364/AO.37.003912 PG 11 WC Optics SC Optics GA ZT886 UT WOS:000074127900013 PM 18273359 ER PT J AU Koplow, JP Kliner, DAV Goldberg, L AF Koplow, JP Kliner, DAV Goldberg, L TI Development of a narrow-band, tunable, frequency-quadrupled diode laser for UV absorption spectroscopy SO APPLIED OPTICS LA English DT Article ID HIGH-POWER; 2ND-HARMONIC GENERATION; SEMICONDUCTOR-LASER; OPTICAL AMPLIFIER; COEFFICIENTS; SYSTEM; STATE; LIGHT; BLUE; SO2 AB A compact, lightweight, low-power-consumption source of tunable, narrow-bandwidth blue and UV radiation is described. In this source, a single-longitudinal-mode diode laser seeds a pulsed, GaAlAs tapered amplifier whose similar to 860-nm output is frequency quadrupled by two stages of single-pass frequency doubling. Performance of the laser system is characterized over a wide range of amplifier duty cycles (0.1-1.0), pulse durations (50 ns-1.0 mu s), peak currents (less than or equal to 14 A), and average currents (less than or equal to 2.0 A). The capabilities and limitations of this source are discussed. We recorded high-resolution, Doppler-limited absorption spectra of nitric oxide and sulfur dioxide near 215 MI; the SO2 spectrum was found to have significantly more structure and higher peak absorption cross sections than previously reported. (C) 1998 Optical Society of America. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Koplow, JP (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 31 TC 21 Z9 23 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JUN 20 PY 1998 VL 37 IS 18 BP 3954 EP 3960 DI 10.1364/AO.37.003954 PG 7 WC Optics SC Optics GA ZT886 UT WOS:000074127900017 PM 18273363 ER PT J AU Odenwald, S Newmark, J Smoot, G AF Odenwald, S Newmark, J Smoot, G TI A study of external galaxies detected by the COBE Diffuse Infrared Background Experiment SO ASTROPHYSICAL JOURNAL LA English DT Article DE diffuse radiation; dust, extinction; galaxies, ISM; galaxies, photometry; infrared, galaxies; surveys ID INTERSTELLAR DUST; IRAS OBSERVATIONS; EMISSION; SAMPLE AB A comparison of the COBE1 Diffuse Infrared Background Experiment (DIRBE) all-sky survey with the locations of known galaxies in the IRAS Catalog of Extragalactic Objects and the Center for Astrophysics Catalog of Galaxies led to the detection of as many as 57 galaxies. In this paper, we present the photometric data for these galaxies and an analysis of the seven galaxies that were detected at lambda > 100 mu m. Estimates of the ratio of the mass of the cold dust (CD) component detected at T-d = 20-30 K to a very cold dust (VCD) component with T-d approximate to 10-15 K suggest that between 2%-100% of the cirrus-like CD mass can also exist in many of these galaxies as VCD. In one galaxy, M33, the DIRBE photometry at 240 mu m suggests as much as 26 times as much VCD may be present as compared to the cirrus-like component. Further submillimeter measurements of this galaxy are required to verify such a large population of VCD. We also present 10 galaxies that were detected in the sky region not previously surveyed by IRAS and that can be used to construct a flux-limited all-sky catalog of galaxies brighter than 1000 Jy with a modest completeness limit of about 65%. C1 Raytheon STX, Goddard SFC, Greenbelt, MD 20771 USA. Appl Res Corp, Landover, MD 20785 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Raytheon STX, Goddard SFC, Code 630-0, Greenbelt, MD 20771 USA. NR 37 TC 27 Z9 27 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1998 VL 500 IS 2 BP 554 EP 568 DI 10.1086/305737 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZX419 UT WOS:000074513900002 ER PT J AU Tran, HD Cohen, MH Ogle, PM Goodrich, RW Alighieri, SD AF Tran, HD Cohen, MH Ogle, PM Goodrich, RW Alighieri, SD TI Scattered radiation from obscured quasars in distant radio galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, active; galaxies, jets; polarization; quasars, general; radio, continuum, galaxies; scattering ID BROAD-LINE REGIONS; HIGH SPATIAL-RESOLUTION; HIGH-REDSHIFT; SEYFERT-2 GALAXIES; OPTICAL POLARIZATION; UNIFICATION SCHEMES; GALACTIC NUCLEI; STAR FORMATION; SPECTROPOLARIMETRY; SPECTRUM AB We present optical spectropolarimetric and imaging polarimetric observations of four high-redshift radio galaxies (HzRGs) obtained with the Low Resolution Imaging Spectrometer of the 10 m Keck I telescope. A broad Mg IT lambda 2800 emission line is detected in the total and polarized flux spectra of 3C 265 and 3C 277.2. The fractional polarization is high, and both it and the position angle are constant with wavelength after accounting for dilution by unpolarized starlight of the host galaxy, which can contribute substantially. An extended unpolarized continuum similar to that observed in other active galactic nuclei is also detected. Imaging polarimetry reveals a rough double-fan morphology of the polarized light coincident with the extended aligned emission regions, with the position angle essentially perpendicular to the radial structure of the extended UV/optical emission and with the degree of polarization increasing with radius away from the nucleus. The radio jets lie inside the extended emission regions and, like every radius, are roughly perpendicular to the polarization position angle. These results strengthen the view that powerful radio galaxies would be called quasars if viewed from the proper direction. Based on the polarimetric data presented in this paper and in previous studies, scattering of radiation from an obscured quasar source appears to be the preferred interpretation over jet-induced star formation for explaining the alignment effect in HzRGs. Both electrons and dust can play a major role in the scattering process. However, the lack of strong direct evidence for either case and our ignorance of the properties and distribution of the scatterers in these galaxies make it very difficult to discriminate between the two. Our data reveal a chance alignment of 3C 343.1 with a foreground galaxy, which dominates the observed optical flux from the system. C1 Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. CALTECH, Palomar Observ, Pasadena, CA 91125 USA. CARA Keck Observ, Kamuela, HI 96743 USA. Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. RP Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, POB 808,7000 East Ave,L-413, Livermore, CA 94550 USA. EM htran@igpp.llnl.gov; mhc@astro.caltech.edu; pmo@astro.caltech.edu; goodrich@keck.hawaii.edu; sperello@arcetri.astro.it RI di Serego Alighieri, Sperello/E-4067-2010 OI di Serego Alighieri, Sperello/0000-0001-8769-2692 NR 81 TC 33 Z9 33 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1998 VL 500 IS 2 BP 660 EP 672 DI 10.1086/305752 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZX419 UT WOS:000074513900012 ER PT J AU Strohmayer, TE Fenimore, EE Murakami, T Yoshida, A AF Strohmayer, TE Fenimore, EE Murakami, T Yoshida, A TI X-ray spectral characteristics of Ginga gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; radiation mechanisms : nonthermal; X-rays : bursts ID BATSE OBSERVATIONS; EVOLUTION; SPECTROSCOPY; ABSORPTION; FEATURES; EMISSION; CATALOG; BRIGHT AB We have investigated the spectral characteristics of a sample of bright gamma-ray bursts detected with the gamma-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2-400 keV region and as such provided a unique opportunity to characterize the largely unexplored X-ray properties of gamma-ray bursts. The photon spectra of the Ginga bursts are well described by a low-energy slope, a bend energy, and a high-energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Gamma-Ray Observatory. However, below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some evidence for a strong rolloff at lower energies in a few events. There is a correlation (Pearson's r = -0.62) between the low-energy slope and the bend energy. We find that the distribution of spectral bend energies extends below 10 keV. There has been some concern in cosmological models of gamma-ray bursts (GRBs) that the bend energy covers only a small dynamic range. Our result extends the observed dynamic range, and, since we observe bend energies down to the limit of our instrument, perhaps observations have not yet limited the range. The Ginga trigger range was virtually the same as that of BATSE, yet we find a different range of fit parameters. One possible explanation might be that GRBs have two break energies, one often in the 50-500 keV range and the other near 5 keV. Both BATSE and Ginga fit with only a single break energy, so BATSE tends to find breaks near the center of its energy range, and we tend to find breaks in our energy range. The observed ratio of energy emitted in the X-rays relative to the gamma rays can be much larger than a few percent and, in fact, is sometimes larger than unity. The average for our 22 bursts is 24%. We also investigated spectral evolution in two bursts. In these events we find strong evidence for spectral softening as well as a correlation between photon intensity and spectral hardness. We also find that the X-ray signal below 30 keV itself softens in both of these events. There is one example of a strong X-ray excess at low energy. In addition to providing further constraints on gamma-ray burst models, the description provided here of burst spectra down to 2 keV should prove useful to future planned efforts to detect bursts at X-ray energies. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Inst Space & Astronaut Sci, Kanagawa 229, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Mail Code 666, Greenbelt, MD 20771 USA. EM stroh@pcasrv.gsfc.nasa.gov; efenimore@lanl.gov NR 44 TC 83 Z9 84 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1998 VL 500 IS 2 BP 873 EP 887 DI 10.1086/305735 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZX419 UT WOS:000074513900030 ER PT J AU Drake, RP Carroll, JJ Estabrook, K Glendinning, SG Remington, BA Wallace, R McCray, R AF Drake, RP Carroll, JJ Estabrook, K Glendinning, SG Remington, BA Wallace, R McCray, R TI Development of a laboratory environment to test models of supernova remnant formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; instabilities; supernova remnants AB Increasingly sophisticated computational models are being used to interpret the increasingly detailed data gathered by modern observatories. This Letter reports the development of a means to verify and validate such models, with particular attention to the context of supernova remnants (SNRs). By using the Nova laser (or other high-energy density facilities), one can produce supersonic plasma ejecta in the laboratory and study their interaction with an ambient, lower density medium. The laboratory system is scaled from the local conditions within young SNRs by keeping constant the quantity velocity x time/spatial dimension. The radiation-hydrodynamic simulations used to establish and optimize the design are reported. A specific experimental implementation is described in which ejecta at similar to 100 km s(-1) are generated, driving a Mach similar to 50 forward shock through a uniform medium. The evolution of the forward and reverse shocks is observed. C1 Univ Michigan, Ann Arbor, MI 48109 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Colorado, Boulder, CO 80309 USA. RP Drake, RP (reprint author), Univ Michigan, 2455 Hayward St, Ann Arbor, MI 48109 USA. RI Drake, R Paul/I-9218-2012 OI Drake, R Paul/0000-0002-5450-9844 NR 20 TC 32 Z9 34 U1 1 U2 10 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1998 VL 500 IS 2 BP L157 EP L161 DI 10.1086/311400 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZX422 UT WOS:000074514200019 ER PT J AU Gates, EI Gyuk, G Holder, GP Turner, MS AF Gates, EI Gyuk, G Holder, GP Turner, MS TI No need for MACHOs in the halo SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; Galaxy : halo; Galaxy : structure ID GALACTIC HALO; DARK-MATTER; BULGE; STARS; MASS AB One interpretation of the more than dozen microlensing events seen in the direction of the LMC is a halo population of 0.5 M. MACHOs that accounts for about half of the mass of the Galaxy. Such an interpretation is not without its problems, and we show that LMC microlensing can be explained by a combination of dark components of the thick disk and spheroid in a viable and detailed model of the Galaxy. In our models, the total mass within 50 kpc is similar to 10(11) M.. about 60% of the value based on halo MACHO models, and the estimate for the lens mass is lower, 0.3 M. versus 0.5 M.. The chemical evolution problems associated with the MACHO progenitors are not resolved. However, since the MACHO distribution does not trace the l/r(2) dark halo, which extends significantly beyond 50 kpc, the total baryon mass fraction of the Galaxy is reduced considerably, which lessens the problem. C1 Adler Planetarium & Astron Museum, Chicago, IL 60605 USA. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. SISSA, I-34014 Trieste, Italy. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Gates, EI (reprint author), Adler Planetarium & Astron Museum, Chicago, IL 60605 USA. NR 30 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1998 VL 500 IS 2 BP L145 EP L148 DI 10.1086/311406 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZX422 UT WOS:000074514200016 ER PT J AU Alexandratos, SD Beauvais, R Duke, JR Jorgensen, BS AF Alexandratos, SD Beauvais, R Duke, JR Jorgensen, BS TI Functionalized polymer foams as metal ion chelating agents with rapid complexation kinetics SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE crosslinked foams; ion exchange; metal ion separations; phosphonic acids ID POLYURETHANE FOAM; RESIN; SEPARATIONS; EXTRACTION; COPOLYMER; SORPTION; MEDIA AB Foams prepared from vinylbenzyl chloride and crosslinked with divinylbenzene were functionalized with trialkylphosphite and tetralkylvinylidene diphosphonate. It was determined that the foams could be uniformly functionalized. Batch studies with the functionalized foams show that high levels of metal ion complexation can be achieved. Foams may therefore offer an important alternative to beads for rapid complexation reactions due to their highly porous structure. (C) 1998 John Wiley & Sons, Inc. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Alexandratos, SD (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 23 TC 28 Z9 28 U1 3 U2 11 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD JUN 20 PY 1998 VL 68 IS 12 BP 1911 EP 1916 DI 10.1002/(SICI)1097-4628(19980620)68:12<1911::AID-APP3>3.0.CO;2-O PG 6 WC Polymer Science SC Polymer Science GA ZK365 UT WOS:000073313100003 ER PT J AU Hino, T Prausnitz, JM AF Hino, T Prausnitz, JM TI Lattice thermodynamics for aqueous salt-polymer two-phase systems SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE aqueous two-phase systems; electrolyte solutions; liquid-liquid equilibria; polymer solutions; salting ID HARD-SPHERE MIXTURES; 2-PHASE SYSTEMS; POLY(ETHYLENE GLYCOL); OSMOTIC COEFFICIENTS; BINARY-MIXTURES; ELECTROLYTES; SEPARATION; INSTABILITIES; 25-DEGREES-C; EQUILIBRIUM AB A lattice model is presented to compute salt-induced liquid-liquid phase separation in aqueous polymer solutions. The Gibbs energy of mixing contains an electrostatic contribution given by Fitter's extension of the Debye-Huckel function, and the extended Flory-Huggins theory that uses empirical functions of temperature and composition as binary interaction parameters. Our Flory-Huggins theory assumes complete dissociation of salt into ions, but it does not distinguish between cation and anion; our theory represents the water-salt-polymer mixture as an incompressible ternary system consisting of water, ion, and polymer. In the extended Flory-Huggins theory, the binary interaction parameter between water and ion, and that between water and polymer, are obtained by correlating the observed activity of water in each of the two relevant binary systems. The electrostatic contribution does not contain adjustable parameters. We show that the electrostatic contribution to the Gibbs energy of mixing is responsible for inducing salt-polymer aqueous two-phase systems. Calculated phase diagrams are compared with experiment for aqueous solutions containing polyethylene glycol and a single salt at room temperature. The efficiency of a salt to form salt-polymer aqueous two-phase systems is discussed in terms of ion valence and the interaction parameter between ion and polymer. (C) 1998 John Wiley & Sons, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Prausnitz, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 32 TC 17 Z9 17 U1 2 U2 11 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD JUN 20 PY 1998 VL 68 IS 12 BP 2007 EP 2017 DI 10.1002/(SICI)1097-4628(19980620)68:12<2007::AID-APP15>3.0.CO;2-Y PG 11 WC Polymer Science SC Polymer Science GA ZK365 UT WOS:000073313100015 ER PT J AU Fukui, Y Doskey, PV AF Fukui, Y Doskey, PV TI Air-surface exchange of nonmethane organic compounds at a grassland site: Seasonal variations and stressed emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CALIFORNIA CENTRAL VALLEY; GAS-PHASE REACTIONS; OXYGENATED HYDROCARBONS; UNITED-STATES; NATURAL HYDROCARBONS; RATE VARIABILITY; PINE FOREST; TRACE GASES; ATMOSPHERE; ISOPRENE AB Emissions of nonmethane organic compounds (NMOCs) were measured by a static enclosure technique at a grassland site in the midwestern United States during the growing seasons over a 2-year period. A mixture of nonmethane hydrocarbons (NMHCs) and oxygenated hydrocarbons (OxHCs) was emitted from the surface at rates exhibiting large seasonal and year-to-year variations. The average emission rate (and standard error) of the total NMOCs around noontime on sunny days during the growing seasons for the 2-year period was 1,300 +/- 170 mu g m(-2) h(-1) (mass of the total NMOCs pet area of enclosed soil surface per hour) or 5.5 +/- 0.9 mu g g(-1) h(-1) (mass of the total NMOCs per mass of dry plant biomass in an enclosure per hour), with about 10% and 70% of the emissions being composed of tentatively identified NMHCs and OxHCs, respectively. Methanol was apparently derived from both the soil and vegetation and exhibited an average emission rate of 460 +/- 73 mu g m(-2) h(-1) (1.4 +/- 0.2 mu g g(-1) h(-1)), which was the largest emission among the NMOCs. The year-to-year variation in the precipitation pattern greatly affected the NMOC emission rates. Emission rates normalized to biomass density exhibited a linear decrease as the growing season progressed. The emission rates of some NMOCs, particularly the OxHCs, from vegetation subjected to hypoxia, frost, and physical stresses were significantly greater than the average values observed at the site. Emissions of monoterpenes (alpha- and beta-pinene, limonene, and myrcene) and cis-3-hexen-1-ol were accelerated during the flowering of the plants and were much greater than those predicted by algorithms that correlated emission rates with temperature. Herbaceous vegetation is estimated to contribute about 40% and 50% of the total NMOC and monoterpene emissions, respectively, in grasslands; the remaining contributions are from woody species within grasslands. Contributions of isoprene emissions from herbaceous vegetation in grasslands are negligible. Grasslands are estimated to contribute about 10% of the total biogenic NMOC emissions in the United States. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Fukui, Y (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. EM Paul_Doskey@qmgate.anl.gov NR 60 TC 54 Z9 56 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 20 PY 1998 VL 103 IS D11 BP 13153 EP 13168 DI 10.1029/98JD00924 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZV631 UT WOS:000074325200006 ER PT J AU Kleinman, LI Daum, PH Lee, JH Lee, NY Weinstein-Lloyd, J Springston, SR AF Kleinman, LI Daum, PH Lee, JH Lee, NY Weinstein-Lloyd, J Springston, SR TI Photochemistry of O-3 and related compounds over southern Nova Scotia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; PHOTOSTATIONARY STATE; HYDROGEN-PEROXIDE; MODEL SIMULATIONS; OZONE FORMATION; RURAL SITE; BUDGET; SUMMER; TROPOSPHERE; ATLANTIC AB Photochemical model calculations have been performed for air masses encountered by the National Research Council's Twin Otter aircraft during the 1993 summer North Atlantic Regional Experiment (NARE) intensive. These calculations use observed values of O-3, NOy, CO, and hydrocarbons as constraints: NO is determined using the ratio NO/NOy measured from the National Center for Atmospheric Research King Air under comparable circumstances. Measurements over coastal locations indicate photochemically aged air masses with relatively low concentrations of NO and an OH reactivity that is dominated by CO and CH4. Samples over land have higher NO and an OH reactivity that is dominated by isoprene. Ozone production rates and H2O2 concentrations are analyzed using radical budget arguments that are applicable to low NOx conditions. The ozone production rate, P(O-3), is predicted to be proportional to Q (1/2)[NO], where Q is the production rate for free radicals. This relation explains 99% of the variance in P(O-3). Over 90% of the variance is explained by [NO] alone. P(O-3) in the coastal samples is about a factor of 4 lower than previous estimates for the eastern United States. This is a consequence of low [NO] in the air masses that are advected to Nova Scotia. C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Kleinman, LI (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. EM kleinman@bnl.gov; phdaum@bnl.gov; jaihlee@bnl.gov; ynlee@bnl.gov; jollyd@bnl.gov; srs@bnl.gov NR 41 TC 9 Z9 9 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JUN 20 PY 1998 VL 103 IS D11 BP 13519 EP 13529 DI 10.1029/97JD01484 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZV631 UT WOS:000074325200031 ER PT J AU Cho, JH Safar, H Maley, MP Willis, JO Coulter, JY Steel, DG Gray, KE AF Cho, JH Safar, H Maley, MP Willis, JO Coulter, JY Steel, DG Gray, KE TI Effects of unidirectional and isotropic columnar defects in Bi2Sr2CaCu2O8 single crystals SO PHYSICA C LA English DT Article DE Bi2Sr2CaCu2O8 single crystals; columnar defects; irreversibility lines ID ION IRRADIATED BI2SR2CACU2O8+DELTA; BOSE-GLASS BEHAVIOR; SUPERCONDUCTORS AB We report the comparative studies of unidirectional columnar defects and isotropic columnar defects in Bi2Sr2CaCu2O8 single crystals. Both types of the columnar defects induce significant enhancements of the irreversibility line and the activation energy. We find the good scalings of the irreversibility lines and the activation energies using the effective matching fields. For the case of isotropic columnar defects, the effective matching field has a large renormalization effect. (C) 1998 Elsevier Science B.V, All rights reserved. C1 Pusan Natl Univ, RCDAMP, Pusan 609735, South Korea. Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea. Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60349 USA. RP Cho, JH (reprint author), Pusan Natl Univ, RCDAMP, Jangjun Dong 30, Pusan 609735, South Korea. NR 13 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN 20 PY 1998 VL 302 IS 2-3 BP 113 EP 118 DI 10.1016/S0921-4534(98)00177-4 PG 6 WC Physics, Applied SC Physics GA ZZ526 UT WOS:000074738200003 ER PT J AU Morosin, B Venturini, EL Dunn, RG Provencio, PN Missert, N Padilla, RR AF Morosin, B Venturini, EL Dunn, RG Provencio, PN Missert, N Padilla, RR TI Structural and compositional characterization of rubidium-containing crystals of the Tl-Ba-Ca-Cu-O superconductors SO PHYSICA C LA English DT Article DE single crystal structure determinations; Tl-Ba-Ca-Cu-O superconductors; rubidium-containing crystals ID NEUTRON-DIFFRACTION; SINGLE-CRYSTALS; TL2BA2CACU2O8; SYSTEMS AB Large single crystals of the Tl-Ba-Ca-Cu-O superconductors have been grown from fluxes including up to 30 mol% Rb of the amount of Tl employed. Various phases have been grown with lattice parameters and superconducting properties similar to crystals grown previously without Rb, though the present crystal plates are usually larger and thicker. There is an increased likelihood of syntactic polycrystal growth as Rb content increases. Successive ion milling combined with energy dispersive X-ray analysis, EDAX, has shown that the Rb is uniformly distributed throughout the plates that are single phase crystals. Precession photographs show sharp diffraction patterns of quality comparable to our Rb-free plates. Magnetically determined Meissner T-c values and transition widths are not significantly altered by Rb substitution. Single crystal X-ray structure refinements have been carried out on several single crystals of each of the four principal phases. In addition various crystal plates have been characterized and studied by transmission electron imaging. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Morosin, B (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN 20 PY 1998 VL 302 IS 2-3 BP 119 EP 129 DI 10.1016/S0921-4534(98)00202-0 PG 11 WC Physics, Applied SC Physics GA ZZ526 UT WOS:000074738200004 ER PT J AU Hunt, RD Beahm, EC Voronin, GF AF Hunt, RD Beahm, EC Voronin, GF TI Partial oxygen pressure and temperature effects on the oxygen content of the Y-Ba-Cu-O melts SO PHYSICA C LA English DT Article DE oxygen stoichiometry; structural phase transition; phase diagram ID PSEUDOBINARY BACUO2-YBA2CU3O6.5-YCUO2.5 SYSTEM; PHASE-DIAGRAM; YBA2CU3O7-X; SUPERCONDUCTORS; STABILITY; LIQUIDUS; OXIDES AB The oxygen content and phase transition temperatures of equilibrated samples with Y:Ba:Cu:O molar ratios of 1:2:3:n (YBa2Cu3Ox phase) and 1:3,4:n (YBa2Cu3Ox + BaCuO2 phases) were determined with a differential thermal analyzer (DTA), a thermal gravimetric analyzer (TGA) and an electrochemical oxygen analyzer. These Y-Ba-Cu-O melts were studied at partial oxygen pressures that ranged from 1 x 10(5) to 6 Pa and at temperatures from 1200 to 1580 K. The oxygen contents of these melts were determined with hydrogen reduction and the TGA. The oxygen content of the 1:2:3:n melts decreased as the temperature increased and as the partial oxygen pressure decreased. The same pattern for the partial oxygen pressure was observed for the oxygen content in the 1:3,4:n melts. However, at a given partial oxygen pressure, the highest oxygen content in a 1,3:4:n melt was observed at a temperature approximately 100 K above the initial melting temperature. The liquidus temperatures for 1:2:3:n and 1:3:4:n always decreased as the partial oxygen pressures decreased. Finally, the compositions of the melts, which included the formation of YBa3Al2O7.5 in the 1:3:4:n melts, are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Moscow MV Lomonosov State Univ, Dept Chem, Moscow 119899, Russia. RP Hunt, RD (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JUN 20 PY 1998 VL 302 IS 2-3 BP 130 EP 136 DI 10.1016/S0921-4534(98)00201-9 PG 7 WC Physics, Applied SC Physics GA ZZ526 UT WOS:000074738200005 ER PT J AU Stimson, S Chen, YJ Evans, M Liao, CL Ng, CY Hsu, CW Heimann, P AF Stimson, S Chen, YJ Evans, M Liao, CL Ng, CY Hsu, CW Heimann, P TI Rotational-resolved pulsed field ionization photoelectron bands for H-2(+)(X-2 Sigma(+)(g), v(+) = 0, 2, 9, and 11) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID QUANTUM-DEFECT THEORY; FINAL-STATE INTERACTIONS; MOLECULAR ION HD+; ANGULAR-DISTRIBUTION; DIATOMIC-MOLECULES; PHOTO-ELECTRONS; HIGH-RESOLUTION; GENERAL THEORY; H-2; INTENSITY AB We present here the assignment and simulation of rotational transitions for the H-2(+) (X-2 Sigma(g)(+), upsilon(+) = 0,2,9 and 11) vibronic bands using the Buckingham-Orr-Sichel (BOS) model. The simulation shows that perturbation of PFI-PE rotational line intensities due to near-resonance autoionization decreases as upsilon(+) increases. Experimental rotational constants for H-2(+) (X-2 Sigma(g)(+), upsilon(+) = 0,2,9 and 11) are determined with higher accuracy than those obtained in previous HeI and NeI photoelectron studies. In agreement with previous experimental and theoretical investigations, only the Delta N=0 and +/-2 rotational branches are observed in the PFI-PE spectrum for H-2. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Accelerator & Fus Res, Adv Light Source, Berkeley, CA 94720 USA. RP Ng, CY (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. EM cyng@ameslab.gov RI Chen, Yu-Ju/E-9481-2015 NR 38 TC 38 Z9 38 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 19 PY 1998 VL 289 IS 5-6 BP 507 EP 515 DI 10.1016/S0009-2614(98)00412-6 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW236 UT WOS:000074389300014 ER PT J AU Strouse, GF Scott, B Swanson, BI Saxena, A Batistic, I Gammel, JT Bishop, AR AF Strouse, GF Scott, B Swanson, BI Saxena, A Batistic, I Gammel, JT Bishop, AR TI Tuning dimensionality in low-dimensional electronic materials SO CHEMICAL PHYSICS LETTERS LA English DT Article ID TETRACYANOQUINODIMETHANE TTF-TCNQ; METAL-COMPLEXES; PHASE-TRANSITIONS; SUPERCONDUCTORS; SOLIDS; SPINS; HOLES; STATE AB We demonstrate how dimensionality can be tuned in complex low-dimensional electronic materials via small perturbations in competing molecular forces. The delicate balance between molecular level forces on observed dimensionality in materials is illustrated by the 1-d to 3-d structural reorganization following deuteration of the ancillary ligands in the halogen-bridged transition-metal charge-transfer complex [Pt(en)(2)I-2][Pt(en)(2)]I-2 (PtI) where en denotes ethylenediamine. Specifically, the impact of competing forces on dimensionality is clearly demonstrated by the temperature-dependent phase transitions in perdeuterated PtI (D-PtI), where small changes in inter-and intra-sheet interactions drive mesoscopic structural changes. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Zagreb, Inst Phys, Zagreb 41001, Croatia. RP Strouse, GF (reprint author), Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 29 TC 2 Z9 2 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JUN 19 PY 1998 VL 289 IS 5-6 BP 559 EP 566 DI 10.1016/S0009-2614(98)00476-X PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZW236 UT WOS:000074389300022 ER PT J AU Timerbaev, AR Semenova, OP Fritz, JS AF Timerbaev, AR Semenova, OP Fritz, JS TI Improved photometric detection of metal ions by capillary zone electrophoresis after precapillary complexation SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT International Ion Chromatography Symposium CY SEP 14-17, 1997 CL SANTA CLARA, CALIFORNIA DE detection, electrophoresis; metal cations; metal complexes; cyclohexanediaminetetraacetic acid ID MASS-SPECTROMETRY; ELEMENTAL SPECIATION; EDTA COMPLEXES; SEPARATION; MAGNESIUM; ONLINE; CHROMATOGRAPHY; CALCIUM; SAMPLES; SERUM AB Precapillary reactions using complexing reagents are increasingly being used to carry out separations of metal ions by capillary zone electrophoresis. To compensate for the sensitivity limitations of on-column photometric detection, several approaches were evaluated. Parameters affecting the sensitivity response of a direct detection system, such as the detection wavelength, sample size, applied voltage, and electrolyte concentration, were examined to produce the best possible sensitivity for metal ions complexed with cyclohexane-1,2-diaminetetraacetic acid. Using injection in the electrokinetic mode, a 2-fold increase in detectability over hydrodynamic (gravity) injection was obtained for certain metal analytes that corresponds to the detection limits in the sub-mu g/l range. A characterization and optimization of photometric detection in an indirect format have been conducted. An organic dye, combined with the carrier electrolyte to impart an absorbance background in the visible range and selected with due account for its spectral and electrophoretic characteristics, was found to provide micromolar-level sensitivities. Feasibility of on-line (stacking) sample concentration for metal complexes has also been demonstrated. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Interuniv Inst Agrobiotechnol, Dept Plant Technol, Tulln, Austria. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Russian Acad Sci, Vernadsky Inst Geochem & Analyt Chem, Moscow 117975, Russia. RP Semenova, OP (reprint author), Interuniv Inst Agrobiotechnol, Dept Plant Technol, Tulln, Austria. RI Timerbaev, Andrei/G-7530-2016 NR 32 TC 16 Z9 17 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUN 19 PY 1998 VL 811 IS 1-2 BP 233 EP 239 DI 10.1016/S0021-9673(98)00270-2 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZX012 UT WOS:000074471400023 ER PT J AU Fritschy, JM Johnson, DK Mohler, H Rudolph, U AF Fritschy, JM Johnson, DK Mohler, H Rudolph, U TI Independent assembly and subcellular targeting of GABA(A)-receptor subtypes demonstrated in mouse hippocampal and olfactory neurons in vivo SO NEUROSCIENCE LETTERS LA English DT Article DE GABA(A)-receptor subunit assembly; subunit gene; chromosomal deletion; p locus; immunofluorescent staining; mouse mutants ID RECOMBINANT GABA(A) RECEPTOR; AMINOBUTYRIC-ACID RECEPTOR; A RECEPTORS; SUBUNITS; LOCALIZATION; MICE; BETA(3)-SUBUNIT; STOICHIOMETRY; CELLS; GENE AB The ability of neurons to display more than a single GABA(A)-receptor subtype per cell requires intricate targeting mechanisms. Analysis by confocal laser scanning microscopy revealed that the alpha 2- and alpha 5-subunits differed strikingly in their subcellular distribution in hippocampal pyramidal cells and olfactory bulb granule cells, while the distribution of the gamma 2-subunit was rather uniform. In mutant mice lacking the alpha 5-subunit gene due to a chromosomal deletion, the absence of the alpha 5-subunit was accompanied by a corresponding decrease of the gamma 2-subunit immunoreactivity. In striking contrast, the subcellular distribution of the gamma 2-subunit was unchanged in these mutant mice. These findings indicate that the assembly of distinct GABA(A)-receptor subtypes in the same neuron is regulated independently. Furthermore, the alpha-subunit is a prime candidate for providing domains which direct subcellular targeting. Published by Elsevier Science Ireland Ltd. C1 Univ Zurich, Inst Pharmacol, CH-8057 Zurich, Switzerland. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Rudolph, U (reprint author), Univ Zurich, Inst Pharmacol, Winterthurerstr 190, CH-8057 Zurich, Switzerland. EM rudolph@pharma.unizh.ch NR 17 TC 70 Z9 76 U1 0 U2 4 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3940 J9 NEUROSCI LETT JI Neurosci. Lett. PD JUN 19 PY 1998 VL 249 IS 2-3 BP 99 EP 102 DI 10.1016/S0304-3940(98)00397-8 PG 4 WC Neurosciences SC Neurosciences & Neurology GA ZZ591 UT WOS:000074745500008 PM 9682826 ER PT J AU Korber, B Theiler, J Wolinsky, S AF Korber, B Theiler, J Wolinsky, S TI Limitations of a molecular clock applied to considerations of the origin of HIV-1 SO SCIENCE LA English DT Editorial Material ID IMMUNODEFICIENCY-VIRUS TYPE-1; REVERSE-TRANSCRIPTASE; ENVELOPE GENES; GAG GENES; SEQUENCE; ISOLATE; RECOMBINATION; TRANSMISSION; INFECTIONS; EVOLUTION C1 Northwestern Univ, Sch Med, Dept Med, Chicago, IL 60611 USA. Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp NIS2, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T10, Los Alamos, NM 87545 USA. RP Wolinsky, S (reprint author), Northwestern Univ, Sch Med, Dept Med, Chicago, IL 60611 USA. RI Wolinsky, Steven/B-2893-2012; OI Wolinsky, Steven/0000-0002-9625-6697; Korber, Bette/0000-0002-2026-5757 FU NIAID NIH HHS [3-Y01-AI-70001-13]; NICHD NIH HHS [R01-HD-31756]; PHS HHS [Y1-A1-4058-03] NR 64 TC 64 Z9 64 U1 3 U2 7 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUN 19 PY 1998 VL 280 IS 5371 BP 1868 EP 1871 DI 10.1126/science.280.5371.1868 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZV618 UT WOS:000074323800041 PM 9669945 ER PT J AU Owens, DK Edwards, DM Shachter, RD AF Owens, DK Edwards, DM Shachter, RD TI Population effects of preventive and therapeutic HIV vaccines in early- and late-stage epidemics SO AIDS LA English DT Article DE HIV; AIDS; AIDS vaccines; HIV-1; HIV seroprevalence ID HUMAN-IMMUNODEFICIENCY-VIRUS; FRANCISCO MENS HEALTH; SAN-FRANCISCO; RECOMBINANT GP160; BISEXUAL MEN; INFECTION; AIDS; IMMUNOGENICITY; TRANSMISSION; SAFETY AB Objective: To evaluate the population effects of potential preventive and therapeutic vaccines in early- and late-stage epidemics in a population of homosexual men. Methods: An epidemic model was used that simulated the course of the epidemic for a population of homosexual men in San Francisco, California. Vaccine programs were evaluated by the number of cases of HIV averted, the effect on the prevalence of HIV, and by the gain in quality-adjusted life years (QALY) for the total population. Results: In the model, a preventive vaccine prevented 3877 cases of HIV infection during a 20-year period, reduced the projected prevalence of HIV infection from 12 to 7% in a late-stage epidemic, and gained 15 908 QALY. A therapeutic vaccine that did not affect the infectivity of vaccine recipients increased the number of cases of HIV infection by 210, resulted in a slight increase in the prevalence of HIV infection from 12 to 15% in a late-stage epidemic, and gained 8854 QALY. If therapeutic vaccines reduced infectivity, their use could produce net gains of QALY in the population that were similar to gains from the use of preventive vaccines. In an early-stage epidemic, the advantage of a preventive vaccine program relative to a therapeutic vaccine program was markedly enhanced. Conclusions: Both preventive and therapeutic vaccine programs provided substantial benefit, but their relative merit depended on which outcome measures were assessed. Evaluation of HIV vaccine programs based solely on cases averted or on prevalence of HIV in the population underestimates the benefit associated with therapeutic vaccine programs. The effect of a therapeutic HIV vaccine on the epidemic outcomes depended markedly on whether the therapeutic vaccine reduced the infectivity of the vaccine recipient. The relative merits of preventive and therapeutic vaccines depend on the stage of the epidemic. Field vaccine trials should evaluate correlates of infectivity, such as HIV viral load. HIV vaccine implementation strategies should be tailored to the dynamics of the epidemic in specific populations. (C) 1998 Lippincott-Raven Publishers. C1 VA Palo Alto Hlth Care Syst, Sect Gen Med 111A, Palo Alto, CA 94304 USA. Stanford Univ, Dept Med, Sect Med Informat, Stanford, CA 94305 USA. Stanford Univ, Dept Hlth Res & Policy, Stanford, CA 94305 USA. Stanford Univ, Dept Engn Econ Syst, Stanford, CA 94305 USA. Sandia Natl Labs, Livermore, CA USA. RP Owens, DK (reprint author), VA Palo Alto Hlth Care Syst, Sect Gen Med 111A, 3801 Miranda Ave, Palo Alto, CA 94304 USA. FU PHS HHS [R-01-09531-01A2] NR 37 TC 20 Z9 20 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0269-9370 J9 AIDS JI Aids PD JUN 18 PY 1998 VL 12 IS 9 BP 1057 EP 1066 DI 10.1097/00002030-199809000-00013 PG 10 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 102HN UT WOS:000074918500014 PM 9662203 ER PT J AU Farrell, JT Taatjes, CA AF Farrell, JT Taatjes, CA TI Infrared frequency-modulation probing of Cl+C3H4 (allene, propyne) reactions: Kinetics of HCl production from 292 to 850 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID THERMAL UNIMOLECULAR REACTIONS; COLLISION RATE CONSTANTS; CL ATOM REACTIONS; CHLORINE ATOMS; PRESSURE-DEPENDENCE; ETHYL RADICALS; LINE-SHAPES; RECOMBINATION; SPECTROSCOPY; C2H4 AB Absolute rate coefficients for the reactions of chlorine atoms with allene (propadiene, H2C=C=CH2) and propyne (HC=C-CH3) have been measured as a function of temperature (292-850 K) and pressure (4-10 Torr) with a laser photolysis/CW infrared long path absorption technique. The reactions are initiated via pulsed laser photolysis of Cl-2 and monitored through CW infrared frequency-modulation spectroscopy of the HCl product. At room temperature (292 K), the reaction of Cl with allene proceeds almost exclusively through addition, with little HCl generated through either abstraction or elimination. HCl production increases with temperature, and becomes unity at T greater than or equal to 800 K. Quantitative HCl yield measurements allow the contributions of addition and abstraction/elimination to the total rate to be determined. The rate coefficient for HCl production is described between 292 and 850 K by the Arrhenius expression, k(metathesis)(allene)(T) = (3.7 +/- 1.7) x 10(-10) exp-[-(1671 +/- 286)/T] cm(3) molecule(-1) s(-1), (all error bars +/-2 sigma precision only). In contrast with the Cl + allene reaction, both addition and metathesis appear to be important channels in the reaction of Cl + propyne near room temperature. The reactions display biexponential HCl time profiles at T less than or equal to 400 K, but at T greater than or equal to 500 K, only single-exponential evolution is observed. The HCl yield at 293 K is approximate to 70% and reaches unity at T greater than or equal to 500 K. A fit of the rate coefficient for HCl production between 400 less than or equal to T less than or equal to 800 K to standard Arrhenius form gives k(metathesis)(propyne)(T) = (3.7 +/- 1.0) x 10(-11) exp[-(685 +/- 151)/T] cm(3) molecule(-1) s(-1). The data over the whole 292-800 K temperature range exhibit curvature and are better fit by the modified Arrhenius expression (with the temperature exponent fixed at 2) k(metathesis)(propyne)(T) = (1.25 +/- 0.21) x 10(-12) (T/298)(2) exp[(500 +/- 93)/T] cm(3) molecule(-1) s(-1) (+/-2 sigma precision). Preliminary measurements are also presented for Cl + isobutene between 300 and 700 K, which were required to comet for the small butene contamination in the propyne, Measurements carried out in Ar buffer indicate that vibrationally excited HCl is formed with both allene and propyne and allow an estimate to be made for k(VET), the HCl (upsilon = 1) + C3H4 vibrational relaxation rate coefficient. In the Cl + allene reaction, approximately half (f = 0.42 +/- 0.10) of the HCl is formed in upsilon = 1, and k(VET) = (2.8 +/- 0.4) x 10(-12) cm(3) molecule(-1) s(-1); with propyne, the corresponding values are f = 0.55 +/- 0.09 and k(VET) = (8.6 +/- 3.6) x 10(-12) cm(3) molecule(-1) s(-1). The qualitatively different dynamics for Cl + aliene vs propyne can be attributed to formation of a resonantly stabilized radical with aliene (chloroallyl), which greatly enhances the addition rate. Comparisons are also made with recent ab initio calculations of energies and transition states for the Cl + C3H4 reactions. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Taatjes, CA (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. NR 48 TC 29 Z9 29 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 18 PY 1998 VL 102 IS 25 BP 4846 EP 4856 DI 10.1021/jp981265r PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV964 UT WOS:000074360000012 ER PT J AU Arkani-Hamed, N Dimopoulos, S Dvali, G AF Arkani-Hamed, N Dimopoulos, S Dvali, G TI The hierarchy problem and new dimensions at a millimeter SO PHYSICS LETTERS B LA English DT Article ID STRINGS AB We propose a new framework for solving the hierarchy problem which does not rely on either supersymmetry or technicolor. In this framework, the gravitational and gauge interactions become united at the weak scale, which we take as the only fundamental short distance scale in nature. The observed weakness of gravity on distances greater than or similar to 1 mm is due to the existence of n greater than or equal to 2 new compact spatial dimensions large compared to the weak scale. The Planck scale M-Pl similar to G(N)(-1/2) is not a fundamental scale; its enormity is simply a consequence of the large size of the new dimensions. While gravitons can freely propagate in the new dimensions, at sub-weak energies the Standard Model (SM) fields must be localized to a 4-dimensional manifold of weak scale "thickness" in the extra dimensions. This picture leads to a number of striking signals for accelerator and laboratory experiments. For the case of n = 2 new dimensions, planned sub-millimeter measurements of gravity may observe the transition from 1/r(2) --> 1/r(4) Newtonian gravitation. For any number of new dimensions, the LHC and NLC could observe strong quantum gravitational interactions. Furthermore, SM particles can be kicked off our 4 dimensional manifold into the new dimensions, carrying away energy, and leading to an abrupt decrease in events with high transverse momentum p(T) greater than or similar to TeV. For certain compact manifolds, such particles will keep circling in the extra dimensions, periodically returning, colliding with and depositing energy to our four dimensional vacuum with frequencies of similar to 10(12) Hz or larger. As a concrete illustration, we construct a model with SM fields localized on the 4-dimensional throat of a vortex in 6 dimensions, with a Pati-Salam gauge symmetry SU(4) X SU(2) X SU(2) in the bulk. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Int Ctr Theoret Phys, I-34100 Trieste, Italy. RP Arkani-Hamed, N (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 15 TC 4467 Z9 4489 U1 25 U2 150 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 18 PY 1998 VL 429 IS 3-4 BP 263 EP 272 DI 10.1016/S0370-2693(98)00466-3 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZZ088 UT WOS:000074694500008 ER PT J AU Graesser, M Morariu, B AF Graesser, M Morariu, B TI A non-perturbative non-renormalization theorem for the Wilsonian gauge couplings in supersymmetric theories SO PHYSICS LETTERS B LA English DT Article AB We present a direct proof that the holomorphic Wilsonian beta-function of a renormalizable asymptotically free supersymmetric gauge theory with an arbitrary semi-simple gauge group, matter content, and renormalizable superpotential is exhausted at 1-loop with no higher loops and no non-perturbative contributions. This is a non-perturbative extension of the well known result of Shifman and Vainshtein. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM graesser@thsrv.lbl.gov; bogdan@physics.berkeley.edu NR 9 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 18 PY 1998 VL 429 IS 3-4 BP 313 EP 318 DI 10.1016/S0370-2693(98)00485-7 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZZ088 UT WOS:000074694500014 ER PT J AU Acciarri, M Adriani, O Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chein, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muheim, F Muijs, AJM Nahn, S Napolitano, M Nessi-Tedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chein, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muheim, F Muijs, AJM Nahn, S Napolitano, M Nessi-Tedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Local multiplicity fluctuations in hadronic Z decay SO PHYSICS LETTERS B LA English DT Article ID HIGH-ENERGY COLLISIONS; QCD JETS; INTERMITTENCY; DETECTOR; ANNIHILATION; CONSTRUCTION; DIMENSIONS; SIMULATION; MOMENTS; Z(0) AB Local multiplicity fluctuations in hadronic Z decays are studied using the L3 detector at LEP. Bunching parameters are used for the first time in addition to the normalised factorial moment method. The bunching parameters directly demonstrate that the fluctuations in rapidity are multifractal. Monte Carlo models show agreement with the data, reproducing the trend, although not always the magnitude, of the factorial moments and bunching parameters. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ist Nazl Fis Nucl, I-20133 Milan, Italy. Rhein Westfal TH Aachen, Inst Phys 1, D-52056 Aachen, Germany. Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany. NIKHEF, Natl Inst High Energy Phys, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, NL-1009 DB Amsterdam, Netherlands. Univ Michigan, Ann Arbor, MI 48109 USA. Lab Annecy Le Vieux Phys Particules, CNRS, IN2P3, F-74941 Annecy Le Vieux, France. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Basel, Inst Phys, CH-4056 Basel, Switzerland. Inst High Energy Phys, Beijing 100039, Peoples R China. 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RI Fiandrini, Emanuele/C-4549-2008; Berdugo, Javier/A-2858-2015; D'Alessandro, Raffaello/F-5897-2015; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; OI Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Longo, Egidio/0000-0001-6238-6787; Ambrosi, Giovanni/0000-0001-6977-9559; Castellini, Guido/0000-0002-0177-0643; Read, Kenneth/0000-0002-3358-7667; Diemoz, Marcella/0000-0002-3810-8530; Doria, Alessandra/0000-0002-5381-2649; Sciacca, Crisostomo/0000-0002-8412-4072; Faccini, Riccardo/0000-0003-2613-5141; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Goldstein, Joel/0000-0003-1591-6014 NR 42 TC 9 Z9 9 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 18 PY 1998 VL 429 IS 3-4 BP 375 EP 386 DI 10.1016/S0370-2693(98)00438-9 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZZ088 UT WOS:000074694500023 ER PT J AU Acciarri, M Adriani, O Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GC Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Landi, G Lapoint, C Lassila-Perini, K Laurikainen, P Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Moulik, T Mount, R Muheim, F Muijs, AJM Nahn, S Napolitano, M Nessi-Tedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JS Tang, SW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, Z Ziegler, F AF Acciarri, M Adriani, O Aguilar-Benitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Boldizsar, L Borgia, B Bourilkov, D Bourquin, M Boutigny, D Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GC Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Costantini, S Cotorobai, F de la Cruz, B Csilling, A Dai, TS D'Alessandro, R de Asmundis, R Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M van Dierendonck, D Di Lodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y El Mamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN Garcia-Abia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Haas, D Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A Hirschfelder, J van Hoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW de Jong, P Josa-Mutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M Kienzle-Focacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Kopp, A Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A Lacentre, P de Guevara, PL Landi, G Lapoint, C Lassila-Perini, K Laurikainen, P Lavorato, A Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P Le Coultre, P Lee, HJ Leggett, C Le Goff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ von der Mey, M Mi, Y Migani, D Mihul, A van Mil, AJW Milcent, H Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Moulik, T Mount, R Muheim, F Muijs, AJM Nahn, S Napolitano, M Nessi-Tedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palit, S Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S Perret-Gallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, M Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D Quartieri, J Rahal-Callot, G Raja, N Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S van Rhee, T Riemann, S Riles, K Rind, O Robohm, A Rodin, J Roe, BP Romero, L Rosier-Lees, S Rosselet, P van Rossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sauvage, G Schafer, C Schegelsky, V Schmidt-Kaerst, S Schmitz, D Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JS Tang, SW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Vlachos, S Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, Z Ziegler, F TI Measurement of tau polarisation at LEP SO PHYSICS LETTERS B LA English DT Article ID LUND MONTE-CARLO; RADIATIVE-CORRECTIONS; DECAY CORRELATIONS; MICHEL PARAMETERS; NEUTRINO HELICITY; JET FRAGMENTATION; E+E ANNIHILATION; PAIR PRODUCTION; POLARIZATION; CONSTRUCTION AB Using the data collected with the L3 detector at LEP between 1990 and 1995, corresponding to an integrated luminosity of 149 pb(-1), the tau longitudinal polarisation has been measured as a function of the production polar angle using the tau decays tau(-) --> h(-)nu(tau) (h = pi,rho,a(1)) and tau(-)-->l(-)<(nu)over bar>(l)nu(tau) (l = e,mu). From this measurement the quantities A(c) and A(tau), which depend on the couplings of the electron and the tau to the Z, are determined to be A(c) = 0.1678 +/- 0.0127 +/- 0.0030 and A(tau) = 0.1476 +/- 0.0088 +/- 0.0062, consistent with the hypothesis of e-tau universality, Under this assumption a value of A(l) = 0.1540 +/- 0.0074 +/- 0.0044 is obtained, yielding the value of the effective weak mixing angle sin(2)<(theta)over bar>(W) = 0.2306 +/- 0.0011. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ist Nazl Fis Nucl, I-20133 Milan, Italy. Rhein Westfal TH Aachen, Inst Phys 1, D-52056 Aachen, Germany. Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany. NIKHEF, Natl Inst High Energy Phys, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, NL-1009 DB Amsterdam, Netherlands. Univ Michigan, Ann Arbor, MI 48109 USA. Lab Annecy Le Vieux Phys Particules, CNRS, IN2P3, F-74941 Annecy Le Vieux, France. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Basel, Inst Phys, CH-4056 Basel, Switzerland. Inst High Energy Phys, Beijing 100039, Peoples R China. Humboldt Univ, D-10099 Berlin, Germany. Univ Bologna, I-40126 Bologna, Italy. Ist Nazl Fis Nucl, I-40126 Bologna, Italy. Tata Inst Fundamental Res, Bombay 400005, Maharashtra, India. Boston Univ, Boston, MA 02215 USA. Northeastern Univ, Boston, MA 02115 USA. Inst Atom Phys, R-76900 Bucharest, Romania. Univ Bucharest, R-76900 Bucharest, Romania. Hungarian Acad Sci, Cent Res Inst Phys, H-1525 Budapest 114, Hungary. MIT, Cambridge, MA 02139 USA. Ist Nazl Fis Nucl, I-50125 Florence, Italy. Univ Florence, I-50125 Florence, Italy. CERN, European Lab Particle Phys, CH-1211 Geneva 23, Switzerland. FBLJA Project, World Lab, CH-1211 Geneva 23, Switzerland. Univ Geneva, CH-1211 Geneva 4, Switzerland. Univ Sci & Technol China, Hefei 230029, Anhui, Peoples R China. Res Inst High Energy Phys, SEFT, SF-00014 Helsinki, Finland. Univ Lausanne, CH-1015 Lausanne, Switzerland. Ist Nazl Fis Nucl, I-73100 Lecce, Italy. Univ Lecce, I-73100 Lecce, Italy. Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Univ Lyon 1, CNRS, IN2P3, Inst Phys Nucl Lyon, F-69622 Villeurbanne, France. CIEMAT, E-28040 Madrid, Spain. Inst Theoret & Expt Phys, Moscow 117259, Russia. Ist Nazl Fis Nucl, I-80125 Naples, Italy. Univ Naples Federico II, I-80125 Naples, Italy. Univ Cyprus, Dept Nat Sci, Nicosia, Cyprus. Catholic Univ Nijmegen, NL-6525 ED Nijmegen, Netherlands. Natl Inst Nucl Phys & High Energy Phys, NL-6525 ED Nijmegen, Netherlands. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. CALTECH, Pasadena, CA 91125 USA. Ist Nazl Fis Nucl, I-06100 Perugia, Italy. Univ Perugia, I-06100 Perugia, Italy. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Princeton Univ, Princeton, NJ 08544 USA. Ist Nazl Fis Nucl, I-00185 Rome, Italy. Univ Roma La Sapienza, I-00185 Rome, Italy. Russian Acad Sci, Inst Nucl Phys, St Petersburg, Russia. Univ Salerno, I-84100 Salerno, Italy. INFN, I-84100 Salerno, Italy. Univ Calif San Diego, San Diego, CA 92093 USA. Univ Santiago, Dept Fis Particulas Elementales, E-15706 Santiago De Compostela, Spain. Bulgarian Acad Sci, Cent Lab Mechatron & Instrumentat, BU-1113 Sofia, Bulgaria. Korea Adv Inst Sci & Technol, Ctr High Energy Phys, Taejon 305701, South Korea. Univ Alabama, Tuscaloosa, AL 35486 USA. Univ Utrecht, NL-3584 CB Utrecht, Netherlands. NIKHEF, NL-3584 CB Utrecht, Netherlands. Purdue Univ, W Lafayette, IN 47907 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. DESY, Inst Hochenergiephys, D-15738 Zeuthen, Germany. Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland. Univ Hamburg, D-22761 Hamburg, Germany. Natl Cent Univ, Chungli, Taiwan. Natl Tsing Hua Univ, Dept Phys, Hsinchu, Taiwan. RP Acciarri, M (reprint author), Ist Nazl Fis Nucl, Via Celoria 16, I-20133 Milan, Italy. RI Fiandrini, Emanuele/C-4549-2008; Lista, Luca/C-5719-2008; Josa, Isabel/K-5184-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; OI Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Produit, Nicolas/0000-0001-7138-7677 NR 40 TC 24 Z9 24 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 18 PY 1998 VL 429 IS 3-4 BP 387 EP 398 DI 10.1016/S0370-2693(98)00406-7 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZZ088 UT WOS:000074694500024 ER PT J AU Wang, J Houk, RS Dreessen, D Wiederin, DR AF Wang, J Houk, RS Dreessen, D Wiederin, DR TI Identification of inorganic elements in proteins in human serum and in DNA fragments by size exclusion chromatography and inductively coupled plasma mass spectrometry with a magnetic sector mass spectrometer SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOSPHATE DIESTERS; HUMAN ERYTHROCYTES; CANCER PREVENTION; HYDROLYSIS; BINDING; DAMAGE; RESOLUTION; REACTIVITY; COMPLEXES; SELENIUM AB A general method to identify trace elements in biological molecules is described. These measurements are made in only a few minutes without preliminary isolation and preconcentration steps; Many unusual or difficult elements, such as Cr, Se, Cd, Th, and U, can be observed at ambient levels bound to proteins in human serum. A new protein or family of proteins, that either contain Se or that bind Se molecules, is found with molecular weight similar to 760 kDa. Binding of metal cations to DNA restriction fragments can be studied by similar procedures both for essential elements such as Mn and Fe and toxic ones such as Cd and Pb. In particular, trace Pb, Cd, and Co are completely bound to DNA fragments. Reduction of chromate to a cation (probably Cr3+) and subsequent binding of the Cr cation to DNA is also demonstrated. C1 Iowa State Univ, US DOE, Ames Lab, Dept Chem, Ames, IA 50011 USA. Transgenom CETAC Technol Inc, Omaha, NE 68107 USA. RP Houk, RS (reprint author), Iowa State Univ, US DOE, Ames Lab, Dept Chem, Ames, IA 50011 USA. EM rshouk@iastate.edu NR 31 TC 35 Z9 35 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 17 PY 1998 VL 120 IS 23 BP 5793 EP 5799 DI 10.1021/ja9735970 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA ZV408 UT WOS:000074301600022 ER PT J AU Linehan, JC Yonker, CR Bays, JT Autrey, ST Bitterwolf, TE Gallagher, S AF Linehan, JC Yonker, CR Bays, JT Autrey, ST Bitterwolf, TE Gallagher, S TI A kinetic study of the thermal loss of ethylene from CpNb(CO)(3)(eta(2)-C2H4) in supercritical fluid solvents SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CARBON-DIOXIDE; HOMOGENEOUS CATALYSIS; FORMIC-ACID; HYDROGENATION; CR(CO)(5)(C2H4); SUBSTITUTION; N2 C1 Pacific NW Natl Lab, Dept Chem Sci, Richland, WA 99352 USA. Univ Idaho, Dept Chem, Moscow, ID 83844 USA. RP Linehan, JC (reprint author), Pacific NW Natl Lab, Dept Chem Sci, POB 999, Richland, WA 99352 USA. NR 19 TC 8 Z9 8 U1 0 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 JUN 17 PY 1998 VL 120 IS 23 BP 5826 EP 5827 DI 10.1021/ja974054t PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZV408 UT WOS:000074301600034 ER PT J AU George, EP Kennedy, RL Pope, DP AF George, EP Kennedy, RL Pope, DP TI Review of trace element effects on high-temperature fracture of Fe- and Ni-base alloys SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 4th International Conference on Ultra-High-Purity Metallic-Base Materials (UHPM-97) CY SEP 11-13, 1997 CL PHILADELPHIA, PENNSYLVANIA ID STRESS RELIEF CRACKING; BORON-DOPED NI3AL; MO-V STEELS; CREEP DUCTILITY; INTERGRANULAR FRACTURE; DYNAMIC EMBRITTLEMENT; ELEVATED-TEMPERATURE; SURFACE-DIFFUSION; NUCLEATION SITES; CR ALLOYS AB Trace elements can have harmful or beneficial effects on elevated-temperature mechanical properties. In iron and low-alloy steels, S at high concentrations forms sulfides which are potent nucleation sites for intergranular creep cavities. As a result, ductility decreases and fracture becomes increasingly intergranular with increasing S concentration. Oxides and nitrides nucleate cavities only in the presence of segregated S; by themselves they are relatively benign. The harmful effects of S can be ameliorated by the addition of carbon and phosphorus. It is unclear whether C and P have beneficial effects of their own, or whether they act merely by counteracting the negative effects of sulfur. Carbides almost never nucleate cavities. In Ni-base alloys, too, S is deleterious, and alloying with strong sulfide getters increases ductility and rupture life. Boron and P interact synergistically and increase stress rupture lives in some alloys but not in others. The detailed mechanism of this interaction is not well understood. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Allvac, Monroe, NC 28110 USA. Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. RP George, EP (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014 NR 104 TC 19 Z9 19 U1 0 U2 7 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD JUN 16 PY 1998 VL 167 IS 2 BP 313 EP 333 DI 10.1002/(SICI)1521-396X(199806)167:2<313::AID-PSSA313>3.0.CO;2-5 PG 21 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZY656 UT WOS:000074645900006 ER PT J AU Thompson, JA Scott, BL Sauer, NN AF Thompson, JA Scott, BL Sauer, NN TI Triethylenetetraminehexaacetic acid complex of lead SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID SOILS AB In the title compound, tetrasodium mu-[3,6,9,12-tetrakis( carboxymethyl)-3,6, 9,12-tetraazatetradecanedioato- 1 kappa(5)O(1),N-3, O-3,N-6,O-6: 2 kappa(5)N(9), (ON12)-N-9,(OO14)-O-12]dilead dinitrate decahydrate, Na-4[Pb-2(C18H24N4O12)](NO3)(2).-10H(2)O, the Pb2+ ions have highly distorted bonding geometry, with a primary coordination number of five and two secondary intermolecular contacts. The Pb-N bond distances range from 2.505(4) to 2.641(4) Angstrom, and the Pb-O bond distances range from 2.454(3) to 2.559 (3) Angstrom. The binuclear lead complexes sit on inversion centers and are bridged to form polymeric structures. The polymers are linked into sheets via N ... O contacts. C1 Polylonix Separat Technol Inc, Dayton, NJ 08810 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thompson, JA (reprint author), Polylonix Separat Technol Inc, Dayton, NJ 08810 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 15 TC 6 Z9 7 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD JUN 15 PY 1998 VL 54 BP 734 EP 736 DI 10.1107/S0108270197018428 PN 6 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 100PR UT WOS:000074825000016 ER PT J AU Janata, J Josowicz, M Vanysek, P DeVaney, DM AF Janata, J Josowicz, M Vanysek, P DeVaney, DM TI Chemical sensors SO ANALYTICAL CHEMISTRY LA English DT Review ID ION-SELECTIVE ELECTRODES; SURFACE-PLASMON-RESONANCE; ELECTROCHEMICAL GAS SENSORS; QUARTZ-CRYSTAL-MICROBALANCE; LANGMUIR-BLODGETT-FILMS; ACOUSTIC-WAVE SENSOR; THICKNESS-SHEAR MODE; AMPEROMETRIC HYDROGEN SENSOR; ARTIFICIAL NEURAL-NETWORK; SOLID-POLYMER ELECTROLYTE C1 Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. No Illinois Univ, Dept Chem, De Kalb, IL 60115 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. RI Vanysek, Petr/A-1949-2016 OI Vanysek, Petr/0000-0002-5458-393X NR 916 TC 138 Z9 139 U1 7 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 EI 1520-6882 J9 ANAL CHEM JI Anal. Chem. PD JUN 15 PY 1998 VL 70 IS 12 BP 179R EP 208R PG 30 WC Chemistry, Analytical SC Chemistry GA ZU095 UT WOS:000074161100008 ER PT J AU Yan, Y Pennycook, SJ Xu, Z Viehland, D AF Yan, Y Pennycook, SJ Xu, Z Viehland, D TI Determination of the ordered structures of Pb(Mg1/3Nb2/3)O-3 and Ba(Mg1/3Nb2/3)O-3 by atomic-resolution Z-contrast imaging SO APPLIED PHYSICS LETTERS LA English DT Article ID CERAMICS; PEROVSKITES; CRYSTALS AB The atomic structure of ordered domains in Ba(Mg1/3Nb2/3)O-3 and La-doped and undoped Pb(Mg1/3Nb2/3)O-3 is Studied by high-resolution Z-contrast imaging. The ordered domain structure in both doped and undoped Pb(Mg1/3Nb2/3)O-3 is determined to be in agreement with the charge balanced random-layer model and inconsistent with the space-charge model. It is shown that La doping in Pb(Mg1/3Nb2/3)O-3 enhances not only the domain size but also the degree of ordering. (C) 1998 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. RP Yan, Y (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM yanfa@solid.ssd.ornl.gov NR 15 TC 102 Z9 105 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 15 PY 1998 VL 72 IS 24 BP 3145 EP 3147 DI 10.1063/1.121574 PG 3 WC Physics, Applied SC Physics GA 108PG UT WOS:000075274200017 ER PT J AU Wei, SH Zhang, SB Zunger, A AF Wei, SH Zhang, SB Zunger, A TI Effects of Ga addition to CuInSe2 on its electronic, structural, and defect properties SO APPLIED PHYSICS LETTERS LA English DT Article AB Using a first-principles band structure method we have theoretically studied the effects of Ga additions on the electronic and structural properties of CuInSe2. We find that (i) with increasing x(Ga) the valence band maximum of CuIn1-xGaxSe2 (CIGS) decreases slightly, while the conduction band minimum (and the band gap) of CIGS increases significantly, (ii) the acceptor formation energies are similar in both CuInSe2 (CIS) and CuGaSe2 (CGS), but the donor formation energy is larger in CGS than in CIS, (iii) the acceptor transition levels are shallower in CGS than in CIS, but the Ga-Cu donor level in CGS is much deeper than the In-Cu donor level in CIS, and (iv) the stability domain of the chalcopyrite phase increases with respect to ordered defect compounds. Our results are compared with available experimental observations. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wei, SH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM shw@sst.nrel.gov RI Zunger, Alex/A-6733-2013; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 19 TC 292 Z9 295 U1 10 U2 133 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JUN 15 PY 1998 VL 72 IS 24 BP 3199 EP 3201 DI 10.1063/1.121548 PG 3 WC Physics, Applied SC Physics GA 108PG UT WOS:000075274200035 ER PT J AU Basilevsky, MV Rostov, IV Newton, MD AF Basilevsky, MV Rostov, IV Newton, MD TI A frequency-resolved cavity model (FRCM) for treating equilibrium and non-equilibrium solvation energies SO CHEMICAL PHYSICS LA English DT Article ID ELECTRON-TRANSFER THEORY; NONLOCAL ELECTROSTATICS; DIELECTRIC FUNCTION; IONIC SOLVATION; DIPOLAR LIQUIDS; POLAR-SOLVENT; DYNAMICS; RELAXATION; FLUIDS AB A refined continuum medium model, denoted as the 'frequency-resolved cavity model' (FRCM), for describing solvation effects of electrically charged solutes in polar solvents is considered. The principal distinction between the commonly accepted Born-Kirkwood-Onsager model and the FRCM treatment is that in the latter case the medium polarization field induced by the solute charge distribution is subdivided into inertial and inertialess components associated with different cavities. The inertialess field, arising from solvent electronic polarization modes, involves an inner cavity confined inside a larger one, which establishes the boundary for inertial polarization modes corresponding to collective orientational and translational motions of solvent molecules outside both cavities. The model is formulated so as to be applicable to complicated chemical solutes, with no symmetry limitations imposed on the shape of their cavities and charge distributions. In introducing two cavities, we find that a single extra parameter in the refined model, chosen to control the distinct sizes of the cavities, is capable of providing the necessary additional flexibility to the FRCM parametrization scheme. By this means one can redistribute inertial and inertialess contributions to equilibrium solvation energies in a way which is consistent with existing experimental data for both equilibrium solvation energy solvent reorganization energy. (C) 1998 Elsevier Science B.V. All rights reserved. C1 LY Karpov Phys Chem Res Inst, Moscow 103064, Russia. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Basilevsky, MV (reprint author), LY Karpov Phys Chem Res Inst, Ul Vorontsovo Pole 10, Moscow 103064, Russia. EM basil@cc.nifhi.ac.ru NR 36 TC 73 Z9 74 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 JUN 15 PY 1998 VL 232 IS 1-2 BP 189 EP 199 DI 10.1016/S0301-0104(98)00101-3 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV733 UT WOS:000074335600015 ER PT J AU Newton, MD Basilevsky, MV Rostov, IV AF Newton, MD Basilevsky, MV Rostov, IV TI A frequency-resolved cavity model (FRCM) for treating equilibrium and non-equilibrium solvation energies - 2: Evaluation of solvent reorganization energies SO CHEMICAL PHYSICS LA English DT Article ID ELECTRON-TRANSFER REACTIONS; DISTANCE; APPROXIMATION; PARAMETERS; MOLECULES; ANIONS AB The frequency-resolved cavity model (FRCM), a generalized continuum reaction field model, which allows for distinct effective solute cavities pertaining to optical top) and inertial tin) solvent response, has been implemented and applied to the evaluation of solvent reorganization energy (E-s) for a number of intramolecular electron transfer (ET) processes in polar media. Specifically, effective radii are defined for the solute atoms: r(infinity )= kappa . r(vdW )(where kappa is taken as a universal scale factor) and r(in) = r(infinity )+ delta (where delta is specific to a particular solvent). Optimal values of kappa and delta are determined through the use of solvation free energy data for small atomic and molecular ions, together with the experimental estimates of solvation reorganization energy (E-s) for intramolecular ET in the steroid-based radical ions studied by Closs, Miller and co-workers [G.L. Closs, L.T. Calcaterra, N.J. Green, K-W. Penfield, J.R. Miller, J. Phys. Chem. 90 (1986) 3673; M.D. Johnson, J.R. Miller, N.S. Green, G.L. Closs, J. Phys. Chem. 93 (1989) 1173; I.R. Miller, B.P. Paulson, R. Bal, G.L. Closs, J. Phys. Chem. 99 (1995) 6923]. With these optimal parameters, E-s is then evaluated for a number of other intramolecular ET processes, yielding results which are in generally good agreement with experimentally based estimates, and which give support for some of the assumptions employed in the analysis of the experimental data. Calculations with conventional solute atom radii (r(infinity) = r(in), with kappa = 1.2 and delta = 0) fitted to equilibrium solvation data yield E-s values exceeding the FRCM results by factors of greater than or equal to 2. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. LY Karpov Phys Chem Res Inst, Moscow 103064, Russia. RP Newton, MD (reprint author), Brookhaven Natl Lab, Dept Chem, POB 5000, Upton, NY 11973 USA. EM newton@bnl.gov NR 30 TC 73 Z9 73 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JUN 15 PY 1998 VL 232 IS 1-2 BP 201 EP 210 DI 10.1016/S0301-0104(98)00102-5 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV733 UT WOS:000074335600016 ER PT J AU Cheney, MA Shin, JY Crowley, DE Alvey, S Malengreau, N Sposito, G AF Cheney, MA Shin, JY Crowley, DE Alvey, S Malengreau, N Sposito, G TI Atrazine dealkylation on a manganese oxide surface SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE abiotic degradation; dealkylation; atrazine; birnessite; calorespirometry; pollutant breakdown ID SOIL; DEGRADATION; BIRNESSITE AB In this paper we report the first observation of abiotic N-dealkylation of the herbicide, atrazine[6-chloro-N-ethylN "-(l-methylethyl)- 1,3,5-triazine-2,4-diamine], by synthetic manganese oxide (delta-MnO(2)). The degradation reaction of the adsorbed herbicide was quantified at 30 degrees C by combined calorimetry, manometry, gas chromatography-mass spectrometry, liquid chromatography, and electron spin resonance spectroscopy. These combined methodologies gave clear evidence for the production of N-dealkylated forms of atrazine over a 48 h period of reaction on the surface of delta-MnO(2). This surface-catalyzed, non-photochemical abiotic N-dealkylation of the herbicide differs from known microbial pathways in soils by a higher rate of reaction and a different distribution of products among N-dealkylated forms. (C) 1998 Elsevier Science B.V. C1 Rutgers State Univ, Cook Coll, Dept Environm Sci, New Brunswick, NJ 08903 USA. Univ Calif Riverside, Dept Soil & Environm Sci, Riverside, CA 92521 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Cheney, MA (reprint author), Rutgers State Univ, Cook Coll, Dept Environm Sci, New Brunswick, NJ 08903 USA. EM cheney@aesop.rutgers.edu RI Crowley, David/C-1216-2014 OI Crowley, David/0000-0002-1805-8599 NR 28 TC 20 Z9 21 U1 3 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD JUN 15 PY 1998 VL 137 IS 1-3 BP 267 EP 273 DI 10.1016/S0927-7757(97)00368-3 PG 7 WC Chemistry, Physical SC Chemistry GA ZV051 UT WOS:000074263400026 ER PT J AU Waldfried, C McAvoy, T Welipitiya, D Dowben, PA Vescovo, E AF Waldfried, C McAvoy, T Welipitiya, D Dowben, PA Vescovo, E TI The influence of enhanced surface magnetism on finite-size scaling SO EUROPHYSICS LETTERS LA English DT Article ID CURIE-TEMPERATURE; FILMS; DEPENDENCE AB The thickness-dependent spin-polarized electronic structure of strained ultrathin and thin films of Gd has been investigated. The surface magnetic structure dominates the magnetic ordering of the ultrathin Gd films. With decreasing thickness some bulk bands exhibit increasingly more "passive" magnetic behavior. These bulk bands resemble a paramagnet over an increasing volume of the bulk Brillouin zone with decreasing film thickness. C1 Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. Univ Nebraska, Ctr Mat Res & Anal, Lincoln, NE 68588 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Waldfried, C (reprint author), Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. NR 24 TC 16 Z9 16 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUN 15 PY 1998 VL 42 IS 6 BP 685 EP 690 DI 10.1209/epl/i1998-00306-3 PG 6 WC Physics, Multidisciplinary SC Physics GA ZW257 UT WOS:000074391300017 ER PT J AU Carlson, CW McFadden, JP Ergun, RE Temerin, M Peria, W Mozer, FS Klumpar, DM Shelley, EG Peterson, WK Moebius, E Elphic, R Strangeway, R Cattell, C Pfaff, R AF Carlson, CW McFadden, JP Ergun, RE Temerin, M Peria, W Mozer, FS Klumpar, DM Shelley, EG Peterson, WK Moebius, E Elphic, R Strangeway, R Cattell, C Pfaff, R TI FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BIRKELAND CURRENTS; SHOCKS; MAGNETOSPHERE; FIELDS AB Observations of plasma particles and fields by the FAST satellite find evidence of acceleration of intense upgoing electron beams by quasi-static parallel electric fields. The beam characteristics include a broad energy spectrum with peak energies between 100 eV and 5 keV, perpendicular temperatures less than 1 eV, and fluxes greater than 10(9)/cm(2)sec. Diverging electrostatic shocks associated with the beams have integrated potentials that match the beam energy. These beams are found in regions of downward Birkeland current and account for the total field-aligned current when they are present. The most energetic ion conics in the auroral zone are found coincident with these beams, in agreement with the model for "trapped" conics. The measured particle densities of the electron beams and associated ion conics are approximately equal and typically range from 1 to 10 cm(-3), with no evidence for additional cold density. The beams are seen frequently at altitudes between 2000 and 4000 km in the winter auroral zone. Their probability of occurrence has a strong dependence on season and altitude and is similar to that for upgoing ion beams in the adjacent upward current regions. This similarity suggests that the density and scale height of ionospheric ions play an important role in the formation of both types of beams. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lockheed Palo Alto Res Labs, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. Univ Minnesota, Tate Lab Phys, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Carlson, CW (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 19 TC 221 Z9 220 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2017 EP 2020 DI 10.1029/98GL00851 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800002 ER PT J AU McFadden, JP Carlson, CW Ergun, RE Mozer, FS Temerin, M Peria, W Klumpar, DM Shelley, EG Peterson, WK Moebius, E Kistler, L Elphic, R Strangeway, R Cattell, C Pfaff, R AF McFadden, JP Carlson, CW Ergun, RE Mozer, FS Temerin, M Peria, W Klumpar, DM Shelley, EG Peterson, WK Moebius, E Kistler, L Elphic, R Strangeway, R Cattell, C Pfaff, R TI Spatial structure and gradients of ion beams observed by FAST SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ELECTROSTATIC SHOCKS; DISTRIBUTIONS; ALTITUDE; ACCELERATION AB High time resolution measurements of ion distributions by the FAST satellite have revealed kilometer scale spatial structure in the low altitude auroral acceleration region. The low altitude edge of the acceleration region appears to contain fingers of potential that extend hundreds of kilometers along B but are only a few to tens of kilometers wide. These fingers of potential do not appear to be strongly correlated with the local current or total potential drop. Gradients in the ion beam energy are found to be consistent with the electric field signatures expected in the quasi-static potential drop model of auroral acceleration. Typical ion beams show gradients of 0.5-1.0 keV/km, with some events as large a 3 keV/km. Integrations of the electric field along the spacecraft velocity are used to calculate parallel potential below FAST and are found to agree well with the ion beam energy for most events. One event is shown where an apparent temporal change in the auroral configuration occurs at the edge of the ion beam producing a disagreement between the beam energy and inferred potential. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lockheed Palo Alto Res Labs, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Minnesota, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McFadden, JP (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 13 TC 63 Z9 63 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2021 EP 2024 DI 10.1029/98GL00648 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800003 ER PT J AU Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L AF Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L TI FAST satellite observations of electric field structures in the auroral zone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PAIRED ELECTROSTATIC SHOCKS; DOUBLE-LAYERS; ALTITUDE; PARTICLE; DISTRIBUTIONS; MAGNETOSPHERE; ACCELERATION; ION AB Electric field and energetic particle observations by the Fast Auroral Snapshot (FAST) satellite provide convincing evidence of particle acceleration by quasi-static, magnetic-field-aligned (parallel) electric fields in both the upward and downward current regions of the auroral zone. We demonstrate this by comparing the inferred parallel potentials of electrostatic shocks with particle energies. We also report nonlinear electric field structures which may play a role in supporting parallel electric fields. These structures include large-amplitude ion cyclotron waves in the upward current region, and intense, spiky electric fields in the downward current region. The observed structures had substantial parallel components and correlative electron flux modulations. Observations of parallel electric fields in two distinct plasmas suggest that parallel electric fields may be a fundamental particle acceleration mechanism in astrophysical plasmas. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Tate Lab Phys, Minneapolis, MN 55455 USA. Lockheed Palo Alto Res Labs, Lockheed Martin, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. RP Ergun, RE (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Peterson, WK/A-8706-2009; Pfaff, Robert/F-5703-2012; OI Peterson, WK/0000-0002-1513-6096; Pfaff, Robert/0000-0002-4881-9715; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 24 TC 208 Z9 210 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 JUN 15 PY 1998 VL 25 IS 12 BP 2025 EP 2028 DI 10.1029/98GL00635 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800004 ER PT J AU Mobius, E Tang, L Kistler, LM Popecki, M Lund, EJ Klumpar, D Peterson, W Shelley, EG Klecker, B Hovestadt, D Carlson, CW Ergun, R McFadden, JP Mozer, F Temerin, M Cattell, C Elphic, R Strangeway, R Pfaff, R AF Mobius, E Tang, L Kistler, LM Popecki, M Lund, EJ Klumpar, D Peterson, W Shelley, EG Klecker, B Hovestadt, D Carlson, CW Ergun, R McFadden, JP Mozer, F Temerin, M Cattell, C Elphic, R Strangeway, R Pfaff, R TI Species dependent energies in upward directed ion beams over auroral arcs as observed with FAST TEAMS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ACCELERATION; WAVES; IONOSPHERE AB Upward flowing field-aligned ion beams over auroral arcs have been observed with the 3-dimensional ion mass spectrograph TEAMS on FAST. We have performed a statistical study on a sample of 77 ion beams from the auroral campaign in early 1997. All observed beams contain substantial amounts of H+, He+ and O+. A clear ordering of the total energies according to mass is found, with H+ having the lowest and O+ the highest energy. The composition varies significantly from beam to beam, with O+/H+ ratios ranging from = 0.1 to 10. No variation of the energy ratio between species is observed as a function of relative abundance, These results are discussed in the light of earlier observations of higher energies for O(+ )in statistical studies of beams during solar minimum and attempts to explain this behavior in terms of beam instabilities. C1 Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Lockheed Palo Alto Res Labs, Palo Alto, CA 94304 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mobius, E (reprint author), Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. RI Peterson, WK/A-8706-2009; Pfaff, Robert/F-5703-2012; OI Peterson, WK/0000-0002-1513-6096; Pfaff, Robert/0000-0002-4881-9715; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 17 TC 19 Z9 20 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 JUN 15 PY 1998 VL 25 IS 12 BP 2029 EP 2032 DI 10.1029/98GL00381 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800005 ER PT J AU Elphic, RC Bonnell, JW Strangeway, RJ Kepko, L Ergun, RE McFadden, JP Carlson, CW Peria, W Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L Pfaff, R AF Elphic, RC Bonnell, JW Strangeway, RJ Kepko, L Ergun, RE McFadden, JP Carlson, CW Peria, W Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L Pfaff, R TI The auroral current circuit and field-aligned currents observed by FAST SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CURRENT-VOLTAGE RELATIONSHIP; ELECTRIC-FIELDS; DE-2; IONOSPHERE; REGIONS; ENERGY; MODEL; ARC AB FAST observes signatures of small-scale downward-going current at the edges of the inverted-V regions where the primary (auroral) electrons are found. In the winter pre-midnight auroral zone these downward currents are carried by upward flowing low- and medium-energy (up to several keV) electron beams. FAST instrumentation shows agreement between the current densities inferred from both the electron distributions and gradients in the magnetic field. FAST data taken near apogee (similar to 4000-km altitude) commonly show downward current magnetic field deflections consistent with the observed upward flux of similar to 10(9) electrons cm(-2) s(-1), or current densities of several mu A m(-2). The electron, field-aligned current and electric field signatures indicate the downward currents may be associated with "black aurora" and auroral ionospheric cavities. The field-aligned voltage-current relationship in the downward current region is nonlinear. C1 Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Lockheed Martin Palo Alto Res Labs, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Elphic, RC (reprint author), Univ Calif Los Alamos Natl Lab, Space & Atmospher Sci Grp, MS D466, Los Alamos, NM 87545 USA. RI Kepko, Larry/D-7747-2012; Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Kepko, Larry/0000-0002-4911-8208; Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 20 TC 63 Z9 63 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2033 EP 2036 DI 10.1029/98GL01158 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800006 ER PT J AU Pfaff, R Clemmons, J Carlson, C Ergun, R McFadden, J Mozer, F Temerin, M Klumpar, D Peterson, W Shelley, E Moebius, E Kistler, L Strangeway, R Elphic, R Cattell, C AF Pfaff, R Clemmons, J Carlson, C Ergun, R McFadden, J Mozer, F Temerin, M Klumpar, D Peterson, W Shelley, E Moebius, E Kistler, L Strangeway, R Elphic, R Cattell, C TI Initial FAST observations of acceleration processes in the cusp SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR CUSP; PRECIPITATION; FIELD; DE-1 AB FAST satellite observations during two encounters with the Earth's cusps near 4000 km are presented. In addition to precipitating magnetosheath particles with isotropic pitch angle distributions, the energetic particle data reveal upgoing ion beams, ion conics, downgoing "inverted-V" electron distributions, and very narrow, intense upgoing electron beams. A rich assortment of DC-coupled electric fields and plasma waves accompany these acceleration processes. In one example, steplike injections of magnetosheath ions are correlated with bursts of upgoing ion beams and downgoing electrons, suggesting that the currents associated with these injections set up local electric potential structures that subsequently drive the acceleration processes. The observations underscore the fact that the cusp is not merely a conduit for the passage of magnetosheath particles and fields, but contains a dynamic internal electrical structure that accelerates particles locally and may alter the precipitating magnetosheath particle populations themselves. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lockheed Palo Alto Lab, Palo Alto, CA USA. Univ New Hampshire, Durham, NH 03824 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Pfaff, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Peterson, WK/A-8706-2009; Pfaff, Robert/F-5703-2012; OI Peterson, WK/0000-0002-1513-6096; Pfaff, Robert/0000-0002-4881-9715; Clemmons, James/0000-0002-5298-5222; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 9 TC 25 Z9 25 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 JUN 15 PY 1998 VL 25 IS 12 BP 2037 EP 2040 DI 10.1029/98GL00936 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800007 ER PT J AU Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Roth, I Muschietti, L Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L AF Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Roth, I Muschietti, L Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelley, E Peterson, W Moebius, E Kistler, L TI FAST satellite observations of large-amplitude solitary structures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WAVES AB We report observations of "fast solitary waves" that are ubiquitous in downward current regions of the mid-altitude auroral zone. The single-period structures have large amplitudes (up to 2.5 V/m), travel much faster than the ion acoustic speed, carry substantial potentials (up to similar to 100 Volts), and are associated with strong modulations of energetic electron fluxes. The amplitude and speed of the structures distinguishes them from ion-acoustic solitary waves or weak double layers. The electromagnetic signature appears to be that of an positive charge (electron hole) traveling anti-earthward. We present evidence that the structures are in or near regions of magnetic-field-aligned electric fields and propose that these nonlinear structures play a key role in supporting parallel electric fields in the downward current region of the auroral zone. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Tate Lab Phys, Minneapolis, MN 55455 USA. Lockheed Palo Alto Res Labs, Lockheed Martin, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. RP Ergun, RE (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM ree@ssl.berkeley.edu; cwc@ssl.berkeley.edu; mcfadden@ssl.berkeley.edu; gdelory@ssl.berkeley.edu; peria@ssl.berkeley.edu; ccc@ssl.berkeley.edu; temerin@ssl.berkeley.edu; ilan@ssl.berkeley.edu; laurent@ssl.berkeley.edu; relphic@lanl.gov; strange@igpp.ucla.edu; rob.pfaff@gsfc.nasa.gov; cattell@belka.spa.umn.edu; klump@agena.space.lookhead.com; moebius@rotor.sr.unh.edu; kistler@rotor.sr.unh.edu RI Peterson, WK/A-8706-2009; Pfaff, Robert/F-5703-2012; OI Peterson, WK/0000-0002-1513-6096; Pfaff, Robert/0000-0002-4881-9715; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 15 TC 341 Z9 344 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2041 EP 2044 DI 10.1029/98GL00636 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800008 ER PT J AU McFadden, JP Carlson, CW Ergun, RE Chaston, CC Mozer, FS Temerin, M Klumpar, DM Shelley, EG Peterson, WK Moebius, E Kistler, L Elphic, R Strangeway, R Cattell, C Pfaff, R AF McFadden, JP Carlson, CW Ergun, RE Chaston, CC Mozer, FS Temerin, M Klumpar, DM Shelley, EG Peterson, WK Moebius, E Kistler, L Elphic, R Strangeway, R Cattell, C Pfaff, R TI Electron modulation and ion cyclotron waves observed by FAST SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR MAGNETOSPHERE AB New observations from the FAST satellite demonstrate strong wave-particle interactions between energetic electrons and H+ EMIC waves in inverted-V arcs. The intense waves are shown to occur in strong upward current regions which contain intense downgoing field-aligned electron fluxes. Electrons near the inverted-V spectral peak have large, factor of 2 to 10, coherent flux modulations at or near the wave frequency. The electron modulations are typically centered at about f(CH+)/2, where f(CH+) is the local H+ cyclotron frequency. The EMIC waves are broadbanded, extending from about 0.3f(CH+) to 0.7f(CH+). These waves also accelerate cold secondary electrons, forming counterstreaming field-aligned electrons at energies up to about 300 eV.In addition, electron modulations at f(CH+) are observed in the density cavities associated with upgoing ion beams. Intense waves at f(CH+) are simultaneously detected and shown to have a magnetic component similar to the EMIC waves. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Lockheed Martin Palo Alto Res Labs, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Minnesota, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McFadden, JP (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 8 TC 55 Z9 55 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 JUN 15 PY 1998 VL 25 IS 12 BP 2045 EP 2048 DI 10.1029/98GL00855 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800009 ER PT J AU Lund, EJ Mobius, E Tang, L Kistler, LM Popecki, MA Klumpar, DM Peterson, WK Shelley, EG Klecker, B Hovestadt, D Temerin, M Ergun, RE McFadden, JP Carlson, CW Mozer, FS Elphic, RC Strangeway, RJ Cattell, CA Pfaff, RF AF Lund, EJ Mobius, E Tang, L Kistler, LM Popecki, MA Klumpar, DM Peterson, WK Shelley, EG Klecker, B Hovestadt, D Temerin, M Ergun, RE McFadden, JP Carlson, CW Mozer, FS Elphic, RC Strangeway, RJ Cattell, CA Pfaff, RF TI FAST observations of preferentially accelerated He+ in association with auroral electromagnetic ion cyclotron waves SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FLICKERING AURORA; ELF WAVES; MECHANISM AB The TEAMS instrument on the FAST satellite has detected events in which He+ ions are resonantly accelerated perpendicular to the magnetic field to energies of several keV. The events occur in association with electromagnetic ion cyclotron (EMIC) waves and conic distributions of up to a few hundred eV in H+ and a few keV in O+. Concentrations of Het can be significantly elevated during the events. Our interpretation is that the He+ ions are accelerated through a cyclotron resonance with the waves. This acceleration is similar to a proposed mechanism for selective ion acceleration in impulsive solar flares. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Lockheed Martin Palo Alto Res Lab, Palo Alto, CA 94304 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Lund, EJ (reprint author), Univ New Hampshire, Ctr Space Sci, Morse Hall, Durham, NH 03824 USA. EM Eric.Lund@unh.edu RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Lund, Eric/0000-0003-1312-9375; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 19 TC 29 Z9 29 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 JUN 15 PY 1998 VL 25 IS 12 BP 2049 EP 2052 DI 10.1029/98GL00304 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800010 ER PT J AU Cattell, C Bergmann, R Sigsbee, K Carlson, C Chaston, C Ergun, R McFadden, J Mozer, FS Temerin, M Strangeway, R Elphic, R Kistler, L Moebius, E Tang, L Klumpar, D Pfaff, R AF Cattell, C Bergmann, R Sigsbee, K Carlson, C Chaston, C Ergun, R McFadden, J Mozer, FS Temerin, M Strangeway, R Elphic, R Kistler, L Moebius, E Tang, L Klumpar, D Pfaff, R TI The association of electrostatic ion cyclotron waves, ion and electron beams and field-aligned currents: FAST observations of an auroral zone crossing near midnight SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDROGEN CYCLOTRON; INSTABILITIES; LINES; H+ AB FAST particle and wave data for a single nightside auroral zone crossing are utilized to examine the free energy source for electrostatic ion cyclotron (EIC) waves. Comparisons of the unstable wave modes, obtained by an electrostatic linear dispersion relation solver, to the observed waves for two intervals with upflowing ion beams and two with upflowing electron beams are consistent with the conclusion that the observed waves near the cyclotron frequencies are EIC which are driven by the electron drift both in the upgoing ion beam regions and in the upgoing electron regions. A limitation is that the drifting bi-Maxwellian model used in the dispersion relation is not a good match to the observed upflowing electron distributions. The observed ion beams do not drive EIC waves; however, the relative drift of the various ion species comprising the ion beam can drive low frequency (1 V/m and often have a magnetic component even above the proton cyclotron frequency (Omega(p)) with amplitudes up to 2nT. Waves with transverse amplitudes greater than 100 mV/m often exhibit large spiky downward pointing field-aligned components with amplitudes that may exceed that of transverse fluctuation. The ratio of electric to magnetic fluctuation amplitude (E-1/B-1) is dose to c. Using the 3 dimensional electric and magnetic field measurements available from FAST it is demonstrated that these waves are in most cases polarized transverse to the ambient magnetic field (B-0) and have linear polarization with wavelengths perpendicular to B(0 )ranging from hundreds of meters to kilometers. Calculations of the Poynting vector associated with these ICWs indicates Poynting fluxes directed downwards along B(0 )for waves below the local ap and generally upwards for waves observed close to and above this frequency with fluxes which may exceed 10% of the total field-aligned electron beam energy flux. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Lockheed Martin Palo Alto Res Labs, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Chaston, CC (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 24 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2057 EP 2060 DI 10.1029/98GL00513 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800012 ER PT J AU Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelly, E Peterson, W Moebius, E Kistler, L AF Ergun, RE Carlson, CW McFadden, JP Mozer, FS Delory, GT Peria, W Chaston, CC Temerin, M Elphic, R Strangeway, R Pfaff, R Cattell, CA Klumpar, D Shelly, E Peterson, W Moebius, E Kistler, L TI FAST satellite wave observations in the AKR source region SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AURORAL KILOMETRIC RADIATION; VIKING SATELLITE; GENERATION; FIELD AB The Fast Auroral SnapshoT (FAST) satellite has made observations in the Auroral Kilometric Radiation (AKR) source region with unprecedented frequency and time resolution. We confirm the AKR source is in a density depleted cavity and present examples in which cold electrons appeared to have been nearly evacuated (n(hot) > n(cold)) Electron distributions were depleted at low-energies and up-going ion beams were always present. Source region amplitudes were far greater than previously reported, reaching 2x10(-4) (V/m)(2)/Hz (300 mV/m) in short bursts with bandwidths generally < 1 kHz. Intense emissions were often at the edge of the density cavity. Emissions were near or below the cold plasma electron cyclotron frequency in the source region, and were almost entirely electromagnetic. The \E\/\B\ ratio was constant as a function of frequency and rarely displayed any features that would identify a cold plasma cutoff or resonance. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Tate Lab Phys, Minneapolis, MN 55455 USA. Lockheed Palo Alto Res Labs, Lockheed Martin, Palo Alto, CA 94304 USA. Univ New Hampshire, Durham, NH 03824 USA. RP Ergun, RE (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 17 TC 140 Z9 141 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2061 EP 2064 DI 10.1029/98GL00570 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800013 ER PT J AU Strangeway, RJ Kepko, L Elphic, RC Carlson, CW Ergun, RE McFadden, JP Peria, WJ Delory, GT Chaston, CC Temerin, M Cattell, CA Mobius, E Kistler, LM Klumpar, DM Peterson, WK Shelley, EG Pfaff, RE AF Strangeway, RJ Kepko, L Elphic, RC Carlson, CW Ergun, RE McFadden, JP Peria, WJ Delory, GT Chaston, CC Temerin, M Cattell, CA Mobius, E Kistler, LM Klumpar, DM Peterson, WK Shelley, EG Pfaff, RE TI FAST observations of VLF waves in the auroral zone: Evidence of very low plasma densities SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID KILOMETRIC RADIATION SOURCES; RELATIVISTIC DISPERSION; PROPAGATION; GENERATION; REGION AB The Fast Auroral SnapshoT (FAST) explorer frequently observes the auroral density cavity, which is the source region for Auroral Kilometric Radiation (AKR). An important factor in the generation of AKR is the relative abundance of hot and cold electrons within the cavity, since hot electrons introduce relativistic modifications to the wave dispersion. VLF wave-form data acquired by FAST within the auroral density cavity show clear signatures of whistler-mode waves propagating on the resonance cone. This allows us to obtain the electron plasma frequency, and the cavity often has densities < 1 cm(-3). Moreover, the hot electrons can be the dominant electron species, enabling AKR to be generated below the cold electron gyro-frequency. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Lockheed Martin Palo Alto Res Lab, Palo Alto, CA 94304 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Strangeway, RJ (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RI Kepko, Larry/D-7747-2012; Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Kepko, Larry/0000-0002-4911-8208; Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Moebius, Eberhard/0000-0002-2745-6978; Cattell, Cynthia/0000-0002-3805-320X NR 13 TC 91 Z9 91 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2065 EP 2068 DI 10.1029/98GL00664 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800014 ER PT J AU Sigsbee, K Cattell, CA Lysak, RL Carlson, CW Ergun, RE McFadden, JP Mozer, F Elphic, RC Strangeway, RJ Tsuruda, K Yamamoto, T Kokubun, S Fairfield, D Pfaff, R Parks, G Brittnacher, M AF Sigsbee, K Cattell, CA Lysak, RL Carlson, CW Ergun, RE McFadden, JP Mozer, F Elphic, RC Strangeway, RJ Tsuruda, K Yamamoto, T Kokubun, S Fairfield, D Pfaff, R Parks, G Brittnacher, M TI FAST - Geotail correlative studies of magnetosphere ionosphere coupling in the nightside magnetosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FIELD AB Data from conjunctions between FAST and Geotail were used to examine the physical processes which mediate coupling between the magnetotail at 30 R-E and the nightside auroral zone near 1.5 R-E. During one conjunction, Geotail observed a large scale recovery of the plasma sheet and several partial thinnings. Two of these encounters with the plasma sheet boundary were recorded by Polar at high latitudes on the dawn flank, indicating the global nature of the plasma sheet motions. Wavelet analysis of the FAST and Geotail electric and magnetic field data revealed low frequency waves which may be involved in magnetosphere-ionosphere coupling. A brief electromagnetic pulse with a frequency of 0.9 Hz consistent with the Alfvenic structures discussed by Lysak [1997] was observed by FAST. Oscillations near this frequency were also observed in the Geotail electric field data. Signatures consistent with field line resonances in the frequency range 0.03 to 0.05 Hz were recorded by both FAST and Geotail. This is the first time these types of structures have been observed simultaneously in the auroral zone and the magnetotail. C1 Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Nagoya Univ, STELAB, Toyokawa 442, Japan. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Washington, Seattle, WA 98195 USA. RP Sigsbee, K (reprint author), Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RI Pfaff, Robert/F-5703-2012; OI Pfaff, Robert/0000-0002-4881-9715; Sigsbee, Kristine/0000-0001-8727-380X; Cattell, Cynthia/0000-0002-3805-320X NR 9 TC 7 Z9 7 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 JUN 15 PY 1998 VL 25 IS 12 BP 2077 EP 2080 DI 10.1029/97GL03769 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800017 ER PT J AU Kistler, LM Mobius, E Klumpar, DM Popecki, MA Tang, L Jordanova, V Klecker, B Peterson, WK Shelley, EG Hovestadt, D Temerin, M Ergun, RE McFadden, JP Carlson, CW Mozer, FS Elphic, RC Strangeway, RJ Cattell, CA Pfaff, RF AF Kistler, LM Mobius, E Klumpar, DM Popecki, MA Tang, L Jordanova, V Klecker, B Peterson, WK Shelley, EG Hovestadt, D Temerin, M Ergun, RE McFadden, JP Carlson, CW Mozer, FS Elphic, RC Strangeway, RJ Cattell, CA Pfaff, RF TI FAST/TEAMS observations of charge exchange signatures in ions mirroring at low altitudes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RING CURRENT IONS; ELECTRIC-FIELDS; MAGNETOSPHERE; PROTON; MODEL; CONVECTION; PARTICLES; STORMS AB Using the TEAMS instrument on FAST, we have observed a case in which signatures of the inner edge of the plasma sheet are clearly observed in the energy spectra of ions mirroring at the FAST altitude. That inner edge is dominated by He+. We show that this is the natural composition expected from charge exchange as the ions drift in from the plasma sheet. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Lockheed Martin Palo Alto Res Lab, Palo Alto, CA 94304 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kistler, LM (reprint author), Univ New Hampshire, Ctr Space Sci, Morse Hall, Durham, NH 03824 USA. RI Pfaff, Robert/F-5703-2012; Peterson, WK/A-8706-2009; OI Pfaff, Robert/0000-0002-4881-9715; Peterson, WK/0000-0002-1513-6096; Cattell, Cynthia/0000-0002-3805-320X; Jordanova, Vania/0000-0003-0475-8743 NR 20 TC 11 Z9 11 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1998 VL 25 IS 12 BP 2085 EP 2088 DI 10.1029/98GL00331 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZV204 UT WOS:000074280800019 ER PT J AU Clark, DL Conradson, SD Keogh, DW Palmer, PD Scott, BL Tait, CD AF Clark, DL Conradson, SD Keogh, DW Palmer, PD Scott, BL Tait, CD TI Identification of the limiting species in the plutonium(IV) carbonate system. Solid state and solution molecular structure of the [Pu(CO3)(5)](6-) ion SO INORGANIC CHEMISTRY LA English DT Article ID URANYL CARBONATE; AQUEOUS-SOLUTION; COMPLEXES; RAMAN; EXAFS AB The identity of the limiting Pu(IV) species under high carbonate concentrations has been determined to be PU(CO3)(5)(6-). Single crystals of [Na6Pu(CO3)(5)](2). Na2CO3. 33H(2)O were obtained from a 0.15 M solution of Pu(IV) in 2.6M Na2CO3. The asymmetric unit contains a complex network consisting of [Pu(CO3)(5)](6-) anions and Na+ cations which are linked through interactions with CO32- and H2O ligands. Each Na+ ion is coordinated to the O atoms of H2O or CO32- ligands such that the Na+ ions achieve either octahedral or square-based pyramidal coordination. The [Pu(CO3)(5)](6-) anion can be viewed as a pseudohexagonal bipyramid with three CO32- ligands in a equatorial plane and two in axial positions. EXAFS data for Pu(IV) in 2.5M Na2CO3 solution were collected at the Pu LIII edge. Curve fitting reveals three shells in the FT spectrum. The first shell contains ten O atoms with Pu-O = 2.42(2) Angstrom; the second shell was fit with five C atoms with Pu- - -C = 2;89(2) Angstrom; and the third shell was fit with five O atoms with Pu- - -O = 4.17(2) Angstrom. These distances and coordination numbers correspond well with the average Pu-O, nonbonding Pu- - -C, and distal Pu- - -O distances of 2.415(7), 2.874(9), and 4.117(10) Angstrom. respectively, found in the [Pu(CO3)(5)](6-) ion in the solid-state structure of [Na6Pu(CO3)(5)](2). Na2CO3. 33H(2)O. The UV-vis diffuse reflectance spectrum of a single crystal of [Na6Pu(CO3)(5)](2). Na2CO3. 33H(2)O ground into a powder is nearly identical to the solution absorption spectrum of the limiting Pu(IV) carbonate complex in 2.5 M Na2CO3 solution. The peak by peak correspondence by position and relative absorption strengths, along with solution EXAFS data, suggest that the Pu(IV) chromophore is the same in both cases, and confirms that the [Pu(CO3)(5)](6-) ion is the limiting species in high carbonate solutions. Crystal data for [Na6Pu(CO3)(5)](2). Na2CO3. 33H(2)O: monoclinic space group P21/c (No. 14), a = 9.860(2) Angstrom, b = 17.427(2) Angstrom, c = 18.210(1) Angstrom, beta = 101.42(1)degrees, Z= 2, R-1 = 0.0337, wR(2) = 0.0775. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. RP Clark, DL (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Mail Stop E500, Los Alamos, NM 87545 USA. RI Clark, David/A-9729-2011; Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 45 TC 46 Z9 47 U1 2 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUN 15 PY 1998 VL 37 IS 12 BP 2893 EP 2899 DI 10.1021/ic971190q PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA ZV268 UT WOS:000074287600013 ER PT J AU Rabinovich, D Bott, SG Nielsen, JB Abney, KD AF Rabinovich, D Bott, SG Nielsen, JB Abney, KD TI Trimethylsilyl iodide as a halide exchange reagent in inorganic chemistry: synthesis and structure of Cp-2*ThI2 (Cp* = eta(5)-C5Me5) SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; pentamethylcyclopentadienyl complexes; thorium complexes; iodotrimethylsilane ID RAY CRYSTAL-STRUCTURES; COMPLEXES; ACTINIDE; REACTIVITY; LIGANDS; HYDRIDE; ALKYL; BOND AB The bis(pentamethylcyclopentadienyl)thorium(IV) complex Cp*2ThI2 (Cp*=eta(5)-C5Me5) was readily synthesized from the dibromo derivative Cp*2ThBr2 using a slight excess of trimethylsilyl iodide (>u(104) >u(101). This suggests that the strong (101) preferred orientation of LiCoO2 films (greater than or equal to 1 mu m thick) is due to the tendency to minimize volume strain energy that arises from differential thermal expansion between the film and the substrate. Additional properties obtained from the GULP calculations include the free energy, heat capacity, and the k=0 vibrational modes. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Hart, FX (reprint author), Univ South, Dept Phys, Sewanee, TN 37383 USA. EM joh@ornl.gov NR 39 TC 63 Z9 65 U1 2 U2 63 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1998 VL 83 IS 12 BP 7560 EP 7566 DI 10.1063/1.367521 PG 7 WC Physics, Applied SC Physics GA 108GJ UT WOS:000075257500021 ER PT J AU Ren, JZ Rose, GA Williams, RS Booth, CH Shuh, DK AF Ren, JZ Rose, GA Williams, RS Booth, CH Shuh, DK TI Atomic structure and phase transitions in disordered Ti1-xGaxN thin films grown by pulsed laser deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CONTACTS; GAN; NITRIDE AB We report here the growth by pulsed laser deposition and characterization of metastable disordered Ti1-xGaxN alloy thin films on Al2O3(0001) substrates. X-ray diffraction and x-ray-absorption fine-structure analyses showed that the films contained a single rocksaltlike atomic structure for 0 less than or equal to x<0.45, a single wurtzite-like structure for 0.75 less than or equal to x less than or equal to 1, and a mixture of both structures for 0.45 less than or equal to x<0.75. Over most of the composition range, the alloy films were predominantly amorphous with some fraction of nanocrystalline material present. Electrical conductivity measurements showed that the structural transition near x approximate to 0.5 is accompanied by a metal-insulator transition. This study provides an increased understanding of the TiN-GaN pseudobinary phase field, which has potential technological implications for metallic contacts to GaN devices. (C) 1998 American Institute of Physics.. C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ren, JZ (reprint author), Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. EM renj@chem.ucla.edu RI Williams, R. Stanley/A-8281-2009; Booth, Corwin/A-7877-2008 OI Williams, R. Stanley/0000-0003-0213-4259; NR 13 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1998 VL 83 IS 12 BP 7613 EP 7617 DI 10.1063/1.367877 PG 5 WC Physics, Applied SC Physics GA 108GJ UT WOS:000075257500027 ER PT J AU Michaelis, A Irene, EA Auciello, O Krauss, AR AF Michaelis, A Irene, EA Auciello, O Krauss, AR TI A study of oxygen diffusion in and out of YBa2Cu3O7-delta thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TRACER DIFFUSION; ELLIPSOMETRY; ANISOTROPY; INSITU; GROWTH AB The c-axis oriented YBa2CU3O7-delta (YBCO) films with superconducting transition temperatures up to 89 K were prepared by ion beam Sputter deposition on single crystal (100) MgO and (100) SrTiO3 substrates. The variation of the oxygen concentration delta during annealing in vacuum and in oxygen was measured in situ and in real time by means of spectroscopic ellipsometry. The ellipsometric measurables Delta and Psi were quantitatively correlated with delta at a photon energy of 4.1 eV. Changes of the oxygen concentration below 1% were resolved. Measurements for different film thicknesses in the range from 15 to 100 nm provided information to elucidate the mechanisms for oxygen out- and in-diffusion. The oxygen out-diffusion rate depends on the layer thickness confirming a bulk diffusion mechanism. The oxygen in-diffusion is relatively independent of layer thickness suggesting that a surface/grain boundary diffusion mechanism is dominant in this case. Additionally, the effect of H2O on the oxygen diffusion was studied. It was found that H2O enhances the oxygen out-diffusion while the in-diffusion remains unchanged or even decreases. The present study shows that ellipsometry provides a powerful tool for the in situ, noninvasive, on-line control of the oxygen content of thin YBCO films. (C) 1998 American Institute of Physics. C1 Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Michaelis, A (reprint author), Univ N Carolina, Dept Chem, CB 3290, Chapel Hill, NC 27599 USA. RI Michaelis, Alexander/R-9240-2016 OI Michaelis, Alexander/0000-0002-5987-1252 NR 19 TC 17 Z9 18 U1 1 U2 14 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1998 VL 83 IS 12 BP 7736 EP 7743 DI 10.1063/1.367947 PG 8 WC Physics, Applied SC Physics GA 108GJ UT WOS:000075257500048 ER PT J AU Giese, A Bracht, H Stolwijk, NA Walton, JT AF Giese, A Bracht, H Stolwijk, NA Walton, JT TI Out-diffusion of Zn from Si: A method to study vacancy properties in Si SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID POINT-DEFECTS; SILICON; GOLD; KINETICS; ZINC AB We report out-diffusion experiments of Zn from homogeneously Zn-doped Si samples which were performed at 1107 degrees C. Depth distributions of Zn recorded by spreading-resistance profiling are accurately described on the basis of simultaneous contributions of the kick-out and dissociative diffusion mechanism. Analysis of the profiles reveals that Zn out-diffusion is mainly mediated by the dissociative mechanism. Fitting of Zn profiles yields data for the transport capacity of vacancies (CVDV)-D-eq in Si and their thermal equilibrium concentration Ce-V(eq). (C) 1998 American Institute of Physics. C1 Univ Munster, Inst Met Forsch, D-48149 Munster, Germany. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Giese, A (reprint author), Univ Munster, Inst Met Forsch, Wilhelm Klemm Str 10, D-48149 Munster, Germany. NR 11 TC 15 Z9 15 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1998 VL 83 IS 12 BP 8062 EP 8064 DI 10.1063/1.367900 PG 3 WC Physics, Applied SC Physics GA 108GJ UT WOS:000075257500091 ER PT J AU Ahuja, R Fast, L Eriksson, O Wills, JM Johansson, B AF Ahuja, R Fast, L Eriksson, O Wills, JM Johansson, B TI Elastic and high pressure properties of ZnO SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRONIC-STRUCTURE; SEMICONDUCTORS ZNO; TRANSITION-METALS; MODEL; BAND; CONSTANTS; OXIDES; PHASE; FILMS AB We have studied the elastic and structural properties of ZnO by means of accurate first-principles total energy calculations using the full potential linear muffin tin orbital method. The calculations are based on the density functional theory and we have used the local density Hedin-Lundqvist parametrization and the generalized gradient approximation of Perdew and Wang for the exchange and correlation potential. The calculated values for the equilibrium volume, bulk modulus, and elastic constants are generally in very good agreement with experiments. At elevated pressures ZnO undergoes a structural phase transition from the relatively open wurtzite structure into the more dense NaCl atomic arrangement. The calculated transition pressure is in good agreement with experiment. (C) 1998 American Institute of Physics. C1 Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ahuja, R (reprint author), Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, Box 530, S-75121 Uppsala, Sweden. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 35 TC 82 Z9 91 U1 0 U2 16 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1998 VL 83 IS 12 BP 8065 EP 8067 DI 10.1063/1.367901 PG 3 WC Physics, Applied SC Physics GA 108GJ UT WOS:000075257500092 ER PT J AU Balooch, M Wu-Magidi, IC Balazs, A Lundkvist, AS Marshall, SJ Marshall, GW Siekhaus, WJ Kinney, JH AF Balooch, M Wu-Magidi, IC Balazs, A Lundkvist, AS Marshall, SJ Marshall, GW Siekhaus, WJ Kinney, JH TI Viscoelastic properties of demineralized human dentin measured in water with atomic force microscope (AFM)-based indentation SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE atomic force microscope (AFM); dentin; collagen; viscoelasticity; mechanical properties; elastic modulus ID HARDNESS; BONE AB Using an atomic force microscope (AFM) with an attachment specifically designed for indentation, we measured the mechanical properties of demineralized human dentin under three conditions: in water, in air after desiccation, and in water after rehydration. The static elastic modulus (Eh(r)(h) = 134 kPa) and viscoelastic responses (tau(epsilon) = 5.1 s and tau(sigma) = 6.6 s) of the hydrated, demineralized collagen scaffolding were determined from the standard Linear solid model of viscoelasticity. No significant variation of these properties was observed with location. On desiccation, the samples showed considerably larger elastic moduli (2 GPa), and a hardness value of 0.2 GPa was measured. Upon rehydration the elastic modulus decreased but did not fully recover to the value prior to dehydration (381 kPa). (C) 1998 John Wiley & Sons, Inc. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94551 USA. Univ Calif San Francisco, Dept Restorat Dent, San Francisco, CA 94143 USA. RP Kinney, JH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, 7000 E Ave, Livermore, CA 94551 USA. EM Kinney3@LLNL.GOV FU NIDCR NIH HHS [P01 DE09859, R01 DE11526] NR 18 TC 121 Z9 124 U1 3 U2 14 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD JUN 15 PY 1998 VL 40 IS 4 BP 539 EP 544 DI 10.1002/(SICI)1097-4636(19980615)40:4<539::AID-JBM4>3.0.CO;2-G PG 6 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA ZL733 UT WOS:000073465000004 PM 9599029 ER PT J AU Srebrow, A Friedmann, Y Ravanpay, A Daniel, CW Bissell, MJ AF Srebrow, A Friedmann, Y Ravanpay, A Daniel, CW Bissell, MJ TI Expression of Hoxa-1 and Hoxb-7 regulated by extracellular matrix-dependent signals in mammary epithelial cells SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE homeobox; mammary gland; morphogenesis; basement membrane; gene expression ID RECONSTITUTED BASEMENT-MEMBRANE; PROTEIN GENE-EXPRESSION; HOMEOBOX GENES; FUNCTIONAL-DIFFERENTIATION; ADHESION MOLECULE; TRANSGENIC MICE; MOUSE HOMEOBOX; ADULT MICE; GLAND; MORPHOGENESIS AB Homeobox-containing genes encode transcriptional regulators involved in cell fate and pattern formation during embryogenesis. Recently, it has become clear that their expression in continuously developing adult tissues, as well as in tumorigenesis, may be of equal importance. In the mouse mammary gland, expression patterns of several homeobox genes suggest a role in epithelial-stromal interactions. Because the stroma and the extracellular matrix (ECM) are known to influence both functional and morphological development of the mammary gland, we asked whether these genes would be expressed postnatally in the gland and also in cell lines in culture and whether they could be modulated by ECM. Using a polymerase chain reaction-base strategy five members of the Hox gene clusters a and b were shown to be expressed in cultured mouse mammary cells. Hoxa-1 and Hoxb-7 were chosen for further analysis. Hoxb-7 was chosen because it had not been described previously in the mammary gland and was modulated at different stages of gland development. Hoxa-1 was chosen because it was reported previously to be expressed only in mammary tumors, and not in normal glands. We showed that culturing the mammary epithelial cell lines SCp2 and CID-9 on a basement membrane (BM) thai was previously shown to induce a lactational phenotype was necessary to turn off Hoxb-7 but a change in cell shape, brought about by culturing the cells on an inert substratum such as polyHEMA, was sufficient to downregulate Hoxa-1. This is the first report of modulation of homeobox genes by ECM. The results provide a rationale for the differential pattern of expression in vivo of Hoxa-1 and Hoxb-7 during different stages of development. The culture model should permit further in-depth analysis of the molecular mechanisms involved in how ECM signaling and homeobox genes may interact to bring about tissue organization. (C) 1998 Wiley-Liss, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Santa Cruz, Dept Biol, Santa Cruz, CA 95064 USA. RP Bissell, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,MS 83-101, Berkeley, CA 94720 USA. NR 77 TC 50 Z9 50 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PD JUN 15 PY 1998 VL 69 IS 4 BP 377 EP 391 DI 10.1002/(SICI)1097-4644(19980615)69:4<377::AID-JCB1>3.0.CO;2-K PG 15 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZP477 UT WOS:000073757400001 PM 9620166 ER PT J AU Ernst, M Meier, BH Tomaselli, M Pines, A AF Ernst, M Meier, BH Tomaselli, M Pines, A TI Time-reversal of cross-polarization in nuclear magnetic resonance SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ECHOES AB It is demonstrated that the time evolution of the heteronuclear polarization-transfer process in a dipolar-coupled nuclear spin system can be reversed, leading to the observation of cross polarization echoes. The cross-polarization echoes are induced by consecutive application of two pulse trains that produce effective Hamiltonians that differ only in sign, Cross-polarization echoes have been recorded for a powder sample of alanine. The time evolution of the spin;system is consistent with both unitary quantum dynamics and with spin thermodynamics of two systems approaching a common spin temperature. (C) 1998 American Institute of Physics. C1 Univ Nijmegen, Chem Phys Lab, NSR Ctr Mol Struct Design & Synth, NL-6525 ED Nijmegen, Netherlands. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Meier, BH (reprint author), Univ Nijmegen, Chem Phys Lab, NSR Ctr Mol Struct Design & Synth, Toernooiveld 1, NL-6525 ED Nijmegen, Netherlands. RI Ernst, Matthias/A-6732-2010; Meier, Beat/K-4066-2016 OI Ernst, Matthias/0000-0002-9538-6086; Meier, Beat/0000-0002-9107-4464 NR 17 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 15 PY 1998 VL 108 IS 23 BP 9611 EP 9613 DI 10.1063/1.476435 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FU UT WOS:000075256100001 ER PT J AU Wang, HB Sun, X Miller, WH AF Wang, HB Sun, X Miller, WH TI Semiclassical approximations for the calculation of thermal rate constants for chemical reactions in complex molecular systems SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-STATE THEORY; QUANTUM-STATISTICAL MECHANICS; ACTIVATED RATE-PROCESSES; DYNAMICS SIMULATIONS; PROTON-TRANSFER; WIGNER APPROACH; S-MATRIX; DISSOCIATION; SCATTERING; COLLISIONS AB Two different semiclassical approaches are presented for extending flux correlation function methodology for computing thermal reaction rate constants, which has been extremely successful for the "direct" calculation of rate constants in small molecule (similar to 3-4 atoms) reactions, to complex molecular systems, i.e., those with many degrees of freedom. First is the popular mixed quantum-classical approach that has been widely used by many persons, and second is an approximate version of the semiclassical initial value representation that has recently undergone a rebirth of interest as a way for including quantum effects in molecular dynamics simulations. Both of these are applied to the widely studied system-bath model, a one-dimensional double well potential linearly coupled to an infinite bath of harmonic oscillators. The former approximation is found to be rather poor while the latter is quite good. (C) 1998 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 Wang, HB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Wang, Haobin/E-1208-2011; Sun, Sean/C-6755-2009 OI Sun, Sean/0000-0002-9077-7088 NR 61 TC 287 Z9 289 U1 5 U2 31 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 15 PY 1998 VL 108 IS 23 BP 9726 EP 9736 DI 10.1063/1.476447 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 108FU UT WOS:000075256100014 ER PT J AU Letts, SA Fort, T AF Letts, SA Fort, T TI Polymerization of oriented monolayers of octadecyl acrylate - 1. Characterization of the reaction products SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE monolayers; polymerization; octadecyl acrylate polymerization; surface potentials; relative surface viscosities; polymer tacticity; monolayer degradation by UV light ID VINYL STEARATE AB Octadecyl acrylate monolayers were polymerized at the nitrogen-water interface. The reaction was initiated by UV radiation and followed by measurement of surface potentials, relative surface viscosities and infrared spectra. Product behavior suggested a high molecular weight and cross-linked polymer. There were some indications that the interfacially polymerized material was stereoregular. The reaction was complicated by UV induced degradation of poly(octadecyl acrylate) monolayers to a product which showed many of the characteristics of poly(acrylic acid). (C) 1998 Academic Press. C1 Vanderbilt Univ, Dept Chem Engn, Nashville, TN 37203 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. RP Fort, T (reprint author), Vanderbilt Univ, Dept Chem Engn, Box 1604,Stn B, Nashville, TN 37203 USA. NR 15 TC 6 Z9 6 U1 0 U2 3 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 JUN 15 PY 1998 VL 202 IS 2 BP 341 EP 347 DI 10.1006/jcis.1998.5508 PG 7 WC Chemistry, Physical SC Chemistry GA ZU572 UT WOS:000074211500015 ER PT J AU Schiller, R Holroyd, RA Nishikawa, M AF Schiller, R Holroyd, RA Nishikawa, M TI Photoinjection of excess electrons into liquid hydrocarbons: a thermodynamic treatment SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE insulating liquid; liquid hydrocarbons; photoinjection; thermodynamic analysis ID CONDUCTION-BAND ENERGY; NONPOLAR LIQUIDS; PRESSURE AB A photocathode immersed in an insulating liquid might inject electrons. The analysis of the wavelength versus photocurrent curve enables one to evaluate the energy of the injected, quasi-free electron in the liquid, i.e. the bottom of the conduction level V-0 The pressure dependencies of V-0 observed with several liquid hydrocarbons indicate certain discrepancies between experimental data and theoretical expectations. Thermodynamic analysis shows that, contrary to theoretical descriptions, the injection proceeds via a polytrope which runs between the isothermal-isochoric and isoentropic-isobaric curves. This being attributed to local perturbations of temperature and pressure by the injection process, an estimate of the time scale of injection can be given, finding characteristic times to be in the order of 0.01-0.1 ps. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Hungarian Acad Sci, Cent Res Inst Phys, Atom Energy Res Inst, H-1525 Budapest, Hungary. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Tokyo, Dept Pure & Appl Sci, Tokyo 153, Japan. RP Schiller, R (reprint author), Hungarian Acad Sci, Cent Res Inst Phys, Atom Energy Res Inst, POB 49, H-1525 Budapest, Hungary. NR 12 TC 1 Z9 1 U1 1 U2 2 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 JUN 15 PY 1998 VL 450 IS 1 BP 21 EP 26 DI 10.1016/S0022-0728(97)00614-1 PG 6 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 100HF UT WOS:000074810200005 ER PT J AU Basilevsky, MV Rostov, IV Newton, MD AF Basilevsky, MV Rostov, IV Newton, MD TI A two-dimensional Born-Oppenheimer treatment of intramolecular electron transfer reactions SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article ID SUPEREXCHANGE PATHWAY CALCULATION; DISTANCE DEPENDENCE; MATRIX-ELEMENTS; CHARGE-TRANSFER; POLAR-SOLVENT; SPACERS; KINETICS; CHAINS; MODEL; HOLE AB The Born-Oppenheimer (BO) formulation of polar solvation is developed and implemented at the semiemperical (PM3) configuration interaction (CI) level, yielding estimates of electron transfer (ET) coupling elements (V-0) for intramolecular ET in several families of radical ion systems. In contrast to the traditional treatment based on a single solvent coordinate and a fixed gas-phase coupling element, the present treatment yields a self-consistent characterization of kinetic parameters in a 2-dimensional solvent framework which includes an exchange coordinate. The dependence of V-0 on inertial solvent contributions and on donor/acceptor separation (r(DA)) is discussed. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Karpov Inst Phys Chem, Moscow 103064, Russia. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Newton, MD (reprint author), Karpov Inst Phys Chem, Ul Vorontsovo Pole 10, Moscow 103064, Russia. EM basil@cc.nifhi.ac.ru; newton1@bnl.gov NR 33 TC 8 Z9 8 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 JUN 15 PY 1998 VL 450 IS 1 BP 69 EP 82 DI 10.1016/S0022-0728(97)00619-0 PG 14 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 100HF UT WOS:000074810200011 ER PT J AU Chen, JH Besser, MF Trivedi, RK Kramer, MJ Sordelet, DJ AF Chen, JH Besser, MF Trivedi, RK Kramer, MJ Sordelet, DJ TI Functionally gradient superconducting foils by plasma spraying SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID SEDIMENTATION; YBA2CU3O7-X; COMPOSITE; WIRES; FILMS AB Functionally gradient composite foils of Y-Ba-Cu-O and silver with a layer thickness of around 100 mu m and certain flexibility, were produced by air plasma spraying. The superconducting phase is formed in sprayed composite foils only after annealing in flowing oxygen above 900 degrees C but can be improved by annealing first in argon at 850 degrees C prior to the oxygen annealing. The effect of argon pre-treatment was found to increase the grain size of YBa2Cu3O7-delta. The behaviour of the graded silver layer in improving the ductility and in the process of recovery of superconductivity of the sprayed coating was investigated. (C) 1998 Kluwer Academic Publishers. C1 Gansu Univ Technol, Lanzhou 730050, Gansu, Peoples R China. Iowa State Univ, Ames Lab, USDOE, Int Inst Theoret & Appl Phys, Ames, IA 50011 USA. RP Chen, JH (reprint author), Iowa State Univ, Ames Lab, USDOE, Int Inst Theoret & Appl Phys, Ames, IA 50011 USA. NR 18 TC 3 Z9 3 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN 15 PY 1998 VL 33 IS 12 BP 3121 EP 3129 DI 10.1023/A:1004395822982 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 149DV UT WOS:000077590600018 ER PT J AU Elsasser, C Zhu, J Louie, SG Fahnle, M Chan, CT AF Elsasser, C Zhu, J Louie, SG Fahnle, M Chan, CT TI Ab initio study of iron and iron hydride: I. Cohesion, magnetism and electronic structure of cubic Fe and FeH SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID GENERALIZED-GRADIENT-APPROXIMATION; GROUND-STATE PROPERTIES; 1ST-PRINCIPLES PSEUDOPOTENTIAL CALCULATIONS; DENSITY-FUNCTIONAL CALCULATIONS; BRILLOUIN-ZONE INTEGRATIONS; SELF-CONSISTENT CALCULATION; TOTAL-ENERGY CALCULATIONS; FERROMAGNETIC BCC IRON; TRANSITION-METALS; MIXED-BASIS AB The ab initio mixed-basis pseudopotential method based on the density-functional theory is applied to study the cohesion, ferromagnetism and electronic structure of iron and iron monohydride with cubic crystal structures. Spin-unpolarized and spin-polarized calculations are used to assess the transferability of norm-conserving ionic pseudopotentials for iron, and the level of accuracy obtainable for structural equations of state with reasonable effort. The influence of generalized gradient corrections on the cohesive properties is investigated. The results are compared directly to corresponding all-electron results obtained by using both FLAPW and LMTO-ASA methods. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Max Planck Inst Met Res, Seestr 92, D-70174 Stuttgart, Germany. NR 97 TC 37 Z9 37 U1 1 U2 15 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 15 PY 1998 VL 10 IS 23 BP 5081 EP 5111 DI 10.1088/0953-8984/10/23/012 PG 31 WC Physics, Condensed Matter SC Physics GA ZX259 UT WOS:000074496300012 ER PT J AU Elsasser, C Zhu, J Louie, SG Meyer, B Fahnle, M Chan, CT AF Elsasser, C Zhu, J Louie, SG Meyer, B Fahnle, M Chan, CT TI Ab initio study of iron and iron hydride: II. Structural and magnetic properties of close-packed Fe and FeH SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID GENERALIZED-GRADIENT APPROXIMATION; DENSITY-FUNCTIONAL CALCULATIONS; BRILLOUIN-ZONE INTEGRATIONS; STACKING-FAULT ENERGIES; GROUND-STATE PROPERTIES; HIGH-PRESSURE; GAMMA-FE; FCC IRON; UNIVERSAL FEATURES; EXCHANGE-ENERGY AB The energetical ordering and magnetic states of hexagonal and double-hexagonal close-packed (hcp, dhcp) as well as face-centred cubic (fcc) Fe and FeH crystals are studied via spin-polarized ab initio total-energy calculations in the local spin-density approximation and with generalized gradient corrections by means of the mixed-basis pseudopotential and the all-electron LMTO-ASA methods. In all three structures, the magnetic spin moments go to zero under volume compression. For pure Fe in the compressed non-magnetic state, the hcp structure is found to have the lowest energy, fee the highest, and the dhcp structure lies in between. The two hexagonal structures have significantly smaller than ideal c/a ratios. For compressed non-magnetic FeH the energetical ordering of the structures is reversed, compared to that for pure Fe, with fee ground-state structure and almost ideal c/a ratios for both hexagonal structures. In the ferromagnetic states at expanded volumes, the energetical orderings are again opposite to those of the non-magnetic states both for Fe and FeH. In ferromagnetic FeH these energy differences are particularly small, yielding almost an energetical degeneracy of all three close-packed structures. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Max Planck Inst Met Res, Seestr 92, D-70174 Stuttgart, Germany. NR 62 TC 22 Z9 22 U1 2 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 15 PY 1998 VL 10 IS 23 BP 5113 EP 5129 DI 10.1088/0953-8984/10/23/013 PG 17 WC Physics, Condensed Matter SC Physics GA ZX259 UT WOS:000074496300013 ER PT J AU Elsasser, C Krimmel, H Fahnle, M Louie, SG Chan, CT AF Elsasser, C Krimmel, H Fahnle, M Louie, SG Chan, CT TI Ab initio study of iron and iron hydride: III. Vibrational states of H isotopes in Fe, Cr and Ni SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID PSEUDOPOTENTIAL CALCULATIONS; ELECTRONIC-STRUCTURE; NEUTRON-SCATTERING; HYDROGEN ISOTOPES; GAMMA-FE; METALS; 4D-TRANSITION; POTENTIALS; PALLADIUM; DEUTERIUM AB Adiabatic potentials, energy levels and wavefunctions for collective vibrational states of hydrogen isotopes in monohydrides of transition metals with face-centred cubic lattices, gamma-FeH and NiH, and with body-centred cubic lattices, alpha-FeH and CrH, are investigated by means of ab initio total-energy calculations in the local density and local spin-density approximations (LDA, LSDA). The study for the different transition-metal monohydrides, including PdH and NbH studied earlier, yields a general insight into the microscopic vibrational potential wells: the topology of their spatial shapes is specific to the metal lattice, but their depths and curvatures change quantitatively in a systematic manner through the transition-metal series. The calculated excitation energies agree very well with results of inelastic neutron scattering (INS) experiments both for non-magnetic NiH, treated within the LDA, and ferromagnetic gamma-FeH, treated within the LSDA. The theoretical data for the two considered hydrides, with bcc structure, for which corresponding experimental data do not exist, provide an ab initio database for the construction of metal-hydrogen interaction models, e.g., for studies of self-trapped vibrational states of isolated H atoms in transition metals. C1 Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. RP Max Planck Inst Met Res, Seestr 92, D-70174 Stuttgart, Germany. NR 40 TC 27 Z9 27 U1 0 U2 9 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 15 PY 1998 VL 10 IS 23 BP 5131 EP 5146 DI 10.1088/0953-8984/10/23/014 PG 16 WC Physics, Condensed Matter SC Physics GA ZX259 UT WOS:000074496300014 ER PT J AU Lee, JH Lalk, TR AF Lee, JH Lalk, TR TI Modeling fuel cell stack systems SO JOURNAL OF POWER SOURCES LA English DT Article DE fuel cells; electrochemistry; mathematical modeling; design AB A technique for modeling fuel cell stacks is presented along with the results from an investigation designed to test the validity of the technique. The technique was specifically designed so that models developed using it can be used to determine the fundamental thermal-physical behavior of a fuel cell stack for any operating and design configuration. Such models would be useful tools for investigating fuel cell power system parameters. The modeling technique can be applied to any type of fuel cell stack for which performance data is available for a laboratory scale single cell. Use of the technique is demonstrated by generating sample results for a model of a Proton Exchange Membrane Fuel Cell (PEMFC) stack consisting of 125 cells each with an active area of 150 cm(2). A PEMFC stack was also used in the verification investigation. This stack consisted of four cells, each with an active area of 50 cm(2). Results from the verification investigation indicate that models developed using the technique are capable of accurately predicting fuel cell stack performance. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. RP Lee, JH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 8 TC 92 Z9 109 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUN 15 PY 1998 VL 73 IS 2 BP 229 EP 241 DI 10.1016/S0378-7753(97)02812-7 PG 13 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA ZY222 UT WOS:000074598500008 ER PT J AU Lee, LL Cochran, HD AF Lee, LL Cochran, HD TI Molecular adsorption: repulsive versus attractive supercritical fluid mixtures SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article; Proceedings Paper CT 4th International Symposium on Supercritical Fluids (ISSF 97) CY MAY 11-14, 1997 CL SENDAI, JAPAN DE adsorption; supercritical fluids; integral equations; nonuniform Ornstein-Zernike; repulsive and attractive mixtures; density profiles ID LENNARD-JONES FLUIDS; PAIR DISTRIBUTION THEORIES; LIQUID-VAPOR INTERFACE; DENSITY PROFILES; PERCUS-YEVICK; NARROW SLITS; HARD-WALL; SOLVENT; SOLUTE AB The behavior and structure of supercritical fluid (SCF) mixtures in contact with an adsorptive solid surface have been determined by the nonuniform Ornstein-Zernike integral equations for the molecular distributions. In this work, we examine the behavior of attractive and repulsive mixtures (A = SCF and B = solute) with respect to adsorption on planar substrates. Properties and fluid structures in the vicinity of the wall (W) are explored. The behavior of a dilute solute B adsorbed to wall W from solvent A (i.e. system AS B/W) is described for the cases where ASB form either an attractive SCF mixture or a repulsive SCF mixture for a temperature where the solvent A is slightly supercritical and for density conditions where A is subcritical, critical, and supercritical. We examine the degree of preferential adsorption of B vis-g-vis the competitive interactions with A and W. This shows the relative adsorptions, while covering a range of states. We find evidence of solute rejection by the SCF toward the wall, when the mixture A + B changes character from 'attractive' to 'repulsive'. The numerical work is very demanding in computer memory and time. Thus, full numerical convergence has not been achieved in the calculations reported here. We have attained partial convergence. However, the qualitative trends are considered unaltered. The mechanisms of solute adsorption in SCF have been demonstrated at a fundamental molecular level. (C) 1998 Elsevier Science B.V. C1 Univ Oklahoma, Dept Chem Engn & Mat Sci, Norman, OK 73019 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Lee, LL (reprint author), Univ Oklahoma, Dept Chem Engn & Mat Sci, 100 E Boyd St, Norman, OK 73019 USA. EM lle@ou.edu NR 18 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD JUN 15 PY 1998 VL 13 IS 1-3 BP 77 EP 81 DI 10.1016/S0896-8446(98)00091-6 PG 5 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 105WT UT WOS:000075098900013 ER PT J AU Takahashi, K Sawamura, S Jonah, CD AF Takahashi, K Sawamura, S Jonah, CD TI Solvent reorganization energies measured by an electron transfer reaction in supercritical ethane SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article; Proceedings Paper CT 4th International Symposium on Supercritical Fluids (ISSF 97) CY MAY 11-14, 1997 CL SENDAI, JAPAN DE solvent reorganization energy; electron transfer; non-polar fluid; Marcus theory; density fluctuation ID FLUID SOLUTIONS; CARBON-DIOXIDE; FLUORESCENCE; BEHAVIOR; EQUATION AB The intermolecular electron transfer reaction between a biphenyl anion and pyrene in supercritical ethane was studied using pulse radiolysis. Second-order electron transfer rates were found to be of the order of 10(11) M-1 s(-1) The rate constants appear to be approximately constant over the pressure range 55-133 bar and slower than the predicted diffusion-controlled rate constants. Two possibilities are discussed that could explain the present results: diffusion constants that are not well predicted by the hydrodynamic equation; or a solvent reorganization energy of approximately 0.35 eV and dependent on pressure. The reorganization energy E-r of non-polar supercritical ethane was estimated from the observed rate constant using the modified Marcus equation. E-r may be larger than normally expected for non-polar solvents because of density fluctuations. (C) 1998 Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Hokkaido Univ, Div Quantum Energy Engn, Sapporo, Hokkaido 060, Japan. RP Jonah, CD (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Takahashi, Kenji/C-8846-2011; Takahashi, Kenji/F-4885-2014 NR 30 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD JUN 15 PY 1998 VL 13 IS 1-3 BP 155 EP 161 DI 10.1016/S0896-8446(98)00047-3 PG 7 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 105WT UT WOS:000075098900024 ER PT J AU Verdier, M Janecek, M Brechet, Y Guyot, P AF Verdier, M Janecek, M Brechet, Y Guyot, P TI Microstructural evolution during recovery in Al-2.5%Mg alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE microstructural evolution; recovery; Al-2.5%Mg alloys ID AL-MG; SINGLE-CRYSTALS; FLOW-STRESS; ALUMINUM AB Microstructural evolution in Al-2.5%Mg alloys with various Fe content deformed by cold rolling [<(epsilon)over bar> = 0.1-3] and recovered during static annealing (160 and 220 degrees C) was studied experimentally using the transmission electron microscopy techniques. Detailed investigations of the dislocation structures at small prestrains reveal a channel-like planar arrangement which does not show significant subgrain growth during annealing, whereas subgrain structures formed at higher prestrains lead to the onset of recrystallization when annealed. The microstructural evolution is discussed in relationship with the mechanical properties (yield stress) of the alloys. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Ecole Natl Super Electrochim & Electrome Grenoble, LTPCM, F-38402 St Martin Dheres, France. Charles Univ, Dept Met Phys, Praha, Czech Republic. RP Verdier, M (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, CMS Mail Stop K765, Los Alamos, NM 87545 USA. EM verdier@lanl.gov OI Milos, Janecek/0000-0003-4447-9810 NR 34 TC 28 Z9 29 U1 1 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 15 PY 1998 VL 248 IS 1-2 BP 187 EP 197 DI 10.1016/S0921-5093(98)00488-2 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ400 UT WOS:000074725600023 ER PT J AU Rawers, J Cook, D Kim, T AF Rawers, J Cook, D Kim, T TI Application of Mossbauer spectroscopy in the characterization of nanostructured materials SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE Mossbauer spectroscopy; nanostructured materials; atomic site characterization ID RESOLUTION ELECTRON-MICROSCOPY; RANDOMLY ARRANGED ATOMS; SOLID-STATE STRUCTURE; NANOCRYSTALLINE MATERIALS; GRAIN-BOUNDARIES; FE; ALLOYS; METALS; IRON; OXIDE AB Understanding of nanostructured materials is often limited by experimental characterization methods that measure only bulk properties. For example, numerous studies have characterized nanostructured materials using X-ray diffraction for phases present, average grain size, internal strain, etc. In this study, Mossbauer analysis is used to characterize the local atomic site characterization, distribution, and concentrations of attrition milled nanostructure powder. Interatomic analysis provided insight into the mechanical alloying process and the resulting nanostructure not previously reported. Iron powder, blends of iron with 2 wt% aluminum powder, and prealloyed iron-aluminum powder were processed with both argon and nitrogen gas as the processing environments. Mechanical processing resulted in micrometer-size particles with essentially defect-free nanograin interiors. Mechanical alloying iron powder with aluminum resulted in the aluminum being restricted to the grain boundary region. Mechanical processing iron powder in a nitrogen gas environment resulted in nitrogen being either on the grain boundary or in the outer layer of the grain boundary distorting the local b.c.c.-Fe lattice into a b.c.t.-Fe lattice. (C) 1998 Elsevier Science S.A. All rights reserved. C1 US DOE, Albany Res Ctr, Albany, OR 97321 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Rawers, J (reprint author), US DOE, Albany Res Ctr, Albany, OR 97321 USA. EM rawers@doe.alrc.gov NR 51 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 15 PY 1998 VL 248 IS 1-2 BP 212 EP 220 DI 10.1016/S0921-5093(98)00486-9 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ400 UT WOS:000074725600026 ER PT J AU Hurst, B Boger, J Botting, T Cooke, L O'Kelly, D Schmitt, RP Srivastava, BK Turmel, W AF Hurst, B Boger, J Botting, T Cooke, L O'Kelly, D Schmitt, RP Srivastava, BK Turmel, W TI Excitation energy deposition from neutron multiplicity distributions for reactions induced with 30 A MeV N-14, Ne-20, Cu-63 and 55 AMeV He-4 SO NUCLEAR PHYSICS A LA English DT Article DE nuclear reactions; measured neutron multiplicities with a 4 pi detector; reactions induced with 30 A MeV N-14, Ne-20, Cu-63 and 55 AMeV He-4; statistical model comparisons; established excitation energy deposition systematics ID HOT NUCLEI; COLLISIONS; EMISSION; TEMPERATURES; BARRIERS; FISSION AB Inclusive neutron multiplicity distributions have been measured for 30 A MeV N-14, Ne-20, Cu-63 and 55 A MeV He-4 beams incident on targets ranging from C-12 to U-238. For the lightest targets, the distributions decrease approximately exponentially with increasing multiplicity. The heavier targets display an additional Gaussian component peaked at higher multiplicities, which is attributable to central collisions. In the latter cases, the most probable multiplicities, M-n*, have been extracted by fitting the data with a simple functional form. These multiplicities are compared to the predictions of the statistical model codes GEMINI and CASCADE using a massive transfer scenario to define the initial conditions. Reasonable agreement is obtained for systems with estimated excitation energies approximate to 100 MeV, but the calculations consistently overpredict the most probable multiplicities for more highly excited systems. Good agreement is observed between the experimental M-n* values and the predictions of the code EUGENE. However, this code gives M-n* values that are consistently lower than those predicted by other statistical model calculations. An alternative procedure is utilized to extract the amount of excitation energy of the composite system. In this approach, the input excitation energy in a standard model code is varied until the predicted M-n* value matches the experimental value. The resulting excitation energies follow systematic trends with the estimated momentum transfer and the N/Z of the system. These patterns are also observed in reactions induced with other projectiles. (C) 1998 Elsevier Science B.V. C1 Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. Lubbock Christian Univ, Environm Sci Lab, Lubbock, TX 79407 USA. RP Hurst, B (reprint author), Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. NR 24 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 JUN 15 PY 1998 VL 636 IS 1 BP 3 EP 27 DI 10.1016/S0375-9474(98)00162-6 PG 25 WC Physics, Nuclear SC Physics GA ZX479 UT WOS:000074520200001 ER PT J AU Kachru, S Klemm, A Oz, Y AF Kachru, S Klemm, A Oz, Y TI Calabi-Yau duals for CHL strings SO NUCLEAR PHYSICS B LA English DT Article ID F-THEORY; MODULI SPACE; COMPACTIFICATIONS; DIMENSIONS; THREEFOLDS; DYNAMICS AB We find M-theory (Type IIA) duals for compactifications of the 9d CHL string to 5d (4d) on K3 (K3 x S-1). The IIA duals are Calabi-Yau orbifolds with non-trivial RR U(1) backgrounds turned on. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Kachru, S (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 30 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUN 15 PY 1998 VL 521 IS 1-2 BP 58 EP 70 DI 10.1016/S0550-3213(98)00228-4 PG 13 WC Physics, Particles & Fields SC Physics GA ZX482 UT WOS:000074520500003 ER PT J AU Lermer, N Barnes, MD Kung, CY Whitten, WB Ramsey, JM Hill, SC AF Lermer, N Barnes, MD Kung, CY Whitten, WB Ramsey, JM Hill, SC TI Spatial photoselection of single molecules on the surface of spherical microcavities SO OPTICS LETTERS LA English DT Article ID SPONTANEOUS-EMISSION RATES; OPTICAL CAVITY; ONE-ATOM; FLUORESCENCE; LASER; LIQUIDS AB We show that ultrasensitive microdroplet-stream fluorescence techniques combined with surfactant forms of Rhodamine dyes can be used to probe single molecules on the surfaces of spherical microcavities. Individual octadecyl Rhodamine B molecules, shown previously by ensemble measurements to be localized and oriented at the surfaces of liquid microspheres, were spatially photoselected primarily along great circles lying perpendicular or parallel to the detection axis by use of polarized laser excitation. A polarization dependence is observed in the distribution of single-molecule fluorescence amplitudes that can be interpreted qualitatively in terms of position-dependent fluorescence-collection efficiencies. (C) 1998 Optical Society of America. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. USA, Res Lab, Adelphi, MD 20783 USA. RP Lermer, N (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 18 TC 7 Z9 7 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 15 PY 1998 VL 23 IS 12 BP 951 EP 953 DI 10.1364/OL.23.000951 PG 3 WC Optics SC Optics GA ZV034 UT WOS:000074261700021 PM 18087394 ER PT J AU Carlson, EW Kivelson, SA Nussinov, Z Emery, VJ AF Carlson, EW Kivelson, SA Nussinov, Z Emery, VJ TI Doped antiferromagnets in high dimension SO PHYSICAL REVIEW B LA English DT Article ID T-J MODEL; QUANTUM HEISENBERG-ANTIFERROMAGNET; PHASE-SEPARATION; HUBBARD-MODEL; SUPERCONDUCTIVITY; INSTABILITY; EXCITATION; POLARONS; BEHAVIOR; LIMIT AB The ground-state properties of the t-J model on a d-dimensional hypercubic lattice are examined in the limit of large d. It is found that the undoped system is an ordered antiferromagnet, and that the doped system phase separates into a hole-free antiferromagnetic phase and a hole-rich phase. The latter is electron free if J>4t and is weakly metallic (and typically superconducting) if J<4t. The resulting phase diagram is qualitatively similar to the one previously derived for d=2 by a combination of analytic and numerical methods. Domain-wall (or stripe) phases form in the presence of weak Coulomb interactions, with periodicity determined by the hole concentration and the relative strength of the exchange and Coulomb interactions. These phases reflect the properties of the hole-rich phase in the absence of Coulomb interactions, and, depending on the value of J/t, may be either insulating or metallic (i.e., an "electron smectic"). C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Carlson, EW (reprint author), Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. NR 48 TC 34 Z9 34 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 23 BP 14704 EP 14721 DI 10.1103/PhysRevB.57.14704 PG 18 WC Physics, Condensed Matter SC Physics GA ZV141 UT WOS:000074273500031 ER PT J AU Blount, MA Simmons, JA Lyo, SK AF Blount, MA Simmons, JA Lyo, SK TI In-plane magnetoresistance studies of an extremely coupled double quantum well SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL ELECTRON GASES; MASS AB We investigate the transport properties of an extremely-coupled AlxGa1-xAs/GaAs double quantum well subject to in-plane magnetic fields B-I. The coupling is sufficiently strong that the symmetric-antisymmetric gap energy Delta(SAS) is larger than the Fermi energy E-F. Thus for all B-I only the lower-energy dispersion branch is occupied. In contrast to systems where Delta(SAS) < E-F, we find: (1) only a single feature in the magnetoresistance, a maximum; (2) a monotonic increase in the cyclotron mass to roughly double the GaAs band mass; and (3) a monotonically increasing Fermi-surface orbit area. These experimental results agree well with our theoretical calculations. C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Blount, MA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 9 Z9 9 U1 2 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 23 BP 14882 EP 14885 DI 10.1103/PhysRevB.57.14882 PG 4 WC Physics, Condensed Matter SC Physics GA ZV141 UT WOS:000074273500053 ER PT J AU Heinrichsmeier, M Fleszar, A Hanke, W Eguiluz, AG AF Heinrichsmeier, M Fleszar, A Hanke, W Eguiluz, AG TI Nonlocal density-functional calculations of the surface electronic structure of metals: Application to aluminum and palladium SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; IMAGE-POTENTIAL STATES; INVERSE-PHOTOEMISSION; PD(111) SURFACE; TRANSITION-METALS; WORK FUNCTION; GROUND-STATE; EXCHANGE; SPECTROSCOPY; RESONANCES AB We report density-functional calculations based on the use of an exchange-correlation potential that depends nonlocally on the electron density at the surface and automatically yields the correct asymptotic shape of the surface Kohn-Sham potential. In our scheme the density-functional nonlocality originates in the insertion of long-range correlations into the electron self-energy, from which we evaluate the exchange-correlation potential for jellium. The solution to that problem is parametrized for use at real metal surfaces. Image-potential surface states and crystal-induced surface states are obtained on the same footing without any fitting parameters. We apply our method in calculations of the surface-electronic structure of (100) and (111) surfaces of aluminum and palladium. C1 Univ Wurzburg, Inst Theoret Phys, D-97074 Wurzburg, Germany. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Univ Wurzburg, Inst Theoret Phys, Am Hubland, D-97074 Wurzburg, Germany. NR 57 TC 35 Z9 35 U1 1 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 23 BP 14974 EP 14982 DI 10.1103/PhysRevB.57.14974 PG 9 WC Physics, Condensed Matter SC Physics GA ZV141 UT WOS:000074273500063 ER PT J AU Lee, TL Bedzyk, MJ AF Lee, TL Bedzyk, MJ TI High-resolution structural analysis of the Sb-terminated GaAs(001)-(2x4) surface SO PHYSICAL REVIEW B LA English DT Article ID THERMAL VIBRATION AMPLITUDES; RAY STANDING WAVES; ATOMIC-STRUCTURE; GAAS(100)-(2X4); DIFFRACTION; SI(001) AB The precise locations of Sb atoms for the GaAs(001):Sb-(2X4) surface were measured by the x-ray standing-wave (XSW) technique, rue XSW results are consistent with symmetric Sb dimers, whose formation has recently been predicted by four competing models. The (004) and (022) XSW analysis determined the Sb dimer height and bond length to be 1.72 and 2.84 Angstrom, respectively. The Sb coverage of the(2 x 4)reconstruction was measured by Rutherford backscattering to be 0.48 monolayers. This coverage agrees with the two proposed structural models that have two Sb dimers per (2X4) unit cell and disagrees with the models that propose one or three Sb dimers. Finally, a(lll) XSW measurement, which tested for lateral displacement of the Sb dimers in the [110] direction, was used to discriminate between the remaining two models. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Northwestern Univ, Ctr Mat Res, Evanston, IL 60208 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lee, TL (reprint author), Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 19 TC 11 Z9 11 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 24 BP 15056 EP 15059 PG 4 WC Physics, Condensed Matter SC Physics GA ZY631 UT WOS:000074643000007 ER PT J AU Fu, HX Zunger, A AF Fu, HX Zunger, A TI Excitons in InP quantum dots SO PHYSICAL REVIEW B LA English DT Article AB The excitonic spectrum of InP quantum dots is investigated using an atomistic pseudopotential approach for the single-particle problem and a state-dependent screened Coulomb interaction for the many-body problem. Our calculations show a different energy distribution of single-particle states relative to the commonly used k.p theory as well as significant parity mixing in the envelope functions, forbidden in 6x6 k.p. The calculated excitonic spectrum, including seven excitons, explains well the recent experimental measurements. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Fu, HX (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 16 TC 30 Z9 30 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 24 BP 15064 EP 15067 DI 10.1103/PhysRevB.57.R15064 PG 4 WC Physics, Condensed Matter SC Physics GA ZY631 UT WOS:000074643000009 ER PT J AU Luthi, SR Gudel, HU Hehlen, MP Quagliano, JR AF Luthi, SR Gudel, HU Hehlen, MP Quagliano, JR TI Electronic energy-level structure, correlation crystal-field effects, and f-f transition intensities of Er3+ in Cs3Lu2Cl9 SO PHYSICAL REVIEW B LA English DT Article ID UP-CONVERSION LASER; RARE-EARTH IONS; LANTHANIDE IONS; PARAMETRIC ANALYSIS; UPCONVERSION LASER; 4F->4F TRANSITIONS; ABSORPTION-SPECTRA; ND-3+; TRIFLUORIDE; SYSTEMS AB Single crystals of 1% Er3+-doped Cs3Lu2Cl9 were grown using the Bridgman technique. From highly resolved polarized absorption spectra measured at 10 and 16 K, and upconversion luminescence and excitation spectra measured at 4.2 K, 114 crystal-field levels from 27 L-2S+1(J)(4f(11)) multiplets of Er3+ were assigned. 111 of these were used for a semiempirical computational analysis. A Hamiltonian including only electrostatic, spin-orbit, and one-particle crystal-field interactions (C-3 upsilon) yielded a root-mean-square standard deviation of 159.8 cm(-1) and could not adequately reproduce the experimental crystal-field energies. The additional inclusion of two-and three-body atomic interactions, giving a Hamiltonian with 16 atomic and 6 crystal-field parameters, greatly reduced the rms standard deviation to 22.75 cm(-1). The further inclusion of the correlation crystal-field interaction (g) over cap(10A)(4), again lowered the rms standard deviation to a final value of 17.98 cm(-1) and provided substantial improvement in the calculated crystal-field splittings of mainly the J =9/2 or J=11/2 multiplets. However, the calculated baricenter energies of some excited-state multiplets deviate from their respective experimental values, and improvements in the atomic part of the effective Hamiltonian are required to correct this deficiency of the model. On the basis of the calculated electronic wave functions, the 12 electric-dipole intensity parameters (C-3 upsilon) Of the total transition dipole strength were obtained from a fit to 95 experimental crystal-field transition intensities. The overall agreement between experimental and calculated intensities is fair. The discrepancies are most likely a result of using the approximate C-3 upsilon rather than the actual C-3 point symmetry of Er3+ in Cs3Lu2Cl9 in the calculations. C1 Univ Bern, Dept Chem & Biochem, CH-3000 Bern 9, Switzerland. Univ Michigan, Opt Sci Lab, Ann Arbor, MI 48109 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Gudel, HU (reprint author), Univ Bern, Dept Chem & Biochem, Freiestr 3, CH-3000 Bern 9, Switzerland. NR 63 TC 14 Z9 14 U1 2 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 24 BP 15229 EP 15241 DI 10.1103/PhysRevB.57.15229 PG 13 WC Physics, Condensed Matter SC Physics GA ZY631 UT WOS:000074643000036 ER PT J AU Kim, HJ Vogelgesang, R Ramdas, AK Rodriguez, S Grimsditch, M Anthony, TR AF Kim, HJ Vogelgesang, R Ramdas, AK Rodriguez, S Grimsditch, M Anthony, TR TI Electronic Raman and infrared spectra of acceptors in isotopically controlled diamonds SO PHYSICAL REVIEW B LA English DT Article ID WIGNER-FANO RESONANCES; SEMICONDUCTING DIAMOND; IMPURITY LEVELS; SCATTERING; SILICON; BORON; PHOTOCONDUCTIVITY; SPECTROSCOPY; BRILLOUIN; PHONONS AB The Lyman spectrum of substitutional boron accepters in diamonds with natural composition and that in a C-13 diamond exhibit remarkably similar features, but shifted to higher energies in the latter by 0.4-1.5 meV. Additional lines appear when the spectra are recorded as a function of temperature, indicating the thermal population of a level Delta'similar to 2 meV above the ground state; this can be interpreted as the spin-orbit splitting of the Is acceptor ground state into 1s(p(3/2)) and Is(p(1/2)), the latter located Delta' above the former. The Raman-allowed 1s(p(3/2))--> 1s(p(1/2)) electronic transition is directly observed at 2.07(1) and 2.01(1) meV in the Raman spectrum of natural and C-13 diamond, respectively. Polarization features of the Delta' Raman line reveal that it is predominantly Gamma(5) in character, as predicted by a theoretical calculation formulated in terms of the known values of Luttinger parameters. The theoretical expression for the Raman cross section for Delta' enables the acceptor concentration to be deduced from an intercomparison of the intensity of the Delta' line and that of the zone-center optical phonon. The presence of boron accepters produces a quasicontinuous absorption spectrum in the range of the optical phonon branch, flanked by a sharp feature at the zone-center optical phonon frequency; their appearance can be attributed to the partial breakdown of the translational symmetry and the activation of otherwise inactive vibrations. C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Gen Elect Co, Corp Res & Dev, Schenectady, NY 12309 USA. RP Kim, HJ (reprint author), Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RI Vogelgesang, Ralf/B-4460-2009 OI Vogelgesang, Ralf/0000-0002-1026-3205 NR 68 TC 30 Z9 30 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JUN 15 PY 1998 VL 57 IS 24 BP 15315 EP 15327 DI 10.1103/PhysRevB.57.15315 PG 13 WC Physics, Condensed Matter SC Physics GA ZY631 UT WOS:000074643000045 ER PT J AU Csaki, C Schmaltz, M Skiba, W Terning, J AF Csaki, C Schmaltz, M Skiba, W Terning, J TI Gauge theories with tensors from branes and orientifolds SO PHYSICAL REVIEW D LA English DT Article ID DUALITY AB We present brane constructions in type-IIA string theory for N=1 supersymmetric SO and Sp gauge theories with tensor representations using an orientifold six-plane. One limit of these setups corresponds to N=2 theories previously constructed by Landsteiner and Lopez, while a different limit yields N=1 SO or Sp theories with a massless tensor and no superpotential. For the Sp-type orientifold projection, a comparison with the field-theory moduli space leads us to postulate two new rules governing the stability of configurations of D-branes intersecting the orientifold. Lifting one of our configurations to M theory by finding the corresponding curves, we rederive the N=1 dualities for SO and Sp groups using semi-infinite D4 branes. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theory Grp, Berkeley, CA 94720 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Csaki, C (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. OI Terning, John/0000-0003-1367-0575 NR 71 TC 14 Z9 14 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 JUN 15 PY 1998 VL 57 IS 12 BP 7546 EP 7560 DI 10.1103/PhysRevD.57.7546 PG 15 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZV143 UT WOS:000074273700049 ER PT J AU Bender, CM Boettcher, S AF Bender, CM Boettcher, S TI Real spectra in non-Hermitian Hamiltonians having PT symmetry SO PHYSICAL REVIEW LETTERS LA English DT Article AB The condition of self-adjointness ensures that the eigenvalues of a Hamiltonian are real and bounded below. Replacing this condition by the weaker condition of PT symmetry, one obtains new infinite classes of complex Hamiltonians whose spectra are also real and positive. These PT symmetric theories may be viewed as analytic continuations of conventional theories from real to complex phase space. This paper describes the unusual classical and quantum properties of these theories. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Clark Atlanta Univ, CTSPS, Atlanta, GA 30314 USA. RP Bender, CM (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. RI Boettcher, Stefan/G-2640-2010 OI Boettcher, Stefan/0000-0003-1273-6771 NR 11 TC 1849 Z9 1871 U1 19 U2 101 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 15 PY 1998 VL 80 IS 24 BP 5243 EP 5246 DI 10.1103/PhysRevLett.80.5243 PG 4 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300002 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, R Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, N Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Kaeffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amadon, A Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Atac, M Azzi-Bacchetta, P Bacchetta, N Bagdasarov, S Bailey, MW de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Barone, M Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bettelli, S Bevensee, B Bhatti, A Biery, K Bigongiari, C Binkley, M Bisello, D Blair, RE Blocker, C Blusk, S Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, R Boudreau, J Breccia, L Bromberg, C Bruner, N Brunetti, R Buckley-Geer, E Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Campbell, M Caner, A Carithers, W Carlsmith, D Cassada, J Castro, A Cauz, D Cerri, A Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chertok, M Chiarelli, G Chiou, CN Chlebana, F Christofek, L Chu, ML Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Costanzo, D Couyoumtzelis, C Cronin-Hennessy, D Culbertson, R Dagenhart, D Daniels, T DeJongh, F Dell'Agnello, S Dell'Orso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Erdmann, W Errede, N Errede, S Fan, Q Feild, RG Feng, Z Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Frisch, H Fukui, Y Gadomski, S Galeotti, S Gallinaro, M Ganel, O Garcia-Sciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gold, M Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L Grosso-Pilcher, C Guillian, G da Costa, JG Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handa, T Handler, R Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hauser, J Hayashi, E Heinrich, J Hao, W Hinrichsen, B Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Huang, Z Huffman, BT Hughes, R Huston, J Huth, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Joshi, U Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Kaeffaber, TA Kelley, K Kennedy, RD Kephart, R Kestenbaum, D Khazins, D Kikuchi, T Kim, BJ Kim, HS Kim, SH Kim, YK Kirsch, L Klimenko, S Knoblauch, D Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korytov, A Kovacs, E Kowald, W Kroll, J Kruse, M Kuhlmann, SE Kuns, E Kurino, K Kuwabara, T Laasanen, AT Lami, S Lammel, S Lamoureux, JI Lancaster, M Lanzoni, M Latino, G LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Long, O Loomis, C Loreti, M Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mazzanti, P McIntyre, P Melese, P Menguzzato, M Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Miyashita, S Moggi, N Moore, E Morita, Y Mukherjee, A Muller, T Murat, P Murgia, S Nakada, H Nakano, I Nelson, C Neuberger, D Newman-Holmes, C Ngan, CYP Nodulman, L Nomerotski, A Oh, SH Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pompos, A Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Reischl, M Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Rosenson, L Roser, R Saab, T Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semeria, F Shah, T Shapiro, MD Shaw, NM Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Sliwa, K Smith, C Snider, FD Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strohmer, R Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, J Suzuki, T Takahashi, T Takano, T Takashima, R Takikawa, K Tanaka, M Tannenbaum, B Tartarelli, F Taylor, W Tecchio, M Teng, PK Teramoto, Y Terashi, K Tether, S Theriot, D Thomas, TL Thurman-Keup, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Ukegawa, F Valls, J van den Brink, SC Vejcik, S Velev, G Vidal, R Vilar, R Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, MJ Warburton, A Watanabe, T Watts, T Webb, R Wei, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Search for chargino-neutralino associated production at the Fermilab tevatron collider SO PHYSICAL REVIEW LETTERS LA English DT Article ID GRAND UNIFICATION; ROOT-S=1.8 TEV; SUPERGRAVITY; SUPERSYMMETRY; COLLISIONS; SPECTRUM; MASS AB We have searched in p (p) over bar collisions at root s = 1.8 TeV for events with three charged leptons and missing transverse energy. In the minimal supersymmetric standard model, we expect trilepton events from chargino-neutralino (<(chi)over tilde>(+/-)(1)<(chi)over tilde>(0)(2) pair production, with subsequent decay into leptons. We observe no candidate e(+)e(-)e(+/-), e(+)e(-)mu(+/-), e(+/-)mu(+)mu(-), or mu(+)mu(-)mu(+/-) events in 106 pb(-1) integrated luminosity. We present limits on the sum of the branching ratios times cross section for the four channels: sigma(<(chi)over tilde>1)(+/-)(<(chi)over tilde>2)B-0(<(chi)over tilde>(+/-)(1)<(chi)over tilde>(0)(2) --> 3l + X) < 0.34 pb, M(<(chi)over tilde>1)(+/-) > 81.5 GeV/c(2), and M(<(chi)over tilde>2)(0) > 82.2 GeV/c(2) for tan beta = 2, mu = -600 GeV/c(2), and M-(q over tilde) = M-(g over tilde). C1 Natl Lab High Energy Phys KEK, Tsukuba, Ibaraki 305, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Chicago, Chicago, IL 60637 USA. Duke Univ, Durham, NC 27708 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Padova, Sez Padova, Ist Nazl Fis Nucl, 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. Acad Sinica, Taipei 11530, Taiwan. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 315, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Abe, F (reprint author), Natl Lab High Energy Phys KEK, Tsukuba, Ibaraki 305, Japan. RI Tartarelli, Giuseppe Francesco/A-5629-2016; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Peters, Michael/B-4973-2009; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015; vilar, rocio/D-7454-2014 OI CHANG, PAO-TI/0000-0003-4064-388X; Meschi, Emilio/0000-0003-4502-6151; Latino, Giuseppe/0000-0002-4098-3502; Wyss, Jeffery/0000-0002-8277-4012; Lancaster, Mark/0000-0002-8872-7292; Bertolucci, Sergio/0000-0003-1738-4736; Bigongiari, Ciro/0000-0003-3293-8522; Gallinaro, Michele/0000-0003-1261-2277; Turini, Nicola/0000-0002-9395-5230; Tartarelli, Giuseppe Francesco/0000-0002-4244-502X; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; NR 33 TC 37 Z9 37 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 15 PY 1998 VL 80 IS 24 BP 5275 EP 5280 DI 10.1103/PhysRevLett.80.5275 PG 6 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300010 ER PT J AU Shaing, KC Aydemir, AY Houlberg, WA Zarnstorff, MC AF Shaing, KC Aydemir, AY Houlberg, WA Zarnstorff, MC TI Theory of enhanced reversed shear mode in tokamaks SO PHYSICAL REVIEW LETTERS LA English DT Article ID EDGE ELECTRIC-FIELD; L-H TRANSITION; NEOCLASSICAL TRANSPORT; POLOIDAL ROTATION; MAGNETIC SHEAR; PLASMAS; CONFINEMENT; REGIME AB It is shown that toroidal-magnetic-field ripple-induced particle flux can drive poloidal E x B speed to bifurcate over the local maximum of the nonlinear poloidal (or parallel) viscosity. Here, E is the electric field, and B is the magnetic field. This mechanism, together with the turbulence suppression due to the radial gradient of the E x B and diamagnetic angular velocity, is employed to explain the enhanced reversed shear mode observed in the core region of tokamaks. C1 Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Oak Ridge Natl Lab, Div Fus Energy, Oak Ridge, TN 37831 USA. RP Shaing, KC (reprint author), Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. NR 32 TC 19 Z9 19 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 15 PY 1998 VL 80 IS 24 BP 5353 EP 5356 DI 10.1103/PhysRevLett.80.5353 PG 4 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300029 ER PT J AU Zhang, ZY Niu, Q Shih, CK AF Zhang, ZY Niu, Q Shih, CK TI "Electronic growth" of metallic overlayers on semiconductor substrates SO PHYSICAL REVIEW LETTERS LA English DT Article ID EPITAXIAL MULTILAYERS; FILMS; GAAS(110); AG; DISLOCATIONS; CONTINUUM; SURFACES; CLUSTERS; DEFECTS; LAYERS AB We present a novel "electronic growth" model for metallic thin films on semiconductor substrates. Depending on the competition between the effects of quantum confinement, charge spilling, and interface-induced Friedel oscillations, different types of film stability are defined, as characterized by the existence of critical/magic thicknesses for smooth growth. In particular, smooth growth can be achieved only above a few monolayers for noble metals, and only for the first layer for alkali metals. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Texas, Dept Phys, Austin, TX 78712 USA. RP Zhang, ZY (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Niu, Qian/G-9908-2013 NR 36 TC 304 Z9 312 U1 7 U2 40 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 15 PY 1998 VL 80 IS 24 BP 5381 EP 5384 DI 10.1103/PhysRevLett.80.5381 PG 4 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300036 ER PT J AU Fu, HX Zunger, A AF Fu, HX Zunger, A TI Quantum-size effects on the pressure-induced direct-to-indirect band-gap transition in InP quantum dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; DEPENDENCE; STATE; SUPERLATTICES; NANOCRYSTALS; CONFINEMENT; EQUATION; GAAS AB We predict that the difference in quantum confinement energies of Gamma-like and X-like conduction states in a covalent quantum dot will cause the direct-to-indirect transition to occur at substantially lower pressure than in the bulk material. Furthermore, the first-order transition in the bulk is predicted to become, for certain dot sizes, a second-order transition. Measurements of the "anticrossing gap" could thus be used to obtain unique information on the Gamma-X-L intervalley coupling, predicted here to be surprisingly large (50-100 meV). C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Fu, HX (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 22 TC 35 Z9 35 U1 0 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 JUN 15 PY 1998 VL 80 IS 24 BP 5397 EP 5400 DI 10.1103/PhysRevLett.80.5397 PG 4 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300040 ER PT J AU Westermann, S Urban, V Pyckhout-Hintzen, W Richter, D Straube, E AF Westermann, S Urban, V Pyckhout-Hintzen, W Richter, D Straube, E TI Comment on '"Lozenge" contour plots in scattering from polymer networks' SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOPOLOGICAL CONSTRAINTS C1 Forschungszentrum Julich, IFF, D-52425 Julich, Germany. Univ Halle Wittenberg, Fachbereich Phys, D-06099 Halle, Germany. Argonne Natl Lab, IPNS, Argonne, IL 60439 USA. RP Forschungszentrum Julich, IFF, Postfach 1913, D-52425 Julich, Germany. RI Richter, Dieter/H-3701-2013; Urban, Volker/N-5361-2015 OI Richter, Dieter/0000-0003-0719-8470; Urban, Volker/0000-0002-7962-3408 NR 8 TC 6 Z9 6 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 15 PY 1998 VL 80 IS 24 BP 5449 EP 5449 DI 10.1103/PhysRevLett.80.5449 PG 1 WC Physics, Multidisciplinary SC Physics GA ZU051 UT WOS:000074156300053 ER PT J AU Smith, DH Powell, V Ahmadi, G AF Smith, DH Powell, V Ahmadi, G TI Analysis of operational filtration data Part II: Incomplete cleaning of candle filters SO POWDER TECHNOLOGY LA English DT Article DE filtration; integrated gasification combined cycle; IGCC; hot-gas cleanup AB A model has been developed for hot-gas filtration by candle filters, which includes incomplete removal of the filter cakes by the cleaning backpulses of compressed air. Operational data from the filtration system of the Integrated Gasification and Cleanup Facility at the Federal Energy Technology Center were analyzed with the model and used to estimate the cake permeability, thickness of cake left on the filter after each backpulse, and total cake thickness vs, time. The statistical R-2 for the fit of the incomplete-cleaning model was 0.93, compared to the R-2 = 0.78 previously obtained for a fit of the 'ideal filtration' model to the same data set. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. US DOE, Fed Energy Technol Ctr, Morgantown, WV 26505 USA. RP Smith, DH (reprint author), W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0032-5910 J9 POWDER TECHNOL JI Powder Technol. PD JUN 15 PY 1998 VL 97 IS 2 BP 139 EP 145 DI 10.1016/S0032-5910(98)00005-9 PG 7 WC Engineering, Chemical SC Engineering GA ZQ940 UT WOS:000073918300007 ER PT J AU Jardret, V Zahouani, H Loubet, JL Mathia, TG AF Jardret, V Zahouani, H Loubet, JL Mathia, TG TI Understanding and quantification of elastic and plastic deformation during a scratch test SO WEAR LA English DT Article DE scratch hardness; elastic and plastic deformation AB An understanding of abrasion resistance and the associated surface deformation mechanisms is of primary importance in the materials engineering and design of many important industrial components undergoing wear and abrasion. Instrumented scratch testing has been shown to be a useful tool for characterization of the abrasion resistance of materials. Although most studies on scratch resistance have been limited to the theoretical case of purely plastic materials, experiments on metals and polymers have shown that the contact mechanics and indentation behavior are strongly influenced by the elastic behavior. In this work, the normal and tangential scratch forces, the penetration depth relative to the initial surface and the three-dimensional topographic relief of the scratched surface are measured. These parameters have allowed us to accurately calculate the actual contact area between the indenter and the material, taking into account both elastic deformation and pile-up phenomena. This contact surface was used to estimate the real mean contact pressure during scratch testing. This pressure was compared to the static hardness of the studied materials, as well as to the classical definitions of the scratch hardness, The ratio between the plastic and elastic deformation during a scratch test with a Berkovich indenter was then related to the ratio of the Elastic modulus to the hardness for the tested bulk materials. This scratch experiments were performed on a wide range of materials from polymers to metals and demonstrate the importance of taking both elastic deformation and pile-up into account in order to accurately understand and characterize the scratch resistance of materials. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Ecole Cent Lyon, Lab Tribol & Dynam Syst, F-69131 Ecully, France. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Jardret, V (reprint author), Nano Instruments Inc, 1001 Larson Dr, Oak Ridge, TN 37830 USA. NR 13 TC 197 Z9 199 U1 2 U2 47 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUN 15 PY 1998 VL 218 IS 1 BP 8 EP 14 DI 10.1016/S0043-1648(98)00200-2 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 102YV UT WOS:000074954600002 ER PT J AU Zanoria, ES Blau, PJ AF Zanoria, ES Blau, PJ TI Effects of machined surface condition on the repeated impact behavior of silicon nitride SO WEAR LA English DT Article DE impact wear; silicon nitride; machining; ground surface ID RESIDUAL-STRESS; CERAMICS; LAYERS; DAMAGE; SI3N4; WEAR AB This study addresses the influence of grinding-induced roughness, subsurface damage and residual stress on the repeated impact behavior of silicon nitride, a leading material for diesel poppet-valves. A ball-on-flat repeated impact tester was used to evaluate the impact wear of GS-44 silicon nitride coupons machined in three different conditions: coarsely ground (with 80-grit wheel), finely ground (with 320-grit wheel), and polished. The impacting ball was made of NBD-200 silicon nitride, and the angles of incidence used were 45 degrees, 60 degrees, 75 degrees, and 90 degrees. Within these angles, the impact wear of the ground GS-44 coupons, which is generally higher than the wear in the polished GS-44, is maximum at 60 degrees and lowest at 90 degrees incidence. Of the two ground coupons, the finely ground surface suffered more wear. In contrast, wear in the polished sample is minimum between 60 degrees and 75 degrees incidence. These observations are explained in terms of the effects of grinding-induced surface conditions on the mode of deformation, wear rate, and the evolution of wear debris deposits during repented impact. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Zanoria, ES (reprint author), Caterpillar PPG, POB 1895, Peoria, IL 61656 USA. NR 16 TC 5 Z9 5 U1 2 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JUN 15 PY 1998 VL 218 IS 1 BP 66 EP 77 DI 10.1016/S0043-1648(98)00190-2 PG 12 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 102YV UT WOS:000074954600008 ER PT J AU Ludziejewski, T Stohlker, T Keller, S Beyer, H Bosch, F Brinzanescu, O Dunford, RW Franzke, B Kozhuharov, C Liesen, D Livingston, AE Menzel, G Meier, J Mokler, PH Reich, H Rymuza, P Stachura, Z Steck, M Stenner, L Swiat, P Warczak, A AF Ludziejewski, T Stohlker, T Keller, S Beyer, H Bosch, F Brinzanescu, O Dunford, RW Franzke, B Kozhuharov, C Liesen, D Livingston, AE Menzel, G Meier, J Mokler, PH Reich, H Rymuza, P Stachura, Z Steck, M Stenner, L Swiat, P Warczak, A TI Electron bremsstrahlung in collisions of 223 MeV/u He-like uranium ions with gaseous targets SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID RELATIVISTIC ATOMIC-COLLISIONS; TRACE-ELEMENT ANALYSIS; X-RAY-EMISSION; FIELD BREMSSTRAHLUNG; ANGULAR-DISTRIBUTION; HEAVY-IONS; CAPTURE; IONIZATION AB The bremsstrahlung process in the domain of strong Coulomb fields has been investigated for N-2 and Ar target electrons colliding with He-like uranium ions at 223 MeV/u. The differential cross sections for bremsstrahlung were measured at laboratory observation angles of 48 degrees, 90 degrees, and 132 degrees. Substantial discrepancies were found between the experimental cross sections and the first-order Born approximation calculations. The reported data provide a new testing ground for non-perturbative treatment of the coupling between radiation and matter in the presence of strong fields. C1 Gesell Schwerionenforsch mbH, D-64220 Darmstadt, Germany. Goethe Univ Frankfurt, D-60486 Frankfurt, Germany. Goethe Univ Frankfurt, D-60054 Frankfurt, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Inst Nucl Studies, PL-05400 Otwock, Poland. Inst Nucl Phys, PL-31342 Krakow, Poland. Jagiellonian Univ, PL-30059 Krakow, Poland. RP Ludziejewski, T (reprint author), Gesell Schwerionenforsch mbH, D-64220 Darmstadt, Germany. EM T.Ludziejewski@gsi.de NR 36 TC 21 Z9 21 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JUN 14 PY 1998 VL 31 IS 11 BP 2601 EP 2609 DI 10.1088/0953-4075/31/11/020 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZX022 UT WOS:000074472400020 ER PT J AU Lucia, LA Wyrozebski, K Chen, LH Geiger, C Whitten, DG AF Lucia, LA Wyrozebski, K Chen, LH Geiger, C Whitten, DG TI Electron transfer photofragmentation reactions in monolayer films at the air/water interface SO LANGMUIR LA English DT Article ID CARBON BOND-CLEAVAGE; RADICAL-ION-PAIRS; MOLECULAR SELF-ASSEMBLIES; LANGMUIR-BLODGETT-FILMS; CATION RADICALS; FRAGMENTATION; DONOR; PHOTOCHEMISTRY; REACTIVITY; PHOTOSENSITIZATION AB A series of photoinduced electron-transfer fragmentation reactions have been studied in compressed monolayer films at the air/water interface. The reactions investigated involve amphiphilic and polymeric derivatives of fragmentable amino alcohol, 1,2-diamine, and pinacol donors and light-absorbing accepters, which are reactive in solution-phase studies from their triplet states. For intralayer studies a surfactant anthraquinone derivative was the light-absorbing acceptor. For comparable "interfacial" studies, the water soluble cation tris(2,2'-bipyridine)ruthenium(II)(2+) (Ru(bpy)(3)(2+)) was the photoactive acceptor from the subphase. The fragmentation reactions all involve oxidative cleavage of a relatively strong C-C bond in the donor. Reaction was followed in each case by monitoring changes in surface pressure that occur when the compressed film is irradiated and maintained at a constant area. Reaction was readily observed in most cases where the donor and light-absorbing substrate are present; however the consequences were found to be quite dependent upon the specific donor substrate. Thus for simple single-chain amphiphiles containing either amino alcohol or 1,2-diamine donor sites, both intralayer and interfacial reactions result in rapid decrease in surface pressure, consistent with destruction of the film as the more hydrophilic redox products are solubilized into the subphase. For a polymeric diamine, much more complex behavior is observed, consistent with a situation where single fragmentation events do not lead to removal of material from the film but multiple fragmentation reactions culminate in film solubilization. Finally, a doublechain amphiphilic pinacol was found to undergo interfacial fragmentation with Ru(bpy)(3)(2+) in the subphase with a concurrent increase in surface pressure to form stable films that do not "dissolve" into the subphase. The isotherms observed following irradiation, decompression, and recompression are consistent with an expansion that occurs as the two-chain amphiphile undergoes redox fragmentation to produce two equivalents of a single-chain amphiphile. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Rochester, Dept Chem, Rochester, NY 14627 USA. Univ Rochester, NSF, Ctr Photoinduced Charge Transfer, Rochester, NY 14627 USA. RP Whitten, DG (reprint author), Univ Calif Los Alamos Natl Lab, CST-1,MS-J565, Los Alamos, NM 87545 USA. NR 47 TC 4 Z9 4 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JUN 13 PY 1998 VL 14 IS 13 BP 3663 EP 3672 DI 10.1021/la9713558 PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZW945 UT WOS:000074464100033 ER PT J AU Hyland, RW Asta, R Foiles, SM Rohrer, CL AF Hyland, RW Asta, R Foiles, SM Rohrer, CL TI Al(fcc): Al3Sc(L1(2)) interphase boundary energy calculations SO ACTA MATERIALIA LA English DT Article ID CRITICAL NUCLEUS SHAPES; FCC-FCC NUCLEATION; KINETICS; AL3SC; CRYSTALLOGRAPHY; ALLOYS; METALS AB These calculations assess the applicability of classical nucleation theory to the reaction f.c.c. --> L1(2) occurring in dilute Al-Sc alloys. The orientation and temperature dependence of the energies of coherent Al(f.c.c.):Al3Sc(L1(2)) interphase boundaries were studied using atomistic simulation and a low temperature expansion (LTE) of the grand potential. Embedded atom method potentials were developed for both sets of calculations. Atomistic 0 K results for the anisotropy of the interphase boundary enthalpy gave gamma((100)) < gamma((110)) Nb>105>Pa was observed and element 105 behaved very differently from its closest homologue Ta. As it is not possible within reasonable effort to model the many presumably mixed fluoride-chloride complexes involved in these studies, theoretical calculations were performed in the pure chloride system predicting a reversed sequence of extraction. To verify this experimentally, and in order to perform a systematic study of halide complexation of the group 5 elements, new batch extraction experiments for Nb, Ta, and Pa were performed with the quarternary ammonium salt Aliquat 336 in pure HF, HCl, and HBr solutions. Based on these results, new chromatographic column separations were elaborated to study separately the fluoride and chloride complexation of element 105 with ARCA II. In the system Aliquat 336-HF, after feeding of the activity onto the column in 0.5 M HF, element 105 did not elute in 4 M HF (Pa fraction) but showed a higher distribution coefficient close to that of Nb (and Ta). In the system Aliquat 336-HCl, after feeding onto the column in 10 M HCl, element 105 showed a distribution coefficient in 6 M HCl close to that of Nb establishing an extraction sequence Pa>Nb greater than or equal to 105>Ta which is theoretically predicted by considering the competition between hydrolysis and complex formation. (C) 1998 Elsevier Science S.A. C1 Univ Mainz, Inst Kernchem, D-55099 Mainz, Germany. Gesell Schwerionenforsch, D-64291 Darmstadt, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kratz, JV (reprint author), Univ Mainz, Inst Kernchem, D-55099 Mainz, Germany. RI McGrath, Christopher/E-8995-2013; Strub, Erik/N-1308-2015 OI Strub, Erik/0000-0002-4136-2871 NR 7 TC 8 Z9 9 U1 3 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 292 EP 295 DI 10.1016/S0925-8388(98)00073-5 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200062 ER PT J AU Thompson, JD Hundley, MF Sarrao, JL AF Thompson, JD Hundley, MF Sarrao, JL TI Correlated f-electron materials near a T=0 magnetic-nonmagnetic boundary: implications for delta-Pu SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE thermal expansion; specific heat; CeRh(2-x)Ru(x)Si(2); Pu; Gruneisen parameter ID INSTABILITY; SYSTEMS; HEAT AB A comparison of magnetic and thermodynamic properties of CeRh(2)Si(2) and CeRh(2-x)Ru(x)Si(2) near their T = 0 magnetic-nonmagnetic boundary accessed by pressure and alloying, respectively, emphasizes the role of disorder in producing non-Fermi-liquid effects. Spatially varying hybridization induced by crystallographic disorder may play a similar though less dramatic role in determining the physical properties of delta-phase plutonium at ambient and high pressures. (C) 1998 Elsevier Science S.A. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thompson, JD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jdt@rayleigh.lanl.gov NR 20 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 335 EP 338 DI 10.1016/S0925-8388(98)00083-8 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200072 ER PT J AU Heathman, S Haire, RG AF Heathman, S Haire, RG TI High-pressure x-ray diffraction studies of Cm-Bk alloys: contribution to the actinide pressure-phase diagram SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE Cm; Bk; alloys; pressure; X-ray study ID TRANSITIONS; METAL AB Curium-berkelium alloys were studied by X-ray diffraction up to 53 GPa to probe their structural behavior under pressure. Two different alloy compositions were studied successfully in this work: one was a Cm-0.70-Bk-0.30 alloy and the second was a Cm-0.46-Bk-0.54 alloy. The goal was to understand the phase and relative volume behavior of both alloys in terms of: (1) bonding, (2) the elements' electronic configurations and (3) their pressure behavior relative to that reported for the pure Am-Cf metals. Given here are the results of the high-pressure studies of these Cm-Bk alloys, and a discussion of the significance of the findings with respect to the published actinide pressure-phase diagram. (C) 1998 Elsevier Science S.A. C1 European Commiss, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Haire, RG (reprint author), European Commiss, Joint Res Ctr, Inst Transuranium Elements, Postfach 2340, D-76125 Karlsruhe, Germany. EM rgh@ornl.gov NR 22 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 342 EP 346 DI 10.1016/S0925-8388(98)00085-1 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200074 ER PT J AU Ogawa, T Kobayashi, F Sato, T Haire, RG AF Ogawa, T Kobayashi, F Sato, T Haire, RG TI Actinide nitrides and nitride-halides in high-temperature systems SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE UN; PuN; NpN; AmN; vaporization; UNCl; UNF; actinide nitride halide; stability diagram; thermodynamics ID THERMODYNAMIC PROPERTIES; VAPORIZATION BEHAVIOR; EQUILIBRIA AB Knowledge of high-temperature actinide mononitrides systems has been extended in two fields. Systematics of the evaporation behavior of actinide mononitrides, including NpN and AmN, are discussed in view of recent experimental data. Secondly, for electrochemical data for the U-N-Cl system in molten salts let us consider equilibria in ternary systems containing halogens. The vaporization behavior of mononitrides together with other equilibrium relationships are described using a sublattice formalism, where the structural vacancy in the nitrogen sublattice is taken into account. (C) 1998 Elsevier Science S.A. C1 Japan Atom Energy Res Inst, Tokai, Ibaraki 31911, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ogawa, T (reprint author), Japan Atom Energy Res Inst, Tokai, Ibaraki 31911, Japan. EM ogawa@sun2sarl.tokai.jaeri.go.jp NR 49 TC 14 Z9 14 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 347 EP 354 DI 10.1016/S0925-8388(98)00086-3 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200075 ER PT J AU Gibson, JK AF Gibson, JK TI High-temperature transuranium organometallic species from laser ablation of actinide-polymer mixtures SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE neptunium organometallics; plutonium organometallics; actinide vaporization; polymer ablation AB pulsed laser ablation of dispersions of f-element compounds in polymers produces novel 'high-temperature' organometallic complex ions. The M+-L from reactions of metal ions (M+) with polymer fragments (L) in the ablation plume are identified by time-of-flight mass spectrometry. Compositions and abundances of M+-L from ablation of UO2 and lanthanides in polyimide (PI) reflected distinctive f-element chemistries; we report here on ablation of (NpO2)-Np-237 and (PuO2)-Pu-242 in PI. Primary products were Np+-CcHh and Pu+-CcHh with 1 less than or equal to c less than or similar to 20-the characteristic complex ion compositions and abundances reveal distinctive chemistries; the transuranium results are compared with those for other f elements. Studies of lanthanides in polystyrene rather than PI excluded N-14 (isobaric with (CH2)-C-12) as a potential ligand constituent, clarifying ion compositions. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 359 EP 362 DI 10.1016/S0925-8388(98)00088-7 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200077 ER PT J AU Becker, JD Cooper, BR Wills, JM Cox, L AF Becker, JD Cooper, BR Wills, JM Cox, L TI Calculated lattice relaxation in Pu-Ga alloys SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE LMTO; plutonium; Hellman-Feynman; gallium; EXAFS ID SYSTEMS; PLUTONIUM; ELEMENTS; BAND AB Hellman-Feynman forces on atoms in Pu-32 and Pu31Ga supercells are calculated with the full-potential LMTO method in the local density approximation. These forces are minimized by adjusting atomic positions using an iterative Broyden scheme. A Pu-32 supercell shows no tendency to relax from a perfect fee lattice. In Pu31Ga the nearest-neighbor shell of plutonium atoms relaxes inward by 1.04% of the initial theoretical bond length (2.86 Angstrom) compared with a measured (EXAFS) value of 3.7% for an alloy with similar composition. Possible sources of the discrepancy between theory and experiment are discussed. (C) 1998 Elsevier Science S.A. C1 Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. NR 21 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 EI 1873-4669 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 367 EP 369 DI 10.1016/S0925-8388(98)00090-5 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200079 ER PT J AU Caspi, E Shaked, H Pinto, H Melamud, M Hu, Z Chmaissem, O Short, S Jorgensen, JD AF Caspi, E Shaked, H Pinto, H Melamud, M Hu, Z Chmaissem, O Short, S Jorgensen, JD TI Pressure effect on the magnetic and crystallographic structures in the U(Ni1-xCux)(2)Ge-2 system SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE pressure effect; neutron diffraction; RKKY model ID NEUTRON-DIFFRACTION AB The pressure effect on the magnetic and crystallographic structures of the materials UCu2Ge2, and U(Ni0.05Cu0.95)(2)Ge-2 are studied by neutron diffraction in the applied pressure range of ambient to 0.63 GPa, at room temperature and 60 K. The compressibilities of the materials are found to be isotropic, and very similar for both materials and temperatures. This isotropy is explained by a free-electron gas control of the compressibility. No pressure effect on the magnetic structures or on the magnitude of the magnetic moments was observed for both materials. This result is discussed in the framework of the RKKY model. (C) 1998 Elsevier Science S.A. C1 Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. Nucl Res Ctr Negev, IL-84190 Beer Sheva, Israel. Argonne Natl Lab, MSD, Argonne, IL 60439 USA. RP Caspi, E (reprint author), Ben Gurion Univ Negev, Dept Phys, POB 653, IL-84105 Beer Sheva, Israel. NR 11 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 378 EP 381 DI 10.1016/S0925-8388(98)00093-0 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200082 ER PT J AU McWhan, DB AF McWhan, DB TI Synchrotron radiation as a probe of actinide magnetism (T7-Al 'magnetism') SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE X-ray scattering; magnetic moments; heavy fermion systems ID X-RAY-SCATTERING; RESONANCE EXCHANGE SCATTERING; POLARIZATION DEPENDENCE; CIRCULAR-DICHROISM; DIFFRACTION; UAS; HOLMIUM; NEUTRON; UO2 AB Polarized beam experiments using synchrotron sources provide a direct measurement of both the orbital- and the spin-angular momentum densities. Similar information can be obtained by applying sum rules for the integral of the imaginary part of the forward-scattering amplitude over two spin-orbit split absorption edges to magnetic circular dichroism (MCD) measurements in ferri- and ferromagnetic materials. Large enhancements of the cross section for magnetic scattering at the M-IV and M-V absorption edges have led to studies of the weak critical scattering above magnetic phase transitions and of the order parameter in heavy fermion systems which have very small moments. These enhancements have also enabled studies of the modification of magnetic order in the near surface regions of crystals where the crystal symmetry is broken. (C) 1998 Elsevier Science B.V. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP McWhan, DB (reprint author), Brookhaven Natl Lab, Bldg 460,POB 5000, Upton, NY 11973 USA. NR 36 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 408 EP 413 DI 10.1016/S0925-8388(98)00100-5 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200089 ER PT J AU Burns, JB Haire, RG Peterson, JR AF Burns, JB Haire, RG Peterson, JR TI Enthalpy of solution of californium oxychloride; calculation of the standard enthalpy of formation of CfOCl SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE californium; oxychloride; enthalpy; berkelium AB The enthalpy of solution of CfOCl in 1.022 mol dm(-3) HCl was measured on the 0.4-1.5 mg scale, and the standard enthalpy of formation at 298 K for this compound was calculated. The CfOCl was prepared by heating in air at 280-320 degrees C the solid hydrated trichloride, obtained by slow evaporation of Cf(III) in HCl solution. X-ray powder diffraction analysis confirmed the material to be the expected oxychloride, which exhibits the PbFCl-type tetragonal structure. Dissolutions of the oxychloride were made at 25.0 degrees C in an isoperibol solution microcalorimeter. Enthalpy of solution values were calculated according to the equation: CfOCl(cr) + 2HCl((sln)) --> CfCl3(sln) + H2O(sln). The Delta(f)H(0) (CfOCl(cr)) was determined to be -920 +/- 7 kJ mol(-1). Interpolation within Delta(f)H(0) (AnOCl((cr))), where An = U, Pu, Am, Cm, and Cf, as a function of An(III) ionic radius yielded Delta(f)H(0) (BkOCl(cr)) = -944 +/- 10 kJ mol(-1). (C) 1998 Elsevier Science S.A. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Pellissippi State Tech Community Coll, Dept Nat Sci, Knoxville, TN 37933 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Transuranium Res Lab, Oak Ridge, TN 37831 USA. RP Peterson, JR (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 676 EP 679 DI 10.1016/S0925-8388(98)00185-6 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200147 ER PT J AU Nash, KL Sullivan, JC AF Nash, KL Sullivan, JC TI Kinetics of actinide complexation reactions SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE actinide; kinetics; complexation; activation parameters; mechanism; ligand ID CHLOROPHOSPHONAZO-III; EUROPIUM ETHYLENEDIAMINETETRAACETATE; DISSOCIATION KINETICS; DIOXOURANIUM(VI) ION; ARSENAZO-III; EXCHANGE; AMERICIUM(III); MEDIA AB We report herein a summary of what is known about actinide complexation kinetics. The systems include actinide ions in the four principal oxidation states (UI, IV, V, and VI) and complex formation and dissociation rates with both simple and complex ligands. Complex formation reactions tend to be rapid, accessible only to rapid-scan and equilibrium perturbation techniques. Complex dissociation reactions exhibit a wider range of rates and are generally more accessible using standard analytical methods. Literature results are described and correlated with the known properties of the individual ions. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Nash, KL (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 32 TC 8 Z9 8 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 712 EP 718 DI 10.1016/S0925-8388(98)00193-5 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200155 ER PT J AU Budantseva, NA Tananaev, IG Fedoseev, AM Delegard, CH AF Budantseva, NA Tananaev, IG Fedoseev, AM Delegard, CH TI Behavior of plutonium(V) in alkaline media SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE plutonium; disproportionation; formal potential; alkaline solutions AB In alkaline solutions with NaOH concentration below 8 M, Pu(V) has been found to be unstable, disproportionating to form Pu(IV) hydrous oxide precipitate and dissolved Pu(VI). Sorption of Pu(V) on the freshly precipitating Pu(IV) hydrous oxide and partial reduction of Pu(VI) by water alpha-radiolysis products complicate disproportionation of Pu(V). Disproportionation and reproportionation equilibrium constants were measured in the range 4-8 M NaOH. The yield of disproportionation and reproportionation reaction products increase with temperature and sharply fall with NaOH concentration. (C) 1998 Elsevier Science S.A. C1 Russian Acad Sci, Inst Phys Chem, Moscow 117915, Russia. Pacific NW Lab, Richland, WA 99352 USA. RP Tananaev, IG (reprint author), Russian Acad Sci, Inst Phys Chem, Leninsky Prospekt 31, Moscow 117915, Russia. OI Delegard, Calvin/0000-0001-6503-9502 NR 14 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 813 EP 816 DI 10.1016/S0925-8388(98)00224-2 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200176 ER PT J AU Arko, AJ Joyce, JJ Cox, LE Morales, L Sarrao, J Smith, JL Fisk, Z Menovsky, A Tahvildar-Zadeh, A Jarrell, M AF Arko, AJ Joyce, JJ Cox, LE Morales, L Sarrao, J Smith, JL Fisk, Z Menovsky, A Tahvildar-Zadeh, A Jarrell, M TI ARPES in strongly correlated 4f and 5f systems: Comparison to the periodic Anderson model (PAM) SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE heavy fermions; electronic structure; Periodic Anderson Model (PAM); narrow f-bands ID HEAVY-FERMION SYSTEMS; SPECTROSCOPIC EVIDENCE; UPT3; PHOTOEMISSION; DIMENSIONS; SPECTRA; STATE AB The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow, nearly temperature-independent bands (i.e., no spectral weight loss or transfer with temperature). A small dispersion of the f-bands above the Kondo temperature is easily measurable so that a Kondo resonance, as defined by NCA, is not evident. Preliminary results, however, indicate that the Periodic Anderson Model (PAM) captures some of the essential physics. Angle-integrated resonant photoemission results on delta-Pu indicate a narrow 5f feature at E-F, similar in width to f-states in Ce and U compounds, but differing in that PES cross-section as a function of h nu suggests substantial 6d admixture. (C) 1998 Elsevier Science S.A. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. Univ Amsterdam, Natuurkundig Lab, NL-1018 XE Amsterdam, Netherlands. Univ Cincinnati, Cincinnati, OH 45221 USA. RP Arko, AJ (reprint author), Univ Calif Los Alamos Natl Lab, MS-K764, Los Alamos, NM 87545 USA. EM arko@lanl.gov RI Zadeh, Niki/F-4532-2014 NR 35 TC 5 Z9 5 U1 0 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 826 EP 830 DI 10.1016/S0925-8388(98)00227-8 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200179 ER PT J AU Antonio, MR Williams, CW Soderholm, L AF Antonio, MR Williams, CW Soderholm, L TI Synthesis and characterization of actinide-exchanged Preyssler heteropolyanions [AnP(5)W(30)O(110)](n-) (An=Th, Am, Cm) SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE heteropolyoxometalate clusters; actinide complexants; preyssler heteropolytungstate anion; actinide exchange; cyclic voltammetry ID LANTHANIDE; CATIONS; (12-); VALENCE AB Interest in the use of heteropolyoxometalate clusters as actinide complexants motivates our studies of the Preyssler heteropolytungstate anion, [NaP5W30O110](14-), and its actinide-exchanged derivatives, [AnP(5)W(30)O(110)](n-). Under specific conditions, substitution of Na+ is possible by La3+ and Th4+ as well as by U4+ and the transuranics Am3+ and Cm3+. Both [AnP(5)W(30)O(110)](11-) (for An = Th4+, U4+) and [AnP(5)W(30)O(110)](12-) (for An=Am3+, Cm3+) as well as [LaP5W30O110](12-) exhibit remarkable redox properties and form heteropoly blues. Although similar, the electrochemistry of the An(3+)/La3+- and An(4+)-exchanged anions are different and distinguishable by cyclic voltammetry in aqueous mineral acid electrolytes. The synthesis of the new Preyssler anion complexes of La3+, Th4+, Am3+, and Cm3+ will be described along with results from cyclic voltammetry measurements. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Antonio, MR (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 27 TC 14 Z9 14 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 846 EP 849 DI 10.1016/S0925-8388(98)00231-X PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200183 ER PT J AU Beitz, JV Williams, CW Liu, GK AF Beitz, JV Williams, CW Liu, GK TI Spectroscopy and dynamics of 5f states of Es3+ in LaF3 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE einsteinium; spectroscopy; photophysics; crystal field theory ID SYSTEMATIC ANALYSIS; SPECTRA AB Using time- and wavelength-resolved laser-induced fluorescence methods, the 5f state spectroscopy and photodynamics of Es-253(3+) in LaF3, have been investigated. Based on an effective operator Hamiltonian model and approximating the metal ion site symmetry as C-2 nu, a set of crystal field parameters has been obtained that fit the 56 assigned levels associated with the seven states of Es3+ that were observed. The F-5(5) emitting state of Es3+ exhibited a decay rate that approached the expected purely radiative decay of the state. This suggests that the shorter lifetime previously found for this state of Es3+ in LaCl3 arose from radiation damage induced by alpha decay of Es-253. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Beitz, JV (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 TC 4 Z9 4 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 850 EP 853 DI 10.1016/S0925-8388(98)00232-1 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200184 ER PT J AU Assefa, Z Haire, RG Stump, NA AF Assefa, Z Haire, RG Stump, NA TI Emission profile of Bk(III) in a silicate matrix: anomalous dependence on excitation power SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE actinide; berkelium; glass; luminescence; spectroscopy ID SPECTRA; IONS; CEF4 AB We have been conducting spectroscopic investigations of the transuranium elements in silicate glasses. These studies included spectroscopic monitoring of the decay profiles of selected short-lived actinides. Although the latter are not candidates for immobilization hosts, their half-lives make them attractive for probing certain fundamental issues. One facet of these studies has been spectroscopic investigations of Bk in a silicate matrix. Optical spectroscopy has shown that the trivalent state of Bk is the stable state in this matrix, and Bk(III) exhibits primarily two emission bands, centered at 15 340 and 13 475 cm(-1). The relative intensities of these two bands exhibit an unusual dependence on excitation power. At low power levels, the 13 475 cm(-1) emission dominates; with increased power levels, the emission intensity of the 13 475 cm(-1) band decreases at a greater rate than the band at 15 340 cm(-1). As a result, this latter band dominates at higher excitation powers. A similar dependence of these two BB(III) emission bands with temperature has also been noted. Details of the emission profile of Bk in this matrix and the basis for the observed power dependence are discussed. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Dept Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Winston Salem State Univ, Dept Phys Sci, Winston Salem, NC 27110 USA. RP Assefa, Z (reprint author), Oak Ridge Natl Lab, Dept Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 9 TC 3 Z9 3 U1 2 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 854 EP 858 DI 10.1016/S0925-8388(98)00233-3 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200185 ER PT J AU Liu, GK Li, ST Beitz, JV Abraham, M AF Liu, GK Li, ST Beitz, JV Abraham, M TI Effects of self-radiation damage on electronic properties of Cm-244(3+) in an orthophosphate crystal of YPO4 SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE radiation damage; inhomogeneous line broadening; orthophosphates ID LUPO4 SINGLE-CRYSTALS; CM3+; ABSORPTION AB The electronic energy level structure of the alpha-emitting isotope Cm-244(3+) (t(1/2)=18.1 years) doped into single crystals of YPO4 has been studied using site-selected laser spectroscopic methods. Electronic transitions between the nominal S-8(7/2) ground state and the D-6(7/2) state of Cm3+ were utilized to characterize the effects of alpha-decay-induced structural damage. The total splitting of the four doublets in the ground multiplet is 12.5 cm(-1), and that of the excited multiplet is 611 cm(-1). Due to radiation damage accumulated in 17 years since the crystals were grown, the inhomogeneous line width of the S-8(7/2) <-> D-6(7/2) transitions is broader than 50 cm(-1) as measured without site selection. The line width of resonant fluorescence Line narrowing (RFLN) is less than 1 cm(-1) at 4 K. A total of 12 satellite lines were observed symmetrically spacing about the RFLN line. The position, width, and intensity of these satellite lines have been analyzed to gain information on the electronic and structural properties of the actinide ions in the disordered lattice of Cm3+:YPO4. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Liu, GK (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM gliu@anlchm.chm.anl.gov NR 13 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 872 EP 875 DI 10.1016/S0925-8388(98)00237-0 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200189 ER PT J AU Wasserman, SR Soderholm, L Rebizant, J Lander, GH AF Wasserman, SR Soderholm, L Rebizant, J Lander, GH TI Surface contamination of single-crystal PuSb SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Actinides-97 Conference CY SEP 21-26, 1997 CL BADEN BADEN, GERMANY DE X-ray resonant exchange scattering; X-ray absorption fine structure; surface contamination; PuSb ID LIGHT ACTINIDE COMPOUNDS; X-RAY-ABSORPTION; SCATTERING AB Pu M-edge X-ray absorption experiments were performed on a single crystal of PuSb in order to understand incongruous X-ray resonant exchange scattering (XRES) results from the same material. Analysis of the extended X-ray absorption fine structure (EXAFS) reveals that there is an amorphous or polycrystalline surface phase on the PuSb. The Pu at the surface of the crystal is coordinated primarily to a first-row main-group element, probably oxygen. In addition, the surface may be slightly deficient in antimony. These EXAFS results are sufficient to explain the absence of an XRES response in this PuSb sample. (C) 1998 Elsevier Science S.A. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. European Commiss, JRC, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. RP Wasserman, SR (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM srw@anl.gov NR 18 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 12 PY 1998 VL 271 BP 882 EP 886 DI 10.1016/S0925-8388(98)00240-0 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZZ011 UT WOS:000074686200192 ER PT J AU Sajonz, P Kele, M Zhong, GM Sellergren, B Guiochon, G AF Sajonz, P Kele, M Zhong, GM Sellergren, B Guiochon, G TI Study of the thermodynamics and mass transfer kinetics of two enantiomers on a polymeric imprinted stationary phase SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE thermodynamic parameters; kinetic studies; mass transfer; enantiomer separation; adsorption isotherms; imprinted polymers; stationary phases, LC; phenylalanine anilide ID CHROMATOGRAPHIC BAND PROFILES; CONCENTRATION-DEPENDENCE; FRONTAL ANALYSIS; NONCOVALENT INTERACTIONS; NETWORK POLYMERS; BINDING; DIFFUSION; SEPARATIONS; MIMICS; SITES AB The adsorption isotherms of D- and L-phenylalanine anilide (PA) on an L-phenylalanine anilide imprinted stationary phase have been determined using staircase frontal analysis, An aqueous buffer-organic solvent mixture has been used as mobile phase. The measurements were done at temperatures of 40, 50, 60 and 70 degrees C for sample concentrations ranging between 5.10(-4) to 1 g/l. It was found that the adsorption data fit well to both the Freundlich and the Bi-Langmuir isotherm models. Examination of the best values of the numerical coefficients of the Bi-Langmuir model shows that the site class representing the binding sites with the highest binding energy exhibits a very low saturation capacity for the non-imprinted enantiomer, indicating a high selectivity for the imprinted L-enantiomer. The low energy site class also shows some selectivity for the L-enantiomer. Mass transfer rate coefficients were obtained for each single breakthrough curve by using the transport model of chromatography. It was found that the mass transfer coefficient of L-PA increases very rapidly with the sample concentration while there is only a slight increase for the other enantiomer. (C) 1998 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. Univ Mainz, Dept Inorgan Chem & Analyt Chem, D-55099 Mainz, Germany. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 29 TC 134 Z9 138 U1 1 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JUN 12 PY 1998 VL 810 IS 1-2 BP 1 EP 17 DI 10.1016/S0021-9673(98)00247-7 PG 17 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA ZW743 UT WOS:000074443300001 ER PT J AU Stankovic, S Espenson, JH AF Stankovic, S Espenson, JH TI Facile oxidation of silyl enol ethers with hydrogen peroxide catalyzed by methyltrioxorhenium SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID MAIN-GROUP ELEMENTS; ALPHA-HYDROXY; METHYLRHENIUM TRIOXIDE; CARBONYL-COMPOUNDS; TRANSITION-METALS; MULTIPLE BONDS; EPOXIDATION; MECHANISM C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 21 TC 26 Z9 26 U1 1 U2 11 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 JUN 12 PY 1998 VL 63 IS 12 BP 4129 EP 4130 DI 10.1021/jo972315b PG 2 WC Chemistry, Organic SC Chemistry GA ZV170 UT WOS:000074277100053 ER PT J AU Smith, CJ Hettich, RL Jompa, J Tahir, A Buchanan, MV Ireland, CM AF Smith, CJ Hettich, RL Jompa, J Tahir, A Buchanan, MV Ireland, CM TI Cadiolides A and B, new metabolites from an ascidian of the genus Botryllus SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID TUNICATE; ALKALOIDS C1 Univ Utah, Dept Med Chem, Salt Lake City, UT 84112 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Hasanuddin, Fac Fisheries & Marine Sci, Ujung Pandang, Indonesia. RP Ireland, CM (reprint author), Univ Utah, Dept Med Chem, Salt Lake City, UT 84112 USA. RI Hettich, Robert/N-1458-2016; Buchanan, Michelle/J-1562-2016; OI Hettich, Robert/0000-0001-7708-786X; Buchanan, Michelle/0000-0002-8078-4575; Tahir, Akbar/0000-0001-5485-0033; Jompa, Jamaluddin/0000-0001-9740-333X NR 10 TC 27 Z9 28 U1 0 U2 2 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 JUN 12 PY 1998 VL 63 IS 12 BP 4147 EP 4150 DI 10.1021/jo980171a PG 4 WC Chemistry, Organic SC Chemistry GA ZV170 UT WOS:000074277100058 ER PT J AU Blatter, F Sun, H Vasenkov, S Frei, H AF Blatter, F Sun, H Vasenkov, S Frei, H TI Photocatalyzed oxidation in zeolite cages SO CATALYSIS TODAY LA English DT Article DE zeolites; photooxidation; alkanes; alkylaromatics; olefins ID SELECTIVE OXIDATION; VISIBLE-LIGHT; ACRYLIC-ACID; OXIDE CATALYSTS; RED-LIGHT; PROPANE; O-2; ETHANE; PHOTOOXIDATION; HYDROCARBONS AB A new concept of room temperature selective oxidation of olefins, alkyl substituted benzenes and alkanes by electron transfer from the hydrocarbon to the oxygen molecule induced by irradiation with visible light is shown. The hydrocarbon radical cation-O(2) charge-transfer pair is generated inside the cavities of alkali or alkaline-earth ion-exchanged zeolites, in which the large electrostatic field stabilizes the highly polar charge-transfer states of hydrocarbon-O(2) collisional pair and allows to control the pathways of further transformation. High selectivities to useful products are obtained using this approach. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, MS Calvin Lab, Berkeley, CA 94720 USA. RP Frei, H (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, MS Calvin Lab, Berkeley, CA 94720 USA. EM hmfrei@1b1.gov NR 85 TC 85 Z9 90 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD JUN 11 PY 1998 VL 41 IS 4 BP 297 EP 309 DI 10.1016/S0920-5861(98)00021-2 PG 13 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA ZW985 UT WOS:000074468800002 ER PT J AU Gibson, JK AF Gibson, JK TI Americium organometallic ions produced by laser ablation of AmO2 in polyimide SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MASS-SPECTROMETRY; CARBON; HYDROCARBONS; IONIZATION; FULLERENES; OXIDES AB Laser ablation into vacuum of a dilute dispersion of AmO2 in polyimide produced organoamericium ions of the general formula AmCxHyNz+. Ion masses were determined by time-of-flight mass spectrometry, and compositions were confidently assigned for most small ions (x less than or equal to 6). Comparisons of product abundances with previous results for lanthanides (Ln) and lighter actinides (An) suggest that Am behaves similarly to a lanthanide element such as Tm-both produced substantial MC2H+ (acetylide) and MC4H+. In contrast, the lighter actinides, Th, U, Np, and Pu, preferentially produced the binary carbides MC2+ and MC4+. The acetylides can be regarded as ionic species comprising M2+ ([M2+-{(-):C=CH}](+)) and the carbides as comprising M3+ ([M3+-{(-):C=C:(-)}](+)). Accordingly, the MC(2)H(+ )vs MC2+ abundances generally correlated with the ionization energies from M2+ to M3+ (IE[M2+]). In addition to the carbide/hydrocarbide complex ions, Am+-hydroxide, -cyanide, -cyanate, and -nitrile ions were produced in abundances generally consistent with IE[Am+] and IE[Am2+]. Both AmCN+ and AmC2H+ comprise nominally divalent Am2+, but the relative abundance of the cyanide (vs acetylide) species was greater for Am than for the preceding An, suggesting a greater degree of ionicity in the Am complexes. Larger AmCxHyNz+ were identified for x up to similar to 12, with compositions consistent with the ionic bonding model used to represent the smaller Am+-R. The formation and possible structures of the larger species are considered with regard to the neutrals produced during ablation of polyimide. In addition, substantial amounts of directly ablated fullerene ions (and neutrals), C-50(+)-C-greater than or equal to 125(+), were produced under favorable ablation conditions. An anomalously intense peak corresponding to C-110(+) is considered to probably comprise a contribution from the metallofullerene of similar mass, Am+-C-90. On the basis of the divalent character of Am, this species could be represented as Am2+-C-90(-), although the present results provide do not indicate whether such a species should be regarded as an exohedral or endohedral metallofullerene. This work extended the production of labile gas-phase organoactinide complexes to the first transplutonium element Am-this technique is applicable to highly radioactive elements not amenable to conventional methods. The results revealed the divalent character of Am not evident for the preceding An. The low-valent sigma-bonded organometallics identified in the gas phase are difficult to isolate for the lanthanide and transuranium actinide elements, but polymer ablation into vacuum accesses transient/metastable species by supplying highly reactive hydrocarbon radicals to a free metal center. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Gibson, JK (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,Bldg 5505, Oak Ridge, TN 37831 USA. NR 33 TC 6 Z9 6 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 11 PY 1998 VL 102 IS 24 BP 4501 EP 4508 DI 10.1021/jp981145j PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV246 UT WOS:000074285000013 ER PT J AU Hessler, JP AF Hessler, JP TI Calculation of reactive cross sections and microcanonical rates from kinetic and thermochemical data SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID RATE CONSTANTS; SHOCK-TUBE; TEMPERATURE; H+O2->OH+O; PRESSURE; DYNAMICS AB In general, kinetic rate data may be represented by van't Hoff's four-parameter equation. When this is true, the mathematical properties of the Laplace transform may be used to derive phenomenological equations that describe the energy-dependent reactive cross sections and microcanonical rates in terms of the same four parameters. Since the macroscopic rate data and microscopic expressions are related by the Laplace transform, these microscopic descriptions do not imply new information; they simply express the information contained in the rate data in another form. The Monte Carlo techniques used to determine confidence envelopes for the rate data may also be used to provide confidence envelopes or "bounds" for the energy-dependent properties. These microscopic expressions may be used to compare and contrast theoretical calculations or as a starting point in RRKM or master equation calculations. Both the forward and reverse H + O-2 <-> OH + O reactions and the associative reaction CH3 + CH3 --> C2H6 are used to illustrate the above ideas. In the first example, the cross section for the reverse reaction shows that it is not dominated by the dipole-quadrupole interaction. The cross section for the forward reaction is obtained by fitting rate data from 158 to 5300 K and peaks just above the threshold of 8354 K. In the second example, comparison to recent theoretical calculations highlights the importance of angular momentum and the centrifugal barrier. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Hessler, JP (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hessler@anl.gov NR 53 TC 25 Z9 25 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 11 PY 1998 VL 102 IS 24 BP 4517 EP 4526 DI 10.1021/jp971416a PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV246 UT WOS:000074285000015 ER PT J AU He, G Tokue, I Macdonald, RG AF He, G Tokue, I Macdonald, RG TI Thermal rate constant for CN+H-2/D-2 -> HCN/DCN+H/D reaction from T=293 to 380K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CN; ABSORPTION; ENERGY; 295-K; O-2; H-2; HCN AB The reaction rate constant for the cyano (CN) radical with hydrogen and deuterium has been determined over the temperature range 293-380 K. The CN radical was detected by time-resolved near-infrared absorption using the CN red system (A2 Pi <-- X(2)Sigma) (2,0) band near 790 nm. These measurements were carried out at low pressures of Ar or He as carrier gas. The diffusion rate of CN in these mixtures was inferred from the diffusion rate of HCN(000) determined using time-resolved infrared absorption of HCN(000) around 3.0 mu m, simultaneously with the detection of CN. These measurements provide accurate thermal rate constant data that will enable a detailed comparison to be made between theoretical predictions and experimental measurements for this prototypical reaction system. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60565 USA. RP Macdonald, RG (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60565 USA. NR 28 TC 20 Z9 20 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 JUN 11 PY 1998 VL 102 IS 24 BP 4585 EP 4591 DI 10.1021/jp980875o PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZV246 UT WOS:000074285000024 ER PT J AU Kivelson, SA Fradkin, E Emery, VJ AF Kivelson, SA Fradkin, E Emery, VJ TI Electronic liquid-crystal phases of a doped Mott insulator SO NATURE LA English DT Article ID SUPERCONDUCTING LA1.85SR0.15CUO4 AB The character of the ground state of an antiferromagnetic insulator is fundamentally altered following addition of even a small amount of charge(1). The added charge is concentrated into domain walls across which a pi phase shift in the spin correlations of the host material is induced. In two dimensions, these domain walls are 'stripes' which can be insulating(2,3) or conducting(4-6)-that is, metallic 'rivers' with their own low-energy degrees of freedom. However, in arrays of one-dimensional metals, which occur in materials such as organic conductors(7), interactions between stripes typically drive a transition to an insulating ordered charge-density-wave (CDW) state at low temperatures. Here it is shown that such a transition is eliminated if the zero-point energy of transverse stripe fluctuations is sufficiently large compared to the CDW coupling between stripes. As a consequence, there should exist electronic quantum liquid-crystal phases, which constitute new states of matter, and which can be either high-temperature superconductors or two-dimensional anisotropic 'metallic' non-Fermi liquids. Neutron scattering and other experiments in the copper oxide superconductor La1.6-xNd0.4SrxCuO4 already provide evidence for the existence of these phases in at least one class of materials. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Emery, VJ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Fradkin, Eduardo/B-5612-2013; OI Fradkin, Eduardo/0000-0001-6837-463X NR 20 TC 730 Z9 731 U1 10 U2 104 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JUN 11 PY 1998 VL 393 IS 6685 BP 550 EP 553 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZT988 UT WOS:000074150100044 ER EF